Residue analysis: Future trends from a historical perspective.

A residue is a trace (microg kg(-1), ng kg(-1)) of a substance, present in a matrix. Residue analysis is a relatively young discipline and a very broad area, including banned (A) substances as well as registered veterinary medicinal products (B substances). The objective of this manuscript is to review future trends in the analysis of residues of veterinary drugs in meat producing animals out of historical perspectives.

Stability of frozen stock solutions of beta-lactam antibiotics, cephalosporins, tetracyclines and quinolones used in antibiotic residue screening and antibiotic susceptibility testing.

The stability of frozen stock solutions of antibiotics belonging to three different families was evaluated using an agar diffusion test, with Bacillus subtilis as a test strain. Diameters of inhibition zones were measured at monthly intervals during 6 months, and the decline in active substance was calculated. Penicillin and amoxicillin lost nearly half of their potency, the cephalosporins ceftiofur and cefapirin one quarter, but ampicillin was more stable.

Microbiological detection of 10 quinolone antibiotic residues and its application to artificially contaminated poultry samples.

To assess if microbiological inhibition tests for detection of antibiotic residues are suitable for routine screening for quinolone residues, the limit of detection (LOD) of 10 different quinolones and fluoroquinolones was determined. Two media were tested, one at pH 6 and the other at pH 8, each seeded with one of the following test strains: Bacillus subtilis, Escherichia coli or Bacillus cereus. LODs of the 10 substances were highest on plates seeded with B.

Interlaboratory study based on a one-plate screening method for the detection of antibiotic residues in bovine kidney tissue.

A microbiological test based on one-plate, seeded with Bacillus subtilis BGA, is frequently used in Belgium as a screening method to monitor antibiotic residues in kidney tissue of slaughter animals. The procedure as described in the National Legislation recommends test agar pH 7.2 from Merck.

Evaluation and establishing the performance of different screening tests for tetracycline residues in animal tissues.

Four methods intended for screening muscle tissue for residues belonging to the tetracycline group were compared using artificially contaminated as well as incurred samples. Two agar diffusion methods were studied: one with Bacillus subtilis as a test strain, the second with Bacillus cereus. Two variants of each method were compared: thin plates for analysis of intact or minced meat, and thick plates for analysis of meat fluid.