Rapid Dot-Blot Immunoassay for Detecting Multiple Salmonella enterica Serotypes

Area of Science:

• Food Microbiology
• Immunodiagnostics
• Bacteriology

Background:

• Salmonella is a significant cause of foodborne infections, often leading to invasive disease and bacteremia.
• Over 2,600 Salmonella serotypes exist, but a few dominate human infections.
• Accurate and rapid identification of prevalent Salmonella serotypes is crucial for public health surveillance.

Purpose of the Study:

• To develop a rapid dot-blot immunoassay for simultaneous detection of high-incidence Salmonella enterica serotypes.
• To evaluate the efficacy of commercial antibodies for Salmonella serotype diagnosis.
• To establish a cost-effective and on-site diagnostic method for Salmonella.

Main Methods:

• Screening of 10 commercial antibodies (4 polyclonal, 6 monoclonal) against 18 key Salmonella serotypes.
• Western blotting was used to assess individual antibody performance.
• Combinations of antibodies were tested in a dot-blot immunoassay format.

Main Results:

• Antibodies Ab 3, Ab 8, and Ab 9 showed high detection rates individually.
• A combination of Ab 3 and Ab 8 identified 15 out of 18 tested serotypes within 3 hours.
• These 15 serotypes account for 53.7% of Salmonella infections in the U.S. (2016).

Conclusions:

• A rapid, cost-effective dot-blot immunoassay using antibody combinations can accurately detect prevalent Salmonella serotypes.
• This method offers a valuable tool for on-site, colorimetric detection of Salmonella.
• The assay facilitates timely identification of key serotypes contributing to foodborne illness.