title: Effect of native microflora on the growth kinetics of salmonella enteritidis strain 04-137 in raw ground chicken.
abstract: Effects of native microflora (NM) on growth kinetics of Salmonella Enteritidis strain 04-137 were studied in raw ground chicken. First, samples of ground chicken with high and low levels of NM (10(7.1) and 10(4.9) CFU/g, respectively) were spiked with Salmonella at doses ranging from 10(1) to 10(4) CFU/g. The growth kinetics, including the rate constant of growth, r, and the lag period, were similar, but the maximum cell level, N(max), was higher at higher initial Salmonella doses for both NM levels. Second, samples of ground chicken with high and low NM levels (10(6.8) and 10(4.7) CFU/g, respectively) were spiked with Salmonella and then stored at various constant temperatures ranging from 8 to 32°C. Both N(max) and r for Salmonella were higher at higher temperatures for both NM levels. Although r for total bacteria, which consisted of NM and Salmonella, was also higher at higher temperatures, N(max) was constant at all temperatures for both NM levels. Further, Salmonella growth was compared among samples of ground chicken with high and low NM levels and samples of sterilized chicken. Salmonella growth, characterized by both N(max) and r, was highest in sterilized chicken, followed by chicken with the low NM level. Our growth model successfully described and analyzed the growth of Salmonella and total bacteria in chicken at constant temperatures; using the data obtained, the model also successfully predicted the growth of Salmonella and total bacteria in chicken stored at dynamic temperatures. Our study clarified the effects that different doses of NM in ground chicken had on the growth kinetics of the Salmonella strain and demonstrated the usability of the growth model for foods with NM.
authors.affiliation: Laboratory of Veterinary Public Health, Faculty of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu, Tokyo, 183-8509 Japan.
authors.forename: Sakha M
authors.initials: SM
authors.lastname: Zaher
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Fujikawa
mesh_terms: D000818:Animals; D015169:Colony Count, Microbial; D003257:Consumer Product Safety; D005506:Food Contamination / Q000032:analysis*; D005516:Food Microbiology; D006801:Humans; D007700:Kinetics; D008954:Models, Biological; D011202:Poultry Products / Q000382:microbiology*; D012477:Salmonella enteritidis / Q000254:growth & development*; D013696:Temperature