Antimicrobial Susceptibility of Group A Streptococci of Different emm Genotypes, Isolated from Patients with Invasive and Non-Invasive Skin and Soft Tissue Infections

Abstract

Objective. Aim. To evaluate the antimicrobial susceptibility of group A streptococci (GAS) of different emm-genotypes, isolated from patients with invasive and non-invasive skin and soft tissue infections. Materials and Methods. Overall 91 strains of GAS isolated during 2008–2011 from patients with invasive and non-invasive skin and soft tissue infections hospitalized in one Moscow’s hospital were included in the study. Identification was done by latex agglutination, genotyping — by CDC protocol. Susceptibility to antimicrobials was evaluated by broth microdilution method in accordance with EUCAST v.4.1 recommendations. Results. Resistance to tetracycline was noted in 50,5% of strains; to azithromycin, clarithromycin and erythromycin — in 17.6%, 15.4% and 15.4% of strains, respectively; 13,2%, 5,5% and 1,1% of strains were non-susceptible to chloramphenicol, clindamycin and levofloxacin. Among tested strains 23.1% were resistant to more than one antimicrobial. Out of 35 different emm genotypes multiresistance was detected in the following emm genotypes: 44.0, 49.8, 65.0, 74.0, 88.2, st 1731.2. Conclusions. The most prominent antimicrobial resistance problem in the tested strains was very high rate on non-susceptibility to tetracycline. All isolates tested, independently of type of infection (invasive and non-invasive) were highly susceptible to penicillin G. Multiresistant Gas isolates were belonging to few international emmгgenotypes.

Keywords

• streptococcus pyogenes
• antimicrobial resistance
• genotype