In vitro Antiparasitic Activity of Camel Milk against Blastocystis sp.

Aim: The aim of the current study was to investigate in vitro anti-protozoal activity of camel, cow, and goat raw milks against Blastocystis sp. strains isolated from symptomatic patients.

Place and Duration of Study: The study was carried out in two major health care centres of Makkah city, Saudi Arabia between 01 January and 30 March 2017.

Methodology: Stool specimens collected from patients and healthy individuals, were examined by microscopy and in vitro cultured using Dulbecco's modified Eagle medium. Cultures were examined after 24, 48, and 72 hrs. Blastocystis sp. subtyping was performed on genomic DNA extracts of positive cultures by polymerase chain reaction using sequence-tagged-site primers. Blastocystis sp. parasites susceptibility assays were performed in 2 ml final volumes seeded with 2x105 parasites and incubated for 48 h at 37°C. Concentrations of 250 µl/ml, 125 µl/ml, 62.5 µl/ml, 31.2 µl/ml, and 15.6 µl/ml of bovine, goat and camel raw milk were tested for their anti-parasitic activity against two Blastocystis sp. isolates identified as ST1 and ST3 subtypes. Metronidazole at (0.1 mg/ml) was used as positive antiparasitic control in all assays.

Results: Out of seven positive cultures, two isolates were identified as ST1 subtype and five isolates as ST3 subtype. A significant in vitro killing effect was obtained with camel raw milk at minimal concentration of 31.2 µl/ml compared to cow raw milk (P<0.05) and goat raw milk (P<0.05), on both subtypes. Both, cow and goat raw milk did not show a noticeable in vitro killing effect at the highest dose of 250 µl/ml.

Conclusion: Raw camel milk revealed a substantial dose-dependent in vitro antiparasitic activity against Blastocystis sp. ST1 and ST3 subtypes, opening a promising perspective for its use in the control of this wide spread gastrointestinal parasite both in humans and livestock. In contrast, cow and goat raw milks did not show noticeable anti-Blastocystis sp. activity against both subtypes.