Colistin Resistance in Bacteria: Current Updates on Mechanism of Action and Combating Strategies

The rapid development of colistin‐resistant bacteria is the biggest global health issue since colistin is referred to as a ‘last‐hope resource’ against life‐threatening infections caused by GNB (Gram‐negative bacteria). Injudicious and excessive colistin application in clinical, agricultural and veterinary practices, as well as plasmid‐mediated horizontal gene transfer and chromosomal mutation, commonly contribute to colistin resistance. The coexistence of the mcr ‐1 gene with mcr variants, other intrinsic genes and other mechanisms might provide additional resistance strength against colistin. To prevent the emergence of colistin‐resistant strains and preserve the therapeutic efficacy of existing antibiotics, we must expand our deep understanding of colistin‐resistant strains at the molecular level. This critical review discusses the mechanism of action, various bacterial resistance mechanisms, the presence of mcr genes in bacterial plasmids, hetero‐resistance, biofilm formation, the horizontal transfer or dispersion of colistin‐resistant genes and combating strategies. Our synthesis underscores the need for strategically aligning mechanistic knowledge with practical therapeutic solutions to combat escalating colistin resistance and inform future medical decision‐making and research planning.