Evaluation and Optimization of a Loop-Mediated Isothermal Amplification (LAMP) Assay for the Detection of Salmonella enterica serovar Typhi Isolated from Food Samples

Document Type : Original Research

Authors
1 Department of Microbiology, Shahr-e-Qods Branch, Islamic Azad University, Tehran, Iran
2 Laboratory Sciences Research Center, Golestan University of Medical Sciences, Gorgan, Iran
Abstract
Background: Foodborne diseases caused by Salmonella are considered as a global health concern, especially in low-income countries. Rapid and specific detection of this infective agent is highly important in the outbreak control. The current study aimed to design and optimize a LAMP method and to compare its sensitivity and efficiency with the PCR method in the detection of S. typhi in food.

Materials & Methods: Food samples including mayonnaise and vegetable salad were inoculated with S. enterica serovar Typhi. Sensitivity and detection limit of LAMP test were investigated at different concentrations of contaminated mayonnaise and vegetable salad. invA gene was chosen as the target gene for bacterial detection by PCR and LAMP tests.

Findings: The detection limit of Samonella was estimated to be 16 CFU/mL using LAMP and PCR. LAMP reaction revealed a visible turbidity, indicating the accurate amplification of the selected target gene and proper identification of Salmonella at different dilutions of the studied food samples.

Conclusion: The present study indicated that LAMP is a rapid, cost-effective, and specific technique for the identification of Salmonella. This method could be used in laboratories with minimal equipment without the need for costly molecular detection methods.

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1. Bhandari DP. Characterization of Flagellin Antigen Using a Panel of Monoclonal Antibodies and Their Applications for Detection of Salmonella Based on Surface Plasmon Resonance: Tennessee State University; 2019.
2. Babar A, Butt SJ, Ullah S. A Review of Prognostic Models on Diagnosis and Therapeutic Strategies of Typhoid Fever. Journal of Medical Bacteriology. 2018;7(1-2):1-12.
3. Olobatoke R. Public health burden of non-typhoidal Salmonella strains in sub-Saharan Africa. Int Res J Public Environ Health. 2017;4(6):112-119.
4. Yang Q, Domesle KJ, Wang F, Ge B. Rapid detection of Salmonella in food and feed by coupling loop-mediated isothermal amplification with bioluminescent assay in real-time. BMC microbiology. 2016;16(1):112.
5. Foddai AC, Grant IR. Methods for detection of viable foodborne pathogens: current state-of-art and future prospects. Applied Microbiology and Biotechnology. 2020:1-8.
6. Zhai L, Liu H, Chen Q, Lu Z, Zhang C, Lv F, et al. Development of a real-time nucleic acid sequence–based amplification assay for the rapid detection of Salmonella spp. from food. Brazilian Journal of Microbiology. 2019;50(1):255-261.
7. Linh Quyen T, Nordentoft S, Chidambara Vinayaka A, Ngo TA, Engelsmenn P, Sun Y, et al. A sensitive, specific and simple loop mediated isothermal amplification method for rapid detection of campylobacter spp. In broiler production. Frontiers in microbiology. 2019;10:2443.
8. Notomi T, Okayama H, Masubuchi H, Yonekawa T, Watanabe K, Amino N, et al. Loop-mediated isothermal amplification of DNA. Nucleic acids research. 2000;28(12):e63-e63.
9. Hara-Kudo Y, Yoshino M, Kojima T, Ikedo M. Loop-mediated isothermal amplification for the rapid detection of Salmonella. FEMS microbiology letters. 2005;253(1):155-161.
10. Havelaar A, Grace D, Wu F. Foodborne diseases from dairy products in developing countries: Hazards and health implications. 2019.
11. Shahbazi S, Karam MRA, Habibi M, Talebi A, Bouzari S. Distribution of extended-spectrum β-lactam, quinolone and carbapenem resistance genes, and genetic diversity among uropathogenic Escherichia coli isolates in Tehran, Iran. Journal of global antimicrobial resistance. 2018;14:118-125.
12. Nair A, Balasaravanan T, Malik SS, Mohan V, Kumar M, Vergis J, et al. Isolation and identification of Salmonella from diarrheagenic infants and young animals, sewage waste and fresh vegetables. Veterinary world. 2015;8(5):669.
13. Köchl S, Niederstätter H, Parson W. DNA extraction and quantitation of forensic samples using the phenol-chloroform method and real-time PCR. Forensic DNA typing protocols: Springer; 2005. p. 13-29.
14. Vickers NJ. Animal Communication: When I’m Calling You, Will You Answer Too? Current Biology. 2017;27(14):R713-R715.
15. Zhang G, Brown EW, González-Escalona N. Comparison of real-time PCR, reverse transcriptase real-time PCR, loop-mediated isothermal amplification, and the FDA conventional microbiological method for the detection of Salmonella spp. in produce. Appl Environ Microbiol. 2011;77(18):6495-6501.
16. Srisawat M, Panbangred W. Efficient and specific detection of Salmonella in food samples using a stn-based loop-mediated isothermal amplification method. BioMed research international. 2015;2015.
17. Yang Q, Domesle KJ, Ge B. Loop-mediated isothermal amplification for Salmonella detection in food and feed: current applications and future directions. Foodborne pathogens and disease. 2018;15(6):309-331.
18. Ravan H, Amandadi M. A rapid and specific detection of pathogenic serovar Salmonella typhimurium by loop-mediated isothermal amplification method (LAMP). 2017.
19. Moganedi K, Goyvaerts E, Venter SN, Sibara M. Optimisation of the PCR-invA primers for the detection of Salmonella in drinking and surface waters following a pre-cultivation step. Water Sa. 2007;33(2).
20. Techathuvanan C, Draughon FA, D'Souza DH. Loop‐mediated isothermal amplification (LAMP) for the rapid and sensitive detection of Salmonella Typhimurium from pork. Journal of food science. 2010;75(3):M165-M172.
21. Zhao X, Wang L, Chu J, Li Y, Li Y, Xu Z, et al. Development and application of a rapid and simple loop-mediated isothermal amplification method for food-borne Salmonella detection. Food Science and Biotechnology. 2010;19(6):1655-1659.
22. Zhang Y, Shan X, Shi L, Lu X, Tang S, Wang Y, et al. Development of a fimY-based loop-mediated isothermal amplification assay for detection of Salmonella in food. Food Research International. 2012;45(2):1011-1015.
23. Wang L, Shi L, Alam M, Geng Y, Li L. Specific and rapid detection of foodborne Salmonella by loop-mediated isothermal amplification method. Food Research International. 2008;41(1):69-74.
24. Chen Z, Zhang K, Yin H, Li Q, Wang L, Liu Z. Detection of Salmonella and several common Salmonella serotypes in food by loop-mediated isothermal amplification method. Food Science and Human Wellness. 2015;4(2):75-79.
25. Nagamine K, Hase T, Notomi T. Accelerated reaction by loop-mediated isothermal amplification using loop primers. Molecular and cellular probes. 2002;16(3):223-230.