Abstract

Fowl spirochaetosis is an acute septicemic disease of avian species caused by Borrelia anserina and is transmitted by a soft tick known as Argas persicus. In this study, theArgas ticks were collected for the isolation and characterization of the B. anserina. Of the 220 tick samples, 40 (18%) showed granular growth in BSK-H medium. Morphological examination was performed by using the dark field and phase contrast microscope. Furthermore, the entire batch of 40 samples reacted positively to polyclonal IgG anti-Borrelia sera in indirect immunofluorescent assay. For molecular characterization of the isolates, a polymerase chain reaction (PCR) was applied using gene specific primers for flagellin gene (fla B). This PCR amplified a product of 750 bp from the bacteria of 32 (80%) out of 40 positive samples. The fla B gene from five samples were sequenced; Sequence and phylogenetic analysis indicated that these isolates belong to B. anserinaand clustered apart from other species of Borrelia. This is the first report presenting the phylogenetic analysis of B. anserina from Pakistan, despite the fact that it remained one of the most devastating diseases for poultry in the region. The results of this study shed light on the Borrelia population in Pakistan and emphasize the importance of using molecular methods to understand the epidemiology and nature of the bacterium. Such understanding is essential in an effort to control the number and impact of outbreaks that are occurring in poultry industry.

Key words: B. anserina, spirochaetosis, poultry diseases, Pakistan, soft ticks