Modulation of transforming growth factor­ß signaling transducers in colon adenocarcinoma cells induced by staphylococcal enterotoxin B.

Colorectal cancer (CRC) is a notable cause of cancer­associated mortality worldwide, making it a pertinent topic for the study of cancer and its treatment. Staphylococcal enterotoxin B (SEB), an enterotoxin produced by Staphylococcus aureus, has been demonstrated to exert anticancer and antimetastatic effects due to its ability to modify cell immunity and cellular signaling pathways. In the current study, SEB was investigated, including whether it exerts its growth inhibitory effects on colon adenocarcinoma cells. This may occur through the manipulation of a key tumor growth factor, termed transforming growth factor­ß (TGF­ß), and its signaling pathway transducer, Smad2/3. The human colon adenocarcinoma HCT116 cell line was treated with different concentrations of SEB, and cell number was measured using MTT assay at different treatment times. Smad2/3 RNA expression level was analyzed in untreated or SEB­treated cells using quantitative polymerase chain reaction, which indicated significant differences between cell viability and Smad2/3 expression levels. SEB effectively downregulated Smad2/3 expression in the HCT116 cells at concentrations of 1 and 2 µg/ml (P=0.0021 and P=0.0017, respectively). SEB concentrations that were effective at inhibiting Smad2/3 expression were correlated with those able to inhibit the proliferation of the cancer cells. SEB inhibited Smad2/3 expression at the mRNA level in a concentration­ and time­dependent manner. The present study thus proposed SEB as an agent able to significantly reduce Smad2/3 expression in colon cancer cells, provoking moderate TGF­ß growth signaling and the reduction of tumor cell proliferation.

Prevalence of the genital tract bacterial infections after vaginal reconstructive surgery.

Due to frequent childbirth, heavy lifting and the structure of the lives of rural women in Shahrekord region, Iran, cystocele and rectocele are of the main medical problems of the women in this area and for its correction, vaginal reconstructive surgery is needed which causes infection. The purpose of this study was to identify the bacteria causing infection after vaginal reconstructive surgery and performing antibiogram to help these patients for faster recovery. Patients enrolled this study were 92 who had undergone previous vaginal reconstructive surgery and now had infection. After examination, the group of patients taking antibiotics (n = 26) were excluded and the remaining 66 completed the study questionnaire. A gynecologist performed sampling; related tests (aerobic and anaerobic culture using an anaerobic culture gas pack jar and type A which provides absolute anaerobic conditions) were performed; antimicrobial susceptibility testing using Disk Diffusion Method was carried out; and the results were recorded. All the positive samples were polymicrobial. Gardnerella vaginalis in 20 cases (31%), peptostreptococci and anaerobic cocci in 9 cases (13.6%), staphylococcus aureus in 8 cases (9.1%), bacteroides and fusobacterium in 7 cases (10.6%), streptococcus group B in 4 cases (6%), yeast cells in 11 cases (16.6%) and Trichomonas vaginalis in wet mount of 4 (6%) existed. Anaerobic bacteria showed 85% sensitivity to clindamycin, 82% to chloramphenicol, 85% sensitivity to ceftizoxime and 45% to penicillin. Facultative anaerobic bacteria showed a sensitivity rate of 90% to ceftizoxime, chloramphenicol and cephalothin. According to our findings, the rate of vaginal bacterial infection in women with vaginal reconstructive surgery has increased; from which, infections with anaerobic bacteria origins have increased dramatically. We recommend antibiotic prophylaxis prior to genital reconstructive surgeries.