Detection of carbapenemase-producing bacteria in a public healthcare center from Venezuela.

Liliana Gomez-Gamboa,Jose Bermudez-Gonzalez,Messaria M Ginestre,Jesvy Velasquez,Armindo Perozo-Mena,Christty Villavicencio,Jessica Villasmil

doi:10.3855/jidc.13567

Abstract

The dramatic increase in the prevalence and clinical impact of infections caused by Carbapenemase-Producing Bacteria in the nosocomial setting in Latin America represents an emerging challenge to public health. The present study detected carbapenemase-producing Gram-negative bacteria in patients from a Hospital from Venezuela, by phenotypic and genotypic methods. The bacterial identification was carried out using conventional methods. The resistance to carbapenems was performed by Kirby-Baüer disk diffusion method, according to CLSI recommendations. The modified Hodge Test, double-disk with phenylboronic acid, double-disk with EDTA and Blue Carba Test were performed to detect phenotypic carbapenemase producers. The carbapenemase-encoding genes blaKPC, blaVIM, blaIMP, blaOXA-2, blaOXA-3, blaOXA-15 and blaOXA-21 were determined. The bacterial species identified were Klebsiella pneumoniae complex (181), Pseudomonas aeruginosa (51), and Acinetobacter baumannii-calcoaceticus complex (119). KPC-type was detected in 40.17% of isolates and VIM-type in 14.53%. KPC-type gene was only identified in K. pneumoniae isolates (77.9%). VIM-type gene was identified in P. aeruginosa (86.27%) and K. pneumoniae isolates (3.87%). There was not detection of IMP-type and OXA-type genes. We found a predominance of K. pneumoniae KPC producers and a high rate of VIM-producing P. aeruginosa. The epidemiology of CPB in Venezuela is rapidly evolving, and enhanced surveillance and reporting are needed across the healthcare continuum.

Highlights

The dramatic increase in the prevalence and clinical impact of infections caused by Carbapenemase-Producing Bacteria in the nosocomial setting in Latin America represents an emerging challenge to public health
OXA (Oxacillinase)-23 is the most widely disseminated class D-carbapenemase in A. baumannii isolates from Latin American countries [9], and Fritsche et al reported the first OXA-23producing Acinetobacter spp. strain isolated in Venezuela in 2002 [10]
To phenotypic detection of metallo-β-lactamase in P. aeruginosa, the modified Hodge Test (MHT) showed 50% of sensitivity, specificity of 71%, PPV 91.7%, PNV 18.5%, RV+ 1.7%, RV- 0.7 and the double disk with EDTA showed a sensitivity of 82%, specificity 57%, PPV 92.3%, PNV 33.3%, RV+ 1.9% and RV- 0.32

Summary

Introduction

The dramatic increase in the prevalence and clinical impact of infections caused by Carbapenemase-Producing Bacteria in the nosocomial setting in Latin America represents an emerging challenge to public health. KPC-type gene was only identified in K. pneumoniae isolates (77.9%). VIM-type gene was identified in P. aeruginosa (86.27%) and K. pneumoniae isolates (3.87%). In Venezuela, sporadic cases of CPB have been reported; KPC (Klebsiella pneumoniae carbapenemase)-producing K. pneumoniae and Enterobacter cloacae were first described between 2009 and 2010 [4] and K. pneumoniae harboring blaVIM (Verona Integron-encoded Metallo-β-lactamase)-type were reported in 2008 [5]. The most frequent carbapenemases in Acinetobacter spp. are carbapenem-hydrolyzing class D β-lactamases (CHDLs) and secondly, metalloenzymes such as VIM, IMP and NDM. OXA (Oxacillinase)-23 is the most widely disseminated class D-carbapenemase in A. baumannii isolates from Latin American countries [9], and Fritsche et al reported the first OXA-23producing Acinetobacter spp. strain isolated in Venezuela in 2002 [10]

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Conclusion