Genomics of small colony variants of clinical Staphylococcus aureus isolates
10.11816/cn.ni.2025-246701
- VernacularTitle:金黄色葡萄球菌临床小菌落变异体的基因组学分析
- Author:
Huihui KUANG
1
;
Lin CONG
;
Hongyan HU
;
Song LI
;
Yue LIU
Author Information
1. 解放军总医院海南医院检验科,海南三亚 572000
- Publication Type:Journal Article
- Keywords:
Staphylococcus aureus;
Small colony variant;
Biofilm;
Whole genome sequencing;
menB gene
- From:
Chinese Journal of Nosocomiology
2025;35(9):1287-1292
- CountryChina
- Language:Chinese
-
Abstract:
OBJECTIVE To explore the molecular characteristics of small colony variants(SCVs)of Staphylococcus aureus isolates so as to provide theoretical bases for clinical control of the persistent and recurrent infections in-duced by the SCVs.METHODS The clinical blood specimens that were collected from the First Affiliated Hospital of Traditional Chinese Medicine University of Guangzhou were cultured to acquire 1 strain of SCV S.aureus S2.The colonial morphology,growth rate,catalase,plasma-coagulase,production capability of biofilm and antimi-crobial susceptibility of the strain SCVs were observed,the growth curve and autolysis curve were drawn,the whole genome sequencing was performed for the S2,the phylogenetic evolution of the genome and the single nu-cleotide polymorphism(SNP)were analyzed.RESULTS The S2 was identified as S.aureus,with the catalase and plasma-coagulase tested positive.The strain was resistant to various types of antibiotics,including macrolides like erythromycin and azithromycin,fluroquinolones such as levofloxacin and ciprofloxacin,and penicillin.The forma-tion of pigment was reduced,the formation of hemolytic rings was low;the growth rate of the strain was slower than that of ATCC 25923(quality control strain)and ZC1(the normal control strain),the autolytic activity of the strain was higher than that of the ATCC 25923 and ZC1,and the biofilm production of the strain was remarkably less than that of the ATCC 29213(P＜0.05).The whole genome sequencing demonstrated that the molecular typ-ing of the S2 was ST239-t030 clone,which harbored a variety of drug resistance genes and virulence genes,and the menB gene had missense mutation.CONCLUSION The formation of SCVs may be associated with the inhibited synthesis of menadione caused by the missense mutation of menB gene.
