胎儿弯曲菌龟亚种中国分离株的种群结构、毒力基因及耐药性分析  

Genetic typing,virulence ggenes and drug resistance analysis of Campylobacter fetus subsp.testudinum

作　　者：陈富 陈燕 陈晓慰 李启伟 许振杰 陈茶 李顺光 屈平华 李松 Chen Fu;Chen Yan;Chen Xiaowei;Li Qiwe;Xu Zhenjie;Chen Cha;Li Shunguang;Qu Pinghua;Li Song(Panyu District Health Management Center,Guangzhou 511490,China;The Second Clinic Medical College,Guangzhou University of Chinese Medicine,Guangzhou 510006,China;The Second Clinic Medical College,Guangzhou University of Chinese Medicine/Department of Laboratory Medicine,Guangdong Provincial Hospital of Chinese Medicine,Guangzhou 510006,China)

机构地区：[1]广州市番禺区健康管理中心,广州511490 [2]广州中医药大学第二临床医学院,广州510006 [3]广州中医药大学第二临床医学院/广东省中医院检验医学部,广州510006

出　　处：《中华微生物学和免疫学杂志》2023年第8期582-588,共7页Chinese Journal of Microbiology and Immunology

基　　金：广东省基础与应用基础科学基金(2021A1515110857)。

摘　　要：目的:了解胎儿弯曲菌龟亚种( Campylobacter fetus subsp. testudinum, Cft)的分子流行病学特征。 方法:对本实验室2010—2022年收集的15株胎儿弯曲菌龟亚种进行全基因组测序,结合GenBank公布的全球 Cft基因组数据进行流行病学分析;MLST-GrapeTree分析 Cft的群体遗传结构;核心基因组单核苷酸多态性位点(cgSNP)构建 Cft的系统发育树,rhierBAPS确定其种群结构;CARD、ResFinder及VFDB注释 Cft的耐药及毒力基因;E-test法进行药敏试验,并参考CLSI-M45空肠/大肠弯曲菌药敏标准进行结果解释。 结果:基于基因组平均核苷酸一致性(ANI)分析,共纳入全球41株 Cft基因组信息,其中人类来源24株,动物来源13株,未知来源4株。流行病学资料显示,24株人类来源菌株中,20株感染对象为黄种人,1例为白种人(配偶是亚裔),其余未知,差异分布具有统计学意义。13株动物来源菌株均分离自爬行动物,包括龟类6株、蛇类4株、蜥蜴类3株。MLST分型显示,中国分离株以ST46为主要序列型,美国则以ST15为主要序列型;Grapetree显示,中国分离株的遗传多态性高于美国分离株;通过cgSNP及BAPS重建的系统发育发现全球 Cft构成6个种群,中国分离株呈散在分布且与动物源菌株亲缘关系密切;美国分离株相对较集中(SC3),且以ST15克隆传播为主;毒力基因分析显示,与鞭毛、糖基化系统及黏附素相关的毒力基因在 Cft中携带率为100.00%,而与侵袭性相关的Ⅳ型分泌系统 virB4、 virB9、 virD4因子及 tetO外排泵基因均存在于新发现的ST74中;15株中国分离株的体外药物敏感性试验结果表明, Cft对环丙沙星耐药率为46.67%,对红霉素敏感性为100.00%。 结论:全球 Cft的群体结构呈现出较高的遗传多态性且感染人群多伴有基础免疫性疾病,其感染可能与食入或接触爬行类动物有关;本次研究发现的中国临床分离株主要流行型为ST46及新发现ST74型别,应引起我们的关注。Objective To analyze the molecular epidemiological characteristics of Campylobacter fetus subsp.testudinum(Cft).Methods Fifteen strains of Cft collected in our laboratory from 2010 to 2022 were subjected to whole-genome sequencing.Their epidemiological characteristics were analyzed based on the global genome data of Cft on GenBank database.MLST-GrapeTree software was used to obtain the genetic structure of Cft strains.A phylogenetic tree was constructed using core-genome single nucleotide polymorphism(cgSNP)analysis,and the sequence clusters were identified using rhierBAPS.Virulence genes and drug resistance genes of Cft strains were annotated using CARD,ResFinder and VFDB database.Their susceptibility to antibiotics was tested using E-test method and the results were analyzed using the CLSI-M45 sensitivity standard for Campylobacter jejuni/Campylobacter coli.Results Based on average nucleotide identity(ANI)analysis,the genome data of 41 Cft strains including 24 isolated from human,13 from animals and four of unknown sources were collected from GenBank database.Among the 24 humanderived strains,20 were linked to Asian descent and only one was linked to Caucasian descent(spouse of Asian descent),showing statistically significant differences in human ethnicity.All of the 13 animal-derived strains were originated from reptilian sources,including six from turtles,four from snakes and three from lizards.MLST revealed that ST46 was the predominant ST in China,while ST15 was the major sequence type in the United States.Grapetree analysis also demonstrated that the genetic diversity in China was greater than that in the United States.The phylogenetic tree constructed based on cgSNP and BAPS identified six distinct sequence clusters.The Chinese isolates were scattered in diverse sequence clusters and closely related to animal-derived strains,while the American isolates mainly belonged to ST15.The genes encoding virulence factors such as flagella,glycosylation systems and adhesins were carried by all of the 41 Cft strains(

关 键 词：基因组测序分型 分子流行病学 毒力基因 

分 类 号：R714.5[医药卫生—妇产科学]