Studies on fowl spirochetosis in Khartoum State

Abstract

Spirochetosis was reported in different poultry farms in Khartoum state. Clinical disease was recorded among different ages and breeds. Based on morphology of the organism, presence of argas persicus clinical signs and post mortem lesions in inoculated chicken, the organism was confirmed as Borrelia anserina. The disease was studied in three different age groups of chicken (Chick, grower and adult) using four field isolates .Short incubation period (2-3) days, severe clinical sings, extensive short duration of spirochete 3-4 day and enlargement and mottling of spleen were shown in older birds. Mild clinical signs, extensive prolong spirochetemia 10-15 days, slight enlargement of the spleen were the main features of the disease in chicks. Histopathological examination of organs of infected birds showed difference between the isolates .Two isolates showed severe changes and damage of the spleen. Disease in local breeds and pigeon was also studied. A trail was carried out to isolate the causative agent in bacteriological media but the organism failed to grew albeit that the organism was isolated in embryonated eggs via different routes successfully. Serological studies showed that Agglutination and immobilization tests were both comparable in detecting Borrelia anserina antibodies. Antigenic and pathogenic study of the 4 field isolate revealed that two isolates (namely:Butri and Soba1) were more pathogenic. xiii Cross protection test between the field isolates showed that the immune response induced by infection with two of the isolate will protect against challenge by the four isolate studied. The effect of storage condition and duration on viability and infectivity of Borrelia anserina was also investigated. In other part of the study, molecular characterization of Borrelia anserina was investigated. After extraction of DNA and amplification no results were obtained.