Acquisition and Transmission of tmexCD1-toprJ1-Positive Plasmids in Clinical ST17 Klebsiella pneumoniae

Lijie Zheng,1,2,* Jie Zhu,1,* Feinan Qian,2 Qizhao Gao,1 Yicheng Wen,1 Hong Du1 1Department of Clinical Laboratory, The Second Affiliated Hospital of Soochow University, Suzhou, Jiangsu, People’s Republic of China; 2Department of Clinical Laboratory, The Affiliated People’s Hospital of Jiangsu University, Zhenjiang, Jiangsu, People’s Republic of China*These authors contributed equally to this workCorrespondence: Hong Du, Department of Clinical Laboratory, The Second Affiliated Hospital of Soochow University, Suzhou, Jiangsu, People’s Republic of China, Email [email protected]: It is well known that bacteria often acquire drug resistance genes through acquiring exogenous resistant plasmids. The tmexCD1-toprJ1-positive plasmid confers tigecycline resistance to bacterial strains.Methods: Three sequence type (ST) 17 Klebsiella pneumoniae strains were isolated from two patients within 5 days. Experimental and comparative genomic analyses were performed to investigate potential transmission routes and antimicrobial resistance phenotype disparities.Results: Strain HD9931 was tigecycline-sensitive, whereas HD9932 and HD10868 were tigecycline-resistant because of the presence of a tmexCD1-toprJ1-positive plasmid. HD10868 exhibited enhanced fitness and greater tigecycline resistance than HD9932 did. Comparative analysis revealed mutations in the AcrAB-TolC efflux pump and lamb in HD9932 and HD10868.Conclusion: Our study highlights the complexity of resistance gene transfer and underscores the need for continued vigilance and research in this field. Keywords: tigecycline resistance, tmexCD1-toprJ1, mutation, plasmids