Prospective evaluation of an easy and reliable work-flow for the screening of OXA-48-producing Klebsiella pneumoniae in endemic settings.

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Prospective evaluation of an easy and reliable work-flow for the screening of OXA-48-producing Klebsiella pneumoniae in endemic settings.

J Hosp Infect. 2020 May 01;:

Authors: Rodríguez-Lucas C, Rodicio MR, Rosete Y, Fernández J

Abstract
BACKGROUND: Carbapenemase-producing Enterobacterales (CPE) represents a serious threat to public health. Clinical microbiology laboratories (CML) need effective protocols for screening and confirmation of CPE.
AIM: To prospectively evaluate an algorithm for the screening of carbapenemase-producing Klebsiella pneumoniae in an OXA-48 endemic hospital.
METHODS: The algorithm was based on a disc diffusion assay using ertapenem and temocillin, which also served as a purity check for routine automated antimicrobial susceptibility testing. All isolates with minimal inhibitory concentrations >0.5 mg/L or zone inhibition diameters <25 mm for ertapenem (criteria 1) and <12 mm for temocillin (criteria 2) were tested sequentially by a OXA-48 lateral-flow immunochromatographic assay, a multiplex PCR which targets VIM, KPC and OXA-48 and, if neither of them were positive, by the modified Hodge or CARBA NP tests.
FINDINGS: Over two years, 2,487 K. pneumoniae were assessed by the algorithm proposed, and 378 (15.20%) complied both criteria. Of these, 98.68% (373/378) were either confirmed as OXA-48 producers or originated from patients with a previous CPE-isolate that maintained the same resistance phenotype over time; the remaining three were VIM producers. Only two out of the 378 isolates (0.53%) did not produce carbapenemase, despite meeting criteria 1 and 2.
CONCLUSION: The algorithm here described combined the most sensitive carbapenem for CPE detection with a cut-off of temocillin highly specific for OXA-48 detection. It is reliable and easy to apply in the routine work-flow of CML, allowing rapid detection of CPE isolates, and hence prompt implementation of infection control measures and targeted antimicrobial regimens.

PMID: 32371082 [PubMed - as supplied by publisher]