Radiotherapy effect on frequency of Candida spp. and on virulence of C. albicans isolated from the oral cavity of head and neck cancer patients

The aim of this study was to investigate the diversity and prevalence of yeasts, and the virulence of C.albicans found in the oral cavity during the course of ionizing radiation treatment of patients with head and neck tumor (HNTP). Samples from 21 HNTP and 24 healthy controls were isolated and identified. C. albicans isolated from two patients during radiotherapy were analyzed for virulence factors. Radiotherapy induced a higher level of both yeast colonization (81% vs 33%) and non-albicans Candida (NAC) colonization (52.4% vs 4.0%) in HNTP than the control group. Patients were colonized by 5 different NAC species: C. glabrata, C. tropicalis, C. parapsilosis, C. krusei and C. kefir. On the other hand, C. albicans colonization was similar in patients and controls (6/21, 28.6% vs 7/24, 29.2%, respectively). Also, of the 11 patients assessed before and during radiotherapy, 5 (45.5%) were colonized before the start of treatment and another 5 (45.5%) during treatment. All of the latter were colonized by NAC species alone. Moreover, we observed a significant and continuous enhancement of C. albicans virulence as the radiotherapy progressed, in the two patients involved in this test. Thus, it is concluded that radiotherapy is an important predisposing factor for the oral candidiasis, including NAC species. Also, it may facilitate the development of more virulent C. albicans strains.

O objetivo deste estudo foi avaliar a diversidade e a prevalência de Cândida, bem como a virulência de Cândida albicans, isoladas da cavidade bucal no decurso de tratamento por radiações ionizantes de pacientes acometidos por tumores de cabeça e pescoço (PTCP). Amostras de 21 pacientes e 24 controles foram analisadas. C. albicans isoladas de dois pacientes ao longo do tratamento radioterápico foram avaliadas para fatores de virulência. A radioterapia induziu um grande aumento da colonização de Cândida como um todo (81% vs 33%) e Cândida não albicans (CNA) em particular (52.4% vs 4.0%) em PTCP quando comparado com controles não irradiados. Cinco espécies diferentes de CNA foram encontradas nos pacientes: C. glabrata, C. tropicalis, C. parapsilosis, C. krusei and C. kefir. Por outro lado, a colonização por C. albicans nestes pacientes e controles foi similar (6/21, 28.6% vs 7/24, 29.2%, respectivamente). Além disso, dos 11 pacientes que foram avaliados antes e durante o tratamento radioterápico, 5 pacientes (45,5%) foram colonizados antes do início da radioterapia e outros 5 (45,5%) durante o tratamento radioterápico. Destes últimos, todos foram colonizados apenas com espécies CNA. Observou-se, ainda, um aumento contínuo e significante da virulência de C. albicans com o progresso da radioterapia nos dois pacientes estudados. Conclui-se que o tratamento radioterápico é um importante fator de desenvolvimento de candidíase oral, incluindo candidíase por espécies não albicans, em pacientes portadores de tumor de cabeça e pescoço. A radioterapia pode, ainda, facilitar o desenvolvimento de cepas mais virulentas de C.albicans.

Anti-inflammatory activity of the extract, fractions and amides from the leaves of Piper ovatum Vahl (Piperaceae).

Leaves of Piper ovatum are known in folk medicine as "joão burandi" or "anestésica" and in traditional Brazilian medicine are used to treat inflammatory disease. The hydroalcoholic extract, fractions, and a mixture of piperovatine (1) and piperlonguminine (2) in a proportion of 2:3 obtained from Piper ovatum were assayed for anti-inflammatory activity by means of carrageenan-induced pleurisy in rats and croton oil-induced ear edema in mice. The hydroalcoholic extract was analyzed by high-performance liquid chromatography. Fraction constituents were evaluated by phytochemical screening, and the mixture of amides (1 and 2) was identified by analyses of spectral data of (1)H and (13)C nuclear magnetic resonance. Acute toxicity of the extract also was evaluated. At 500mg/kg, the hydroalcoholic extract of Piper ovatum leaves did not reduce the volume of inflammatory pleural exudates compared with control animals. However, the hydroalcoholic extract and fractions F1-F3 at doses of 5.0mg/ear and a mixture of piperovatine (1) and piperlonguminine (2) at doses of 2.5, 1.25, and 0.625mg/ear significantly reduced the degree of ear edema. Taken together, the results indicate that the amide fractions piperovatine and piperlonguminine showed the greatest inhibitory activity of topical inflammation induced by croton oil.

Vulvovaginal candidiasis is associated with the production of germ tubes by Candida albicans.

Twenty Candida albicans strains isolated from women attended at the Teaching and Research in the Laboratory of Teaching and Research in Clinical Analysis of the State University of Maringa, Paraná, Brazil, have been analyzed. Yeasts were identified by classical methods and patients subdivided into asymptomatic, vulvovaginal candidiasis(VVC) and recurrent vulvovaginal candidiasis (RVVC) groups. Yeasts were incubated in RPMI + fetal calf serum to analyze germ tubes every two hours, up to 10 h. In vitro sensitivity to fluconazole, itraconazole, ketoconazole, amphotericin B and nystatin was analyzed according to NCCLS-M27-A microdilution assay. Yeast isolated from symptomatic women produced significantly more germ tubes than asymptomatic women (P < 0.05). However, no significant difference between yeasts from VVC and RVVC occurred (P > 0.05). Variation between MIC50 and MIC90 of tested antifungal agents was slight among isolated yeasts, while no resistant yeasts were detected. Nevertheless, VVC yeasts were more DDS (reduced dose-dependent susceptibility) for nystatin and RVVC were more DDS for ketoconazole. Results suggest that colonization by yeast in the vagina and lack of symptoms may be partially explained by the yeast's sparse capacity to form germ tubes, On the other hand, RVVC was not associated with antimicrobial resistance. DDS high frequency for nystatin and ketoconazole indicates that identification, and susceptibility of antifungals tests are important to management of VVC.