چکیده انگلیسی مقاله |
Bacterial co-infections can probably influence the pathogenicity of H9N2 low pathogenic avian influenza virus (AIV). This study aimed to evaluate the effect of exposure time to Escherichia coli (O:2) on the pathogenicity of H9N2 AIV in broiler chickens. Three hundred and sixty broiler chickens were randomly allocated to six equal groups. At the age of 26 days, all chicks except groups 5 and 6 were inoculated intra-nasally with H9N2 virus. At the same time, the birds in groups 1 and 5 were infected with E. coli via spray route. Birds in groups 3 and 2 were infected with E. coli three days prior to and three days post AI challenge, respectively. Mortality rates, clinical signs, gross and microscopic lesions, excretion and duration of virus shedding in faecal and tracheal samples and seroconversion to H9N2 virus were assessed in the challenged groups. The highest mortality rate was observed in chickens inoculated with H9N2 followed by E. coli. The most severe clinical signs, gross lesions, mortality rate and virus detection were observed at day 6 post challenge (PC) in birds of group 2, while the duration of virus shedding was longer in group 3 (E. coli followed by H9N2) than other groups. In conclusion, E. coli infection prior to, after or concurrently with H9N2 virus infection could exacerbate the adverse effects of the virus. Our results indicate that E. coli and H9N2 together can mutually exacerbate the condition of either disease in broiler chicks as compared to single infected birds. |
نویسندگان مقاله |
n. mosleh | avian diseases research center, school of veterinary medicine, shiraz university, shiraz, iran; department of clinical sciences, school of veterinary medicine, shiraz university, shiraz, iran سازمان اصلی تایید شده: دانشگاه شیراز (Shiraz university)
h دادرس | department of clinical sciences, school of veterinary medicine, shiraz university, shiraz, iran سازمان اصلی تایید شده: دانشگاه شیراز (Shiraz university)
k اساسی | avian diseases research center, school of veterinary medicine, shiraz university, shiraz, iran; department of clinical sciences, school of veterinary medicine, shiraz university, shiraz, iran سازمان اصلی تایید شده: دانشگاه شیراز (Shiraz university)
محمدجواد taebipour | m j graduated from school of veterinary medicine, shiraz university, shiraz, iran سازمان اصلی تایید شده: دانشگاه شیراز (Shiraz university)
سید سعید توحیدی فر | s s graduated from school of veterinary medicine, shiraz university, shiraz, iran سازمان اصلی تایید شده: دانشگاه شیراز (Shiraz university)
gh فرجانی کیش | graduated from school of veterinary medicine, shiraz university, shiraz, iran; department of pathobiology, school of veterinary medicine, lorestan university, khorramabad, iran سازمان اصلی تایید شده: دانشگاه لرستان (Lorestan university)
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