Caracterización molecular de cepas de Staphylococcus aureus resistentes a meticilina ST398 en pacientes con infecciones cutáneas y sus familiares

Introduction

Livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) of sequence type ST398 is a genetic lineage also described in human infections.

Methods

Cutaneous infections related with MRSA ST398 are described in 3 patients, two of them pig farmers. The MRSA nasal carriage by patients and their relatives was also studied. MRSA ST398 strains were typed (SCCmec, spa, agr and MLST) and the antimicrobial resistance pattern and virulence genes were determined.

Results

Twenty MRSA ST398 isolates were recovered in lesions of three patients, and in nasal samples of two patients and five relatives. Isolates were typed: spa-type t011 or t108; agr-type I and SCCmec IVa or V. MRSA strains were tetracycline-resistant and 15 of them showed a phenotype and genotype of multi-resistance, but they were free of tested virulence genes.

Conclusions

LA-MRSA ST398 is an emergent problem in our country, mainly associated with skin and soft tissue infections in people with professional relationships with pig farms. Tetracycline resistance is an important marker for MRSA ST398 detection.