Submitted to: International Journal of Food Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/1/1997
Publication Date: N/A
Interpretive Summary: Food poisoning resulting from bacterial contamination of poultry meat continues to be a health concern for the public at large. Young chicks of a few days of age are particularly prone to harboring the bacteria that cause food poisoning. One way to prevent such food poisoning is to give young chicks bacteria from healthy adult chickens. These young chicks can now exclude the bacteria that cause food poisoning. Using specialized proteins, we have been able to quantify individual bacteria in such a mixture from adult birds. These findings are relevant for the industry, producer and consumer since we can now identify and quantify which bacteria play a critical role in determining resistance to food poisoning. Such findings can lead to a healthier more wholesome food product for the consumer.
Technical Abstract: Murine monoclonal antibodies were used in an enzyme-linked immunosorbent assay (ELISA) for the detection and quantification of selected probiotic bacteria present in a continuous-flow competitive exclusion culture known to be effective at reducing chicken cecal and crop colonization by Salmonella typhimurium. Veillonella, Enterococcus avium, and S. typhimurium were grown anaerobically in batch culture of Viande Levure broth, in pure culture, and mixed culture. The mixed cultures produced significantly more acetate and propionate than any of the pure cultures with acetate and propionate being the predominant volatile fatty acids. The association in mixed culture resulted in a significant increase in cell number compared to the respective pure cultures. The ELISA was capable of detecting 10**4 cell/ml of the bacteria. The plots of cell number determined by the ELISA versus direct plating increased in accordance with increases in cell numbers and r**2 values of 0.950, 0.922, and 0.940 for the pure culture incubations and 0.901, 0.924, and 0.905 in mixed culture incubations for E. avium, S. typhimurium and Veillonella, respectively, were observed. The results indicate that the monoclonal antibodies can be used to quantitatively assay individual probiotic bacterial species grown in a mixed culture incubation.