Incidence and Susceptibility Pattern of Methicillin Resistant Coagulase-Negative Staphylococci Isolated From a Tertiary Care Hospital of Pakistan

BACKGROUND: Methicillin resistant coagulase-negative Staphylococci are resistant organisms causing infections associated with high morbidity and mortality. Methicillin resistant Staphylococcus epidermidis (MRSE), is especially important with respect to admitted patients with indwelling catheters and other installed invasive devices where these organisms are known to be found. As a result, such lifesaving measures may prove fatal from subsequent infection and sepsis by these pathogens. Therefore, to limit such conditions in patients, the spread of MRSE and related organisms in the hospitals have to be effectively controlled. OBJECTIVES: This study was carried out to determine the frequency of methicillin resistant organisms among all isolated coagulase negative Staphylococci (CoNS) and to find effective antibiotics against these microorganisms. PATIENTS AND METHODS: All samples sent to the lab were routinely processed according to standard microbiological procedures and the cultures yielding growth of CoNS were selected for the study. All samples containing CoNS collected over a 2 year-period, were included irrespective of patients' age and gender. The antibiogram of the organisms was recorded according to CLSI guidelines and the ratio of methicillin resistant organisms determined. RESULTS: From a total of 299 isolated coagulase negative Staphylococci (CoNS), 40.1% were methicillin resistant. A high proportion of these organisms (more than 50%) were resistant to cephalosporins, aminoglycosides and quinolones while only a small number were found to show resistance to linezolid, minocycline, chloramphenicol and rifampicin. There were no resistant organisms against vancomycin. CONCLUSIONS: A considerable amount of methicillin resistant organisms found among CoNS in our region. The above stated antibiotics would prove effective in limiting these infections. Clinicians should keep these facts in mind while treating their patients.