Genetic Analysis of an Ambler Class A Extended-Spectrum Beta-Lactamase from Capnocytophaga ochracea

A beta-lactamase gene ( cfxA3 , 966 bp) was isolated from a beta-lactam-resistant Capnocytophaga ochracea clinical isolate and amplified using primers from the cfxA gene of Bacteroides vulgatus . The MICs of third-generation cephalosporins were much higher than those of the transconjugant Escherichia coli strain. The deduced protein sequence, by comparison with CfxA2 of Prevotella intermedia , had a Y239D substitution and possessed the characteristics of a class A, group 2e beta-lactamase.