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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1990-4-19
pubmed:abstractText
Twenty Pseudomonas maltophilia isolates were examined for susceptibility to beta-lactam antibiotics, including carbapenems, and for beta-lactamase production. All the isolates were resistant to imipenem (MICs 64-512 mg/l) and to a lesser extent, to meropenem (MICs 16-256 mg/l). None of the isolates produced significant amounts of beta-lactamase without induction. Among the beta-lactams studied imipenem proved to be the most potent inducer; meropenem was a weaker inducer. Interestingly, 6-amino-penicillanic acid, even in concentrations up to 100 mg/l, entirely lacked induction activity. In any case enzyme production was drug concentration dependent and transient. Isoelectric focusing revealed 6 different enzymes distinguished by their different isoelectric points (pH 6.2, 8.3, 8.5, 9.0, 9.2 and 9.4). This suggested the lack of a unique beta-lactamase profile in P. maltophilia. Addition of 5 mM cyclic AMP (cAMP) or 0.5 mM cAMP-N6, O2-dioctanoyl (a lipophilic derivative) resulted in a marked drop of beta-lactamase induction by imipenem as compared to the control assay. Monitoring of carbapenem hydrolysis by cell-free supernatants revealed inactivation of both carbapenems. Meropenem was inactivated about 5 times more rapidly than imipenem. Our studies revealed that beta-lactamase production in P. maltophilia as well as growth kinetics were influenced to a considerable extent by the nutrient medium employed.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0009-3157
pubmed:author
pubmed:issnType
Print
pubmed:volume
36
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
117-26
pubmed:dateRevised
2009-11-11
pubmed:meshHeading
pubmed:year
1990
pubmed:articleTitle
Heterogeneity of beta-lactamase production in Pseudomonas maltophilia, a nosocomial pathogen.
pubmed:affiliation
Department of Medical Microbiology and Immunology, Ruhr-University, Bochum, FRG.
pubmed:publicationType
Journal Article, Comparative Study