Journal Article

Molecular characteristics and virulence gene profiles of Staphylococcus aureus isolates in Hainan, China

Li, Yirong, Li, Xuehan, Huang, Tao, Xu, Kai, Li, Chenglin

2019

Overview

Background There have been no reports regarding the molecular characteristics, virulence features, and antibiotic resistance profiles of Staphylococcus aureus ( S. aureus ) from Hainan, the southernmost province of China. Methods Two hundred twenty-seven S. aureus isolates, consisting of 76 methicillin-resistant S. aureus (MRSA) and 151 methicillin-susceptible S. aureus (MSSA), were collected in 2013–2014 and 2018–2019 in Hainan, and investigated for their molecular characteristics, virulence genes, antibiotic resistance profiles and main antibiotic resistance genes. Results Forty sequence types (STs) including three new STs (ST5489, ST5492 and ST5493), and 79 Staphylococcal protein A ( spa ) types were identified based on multilocus sequence typing (MLST) and spa typing, respectively. ST398 (14.1%, 32/227) was found to be the most prevalent, and the prevalence of ST398-MSSA increased significantly from 2013 to 2014 (5.5%, 5/91) to 2018–2019 (18.4%, 25/136). Seventy-six MRSA isolates were subject to staphylococcus chromosomal cassette mec (SCC mec ) typing. SCC mec- IVa was the predominant SCC mec type, and specifically, ST45-SCC mec IVa, an infrequent type in mainland China, was predominant in S. aureus from Hainan. The antibiotic resistance profiles and antibiotic resistance genes of S. aureus show distinctive features in Hainan. The resistant rates of the MRSA isolates to a variety of antibiotics were significantly higher than those of the MSSA isolates. The predominant erythromycin and tetracycline resistance genes were ermC (90.1%, 100/111) and tetK (91.8%, 78/85), respectively. Eleven virulence genes, including the Panton-Valentine leukocidin ( pvl ) and eta , were determined, and the frequency of eta and pvl were found to be 57.3 and 47.6%. Such high prevalence has never been seen in mainland China before. Conclusion S. aureus isolates in Hainan have unique molecular characteristics, virulence gene and antibiotic resistance profiles, and main antibiotic resistance genes which may be associated with the special geographical location of Hainan and local trends in antibiotic use.

• Publisher: BioMed Central,BioMed Central Ltd,BMC
• Subject: Analysis / Anti-Bacterial Agents - pharmacology / Antibacterial agents / Antibiotics / Antimicrobial susceptibility test / Bacterial and fungal diseases / Bacterial genetics / Bacterial Proteins - genetics / Bacterial Toxins - genetics / China / Disease susceptibility / Drug Resistance, Bacterial - drug effects / Drug Resistance, Bacterial - genetics / Erythromycin / Exotoxins - genetics / Genes / Genetic aspects / Humans / Infectious Diseases / Internal Medicine / Leukocidins - genetics / Medical care / Medical Microbiology / Medicine / Medicine & Public Health / Methicillin / Methicillin-Resistant Staphylococcus aureus - drug effects / Methicillin-Resistant Staphylococcus aureus - genetics / Methicillin-Resistant Staphylococcus aureus - isolation & purification / Methicillin-Resistant Staphylococcus aureus - pathogenicity / Microbial drug resistance / Microbial Sensitivity Tests / Molecular characterization / Multilocus Sequence Typing / Oxacillin / Parasitology / Prevalence studies (Epidemiology) / Research Article / Services / Staphylococcal Infections - drug therapy / Staphylococcal Infections - microbiology / Staphylococcus aureus / Staphylococcus aureus - drug effects / Staphylococcus aureus - genetics / Staphylococcus aureus - isolation & purification / Staphylococcus aureus - pathogenicity / Tetracyclines / Tropical Medicine / Virulence (Microbiology) / Virulence - genetics / Virulence Factors - genetics / Virulence gene