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Salmonella

Salmonellosis (lat., English - Salmonellosis; paratyphoid) - a large group of zoonotic diseases of mainly farm animals, characterized in young animals with acute course of fever, septicemia, toxicosis and diarrhea, and with subacute and chronic - pneumonia and arthritis; in adult females, by abortion; in humans, it proceeds in the form of foodborne toxicoinfections (see color insert).

Historical background, distribution, hazard and damage. For the first time, Salmonella (S. choleraesuis) was isolated from pig corpses in 1885 by American scientists Salmon and Smith. Subsequently, at the end of the 19th century, similar bacteria were isolated from calves, mice, rats, chickens and chickens, from aborted fetuses of mares. Previously, these diseases were described under the name "paratyphoid." In 1934, the International Society of Microbiologists recommended that the bacteria of this group be called salmonella (in honor of the discoverer of Salmon), and the diseases caused by them are called salmonella. In our country, salmonellosis was first established at the end of the 20s of the last century in calves, sheep, pigs, and then in other animals.

Currently, salmonellosis is widespread in many countries of the world, occupies a large share among infectious diseases and is a major veterinary and biomedical problem, since there is a very high risk of human salmonella infection from sick animals and through food products.

The damage caused by salmonellosis is very high and consists of losses caused by the death of young animals, the lag in growth and development of sick animals, as well as the costs associated with the organization of preventive and therapeutic measures.

The causative agents of the disease. Bacteria of the Salmonella genus, assigned to the family of enterobacteria, currently unite more than 2300 serovars, divided into 52 serogroups, most of which have independent names. Pathogenic to animals and humans. The main pathogens of animal salmonellosis belong to serogroups B, C, and D. The list of the main and rare pathogens of animal salmonellosis is shown in Table 1.6.

1.6. The causative agents of salmonellosis in animals

According to their resistance to chemical disinfectants, salmonella belong to the group of unstable (the first group). In soil, manure are stored for 9 ... 10 months, in drinking water - 10 ... 120 days, in room dust - 8 ... 18 months, in salted and smoked meat - 2.5 ... 3 months, in cottage cheese, oil - 6 months. Freezing is carried out for 4 ... 5 months, heating to 80 ° C for up to 15 minutes. 2% hot solutions of sodium or potassium hydroxide, 2% solutions of formaldehyde, chlorine preparations (iodine monochloride, bleach, etc. ) with a content of at least 2% active chlorine, 1% iodine, 3% hydrogen peroxide, vircon C 1: 100 and other drugs have a detrimental effect on salmonella when exposed for at least 1 hour.

Epizootology. Salmonella is pathogenic for animals of many species, including birds, but clinically significant disease is usually caused by individual serological variants that have adapted to specific species. In a dysfunctional salmonellosis farm, some of the young grow ill. Most infected young and adult animals are asymptomatic and remain salmonella carriers for a long time. The most important epizootological data are given in table 1.7.

1.7. Epizootological Characterization of Salmonella

If the resistance of the body is weak, the pathogen multiplies, and the microbial cells are partially destroyed with the release of endotoxin. Inflammation develops in the breeding places (intestinal mucosa, gall bladder, liver), and endotoxin causes exudative processes and diapedesis with the subsequent appearance of profuse hemorrhage on the serous and mucous membranes and leads to necrosis of liver, spleen and kidney cells. Damage to the lungs, joints, brain, uterus and fetus are possible. The death of the animal occurs from dehydration, numerous hemorrhages, intoxication and sepsis.

The course and clinical manifestations. Salmonellosis in young animals is acute, subacute, chronically and atypical (in calves). The incubation period ranges from 1 ... 3 to 7 days depending on the resistance of the organism, virulence and the dose of the pathogen, as well as the method of infection and the conditions in which the susceptible animal is located.

In calves, the acute course of the disease is observed up to 1.5 months of age. There is an increase in body temperature to 40 ... 41.7 ° C, weakness, increased heart rate (100 ... 160 beats per 1 min) and respiration (30 ... 51 in 1 min), which becomes superficial, abdominal type. Diarrhea appears on the 2nd day after a fever, and sometimes later. Feces become liquid, from yellow to green, with flakes of mucus and fibrin, often with layers of blood. The tail and back of the body are contaminated with feces. With the onset of diarrhea, body temperature decreases, trembling and twitching appear in the area of ​​the femoral and ulnar muscle groups. The calf gradually loses weight, weakens, the hairline loses its luster, they are marked by an unsteady gait, conjunctivitis and rhinitis. Urination becomes frequent, painful, shortness of breath. In the acute course of the disease in a semi-coma state, the animal dies on the 5th ... 10th day.

Piglets in acute course refuse to feed, are depressed, burrow into the litter, lie, body temperature rises to 41 ... 42 "C. Conjunctiva reddening with a bluish tinge and gastrointestinal tract dysfunction are noted. Feces are light yellow in color, sometimes with an admixture of mucus and blood, in individual piglets vomiting, focal redness or blueness in the abdomen, ears and groins appears on the skin.

With untimely treatment, after 2 ... 7 days 70 ... 80% of pigs die, in the rest, salmonellosis takes a subacute or chronic course.

In lambs, the course of the disease is predominantly acute. Body temperature rises to 41 ... 41.5 ° C, pulse and breathing become more frequent, appetite and sucking reflex are disturbed, the general condition is depressed. Usually, diarrhea appears on the 2nd ... 3rd day of illness, feces become liquid, with streaks of blood and whitish clots, the lambs die on the 2nd ... 5th day. In lambs 1 ... 3 months of age, the disease occurs subacute. Animals refuse to feed.

In foals in acute course, the body temperature rises to 40 ... 41 "C, the pulse increases, but is poorly palpated, diarrhea appears, watery feces, yellow in color, with streaks of mucus and indigestible clots of milk. The mucous membranes are pale, the hair loses shine, the foal the joints of the extremities swell sharply, they are painful on palpation. In the acute course of the disease, the foals die within 2 ... 3 days.

The subacute course of the disease is characterized by less severe symptoms and subfebrile fever. The general condition of the animal is depressed, the hair loses its luster. Diarrhea is replaced by constipation, pneumonia begins (expiration from the nasal passages, cough, wheezing in the lungs, fever of an alternating type).

In chronic salmonellosis, which often develops after an acute or subacute course, signs of pneumonia predominate along with diarrhea. Chronic patients sharply lag behind in growth, their fatness decreases; carpal, knee, and tarsal joints are affected. In piglets, in addition, the skin loses its elasticity, scabby eczema appears on it, the skin of the auricles acquires a dark violet color and foci of necrosis appear.

The nervous form of salmonellosis in piglets, which is rare, resembles Aujeszky’s disease. At the same time, along with high fever, increased heart rate and breathing, impaired appetite, grinding of teeth is observed, the head twitches convulsively, and sometimes there are nervous attacks.

In fur-bearing animals, salmonellosis raises body temperature, diarrhea and often vomiting are noted. In acute course, patients die on the 2nd ... 3rd day, in subacute - on the 7th ... 14th day. In females who became ill during the rut or pregnancy, infertility (14 ... 20%), abortion (up to 15%) and mortality up to 20% of young animals in the first 10 days are observed.

In sheep and horses, salmonellosis occurs as a salmonella abortion in ewes and mares, or in the death of newborn animals. In sheep, the incubation period is 2 ... 7 days. The leading clinical symptom is abortion in the last month of coagulation; retention of the placenta, endometritis, and pyometra are also noted. In severe septic conditions after an abortion, animals may die. In horses, the incubation period is 1 ... 7 days. Mares have abortions on the 4th ... 8th month of the draw, other signs, as a rule, are not observed.

Pathological signs. Pathological changes in salmo-nonlesis have a certain diagnostic value.

In acute calves, exudate accumulates in the abdominal cavity, and the abdominal lymph nodes are enlarged. Bile is yellow-green in color, creamy consistency, hemorrhages and ulcers on the mucous membrane of the gall bladder are frequent. The spleen is enlarged, gray or gray-yellow; kidneys of pink or gray-yellow color, in some places spot hemorrhages are visible, the capsule is easily removed. With the incision of the affected lung lobes, a mucopurulent mass is secreted.
Bronchial and mediastinal lymph nodes are enlarged, with hemorrhages. With a subacute course, the liver is enlarged, pinpoint hemorrhages with the presence of salmonella nodes are noticeable. The spleen is enlarged. However, more often, changes are noted in the lungs. In a chronic course, the lungs are blue-red in color, there are foci of necrosis of various sizes, often the surface of the lung fuses with the costal pleura. Bronchial lymph nodes are sharply enlarged, bumpy, pink-red in color. The liver is enlarged, flabby consistency, easily bursts.

Piglets in the acute course of the disease have hemorrhages in the spleen, kidneys, epicardium, mucous membrane of the stomach and intestines, under the pulmonary pleura. The mucous membrane of the small intestine is edematous, hyperemic, with foci of superficial necrosis, and the folding of the mucous membrane in the large intestine is enhanced. Lymph nodes are enlarged, there are hemorrhages. The spleen is dark red in color, with a dense pulp, its size is more than normal. The liver is slightly enlarged, unevenly colored. The kidneys are dark in color. The lungs are sometimes swollen. With a subacute course in the large intestine, necrosis of the lymphatic follicles and diphtheria inflammation of the mucous membrane are detected. The mucous membrane of the stomach is partially necrotic; focal fibrinous pneumonia is characteristic. In the chronic course, pathological changes in the large intestine and lungs are more pronounced.

In sheep, hemorrhagic inflammation of the mucous membrane of the abomasum and small intestine in fallen lambs is detected. Slightly enlarged spleen and lymph nodes. The lungs are inflamed, there are spot hemorrhages on the surface, and sometimes fibrinous overlay. In aborted fetuses, puffiness of the subcutaneous tissue, sometimes its emphysema, is expressed. On the endocardium, epicardium and in the serous membranes of hemorrhage. The liver is enlarged, dark cherry, flabby. The kidneys are softened, flabby, sometimes a mushy consistency, the capsule is easily removed from them. The spleen is enlarged, the pulp drains from the surface of the incision. The mucous membrane of the abomasum and intestines is swollen, reddened, and sometimes with hemorrhages.

In horses, the spleen of fallen foals is increased by 2 ... 3 times, acute serous lymphadenitis, degeneration of parenchymal organs, hemorrhagic or diphtheria enteritis, catarrhal bronchopneumonia. Aborted fetuses have yellowness and swelling of the skin, subcutaneous tissue, mucous membranes and serous membranes. In serous cavities, fluid accumulation. Hemorrhages in the mucous membranes and pericardium. Spleen, liver, kidneys are enlarged, flabby consistency.

Diagnostics and differential diagnostics. The diagnosis is established on the basis of the analysis of epizootic, clinical and pathological data, as well as the results of bacteriological studies. For bacteriological research, samples of parenchymal organs (liver with gall bladder and lymph nodes, heart, lungs, spleen, kidney) are sent to the laboratory; mesenteric lymph nodes; tubular bone; aborted fruits with fruit membranes and amniotic fluid. To establish salmonella, the liver and spleen are examined. The material for intravital diagnosis is blood and feces of sick animals. Bacteriological studies are carried out in accordance with the guidelines “Laboratory diagnosis of human and animal salmonella, detection of salmonella in feed, food and environmental objects”. The scheme of the study of pathological material for salmonellosis is presented in Figure 1.6.

Fig. 1.6. The scheme for the study of pathological material in salmonellosis

Differential diagnosis in calves excludes escherichiosis, streptococcosis, rota- and coronavirus diarrhea, adenovirus pneumoenteritis and parainfluenza; in piglets - Escherichiosis, dysentery, streptococcosis, plague, viral gastroenteritis; in lambs - anaerobic dysentery, eimeriosis; foals have streptococcosis, escherichiosis; in animals of all kinds - pasteurellosis, nonspecific gastroenteritis, pneumonia, in ewes and mares - brucellosis, chlamydia, campylobacteriosis and abortions of a different nature. Differentiate these diseases from salmonellosis on the basis of bacteriological and serological studies.

Immunity, specific prevention. In case of salmonellosis in animals, intense active immunity is formed (up to 8 ... 9 months). Passive (serum or colostrum) immunity is also formed. For the specific prophylaxis of salmonellosis in animals, inactivated formolvac vaccines are used [against salmonellosis (paratyphoid) of calves, piglets, lambs, fur animals, salmonella abortion of mares, sheep, etc.], as well as live vaccines from the generated strains (against salmonellosis of calves, pigs, pigs , sheep, etc.) registered in the Russian Federation. In addition, the associated vaccines are used against salmonellosis, pasteurellosis and streptococcosis of piglets, against salmonellosis and colibacteriosis of fur animals.

Animals are vaccinated against salmonellosis: when clinically ill animals are detected; in the presence of abortions of salmonella etiology; when salmonella carriers are detected; when setting young growth for fattening.

Prevention Prevention of salmonellosis is carried out in accordance with current Veterinary and sanitary rules. An important link in the prevention of the disease is the compilation of the main herd with animals that are safe for salmonellosis. Along with vaccination, the main thing in the prevention of salmonellosis is the full feeding of pregnant cows, pregnant sows and mares, the creation of the necessary animal health conditions during calving, farrowing, lambing and foraging, and the adherence to the system for receiving and preserving newborn young animals. The joint keeping of animals of various types and directions is not allowed. Salmonella-seeded feed is disinfected or destroyed. To prevent gastrointestinal upsets, young animals should be given probiotics and complex premixes.

In all cases of forced slaughter of animals, meat and organs are subjected to mandatory bacteriological examination for salmonellosis and, in case of confirmation of the diagnosis, the meat is processed in accordance with the current Rules for veterinary inspection of slaughtered animals and veterinary examination of meat and meat products.

Treatment. Sick animals are isolated, they organize diet feeding and complex treatment aimed at destroying the pathogen in the body, eliminating intoxication and restoring digestive and respiratory functions. As a specific therapy, polyvalent antitoxic serum against salmonellosis and escherichiosis of calves, piglets, lambs, sheep and birds is used. Good results are obtained with antibiotic treatment (except for penicillin group drugs) in combination with sulfanilamide drugs (ethazole, sulfadimezin, norsulfazole, etc.). For the prevention and treatment of piglets, furabimin (biovit-80, furazolidone and disulformin) is used, Spectam B, streptonamide, etc.

Control measures. When a diagnosis of salmonellosis is established, restrictions are introduced and measures are taken taking into account the type of animal. The single events carried out during salmonellosis of animals, except for birds, are presented in Figure 1.7.

In salmonellosis-poor households, against the background of colostral immunity, active vaccination of animals must be carried out at 10 ... 20 days of age twice with subsequent revaccination. Young animals with severe salmonellosis, poorly treatable, are subject to culling and surrender to a sanitary slaughterhouse.

Skins, wool, fluff, feathers of forced animals are decontaminated in accordance with the current instruction on the disinfection of raw materials of animal origin and the implementation of measures for its preparation, storage and processing.

The farm (farm, pigsty, section, koshara, stable, etc.) is considered to be salvaged from salmonellosis 30 days after the last case of isolating clinically sick animals, and in horses 45 days after abortion, vaccination and final disinfection.

Measures to protect people from salmonellosis. People become infected when they eat food that is seeded with salmonella in the process of their receipt, processing, transportation and sale, which have undergone insufficient cooking or were stored in violation of established regimes. Возможно заражение через предметы бытовой и производственной обстановки, а также через воду.

Сальмонеллы, кроме того, вызывают у человека брюшной тиф (Salmonella typhi) и паратиф (Salmonella paratyphi А, В, С), к которым животные не восприимчивы. С целью профилактики сальмонеллеза у людей во всех случаях вынужденного убоя животных мясо и органы подвергают обязательному бактериологическому исследованию на сальмонеллез и в случае подтверждения диагноза мясо перерабатывают в соответствии с действующими Правилами ветеринарного осмотра убойных животных и ветсанэкспертизы мяса и мясных продуктов. С целью ограничения роли человека как источника возбудителя инфекции проводят мероприятия, направленные на выявление и регистрацию больных сальмонеллезом и бактерионосителей, их госпитализацию проводят в соответствии с Методическими указаниями по эпидемиологии и профилактике сальмонеллезов (1985).

Fig. 1.7. Мероприятия, проводимые при сальмонеллезе животных

Контрольные вопросы и задания. 1. Охарактеризуйте этиологическую структуру и основные нозологические формы сальмонеллезов у разных видов животных. 2. Почему сальмо-неллезы относят к факторно-инфекционным болезням? 3. Охарактеризуйте течение и формы клинического проявления сальмонеллезов у животных разного вида и возраста. 4. Проведите дифференциальную диагностику сальмонеллезов от колибактериоза, стрептококкоза и анаэробной энтеротоксемии по комплексу данных. 5. Назовите методы прижизненной и посмертной диагностики сальмонеллезов. Когда окончательный диагноз считается установленным? 6. Назовите методы и средства комплексной терапии и специфической иммунопрофилактики сальмонеллезов. 7. Какую опасность представляют сальмонеллезы для животных и человека? 8. Сформулируйте меры общей и специфической профилактики сальмонеллезов у животных и человека.
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САЛЬМОНЕЛЛЕЗЫ

  1. Salmonella
    Salmonellosis of birds (Latin, English - Salmonellosis; paratyphoid, infectious diarrhea of ​​birds) is a disease characterized by an acute course of septicemia in young animals and latent infection in an adult bird. Historical background, distribution, hazard and damage. Salmonella is widespread. Salmonella was first isolated from pig organs by American veterinarians Salmon and Smith in 1885.
  2. Salmonellosis
    Salmonellosis (salmonellosis) is an infectious disease of birds, mainly young animals, characterized by diarrhea, conjunctivitis, septicemia, intestinal damage and exhaustion. Etiology. The causative agents of the disease S. typhimurium, S. enteritidis, S. сholeraesuis, short gram-negative, motile, spores and capsules not forming sticks. In the external environment retains its biological properties
  3. SALMONELLOSIS AND THEIR PREVENTION
    According to the classification of foodborne diseases, salmonellosis was previously assigned to the group of microbial food poisoning that causes toxic infections. Currently, according to the current classification, salmonellosis is assigned to the group of acute intestinal infections, where they are allocated in an independent section: "Other salmonella intestinal toxicoinfections." However, in their appearance, course, prevention, they also
  4. SALMONELLOSIS (SALMONELLOSIS)
    Salmonellosis is an acute contagious disease that affects mainly puppies of weaned age. Etiology. The genus Salmonella includes 65 groups and is widespread in nature. Salmonella parasitizes in the body of domestic as well as wild animals, including birds, fish, reptiles. Many species are highly pathogenic and dangerous to humans. In dogs, Salm is more often secreted. cholerae suis, S.
  5. Salmonella
    Salmonellosis (lat., English. - Salmonellisis) - a disease of adult bees, manifested by damage to the digestive system. The causative agents of the disease. The disease can be caused by various representatives of the genus Salmonella: S. typhimurium, S. gallinarum-pullorum, S. enteritidis, S. dublin, S. florida (see part 1, Salmonella). Salmonella is pathogenic to animals and birds of many species and is often found
  6. Salmonellosis
    Salmonellosis (salmonellosis) - an infectious disease of young animals, characterized by a violation of the digestive tract, the development of toxemia, sepsis, sometimes metritis and abortion. Etiology. The causative agent of the disease is a gram-negative movable rod with rounded ends, it does not form spores and capsules, it is relatively stable in the external environment. Disease in small animals
  7. Salmonellosis
    Salmonellosis (salmonellosis) is an infectious disease of young farm animals and fur animals, characterized in acute course by fever and enteritis, and in chronic - pneumonia and joint damage. Etiology. The causative agent in piglets is S. cholerae suis and its variants; in calves - S. dublin, less commonly S. typhimurium and S. enteritidis; in lambs, S. abortus ovis; in foals
  8. Salmonella
    Salmonellosis is an acute infectious disease caused by microbes of the genus Salmonella, occurring mainly with gastrointestinal tract lesions, less often in the form of generalized forms. Clinical diagnosis The incubation period for the alimentary route of infection is 12-24 hours, for contact - 3-7 days. Gastrointestinal form. Gastritis, enteritis, gastroenteritis. The onset is acute. Fever, pain in
  9. Salmonellosis
    Cause The causative agents of the disease are salmonella, motile sticks with flagella, which are found in foods such as eggs, meat and milk. Favorable conditions for the propagation of salmonella are created in hot weather. Products at risk include ice cream, creamy desserts, mayonnaises, salads, egg-protein based dishes (creams, cakes), milkshakes, soft-boiled eggs, etc.
  10. Salmonellosis and other acute intestinal diarrheal infections
    Training target: using diagnostic algorithms, be able to establish a diagnosis of salmonellosis, escherichiosis and other acute intestinal diarrheal diseases, determine the clinical form, severity, stage of the disease, and prescribe adequate treatment; conduct dispensary observation. Assignment for independent study of the topic. Using the textbook and lecture material for the acquisition
  11. Salmonellosis of ostriches
    Salmonellosis is an infectious disease characterized by septicemia, a fibrinous diphtheria of the intestine. Etiology. In ostriches, Salmonella enteridis is most often isolated. These are short gram-negative movable sticks with rounded ends. They do not form spores and capsules; they are cultivated under aerobic and anaerobic conditions. Epizootological data. The main source of pathogen
  12. Salmonellosis
    Это кишечные заболевания, вызываемые бактериями рода Сальмонелла (исключение - сальмонелла, вызывающая брюшной тиф и паратифы), с выраженными симптомами интоксикации организма. Эти микроорганизмы устойчивы во внешней среде, хорошо переносят низкие температуры, выживают в воде и домашних предметах при комнатной температуре до 45-90 дней. В соленом мясе - 2-3 месяца, в молоке - 2-40 дней. At
  13. Salmonellosis
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  14. Salmonella
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