DEVELOPMENT OF A RAPID DIAGNOSTIC KIT FOR DETECTION OF SALMONELLA ENTERITIDIS IN FOOD USING INDIRECT COAGGLUTINATION TECHNIQUE

Abstract

The objective of this study was to develop a rapid, simple, cheap, sensitive, and specific assay for detection of Salmonella Enteritidis in food. The kit-prototype was developed by using indirect coagglutination technique with three main components, namely Staphylococcus aureus Cowan I, rabbit IgG anti-chicken Fc IgY and chicken IgY anti-S. Enteritidis. Isa Brown layer chickens were used to produce specific antibodies against S. Enteritidis. Monospecific antisera were prepared by absorption method. Staphylococcus aureus Cowan I was coupled with rabbit IgG anti-chicken Fc IgY and monospecific antisera anti-S. Enteritidis. Kit-prototype was compared with multiplex polymerase chain reaction to determine sensitivity and specificity of kit-prototype. Artificially inoculated food sample was used to determine the limit of detection of kit-prototype in a food sample. Indirect coagglutination kit-prototype was able to differentiate positive control from negative control without self-agglutination reaction. This assay has a high specificity to S. Enteritidis without significant cross-reactivity towards other bacteria. Kit-prototype was able to detect 108 CFU/mL of S. Enteritidis in the buffer and 1 CFU/mL of S. Enteritidis in a food sample after selective enrichment procedure. The application of this kit was able to give a fast result (reaction can be observed in 10 sec), to be applied in a sample without extraction in the preparation of antigen and to reduce detection time of S. Enteritidis in food until 4 days.