Mobilization of qnrB2 and ISCR1 in plasmids.

Division of Molecular and Genomic Medicine, National Health Research Institutes, Miaoli, Taiwan.
Antimicrobial Agents and Chemotherapy (Impact Factor: 4.57). 01/2009; 53(3):1235-7. DOI: 10.1128/AAC.00970-08
Source: PubMed

ABSTRACT The DNA sequences of two IncHI2 plasmids, pEC-IMP and pEC-IMPQ, from metallo-beta-lactamase-producing Enterobacter cloacae clinical isolates were determined. The two conjugative plasmids are almost identical, but pEC-IMPQ carries an additional segment containing an orf513 (ISCR1), a truncated 3' conserved sequence, and a qnrB2. Comparative analyses provide support for the proposed ISCR1-mediated gene mobilization.

  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Two plasmids carrying blaKPC-2 isolated from carbapenem-resistant Escherichia coli (CR-EC) and carbapenem-resistant Klebsiella pneumoniae (CR-KP), respectively, were completely sequenced. The CR-KP strain was selected from an outbreak in 2012, and the CR-EC strain was the first blaKPC-2-carrying E. coli identified in the same carbapenem resistance monitoring programme in Taiwan. Antimicrobial susceptibility tests, multilocus sequence typing (MLST) and the conjugal transfer of plasmids were performed. Complete sequencing of the plasmids was performed using a shotgun approach. The CR-EC and CR-KP strains in this study were determined to be ST410 and ST11, respectively, by MLST. From CR-EC, we identified a 145 kb conjugative plasmid that carries blaKPC-2, blaCMY-2, blaCTX-M-3 and blaTEM-1. The plasmid is a chimera composed of three regions related to IncI, IncN and RepFIC replicons. From CR-KP, we identified an 86.5 kb plasmid, pKPC-LK30, which carries blaKPC-2 and blaSHV-11. The plasmid is very similar to two blaKPC-2-carrying IncFIIK plasmids, but lacks one of the replication origins and cannot conjugate. The differences in cross-species transferability of the two plasmids can be explained by genetic differences between their backbones and could have resulted in the confined blaKPC-2-carrying CR-KP outbreak in Taiwan. Plasmid pKPC-LKEc is the first blaKPC-2-carrying plasmid identified from CR-EC in Taiwan. With relatively high transferability it should be closely monitored.
    Journal of Antimicrobial Chemotherapy 10/2013; · 5.34 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The gene for New Delhi metallo-β-lactamase 1 (NDM-1) has been reported to be transmitted via plasmids which are easily transferable and capable of wide distribution. We report the isolation of two NDM-1 producing strains and possible in vivo transfer of blaNDM-1 in a patient. Clinical samples were collected for bacterial culture and antibiotic susceptibility testing from a patient during a 34-day hospitalization. The presence of blaNDM-1 was detected by PCR and sequencing. Plasmids of interest were sequenced. Medical records were reviewed for evidence of association between the administration of antibiotics and the acquisition of the NDM-1 resistance. A NDM-1 positive Raoultella planticola was isolated from blood on the ninth day of hospitalization without administration of any carbapenem antibiotics and a NDM-1 positive Escherichia coli was isolated from feces on the 29th day of hospitalization and eight days after imipenem administration. The blaNDM-1 was carried by a 280 kb plasmid pRpNDM1-1 in R. planticola and a 58 kb plasmid pEcNDM1-4 in E. coli. The two plasmids shared a 4812 bp NDM-1-ISCR1 element which was found to be excisable from the plasmid as a free form and transferrable in vitro to a NDM-1 negative plasmid from E. coli. blaNDM-1 was embedded in an ISCR1 complex class 1 integron as a novel 4812 bp NDM-1-ISCR1 element. The element was found to be able to self excise to become a free form, which may provide a new vehicle for NDM-1 dissemination. This mechanism could greatly accelerate the spread of NDM-1 mediated broad spectrum β-lactam resistance.
    PLoS ONE 01/2014; 9(3):e89893. · 3.53 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Four nontyphoidal Salmonella strains with resistance to extended-spectrum cephalosporins and nonclassical quinolone resistance phenotype were studied. Two S. Give were isolated from pediatric patients with acute gastroenteritis, and two S. Heidelberg were recovered from raw chicken meat. Phenotypic characterization included antimicrobial susceptibility testing and detection of extended-spectrum β -lactamases (ESBLs) by the double-disc synergy method. The detection of quinolone resistance-determining regions (QRDR) of gyrA, gyrB, and gyrC genes, bla ESBLs genes, and plasmid-mediated quinolone resistance (PMQR) determinants was carried out by molecular methods. Plasmid analysis included Southern blot and restriction patterns. Transferability of resistance genes was examined by transformation. bla TEM-1 + bla SHV-12 genes were detected in S. Give SG9611 and bla TEM-1 + bla CTX-M-2 in the other three strains: S. Give SG9811, S. Heidelberg SH7511, and SH7911. Regardless of origin and serovars, the qnrB19 gene was detected in the 4 strains studied. All determinants of resistance were localized in plasmids and successfully transferred by transformation. This study highlights the circulation of qnrB19 associated with bla TEM-1, bla SHV-12, and bla CTX-M-2 in S. Give and S. Heidelberg in Venezuela. The recognition of factors associated with increasing resistance and the study of the molecular mechanisms involved can lead to a more focused use of antimicrobial agents.
    International Journal of Microbiology 01/2013; 2013:628185.

Full-text (2 Sources)

Available from
Jun 2, 2014