Carbapenemase-producing enterobacteriaceae recovered from a Spanish river ecosystem.

Núria Piedra-Carrasco,William Calero-Cáceres,Maite Muniesa,Thais Cornejo-Sánchez,Alba Mir-Cros,Maryury Brown-Jaque,Anna Fàbrega,Juan José González-López,Yung-Fu Chang

doi:10.1371/journal.pone.0175246

Núria Piedra-Carrasco, William Calero-Cáceres + Show 7 more

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https://doi.org/10.1371/journal.pone.0175246

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Abstract

The increasing resistance to carbapenems is an alarming threat in the fight against multiresistant bacteria. The dissemination properties of antimicrobial resistance genes are supported by their detection in a diverse population of bacteria, including strains isolated from the environment. The objective of this study was to investigate the presence of carbapenemase-producing Enterobacteriaceae (CPE) collected from a river ecosystem in the Barcelona metropolitan area (Spain). Identification of β-lactamases and other resistance determinants was determined as was the antimicrobial susceptibility profile. Moreover, screening of virulence factors, plasmid addiction systems, plasmid partition systems and replicon typing was performed. The results identified 8 isolates belonging to different species (Escherichia coli, Enterobacter cloacae, Klebsiella pneumoniae, Klebsiella oxytoca, Raoultella ornithinolytica). The most prevalent enzyme was KPC-2 (n = 6), followed by VIM-1 (n = 2) and IMI-2 (n = 1), whereas no OXA-48-type was detected. In addition, one strain was positive for both KPC-2 and VIM-1 enzymes. All the carbapenemase-encoding plasmids carried at least one plasmid addiction or partition system, being vagCD and parAB the most frequently detected, respectively. E. coli and K. pneumoniae isolates carried a low number of virulence-associated factors and none of the detected clones has previously been identified in the clinical setting. These findings support the high dissemination potential of the carbapanemase-encoding genes and reinforce the idea that the environment is another reservoir that may play an important role in the capture, selection and dissemination of carbapenem resistance genes.

Highlights

The current therapeutic options to combat infections caused by the increasingly detected Escherichia coli and Klebsiella pneumoniae clinical isolates resistant to third and/or fourth generation cephalosporins are becoming increasingly fewer [1]
The molecular studies revealed that 5 isolates carried KPC-2 (3 E. coli, 1 K. pneumoniae, 1 Enterobacter cloacae), 1 strain was positive for VIM-1 (R. ornithinolytica) and 1 for IMI-2 (E. cloacae), whereas the remaining isolate (Klebsiella oxytoca) carried two carbapenemases: KPC2 and VIM-1 (Table 1)
The analysis of plasmid addiction systems (PAS) of the carbapenemase-encoding plasmids detected in the present study revealed that VagCD was the most prevalent system, being present in 4 (50%) strains (E. coli 1-CAR, R. ornithinolytica 5-CAR, K. pneumoniae 6-CAR, E. cloacae 7-CAR), followed by the ParDE (12.5%) and CcdAB (12.5%) systems which were codetected in the same strain (E. coli 4-CAR) (Table 1)

Summary

Introduction

The current therapeutic options to combat infections caused by the increasingly detected Escherichia coli and Klebsiella pneumoniae clinical isolates resistant to third and/or fourth generation cephalosporins are becoming increasingly fewer [1]. Research in Infectious Diseases (REIPI RD12/ 0015/0003) (http://reipi.org/), and the Spanish Ministry of Health (FIS PI15/00604 to JGL). WC-C is recipient of PhD fellowship SENESCYT 2012 from the Republic of Ecuador Government. MB-J has a grant from COLCIENCIAS (Republic of Colombia). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

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