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A High-throughput Platform for the Screening of Salmonella spp./Shigella spp.
Published on: November 7, 2018
Evaluation of LAMP for detection of Shigella from stool samples in children
Ramya Raghavan1, Shouao Wang2, Nandini Dendukuri2
1Department of Microbiology, Jawaharlal Institute of Postgraduate Medical Education and Research, Puducherry, India.
Insights
Loop-mediated isothermal amplification (LAMP) accurately detects Shigella in children's stool samples. This sensitive and specific method offers a reliable alternative to traditional diagnostic techniques for Shigella infections.
Area of Science:
- Microbiology
- Molecular Diagnostics
- Pediatric Infectious Diseases
Background:
- Accurate diagnosis of Shigella is crucial for managing pediatric diarrheal diseases.
- Traditional diagnostic methods like culture and PCR have limitations in speed and sensitivity.
Purpose of the Study:
- To evaluate the diagnostic accuracy of loop-mediated isothermal amplification (LAMP) for detecting Shigella in pediatric stool samples.
Main Methods:
- Stool samples from children with acute watery diarrhea or dysentery were analyzed using culture, conventional PCR, and LAMP.
- Genomic sequencing was employed for LAMP-positive, culture/PCR-negative samples.
- LAMP results were compared against a composite reference standard (culture and conventional PCR).
Main Results:
- LAMP demonstrated high sensitivity (100%) and improved specificity (98.2%) after latent class analysis.
- Initial specificity was 51.6%, with sensitivity at 100% compared to the composite reference standard.
- Latent class analysis, assuming perfect specificity of genomic sequencing, refined LAMP's accuracy metrics.
Conclusions:
- Loop-mediated isothermal amplification (LAMP) is a highly sensitive and specific diagnostic tool for Shigella detection in children's stool.
- The standardized LAMP procedure is suitable for direct application to clinical samples.
- LAMP offers a valuable alternative to culture and conventional PCR for diagnosing Shigella infections in pediatric patients.
Background:
To assess the diagnostic accuracy of loop-mediated isothermal amplification (LAMP) for the detection of Shigella from 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 of Shigella from stool samples of children as compared to both culture and conventional PCR.
