Blastocystis spp. contaminated water sources in aboriginal settlements

Blastocystis has been increasingly reported in water bodies. However, lack of studies to determine the presence of Blastocystis in water used by the aborigines in Malaysia has led to the birth of this research. This study was therefore aimed to determine the occurrence of Blastocystis in water samples in aboriginal settlements in Pahang, Malaysia. Water samples collected from seven sampling points of two rivers and other water sources in the villages were subjected to filtration and cultivation followed by trichrome staining. The trichrome stained slides were observed microscopically under 1000X magnification for the presence of Blastocystis. River samples were also measured for physicochemical parameters. From this study, 42.9% of the river water and 6.25% of other water samples were positive for Blastocystis. All river samples showed presence of Escherichia coli and Enterobacter aerogenes, indicating faecal contamination. Statistical analysis showed Blastocystis occurrence in the river were significantly correlated conductivity, turbidity, chemical oxygen demand (COD), total dissolved solid (TDS), concentration of sulfate and faecal coliforms. The river water used by the aborigines is a probable source for Blastocystis transmission in this community. Therefore, protection of the river from organic material and faecal contaminations are highly required in order to control the contamination by Blastocystis.

Occurrence of Blastocystis sp. in water catchments at Malay villages and Aboriginal settlement during wet and dry seasons in Peninsular Malaysia

In the tropics, there are too few studies on isolation of Blastocystis sp. subtypes from water sources; in addition, there is also an absence of reported studies on the occurrence of Blastocystis sp. subtypes in water during different seasons. Therefore, this study was aimed to determine the occurrence of Blastocystis sp. subtypes in river water and other water sources that drained aboriginal vicinity of highly endemic intestinal parasitic infections during wet and dry seasons. Water samples were collected from six sampling points of Sungai Krau (K1–K6) and a point at Sungai Lompat (K7) and other water sources around the aboriginal villages. The water samples were collected during both seasons, wet and dry seasons. Filtration of the water samples were carried out using a flatbed membrane filtration system. The extracted DNA from concentrated water sediment was subjected to single round polymerase chain reaction and positive PCR products were subjected to sequencing. All samples were also subjected to filtration and cultured on membrane lactose glucuronide agar for the detection of faecal coliforms. During wet season, Blastocystis sp. ST1, ST2 and ST3 were detected in river water samples. Blastocystis sp. ST3 occurrence was sustained in the river water samples during dry season. However Blastocystis sp. ST1 and ST2 were absent during dry season. Water samples collected from various water sources showed contaminations of Blastocystis sp. ST1, ST2, ST3 and ST4, during wet season and Blastocystis sp. ST1, ST3, ST8 and ST10 during dry season. Water collected from all river sampling points during both seasons showed growth of Escherichia coli and Enterobacter aerogenes, indicating faecal contamination. In this study, Blastocystis sp. ST3 is suggested as the most robust and resistant subtype able to survive in any adverse environmental condition. Restriction and control of human and animal faecal contaminations to the river and other water sources shall prevent the transmission of Blastocystis sp. to humans and animals in this aboriginal community.