Characterization of two multidrug-resistant Klebsiella pneumoniae harboring tigecycline-resistant gene tet(X4) in China

Frontiers in Microbiology

Microbiology

Li-Na Qin¹  Bin Yan²  Guo-Bao Tian³  Yu Feng³  Xilong Guo³  Yanxian Yang³  Yiping Wu³  Jieyun Chen³  Ruowen He⁴  Mingyang Qin⁵  Lei Xu⁶  Runping Zhao⁶  Min Dai⁶ 

[1] Faculty of Forensic Medicine, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China;Guangdong Province Translational Forensic Medicine Engineering Technology Research Center, Sun Yat-sen University, Guangzhou, China;Program in Pathobiology, the Fifth Affiliated Hospital, Zhongshan School of Medicine, Sun Yat-sen University, Guangdong, China;Advanced Medical Technology Center, The First Affiliated Hospital, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China;Department of Neonatal Surgery, Guangzhou Women and Children's Medical Center, Guangzhou, China;Program in Pathobiology, the Fifth Affiliated Hospital, Zhongshan School of Medicine, Sun Yat-sen University, Guangdong, China;Advanced Medical Technology Center, The First Affiliated Hospital, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China;Key Laboratory of Tropical Diseases Control, Ministry of Education, Sun Yat-sen University, Guangzhou, China;Program in Pathobiology, the Fifth Affiliated Hospital, Zhongshan School of Medicine, Sun Yat-sen University, Guangdong, China;Advanced Medical Technology Center, The First Affiliated Hospital, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China;Key Laboratory of Tropical Diseases Control, Ministry of Education, Sun Yat-sen University, Guangzhou, China;Microbiome Medicine Center, Department of Laboratory Medicine, Zhujiang Hospital, Southern Medical University, Guangzhou, China;School of Basic Medical Sciences, Xinxiang Medical University, Xinxiang, China;School of Public Health, Shandong University, Jinan, China;School of Laboratory Medicine, Chengdu Medical College, Chengdu, China;

关键词: Klebsiella pneumoniae;    tigecycline resistance;    tet;    horizontal transfer;    swine;   

DOI  :  10.3389/fmicb.2023.1130708

 received in 2022-12-23, accepted in 2023-03-27,  发布年份 2023

来源: Frontiers

【 摘 要 】

ObjectivesTigecycline is recognized as one of the last-line antibiotics to treat serious bacterial infection caused by carbapenem-resistant Klebsiella pneumoniae (CRKP). The plasmid-borne gene tet(X4) mediates high resistance to tigecycline. However, the prevalence and genetic context of tet(X4) in K. pneumoniae from various sources are not fully understood. Here, we investigated the prevalence of tet(X4)-positive K. pneumoniae and characterized the genetic context of tet(X4)-bearing plasmids in K. pneumoniae isolates.MethodsPolymerase chain reaction (PCR) was used to detect the tet(X4) gene. The transferability of the tet(X4)-carrying plasmids was tested by conjugation assays. The Galleria mellonella infection model was used to test virulence of tet(X4)-positive strains. Whole-genome sequencing and genome-wide analysis were performed to identify the antimicrobial resistance and the virulence genes, and to clarify the genetic characteristics of the tet(X4)-positive isolates.ResultsAmong 921 samples, we identified two tet(X4)-positive K. pneumoniae strains collected from nasal swabs of two pigs (0.22%, 2/921). The two tet(X4)-positive isolates exhibited high minimum inhibitory concentrations to tigecycline (32–256 mg/L) and tetracycline (256 mg/L). The plasmids carrying the tet(X4) gene can transfer from the donor strain K. pneumoniae to the recipient strain Escherichia coli J53. Genetic analysis of the complete sequence of two tet(X4)-carrying plasmids pTKPN_3-186k-tetX4 and pTKPN_8-216k-tetX4 disclosed that the tet(X4) gene was flanked by delta ISCR2 and IS1R, which may mediate the transmission of the tet(X4) gene.ConclusionThe prevalence of tet(X4)-positive K. pneumoniae among different sources was low. ISCR2 and IS1R may contribute to the horizontal transfer of tet(X4) gene. Effective measures should be taken to prevent the transmission of tet(X4)-producing K. pneumoniae in humans or animals.

【 授权许可】

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Copyright © 2023 Yang, He, Wu, Qin, Chen, Feng, Zhao, Xu, Guo, Tian, Dai, Yan and Qin.