Infecção do trato urinário por leveduras do gênero Candida ­ revisão de literatura / Urinary tract infection by yeast of the genus Candida - literature review / Infección del tracto urinario causada por levaduras del género Candida - revisión de la literatura

A ocorrência das infecções do trato urinário (ITU) causadas por leveduras do gênero Candida estão aumentando consideravelmente nas últimas décadas, sendo a Candida albicans a mais comumente diagnosticada como causadora deste tipo de infecções. Contudo, outras espécies, como exemplo da Candida tropicalis, estão emergindo como preocupantes causadores da doença. Neste sentido, o objetivo do presente trabalho é revisar os aspectos relacionados com as ITU causadas por leveduras do gênero Candida. Foi realizada uma pesquisa na base de dados PubMed, buscando artigos sobre a epidemiologia, patogenia e tratamento das ITU causadas por leveduras do gênero Candida. As espécies de Candida são os fungos patogênicos oportunistas mais relevantes causadores de infecções nosocomiais e podem causar infecção no trato urinário, tanto inferior (ureteres, bexiga e uretra) quanto superior (rins), principalmente em pacientes imunocomprometidos. Existem alguns fatores predisponentes, como gênero feminino, idade avançada, diabetes mellitus, hospitalização prolongada, imunossupressão, gravidez, hipertensão, neutropenia, cálculos renais, infecções nosocomiais, terapia antibiótica e procedimentos, como a cateterização, que atuam como facilitadores das ITU por Candida spp. A doença pode ocorrer de forma assintomática, porém, pode evoluir para casos mais graves com comprometimento sistêmico em situações de candidemia que pode causar a morte do paciente, principalmente se tratando de indivíduos imunocomprometidos. Sendo assim, devido ao risco existente, a doença não pode ser negligenciada e um diagnóstico preciso e um tratamento adequado devem ser estabelecidos.

The occurrence of urinary tract infections (UTI) caused by yeasts of the genus Candida has increased considerably in recent decades, with Candida albicans being the most commonly diagnosed as causing this type of infections. However, other species, such as Candida tropicalis, are emerging as worrisome causes of the disease. In this sense, the objective of the present paper is to review the aspects related to the UTI caused by yeasts of the genus Candida. A search was carried out in the PubMed database, searching for articles on the epidemiology, pathogenesis and treatment of UTI caused by yeasts of the genus Candida. Candida species are the most relevant opportunistic pathogenic fungi that cause nosocomial infections and can cause both lower (ureters, bladder and urethra) and upper (kidneys) urinary tract infections, especially in immunocompromised patients. There are some predisposing factors, such as female gender, advanced age, diabetes mellitus, prolonged hospitalization, immunosuppression, pregnancy, hypertension, neutropenia, kidney stones, nosocomial infections, antibiotic therapy and procedures, such as catheterization, that act as facilitators of UTI by Candida spp. The disease can occur asymptomatically, however, it can progress to more severe cases with systemic involvement in situations of candidemia that can cause the death of the patient, especially in immunocompromised individuals. Therefore, due to the existing risk, the disease cannot be neglected and an accurate diagnosis and adequate treatment must be established.

La aparición de infecciones del tracto urinario (ITU) causadas por levaduras del género Candida ha aumentado considerablemente en las últimas décadas. Candida albicans es la infección por levaduras más comúnmente diagnosticada. Sin embargo, otras especies, como la Candida tropicalis, están surgiendo como causa preocupante de la enfermedad. En este sentido, el objetivo del presente trabajo es revisar los aspectos relacionados con la ITU causada por levaduras del género Candida. Se realizó una búsqueda en la base de datos PubMed, buscando artículos sobre la epidemiología, la patogénesis y el tratamiento de la ITU causada por levaduras del género Candida. Las especies de Candida son los hongos patógenos oportunistas más relevantes que causan infecciones nosocomiales y pueden provocar infecciones del tracto urinario inferior (uréteres, vejiga y uretra) y superior (riñones), especialmente en pacientes inmunodeprimidos. Existen algunos factores predisponentes, como el sexo femenino, la edad avanzada, la diabetes mellitus, la hospitalización prolongada, la inmunosupresión, el embarazo, la hipertensión, la neutropenia, los cálculos renales, las infecciones nosocomiales, la terapia con antibióticos y los procedimientos como el cateterismo, que actúan como facilitadores de la ITU por Candida spp. La enfermedad puede presentarse de forma asintomática, pero puede evolucionar a casos más graves con afectación sistémica en situaciones de candidemia que pueden causar la muerte del paciente, especialmente en individuos inmunodeprimidos. Por lo tanto, debido al riesgo existente, no se puede descuidar la enfermedad y se debe establecer un diagnóstico preciso y un tratamiento adecuado.

Mycotic aortic aneurysm in a debilitated patient with compromised immunity; beware of Candida! / Aneurisma micótico da aorta em paciente debilitado com imunidade comprometida - um alerta para Cândida

Abstract Candida is a rare cause of infected aortic aneurysms. We report the case of a diabetic patient with end stage kidney disease who underwent repair of a leaking abdominal aortic aneurysm. He was on long-term antibiotic treatment for malignant otitis externa. Candida albicans was isolated from the culture of the excised aneurysm wall. An infected aortic aneurysm due to Candida has not been previously reported in a patient with malignant otitis externa. This case report aims to highlight that Candida should be suspected as a cause of infected aortic aneurysms in patients with debilitation and chronic immunosuppression. Management of such cases can be extremely challenging, especially in resource-poor settings, and we will be touching upon the advantages and disadvantages of various treatment options.

Resumo A cândida é uma causa rara de aneurismas da aorta infecciosos. Relatamos o caso de um paciente diabético com doença renal terminal, que foi submetido a reparo de aneurisma da aorta abdominal com vazamento. Ele estava em tratamento de longo prazo com antibióticos para otite externa maligna. A Candida albicans foi isolada da cultura da parede do aneurisma que sofreu a excisão. Não há relatos prévios de aneurisma da aorta infeccioso causado por cândida em pacientes com otite externa maligna. Este relato de caso visa reforçar que a cândida deve ser uma das suspeitas de causa de aneurisma da aorta infeccioso em pacientes debilitados e com imunossupressão crônica. O manejo desses casos pode ser extremamente desafiador, principalmente em contextos em que os recursos são escassos, e mencionaremos as vantagens e desvantagens das diversas opções de tratamento.

Relationship between antifungal susceptibility profile and virulence factors in Candida albicans isolated from nail specimens

Abstract INTRODUCTION: The aim of this study was to evaluate some virulence factors in Candida albicans isolates from patients with onychomycosis and determine the correlation between these factors and the antifungal resistance profile. METHODS: Seventy species of C. albicans were confirmed using polymerase chain reaction amplification of the HWP1 gene. According to the Clinical & Laboratory Standards Institute guidelines, the susceptibility profile of four antifungal agents was investigated, and the production of aspartyl protease, phospholipase, haemolysin, and biofilm was determined. The correlation between these profiles was also investigated. RESULTS: The isolates indicated different levels of resistance and production of virulence factors. Significant correlations were observed between the minimum inhibitory concentration (MIC) of fluconazole/itraconazole and biofilm production, between phospholipase production and fluconazole/itraconazole MIC, and between fluconazole MIC and hemolytic activity in C. albicans isolates. The results also showed significant correlations between phospholipase activity and biofilm production. CONCLUSIONS: Our findings will contribute to a better understanding of the pathogenesis of C. albicans and characterize the relationship between virulence factors and antifungal resistance, which may suggest new therapeutic strategies considering the possible involvement of the virulence mechanism in the effectiveness of treatment.

Effect of Trigonella foenum Extract and ZiO2 Nanoparticles on Some Pathogenic Fungi and Bacteria

Aim: The current venture, were made to evaluate the inhibitory effect of Trigonella foenum seed Extract and ZiO2 Nanoparticles on some selected species of Fungi and Bacteria. Materials and Methods: two bacterial species included Pseudomonas aeruginosa and Staphylococcus aureus and three fungal species which is Cryptococcus neoformans, Candidda albicans and Chaetomium were used to evaluate the antibacterial activity of Trigonella foenum Extract and ZiO2 Nanoparticles. Results: This study showed that the Zirconium Oxide (ZiO2) nanoparticles have antifungal and antibacterial activities on the isolates of Cryptococcus neoformans, Candida alicans and Staphylococcus aureus, respectively. While the antimicrobial activity of Zirconium Oxide nanoparticles on the Chaetomium and Pseudomonas aeruginosa was negative. All tested fungi and bacterial isolates were found to be sensitive to Trigonella foenum seed extract, the results of the compination of the ZiO2 Nanoparticle and the Trigonella foenum seed extract were poisitive for all tested fungi isolates and bacterial isolates. The XRD analysis was done for Zirconium Oxide nanoparticles and the result showed that the biocrystallization on the surface of the Zirconium Oxide manoparticles. The average partides size was about (29.8) nm. Conclusions: This investigation conclude that the use of Trigonella foenum seed Extract has the effect of killing all bacteria and fungi under study, result indicate the Trigonella foenun seed Extract best antibacterial efficacy than the ZiO2 together (AU)

Differences by Resistotyping Between C. albicans Strains Isolated from the Oral Cavity of HIV+ and Seronegative Patients / Diferencias por resistotipificación entre cepas de C. albicans aisladas de la cavidad oral de pacientes VIH+ y seronegativos

Abstract Candida albicans is the etiological agent most frequently associated with oral candidiasis in human immunodeficiency virus (HIV) carriers. Strain typification is important to disease epidemiology, particularly with simple, low-cost methodologies such as resistotyping. The present study was designed to use resistotyping to identify possible phenotypic differences between C. albicans strains isolated from the oral cavity of HIV+ and HIV-seronegative patients. Analyses were run using resistotyping (boric acid, cetrimide, sodium periodate, sodium selenite and silver nitrate) to identify phenotypical differences between C. albicans. Descriptive statistics was performed. Of the 149 clones isolated from HIV+ patients the most frequent (47.0%) resistotype was ABCDE. The most frequent resistotype (64.8%) in the 74 clones from HIV-seronegative patients was --CDE. Phenotypic differences were identified between the strains isolated from each group. HIV+ patients exhibited greater strain diversity. Although it has limitations, resistotyping effectively identified differences between C. albicans strains.

Resumen Candida albicans es el agente etiológico más frecuentemente asociado con la candidiasis oral en portadores del virus de la inmunodeficiencia humana (VIH). La tipificación de la cepas es importante para conocer la epidemiología de la enfermedad, particularmente con metodologías simples y de bajo costo, como la resistotipificación. El presente estudio fue diseñado para identificar posibles diferencias fenotípicas por el método de resistotipificación entre cepas de C. albicans aisladas de la cavidad oral de pacientes VIH+ y seronegativos. Se realizó estadística descriptiva. Los análisis se realizaron utilizando resistotipificación (ácido bórico, cetrimida, peryodato de sodio, selenito de sodio y nitrato de plata) para identificar diferencias fenotípicas entre C. albicans. De las 149 clonas aisladas de pacientes VIH+, el resistotipo más frecuente (47.0%) fue ABCDE. El resistotipo más frecuente (64.8%) en las 74 clonas de pacientes seronegativos al VIH fue --CDE. Se identificaron diferencias fenotípicas entre las cepas aisladas de cada grupo. Los pacientes VIH + exhibieron una mayor diversidad de cepas. Aunque tiene limitaciones, la resistotipificación identificó de manera efectiva las diferencias entre las cepas de C. albicans.

Novas tendências de combate ao biofilme de Candida em próteses dentárias / New trends to combat Candida biofilm in dental prosthetics

Apesar de a espécie Candida albicans ser efetivamente o microrganismo mais frequentemente associado a estomatite protética, as espécies de Candida não albicans já foram isoladas nas superfícies de dentaduras e da mucosa oral de indivíduos com essa lesão eritematosa. A virulência das espécies de Candida e a capacidade de adesão a polímeros acrílicos são condições prévias para a colonização e o desenvolvimento de biofilmes em superfícies de dentaduras. Estudos recentes focam na tentativa de modificação das resinas acrílicas para diminuir a adesão de cepas patogênicas e formadoras de biofilme do gênero Candida spp. Dentro desse aspecto, esta revisão sistematiza o atual panorama epidemiológico da estomatite protética associada ao uso de próteses dentárias, bem como as atuais e novas opções de combate ao biofilme fúngico especializado na adesão desse tipo de biomaterial. (AU)

Although the Candida albicans species is effectively the microorganism most frequently associated with prosthetic stomatitis, Candida non-albicans species have already been isolated from the denture and oral mucosal surfaces of individuals with this erythematous lesion. The virulence of Candida species and the ability to adhesion to acrylic polymers are preconditions for the colonization and development of biofilms on denture surfaces. Recent studies focus on the attempt to modify the acrylic resins to reduce the adhesion of pathogenic and biofilm forming strains of the genus Candida spp. In this aspect, this review systematizes the current epidemiological panorama of prosthetic stomatitis associated with the use of dental prostheses, as well as new options for combating the fungal biofilm specialized in the adhesion of this type of biomaterial. (AU)

Phagocytosis and nitric oxide production by peritoneal adherent cells in response to Candida albicans in aging: a collaboration to elucidate the pathogenesis of denture stomatitis

Abstract Elderly denture wearers are commonly affected by Candida-associated denture stomatitis (DS), an inflammatory process of the oral mucosa strongly associated with Candida spp and other microorganisms, as well as local and systemic factors. The impaired immune response against pathogens is among the inherent host factors that have been also associated with the pathogenesis of DS. Mononuclear phagocytes respond to the pathogens through phagocytosis followed by the production of several substances inside the phagosomes, among them are the reactive nitrogen species (RNS). A failure in these mechanisms may contribute to the DS development. Objective The aim of this study was to investigate the influence of aging on the internalization and the production of nitric oxide (NO) by peritoneal adherent cells (PAC), in response to Candida albicans (C. albicans). Material and methods PAC obtained from young and aged mice were challenged with dead or viable C. albicans by using predetermined proportions (cells:yeast) for 30 and 120 minutes. Phagocytosis was analyzed by acridine orange dye, and NO production by the Griess reaction. Results C. albicans phagocytosis by PAC from aged mice was similar to that of young mice, although the cells from older mice cells present more internalized fungi compared with matched control. In addition, a tendency towards impaired NO production by peritoneal mononuclear phagocytes from aged mice was observed. Conclusions PAC from aged mice may capture and store many fungi, which in turn may mean that these cells are effectively unable to eliminate fungi, probably due to impaired NO production. Therefore, considering the important role of C. albicans overgrowth in the pathogenesis of DS and the aspects observed in this study, aging may favor the onset and severity of local candidosis such as DS and its systemic forms.

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.

Extracellular phospholipase production of oral Candida albicans isolates from smokers, diabetics, asthmatics, denture wearers and healthy individuals following brief exposure to polyene, echinocandin and azole antimycotics

Abstract Objective Candida albicans is the primary causative agent of oral candidosis, and one of its key virulent attributes is considered to be its ability to produce extracellular phospholipases that facilitate cellular invasion. Oral candidosis can be treated with polyenes, and azoles, and the more recently introduced echinocandins. However, once administered, the intraoral concentration of these drugs tend to be sub-therapeutic and rather transient due to factors such as the diluent effect of saliva and cleansing effect of the oral musculature. Hence, intra-orally, the pathogenic yeasts may undergo a brief exposure to antifungal drugs. We, therefore, evaluated the phospholipase production of oral C. albicans isolates following brief exposure to sub-therapeutic concentrations of the foregoing antifungals. Materials and methods Fifty C. albicans oral isolates obtained from smokers, diabetics, asthmatics using steroid inhalers, partial denture wearers and healthy individuals were exposed to sub-therapeutic concentrations of nystatin, amphotericin B, caspofungin, ketoconazole and fluconazole for one hour. Thereafter the drugs were removed and the phospholipase production was determined by a plate assay using an egg yolk-agar medium. Results The phospholipase production of these isolates was significantly suppressed with a percentage reduction of 10.65, 12.14, 11.45 and 6.40% following exposure to nystatin, amphotericin B, caspofungin and ketoconazole, respectively. This suppression was not significant following exposure to fluconazole. Conclusions Despite the sub-therapeutic, intra oral, bioavailability of polyenes, echinocandins and ketoconazole, they are likely to produce a persistent antifungal effect by suppressing phospholipase production, which is a key virulent attribute of this common pathogenic yeast.

Principais patógenos envolvidos em casos de sepse em pacientes queimados: uma revisão de literatura / Main pathogens involved in the cases of sepsis in burned patients: a review on the literature / Principales patógenos en los casos de sepsis em pacientes quemados: una revisión de literatura

Objetivo: Buscou-se no presente trabalho identificar os principais patógenos envolvidos em infecções em pacientes queimados, bem como enfatizar a relevância do diagnóstico adequado para o tratamento de sepse. Método: Para a realização do presente trabalho, foi feito levantamento bibliográfico de caráter exploratório e obtidos 33 estudos relevantes. A coleta de informações ocorreu nos meses de março a novembro de 2016. Resultados: Dentre os principais patógenos presentes em queimados, que podem gerar quadro de sepse, estão Pseudomonas aeruginosa, Staphylococcus aureus, Acinetobacter sp, Candida albicans e Proteus sp. Esses podem, ou não, estar relacionados à própria microbiota do paciente. O processo de infecção, com perda da primeira linha de defesa imunológica, deixa o organismo suscetível à entrada e instalação de microrganismos. O tratamento da sepse depende de fatores relevantes, que incluem a gravidade da lesão e o agente causador da infecção. Conclusão: O risco de ocorrência de sepse, associada às infecções em queimados nas unidades de tratamento intensivo, pode ser reduzido com o diagnóstico adequado e acompanhamento do paciente.

Objective: This article aimed to identify the main pathogens involved in infections in burned patients, as well as to emphasize the relevance of the appropriate diagnosis for the treatment of sepsis. Methods: For the accomplishment of the present work, it was carried out a bibliographic survey of exploratory character and 33 relevant studies were obtained. Data collection was carried out from March to November 2016. Results: Among the main pathogens present in burnt patient related with sepsis are Pseudomonas aeruginosa, Staphylococcus aureus, Acinetobacter sp, Candida albicans and Proteus sp. These pathogens may or may not be related to the patients microbiota. The infection process, with loss of the first line of immune defense, leaves the organism susceptible to the entry and installation of microorganisms. Treatment of sepsis depends on relevant factors including the severity of the lesion and the agent of the infection. Conclusion: The risk associated with sepsis in burned patients may be reduced with appropriate diagnosis and monitoring.

Objetivo: El objetivo de este artículo fue identificar los principales patógenos asociados en infecciones en pacientes com quemaduras, así como enfatizar la relevancia del diagnóstico adecuado para el tratamiento de la sepsis. Métodos: Para el desarrollo del presente trabajo, se realizó una búsqueda bibliográfica de caracter exploratório, siendo considerados relevantes 33 estudios. La búsqueda de datos se realizó de marzo a noviembre de 2016. Resultados: Entre los principales patógenos presentes en pacientes quemados relacionados con la sepsis se destacaron Pseudomonas aeruginosa, Staphylococcus aureus, Acinetobacter sp, Candida albicans y Proteus sp. Estos patógenos pueden o no estar relacionados con la microbiota del paciente. El proceso de infección, con la pérdida de la primera línea de defensa inmunológica, deja el organismo susceptible a la entrada e instalación de microorganismos. El tratamiento de la sepsis depende de factores relevantes, incluyendo la gravedad de la lesión y el agente de la infección. Conclusión: El riesgo asociado con la sepsis en pacientes quemados puede reducirse con un diagnóstico y seguimiento adecuados.

Citronellal-induced disruption of membrane homeostasis in candida albicans and attenuation of its virulence attributes

Abstract: INTRODUCTION There is an increasing burden of multidrug resistance. As a result, deciphering the mechanisms of action of natural compounds with antifungal activity has gained considerable prominence. We aimed to elucidate the probable mechanism of action of citronellal, a monoterpenoid found in the essential oil extracted from Cymbopogon plants, against Candida albicans. METHODS Drug susceptibility was measured by broth microdilution and spot assays. Ergosterol levels were estimated using the alcoholic potassium hydroxide method and H+ extrusion was assessed by monitoring the glucose-induced acidification of the external medium. Virulence traits were studied by hyphal morphogenesis and biofilm formation, along with fungal cell adherence to polystyrene surface and human oral epithelial cells. RESULTS Citronellal showed anticandidal activity against C. albicans and non-albicans species of Candida at a minimum inhibitory concentration of 1 mg/ml. Citronellal interfered with membrane homeostasis, which is the major target of known antifungal drugs, by increasing the hypersensitivity of the fungi to membrane-perturbing agents, reducing ergosterol levels, and diminishing glucose-induced H+ extrusion. In addition, oxidative and genotoxic stresses were induced via an increased production of reactive oxygen species. Furthermore, citronellal inhibited the virulent attributes of yeast-to-hypha transition and biofilm formation. It also reduced cell adherence to polystyrene surface and the human oral epithelial cells. CONCLUSIONS This is the first study to propose the cell membrane, morphogenetic switching, biofilm formation, and cell adherence of Candida albicans as potential targets for the anticandidal activity of citronellal. However, clinical investigations on the therapeutic applications of citronellal are required.

Lactobacillus rhamnosus pode alterar a virulência de Candida albicans / Lactobacillus rhamnosus may change the virulence of Candida albicans

OBJETIVO: Avaliar a influência de Lactobacillus rhamnosusna expressão dos fatores de virulência de Candida albicans in vitro.MÉTODOS: Uma suspensão de L. rhamnosusfoi inicialmente cultivada em ágar MRS. No dia seguinte, foi adicionado ágar Sabouraud dextrose sobre o crescimento dos lactobacilos e C. albicansfoi cultivada, por 24, 48 e 72 horas. As cepas de Candidaforam então isoladas para investigação da capacidade de formação de biofilme, por meio do cultivo em placas de 96 poços e leitufra das densidades ópticas e contagem de unidades formadoras de colônia por mL (UFC/mL). Também se investigou a capacidade de formação de tubo germinativo, após incubação em soro de cavalo e contagem em 200 células. Os resultados foram comparados aos observados nas cepas de Candidacultivadas na ausência de L. rhamnosus, utilizando o teste tde Student para análise estatística.RESULTADOS: Observou-se uma redução significativa no crescimento de C. albicans na presença de lactobacilos após 24, 48 ou 72 horas. Também foi observada redução significativa na formação de tubo germinativo após a interação por 48 ou 72 horas. Quanto à formação de biofilme, não foi observada diferença significante entre as cepas de Candidacultivadas na presença ou na ausência de lactobacilos.CONCLUSÃO: Os resultados sugerem que L. rhamnosusé capaz de influenciar significativamente o crescimento e a expressão de fatores de virulência de C. albicans in vitro, podendo interferir na patogenicidade desses micro-organismos.

PURPOSE: To investigate the influence of Lactobacillus rhamnosus in the expression of virulence factors of Candida albicans in vitro.METHODS: A suspension of L. rhamnosus was initially grown in MRS agar. The other day, Sabouraud dextrose agar was added on the growth of lactobacilli and C. albicans was seeded for 24, 48 and 72 hours. Candida strains were then isolated for investigation of the ability of biofilm formation, by means of cultivation into 96 wells plaque, and reading the optical densities and counting colony forming units per mL. Also the ability of germ tube formation was investigated, after incubation in horse serum and counting of 200 cells. The results were compared to Candida strains grown in the absence of L. rhamnosus, using Student's t test for statistical analysis.RESULTS: there was a significant reduction in the growth of C. albicans in the presence of lactobacilli after 24, 48 or 72 hours. Significant reduction was also observed in germ tube formation after interaction for 48 or 72 hours. For biofilm formation, no statistically significant difference was observed between the Candida strains grown in the presence or absence of lactobacilli.CONCLUSION: The results suggest that L. rhamnosus is able to influence significantly the growth and expression of virulence factors of C. albicans in vitro, and may interfere with pathogenicity of these micro-organisms.

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 ...

Presença de fungos do gênero Candida em próteses totais de idosos institucionalizados / Presence of Candida in dentures of institutionalized elderly

As infecções que afetam a cavidade bucal são de origem polimicrobiana e, muitas vezes, ocorrem devido … presença de fungos do gênero Candida. Esses microrganismos comportam-se como anfibiontes, isto é, são capazes de agredir o hospedeiro quando as condições ambientais e imunológicas são favoráveis, como em pacientes imunocomprometidos, com disfunções metabólicas ou que sofreram traumas mecânicos, químicos ou térmicos. O objetivo do presente estudo foi verificar a ocorrência de fungos do gênero Candida em próteses totais de idosos institucionalizados em uma Instituição asilar de Passo Fundo – RS. Os dados foram coletados a partir de amostras das 42 próteses com auxílio de swab estéril. As amostras foram semeadas em  gar Sabouraud Dextrose com cloranfenicol e incubadas por 72 horas a 37§C. Os resultados mostraram que do total de amostras, 33 (79%) apresentaram leveduras do gênero Candida. Dentre essas, 18 (54,5%) foram de C. albicans, 8 de (24,3%) de C. kruzei e 7 (21,2 %) de C. tropicalis

Infections that affect the oral cavity are polymicrobial and often occur due to the presence of Candida. These microorganisms behave as anfibiontes, it means they are able to attack the host when immunological and environmental conditions are favorable, as in immunocompromised patients with metabolic dysfunctions or that underwent mechanical, chemical or thermal trauma. The aim of this study was to verify the occurrence of Candida in dentures used by elderly institutionalized in an asylum in Passo Fundo (Rio Grande do Sul -Brazil). Data were collected from samples of 42 prostheses with the aid of a sterile swab. The samples were plated on Sabouraud dextrose agar with chloramphenicol and incubated for 72 hours at 37 øC. The results showed that from the overall number of samples, 33 (79%) had Candida yeasts. Among these, 18 (54.5%) were C. albicans, 8 (24.3%) of C. kruzei, and 7 (21.2%) of C. tropicalis

Cinética da colonização bucal por Candida spp. durante a corticoterapia tópica / Universidade Federal de Minas Gerais. Faculdade de Odontologia

A candidíase bucal é uma importante alteração secundária à corticoterapia tópica bucal. O presente estudo tem o objetivo de avaliar a colonização bucal por cinco espécies de candida durante a corticoterapia tópica e investigar a patogenicidade e a suscetibilidade in vitro ao fluconazol e à anfotericina B. Amostras de raspado bucal de 11 pacientes com líquen plano bucal (LPB) sintomático foram coletadas antes (dia 0), 7 e 30 dias após o início da corticoterapia. Métodos convencionais de identificação e quantificação de candida spp...

Interacción Candida albicans-Hospedero: un proceso complejo en el que la inmunidad innata juega un importante papel / Candida albicans-host interaction: a complex process in which the innate immunity play an important role

Candida albicans es una levadura comensal, que bajo ciertas circunstancia puede convertirse en patógeno. La capacidad de cambiar se forma constituye un factor de virulencia, permitiéndole a la levadura invadir y diseminarse. El sistema inmune innato es capaz de reconocer las diferentes morfologías de C. albicans activando receptores (PRRs) que reconocen PAMPs o patrones moleculares conservados. Las células inmunes más importantes son los macrófagos y los neutrófilos que desencadenan una respuesta efectora a través de la fagocitosis y la activación de estrés oxidativo contra C. albicans. Las células dendríticas, por su parte expresan la mayoría de los PRRs involucrados en el reconocimiento de C. albicans activando la secreción de citoquinas hacia una respuesta tipo TH1 (inducida por INF tipo1, IL-12, INFγ, ), Treg (inducida por TGFβ, IL-10) y TH17 (inducida por IL-23, IL6). Las células epiteliales no sólo constituyen una barrera física frente a la infección por C. albicans, sino son fundamentales en el reconocimiento primario de este microorganismo. Mediante una respuesta bifásica estas células activan diferencialmente, vías de transducción de señales que determinan que no se active una respuesta de citoquinas frente a la presencia de blastoconidios (forma comensal) y que se active frente a presencia de hifas (forma invasora). Por su parte, C. albicans es capaz de desarrollar mecanismos evasivos de la respuesta inmune. Esta compleja interacción y hongo-hospedero determina si el hospedero será capaz de eliminar a este microorganismo o si éste finalmente invadirá expresando su virulencia.

Candida albicans is a comensal microorganism that under certain circumstances is able to transform into a pathogen. This ability to switch constitute a virulence factor that C. albicans uses to invade and spread. The innate immune system recognize the different forms of C. albicans activating receptors (PRRs) that recognize PAMPs or conserved molecular patterns. The most important immune cells are macrophages and neutrophils that generate an effector response through phagocytosis and oxidative burst against C. albicans. Dendritic cells express the most of PRRs involved in the recognition of C. albicans activating the cytokines synthesis forward to a TH1 (induced by INF tipo1, IL-12, INFγ), Treg (induced by TGFβ, IL-10) y TH17 (induced by IL- 23, IL6) immune response. Epithelial cells not only constitute a physical barrier against C. albicans, but they are crucial in the first recognition of this microorganism. Through a biphasic response these cells differentially activate pathways that determine a no cytokine response when blastoconidia (commensal form) is present and an inflammatory response in presence of hyphae (pathogenic form). C. albicans develops immune evasive mechanism. This complex host-fungi interaction determines if the host will eradicate the infection or if this microorganism will invade the host, expressing it virulence.

Determination of germ tube, phospholipase, and proteinase production by bloodstream isolates of Candida albicans

Introduction Candida albicans is a commensal and opportunistic agent that causes infection in immunocompromised individuals. Several attributes contribute to the virulence and pathogenicity of this yeast, including the production of germ tubes (GTs) and extracellular hydrolytic enzymes, particularly phospholipase and proteinase. This study aimed to investigate GT production and phospholipase and proteinase activities in bloodstream isolates of C. albicans. Methods One hundred fifty-three C. albicans isolates were obtained from blood samples and analyzed for GT, phospholipase, and proteinase production. The assays were performed in duplicate in egg yolk medium containing bovine serum albumin and human serum. Results Detectable amounts of proteinase were produced by 97% of the isolates, and 78% of the isolates produced phospholipase. GTs were produced by 95% of the isolates. A majority of the isolates exhibited low levels of phospholipase production and high levels of proteinase production. Conclusions Bloodstream isolates of C. albicans produce virulence factors such as GT and hydrolytic enzymes that enable them to cause infection under favorable conditions. .

Colonização da dentina humana por Candida albicans / Human enamel colonization of Candida albicans

Introdução: a Candida albicans é um componente da microbiota indígena do indivíduo e pode colonizar o ambiente endodôntico. Objetivo: usando um modelo de infecção dentinária in vitro, avaliar o padrão de colonização da dentina por essa espécie microbiana, bem como a influência do tigmotropismo nesse evento. Métodos: foi utilizado um aparato composto por dois frascos de vidro conectados por um anel de silicone. Internamente, esses frascos eram se-parados por um disco de acrílico contendo um fragmento de dentina humana na sua porção central. Ambos os frascos foram preenchidos com caldo Sabouraud, mas Candida albicans foi inoculada no frasco superior. Após 72 horas a 37ºC, o aparato foi desmontado sob condições assépticas e o fragmento dentinário preparado para microscopia eletrônica. Resultados: a amostra de Candida albicans 1015 foi capaz de penetrar ativamente os túbulos dentinários, sendo as hifas a principal forma de crescimento durante a invasão primária dos túbulos dentinários. Células leveduriformes foram observadas nas camadas mais internas da dentina. Conclusões: a direção de ponta da hifa não foi influenciada pela natureza tubular da dentina. Nesse aspecto, somente o pleomorfismo tem um papel significativo na colonização da dentina humana por leveduras.

Comparative study of Candida by conventional and CHROMagar method in non-denture and denture wearers by oral rinse technique.

Introduction: Candidal species colonizes the oral cavities of healthy individuals without dentures and also of denture wearers. Soft liners and tissue conditioning materials have been found to support the growth of Candida albicans which may predispose to lesions. The most important and common candidal species are C. albicans, C. tropicalis, and C. glabrata. C albicans is usually isolated from both the fitting surface of the denture and the denture-bearing mucosa of the affected patients. The aim of this study was to isolate, quantify, and speciate candidal species in non-denture wearers (controls) and denture wearers (study group) by the oral rinse technique. Isolation was done using Sabouraud dextrose agar (SDA). Speciation was done using conventional methods like the germ tube test, carbohydrate fermentation test, urease test, as well as the CHROMagar method. Aims and Objective: 1) To assess the prevalence of Candida in non-denture wearers and in denture wearers by oral rinse technique, with isolation on SDA; 2) to speciate and quantify Candida in non-denture wearers and denture wearers by using conventional methods (germ tube test, carbohydrate fermentation test, urease test) and the CHROMagar method; 3) to assess the influence of smoking and diabetes on candidal species among the denture wearers; and 4) to assess the sensitivity and specificity of SDA and CHRO Magar Materials and Methods: Salivary samples for Candida evaluation were collected from the subjects in sterile sample containers, using the oral rinse technique. Results: C glabrata was the most commonly found species among denture wearers and non-denture wearers both by conventional and CHROMagar methods. In males, C. albicans was the predominant species, whereas C. glabrata was the predominant species in females. Candidal colonization was higher in denture wearers compared to non-denture wearers, especially among females. The CHROMagar method was more rapid compared to conventional methods. In the present study, CHROMagar Candida showed 100% specificity and 100% sensitivity when compared to SDA and conventional methods.