Prevalence and molecular characteristics of extended-spectrum ß-lactamase genes in Escherichia coli isolated from diarrheic patients in China

Li Bai; Lili Wang; Xiaorong Yang; Juan Wang; Xin Gan; Wei Wang; Jin Xu; Qian Chen; Ruiting Lan; Séamus Fanning; Fengqin Li

doi:10.3389/fmicb.2017.00144

Prevalence and molecular characteristics of extended-spectrum ß-lactamase genes in Escherichia coli isolated from diarrheic patients in China

Li Bai, Lili Wang, Xiaorong Yang, Juan Wang, Xin Gan, Wei Wang, Jin Xu, Qian Chen, Ruiting Lan, Séamus Fanning, Fengqin Li^*

^*Corresponding author for this work

Research output: Contribution to journal › Article › peer-review

13 Citations (Scopus)

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Abstract

Background: The emergence and spread of antimicrobial resistance has become a major global public health concern. A component element of this is the spread of the plasmid-encoded extended-spectrum b-lactamase (ESBL) genes, conferring resistance to third-generation cephalosporins. The purpose of this study was to investigate the molecular characteristics of ESBL-encoding genes identified in Escherichia coli cultured from diarrheic patients in China from 2013 to 2014.

Materials and Methods: A total of 51 E. coli were confirmed as ESBL producers by double-disk synergy testing of 912 E. coli isolates studied. Polymerase chain reaction (PCR) and DNA sequencing were performed to identify the corresponding ESBL genes. Susceptibility testing was tested by the disk diffusion method. Plasmids were typed by PCR-based replicon typing and their sizes were determined by S1-nuclease pulsed-field gel electrophoresis. Multi-locus sequence typing (MLST) and phylogrouping were also performed. Broth mating assays were carried out for all isolates to determine whether the ESBL marker could be transferred by conjugation.

Results: Of the 51 ESBL-positive isolates identified, bla_CTX-M, bla_TEM, bla_OXA, and bla_SHV were detected in 51, 26, 3, 1 of these isolates, respectively. Sequencing revealed that 7 bla_CTX-M subtypes were detected, with bla_CTX-M-14 being the most common, followed by bla_CTX-M-79 and bla_CTX-M-28. Of the 26 TEM-positive isolates identified, all of these were bla_TEM-1 genotypes. All isolates contained one to three large plasmids and 10 replicon types were detected. Of these, IncFrep (n = 50), IncK/B (n = 31), IncFIB (n = 26), IncB/O (n = 14), and IncI1-Ir (n = 8) replicon types were the predominating incompatibility groups. Twenty-six isolates demonstrated the ability to transfer their cefotaxime resistance marker at high transfer rates. MLST typing identified 31 sequence types and phylogenetic grouping showed that 12 of the 51 donor strains belonged to phylogroup B2.

Conclusion: This study highlights the diversity of the ESBL producing E. coli and also the diversity of ESBL genes and plasmids carrying these genes in China, which poses a threat to public health.

Original language	English
Article number	144
Journal	Frontiers in Microbiology
Volume	8
DOIs	https://doi.org/10.3389/fmicb.2017.00144
Publication status	Published - 13 Feb 2017
Externally published	Yes

Bibliographical note

Funding Information:
This work was supported by National Natural Science Foundation of China (81402685) and Beijing Talents Fund (2015000021223ZK35)

Publisher Copyright:
© 2017 Bai, Wang, Yang, Wang, Gan, Wang, Xu, Chen, Lan, Fanning and Li.

Keywords

China
Conjugation
Escherichia coli
Extended-spectrum ß-lactamase genes
Horizontal gene transfer
Human
S1 nuclease digestion

ASJC Scopus subject areas

Microbiology
Microbiology (medical)

UN SDGs

This output contributes to the following UN Sustainable Development Goals (SDGs)

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10.3389/fmicb.2017.00144Licence: CC BY

Prevalence and Molecular Characteristics of Extended-Spectrum β-Lactamase Genes in Escherichia coli Isolated from Diarrheic Patients in China
Copyright 2017 the authors. This is an open access article published under a Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution and reproduction in any medium, provided the author and source are cited.
Final published version, 1.82 MBLicence: CC BY

Cite this

@article{13781624cfa943eaa27c0e321f39bf64,

title = "Prevalence and molecular characteristics of extended-spectrum {\ss}-lactamase genes in Escherichia coli isolated from diarrheic patients in China",

abstract = "Background: The emergence and spread of antimicrobial resistance has become a major global public health concern. A component element of this is the spread of the plasmid-encoded extended-spectrum b-lactamase (ESBL) genes, conferring resistance to third-generation cephalosporins. The purpose of this study was to investigate the molecular characteristics of ESBL-encoding genes identified in Escherichia coli cultured from diarrheic patients in China from 2013 to 2014. Materials and Methods: A total of 51 E. coli were confirmed as ESBL producers by double-disk synergy testing of 912 E. coli isolates studied. Polymerase chain reaction (PCR) and DNA sequencing were performed to identify the corresponding ESBL genes. Susceptibility testing was tested by the disk diffusion method. Plasmids were typed by PCR-based replicon typing and their sizes were determined by S1-nuclease pulsed-field gel electrophoresis. Multi-locus sequence typing (MLST) and phylogrouping were also performed. Broth mating assays were carried out for all isolates to determine whether the ESBL marker could be transferred by conjugation. Results: Of the 51 ESBL-positive isolates identified, blaCTX-M, blaTEM, blaOXA, and blaSHV were detected in 51, 26, 3, 1 of these isolates, respectively. Sequencing revealed that 7 blaCTX-M subtypes were detected, with blaCTX-M-14 being the most common, followed by blaCTX-M-79 and blaCTX-M-28. Of the 26 TEM-positive isolates identified, all of these were blaTEM-1 genotypes. All isolates contained one to three large plasmids and 10 replicon types were detected. Of these, IncFrep (n = 50), IncK/B (n = 31), IncFIB (n = 26), IncB/O (n = 14), and IncI1-Ir (n = 8) replicon types were the predominating incompatibility groups. Twenty-six isolates demonstrated the ability to transfer their cefotaxime resistance marker at high transfer rates. MLST typing identified 31 sequence types and phylogenetic grouping showed that 12 of the 51 donor strains belonged to phylogroup B2. Conclusion: This study highlights the diversity of the ESBL producing E. coli and also the diversity of ESBL genes and plasmids carrying these genes in China, which poses a threat to public health.",

keywords = "China, Conjugation, Escherichia coli, Extended-spectrum {\ss}-lactamase genes, Horizontal gene transfer, Human, S1 nuclease digestion",

author = "Li Bai and Lili Wang and Xiaorong Yang and Juan Wang and Xin Gan and Wei Wang and Jin Xu and Qian Chen and Ruiting Lan and S{\'e}amus Fanning and Fengqin Li",

note = "Funding Information: This work was supported by National Natural Science Foundation of China (81402685) and Beijing Talents Fund (2015000021223ZK35) Publisher Copyright: {\textcopyright} 2017 Bai, Wang, Yang, Wang, Gan, Wang, Xu, Chen, Lan, Fanning and Li.",

year = "2017",

month = feb,

day = "13",

doi = "10.3389/fmicb.2017.00144",

language = "English",

volume = "8",

journal = "Frontiers in Microbiology",

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Prevalence and molecular characteristics of extended-spectrum ß-lactamase genes in Escherichia coli isolated from diarrheic patients in China. / Bai, Li; Wang, Lili; Yang, Xiaorong; Wang, Juan; Gan, Xin; Wang, Wei; Xu, Jin; Chen, Qian; Lan, Ruiting; Fanning, Séamus; Li, Fengqin.

In: Frontiers in Microbiology, Vol. 8, 144, 13.02.2017.

Research output: Contribution to journal › Article › peer-review

TY - JOUR

T1 - Prevalence and molecular characteristics of extended-spectrum ß-lactamase genes in Escherichia coli isolated from diarrheic patients in China

AU - Bai, Li

AU - Wang, Lili

AU - Yang, Xiaorong

AU - Wang, Juan

AU - Gan, Xin

AU - Wang, Wei

AU - Xu, Jin

AU - Chen, Qian

AU - Lan, Ruiting

AU - Fanning, Séamus

AU - Li, Fengqin

N1 - Funding Information: This work was supported by National Natural Science Foundation of China (81402685) and Beijing Talents Fund (2015000021223ZK35) Publisher Copyright: © 2017 Bai, Wang, Yang, Wang, Gan, Wang, Xu, Chen, Lan, Fanning and Li.

PY - 2017/2/13

Y1 - 2017/2/13

N2 - Background: The emergence and spread of antimicrobial resistance has become a major global public health concern. A component element of this is the spread of the plasmid-encoded extended-spectrum b-lactamase (ESBL) genes, conferring resistance to third-generation cephalosporins. The purpose of this study was to investigate the molecular characteristics of ESBL-encoding genes identified in Escherichia coli cultured from diarrheic patients in China from 2013 to 2014. Materials and Methods: A total of 51 E. coli were confirmed as ESBL producers by double-disk synergy testing of 912 E. coli isolates studied. Polymerase chain reaction (PCR) and DNA sequencing were performed to identify the corresponding ESBL genes. Susceptibility testing was tested by the disk diffusion method. Plasmids were typed by PCR-based replicon typing and their sizes were determined by S1-nuclease pulsed-field gel electrophoresis. Multi-locus sequence typing (MLST) and phylogrouping were also performed. Broth mating assays were carried out for all isolates to determine whether the ESBL marker could be transferred by conjugation. Results: Of the 51 ESBL-positive isolates identified, blaCTX-M, blaTEM, blaOXA, and blaSHV were detected in 51, 26, 3, 1 of these isolates, respectively. Sequencing revealed that 7 blaCTX-M subtypes were detected, with blaCTX-M-14 being the most common, followed by blaCTX-M-79 and blaCTX-M-28. Of the 26 TEM-positive isolates identified, all of these were blaTEM-1 genotypes. All isolates contained one to three large plasmids and 10 replicon types were detected. Of these, IncFrep (n = 50), IncK/B (n = 31), IncFIB (n = 26), IncB/O (n = 14), and IncI1-Ir (n = 8) replicon types were the predominating incompatibility groups. Twenty-six isolates demonstrated the ability to transfer their cefotaxime resistance marker at high transfer rates. MLST typing identified 31 sequence types and phylogenetic grouping showed that 12 of the 51 donor strains belonged to phylogroup B2. Conclusion: This study highlights the diversity of the ESBL producing E. coli and also the diversity of ESBL genes and plasmids carrying these genes in China, which poses a threat to public health.

AB - Background: The emergence and spread of antimicrobial resistance has become a major global public health concern. A component element of this is the spread of the plasmid-encoded extended-spectrum b-lactamase (ESBL) genes, conferring resistance to third-generation cephalosporins. The purpose of this study was to investigate the molecular characteristics of ESBL-encoding genes identified in Escherichia coli cultured from diarrheic patients in China from 2013 to 2014. Materials and Methods: A total of 51 E. coli were confirmed as ESBL producers by double-disk synergy testing of 912 E. coli isolates studied. Polymerase chain reaction (PCR) and DNA sequencing were performed to identify the corresponding ESBL genes. Susceptibility testing was tested by the disk diffusion method. Plasmids were typed by PCR-based replicon typing and their sizes were determined by S1-nuclease pulsed-field gel electrophoresis. Multi-locus sequence typing (MLST) and phylogrouping were also performed. Broth mating assays were carried out for all isolates to determine whether the ESBL marker could be transferred by conjugation. Results: Of the 51 ESBL-positive isolates identified, blaCTX-M, blaTEM, blaOXA, and blaSHV were detected in 51, 26, 3, 1 of these isolates, respectively. Sequencing revealed that 7 blaCTX-M subtypes were detected, with blaCTX-M-14 being the most common, followed by blaCTX-M-79 and blaCTX-M-28. Of the 26 TEM-positive isolates identified, all of these were blaTEM-1 genotypes. All isolates contained one to three large plasmids and 10 replicon types were detected. Of these, IncFrep (n = 50), IncK/B (n = 31), IncFIB (n = 26), IncB/O (n = 14), and IncI1-Ir (n = 8) replicon types were the predominating incompatibility groups. Twenty-six isolates demonstrated the ability to transfer their cefotaxime resistance marker at high transfer rates. MLST typing identified 31 sequence types and phylogenetic grouping showed that 12 of the 51 donor strains belonged to phylogroup B2. Conclusion: This study highlights the diversity of the ESBL producing E. coli and also the diversity of ESBL genes and plasmids carrying these genes in China, which poses a threat to public health.

KW - China

KW - Conjugation

KW - Escherichia coli

KW - Extended-spectrum ß-lactamase genes

KW - Horizontal gene transfer

KW - Human

KW - S1 nuclease digestion

U2 - 10.3389/fmicb.2017.00144

DO - 10.3389/fmicb.2017.00144

M3 - Article

AN - SCOPUS:85014482135

VL - 8

JO - Frontiers in Microbiology

JF - Frontiers in Microbiology

SN - 1664-302X

M1 - 144

ER -

Prevalence and molecular characteristics of extended-spectrum ß-lactamase genes in Escherichia coli isolated from diarrheic patients in China

Abstract

Bibliographical note

Keywords

ASJC Scopus subject areas

UN SDGs

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