Methicillin-Resistant (MRSA) Clonal Replacement in a Malaysian Teaching Hospital: Findings from an Eight-Year Interval Molecular Surveillance.

Periodical surveillance on nosocomial pathogens is important for antimicrobial stewardship and infection control. The first methicillin-resistant (MRSA) molecular surveillance in Hospital Canselor Tuanku Muhriz (HCTM), a Malaysian teaching hospital, was performed in 2009. The dominant clone was identified as an MRSA carrying SCC type III-SCC with and + toxin genes. In this study, we report the findings of the second HCTM MRSA surveillance carried out in 2017, after an interval of 8 years. Antibiotic susceptibility testing, SCC, toxin gene, and typing were performed for 222 MRSA strains isolated in 2017. Most strains were resistant to ciprofloxacin, erythromycin, clindamycin, cefoxitin, and penicillin ( = 126, 56.8%), belong to SCC type IV ( = 205, 92.3%), type t032 ( = 160, 72.1%) and harboured + toxin genes ( = 172, 77.5%). There was significant association between resistance of the aforementioned antibiotics with SCC type IV ( < 0.05), t032 ( < 0.001), and + carriage ( < 0.05). Results from this second MRSA surveillance revealed the occurrence of clonal replacement in HCTM during an interval of not more than 8 years. Investigation of the corresponding phenotype changes in this new dominant MRSA clone is currently on-going.