Properties of IRT-14 (TEM-45), a newly characterized mutant of TEM-type beta-lactamases
نویسندگان
چکیده
منابع مشابه
The structural bases of antibiotic resistance in the clinically derived mutant beta-lactamases TEM-30, TEM-32, and TEM-34.
Widespread use of beta-lactam antibiotics has promoted the evolution of beta-lactamase mutant enzymes that can hydrolyze ever newer classes of these drugs. Among the most pernicious mutants are the inhibitor-resistant TEM beta-lactamases (IRTs), which elude mechanism-based inhibitors, such as clavulanate. Despite much research on these IRTs, little is known about the structural bases of their a...
متن کاملTEM-121, a novel complex mutant of TEM-type beta-lactamase from Enterobacter aerogenes.
Enterobacter aerogenes clinical isolate LOR was resistant to penicillins and ceftazidime but susceptible to cefuroxime, cephalothin, cefoxitin, cefotaxime, ceftriaxone, and cefepime. PCR and cloning experiments from this strain identified a novel TEM-type beta-lactamase (TEM-121) differing by five amino acid substitutions from beta-lactamase TEM-2 (Glu104Lys, Arg164Ser, Ala237Thr, Glu240Lys, an...
متن کاملIn vivo selection of a complex mutant TEM (CMT) from an inhibitor-resistant TEM (IRT) during ceftazidime therapy.
OBJECTIVES A relapse from Escherichia coli bloodstream infection was observed in a patient with acute leukaemia treated with ceftazidime for 7 days for febrile neutropenia. Whereas the original E. coli isolate was resistant to β-lactam/β-lactamase inhibitor combinations (EC1), the relapse E. coli isolate showed a similar phenotype but with resistance extended to ceftazidime (EC2). We investigat...
متن کاملA237T as a modulating mutation in naturally occurring extended-spectrum TEM-type beta-lactamases.
A TEM-1 beta-lactamase derivative containing the single amino acid substitution A237T slightly increased (from 24 to 32 microg/ml) the cephalothin MIC for Escherichia coli RYC1000 but did not influence the activities of cefotaxime, ceftazidime, and aztreonam (MICs of 0.03, 0.12, and 0.06 microg/ml, respectively). Despite its apparent neutrality, addition of the A237T mutation to the pair of mut...
متن کاملPrevalence of TEM Beta-Lactamases and Determination of MIC of four Different Classes of Antibiotics in Klebsiella pneumonaia Clinical Isolates
Background & Aims: Organisms producing TEM-β-lactamase are emerging around the world as a source of resistance to β-lactam antibiotics such as three generation cephalosporins. In this study, we used a polymerase chain reaction (PCR) to identify genes TEM for Extended-spectrum β-lactamase (ESBLs) producing clinical isolates of Klebsiella pneumonia from hospitals of Boro...
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ژورنال
عنوان ژورنال: Antimicrobial Agents and Chemotherapy
سال: 1997
ISSN: 0066-4804,1098-6596
DOI: 10.1128/aac.41.2.374