Background This study was aimed to investigate the clinical and molecular epidemiology of Staphylococcus aureus(S.aureus)isolated from Chinese children and determine the possible relationship among the accessory gene ...Background This study was aimed to investigate the clinical and molecular epidemiology of Staphylococcus aureus(S.aureus)isolated from Chinese children and determine the possible relationship among the accessory gene regulator(agr)groups and genotypes,as well as among the virulence genes and disease types.Methods S.aureus strains were isolated from Beijing Children's Hospital between October 2017 and October 2019.The isolates and 19 virulence genes were characterized using multi-locus sequence typing,staphylococcal protein A(spa),staphylococcal cassette chromosome mec,and agr typing.Results A total of 191 non-repetitive S.aureus clinical isolates were divided into 33 sequence types(STs),18 clonal com-plexes(CCs),and 59 spa types.ST59(39.8%),t437(37.7%),and agrⅠ(84.8%)were the predominant types.CC59,CC25,CC22,CC951,CC8,and CC398 belonged to agrⅠ.CC5 and CC15 were assigned to agrⅡ,and CC30 was characterized as agrⅢ.CC121 was classified under agrⅣ.The eta,etb,and bbp genes were more prevalent in agrⅣ(P<0.001 for each),while tst was more prevalent in agr groupⅢcompared to the other groups(P<0.001).Nearly all isolates that harbored lukS/F-PV belonged to agrⅠ(P=0.005).However,the correlation between disease types and agr groups was not significant(P>0.05).Conclusions An association among the agr groups and genotypes,as well as specific toxin genes,was observed among the S.aureus strains isolated from Chinese children.However,a statistical correlation was not found among the agr groups and disease types.展开更多
目的探讨运用基质辅助激光解吸电离飞行时间质谱(matrix-assisted laser desorption/ionization time of flight mass spectrometry,MALDI-TOF MS)技术对金黄色葡萄球菌小菌落变异型的特征性蛋白指纹图谱进行深度研究的价值。方法分别...目的探讨运用基质辅助激光解吸电离飞行时间质谱(matrix-assisted laser desorption/ionization time of flight mass spectrometry,MALDI-TOF MS)技术对金黄色葡萄球菌小菌落变异型的特征性蛋白指纹图谱进行深度研究的价值。方法分别采用传统生化鉴定、16S r RNA测序技术和MALDI-TOF MS技术对1株小菌落变异型金黄色葡萄球菌进行鉴定,通过质谱鉴定系统VITEK MS的质谱科研模式获取金黄色葡萄球菌小菌落突变株(small colony variants,SCV)的质谱图,分析代表金黄色葡萄球菌agr和sig B系统的m/z表达强度,并用SARAMIS软件构建基于质谱峰谱特征的系统发育树。结果使用MALDI-TOF MS技术鉴定该菌株为金黄色葡萄球菌,与传统生化鉴定、16S rRNA测序技术的鉴定结果一致。其菌落形态符合典型SCV菌株的特征,预示生物膜形成的PSMα3(m/z 2634.4)、PSMα1(m/z 2286.8)和PSMα4(m/z 2198.6)的表达强度分别为100%、76.1%和32.3%,反映急性早期感染状态的agr调控系统的delta毒素强度只有10%;反映慢性、复发性感染的sigB调控系统的峰谱相对强度均<25%,该菌株和科研菌种库SCV的系统发育树近似度>70%。结论 MALDI-TOF MS技术不仅能够快速准确鉴定不典型金黄色葡萄球菌,且生成的质谱图能够初步提示菌株在宿主体内的感染状态,表明该技术具有极大的应用前景。展开更多
基金This study was funded by the Beijing Natural Science Foundation(No.7172075)the National Natural Science Foundation of China(No.81571948).
文摘Background This study was aimed to investigate the clinical and molecular epidemiology of Staphylococcus aureus(S.aureus)isolated from Chinese children and determine the possible relationship among the accessory gene regulator(agr)groups and genotypes,as well as among the virulence genes and disease types.Methods S.aureus strains were isolated from Beijing Children's Hospital between October 2017 and October 2019.The isolates and 19 virulence genes were characterized using multi-locus sequence typing,staphylococcal protein A(spa),staphylococcal cassette chromosome mec,and agr typing.Results A total of 191 non-repetitive S.aureus clinical isolates were divided into 33 sequence types(STs),18 clonal com-plexes(CCs),and 59 spa types.ST59(39.8%),t437(37.7%),and agrⅠ(84.8%)were the predominant types.CC59,CC25,CC22,CC951,CC8,and CC398 belonged to agrⅠ.CC5 and CC15 were assigned to agrⅡ,and CC30 was characterized as agrⅢ.CC121 was classified under agrⅣ.The eta,etb,and bbp genes were more prevalent in agrⅣ(P<0.001 for each),while tst was more prevalent in agr groupⅢcompared to the other groups(P<0.001).Nearly all isolates that harbored lukS/F-PV belonged to agrⅠ(P=0.005).However,the correlation between disease types and agr groups was not significant(P>0.05).Conclusions An association among the agr groups and genotypes,as well as specific toxin genes,was observed among the S.aureus strains isolated from Chinese children.However,a statistical correlation was not found among the agr groups and disease types.
