Abstract:Objective To understand the clinical distribution characteristics and antimicrobial resistance of Staphylococcus aureus (SA), as well as the staphyloccal casette chromosomal mec (SCCmec) typing and panton-valentine leukocdin (PVL) gene expression of methicillin-resistant SA (MRSA) in local pediatric patients, so as to provide evidence for the prevention and treatment of MRSA infection. Methods Clinical distribution and antimicrobial resistance characteristics of SA and MRSA isolated from various clinical specimens of a children's hospital in Suzhou from 2016 to 2021 were analyzed retrospectively. The mecA, SCCmec typing and PVL gene expression of 161 MRSA strains were detected by polymerase chain reaction (PCR). Results A total of 4 967 SA strains were detected in this hospital from 2016 to 2021, of which 1 730 strains (34.83%) were MRSA, detection rate of MRSA in 2018 (39.25%) was the highest. Detection rate of MRSA in 2018 (39.25%) was the highest. MRSA mainly came from sputum (1 091 strains), pus (382 strains), and ear pus (149 strains). Detection rates of MRSA from hospitalized children in different years were significantly different (P < 0.001), while those from outpatient children in different years were not (P=0.885). SA showed a high resistance rate to penicillin, but no strains resistant to vancomycin, teicoplanin or linezolid were detected. The resistance rates of MRSA to macrolides and tetracyclines were higher than those of methicillin-sensitive SA (MSSA) (P < 0.01), but the resistance rates to quinolones, aminoglycosides, and trimethoprim-sulfamethoxazole were lower than those of MSSA (P < 0.01). All of the 161 MRSA strains expressed the mecA gene, but not the PVL gene. SCCmec type Ⅱ (63.98%) was the main type of SCCmec, followed by SCCmec Ⅴ (16.77%) and SCCmec Ⅲ (12.42%). Conclusion Although the detection rate of MRSA in this hospital has decreased in recent years, it is still around 30%. Community-acquired infection is an important source of MRSA. Therefore, in addition to strengthening measures such as antimicrobial management, bacterial antimicrobial resistance monitoring, and healthcare-associated infection control, controlling MRSA in children in Suzhou region also requires strengthening community management to reduce the incidence of MRSA.