title: An optimized work-flow to reduce time-to-detection of carbapenemase-producing Enterobacteriaceae (CPE) using direct testing from rectal swabs.
abstract: Rapid detection of patients with carbapenemase-producing Enterobacteriaceae (CPE) is essential for the prevention of nosocomial cross-transmission, allocation of isolation facilities and to protect patient safety. Here, we aimed to design a new laboratory work-flow, utilizing existing laboratory resources, in order to reduce time-to-diagnosis of CPE. A review of the current CPE testing processes and of the literature was performed to identify a real-time commercial polymerase chain reaction (PCR) assay that could facilitate batch testing of CPE clinical specimens, with adequate CPE gene coverage. Stool specimens (210) were collected; CPE-positive inpatients (n = 10) and anonymized community stool specimens (n = 200). Rectal swabs (eSwab™) were inoculated from collected stool specimens and a manual DNA extraction method (QIAamp® DNA Stool Mini Kit) was employed. Extracted DNA was then processed on the Check-Direct CPE® assay. The three step process of making the eSwab™, extracting DNA manually and running the Check-Direct CPE® assay, took <5 min, 1 h 30 min and 1 h 50 min, respectively. It was time efficient with a result available in under 4 h, comparing favourably with the existing method of CPE screening; average time-to-diagnosis of 48/72 h. Utilizing this CPE work-flow would allow a 'same-day' result. Antimicrobial susceptibility testing results, as is current practice, would remain a 'next-day' result. In conclusion, the Check-Direct CPE® assay was easily integrated into a local laboratory work-flow and could facilitate a large volume of CPE screening specimens in a single batch, making it cost-effective and convenient for daily CPE testing.
authors.affiliation: a Department of Clinical Microbiology , University Hospital Limerick , Limerick , Ireland.|b Centre for Interventions in Infection, Inflammation & Immunity (4i) and Graduate-Entry Medical School , University of Limerick , Limerick , Ireland.
authors.forename: C
authors.initials: C
authors.lastname: O'Connor
authors.affiliation: b Centre for Interventions in Infection, Inflammation & Immunity (4i) and Graduate-Entry Medical School , University of Limerick , Limerick , Ireland.
authors.forename: M G
authors.initials: MG
authors.lastname: Kiernan
authors.affiliation: a Department of Clinical Microbiology , University Hospital Limerick , Limerick , Ireland.
authors.forename: C
authors.initials: C
authors.lastname: Finnegan
authors.affiliation: a Department of Clinical Microbiology , University Hospital Limerick , Limerick , Ireland.
authors.forename: M
authors.initials: M
authors.lastname: O'Hara
authors.affiliation: a Department of Clinical Microbiology , University Hospital Limerick , Limerick , Ireland.
authors.forename: L
authors.initials: L
authors.lastname: Power
authors.affiliation: a Department of Clinical Microbiology , University Hospital Limerick , Limerick , Ireland.|b Centre for Interventions in Infection, Inflammation & Immunity (4i) and Graduate-Entry Medical School , University of Limerick , Limerick , Ireland.
authors.forename: N H
authors.initials: NH
authors.lastname: O'Connell
authors.affiliation: b Centre for Interventions in Infection, Inflammation & Immunity (4i) and Graduate-Entry Medical School , University of Limerick , Limerick , Ireland.
authors.forename: C P
authors.initials: CP
authors.lastname: Dunne
mesh_terms: D000465:Algorithms; D001426:Bacterial Proteins / Q000096:biosynthesis; D015373:Bacterial Typing Techniques / Q000379:methods*; D004755:Enterobacteriaceae / Q000201:enzymology / Q000302:isolation & purification*; D004756:Enterobacteriaceae Infections / Q000175:diagnosis* / Q000382:microbiology*; D005243:Feces / Q000382:microbiology*; D006801:Humans; D012007:Rectum / Q000382:microbiology; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013048:Specimen Handling / Q000379:methods; D057188:Workflow; D016526:Workload; D001618:beta-Lactamases / Q000096:biosynthesis
chemical_list: D001426:Bacterial Proteins; D001618:beta-Lactamases; C063912:carbapenemase
keywords: carbapenemase-producing; check-direct CPE®; eSwab™; Enterobacteriaceae; polymerase chain reaction