249 Tropical Biomedicine 34(1): 249–255 (2017) Research Note Morphological and molecular detection of Blastocystis in wildlife from Tioman Island, Malaysia Mohd Zain, S.N. 1* , Farah Haziqah, M.T. 1 , Woh, P.Y. 1 , Fazly Ann, Z. 2 , Vickneshwaran, M. 3 , Mohd Khalid, M.K.N. 4 , Arutchelvan, R. 5 and Suresh, K. 5 1 Institute of Biological Sciences, Faculty of Sciences, University of Malaya, 50603 Kuala Lumpur, Malaysia 2 Veterinary Research Institute, Department of Veterinary Services, 59, Jalan Sultan Azlan Shah, 31400 Ipoh, Perak, Malaysia 3 Disease Control Division, Ministry of Health, Level 3 Block E 10, Complex E, Precint 1, Federal Govenment Administrative Centre, 62590 Putrajaya, Malaysia 4 Molecular Diagnostics and Protein Unit, Specialised Diagnostics Centre, Institute for Medical Research, Jalan Pahang, 50588 Kuala Lumpur, Malaysia 5 Department of Parasitology, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia * Corresponding author e-mail: nsheena@um.edu.my Received 29 July 2016; received in revised form 17 October 2016; accpeted 20 October 2016 Abstract. Blastocystis infection is widely reported in wildlife, livestocks and in non-human primates however, occurrence in Malaysian wildlife is scarce. A wildlife survey on Tioman Island captured six water monitor lizard (Varanus salvator), four mouse-deer (Tragulus sp.) and one Malayan porcupine (Hystrix brachyura) based on convenience sampling. Intestinal contents from each animal were subjected to in vitro cultivation method using Jones medium supplemented with 10% horse serum. Low prevalence of infections was detected with only 1/6 (16.7%) water monitor lizard and 1/4 (25%) mouse-deer infected. The vacuolated form was the most common cell form found in both cultures with similar morphology to B. hominis. However, the monitor lizard isolate propagated well in the laboratory for several months using Jones medium while mouse-deer isolate could not be maintained for more than a week. The reptilian isolates grew optimally at a lower temperature of 24ºC compared to 37ºC for the mouse-deer isolate. Using the DNA barcoding method, both isolates were confirmed to be Blastocystis sp. Sequence obtained from a monitor lizard isolate has 94% sequence identity to B. lapemi, an isolate recovered from a reptile sea-snake whereas a mouse-deer isolate has 99% sequence identitical to B. hominis HJ01-7. The phylogenetic tree revealed that the monitor lizard isolate were positioned within the herptiles clade (clade VIII) while the mouse deer isolate located at the homoithermal clade (clade IV). The present paper is the first report on the presence as well as genetic characteristics of Blastocystis in wildlife captured from Tioman Island, Pahang. Humans isolates are known as B. hominis (Brumpt, 1912) while non-human isolates are termed Blastocystis sp. as most animal isolates have not been genetically analyzed (Stenzel and Boreham, 1996; Yoshikawa et al., 2004a). Due to the general morphological similarities among the different isolates and polymorphism within isolates, other criteria, such as optimal growth temperature, karyotypic profiles and gene sequences have been employed to differentiate isolates of different hosts. Only a handful of isolates from specific hosts are successfully published namely; B. ratti for rats (Chen et al., 1997), B. galli for chickens (Belova, 1998), B. anatis for domestic ducks (Belova, 1991), B. anseri for domestic geese (Belova,