Identification and evolution of novel cfr -carrying plasmids in XDR Klebsiella pneumoniae strains from a chicken farm

• Published in: Microbiology spectrum Vol. 13; no. 5; p. e0262824
• Main Authors: Feng, Yiming, Li, Tiantian, Zhao, Shiyun, Zheng, Mengxiang, Shen, Jiaxing, Wu, Xiaoying, Li, Xuexue, Zhai, Yajun, Yuan, Li, Liu, Jianhua, Hu, Gongzheng, Pan, Yushan, He, Dandan
• Format: Journal Article
• Language: English
• Published: United States American Society for Microbiology 06.05.2025
• Subjects: Animals; Anti-Bacterial Agents - pharmacology; Antimicrobial Chemotherapy; Bacterial Proteins - genetics; cfr; Chickens - microbiology; Drug Resistance, Multiple, Bacterial - genetics; Evolution, Molecular; Farms; Fusion plasmid; Klebsiella Infections - microbiology; Klebsiella Infections - veterinary; Klebsiella pneumoniae; Klebsiella pneumoniae - classification; Klebsiella pneumoniae - drug effects; Klebsiella pneumoniae - genetics; Klebsiella pneumoniae - isolation & purification; Microbial Sensitivity Tests; Plasmids - genetics; Poultry Diseases - microbiology; Research Article; TnAs1; Whole Genome Sequencing; Klebsiella pneumoniae; cfr; Fusion plasmid; TnAs1
• ISSN: 2165-0497; 2165-0497
• DOI: 10.1128/spectrum.02628-24

This study highlights the alarming role of K. pneumoniae in the spread of antibiotic resistance within agricultural environments. Two strains isolated from a chicken farm were found to carry the cfr gene, conferring resistance to multiple critical antibiotics, including tigecycline and colistin. Despite their genetic similarity, the strains exhibited distinct plasmid structures, emphasizing the complexity of plasmid evolution. The identification of a fusion plasmid and its derived plasmids underscores the dynamic nature of resistance gene transfer facilitated by recombination events. Importantly, the transferability of the cfr -positive plasmid to E. coli demonstrates the potential for cross-species dissemination. This work sheds light on how agricultural practices contribute to the persistence and evolution of resistance genes, with significant implications for public health and the global fight against antimicrobial resistance.