Theses and Dissertations


Tianmin Li

Issuing Body

Mississippi State University


Zhang, Li

Committee Member

Sukumaran, Anuraj

Committee Member

Cheng, Wen-Hsing

Committee Member

Kiess, Aaron S.

Date of Degree


Original embargo terms

Complete embargo for 1 year

Document Type

Graduate Thesis - Open Access


Food Safety

Degree Name

Master of Science


College of Agriculture and Life Sciences


Department of Poultry Science


Avian pathogenic Escherichia. coli (APEC) and Campylobacter are pathogenic threats to poultry and human health, respectively. In this study, the prevalence of these pathogens in Mississippi broilers and their antimicrobial resistance (AMR) properties were investigated, and a multidrug-resistant APEC strain (APEC-O2-MS1170) was further explored by whole-genome sequencing (WGS). The efficacy of in ovo injection of Lactobacillus in reducing the APEC in broilers was evaluated. Results revealed a high prevalence of APEC and Campylobacter in broilers and broiler products. A lot of isolates were resistant to antibiotics of different sorts. Moreover, the in ovo administration of Lactobacillus did not reduce the incidence of APEC. The WGS of APEC-O2-MS1170 revealed its detailed AMR and virulence properties and alerted a potential zoonotic risk. In conclusion, the Lactobacillus did not reduce the incidence of APEC in broilers, and the prevalence and AMR of APEC and Campylobacter are still challenges faced by the poultry industry.



Avian pathogenic Escherichia coli||Campylobacter||multidrug-resistant||virulence gene||whole-genome sequencing