Staphylococcus aureus prevalence and antimicrobial susceptibility in isolates from skin and soft tissue infections in outpatients

Abstract

Background: Skin and soft tissues infections (SSTIs) are the third cause of medical consultation in our hospital. S.aureus is the most frequent etiologic agent isolated in SSTIs and methicillin-resistant is the most important resistance mechanism. Our objective was to analyze the prevalence of etiologic agents causing SSTIs in outpatients and to study its antimicrobial susceptibility.

Methods:Descriptive and retrospective study that included all outpatient SSTIs samples from October 2017 to April 2022.

Results: We obtained 180 positive cultures of samples from SSTIs during the study period, 12 were polymicrobial infections. Of a total of 307 isolates: the most frequently isolated microorganism was S.aureus (111; 36.2%). We found 71 SAMR (64%) and 40 SAMS (36%). Of the MRSA, 67 (95%) were community (SAMRC) due to microbiological criteria, and 4 hospital MRSA (5%). Of the SAMRC strains, 44 (66%) had no accompanying resistance, 15 (22%) were resistant to erythromycin, 12 (18%) to gentamicin, and 7 (10%) to clindamycin.

Conclusions: The most frequently isolated microorganism in SSTIs was S.aureus and 67 isolates were categorized as SAMRC, therefore it is necessary to consider SAMRC as a frequent pathogen. Due to the low resistance found for CLI and TMS, they should be considered for empirical treatment in SSTIs in outpatients.