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Salmonella

Salmonellosis (Latin, English - Salmonellosis; paratyphoid fever) - a large group of zoonotic diseases, mainly agricultural animals, characterized by young animals with acute fever, septicemia, toxicosis and diarrhea, and with subacute and chronic - pneumonia and arthritis; in adult females, abortions; in people it occurs in the form of food toxicoinfections (see color inset).

Historical background, distribution, degree of danger and damage. For the first time Salmonella (S. choleraesuis) from the corpses of pigs was isolated in 1885 by American scientists Salmon and Smith. Later, at the end of the 19th century, similar bacteria were isolated from calves, mice, rats, chickens and chickens, from the aborted mares. Previously, these diseases have been described under the name "paratyphus". In 1934, the International Society of Microbiologists recommended that bacteria of this group be called Salmonella (after the discoverer of Salmon), and the diseases caused by them are Salmonella. In our country, salmonellosis was first established in the late 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 proportion among infectious diseases and is a major veterinary and biomedical problem, since the risk of infection with human salmonellosis is very great from sick animals and through food products.

The damage caused by salmonellosis is very high and consists of the losses caused by the deaths of young animals, the lag in the growth and development of the animals that had been ill, and also the costs associated with the organization of preventive and curative measures.

Pathogens. Bacteria of the genus Salmonella, assigned to the family of enterobacteria, currently unite more than 2,300 serovars, divided into 52 serogroups, most of which have independent names. Pathogens for animals and humans. The main pathogens of salmonellosis in animals are serogroups B, C, and D. A list of the main and rarely encountered pathogens of salmonellosis in animals is given in Table 1.6.

1.6. Causative agents of salmonellosis animals

By resistance to chemical disinfectants, salmonella are classified as unstable (first group). In the soil, manure is 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, butter - 6 months. Freezing is transferred for 4 ... 5 months, heating to 80 "C - up to 15 minutes. 2% hot solutions of sodium or potassium hydroxide, 2% solutions of formaldehyde, chlorine-containing preparations (iodine monochloride, bleach, etc. a) with a content of at least 2% active chlorine, 1% iodez, 3% hydrogen peroxide, vir-con C 1: 100, and other agents have a detrimental effect on salmonella during an exposure of at least 1 h.

Epizootology. Salmonella pathogens for animals of many species, including birds, but clinically severe disease usually cause separate serological variants, adapted to specific species. In a dysfunctional salmonellosis farm, part of the young catches. The majority of infected young and adult animals are asymptomatic and remain Salmonella carriers for a long time. The most important epidemiological data are given in table 1.7.

1.7. Epizootologichesky characteristic of Salmonella

If the resistance of the body is weak, then the pathogen multiplies, and the microbial cells are partially destroyed with the release of endotoxin. In reproduction sites, inflammation develops (intestinal mucosa, gallbladder, liver), and endotoxin causes exudative processes and diapedesis with subsequent appearance of abundant hemorrhages on the serous and mucous membranes and leads to necrosis of the cells of the liver, spleen and kidneys. Damage to the lungs, joints, brain, uterus and fetus. The death of the animal comes from dehydration, numerous hemorrhages, intoxication and sepsis.

Current and clinical manifestations. Salmonellosis in young animals occurs acutely, subacutely, chronically and atypically (in calves). The incubation period varies from 1 ... 3 to 7 days depending on the resistance of the organism, virulence and dose of the pathogen, as well as the mode of infection and the conditions in which the susceptible animal is.

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 per 1 min), which becomes superficial, of the abdominal type. Diarrhea appears on the 2nd day after the temperature rises, and sometimes later. The feces become liquid, from yellow to green, with flakes of mucus and fibrin, often with layers of blood. The tail and the back of the body are polluted with feces. With the advent of diarrhea, body temperature decreases, trembling and twitching in the femoral and ulnar muscle groups appear. The calf gradually loses weight, weakens, the scalp loses shine, gait staggering, conjunctivitis and rhinitis are noted. Urination becomes frequent, painful, intermittent breathing. In the acute course of the disease in a semi-comatose state, the animal dies on the 5th ... 10th day.

In case of acute course, piglets refuse to feed, are oppressed, burrow into the litter, lie, body temperature rises to 41 ... 42 "C. Reddening of the conjunctiva with a bluish tinge and dysfunction of the gastrointestinal tract are noted. Cal light yellow color, sometimes an admixture of mucus and blood, individual pigs vomit.Focus on the skin appear reddening or blue in the abdomen, ears and groins.

In case of late 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. The body temperature rises to 41 ... 41.5 ° C, the pulse and breathing become more frequent, the appetite and the sucking reflex are disturbed, the general condition is depressed. Usually, diarrhea appears on the 2nd ... 3rd day of the disease, the 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 is subacute. Animals refuse to feed.

In foals, during acute flow, the body temperature rises to 40 ... 41 "C, the pulse quickens, but it is weakly palpable, diarrhea appears, watery feces, yellow in color, with streaks of mucus and undigested milk clots. The mucous membranes are pale, the hair loses shine, and the foal exhausted. The joints of the extremities swell up 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 low-grade fever. The general condition of the animal is depressed, the scalp loses shine. Diarrhea gives way to constipation, pneumonia begins (outflow from the nasal passages, cough, wheezing in the lungs, fever of intermittent type).

In chronic salmonellosis, which often develops after an acute or subacute course, signs of pneumonia predominate along with diarrhea. Patients chronicles sharply lag behind in growth, their fatness decreases; affects the carpal, knee, tarsus joints. In piglets, in addition, the skin loses its elasticity, scabby eczema appears on it, the skin of the auricles acquires a dark purple color and there are centers of necrosis.

The nervous form of salmonellosis in piglets, which is rare, resembles Aujeszky's disease. At the same time, along with high temperature, increased pulse and respiration, anorexia, there is gnashing of teeth, head twitching, and sometimes nervous seizures occur.

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

In sheep and horses, salmonellosis occurs in the form of a salmonella abortion in ewes and mares, or 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 malnutrition, as well as retention of the afterbirth, endometritis, and pyometra. In severe septic flow after an abortion, animals may die. In horses - the incubation period is 1 ... 7 days. Abortions in mares occur on the 4th-8th month of the foal, other signs, as a rule, are not observed.

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

Exhaust accumulates in calves with an acute course in the abdominal cavity, and the abdominal lymph nodes are enlarged. Yellow-green bile, creamy consistency, hemorrhages and ulcers on the mucous membrane of the gallbladder are frequent. The spleen is enlarged, gray or gray-yellow; the kidneys are pink or gray-yellow, dotted hemorrhages are seen in places, the capsule is easily removed. At a section of the affected lobes of the lungs, a mucopurulent mass is released.
Bronchial and mediastinal lymph nodes are enlarged, with hemorrhages. With subacute liver enlarged, visible hemorrhages with the presence of Salmonella nodes. Spleen enlarged. However, changes are more often noted in the lungs. In chronic course, the lungs are blue-red, there are foci of necrosis of various sizes, often the surface of the lung coalesces with the costal pleura. Bronchial lymph nodes are sharply enlarged, lumpy, on a section of pink-red color. The liver is enlarged, flabby consistency, easily torn.

In the case of the acute course of the disease, piglets have hemorrhages in the spleen, kidneys, on the 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, in the large intestine the folding of the mucous membrane is enhanced. Lymph nodes are enlarged, there are hemorrhages. The spleen is dark red in color, with dense pulp, its size is above the norm. The liver is slightly enlarged, unevenly stained. The buds are dark in color. The lungs are sometimes swollen. In case of subacute course in the large intestine, necrosis of the lymphatic follicles and diphtheria inflammation of the mucous membrane are detected. The gastric mucosa is partially necrotic; characteristic focal fibrinous pneumonia. In the chronic course, pathological changes in the large intestine and lungs are more pronounced.

Sheep are found to have hemorrhagic inflammation of the mucous membrane of the abomasum and small intestine in fallen lambs. Slightly enlarged spleen and lymph nodes. The lungs are inflamed, on the surface are pinpoint hemorrhages, and sometimes fibrinous overlap. In aborted fetuses, swelling of the subcutaneous tissue is expressed, sometimes its emphysematous. On the endocardium, epicardium and in the serous membranes of hemorrhage. The liver is enlarged, dark cherry color, flabby. The kidneys are softened, flabby, sometimes a pasty 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 swollen, reddened, and sometimes with hemorrhages.

In horses, the spleen of fallen foals is enlarged 2 ... 3 times, acute serous lymphadenitis, degeneration of parenchymal organs, hemorrhagic or diphtheria enteritis, catarrhal bronchopneumonia. In aborted fruits, 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, kidney enlarged, flabby consistency.

Diagnostics and differential diagnostics. The diagnosis is made on the basis of an analysis of epizootological, clinical, and pathological data, as well as the results of bacteriological studies. For bacteriological examination, 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 salmonellosis, a liver and spleen are examined. The material for in vivo diagnosis are the blood and feces of sick animals. Bacteriological studies are carried out in accordance with the guidelines "Laboratory diagnosis of human and animal salmonellosis, the detection of Salmonella in feed, food and environmental objects." The scheme for the study of pathological material for salmonellosis is presented in Figure 1.6.

Fig. 1.6. The scheme of the study of pathological material with salmonellosis

In the differential diagnosis of calves exclude colibacillosis, streptococcosis, rota-and coronavirus diarrhea, adenoviral pneumoenteritis and parainfluenza; in piglets - colibacillosis, dysentery, streptococcosis, plague, viral gastroenteritis; in lambs, anaerobic dysentery, ameriosis; in foals - streptococcosis, escherichiosis; in animals of all kinds - pasteurellosis, non-specific gastroenteritis, pneumonia, in ewes and mares - brucellosis, chlamydia, campylobacteriosis and abortions of a different nature. Differentiate these diseases from salmonellosis based on bacteriological and serological studies.

Immunity, specific prevention. When perebolevanii salmonnlezlezy animals formed intense active immunity (up to 8 ... 9 months). Passive (serum or youth) immunity is also formed. For specific prevention of salmonellosis in animals using inactivated formolkvastsovye vaccine [against salmonellosis (S. paratyphi) calves, piglets, lambs, fur animals, Salmonella abortion mares, sheep, etc.], As well as live vaccines of atgenuirovannyh strains (against salmonellosis calves, pigs, piglets , sheep, etc.), registered in the Russian Federation. In addition, the associated vaccines against salmonellosis, pasteurellosis and streptococcosis of piglets, against salmonellosis and colibacteriosis of fur-bearing animals are used.

Animals are vaccinated against salmonellosis: when detecting clinically sick animals; in the presence of salmonella etiology abortions; when identifying Salmonellosis; when setting up young animals for fattening.

Prevention. Prevention of salmonellosis is carried out in accordance with the current Veterinary and Health Regulations. An important link in the prevention of the disease is the completion of the main herd with animals that are safe for salmonellosis. Along with vaccination, salmonella prophylaxis focuses on full feeding of pregnant cows, pregnant sows and foals, creating the necessary zoohygienic conditions for calving, farrowing, lambing and colts, following the system for obtaining and preserving newborn young. The joint keeping of animals of various types and directions is not allowed. Feed, contaminated Salmonella, disinfect or destroy. To prevent gastrointestinal disorders, 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, if the diagnosis is confirmed, the meat is processed in accordance with the current Rules for veterinary examination of slaughter animals and veterinary expertise of meat and meat products.

Treatment. Sick animals are isolated, they organize dietary feeding and complex treatment, aimed at destroying the pathogen in the body, eliminating intoxication and restoring digestive function and respiration. Polyvalent antitoxic serum against salmonellosis and escherichiosis of calves, pigs, lambs, sheep and birds is used as a specific therapy. Good results are obtained with antibiotic treatment (except for drugs of the penicillin group) in combination with sulfa drugs (etazol, sulfadimezin, norsulfazole, etc.). For the prevention and treatment of piglets, furabimine (biovit-80, furazolidone and disul-formin), spectra B, streptonamide, etc. are used.

Control measures. When a diagnosis of salmonellosis is established, restrictions are imposed and measures are taken according to the type of animal. Single events carried out with salmonellosis of animals, except for birds, are presented in Figure 1.7.

In farms with dysfunctional salmonellosis, against the background of colostral immunity, active vaccination of animals should be carried out at 10 ... 20 days of age, followed by revaccination twice. Youngsters with a severe course of salmonellosis that are difficult to treat, should be discarded and put to the sanitary slaughterhouse.

The skins, wool, down, feather of animals that are forcedly killed are disinfected in accordance with the current guidelines for disinfecting raw materials of animal origin and taking measures for its preparation, storage and processing.

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

Measures to protect people from salmonellosis. People become infected through the use of foodstuffs, which are seeded with salmonella in the process of their production, processing, transportation and sale, which have undergone insufficient culinary treatment or were stored in violation of established regimes. Infection is possible through household and work environment items, as well as through water.

Salmonella, in addition, causes typhoid fever (Salmonella typhi) and paratyphoid fever (Salmonella paratyphi A, B, C) in humans, to which animals are not susceptible. 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

Control questions and tasks. 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
    Birds salmonellosis (Latin, English - Salmonellosis; paratyphoid, infectious diarrhea of ​​birds) is a disease characterized by an acute course in the form of septicemia in young and latent infection in adult birds. Historical background, distribution, degree of danger and damage. Salmonella is widespread. For the first time, salmonella was isolated from the organs of pigs by American veterinarians Salmon and Smith in 1885.
  2. Salmonellosis
    Salmonellosis (salmonellosis) is an infectious disease of birds, predominantly young, characterized by diarrhea, conjunctivitis, septicemia, bowel disease and exhaustion. Etiology. Pathogens S. typhimurium, S. enteritidis, S. сholeraesuis, short gram-negative, motile, spores and capsules that do not form sticks. In the external environment retains its biological properties
  3. Salmonella and their prophylaxis
    Earlier, according to the classification of foodborne diseases, salmonellosis was attributed to the group of microbial food poisoning causing toxicoinfection. Currently, according to the current classification, salmonellosis is attributed to the group of acute intestinal infections, where they are separated into an independent rubric: "Other Salmonella intestinal toxicoinfections". However, in their occurrence, course, prevention, they also
  4. SALMONELLOSIS (SALMONELLOSIS)
    Salmonellosis is an acute contagious disease affecting mainly puppies of weaning age. Etiology. The genus Salmonella includes 65 groups and is widely distributed in nature. Salmonella parasites in the body domestic, as well as wild animals, including birds, fish, reptiles. Many species are highly pathogenic and dangerous to humans. In dogs, Salm is more common. cholerae suis, S.
  5. Salmonella
    Salmonellosis (Latin, Eng. - Salmonellisis) - a disease of adult bees, manifested by the defeat of the digestive system. Pathogens. The disease can be caused by various members of the genus Salmonella: S. typhimurium, S. gallinarum-pullorum, S. enteritidis, S. dublin, S. florida (see part 1, Salmonella). Salmonella pathogens for animals and birds of many species and are often found
  6. Salmonellosis
    Salmonellosis (salmonellosis) is an infectious disease of young animals, characterized by a disorder of the function of the digestive tract, the development of toxemia, sepsis, and sometimes metritis and abortions. Etiology. The causative agent of the disease is a Gram-negative mobile rod with rounded ends, does not form a spore and capsules, 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-bearing animals, characterized by acute course of fever and enteritis, and chronic infection - pneumonia and joint damage. Etiology. The pathogen in piglets - S. cholerae suis and its variants; in calves, S. dublin, less commonly S. typhimurium and S. enteritidis; in lambs - S. abortus ovis; in foals
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  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 breeding Salmonella are created during hot weather. Products at risk include ice cream, creamy desserts, mayonnaise, salads, egg-protein-based dishes (creams, cakes), milkshakes, soft-boiled eggs, etc.
  10. Salmonellosis and other acute intestinal diarrheal infections
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  13. Salmonella
    Salmonellosis is an acute infectious disease of humans and animals, caused by salmonella serovars and occurs in children more often in the form of gastrointestinal, less often typhoid and septic forms. Etiology. Salmonella are motile gram-negative bacteria that do not have capsules and do not form spores. The main antigens of Salmonella are flagellated (H), cell wall antigens (O) and
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    Salmonellosis is an infectious disease of bee colonies, accompanied by the death of adult bees. Etiology. The causative agent is Sal. typhi murium, Sal. cholerae suis, etc. This is a Gram-negative, mobile (except Sal. Pullorum gallinarum), spores and capsules that do not form a stick. Optional aerobic, size 2-4 x 0.3-0.5 microns. It is well painted with all aniline dyes. Epizootology. Disease
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