Methicillin-resistant S.aureus (MRSA) in food-clinical significance for public and animal health

MRSA (Methicillin-resistant S. aureus) has been discovered in 1961. Since then, the global epidemiology of MRSA has significantly worsened (with the exception of few countries including Scandinavia) and MRSA is currently considered one of the most dangerous and widespread antibiotic resistance mechanism. During the 20th century, the finding of MRSA in animal was rare and in almost 100% of case, humans (owners) were considered primary carriers. Due to the specific adaptation of staphylococci to the certain animal species, it was also considered that MRSA are not zoonotic agents. Despite those claims, the cases of spreading of serious MRSA infection from animal to humans were reported and, at the beginning of 21 st century, MRSA were declared as zoonotic agents (although, the question of whether the humans or animal were primary carriers is still the subject of scientific debates). The importance of MRSA in the 21 st century has spread from the field of human and veterinary medicine to the food industry. The presence of MRSA in beef or chicken or in any other meat (or milk) product is expected when MRSA are present in the organism of food animals. The presence of MRSA in food is much more complicated to study because contamination of food with MRSA is possible during any stage of the food production and even during market sales. However, the majority of food authorities in their reports claim that the risk of MRSA infection in humans via contaminated food is extremely low. Accordingly, MRSA are not considered as foodborne pathogens and, there are no legal obligations for the routine investigation of the presence of MRSA in foods of animal origin, although it is suggested that such investigations should be conducted on a voluntary basis. Nevertheless, we are witnessing that clinical microbiology and food hygiene have completely different views on significance of MRSA and its impact on public and animal health. In this lecture, these differences will be discussed.

کلیدواژه ها:

MRSA ، Zoonotic agents ، Foodbome pathogen