Characterization of RASA-1, a novel class A extended-spectrum beta-lactamase from Riemerella anatipestifer

A novel chromosomally-located beta-lactamase gene, bla(RASA-1), was identified in Riemerella anatipestifer RA-CH-1. The RASA-1, encoded by bla(RASA-1), was a class A extended-spectrum beta-lactamase (ESBL), which shared 42.7% and 40.5% identities with the RAA-1 and CGA-1 beta-lactamase, respectively. Overexpression of RASA-1 in Escherichia coli confers broad resistance to beta-lactams and the purified native RASA-1 revealed ESBL-like hydro-lysis activity. Blasting in GenBank showed that bla(RASA-1) was exclusively detected in Riemerella anatipestifer. Moreover, sequence analysis revealed that this gene was located within the multi-resistance region of Riemerella anatipestifer genome.

Automated summary

A novel chromosomally-located beta-lactamase gene, bla(RASA-1), was identified in Riemerella anatipestifer RA-CH-1. The encoded RASA-1 is a class A extended-spectrum beta-lactamase (ESBL) that confers broad resistance to beta-lactams.