Center of Infectious Diseases, West China Hospital, Sichuan University, Guoxuexiang 37, Chengdu 610041, Sichuan, China; Division of Infectious Diseases, State Key Laboratory of Biotherapy, Guoxuexiang 37, Chengdu 610041, Sichuan, China; Center for Pathogen Research, West China Hospital, Sichuan University, Guoxuexiang 37, Chengdu 610041, Sichuan, China.
Laboratory of Bacterial Genetics, Centre for Epidemiology and Microbiology, National Institute of Public Health, Šrobárova 48, 100 42 Prague 10, Czech Republic.
Syst Appl Microbiol. 2019 May;42(3):319-325. doi: 10.1016/j.syapm.2019.02.001. Epub 2019 Feb 15.
We studied the taxonomic position of six phenetically related strains of the genus Acinetobacter, which were recovered from hospital sewage in China and showed different patterns of resistance to clinically important antibiotics. Whole-genome sequencing of these strains and genus-wide phylogeny reconstruction based on a set of 107 Acinetobacter core genes indicated that they formed a separate and internally cohesive clade within the genus. The average nucleotide identity based on BLAST and digital DNA-DNA hybridization values between the six new genomes were 97.25-98.67% and 79.2-89.3%, respectively, whereas those between them and the genomes of the known species were ≤78.57% and ≤28.5%, respectively. The distinctness of the strains at the species level was also supported by the results of the cluster analysis of the whole-cell protein fingerprints generated by MALDI-TOF MS. Moreover, the strains displayed a catabolically unique profile and could be differentiated from the phylogenetically closest species at least by their inability to grow on d,l-lactate. A total of 18 different genes were found in the six genome sequences which encode resistance to seven classes of antimicrobial agents, including clinically important carbapenems, oxyimino-cephalosporins, or aminoglycosides. These genes occurred in five different combinations, with three to 10 different genes per strain. We conclude that the six strains represent a novel Acinetobacter species, for which we propose the name Acinetobacter cumulans sp. nov. to reflect its ability to acquire and cumulate diverse resistance determinants. The type strain is WCHAc060092 (ANC 5797=CCTCC AB 2018119=GDMCC 1.1380=KCTC 62576).
我们研究了六株表型相关的不动杆菌属菌株的分类地位，这些菌株从中国医院污水中分离得到，对临床上重要的抗生素表现出不同的耐药模式。这些菌株的全基因组测序和基于 107 个不动杆菌核心基因的全属系统发育重建表明，它们在属内形成了一个独立的、内部一致的分支。基于 BLAST 的平均核苷酸同一性和数字 DNA-DNA 杂交值，这六个新基因组之间的数值分别为 97.25-98.67%和 79.2-89.3%，而它们与已知种基因组之间的数值分别为≤78.57%和≤28.5%。MALDI-TOF MS 生成的全细胞蛋白指纹图谱聚类分析结果也支持这些菌株在种水平上的独特性。此外，这些菌株表现出独特的代谢特征，至少可以通过不能在 d,l-乳酸上生长来与亲缘关系最近的种区分开来。在这六个基因组序列中发现了总共 18 个不同的基因，这些基因编码对包括临床上重要的碳青霉烯类、氧肟头孢菌素类或氨基糖苷类在内的七种抗菌药物的耐药性。这些基因出现在五个不同的组合中，每个菌株有 3 到 10 个不同的基因。我们得出结论，这六个菌株代表了一个新的不动杆菌种，我们提议将其命名为 Acinetobacter cumulans sp. nov.，以反映其获得和积累多种耐药决定因子的能力。模式菌株为 WCHAc060092（ANC 5797=CCTCC AB 2018119=GDMCC 1.1380=KCTC 62576）。
