Swine erysipelas (Erysipelas suum) is an infectious disease characterized in acute septicemia and inflammatory erythema of the skin, and in chronic - endocarditis and arthritis.
Historical reference ... The causative agent of swine erysipelas was identified and described by R. Koch (1878), Löffler (1881, 1885), L. Pasteur and L. Tuillier (1882), vaccines from weakened strains of the causative agent of erysipelas were obtained by L, Pasteur (1883), and anti-erysipelas - Lorenz and Leclanche (1885-1896). Later, vaccine strains were produced by D.F.
Information about the pathogen... The bacterium Erysipelothrix insidiosa is the only member of the genus Erysipelothrix in the Lactobacillaceae family. Erysipelas is a ubiquitous (ubiquitous) microorganism. E. insidiosa have different morphological, virulent, antigenic and immunogenic properties, depending on the habitat.
The microbe is undemanding to nutrient media. It grows well in aerobic and anaerobic conditions on BCH, Hottinger's medium at a temperature of 36 - 38 ° C and a pH of 7.4 - 7.8 (the addition of 0.5% glucose and 5-10% horse serum stimulates growth). Bacteriine are mobile, do not form spores and capsules, stained with solutions of basic aniline dyes and according to Gram. On solid nutrient media, they form smooth (S), rough (R) and transitional (O) colonies. In smears from old broth cultures, R-colonies and in imprints from affected organs at chronic course erysipelas, show bacteria elongated to 6 - 8 microns, located in the form of long chains (filamentous form).
The causative agent of erysipelas has triantigenic types - A, B and N. The disease is caused mainly by type A, less often type B and very rarely type N (it is often isolated from healthy animals) Type B has high immunogenic properties and is used for the production of vaccines. Of laboratory animals, mice and pigeons are most susceptible to erysipelas bacteria.
The stability of the causative agent of erysipelas in the external environment is high; in soil and water, in corpses and slurry, it persists for many months Salting and smoking pork products does not kill it. Erysipelas bacteria are sensitive to high temperatures, some antibiotics and disinfectants, including solutions of caustic soda and formaldehyde (2%), chlorine lime (10%), phenol (3%) and others in conventional concentrations.
Epizootological data... Erysipelas is the most common infectious disease in pigs worldwide. It is recorded almost everywhere in the form of sporadic cases or epizootic outbreaks. Most often, pigs get sick at the age of 3-12 months. The stability of suckers for up to 40 days is associated with passive immunity, and in adult animals - with age-related natural resistance and latent disease.
In addition to pigs, erysipelas is sporadically found in horses, cattle, sheep, reindeer, dogs and many wild mammals and zoo birds. Among lambs, turkeys and ducks, as well as among rodents, erysipelas can manifest itself as a significant epizootic outbreak. Erysipelas and a person are also ill.
Microcarriers are widespread among many species of domestic and wild animals, especially among pigs, rodents and birds. The causative agent of erysipelas can often be isolated from the body of marine and river fish, insects and arthropods. The high resistance of the pathogen in the external environment and its permanent circulation in nature provide a wide and constant reservoir of the causative agent of erysipelas and the enzootic nature of the disease. This made it possible to attribute erysipelas to natural focal diseases.
The source of the causative agent of erysipelas is clearly sick pigs, which excrete microbes in urine and feces, and clinically healthy pigs - carriers of bacteria. In the latent form, the bacteria of erysipelas, usually localized in the tonsils and intestinal follicles, can, under stress, especially under the influence of high temperature and with protein deficiency, cause a clinical manifestation of the disease. As a result, epizootic outbreaks of erysipelas in farms often occur endogenously, without the introduction of the pathogen from the outside.
Factors of transmission of the causative agent of erysipelas are infected items of care, food and water, animal slaughter products, corpses, soil, etc. The pathogen is transferred more often by rodents, flies and birds. The main route of spread of the pathogen is the forage, less often - the transmission and contact.
Soil is important in the spread of erysipelas.... Erysipelas, being a soil infection, has a pronounced spring-summer seasonality and often occurs among replacement and fattening young animals. High temperature combined with high humidity, keeping pigs in stuffy, poorly ventilated rooms, solar stress, transportation, lack of protein, minerals and vitamins in the diet reduce resistance to erysipelas and at the same time contribute to the emergence, widespread occurrence, severity of clinical manifestation and intensity of the epizootic process ... An epizootic feature of erysipelas is its stationarity, manifested by repeated outbreaks mainly in the warm season. The duration of an epizootic outbreak, morbidity and mortality depend on the technology of pig breeding, timely and accurate diagnosis disease, virulence and type of pathogen, immunological structure of the herd and careful implementation of health measures. Epizootic outbreaks, as a rule, do not tend to be widespread: the incidence usually does not exceed 20-30%, the mortality rate is 55-80%.
Pathogenesis. The erysipelas bacteria that enter the body first multiply in the places of primary localization (tonsils, solitary follicles, places of skin damage), causing increasing sensitization of the body (allergy). If the erysipelas pathogen enters the body with high natural resistance, then primary process may be limited to a local infection that is asymptomatic or with mild clinical signs, ending with the formation of immunity. Under unfavorable environmental conditions and stress, erysipelas bacteria overcome local protective barriers, penetrate the blood and parenchymal organs, causing septicemia. Intensive multiplication of bacteria and the accumulation of toxic products leads to inflammation and deep dystrophic changes in organs and tissues. Generalized infection is accompanied by the development of blood clots, edema, congestion during internal organs and skin, tissue metabolism disorders. In the acute course of the disease, severe clinical signs of septicemia (hyperthermia, heart failure, pulmonary edema) are pronounced, ending in a lethal outcome.
In animals with residual immunity, as well as when a weakly virulent pathogen is introduced, the infectious process has a more benign course. The disease in such cases proceeds subacutely and chronically and is manifested mainly by hyperemia and local inflammation of the skin in the form of rhomboid erysipelas, verrucous endocarditis and arthritis. Protective-immunological reactions are noticeably manifested in the places of predominant localization of bacteria. The outcome of the disease depends on the depth of damage to organs and tissues and the degree of functional disorders.
Clinical signs and flow... The incubation period is 2 - 5 days, but may be longer. Depending on the amount and virulence of the pathogen, the gate of infection, the susceptibility of animals and environmental factors, erysipelas can proceed with lightning speed, acutely, subacutely and chronically. There are also septic, skin (urticaria) and latent forms.
The lightning-fast course is recorded relatively rarely, mainly in fattening pigs aged 7-10 months, kept in poor zoohygienic conditions or during transportation. Erysipelas is manifested by sharp depression, hyperthermia and rapidly progressing heart weakness without the appearance of red spots on the skin (white form of erysipelas). The disease ends in death within a few hours.
The acute course is most typical for the septic form of erysipelas, it is often recorded at the beginning of an epizootic outbreak. The disease begins with oppression general condition and a sudden rise in body temperature to 42 ° C and above. Sick animals are separated from the general group and lie more; move reluctantly, there is a tense, painful, stilted gait. Animals refuse to feed, they develop constipation, chills and heart failure. Sometimes vomiting is observed, and diarrhea in weaned pigs.
Weakening of cardiac activity leads to pulmonary edema, difficulty breathing and cyanosis of the skin in submandibular region as well as neck and abdominal wall... Erythematous spots of pale pink, and subsequently dark red, of various sizes and shapes, appear on the 1st or 2nd day after the onset of the disease only in individual animals. The disease lasts 2-4 days and without curative care often ends with the death of the animal.
The subacute course of erysipelas manifests itself comparatively easier in the cutaneous form (urticaria), which is characterized by an increase in temperature up to 41 ° C and above, weakness, decreased appetite and thirst. For urticaria, a characteristic sign is the formation after 1-2 days on the scalp 'and the trunk, less often on other parts of the body, dense inflamed swellings of a square, rhombic and less often round shape. The number and size of erythematous spots vary greatly among themselves, capturing extensive areas of the skin. In most cases, urticaria is benign, and when the animal recovers, the spots gradually fade and disappear. In their place, in mild cases, the skin epithelium is desquamated, and in severe cases, skin necrosis and its rejection occurs with filling of defects with scar tissue. The illness lasts 7-12 days and in most cases, especially when timely treatment, ends with recovery. Only sometimes it becomes aggravated and turns into the usual septicemic form.
The chronic course of erysipelas in rare cases is an independent manifestation of the disease. For the most part this is just a continuation of the septic form or urticaria with complications manifested by diffuse (erysipelas) skin necrosis, verrucous endocarditis and chronic damage to other organs.
With severe necrosis, large areas of skin turn into a solid dark red eminence with a blackish tinge in the form of a dense and dry, shell-like necrotic crust.The erysipelas lasts for months until necrotic tissue is rejected by suppuration Animals are poorly fed, which necessitates their slaughter ...
Verrucous endocarditis is manifested by impaired cardiac activity, progressive weakness, shortness of breath, congestion, anemia and emaciation. The outcome of the disease depends on the severity of the damage to the heart valves.
Erysipelas polyarthritis initially manifests itself as hot swelling and soreness, more often in the hock and femoral joints, less often in the carpal and fetal joints; animals move with difficulty; later signs acute inflammation disappears and deformation of the joints occurs, which causes lameness and restricts the movement of animals.
Pathological changes in pig erysipelas are varied, which is determined by the course and form of the disease. In pigs that died during the acute course of the disease, changes are found inherent in the septic process. The skin of a non-exhausted corpse in the area of the dewlap and perineum is cyanotic, dark red areas of various sizes are found on the back and sides with urticaria. The serous integuments of the internal cavities and organs are covered with fibrin threads and are often strewn with small hemorrhages. The lymph nodes are enlarged, sharply hyperemic with clearly protruding follicles. The spleen is enlarged, the liver is filled with blood and parenchymal degenerated, the kidneys are swollen, dark cherry in color, with minor hemorrhages in the cortical layer (hemorrhagic glomerulonephritis), in the lungs there is often pronounced edema and sometimes foci of bronchopneumonia. Cardiac muscle is soft. The mucous membrane of the fundus of the stomach and small intestines, as a rule, is edematous and hyperemic, with many punctate and banded hemorrhages. In the chronic course of erysipelas, changes are found characteristic of verrucous endocarditis (warty growths on the valves), and with inflammation of the joints, fibrous growths synovial membranes.
Diagnosis... Lifetime clinical diagnosis in the acute course of erysipelas and urticaria, it is mainly based on characteristic skin lesions that appear against the background general violations It is necessary to take into account epizootic data and high therapeutic effectiveness antipyretic serum and antibiotics. For the postmortem diagnosis, the most characteristic are: enlargement of the spleen, acute catarrhal gastroenteritis, hemorrhagic lymphodenitis, glomerulonephritis.
An accurate diagnosis is made based on the results of bacteriological research, for which pieces of the spleen, liver, kidney and tubular bone... In the laboratory, microscopy of smears stained according to Gram is carried out, and the pathogen is isolated by inoculation on nutrient media. If necessary, white mice or pigeons are infected with an emulsion from parenchymal organs. For the diagnosis of erysipelas, an immunofluorescence test is also recommended.
Differential diagnosis... The acute septic form of erysipelas and urticaria must be differentiated from plague, pasteurellosis, salmonellosis, listeriosis, anthrax, sun and heat stroke. In a chronic course, it is necessary to exclude the chronic course of plague, mycoplasmous polyserositis, polyarthritis, streptococcal and corynebacterial infections, rickets and osteomalacia.
Treatment... Effective medicinal preparations are antipyretic serum and antibiotics. Serum is injected subcutaneously or intramuscularly at a dose of 1 - 1.5 ml per 1 kg of live weight of the animal. At grave condition animal best healing effect is achieved if half of the serum dose is injected into the ear vein. Many antibiotics are also effective for erysipelas - penicillin, streptomycin, oxytetracycline, ekmonovocilin, erythromycin, etc. It is preferable to use penicillin at a dose of 2 - 3 thousand units per 1 kg of animal live weight at intervals of 6 - 8 hours.
The best results are obtained with joint application serum with antibiotics. If, after 8-12 hours of treatment, the patient's condition does not improve, serum and antibiotics are re-administered. Specific therapy must be combined with symptomatic treatment.
Immunity... Pigs that have had erysipelas acquire intense and long-term immunity, which is associated with specific phagocytosis and serum antibodies. For the immunization of pigs against birth in the USSR, live vaccines are mainly used (a vaccine from the Romanian strain BP-2 and a deposited vaccine from a strain of D.F. Konev), as well as a concentrated aluminum hydroxide formol vaccine. Pigs over 2 months of age are vaccinated (piglets usually 2 weeks after weaning). The vaccine from the BP-2 strain is used once, the adeponded and inactivated vaccines - twice with an interval of 12-14 days. Animals are revaccinated after 4-5 months.
Prevention and control measures... An effective fight against this disease is possible only by carrying out planned widespread, general and specific preventive measures. General prevention consists in strict observance of veterinary and sanitary rules and technological requirements for the placement, care and feeding of pigs in order to obtain and raise sustainable young animals. Particular attention is paid to the balance of diets in protein, trace elements and vitamins, as well as to the prevention of heat stress. Manure removal, cleaning of premises and the territory of the pig farm, routine disinfection and control of rodents and flies are systematically carried out.
The most important method of specific prophylaxis is preventive vaccination with vaccines. Vaccination should be carried out routinely and systematically with 100% coverage of all pig herds of public and individual farms to be vaccinated. If the farms carry out protective vaccinations against other infectious diseases (plague, Aujeszky's disease, salmonellosis).
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Erysipelas(Latin - Erysipelas suum, Erysipelothrix rhusiopathiae, Rhusiopathia suia; English - Swine Erysipelas, Diamond disease; erysipeloid) is an acute disease of young pigs, characterized by fever, septicemia and inflammatory erythema of the skin, and in chronic arthritis, endocarditis and color insert).
Historical background, distribution T injury, degree of danger T and and damage. The causative agent of pig erysipelas was discovered in 1882 by French scientists L. Pasteur and L. Tuillier. The first vaccine against erysipelas of pigs from weakened bacteria in France was also produced by L. Pasteur (1883), in Russia, somewhat later, by P.I.Borovsky (1896) and D.F.Konev (1899). Anti-erysipelas serum was first obtained in Germany and France (1885-1896).
Erysipelas is one of the most widespread infectious diseases in pigs. She is registered in almost all European countries, and especially in the countries of Central, Southern and South-Eastern Europe. It is also found in the USA, Canada, China, Japan, Korea and other countries. In Russia, pig erysipelas is also widespread.
Economic damage is made up of losses from deaths, forced slaughter of pigs and costs associated with the introduction of restrictions, treatment and mass immunization of animals.
The causative agent of the disease. The causative agent of erysipelas Erysipelotrix insidiosa (E. rhusiopathiae) belongs to the ubiquitous (ubiquitous) microorganisms. It is found in the body of clinically healthy pigs (in the tonsils, intestines, gallbladder), in rodents and insectivores, fish, ticks, isolated from various decaying organic substrates: river silt, municipal wastewater, etc.
E. insidiosa - gram-positive motionless straight or slightly curved rods, located singly or in pairs, do not form spores and capsules, catalose-negative. In the smears-prints from the affected organs in the chronic course of the disease, bacteria are found located in the form of long chains (filamentous form). The pathogen grows well in aerobic and anaerobic nutrient media under normal conditions. Of laboratory animals, mice and pigeons are most susceptible to erysipelas bacteria.
The species E. rhusiopathiae has 22 serovars. The most common are serovars 1 and 2, which were previously designated A and B.
The stability of the causative agent of erysipelas in the external environment is high; in rotting corpses and organs of pigs buried in the soil, it lasts 10 ... 12 months; in soils rich in organic matter - 7 ... 9 months; in slurry - up to 290 days, tap water - 100 ... 108 days; in pig urine - 113 ... 145 days; in feces - 38 ... 78 days. In salted pork, microbes survive up to 6 months; in smoked products - up to 3 months. Under the influence of direct sunlight, bacteria die after 10 ... 12 days, and drying in diffused light kills them after 3 ... 4 weeks. The microbe is resistant to aminoglycosides (neomycin, kanamycin, monomycin); sensitive to high temperature, penicillin, erythromycin, tetracycline, gentamycin.
In terms of resistance to chemical disinfectants, the causative agent of erysipelas belongs to the group of unstable (group I). 2% solutions of sodium hydroxide, formalin, bleach, 3% hydrogen peroxide solution, 1% solution of iodide and Vircon C in the ratio 1 : 100, etc.
Epizootology. Erysipelas belongs to natural focal diseases, which is associated with the high resistance of the pathogen in the external environment and its circulation in nature, ensuring the constancy of the reservoir of the pathogen. In the case of a latent form, erysipelas bacteria are localized in the tonsils and intestinal follicles and under stress, especially under the influence of high temperature and with a lack of minerals and vitamins in the diet against the background of excess protein, they can cause a clinical manifestation of the disease. As a result, epizootic outbreaks of erysipelas in farms often occur endogenously, without the introduction of the pathogen from the outside.
The most important epizootic data on the disease are presented in Table 1.14.
1.14. Epizootological characteristics of pig erysipelas
| Index | 1 Feature |
| Species and age susceptibility | More often pigs aged 3 ... 12 months. Sporadically, horses, cattle, sheep, reindeer, dogs and many wild mammals and zoo birds. In the form of an epizootic outbreak - in lambs, turkeys, ducks, as well as among rodents. A person is sick |
| Sources and reservoirs of the causative agent of the disease | Sick pigs excreting microbes in urine and feces, and clinically healthy pigs carrying bacteria; reservoir of the pathogen - rodents and insectivores - carriers and excretors of bacteria |
| Mode of infection and transmission mechanism | The main route of infection is alimentary, less often - transmission, aerogenic and contact. Factors of transmission of the pathogen - infected items of care, food and water, animal slaughter products, corpses, soil, etc. The pathogen is carried more often by rodents, flies and birds |
| Intensity of manifestation | Erysipelas manifests itself in the form of isolated cases or short flashes, repeated indefinitely |
| Seasonality and frequency | The spring-summer seasonality is expressed. Stationarity is characteristic, periodicity - mainly in the warm season |
| Predisposing factors | High temperature combined with high humidity, keeping pigs in stuffy, poorly ventilated areas, heat stress, transportation, lack of protein, minerals and vitamins in the diet reduce resistance to erysipelas |
| Morbidity and mortality | The incidence does not exceed 20 ... 30%, mortality 55 ... 80% |
Pa T ogenesis. Bacteria that have penetrated into the body first multiply in the places of primary localization in the tonsils, solitary intestinal follicles, lymph gaps of the skin, sensitizing the body with toxic products. If the resistance of the animal's body is high enough, then the primary process may be limited to a local infection that is asymptomatic or with mild clinical signs and end with recovery and the formation of immunity. With an unfavorable course, bacteria overcome defense mechanisms, penetrate into the lymph, blood and parenchymal organs, causing septicemia. Generalization of infection and accumulation of toxic products of bacteria are accompanied by degenerative and necrobiotic changes in tissues, blockade of RES, suppression of phagocytic defense, metabolic disorders and severe functional disorders. Degenerative changes in cardiovascular system lead to the development of edema, blood clots, congestion in parenchymal organs, skin, intoxication, rapidly increasing heart weakness and death.
When a weakly virulent pathogen is introduced, as well as in animals with residual immunity, the infectious process proceeds subacutely and chronically and is manifested mainly by hyperemia and local inflammation of the skin in the form of diamond-shaped erysipelas, verrucous endocarditis and arthritis. The outcome of the disease depends on the depth of damage to organs and tissues and the degree of functional disorders.
Course and clinical manifestation. The incubation period is 2 ... 8 days, less often up to 14 days and rarely longer. Depending on the virulence of the pathogen, the gate of infection, the susceptibility of animals and environmental factors, erysipelas proceeds with lightning speed, acutely, subacutely and chronically. There are also septic, skin (urticaria) and latent forms.
Lightning current occasionally observed in pigs aged 7 ... 10 months, fattening, when kept in stuffy, poorly ventilated premises or during transportation. The disease is accompanied by an increase in body temperature, refusal to feed, rapidly advancing heart weakness, and sometimes disturbances from the outside nervous system, typical for meningoencephalitis, ends after a few hours with a lethal outcome without the appearance of erythematous spots on the skin (white form of erysipelas).
At acute current the disease manifests itself rapid rise body temperature up to 42 ° C and above, refusal to feed, chills, general weakness, cardiac disorders, symptoms of atony of the gastrointestinal tract and constipation. Pigs rarely get up, move with difficulty due to weakness hind limbs... Conjunctivitis often develops. Then the symptoms of heart weakness, pulmonary edema and congestion increase, giving the skin in the ears, neck, submandibular space, perineum, and abdominal wall a cyanotic color. The disease lasts 2 ... 4 days.
Subacute course(urticaria) is accompanied by an increase in body temperature up to 41 ° C or more, lethargy, decreased appetite, thirst and the development of skin exanthema after 1 ... 2 days, characterized by the formation on the scalp, trunk, less often in other areas of dense swelling, first pale pink and then dark red, round, square or rectangular. Individual swellings can merge with each other, capturing large areas of the skin. With their appearance, the general condition of the animals improves, the body temperature decreases. The prognosis is often favorable. With deep and extensive dermatitis, the affected areas of the skin undergo necrosis. The duration of the disease is 7 ... 12 days.
Chronic course erysipelas of pigs follows an acute illness, urticaria or latent infection, manifests itself as symptoms of verrucous endocarditis, serous, serous fibrinous polyarthritis or skin necrosis. Verrucous endocarditis is accompanied by impaired cardiac activity, progressive weakness, shortness of breath, congestion in the skin, emaciation, anemia. With polyarthritis, the tarsal, hock, less often carpal and fetlock joints are involved in the process, which swell and become painful. V severe cases deformation of the joints and atrophy of the muscles of the extremities are observed.
Skin necrosis is rare. Disease in pregnant sows last stage pregnancy may be accompanied by abortion. Hematological changes in pig erysipelas are characterized by leukocytosis with an increase in the number of young forms of polymorphonuclear cells, an increase in the number of eosinophils (sometimes 10 times), especially in urticaria. With prolonged verrucous endocarditis, the content of hemoglobin and erythrocytes decreases.
Sheep rarely get sick with erysipelas. The disease manifests itself in the form of erysipelas. Lambs aged from several weeks to 4 ... 8 months are mainly affected. Characteristic signs: cough, mucopurulent discharge from the eyes and nasal cavity, phenomena of catarrhal brochopneumonia. Sometimes lameness, swelling of the joints is noted.
In birds (chickens, turkeys, ducks, geese), the disease is manifested by oppression, refusal to feed, diarrhea, decreased egg production, the development of catarrhal inflammation of the mucous membrane of the nose and throat, inactivity, blue discoloration of the crest and earrings, sometimes swelling of the joints.
Pathological signs. In animals that have died in an acute or subacute course of the disease, characteristic lesions of the skin in the dewlap, abdominal wall, perineum, ears and limbs in the form of dark purple spots of various sizes and shapes are revealed. Bloody, frothy fluid is discharged from the nasal openings. An autopsy reveals a picture typical of a septicemic process. Congestive hyperemia is pronounced. Serous integuments of the chest, pericardial and abdominal cavities and internal organs are covered with fibrin filaments and are often strewn with small hemorrhages. The blood is dark red and does not coagulate well. The tonsils are swollen, juicy and hyperemic. Lymph nodes in a state of serous inflammation, enlarged, juicy, diffusely colored in red-violet color, follicles are enlarged, liver, kidneys, heart in a state of granular degeneration and congestive hyperemia. In the kidneys, a picture of glomerulonephritis is observed. They are enlarged, flabby. The spleen is enlarged, slightly flabby, a condition characteristic of acute splenitis (septic spleen) is expressed. In the section, the color is cherry red, the pattern of follicles and trabeculae is shaded, the pulp is easily scraped off. Acute catarrhal inflammation in stomach and intestines. The wall of the stomach and thin department the intestines are thickened, the mucous membrane is swollen, bright red, sometimes with punctate hemorrhages, abundantly covered with thick, viscous, difficult to wash off mucus. In the lungs - pronounced edema, sometimes foci of bronchopneumonia. The lobes of the lung are unresponsive, doughy, reddish with a blue tinge. In the trachea and bronchi, a frothy reddish fluid.
With a subacute course, dead necrotic areas of a rhomboid, square or round shape are found in various areas of the skin.
In case of chronic course, ulcerative or warty endocarditis, arthritis and skin necrosis are established at autopsy. With erysipelas endocarditis, bicuspid valves are most often affected, less often tricuspid valves and a pulmonary valve. Inflammation of the joints is characterized by fibrinous enlargement of the synovial membranes. Skin necrosis in the form of dead areas on the ears, back, shoulder blades, tail look like dense, dark brown or black colored scabs (dry gangrene).
Diagnostics and differential diagnostics. V Diagnostics take into account epizootological data, clinical manifestation of the disease, characteristic pathological signs, and the final diagnosis is made according to the results of bacteriological examination, for which pieces of the spleen, liver and tubular bone are sent to the laboratory, and if a chronic course is suspected, the heart. Laboratory diagnostics are carried out in accordance with the guidelines " Laboratory diagnostics faces of pigs. Diagnosis of swine erysipelas is shown in Figure 1.10.
At differential diagnosis the acute septic form of erysipelas and urticaria must be distinguished from plague, pasteurellosis, salmonellosis, listeriosis, anthrax, sun and heat stroke. In a chronic course, exclude plague, mycoplasma polyserositis and polyarthritis, streptococcal and corynebacterial infections, rickets and osteomalacia.
Rice. 1.10. Laboratory diagnostics of swine erysipelas
Rice. 1.11. Measures to eliminate erysipelas
Immunity, specific prophylaxis. Recovered animals acquire intense and long-term immunity, which is associated with specific phagocytosis and serum antibodies. For the immunization of pigs against erysipelas in Russia, a live dry vaccine from the BP-2 strain and a deposited vaccine are used. In vaccinated animals, immunity lasts for 6 months. Pigs over 2 months of age are vaccinated. Vaccines against Aujeszky's disease and swine erysipelas are also used; against parvovirus disease, leptospirosis, Aujeszky's disease, reproductive-respiratory syndrome and swine erysipelas (PLARR).
For passive immunization apply hyperimmune serum. Immunity against erysipelas develops in pigs after 1 day and lasts up to 14 days.
Prevention. General prevention consists in strict observance of veterinary and sanitary rules and technical requirements for the placement, care and feeding of pigs in order to obtain and raise sustainable young animals. Particular attention is paid to the balance of the diet in terms of protein, trace elements and vitamins, as well as to the prevention of heat stress. Manure cleaning, cleaning of the premises and territory of the pig farm, routine disinfection, deratization and disinfection are systematically carried out. The acquired pigs are quarantined for 30 days. Waste from kitchens, slaughterhouses and canteens is fed only after boiling. The most important method of specific prevention of swine erysipelas is preventive vaccination with vaccines, which should be carried out in a planned and systematic manner with 100% coverage of the entire swine population of public and individual farms.
Treatment. Antiphosphorous serum and antibiotics (penicillin, streptomycin, oxytetracycline, ekmonovocinin, erythromycin, etc.) are effective. The best results are obtained with the joint administration of serum with antibiotics. Specific therapy combined with symptomatic treatment.
Control measures. Measures to eliminate swine erysipelas are shown in Figure 1.11.
Erysipelas in humans (erysipeloid). It affects mainly people of certain professions: workers at slaughterhouses, meat processing plants, fish industries, veterinary specialists. The transmission factor is foodstuffs- pork, fish, etc. Infection occurs through damaged skin... Usually the skin of the fingers is affected, less often the wrists and forearms, often the joints of the fingers are involved in the process, which swell and become painful. The duration of the disease is 10 ... 20 days.
Strict adherence to personal preventive measures, immediate treatment of any wound with a 2% alcohol solution of iodine protects against infection. From remedies use antibiotics.
Control questions and tasks. 1. Who is the source and reservoir of the erysipelas causative agent? 2. Can a disease arise in a prosperous farm without the introduction of the pathogen from the outside and under what conditions? 3. Describe the forms of clinical manifestation of erysipelas in different streams disease. 4. What data can be used to distinguish erysipelas from classical swine fever? 5. Name the general and specific methods and means of preventing swine erysipelas in animals and humans.
The causative agent of pig erysipelas is a bacterium Erysipelothrix rhusiopathiae... It causes an infectious disease, characterized in acute septicemia and inflammatory erythema of the skin, in chronic - endocarditis and arthritis. Animals are sick mainly at the age of 3-12 months.
The bacterium was discovered by L. Pasteur and L. Tuillier in 1882. Representative of the department Firmicutes and kind Erysipelothrix.
Morphology. The causative agent is a thin straight or slightly curved small stick 0.2-0.3x1.5-2 microns in size. In old broth cultures and in overlays on heart valves with verrucous endocarditis, elongated and filamentous forms are found. The bacteria are immobile. Spores and capsules do not form, gram-positive, stain well with conventional aniline dyes.
Cultivation. It grows in aerobic and anaerobic conditions, preferably in an atmosphere with reduced oxygen pressure, containing 5-10% CO 2 (microaerophile). It is cultivated in MPB, on MPA, MPG, PZHA (0.15-0.2% agar), Hottinger's broth, Saint-Ivagni's selective medium (agar medium with 0.1% crystal violet and 1% sodium azide). Optimal conditions for growth: temperature 36-37 0 С, pH 7.2-7.6. In the BCH it causes a slight turbidity without the formation of a wall ring and a film, when shaking the tube, moiré waves are clearly visible: after 48-72 hours the medium clears somewhat, a precipitate forms at the bottom of the tube, which rises in the form of a cloud when shaken.
On MPA, the pathogen grows in the form of small dewy translucent colonies (S-form), which are hardly distinguishable with the naked eye: S-forms are isolated during septicemia. In the chronic course of the disease, colonies of the R-form can grow - large, with an uneven rough surface and root-like processes extending from the edge.
In a column of gelatin, when sowing with an injection after 6-10 days, horizontal delicate processes resembling a brush depart from the grayish-white rod; gelatin does not liquefy.
Biochemical properties. Pig erysipelas bacteria emit hydrogen sulfide, do not form indole and catalase; most strains decompose with the formation of acid without gas lactose, glucose, galactose, levulose, rarely - xylose, arabinose, maltose and rhamnose, do not ferment sucrose, mannitol and salicin.
Antigenic structure. According to the content of antigens, swine erysipelas bacteria can be divided into three groups: A, B and N. Antigen N is a common species. Serovars A and B differ in their haptens. Serovar B strains carry a hemagglutinating and soluble immunogenic antigen and are therefore particularly suitable for active immunization.
From sick pigs, as well as from healthy bacteria carriers, mainly serovar A strains (up to 95%) are isolated, less often serovar B, and very rarely - N.
Stability. The causative agent is highly resistant to the external environment. In the carcasses of animals, it can persist, and sometimes reproduce for 3-4 months. In soils rich in organic matter, it lasts 7-8 months, in slurry - up to 20 days, in tap water - 108, in river water at 4 ° C - 75-86, in pig urine - 113-145, in feces - 38-75 days. In salted pork, bacteria survive up to 6 months, in smoked products - up to 3 months. Direct sunlight kills after 10-12 days, drying in diffused light - after 3-4 weeks; heating at 50 0 С - after 15 minutes, at 70 0 С - after 5 minutes.
The bacterium is not resistant to antibiotics and disinfectants. Particularly effective are 2-3% sodium hydroxide solutions, 20% slurry of freshly slaked lime, 2% formaldehyde solution, 5% hot soda ash solution.
Pathogenicity. Pigs are susceptible to the causative agent of the disease, especially between the ages of 3 months and 1 year. Sporadic cases of the disease have been reported in horses, cattle, sheep, deer, and dogs. Dolphins, many species of rodents and insectivores, ducks and geese, as well as chickens and turkeys are susceptible. Erysipelas bacteria are also pathogenic for humans. Found on the surface of the body, in the intestines and even the muscles of some species of marine and freshwater fish, for which they are not pathogenic.
White mice and pigeons are susceptible to experimental infection; they die after 2-5 days. Less sensitive are rabbits, which die on the 3rd-6th day after intravenous infection.
Pathogenesis. Infection of pigs and other species of animals, including birds, occurs when the pathogen penetrates alimentary, through damaged skin, or through the bites of blood-sucking insects. Bacteria that enter the body do not immediately penetrate into the blood and internal organs; they often settle in the tonsils and solitary intestinal follicles. Reproducing at the site of primary localization, they release toxic substances that cause sensitization of the body. With an unfavorable course of the disease, the pathogen is disseminated by lymphogenous and hematogenous pathways, sepsis develops, toxic products of bacteria accumulate, dystrophic and necrobiotic changes in tissues occur, phagocytosis is suppressed, severe functional disorders of the cardiovascular system and death of animals occur.
In the subacute and chronic course of the disease, the pathogen is localized and its toxic products are rendered harmless, the synthesis of specific immunoglobulins and phagocytosis is activated, allergic reactions prevail, manifested in the form of cutaneous exanthema, verrucous endocarditis and serous fibrinous arthritis. Possible persistence of the causative agent of pig erysipelas in the body of animals.
Epizootological data. Pig erysipelas belongs to natural focal diseases, which is associated with the high resistance of the pathogen in the external environment and its circulation in nature, which ensure the constancy of the reservoir of the pathogen.
Under natural conditions, the erysipelas is pathogenic for pigs, lambs, chickens, pigeons. The most susceptible are pigs aged 3-12 months. Piglets under 40 days of age are not susceptible due to colostral immunity.
The source of the pathogen is sick animals and clinically healthy pigs carrying bacteria. The main route of infection is alimentary, less often - transmission and contact. Factors of transmission of the pathogen are contaminated objects of the external environment, soil, animal corpses, slaughterhouse waste.
Epizootic outbreaks are usually not widespread: the incidence usually does not exceed 20-30%, the mortality rate is 35-80%. Swine erysipelas are reported as sporadic cases throughout the world.
Pre-slaughter diagnostics. Swine erysipelas can occur in three forms: acute (erysipelas), subacute, or cutaneous (urticaria), and chronic. The latter is a consequence of the two previous ones. With erysipelas septicemia, the body temperature of the animal rises to 42 0 C, the animal is depressed, buries itself in the litter, trembles, on the more tender areas of the skin, red spots with a bluish tint are visible, which turn pale with pressure. There is a weakness in the rear, unwillingness to move, conjunctivitis, salivation, with urticaria, in addition to these signs, a rash of red spots of a rectangular or irregular shape on the entire surface of the skin. The chronic form of the disease is characterized either by the development of diffuse erysipelas with purulent rejection of dead skin areas, or by the development of verrucous endocarditis with a sharp violation of cardiac activity (tachycardia), or by damage to the joints of the extremities (deformation, soreness, lameness).
Post-mortem diagnostics. Pathological changes in pig erysipelas are varied, which is determined by the course and form of the disease. The skin and subcutaneous fat under the red spots are saturated with bloody infiltrate, blood vessels are full of blood, there are hemorrhages. The carcass is poorly drained of blood, some muscles are flabby, of a changed (gray-red) color. Lymph nodes, especially in the head area, are enlarged, filled with blood, often with hemorrhages. On the serous membranes, fibrin deposition, hemorrhages. The lungs are swollen, filled with blood, signs of catarrhal bronchopneumonia are found. The liver is spotty-clayey in color, enlarged, full-blooded. In the kidneys, venous stasis, the border between the cortical and medullary layers is smoothed, hemorrhagic infarctions are visible on the surface, the consistency is flabby. The mucous membrane of the duodenum and jejunum is hyperemic, covered with mucus, often with hemorrhages (especially with septicemia erysipelas). The spleen is full-blooded, enlarged, with hemorrhages. In the chronic course of the disease, lesions of the heart valves are found in the form of loose warty growths, as well as arthritis (bloody synovia, with fibrin flakes).
In terms of differential diagnosis, erysipelas should be distinguished from swine fever and pasteurellosis. The final diagnosis is based on the results. bacteriological research.
Laboratory diagnostics. For research, the whole animal corpse or heart, liver, spleen, kidney and tubular bone are sent to the laboratory. If you suspect a chronic course - necessarily the heart.
Identification of the causative agent of erysipelas is carried out using microscopic, bacteriological and serological (RA, RIF) methods.
Microscopy. Smears-prints from organs are stained according to Gram. In positive cases, gram-positive rods are found in smears, located singly, in pairs or in clusters, in chronic course - long intertwining threads.
Sowing on nutrient media. Inoculations are made from the blood of the heart with damaged valves, kidney, spleen, liver, bone marrow in BCH or Hottinger's broth and on MPA. Crops are incubated at 36-37 0 C for 18-24 hours, and in the absence of growth - another day. The isolated culture is identified by morphological, tinctorial, cultural and biochemical properties as well as in the reaction of agglutination with positive serum.
Biochemical activity is determined on Giss media with glucose, lactose, sucrose and mannitol. At the same time, the formation of hydrogen sulfide and catalase is determined.
Agglutination reaction. RA is put with hyperimmune medicinal serum. A drop of serum at a dilution of 1:50 is applied to a glass slide, then a daily agar culture is introduced in a loop and thoroughly rubbed. In the positive case, agglutination occurs quickly, the agglutinate looks like dense small lumps.
A culture that produces hydrogen sulfide, does not form catalase, decomposes glucose, lactose (without gas) and does not ferment sucrose and mannitol, giving positive RA, is referred to as the causative agent of erysipelas.
To detect erysipelas in pathological material, as well as to identify isolated cultures, the method of fluorescent antibodies is used.
Biological test. White mice or pigeons are infected with a suspension (1:10) from organs or a broth culture; mice are infected subcutaneously (0.1-0.2 ml), pigeons - intramuscularly (0.2-0.3 ml). Mice and pigeons die in 2-4 days. The organs of the dead are sown in the BCH and on the MPA to isolate a pure culture of the pathogen.
Differential diagnosis. The swine erysipelas bacterium must be differentiated from the causative agent of murine septicemia ( Bad. murisepticum), which is non-pathogenic for pigeons, ferments sucrose, does not give RA with specific erysipelas, as well as from the causative agent of listeriosis.
Specific prophylaxis. Recovered pigs acquire persistent and long-term immunity. Post-vaccination active immunity lasts on average 4-6 months, passive - up to 2 weeks.
L. Pasteur (1883) was the first to apply preventive vaccinations of pigs against erysipelas with attenuated cultures. In Russia, P.I.Borovsky (1897) and D.F.Konev (1904) received live vaccines against pig erysipelas. In our country, a concentrated aluminum hydroxide formol vaccine against swine erysipelas and a vaccine against swine erysipelas from the BP-2 strain are used.
For passive prophylaxis and treatment of sick animals, hyperimmune serum is used. Antibiotics (penicillin, streptomycin, oxytetracycline, erythromycin, etc.) have a positive effect in treatment, especially in combination with hyperimmune serum.
Veterinary and sanitary assessment and measures. Carcasses and products of slaughter from animals, sick and suspicious of the disease, are prohibited to release in raw form. In the presence of dystrophic or pathological changes in the muscles, the carcass and internal organs are sent for disposal. If there are no changes, the slaughter products are received according to the results of bacteriological studies for the presence of Salmonella. If they are found, the carcasses are neutralized by boiling, sent to the production of meat loaves, canned food according to established mode... Internal organs are disposed of. In case of a negative test result, the carcass, unaffected internal organs, as well as bacon can be sent to the preparation of boiled and boiled-smoked sausages in compliance with the established heat treatment regime, or they can be rendered harmless by boiling. The affected internal organs and intestines are disposed of. Blood obtained from the slaughter of animals sick with erysipelas is allowed to be processed into technical and feed products by boiling at a temperature in the mass of at least 80 0 C for 2 hours with frequent stirring, as well as into dry animal feed. The skins must be disinfected in a strong solution. table salt(26%) with the addition of 1% hydrochloric acid. Workers and veterinary personnel when processing pigs with erysipelas must comply with personal preventive measures. If you cut your hands, you need to contact the health center, having previously treated the cut site with tincture of iodine. The room where sick animals were kept and the place of their slaughter should be disinfected with hot 2% sodium hydroxide solution, 5% soda ash solution, clarified bleach solution or 1% formaldehyde solution.
Swine erysipelas is a septic anthropozoonotic infectious disease characterized by hemorrhagic gastroenteritis, nephritis, hemorrhages on the serous and mucous membranes, and enlarged spleen. With untimely delayed diagnosis and taking measures, many animals die.
The causative agent of pig erysipelas is Erysipelothrix rhusiopathiae, discovered by Pasteur in 1882. It is found in pigs, mice, lambs, calves, turkeys, ducks, fish, and also humans. Therefore, it is more correct to call this group of diseases not swine erysipelas, but erysipeloid.
General characteristics and properties
Morphology and tinctorial properties. E. rhusiopathiae is a polymorphic, short bacillus 0.2-0.3x0.5-1.5 microns in size, located singly and in chains. Immobile. Does not form a spore and capsules. Bacteria multiply by lacing with the formation of heteromorphic cells. In old cultures, as well as in smears from endocardial growths, from meninges E. rhusiopathiae forms long, sinuous filaments or tangles. In smears from the kidneys, liver, spleen, bacteria are located singly, in pairs or in small nests. Phagocytosed bacteria are also found.
The microbe stains well with ordinary aniline paints, gram-positive.
Cultivation. E. rhusiopathiae is a microaerophile. Unpretentious to nutrient media. It is cultivated on PMB, MPA, MPG, milk, semi-liquid agar (MPB with 0.05-0.15% agar), blood serum, media with carbohydrates, Saint-Ivagni's selective medium (agar medium containing 0.1% crystal violet and 1% sodium azide). Growth on nutrient media with a pH of 7.2-7.6 is observed at an optimal temperature of 37 ° C within a day under aerobic and microaerophilic conditions. A slight turbidity appears on the broth, a slight grayish precipitate; on the agar, colonies are small, delicate, transparent in the form of dew droplets; on gelatin, when sown with an injection after 6-10 days, horizontal, delicate, fringed processes resembling the shape of a lamp brush depart from the grayish-white rod. Gelatin does not liquefy.
Biochemical properties. The microbe forms H2S; ferments with the formation of acid lactose, glucose, levulose, galactose, to a weak degree xylose, and sometimes arabinose, maltose and rhamnose.
Stability. Despite the fact that E. rhusiopathiae does not form a spore, it is very resistant to external influences... Its viability in liquid media in sealed ampoules lasts up to 17-35 years, in rotten cadaveric material - for months, in river water - up to 73 days, urine - up to 203, feces - up to 94, in soil suspension - up to 108 days. Drying withstands up to three weeks.
However, heating kills the erysipelas already at 50 ° C after 15 minutes, and at 70 ° С - after 5 minutes. But at when cooking thick pieces of meat, the bacteria dies only after 2.5 hours. It survives during the winter. Frying and braising will not sterilize the erysipelas. The bacterium was found in smoked pork through 90, and in corned beef - 170 days after production. Regular disinfectant solutions effective. Sensitive to UV rays.
Pathogenicity. Erysipelas is widespread in the animal kingdom. Under natural conditions, it is pathogenic for pigs, lambs, turkeys, chickens, ducks, pigeons. It is found in crows, sparrows, bustards, flamingos and other birds, in seals, dolphins, as well as in ixodid ticks and zoo mammals - squirrels, sika deer. For river and sea fish erysipelas is a saprophyte. A person who has erysipeloid in the form of local (more often on the palms, hands, wrist joints) serous inflammation of the skin with expansion of the lymphatic passages without necrosis is also susceptible to erysipelas. Especially susceptible to experimental subcutaneous infection are white mice and pigeons, which die after 2-5 days, rabbits are less sensitive, which die after 3-6 days after intravenous infection.
The incubation period of pig erysipelas is from 1 to 8 days. In clinically healthy pigs, the carrier of erysipelas is widespread. It was found in 30-50% of healthy pigs in the tonsils and intestines in dysfunctional farms. In such farms, rats and mice carry bacteria, up to 20.3% (Tilga).
Various forms of swine erysipelas: fulminant, acute, subacute, chronic and asymptomatic carriers of bacteria, are determined by the variability of the erysipelas and the different reactivity of pigs.
Pathogenesis. The causative agent of erysipelas enters the animal's body in various ways. With oral infection, bacteria initially settle in the tonsils and solitary intestinal follicles, and when infected through skin scratches, in the lymph gaps of the affected area, around which a local inflammatory process occurs. After a few days, microbes overcome protective barriers, enter the bloodstream, multiply in it and spread throughout the body. The septic process causes a febrile reaction, a violation of tissue metabolism, dystrophic and necrotic changes in the parenchymal organs and the cardiovascular system, which leads to the formation of blood clots, edema and death. With a well-expressed reactivity of the animal, the body organizes an effective defense against the pathogen, which inhibits with its aggressors at the beginning diseases resistance of leukocytes and macrophages RES, and, although they phagocytose microbes, lysis of the latter does not occur (incomplete phagocytosis). With the appearance of agglutinins, precipitins and complement-binding substances, antiagressins, the combined action of phagocytosis with antibodies leads to the elimination of the pathogen.
Antigenic structure. Erysipelas contains two antigens: a heat-labile group and a heat-stable species. Based serological research(reactions of precipitation, agglutination, hemagglutination), two serovars were established. Serovar A is more virulent for pigs and serovar B is less virulent. Serovar A is excreted in cultures from pigs with erysipelas most often (up to 95%). The common species is the N.
Immunity. Pigs that have had erysipelas acquire a persistent immunity... It is determined by an increase in the activity of macro- and microphages, an increase in the opsonizing properties of blood, the formation of specific agglutinins, precipitins, antiagressins, complement-binding substances, and the development of an allergic state.
(Swine Erysipelas) is an infectious disease accompanied, in acute course, by the phenomena of septicemia and inflammatory erythema of the skin, and in chronic - by endocarditis and skin necrosis.
The study faces many famous scientists in the world studied, who determined the main morphological, cultural and pathogenic properties of the pathogen (Pasteur, Tuis, Kitt, Konev, Vishelessky, etc.). Methods and means of prophylactic vaccinations were developed (Pasteur, Konev, Lorenz) and an anti-serum with high protective and medicinal properties was obtained (Lorenz, Laklania, 1895-1899). In subsequent years and until now, scientists continue to study the variability of erysipelas bacteria and their antigenic properties, develop methods of intravital diagnostics, improve the means of active prevention and treatment of the disease. Many scientists consider the words spoken about the face in 1903 by Nakard and Lekleinch to be true in our time: “ Current state knowledge does not allow us to explain the mysterious behavior of this disease. " Erysipelas is still one of the most common pig diseases in the world. In addition to pigs, cattle and small cattle, horses, reindeer, many wild mammals, domestic and wild birds are sick. Microcarriers are widespread among domestic and wild animals, birds and, especially, rodents. The causative agent of erysipelas is often found in the body of sea and river fish, dolphins, insects and arthropods. Erysipelas and a person are also ill. Swine erysipelas (erysepiloid) in humans is an infectious skin disease caused by a bacillus pork face... Infection occurs when working with meat, fish, poultry, especially when the skin is injected with a fish bone. More common in butchers, slaughterhouse workers, and housewives. After the incubation period (1-2 days), a limited red spot appears at the site of skin damage, more often on the fingers. Then the spot increases in size, turns pale in the center, and acquires a bluish-red color along the periphery. After 2-3 weeks, the stain disappears without leaving a trace. Patients may experience swelling and tenderness of the joints, an increase in lymphatic regional nodes, fever.
Prevention of minor injuries in working farms, meat and fish processing plants, immediate treatment of damaged skin with disinfectants, avoids erysipelas.
The widespread occurrence of erysipelas in nature indicates a variety of sources of this infection for pigs. The most important should be considered:
1) pigs sick with various clinical, as well as latent forms faces;
2) non-neutralized products of slaughter of pigs sick with erysipelas:
3) areas of soil infected with erysipelas bacteria:
4) rodents and insects - carriers of erysipelas.
Erysipelas has a fairly high stability in the external environment. Bacteria die at 70 ° C in 5 minutes, at 50 ° C in 15 minutes. The sun's rays kill bacteria in 10-12 days, when stored at room temperature remain viable in the light for 3-4 weeks. Antibiotics and disinfectants have a detrimental effect on bacteria (2-3% NaOH solution, 1-2% formaldehyde solution, 0.5% Virocid solution, etc.). In cadaveric material, the erysipelas bacteria persists for 3-8 months: in slurry, feces and urine of pigs for 1-4 months; in river water - up to 3 months: in soil containing organic matter with an alkaline reaction (manure, urine, etc.) - up to 8 months; in corned beef and smoked meat - up to 3 months. The bacteria remain viable in frozen meat, dry blood, or fishmeal.
One of the most dangerous sources is pigs with acute current erysipelas, in which in clinical period, and also some time after recovery with urine and feces is excreted a large number of virulent bacteria. The more acute cases of erysipelas are observed on the farm in spring, the more often repeated outbreaks of this disease are observed, and the greater the danger of such farms becoming stationary foci of infection.
Very dangerous and chronic forms of erysipelas since in this case, bacteria are not only in the affected tissues, but are also secreted during external environment with urine and feces.
Clinically healthy pigs can also be a source of infection. Carriage of erysipelas bacteria by healthy pigs cannot be regarded as a purely mechanical phenomenon. In places where bacteria are localized in carriers, for example, in the tonsils, inflammatory foci are observed, indicating an active course of the process in the affected tissues.
Based on this, the carrier erysipelas bacteria healthy pigs should be considered as a latent, or "dormant" infection, in which the body, by its protective biological reactions, limits the ability of bacteria to penetrate into the bloodstream and internal organs. However, such a condition is not stable: it can turn into asymptomatic re-illness, in which the animal acquires immunity, or under unfavorable conditions that weaken the body's resistance, bacteria can become active, go beyond the primary focus and cause a disease with clinical signs.
Great value in the distribution faces have slaughter products of sick pigs, the neutralization of which is not always given due attention.
The rather widely practiced forced slaughter of sick pigs at home is one of the main reasons for the significant distress of these farms for this disease.
Noting the role of soil as a source of the causative agent of erysipelas, it is necessary to note not the soil in general, but certain
the territory of farms (walking yards, dumping sites for manure, summer camps, pastures and, especially, places where pigs sick with erysipelas were kept or slaughtered).
Pig erysipelas most often it is registered and takes a stationary course in farms where. along with poor zoogignic conditions, there are a large number of mice and rats. A direct relationship was established between the development of an erysipelas epizootic among rodents and subsequent outbreaks of erysipelas among pigs.
Pigs are predominantly sick young age- from 3 to 12 months. The incidence ranges from 20-30%. lethality -55-80%.
Suckling pigs are resistant to erysipelas. The acute septic form of the disease is observed in them very rarely, mainly at the age of more than 40 days and more often in farms where early weaning of suckers from mothers is practiced.
Replacement and fattening pigs are most susceptible to erysipelas. Adults are more resistant to disease. In nature, along with highly virulent erysipelas bacteria, there are variants with reduced virulence and variants that have completely lost their virulent properties. The consequences of infection with bacteria of different virulence will be different. The high resistance of older pigs, apparently, is to some extent associated with the acquisition of immunity on the basis of asymptomatic illness. This immunity from sows is transmitted through milk to the piglets, making them resistant.
Susceptibility to erysipelas, to a large extent, also depends on the conditions of feeding and keeping the pigs. The lack of minerals and vitamins in the diet, as shown by the work of some researchers, reduces the natural resistance to this disease. In fattening groups of pigs on an abundant carbohydrate diet and deprived of walks, erysipelas is always difficult, in an acute and even lightning-fast form.
External factors that reduce resistance to this disease include high ambient temperatures, especially in combination with high humidity and overheating of the pig's body due to excessive insolation or physical exertion during regrouping, etc.
Usually, the highest rise in the incidence of erysipelas in farms in summer is more often observed on hot days when pigs are kept in stuffy, poorly ventilated rooms with high humidity.
Pig erysipelas belongs to the group of infectious diseases with a pronounced seasonal frequency. The incidence of erysipelas increases markedly with the onset of spring. The number of animals suffering from erysipelas increases, and in summer and early autumn reaches a maximum. In winter, the incidence decreases markedly. In Crimea and southern Ukraine, in warm winter conditions, the disease can be registered in winter, which must be taken into account when drawing up a vaccination schedule.
In addition to seasonal periodicity, erysipelas epizootics also show annual fluctuations.
Epizootological feature faces is the nature of its course in dysfunctional farms. Usually, erysipelas appears either in the form of isolated cases, or in the form of short outbreaks, repeating at the most indefinite intervals. The disease never covers all animals of the disadvantaged group, and even more so the livestock of the entire economy.
Pathogenesis. In vivo in pigs erysipelas fall through digestive tract or through damaged skin. Artificial reproduction of the disease is not always possible with the introduction of a pathogenic agent orally, intravenously or intramuscularly, more often it is possible with intradermal administration and through scarified skin (Forner-Dinter method). In the body, erysipelas bacteria multiply in the places of primary localization: when infected through the skin - in the lymph nodes, and with oral infection - in the tonsils, intestinal follicles. The bacteria release toxins that cause inflammatory processes in organs and tissues, increase the permeability of blood vessels, which leads to hemorrhages, the formation of blood clots in the vessels, the appearance of edema and congestion with impaired tissue metabolism. The heart muscle is affected. Erysipelas bacteria overcome the body's defense mechanisms and through lymphatic vessels enter the blood, tissues and organs. In the septic form, there is a massive proliferation of bacteria and the accumulation of toxins, which leads to the suppression of protective reactions, deep degenerative changes and functional disorders. With the subacute and chronic course of erysipelas, the number of leukocytes in the blood increases, agglutinins are produced, and protective and compensatory reactions develop, aimed at restoring impaired body functions, localizing the pathogen and neutralizing toxins.
The clinical picture. The incubation period of the disease can last from one to eight days and depends on the resistance of the animals, the pathogenicity of the pathogen strain and the place of entry of the bacteria into the body. Depending on the clinical symptoms and the timing of the course, there are four forms of the disease:
Lightning erysipelas... Most often found among pigs aged 7-10 months of the fattening group, which are kept in poorly ventilated premises during the summer. Clinical signs are characterized by a sharp increase in body temperature up to 42.5 ° C and above, refusal to feed, depression, rapid breathing and heart weakness. The disease lasts for several hours and ends in death. Due to the absence of erythema spots on the skin, the disease is called the white form of erysipelas. The diagnosis is made after bacteriological examination of materials from corpses.
Acute erysipelas... The first signs of the disease are a rise in temperature for several hours to 42 ° C and above, loss of appetite, development general weakness and chills. The pigs lie down, get up reluctantly, the gait is shaky, the hind limbs are weak. Conjunctivitis often develops with the release of a serous-mucous secretion. On the part of the gastrointestinal tract, symptoms of atony and constipation appear, sometimes vomiting is noted.
After 24-48 hours from the onset of the disease, edematous swellings of a pale pink color appear on the skin of the neck, back and sides of various shapes and size. Subsequently, these spots acquire a clear outline and purple color. The condition of patients is rapidly deteriorating, the pulse becomes weak and frequent (up to 100 beats per minute), develops pulmonary edema, breathing is hoarse with difficulty. The disease usually lasts 2-4 days and often ends with the death of the animal.
Subacute or cutaneous (urticaria) form of erysipelas... In comparison with the described more benign form of the disease, which lasts 7-12 days with an increase in temperature to 41 ° C, a decrease in appetite, the development of thirst and general weakness. 1-2 days after the temperature rises, small (from 2x2 to 3x4 cm) swelling of the skin from colorless to pink-colored, acquiring a red-purple or bluish color with outlined edges, appear on the head, neck, back and sides. The shape of the spots is round, rhomboid, crescent or rectangular. From the moment the spots appear, the patient's condition improves, the temperature drops, the appetite is restored. At the site of the spots, necrosis and desquamation of the epithelium can develop. With extensive dermatitis, the disease sometimes turns into chronic form... Among overweight pigs, the disease can become septic and end in death. The cutaneous form of the bowl ends with the recovery of sick pigs.
Chronic erysipelas... More often it is a continuation of an acute or subacute forms diseases, but can be registered as a latent infection. It is very often accompanied by arthritis and polyarthritis of all joints and extremities with the development of joint deformity, lameness and difficulty walking. Verrucous endocarditis develops, leading to heart failure. shortness of breath, general weakness. Pigs lose their appetite, lose weight and become weaker. The affected areas of the skin are necrotic. become dry, brittle, dark brown in color. On the border with living tissue, purulent inflammation and the formation of scar tissue can develop. The disease can sometimes last for several months, wave-like changing the periods of exacerbation of the disease with periods of apparent well-being. The death of patients can occur suddenly due to heart failure. At good conditions keeping and feeding pigs can gain weight, and during slaughter they are found to have endocardial damage.
Pathological changes. When examining the corpses of dead pigs with acute and subacute course of the disease, characteristic lesions of the skin, foamy outflows from the nasal passages in case of development of pulmonary edema are noted.
The presence of serous fluid with fibrin filaments is noted in the chest and abdominal cavities and the heart bag. Fibrin filaments can cover the parenchymal organs and intestines. The lungs are gyneremic, edematous, in the bronchi and trachea there is a foamy liquid. The blood vessels are filled with dark. poorly clotted blood. The lymph nodes are swollen, reddened, in the gastrointestinal tract, catarrhal-hemorrhagic inflammation of the mucous membranes is noted. Peyer's patches and solitary follicles are swollen and enlarged.
The liver is filled with blood, dark cherry color. The kidneys are dark cherry in color with hemorrhages under the capsule. The muscle of the heart is flabby, pale.
In the chronic course of erysipelas, red-gray growths in the form of warts or "cauliflower" (verrucous endocarditis) form on the heart valves.
With erysipelas arthritis, a thick serous fluid with an admixture of blood is found in the joint cavities when destroyed cartilage tissue, which sometimes leads to bone caries and joint deformities. Changes in the internal organs are similar to changes in the subacute course of erysipelas.
Erysipelas disease is diagnosed on the basis of clinical, postmortem and laboratory data. Bacteriological diagnosis includes: microscopy; isolation of a pure culture of the pathogen and a bioassay on white mice or pigeons.
Microscopy. Prepare smears-prints or smears from the blood of the heart, kidneys and spleen. In positive cases, after Gram staining, Gram-positive rods are found, located singly or in the form of clusters. In smears-prints from the surface of the heart valves in the case of endocarditis, microbial forms are found in the form of threads and their plexuses.
Isolation of a pure culture of the pathogen. Inoculations are made from the affected areas of the skin, spleen, bone marrow, liver, from the blood of the heart, from overlays on the heart valves in the BCH or Hotinger's broth. Abroad, inhibitory media based on sodium azide, crystal violet are used, as well as a medium based on tryptose phosphate broth of 5% horse serum, kanamycin, neomycin, vancomycin and novobiocin. These media inhibit the growth of other microorganisms and practically do not affect the growth of erysipelas.
Pig erysipelas(Bact. Erysipelothrix Rhusiopathiae) discovered by Pasteur and Tuillier in 1882, is an immobile thin, slender, straight or slightly curved rod 0.2-0.3x0.5-2.0 microns in size, which does not form spores and capsules. The bacteria are gram-positive. well stained with conventional aniline dyes. In old broth cultures and from overlays on heart valves with endocarditis, elongated filamentous forms are found. Erysipelas bacteria grow well in both aerobic and anaerobic conditions on most known nutrient media. On MPA, the pathogen grows in the form of small dewy translucent colonies (S-form). With septicemia, S-forms are released. and in the chronic course of the disease - R-form - in the form of large colonies with an uneven rough surface and root-shaped processes extending from the edge.
The isolated culture is identified by morphological, tinctorial, cultural and biochemical properties, as well as in the agglutination reaction with positive serum.
Biochemical activity is determined on His media with glucose, lactose, sucrose and mannitol. At the same time, the formation of hydrogen sulfide and catalase is determined.
Agglutination reaction (RA). RA is put with hyperimmune medicinal serum. A drop of serum is applied to a glass slide at a dilution of 1:50. then a daily agar culture is introduced in a loop and thoroughly triturated. In the positive case, agglutination occurs quickly, the agglutinate looks like dense small lumps.
A culture that produces hydrogen sulfide and does not form catalase. decomposing glucose, lactose (without gas) and non-fermenting sucrose and beckoning, giving positive RA, are referred to as the causative agent of erysipelas.
To detect erysipelas in pathological material, as well as to identify isolated cultures, the method of fluorescent antibodies is used.
Bioassay. To infect laboratory animals, use a 10% suspension from parenchymal organs from sick animals or a daily culture of the erysipelas pathogen grown on liquid or solid media. White mice and pigeons are especially sensitive to the pathogen. As a result subcutaneous administration mice (0.1-0.2 ml) and pigeons intramuscularly (0.2-0.3 ml) culture of erysipelas have photophobia, conjunctivitis, lethargy and death occurs in 2-4 days. In the case of selection of gmt material from chronic pigs or obtaining a weakly virulent culture, infected mice and pigeons die within up to 6 days or survive. From the blood and organs of the fallen, smears are made, prints and inoculations on MP B and MPA for microscopy and isolation of the pathogen culture.
A laboratory diagnosis is considered established if at least one of the indicators is obtained:
- detection of the causative agent of erysipelas in patmaterial from sick pigs;
- isolation from the pathological material of a pure culture or, together with the accompanying microflora, of a culture with properties characteristic of the causative agent of erysipelas;
- the death of animals infected during the bioassay and the isolation from them of a culture with properties characteristic of the causative agent of erysipelas.
When diagnosing “ Pig erysipelas»It is necessary to exclude:
swine fever is an acutely contagious disease of pigs, registered at any time of the year, affecting animals of all ages. The skin of the abdomen, perineum, dewlap is often colored purple-red with multiple punctate hemorrhages. When opening corpses, infarctions in the spleen, marbling of the lymph nodes, hemorrhages on the epiglottis, kidneys, and bladder are distinguished:
Pasteurellosis - hemorrhagic septicemia of pigs is acute or in the form of a secondary infection. The disease is characterized by lesion of the lungs with hemorrhages on the serous membranes of the chest cavity and parenchymal organs with the presence of serous-fibrinous transudate in the thoracic-abdominal cavity. In the chronic course of the disease, the pigs are severely emaciated. Take into account laboratory research data;
Listeriosis - occurs more often among suckling pigs and weaners in the form of limited outbreaks with signs of fever, refusal to eat, rapid breathing and general weakness. Abortions and stillbirths are recorded among pregnant sows. Be sure to take into account the results of bacteriological studies;
Anthrax - is extremely rare in pigs and manifests itself most often in the form of severe tonsillitis with severe edema pharyngeal area. Laboratory research are obligatory and give a real diagnosis;
Sunstroke and heatstroke - taking into account weather conditions and bacteriological studies, it can be differentiated from erysipelas. Clinically manifested by rapid breathing, cardiac disorder, an increase in body temperature to 43 ° C, convulsions and death in the first hours of the onset of symptoms.
Treatment. If erysipelas occurs on the farm, it is necessary to vaccinate clinically healthy pigs, and patients and suspects in the disease are isolated and treated with anti-erysipelas hyperimmune serum and antibiotics. With a severe form of the disease and weakened cardiac activity, the therapeutic dose of serum (1-1.5 ml / kg) is best administered in 2-3 doses intramuscularly with an interval of 30-40 minutes between injections. A good effect is provided by the simultaneous administration of serum and an antibiotic dissolved in it. With an outbreak of erysipelas, the introduction of fast-acting drugs of the penncillin series (streptomycin, erythromycin, etc.) in combination with antibiotics of prolonged and wide range actions (Enroxan-100. Farmaxin-200, etc.). It must be remembered that the use of antibiotics only controls the infection but does not eliminate the carriers.
Control and prevention measures. Considering the variety of sources of infection and factors contributing to its spread, only a set of measures will help to successfully fight the disease of pigs with erysipelas.
Preventive vaccination is considered the main method of fighting erysipelas of pigs all over the world. Back in 1883, Pasteur made the first attempts to vaccinate pigs with weakened erysipelas. In those days, after vaccination, the mortality rate of pigs was up to 20%. In Russia, live vaccines were produced and used by P.I. Borovsky. (1897). D.F. Konev (1904 1908, 1913), P.S. (1940) and many others.
In 1931, the strain BP-2 - "Bucharest" (WR-2B) was isolated from the corpse of a pig. which, after long passages on nutrient media, lost its pathogenicity in pigs, remaining in them highly immunogenic and weakly pathogenic in white mice. Strain "BP-2B" belongs to the serological type "N", has a common species antigen, but does not contain haptens. Of all the strains used abroad, as well as in the CIS countries and in Ukraine, "BP-2" has significant advantages in terms of immunobiological indicators: high immunogenicity, apathogenicity, absence of post-vaccination complications, rapid formation and sufficient duration of immunity. For decades, work was carried out with the strain and the production of vaccines against swine erysipelas from the BP-2 strain.
Conducting successive passages on nutrient media naturally led to a decrease in the immunogenic properties of the BP-2 strain and, as a consequence, to an increase in the immunizing dose to 50-200 million bacterial cells.
Research and Production Enterprise "Bio-Test-Laboratory" has acquired in one of the foreign countries technology and vaccine strain "WR-2B" for the production of vaccine against swine erysipelas. The WR-2B strain with which Academician Brauner worked was obtained by him from the Pasteur Institute in Bucharest. The vaccine prepared according to the technology of Academician Brauner, registered in Ukraine under the trademark "Vaccine BS". is highly immunogenic and apathogenic for pigs.
Particularly noteworthy is the fact that the "BS vaccine" from the high immunogenic strain "WR-2B". containing at least 4 million live erysipelas in a single dose, creates a stable immunity and protects pigs from disease with a single injection for 6 months both on the farm and with a control infection with a pathogenic strain of erysipelas in an acute experiment.
Lyophilization of "BS vaccine" contributes to its storage for 12 months and preservation of immunogenic properties for the entire storage period.
Clinically healthy pigs are vaccinated, and sick and suspected pigs are isolated and treated. After 14-21 days after treatment (with the use of therapeutic serum), recovered pigs are vaccinated. In order to prevent the disease, all pigs are vaccinated, starting from 2 months of age (mass vaccination) with revaccination of the livestock after 6 months. It is very important to graft growing young stock throughout the year. In some individuals, a skin reaction in the form of urticaria and erythema at the injection site of the vaccine is possible without deteriorating the general condition of the animal, fever, while maintaining appetite. This reaction is not massive and usually goes away in 2-3 days without treatment and antibiotics.
General preventive actions for swine erysipelas, include the elimination of sources of infection by carrying out deratization, routine and periodic cleaning and disinfection of pigsties, walking areas, summer camps... They carry out zootechnical and veterinary measures aimed at obtaining and raising a healthy livestock of pigs. Forced slaughter of the sick pig erysipelas carried out in a specially designated place, the meat from them must be boiled for at least 2 hours.
However, it should be emphasized that the most effective measure in the prevention of swine erysipelas is specific vaccination with highly immunogenic drugs, in particular, "BS vaccine". Its application makes it possible to free farms from the disease of pigs with erysipelas and makes it possible to receive in full the profit that the farm loses when it occurs.
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