No abstract

Estrogen is a neuro-protective hormone in various central nervous system (CNS) disorders. The present study evaluated the role of estrogen during experimental autoimmune encephalomyelitis (EAE) at doses selected to mimic any suppressive potential from the hormone during pregnancy. Here, mice were ovariectomized and then 2 weeks later treated with MOG antigen to induce EAE. Concurrently, mice then received (subcutaneously) an implanted pellet to deliver varying estrogen amounts over a 21-day period. Clinical scores and other parameters were monitored daily for the 21 days. At the end of the period, brain/spinal cord histology was performed to measure lymphocyte infiltration; T-cell profiles were determined through ELISA, flow cytometry, and real-time PCR. Transcription factor expression levels in the CNS were assessed using real-time PCR; T-cell differentiation was evaluated via flow cytometry. The results demonstrated that estrogen inhibited development of EAE. Histological studies revealed limited leukocyte infiltration into the CNS. High and medium dose of estrogen increased T H 2 and T reg cell production of interleukin (IL)-4, IL-10, and transforming growth factor (TGF)-b, but concurrently resulted in a significant reduction in production of interferon (IFN)-c, IL-17, and IL-6. Flow cytometry revealed there were also significant decreases in the percentages of T H 1 and T H 17 cells, as well as significant increase in percentages of T reg and T H 2 cells in the spleen and lymph nodes. Real-time PCR results indicated that high-and medium-dose estrogen treatments reduced T-bet and ROR-ct factor expression, but enhanced Foxp3 and GATA3 expression. Collectively, these results demonstrated that a medium dose of estrogen -similar to a pregnancy level of estrogen -could potentially reduce the incidence and severity of autoimmune EAE and possibly other autoimmune pathologies.ARTICLE HISTORY

A total of 100 Staphylococcus aureus strains were isolated from 1,047 food samples. In addition to biotyping all isolates, the occurrence of the tst gene and protein were evaluated by PCR and the RPLA test, respectively. Moreover, polymorphism of the X-region of the protein A gene was analyzed by PCR-RFLP. TSST 1 was detected in 12 strains and production of TSST 1 in all strains was confirmed by RPLA assay. It was noteworthy that 66.7% of TSST 1 -producing S. aureus strains belonged to the human biotype. The result of genotyping amplification of the spa gene displayed size polymorphisms and revealed seven different clusters ranging from 1,200 bp to 1,600 bp. Digestion of amplicons with HindIII and HaeII resulted in six distinct patterns for each of them. An amplicon of 1,450 bp in size was the predominant type of Spa-PCR product. The accuracy of the Spa typing system by PCR-RFLP was 100%, thus confirming this method as a reliable tool in routine epidemiological investigation for S. aureus.

Foodborne disease due to Staphylococcus aureus is a common and important disease worldwide. Molecular typing of S. aureus strains plays a crucial role in epidemiological studies examining the origin and performing surveillance of major infections. In this survey, we collected 913 food samples and detected 93 S. aureus isolates by using culture and biochemical tests. Subsequently, the X region of the protein A gene was amplified by the polymerase chain reaction (PCR) and amplicons were digested with HaeII and HindIII. Seven different patterns, ranging in length between 1200 and 1600 bp, showed gene polymorphism of the spa gene. The most prevalent spa types were D (20%) and C (16%) in dairy products and D (6%) and E (3%) in meat products. Consequently, 16 genotypes were obtained by HaeII digestion. Typeability of PCR - restriction fragment length polymorphism in genotyping of S. aureus strains in our study was perfect. Therefore, this method is a reliable, rapid, and powerful system in epidemiological investigations.

Background: Methicillin-Resistant Staphylococcus aureus (MRSA) plays an important role in gastrointestinal diseases. The goal of this research was to determine phenotypic and genotypic characteristics of MRSA isolated from dairy and meat products in Iran. Methods: Ninety-three S. aureus isolates were prepared which had been obtained in our previous study. Antimicrobial susceptibility testing was done using disk diffusion method. The isolates were further analyzed by mecA gene detection. Staphylococcal Enterotoxins (SEs) and Toxic Shock Syndrome Toxin 1 (TSST1) were screened. Biotyping and molecular typing were done by short sequence repeats of spa and coa genes. Results: Five out of 93 S. aureus isolates (5.37%) included mecA. All five MRSA isolates were sensitive to at least six tested antibiotics and none were resistant to vancomycin. Furthermore, two isolates were multidrug resistant. Four isolates produced SEs and TSST1. Three out of 5 isolates were related to human biotype and two belonged to non-host-specific biotype. Conclusion: Presence of MRSA in dairy and meat products may be an important hygienic risk for the Iranian consumers, especially for immunocompromised people.