MSPTM 2019 Annual Scientific Conference
13 - 14 March 2019
InterContinental Kuala Lumpur




E-Poster Presentation Competition for Student
Scaling Up Efforts in Tropical Disease and Vector Control through Evidence-Based Research
Medical Microbiology & Parasitology


Main Author
Arutchelvan Rajamanikam1
Presenting Author
Arutchelvan Rajamanikam1
Ho Shiaw Hooi2
Tan Tian Chye1
Chandramathi Samudi3
Suresh Kumar Govind1

Authors' Institution

Department / Institution / Country
Parasitology / University of Malaya / Malaysia1
Department of Medicine / University of Malaya / Malaysia2
Medical Microbiology / University of Malaya / Malaysia3
Abstract Content

Blastocystis sp. is a protozoan parasite with global distribution. Studies have reported contradicting pathogenicity of Blastocystis sp. isolated from different population. The role of gut flora in Blastocystis sp. infection is scarcely reported and not conclusive. In this study, Blastocystis sp. was isolated from symptomatic and asymptomatic individuals of 2 distinct communities’ namely urban dwellers and orang asli populations. The parasites were genotyped and only ST3 isolates were included in the study. The phenotypic characteristics were studied by assessing growth profile, morphology, ultrastructure and robustness of the cells. Subsequently, the pathogenic potentials of parasites from both groups were studied by assessing the solubilized antigens for protease activity and its ability proliferate cancer cells. There was a higher parasite count with granular and apoptotic forms in parasites isolated from  orang asli Blastocystissp. infected individuals. Predominant fuzzy coat surrounding the parasite with amoebic formation was seen in parasite cultures isolated from  urban symptomatic persons only.  Parasites from orang asli cultures possessed greater robustness as evidenced by the resistance to high concentrations of metronidazole and the inability to lyse in distilled water. There was significantly higher protease activity seen in parasites from orang asli isolates with predominance of cysteine protease in symptomatic and serine protease in asymptomatic isolates. However, only solubilized antigen from urban symptomatic isolates showed significant proliferation of cancer cells. This study for the first time showed phenotypic variation of ST3 Blastocystis sp. isolated from urban and orang asli population. The variation seen can be attributed to the difference in gut microbiome between studied populations. This study demonstrates the importance of identifying the locations and lifestyles of the people during sample collection before over-generalizing the prevalence data and implicating subtypes to pathogenicity. Environment has been shown to  play a major role in Blastocystis sp. infection. 

Keywords: Blastocystis sp.; urban; orang asli; phenotypic variation
Requires Audio or Video system for Presentation?: No