EN
The aim of the study was to assess the prevalence of virulent and non-virulent R. equi strains in horse farms with enzootic and sporadic rhodococcosis. Based on the microbiological culture, a progressive growth of the number of bacteria in soil samples was found that was correlated with the air temperature growth and independent of the farm epizootic status. The number of virulence strains in the soil was dependent on the time of sample collection and type of stud. PCR is a useful method for classifying bacteria from the R. equi species and to detect the virulence marker. Comparison of microbiological culture and PCR suggests caution in interpreting culture results in terms of the identification of all bacterial colonies as belonging to Rhodococcus equi species