Zakaria Azza S, Edward Eva A, Mohamed Nelly M
Microbiology and Immunology Department, Faculty of Pharmacy, Alexandria University, Alexandria 21500, Egypt.
Microorganisms. 2021 Apr 10;9(4):799. doi: 10.3390/microorganisms9040799.
The reintroduction of colistin, a last-resort antibiotic for multidrug-resistant pathogens, resulted in the global spread of plasmid-mediated mobile colistin resistance () genes. Our study investigated the occurrence of colistin resistance among isolated from patients with urinary tract infections admitted to a teaching hospital in Egypt. Out of 67 isolates, three isolates were colistin-resistant, having a minimum inhibitory concentration of 4 µg/mL and possessing the gene. A double mechanism of colistin resistance was detected; production of along with amino acid substitution in PmrB (E123D and Y358N) and PmrA (G144S). Broth mating experiments inferred that was positioned on conjugative plasmids. Whole-genome sequencing of EC13049 indicated that the isolate belonged to O23:H4-ST641 lineage and to phylogroup D. The -bearing plasmid corresponded to IncHI2 type with a notable similarity to other plasmids previously recovered from Egypt. The unbanned use of colistin in the Egyptian agriculture sector might have created a potential reservoir for the gene in food-producing animals that spread to humans. More proactive regulations must be implemented to prevent further dissemination of this resistance. This is the first characterization of -carrying IncHI2:ST4 plasmid recovered from of a clinical source in Egypt.
多粘菌素是治疗多重耐药病原体的最后一道防线，其重新使用导致了质粒介导的可移动多粘菌素耐药性（mcr）基因在全球范围内传播。我们的研究调查了从埃及一家教学医院收治的尿路感染患者中分离出的大肠杆菌中多粘菌素耐药性的发生情况。在67株分离菌中，有3株对多粘菌素耐药，最低抑菌浓度为4μg/mL，并携带mcr基因。检测到多粘菌素耐药的双重机制；在PmrB（E123D和Y358N）和PmrA（G144S）中产生磷酸乙醇胺并伴有氨基酸取代。肉汤交配实验推断mcr位于接合质粒上。EC13049的全基因组测序表明，该分离株属于O23:H4-ST641谱系和D系统发育群。携带mcr的质粒对应于IncHI2型，与先前从埃及分离出的其他mcr质粒有显著相似性。埃及农业部门对多粘菌素的无限制使用可能在产食用动物中为mcr基因创造了一个潜在的储存库，该基因随后传播到了人类。必须实施更积极主动的监管措施，以防止这种耐药性的进一步传播。这是从埃及临床来源的大肠杆菌中分离出的携带mcr的IncHI2:ST4质粒的首次特征描述。
