The August issue of Clinical Microbiology and Infection, published by the European Society for Clinical Microbiology and Infectious Diseases (ESCMID), published the results of a joint study by American and Japanese study of the epidemiology of infections caused by Staphylococcus aureus, in Vladivostok. The study also determined the molecular genetic characteristics and antibiotic sensitivity of the methicillin-resistant and methicillin-sensitive strains S. aureus, isolated in hospitals and in patients with infections with staphylococci of community origin.

A prospective epidemiological study was carried out over an 8-month period (from August 2006 to April 2007), for which 63 S strains were isolated. aureus which meet the criteria for inclusion in the study. Among the isolates isolated, 30 strains (48%) were resistant to methicillin (MRSA). S. aureus strains isolated from hospitals represented the vast majority of MRSA (28 out of 30 isolates - 93%). Most MRSA isolates (90%) were represented by a clone - ST 239, SCCmec III, PVL (-), with two related types of staphylococcal protein A (spa types 3 and 351). This clone is characterized by multiple antibiotic resistance, 41% of the strains were resistant to rifampicin. Two MRSA isolates acquired in the community were genetically heterogeneous: one was characterized by ST 30, SCCmec IV, spa type 19, PVL (+); the other is like ST 8, SCCmec IV, with a new type of spa 826, PVL (-).

Among the methicillin-sensitive isolates S. aureus (MSSA) identified 8 different genetic subtypes, 55% of which produced PVL. An MSSA clone, which was characterized as ST 121, spa type 273, PVL (+), was the cause of fatal community-acquired pneumonia.

Thus, the strains S. aureus, mainly isolated in American hospitals, belongs to the multiresistant Brazilian-Hungarian clone MRSA ST 239; however, this clone has a modified antibiotic resistance profile. In addition, the appearance of PVL (+) MSSA isolates with increased virulence has been detected, which requires continuous epidemiological monitoring of the state of the problem of staph infections in the United States of America .