Evaluation of the Revogene Carba C Assay for Detection and Differentiation of Carbapenemase-Producing Gram-Negative Bacteria

Abstract

The Revogene Carba C assay (formerly GenePOC Carba assay) is a multiplex nucleic acid-based in vitro diagnostic test intended for the detection of carbapenemase-producing Enterobacterales (CPE) from cultured colonies. This assay was evaluated directly on colonies of 118 well-characterized Enterobacterales with reduced susceptibility to carbapenems and on 49 multidrug-resistant (MDR) Pseudomonas aeruginosa and 40 MDR Acinetobacter baumannii isolates. The Revogene Carba C assay’s performance was high, as it was able to detect the five major carbapenemases (NDM, VIM, IMP, KPC, and OXA-48). In Enterobacterales, sensitivity and specificity were 100%. When extrapolating the results to the French CPE epidemiology between 2012 and 2018, this assay would have detected 99.28% of the 9,624 CPE isolates sent to the French NRC, missing 69 CPE isolates (2 GES-5, 10 OXA-23, 2 TMB-1, 1 SME-4, 53 IMI, and 1 FRI). The overall sensitivity and specificity for CP P. aeruginosa were 93.7 and 100%, respectively, as two rare IMP variants (IMP-31 and -46) were not detected. Extrapolating these results to the French epidemiology of CP P. aeruginosa in 2017, 93.3% would have been identified, missing only 1 DIM and 10 GES variants. The Revogene Carba C assay accurately identified the targeted carbapenemase genes in A. baumannii, but when extrapolating these results to the French CP A. baumannii epidemiology of 2017, only 12.50% of them could be detected, as OXA-23 is the most prevalent carbapenemase in CP A. baumannii. The Revogene Carba C assay showed excellent sensitivity and specificity for the five most common carbapenemases regardless of the bacterial host. It is well adapted to the CPE and CP P. aeruginosa epidemiology of many countries worldwide, which makes it suitable for use in the routine microbiology laboratory, with a time to result of ca. 85 min for eight isolates simultaneously.

Carbapenemasas en aislamientos de Pseudomonas aeruginosa resistentes a carbapenémicos aisladas en hospitales de Chile

“…Esta frecuencia es mayor que la informada en estudios previos realizados en Latinoamérica 6 y en un estudio más reciente realizado con cepas aisladas en Perú entre 2014 y 2015, se informa que sólo 10% de ellas son productoras de carbapenemasas, y todas ellas correspondieron a una MBL que no fue identificada 19 . Por otra parte, además se puede evidenciar que la presencia del gen bla KPC , el más comúnmente identificado en bacilos gramnegativos en Chile 7 , ha comenzado a desplazar al gen bla VIM , que era el que habitualmente se describía en aislados de P. aeruginosa recuperados en hospitales de Chile 5 y también del mundo 20,23 . Sin embargo, no se encontró aislados que co-portaran simultáneamente ambos genes, como se ha descrito previamente para cepas de P. aeruginosa aisladas en Chile [21][22][23] .…”

“…En Chile, existe muy poca información acerca de la resistencia enzimática a imipenem y meropenem exhibida por cepas de P. aeruginosa [5][6][7] , y por esto, el objetivo de este estudio fue determinar el tipo de carbapenemasa en un grupo de aislados de P. aeruginosa resistentes a carbapenémicos y la relación genética entre los aislados productores de carbapenemasas.…”

Evaluation of the EasyScreen™ ESBL/CPO Detection Kit for the Detection of ß-Lactam Resistance Genes

“…Molecular methods are now available for detecting carbapenemase genes from bacterial cultures but also directly from clinical specimens in less than an hour [ 28 ]. These tests usually screen either for the five most prevalent carbapenemases [ 27 , 29 , 30 , 31 , 32 , 33 ] or for some CTX-M-like enzymes [ 33 ] but miss minor carbapenemases [ 10 , 27 , 29 , 30 , 31 , 32 , 33 ].…”

Phacoemulsification and nucleic acid-enriched aerosol: considerations from an eye model of cataract simulation

“…Corroborating data indicate that ocular fluids (mainly tears) might represent a “reservoir” for viral replication [ 7 – 9 ]. Some molecular (mainly viral sequences) and antigenic (protein)-based tests have been included in the standard screening procedures (venous blood, dedicated pre/post-surgery swabs, and oropharyngeal/nasopharyngeal swabs) that precede surgery [ 10 – 12 ]. The possibility of a spread of infected 5-µm-droplet aerosols (0.1–> 100 μm in diameter) generated during cataract surgery cannot be excluded [ 13 – 15 ].…”