Study of prevalence of Gallibacterium in chickens in Bangladesh

Abstract

The aim of the present study was to determine the prevalence of Gallibacterium spp. in chickens in Bangladesh through a cross-sectional study. A six months long study was conducted from July 2012 to December 2012 in the Chittagong and Gazipur districts. A questionnaire was used to record additional information, such as age of bird, kind of farm, sex, pathological lesion present, sample collection site etc. In total, 127 dead and live chickens were sampled of which 62 were broiler and 65 were layer birds. From these 127 chickens 156 swab samples were collected. All the swab samples were streaked onto blood agar base supplemented with 5% citrated bovine blood. After overnight incubation, if any colonies were found with about 1-2 mm in diameter plus a clear β-haemolytic zone, they were primarily considered as Gallibacterium. Such colonies were further tested with catalase and oxidase tests and those gave positive results were identified as Gallibacterium. They were subsequently preserved and finally tested with PCR using DNA from boiled isolates and previously published primer set to detect a 16S rRNA gene specific for Gallibacterium. The results disclose that the prevalence of Gallibacterium in chickens was about 20% and its prevalence in layer and broiler chickens were 12.9% and 26.2%, respectively (P>0.05). The isolation rate of Gallibacterium was higher from trachea compared with any other organs/sites. PCR test with the use of primers: 1133fgal (5’–TAT TCT TTG TTA CCA RCGG–3’) (Forward primer) and 114r (5’–GGT TTC CCC ATT CGG–3’) (reverse primer) might have poor sensitivity, if DNA is used from boiling of the isolates.