Identification of a chromosome-borne class C beta-lactamase from Erwinia rhapontici.

OBJECTIVES

To characterize the beta-lactamase gene content of Erwinia rhapontici.

METHODS

The beta-lactamase gene was cloned, sequenced and expressed in Escherichia coli.

RESULTS

The cloned gene conferred a resistance pattern of an Ambler class C beta-lactamase in E. coli. The AmpC-type enzyme had a pI value of 8.6 and shared 62% amino acid sequence identity with that of Escherichia fergusonii. The ampC gene was associated with a regulatory ampR gene and beta-lactamase production was inducible.

CONCLUSIONS

This work provides further evidence of the molecular heterogeneity of beta-lactamases in Erwinia spp. and that plant-pathogenic enterobacterial species may constitute a reservoir of antibiotic resistance genes.