Perfil genômico e sensibilidade a antifúngicos de amostras sequenciais de Candida spp. isoladas da cavidade oral de indivíduos infectados pelo vírus da imunodeficiência humana

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Estudo da eficácia da terapia fotodinâmica, mediada pelos fotossensibilizadores Photodithazine® e Curcumina, sobre biofilmes multi-espécies formados por Streptococcus mutans, Candida albicans e Candida glabrata

Pós-graduação em Reabilitação Oral - FOAR

Candida dubliniensis: prevalência na cavidade bucal de pacientes diabéticos, com câncer de mama e hansenianos e patogenicidade experimental

O objetivo deste estudo foi avaliar a presença de C. dubliniensis dentre isolados bucais de pacientes com Diabetes mellitus do tipo I (n=39) e II (n=36), hansenianos (n=38) e sob quimioterapia para o câncer de mama (n=30) e de respectivos indivíduos controle pareados quanto à idade, gênero e condições bucais. Um total de 479 isolados previamente identificados por testes fenotípicos (formação de tubo germinativo, produção de hifas/pseudohifas/clamidoconídeos, fermentação e assimilação de carboidratos) e identificadas como C. albicans/C. dubliniensis foram incluídos no estudo. A existência de C. dubliniensis dentre os isolados foi analisada usando protocolo validado de PCR multiplex. Foi também realizado estudo de patogenicidade experimental utilizando camundongos em modelo de infecção sistêmica, objetivando comparar a virulência e cinética de infecção de C. dubliniensis com outras espécies do gênero Candida. Um isolado (0.002%) de C. dubliniensis foi detectado entre os isolados do grupo controle. Esta espécie não foi encontrada dentre os isolados dos outros grupos de pacientes. C. dubliniensis foi menos virulenta para camundongos em relação a C. albicans e C. tropicalis e mais virulenta do que C. krusei. O estudo da cinética de infecção mostrou infecção persistente no rim e no fígado mesmo após 21 dias da inoculação de C. dubliniensis. Conclui-se que a detecção de C. dubliniensis dentre os isolados clínicos foi baixa e observada apenas no grupo controle. C. dubliniensis foi menos virulenta para camundongos que C. albicans e C. tropicalis e causou infecção prolongada no rim e no fígado

The antimicrobial effects of Citrus limonum and Citrus aurantium essential oils on multi-species biofilms

The aim of this study was to evaluate the effects of Citrus limonum and Citrus aurantium essential oils (EOs) compared to 0.2% chlorhexidine (CHX) and 1% sodium hypochlorite (NaOCl) on multi-species biofilms formed by Candida albicans, Enterococcus faecalis and Escherichia coli. The biofilms were grown in acrylic disks immersed in broth, inoculated with microbial suspension (106 cells/mL) and incubated at 37°C / 48 h. After the biofilms were formed, they were exposed for 5 minutes to the solutions (n = 10): C. aurantium EO, C. limonum EO, 0.2% CHX, 1% NaOCl or sterile saline solution [0.9% sodium chloride (NaCl)]. Next, the discs were placed in sterile 0.9% NaCl and sonicated to disperse the biofilms. Tenfold serial dilutions were performed and the aliquots were seeded onto selective agar and incubated at 37°C / 48 h. Next, the number of colony-forming units per milliliter was counted and analyzed statistically (Tukey test, p ≤ 0.05). C. aurantium EO and NaOCl inhibited the growth of all microorganisms in multi-species biofilms. C. limonum EO promoted a 100% reduction of C. albicans and E. coli, and 49.3% of E. faecalis. CHX was less effective against C. albicans and E. coli, yielding a reduction of 68.8% and 86.7%, respectively. However, the reduction of E. faecalis using CHX (81.7%) was greater than that obtained using C. limonum EO. Both Citrus limonum and Citrus aurantium EOs are effective in controlling multi-species biofilms; the microbial reductions achieved by EOs were not only similar to those of NaOCl, but even higher than those achieved by CHX, in some cases.

Enzymatic activity profile of a Brazilian culture collection of Candida albicans isolated from diabetics and non-diabetics with oral candidiasis

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Subacute and Reproductive Oral Toxicity Assessment of the Hydroethanolic Extract of Jacaranda decurrens Roots in Adult Male Rats

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Presença de Microorganismos dos gêneros staphyococcus e candida na cavidade bucal humana

Pós-graduação em Biopatologia Bucal - ICT

Oral microbial colonization in children with sickle cell anaemia under long-term prophylaxis with penicillin

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Composition and antifungal activity against Candida albicans, C. parapsilopisis, Candida krusei and Cryptococcus neoformans of essential oils from leaves of Piper and Peperomia species

This study was addressed to investigate the composition and antifungal activity of essential oils from leaves of Piperaceae species (Piper aduncum, Piper amalago, Piper cernuum, Piper diospyrifolium, Piper crassinervium, Piper gaudichaudianum, Piper solmsianum, Piper regnellii, Piper tuberculatum, Piper umbelata and Peperomia obtusifolia) against Candida albicans, C. parapsilosis, C. krusei and Cryptococcus neoformans. The essential oils from P. aduncum, P. gaudichaudianum and P. solmsianum showed the highest antifungal activity against Cryptococcus neoformans with the MIC of 62.5, 62.5 and 3.9 mg.mL-1, respectively. The oil from P. gaudichaudianum showed activity against C. krusei with MIC of 31.25 mg.mL-1.

Prevalence of Candida spp. during radiographic examination in Diabetes mellitus patients

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Do oral biofilms influence the wear and corrosion behavior of titanium?

The main aim of this work was to study the simultaneous wear-corrosion of titanium (Ti) in the presence of biofilms composed of Streptococcus mutans and Candida albicans. Both organisms were separately grown in specific growth media, and then mixed in a medium supplemented with a high sucrose concentration. Corrosion and tribocorrosion tests were performed after 48 h and 216 h of biofilm growth. Electrochemical corrosion tests indicated a decrease in the corrosion resistance of Ti in the presence of the biofilms although the TiO2 film presented the characteristics of a compact oxide film. While the open circuit potential of Ti indicated a tendency to corrosion in the presence of the biofilms, tribocorrosion tests revealed a low friction on biofilm covered Ti. The properties of the biofilms were similar to those of the lubricant agents used to decrease the wear rate of materials. However, the pH-lowering promoted by microbial species, can lead to corrosion of Ti-based oral rehabilitation systems.

Antimicrobial Photodynamic Therapy in the Treatment of Oral Candidiasis in HIV-Infected Patients

Objective: Antimicrobial photodynamic therapy (aPDT) has been used to combat local infections, and it consists of the combination of a photosensitizer, a light source, and reactive oxygen species (ROS) to kill microbial cells. In this study, we evaluated the effectiveness of aPDT in the treatment of candidiasis in HIV-infected patients. Methods: Twenty-one patients were divided into three groups. Control group (CG) was treated with the conventional medication for candidiasis (fluconazole 100 mg/day during 14 days). Laser group (LG) was subjected to low-level laser therapy (LLLT), wavelength 660 nm, power of 30 mW, and fluence of 7.5 J/cm(2), in contact with mucosa during 10 sec on the affected point. An aPDT group (aPDTG) was treated with aPDT, that is, combination of a low-power laser and methylene blue 450 mu g/mL. Pre-irradiation time was 1 min. Parameters of irradiation were the same ones as for the LG, and patients were single irradiated. Patients were clinically evaluated and culture analysis was performed before, immediately after, and 7, 15, and 30 days after the treatment. Results: Our results showed that fluconazole was effective; however, it did not prevent the return of the candidiasis in short-term. LLLT per se did not show any reduction on Candida spp. aPDT eradicated 100% of the colonies of this fungus and the patients did not show recurrence of candidiasis up to 30 days after the irradiation. Conclusions: These findings suggest that aPDT is a potential approach to oral candidiasis treatment in HIV-infected patients.

Treatment with probiotics in experimental oral colonization by Candida albicans in murine model (DBA/2)

The aim of this study is to evaluate the oral colonization by Candida albicans in experimental murine immunosuppressed DBA/2 and treatment with probiotic bacteria. To achieve these objectives, 152 DBA/2-immunosuppressed mice were orally inoculated with a suspension of C. albicans containing 10(8) viable yeast cells, the animals were treated with nystatin or with the probiotics (Lactobacillus acidophilus and Lactobacillus rhamnosus). Evaluations were performed by Candida count from oral mucosa swabbing. The oral mucosa colonization by C. albicans started at day 1 after inoculation, remained maximal from day 3 until day 7, and then decreased significantly. Probiotics reduced the C. albicans colonization significantly on the oral mucosa in comparison with the untreated animal group. In the group treated with L. rhamnosus, the reduction in yeast colonization was significantly higher compared with that of the group receiving nystatin. Immunosuppressed animal model DBA/2 is a relevant model for experimental Candida oral colonization, and the treatment with probiotics in this model may be an effective alternative to prevent it. Oral Diseases (2012) 18, 260-264

Effect of ozone on periodontopathogenic species--an in vitro study

The in vitro study was aimed to determine the effect of ozone on periodontopathogenic microorganisms. Ozone was generated for 6 s-2 × 24 s (corresponding to 0.56 mg-2 × 2.24 mg of ozone) against 23 mainly anaerobic periodontopathogenic species. Agar diffusion test was used as a screening method. Then, the killing activity was tested in a serum-free environment and with 25% v/v inactivated serum. Further, the effect of ozone on bactericidal activity of native serum was analyzed against Fusobacterium nucleatum, Porphyromonas gingivalis, and Aggregatibacter actinomycetemcomitans. Agar diffusion test showed a high efficacy of ozone against microorganisms, especially against Porphyromonas gingivalis. This result was confirmed by the killing tests; most of the strains in a concentration of 10(5) were completely eliminated after twofold 18-s application of ozone. Only four of the six potentially "superinfecting" species (Staphylococcus aureus, Enterococcus faecalis, Enterobacter cloacae, Candida albicans) survived in part. Addition of heat-inactivated serum reduced the killing rate of ozone by 78% after 6-s and by 47% after twofold 18-s exposures; no strain was completely eradicated after any application of ozone. The bactericidal effect of native serum was enhanced after application of ozone; no effect was visible on the included A. actinomycetemcomitans strain which was found to be completely resistant to the bactericidal action of serum. In conclusion, (a) ozone has a strong antibacterial activity against putative periodontopathogenic microorganisms, and (b) the bactericidal effect is reduced in the presence of serum. Ozone may have potential as an adjunctive application to mechanical treatment in periodontitis patients.

Enhanced clearance of Candida albicans from the oral cavities of mice following oral administration of Lactobacillus acidophilus

Orally administered live Lactobacillus acidophilus was assessed for its capacity to enhance clearance from the oral cavity of DBA/2 mice shown previously to be 'infection prone'. L. acidophilus fed to DBA/2 mice significantly shortened the duration of colonization of the oral cavity compared to controls. Enhanced clearance of Candida albicans correlated with both early mRNA gene expression for interleukin (IL)-4 and interferon (IFN)-gamma and expression of their secreted products in cultures of cervical lymph nodes stimulated with Candida antigen. In addition rapid clearance correlated with higher levels of IFN-gamma and nitric oxide in saliva. Delayed clearance, less pronounced levels of the cytokine response, saliva IFN-gamma and nitric oxide, and later mRNA expression for IL-4 and IFN-gamma relative to feeding with the L. acidophilus isolate were noted in mice fed a different Lactobacillus isolate (L. fermentum). These observations indicate significant variations in individual isolates to activate the common mucosal system.