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ARS Home » Southeast Area » Mississippi State, Mississippi » Poultry Research » Research » Publications at this Location » Publication #424867
Research Project: Intervention Strategies to Mitigate Avian Escherichia coli Infections and Antimicrobial Resistance in the Poultry Environment

Location: Poultry Research

Title: APPLIED RESEARCH NOTE: Development of an Avian Pathogenic Escherichia coli infection model in layer chickens

Author
item Robinson, Kelsy
item Magee, Christopher
item FORD, A - Oklahoma State University
item Evans, Jeffrey

Submitted to: Poultry Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/2/2025
Publication Date: N/A
Citation: N/A

Interpretive Summary: Avian Pathogenic Escherichia coli (APEC) is responsible for the systemic disease colibacillosis which poses a serious threat to the health, welfare, and productivity of commercial poultry. In layer chickens APEC infections result in significant economic losses due to decreased egg production during the peak production and late lay periods. The ability to develop and test novel methods of control for APEC depends upon the availability of robust disease models. While multiple disease models have been developed for APEC infections in broiler chickens, limited publications discuss APEC models in layers. This study reports the development of an effective disease model capable of mimicking APEC airsacculitis seen in layer production systems.

Technical Abstract: Development of novel means of control for Avian Pathogenic Escherichia coli (APEC) is dependent upon robust disease models. While multiple APEC airsacculitis and colibacillosis models have been described in the literature for broiler chickens, only a few have focused on layer chickens with none investigating the common airway route of infection. We describe here two studies focused on the development of an APEC airsacculitis disease model in layer chickens. In the first study, four-week-old cockerels were inoculated with one of four APEC strains at one of four doses (0, 1 x 102, 1 x 104, and 1 x 106 CFU/mL) and evaluated for signs of airsacculitis for 10 days post-inoculation. While a difference in disease timing and severity by strain and dose was observed, none of the strains exhibited a strong enough disease presence to make the model viable for testing novel therapeutics. Therefore, a second study was undertaken in which 14-week-old hens previously vaccinated against Mycoplasma gallisepticum were inoculated with a virulent APEC strain. Evaluation of airsacculitis scores at 2-, 5-, and 7-days post-inoculation revealed a consistent increase in airsacculitis incidence. While further studies are needed to validate this model, the current results indicate the combination of Mycoplasma gallisepticum vaccination with APEC infection to be a promising APEC disease model for use in layer chickens.