Phylogeny and S1 Gene Variation of Infectious Bronchitis Virus Detected in Broilers and Layers in Turkey.
The avian coronavirus infectious bronchitis virus (AvCoV-IBV) is recognized as an important global pathogen because new variants are a continuous threat to the poultry industry worldwide. This study investigates the genetic origin and diversity of AvCoV-IBV by analysis of the S1 sequence derived from 49 broiler flocks and 14 layer flocks in different regions of Turkey. AvCoV-IBV RNA was detected in 41 (83.6%) broiler flocks and nine (64.2%) of the layer flocks by TaqMan real-time RT-PCR. In addition, AvCoV-IBV RNA was detected in the tracheas 27/30 (90%), lungs 31/49 (62.2%), caecal tonsils 7/22 (31.8%), and kidneys 4/49 (8.1%) of broiler flocks examined. Pathologic lesions, hemorrhages, and mononuclear infiltrations were predominantly observed in tracheas and to a lesser extent in the lungs and a few in kidneys. A phylogenetic tree based on partial S1 sequences of the detected AvCoV-IBVs (including isolates) revealed that 1) viruses detected in five broiler flocks were similar to the IBV vaccines Ma5, H120, M41; 2) viruses detected in 24 broiler flocks were similar to those previously reported from Turkey and to Israel variant-2 strains; 3) viruses detected in seven layer flocks were different from those found in any of the broiler flocks but similar to viruses previously reported from Iran, India, and China (similar to Israel variant-1 and 4/91 serotypes); and 4) that the AVCoV-IBV, Israeli variant-2 strain, found to be circulating in Turkey appears to be undergoing molecular evolution. In conclusion, genetically different AvCoV-IBV strains, including vaccine-like strains, based on their partial S1 sequence, are circulating in broiler and layer chicken flocks in Turkey and the Israeli variant-2 strain is undergoing evolution.
A University of Istanbul, Veterinary Faculty, Department of Virology, Avcilar, Istanbul, Turkey.
Huseyin
H
Yilmaz
A University of Istanbul, Veterinary Faculty, Department of Virology, Avcilar, Istanbul, Turkey.
Eda
E
Altan
A University of Istanbul, Veterinary Faculty, Department of Virology, Avcilar, Istanbul, Turkey.
Utku Y
UY
Cizmecigil
B University of Istanbul, Veterinary Faculty, Department of Pathology, Avcilar, Istanbul, Turkey.
Aydin
A
Gurel
B University of Istanbul, Veterinary Faculty, Department of Pathology, Avcilar, Istanbul, Turkey.
Gulay Yuzbasioglu
GY
Ozturk
B University of Istanbul, Veterinary Faculty, Department of Pathology, Avcilar, Istanbul, Turkey.
Ozge Erdogan
OE
Bamac
A University of Istanbul, Veterinary Faculty, Department of Virology, Avcilar, Istanbul, Turkey.
Ozge
O
Aydin
C Pirbright Institute, Compton Laboratory, Compton, Newbury, Berkshire, RG20 7NN, UK.
Paul
P
Britton
D Division of Comparative Biomedical Sciences, OIE/FAO and Istituto Zooprofilattico, Sperimentale delle Venezie, Viale dell'Università, 10, 35020, Legnaro (Padova), Italy.
Isabella
I
Monne
E University of Firat, Veterinary Faculty, Department of Microbiology, Elazig, Turkey.
Burhan
B
Cetinkaya
F Institute of Ageing and Chronic Disease and School of Veterinary Science, University of Liverpool, Leahurst, Neston, CH64 7TE, UK.
Kenton L
KL
Morgan
G Department of Diagnostic Medicine and Pathobiology, College of Veterinary Medicine, Kansas State University, 1800 Denison Avenue, Manhattan, KS 66506.
Bonto
B
Faburay
G Department of Diagnostic Medicine and Pathobiology, College of Veterinary Medicine, Kansas State University, 1800 Denison Avenue, Manhattan, KS 66506.
Juergen A
JA
Richt
A University of Istanbul, Veterinary Faculty, Department of Virology, Avcilar, Istanbul, Turkey.
Nuri
N
Turan
D000818:Animals; D036022:Capsid Proteins / Q000235:genetics* / Q000378:metabolism; D002645:Chickens; D018352:Coronavirus Infections / Q000662:veterinary* / Q000821:virology; D014644:Genetic Variation; D001351:Infectious bronchitis virus / Q000145:classification / Q000235:genetics*; D010802:Phylogeny; D011201:Poultry Diseases / Q000821:virology*; D060888:Real-Time Polymerase Chain Reaction / Q000662:veterinary; D017423:Sequence Analysis, RNA / Q000662:veterinary; D014421:Turkey
D036022:Capsid Proteins
AvCoV; IBV; S1 sequence; avian coronavirus; chicken; phylogenetic