Jiayue Lu1, Ning Dong2, Congcong Liu1, Yu Zeng1, Qiaoling Sun1, Hongwei Zhou1, Yanyan Hu1, Sheng Chen2, Zhangqi Shen3, Rong Zhang1. 1. Department of Clinical Laboratory, Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310009, China. 2. Department of Infectious Diseases and Public Health, Jockey Club College of Veterinary Medicine and Life Sciences, City University of Hong Kong, Kowloon, Hong Kong. 3. Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Veterinary Medicine, China Agricultural University, Beijing, China.
Abstract
OBJECTIVES: To investigate the nationwide prevalence of mcr-1-positive Klebsiella pneumoniae (MCRPKP) strains among healthy adults in China and identify their phenotypic and genomic characterizations. METHODS: A total of 7401 rectal swab samples were collected from healthy individuals in 30 hospitals located in 30 provinces and municipalities of mainland China in 2016. Colistin-resistant bacteria were enriched in colistin-supplemented lysogeny broth. MCRPKP strains were isolated and characterized with MALDI-TOF MS, PCR analysis and antimicrobial susceptibility testing. The genomic characteristics of MCRPKP strains were determined by WGS and bioinformatics analysis. RESULTS: Seven MCRPKP strains and one mcr-1-positive Klebsiella variicola strain were selectively isolated from six locales (three from Henan and one from each of Tianjin, Jiangxi, Yunnan, Gansu and Tibet). Antimicrobial susceptibility testing results indicated that all mcr-1-positive strains were susceptible to meropenem, aztreonam and ceftazidime/avibactam. WGS analysis suggested these strains belonged to seven distinct STs: ST15, ST1425, ST1462, ST273, ST307, ST391 and ST37-SLV. mcr-1 genes were carried by diverse plasmids, including IncHI2 (n = 3), IncX4 (n = 2), IncHI2/IncN (n = 1), IncFIB (n = 1) and one other plasmid type. Two ST15 strains harboured both mcr-1 and mcr-8 genes, which has not been reported before. CONCLUSIONS: Our data indicated a low prevalence of mcr-1-positive Klebsiella strains (0.11%, 8/7401) in healthy individuals in mainland China and most of these strains remained susceptible to clinically important antibiotics. The prevalence and coexistence of mcr-1 and mcr-8 in K. pneumoniae may further threaten public health through either the food chain or environmental routes.
OBJECTIVES: To investigate the nationwide prevalence of mcr-1-positive Klebsiella pneumoniae (MCRPKP) strains among healthy adults in China and identify their phenotypic and genomic characterizations. METHODS: A total of 7401 rectal swab samples were collected from healthy individuals in 30 hospitals located in 30 provinces and municipalities of mainland China in 2016. Colistin-resistant bacteria were enriched in colistin-supplemented lysogeny broth. MCRPKP strains were isolated and characterized with MALDI-TOF MS, PCR analysis and antimicrobial susceptibility testing. The genomic characteristics of MCRPKP strains were determined by WGS and bioinformatics analysis. RESULTS: Seven MCRPKP strains and one mcr-1-positive Klebsiella variicola strain were selectively isolated from six locales (three from Henan and one from each of Tianjin, Jiangxi, Yunnan, Gansu and Tibet). Antimicrobial susceptibility testing results indicated that all mcr-1-positive strains were susceptible to meropenem, aztreonam and ceftazidime/avibactam. WGS analysis suggested these strains belonged to seven distinct STs: ST15, ST1425, ST1462, ST273, ST307, ST391 and ST37-SLV. mcr-1 genes were carried by diverse plasmids, including IncHI2 (n = 3), IncX4 (n = 2), IncHI2/IncN (n = 1), IncFIB (n = 1) and one other plasmid type. Two ST15 strains harboured both mcr-1 and mcr-8 genes, which has not been reported before. CONCLUSIONS: Our data indicated a low prevalence of mcr-1-positive Klebsiella strains (0.11%, 8/7401) in healthy individuals in mainland China and most of these strains remained susceptible to clinically important antibiotics. The prevalence and coexistence of mcr-1 and mcr-8 in K. pneumoniae may further threaten public health through either the food chain or environmental routes.
Authors: Piotr Majewski; Anna Gutowska; David G E Smith; Tomasz Hauschild; Paulina Majewska; Tomasz Hryszko; Dominika Gizycka; Boguslaw Kedra; Jan Kochanowicz; Jerzy Glowiński; Justyna Drewnowska; Izabela Swiecicka; Pawel T Sacha; Piotr Wieczorek; Dominika Iwaniuk; Anetta Sulewska; Radoslaw Charkiewicz; Katarzyna Makarewicz; Agnieszka Zebrowska; Slawomir Czaban; Piotr Radziwon; Jacek Niklinski; Elzbieta A Tryniszewska Journal: Front Microbiol Date: 2021-12-10 Impact factor: 5.640