Open AccessEvaluation of LAMP for detection of Shigella from stool samples in children
Author(s) -
Ramya Raghavan,
Shouao Wang,
Nandini Dendukuri,
Sitanshu Sekhar Kar,
Subramanian Mahadevan,
Barath Jagadisan,
Jharna Mandal
Publication year - 2020
Publication title -
access microbiology
Language(s) - English
Resource type - Journals
ISSN - 2516-8290
DOI - 10.1099/acmi.0.000169
Subject(s) - loop mediated isothermal amplification , shigella , dysentery , medicine , microbiological culture , positive predicative value , shigellosis , microbiology and biotechnology , gastroenterology , biology , salmonella , bacteria , predictive value , genetics , dna
Background To assess the diagnostic accuracy of loop-mediated isothermal amplification (LAMP) for the detection ofShigellafrom stool samples from children. Methods Consecutive stool samples from children aged <13 years old who presented with acute watery diarrhoea or dysentery to the Department of Paediatrics were collected and processed in the Department of Microbiology. All the stool samples were subjected to culture, conventional PCR and LAMP. Genomic sequencing was performed for samples that were positive by LAMP but negative by both culture and conventional PCR. The LAMP results were compared to those from culture and to a composite reference standard based on culture and conventional PCR. Results Amongst the 374 stool samples tested, 291 samples were positive by LAMP and 213 were positive by the composite reference standard. The sensitivity of LAMP was 100 % (98.3–100 %) and its specificity was 51.6 % (43.6–59.5 %) with a disease prevalence of 57 %. The sensitivity and specificity of LAMP improved to 99.3 % (94.2–100) and 98.2 % (94.5–99.9), respectively, using latent class analysis, while assuming that genomic sequencing has perfect specificity. Discussion The authors have standardized the LAMP procedure for direct application to clinical stool samples. LAMP is a sensitive and specific method for the diagnosis ofShigellafrom stool samples of children as compared to both culture and conventional PCR.