AVIAN CORONAVIRUS IN EGYPT: EPIDEMIOLOGICAL ACUITIES AND PATHOGENICITY IN COMMERCIAL BROILER CHICKENS

Infectious bronchitis virus (IBV), a gamma coronavirus, is responsible for a highly contagious disease in chickens resulting in substantial economic losses to the poultry industry around the world. The emergence of new types of IBVs is considered one of the major concerns regarding to IB. A prelimi...

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Main Authors: Ali Mahmoud, Reham ElBakrey, Shimaa Mansour, Amal Eid
Format: Article
Language:English
Published: University of Ljubljana Press (Založba Univerze v Ljubljani) 2021-12-01
Series:Slovenian Veterinary Research
Subjects:
Online Access:https://www.slovetres.si/index.php/SVR/article/view/1432
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author Ali Mahmoud
Reham ElBakrey
Shimaa Mansour
Amal Eid
author_facet Ali Mahmoud
Reham ElBakrey
Shimaa Mansour
Amal Eid
author_sort Ali Mahmoud
collection DOAJ
description Infectious bronchitis virus (IBV), a gamma coronavirus, is responsible for a highly contagious disease in chickens resulting in substantial economic losses to the poultry industry around the world. The emergence of new types of IBVs is considered one of the major concerns regarding to IB. A preliminary diagnosis of IB was made based on the flock history and the characteristic pathologic findings. In the cur-rent study, we investigated the outbreaks of respiratory signs and diarrhea in broiler chickens (n=77) be-tween 2014 and 2018. Upon necropsy, the affected chickens showed tracheal and kidney lesions, sugges-tive of IBV. The IBV was detected in 33 farms using real-time reverse transcription-PCR, targeting the nu-cleocapsid gene. Investigation of IBV among vaccinated chickens would considerably ameliorate the pre-sent immunization programs and support the development of more effective vaccines. The IBV was de-tected in vaccinated birds (45.8%). The virus was isolated in fertile chicken eggs, which revealed embry-onic mortality (20-40%) within 5-7 days after the 3rd passage, small embryos or dwarfing up to 30.2% versus non-inoculated ones. Virus pathogenicity was determined experimentally in 7-day-old broiler chickens inoculated oculo-nasally with 104 median embryo infective dose. The infected birds experienced severe respiratory signs, diarrhea and tracheal and renal lesions. The virus displayed a wide range of tissue tropism, particularly in the trachea, lungs and kidneys, and was shed via the respiratory tract and cloaca. The results emphasized the significance of conducting a comprehensive surveillance of IBV infections among chicken flocks in Egypt and provide significant insights into the virulence properties of IBV. Further studies of nucleotide sequence analysis of circulating IBV strains and evaluation of vaccine efficacy are needed.
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spelling doaj.art-0e3443ada7fd4d37b0841f4c23ef73412024-04-03T12:38:30ZengUniversity of Ljubljana Press (Založba Univerze v Ljubljani)Slovenian Veterinary Research1580-40032385-87612021-12-015824-Suppl10.26873/SVR-1432-2021AVIAN CORONAVIRUS IN EGYPT: EPIDEMIOLOGICAL ACUITIES AND PATHOGENICITY IN COMMERCIAL BROILER CHICKENSAli Mahmoud0Reham ElBakrey1Shimaa Mansour2Amal Eid3Department of Avian and Rabbit Medicine, Faculty of Veterinary Medicine, Zagazig University, Zagazig, Sharkia 44511, Egypt. - Veterinary Medicine Directorate, Mansoura, Dakahlia, Egypt.Department of Avian and Rabbit Medicine, Faculty of Veterinary Medicine, Zagazig University, Zagazig, Sharkia 44511, EgyptDepartment of Virology, Faculty of Veterinary Medicine, Zagazig University, Zagazig, Sharkia 44511, Egypt.Department of Avian and Rabbit Medicine, Faculty of Veterinary Medicine, Zagazig University, Zagazig, Sharkia 44511, Egypt. Infectious bronchitis virus (IBV), a gamma coronavirus, is responsible for a highly contagious disease in chickens resulting in substantial economic losses to the poultry industry around the world. The emergence of new types of IBVs is considered one of the major concerns regarding to IB. A preliminary diagnosis of IB was made based on the flock history and the characteristic pathologic findings. In the cur-rent study, we investigated the outbreaks of respiratory signs and diarrhea in broiler chickens (n=77) be-tween 2014 and 2018. Upon necropsy, the affected chickens showed tracheal and kidney lesions, sugges-tive of IBV. The IBV was detected in 33 farms using real-time reverse transcription-PCR, targeting the nu-cleocapsid gene. Investigation of IBV among vaccinated chickens would considerably ameliorate the pre-sent immunization programs and support the development of more effective vaccines. The IBV was de-tected in vaccinated birds (45.8%). The virus was isolated in fertile chicken eggs, which revealed embry-onic mortality (20-40%) within 5-7 days after the 3rd passage, small embryos or dwarfing up to 30.2% versus non-inoculated ones. Virus pathogenicity was determined experimentally in 7-day-old broiler chickens inoculated oculo-nasally with 104 median embryo infective dose. The infected birds experienced severe respiratory signs, diarrhea and tracheal and renal lesions. The virus displayed a wide range of tissue tropism, particularly in the trachea, lungs and kidneys, and was shed via the respiratory tract and cloaca. The results emphasized the significance of conducting a comprehensive surveillance of IBV infections among chicken flocks in Egypt and provide significant insights into the virulence properties of IBV. Further studies of nucleotide sequence analysis of circulating IBV strains and evaluation of vaccine efficacy are needed. https://www.slovetres.si/index.php/SVR/article/view/1432IBVRT-PCRpathogenicityclinical scoringhistopathologynephropathogenic strain
spellingShingle Ali Mahmoud
Reham ElBakrey
Shimaa Mansour
Amal Eid
AVIAN CORONAVIRUS IN EGYPT: EPIDEMIOLOGICAL ACUITIES AND PATHOGENICITY IN COMMERCIAL BROILER CHICKENS
Slovenian Veterinary Research
IBV
RT-PCR
pathogenicity
clinical scoring
histopathology
nephropathogenic strain
title AVIAN CORONAVIRUS IN EGYPT: EPIDEMIOLOGICAL ACUITIES AND PATHOGENICITY IN COMMERCIAL BROILER CHICKENS
title_full AVIAN CORONAVIRUS IN EGYPT: EPIDEMIOLOGICAL ACUITIES AND PATHOGENICITY IN COMMERCIAL BROILER CHICKENS
title_fullStr AVIAN CORONAVIRUS IN EGYPT: EPIDEMIOLOGICAL ACUITIES AND PATHOGENICITY IN COMMERCIAL BROILER CHICKENS
title_full_unstemmed AVIAN CORONAVIRUS IN EGYPT: EPIDEMIOLOGICAL ACUITIES AND PATHOGENICITY IN COMMERCIAL BROILER CHICKENS
title_short AVIAN CORONAVIRUS IN EGYPT: EPIDEMIOLOGICAL ACUITIES AND PATHOGENICITY IN COMMERCIAL BROILER CHICKENS
title_sort avian coronavirus in egypt epidemiological acuities and pathogenicity in commercial broiler chickens
topic IBV
RT-PCR
pathogenicity
clinical scoring
histopathology
nephropathogenic strain
url https://www.slovetres.si/index.php/SVR/article/view/1432
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AT shimaamansour aviancoronavirusinegyptepidemiologicalacuitiesandpathogenicityincommercialbroilerchickens
AT amaleid aviancoronavirusinegyptepidemiologicalacuitiesandpathogenicityincommercialbroilerchickens