The effects of essential oils, extracts and powder of Satureja bachtiarica bung on the bacterial growth of Staphylococcus aureus in cream cheese

Background and aims: Staphylococcus aureus is an important contaminant of milk and dairy products. It can cause a wide range of illnesses including, food poisonings and nosocomial infections. The aim of this study was to compare the antimicrobial effects of the essential oil , aqueous extract and powder of the Satureja bachtiarica on staphylococcus aureus. Methods: Satureja bachtiarica was collected from the heights of the province of Chaharmahal va Bakhtiari and its extract and essential oil were collected. The bacteria staphylococcus aureus was obtained from the Iranian Research Organization for Science and Technology. The bacterium was inoculated in equal amounts to specimens of cream cheese; afterward different concentrations of the essential oil , aqueous extract, and herbal powder were produced and inoculated in in equal amounts to the cream cheese specimens; subsequently, the specimens were checked 20, 40 and 60 days after inoculation. In the end, the microbial activity of the essential oil , aqueous extract and herbal powder were reported according to mg/ml. Results: The minimum growth of the bacteria staphylococcus aureus was observed in the 1000 milligram concentrations of essential oils and 125 mg of the aqueous extract and 125 mg of powder of the plant. At all the concentrations tested the pH changes in the fortieth day, and the changes in the rigidity of the cream cheese specimens were significant as well. At some of the concentrations of the aqueous extract and some concentrations of the herbal powder the changes in the texture of the cream cheeses, comparing to the controls, were significant. Conclusion: The essential oil , aqueous extract and powder of the Satureja bachtiarica have a great inhibiting effect on the growth of the bacterium staphylococcus aureus. Thus, it can be used as a natural preservative in foods with high lipid content

Bactericidal and Bacteriostatic effect of sesame oil, olive oil and their synergism on Escherichia coli in vitro

Background and aims: Escherichia coli is one of the important bacteria in nosocomial infections and its resistance to a wide range of antibiotics caused many problems for doctors and patients. So, it was attempted to find new substitution for these antibiotics. The aim of the present study was to determine the antimicrobial effect of olive oil, sesame oil and their synergism on E. coli. Methods: In this study, olive oil and sesame oil were extracted by cold press assay and standard strain of lyophilized E. coli ATCC 25922 was prepared from the Iranian Research Organization for Science and Technology. Olive oil, sesame oil and their synergism, with the same proportion, in concentrations of 2 mg/ml to 1024 mg/ml were made individually and their MBC and MIC amounts were determined by broth micro dilution. Results: This study declared MIC and MBC for olive oil; 16 mg/ml and 64 mg/ml, for sesame oil and their mixture; 64 mg/ml and 265mg/ml, respectively. Conclusion: The study showed that both oils and their synergism inhibits the growth of bacteria and the antibacterial properties of sesame oil is approximately equal to the mixture of olive oil and sesame oil and although the oils have good antibacterial effect, there was no synergetic effect in these oils

Prevalence of Virulence Genes etA, etB in Community Acquired Methicillin-Resistant Staphylococcus aureus in Patients Referred to Teaching Hospital by PCR in Shahrekord, 2014

Abstract Background: Colonization with MRSA is no longer limited to hospitalized patients or persons with predisposing risk factors and at present there are several strains of community-acquired MRSA (CA-MRSA). The purpose of this study is to determine etA and etB genes in isolated Staphylococcus aureus strains of clinical samples from teaching hospital in Shahrekord in 2014. Materials and Methods: In this descriptive study, 220 clinical samples were collected from teaching hospitals in Shahrekord. The microbiologic characteristics of isolates were determined using microbiologyic standard methods. The MRSA detection was carried out on oxacillin agar medium. The detection of virulence genes etA and etB was used by PCR. Inducible resistance to clindamycin was tested by "D-test". Results: In 220 isolates, 110 detected as S. aureus and 13 as MRSA. Inducible clindamycin resistance was seen in 4 (3.5%) of the isolates. The frequency of genes etA, etB in studied strains was 7.6 and 15.3, respectively. Also, Inducible resistance to clindamycin was seen in four isolates(%2). Conclusion: The results of this study confirme the presence of community- acquired strains in Shahrekord. The results of this study indicate the presence of genes etA and etB in the strains studied, transforming into the strains of Staphylococcus aureus resistant to methicillin obtained from hospital, the development and transfering these strains in the community