Poultry meat is one of the major animal protein sources necessary to meet the global protein demand. Sustainability in broiler production is the key to achieving its continuous supply, and broiler breeders play a critical role in maintaining this sustainability by providing good quality chicks. Colibacillosis, the disease caused by avian pathogenic Escherichia coli (APEC), causes severe economic losses to the poultry industry globally. Moreover, APEC causes an additional burden among broiler breeders, such as a decrease in egg production and mortality among these birds. There is vertical transmission of APEC to the broiler chicks through eggs, resulting in increased first-week mortality and subsequent horizontal transmission at the hatchery. In this regard, the vertical transmission of antibiotic resistance genes is another concern that needs attention. Controlling several diseases in broiler breeders would possibly reduce the first-week mortality in chicks, thereby maintaining the production level. For that, constant monitoring of the bacterial populations is critical. Moreover, amidst the increased antibiotic resistance pattern, more focus on alternative treatment strategies like vaccines, probiotics, and bacteriophages is necessary. Future research focusing on strategies to mitigate APEC in broiler breeders would be one of the finest solutions for sustainable broiler production.

Avian pathogenic Escherichia coli (APEC) causes colibacillosis in poultry, a leading cause of poultry mortality worldwide. It is crucial to control APEC in broiler breeders as it is vertically transferred to progeny via eggs. However, there is only limited knowledge on the current APEC population in breeders. This study characterized 28 APEC strains isolated from broiler breeders with colibacillosis. The genotypic-virulence characteristics as well as antimicrobial and heavy-metal resistance patterns of the isolates were determined. Results showed that O88 is the most prevalent serogroup and B2 is the predominant phylogenetic group. Among virulence genes, genes for iron acquisition (iroN and iutA), protectins (iss and ompT), and toxin production (hlyF) exhibited the highest prevalence. Further, 93% of the isolates carried at least one antimicrobial resistance gene with highest prevalence for tetracycline gene tetA. Among the isolates, 10.71% exhibited multidrug resistance. All isolates carried at least one heavy-metal resistance gene with the highest prevalence for arsenic gene arsC and the highest resistance towards silver. Our findings provide insight into the characteristics of current APEC populations in broiler breeders in Mississippi. This will help future research on the pathogenesis of APEC and the development of effective prevention and control strategies against APEC in broiler breeders.