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...

A beta-lactamase with an M(r) of 29,000 and a pI of 7.6 was partially purified from a clinical isolate of Shigella dysenteriae. The bla gene encoded the SHV-11 enzyme carrying the substitution Leu-->Gln at position 35 and was linked to a strong promoter. This variant, unlike the prototype SHV-1 enzyme, hydrolyzed oxacillin, cloxacillin, and oxyiminocephalosporins such as cefotaxime.

beta-Lactamase production was investigated in cultures of 25 Klebsiella pneumoniae isolates isolated at a hospital in Durban, South Africa, in 1994 and 1996. Twenty of these isolates gave ceftazidime MIC/ceftazidime plus clavulanate MIC ratios of >/=8, implying production of extended-spectrum beta-lactamases (ESBLs), and DNA sequencing identified an ESBL gene (bla(TEM-53)) in a further two isol...

OBJECTIVE Pseudomonas aeruginosa is one of the most important causes of nosocomial infections and can acquire resistant to many antimicrobials, including β-lactams. The aim of this study was to detect the prevalence of SHV type extended-spectrum beta-lactamase (ESBL), antimicrobial resistance patterns of the P. aeroginusa and risk factors in hospitalized patients in two teaching hospitals in Sa...

Abstract Multidrug resistance is one of the worldwide public health concerns. Water represents most suitable environment, for exchange antibiotic genes among pathogenic to non-pathogenic bacteria. Therefore, we aimed screen presence bla NDM-1 , TEM SHV CTX-M and mcr1–5 water samples from different locations Lower Himachal Pradesh. We examined genotypic incidences CTXM by polymerase chain reacti...

Abstract β-lactamases are a diverse class of enzymes produced by bacteria that present major cause for resistance to β-lactams. In this study we analysed 159 fecal samples from dairy cows, the presence presumptive ESBL, AmpC, and carbapenemase-producing E. coli . Phylotyping was done using Clermont phylo-typing method, targeting arpA, ChuA, YjaA genes, along with DNA fragment TspE4.C2. Convetio...

From 1992 to 1997, only six sporadic isolates of Salmonella enterica serotype Enteritidis from patients with cases of gastroenteritis in southern Italy exhibited resistance to broad-spectrum cephalosporins. Five isolates produced SHV-12, and one isolate encoded a class C beta-lactamase. The bla(SHV-12) gene was located in at least two different self-transferable plasmids, one of which also carr...

Extended-spectrum beta-lactamases (ESBLs) emerge by point mutation from non-extended-spectrum precursors. The aims of this study were to reveal the basis for variations in resistance levels found in a collection of 21 Klebsiella pneumoniae clinical isolates from Brisbane, Australia. Previous studies have shown that 20 of these isolates possess bla(SHV-11), bla(SHV-2a), and/or bla(SHV-12), and t...