The aim of this study was to perform an in-house validation of multiplex PCR method for C. botulinum detection in food and feed samples. The study was carried out on food and feed matrixes artificially contaminated by spores of C. botulinum reference strains. The following characteristic parameters for qualitative detection were estimated: limit of detection expressed as LOD50 according to the Spearman-Kärber formula, specificity, sensitivity, and accuracy according to the PN-EN ISO 16140:2004. The validated method showed high specificity. Specific PCR products were revealed only for DNA obtained from samples contaminated with C. botulinum spores. PCR inhibition was observed, especially during examination of contaminated feed. The calculated LOD50 for feed was nearly 10 times higher than for food. The implemented method enables to obtain test results during 3 d without time- consuming process of isolation and proving the ability of strains to produce botulinum toxins.
Introduction: The influence of feeding genetically modified MON 810 hybrid maize on the growth and haematological and biochemical indices of rats was tested.
Material and Methods: Two conventional (non-GM) and two test (MON 810) lines of maize were used in semi-purified diets at the level of 40% w/w. The non-GM I, MON 810 I, non-GM II, and MON 810 II maize lines were near-isogenic. A total of 40 male 6-week-old Wistar-derived rats were assigned to four equal feeding groups corresponding to the four maize lines for 16 weeks. Overall, health, body weight gain, clinical pathology parameters, gross changes, and appearance of tissues were compared between groups.
Results: There were no statistically significant differences in the weight gain or relative organ weights of rats, but there were some non diet-related histopathological changes in the liver, kidneys, and spleen. Except for creatinine level, no diet-related effects were observed in haematology or most of the biochemical indices. Transgenic DNA of MON 810 maize was not detected in the tissues or faeces nor in the DNA of E. coli isolated from the rectum digesta of rats given transgenic feeds. In our experiment, various metabolic indices of rats fed non-GM diets or genetically modified (MON 810) maize for 16 weeks were similar. No adverse nutrition-related health effects were detected.
Conclusion: MON 810 maize seems to be as safe as the conventional maize lines.