Université de Lyon - ANSES, Unité Antibiorésistance et Virulence Bactériennes, Lyon, France.
J Antimicrob Chemother. 2018 Apr 1;73(4):867-872. doi: 10.1093/jac/dkx489.
In Asian countries, blaCTX-M-55 is the second most common ESBL-encoding gene. blaCTX-M-55 frequently co-localizes with fosA and rmtB genes on epidemic plasmids, which remain sporadic outside Asia. During 2010-13, we investigated CTX-M-55-producing Escherichia coli isolates and their co-resistance to fosfomycin, aminoglycosides, fluoroquinolones and colistin as part of a global survey of ESBLs in animals in France.
blaCTX-M-55, fosA, rmtB and plasmidic quinolone and colistin resistance genes were characterized by PCR, sequencing and hybridization experiments. Plasmids were classified according to their incompatibility groups and subtypes. Genotyping was performed by MLST and repetitive extragenic palindromic sequence-based PCR.
Twenty-one E. coli isolates from bovines (n = 16), dogs (n = 2), horses (n = 2) and a monkey harboured blaCTX-M-55, were MDR and belonged to ST744 (n = 9) and 10 other clones. blaCTX-M-55 was mostly located on IncF (n = 19), but also on IncI1 (n = 2) plasmids. On IncF33:A1:B1 plasmids, blaCTX-M-55 co-localized with the rmtB and aac(6')-Ib genes and in one isolate with the fosA3 allele. Ten IncF46:A-:B20 plasmids, which were found in different clones from unrelated animals, also carried the mcr-3 gene. blaCTX-M-55-carrying IncF18:A-:B1 plasmids were found in different animal species from distinct locations and periods, and one additionally carried the fosA4 gene. One isolate harboured the mcr-1 gene, which did not co-localize with blaCTX-M-55.
A large diversity of E. coli clones and plasmid types supported the spread of blaCTX-M-55, together with atypical resistance genes, in various animal species in France. fosA and rmtB genes are emerging among animals in Europe and this issue is of concern for public health.
在亚洲国家，blaCTX-M-55 是第二常见的 ESBL 编码基因。blaCTX-M-55 常与流行质粒上的 fosA 和 rmtB 基因共存，而这些基因在亚洲以外地区则较为分散。在 2010 年至 2013 年期间，我们调查了 CTX-M-55 产生的大肠杆菌分离株及其对磷霉素、氨基糖苷类、氟喹诺酮类和粘菌素的共同耐药性，这是法国对动物中 ESBL 进行全球调查的一部分。
通过 PCR、测序和杂交实验对 blaCTX-M-55、fosA、rmtB 和质粒型喹诺酮类和粘菌素耐药基因进行了特征描述。根据其不相容性群和亚型对质粒进行分类。通过 MLST 和重复外回文序列基于 PCR 进行基因分型。
从牛（n=16）、狗（n=2）、马（n=2）和一只猴子中分离出 21 株携带 blaCTX-M-55 的大肠杆菌，这些菌均为 MDR 菌，属于 ST744（n=9）和其他 10 个克隆。blaCTX-M-55 主要位于 IncF（n=19）上，但也位于 IncI1（n=2）质粒上。在 IncF33:A1:B1 质粒上，blaCTX-M-55 与 rmtB 和 aac(6')-Ib 基因共存，在一个分离株中与 fosA3 等位基因共存。在来自不同动物的不同克隆中发现了 10 个 IncF46:A-:B20 质粒，这些质粒也携带 mcr-3 基因。在不同地点和不同时期来自不同动物物种的 IncF18:A-:B1 质粒上携带 blaCTX-M-55，其中一个分离株还携带 fosA4 基因。一个分离株携带 mcr-1 基因，该基因与 blaCTX-M-55 不共存。
在法国，不同动物物种中存在着大量的大肠杆菌克隆和质粒类型，这支持了 blaCTX-M-55 与非典型耐药基因的传播。fosA 和 rmtB 基因在欧洲动物中正在出现，这是一个公共卫生关注的问题。
