title: Pathogenic waterborne free-living amoebae: An update from selected Southeast Asian countries.
abstract: Data on the distribution of free-living amoebae is still lacking especially in Southeast Asian region. The aquatic environment revealed a high occurrence of free-living amoebae (FLA) due to its suitable condition and availability of food source, which subsequently causes infection to humans. A total of 94 water samples consisted of both treated and untreated from Laos (31), Myanmar (42), and Singapore (21) were investigated for the presence of pathogenic FLA. Each water sample was filtered and cultured onto non-nutrient agar seeded with live suspension of Escherichia coli and incubated at room temperature. Morphological identification was conducted for both trophozoites and cysts via microscopic stains (Giemsa and immunofluorescence). The presence of Naegleria-like structures was the most frequently encountered in both treated and untreated water samples, followed by Acanthamoeba-like and Vermamoeba-like features. To identify the pathogenic isolates, species-specific primer sets were applied for molecular identification of Acanthamoeba, Naegleria, and Vermamoeba. The pathogenic species of Acanthamoeba lenticulata and A. triangularis were detected from untreated water samples, while Vermamoeba vermiformis was found in both treated and untreated water samples. Our results suggested that poor water quality as well as inadequate maintenance and treatment might be the cause of this alarming problem since chlorine disinfection is ineffective in eradicating these amoebas in treated water samples. Regular monitoring and examination of water qualities are necessary in order to control the growth, hence, further preventing the widespread of FLA infections among the public.
authors.affiliation: Department of Parasitology (Southeast Asia Water Team), Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.
authors.forename: Mohamad Azlan
authors.initials: MA
authors.lastname: Abdul Majid
authors.affiliation: Department of Parasitology (Southeast Asia Water Team), Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.
authors.forename: Tooba
authors.initials: T
authors.lastname: Mahboob
authors.affiliation: Department of Parasitology (Southeast Asia Water Team), Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.
authors.forename: Brandon G J
authors.initials: BG
authors.lastname: Mong
authors.affiliation: Department of Parasitology (Southeast Asia Water Team), Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.
authors.forename: Narong
authors.initials: N
authors.lastname: Jaturas
authors.affiliation: Department of Parasitology (Southeast Asia Water Team), Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.
authors.forename: Reena Leeba
authors.initials: RL
authors.lastname: Richard
authors.affiliation: Department of Parasitology (Southeast Asia Water Team), Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.
authors.forename: Tan
authors.initials: T
authors.lastname: Tian-Chye
authors.affiliation: Department of Medical Laboratory, Faculty of Medical Technology, University of Health Sciences, Vientiane, Laos PDR.
authors.forename: Anusorn
authors.initials: A
authors.lastname: Phimphila
authors.affiliation: Department of Medical Laboratory, Faculty of Medical Technology, University of Health Sciences, Vientiane, Laos PDR.
authors.forename: Panomphanh
authors.initials: P
authors.lastname: Mahaphonh
authors.affiliation: Ecological Laboratory, Advancing Life and Regenerating Motherland (ALARM), Yangon, Myanmar.
authors.forename: Kyaw Nyein
authors.initials: KN
authors.lastname: Aye
authors.affiliation: Ecological Laboratory, Advancing Life and Regenerating Motherland (ALARM), Yangon, Myanmar.
authors.forename: Wai Lynn
authors.initials: WL
authors.lastname: Aung
authors.affiliation: Institute of Water Policy, National University of Singapore, Singapore, Singapore.
authors.forename: Joon
authors.initials: J
authors.lastname: Chuah
authors.affiliation: Department of Geography, National University of Singapore, Singapore, Singapore.
authors.forename: Alan D
authors.initials: AD
authors.lastname: Ziegler
authors.affiliation: Chulabhorn International College of Medicine, Thammasat University, Pathum Thani, Thailand.
authors.forename: Atipat
authors.initials: A
authors.lastname: Yasiri
authors.affiliation: Department of Microbiology, Faculty of Science, Prince of Songkhla University, Hat-Yai, Thailand.
authors.forename: Nongyao
authors.initials: N
authors.lastname: Sawangjaroen
authors.affiliation: Department of Parasitology (Southeast Asia Water Team), Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.
authors.forename: Yvonne A L
authors.initials: YA
authors.lastname: Lim
authors.affiliation: Department of Parasitology (Southeast Asia Water Team), Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.
authors.forename: Veeranoot
authors.initials: V
authors.lastname: Nissapatorn
mesh_terms: D000656:Amoeba / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D044466:Asian People; D001483:Base Sequence; D006801:Humans; D010802:Phylogeny; D014871:Water Microbiology