Increased incidence of MRSA in community-acquired skin and soft tissue infections

According to the results of a prospective study undertaken by American scientists, community strains of methicillin-resistant Staphylococcus aureus (MRSA), isolated from urban patients who have made a request to the emergency department, are the main agents responsible for skin and soft tissue infections.

During the work, a cultural study of smears from the anterior nasopharynx and infectious material was carried out in 137 urban patients with necrotizing soft tissue infections, wound infections, ulcers, septic bursitis or abscess.

Of the 119 isolates isolated from S.aureus, 75% were resistant to methicillin. The total frequency of release of MRSA from infectious material was 51%. Of the 85 genotyped MRSA strains, 99% had the SCCmecIV gene, indicating their community origin. Of the 89 MRSA strains tested for antibiotic sensitivity, 100% were sensitive to vancomycin and trimethoprim / sulfamethoxazole, 94% to clindamycin, 86% to tetracycline and 57% to levofloxacin.

According to the results of the multivariate analysis, the main predictors of the occurrence of an MRSA infection were the presence of furunculosis (odds ratio of 28.6) and belonging to the white race (odds ratio of 3.8). Recent hospitalization, the use of antibiotics and intravenous drugs have had no pronounced effect on the likelihood of infection.

In view of the above, beta-lactam antibiotics such as cephalexin in some countries and regions cannot be considered an adequate tool for the empirical treatment of skin and soft tissue infections. For the treatment of this group of infections, drugs such as trimethoprim / sulfamethoxazole, clindamycin or vancomycin should be used.