Decoding genotypic antimicrobial resistance amongst colistin-resistant Gram-negative bloodstream isolates at a South African academic healthcare facility

This study analyzed colistin-resistant Gram-negative bacteria causing bloodstream infections in paediatric patients at a tertiary hospital in Soweto, South Africa (2023–2024). Using whole-genome sequencing, researchers examined resistant isolates of Klebsiella pneumoniae, Acinetobacter baumannii, and Escherichia coli. The results revealed high-risk global clones of K. pneumoniae carrying major resistance genes (blaNDM and blaOXA-48), with genetic clustering suggesting a possible hospital outbreak. Colistin resistance in K. pneumoniae and E. coli was mainly linked to chromosomal mutations in the mgrB and PmrB genes, rather than plasmid-mediated resistance. The findings highlight the importance of genomic surveillance to detect high-risk resistant strains and better manage hospital infections in paediatric settings.