title: Detection of four Plasmodium species by genus- and species-specific loop-mediated isothermal amplification for clinical diagnosis.
abstract: Loop-mediated isothermal amplification (LAMP), a novel nucleic acid amplification method, was developed for the clinical detection of four species of human malaria parasites: Plasmodium falciparum, P. vivax, P. malariae, and P. ovale. We evaluated the sensitivity and specificity of LAMP in comparison with the results of microscopic examination and nested PCR. LAMP showed a detection limit (analytical sensitivity) of 10 copies of the target 18S rRNA genes for P. malariae and P. ovale and 100 copies for the genus Plasmodium, P. falciparum, and P. vivax. LAMP detected malaria parasites in 67 of 68 microscopically positive blood samples (sensitivity, 98.5%) and 3 of 53 microscopically negative samples (specificity, 94.3%), in good agreement with the results of nested PCR. The LAMP reactions yielded results within about 26 min, on average, for detection of the genus Plasmodium, 32 min for P. falciparum, 31 min for P. vivax, 35 min for P. malariae, and 36 min for P. ovale. Accordingly, in comparison to the results obtained by microscopy, LAMP had a similar sensitivity and a greater specificity and LAMP yielded results similar to those of nested PCR in a shorter turnaround time. Because it can be performed with a simple technology, i.e., with heat-treated blood as the template, reaction in a water bath, and inspection of the results by the naked eye because of the use of a fluorescent dye, LAMP may provide a simple and reliable test for routine screening for malaria parasites in both clinical laboratories and malaria clinics in areas where malaria is endemic.
authors.affiliation: Cell-Free Science and Technology Research Center, Ehime University, Matsuyama, Ehime 790-8577, Japan.
authors.forename: Eun-Taek
authors.initials: ET
authors.lastname: Han
authors.forename: Risa
authors.initials: R
authors.lastname: Watanabe
authors.forename: Jetsumon
authors.initials: J
authors.lastname: Sattabongkot
authors.forename: Benjawan
authors.initials: B
authors.lastname: Khuntirat
authors.forename: Jeeraphat
authors.initials: J
authors.lastname: Sirichaisinthop
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Iriko
authors.forename: Ling
authors.initials: L
authors.lastname: Jin
authors.forename: Satoru
authors.initials: S
authors.lastname: Takeo
authors.forename: Takafumi
authors.initials: T
authors.lastname: Tsuboi
mesh_terms: D000818:Animals; D001483:Base Sequence; D001769:Blood / Q000469:parasitology; D016054:DNA, Protozoan / Q000235:genetics; D004275:DNA, Ribosomal / Q000235:genetics; D006801:Humans; D008288:Malaria / Q000175:diagnosis* / Q000469:parasitology*; D008969:Molecular Sequence Data; D021141:Nucleic Acid Amplification Techniques / Q000379:methods*; D010961:Plasmodium / Q000145:classification* / Q000302:isolation & purification*; D016133:Polymerase Chain Reaction / Q000379:methods; D012337:RNA, Ribosomal, 18S / Q000235:genetics; D012680:Sensitivity and Specificity
chemical_list: D016054:DNA, Protozoan; D004275:DNA, Ribosomal; D012337:RNA, Ribosomal, 18S