Center of Infectious Diseases, West China Hospital (Huaxi), Sichuan University, Guoxuexiang 37, Chengdu, 610041, China.
Division of Infectious Diseases, State Key Laboratory of Biotherapy, Chengdu, China.
Antonie Van Leeuwenhoek. 2023 Jul;116(7):643-651. doi: 10.1007/s10482-023-01833-0. Epub 2023 Apr 26.
Two Enterobacter strains 155092 and 170,225 were isolated from clinical samples, pus and sputum, from two hospitalised patients separately, in China. Preliminary identification using Vitek II microbiology system assigned the strains to the Enterobacter cloacae complex. The two strains were subjected to genome sequencing and genome-based taxonomy analysis with type strains of all Enterobacter species and those within closely related genera Huaxiibacter, Leclercia, Lelliottia, and Pseudoenterobacter. The average nucleotide identity (ANI) and in silico DNA-DNA hybridisation (isDDH) values between the two strains were 98.35% and 89.4%, respectively, suggesting that they belong to one species. The two strains had the highest ANI (95.02% and 95.04%) with the type strain of Enterobacter quasiroggenkampii. Their highest isDDH values, also seen with the type strain of E. quasiroggenkampii, were 59.5% and 59.8%, well below the 70% cutoff to define species. The two strains were also characterised for morphological and biochemical features by a set of experiments and observations. The abilities of metabolising gelatin and L-rhamnose could differentiate the two strains from all currently known Enterobacter species. Collectively, the two strains represent a novel Enterobacter species, for which we propose Enterobacter pseudoroggenkampii sp. nov. as the species name. The type strain of this novel species is155092 (= GDMCC 1.3415 = JCM 35646). The two strains also carried multiple virulence factors comprising aerobactin-encoding iucABCD-iutA and salmochelin-encoding iroN. The two strains also had chromosomally located qnrE, a gene associated with reduced susceptibility to quinolones, suggesting that this species is a potential reservoir of qnrE genes.
两株肠杆菌属细菌 155092 和 170225 分别从中国两名住院患者的临床样本（脓液和痰液）中分离得到。Vitek II 微生物系统的初步鉴定将这些菌株归入阴沟肠杆菌复合体。对这两株菌进行了全基因组测序和基于基因组的分类学分析，包括所有肠杆菌属物种的模式株以及与其密切相关的属（希瓦氏菌属、莱氏菌属、利斯特菌属和类假肠杆菌属）的模式株。这两株菌的平均核苷酸同一性（ANI）和体外 DNA-DNA 杂交（isDDH）值分别为 98.35%和 89.4%，表明它们属于同一个种。这两株菌与准罗氏菌（Enterobacter quasiroggenkampii）的模式株的 ANI 最高（分别为 95.02%和 95.04%）。它们与准罗氏菌的模式株的最高 isDDH 值（也为 59.5%和 59.8%）也低于定义种的 70%界限。这两株菌还通过一系列实验和观察对其形态和生化特征进行了表征。能够代谢明胶和 L-鼠李糖的能力可以将这两株菌与所有已知的肠杆菌属物种区分开来。总的来说，这两株菌代表了一种新的肠杆菌属物种，我们提议将其命名为假罗氏菌（Enterobacter pseudoroggenkampii）sp. nov.。该新物种的模式株为 155092（=GDMCC 1.3415=JCM 35646）。这两株菌还携带多种毒力因子，包括编码 aerobactin 的 iucABCD-iutA 和编码 salmochelin 的 iroN。这两株菌还在染色体上携带了 qnrE，这是一个与喹诺酮类药物敏感性降低相关的基因，表明该物种是 qnrE 基因的潜在库。
