The aim of this study was to develop a nanoparticle-based cell capture system combined with a lateral flow test strip (LFT) assay for rapid detection of Campylobacter jejuni from poultry samples. The developed assay was bench-marked against the standard modified Charcoal Cefoperazone Deoxycholate Agar (mCCDA) method according to ISO16140:2003 procedures. The synthesized ferromagnetic nanoparticles (FMNs) were modified with glutaraldehyde, then functionalized with polyclonal antibodies for specific C. jejuni capture and concentration from poultry samples. After lysing captured cells, DNA from C. jejuni was amplified by PCR using the primers designed to target the hipO gene, and the PCR amplicons were detected with the lateral flow test strip assay. Following the ISO16140:2003 guidelines, the relative detection limit, and the inclusivity and exclusivity tests were determined. The results showed that the limit of detection (LOD) of the assay was 10 or 1 cfu/ml with C. jejuni in pure culture and 10-10 cfu/ml with target cells spiked in poultry sample. In addition, the inclusivity and exclusivity tests were found to be 100%. Using field chicken samples (n = 60), the assay showed relative accuracy, relative specificity, and relative sensitivity of 96.67%, 100% and 93.33%, respectively. The positive predictive values (PPV) and negative predictive values (NPV), and the kappa index of concordance (k) were calculated as 100% and 93.75%, and 0.93, respectively. The developed assay required approximately 3 h to complete and gave results comparable to those analyzed by the standard culture method, which required 5-7 days. The assay is rapid, easy-to-use, and has potential to be directly applied to C. jejuni detection in various categories of poultry samples.

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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.