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rdf:type |
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lifeskim:mentions |
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pubmed:issue |
4
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pubmed:dateCreated |
2008-3-27
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pubmed:databankReference |
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pubmed:abstractText |
We report on a novel CTX-M extended-spectrum beta-lactamase (ESBL), designated CTX-M-42, with enhanced activity toward ceftazidime. CTX-M-42 was identified in a hypermutable Escherichia coli nosocomial isolate (isolate Irk2320) and is a Pro167Thr amino acid substitution variant of CTX-M-3. By molecular typing of ESBL-producing E. coli strains previously isolated in the same hospital ward, we were able to identify a putative progenitor (strain Irk1224) of Irk2320, which had a mutator phenotype and harbored the CTX-M-3 beta-lactamase. To reproduce the natural evolution of CTX-M-3, we selected for ceftazidime resistance mutations in bla CTX-M-3 gene in vitro both in clinical isolate Irk1224 and in laboratory-derived hypermutable (mutD5) strain GM2995. These experiments yielded CTX-M-3 Pro167Ser and CTX-M-3 Asn136Lys mutants which conferred higher levels of resistance to ceftazidime than to cefotaxime. CTX-M-3 Asn136Lys had a level of low activity toward ampicillin, which may explain its absence from clinical isolates. We conclude that the selection of CTX-M-42 could have occurred in vivo following treatment with ceftazidime and was likely facilitated by the hypermutable background.
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pubmed:commentsCorrections |
http://linkedlifedata.com/resource/pubmed/commentcorrection/18212109-10875286,
http://linkedlifedata.com/resource/pubmed/commentcorrection/18212109-11709308,
http://linkedlifedata.com/resource/pubmed/commentcorrection/18212109-12205064,
http://linkedlifedata.com/resource/pubmed/commentcorrection/18212109-12775683,
http://linkedlifedata.com/resource/pubmed/commentcorrection/18212109-14638473,
http://linkedlifedata.com/resource/pubmed/commentcorrection/18212109-14693512,
http://linkedlifedata.com/resource/pubmed/commentcorrection/18212109-15105092,
http://linkedlifedata.com/resource/pubmed/commentcorrection/18212109-15105882,
http://linkedlifedata.com/resource/pubmed/commentcorrection/18212109-15155242,
http://linkedlifedata.com/resource/pubmed/commentcorrection/18212109-15201232,
http://linkedlifedata.com/resource/pubmed/commentcorrection/18212109-15273085,
http://linkedlifedata.com/resource/pubmed/commentcorrection/18212109-15365030,
http://linkedlifedata.com/resource/pubmed/commentcorrection/18212109-15728940,
http://linkedlifedata.com/resource/pubmed/commentcorrection/18212109-15935499,
http://linkedlifedata.com/resource/pubmed/commentcorrection/18212109-16436733,
http://linkedlifedata.com/resource/pubmed/commentcorrection/18212109-16785225,
http://linkedlifedata.com/resource/pubmed/commentcorrection/18212109-16842578,
http://linkedlifedata.com/resource/pubmed/commentcorrection/18212109-16842579,
http://linkedlifedata.com/resource/pubmed/commentcorrection/18212109-16891630,
http://linkedlifedata.com/resource/pubmed/commentcorrection/18212109-16942899,
http://linkedlifedata.com/resource/pubmed/commentcorrection/18212109-17158117,
http://linkedlifedata.com/resource/pubmed/commentcorrection/18212109-17258896,
http://linkedlifedata.com/resource/pubmed/commentcorrection/18212109-2039479,
http://linkedlifedata.com/resource/pubmed/commentcorrection/18212109-3266988,
http://linkedlifedata.com/resource/pubmed/commentcorrection/18212109-4614067,
http://linkedlifedata.com/resource/pubmed/commentcorrection/18212109-9350772
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pubmed:language |
eng
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pubmed:journal |
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pubmed:citationSubset |
IM
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pubmed:chemical |
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pubmed:status |
MEDLINE
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pubmed:month |
Apr
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pubmed:issn |
0066-4804
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pubmed:author |
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pubmed:issnType |
Print
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pubmed:volume |
52
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
1297-301
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pubmed:dateRevised |
2009-11-19
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pubmed:meshHeading |
pubmed-meshheading:18212109-Anti-Bacterial Agents,
pubmed-meshheading:18212109-Ceftazidime,
pubmed-meshheading:18212109-Cephalosporin Resistance,
pubmed-meshheading:18212109-Directed Molecular Evolution,
pubmed-meshheading:18212109-Escherichia coli,
pubmed-meshheading:18212109-Escherichia coli Proteins,
pubmed-meshheading:18212109-Evolution, Molecular,
pubmed-meshheading:18212109-Humans,
pubmed-meshheading:18212109-Microbial Sensitivity Tests,
pubmed-meshheading:18212109-Molecular Sequence Data,
pubmed-meshheading:18212109-Mutation,
pubmed-meshheading:18212109-Selection, Genetic,
pubmed-meshheading:18212109-Sequence Analysis, DNA,
pubmed-meshheading:18212109-beta-Lactamases
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pubmed:year |
2008
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pubmed:articleTitle |
Convergent in vivo and in vitro selection of ceftazidime resistance mutations at position 167 of CTX-M-3 beta-lactamase in hypermutable Escherichia coli strains.
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pubmed:affiliation |
Institute of Antimicrobial Chemotherapy, Krupskaya str. 28, PO Box 5, Smolensk, Russia.
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pubmed:publicationType |
Journal Article
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