Purpose: As an expansion of a previously successful program, the Vermont Institute for Artisan Cheese provided one-on-one technical assistance to 9 Vermont cheese makers through targeted, comprehensive audits and microbiological data collection to identify and mitigate risks specific to each business.
Methods: Sponge samples collected from target areas based on facility conditions and traffic patterns were analyzed for aerobic bacteria (n = 89), coliforms (n = 150), and Listeria species (n = 268). Results were used to develop risk mitigation strategies. Samples of raw milk, curds, whey, brine, and finished cheese were collected and screened for Listeria monocytogenes, Salmonella, Escherichia coli O157:H7 and Staphylococcus aureus. Follow up visits were conducted to assess the implementation of recommendations and to collect samples for follow up analysis.
Results: In addition to reduction in aerobic bacteria and coliforms, Listeria spp. and L. monocytogenes contamination rates for non-food contact surfaces decreased from 18.2% to 6.3%, and 4.9% to 2.5%, respectively. Staph. aureus was the most common organism isolated from in-process samples and brine although L. monocytogenes was detected in the milk, whey and resulting cheese from one farm on both visits which was preliminarily traced back to contaminated feed. No E. coli O157:H7 or Salmonella were detected in any sample.
Significance: Our data confirm the value of this type of program as an effective tool to help businesses better understand and manage food safety risks and validate preventive controls, with declines in incidence and levels of target pathogens and indicator organisms between visits.