Amino acid substitutions causing inhibitor resistance in TEM -lactamases compromise the extended-spectrum phenotype in SHV extended-spectrum -lactamases
نویسندگان
چکیده
منابع مشابه
Contribution of natural amino acid substitutions in SHV extended-spectrum beta-lactamases to resistance against various beta-lactams.
SHV extended-spectrum beta-lactamases (ESBLs) arise through single amino acid substitutions in the parental enzyme, SHV-1. In order to evaluate the effect of genetic dissimilarities around the structural gene on MICs, we had previously devised an isogenic system of strains. Here, we present an extended version of the system that now allows assessment of all major types of SHV beta-lactamases as...
متن کاملExtended - spectrum Beta - lactamases
Beta-lactamase enzymes (BLs) have become the most worrisome mediators of antimicrobial resistance expressed by gram-negative bacteria (GNB). The multiple families of BLs have in common the ability to hydrolyze the -lactam rings of one or more members of the penicillins, cephalosporins, cephamycins, carbapenems, and monobactams. Extended-spectrum -lactamases (ESBLs) are a subset of BLs that conf...
متن کاملExtended-spectrum beta-lactamases.
At least 30 extended-spectrum beta-lactamases (ESB) have emerged responsible for resistance to indigestible beta-lactams (C3G) since their discovery in West Germany in 1983. Most of them are produced by enterobacteria and essentially K. pneumoniae which appeared susceptible to oxyimino-beta-lactams. A double-disk test was useful to detect such nosocomial isolates of enterobacteria (urines, bloo...
متن کاملSingle amino acid replacements at positions altered in naturally occurring extended-spectrum TEM beta-lactamases.
By directed mutagenesis, we constructed a set of seven TEM-1 derivatives containing single replacements in each one of the amino acids substituted in naturally occurring extended-spectrum TEM beta-lactamases. The exact contribution of each mutation to the resistance phenotype was determined. In addition, mutant enzyme production and stabilities were studied. Five of seven mutations determined t...
متن کاملThe Prevalence of TEM and SHV Genes among Extended-Spectrum Beta-Lactamases Producing Escherichia Coli and Klebsiella Pneumoniae
Objective(s) Production of extended-spectrum beta-lactamases (ESBLs) by enteric bacteria continues to be a major problem in hospitals and community. ESBLs producing bacteria cause many serious infections including urinary tract infections, peritonitis, cholangitis and intra-abdominal abscess. The aim of this study was to determine the prevalence of ESBLs producing Escherichia coli and Klebsiel...
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ژورنال
عنوان ژورنال: Journal of Antimicrobial Chemotherapy
سال: 2001
ISSN: 0305-7453,1460-2091
DOI: 10.1093/jac/47.5.547