[Epizootiological evaluation of the peroral and vaginal infection of sheep with S. abortus ovis]. / Epizootologichna otsenka na peroralnoto i vaginalnoto zaraziavane na ovtse sus S. abortus ovis.

Epizootiologic evaluation is made of the oral and the vaginal Salmonella abortus ovis infection in sheep in view of the occurrence and persistence of the infection within the sheep flocks. It has been established that the presence of carriers of infection depends on the physiologic status of the animals at the time of contracting the infection. Abortion, lambing, and the setting in of estrus were shown to affect favourably the existing carrier status. Salmonella abortus ovis organisms were most commonly isolated from the uterus, ovaries, mesenterial lymph nodes, and the duodenum.

[Potential manifestation of fowl typhoid in chicks fed Salmonella gallinarum-contaminated feed]. / Vuzmozhnost za proiavlenie na tif pri malki pileta, zakhranvani s furazh, kontaminiran sus Salmonella gallinarum.

The possibility was checked to infect young birds with fowl typhoid through feeding them with S. gallinarum--contaminated forage. The three test groups of birds were kept on the floor of one and same premise, and a fourth group was kept separately in isolation. The feed offered to the first and second test group was contaminated at the rate of 5.10(8) and 1.2.10(8) microbial cells, respectively. With the first group, where feed contamination was at the rate of 6.10(6) S. gallinarum cells per bird, mortality rate ran as high as 61 per cent, 53 per cent of the total number of birds dying of typhoid septicaemia. With the second group, where feed contamination was 1.2.10(6) S. gallinarum cells per bird the total rate of mortality was 34 per cent, 32 per cent of the birds dying of typhoid septicaemia. With the third group, exposed to air-borne infection and offered Salmonella-free feed only, 8 per cent of the birds died of typhoid. It was found that the manifestation and the intensity of the epizootic process were in direct dependence on the microbial number, and that air played a part in transmitting S. gallinarum to young birds raised on the floor.

[Resistance of Salmonella abortus ovis to disinfectant agents]. / Ustoichivost na Salm. abortus ovis spriamo niakoi dezinfektsionni sr edstva.

By the method "test-vector" the influence of solutions of chlorinated lime, chloramine, sodium base formalin was investigated over 30 strains Salm. abortus ovis isolated from fecal and vaginal samples, as well as from aborted foetus. It was established that S. abortus ovis manifests different stability against the separated disinfectants. These microorganisms are most sensitive to the action of chlorine preparations. For that reason is recommended to use the chlorinated lime and the chloramine with priority for disinfection of Salm. abortus ovis.

[The epizootic process in ewe lambs experimentally infected with Salmonella abortus ovis and Chlamydia psittaci var. ovis]. / Epizootichen protses pri dzvizki, eksperimentalno zarazeni sus Salmonella abortus ovis i Chlamydia psittaci var. ovis.

Studied was the dynamics of antibody production and Salmonella shedding in a flock of year-old female sheep affected with a mixed form of infection of Salmonella abortus ovis and Chlamydia psittaci var. ovis. It was established that in the presence of a mixed infection dominating was the part played by Chlamydia organisms. The apparent epizootic process with these agents usually ran its course in the later period of pregnancy, while Salmonella organisms acted by the end of the first half of pregnancy. The carrying out of a tentative serologic study during estrus contributes to revealing the state of Salmonella harbouring.

[Diagnostic value of serological and bacteriological methods in sheep affected with S. abortus-ovis and Chlamydia psittaci var. ovis infections]. / Diagnostichna stoinost na serologichniia i bakteriologichniia metod pri ovtse, zasegnato ot infektsiia sus S. abortus-ovis i Chlamydia psittaci var. ovis.

It was found that the shedding of Salmonella organisms by sheep with Salmonella abortions was most active during the first fifteen days following abortions or lambing. In sheep affected with a mixed Salmonella abortus ovis and Chlamydia psittaci var. ovis infection this period was longer (about 30 days). The excretion of Salmonella organisms was more strongly manifested with the vaginal discharge than with the feces, urine, and milk. No correlation was established between the titer value of the antibody level against Salmonella abortus ovis and the results of the bacteriologic investigations. There was such correlation only with animals with y positive hemoculture finding in but the period from the first to third day following abortion.

[An attempt to create a factorial model of the epizootic process in sheep infected with S. abortus ovis]. / Opit za postroiane na faktoren model na epizootichen protses pri ovtse, zarazeni ot infektsiia sus S. abortus ovis.

Experiments were carried out to build up a factorial model with a group of sheep at different age in an infected region. Studied were the aspects of the disease as caused by Salmonella abortus ovis alone and in combination with Chl. ps. var. ovis. It was found that the factorial model can explain sufficiently well (77.22 per cent) the discussed system--the epizootic process with year-old females and sheep affected with pure and mixed infection. The epizootic process with a mixed infection in these animals ran its course at high intensity. In the case of a pure infection the process was more intensive with young females. With lambs it showed higher intensity when a mixed infection was present.

[A new method for determining an infectivity index in assessing the intensity of an epizootic process]. / Nov metod za opredeliane indeksa na porazenost pri otsenka na intenzivnostta na epizootichniia protses.

A new method was suggested to determine the index of deadliness in fixing the intensity of the epizootic process as manifested in its two forms--apparent and inapparent. The method is based on the calculus of probability--a most general formula for the sum of any kind of events. The results obtained have been compared with those reached with the already existing two other methods. The model employed consist of theoretically composed examples corresponding to similar ones in the practice as well as of investigations on Salmonella abortions in sheep. The new method can be employed with all kinds of initial data and results in various variants.

[Intensity of the epizootic process in sheep infected with S. abortus ovis and Chlamydia psittaci var. ovis]. / Vurkhu intenzivnostta na epizootichniia protses pri ovtse, zasegnati ot S. abortus ovis i Chlamydia psittaci var. ovis.

An attempt was made to analyze comparatively the intensity of the epizootic process in young female sheep, ewes (second pregnancy, with no records of abortions in their first pregnancy) and their lambs either with an infection of Salmonella abortus ovis only or with a mixed infection of S. abortus ovis and Chlamydia psittaci var. ovis. This was reached through following up and studying the parameters morbidity, mortality, lethality, index of infectedness, index of deadlines, and fertility. It was found that the intensity of the apparent epizootic process was highest with young females affected with a mixed infection, and it was lowest with ewes affected with a pure infection (Salmonella abortion). The intensity of the inapparent epizootic process was best manifested in the young females affected with a pure Salmonella abortion. With these animals both the index of infectedness and the index of deadlines had highest values.

[Role of rams in the epizootiology of salmonellal abortion in sheep]. / Roliata na kochovete v epizootologiiata na salmonelozniia abort po ovtsete.

Studied was the susceptibility of rams to a Salmonella abortus ovis infection. It was found that the animals could resist the oral experimental infection when the causative agent was introduced in the form of 20 ml broth culture or when the environment was contaminated with it. The Salmonella abortus ovis infection was found to be transmitted from infected rams to normal ewes and vice versa, chiefly through sexual route.

[Survivability and penetration capacity of bull spermatozoa frozen by 3 technics]. / Prezhiviaemost i penetratsionna sposobnost na spermatozoidite ot bik, zamrazeni po tri razlichni tekhnologii.

Studied was the survival and penetration capacity of bull spermatozoa frozen after the following technologies--pellet, straw, and minitube--and the results obtained were compared via biologic experiments. The minitube technology of freezing the semen led to higher thermal resistance of the spermatozoa as against freezing in the form of straws and pallets (363.5 +/- 8.02 min, 356.25 +/- 7.79 min, and 339.00 +/- 8.44 min, respectively). The differences established were statistically highly significant (P less than 0.001). The penetration capacity of spermatozoa in an estral secretion of cows was highest at freezing in the form of minitubes (1.70 +/- 0.54 mm/min). The same was lower with straws (1.53 +/- 0.02 mm/min), and lowest--with pellets (1.52 +/- 0.04 mm/min). The differences were statistically significant (P less than 0.01). The fertilization capacity of spermatozoa frozen with the employment of the three technologies was best with the use of minitubes and straws--50.20, resp., 49.67 per cent, and lowest with the use of pellets--45.22 per cent.

[Incidence of salmonellosis abortion in sheep in Bulgaria 1970-1984]. / Razprostranenie na salmonelozniia abort po ovtsete v Bulgariia za perioda 1970-1984 g.

Studied was the spread of Salmonella-induced abortions in ewes for a period of 15 years (1970-1984) on the base of the epizootic information available and of the calculation of the index of epizooticity, the index of occurrence, and the coefficient of repeatability (return rate). It was found that the first index, which characterizes the epizootic process with regard to time, was 100 percent in eleven districts of the country. Salmonellosis abortions was invariably observed during the entire period of fifteen years. On the base of the epizootic state the districts are subdivided into five categories which makes it possible to zonate the country's territory with special emphasis on the spreading of Salmonella abortions in ewes.

[Salmonella abortus ovis carrier state in dogs and rats]. / Prouchvaniia vurkhu nositelstvoto na Salmonella abortus ovis pri kucheta i plukhove.

Serologic and bacteriologic investigations were carried out with 10 dogs, guarding sheep flocks with and without Salmonella abortions, and 17 grey rats. It was found that both species of animals could harbour Salmonella abortus ovis provided they swallowed infective material (aborted fetuses and fetal membranes). It was shown that although lasting but 2 to 3 months only the carrier state could play a definite part in the epizootiology of Salmonella abortions in sheep.

[Fluctuations in susceptibility of pigs to erysipelas depending on age]. / Prouchvaniia vurkhu kolebaniiata vuv vuzpriemchivostta na prasetata kum chervenka v zavisimost ot vuzrastta.

The results of experiments have shown that up to their second month of age pigs are not susceptible to Erysipelothrix rhusiopathiae infection. The invasion of the infective agent into the body of sich pigs neither causes an outbreak of the disease nor brings about changes in the immunologic indices under investigation, which shows that no infection process develops in these animals. At a later age infecting the pigs both with a broth culture of the pathogen and with material from organs, using the same doses as in the case of younger pigs has led to the development of a clinical process followed by enhancement of phagocytosis and rise of agglutination titers.

[Inactivated saponin vaccine against salmonellal abortion in sheep]. / Inaktivirana saponinova vaksina protiv salmonelozniia abort po ovtsete.

An inactivated saponine vaccine is prepared from five highly immunogenic Salmonella abortus ovis strains, selected by means of a biological test on white rats. Saline was used as a diluent of the vaccine, with the addition of 30 per cent glycerine, 0.012 per cent saponine and 0.1 per cent propiolactone. The optimum immunization dose of 5 cm3 is injected singly subcutaneously behind the elbow, two and a half months after impregnation. The vaccine is applied on infected farms before the disease occurs. The cellular-humoral immunity, which forms 14 days after the injection, lasts 4--5 months and protects the sheep against salmonellosis abortion.

[Relationship between the sensitivity of the delayed agglutination test and synthetic detergents]. / Povliiavane chuvstvitelnostta na bavnata aglutinatsionna reaktsiia ot sintetichni pochistvashti preparati.

Residual amounts of detergents (Losk, Bio-73, Alka-lux, Bourgas, Bourgaslux, and Vero) in a concentration of 10-5 to 10-7 in physiologic saline can inhibit the agglutination titers by 3 to 5 degrees. This could mislead in the assessment of the reaction with regard to its diagnostic value. It is admitted that the inhibition produced is due to changes in the antibodies--drop in the total protein and light variations in all protein fractions as well as in the probable surface deterioration of the antigen, leading to its defective agglutinability. It is suggested to rinse more than five times all glassware that has been cleaned with detergents.

[Diagnostic value of serological methods and of the allergy method in studying pullorum disease-fowl typhoid in poultry]. / Prouchvaniia vurkhu diagnostichnata stoinost na serologichnite metodi i alergichniia metod na izsledvane pri tif-pulorozata po ptitsite.

It was established that the positive allergy reaction was best expressed at the forty-eighth hour following the introduction of the allergen. The diagnostic value of the allergy reaction was not shown to surpass that of the serum agglutination reaction. It proved to be close to the value of the other serologic methods of examination (the whole-serum and whole-blood agglutination tests). The allergy method of investigation could be used as a tentative method, resp., reaction test for the detection of infected foci, however, the complete recovery of the infected poultry farms could be achieved with the use of the serologic methods of investigation. The latter could be applied at intervals of 10 to 20 days to detect the carriers of infection.

[Immunosuppressive activity of several drugs and their effect on antibody formation in pullorum disease]. / Imunodepresivna aktivnost na niakoi lekarstva i vliianieto im vurkhu antitialoobrazuvaneto pri tif-pulorozata.

Furazolidon given alone or in combination with chloramphenicol, with spectinomycin, with gentamycin or with sodium arsenilate as well as chlorpyrazine, applied alone, suppress the clinical manifestation of pullorum disease in birds both in the experimental and in the spontaneous outbreak of the disease. These medicinal drugs lower the production of agglutinins in birds--mostly the combination furazolidon+chloramphenicol, followed by furazolidon+sodium arsenilate. The same combinations do not prove essentially effective in influencing the development of the morphologic lesions and do not fully exempt the body from the causative agent of pullorum disease.