Antibiotic Resistance Conferred by a Class I Integron and SXT Constin in
            <i>Vibrio cholerae</i>
            O1 Strains Isolated in Laos

Iwanaga, Masaaki; Toma, Claudia; Miyazato, Tomonori; Insisiengmay, Sithat; Nakasone, Noboru; Ehara, Masahiko

doi:10.1128/aac.48.7.2364-2369.2004

Cited by 115 publications

(83 citation statements)

References 26 publications

(33 reference statements)

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“…Salmonella pathogenicity islands have been associated with mobile common regions that have also been associated with other mobile elements called SXT regions. These regions can be mobilized under bacterial stress, as has been shown recently when resistant elements linked to SXT increased 300-fold when the bacterium was exposed to fluoroquinolones (9,67). Further analysis of the Brazilian P. aeruginosa isolates demonstrated that the upstream DNA contained common regions or CR elements, in this case CR4 (130).…”

Section: Genetic Apparatus Of Transferable Mblsmentioning

confidence: 92%

Metallo-β-Lactamases: the Quiet before the Storm?

et al. 2005

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SUMMARY The ascendancy of metallo-β-lactamases within the clinical sector, while not ubiquitous, has nonetheless been dramatic; some reports indicate that nearly 30% of imipenem-resistant Pseudomonas aeruginosa strains possess a metallo-β-lactamase. Acquisition of a metallo-β-lactamase gene will invariably mediate broad-spectrum β-lactam resistance in P. aeruginosa, but the level of in vitro resistance in Acinetobacter spp. and Enterobacteriaceae is less dependable. Their clinical significance is further embellished by their ability to hydrolyze all β-lactams and by the fact that there is currently no clinical inhibitor, nor is there likely to be for the foreseeable future. The genes encoding metallo-β-lactamases are often procured by class 1 (sometimes class 3) integrons, which, in turn, are embedded in transposons, resulting in a highly transmissible genetic apparatus. Moreover, other gene cassettes within the integrons often confer resistance to aminoglycosides, precluding their use as an alternative treatment. Thus far, the metallo-β-lactamases encoded on transferable genes include IMP, VIM, SPM, and GIM and have been reported from 28 countries. Their rapid dissemination is worrisome and necessitates the implementation of not just surveillance studies but also metallo-β-lactamase inhibitor studies securing the longevity of important anti-infectives.

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Section: Genetic Apparatus Of Transferable Mblsmentioning

confidence: 92%

Metallo-β-Lactamases: the Quiet before the Storm?

et al. 2005

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“…3). DCChl2503, DCChl2510, DCChl2512 and DCChl2516-2 encoded proteins are involved in ribosome protection, recycling and biogenesis, which could weaken the bacteriostatic effect of chloramphenicol, resulting in the resistance to chloramphenicol (Dittrich and Schrempf, 1992;Granneman et al, 2006;Iwanaga et al, 2004).…”

Section: Chloramphenicol Resistancementioning

confidence: 99%

Functional metagenomic characterization of antibiotic resistance genes in agricultural soils from China

Wei

et al. 2014

Environment International

151

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“…Genes specific to each ICE are interspersed in the conserved sequence, and hot spots have been identified as targets for different insertions. SXT MO10 , R391, and more than 25 related ICEs (1,9,29,38) were recently grouped within the SXT/R391 family (7); all these ICEs are characterized by a highly conserved integrase, Int SXT , and by the ability to integrate into the 5Ј end of prfC, a nonessential gene involved in the termination of translation (28).…”

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Identification of the Origin of Transfer (oriT) and a New Gene Required for Mobilization of the SXT/R391 Family of Integrating Conjugative Elements

et al. 2008

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Integrating conjugative elements (ICEs) are self-transmissible, mobile elements that are widespread among bacteria. Following their excision from the chromosome, ICEs transfer by conjugation, a process initiated by a single-stranded DNA break at a specific locus called the origin of transfer (oriT). The SXT/R391 family of ICEs includes SXT MO10 , R391, and more than 25 related ICEs found in gammaproteobacteria. A previous study mapped the oriT locus of SXT MO10 to a 550-bp intergenic region between traD and s043. We suspected that this was not the correct oriT locus, because the identical traD-s043 region in R391 and other SXT/R391 family ICEs was annotated as a gene of an unknown function. Here, we investigated the location and structure of the oriT locus in the ICEs of the SXT/R391 family and demonstrated that oriT SXT corresponds to a 299-bp sequence that contains multiple imperfect direct and inverted repeats and is located in the intergenic region between s003 and rumB. The oriT SXT locus is well conserved among SXT/R391 ICEs, like R391, R997, and pMERPH, and cross-recognition of oriT SXT and oriT R391 by R391 and SXT MO10 was demonstrated. Furthermore, we identified a previously unannotated gene, mobI, located immediately downstream from oriT SXT , which proved to be essential for SXT MO10 transfer and SXT MO10 -mediated chromosomal DNA mobilization. Deletion of mobI did not impair the SXT MO10 -dependent transfer of the mobilizable plasmid CloDF13, suggesting that mobI has no role in the assembly of the SXT MO10 mating pair apparatus. Instead, mobI appears to be involved in the recognition of oriT SXT .Integrating conjugative elements (ICEs) are a large family of self-transmissible mobile genetic elements that are widespread among bacteria (8,12). These elements confer a range of properties upon the host bacteria, including resistance to antibiotics and heavy metals, virulence, symbiosis establishment, and alternative metabolic pathways. ICEs are made of a core set of genes ensuring their maintenance, mobility, and regulation (8,12,44,50).Following their excision from the chromosome of the host cell as a circular intermediate, ICEs transfer by conjugation, using a mechanism similar to that of conjugative plasmids (8,15,19,23,32,39). Integration into and excision from the chromosome occur by recombination mediated by an ICEencoded site-specific recombinase called integrase (Int) (10). Several ICEs are able to mobilize nonconjugative plasmids in cis and in trans as well as chromosomal DNA in an Hfr-like manner (27).Conjugative DNA transfer takes place in two key steps: (i) biochemical processing of the DNA molecule for transfer and (ii) assembly of a mating apparatus bridging the donor and recipient cells to allow DNA transfer. Typically conjugative DNA transfer is initiated at a specific cis-acting site called the origin of transfer (oriT), required for efficient translocation of the DNA to the recipient cell (23,39). A DNA relaxase encoded by the conjugative element recognizes the oriT locus and cleaves o...

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Antibiotic Resistance Conferred by a Class I Integron and SXT Constin in Vibrio cholerae O1 Strains Isolated in Laos

Cited by 115 publications

References 26 publications

Metallo-β-Lactamases: the Quiet before the Storm?

Metallo-β-Lactamases: the Quiet before the Storm?

Functional metagenomic characterization of antibiotic resistance genes in agricultural soils from China

Identification of the Origin of Transfer (oriT) and a New Gene Required for Mobilization of the SXT/R391 Family of Integrating Conjugative Elements

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