Persistence survey of Toxic Shock Syndrome toxin-1 producing Staphylococcus aureus and serum antibodies to this superantigen in five groups of menstruating women

Background: Menstrual Toxic Shock Syndrome (mTSS) is thought to be associated with the vaginal colonization with specific strains of Staphylococcus aureus TSST-1 in women who lack sufficient antibody titers to this toxin. There are no published studies that examine the seroconversion in women with various colonization patterns of this organism. Thus, the aim of this study was to evaluate the persistence of Staphylococcus aureus colonization at three body sites (vagina, nares, and anus) and serum antibody to toxic shock syndrome toxin-producing Staphylococcus aureus among a small group of healthy, menstruating women evaluated previously in a larger study. Methods: One year after the completion of that study, 311 subjects were recalled into 5 groups. Four samples were obtained from each participant at several visits over an additional 6-11 month period: 1) an anterior nares swab; 2) an anal swab; 3) a vagina swab; and 4) a blood sample. Gram stain, a catalase test, and a rapid S. aureus-specific latex agglutination test were performed to phenotypically identify S. aureus from sample swabs. A competitive ELISA was used to quantify TSST-1 production. Human TSST-1 IgG antibodies were determined from the blood samples using a sandwich ELISA method. Results: We found only 41% of toxigenic S. aureus and 35.5% of non-toxigenic nasal carriage could be classified as persistent. None of the toxigenic S. aureus vaginal or anal carriage could be classified as persistent. Despite the low persistence of S. aureus colonization, subjects colonized with a toxigenic strain were found to display distributions of antibody titers skewed toward higher titers than other subjects. Seven percent (5/75) of subjects became seropositive during recall, but none experienced toxic shock syndrome-like symptoms. Conclusions: Nasal carriage of S. aureus appears to be persistent and the best predicator of subsequent colonization, whereas vaginal and anal carriage appear to be more transient. From these findings, it appears that antibody titers in women found to be colonized with toxigenic S. aureus remained skewed toward higher titers whether or not the colonies were found to be persistent or transient in nature. This suggests that colonization at some point in time is sufficient to elevate antibody titer levels and those levels appear to be persistent. Results also indicate that women can become seropositive without experiencing signs or symptoms of toxic shock syndrome

New loci for body fat percentage reveal link between adiposity and cardiometabolic disease risk

To increase our understanding of the genetic basis of adiposity and its links to cardiometabolic disease risk, we conducted a genome-wide association meta-analysis of body fat percentage (BF%) in up to 100,716 individuals. Twelve loci reached genome-wide significance (P < 5 x 10(-8)), of which eight were previously associated with increased overall adiposity (BMI, BF%) and four (in or near COBLL1/GRB14, IGF2BP1, PLA2G6, CRTC1) were novel associations with BF%. Seven loci showed a larger effect on BF% than on BMI, suggestive of a primary association with adiposity, while five loci showed larger effects on BMI than on BF%, suggesting association with both fat and lean mass. In particular, the loci more strongly associated with BF% showed distinct cross-phenotype association signatures with a range of cardiometabolic traits revealing new insights in the link between adiposity and disease risk