Evolution of TEM-Type Enzymes: Biochemical and Genetic Characterization of Two New Complex Mutant TEM Enzymes, TEM-151 and TEM-152, from a Single Patient
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منابع مشابه
Evolution 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 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 کاملThe 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 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 کاملBiochemical characterization of TEM-92 extended-spectrum beta-lactamase, a protein differing from TEM-52 in the signal peptide.
A bla(TEM-92) gene was cloned from a Proteus mirabilis isolate and expressed in Escherichia coli. Production of the enzyme caused reduction of susceptibility to penicillins and narrow- to expanded-spectrum cephalosporins but not to moxalactam and cephamycins. Determination of kinetic parameters with the purified enzyme revealed hydrolysis of expanded-spectrum cephalosporins, while cephamycins, ...
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ژورنال
عنوان ژورنال: Antimicrobial Agents and Chemotherapy
سال: 2007
ISSN: 0066-4804,1098-6596
DOI: 10.1128/aac.01058-06