Characterization of OXA-48-like-producing Enterobacteriaceae isolated from river water in Algeria

International audienceThe spread of carbapenemase-producing Enterobacteriaceae (CPE) is a significant problem for healthcare worldwide. The prevalence of carbapenem-resistant Enterobacteriaceae (CPE) in water environments in Algeria are unknown. The aim of this study was to screen for the presence of CPE isolates in the Soummam River in Bejaia, Algeria. Isolates of Enterobacteriaceae recovered from twelve samples of river water and showing reduced susceptibility to carbapenems were included in this study. The isolates were identified by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS). Isolates were subjected to antimicrobial susceptibility testing and the modified Carba NP test. Carbapenemase and extendedspectrum b-lactamase (ESBL) determinants were studied by PCR amplification and sequencing. The clonal relatedness between isolates was studied by Multilocus Sequence Typing (MLST) method. A total of 20 carbapenem-resistant Enterobacteriaceae strains were included in this study, identified as Escherichia coli (n = 12), Klebsiella pneumoniae (n = 3), Raoultella ornithinolytica (n = 3), Citrobacter freundii (n = 1) and Citrobacter braakii (n = 1). Carbapenemase genes identified in this study included blaOXA-48, observed in 17 isolates (9 E. coli, 3 K. pneumoniae, 3 R. ornithinolytica, 1 C. freundii and 1 C. braakii), and blaOXA-244, a variant of blaOXA-48, was found in three E. coli isolates. MLST showed that 12 E. coli strains belonged to six different sequence types (ST559, ST38, ST212, ST3541, 1972 and ST2142), and we identified three different STs in K. pneumoniae isolates, including ST133, ST2055, and a new sequence type: ST2192. This study showed the presence of OXA-48-like-producing Enterobacteriaceae in water environments and highlighted the potential role of aquatic environments as reservoirs of clinically relevant antimicrobial-resistant bacteria, with the potential to spread throughout the community. (C) 2017 Elsevier Ltd. All rights reserved

Characterisation of bla(OXA)(-538), a new variant of bla(OXA-48), in Shewanella xiamenensis isolated from river water in Algeria

International audienceObjectives: In this study, the presence of carbapenemase genes in Shewanella xiamenensis strains isolated from river water in Bejaia, Algeria, was investigated. Methods: Four isolates of S. xiamenensis were isolated from water from Soummam River. The isolates were identified by matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF/MS) and sequencing of the 16S rRNA and gyrB genes. Isolates were subjected to antimicrobial susceptibility testing. Carbapenemase production was screened using phenotypic tests. PCR and sequencing were used to identify carbapenemase genes in the isolates. The genetic context of the bla(OXA-48-like )gene was investigated by sequencing the whole genome of strain AS58. Results: All four S. xiamenensis strains harboured bla(OXA-48-like) genes. They exhibited different resistance patterns and had imipenem minimum inhibitory concentrations (MICs) of >= 0.5 mg/L. Sequencing of bla(OXA-48-like) genes from the S. xiamenensis isolates showed that two strains harboured bla(OXA-181), one strain harboured bla(OXA-199) and one strain exhibited a new variant of the bla(OXA-48-like) gene, named bla(OXA-538). This new variant shared 98% nucleotide identity with bla(OXA-162), with three amino acid changes (G201A, A213G and I219F). Conjugation assays with Escherichia coli J53 recipient were performed but no transconjugants were obtained. Analysis of the genome of AS58 Touati strain confirmed the chromosomal location of the bla(OXA-538) gene. Conclusion: This study showed that environmental water holds a diversity of S. xiamenensis strains harbouring bla(OXA-48-like) genes and may play an important role in the dissemination and spread of these genes from the environment to humans. (C) 2017 International Society for Chemotherapy of Infection and Cancer. Published by Elsevier Ltd. All rights reserved