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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
3
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pubmed:dateCreated |
1994-8-23
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pubmed:abstractText |
The effects of enterobacterial beta-lactamases were studied for biapenem (L627), a new carbapenem. Susceptibility tests were performed for isogenic mutant series of Citrobacter freundii, Enterobacter cloacae, Morganella morganii, Serratia marcescens and Proteus vulgaris which varied only in chromosomal beta-lactamase expression. beta-Lactamase-derepressed organisms in these series were as susceptible as beta-lactamase-inducible strains to biapenem; beta-lactamase-basal mutants were up to eight-fold more susceptible. Similar patterns of relative activity against the different expression types were noted for imipenem and biapenem. These data were related to direct induction and hydrolysis assays: biapenem, like imipenem, was a strong inducer of several Class I enzymes and of the P. vulgaris cefuroximase and, like the other carbapenems, was only very slowly hydrolysed by these enzymes. Moreover, like meropenem, biapenem reversibly deactivated these beta-lactamases. Piperacillin and the cephalosporins, tested as comparators, were more labile than carbapenems to the Class I enzymes, were weak inducers below their MICs and lacked deactivator function. In consequence their MICs were higher for derepressed organisms than for those with inducible or basal beta-lactamase expression. Unlike the carbapenems, they selected derepressed mutants from inducible populations. Biapenem, like imipenem and meropenem, retained full activity against most transconjugants of Escherichia coli K-12 that produced plasmid-mediated beta-lactamases, including extended-spectrum TEM mutants. Only production of OXA-10 (previously PSE-2) enzyme gave a slight reduction in susceptibility to the new carbapenem. Biapenem resistance (MIC 16 mg/L) did, however, occur in S. marcescens S6, which produced a chromosomal carbapenemase. This enzyme hydrolysed biapenem. Overall, our findings indicate that biapenem shares the favourable properties of imipenem and meropenem in its interactions with the most important beta-lactamases of enterobacteria.
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pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical | |
pubmed:status |
MEDLINE
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pubmed:month |
Mar
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pubmed:issn |
0305-7453
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:volume |
33
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
453-64
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pubmed:dateRevised |
2006-11-15
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pubmed:meshHeading |
pubmed-meshheading:8040111-Drug Resistance, Microbial,
pubmed-meshheading:8040111-Enterobacteriaceae,
pubmed-meshheading:8040111-Enzyme Induction,
pubmed-meshheading:8040111-Hydrolysis,
pubmed-meshheading:8040111-Microbial Sensitivity Tests,
pubmed-meshheading:8040111-Thienamycins,
pubmed-meshheading:8040111-beta-Lactamases
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pubmed:year |
1994
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pubmed:articleTitle |
Comparative in-vitro activity of biapenem against enterobacteria with beta-lactamase-mediated antibiotic resistance.
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pubmed:affiliation |
Department of Medical Microbiology, London Hospital Medical College, UK.
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pubmed:publicationType |
Journal Article,
Comparative Study,
Research Support, Non-U.S. Gov't
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