Background
The
Conclusion
This study provides data on the growth of Campylobacter in a range of laboratory media, caecal contents, and in broilers which may be used to develop predictive models and/or inform science-based control strategies such as the maximum time between flock testing and slaughter, logistical slaughter, and single-stage depopulation of broiler units.
Methods
Bolton and brain heart infusion broths and recovered caecal material were inoculated with 10 poultry strains of Campylobacter (eight Campylobacter jejuni and two Campylobacter coli), incubated under microaerobic conditions, and Campylobacter concentrations determined periodically using the ISO 10272:2006 method. Caeca from 10 flocks, infected at first thinning, were used to characterise Campylobacter growth in the live birds. Mean generation times (G) (early lag to exponential phase) were calculated using the formula: G=t/3.3 logb/B. Mean lag times and µmax were calculated using the Micro Fit(©) Software (Version 1.0, Institute of Food Research). Statistical comparison was performed using GENSTAT ver. 14.1 (VSN International Ltd., Hemel, Hempstead, UK).
Results
The mean lag periods in Bolton broth, brain heart infusion broth, caecal material, and in the live bird were estimated to be 6.6, 6.7, 12.6, and 31.3 h, respectively. The corresponding mean generation times were 2.1, 2.2, 3.1, and 6.7 h, respectively; maximum growth rates were 0.7, 0.8, 0.4, and 2 generations h(-1) and the maximum populations obtained in each matrix were 9.6, 9.9, 7.8, and 7.4 log10 CFU/g, respectively.