Nva Research Update Newsletter

Candida albicans is a major cause of oropharyngeal, vulvovaginal and hematogenously disseminated candidiasis. Endocytosis of C. albicans hyphae by host cells is a prerequisite for tissue invasion. This internalization involves interactions between the fungal invasin Als3 and host Eor Ncadherin. Als3 shares some structural similarity with InlA, a major invasion protein of the bacterium Listeria monocytogenes. InlA mediates entry of L. monocytogenes into host cells through binding to Ecadherin. A role in internalization, for a non classical stimulation of the clathrin-dependent endocytosis machinery was recently highlighted. Based on the similarities between the C. albicans and L. monocytogenes invasion proteins, we studied the role of clathrin in the internalization of C. albicans. Using live-cell imaging and indirect immunofluorescence of epithelial cells infected with C. albicans, we observed that host E-cadherin, clathrin, dynamin and cortactin accumulated at sites of C. albicans internalization. Similarly, in endothelial cells, host N-cadherin, clathrin and cortactin accumulated at sites of fungal endocytosis. Furthermore, clathrin, dynamin or cortactin depletion strongly inhibited C. albicans internalization by epithelial cells. Finally, beads coated with Als3 were internalized in a clathrin-dependent manner. These data indicate that C. albicans, like L. monocytogenes, hijacks the clathrin-dependent endocytic machinery to invade host cells. Validation of an immunologic diagnostic kit for infectious vaginitis by trichomonas vaginalis, candida spp., and gardnerella vaginalis. Bravo AB, Miranda LS, Lima OF, Cambas AV, Hernandez ML, Alvarez JM Diagn Microbiol Infect Dis. 2009 Mar;63(3):257-60. FemPure is a kit for the rapid diagnosis of vaginitis by Trichomonas vaginalis, Candida spp., and Gardnerella vaginalis, based on aggregation of latex particles joined to specific antibodies. The validation of the method involved the parameters specificity, detection limit, robustness, clinical sensitivity, and clinical specificity. Also, samples analyzed in parallel by the validated test and other recognized tests conducted by external laboratory were included. The method was specific for the 3 infectious agents, and no cross-reaction with other microorganisms usually present in vaginal exudates. The detection limit > or =1 x 10(6) CFU/mL for Candida albicans and G. vaginalis avoids the detection of concentrations considered normal flora, whereas T. vaginalis was detected until 1 x 10(5) cells/mL. Values of clinical sensitivity > or =80% and clinical specificity > or =90% and concordance > or =90% were found between samples evaluated in parallel by different methods. Robustness showed that the test can be used in laboratories with different management systems; its simple implementation without equipment allows the use in primary health care areas. Association between group A beta-haemolytic streptococci and vulvovaginitis in adult women: a case-control study. Bruins MJ, Damoiseaux RA, Ruijs GJ Eur J Clin Microbiol Infect Dis. 2009 Apr 3. [Epub ahead of print] Guidelines for the management of vaginal discharge mention Candida albicans, Trichomonas vaginalis, bacterial vaginosis, Chlamydia trachomatis and Neisseria gonorrhoeae as causes and do not recommend full microbiological culture. The role of non-group B beta-haemolytic streptococci in vaginal cultures is unclear, except for group A streptococci that are known to cause vulvovaginitis in children. In a casecontrol study, we investigated the association between non-group B beta-haemolytic streptococci and vulvovaginitis in adult women. Cases were women with recurrent vaginal discharge from whom a sample was cultured. Controls were asymptomatic women who consented to submitting a vaginal swab. Group A streptococci were isolated from 49 (4.9%) of 1,010 cases and not from the 206 controls (P < 0.01). Isolation rates of group C, F and G streptococci were low and did not differ statistically between cases and controls. Group A beta-haemolytic streptococci are associated with vaginal discharge in adult women. The other non-group B streptococci require more study. For the adequate management of vaginal discharge, culturing is necessary if initial treatment fails. Guidelines should be amended according to these results. Langerhans cells in lichen sclerosus of the vulva and lichen sclerosus evolving in vulvar squamous cell carcinoma. Raspollini MR, Baroni G, Taddei GL Histol Histopathol. 2009 Mar;24(3):331-6. Vulvar lichen sclerosus (LS) represents a benign chronic inflammatory skin lesion that carries a risk for development of vulvar squamous cell carcinoma (SCC). We aimed at determining whether premalignant changes in vulvar LS, a multifactorial disease, presenting a welter of evidence implicating the immune system in its pathogenesis, could be identified by analysing the Langerhans' cells (LCs), the primary cell responsible for antigen recognition and presentation. The relationship existing between inflammation and cancer due to chronic infection, and demonstrated in many solid tumors, led us to study LCs in eight cases of vulvar LS, which showed an evolution to carcinoma of the vulva and in ten cases of unchanged vulvar LS in matched patients by immunohistochemistry for antibodies CD1a and S100. We did not find a statistically significantly different number of LCs counted either in S100 stained specimens, nor in CD1a stained specimens of LS epithelium in unchanged or evolving cases. The data emerging in our study do not support the hypothesis that the variation in the number of LCs may be related to the development of SCC in late stage LS cases. The expanding spectrum of cutaneous borreliosis. Eisendle K, Zelger B G Ital Dermatol Venereol. 2009 Apr;144(2):157-71. The known spectrum of skin manifestations in cutaneous Lyme disease is continuously expanding and can not be regarded as completed. Besides the classical manifestations of cutaneous borreliosis like erythema (chronicum) migrans, borrelial lymphocytoma and acrodermatitis chronica atrophicans evidence is growing that at least in part also other skin manifestations, especially morphea, lichen sclerosus and cases of cutaneous B-cell lymphoma are causally related to infections with Borrelia. Also granuloma annulare and interstitial granulomatous dermatitis might be partly caused by Borrelia burgdorferi or similar strains. There are also single reports of other skin manifestations to be associated with borrelial infections like cutaneous sarcoidosis, necrobiosis lipoidica and necrobiotic xanthogranuloma. In addition, as the modern chameleon of dermatology, cutaneous borreliosis, especially borrelial lymphocytoma, mimics other skin conditions, as has been shown for erythema anulare centrifugum or lymphocytic infiltration (Jessner Kanof) of the skin. Melanocytic proliferations associated with lichen sclerosus in adolescence. Bussen SS. Arch Gynecol Obstet. 2009 Mar 28. [Epub ahead of print] Lichen sclerosus is found in children with an estimated prevalence of at least 1 in 900. Pigmentation in lichen sclerosus is infrequent and melanocytic proliferations in lichen sclerosis are rare and difficult to interpret. In this report, we describe the case of a prepubertal girl presenting with a junctional melanocytic nevus of the labia minora superimposed by lichen sclerosus. The lesion was completely excised and free margins confirmed by histological examination. After a 3 months course of topical clobetasol treatment the girl remained asymptomatic. No local recurrence was notified with a follow-up time of 12 months. Vulvar cancer and the need for awareness of precursor lesions. Maclean AB, Jones RW, Scurry J, Neill S J Low Genit Tract Dis. 2009 Apr;13(2):115-7. Vulvar cancer continues to rise in incidence. In the absence of screening, attempts to reduce this cancer must focus on recognizing precursor lesions, namely, lichen sclerosus and vulvar intraepithelial neoplasia (VIN). The steep rise in human papillomavirus-repeated VIN will fall after the introduction of vaccination against human papillomavirus; in the meantime, those patients with VIN must be treated and then reviewed carefully and frequently. Lichen sclerosus has a 3% to 5% risk of progressing to vulvar cancer. Recommendations about which patients require referral to and follow-up by specialists/specialist clinics are given. Response of vulval lichen sclerosus and squamous hyperplasia to photodynamic treatment using sustained topical delivery of aminolevulinic acid from a novel bioadhesive patch system. Zawislak AA, McCluggage WG, Donnelly RF, Maxwell P, Price JH, Dobbs SP, McClelland HR, Woolfson AD, Mccarron PA Photodermatol Photoimmunol Photomed. 2009 Apr;25(2):111-3. This study evaluated the clinical and histopathological responses of vulval lichen sclerosus (LS) and squamous hyperplasia (SH) to photodynamic therapy (PDT). A novel bioadhesive patch containing aminolevulinic acid (ALA) at a dose of (38 mg/cm(2)) was used to treat 10 patients before irradiation with light of 630 nm. Clinical, histopathological and pathological responses to treatment were assessed at 6 weeks post-treatment. After 17 cycles of PDT, six patients reported significant symptomatic relief and no cutaneous photosensitivity. Histopathological differences were not demonstrated, but statistically significant induction of apoptosis was seen. It can be concluded that ALA-PDT patch-based formulation is pragmatic and primarily offers symptomatic management of vulval LS and SH.