Original scientific paper

https://doi.org/10.24099/vet.arhiv.0818

Evaluation of a rapid enzyme immunoassay test for diagnosis of contamination of milk, water and feces to Salmonella Typhimurium

Mohammad Khosravi orcid.org/0000-0001-9510-3464 ; Department of Pathobiology, Faculty of Veterinary Medicine, Shahid Chamran University of Ahvaz, Iran
Darioush Gharibi ; Department of Pathobiology, Faculty of Veterinary Medicine, Shahid Chamran University of Ahvaz, Iran
Najmeh Moradi ; Graduated Student, Faculty of Veterinary Medicine, Shahid Chamran University of Ahvaz, Iran
Masood Ghorbanpoor ; Department of Pathobiology, Faculty of Veterinary Medicine, Shahid Chamran University of Ahvaz, Iran

Abstract

Serology-based detection methods have more applicable characteristics than standard bacterial culture methods. The aim of this study was to evaluate a cost-efficient, rapid, sensitive and simple test to diagnose milk, water and feces contaminated with Salmonella enteric subsp. enterica serovar Typhimurium (S. Typhimurium). The method developed was based on the addition of HRP-conjugated anti-Salmonella antibodies to the sample, precipitation of the complexes formed using centrifuge, and evaluation of the peroxidase activity of the sample supernatants. Raw cow’s milk, water and cattle feces samples were spiked with seven concentrations of S. Typhimurium. The optimized test recorded an accurate volume and concentration of HRP-conjugated antibodies, the bacteria, samples, ionic compounds and the precise time of the reaction. Also, the method of the test and standard sample preparation were carefully optimized. The tests were repeated at least ten times, and the minimum level of detectable bacteria was determined for each repetition. The results obtained were compared with the conventional bacterial culture method. The results showed that in an optimal condition, conjugated anti-Salmonella antibodies interacted with the bacteria in any matrix. The developed method can detect at least 30, 30, 3×103, and 3×103 cell/mL of S. Typhimurium in water, PBS, milk and feces samples respectively, in less than 20 minutes. Also, antibody detection using this EIA can detect an antibody concentration range of 4.3-70 μg/mL. The developed method is a rapid, cost-efficient and simple assay, and can be used to detect S. Typhimurium in various samples.

Keywords

EIA; Salmonella Typhimurium; water; milk; feces

Hrčak ID:

245823

URI

https://hrcak.srce.hr/245823

Publication date:

10.11.2020.

Article data in other languages: croatian

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