ARS | Publication request: IncA/C Plasmid-Mediated Florfenicol Resistance in the Catfish Pathogen Edwardsiella ictaluri

Submitted to: Antimicrobial Agents and Chemotherapy
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 12, 2008
Publication Date: November 24, 2008
Citation: Welch, T.J., Evenhuis, J., White, D.G., Mcdermott, P.F., Harbottle, H., Miller, R., Griffin, M., Wise, D. 2008. IncA/C Plasmid-Mediated Florfenicol Resistance in the Catfish Pathogen Edwardsiella ictaluri. Antimicrobial Agents and Chemotherapy. 53(2):845-846.

Interpretive Summary: The antibiotic florfenicol has recently been approved for use in US aquaculture for the treatment of several infectious diseases that affect cultured finfish including Enteric Septicemia of Catfish caused by Edwardsiella ictaluri. Here we report the first identification of florfenicol resistance in E. ictaluri. The resistance observed in this isolate was associated with a mobile plasmid conferring resistance to multiple antimicrobial drugs. It is also relevant to note that the plasmid identified in this study confers decreased sensitivity to all three antimicrobial drugs that are currently approved for use in US aquaculture and therefore further dissemination of this plasmid could have a profound affect on the performance of antimicrobial drug use in the US aquaculture industry.

Technical Abstract: Florfenicol has recently been approved for the treatment of enteric septicemia of catfish caused by Edwardsiella ictaluri. Here we report the identification of florfenicol resistance in a clinical isolate of E. ictaluri. Resistance in this isolate is associated with a mobile IncA/C plasmid conferring a multidrug resistance phenotype.