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.
Department of Parasitology (Southeast Asia Water Team), Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia;Department of Parasitology (Southeast Asia Water Team), Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia;Department of Parasitology (Southeast Asia Water Team), Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia;Department of Parasitology (Southeast Asia Water Team), Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia;Department of Parasitology (Southeast Asia Water Team), Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia;Department of Parasitology (Southeast Asia Water Team), Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia;Department of Medical Laboratory, Faculty of Medical Technology, University of Health Sciences, Vientiane, Laos PDR;Department of Medical Laboratory, Faculty of Medical Technology, University of Health Sciences, Vientiane, Laos PDR;Ecological Laboratory, Advancing Life and Regenerating Motherland (ALARM), Yangon, Myanmar;Ecological Laboratory, Advancing Life and Regenerating Motherland (ALARM), Yangon, Myanmar;Institute of Water Policy, National University of Singapore, Singapore, Singapore;Department of Geography, National University of Singapore, Singapore, Singapore;Chulabhorn International College of Medicine, Thammasat University, Pathum Thani, Thailand;Department of Microbiology, Faculty of Science, Prince of Songkhla University, Hat-Yai, Thailand;Department of Parasitology (Southeast Asia Water Team), Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia;Department of Parasitology (Southeast Asia Water Team), Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
Recommended Citation:
Mohamad Azlan Abdul Majid,Tooba Mahboob,Brandon G. J. Mong,et al. Pathogenic waterborne free-living amoebae: An update from selected Southeast Asian countries[J]. PLOS ONE,2017-01-01,12(2)