Investigations of the prevalence and virulence of Candida albicans in periodontal and endodontic lesions in diabetic and normoglycemic patients

Abstract Pulpal and periodontal tissues have similar microbiota that allows cross-contamination between the pulp and periodontal tissues. Objective The aim of this study was to investigate the prevalence of isolated Candida albicans from periodontal endodontic lesions in diabetic and normoglycemic patients, and the fungi's virulence in different atmospheric conditions. Material and Methods A case-control study was conducted on 15 patients with type 2 diabetes mellitus (G1) and 15 non-diabetics (G2) with periodontal endodontic lesions. Samples of root canals and periodontal pockets were plated on CHROMagar for later identification by polymerase chain reaction (PCR) and virulence test. Results C. albicans was identified in 79.2% and 20.8% of the 60 samples collected from diabetic and normoglycemic patients, respectively. Of the 30 samples collected from periodontal pockets, 13 showed a positive culture for C. albicans, with 77% belonging to G1 and 23% to G2. Of the 11 positive samples from root canals, 82% were from G1 and 18% from G2. Production of proteinase presented a precipitation zone Pz<0.63 of 100% in G1 and 72% in G2, in redox and negative (Pz=1), under anaerobic conditions in both groups. Hydrophobicity of the strains from G1 indicated 16.4% with low, 19.3% with moderate, and 64.3% with high hydrophobicity in redox. In G2, 42.2% had low, 39.8% had moderate, 18% had high hydrophobicity in redox. In anaerobic conditions, G1 showed 15.2% with low, 12.8% with moderate, and 72% with high hydrophobicity; in G2, 33.6% had low, 28.8% had moderate, and 37.6% had high hydrophobicity. There was statistical difference in the number of positive cultures between G1 and G2 (p<0.05) with predominance in G1. There was statistical difference for all virulence factors, except hemolysis (p=0.001). Conclusions Candida albicans was isolated more frequently and had higher virulence in diabetic patients.

Candida dubliniensis does not show phospholipase activity: true or false? / Candida dubliniensis não evidencia atividade fosfolipásica: verdadeiro ou falso?

INTRODUCTION: The phospholipase activity in Candida albicans and Candida dubliniensis isolated from oral candidiasis cases were studied. METHODS: The phospholipase activity was evaluated in egg yolk agar. RESULTS: All the C. albicans isolates (n = 48) showed phospholipase activity (mean Pz = 0.66). However, none of the C. dubliniensis isolates (n = 24) showed this activity. CONCLUSIONS: The authors discuss whether these findings are a true characteristic of C. dubliniensis or a consequence of the methodology employed, which includes the possibility that NaCl may have inhibited the enzymatic activity of C. dubliniensis.

INTRODUÇÃO: Avaliou-se a atividade fosfolipásica em Candida albicans e Candida dubliniensis isoladas de casos de candidíase oral. MÉTODOS: A atividade de fosfolipase foi avaliada em ágar gema de ovo. RESULTADOS: Todos os isolados de C. albicans (nº = 48) evidenciaram atividade fosfolipásica (média Pz = 0.66). Todavia, nenhum isolado de C. dubliniensis (nº= 24) demonstrou esta atividade. CONCLUSÕES: Os autores discutem se estes achados são uma característica verdadeira de C. dubliniensis ou uma conseqüência da metodologia empregada, a qual inclui a possibilidade de que o NaCl seja inibidor da atividade enzimática de C. dubliniensis.

Epidemiology and phospholipase activity of oral Candida spp. among patients with central nervous system diseases before and after dental cleaning procedure

Patients suffering of diseases that affect central nervous system may be considered more susceptible to the infectious diseases of mouth. Sixty-nine patients suffering of cerebral palsy, Down's syndrome and metal retardation were submitted to saliva examination for the presence of Candida spp. before and after a procedure of dental cleaning. The isolates were submitted to assay for verifying phospholipase production. 55.10 percent of the patients provided isolation of Candida spp. The frequency of isolation obtained before dental procedure was: C. albicans (83.33 percent), C. krusei (8.33 percent) and C. kefyr, C. parapsilosis and C. glabrata (2.78 percent each). The frequency after the procedure was: C. albicans (68.57 percent), C. parapsilosis (11.43 percent), C. krusei and C. kefyr (8.57 percent each) and Candida glabrata (2.86 percent). We verified significantly difference (p < 0.01) between populations obtained at the two examinations. Phospholipase production was verified only among C. albicans strains and the proportion of producers was higher when testing isolates obtained after dental cleaning procedure. Studies focused on Candida spp. isolation are useful for better comprehension of the role of these yeasts on the oral flora from patients with cerebral palsy, Down's syndrome and metal retardation.

Candida albicans isolates from the oral mucosa of healthy carriers

Foram estudadas 30 amostras de Candida albicans, isoladas da mucosa bucal de portadores saudáveis, dentados, fumantes e näo fumantes. O estudo compreendeu tanto características morfofisiológicas (padräo, clássico), como algumas propriedades tidas como fatores de virulência in vitro da levedura (produçäo de proteinase e fosfolipase). A partir do perfil estudado, foi possível compor biotipos, que foram discutidos, à luz da interaçäo da levedura com o meio bucal humano. Dentre os 11 biotipos encontrados, o mais frequente foi 11114 (36,7 por cento), seguido de 11124 e 221114, ambos com 13,4 por cento e 2114 com 10,0 por cento. Todos os demais figuraram com frequência de 3,3 por cento

Toxins of Moraxella bovis: effect on substrates and cells

Culturas totais em meio líquido e filtrados, de 12 cepas de Moraxella bovis, foram testados para determinar a presença de gelatinase, DNAse, lecitinase e dermonecrotoxinas. Foi também estudado seu efeito citotóxico sobre 5 culturas celulares de linhagem. Nas culturas totais demonstrou-se a presença de gelatinase e DNAse. Os filtrados produziram dermonecrose em cobaias brancas e efeito citotáxico em células BHK 21 (Cl.13), mas näo nas outras linhagens. A atividade tanto das culturas totais quanto dos filtrados foi eliminada por aquecimento a 100oC. Discute-se a participaçäo destas toxinas na patogênese e no controle da ceratoconjuntivite infecciosa bovina