A presumptive chromosomal cephalosporinase (pI, 9.0) from a clinical strain of Acinetobacter genomic species 3 (AG3) is reported. The nucleotide sequence of this beta-lactamase shows for the first time the gene encoding an AmpC enzyme in AG3. In addition, the biochemical properties of the novel AG3 AmpC beta-lactamase are reported

Klebsiella pneumoniae KpQ3 is a multidrug-resistant isolate obtained from a blood culture of a patient in a burn unit in the Hospital Universitario La Paz (Madrid, Spain) in 2008. The genome contains multiple antibiotic resistance genes, including a plasmid-mediated DHA-1 cephalosporinase gene.

Antimicrobial susceptibility was determined in 15 epidemiologically unrelated clinical isolates of Acinetobacter genospecies 3. Moreover, the mechanisms of resistance to some beta-lactam antibiotics may be associated with the presence of a chromosomal cephalosporinase, AmpC, and the resistance to quinolones related to mutations in the gyrA and parC genes.

Outbreaks of multidrug-resistant bacterial infections have become more frequent worldwide owing to the emergence of several different classes of β-lactamases. In this study, the molecular, biochemical and structural characteristics of an Acinetobacter-derived cephalosporinase (ADC)-type class C β-lactamase, ADC-68, isolated from the carbapenem-resistant A. baumannii D015 were investigated. The ...

OBJECTIVES Considering the hypothesis that the high biliary elimination of ceftriaxone could be responsible for the selection of Enterobacteriaceae harbouring high-level AmpC β-lactamase (HL-CASE), the use of ceftriaxone was discontinued in our hospital in 2006 and replaced with cefotaxime. METHODS Antibiotic consumption, expressed as defined daily dose (DDD)/1000 patient-days (PD), and HL-CA...

The cephalosporin beta-lactamase (cephalosporinase) was purified from a strain of Proteus morganii which showed resistance to cephalosporins. The optimal pH was about 8.5, and the optimal temperature was 40 degrees C. The isoelectric point was 8.7 and the molecular weight was estimated to be about 41,000 from sodium dodecyl sulfate-acrylamide gel electrophoresis. The enzyme activity was inhibit...

In an experimental model of peritoneal infection by cephalosporinase- (Ia and Ic) producing bacteria in mice, the reduction of cefoxitin, cefmetazole, and cefazolin concentrations in peritoneal fluid was observed in the mice infected with the Ia enzyme producer, whereas cefbuperazone concentrations were not reduced.