Tehran University Medical Journal

Background: Staphylococcus aureus is one the most common pathogens causing community-acquired infections and a major concern for public health, and the other hands antibiotic resistance is also of great concern for public health authorities also Staphylococcus aureus produce a lot of virulence factors such as variety of exoproteins included toxic shock syndrome and exfoliative toxin which causes colonization and different infections in their host. The aims of current study were to evaluate the prevalence of Toxic shock syndrome toxin 1 (TSST-1) and ETs genes in isolated S. aureus strains using polymerase chain reaction (PCR) assay. Methods: This cross-sectional study was performed on 100 methicillin-resistant staphylococcal aureus (MRSA) and 100 methicillin-sensitive staphylococcal aureus (MSSA) isolated from clinical specimens of inpatients, outpatients hospitals and nasal carriers in Hamadan University from October 2013 to August 2014. Identified species by biochemical methods were confirmed by the PCR method. Antibiotic resistance was performance by disk diffusion and the presence of TSST-1 and ETs genes was investigated using PCR. Results: Of the 100 isolates MRSA examined, the most frequent resistance was observed to ciprofloxacin (95%), followed by tetracycline (91%), erythromycin (92%), Gentamicin (90%), Rifampin (85%), trimethoprim-sulfamethoxazole (85%), clindamycin (80%) and cefoxitin (100%). Of the 100 isolates MSSA examined, the most frequent resistance was observed to erythromycin (68%), ciprofloxacin (66%), followed by tetracycline (52%), gentamicin (25%), clindamycin (46%), rifampin (45%), trimethoprim-sulfamethoxazole (66%) and cefoxitin (0%). Prevalence of TSST-1 and ETs genes were determined 13% (n=26) isolates, totally. Also the prevalence of TSST-1 was 11% (n=22) and ETs genes was 2% (n=4) isolates and none of the investigated isolates carried eta gene. Conclusion: The increasingly prevalence of MRSA and emerging its antibiotic resistance in clinical isolates can be considered a serious problem for public health. Detection of the high rate prevalence of TSST genes in current study is considered as a serious problem and existing and circle of these strains in according to colonization in community especially old people and immunocompromised patients is very serious.

Background: Breast cancer is the most common cancer in women around the world. It has been known for over a century that androgens and androgen receptor (AR) play a role in normal and neoplastic breast cells. The aim of this study was to determined the AR expression on tumor cells and its correlation with other prognostic and predictive factors as well as contribution of AR in patients overall survival (OS) and disease- free survival (DFS). Methods: This retrospective cross-sectional study performed on 189 patients who referred to Medical Oncology Ward of Cancer Institute, Tehran University of Medical Sciences, from April 2007 to February 2010. We performed an immunohistochemistry study for AR (AR441 clone, Dako, Germany) (10% cut-off point) and Ki-67 MIB-1 clone, Dako, Germany) on paraffin embedded blocks. Other data were extracted from patients’ documents. Results: Overall, AR expression was 49.1%. Mean age of the patients with and without AR was 47.86 and 48.49 years, respectively. AR positive tumors presented more in stage I/II than III/IV (P=0.02) and AR were more positive for estrogen receptor positive, lower grade of tumor (grade I/II versus III) and lower Ki-67 (P=0.01). AR positivity had neither correlation with progesterone receptor, HER2/neu, P53 expression or menopausal status. OS and DFS were higher in AR positive patients but did not reach statistical significance. In triple-negative breast cancer (TNBC) group, 25% of tumors showed AR expression. AR had non-significant positive correlation with OS in TNBC cancer patients. OS and DFS had significant statistic positive correlation with ER, PR and stage regardless of AR status. Conclusion: Based on this study, although androgen receptor expression showed correlation with other prognostic factors for survival in patients, we didn’t find statistically significant independent relationship between AR and overall survival in patients. As far as there isn’t any targeted therapy for triple-negative breast cancer (TNBC), prospective basic and clinical studies regarding AR inhibitors in the treatment of TNBC seems to be logical and valuable.