[Molecular epidemiological characteristics of methicillin-resistant Staphylococcus aureus during 2017-2018 at a...

Objective: To identify the epidemic clones of MRSA isolates at a hospital in shanghai. Methods: A total of 72 MRSA isolates have been isolated from a second grade hospital between 2017 and 2018, including 32 CA-MRSA isolates, 13 HA-MRSA isolates and 26 MRSA isolates from environment. In this study, MLST and PFGE typing methods were used to analyze the molecular epidemiology of the MRSA isolates. Results: A total of 72 MRSA isolates have been obtained including 46 isolates from clinical specimens, 26 isolates from environments. The 46 MRSA isolates from clinical specimens consisted of 33 CA-MRSA (community-acquired MRSA) and 13 HA-MRSA (hospital-acquired MRSA). Furthermore, these patients infected with MRSA isolates were mostly distributed in the department of geriatrics (34.8%, 16/46), internal medicine (26.1%, 12/46) and surgery (26.1%, 12/46). MLST typing results showed that ST764 was predominant in isolates from both clinical specimens and hospital environments. Furthermore, PFGE typing results showed that most ST764 MRSA had high homolog (>90%). Conclusion: ST764 MRSA isolates might spread in community, hospital and environments. Therefore, continuous monitoring of MRSA and its variation may be useful in understanding the involvement of epidemic clone, and in searching new strategies to control MRSA infection.