Liang Ganfeng, Rao Yuting, Wang Shuang, Chi Xiaohui, Xu Hao, Shen Yang
Department of Infectious Diseases, The First Hospital of Taizhou, Taizhou, People's Republic of China.
Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, People's Republic of China.
Infect Drug Resist. 2021 Aug 10;14:3011-3017. doi: 10.2147/IDR.S321732. eCollection 2021.
The emergence of the plasmid-borne colistin-resistant gene () poses a great threat to human health. What is worse, the recent observations of the coexistence of with carbapenemase encoding genes in some bacteria caused even more concern. Yet, there is a lack of observations of such strains in the human gut.
The isolation of L889 was performed on selective medium plates. Antibiotic susceptibilities were determined by an agar dilution and a broth microdilution method. Multi-locus sequence typing (MLST) and acquired resistance genes were also characterized. Transferability of /-carrying plasmids was determined by conjugation, replicon typing and S1-Pulsed-field gel electrophoresis (S1-PFGE), and Southern blotting. The sequences of these plasmids were analyzed by using whole-genome sequencing with Illumina Novaseq and Nanopore platforms.
L889 was identified as ST1101 concomitantly carrying and from a stool sample. Antimicrobial susceptibility tests showed that it was resistant to various antimicrobial agents and only susceptible to tigecycline. Notably, was located on a ~114-kb untypable plasmid, while was located on a ~63-kb IncI2 plasmid.
Our research, to our knowledge, first reported an ST1101 strain with an untypeable -harbouring plasmid and an IncI2 -carrying plasmid. The colonized strains potentially contribute to the dissemination and transfer of and to clinical isolates, which is a considerable threat to public health and should be closely monitored.
质粒携带的黏菌素耐药基因（）的出现对人类健康构成了巨大威胁。更糟糕的是，最近在一些细菌中观察到该基因与碳青霉烯酶编码基因共存，这引起了更多关注。然而，在人类肠道中缺乏对这类菌株的观察。
在选择性培养基平板上分离L889。通过琼脂稀释法和肉汤微量稀释法测定抗生素敏感性。还对多位点序列分型（MLST）和获得性耐药基因进行了鉴定。通过接合、复制子分型和S1-脉冲场凝胶电泳（S1-PFGE）以及Southern印迹法测定携带/-的质粒的可转移性。使用Illumina Novaseq和Nanopore平台进行全基因组测序分析这些质粒的序列。
从一份粪便样本中鉴定出L889为ST1101，同时携带和。抗菌药物敏感性测试表明它对多种抗菌药物耐药，仅对替加环素敏感。值得注意的是，位于一个约114 kb的不可分型质粒上，而位于一个约63 kb的IncI2质粒上。
据我们所知，我们的研究首次报道了一株ST1101菌株，其携带一个不可分型质粒和一个携带IncI2的质粒。定殖的菌株可能有助于和向临床分离株的传播和转移，这对公共卫生是一个相当大的威胁，应密切监测。
