Genomic characterization and outbreak investigations of methicillin-resistant Staphylococcus aureus in a county-level hospital in China

• DOI: 10.3389/fmicb.2024.1387855
• Publication Date: 2024-04-04T11:43:36Z
• Authors: Linyao Huang; Liangrong Zhu; Jianxin Yan; Yajing Lin; Ding Ding; Long He; Yexuzi Li; Yi Ying; Lijiong Shen; Yuhan Jiang; Haijun Cai; Tian Jiang
• Keywords: SCCmec; Multilocus sequence typing; Molecular Epidemiology

Methicillin-resistant Staphylococcus aureus (MRSA) is a common pathogen contributing to healthcare-associated infections, which can result in multiple sites infections. The epidemiological characteristics of MRSA exhibit variability among distinct regions and healthcare facilities. aim this study was investigate the molecular epidemiology nosocomial outbreak county-level hospital China. A total 130 non-repetitive strains were collected from December 2020 November 2021. Whole-genome sequencing (WGS) performed identify antimicrobial resistance virulence factors. Phylogenetic analysis conducted ascertain genetic diversity phylogenetic relationships. Independent transmission scenarios determined by phylogeny derived single nucleotide polymorphisms (SNPs) within core genome. All isolates intensive care unit (30.00%, 39/130), department otorhinolaryngology (10.00%, 13/130) burn (9.23%, 12/130). clinical samples mainly included phlegm (53.85%, 70/130), purulent fluid (24.62%, 32/130), secretions (8.46%, 11/130). rates erythromycin, clindamycin ciprofloxacin 75.38, 40.00, 39.23%, respectively. belonged 11 clonal complexes (CCs), with major prevalent types CC5, CC59, CC398, accounting for 30.00% (39/130), 29.23% (38/130), 16.92% (22/130), Twenty sequence (STs) identified, ST59 (25.38%, 33/130) dominant lineage, followed ST5 (23.84%, 31/130) ST398 (16.92%, 22/130). Three different SCCmec investigated, most type IV (33.85%, 44/130), II (27.69%, 36/130) III (0.77%, 1/130). structures CC5-ST5-t2460-SCCmec IIa, CC59-ST59-t437-SCCmec CC398-ST398-t034-SCCmec (−), 14.62% (19/130), 13.84% (18/130), Only 12 panton-valentine leucocidin (PVL) positive identified. Two independent outbreaks detected, one consisting 22 PVL-negative belongs IIa other 8 CC5-ST5-t311-SCCmec IIa. Overall, our indicated that CC5 lineage emerged as predominant epidemic clone MRSA, responsible China, highlighting necessity strengthen infection control measures such