Effects of different phylotypes of avian pathogenic Escherichia coli isolated from broiler chickens with colibacillosis on heterophils functional activities: an in vitro study.

Avian pathogenic Escherichia coli (APEC) is a major cause of colibacillosis and is associated with economic losses to the poultry production worldwide. Heterophils are the first line of immune defense of the avian host against invasive pathogens. In this study, APEC isolates from chickens with colibacillosis were assigned to phylogenetic groups and immunological activities of heterophils against these groups were examined. A total of 92 APEC isolates was obtained from 106 samples of diverse organs collected from chickens with colibacillosis from different farms in West Azerbaijan province, Iran. Isolates were assigned to phylogenetic groups based on the Clermont triplex PCR method, and immunological activities (including phagocytosis, respiratory burst and bacterial killing) of heterophils against these groups were examined. As results, the frequency of A, B1, B2 and D groups were 35.87, 44.57, 5.43 and 14.13%, respectively. In addition, opsonized Escherichia coli isolates belonging to B1 group significantly enhanced the level of respiratory burst (0.52 ± 0.02%) while the killing level of them was significantly lower than the other groups (29.40 ± 5.09%). There was no significant difference in phagocytic activity of heterophils against the phylogenetic groups. In conclusion, incomplete immune responses to B1 phylogenetic group maybe a principal cause of mortality by colibacillosis caused by this group. It is suggested to study heterophilic immune reaction against E. coli phylogenetic group for development of effective prevention strategy.

Citation

Somayyeh Ahmadi, Habib Dastmalchi Saei, Seyed Meisam Abtahi Froush, Mohammad Zavarshani. Effects of different phylotypes of avian pathogenic Escherichia coli isolated from broiler chickens with colibacillosis on heterophils functional activities: an in vitro study. Veterinaria italiana. 2021 Dec 31;57(4):305-310

Mesh Tags

PMID: 35593493

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