Validation of a Rapid Visual Screening of Campylobacter jejuni in Chicken Using Antibody-Conjugated Fluorescent Dye-Doped Silica Nanoparticle Reporters

The objective of this work was to validate the antibody-conjugated fluorescent dye-doped silica nanoparticle- (FDS-NP-) based assay for the rapid detection of Campylobacter jejuni in chicken samples using ISO16140:2003 single-laboratory validation guidelines. This assay reversed the paradigm of microbial testing. The noncultured FDS-NPs increased the fluorescent light signal of the test, not the cell numbers, and significantly reduced the detection time. Validation results showed that relative detection level (LOD) of the assay was 103 cfu/ml. The antibody-conjugated FDS-NPs were evaluated for the detection of C. jejuni in 140 chicken samples collected from slaughterhouses (50 carcass rinse water, 60 rectal swabs, and 30 viscera contents) against ISO 10272 reference method with duplex PCR confirmation. The relative accuracy (AC), relative specificity (SP), and relative sensitivity (SE) were 95.67%, 100%, and 94.87%, respectively. The inclusivity test of C. jejuni strains was 100% positive. The exclusivity test demonstrated no cross-reactivity with 32 strains of non-Campylobacter strains. The FDS-NP assay was very fast and specific, with time to result of 30 min compared with the 2–5 days required by the reference method. The noncultured FDS-NPs demonstrated comparable performance to the cultured reference method to detect C. jejuni in poultry samples. It is applicable for effective screening of poultry product category.