Molecular Characteristics, Antimicrobial Resistance and Virulence Gene Profiles of Isolates from Wuhan, Central China.

PURPOSE

This study aimed to investigate the molecular characteristics, antimicrobial resistance and virulence genes profiles of isolates from Wuhan, central China.

MATERIALS AND METHODS

A total of 302 non-duplicate isolates were collected successively during January-December 2018 and subjected to multi-locus sequence typing (MLST), () typing and (PVL) and A, B, C, D, E, G, H and I ( and ) detection. All methicillin-resistant (MRSA) isolates were additionally subjected to staphylococcal chromosomal cassette (SCC) typing.

RESULTS

Of the 302 isolates, 131 were categorised as MRSA, yielding a rate 1.4 times the average rate in China during 2018 (43.4% vs 30.9%). Thirty-one sequence types (STs) and 82 types were identified. The most prevalent clones were ST5-t2460 (10.9%), ST239-t030 (9.3%), ST188-t189 (7.9%) and ST59-t437 (6.3%). Notably, the continued prevalence of ST239-t030 in Wuhan differs from other areas in China. SCC types and subtypes I, II, III, IVa and V were present in 0.8%, 36.6%, 26.0%, 20.6% and 8.4% of MRSA isolates. A comprehensive analysis identified ST5-t2460-SCC II (25.2%,), ST239-t030-SCC III (19.8%) and ST59-t437-SCC IVa (7.6%) as the major clones among MRSA isolates. The genes and were detected at respective frequencies of 11.9%, 42.1%, 49.7%, 45.0%, 20.9%, 33.8%, 60.5%, 25.8% and 66.9%.

CONCLUSION

ST239-t030 remains one of the most prevalent clones in isolates from Wuhan, leading us to conclude that isolates from Wuhan possess unique molecular characteristics. The isolates also exhibit unique antimicrobial resistance profiles and harbour relatively high numbers of enterotoxin virulence genes, compared with other reports from China.