Staphylococcus mastitis, biofilms, and antibiotic resistance: Barriers to milk quality and food safety on artisanal and farmstead cheese producing farms in Vermont

Staphylococcus mastitis, biofilms, and antibiotic resistance: Barriers to milk quality and food safety on artisanal and farmstead cheese producing farms in Vermont

Summary

The objective of this project is to support farmstead cheese producers with improved knowledge on mastitis, milk quality and food safety. The primary objective of this research is to quantify the diversity of Staphylococcus bacteria on farms that make artisan cheese and to describe the sources for potential pathogenic and beneficial members of this genus. Our goal is to identify potential practices that prevent persistence of pathogens while encouraging beneficial microbes. Work on this project was initiated in early November, 2014. We initiated molecular and phenotypic typing of Staphylococcus bacterial isolates obtained from one farm. Based on our work in the first month, we estimate we can complete molecular species identification on 48 isolates every 2 weeks, or approximately 100 isolates per month. We are on track to complete farm visits, sample collection and laboratory analysis in the first year of this two year project

Objectives/Performance Targets

Below are the objectives we intend to achieve in the next duration of the project. They have not changed as stipulated in the original proposal
1. To identify the sources of Staphylococcus species on farms that make farmstead cheese.
We will describe the detailed distribution of the CNS species on 5 dairy farms that make artisan or farmstead cheese. Under this objective we will use sequence-based molecular methods to describe the comparative distribution of bacteria isolated from various sources or niches on these farms.
The specific aims of this objective are to:
a. Identify the CNS species that are opportunistic mastitis pathogens and determine their sources on these farms.
b. Identify the CNS species that are normal flora of the udder and teat skin but are not commonly isolated from cases of mastitis, and describe these as a component of the beneficial teat skin commensal bacteria.
c. Identify the sources of CNS species that are known beneficial bacteria in cheese maturation.

Work has been initiated under this objective. Since funds became available; we have successfully completed typing of over 200 bacterial isolates from one artisan cheese farm.

2. To quantify the association between antibiotic resistance or biofilm formation and the staphylococci species or strains isolated from various sources on dairy farms
The specific aims of this objective are to:
a. Quantify the prevalence of antimicrobial resistance among the various CNS species isolated from different sources on artisan cheese farms.
b.Quantify the prevalence of biofilm forming bacteria among the various CNS species isolated from different sources on artisan cheese farms

Work under this objective will be started in 2015.

We have successfully recruited 2 undergraduate students to work on the project in the summer of 2015. We will add these participants in the next annual review

Accomplishments/Milestones

We have demonstrated the proposed PCR-based species typing system is able to discriminate among the staphylococcus species isolated from these farms and we have established laboratory methods and protocols. This project is progressing as expected and we anticipate completing the majority of sample collection and analysis in 2015. The two undergraduate students who will be working on this project over the summer of 2015 will contribute to completion of the research objectives in year 1 of the project. In year 2 (2016), we anticipate completing outreach objectives.

Impacts and Contributions/Outcomes

Nothing to report at this time. We anticipate improved understanding of Staphylococcus epidemiology and ecology on dairy farms will give more insight to the contribution of specific species and strains in this diverse group of bacteria. This will enable farmers and extension service providers to design control strategies for the pathogenic species. Controlling staphylococcus mastitis on farms that make artisan cheese will improve profitability, product quality, and cattle health and welfare.

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