C M Rooney1,2, A E Sheppard3,4, E Clark2, K Davies1,2, A T M Hubbard3, R Sebra5, D W Crook3,4, A S Walker3,4, M H Wilcox1,2, C H Chilton2. 1. Leeds Teaching Hospitals NHS Trust, Department of Microbiology, Old Medical School, Thoresby Place, Leeds, UK. 2. University of Leeds, Healthcare Associated Infection Research Group, Department of Microbiology, Old Medical School, Thoresby Place, Leeds, UK. 3. Nuffield Department of Medicine, University of Oxford, Henry Wellcome Building for Molecular Physiology, Old Road Campus, Headington, Oxford, UK. 4. NIHR Health Protection Unit in Healthcare Associated Infections and Antimicrobial Resistance at University of Oxford in partnership with Public Health England, Oxford, UK. 5. Icahn Institute and Department of Genetics and Genomic Sciences, Icahn School of Medicine, Mount Sinai, 1 Gustave L. Levy Place, New York, NY, USA.
Abstract
BACKGROUND: Carbapenemase-producing Enterobacteriaceae (CPE) pose a major global health risk. Mobile genetic elements account for much of the increasing CPE burden. OBJECTIVES: To investigate CPE colonization 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 BioMérieux 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 then 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™). CPE gene dissemination was tracked using PacBio long-read sequencing. RESULTS: CPE populations increased during inoculation, plateauing at ∼105 log10 cfu/mL in both models and persisting throughout the experiments (>65 days), with no evidence of CPE 'washout'. After antibiotic administration, there was evidence of interspecies plasmid transfer of blaKPC-2 (111742 bp IncFII/IncR plasmid, 99% identity to pKpQIL-D2) and blaNDM-1 (∼170 kb 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-1K. pneumoniae with one chromosomal single-nucleotide variant compared with 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 colonization, clonal expansion and resistance gene transfer within intact human colonic microbiota. Furthermore, under antibiotic selective pressure, new resistant populations emerge, emphasizing the need to control exposure to antimicrobials.
BACKGROUND: Carbapenemase-producing Enterobacteriaceae (CPE) pose a major global health risk. Mobile genetic elements account for much of the increasing CPE burden. OBJECTIVES: To investigate CPE colonization 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 BioMérieux 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 then 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™). CPE gene dissemination was tracked using PacBio long-read sequencing. RESULTS: CPE populations increased during inoculation, plateauing at ∼105 log10 cfu/mL in both models and persisting throughout the experiments (>65 days), with no evidence of CPE 'washout'. After antibiotic administration, there was evidence of interspecies plasmid transfer of blaKPC-2 (111742 bp IncFII/IncR plasmid, 99% identity to pKpQIL-D2) and blaNDM-1 (∼170 kb 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-1K. pneumoniae with one chromosomal single-nucleotide variant compared with 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 colonization, clonal expansion and resistance gene transfer within intact human colonic microbiota. Furthermore, under antibiotic selective pressure, new resistant populations emerge, emphasizing the need to control exposure to antimicrobials.
Authors: C A Hobson; L Vigue; S Naimi; B Chassaing; M Magnan; S Bonacorsi; B Gachet; I El Meouche; A Birgy; O Tenaillon Journal: JAC Antimicrob Resist Date: 2022-07-05
Authors: Marta Hernández-García; Blanca Pérez-Viso; Carolina Navarro-San Francisco; Fernando Baquero; María Isabel Morosini; Patricia Ruiz-Garbajosa; Rafael Cantón Journal: EClinicalMedicine Date: 2019-10-17
Authors: Anthony M Buckley; Ines B Moura; James Altringham; Duncan Ewin; Emma Clark; Karen Bentley; Vikki Wilkinson; William Spittal; Georgina Davis; Mark H Wilcox Journal: J Antimicrob Chemother Date: 2021-12-24 Impact factor: 5.790