cfr and optrA gene based characterization of linezolid resistant Staphylococcus haemolyticus in a tertiary care hospital in western Uttar Pradesh, India

Background: Staphylococcus haemolyticus is a clinically significant Coagulase Negative Staphylococci (CoNS) accountable for various infections and is often multi-drug resistant along with resistance to linezolid. Aim and Objectives: This study was carried out to detect the presence of cfr and optrA gene in clinical isolates of linezolid resistant S. haemolyticus in a tertiary care hospital. Material and Methods: A total of 227 clinical isolates of S. haemolyticus recovered from various clinical samples were tested to determine susceptibility to linezolid by phenotypic method. Further, the presence of cfr & optrA gene was looked for, in clinical isolates of S. haemolyticus. Results: S. haemolyticus was isolated predominantly from inpatient department mainly from blood culture (85%). Linezolid resistance was confirmed in 9.2% isolates of S. haemolyticus phenotypically and they were also methicillin resistant. On genotypic characterization, cfr gene could be detected in 7.04% the isolates. However, all the isolates were negative for optrA gene. Conclusion: Emergence of resistance to linezolid in S. haemolyticus was reported for the first time. The presence of cfr gene is the most common mechanism of resistance to linezolid. Correct identification of these isolates and adherence to strict infection control protocols will help in better clinical outcomes.