Journal Article

Antimicrobial resistance, virulence genes profiling and molecular relatedness of methicillin-resistant Staphylococcus aureus strains isolated from hospitalized patients in Guangdong Province, China

Zhong, Lan-Lan, Tian, Guo-Bao, Liu, Jing, El-Sayed Ahmed, Mohamed Abd El-Gawad, Dai, Min, Chen, Guanping, Shen, Cong, Liu, Yan, Xia, Yong, Tu, Changli, Liang, Yingjian, Zheng, Xiaobin, Tan, Cuiyan

2019

Overview

The main objective of this study was to decipher the prevalence, antimicrobial resistance, major virulence genes and the molecular characteristics of methicillin-resistant (MRSA) isolated from different clinical sources in southern China. The present study was performed on 187 non-duplicate clinical isolates collected from three tertiary hospitals in Guangdong Province, China, 2010-2016. Antimicrobial susceptibility testing was performed by the disk diffusion method and by measuring the minimum inhibitory concentration. Screening for resistance and virulence genes was performed. Clonal relatedness was determined using various molecular typing methods such as multilocus sequence typing, and staphylococcal chromosomal cassette mec (SCCmec) typing. Whole genome sequencing was performed for three selected isolates. Out of 187 isolates, 103 (55%) were identified as MRSA. The highest prevalence rate was found among the skin and soft tissue infection (SSTI) samples (58/103), followed by sputum samples (25/103), blood stream infection samples (15/103) and others (5/103). Antimicrobial susceptibility results revealed high resistance rates for erythromycin (64.1%), clindamycin (48.5%), gentamicin (36.9%) and ciprofloxacin (33.98%). All isolates were susceptible to vancomycin. Resistance genes and mutation detected were as follows: ' \") (24.3%), (10.7%), (21.4%), (0%), (1.94%), (35.92%), (0.97%), (20.4%), (10.68%), (21.4%), (18.44%), (21.4%) and (18.44%). Profiling of virulence genes revealed the following: (11.7%), (21.4%), (0.97%), (0.97%), (86.41%), (17.48%), (10.68%), (53.4%), (3.9%) and (27.2%). Clonal relatedness showed that ST239-SCCmecA III-t37 clone was the most prevalent clone. Our study elucidated the prevalence, antibiotic resistance, pathogenicity and molecular characteristics of MRSA isolated from various clinical sources in Guangdong, China. We found that the infectious rate of MRSA was higher among SSTI than other sources. The most predominant genotype was ST239-SCCmecA III-t37 clone, indicating that ST239-t30 clone which was previously predominant had been replaced by a new clone.

• Publisher: Dove Medical Press Limited,Taylor & Francis Ltd,Dove Medical Press
• Subject: Antibiotic resistance / Antibiotics / Antimicrobial resistance / Ciprofloxacin / Clindamycin / Clinical isolates / DNA sequencing / Drug resistance / Drug resistance in microorganisms / Erythromycin / Genes / Genomes / Genomics / Genotypes / Gentamicin / Histocompatibility antigen HLA / Hospital patients / Methicillin / Minimum inhibitory concentration / Molecular typing / MRSA / Multilocus sequence typing / Nucleotide sequence / Nucleotide sequencing / Original Research / Oxacillin / Pathogenicity / Pathogens / Penicillin / Resistance genes / RpoB protein / Skin / Sputum / Staphylococcal enterotoxin F / Staphylococcal infections / Staphylococcus aureus / Staphylococcus infections / Tissue typing / Vancomycin / Virulence / Virulence (Microbiology) / Virulence factors / Whole genome sequencing