Evaluation of Different PCR Techniques in Diagnosis of Camel (Camellus Dromedary) Brucellosis in Sudan

Abstract

Fifteen tissue samples of lymph nodes and spleens from Brucella sero-positive camels were subjected to Four polymerase chain reaction (PCR) tests, which were, abortus melitensis ovis suis (AMOS) PCR, Bruce-ladder multiplex PCR, Multilocus Variable Number of Tandem Repeats (MLVA) and the Real-time PCR (RT-PCR). Extraction of Brucella DNA from tissue samples was done by heat, which was found to be satisfactory for conduction of the tests. Brucella species could be distinguished according to the banding pattern and the amplification fragment length polymorphisms which is a diagnostic tool of specific strains. In this study, we evaluated the performances of newly designed real-time PCR assays using TaqMan probes and targeting the insertion sequence IS711, for the detection of Brucella at genus level. Real-time PCR assays are easy-to-use, produce results faster than conventional PCR systems while reducing DNA contamination risks. The IS711-based real-time PCR assay is specific and highly sensitive and appears as an efficient and reproducible method for the rapid and safe detection of the genus Brucella. MLVA assay has the same advantages of multiplex PCR beside it can differentiate Brucella isolates on biovar level (genotyping). Bruce-ladder PCR assay is recommended for testing the seed cultures commonly used in the production of living Brucella vaccines (Rev-1, S19 and RB51) and in evaluating them in quality control laboratories and also in identification and differentiation of Brucella isolates. PCR techniques are recommended to be used for identification of Brucella instead of isolation, which is dangerous and complex.