Mupirocin Resistance in Coagulase Negative Staphylococcus Isolated from Rural Population - An Underestimated Threat?

BACKGROUND CoNS when exposed to repeated or prolonged treatment with mupirocin ointment, may become a reservoir of high-level resistance determinants and then pass on this resistance to S. aureus. CoNS usually tends to be reservoirs of antimicrobial resistance factors, hence they generally lead to recurrence of multi-drug resistance. Hence, it is imperative to identify and discriminate the strains of S. aureus and CoNS. We wanted to analyse mupirocin resistance in coagulase negative Staphylococcus isolated from a rural population. METHODS This study was performed in the Department of Microbiology, SMCH (Ghaziabad) among indoor as well as OPD patients of a tertiary care hospital. All coagulase negative Staphylococcus strains were taken from patient's clinical specimens visiting the OPD or from patients getting treatment from the hospital. CoNS were identified by standard biochemical tests. An inhibition zonal area < 21 mm was considered as resistant. RESULTS Mupirocin resistance was found to be 7 % in MRCoNS and 5 % in MSCoNS. MupRH and MupRL were 5 % and 7 % respectively. Only 5 (5 %) isolates showed MIC more than 512 mu g / mL as described. CONCLUSIONS In case of emergence of mupirocin resistance, other decolonization options ought to be considered.