RESUMEN
Several mycoplasma species produce various diseases in different animal species. M. bovis has been described as the cause of mastitis, arthritis, pneumonia and infertility in cattle. Furthermore, this species has been the most frequently isolated agent producing bovine mastitis. The objective of this study was to isolate and typify mycoplasma strains from a clinical mastitis outbreak in a dairy farm of Buenos Aires Province. A total of 279 samples were studied (276 from pooled quarter milk of cows with clinical mastitis that did not respond to antibiotic therapy, 1 from bulk tank milk and 2 preputial swabs from bulls). The isolated mycoplasma strains (n = 12) were further characterized by biochemical analysis, serological studies and electrophoretic analysis of the protein profiles (SDS-PAGE). Based upon these studies, the isolated strains were identified as Mycoplasma bovis. This is the first report of isolation of this microorganism in Argentina. Therefore the results described here could be very useful to improve mastitis control in dairy farms.