Iranian Journal of

Background and Objective: Environmental pollution with heavy metals and consequently their entry into food chains leads to irreparable damage to human health. The aim of this study was to determine the concentration of heavy metals including copper, zinc, lead and cadmium in blood and milk of grazing livestock around Zinc industry in Zanjan province (VSIPZ).
Materials and Methods: A total of 10 samples of grazing blood and milk were taken in each of the four geographical directions of the desired location. Also, in order to compare the current situation in the study area with the non-polluted areas, the control area (Qarah Poshtlu area of Zanjan) was considered. Dry ash method was used to digest organic matter.
Results: The results showed that the concentration of copper in the blood of cows and sheeps and the concentration of lead in the blood of cows in the west of VSIPZ was higher than the control group (p <0.05). There was no significant difference between the study areas and the control in terms of zinc and cadmium concentration in blood samples. Copper concentrations in cows and sheeps milk were lower than the control group in the southern and eastern regions of the VSIPZ, respectively (p <0.05). Zinc and lead concentrations in sheeps’ milk were higher than the control in the south and west of the VSIPZ, respectively (p <0.05).
Conclusion: In general, the results implied that the accumulation of lead in sheeps’ milk in the west of VSIPZ is more than maximum allowable concentration and can endanger the health of consumers.

Background and Objective: One of the main causes of cheese contamination with S.aureus is the use of unpasteurized milk. Improper cheese processing methods can also lead to contamination with this bacterium. Considering the significant role of S.aureus in foodborne intoxications and the World Health Organization’s recommendation for continuous surveillance of this bacterium, this cross-sectional study aims to determine the prevalence and antibiotic resistance pattern of S.aureus in traditional sheep cheese from Chalous (Mazandaran Province, Iran).
Materials and Methods: A total of 45 samples of traditional sheep cheese were randomly collected from local dairy shops in Chalous. Initially, the samples were examined for contamination with S.aureus using culture-based methods. Finally, the antibiotic resistance pattern of the isolates against nine different antibiotics were determined using the disk diffusion method.
Results: Among 45 collected samples of traditional sheep cheese, 17 samples (37.8%) were contaminated with S. aureus. Of the 18 isolates obtained from traditional Chalus cheese samples, the highest resistance was observed against penicillin (64.7%) and tetracycline (58.8%), whereas the lowest resistance was detected against gentamicin and erythromycin (23.5%). Moreover, the 17 isolates obtained from traditional sheep cheese samples exhibited simultaneous resistance to 2 to 8 antibiotics.
Conclusion: A high level of contamination with S.aureus in traditional sheep cheeses produced in Chalous (Mazandaran, Iran), was observed. Adherence to hygienic practices in dairy farms and the implementation of public health education can help prevent secondary contamination during cheese processing and reduce the widespread dissemination of this bacterium in traditional dairy products.