[False-positive results obtained on examining slaughtered animals for the presence of antibiotic residues (author’s transl)].

The research paper aims to identify if false-positive results are likely when testing slaughtered animals for antibiotic residues using the Sarcina lutea kidney test and Bacillus subtilis BGA test.

Methodology

• The researchers conducted studies on emergency slaughtered animals, specifically cattle, calves, swine, and horses, to evaluate the presence of antibiotic residues.
• Two types of tests were used – the Sarcina lutea kidney test and the Bacillus subtilis BGA test.
• The animals’ history and medication information were gathered to check if they had been given any antibiotics.
• Samples from animals under stress prior to slaughter were also tested.

Results from the Sarcina lutea kidney test

• When the Sarcina lutea kidney test showed a positive result in cattle, calves, and swine, the researchers found penicillin residuals, even though the animals had reportedly not been given antibiotics.
• Possible sources of penicillin residues were identified as the syringe used for testing or the injected fluid, both of which might have been contaminated.
• Testing in horses, especially those that had been in a stressful state before slaughter, occasionally yielded false-positive results.

Results from the Bacillus subtilis BGA test

• With the Bacillus subtilis BGA test, a significant number of false-positive results were obtained.
• This issue raised questions about the reliability of this test method, particularly for kidney examination.
• Several drugs used in veterinary medicine appeared to inhibit the growth of the test organisms, Sarcina lutea and Bacillus subtilis, in vitro (in the lab). Nevertheless, these drugs did not generate positive results in the Sarcina lutea kidney test when used therapeutically (in vivo).
• However, when animals were administered lidocaine and calcium borogluconate, false-positive results were obtained using the Bacillus subtilis BGA renal medullary test.

Conclusions

• The findings from both methods question the accuracy of false-positive results during tests for antibiotic residues in slaughtered animals, suggesting that test methods or conditions might affect results.
• The results may lead to revisions of current testing protocols or encourage further research into other methods of antibiotic residue examination.