Protein-kinase-C-independent activation of arachidonate release and prostaglandin E2 formation in macrophages interacting with certain bacteria.
(59/222)
Certain bacterial species, of which we selected Fusobacterium nucleatum, Gardnerella vaginalis, Peptostreptococcus anaerobius and Propionibacterium acnes, were found to induce release of arachidonic acid in a dose- and time-dependent manner in mouse macrophages. The release of arachidonic acid showed a characteristic lag period of approximately 10 min and was accompanied by selective transformation into prostaglandin E2. Bacteria killed by various methods caused a similar response, indicating that bacterial surface structures rather than secreted products were involved. Down-regulation of protein kinase C by treatment of macrophages with 4 beta-phorbol 12-myristate 13-acetate hardly affected the response to bacteria at all, except for a partial inhibition in the case of P. acnes. Furthermore, the generation of prostaglandin E2 was synergistically enhanced when macrophages were exposed to both bacteria and phorbol ester. It is also unlikely that bacterial activation was mediated exclusively via a rise in cytosolic [Ca2+], since bacteria stimulated the release of arachidonic acid also when [Ca2+] was clamped at various levels and since the response to bacteria was enhanced in an additive to synergistic manner when combined with calcium ionophore. Changes in protein phosphorylation in macrophages exposed to F. nucleatum (Gram-negative) were virtually identical to those seen with bacterial lipopolysaccharide, while P. anaerobius (Gram-positive) induced enhanced labeling of a single detectable phosphoprotein. In both cases, the changes in protein phosphorylation showed a time lag of 4-8 min and occurred independently of protein kinase C, consistent with a possible role in signal transduction. These results demonstrate that certain bacteria cause activation of arachidonic acid release and prostaglandin E2 formation in mouse macrophages; that the response is independent of protein kinase C and that it is not wholly mediated via a rise in cytosolic [Ca2+]. (+info)
Microbiological, epidemiological and clinical correlates of vaginal colonisation by Mobiluncus species.
(60/222)
The microbiological and epidemiological correlates of vaginal colonisation by Mobiluncus species were examined among randomly selected women attending a sexually transmitted disease (STD) clinic. Women positive for Trichomonas vaginalis were excluded. Mobiluncus spp. were detected by Gram stained vaginal smear in 21% of 633 STD clinic patients, including 53% of those with and 4% of those without bacterial vaginosis (BV), as diagnosed by clinical criteria. Gardnerella vaginalis and Mycoplasma hominis detected by vaginal culture and Mobiluncus detected by vaginal Gram stain were each independently associated with BV after adjusting by logistic regression for the presence of sexually transmitted disease pathogens, gravidity, parity and number of lifetime sexual partners (p less than 0.001 for each organism). Bacterial vaginosis was negatively correlated with isolation of lactobacilli, yeast and herpes simplex virus. After adjusting for presence or absence of BV, women with Mobiluncus were more likely to harbour G vaginalis (odds ratio 5.6, 95% confidence interval 1.6-19.5), M hominis (OR 3.7, 95% CI 2.0-7.0) and Neisseria gonorrhoeae (OR 2.9, 95% CI 1.4-6.0) and less likely to harbour vaginal yeast (OR 0.4, 95% CI 0.2-1.0); were more likely to be black (OR 2.7, 95% CI 1.5-4.6), and to have been pregnant (OR 1.8, 95% CI 1.1-3.1); but after the adjustment for BV, vaginal colonisation by Mobiluncus was not associated with symptoms of odour, abdominal pain, menstrual irregularities, or with adnexal tenderness. In summary, Mobiluncus, Gardnerella vaginalis and Mycoplasma hominis were independently associated with a clinical diagnosis of bacterial vaginosis, and Mobiluncus was further associated with the presence of BV-associated microorganisms (M hominis and G vaginalis), N gonorrhoeae, black race, and gravidity. (+info)
Adhesion of human probiotic Lactobacillus rhamnosus to cervical and vaginal cells and interaction with vaginosis-associated pathogens.
(61/222)