College of Veterinary Medicine, Henan Agricultural University, Zhengzhou, 450046, PR China.
Institute of Microbiology and Epizootics, Centre for Infection Medicine, Department of Veterinary Medicine, Freie Universität Berlin, Berlin, Germany.
Vet Microbiol. 2021 Nov;262:109218. doi: 10.1016/j.vetmic.2021.109218. Epub 2021 Aug 30.
The emergence and rapid increase of carbapenem-resistant Enterobacteriaceae among food-producing animals poses a serious threat to public health. The aim of this study was to investigate the presence and dissemination of bla in porcine Klebsiella pneumoniae isolates. Of 19 meropenem-resistant K. pneumoniae isolates, 18 were bla-positive and one carried bla. Susceptibility testing indicated that all bla-carrying K. pneumoniae showed a multiple drug resistance (MDR) profile. The bla gene was located on a conjugative IncX3 plasmid of ∼46-kb in all 18 bla-carrying isolates. MLST analysis revealed that ST340 (n = 8), a member of the worldwide existing high-risk epidemic clonal group 258 (CG258), was predominant. Furthermore, whole genome sequence (WGS) analysis for one representative ST340 K. pneumoniae Kp19110124 showed a MDR profile for a wide range of antimicrobial agents, including meropenem, various cephalosporins, azteonam, gentamicin, ciprofloxacin, and florfenicol. Phylogenetic analysis exhibited that K. pneumoniae ST340 strains were clustered into one branch, which had spread across host species and across continents. Among them, K. pneumoniae Kp19110124 displayed a very close relationship with a clinical isolate collected from a patient in Canada. In conclusion, these results reveal the presence of a bla-carrying conjugative IncX3 type plasmid into K. pneumoniae ST340 clone, which then may accelerate the dissemination of the bla gene in porcine K. pneumoniae isolates. The detection of high-risk bla-carrying K. pneumoniae ST340 in food-producing animal poses a serious threat to public health.
产肠杆菌科细菌中碳青霉烯类耐药菌的出现和快速增加对公共卫生构成了严重威胁。本研究旨在调查猪肺炎克雷伯菌分离株中 bla 的存在和传播情况。在 19 株美罗培南耐药肺炎克雷伯菌分离株中，18 株 bla 阳性，1 株携带 bla。药敏试验表明，所有携带 bla 的肺炎克雷伯菌均表现出多重耐药（MDR）表型。bla 基因位于 18 株 bla 携带肺炎克雷伯菌的所有接合型 IncX3 质粒中，大小约为 46kb。MLST 分析显示，ST340（n=8），一种存在于全球高风险流行克隆群 258（CG258）中的成员，占主导地位。此外，对一株代表 ST340 肺炎克雷伯菌 Kp19110124 的全基因组序列（WGS）分析显示，其对包括美罗培南在内的多种抗菌药物具有 MDR 表型，如各种头孢菌素、氨曲南、庆大霉素、环丙沙星和氟苯尼考。系统发育分析表明，肺炎克雷伯菌 ST340 菌株聚类为一个分支，该分支已在宿主物种和各大洲之间传播。其中，肺炎克雷伯菌 Kp19110124 与加拿大一名患者分离的临床株关系非常密切。总之，这些结果表明，bla 携带的可接合 IncX3 型质粒已进入肺炎克雷伯菌 ST340 克隆，这可能加速 bla 基因在猪肺炎克雷伯菌分离株中的传播。食源性生产动物中高风险 bla 携带肺炎克雷伯菌 ST340 的检测对公共卫生构成严重威胁。
