Neil Woodford1, Li Xu-McCrae2, Shazad Mushtaq1, Houdini Ho Tin Wu2,3, Matthew J Ellington1, Owen Lancaster2, Frances Davies4, Hugo Donaldson4, G Gopal Rao5, Anita Verma6, David W Wareham7, Holly Ciesielczuk7, Gregory G Stone8, Paurus M Irani9, Simon Bracher10, Peter M Hawkey2,3. 1. Antimicrobial Resistance and Healthcare Associated Infections (AMRHAI) Reference Unit, National Infection Service, Public Health England, London NW9 5EQ, UK. 2. Specialist Microbiology Service, National Infection Service, Public Health England, Birmingham B9 5SS, UK. 3. Institute of Microbiology and Infection, University of Birmingham, Birmingham B15 2TT, UK. 4. Imperial Healthcare NHS Trust, London, UK. 5. London North West Healthcare NHS Trust, London, UK. 6. King's College Hospital, NHS Foundation Trust, London, UK. 7. Division of Infection, Barts Health NHS Trust, London E1 2ES, UK. 8. AstraZeneca, Waltham, MA, USA. 9. AstraZeneca, London, UK. 10. IndigoMedical Limited, Milton Keynes, UK.
Abstract
Objectives: Although carbapenem susceptibility testing has been recommended for all Enterobacteriaceae from clinical specimens, for practical reasons a carbapenem is not included in many primary antibiotic panels for urine specimens. The 'iCREST' study sought carbapenemase-producing Enterobacteriaceae (CPE) in routine urine specimens yielding Gram-negative growth in five diagnostic laboratories in the UK. We sought also to compare locally and centrally determined MICs of meropenem and ceftazidime/avibactam. Methods: Positive growth from up to 2000 urine specimens per laboratory was plated onto chromID® CARBA SMART agar. Suspected CPE colonies were tested locally by Etest for susceptibility to meropenem and ceftazidime/avibactam, and referred to central laboratories for PCR confirmation of CPE status and microbroth MIC determination. Results: Twenty-two suspected CPE were identified from 7504 urine specimens. Ten were confirmed by PCR to have NDM (5), IMP (2), KPC (2) or OXA-48-like (1) carbapenemases. Locally determined ceftazidime/avibactam MICs showed complete categorical agreement with those determined centrally by microbroth methodology. The seven ceftazidime/avibactam-resistant isolates (MICs ≥256 mg/L) had NDM or IMP metallo-carbapenemases. Conclusions: The frequency of confirmed CPE among Gram-negative urinary isolates was low, at 0.13% (10/7504), but CPE were found in urines at all five participating sites and the diversity of carbapenemase genes detected reflected the complex epidemiology of CPE in the UK. These data can inform local policies about the cost-effectiveness and clinical value of testing Gram-negative bacteria from urine specimens routinely against a carbapenem as part of patient management and/or infection prevention and control strategies.
Objectives: Although carbapenem susceptibility testing has been recommended for all Enterobacteriaceae from clinical specimens, for practical reasons a carbapenem is not included in many primary antibiotic panels for urine specimens. The 'iCREST' study sought carbapenemase-producing Enterobacteriaceae (CPE) in routine urine specimens yielding Gram-negative growth in five diagnostic laboratories in the UK. We sought also to compare locally and centrally determined MICs of meropenem and ceftazidime/avibactam. Methods: Positive growth from up to 2000 urine specimens per laboratory was plated onto chromID® CARBA SMART agar. Suspected CPE colonies were tested locally by Etest for susceptibility to meropenem and ceftazidime/avibactam, and referred to central laboratories for PCR confirmation of CPE status and microbroth MIC determination. Results: Twenty-two suspected CPE were identified from 7504 urine specimens. Ten were confirmed by PCR to have NDM (5), IMP (2), KPC (2) or OXA-48-like (1) carbapenemases. Locally determined ceftazidime/avibactam MICs showed complete categorical agreement with those determined centrally by microbroth methodology. The seven ceftazidime/avibactam-resistant isolates (MICs ≥256 mg/L) had NDM or IMP metallo-carbapenemases. Conclusions: The frequency of confirmed CPE among Gram-negative urinary isolates was low, at 0.13% (10/7504), but CPE were found in urines at all five participating sites and the diversity of carbapenemase genes detected reflected the complex epidemiology of CPE in the UK. These data can inform local policies about the cost-effectiveness and clinical value of testing Gram-negative bacteria from urine specimens routinely against a carbapenem as part of patient management and/or infection prevention and control strategies.
Authors: M Massongo; L Ngando; E W Pefura Yone; Ariane NZouankeu; W Mbanzouen; M C Fonkoua; A Ngandjio; J Tchatchueng; D Barger; M C Tejiokem Journal: Biomed Res Int Date: 2021-05-22 Impact factor: 3.411