ABSTRACT
        Background and Objectives: Several virulence factors are involved in the pathogenesis of Staphylococcus aureus. Surface proteins such as collagen binding proteins (Cna) and fibronectin-binding proteins (FnBP) are important factors in adhesion and invasion of S. aureus. The aim of this study was to evaluate the frequency of adherence genes cna, fnbA and fnbB S. aureus isolates from traditional cheese.
        Methods: All 22 isolates tested were identified as S. aureus. The isolates were tested for the presence of adherence genes cna, fnbA and fnbB using specific primers in polymerase chain reaction assay. 
        Results: Six isolates (27.27%) were positive for the can gene. Of the 22 isolates studied, one isolate was positive for fnbA and one was positive for the fnbB. Co-presence of the genes examined was not observed in any of the isolates.
        Conclusion: The results indicate the weak biofilm formation ability of the S. aureus isolates from traditional cheese.
        Keywords: Staphylococcus aureus, Biofilm, Genes, Cheese. 

ABSTRACT
          Background and Objectives: Determining the genetic relationship between S. aureus isolates is important for epidemiological surveillance and control of infections caused by this bacterium. The present study was conducted to determine polymorphisms of coagulase gene (coa) among S. aureus isolates from pastry and cheese samples using restriction fragment length polymorphism (RFLP) analysis.
         Methods: Overall, 65 S. aureus isolated from pastry (n=45) and cheese (n=20) samples were examined for the coa gene by polymerase chain reaction (PCR). PCR products were digested with AluI enzyme and the products were assessed using gel electrophoresis.
          Results: Except for two isolates, all isolates were positive in coa-PCR and produced four different PCR products, with molecular sizes ranging from 570 to 970 bp. Overall; five distinct RFLP patterns were detected (I-V). Although pattern types I and III were present in isolates from both samples, types I and IV were mainly present in isolates from cheese and pastry samples, respectively.
        Conclusion: PCR-RFLP analysis of the coa gene indicates that S. aureus isolates from pastry and cheese samples may be originated from different sources. However, as one pattern type was predominant in each group, it can be concluded that majority of the isolates may have the same origin.
          Keywords: Staphylococcus aureus, PCR-RFLP, Coagulase, Pastry, Cheese.

ABSTRACT
           Background and Objectives: Local cheese made from raw milk is one of the most commonly consumed dairy products in the world. Mycotoxin contamination of foodstuff and its transmission to consumers are extremely important public health issues. The purpose of this survey was to determine the level of aflatoxin M1 (AFM1) residues in Koupeh cheese, a traditional fermented Iranian cheese produced in spring and summer.
           Methods: We randomly collected 48 local cheese samples produced in Mahabad (northwest of Iran) during spring and summer. The level of AFM1 was measured by enzyme-linked immunosorbant assay using commercial kits and a microplate reader.
           Results: All samples contained measurable amounts of AFM1. Cow milk cheese samples contained higher level of AFM1 compared to sheep milk cheese samples. The level of AFM1 in the samples from both animals was lower in summer. There was no significant difference between the mean level of AFM1 in summer and spring. Moreover, 33.3% of cow milk cheese samples collected in spring and 16.6% of the samples collected in summer contained toxin levels higher than the maximum allowed concentration set by the European Commission (250 ng/Kg) and by the Institute of Standards and Industrial Research of Iran (200 ng/Kg).
           Conclusion: The results of this study show that the level of AFM1in Koupeh cheese is influenced by the livestock type and production season, in a way that the level of contamination is higher in spring.
           Keywords: Cheese, Cultured Milk Products, Aflatoxin M1, ELISA.