Submitted to: American Society of Microbiologists Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: May 10, 1996
Publication Date: N/A
A continuous flow (CF) culture composed of 29 cecal bacterial strains from adult broilers has been shown to increase resistance of chicks to Salmonella typhimurium. Efficacy of this culture has been correlated with increased concentrations of propionic acid and volatile fatty acids (VFA). Production of these acids is a complex process and a greater understanding of interactions between microbial populations present is necessary to understand the mechanisms that prevent establishment of salmonellae in the ceca. S. typhimurium, and two CF organisms, Enterococcus avium and a Veillonella species were grown in a pure and mixed culture for 24h in Viande Levure medium to assess associative interactions. Brilliant green agar and mEnterococcus agar were used for the isolation of Salmonella and Enterococcus, respectively. Veillonella was enumerated as the yellow colonies on tryptic soy agar containing 60mM lactate and 1% vancomycin. Monoclonal antibodies were also used to confirm detection of Veillonella in the mixed culture. Growth rates (h**-1) for Enterococcus, Salmonella, and Salmonella in 6mM glucose were 1.37, .512 and .278, respectively. The growth rate for Veillonella was higher on lactate than on glucose in pure culture (.528 in 10mM lactate) and propionate was the major VFA produced. Enterococcus, Veillonella, and Salmonella produced 118, 34.7, and 3.2 (umol/ml) of lactate in 10h in pure culture. However, in mixed culture the lactate concentration was 3.3 with acetate and propionate as the predominant VFA. The results suggest that lactate produced by Enterococcus is utilized by Veillonella and increases Veillonella cell numbers from 10**8 in pure culture to 10**11 in mixed culture.