Validation and Evaluation of Lateral Flow Tests for the Detection of Antimicrobial Residues on Poultry Feathers

Persistence of antimicrobial drugs (AMDs) administered to poultry is longer in feathers than in edible tissues. Hence, poultry feathers are a suitable matrix to investigate historical exposure contributing to antimicrobial resistance, since current detection methods are either non-specific or highly technical and costly. Here we present an analysis of the performance of lateral flow test (LFT) panels in the detection of five AMD classes, namely sulfonamides, tetracyclines, beta-lactams, quinolones, and aminoglycosides, on chicken feather samples. The limit of detection (LOD) of eight AMD substances was determined between 4.7 μg/kg for enrofloxacin and 700 μg/kg for streptomycin. The performance of feather LFT was evaluated for four AMD classes against the reference method (LC-MS/MS). From 79 samples collected from the field, LFT test specificity ranged from 0.63 (quinolones) to 0.95 (tetracyclines). Test sensitivity ranged from 0.15 (beta-lactams) to 0.78 (quinolones and tetracyclines). LFT testing had the greatest discriminatory power for tetracyclines (specificity 0.95 and sensitivity 0.78). LFT had similar test characteristics for sulfonamides and quinolones and performed poorly for beta-lactams. Poor recovery rates (< 15%) were observed in neomycin, kanamycin, and ampicillin. These methods are suitable for preliminarily screening tetracyclines, sulfonamides, and quinolones, with recommendations for further extraction protocols.