State Key Laboratory of Microbial Technology, Shandong University, Jinan, Shandong, China.
Lett Appl Microbiol. 2011 Apr;52(4):427-9. doi: 10.1111/j.1472-765X.2011.03016.x. Epub 2011 Feb 21.
To investigate the occurrence of fosfomycin-resistant (fos(R) ) bacteria in aquatic environments.
A fos(R) strain of Enterobacter cloacae was isolated from a water sample collected at a site (50°41'33·44″N, 119°19'49·50″W) near the mouth of the Salmon River at Salmon Arm, in south-central British Columbia, Canada. The strain was identified by PCR screening for plasmid-borne, fosA-family amplicons, followed by selective plating. Sequencing of the resistance gene cloned using PCR primers to conserved flanking DNA revealed a new allele (95% amino acid identity to fosA), and I-Ceu I PFGE showed that it was chromosomally located. In Escherichia coli, the cloned DNA conferred a greater resistance to fosfomycin than its fosA counterpart.
Gene fosA2 conferred fosfomycin resistance in an environmental isolate of Ent. cloacae.
The repurposing of older antibiotics should be considered in the light of existing reservoirs of resistance genes in the environment.
调查水生环境中磷霉素耐药（fos(R)）细菌的发生情况。
从加拿大不列颠哥伦比亚省中南部鲑鱼臂鲑鱼河口附近的一个地点（50°41'33·44″N，119°19'49·50″W）采集的水样中分离出一株阴沟肠杆菌 fos(R) 菌株。该菌株通过针对质粒携带的 fosA 家族扩增子的 PCR 筛选进行鉴定，然后进行选择性平板培养。使用针对保守侧翼 DNA 的 PCR 引物克隆耐药基因，并对其进行测序，结果显示存在一个新的等位基因（与 fosA 的氨基酸同一性为 95%），I-Ceu I PFGE 显示其位于染色体上。在大肠杆菌中，克隆 DNA 赋予的磷霉素耐药性强于其 fosA 对应物。
在阴沟肠杆菌的环境分离株中，fosA2 基因赋予了磷霉素耐药性。
鉴于环境中存在耐药基因的现有储库，应考虑重新利用较旧的抗生素。
