Comparative analysis of agr locus diversification and overall genetic variability among bovine and human Staphylococcus aureus isolates.

The accessory gene regulator (agr) is a central system that controls the expression of Staphylococcus aureus virulence factors. In this study, the distribution of agr alleles, defined by agr restriction fragment length polymorphism within agr interference groups, among S. aureus isolates from bovine and human origin was measured with PCR-based techniques. Statistically highly significant associations of some agr alleles with the infection of a specific host were found. The genetic difference between the two S. aureus populations was further stressed after analysis of their genetic background by binary typing.