FRI-2 carbapenemase-producing Enterobacter cloacae complex in the UK.
Meunier DAntimicrobial Resistance and Healthcare Associated Infections (AMRHAI) Reference Unit, National Infection Service, Public Health England, London, UK.
Findlay JAntimicrobial Resistance and Healthcare Associated Infections (AMRHAI) Reference Unit, National Infection Service, Public Health England, London, UK.
Doumith MAntimicrobial Resistance and Healthcare Associated Infections (AMRHAI) Reference Unit, National Infection Service, Public Health England, London, UK.
Godoy DAntimicrobial Resistance and Healthcare Associated Infections (AMRHAI) Reference Unit, National Infection Service, Public Health England, London, UK.
Perry CAntimicrobial Resistance and Healthcare Associated Infections (AMRHAI) Reference Unit, National Infection Service, Public Health England, London, UK.
Pike RAntimicrobial Resistance and Healthcare Associated Infections (AMRHAI) Reference Unit, National Infection Service, Public Health England, London, UK.
Gronthoud FDepartment of Microbiology, University Hospital of South Manchester NHS Foundation Trust, Manchester, UK.
Shryane TPublic Health England North West, Manchester, UK.
Poirel LEmerging Antibiotic Resistance Unit, Medical and Molecular Microbiology, Department of Medicine, Faculty of Science, University of Fribourg, Fribourg, Switzerland.
Welfare WPublic Health England North West, Manchester, UK.
Woodford NAntimicrobial Resistance and Healthcare Associated Infections (AMRHAI) Reference Unit, National Infection Service, Public Health England, London, UK.
Hopkins KLAntimicrobial Resistance and Healthcare Associated Infections (AMRHAI) Reference Unit, National Infection Service, Public Health England, London, UK.
English
Objectives Detection of rarer carbapenemases is challenging, as it requires molecular assays with comprehensive coverage or the use of phenotypic methods for the detection of carbapenemase activity. We describe a new class A carbapenemase, FRI-2, in an Enterobacter cloacae complex isolate following implementation of an in-house multiplex PCR for the detection of 'rare' class A carbapenemases.
Methods MICs were determined by agar dilution. A carbapenem-resistant E. cloacae complex isolate was tested by PCR for the class A carbapenemases blaKPC, blaFRI, blaIMI, blaGES and blaSME. Carbapenemase activity was assessed using Carba NP and the carbapenem inactivation method. Whole genome and plasmid analyses of the clinical isolate and the FRI-2 transformant were performed by WGS, respectively. Typing was carried out by PFGE.
Results The E. cloacae complex isolate showed resistance to imipenem (MIC = 16 mg/L), meropenem (MIC = 8 mg/L) and ertapenem (MIC = 8 mg/L), but remained susceptible to piperacillin/tazobactam (MIC = 8 mg/L). Carbapenemase activity was confirmed in the isolate by both phenotypic methods. A blaFRI-1-like gene was detected by PCR and analysis of WGS data of the clinical isolate identified an ORF of 885 bp, which showed 97% nucleotide identity with blaFRI-1 and was named blaFRI-2. WGS of the transformant indicated blaFRI-2 was located on a 108 kb IncF/IncR plasmid. The FRI-2-positive E. cloacae complex isolate belonged to a novel ST (ST829).
Conclusions The possible circulation of rarer carbapenemases in clinical settings highlights the role of phenotypic tests to detect carbapenemase activity when molecular assays are negative for the 'big 5' carbapenemase families.