[Biological properties of Mycoplasma isolated from bulls' semen]

The occurrence of Mycoplasma in bulls' semen obtained from different Artificial Insemination Centers in Poland was studied. Out of 380 semen samples 234 mycoplasma strains were isolated (61%). Nutritional requirements and biochemical properties of the isolated strains were studied. On the basis of the results of catabolism of glucose and arginine three different groups of isolates were found. The final identification was determined by growth inhibition test and indirect antibody fluorescent technique. 98% of the isolated strains were classified. In Acholeplasma genus two species were found: A. laidlawii and A. modicum. In the genus of Mycoplasma the majority of isolates were identified as M. bovigenitalium (76%). The remaining strains belonged to three other species: M. bovis, M. bovirhinis, M. arginini and to serological group number 7. The sensitivity of isolates to streptomycin and their viability at different temperature were examined. The occurrence of the pathogenic Mycoplasma strains in the examined bulls' semen, their long survival time at -196 degrees C (24 months) and the resistance of some strains to streptomycin indicate the necessity to examine the semen before it is used in artificial insemination.