[Seasonal dynamics and the prevention of the meningoencephalitic form of listeriosis in lambs]. / Sezonna dinamika i profilaktika na meningoentsefalitnata forma na listerioza pri agneta.

The seasonal dynamics of the meningoencephalitic form of listeriosis in lambs was followed up. The peak values in the disease course were found to be in the months of February and March. It is likely that outbreaks coincide with the start in feeding the lambs with roughage. The disease was bacteriologically and histologically shown to run its course primarily in lambs aged up to 6 months. Only in 3 cases the affected lambs were up to ten days of age. The changes in the central nervous system were characterized by leukocytic infiltration and diffuse glial proliferation (in 60.2 per cent of the cases), while in adult sheep predominated the focal glial proliferation. Liver and kidney cells showed necrobiotic changes. The use of the method of antibiotic prophylaxis led to recurrence of the disease, while immunizations with an inactivated vaccine against listeriosis suppressed further outbreaks.

[Immunoprophylaxis of listeriosis in sheep with a killed vaccine]. / Imunoprofilaktika na listerioza po ovtsete s ubita vaksina.

Experiments were carried out with 20 young ewes, 20 rabbits, 20 guinea pigs, and 10000 sheep and lambs, using a killed vaccine of Listeria 1 and 4c with heat under the protection of antidenaturation agents. Bacteriologic, histologic, and histochemical investigations and lung macrophage cultures were used to establish the changes in untreated, vaccinated, and challenged vaccinated animals. Listeria organisms from the challenged animals were isolated in sporadic cases from the barin and viscera, while from untreated and infected animals such organisms were isolated during the entire period of investigation. The use of cultures demonstrated the part played by cell immunity as early as the 3rd to 7th day following vaccination. It was found that the vaccine inhibited the development of pathologic lesions of intoxication in the body and led to the immunologic rebuild of animals. The vaccination of both sheep and lambs in herds with listeriosis suppressed the disease and the mortality thereof.

[Effect of levamisole on the formation of agglutinins against salmonellosis in weaned lambs]. / Vliianie na levamizola vurkhu izgrazhdaneto na aglutinini sreshtu salmonelozata po shiletata.

In order to follow up the effect of levamizol on the titer of agglutinins a killed vaccine of Salmonella abortus ovis; S. enteritidis, and S. typhimurium strains was used under protection of antidenaturating agents (80 per cent sac charose) and levamizol ICI at the rate of 10 mg per kg body mass. Experiments were carried out with a total of 20 rabbits and 36 weaned lambs, divided into groups and injected with vaccine, vaccine and levamizol simultaneously, vaccine with levamizol following on the 3rd day, and vaccine and levamizol following on the 7th day, respectively. Results obtained by means of slow agglutination and hemagglutination showed that agglutinins had highest titers in the groups that received vaccine and levamizol simultaneously. The changes established with histologic investigations of the rabbits confirmed the importance of the simultaneous application of vaccine and levamizol for the immunologic 'reconstruction' of the body. Immunoelectrophoretic investigations concerning the globulins of the various groups did not point to essential differences having anything to do with the use of levamizol.

[Causes of death in chicks in the 1st days after hatching]. / Prouchvane na prichinite za smurtnostta po piletata prez purvite dni sled izliupvaneto.

Scientific and productional experiments and complex investigations were carried out on breeding eggs, chick embryos, newly hatched birds, and ecologic habitats of two broiler dressing combines. It was found that the basic reasons for the morbidity and mortality of chicks in the first days following hatching were: the eggs chosen for hatching were of a lower biologic value due to deficient feeding (1); the veterinary, sanitary, and hygiene requirements with regard to the production, shipping, storing, and hatching of breeding eggs were overlooked (2); the little birds were offered feed mixtures of low value, along with admission of other drawback in their feeding (3); during the first days of raising the birds were kept at lower temperatures and lower relative humidity on the premises.

[Bacterial contamination, clinical and pathohistological findings in the sex organs of cows following parturition]. / Bakteriologichno absemeniavane, klinichni i patokhistologichni nakhodki v polovite organi na kravi sled razhdane.

Studied were a total of 119 cows of the Bulgatian Brown breed in different physiologic status at various numbers of days following parturition. Thirty-seven of the animals showed puerperal endometritis, while the remaining showed a normal course during puerperium. Uterine secretion and biopsic material for bacteriologic and histologic investigation were taken from all cows. Sixteen species of organisms were isolated from the animals with endometritis, and 12 species - from those with normal puerperium. Highest bacterial counts in both groups were found on the eighth to twelfth day, however, with the endometritis-affected cows they remained at a comparatively high level up to the 40th day after giving birth. With the cows of normal puerperium the bacterial count was found to drop abruptly after the twelfth day. No correlation was found between the bacterial and the histologic finding. Histologically, recovery processes set in by the 25th-30th day and clinically, the involution of the uterus set in by the 30th-35th day after calving.

[Comparative clinical, bacteriological and pathohistological studies of the sex organs of infertile cows]. / Sravnitelni klinichni, bakteriologichni i patokhistologichni izsledvaniia na polovite organi pri nezaplozhdashti se kravi.

Investigations were performed with materials from 39 cows divided into two groups: I -- internal sexual organs of 29 cows slaughtered because of infertility; and II -- biopsy material from 10 cows that showed symptomies sterility. The same material was studied microbiologically and histopathologically by routine methods. The material was taken from the cervix, the uterus, and the horns. Bacteriologically, the presence was established of Str. uberis. E. coli, Str. dysgalactiae, Staph. et albus et citreus, Corynebacterium pyogenes, Proteus vulgaris, Str. agalactiae, Candida albicans, Clostridium sp., and others. Organisms were also isolated from the genitalia of cows showing no clinical symptoms of endometritis. Histologically, the cervix of the animals in the 1st group presented necrobiosis of the glandular epithelium, and reticulohistiocytic proliferation. Most characteristic were the changes in the uterine corpus where stasis, oedema, low necrobiotic epithelium of the glands, and a surrounding reticulocytic proliferation with the presence of lymphocytes and plasmatic cells were observed. It was found that no direct correlation between the histologic changes, the microbiologic, and the clinic results.

[Pathomorphological studies of spontaneous and experimental abortions in cows and guinea pigs]. / Patomorfologichni prouchvaniia pri spontanni i eksperimentalni aborti u kravi i morski svincheta.

The morphologic studies of aspergillosis abortions in cows and guinea pigs were carried out on 83 spontaneously affected aborted cattle fetuses, pregnant guinea pigs and their offsprings. Fifty-four fetuses were of spontaneously aborted cows from 12 farms along with 15 pregnant guinea pigs experimentally infected with Aspergillus fumigatus and a total of 14 fetuses of theirs. Microscopically, both in the cattle fetuses and in guinea pigs and their fetuses there were stasis, thrombosis, diapedetic hemorrhages, hyperplasia of the reticulohistiocytes, necrobiosis, and a good amount of polysaccharides in the investigated organs at the absence of hyalin in them. Special staining of cross sections of the studied viscera revealed hyphae of Aspergillus fumigatus--in the blood vessels and the tissue of the organs in spontaneously and experimentally infected, resp., aborted cattle fetuses as well as in guinea pigs but not in their fetuses.

[Hematologic and histochemical changes in the bodies of sheep experimentally infected with listeriae]. / Vurkhu niakoi khematologichni i khistokhimichni promeni v organizma na eksperimentalno zarazeni ovtse s listerii.

Hematologic and histologic investigations were carried out on forty experimentally infected young ewes to which the infection was introduced through venous, intratracheal, and oral route as well as along the branches of nervus trigeminus parallel to the study of 3 control sheep, 12 albino mice, and other four young sheep that were injected with a water-extractive antigen obtained from Listeria. It was established that the leukocyte count rose in the first days following infection along with neutrophilia, lymphopenia, and monocytosis of a varying degree in the different animals, depending on the way of infection. Most indifferent with regard to the hematologic indices proved animals that were orally inoculated. With such animals there was also eosinophilia, which was lacking in the other experimental animals. Glycogen was predominantly found in the blood vessel walls, in the neutrophile leukocytes, the nervous tissue, and the necrotic foci, most likely in connection with the transportation of Listerial organisms and their toxic products. A drop up to the full disappearance of phospholipids was established as well as a rise of the ganglioside.

[Bacteriological and pathohistological studies of sheep experimentally infected with Listeria]. / Bakteriologichni i patokhistologichni izsledvaniia vurkhu ovtse, eksperimentalno zarazeni s listerii

A total of forty gimmers (eight of which spleen-ectomized) were i/v, orally, intratracheally, and along the branching of n. infraorbitalis infected with a 24-hour broth culture of Listeria monocytogenes. The meningoencephalite form of listeriosis was induced in two of the animals infected intraveneously, in one animal of those infected orally, and in one of those infected in the branching of nervus infraorbitalis. The most typical microscopic changes were established in the case of infection through the veins and the nerves. It was concluded that these were probably the most often occurring ways of infection and dissemination of Listeria. However, the resistance of the host organism, the number of bacteria, and the virulence were also of interest. Toxic injury of the brain and the viscera of all infected sheep were also found.

[Toxic action of Listeria monocytogenes]. / Toksichno deistvie na Listeria monocytogenes

Two hoggets and 56 albino mice were used to study the effect of a water-extracted antigen of Listeria monocytogenes, strains 1,4b and St. r., through freezing, thawing, shaking, and filtrating (Seitz filter). A histologic examination was made of sections of the brain, lungs, heart, liver, spleen, and kidneys, stained with hematoxylin-eosin. Most characteristic of the toxic effect were the necrobiotic changes in the brain and viscera as well as the histiocytic infiltrations with the formation of granulomas. The extracted antigen could be inactivated at 60 degrees C. The mortality rate of mice infected with both the antigen and Listeria organisms was highest, and this showed that the toxic substance participates in the Listeria infection.