To provide further evidence of waterborne transmission of Blastocystis, a total of 31 wastewater treatment plants from geographically distinct locations across the Philippines were sampled for influent and effluent sewage samples. In vitro cultivation was the method of choice to increase sensitivity of detection. Blastocystis cysts were detected in 15% (9/62) of the samples using in vitro culture. Moreover, influent and effluent samples were 23% (7/31) and 7% (2/31) positive for the parasite, respectively. The presence of viable cysts in treated samples may be an indication of the inefficiency of the treatment process in preventing Blastocystis from entering the environment. Polymerase chain reaction and sequencing of the full-length small subunit ribosomal RNA (SSU rRNA) genes of the nine wastewater isolates were performed. The SSU rRNA gene sequences of the isolates showed very high similarity (98 to 99%) to homologous sequences of Blastocystis described previously. The phylogenetic tree constructed showed that the wastewater isolates clustered with each other with good bootstrap support and belonged to two subtypes (ST) – ST1 and ST2. This is the first report of subtyping Blastocystis isolates from wastewater samples and gives further emphasis to the remarkable genetic diversity of the parasite.
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Research Article|
February 03 2011
Detection and subtype identification of Blastocystis isolates from wastewater samples in the Philippines
Jan Ervin G. Banaticla;
Jan Ervin G. Banaticla
1Institute of Biology, College of Science, University of the Philippines, Diliman, Quezon City 1101, Philippines
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Windell L. Rivera
1Institute of Biology, College of Science, University of the Philippines, Diliman, Quezon City 1101, Philippines
Fax: +63 2 920 5471; E-mail: [email protected]
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J Water Health (2011) 9 (1): 128–137.
Article history
Received:
July 21 2010
Accepted:
September 13 2010
Citation
Jan Ervin G. Banaticla, Windell L. Rivera; Detection and subtype identification of Blastocystis isolates from wastewater samples in the Philippines. J Water Health 1 March 2011; 9 (1): 128–137. doi: https://doi.org/10.2166/wh.2010.127
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