Effect of estrogens on bacterial adherence to HeLa cells

The Role of 17β-Estrogen in Escherichia coli Adhesion on Human Vaginal Epithelial Cells via FAK Phosphorylation

Estrogen, the predominant sex hormone, has been found to be related to the occurrence of vaginal infectious diseases. However, its role in the occurrence and development of bacterial vaginitis caused by Escherichia coli is still unclear. The objective of this study was to investigate the role of 17β-estrogen in E. coli adhesion on human vaginal epithelial cells. The vaginal epithelial cell line VK2/E6E7 was used to study the molecular events induced by estrogen between E. coli and cells. An adhesion study was performed to evaluate the involvement of the estrogen-dependent focal adhesion kinase (FAK) activation with cell adhesion. The phosphorylation status of FAK and estrogen receptor α (ERα) upon estrogen challenge was assessed by Western blotting. Specific inhibitors for ERα were used to validate the involvement of ERα-FAK signaling cascade. The results showed that, following stimulation with 1,000 nM estrogen for 48 h, transient activation of ERα and FAK was observed, as was an increased average number of E. coli cells adhering to vaginal epithelial cells. In addition, estrogen-induced activation of ERα and FAK was inhibited by the specific inhibitor of ERα, especially when the inhibitor reached a 10 μM concentration and acted for 1 h, and a decrease in the number of adherent E. coli cells was observed simultaneously. However, this inhibitory effect diminished as the concentration of estrogen increased. In conclusion, FAK and ERα signaling cascades were associated with the increasing E. coli adherence to vaginal epithelial cells, which was promoted by a certain concentration of estrogen.

Hormonal contraceptive use and Staphylococcus aureus nasal and throat carriage in a Norwegian youth population

BACKGROUND

Use of hormonal contraceptives has been associated with Staphylococcus aureus nasal carriage in adult women. However, the role of hormonal contraceptives in S. aureus colonization among adolescents and associations with progestin only contraceptives are unknown.

METHODS

We obtained nasal and throat swab samples from 439 girls aged 17-21 years in the population-based Tromsø study Fit Futures, 2012-2013, Norway, with information on lifestyle, health and biomarkers. We used multivariable logistic regression to study the association between use of hormonal contraceptives and Staphylococcus aureus carriage while adjusting for potential confounding factors.

RESULTS

Staphylococcus aureus nasal carriage prevalence were 34%, 42%, and 61% among progestin-only users, non-users, and progestin-estrogen combination contraceptive users, respectively (P<0.001). Use of combination contraceptives doubled the odds of nasal carriage (non-users reference; OR = 2.31, 95%CI = 1.43-3.74). The OR of nasal carriage was 0.29 among progestin-only users compared to combination contraceptives users (95% CI = 0.12-0.67).

DISCUSSION

In this study, use of combination hormonal contraceptives was associated with higher risk of Staphylococcus aureus nasal carriage in adolescent girls. Experimental design studies are needed to establish the role of exogenous sex steroids in Staphylococcus aureus colonization in women.

Blood Groups in Infection and Host Susceptibility

Blood group antigens represent polymorphic traits inherited among individuals and populations. At present, there are 34 recognized human blood groups and hundreds of individual blood group antigens and alleles. Differences in blood group antigen expression can increase or decrease host susceptibility to many infections. Blood groups can play a direct role in infection by serving as receptors and/or coreceptors for microorganisms, parasites, and viruses. In addition, many blood group antigens facilitate intracellular uptake, signal transduction, or adhesion through the organization of membrane microdomains. Several blood groups can modify the innate immune response to infection. Several distinct phenotypes associated with increased host resistance to malaria are overrepresented in populations living in areas where malaria is endemic, as a result of evolutionary pressures. Microorganisms can also stimulate antibodies against blood group antigens, including ABO, T, and Kell. Finally, there is a symbiotic relationship between blood group expression and maturation of the gastrointestinal microbiome.

Hormonal contraceptive use and persistent Staphylococcus aureus nasal carriage

BACKGROUND

Human nares colonized with Staphylococcus aureus are the most important reservoir for this pathogen. We studied the influence of sex and hormonal contraceptive use on persistent S. aureus nasal carriage.

METHODS

We conducted a cohort study in healthy volunteers and determined carriage status at baseline and again at follow-up by using the results of 2 swab samples at each time point. We applied logistic regression to analyze associations of interest.

RESULTS

At baseline, 266 of 1180 volunteers (22.5%) were classified as persistent nasal carriers. Compared with women not using hormonal contraceptives, women taking reproductive hormones (odds ratio [OR]. 1.88; 95% confidence interval [CI], 1.29-2.75; P = .001) and men (OR., 1.57; 95% CI, 1.08-2.28; P = .02) were more likely to be persistent carriers. These associations remained stable after adjusting for known risk factors of nasal carriage. Women taking hormonal contraceptives and being persistent carriers at baseline were more likely to remain carriers after a median follow-up time of 70 days than women not using such medication (OR, 3.25; 95% CI, 1.44-7.34; P = .005). No patterns of association could be observed between persistent carriage among women and type of progestin or dose of estrogen used. Assuming causality and using estimates from multivariable logistic regression, we approximated that 20% (95% CI, 2.4%-34.9%) of persistent nasal carriage among women represented by our sample is attributable to hormonal contraception (population-attributable fraction).

CONCLUSIONS

The widespread use of hormonal contraception may substantially increase the human S. aureus reservoir with potential impact on S. aureus infection and transmission.

A morphologist's approach to the vagina--age-related changes and estrogen sensitivity

This paper reviews basic facts on vagina histology and ultrastructure with respect to passage of different substances and drugs through the epithelium. Particular interest is devoted to the action mechanism of topically-applied vaginal estrogen, its binding to receptors in different vaginal cell types, and possible local metabolic routes. Differences in estrogen sensitivity between uterus and vagina are discussed as well as the background for the high vaginal sensitivity.

Influence of the estrous cycle on the development of upper genital tract pathology as a result of chlamydial infection in the guinea pig model of pelvic inflammatory disease

Guinea pigs were infected intravaginally with the chlamydial agent of guinea pig inclusion conjunctivitis at varying times during the estrous cycle. Genital tract tissues were collected 30 days after infection and processed for histopathological analysis. No difference was seen in the course of lower genital tract infection. However, a significantly greater percentage of tissues from animals infected on day 11 of the cycle were found to have chronic inflammation and fibrosis in the mesosalpinx compared to those from animals infected on day 6 or day 16. In addition, a significantly greater percentage of oviduct tissues from day 11-infected guinea pigs had marked tubal dilatation when compared to oviducts from day 6-or day 16-infected animals. The increased incidence of pathological changes was also noted in the endocervix, uterine fundus, and uterine horns but not the exocervix. These data indicate that the time of the estrous cycle and the corresponding hormonal influences may be an important influence on the development of upper genital tract disease.

Virulence factors in Escherichia coli urinary tract infection

Uropathogenic strains of Escherichia coli are characterized by the expression of distinctive bacterial properties, products, or structures referred to as virulence factors because they help the organism overcome host defenses and colonize or invade the urinary tract. Virulence factors of recognized importance in the pathogenesis of urinary tract infection (UTI) include adhesins (P fimbriae, certain other mannose-resistant adhesins, and type 1 fimbriae), the aerobactin system, hemolysin, K capsule, and resistance to serum killing. This review summarizes the virtual explosion of information regarding the epidemiology, biochemistry, mechanisms of action, and genetic basis of these urovirulence factors that has occurred in the past decade and identifies areas in need of further study. Virulence factor expression is more common among certain genetically related groups of E. coli which constitute virulent clones within the larger E. coli population. In general, the more virulence factors a strain expresses, the more severe an infection it is able to cause. Certain virulence factors specifically favor the development of pyelonephritis, others favor cystitis, and others favor asymptomatic bacteriuria. The currently defined virulence factors clearly contribute to the virulence of wild-type strains but are usually insufficient in themselves to transform an avirulent organism into a pathogen, demonstrating that other as-yet-undefined virulence properties await discovery. Virulence factor testing is a useful epidemiological and research tool but as yet has no defined clinical role. Immunological and biochemical anti-virulence factor interventions are effective in animal models of UTI and hold promise for the prevention of UTI in humans.

Entry of genital Chlamydia trachomatis into polarized human epithelial cells

To study the initial invasion process(es) of genital chlamydiae, a model system consisting of hormonally maintained primary cultures of human endometrial gland epithelial cells (HEGEC), grown in a polarized orientation on collagen-coated filters, was utilized. After Chlamydia trachomatis inoculation of the apical surface of polarized HEGEC, chlamydiae were readily visualized, by transmission electron microscopy, in coated pits and coated vesicles. This was true for HEGEC maintained in physiologic concentrations of estrogen (proliferative phase) and of estrogen plus progesterone (secretory phase), despite the finding that association of chlamydiae with secretory-phase HEGEC is significantly reduced (P = 0.025; A.S. Maslow, C.H. Davis, J. Choong, and P.B. Wyrick, Am. J. Obstet. Gynecol. 159:1006-1014, 1988). In contrast, chlamydiae were rarely observed in the clathrin-associated structures if the HEGEC were cultured on plastic surfaces. The same pattern of coated pit versus noncoated pit entry was reproducible in HeLa cells. The quantity of coated pits associated with isolated membrane sheets derived from HeLa cells, grown on poly-L-lysine-coated cover slips in medium containing the female hormones, was not significantly different as monitored by radiolabeling studies and by laser scanning microscopy. These data suggest that culture conditions which mimic in vivo cellular organization may enhance entry into coated pits for some obligate intracellular pathogens.

Effect of 17 beta-estradiol on adherence of Escherichia coli to human endometrial stromal cells

The effect of 17 beta-estradiol on in vitro adherence of six strains of uropathic Escherichia coli to human endometrial stromal cells was examined. In contrast to the findings of earlier investigations using murine urogenital cells and malignant human urogenital cell lines, our studies showed no significant effect of 17 beta-estradiol on adherence.

Stress and intestinal microflora

In this overview the actual international knowledge regarding phenomenons and their proven or speculated mechanisms of adaptative microecological, hormonal and immunological responses to neuroemotional stress conditions including space-flights is represented. In most cases a decreased stability of the intestinal microflora provokes further reactions of the body. The necessity to predict the various possible disorders and to find optimal measures for their prophylaxis and elimination is emphasized.

Enhancement of Escherichia coli adherence to epithelial cells derived from estrogen-stimulated rats

The effect of exogenous estrogen administered to male and oophorectomized female rats was investigated with regard to in vitro adherence of eight uropathogenic strains of Escherichia coli to exfoliated bladder and vaginal epithelial cells. Uroepithelial cells obtained from estrogenized male and estrogenized oophorectomized female rats and vaginal cells obtained from estrogenized oophorectomized female rats demonstrated significantly enhanced (P less than 0.005) host cell avidity for E. coli attachment, irrespective of bacterial adhesin expressed, when compared with such cells from nonestrogenized male and female oophorectomized rats. These animal studies suggest that female reproductive hormones may contribute to urinary-tract infection in premenopausal females by enhancing susceptibility to E. coli colonization of uroepithelial cells.

Adherence of Trichomonas vaginalis to cell culture monolayers

The in vitro adherence to WISH cells of a pathogenic Trichomonas vaginalis strain was studied with a method utilizing thymidine-labeled protozoa. A marked dose-related adherence was observed. Glutaraldehyde fixed trichomonads were not adherent. The presence of fetal calf serum during the assay did not influence attachment. Concanavalin A inhibited adherence of protozoa. Complete or partial inhibition of adherence was achieved by preincubating WISH cells with Lactobacillus fermentum or Streptococcus agalactiae. Finally, pretreatment of cells with alpha-estradiol, beta-estradiol, progesterone and estrone influenced attachment of protozoa, whereas estriol was ineffective. These results suggest that adherence of Trichomonas vaginalis is dependent on different factors, whose manipulation may have clinical relevance in preventing recurrence of trichomonad vaginitis.

Effect of estrogen (17 beta-estradiol) on the susceptibility of mice to disseminated gonococcal infection

Studies of the effect of sex hormones on the susceptibility of mice to the disseminated gonococcal infection demonstrated significantly enhanced susceptibility of mice injected with estrogen (17 beta-estradiol). In mice treated with estradiol, bacteremia progressively developed within 12 h postinoculation and mice died within the next 6 h, whereas bacteremia in mice treated with progesterone was completely cleared within 3 h postinoculation. The administration of estradiol affected the function of polymorphonuclear leukocytes (PMN) responsible for eliminating gonococci, but the administration of progesterone did not. The bactericidal activity of PMN mediated by myeloperoxidase was affected by estradiol, but the capacity of PMN to release superoxide anion was not. Furthermore, peritoneal cell analysis demonstrated that the infiltration of PMN in the peritoneal cavity of estradiol-treated mice significantly decreased when mice were injected intraperitoneally with gonococci. These effects on PMN by estradiol may play an important role in the enhanced susceptibility of estradiol-treated mice to gonococcal infection.

Adherence of Escherichia coli in pathogenesis of endometritis and effects of estradiol examined by scanning electron microscopy

Escherichia coli was inoculated into the uterine lumen of ovariectomized rats, and the endometrial surfaces were examined by scanning electron microscopy. Adherence of E. coli to the epithelium and destruction of the surface leading to purulent endometritis were noticed. When rats were treated previously with estradiol, adherence of E. coli was not detected.

Zinc and bacterial adherence

Zinc significantly enhances the ability of piliated Gram-negative and Gram-positive bacteria to attach to HeLa cells. This effect is related to the concentration of zinc and degree of bacterial piliation, and is not present with unpiliated organisms. Bacterial viability is not necessary for this effect, and sulfhydryl blockers decrease the response. These data suggest that zinc can bind to bacterial pili and augment bacterial adherence; in this manner, zinc may act as a virulence factor.