Genetic Diversity of Polymyxin Resistance Genes in Klebsiella pneumoniae Clinical Isolates.

ABSTRACT: This study investigates the genetic diversity and evolutionary mechanisms driving polymyxin resistance in Klebsiella pneumoniae, a critical priority pathogen. By analysing mgrB, phoPQ and pmrAB genes in susceptible (PM-S) and resistant (PM-R) populations through neutrality tests (Tajima D, Fu & Li's D) we uncovered polygenic adaptation and positive selection as a key driver of resistance. High genetic diversity was observed across all loci, with mgrB insertions dominating PM-R populations. Negative Tajima and Fu & Li's D values and excess rare alleles revealed recent population expansions linked to the reintroduction of polymyxins in the 2010s. Positive selection via selective sweeps was detected in PM-R isolates, exemplified by the rapid spread of haplotype 27, which presents mgrB inserti

SUBMITTER: Serwy DM 

PROVIDER: S-EPMC12817155 | biostudies-literature | 2026 Jan

REPOSITORIES: biostudies-literature