Effect of ozonized olive oil on oral levels of Candida spp. in patients with denture stomatitis / Efeito do óleo de oliva ozonizado sobre os níveis orais de Candida spp. em pacientes com estomatite protética

Objective: The aim of this study was to evaluate the effect of ozonized olive oil (OZ) on the oral levels of Candida spp. in patients with denture stomatitis. Material and Methods: In vitro tests were performed to validate antifungal activity and to standardize OZ conditions. Antifungal activity was screened against C. albicans and five non-albicans species (C. tropicalis, C. dubliniensis, C. krusei, C. guilliermondii, and C. parapsilosis). Also, the effects on C. albicans planktonic and biofilm were evaluated. After validation, OZ was included in a therapeutic protocol of denture stomatitis in vivo. Thirty patients used OZ and 20 used sodium bicarbonate (SB) for 14 days. After 7 and 14 days, clinical evaluation, isolation and identification of yeasts were performed. Isolates were identified by phenotypic and genotypic tests. Ozonated oil showed in vitro antifungal activity against all species of Candida. Ozonated oil reduced the number of viable cells in C. albicans biofilms. Oral candidal levels were lower in relation to baseline both after after 14 days of treatment with SB and OZ. Results: A total of 493 Candida spp. isolates was obtained and 80% were identified as C. albicans. Remission of denture stomatitis was observed in all patients after 7 days of treatment in both groups. Conclusion: Within the limits of the study we can conclude that ozonized olive oil can be a new alternative for the control of biofilm in patients with denture stomatitis. (AU)

Objetivo: O objetivo deste estudo foi avaliar o efeito do óleo ozonizado (OZ) sobre os níveis orais de Candida spp. em pacientes com estomatite protética. Material e Métodos: Testes in vitro foram realizados para validar a atividade antifúngica e padronizar as condições do OZ. A atividade antifúngica foi avaliada contra C. albicans e cinco espécies não-albicans (C. tropicalis, C. dubliniensis, C. krusei, C. guilliermondii e C. parapsilosis). Além disso, os efeitos sobre C. albicans planctônico e biofilme foram avaliados. Após validação, o OZ foi incluído em um protocolo terapêutico de estomatite protética in vivo. Trinta pacientes usaram OZ e 20 usaram bicarbonato de sódio (SB) por 14 dias. Após 7 e 14 dias, foram realizadas avaliações clínicas, isolamento e identificação de leveduras. Os isolados foram identificados por testes fenotípicos e genotípicos. O óleo ozonizado mostrou atividade antifúngica in vitro contra todas as espécies de Candida. O óleo ozonizado reduziu o número de células viáveis em biofilmes de C. albicans. Os níveis orais de candidíase foram menores em relação aos valores basais após 14 dias de tratamento com SB e OZ. Resultados: Um total de 493 Candida spp. isolados foram obtidos e 80% foram identificados como C. albicans. A remissão da estomatite protética foi observada em todos os pacientes após 7 dias de tratamento em ambos os grupos. Conclusão: Dentro dos limites do estudo podemos concluir que o óleo de oliva ozonizado pode ser uma nova alternativa para o controle do biofilme em pacientes com estomatite protética.(AU)

Terapias alternativas para o tratamento da estomatite por prótese total: modelo experimental in vivo em ratos / Alternative therapies for denture stomatitis treatment: in vivo experimental model in rats

A estomatite por prótese (EP) é uma condição multifatorial que acomete frequentemente usuários de prótese total e geralmente é relacionada com Candida albicans. Devido aos efeitos tóxicos da terapia antifúngica, novas terapias para EP são necessárias. Objetivos: O objetivo deste estudo foi avaliar a eficácia do extrato aquoso de Buchenavia tomentosa e bicarbonato de sódio frente a C. albicans em um modelo de EP em ratos. Material e Métodos: Um aparelho de resina acrílica simulando a base da prótese total foi fixado cobrindo o palato de 48 ratos machos seguido por indução da candidose. Os ratos foram divididos em 4 grupos (n=12): controle, bicarbonato de sódio, B. tomentosa e nistatina (controle positivo). Cada grupo foi subdividido de acordo com o período de tratamento; 24 horas (n=6) e 48 horas (n=6). Os animais foram sacrificados e os aparelhos foram removidos para contagem de C. albicans e análise por microscopia eletrônica de varredura. Resultados: Após 24 horas de tratamento, observou-se redução significativa da contagem de C. albicans tanto B. tomentosa quanto nistatina (nistatina x controle, p<0,01; B. tomentosa x controle, p=0,03). Os resultados foram confirmados pela análise histológica. Conclusão: Tanto o extrato aquoso de B. tomentosa e o bicarbonato de sódio foram capazes de reduzir significativamente as contagens de C. albicans em modelo experimental de EP (AU)

Background: Denture stomatitis (DS) is a multifactorial condition that commonly affects denture users and is mainly caused by Candida albicans. Due to the toxic effects of antifungal therapy, new therapies for DS are claimed. Objective: The aim of the study was to evaluate the efficacy of aqueous extract of Buchenavia tomentosa and sodium bicarbonate against C. albicans in a model of DS in rats. Material and Methods: An acrylic resin device simulating a denture base was fixed covering the palate of forty-eight male rats followed by candidiasis induction. Rats were divided into 4 groups (n = 12): Control, sodium bicarbonate, B. tomentosa and nystatin (positive control). Each group was subdivided according to the period of treatment; 24 h (n = 6) and 48 h (n = 6). Animals were sacrificed and had their devices removed for C. albicans counts and SEM analysis. The palate mucosa was removed and processed for histopathologic analysis. Results: After 24 h of treatment, both B. tomentosa and nystatin groups reduced significantly C. albicans counts when compared to control (nystatin x control, p < 0.01; B. tomentosa x control, p = 0.03). The results were confirmed by the histologic analysis. Conclusion: Both the aqueous extract of B. tomentosa and sodium bicarbonate was able to significantly decrease C. albicans counts in an experimental model of DS (AU)

Cymbopogon citratus essential oil: effect on polymicrobial caries-related biofilm with low cytotoxicity

Abstract The objective of this study was to evaluate the effects of Cymbopogon citratus essential oil and its main compound (citral) against primary dental colonizers and caries-related species. Chemical characterization of the essential oil was performed by gas chromatography/mass spectroscopy (GC/MS), and the main compound was determined. Antimicrobial activity was tested against Actinomyces naeslundii, Lactobacillus acidophilus, S. gordonii, S. mitis, S. mutans, S. sanguinis and S. sobrinus. Minimum inhibitory and bactericide concentrations were determined by broth microdilution assay for streptococci and lactobacilli reference, and for clinical strains. The effect of the essential oil on bacterial adhesion and biofilm formation/disruption was investigated. Negative (without treatment) and positive controls (chlorhexidine) were used. The effect of citral on preformed biofilm was also tested using the same methodology. Monospecies and microcosm biofilms were tested. ANOVA or Kruskal-Wallis tests were used (α=0.05). Cytotoxicity of the essential oil to human keratinocytes was performed by MTT assay. GC/MS demonstrated one major component (citral). The essential oil showed an inhibitory effect on all tested bacterial species, including S. mutans and L. acidophilus. Essential oil of C. citratus (10X MIC) reduced the number of viable cells of lactobacilli and streptococci biofilms (p < 0.05). The essential oil inhibited adhesion of caries-related polymicrobial biofilm to dental enamel (p < 0.01). Citral significantly reduced the number of viable cells of streptococci biofilm (p < 0.001). The essential oil showed low cytotoxicity to human keratinocytes. Based on these findings, this study can contribute to the development of new formulations for products like mouthwash, against dental biofilms.

Effectiveness of photodynamic therapy on Candida species isolated from oral samples of children exposed and not exposed to HIV / Efetividade da terapia fotodinâmica sobre espécies de Candida isoladas de amostras bucais de crianças expostas e não expostas ao HIV

ABSTRACT Objective: Identify yeast species isolated from unexposed, exposed and HIV-carrier children, and verify the effectiveness of low power laser photodynamic therapy (PDT) on the yeasts species belonging to the Candida genus. Methods: Fifty children assisted by the Public Health Program of the city of Vitória da Conquista, Bahia, were selected and divided into three groups: unexposed to HIV, exposed to HIV during pregnancy, and HIV-carrier. Saliva samples were collected in a disposable sterile universal container and were plated to Sabouraud dextrose agar supplemented with 0.1 mg/mL chloramphenicol. The plates were incubated at 37°C for 48 h. Three strains of each patient were identified by using an API 20 C AUX system. The strains were submitted to photodynamic therapy (PDT) with a 660 nm low power laser and methylene blue dye at different times of irradiation (90, 180 and 282 sec.). Results: The results showed that the most prevalent species was Candida albicans followed by Candida famata (second most prevalent in unexposed to HIV and HIV carriers)) and Candida parapsilosis (second most prevalent in exposed to HIV group). The CFU/mL of Candida spp. decreased significantly (p<0,05) in all groups treated with PDT compared to the controls. Photodynamic therapy treatments at different exposure times (e.g., PS+L90+, PS+L180+, PS+L282+) revealed that the exposure time of 282 sec. gave the highest reduction of the mean logarithmic CFU/mL. Conclusion: Candida albicans was the most prevalent Candida species in these three groups and Candida non-albicans species, when combined, amounted to a significant percentage of Candida isolates. Photodynamic therapy was effective in inactivating the Candida spp. isolated from the oral cavity of children not exposed to HIV, exposed to HIV and HIV-carriers, with the best photodynamic therapy irradiation time being 282 sec.

RESUMO Objetivo: Identificar espécies de leveduras isoladas de crianças não expostas, expostas ao HIV e portadoras de AIDS, e verificar a eficácia da terapia fotodinâmica com laser de baixa potência sobre as espécies de leveduras pertencentes ao gênero Candida. Métodos: Cinquenta crianças atendidas pelo Programa de Saúde Pública da cidade de Vitória da Conquista, Bahia, foram selecionadas e divididas em três grupos: não expostas ao HIV, expostas ao HIV durante a gravidez e portadoras da AIDS. Amostras de saliva foram coletadas em um recipiente universal descartável estéril e foram semeadas em ágar Sabouraud dextrose suplementado com 0,1 mg / mL de cloranfenicol. As placas foram incubadas a 37°C durante 48h. Três cepas de cada paciente foram identificadas utilizando o sistema API 20 C AUX. As cepas foram submetidas à Terapia Fotodinâmica com laser de baixa potência de 660 nm e corante azul de metileno em diferentes tempos de irradiação (90, 180 e 282 segundos). Resultados: Os resultados mostraram que a espécie isolada mais prevalente nos grupos estuddos foi Candida albicans, seguida de Candida famata (segunda mais prevalene nos grupos não expostos ao HIV e com AIDS) e Candida parapsilosis (segunda mais prevalente no grupo exposto ao HIV). Houve diminuição significante de CFU/ml de Candida spp. (p <0,05) em todos os grupos tratados com terapia fotodinâmica, em comparação com os controles. A terapia fotodinâmica, nos diferentes tempos (e.g., PS+L90+, PS+L180+, PS+L282+) mostrou que o tempo de 282 seg. apresentou a maior redução em media de logarítmo de UFC/mL. Conclusão: Candida albicans foi a espécie de Candida mais prevalente isolada nos três grupos e as espécies de Candida não-albicans, quando combinadas, contribuíram com porcentagem significativa dos isolados de Candida. A PDT foi eficaz na inativação de Candida spp. isoladas a partir da cavidade oral de crianças não expostas, expostas ao HIV e portadoras da AIDS, com o melhor tempo de irradiação sendo o de 282 seg.

Influence of different fermentable carbohydrates on dual species biofilms of S. mutans and A. naeslundii: a pilot study / Influência de diferentes carboidratos fermentáveis em biofilmes de duas espécies com S. mutans e A. naeslundii - um estudo piloto

Objetivo: O propósito deste estudo foi analisar o efeito da presença de diferentes carboidratos fermentáveis na biomassa e acidogenicidade do biofilme formado por Streptococcus mutans ATCC 25175 em associação com Actinomyces naeslundii ATCC 19039. Material e Métodos: Biofilmes com uma ou duas espécies cresceram em poços de placas de microtitulação em igual concentração, por 24 h a 37 ºC. Carboidratos foram adicionados em concentração de 2%: maltose, sacarose, glicose e lactose, além disso, como controle negativo, caldo BHI (0.2% de sacarose) foi usado. O pH foi medido individualmente para avaliar a acidogenicidade após 24 h, imediatamente após troca do meio de cultura e 30 min, 1 h e 2 h depois. Cristal violeta foi usado como indicador do total de biomassa formada após 24 h de incubação e a absorbância foi medida a 590 nm. Teste de Tukey foi utilizado para todas as análises estatísticas. Resultados: Em geral, maior quantidade de biomassa foi formada por biofilmes dupla-espécie que única-espécie na presença de todos os carboidratos, exceto glicose. Biofilmes formados por S. mutans mostraram significativamente maior acidogenicidade que o grupo controle apenas após 24 h. Em biofilmes dupla-espécie, maior acidogenicidade foi encontrada após 24 h na presença de sacarose, lactose, maltose e no grupo controle. Conclusão: Esses achados indicam que o tipo de biofilme e o carboidrato usado podem influenciar ambas: formação de biomassa e taxa de queda do pH.

Objective: The aim of this study was to elucidate the effect of presence of different fermentable carbohydrates in the biomass and acidogenicity of biofilm formed by Streptococcus mutans ATCC 25175 in association with Actinomyces naeslundii ATCC 19039. Material and Methods: Single and dualspecies biofilms were grown on wells of microtiter plates at equal concentration for 24 h at 37 ºC. Carbohydrates were added at 2%: maltose, sucrose, glucose and lactose and as negative control, BHI Broth (0.2% glucose) was used. The pH of each culture was measured to assess acidogenicity after 24 h, immediately after changing the culture medium and 30 min, 1 h and 2 h after. Crystal violet was used asindicator of the total attached biofilm biomass after 24 h incubation and the absorbance was measured at 590 nm. Tukey Multiple Comparison Test was performed for all the statistical analysis. Results: Higher amount of biomass was formed by dualspecies than single-species biofilm in the presence of all carbohydrates, except to glucose. S. mutans biofilms showed statistically significant higher acidogenicity than control group only after 24 h. In dual-species biofilms the highest acidogenicity were found after 24 h for sucrose, lactose, maltose and the control group. Conclusion: The findings indicate that the type of biofilm (single or dual-species) and the carbohydrate used may influence amount of biomass formed and rate of the pH reduction.

Evaluation of caries-associated virulence of biofilms from Candida albicans isolated from saliva of pediatric patients with sickle-cell anemia

A previous study demonstrated that the amount of Candida spp. in saliva is higher in children with sickle-cell disease. The results from a recent study demonstrate its participation in the etiology of dental caries. Objective This study assessed caries-associated virulence (production of acid, extracellular polysaccharides, proteins and metabolic activity) of biofilms from Candida albicans isolated from saliva of patients with sickle-cell anemia in comparison to isolates obtained from matched healthy children. Material and Methods The isolates were previously obtained from 25 children (4-6 years) and their matched controls (healthy children). One isolate of C. albicans per children was used, totaling 25 isolates per group. The C. albicans biofilms were grown for five days and analyzed regarding the production of lactic acid, extracellular polysaccharides, proteins and metabolic activity. The production of lactic acid was determined by the enzymatic method. The concentration of extracellular polysaccharides was determined by the phenol-sulphuric acid method, and the concentration of the protein was analyzed using the QuantiPro BCA kit. The XTT reduction was used to verify the metabolic activity. The data were analyzed with GraphPad Prism at 5%. Results The Mean±standard deviation for acid production, extracellular polysaccharides, proteins and metabolic activity of isolates from sickle-cell group was, respectively: 7.1±5.0 mmol/L; 15.6±2.5 μg glucose/mg biofilm; 7,503±3,097 μg/mL; A490 3.5±0.7. For isolates from control group the values obtained were: 3.5±3.3 mmol/L; 12.8±3.4 μg glucose/mg biofilm; 4,995±682 μg/mL; A490 3.4±0.5. The C. albicans isolates from patients with sickle-cell anemia produced a significantly greater quantity of acids (p=0.025), polysaccharides (p=0.025) and proteins (p=0.047) compared with the isolates from control group. However, there was ...

Participation of micro-organisms of dental interest in the etiology of Burning Mouth Syndrome / Participação dos micro-organismos de interesse odontológico na etiologia da Síndrome de Ardência Bucal

Objective: The Burning Mouth Syndrome (BMS) is a pathologic entity characterized by the presence of chronic symptoms of burning or pain in normal oral mucosa. It mainly affects women in the postmenopausal period, and its cause is unknown, but as there is an association with biological and psychological factors, it may assume a multifactorial etiology. Considering the unclear etiology of BMS, studies that contribute to its understanding are of great importance. In order to achieve a better understanding regarding microbial etiological factors of this disease, the aim of this review is to compile studies on possible involvement of micro-organisms of dental interest in the etiology of BMS. Studies have reported that patients with BMS harbor greater amount of intraoral Candida and Enterobacteriaceae than patients without clinical manifestations of this disease. Methods: Different sources such as articles, books and journals, published in the world literature were used in this research. These sources were accessed by databases like PubMed, SciELO, Scopus or search of full text. Conclusion: Studies in the literature have suggested that Candida and Enterococcus were correlated with BMS, although they might not necessarily be considered as an etiological factor but a predisposing factor. However, further studies that aim to elucidate relation between BMS and infectious factors are necessary.

Objetivo: A síndrome da ardência bucal (SAB) é uma entidade patológica caracterizada pela presença de sintomas crônicos de ardor ou dor na mucosa oral clinicamente normal. Afeta principalmente mulheres no período pós-menopausa, sendo sua causa desconhecida, mas sua relação com uma completa associação de fatores biológicos e psicológicos nos faz supor uma etiologia multifatorial. Considerando a etiologia ainda não esclarecida da Síndrome da Ardência Bucal, estudos que contribuam para o esclarecimento desta são de extrema relevância. Visando maior entendimento com relação aos fatores etiológicos microbianos da doença, o objetivo desta revisão de literatura foi compilar estudos sobre possível participação de micro-organismos de interesse odontológico na etiologia da SAB. Estudos afirmam que pacientes com SAB abrigam maior quantidade de Candida e Enterobactérias intraorais que pacientes sem manifestações clínicas dessa patologia. Métodos: Nesta pesquisa foram utilizadas diferentes fontes, como artigos, livros e revistas publicados na literatura mundial. Estas fontes foram acessados por bases de dados como (PubMed, Scielo, Scopus) ou por pesquisa do texto integral. Conclusão: Estudos na literatura sugerem que Candida e Enterococcus possuem correlação com a Síndrome de Ardência Bucal, embora não possam ser necessariamente considerados como um fator etiológico e sim um fator pré-disponente. No entanto, mais estudos com o objetivo de elucidar como ocorre essa relação entre a SAB e os fatores infecciosos são necessários.

In vitro antimicrobial activity of AH Plus, EndoREZ and Epiphany against microorganisms.

Objective : The aim of the present study was to evaluate the antimicrobial activity of endodontic sealers against microorganisms. Materials and Methods : The agar diffusion method was used. A double base layer of Mueller Hinton agar was done. The microorganisms used were: Candida albicans, Enterococcus faecalis, Escherichia coli and Staphylococcus aureus. The wells were obtained by removing a standardized portion of the agar. After the distribution of the sealers, Petri plates were incubated for 24 h. Inhibition halos formed around the wells were measured. Results : Epiphany did not show any antimicrobial activity on the tested microorganisms (without inhibition halo). The AH Plus showed the greatest inhibition halo on C. albicans followed by EndoREZ on S. aureus. EndoREZ also showed greater inhibition halo in comparison to AH Plus on E. faecalis and E. coli. Conclusion : It could be concluded that AH Plus and EndoREZ showed antimicrobial activity against all the tested microorganisms. No antimicrobial activity was observed for Epiphany.

Opportunistic microorganisms in patients undergoing antibiotic therapy for pulmonary tuberculosis

Antimicrobial therapy may cause changes in the resident oral microbiota, with the increase of opportunistic pathogens. The aim of this study was to compare the prevalence of Candida, Staphylococcus, Pseudomonas and Enterobacteriaceae in the oral cavity of fifty patients undergoing antibiotic therapy for pulmonary tuberculosis and systemically healthy controls. Oral rinsing and subgingival samples were obtained, plated in Sabouraud dextrose agar with chloramphenicol, mannitol agar and MacConkey agar, and incubated for 48 h at 37ºC. Candida spp. and coagulase-positive staphylococci were identified by phenotypic tests, C. dubliniensis, by multiplex PCR, and coagulase-negative staphylococci, Enterobacteriaceae and Pseudomonas spp., by the API systems. The number of Candida spp. was significantly higher in tuberculosis patients, and C. albicans was the most prevalent specie. No significant differences in the prevalence of other microorganisms were observed. In conclusion, the antimicrobial therapy for pulmonary tuberculosis induced significant increase only in the amounts of Candida spp.

In vitro adherence of Candida albicans isolated from patients with chronic periodontitis

Adherence is considered an extremely important virulence factor in yeast. OBJECTIVE: The aim of this study was to analyze the adherence to epithelial cells of C. albicans isolated from patients with chronic periodontitis in comparison to healthy patients. MATERIAL AND METHODS: Candida albicans cells isolated from individuals with chronic periodontitis (n=25) and healthy controls (n=25) were included in this study. Suspensions of C. albicans (10(6) cells/mL) and epithelial cells (10(5) cells/mL) were mixed and incubated at 37ºC for 1 h. The number of yeasts adhered to 25 epithelial cells was counted. RESULTS: The number of C. albicans cells adhered to epithelial cells was statistically higher in the chronic periodontitis group than in the control group (Student's t-test, p=0.000). CONCLUSION:The results of the present study suggest a higher Candida adherence of samples isolated from patients with chronic periodontitis.

HAART therapy does not reduce the proteinase and phospholipase secretion by oral Candida albicans isolated from HIV-positive patients

Production of exoenzymes, specifically the proteinase and phospholipase, is considered one of the most important of pathogenicity mechanisms of C. albicans, which is crucial for tissue invasion. This study aimed at evaluating the production of these exoenzymes in 50 oral C. albicans isolates from HIV-positive (HIV+) patients treated with highly active anti-retroviral therapy (HAART), and from 50 control individuals. For testing the production of phospholipase and proteinase, the culture media containing egg yolk and bovine albumin were used, respectively. The results were obtained by measuring the diameter of the colony and divided by the diameter of colony plus the precipitation zone, defined as Pz. Data were statistically analyzed by Student’s t test (5). Statistically significant difference (p = 0.001) was observed between the mean values of Pz for proteinase in isolates from HIV+ patients (Pz = 0.358±0.295) and from control group (Pz = 0.660±0.370). The same results were observed for phospholipase production (Pz = 0.399±0.227 for HIV+ group; Pz =0.635±0.292 control group). Both enzymes were highly produced by C. albicans isolated from HIV+ patients when compared with those secreted by C. albicans obtained from control group, suggesting that HAART did not reduce the secretion of these enzymes by this pathogenic fungus infecting HIV+ patients.

In vitro evaluation of the action of irrigating solutions associated with intracanal medications on Escherichia coli and its endotoxin in root canals

OBJECTIVE: The purpose of this study was to evaluate the effcacy of auxiliary chemical substances and intracanal medications on Escherichia coli and its endotoxin in root canals. MATERIAL AND METHODS: Teeth were contaminated with a suspension of E. coli for 14 days and divided into 3 groups according to the auxiliary chemical substance used: G1) 2.5 percent sodium hypochlorite (NaOCl); G2) 2 percent chlorhexidine gel (CLX); G3) pyrogenfree solution. After, these groups were subdivided according to the intracanal medication (ICM): A) Calcium hydroxide paste (Calen®), B) polymyxin B, and C) Calcium hydroxide paste+2 percent CLX gel. For the control group (G4), pyrogen-free saline solution was used without application of intracanal medication. Samples of the root canal content were collected immediately after biomechanical preparation (BMP), at 7 days after BMP, after 14 days of intracanal medication activity, and 7 days after removal of intracanal medication. The following aspects were evaluated for all collections: a) antimicrobial activity; b) quantifcation of endotoxin by the Limulus Amebocyte Lysate test (LAL). Results were analyzed by the Kruskal-Wallis and Dunn's tests at 5 percent signifcance level. RESULTS: The 2.5 percent NaOCl and CLX were able to eliminate E. coli from root canal lumen and reduced the amount of endotoxin compared to saline. CONCLUSIONS: It was concluded that 2.5 percent NaOCl and CLX were effective in eliminating E. coli. Only the studied intracanal medications were to reduce the amount of endotoxin present in the root canals, regardless of the irrigant used.

Effectiveness of 2 percent peracetic acid for the disinfection of gutta-percha cones

The aim of this study was to evaluate the effectiveness of 2 percent peracetic acid for the disinfection of gutta-percha cones contaminated in vitro with Escherichia coli, Staphylococcus aureus, Streptococcus mutans, Candida albicans and Bacillus subtilus (in spore form). Two hundred and twenty-five gutta-percha cones were contaminated with standardized suspensions of each microorganism and incubated at 37°C for 24 h. The cones were divided into 10 experimental groups (n = 15), according to the microorganism tested and disinfection testing times. The disinfection procedure consisted of immersing each cone in a plastic tube containing the substance. The specimens remained in contact with the substance for 1 or 2.5 minutes. Afterwards, each cone was transferred to a 10 percent sodium thiosulphate solution (Na2S2O3) to neutralize the disinfectant. Microbial biofilms adhering to the cones were dispersed by agitation. Aliquots of 0.1 ml of the suspensions obtained were plated on Sabouraud dextrose agar, or brain and heart infusion agar, and incubated at 37°C for 24 h. The results were expressed in colony forming units (CFU/ml) and the data were submitted to the Wilcoxon Signed Rank Test (level of significance at 0.05). A significant reduction was observed, after 1 minute of exposure, in the test solution for C. albicans (p = 0.0190), S. aureus (p = 0.0001), S. mutans (p = 0.0001), B. subtilis (p = 0.0001), and E. coli (p = 0.0001). After 2.5 minutes of exposure, 100 percent of the microbial inocula were eliminated. It was concluded that the 2 percent peracetic acid solution was effective against the biofilms of the tested microorganisms on gutta-percha cones at 1 minute of exposure.

In vitro antifungal susceptibility of Candida spp. oral isolates from HIV-positive patients and control individuals

Oropharyngeal candidiasis is the most common fungal infection among HIV-positive patients. This condition can be treated with either systemic or topical antifungal agents; treatments are usually indicated empirically on the basis of clinical data. The knowledge of in vitro antifungal susceptibility is important to determine correct therapeutic guides for the treatment of fungal infections. Therefore, the objective of this study was to determine the antifungal susceptibility profile of oral Candida isolates from HIV-positive patients and control individuals. Amphotericin B, fluconazole, flucytosine, nystatin and ketoconazole were tested according to the methodology of microdilution proposed by the Clinical and Laboratory Standards Institute (CLSI); results were recorded in values of minimal inhibitory concentration (MIC). A total of 71 Candida isolates from HIV-positive patients were examined with the following species represented: C. albicans (59), C. tropicalis (9), C. glabrata (1), C. guilliermondii (1) and C. krusei (1). A total of 15 Candida isolates were evaluated from control individuals comprised of 11 C. albicans and 4 C. tropicalis samples. Our results demonstrated that the tested antifungal agents showed good activity for most isolates from both groups; however, variability in MIC values among isolates was observed.

Presence of Candida spp. in the oral cavity of heart transplantation patients

Candida spp. can lead to infections or even fungal sepsis particularly among immunocompromized individuals. OBJECTIVE: The aim of the present study was to analyze the presence of Candida spp. among patients subjected to orthotopic heart transplantation. MATERIAL AND METHODS: Oral rinses from 50 patients subjected to orthotopic heart transplantation, aged 13 to 70 years, 40 males and 10 females, were examined. Sex-age-oral conditions matched-control included 50 individuals who were not subjected to any kind of transplantation and were not immunocompromized for any other reason. Counts of yeasts were expressed as median values of logarithm of cfu/mL and were statistically compared by Mann-Whitney's test. The heart transplant and control groups were compared for the presence of Candida spp. by chi-square test (p<0.05). RESULTS: The results showed statistically significant difference (p=0.001) in the prevalence of Candida spp. between the transplantation and control groups. Counts of yeasts (cfu/mL) in the transplanted group were significantly higher than in the control group (p=0.005). Candida albicans was the most prevalent species isolated from both groups. CONCLUSIONS: It was concluded that Candida yeast counts were higher in the heart transplant recipients than in the controls. There was higher variation of Candida species among the heart transplant patients and the most frequently isolated samples were: Candida albicans, Candida glabrata and Candida tropicalis. Isolates of Candida dubliniensis was not found in either of the groups.

Atividade antifúngica de uma pomada à base de chamomilla recutita sobre candida albicans / Antifungal activity of chamomilla recutita based pomade on candida albicans

O objetivo do estudo foi avaliar a atividade antifúngica de uma pomada à base de [Chamomilla recutita (L) Rauschert] (camomila) sobre espécies do gênero Cândida. Vinte e seis isolados clínicos Cân- dida (e. a/bicans, e. dub/iniensis, e. krusei, e. parapsi/osis) e três cepas de referência foram semeadas em ágar Sabouraud dextrose a 3rC/24h antes da realização do experimento. Foi realizada a diluição seriada do produto nas concentrações de 500f0, 250f0, 12,5%, 6,25%, 3,12%, 1,56% e 0,78% em ágar RPMI tamponado com MOPS. Foram obtidas suspensões padronizadas na escala 5 de McFarland em solução fisiológica esterilizada (NaCI 0,9%) de cada isolado a ser avaliado. Posteriormente, as suspensões dos microrganismos foram semeadas em placas de Petri contendo o produto teste + ágar RPMI através de replicador de Steers e incubadas em estufa bacteriológica a 3rC/24h. Um controle de crescimento foi incluído no estudo e os testes foram realizados em duplicata. O resultado foi avaliado através da observação da presença ou ausência de crescimento de colônias no ágar. Os testes mostraram que das 26 amostras avaliadas, 14 amostras (53,9%) foram inibidas na concentração de 500f0, 11 amostras (42,3%) foram inibidas na concentração de 25%, uma amostra (3,9%) foi inibida na concentração de 12,5%. A pomada não teve efeitos inibitórios sobre a cepa de referência e. krusei. A partir dos resultados obtidos, concluiu-se que o produto testado apresentou atividade antifúngica in vitro sobre a maioria dos isolados de Cândida avaliados.

The aim of this study was to evaluate the antifungal activity of a chamomile [Chamomilla recutita (L) Rauschert] based ointment. Twenty-six clinical isolates of Candida (e. a/bicans, e. dub/iniensis, e. krusei, e. parapsi/osis) and three reference strains were spread onto Sabouraud dextrose agar and incubated under 37°C/24 h before the experiment. The ointment was serially diluted (500f0, 25%, 12.5%, 6.25%,3.12%, 1.56% and 0.78%) in RMPI agar buffered with MOPS. Standardized suspensions of each strain were prepared in saline solution (NaCl 0.9%) based on scale 5 of McFarland. Next, the suspensions of each microorganism were plated on Petri using a Steers replicator and incubated at 37°C/24 h. A positive control was included and the tests were performed in duplicate. The result was evaluated by the observation the presence or absence the colonies on the agar. The tests showed that from the 26 isolates evaluated, 14 (53,9%) were inhibited by the concentration of 500/0, 11 strains (42,3%) were inhibited by the concentration of 25%, one strain (3.9%) were inhibited by the concentration of 12.5%. The ointment did not show inhibitory effects on e. krusei reference strain. Based on the results obtained, we concluded that the product evaluated showed antifungal activity in vitro on the majority of the tested isolates.

Evaluation of alternative methods for the disinfection of toothbrushes

The aim of this study was to evaluate alternative methods for the disinfection of toothbrushes considering that most of the previously proposed methods are expensive and cannot be easily implemented. Two-hundred toothbrushes with standardized dimensions and bristles were included in the study. The toothbrushes were divided into 20 experimental groups (n = 10), according to microorganism considered and chemical agent used. The toothbrushes were contaminated in vitro by standardized suspensions of Streptococcus mutans, Streptococcus pyogenes, Staphylococcus aureus or Candida albicans. The following disinfectants were tested: 0.12 percent chlorhexidine digluconate, 50 percent white vinegar, a triclosan-containing dentifrice solution, and a perborate-based tablet solution. The disinfection method was immersion in the disinfectant for 10 min. After the disinfection procedure, the number of remaining microbial cells was evaluated. The values of cfu/toothbrush of each group of microorganism after disinfection were compared by Kruskal-Wallis ANOVA and Dunn's test for multiple comparisons (5 percent). The chlorhexidine digluconate solution was the most effective disinfectant. The triclosan-based dentifrice solution promoted a significant reduction of all microorganisms' counts in relation to the control group. As to the disinfection with 50 percent vinegar, a significant reduction was observed for all the microorganisms, except for C. albicans. The sodium perborate solution was the less effective against the tested microorganisms. Solutions based on triclosan-containing dentifrice may be considered effective, nontoxic, cost-effective, and an easily applicable alternative for the disinfection of toothbrushes. The vinegar solution reduced the presence of S. aureus, S. mutans and S. pyogenes on toothbrushes.

Análise da efetividade da instrumentação associada à terapia fotodinâmica antimicrobiana e a medicação intracanal na eliminação de biofilmes de Enterococcus faecalis / Analysis of the effectiveness of the instrumentation associated to antimicrobial photodynamic therapy and root canal dressing in the elimination of Enterococcus faecalis in root canals

A eliminação total dos microrganismos dos canais radiculares é um procedimento de dificuldade extrema. O objetivo deste estudo foi avaliar in vitro a efetividade da instrumentação associada à Terapia Fotodinâmica (TFD) na eliminação de Enterococcus faecalis ATCC 29212 nos canais radiculares. Foram utilizadas 20 raízes dentárias humanas contaminadas com Enterococcus faecalis tendo 14 dias como período de incubação. Após esse tempo, foi realizada coleta do conteúdo intracanal que foi semeado em meio de cultura Tryptic Soy Agar. Das 20 raízes dentárias humanas, 10 foram utilizadas no grupo teste, em que os canais foram instrumentados e preenchidos com associação do corante azuleno 25% e Endo-PTC (5g azuleno/15g Endo-PTC) durante 5 minutos e irradiados com laser ArGaAl por 3 minutos; as outras 10 raízes dentárias foram utilizadas no grupo controle, em que houve apenas a fase de instrumentação e não foi realizada a TFD. Outras duas coletas foram feitas, sendo uma imediatamente e outra após 7 dias da TFD, as quais receberam medicação intracanal (polimixina B com clorexidina gel 2%) por 14 dias. A última coleta foi realizada depois de 7 dias da remoção da medicação. Os dados obtidos foram submetidos à análise estatística Mann-Whitney (5%). Concluiu-se que a instrumentação associada à TFD frente a Enterococcus faecalis foi efetiva, mas não eliminou totalmente o biofilme intracanal monoespécie. Após o uso de medicação intracanal com clorexidina gel 2% associada à polimixina B, não houve diferença no número de UFCs de Enterococcus faecalis entre o grupo tratado com TFD e aquele em que foi utilizada apenas a instrumentação

The total elimination of microorganisms in root canals is an extremely difficult procedure. The aim of this study was to evaluate the in vitro efficacy of photodynamic therapy (PDT) associated to instrumentation for the elimination of Enterococcus faecalis ATCC 29212 in root canals. Twenty human dental roots were inoculated with E. faecalis. After 14 days of incubation, the results of intracanal content sampling were plated on tryptic soy agar. The canals were instrumented and filled with a mixture of 25% azulene and Endo-PTC for 5 min, and the test group was irradiated with an ArGaAl laser for 3 min. Two more samplings that received intracanal medication (polymixin B with 2% chlorhexidine gel) for 14 days were performed, one immediately and another 7 days after the photodynamic therapy. The last sampling was performed 7 days after removing the medication. The data were analyzed using the Mann-Whitney test. It could be concluded that the photodynamic therapy associated to instrumentation was effective against E. faecalis but did not totally eliminate the intracanal monospecies biofilm. After using the 2% chlorhexidine gel and polymixin B intracanal medication, no significant difference in the number of Enterococcus faecalis colony-forming unit (CFU) was observed between the group treated with PDT and the group treated with instrumentation only.

Isolamento de candida spp. com utilização de meio de cultura cromogênico CHROMagar candida / Isolation of candida spp. using of the chromogenic culture medium CHROMagar candida

O objetivo do presente estudo foi comparar o isolamento e identificação de leveduras do gênero Candida em meio de cultura cromogênico CHROMagar Candida com o isolamento convencional em ágar Sabouraud dextrose com cloranfenicol. Foram coletadas amostras de saliva de 50 indivíduos com idades entre 13 e 70 anos. Os participantes realizaram enxágue bucal com solução fisiológica esterilizada e tamponada com fosfato (PBS) durante 30 s. Essas amostras foram semeadas em CHROMagar Candida e ágar Sabouraud dextrose com cloranfenicol e incubadas a 37°C por 48h. A seguir, foi realizada a contagem de unidades formadoras de colônias (UFC/mL) em CHROMagar Candida e em ágar Sabouraud. Foi realizada a identificação presuntiva das espécies de Candida em CHROMagar através da observação da morfologia e cor das colônias. As colônias de Candida foram isoladas para identificação fenotípica convencional por meio das provas de produção de tubos germinativos, formação de hifas e clamidoconídeos, fermentação e assimilação de açúcares, diferencial de temperatura e urease. Os isolados identificados como C. albicans também foram analisados genotipicamente, pela técnica de Reação em Cadeia da Polimerase, para diferenciação de C. dubliniensis. Os resultados demonstraram que o ágar Sabouraud apresentou maior contagem de leveduras (UFC/mL) em relação ao CHROMagar, entretanto sem diferença estatisticamente significante. O CHROMagar foi eficaz na pré-identificação de Candida albicanse Candida tropicalis. Concluiu-se que ambos os meios foram eficazes para o crescimento de leveduras, sendo queo ágar Sabouraud dextrose com cloranfenicol apresentou maior quantidade de UFC/mL. O CHROMagar possibilitou a identificação presuntiva da maioria das espécies de Candida.

The aim of this study was to compare the isolation and identification of yeasts of gender Candida by medium CHROMagarCandida with the convencional medium Sabouraud Dextrose agar with chloramphenicol. Fifty samples of saliva werecollected from individuals between 13 to 70 years old. The individuals rinsed their mouth with sterile phosphate bufferedsaline (PBS) for 30 seconds. Those samples were plated in CHROMagar Candida and Sabouraud Dextrose agar withchloramphenicol, and incubated at 37°C for 48h. After that, the number of colony-forming units per mL (CFU/mL) werecounted in CHROMagar Candida and Sabouraud Dextrose agar. The presumptive identification of Candida species inCHROMagar was carried out by color and morphology of colonies. The Candida colonies were isolated in order toperform phenotypic identification through the production of germinative tubes, presence of hyphae and chlamydospores,carbohydrate fermentation and assimilation, temperature differentiate, and urease test. The isolates identified as C. albicans were analyzed by genotypic characterization using the Polymerase Chain Reaction (PCR) to discriminate C.dubliniensis. The results demonstrated that Sabouraud Dextrose agar presented higher number of Candida (CFU/mL) in relation to the CHROMagar, however no statistical difference was observed. The CHROMagar was effective for presumptive identification of C. albicans and C. tropicalis. It was concluded that both medium were effective for growingof yeasts, with higher number of UFC/mL in CHROMagar. The CHROMagar allowed the presumptive identification of the most Candida species.

Effect of sodium bicarbonate on Candida albicans adherence to thermally activated acrylic resin

The purpose of this study was to evaluate the effect of 5 percent sodium bicarbonate on the adherence of Candida albicans to thermally activated acrylic resin. Fifty 4 mm² specimens of acrylic resin were obtained using a metallic matrix. The specimens received chemical polishing, were sterilized and then immersed in Sabouraud broth, inoculated with Candida albicans standardized suspension. After 24 hours of incubation at 37ºC, the specimens were divided into four groups according to the substance used for disinfection (5 percent sodium bicarbonate, 0.12 percent digluconate chlorhexidine, vinegar and Corega Tabs). A control group was included, in which distilled water was used. The adhered microorganisms were dispersed, diluted and plated onto culture media to determine the number of colony-forming units (cfu/mL). The results were analyzed through the Mann-Whitney statistical test at the 5 percent level of significance. Only 0.12 percent digluconate chlorhexidine and 5 percent sodium bicarbonate presented a statistically significant difference (p = 0.0010 and p = 0.0156, respectively) compared to the control group, decreasing the number of cfu/mL. However, when the different disinfecting solutions were compared with each other, only 0.12 percent digluconate chlorhexidine presented a statistically significant difference in the reduction of cfu/mL. It was concluded that although 0.12 percent digluconate chlorhexidine was more effective in the reduction of Candida albicans adherence values to thermally activated acrylic resin, 5 percent sodium bicarbonate also proved to be a viable alternative.