title: Development of a rapid, simple method for detecting Naegleria fowleri visually in water samples by loop-mediated isothermal amplification (LAMP).
abstract: Naegleria fowleri is the causative agent of the fatal disease primary amebic meningoencephalitis. Detection of N. fowleri using conventional culture and biochemical-based assays is time-consuming and laborious, while molecular techniques, such as PCR, require laboratory skills and expensive equipment. We developed and evaluated a novel loop-mediated isothermal amplification (LAMP) assay targeting the virulence-related gene for N. fowleri. Time to results is about 90 min and amplification products were easily detected visually using hydroxy naphthol blue. The LAMP was highly specific after testing against related microorganisms and able to detect one trophozoite, as determined with spiked water and cerebrospinal fluid samples. The assay was then evaluated with a set of 80 water samples collected during the flooding crisis in Thailand in 2011, and 30 natural water samples from border areas of northern, eastern, western, and southern Thailand. N. fowleri was detected in 13 and 10 samples using LAMP and PCR, respectively, with a Kappa coefficient of 0.855. To the best of our knowledge, this is the first report of a LAMP assay for N. fowleri. Due to its simplicity, speed, and high sensitivity, the LAMP method described here might be useful for quickly detecting and diagnosing N. fowleri in water and clinical samples, particularly in resource-poor settings.
authors.affiliation: Department of Protozoology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.
authors.forename: Aongart
authors.initials: A
authors.lastname: Mahittikorn
authors.affiliation: Department of Protozoology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.
authors.forename: Hirotake
authors.initials: H
authors.lastname: Mori
authors.affiliation: Department of Protozoology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.
authors.forename: Supaluk
authors.initials: S
authors.lastname: Popruk
authors.affiliation: Section of Bacterial Pathogenesis, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan; Department of Microbiology, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
authors.forename: Amonrattana
authors.initials: A
authors.lastname: Roobthaisong
authors.affiliation: Department of Protozoology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.
authors.forename: Chantira
authors.initials: C
authors.lastname: Sutthikornchai
authors.affiliation: Department of Protozoology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.
authors.forename: Khuanchai
authors.initials: K
authors.lastname: Koompapong
authors.affiliation: Department of Epidemiology, Faculty of Public Health, Mahidol University, Bangkok, Thailand.
authors.forename: Sukhontha
authors.initials: S
authors.lastname: Siri
authors.affiliation: Department of Protozoology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.
authors.forename: Yaowalark
authors.initials: Y
authors.lastname: Sukthana
authors.affiliation: Department of Parasitology, Faculty of Medical Technology, Mahidol University, Bangkok, Thailand.
authors.forename: Duangporn
authors.initials: D
authors.lastname: Nacapunchai
mesh_terms: D016848:Naegleria fowleri / Q000235:genetics*; D021141:Nucleic Acid Amplification Techniques / Q000379:methods*; D012680:Sensitivity and Specificity; D013785:Thailand; D014774:Virulence / Q000235:genetics; D014867:Water / Q000032:analysis* / Q000737:chemistry / Q000469:parasitology*
chemical_list: D014867:Water
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