IS26-mediated amplification of blaOXA-1and blaCTX-M-15with concurrent outer membrane porin disruption associated with de novo carbapenem resistance in a recurrent bacteraemia cohort
| Autor: | David E. Greenberg, Blake Hanson, Awdhesh Kalia, Cesar A. Arias, Xiqi Li, Jiwoong Kim, Pranoti Sahasrabhojane, William C Shropshire, Samuel A. Shelburne, Reed Pifer, Jessica Galloway-Peña, Samuel L. Aitken, Micah M. Bhatti |
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| Rok vydání: | 2020 |
| Předmět: |
Microbiology (medical)
Transposable element Porins Bacteremia Microbial Sensitivity Tests Biology beta-Lactamases chemistry.chemical_compound Antibiotic resistance Bacterial Proteins Gene duplication polycyclic compounds Humans Pharmacology (medical) Copy-number variation Gene Original Research Pharmacology Genetics carbapenémicos biochemical phenomena metabolism and nutrition bacterial infections and mycoses Anti-Bacterial Agents Beta-Lactamasas Enterobacteriaceae resistentes a los carbapenémicos Infectious Diseases Carbapenems chemistry Porin bacteria Mobile genetic elements Ertapenem |
| Zdroj: | Repositorio U. El Bosque Universidad El Bosque instacron:Universidad El Bosque J Antimicrob Chemother |
| ISSN: | 1460-2091 0305-7453 |
| DOI: | 10.1093/jac/dkaa447 |
| Popis: | Background Approximately half of clinical carbapenem-resistant Enterobacterales (CRE) isolates lack carbapenem-hydrolysing enzymes and develop carbapenem resistance through alternative mechanisms. Objectives To elucidate development of carbapenem resistance mechanisms from clonal, recurrent ESBL-positive Enterobacterales (ESBL-E) bacteraemia isolates in a vulnerable patient population. Methods This study investigated a cohort of ESBL-E bacteraemia cases in Houston, TX, USA. Oxford Nanopore Technologies long-read and Illumina short-read sequencing data were used for comparative genomic analysis. Serial passaging experiments were performed on a set of clinical ST131 Escherichia coli isolates to recapitulate in vivo observations. Quantitative PCR (qPCR) and qRT–PCR were used to determine copy number and transcript levels of β-lactamase genes, respectively. Results Non-carbapenemase-producing CRE (non-CP-CRE) clinical isolates emerged from an ESBL-E background through a concurrence of primarily IS26-mediated amplifications of blaOXA-1 and blaCTX-M-1 group genes coupled with porin inactivation. The discrete, modular translocatable units (TUs) that carried and amplified β-lactamase genes mobilized intracellularly from a chromosomal, IS26-bound transposon and inserted within porin genes, thereby increasing β-lactamase gene copy number and inactivating porins concurrently. The carbapenem resistance phenotype and TU-mediated β-lactamase gene amplification were recapitulated by passaging a clinical ESBL-E isolate in the presence of ertapenem. Clinical non-CP-CRE isolates had stable carbapenem resistance phenotypes in the absence of ertapenem exposure. Conclusions These data demonstrate IS26-mediated mechanisms underlying β-lactamase gene amplification with concurrent outer membrane porin disruption driving emergence of clinical non-CP-CRE. Furthermore, these amplifications were stable in the absence of antimicrobial pressure. Long-read sequencing can be utilized to identify unique mobile genetic element mechanisms that drive antimicrobial resistance. |
| Databáze: | OpenAIRE |
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