Application of The Established Protocol For The Detection of Blastocystis SP In Water Samples

Abstract

A protocol for water sample processing for the detection of Blastocystis sp. was previously established. The protocol was applied in 106 various water samples (31 river, 12 lake, 13 tap and 50 bottled drinking water). Briefly, 1.0 L water sample was collected and processed on the same day, centrifuged at 1400 x g for 10 min. For the isolation of Blastocystis sp. cysts, parasite pellet was on top of Ficoll-Paque™ PLUS, centrifuged at 1400 x g for 20 min and washed twice using 0.9% saline with centrifugation at 1400 x g for 10 min. Pellet was reconstituted in 1ml PBS. A minimum of 100 µl of the mixture was inoculated in 3 ml Jones’ medium supplement with 10% horse serum, incubated at 37°C and examined for any presence of vacuolar forms of Blastocystis sp. after 3 days of inoculation. The results were presented as the percentage of occurrence of vacuolar forms of Blastocystis sp. using in vitro cultivation. The quality of water samples including physical parameters, faecal coliform counts and chemical content of water samples were determined. Blastocystis sp. was detected in 13.2% (14/106) of the water samples. The parasite was only detected in river samples (14/35, 45.2%), while this parasite was absent from all other water sources (lake, tap and bottled drinking water). It indicated that river samples were contaminated with faecal materials containing Blastocystis sp. This concur with the quality of the water samples that contained high turbidity (60.89 NTU) were highly contaminated with faecal materials as indicated by the presence of Enterobacter sp. (2.87 ± 2.70 colony X 106/ 100 ml water sample), Escherichia coli (1.19 ± 1.10 colony X 106/ 100 ml water sample), ammonia (5.14 ± 4.83 mg/ L water sample), nitrate (0.18 ± 0.09 mg/ L water sample) and nitrite (0.075 ± 0.047 mg/ L water sample).