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RAA Enzyme Is a New Family of Class A Extended-Spectrum β-Lactamase from Riemerella anatipestifer Strain RCAD0122
Hongyan Luo1, Dekang Zhu2, Mengru Li1
1College of Veterinary Medicine, Southwest University, Chongqing, China.
Antimicrobial Agents and Chemotherapy
|January 3, 2022
Summary
A novel beta-lactamase gene, blaRAA-1, was discovered in Riemerella anatipestifer, encoding an extended-spectrum beta-lactamase (ESBL) with hydrolysis activity. While transferable, this gene is not currently widespread.
Area of Science:
- Microbiology
- Genomics
- Drug Resistance
Background:
- Riemerella anatipestifer is a significant pathogen in poultry.
- The emergence of antibiotic resistance, particularly beta-lactamases, poses a threat to animal and public health.
Purpose of the Study:
- To identify and characterize novel beta-lactamase genes in Riemerella anatipestifer.
- To investigate the genetic basis and transferability of extended-spectrum beta-lactamase (ESBL) production.
Main Methods:
- Whole-genome sequencing of Riemerella anatipestifer isolate RCAD0122.
- Bioinformatic analysis to identify beta-lactamase genes.
- Kinetic assays of purified enzyme.
- Natural transformation experiments.
- Epidemiological surveillance.
Main Results:
- Discovery of a novel chromosomally located class A ESBL gene, blaRAA-1.
- The encoded enzyme, RAA-1, exhibits ESBL-like hydrolysis activity and shares <=65% amino acid identity with known beta-lactamases.
- The blaRAA-1 gene is transferable to homologous strains via natural transformation.
- Epidemiological data indicates blaRAA-1 is not currently prevalent.
Conclusions:
- A novel ESBL, RAA-1, has been identified in Riemerella anatipestifer, contributing to the understanding of antimicrobial resistance mechanisms.
- The transferability of blaRAA-1 highlights the potential for its spread within bacterial populations.
- Current low prevalence suggests a need for ongoing monitoring of this resistance gene.
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