血流感染金黄色葡萄球菌毒力基因、agr分型及生物膜形成能力调查  

Investigation of virulence genes,agr typing and biofilm formation ability of Staphylococcus aureus in bloodstream infection

作　　者：贾佳[1] 纪玥玥 高硕[1] 张燕[1] 周万青[1] 沈瀚[1] JIA Jia;JI Yueyue;GAO Shuo;ZHANG Yan;ZHOU Wanqing;SHEN Han(Department of Laboratory Medicine,Nanjing Drum Tower Hospital,Affiliated Hospital of Medical School,Nanjing University,Nanjing 210000,Jiangsu,China)

机构地区：[1]南京大学医学院附属鼓楼医院检验科,南京210000

出　　处：《临床检验杂志》2023年第2期117-122,共6页Chinese Journal of Clinical Laboratory Science

基　　金：南京市医学科技发展资金(QRX17143);南京大学中国医院改革发展研究院课题;南京鼓楼医院医学发展医疗救助基金会资助项目(NDYG2022048)。

摘　　要：目的探讨血液来源金黄色葡萄球菌耐药性、毒力基因、agr分型、生物膜形成能力,并比较甲氧西林敏感株与耐药株间的差异。方法收集2019年1月—2020年12月102株血液分离非重复金黄色葡萄球菌菌株,采用全自动微生物鉴定药敏分析系统进行药物敏感性检测;采用PCR及多重PCR分析菌株毒力基因携带情况及agr基因多态性;采用96孔板结晶紫染色法检测生物膜形成能力。采用卡方检验和Fisher精确概率法比较分析甲氧西林耐药金黄色葡萄球菌(MRSA)和甲氧西林敏感金黄色葡萄球菌(MSSA)菌株间耐药性、毒力基因、agr分型及生物膜形成能力的差异。结果102株金黄色葡萄球菌中,43株为MRSA,59株为MSSA。毒力基因普遍表达葡萄黄质蛋白基因crtN(99.0%)、溶血素基因(hla 97.1%、hlb 98.0%、hld 96.1%),其次为表面因子CP8合成酶基因cap8H(34.3%)、中毒性休克综合征毒素-1基因tst(21.6%),其中携带crtN/hla/hlb/hld 4种毒力基因组合的菌株最多(48株)。agr分型阳性率为97.1%,其中agrⅠ型占56.9%,agrⅡ型占36.3%,agrⅢ型占4.9%,未检测出agrⅣ型,agr未获分型3株。生物膜形成阳性共28株,其中12株可形成强生物膜。MRSA菌株对环丙沙星、四环素、红霉素、克林霉素、左氧氟沙星、莫西沙星的耐药率高于MSSA菌株(P<0.05);MRSA菌株tst基因携带率高于MSSA(P<0.01),cap8H基因携带率低于MSSA(P<0.05),差异有统计学意义;MRSA菌株中agrⅠ和agrⅡ型各占46.51%和48.84%;MRSA菌株更倾向形成中等或弱生物膜,与MSSA菌株相比在生物膜形成能力上差异无统计学意义。结论临床分离血流感染金黄色葡萄球菌存在多种毒力基因、agr分型、生物膜形成能力,需加强监测。Objective To investigate drug resistance,virulence genes,agr typing and biofilm-forming ability of blood derived Staphylococcus aureus,and compare the differences between methicillin-sensitive strains and drug-resistant strains.Methods A total of 102 strains of non-duplicate Staphylococcus aureus isolated from blood samples were collected from January 2019 to December 2020,and drug sensitivity was detected by full automatic microbial identification/drug sensitivity analysis system.The carrying virulence gene of the strains and agr gene polymorphism were analyzed by PCR and multiple PCR.The formation ability of biofilm was determined by crystal violet method in 96-well plate.Chi-square test and Fisher′s exact test were used to compare the differences in drug resistance,virulence genes,agr typing and biofilm-forming ability between methicillin-resistant Staphylococcus aureus(MRSA)and methicillin-sensitive Staphylococcus aureus(MSSA)strains.Results Among the 102 strains of Staphylococcus aureus,43 strains were MRSA and 59 strains were MSSA.Virulence genes commonly expressed lutein crtN(99.0%),hemolysin gene(97.1%hla,98.0%hlb,96.1%hld),followed by surface factor CP8 synthetase gene cap8H(34.3%),toxic shock toxin-1 gene tst(21.6%).Among them,the most strains carried crtN/hla/hlb/hld virulence gene combination(48 strains).The positive rate of agr type was 97.1%,of which 56.9%were agr typeⅠ,36.3%were agr typeⅡand 4.9%were agr typeⅢ.No agr typeⅣwas detected,and 3 strains were agr negative.A total of 28 strains showed positive biofilm formation,among which 12 strains formed strong biofilm.The resistance rates of MRSA strains to ciprofloxacin,tetracycline,erythromycin,clindamycin,levofloxacin and moxifloxacin were higher than those of MSSA strains(P<0.05).The tst gene carrying rate in MRSA strains was higher than that in MSSA stains(P<0.01),while cap8H gene carrying rate was lower than that in MSSA strains(P<0.05)with statistically significant difference.In MRSA strains,agr typeⅠand agr typeⅡaccounted for 46.

关 键 词：甲氧西林耐药金黄色葡萄球菌 血流感染 附属基因调节因子agr 毒力基因 生物膜 

分 类 号：R446.5[医药卫生—诊断学]