Co-occurrence of mcr-1 mediated colistin resistance and β-lactamase-encoding genes in multidrug-resistant Escherichia coli from broiler chickens with colibacillosis in Tunisia

Sana Dhaouadi; Leila Soufi; Amani Hamza; Didier Fedida; Chtioui Zied; Emna Awadhi; Mohamed Mtibaa; Bilel Hassen; Ameur Cherif; Carmen Torres; Mohamed Salah Abbassi; Ramzi Boubaker Landolsi

doi:10.1016/j.jgar.2020.03.017

Co-occurrence of mcr-1 mediated colistin resistance and β-lactamase-encoding genes in multidrug-resistant Escherichia coli from broiler chickens with colibacillosis in Tunisia

J Glob Antimicrob Resist. 2020 Sep:22:538-545. doi: 10.1016/j.jgar.2020.03.017. Epub 2020 Apr 3.

Authors

Affiliations

¹ Manouba University, ISBST, BVBGR-LR11ES31, Biotechpole Sidi Thabet, Ariana, Tunisia; University of Tunis El Manar, Farhat Hached El Manar Campus - B.P. 94, Rommana City, Tunis, Tunisia.
² Manouba University, ISBST, BVBGR-LR11ES31, Biotechpole Sidi Thabet, Ariana, Tunisia.
³ Ceva Animal Health, Tunis, Tunisia.
⁴ Taissir Agricol Society, Tunis, Tunisia.
⁵ University of Tunis El Manar, Institute of Veterinary Research of Tunisia-Laboratory of Bacteriological Research, Tunis, Tunisia.
⁶ Área de Bioquímica y Biología Molecular, Universidad de La Rioja, Logroño, Spain.
⁷ Manouba University, ISBST, BVBGR-LR11ES31, Biotechpole Sidi Thabet, Ariana, Tunisia. Electronic address: ramzi.b.landolsi@gmail.com.

PMID: 32251867
DOI: 10.1016/j.jgar.2020.03.017

Abstract

Objectives: Colibacillosis caused by avian pathogenic Escherichia coli (APEC) is considered a major hindrance in poultry farming worldwide. This study aimed to characterize the genetic content and the relatedness between multidrug-resistant E. coli isolates from broiler chickens died due to colibacillosis from three farms from Tunisia.

Methods: One hundred samples were collected from chickens' fresh carcasses from three poultry farms in Tunisia. E. coli isolation and identification were performed. Then, antimicrobial susceptibility regarding antibiotics, the ability to produce β-lactamases and minimum inhibitory concentration for colistin were determined according to Clinical and Laboratory Standards Institute guidelines. β-Lactam and non-β-lactam antimicrobial resistance genes, integrons, virulence genes, and phylogenetic groups were investigated using polymerase chain reaction. The genetic relatedness of the E. coli isolates was analysed by pulsed field gel electrophoresis (PFGE) and multilocus sequence typing (MLST).

Results: A high infection rate of E. coli (50%) in infected organs of chickens was observed. The majority of E. coli isolates were multidrug resistant (96%); among them, 24% were colistin resistant and 30% were ESBL producing. Seven of 12 colistin-resistant isolates harboured the mcr-1 gene; among them, 10 were ESBL producing and carried bla_CTX-M-1, bla_TEM, and bla_SHV β-lactamase-encoding genes. E. coli isolates were assigned to different phylogroups but most of them (74%) belonged to the pathogenic phylogroup B2. Molecular typing by PFGE showed that some E. coli isolates harbouring ESBL-mcr-1 genes were clonally related. MLST revealed the presence of four different ST lineages among ESBL- and mcr-1-carrying E. coli: ST4187, ST3882; ST5693, and ST8932 with clonal dissemination of E. coli ST4187 between two of the farms.

Conclusion: This is the first report of ESBL-mcr-1-carrying E. coli isolates of a clinically relevant phylogenetic group (B2) from chickens that died due to colibacillosis in Tunisian poultry farms.

Keywords: B2 phylogroup; Broiler chickens; Colibacillosis; E. coli; ESBL; MDR; mcr-1.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animals
Chickens
Colistin* / pharmacology
Escherichia coli / genetics
Escherichia coli Proteins* / genetics
Multilocus Sequence Typing
Phylogeny
Tunisia / epidemiology
beta-Lactamases / genetics

Substances

Escherichia coli Proteins
MCR-1 protein, E coli
beta-Lactamases
Colistin