title: Clinical evaluation of a loop-mediated isothermal amplification (LAMP) assay for rapid detection of Neisseria meningitidis in cerebrospinal fluid.
abstract: BACKGROUND
  Neisseria meningitidis (Nm) is a leading causative agent of bacterial meningitis in humans. Traditionally, meningococcal meningitis has been diagnosed by bacterial culture. However, isolation of bacteria from patients' cerebrospinal fluid (CSF) is time consuming and sometimes yields negative results. Recently, polymerase chain reaction (PCR)-based diagnostic methods of detecting Nm have been considered the gold standard because of their superior sensitivity and specificity compared with culture. In this study, we developed a loop-mediated isothermal amplification (LAMP) method and evaluated its ability to detect Nm in cerebrospinal fluid (CSF).
  
  
  RESULTS
  We developed a meningococcal LAMP assay (Nm LAMP) that targets the ctrA gene. The primer specificity was validated using 16 strains of N. meningitidis (serogroup A, B, C, D, 29-E, W-135, X, Y, and Z) and 19 non-N. meningitidis species. Within 60 min, the Nm LAMP detected down to ten copies per reaction with sensitivity 1000-fold more than that of conventional PCR. The LAMP assays were evaluated using a set of 1574 randomly selected CSF specimens from children with suspected meningitis collected between 1998 and 2002 in Vietnam, China, and Korea. The LAMP method was shown to be more sensitive than PCR methods for CSF samples (31 CSF samples were positive by LAMP vs. 25 by PCR). The detection rate of the LAMP method was substantially higher than that of the PCR method. In a comparative analysis of the PCR and LAMP assays, the clinical sensitivity, specificity, positive predictive value, and negative predictive value of the LAMP assay were 100%, 99.6%, 80.6%, and 100%, respectively.
  
  
  CONCLUSIONS
  Compared to PCR, LAMP detected Nm with higher analytical and clinical sensitivity. This sensitive and specific LAMP method offers significant advantages for screening patients on a population basis and for diagnosis in clinical settings.
authors: Department of Pharmacy, College of Pharmacy, Hanyang University, Ansan, Republic of Korea; Institute of Pharmacological Research, Hanyang University, Ansan, Republic of Korea.
authors: DoKyung
authors: D
authors: Lee
authors: Department of Pharmacy, College of Pharmacy, Hanyang University, Ansan, Republic of Korea; Institute of Pharmacological Research, Hanyang University, Ansan, Republic of Korea.
authors: Eun Jin
authors: EJ
authors: Kim
authors: Wayne State University, Eugene Applebaum College of Pharmacy & Health Sciences, Department of Pharmacy Practice, Detroit, Michigan, United States of America.
authors: Paul E
authors: PE
authors: Kilgore
authors: Translational Research Division, International Vaccine Institute, Seoul, Republic of Korea.
authors: Soon Ae
authors: SA
authors: Kim
authors: Department of Bacteriology I, National Institute of Infectious Diseases, Tokyo, Japan.
authors: Hideyuki
authors: H
authors: Takahashi
authors: Department of Bacteriology I, National Institute of Infectious Diseases, Tokyo, Japan.
authors: Makoto
authors: M
authors: Ohnishi
authors: National Institute of Hygiene and Epidemiology, Hanoi, Vietnam.
authors: Dang Duc
authors: DD
authors: Anh
authors: Guangxi Zhuang Autonomous Region Health Bureau, Nanning, Guangxi, China.
authors: Bai Qing
authors: BQ
authors: Dong
authors: Chonbuk National University School of Medicine, Jeonju, Korea.
authors: Jung Soo
authors: JS
authors: Kim
authors: Kaneka Corporation, Osaka, Japan.
authors: Jun
authors: J
authors: Tomono
authors: Kaneka Corporation, Osaka, Japan.
authors: Shigehiko
authors: S
authors: Miyamoto
authors: Eiken Chemical Co., Ltd, Tochigi, Japan.
authors: Tsugunori
authors: T
authors: Notomi
authors: Department of Pharmacy, College of Pharmacy, Hanyang University, Ansan, Republic of Korea; Institute of Pharmacological Research, Hanyang University, Ansan, Republic of Korea.
authors: Dong Wook
authors: DW
authors: Kim
authors: Department of Oral Health Sciences, Nihon University School of Dentistry, Tokyo, Japan; Dental Research Center, Nihon University School of Dentistry, Tokyo, Japan.
authors: Mitsuko
authors: M
authors: Seki
mesh_terms: D000328:Adult; D001483:Base Sequence; D002555:Cerebrospinal Fluid / Q000382:microbiology*; D002648:Child; D004269:DNA, Bacterial / Q000235:genetics / Q000302:isolation & purification*; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008585:Meningitis, Meningococcal / Q000134:cerebrospinal fluid* / Q000382:microbiology; D009345:Neisseria meningitidis / Q000302:isolation & purification* / Q000472:pathogenicity
chemical_list: D004269:DNA, Bacterial