We biochemically characterized the Klebsiella pneumoniae extended-spectrum SHV-55 enzyme carrying the amino acid substitutions Tyr73Phe (as in SHV-28) and Gly2383Ser and Glu2403Lys (both found in SHV-5) identified in a previous study (5). The SHV-55 extended-spectrum -lactamase differed from SHV-5 only in the signal peptide region (1). The blaSHV-55 gene was obtained as described by Mendonça et...

BACKGROUND Extended-spectrum beta-lactamases (ESBLs) belonging to the SHV family remain a major cause of ESBL-positive phenotypes in Klebsiella pneumoniae. The bla(SHV) gene is a normal constituent of the K. pneumoniae chromosome. However, most ESBL-encoding bla(SHV) genes found in K. pneumoniae are plasmid borne. The objective was to determine the contribution of promoter variants to the expre...

An inhibitor-resistant beta-lactamase (SHV-10), derived from an SHV-5 variant (SHV-9), was found in an Escherichia coli clinical isolate. In SHV-10, Ser-130 was replaced by Gly. The enzyme partially retained its ability to hydrolyze penicillins, but its activity against cephalosporins was drastically reduced. A Ser-130-->Gly mutant of the prototype SHV-5, obtained by site-directed mutagenesis, ...

Ligase chain reaction (LCR) is a recently developed technique that employs a thermostable ligase and allows for the discrimination of DNA sequences differing in only a single base pair. The method has been adapted and applied to differentiation of blaSHV genes. We have developed an LCR typing method to characterize point mutations in genes for SHV-derived extended-spectrum b-lactamases with fou...

Our laboratory has been concerned with the structure and function of the decapentaplegic gene complex (DPP-C) in Drosophila melanogaster. To define the boundaries of the complex, we have studied the genetics of mutations allelic to a previously discovered mutation shortvein (shv), known to reside near decapentaplegic. We found that shortvein resides distal to Hin-d and dpp within the same polyt...

The aims of this study were (a) to determine the prevalence of subjects with semen hyperviscosity (SHV) in a large population of male partners of subfertile couples; (b) to identify any correlation between SHV and infections or inflammation of the genital tract; (c) to assess the effects of therapeutic approaches for treating SHV; and (d) to assess sperm kinetic parameters after successful trea...

Plasmid encoded SHV enzymes represent an important sub-group of class A β-lactamases causing an ESBL phenotype which is increasingly found in Enterobacteriaceae including Klebsiella pneumoniae. The chromosomally encoded β-lactamase LEN and OKP enzymes, which so far only have been found in K. pneumoniae, do not hydrolyse extendedspectrum cephalosporins. In the present study, multiple displacemen...

Klebsiella pneumoniae causing primary liver abscess (PLA) is emerging. This study identified the beta-lactamases genes of K. pneumoniae isolates in Taiwan. The susceptibilities of beta-lactam antibiotics of 30 K. pneumoniae strains associated with primary liver abscess and 30 noninvasive strains were analyzed. The beta-lactamase genes of randomly selected 24 strains from community-acquired infe...

Extended-spectrum beta-lactamases (ESBLs) are widespread in hospital settings worldwide. The present investigation was undertaken to assess the distribution and prevalence of ESBLs belonging to the TEM and SHV families in 448 ESBL-producing clinical isolates of Enterobacteriaceae collected from 10 different Italian hospitals. The natures of TEM and SHV determinants were identified by direct seq...

Extended-spectrum beta-lactamases (ESBLs), e.g., ESBLs of the TEM or SHV type, compromise the efficacies of expanded-spectrum cephalosporins. An SHV non-ESBL that hydrolyzes only narrow-spectrum cephalosporins can be converted into an SHV ESBL through substitutions at three amino acid positions, 179, 238, or 238--240. In order to improve detection of SHV ESBLs, a novel method, based on real-tim...