TEM-109 (CMT-5), a Natural Complex Mutant of TEM-1 β-Lactamase Combining the Amino Acid Substitutions of TEM-6 and TEM-33 (IRT-5)
نویسندگان
چکیده
منابع مشابه
In 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...
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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...
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TEM-1 1-lactamase is the most prevalent plasmid-mediated 13-lactamase in gram-negative bacteria. Recently, TEM I-lactamase variants with amino acid substitutions in the active-site pocket of the enzyme have been identified in natural isolates with increased resistance to extended-spectrum cephalosporins. To identify other amino acid substitutions that alter the activity of TEM-1 towards extende...
متن کاملEvolution of TEM-type enzymes: biochemical and genetic characterization of two new complex mutant TEM enzymes, TEM-151 and TEM-152, from a single patient.
Two clinical isolates of Escherichia coli, CF1179 and CF1295, were isolated from a patient hospitalized in the hematology unit of the University Hospital of Clermont-Ferrand, Clermont-Ferrand, France. They were resistant to penicillin-clavulanate combinations and to ceftazidime. The double-disk synergy test was positive only for isolate CF1179. Molecular comparison of the isolates showed that t...
متن کاملA bla(TEM-1b)-derived TEM-6 beta-lactamase: a case of convergent evolution.
Since the first communication describing an organism that produces an enzyme capable of hydrolyzing extended-spectrum cephalosporins (5, 6), several outbreaks of Enterobacte-riaceae resistant to oxyimino--lactams have been reported. In these cases, the adopted survival strategy of bacteria challenged by the introduction of aztreonam, cefotaxime, ceftazi-dime, and other oxyimino--lactams was t...
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ژورنال
عنوان ژورنال: Antimicrobial Agents and Chemotherapy
سال: 2005
ISSN: 0066-4804,1098-6596
DOI: 10.1128/aac.49.11.4443-4447.2005