Molecular Based Survey of Pathogens Associated with Respiratory Disease Outbreaks in Broiler Chickens in Accra

Abstract

Respiratory diseases in poultry are caused by a host of pathogens that act either singly or in association with each other. The clinical signs elicited by some poultry respiratory pathogens are similar and may confuse diagnostic efforts. Definitive diagnoses involving the use of sensitive, robust and rapid laboratory method are important for the identification and differentiation of specific agent(s) during infection. Our study aimed at identifying the involvement of Infectious Bronchitis Virus, Newcastle Disease Virus and Mycoplasma gallisepticum (MG) in outbreaks of respiratory diseases in chickens in the Ga-East district of Greater Accra using the Polymerase Chain Reaction technique (PCR). Twenty (20) trachea swabs were obtained from four chicken flocks (5 per flock) with acute respiratory diseases. RNA and DNA were extracted from each sample individually. The S1 glycoprotein gene, MgC₂ gene and fusion protein gene of IBV, MG and NDV respectively, was individually target in a single tube PCR reaction. Amplicons were resolved on a 1% agarose gel stained with Ethidium bromide and visualized with a UV trans-illuminator. Twenty percent (20%) of samples tested negative to all three pathogens. IBV and NDV as single agents were detected in 40% and 20% of the samples respectively. Twenty percent (20%) of the samples were found to be co-infected with IBV and NDV. None of the samples tested positive to MG. IBV and NDV play major roles in outbreaks of respiratory diseases in commercial broiler chickens in Ga-East district of Accra.

Keywords: Respiratory pathogens, Broilers, Ghana, Polymerase Chain Reaction