Showing papers by "Shiri Navon-Venezia published in 2015"

MLST reveals potentially high-risk international clones of Enterobacter cloacae

Abstract: Objectives: To perform the first multinational Enterobacter cloacae clonality study, using the MLST scheme newly developed in Japan Methods: The analysis included 195 rectal carriage E cloacae isolates resistant to expanded-spectrum cephalosporins (ESCs), collected from patients in 12 hospital units across Europe and Israel All of the isolates were typed by PFGE and 173 isolates were subjected to MLST ESC resistance was analysed phenotypically; genes encoding ESBLs and carbapenemases were identified by PCR and sequencing Results: MLST distinguished 88 STs, which correlated with the PFGE data PFGE was more discriminatory, producing 129 pulsotypes (169 patterns) Numerous STs were observed in several countries each The most widespread were ST66, ST78, ST108 and ST114, each having at least 10 isolates from three to five countries, diversified into multiple pulsotypes, with clusters of related isolates in one or more centres Analysis of the STs against the MLST database revealed several epidemic clonal complexes, such as those with central genotypes ST74 (including ST78) or ST114 (including ST66) ESC resistance was equally related to overexpression of the AmpC cephalosporinase and to ESBL production Among ESBL producers some spreading subclones were identified, including specific ST66, ST78 and ST114 pulsotypes, associated with CTX-M-15 production Several isolates produced carbapenemase VIM-1 or KPC-2 Conclusions: Together with the information available in the MLST database, our results suggest that, like Escherichia coli and Klebsiella pneumoniae, E cloacae harbours clonal lineages of increased epidemic potential that may be associated with resistance spread

Persistence of Klebsiella pneumoniae ST258 as the predominant clone of carbapenemase-producing Enterobacteriaceae in post-acute-care hospitals in Israel, 2008–13

Abstract: Objectives To study the molecular characteristics of carbapenemase-producing Enterobacteriaceae (CPE) in post-acute-care hospitals (PACHs) in Israel and to analyse the temporal changes between 2008 and 2013. Methods CPE isolates were obtained during two cross-sectional, point prevalence national surveys of PACHs in Israel performed in 2008 and 2013. Surveillance cultures were collected by streaking rectal swabs onto selective media. Isolates were identified to species level and tested for blaKPC, blaNDM and blaOXA-48 by PCR and by the Carba NP test. Molecular typing was done by PCR for the pilv-l gene, designed for the ST258 KPC-producing Klebsiella pneumoniae (KPC-KP) clone, BOX-PCR and MLST. Results The prevalence of CPE carriage in the first survey was 184/1147 (16%); all of the isolates were KPC-KP. The prevalence of CPE carriage in the second survey was 127/1287 (9.9%); of these isolates, 113 (89%) were KPC-KP, 9 (7%) were other KPC-producing species and 5 (4%) were NDM- and OXA-48-producing CPE (n = 1 and 4, respectively). The proportion of the KPC-KP population represented by the ST258 clone increased from 120/184 (65%) in 2008 to 91/113 (80%) in 2013. In 58% (71/122) of the KPC-CPE carriers identified in the 2013 survey, the source of acquisition was determined to be the PACH itself. All four OXA-48 CPE were acquired either directly or indirectly from patients arriving from the Palestinian Authority or Syria. Conclusions Despite the decreased prevalence of CPE in Israeli PACHs, and the emergence of new types of CPE, the KPC-KP ST258 clone remains the predominant clone represented.

Genomic and Functional Characterization of qnr-Encoding Plasmids from Municipal Wastewater Biosolid Klebsiella pneumoniae Isolates.

Abstract: Municipal wastewater treatment facilities are considered to be "hotspots" for antibiotic resistance, since they conjoin high densities of environmental and fecal bacteria with selective pressure in the form of sub-therapeutic concentrations of antibiotics. Discharged effluents and biosolids from these facilities can disseminate antibiotic resistant genes to terrestrial and aquatic environments, potentially contributing to the increasing global trend in antibiotic resistance. This phenomenon is especially pertinent when resistance genes are associated with mobile genetic elements such as conjugative plasmids, which can be transferred between bacterial phyla. Fluoroquinolones are among the most abundant antibiotic compounds detected in wastewater treatment facilities, especially in biosolids, where due to their hydrophobic properties they accumulate to concentrations that may exceed 40 mg/L. Although fluoroquinolone resistance is traditionally associated with mutations in the gyrA/topoisomerase IV genes, there is increasing evidence of plasmid-mediated quinolone resistance, which is primarily encoded on qnr genes. In this study, we sequenced seven qnr-harboring plasmids from a diverse collection of Klebsiella strains, isolated from dewatered biosolids from a large wastewater treatment facility in Israel. One of the plasmids, termed pKPSH-11XL was a large (185.4 kbp), multi-drug resistance, IncF-type plasmid that harbored qnrB and 10 additional antibiotic resistance genes that conferred resistance to five different antibiotic families. It was highly similar to the pKPN3-like plasmid family that has been detected in multidrug resistant clinical Klebsiella isolates. In contrast, the six additional plasmids were much smaller (7-9 Kbp) and harbored a qnrS -type gene. These plasmids were highly similar to each other and closely resembled pGNB2, a plasmid isolated from a German wastewater treatment facility. Comparative genome analyses of pKPSH-11XL and other pKPN3-like plasmids concomitant to phylogenetic analysis of housekeeping genes from host Klebsiella strains, revealed that these plasmids are limited to a predominantly human-associated sub-clade of Klebsiella, suggesting that their host range is very narrow. Conversely, the pGNB2-like plasmids had a much broader host range and appeared to be associated with Klebsiella residing in natural environments. This study suggests that: (A) qnrB-harboring multidrug-resistant pKPN3-like plasmids can endure the rigorous wastewater treatment process and may therefore be disseminated to downstream environments; and (B) that small qnrS-harboring pGNB2-like plasmids are ubiquitous in wastewater treatment facilities and are most likely environmental in origin.