Group B streptococcus serotype prevalence in reproductive-age women at a tertiary care military medical center relative to global serotype distribution

<p>Abstract</p> <p>Background</p> <p>Group B <it>Streptococcus </it>(GBS) serotype (Ia, Ib, II-IX) correlates with pathogen virulence and clinical prognosis. Epidemiological studies of seroprevalence are an important metric for determining the proportion of serotypes in a given population. The purpose of this study was to evaluate the prevalence of individual GBS serotypes at Madigan Healthcare System (Madigan), the largest military tertiary healthcare facility in the Pacific Northwestern United States, and to compare seroprevalences with international locations.</p> <p>Methods</p> <p>To determine serotype distribution at Madigan, we obtained GBS isolates from standard-of-care anogenital swabs from 207 women of indeterminate gravidity between ages 18-40 during a five month interval. Serotype was determined using a recently described molecular method of polymerase chain reaction by capsular polysaccharide synthesis (cps) genes associated with pathogen virulence.</p> <p>Results</p> <p>Serotypes Ia, III, and V were the most prevalent (28%, 27%, and 17%, respectively). A systematic review of global GBS seroprevalence, meta-analysis, and statistical comparison revealed strikingly similar serodistibution at Madigan relative to civilian-sector populations in Canada and the United States. Serotype Ia was the only serotype consistently higher in North American populations relative to other geographic regions (p < 0.005). The number of non-typeable isolates was significantly lower in the study (p < 0.005).</p> <p>Conclusion</p> <p>This study establishes PCR-based serotyping as a viable strategy for GBS epidemiological surveillance. Our results suggest that GBS seroprevalence remains stable in North America over the past two decades.</p

CD152 (CTLA-4) Determines CD4 T Cell Migration In Vitro and In Vivo

BACKGROUND:Migration of antigen-experienced T cells to secondary lymphoid organs and the site of antigenic-challenge is a mandatory prerequisite for the precise functioning of adaptive immune responses. The surface molecule CD152 (CTLA-4) is mostly considered as a negative regulator of T cell activation during immune responses. It is currently unknown whether CD152 can also influence chemokine-driven T cell migration. METHODOLOGY/PRINCIPAL FINDINGS:We analyzed the consequences of CD152 signaling on Th cell migration using chemotaxis assays in vitro and radioactive cell tracking in vivo. We show here that the genetic and serological inactivation of CD152 in Th1 cells reduced migration towards CCL4, CXCL12 and CCL19, but not CXCL9, in a G-protein dependent manner. In addition, retroviral transduction of CD152 cDNA into CD152 negative cells restored Th1 cell migration. Crosslinking of CD152 together with CD3 and CD28 stimulation on activated Th1 cells increased expression of the chemokine receptors CCR5 and CCR7, which in turn enhanced cell migration. Using sensitive liposome technology, we show that mature dendritic cells but not activated B cells were potent at inducing surface CD152 expression and the CD152-mediated migration-enhancing signals. Importantly, migration of CD152 positive Th1 lymphocytes in in vivo experiments increased more than 200% as compared to CD152 negative counterparts showing that indeed CD152 orchestrates specific migration of selected Th1 cells to sites of inflammation and antigenic challenge in vivo. CONCLUSIONS/SIGNIFICANCE:We show here, that CD152 signaling does not just silence cells, but selects individual ones for migration. This novel activity of CD152 adds to the already significant role of CD152 in controlling peripheral immune responses by allowing T cells to localize correctly during infection. It also suggests that interference with CD152 signaling provides a tool for altering the cellular composition at sites of inflammation and antigenic challenge

The epidemiology of bacterial vaginosis in relation to sexual behaviour

<p>Abstract</p> <p>Background</p> <p>Bacterial vaginosis (BV) has been most consistently linked to sexual behaviour, and the epidemiological profile of BV mirrors that of established sexually transmitted infections (STIs). It remains a matter of debate however whether BV pathogenesis does actually involve sexual transmission of pathogenic micro-organisms from men to women. We therefore made a critical appraisal of the literature on BV in relation to sexual behaviour.</p> <p>Discussion</p> <p><it>G. vaginalis </it>carriage and BV occurs rarely with children, but has been observed among adolescent, even sexually non-experienced girls, contradicting that sexual transmission is a necessary prerequisite to disease acquisition. <it>G. vaginalis </it>carriage is enhanced by penetrative sexual contact but also by non-penetrative digito-genital contact and oral sex, again indicating that sex <it>per se</it>, but not necessarily coital transmission is involved. Several observations also point at female-to-male rather than at male-to-female transmission of <it>G. vaginalis</it>, presumably explaining the high concordance rates of <it>G. vaginalis </it>carriage among couples. Male antibiotic treatment has not been found to protect against BV, condom use is slightly protective, whereas male circumcision might protect against BV. BV is also common among women-who-have-sex-with-women and this relates at least in part to non-coital sexual behaviours. Though male-to-female transmission cannot be ruled out, overall there is little evidence that BV acts as an STD. Rather, we suggest BV may be considered a sexually enhanced disease (SED), with frequency of intercourse being a critical factor. This may relate to two distinct pathogenetic mechanisms: (1) in case of unprotected intercourse alkalinisation of the vaginal niche enhances a shift from lactobacilli-dominated microflora to a BV-like type of microflora and (2) in case of unprotected and protected intercourse mechanical transfer of perineal enteric bacteria is enhanced by coitus. A similar mechanism of mechanical transfer may explain the consistent link between non-coital sexual acts and BV. Similar observations supporting the SED pathogenetic model have been made for vaginal candidiasis and for urinary tract infection.</p> <p>Summary</p> <p>Though male-to-female transmission cannot be ruled out, overall there is incomplete evidence that BV acts as an STI. We believe however that BV may be considered a <it>sexually enhanced disease</it>, with frequency of intercourse being a critical factor.</p

Greenwash and Green Trust: The Mediation Effects of Green Consumer Confusion and Green Perceived Risk

[[abstract]]The paper explores the influence of greenwash on green trust and discusses the mediation roles of green consumer confusion and green perceived risk. The research object of this study focuses on Taiwanese consumers who have the purchase experience of information and electronics products in Taiwan. This research employs an empirical study by means of the structural equation modeling. The results show that greenwash is negatively related to green trust. Therefore, this study suggests that companies must reduce their greenwash behaviors to enhance their consumers’ green trust. In addition, this study finds out that green consumer confusion and green perceived risk mediate the negative relationship between greenwash and green trust. The results also demonstrate that greenwash is positively associated with green consumer confusion and green perceived risk which would negatively affect green trust. It means that greenwash does not only negatively affect green trust directly but also negatively influence it via green consumer confusion and green perceived risk indirectly. Hence, if companies would like to reduce the negative relationship between greenwash and green trust,they need to decrease their consumers’ green consumer confusion and green perceived risk.[[notice]]補正完畢[[journaltype]]國外[[incitationindex]]SSCI[[booktype]]紙本[[booktype]]電子版[[countrycodes]]NL