Progress in the Study of Polymyxin Heteroresistance Molecular Mechanisms

Polymyxins, a class of cyclic peptide antibiotics, have become the last line of defense against gram-negative bacterial infections as the number of multidrug-resistant bacteria continues to rise. Heteroresistance refers to the presence of subpopulations within the same strain with varying sensitivities to antibiotics, which cannot be detected by standard clinical tests and may result in treatment failure. In several common gram-negative bacteria, mutations in the PhoPQ and PmrAB two-component systems are key contributors to polymyxin heteroresistance. This review aims to summarize recent research on the mechanisms of polymyxin heteroresistance in gram-negative bacteria, so as to provide insights for developing rapid detection methods and improving clinical treatment strategies.