Phenotypic susceptibility patterns of Staphylococcus aureus of skin and soft tissues in hospitalized patients

Abstract

Introduction: phenotypic susceptibility patterns of Staphylococcus aureus are the best expression of its phenotypic study nowadays. Objective: to identify phenotypic patterns of susceptibility to methicillin resistant and sensitive strains. Method: a cross-sectional, descriptive study was carried out at the Arnaldo Milián Castro Hospital from 2013 to 2017 on Staphylococcus aureus isolated in skin and soft parts of hospitalized patients that presented the complete antibiogram consisting of: methicillin, ciprofloxacin, chloramphenicol, gentamicin and cotrimoxazole, classified as resistant or sensitive; 16 patterns were created with the last four antimicrobials in that pre-established order. The population was 1 789 isolates. A distribution frequency of each pattern was obtained and statistical analysis was performed as Chi square of independence and Cramer’s V. Results: the 16 phenotypic patterns of susceptibility circulated; the 13, 1 and 15 were the largest isolates in the five years covered by the study. There was dependence between the methicillin susceptibility and patterns 13 (RSSS), 1 (SSSS), 15 (RSRR), 16 (RSRS), 2 (SSSR), 9 (RRRR) and 3 (SSRR); this association was moderate with patterns 13 and 1, while it was low with the remaining five patterns. Whenever sensitive methicillin was present, patterns 1, 2 and 3 were found more frequently, and if methicillin was resistant, the most frequent patterns were 13, 15, 16 and 9. Conclusions: there was pleomorphism of Staphylococcus aureus strains in skin and soft tissue infections with predominance of statistical association to resistant methicillin.

Keywords

• patrones fenotípicos
• staphylococcus aureus