High Prevalence of 16S rRNA Methyltransferase Genes in Carbapenem-Resistant Klebsiella pneumoniae Clinical Isolates Associated with Bloodstream Infections in 11 Chinese Teaching Hospitals

Xiaofei Shen; Li Liu; Jingyi Yu; Wenxiu Ai; Xingwei Cao; Qing Zhan; Yinjuan Guo; Liangxing Wang; Fangyou Yu

doi:10.2147/IDR.S254479

High Prevalence of 16S rRNA Methyltransferase Genes in Carbapenem-Resistant Klebsiella pneumoniae Clinical Isolates Associated with Bloodstream Infections in 11 Chinese Teaching Hospitals

Infect Drug Resist. 2020 Jul 9:13:2189-2197. doi: 10.2147/IDR.S254479. eCollection 2020.

Authors

Xiaofei Shen¹, Li Liu², Jingyi Yu², Wenxiu Ai¹, Xingwei Cao³, Qing Zhan⁴, Yinjuan Guo^{5

6}, Liangxing Wang¹, Fangyou Yu^{5

6}

Affiliations

¹ Department of Respiratory Medicine, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou 325000, People's Republic of China.
² Department of Laboratory Medicine, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou 325000, People's Republic of China.
³ Jiangxi Provincial Key Laboratory of Medicine, Clinical Laboratory of the Second Affiliated Hospital of Nanchang University, Nanchang 330006, People's Republic of China.
⁴ Jiangxi Provincial Key Laboratory of Preventive Medicine, Nanchang University, Nanchang 330006, People's Republic of China.
⁵ Department of Clinical Laboratory Medicine, Shanghai Pulmonary Hospital, Tongji University School of Medicine, Shanghai 200082, People's Republic of China.
⁶ Shanghai Key Laboratory of Tuberculosis, Shanghai Pulmonary Hospital, Tongji University School of Medicine, Shanghai 200082, People's Republic of China.

Abstract

Objective: The 16S rRNA methylase-mediated high-level resistance to aminoglycosides has become a great concern. The purpose of the study was to investigate the occurrence of 16S rRNA methyltransferase (RMTase) genes in carbapenem-resistant Klebsiella pneumoniae (CRKP) clinical isolates associated with bloodstream infections (BSIs) in China.

Methods: From July 2015 to December 2018, a total of 137 unique CRKP clinical isolates associated with BSIs were collected from 11 Chinese teaching hospitals. PCR and DNA sequencing were used to identify 16S RMTase genes. Whole-genome sequencing (WGS) was performed on all CRKP clinical isolates. Relevant information was extracted from WGS data (antibiotic resistance determinants, K-type and wzi allelic types). All 16S RMTase-producing CRKP clinical isolates were characterized by antimicrobial susceptibility testing, multilocus sequence typing (MLST) and pulsed-field gel electrophoresis (PFGE).

Results: In this study, 137 CRKPs were found to harbor at least one carbapenemase gene. Among 137 CRKPs, 78 (56.9%, 78/137) were positive for 16S RMTase genes (5 for armA, 70 for rmtB, 3 for both armA and rmtB) and highly resistant to gentamicin and amikacin (MICs ≥256 mg/L). Seventy-five isolates harboring 16S RMTase genes also produced ESBLs. In this study, 5 sequence types (STs) and 6 capsule serotypes were found among 78 isolates positive for 16S RMTases genes, while 14 STs and 6 capsule serotypes were found among 59 isolates negative for 16S RMTases genes. Compared with the isolates negative for 16S RMTases genes, the STs and capsular serotypes of 16S RMTases-positive strains are more concentrated. Among 78 16S RMTases-positive strains, the most prevalent clone type is ST11-PFGE-B-KL64-wzi64 (62.8%, 49/78), which mainly carries the rmtB and bla_KPC genes and is distributed in 7 provinces in China.

Conclusion: A high prevalence of 16S RMTase genes was found among CRKP clinical isolates associated with BSIs from Chinese teaching hospitals, which was attributed to the dissemination of the ST11-PFGE-B-KL64-wzi64 clone.

Keywords: 16S RMTase genes; BSIs; CRKP; aminoglycosides; molecular characteristics.