Med. Weter. 76 (4), 226-231, 2020
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| SAJID UMAR, HASAN ONGOR, ERHAN BAYRAKTAR,
HAZAL OZTURK GURGEN, BELGI DIREN SIGIRCI, ESRA SATIR,
KAYHAN OZKAN, NURI TURAN*, AYSUN YILMAZ*, AYDIN GUREL,
SEYYAL AK, BURHAN CETINKAYA**, HUSEYIN YILMAZ |
| First report on the molecular detection, phylogeny,
virological and pathological investigations of
Avibacterium paragallinarum in chickens in Turkey |
| Avibacterium paragallinarum is an important pathogen affecting the respiratory tract of chickens. There
is a paucity of information on the molecular characteristics and pathology of A. paragallinarum in Turkish
poultry flocks. In the present study, broiler and layer flocks (n = 2) suspected of viral infections with
serious respiratory signs and significant mortality were visited. Chickens showed various disease signs and
necropsy lesions, including purulent nasal discharge, respiratory distress, facial edema, sticky eyes, mucoid
tracheitis, hemorrhagic inflammation of the infraorbital sinuses along with fibrinous mass and conjunctivitis.
Histopathological lesions included loss of cilia along with necrosis and exfoliation of the superficial mucosal
epithelium of the trachea, facial cellulitis, dermatitis, fibrinous plasmatic edema and infiltration of inflammatory
cells, especially heterophils. A. paragallinarum was detected in tissue samples by species-specific polymerase
chain reaction (PCR). The sequencing and phylogenetic analysis of the core region of the hemagglutinin (HA)
gene revealed that Turkish strains detected here belonged to serotype A (serovar A1). They were related to
strains reported from India (VRDC), the United States (0083), and Japan (0221), which are representatives of
serovar A1. A homology of 88-90% was found between Indian strains and the Turkish strains detected in this
study. Surprisingly, only vaccine strains of infectious bronchitis virus (IBV) were detected as a co-infecting agent
in all samples positive for A. paragallinarum. Our findings suggest that A. paragallinarum may be an emerging
pathogen in Turkish poultry flocks, and direct PCR may facilitate rapid diagnosis of infectious coryza. These
results will also help to develop control strategies for A. paragallinarum. |
| Keywords: Avibacterium paragallinarum, chicken, PCR, histopathology, phylogenetic analysis, Turkey |