Background and Aim: In recent decades, widespread antibiotic resistance in nosocomial infections due to gram-negative bacteria which can cause high mortality rates have significantly increased, especially in intensive care units. Polymyxin resistance, colistin in particular, as the last therapeutic resort, has been reported globally. The purpose of this study was to evaluate the mechanisms of resistance to colistin and the logical approach to the use of this antibiotic.
Materials and Methods: The research method was a narrative review. Data were collected by searching WOS (Web of Science), Scopus, PubMed, SID (Scientific Information Database), Science Direct, and Google Scholar search engines by using the keywords of colistin, antibiotic resistance, gram-negative bacteria, epidemiology, Iran, extended-spectrum beta-lactamases (ESBLs), molecular mechanisms or combinations of them from 2000 to 2019.
Results: The most common molecular mechanisms of colistin resistance were mcr-1, mcr-like genes, increased pmrC expression, outer membrane changes in gram-negative bacteria, and mutations in the mgrB. Combination therapy using colistin with other antibiotics was an effective treatment strategy in life-threatening infections.
Conclusion: mcr-1 and pet-1 transferase were the most prevalent molecular mechanisms for colistin resistance and combinations of colistin with other antibiotics were effective in the treatment of severe infections