Characterisation of Early Positive mcr-1 Resistance Gene and Plasmidome in Escherichia coli Pathogenic Strains Associated with Variable Phylogroups under Colistin Selection

Antibiotics

卷:10

Peadar O’Gaora¹  Benjamin Roques¹  Scott V. Nguyen²  Daniel Hurley²  Li Bai²  Ankita Naithani²  Guerrino Macori²  Séamus Fanning²  James L. Bono³  Farid El Garch⁴  Christine Miossec⁴  Frédérique Woehrlé⁴ 

[1] Conway BioMolecular Institute, UCD School of Biomolecular & Biomedical Science, University College Dublin, Belfield, D04 N2E5 Dublin, Ireland;

[2] UCD-Centre for Food Safety, UCD School of Public Health, Physiotherapy and Sports Science, University College Dublin, Belfield, D04 N2E5 Dublin, Ireland;

[3] United States Meat Animal Research Center, United States Department of Agriculture (USDA), State Spur 18D, Clay Center, NE 68938, USA;

[4] Vétoquinol SA, BP 189 CEDEX, 70204 Lure, France;

关键词: antimicrobial resistance;    Escherichia coli;    colistin resistance;    whole genome sequencing;    mcr-1 gene;    plasmid;   

DOI  :  10.3390/antibiotics10091041

来源: DOAJ

【 摘 要 】

An antibiotic susceptibility monitoring programme was conducted from 2004 to 2010, resulting in a collection of 143 Escherichia coli cultured from bovine faecal samples (diarrhoea) and milk-aliquots (mastitis). The isolates were subjected to whole-genome sequencing and were distributed in phylogroups A, B1, B2, C, D, E, and G with no correlation for particular genotypes with pathotypes. In fact, the population structure showed that the strains belonging to the different phylogroups matched broadly to ST complexes; however, the isolates are randomly associated with the diseases, highlighting the necessity to investigate the virulence factors more accurately in order to identify the mechanisms by which they cause disease. The antimicrobial resistance was assessed phenotypically, confirming the genomic prediction on three isolates that were resistant to colistin, although one isolate was positive for the presence of the gene mcr-1 but susceptible to colistin. To further characterise the genomic context, the four strains were sequenced by using a single-molecule long read approach. Genetic analyses indicated that these four isolates harboured complex and diverse plasmids encoding not only antibiotic resistant genes (including mcr-1 and bla) but also virulence genes (siderophore, ColV, T4SS). A detailed description of the plasmids of these four E. coli strains, which are linked to bovine mastitis and diarrhoea, is presented for the first time along with the characterisation of the predicted antibiotic resistance genes. The study highlighted the diversity of incompatibility types encoding complex antibiotic resistance elements such as Tn6330, ISEcp1, Tn6029, and IS5075. The mcr-1 resistance determinant was identified in IncHI2 plasmids pCFS3273-1 and pCFS3292-1, thus providing some of the earliest examples of mcr-1 reported in Europe, and these sequences may be a representative of the early mcr-1 plasmidome characterisation in the EU/EEA.

【 授权许可】

Unknown