The current epidemiological status of infectious coryza and efficacy of PoulShot Coryza in specific pathogen-free chickens

Infectious coryza (IC) is an infectious disease caused by Avibacterium (Av.) paragallinarum. IC is known to cause economic losses in the poultry industry via decreased egg production in layers. Between 2012 and 2013, Av. paragallinarum was isolated from seven chicken farms by Chungbuk National University. We identified Av. paragallinarum, the causative pathogen of IC by polymerase chain reaction (PCR) and serovar serotype A, by multiplex PCR. Antibiotic sensitivity tests indicated that a few field-isolated strains showed susceptibility to erythromycin, gentamicin, lincomycin, neomycin, oxytetracycline, spectinomycin, and tylosin. A serological survey was conducted to evaluate the number of flocks that were positive for Av. paragallinarum by utilizing a HI test to determine the existence of serovar A. Serological surveys revealed high positivity rates of 86.4% in 2009, 78.9% in 2010, 70.0% in 2011, and 69.6% in 2012. We also challenged specific pathogen-free chickens with isolated domestic strains, ADL121286 and ADL121500, according to the measured efficacy of the commercial IC vaccine, PoulShot Coryza. We confirmed the effectiveness of the vaccine based on relief of clinical signs and a decreased re-isolation rate of ADL121500 strain. Our results indicate IC is currently prevalent in Korea, and that the commercial vaccine is effective at protecting against field strains.

Identificação de Avibacterium paragallinarum em frangos de corte e poedeiras comerciais no Estado de Pernambuco / Avibacterium paragallinarum identification in broiler and commercial laying hens in the state of Pernambuco, Brazil

As aves da indústria avícola brasileira são suscetíveis a surtos de doenças infecciosas relacionadas a perdas econômicas, principalmente por enfermidades infecciosas causadas por Mycoplasma, Avibacterium paragallinarum e vírus que acometem o trato respiratório. Objetivou-se neste estudo pesquisar o envolvimento de A. paragallinarum em surto de doença respiratória aviária. Foram coletados 18 swabs da região infraorbitária dos seios nasais de aves, sendo seis amostras de frangos de corte com sinais clínicos e 12 de poedeiras com sinais clínicos. As amostras foram cultivadas em meios específicos para o agente e também testadas com a técnica molecular Reação em Cadeia de Polimerase. Das amostras analisadas no isolamento, 100% foram negativas. Na PCR, duas (16,66%) foram positivas. A detecção de A. paragallinarum na PCR em galinhas poedeiras com sinais clínicos respiratótios indica que esta bactéria está associada à etiologia da síndrome respiratória das aves nas granjas no estado de Pernambuco...

Pullets of the Brazilian poultry industry are susceptible to outbreaks of infectious diseases with economic losses, mainly caused by Mycoplasma, Avibacterium paragallinarum and viruses affecting the respiratory tract. The objective of this study was to verify the involvement of A. paragallinarum in an outbreak of avian respiratory disease. Eighteen swabs from the infra-orbital sinuses were collected, six samples from broilers and twelve from hens with clinical signs. The samples were cultured in specific media for the agent and also tested with the molecular technique of Polymerase Chain Reaction (PCR). All samples cultured in specific media were negative; PCR revealed two samples (16.66%) as positive. The detection of A. paragallinarum by PCR in laying hens with clinical respiratory signs indicates that this bacterium is associated with the etiology of respiratory syndrome in poultry farms in the state of Pernambuco...