Abstract
To study the genetic diversity among Escherichia coli strains isolated from bovine fecal and milk samples, nineteen isolates of E. coli were typed by random amplification of polymorphic DNA (RAPD). Clusters of strains were defined on the basis of the epidemiological data and subsequently phylogenetic tree was created and revealed 4 clusters. The obtained results indicated that the serotypes causing bovine mastitis were similar genetically to that causing diarrhea. This type of information can be used in clinical setting to discriminate ongoing epidemics of E. coli from incidentally increased infection rate.