Identification of a new allelic variant of the Acinetobacter baumannii cephalosporinase, ADC-7 beta-lactamase: defining a unique family of class C enzymes.

ABSTRACT: Acinetobacter spp. are emerging as opportunistic hospital pathogens that demonstrate resistance to many classes of antibiotics. In a metropolitan hospital in Cleveland, a clinical isolate of Acinetobacter baumannii that tested resistant to cefepime and ceftazidime (MIC = 32 microg/ml) was identified. Herein, we sought to determine the molecular basis for the extended-spectrum-cephalosporin resistance. Using analytical isoelectric focusing, a beta-lactamase with a pI of > or = 9.2 was detected. PCR amplification with specific A. baumannii cephalosporinase primers yielded a 1,152-bp product which, when sequenced, identified a novel 383-amino-acid class C enzyme. Expressed in Escherichia coli DH10B, this beta-lactamase demonstrated greater resistance against ceftazidime and cefotaxime than ce

SUBMITTER: Hujer KM 

PROVIDER: S-EPMC1168656 | biostudies-literature | 2005 Jul

REPOSITORIES: biostudies-literature