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Background and purpose: Since long time ago herbal products and spices have been used as powders, essential oils (EOs), and extracts. They consist of antimicrobial components and could be applied as natural food preservatives. In the present work, the antiviral effect of cinnamon, rosemary, and zataria EOs has been investigated against norovirus surrogates including feline calicivirus (FCV) and murine norovirus (MNV).

Materials and methods: Different concentrations of EOs were individually mixed with each virus at titers of ca. 7-8 log TCID50/ml and incubated for 2 h at 4ºC and 37 ºC. The infectivity of the recovered viruses was evaluated by cell-culture assays.

Results: At 37 ºC, 3% of cinnamon, 2.5% of rosemary and 0.1% of zataria EOs decreased the FCV titers by 2. 38, 3.38, and 4.51 log TCID50/ml, respectively. At lower concentrations they were found to be less effective. Also, different concentrations of EOs decreased MNV titers by 0.25-1.44 log TCID50/ml. The maximum titer reduction (4.51 log TCID50/ml) was achieved when the FCV was treated at 37 ºC with 0.1% of zataria EO.

Conclusion: The reduction on the infectivity titers found for the tested norovirus surrogates with these EOs highlighted their potential role as biopreservatives to improve food hygiene and shelflife.

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Background and purpose: Prevalence of antibiotic resistant Staphylococcus aureus strains in foodstuff is becoming a serious health problem, especially in developing countries. This research was conducted to investigate the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) in traditional cheese samples in Mazandaran province, Iran. 
Materials and methods: In this descriptive cross-sectional study, the presence of MRSA was investigated using specific mecA primers by PCR in 360 cheese samples in Mazandaran province, which were collected during one year. The resistance of isolates to vancomycin, erythromycin, oxacillin, ciprofloxacin, penicillin, tetracycline, gentamycin, and cotrimoxazol was determined through disc diffusion method.
Results: Among the samples tested, 62.2% were contaminated by S. aureus (average count of 3.96 log cfu g^-1). From 224 isolates 199 (88.8%) were methicillin-resistant. MRSA resistance to antibiotics was as follows: gentamycin 77%, cotrimoxazol 75%, vancomycin 68%, ciprofloxacin 60%, oxacillin 52%, tetracycline 29%, erythromycin 15%, and penicillin 10%.
Conclusion: The results showed high levels of contamination to MRSA in traditional cheese samples. Proper hygienic handling in farms, using pasteurized milk, and providing people with ample information about health guidelines could prevent cross contamination during processing and prevalence of the bacteria in traditional products.