Certain Epidemiological Aspects of AeromonasHydrophila Infection in Chickens

Awaad, M. H. H., M. E. Hatem, W. A. A. El-Ghany, A. El-Sawy, and A. Fathi., "Certain Epidemiological Aspects of AeromonasHydrophila Infection in Chickens", Journal of American Science, vol. 7, issue 4, 2011.


Aeromonashydrophila (A. hydrophila) is one of enteric poultry pathogens of public health importance.This work was designed to investigate certain epidemiological aspects of A. hydrophilaincluding its viability, cycleof infection and its pathogenicity to chicks. A gentamicin resistant A. hydrophila strain (GR A. hydrophila strain)was prepared. The results showed that GR A. hydrophila survived in water for 26 days at room temperature and alsoit could be persist in chicken crates, feces, ration, saw dust and straw for 11, 9, 23, 22 and 17 days, respectively. GRA. hydrophila could induce 8.3% embryonic mortality after dipping of the eggs in infected broth culture. Hatchedchicks from GR A. hydrophila infected eggs showed mortalities reaching 13.3 and 1.7 % during 1st and 2nd weekpost hatching, respectively. Survived infected chicks exhibited signs and lesions of omphalitis, enteritis andsepticaemia and depression in heir weight gain. The rate of GR A. hydrophila re-isolation from dead embryosreached 100%, while it was 95.6, 26, 8.7, 4.4, 2.2 and 4.3% from intestine, liver, heart, spleen, kidney and lung,respectively in sacrificed survivors. Fecal shedding of GR A. hydrophila in chicken breeders revealed higherpercentage in orally infected birds than subcutaneously infected ones. Addition of probiotic to the ration of orallyinfected group resulted in lowering the shedding rate. Re-isolation of the organism from egg shells reached 12 % inorally infected breeders compared to 4 % in orally infected probiotic treated birds. Samples taken from reproductiveand internal organs of parent chicken hens were negative for GR A. hydrophila re-isolation. In conclusion; GR A.hydrophila survives for several weeks in contaminated water, ration and litter. The organism may infect birds byoral route and can colonize intestine. GR A. hydrophila is not congenitally transferred as ovary and oviduct do notplay a role in dissemination of A. hydrophila infection. Addition of probiotic to the ration can reduce fecal sheddingrate as well as re-isolation of A. hydrophila from the egg shells.



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