Validation of the AnticFast® Beta-Lactams Rapid Test Kit for Detection of Beta-Lactams (Penicillins and Cephalosporins) in Raw Cow's Milk: AOAC Performance Tested MethodSM 032303.

Background: AnticFast® Beta-Lactams Rapid Test Kit is a qualitative two-step (2 min + 5 min) rapid lateral flow assay to detect β-lactam (penicillins and cephalosporins) antibiotic residues in raw commingled cow's milk.

Objective: The method performance was evaluated according to Commission Decision 2002/657/EC, Commission Implementing Regulation 2021/808, and Community Reference Laboratories Residues Guidelines for the Validation of Screening Methods for Residues of Veterinary Medicines.

Methods: The AnticFast Beta-Lactams Rapid Test Kit was evaluated for detection capability, selectivity, false-positive results, repeatability, robustness, suitability for various milk types and milk compositions, milks from various species, and test kit consistency and stability. Samples included milks spiked at concentrations bracketing the EU maximum residue limits (MRLs) for β-lactams as well as bulk farm and tanker milks.

Results: The AnticFast Beta-Lactams Rapid Test Kit is specific for the detection of β-lactams in milk and does not detect compounds from other antibiotic families. Interference was seen with clavulanic acid, a β-lactamase inhibitor, which was expected. The test can detect all residues of β-lactams (penicillins and cephalosporins) present on the EU-MRL list for milk at their respective MRL except for desfuroylceftiofur and cephalexin, which were above the MRL. No false positives were detected in the 602 (300 blank farm and 302 tanker load) samples tested. Robustness testing indicated that the detection in heat-treated milk types may be slightly hampered. For substances with a detection capability well below the MRL, this interference does not cause problems since detection at MRL remains guaranteed, but care should be taken for substances with a CCβ at or near their MRL. Diminished sample flow was seen with reconstituted milk powder and blank ewes' milk, so sample flow should always be verified for these milk types.

Conclusions: Results of this validation show that the AnticFast Beta-Lactams Rapid Test Kit is a reliable test for rapid screening of raw cows' milk for residues of β-lactam antibiotics.

Highlights: AnticFast Beta-Lactams Rapid Test Kit is an easy, realiable, robust and highly specific test for screening of raw cows' milk for residues of penicillins and cephalosporins.