Rooney, C;
Sheppard, AE;
Clark, E;
Davies, K;
Hubbard, ATM;
Sebra, R;
Crook, DW;
... Chilton, C; + view all
(2019)
Dissemination of multiple carbapenem resistance genes in an in-vitro gut model simulating the human colon.
Journal of Antimicrobial Chemotherapy
, 74
(7)
pp. 1876-1883.
10.1093/jac/dkz106.
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Abstract
Background Carbapenemase-producing Enterobacteriaceae (CPE) pose a major global health risk. Mobile genetic elements account for much of the increasing CPE burden. Objective To investigate CPE colonisation and the impact of antibiotic exposure on subsequent resistance gene dissemination within the gut microbiota using a model to simulate the human colon. Methods Gut models seeded with CPE-negative human faeces (screened with BioMerieux chromID® CARBA SMART (Carba-Smart), Cepheid Xpert® Carba-R assay (XCR)) were inoculated with distinct carbapenemase-producing Klebsiella pneumoniae strains (KPC, NDM) and challenged with imipenem or piperacillin/tazobactam, meropenem. Resistant populations were enumerated daily on selective agars (Carba-Smart); CPE genes were confirmed by PCR (XCR, Check-Direct CPE Screen for BD MAX™ (CDCPE)). CPE gene dissemination was tracked using PacBio® long-read sequencing. Results CPE populations increased during inoculation, plateauing at ~10x5 log10cfu/mL in both models and persisting throughout the experiments (>65 days), with no evidence of CPE ‘washout’. Post-antibiotic administration, there was evidence of interspecies plasmid transfer of blaKPC-2 (111,742bp IncFII/IncR plasmid, 99% identity to pKpQIL-D2) and blaNDM-1 (~200kb IncFIB/IncFII plasmid), and CPE populations rose from <0.01% to >45% of the total lactose-fermenting populations in the KPC model. Isolation of a blaNDM-1 K. pneumoniae isolate with one chromosomal single nucleotide variant versus the inoculated strain indicated clonal expansion within the model. Antibiotic administration exposed a previously undetected K. pneumoniae encoding blaOXA-232 (KPC model). Conclusions CPE exposure can lead to colonisation, clonal expansion and resistance gene transfer within intact human colonic microbiota. Furthermore, under antibiotic selective pressure, new resistant populations emerge, emphasising the need for antimicrobial-exposure control.
| Type: | Article |
|---|---|
| Title: | Dissemination of multiple carbapenem resistance genes in an in-vitro gut model simulating the human colon |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1093/jac/dkz106 |
| Publisher version: | https://doi.org/10.1093/jac/dkz106 |
| Language: | English |
| Additional information: | This version is the author accepted manuscript. For information on re-use, please refer to the publisher’s terms and conditions. |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Population Health Sciences > Inst of Clinical Trials and Methodology UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Population Health Sciences > Inst of Clinical Trials and Methodology > MRC Clinical Trials Unit at UCL |
| URI: | https://discovery.ucl.ac.uk/id/eprint/10069460 |
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