一株多重耐药猪源ST37型肺炎克雷伯菌铁载体因子的遗传多样性分析  

Genetic Diversity of Siderophores in a Multi-Drug Resistant Klebsiella pneumoniae ST37 of Swine Origin

作　　者：闫鹤[1] 梁慧贤 YAN He;LIANG Huixian(School of Food Science and Engineering,South China University of Technology,Guangzhou 510640,Guangdong,China)

机构地区：[1]华南理工大学食品科学与工程学院,广东广州510640

出　　处：《华南理工大学学报（自然科学版）》2021年第11期19-26,共8页Journal of South China University of Technology(Natural Science Edition)

基　　金：“十三五”国家重点研发计划项目(2016YFD0500606);华南理工大学中央高校建设世界一流大学(学科)和特色发展引导专项资金资助项目(K5174960);华南理工大学中央高校基本科研业务费专项资金资助项目(D2170320)。

摘　　要：肺炎克雷伯菌是获得性感染相关的条件致病菌,被WHO列为急需研发新抗生素的耐药致病菌。铁载体因子是肺炎克雷伯菌在宿主细胞内增殖的重要毒力因子,主要包括肠杆菌素、耶尔森菌素、气杆菌素和沙门菌素。笔者前期从病猪的肝脏分离到一株多重耐药ST37型(ST)肺炎克雷伯菌KP200,文中利用生物信息学软件,分析KP200与来自NCBI的ST37型的160株肺炎克雷伯菌菌株铁载体因子的进化关系及遗传多样性。单拷贝核心基因组进化树分析表明,KP200与1株中国的人源肺炎克雷伯菌位于同一个进化支,相似度为99.8%;铁载体因子分析表明,所有161株ST37型肺炎克雷伯菌都携带肠杆菌素entABCEF和fepABC,KP200与其他15株肺炎克雷伯菌携带气杆菌素转运基因iutA,且这些iutA基因序列间核苷酸相似性为73.49%~100%。与高毒力肺炎克雷伯菌NTUH-K2044携带的iutA核苷酸序列比较,发现KP200携带的iutA核苷酸序列中两个碱基突变,导致两个氨基酸替换:即亮氨酸替换成苯丙氨酸、缬氨酸替换成亮氨酸。本研究为肺炎克雷伯菌ST37型别菌株的进化及其毒力分析提供了基础数据。Klebsiella pneumoniae is a opportunistic pathogen associated with acquired infections and is listed by the World Health Organization(WHO)as a drug-resistant pathogen that urgently needs to develop new antibiotics.Siderophores is an important virulence factor for K.pneumoniae to proliferate in host cells,mainly including enterobactin,yersiniabactin,aerobactin,and salmochelin.A multi-drug resistant K.pneumoniae ST37 KP200 was isolated from the liver of sick pigs.This study analyzed the evolutionary relationship and genetic diversity of si-derophores of KP200 and 160 K.pneumoniae ST37 strains from NCBI with bioinformatics software.The single-copy core genes analysis results show that KP200 and a Chinese K.pneumoniae of human origin locate in the same clade with similarity of 99.8%.Siderophores analysis shows that all ST37 strains carry enterobactin entABCEF and fepABC.KP200 and other 15 K.pneumoniae strains carry aerobactin transporter gene iutA.The nucleotide homo-logy of 16 iutA gene sequences is 73.49%~100%.Compared with the iutA nucleotide sequence carried by the hypervirulent K.pneumoniae NTUH-K2044,it finds that the iutA nucleotide carried by KP200 results in two amino acid substitutions due to two base mutations:Leu is replaced by Phe and Val is replaced by Leu.This study provides basis for studying the evolution and virulence of K.pneumoniae ST37.

关 键 词：耐药致病菌 肺炎克雷伯菌 铁载体因子 进化关系 遗传多样性 

分 类 号：S852.61[农业科学—基础兽医学]