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Published on: November 4, 2016
Methicillin-Resistant Staphylococcus aureus (MRSA) in Dairy Products and Bulk-Tank Milk (BTM)
Camino González-Machado1,2, Rosa Capita1,2, Carlos Alonso-Calleja1,2
1Department of Food Hygiene and Technology, Veterinary Faculty, University of León, E-24071 León, Spain.
Abstract:
In order to contribute to an assessment of the role of food in the risks of transmission of methicillin-resistant Staphylococcus aureus (MRSA), a review was undertaken of research on this microorganism in milk and dairy products published from January 2001 to February 2024. A total of 186 publications were selected, 125 for dairy products and 61 for bulk-tank milk (BTM). MRSA was detected in 68.8% of the research into dairy products and 73.8% of investigations relating to BTM, although in most studies the prevalence was less than 5%. Of the set of S. aureus strains isolated, approximately 30% corresponded to MRSA. The foods most extensively contaminated with this microorganism were raw milk and some types of soft cheese. Determination of the mecA gene on its own is known not to suffice for the detection of all MRSA strains. The great diversity of techniques used to study MRSA in milk and dairy products made it difficult to draw comparisons between studies. It would thus be advisable to develop a standardized protocol for the study of this microorganism in foods.
Insights
Methicillin-resistant Staphylococcus aureus (MRSA) is present in many dairy products and bulk-tank milk, though often at low levels. Standardized detection methods are needed for accurate risk assessment in food.
Area of Science:
- Food safety
- Microbiology
- Public health
Background:
- Methicillin-resistant Staphylococcus aureus (MRSA) poses a foodborne transmission risk.
- Understanding MRSA prevalence in milk and dairy is crucial for public health.
- Previous research on MRSA in food requires synthesis.
Purpose of the Study:
- To review and assess research on MRSA in milk and dairy products.
- To evaluate the role of food in MRSA transmission risks.
- To identify research gaps and methodological challenges.
Main Methods:
- Systematic literature review of publications from January 2001 to February 2024.
- Analysis of 186 selected studies on dairy products (125) and bulk-tank milk (61).
- Evaluation of MRSA detection rates and prevalence in selected food matrices.
Main Results:
- MRSA was detected in 68.8% of dairy product studies and 73.8% of bulk-tank milk studies.
- Prevalence was generally below 5% in most positive studies.
- Raw milk and soft cheeses showed the highest contamination; approximately 30% of S. aureus strains were MRSA.
- The mec A gene alone is insufficient for comprehensive MRSA detection.
Conclusions:
- MRSA is frequently detected in milk and dairy products, indicating a potential food safety concern.
- Methodological diversity hinders direct comparison of study findings.
- A standardized protocol for MRSA detection in food is recommended to improve risk assessment.
