[Experiments to identify Mycoplasma isolates from cell cultures]. / Opiti za identifitsirane na mikoplazmeni izolati ot kletuchni kulturi.

Identified were various species of Mycoplasma organisms isolated from three continuous cell lines--BHK-21, SPZF, and TT. On the base of cultural, biochemical, and serological investigations the isolates were defined as M. bovirhinis, M. arginini, and A. laidlawii. The bovine sera, used to culture the cell lines were shown to be the basic source of contamination with Mycoplasma organisms. This made it necessary to carry out a preliminary study on each batch of serum for Mycoplasma contamination prior to its use for laboratory and productional needs.

[A method for demonstrating mycoplasmas]. / Metod za dokazvane na mikoplazmi.

Bisbenzimid-marked continuous cell lines were investigated via fluorescent microscopy. The presence of Mycoplasma DNA was demonstrated in the cytoplasm with some of them. The method employed for the demonstration of Mycoplasma contamination is readily applicable, and could be used for control on continuous cell lines.

[Isolation of Campylobacter spp. from calves in Bulgaria]. / Izolirane na Campylobacter spp. ot teleta u nas.

Studied were a total of 58 samples, containing intestinal content of calves that had died of enteritis as well as fecal samples and samples from clinically normal calves. Campylobacter spp. were isolated in 8.8 per cent of the cases. The isolated 5 strains was determined as Campylobacter fetus subsp. intestinalis. This is the first communication on the isolation of Campylobacter spp. in this country.

[Isolation of Haemophilus somnus from cattle]. / Izolirane na Haemophilus somnus ot goveda.

Studied were a total of 220 samples of material taken from the respiratory tract of calves and from fetuses of cows that miscarried for the presence of Haemophilus bacteria. Haemophilus somnus was isolated for the first time in this country from the respiratory tract of calves (10.1 per cent) and from fetuses of cows with abortions (6.2 per cent). Haemophilus somnus was found in calves that had contracted respiratory diseases in 13 per cent of the cases, and in clinically normal calves--in 3.5 per cent of the cases. It was isolated both in pure culture and in mixed culture with P. multocida, M. bovirhinis, M. arginini, V. fetus, and C. pyogenes. As many as 21 strains of Haemophilus somnus were isolated, having the same morphologic, cultural, and biochemical properties characteristic of the species.

[Abortions in cows caused by Corynebacterium pyogenes]. / Aborti po kravite, prichineni ot Corynebacterium pyogenes.

Bacteriologic investigations of embryos, fetuses, and placentae of cows that had miscarried, uterine and milk samples taken from animals with endometritis and mastitis, and bull semen samples revealed the presence of Corynebacterium pyogenes. It was established that this organism ranks first in the group of occasionally pathogenic microflora that was associated with the occurrence of abortions in cows. It was isolated from in 9.2 per cent of the cases from fetuses, 5.3 per cent of the cases from embryos, and 8.1 per cent of the cases from placentae. On farms with records of Corynebacterium pyogenes abortions all endometritis and mastitis cases could be associated with the same infection. The organisms was demonstrated in the uterine secretion in both clinically normal cows and bull semen. Corynebacterium pyogenes was found to be viable for a long time, and, therefore, represented a serious source of infection--abortions, endometritis, and mastitis.

[Bacteriological and morphological findings in aborted cattle fetuses]. / Bakteriologichni i patomorfologichni nakhodki v abortirani fetusi ot kravi.

Bacteriologic investigations were carried out on a total of 142 fetuses aborted by cows. C. pyogenes, V. fetus, Streptococcus pyogenes animalis (Sofia), M. bovigenitalium, A. laidlawii, E. coli, and B. subtilis were isolated from 34 fetuses (24 per cent). Besides, single of these species were found in 80 per cent of the positive cases, and a mixed infection--in 20 per cent. The morphologic changes in all 34 fetuses that were positive were seen chiefly in the lungs and liver. Such lesions, however, were not instrumental in differentiating the etiologic agent.

[Immunity in genital bacterial infections in cows]. / Vurkhu imuniteta pri niakoi genitalni bakteriini infektsii po kravite.

A total of 313 cows were investigated in order to establish the agents that most frequently caused genital diseases in cows on 5 farms where the experiments were carried out. In animals that had miscarried as well as in those that had recovered from metritis specific antibodies were found against the isolated causative agents, having titers in the vaginal mucus from 1:160 to 1:320, and in the blood serum--from 1:160 up to 1:1280. Strains were selected from the most frequently isolated bacterial species to produce a killed polybacterial adsorbate baccine. It was used 152 cows on the same farms in the eighth month of first or second gestation. The treated animals built immunity of a varying intensity, which was demonstrated with the appearance of specific antibodies of titers in the vaginal mucus ranging from 1:80 to 1:640, and in the blood serum--from 1:80 to 1:1280, and with marked resistance against the bacterial agents used in the vaccine.

[Relationship between infections of the genitalia and udder in cows]. / Vruzkata mezhdu infektsiite na poloviia aparat i vimeto na kravite.

It was found that the pathogenic and occasionally pathogenic bacteria were readily transmitted in cows, originating from the genital tract, and more specifically from the uterine and vaginal discharge to the udder through the lactogenic route. The study of a total of 183 metritis-affected cows for the presence of Streptococcus uberis revealed that the pathogen could be found in the genital tract and in the udder in 20.7 per cent of the investigated cows, and it could be isolated simultaneously from the two organs in 82.6 per cent of the cases. In another group of cows also affected with metritis the study for the presence of different bacterial agents established coincidence in their simultaneous isolation from the uters and the udder in 61.2 per cent of the cases.

[Studies of immunity in mastitis in cows]. / Prouchvaniia vurkhu imuniteta pri mastitite po kravite.

Studies were carried out to establish the specific antibodies in the milk and blood sera of cows recovered from a spontaneous infection of the udder caused by streptococci, staphylocci, Corynebacteria, and some representatives of Escherichia coli as well as of cows immunized with a polybacterial vaccine. Followed up was likewise the resistance of the udder in vaccinated cows to bacterial infections. It was found that in both groups of animals the specific antibodies' titer ranged from 1:80 to 1:1280. Cows vaccinated in the eighth month of pregnancy developed immunity that varied in its effect, however, was able to protect the udder during the following lactation from infection caused by the respective bacterial specie against which the vaccine was produced.

[Study of Mycoplasma from the genital apparatus of cattle]. / Prouchvane na mikoplazmi ot poloviia aparat na goveda

The study on vaginal mucous secretion in cows with metritis and vaginitis, on fetuses and placentae of cows that had miscarried as well as on preputial secretion of bulls revealed the presence of Mycoplasma organisms associated with V. fetus and other bacterial species. By their reaction to cholesterol, digitonin, sodium polyanetol sulfonate as well as their serum and temperature requirements, the formation of films and spots, their phosphatase activity and biochemical and serologic behaviour the mycoplasmas isolated from the genital tract of cows were specified as A. laidlawii and A. axanthum. From both cows and bulls T-forms of mycoplasmas were isolated. The strains determined as A. laidlawi showed deviations from the species characteristics by the fermentation of glucose, hydrolysis of esculine, and reduction of 2,3,5-triphenyl-tetrazolium chloride.