Masoud Dadashi - Department of Microbiology, School of Medicine, Alborz University of Medical Sciences, Karaj, Iran
Fatemeh Sameni - Department of Microbiology, Faculty of Medicine, Shahed University, Tehran, Iran
Nazila Bostanshirin - Department of Microbiology, School of Medicine, Alborz University of Medical Sciences, Karaj, Iran
Somayeh Yaslianifard - Department of Microbiology, School of Medicine, Alborz University of Medical Sciences, Karaj, Iran
Nafiseh Khosravi-Dehaghi - Department of Pharmacognosy, School of Pharmacy, Alborz University of Medical Sciences, Karaj, Iran
Mohammad Javad Nasiri - Department of Microbiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran

Background and Aim : The continuing rise in infections caused by multidrug-resistant (MDR)bacteria is one of the most serious public-health issues in society today. Colistin is a last-resortantimicrobial drug used to treat infections caused by MDR Gram-negative bacteria, thereforeresistance to this antibiotic is extremely hazardous. The current study aimed to evaluate the globalprevalence and distribution of colistin resistance genes among human clinical isolates ofEscherichia coli by systematic review.Methods : PubMed, Embase and Web of Science databases were systematically searched. Forfurther evaluation, all original English language articles that reported colistin resistance in E. coliclinical isolates published between ۲۰۰۰ and ۲۰۲۰ were examined.Results : Of ۴۸۵۷ initial articles, after various stages of review and evaluation ۱۹۰ related articleswere selected for the systematic review. More than ۷۹% of the publications selected in this researchwere published from ۲۰۱۴–۲۰۲۰. In Asia, Europe, America, Africa and Oceania, the prevalenceof mobile colistin resistance (mcr)-harbouring colistin-resistant E. coli was ۶۶.۷۲%, ۲۵.۴۹%,۵.۱۹%, ۲.۲۷% and ۰.۳۲ %, respectively.Conclusion : The recent widespread dissemination of E. coli strains harbouring mcr genesconferring colistin resistance, especially in Asia and Europe, is concerning and requires moreattention.

Escherichia coli, mcr, Colistin, Antibiotic resistance, Systematic review