Submitted to: International Poultry Scientific Forum
Publication Type: Abstract Only
Publication Acceptance Date: 10/22/2009
Publication Date: 1/25/2010
Citation: Cox Jr, N.A., Richardson, L.J., Cray, P.J., Cason Jr, J.A., Buhr, R.J. 2010. S. Enteritidis growth characteristics utilizing different enrichment broths which contain other Salmonella serovars and extraneous bacteria. International Poultry Scientific Forum. January 25 -26, 2010. Atlanta, GA. Interpretive Summary:
Technical Abstract: S. Enteritidis (SE) is associated with poultry and human foodborne outbreaks. SE isolation from poultry environments can be problematic using cultural methods when other serotypes are present. The objective was to evaluate non-stressed and stressed SE marker strain growth in buffered peptone water (BPW), universal preenrichment (UP), and tetrathionate (TET) with other Salmonella and non-Salmonella microflora present. Two experiments were performed with two replications per experiment. In experiment 1, enrichment broth tubes were inoculated with log 1.8 cfu/ml of marker SE (naladixic acid resistance greater than 200ppm) and equally divided into four sets with three tubes per set. For experiment 2, a log 1.8 cfu/ml of marker SE was inoculated onto 2.54 cm2 hatchery trayliners and left exposed to desiccation for 48 hrs and then individually placed into enrichment broths. Set 1 served as the control; set 2 contained the SE marker with log 2 cfu/ml of S. Kentucky, S. Typhimurium and S. Enteritidis (field strain) cocktail; set 3 contained a 1:3 ratio of enrichment broth to fecal material; while set 4 contained fluff at the same ratio as in set 3. For the non-stressed SE marker, growth in BPW averaged log 8.5, 4.9, 2.3, and 2.9 cfu/ml for the control, cocktail, feces, and fluff, respectively. Growth in UP averaged log 8.7, 3.9, 3.6, and 4.9 cfu/ml for the control, cocktail, feces, and fluff, respectively, while growth in TET averaged log 8.1, 2.5, 1.5, and 2.8 cfu/ml for the control, cocktail, feces, and fluff, respectively. For the stressed SE marker, growth in BPW averaged log 8.05, 3.92, 4.75, and 5.08 cfu/ml for the control, cocktail, feces, and fluff, respectively. Growth in UP averaged log 8.17, 3.74, 4.88, and 5.39 cfu/ml for the control, cocktail, feces, and fluff, respectively, while growth in TET averaged log 8.1, 4.64, 6.7, and 5.56 cfu/ml for the control, cocktail, feces, and fluff, respectively. No significant difference (p>0.05) in SE marker growth was observed in pure culture between the enrichment broths. Adding other Salmonella strains, feces, and fluff significantly (p=0.05) reduced SE marker growth in each enrichment broth and significant differences between enrichment broths were noted. Further investigations on factors that affect SE growth during cultivation may enable cultivation method developments where specificity is geared toward SE recovery.