Abstract

Background:
Rats are the most difficult problem faced by farmers in every planting season. Various methods ranging from mechanical, chemical, and biological methods have been used but have not been efficient and effective.

Aim:
This study aimed to obtain a biological control agent for rats through the stages of isolation and characterization of Sarcocystis singaporensis derived from the feces of reticulated pythons or pythons (Malayopython reticulatus, M. reticulatus) in Surabaya, both morphologically and molecularly, and testing the potential for rat infection through blood hematology assessment.

Methods:
The method uses 10 reticulated pythons or pythons, then isolated sporocysts from feces with a float test, to see the morphology using an Optilab microscope, after which molecular characterization is carried out using polymerase chain reaction (PCR) with specific primers 18S rRNA specific for S. singaporensis with a target of 900-1,000 bp, then the results obtained are continued with sequencing and phylogenetic tree analysis also including reference sequences of S. singaporensis from GenBank. In addition, a potential infection test was conducted on rats in two experiments. Experiment 1 consisted of four treatment groups: control, doses of 4,000 sporocysts, 75,000 sporocysts, and 200,000 sporocysts administered orally for 14 days, followed by blood sampling for a complete blood count. Experiment 2 consisted of three treatment groups: doses of 300,000 sporocysts, 400,000 sporocysts, and 500,000 sporocysts to observe more severe impacts due to treatment, including death without necropsy and blood sampling for a complete blood count.

Results:
The research results showed that sporocysts from the feces of reticulated pythons, both morphologically and molecularly, were identical to S. singaporensis.

Conclusion:
The Surabaya isolate was proven to cause death in mice at a dose of 500,000 sporocysts.

Key words: S. singaporensis; Rats; Python snake; Sporocyst.