Genetic and parasitological identification of Trypanosoma evansi infecting cattle in South Sulawesi, Indonesia

Background and Aim: Sulawesi is an Indonesian island located within the Wallacea region that contains a distinctive mix
of Asian and Australasian species. This distinctiveness extends to parasites, including Trypanosoma evansi, the cause of surra. Surra has non-specific clinical signs such as anemia, anorexia, weight loss, drop in milk production, and reproductive disorders which cause economic losses. Due to the trade of livestock, surra has spread in Indonesia from one island to another. The aim of this study was to investigate the trypanosomes infecting cattle in South Sulawesi, using internal transcribed spacer (ITS2) ribosomal DNA (rDNA) sequencing.

Materials and Methods: A total of 100 whole blood samples were collected from cattle in Makassar, South Sulawesi Province, Indonesia. All samples were tested using conventional parasitological methods (CPT), namely, thin blood smear, buffy coat smears, and polymerase chain reaction (PCR) testing. Positive PCR results were sequenced and phylogenetically analyzed.

Results: Only one of the 100 samples was found to be positive with microscopic observation; however, PCR analysis
revealed that 3% (3/100) of samples were positive. Sequencing identified the positive samples as T. evansi, China isolate (KU552344), with a homology of 99%. Two out of three sequences showed variations in ITS2 region.
Conclusion: Based on CPT and molecular analysis, T. evansiisolates from infected cattle in South Sulawesi demonstrate genetic diversity of ITS2 sequences.