Cellulose Synthase in Atacama Cyanobacteria and Bioethanol Production from Their Exopolysaccharides.

Cyanobacteria produce exopolysaccharides (EPSs) as an adaptative mechanism against ultraviolet radiation and desiccation. Cellulose is present in the extracellular polymeric substance in some cyanobacteria genera and it has been proposed as a raw material for biofuel production. The goal of this work was to evaluate the cellulose presence in EPS of Atacama cyanobacteria strains and its use as an alternative and innovative biological source to produce bioethanol. The presence of cellulose was evaluated using techniques of molecular biology, bioinformatics, and electronic microscopy. The conserved motif D,D,D,35QXXRW, characteristic of processive ß-glycosyltransferase in all cellulose-producing organisms, was identified in the genome of the LLA-10 strain. This is evidence that cellulose synthase in the LLA-10 strain is a functional enzyme. EPS from Atacama cyanobacteria was hydrolyzed by ß-glucosidases (cellobiase and cellulase) and the released glucose was yeast-fermented to ethanol. Ethanol production reached 172.69 ± 0.02 mg ethanol/g EPS after 48 h of incubation. These results are the first step in the evaluation of EPS produced by native cyanobacteria isolated from northern Chile for future biotechnological applications such as the production of bioethanol.

UV-A Irradiation Increases Scytonemin Biosynthesis in Cyanobacteria Inhabiting Halites at Salar Grande, Atacama Desert.

Microbial consortia inhabiting evaporitic salt nodules at the Atacama Desert are dominated by unculturable cyanobacteria from the genus Halothece. Halite nodules provide transparency to photosynthetically active radiation and diminish photochemically damaging UV light. Atacama cyanobacteria synthesize scytonemin, a heterocyclic dimer, lipid soluble, UV-filtering pigment (in vivo absorption maximum at 370 nm) that accumulates at the extracellular sheath. Our goal was to demonstrate if UV-A irradiations modulate scytonemin biosynthesis in ground halites containing uncultured Halothece sp. cyanobacteria. Pulverized halite nodules with endolithic colonization were incubated under continuous UV-A radiation (3.6 W/m2) for 96 h, at 67% relative humidity, mimicking their natural habitat. Scytonemin content and relative transcription levels of scyB gene (a key gene in the biosynthesis of scytonemin) were evaluated by spectrophotometry and quantitative RT-PCR, respectively. After 48 h under these experimental conditions, the ratio scytonemin/chlorophyll a and the transcription of scyB gene increased to a maximal 1.7-fold value. Therefore, endolithic Halothece cyanobacteria in halites are metabolically active and UV radiation is an environmental stressor with a positive influence on scyB gene transcription and scytonemin biosynthesis. Endolithobiontic cyanobacteria in Atacama show a resilient evolutive and adaptive strategy to survive in one of the most extreme environments on Earth.

[Antifungal activity of mouthwashes against Candida albicans and Rhodotorula mucilaginosa: An in vitro study]. / Actividad antifúngica de los enjuagues bucales frente a Candida albicans y Rhodotorula mucilaginosa: un estudio in vitro.

BACKGROUND: Candida albicans and Rhodotorula mucilaginosa are yeasts of clinical importance in the oral cavity. In immunocompromised patients they can cause some pathologies that must be controlled with antimicrobials. AIMS: To evaluate and compare the antimicrobial efficacy of commercially available mouthrinses against strains of C. albicans and R. mucilaginosa. METHODS: The six mouthwashes studied in vitro were formulated (alone or in combination) with chlorhexidine (CHX) 0.12%, CHX 0.1%, CHX 0.05%, cetylpyridinium chloride (CPC) 0.075%, CPC 0.05%, and essential oils. Ten C. albicans and R. mucilaginosa isolates each were studied. The agar diffusion method (Mueller Hinton II), with incubation at 32°C was used to evaluate the antifungal activity. RESULTS: The results of this study indicate that mouthwashes with CHX 0.1%, CHX 0.12%, CHX 0.05% + CPC 0.05%, CHX 0.12% + CPC 0.05% and CPC 0.075% have an antifungal effect against C. albicans and R. mucilaginosa. CHX 0.1% led to the broadest inhibition zone for C. albicans and R. mucilaginosa (25.65±2.39mm and 40.05±3.31mm). Essential oils did not show any antifungal activity. Statistical analysis showed no statistical difference between mouth rinses CHX 0.1%, CHX 0.12% and CHX 0.12% + CPC 0.05% (p=0.0001) against C. albicans and R. mucilaginosa. CONCLUSIONS: Mouthwashes with CHX showed higher antifungal activity against C. albicans and R. mucilaginosa than other mouthwashes studied.

Actividad antifúngica de los enjuagues bucales frente a Candida albicans y Rhodotorula mucilaginosa: un estudio in vitro / Antifungal activity of mouthwashes against Candida albicans and Rhodotorula mucilaginosa: an in vitro study

ANTECEDENTES: Candida albicans y Rhodotorula mucilaginosa son levaduras de importancia clínica en la cavidad oral. En pacientes inmunocomprometidos estas levaduras pueden producir enfermedades que deben ser controladas con antimicrobianos. OBJETIVOS: Evaluar y comparar la eficacia antifúngica de seis enjuagues bucales comerciales frente a aislamientos de C. albicans y R. mucilaginosa. MÉTODOS: Fue evaluada in vitro la eficacia de seis enjuagues bucales formulados (solos o en combinación) con clorhexidina (CHX) 0,12%; CHX 0,1%; CHX 0,05%; cloruro de cetilpiridinio (CPC) 0,075%; CPC 0,05% y aceites esenciales. Fueron utilizados diez aislamientos de C. albicans y otros diez de R. mucilaginosa. Mediante el método de difusión en placa con agar Mueller Hinton (modificado) se midieron los halos de inhibición previa incubación a 32°C. RESULTADOS: Los resultados de este estudio indican que enjuagues bucales con CHX 0,1%; CHX 0,12%; CHX 0,05% + CPC 0,05%; CHX 0,12% + CPC 0,05% y CPC 0,075% ejercen un efecto antifúngico frente a C. albicans y R. mucilaginosa. CHX 0,1% dio lugar a la mayor zona de inhibición para C. albicans y R. mucilaginosa (25,65±2,39mm y 40,05±3,31mm). El enjuague con aceites esenciales no tuvo actividad antifúngica alguna. El análisis estadístico no mostró diferencia entre los enjuagues bucales CHX 0,1%; CHX 0,12% y CHX 0,12% + CPC 0,05% (p = 0,0001) frente a C. albicans y R. mucilaginosa. CONCLUSIONES: Los enjuagues bucales con CHX mostraron una mejor actividad antifúngica contra C. albicans y R. mucilaginosa que los restantes enjuagues estudiados

BACKGROUND: Candida albicans and Rhodotorula mucilaginosa are yeasts of clinical importance in the oral cavity. In immunocompromised patients they can cause some pathologies that must be controlled with antimicrobials. AIMS: To evaluate and compare the antimicrobial efficacy of commercially available mouthrinses against strains of C. albicans and R. mucilaginosa. METHODS: The six mouthwashes studied in vitro were formulated (alone or in combination) with chlorhexidine (CHX) 0.12%, CHX 0.1%, CHX 0.05%, cetylpyridinium chloride (CPC) 0.075%, CPC 0.05%, and essential oils. Ten C. albicans and R. mucilaginosa isolates each were studied. The agar diffusion method (Mueller Hinton II), with incubation at 32°C was used to evaluate the antifungal activity. RESULTS: The results of this study indicate that mouthwashes with CHX 0.1%, CHX 0.12%, CHX 0.05% + CPC 0.05%, CHX 0.12% + CPC 0.05% and CPC 0.075% have an antifungal effect against C. albicans and R. mucilaginosa. CHX 0.1% led to the broadest inhibition zone for C. albicans and R. mucilaginosa (25.65±2.39mm and 40.05±3.31mm). Essential oils did not show any antifungal activity. Statistical analysis showed no statistical difference between mouth rinses CHX 0.1%, CHX 0.12% and CHX 0.12% + CPC 0.05% (p = 0.0001) against C. albicans and R. mucilaginosa. CONCLUSIONS: Mouthwashes with CHX showed higher antifungal activity against C. albicans and R. mucilaginosa than other mouthwashes studied

Epidemiología y susceptibilidad antifúngica de especies causantes de candidemia en la ciudad de Valdivia, Chile / Epidemiology and antifungal susceptibility of species producing candidemia in Valdivia, Chile

Resumen Introducción: La epidemiología de la candidemia en Chile es poco conocida, a pesar de ser una enfermedad frecuente y grave. Objetivos: Analizar la incidencia y perfil de susceptibilidad in vitro de especies del género Candida causantes de candidemia en el Hospital Base Valdivia. Material y Métodos: Se identificó todos los casos de candidemia ocurridos en la institución entre marzo de 2009 y agosto de 2011. Se estudió la distribución de especies y susceptibilidad in vitro por el método de disco difusión. Resultados: Se estudiaron 27 episodios de candidemia. La incidencia varió de 0,3 a 0,7 por 1.000 egresos (según servicio clínico). Fueron factores de riesgo: la hospitalización, uso previo de antimicrobianos, edad avanzada y enfermedad de base (insuficiencia renal, enfermedad cardiaca y pulmonar). La especie más frecuente fue C. albicans seguida de C. tropicalis, C. glabrata y C. krusei. Voriconazol fue el antifúngico con mejor actividad in vitro y hubo resultados variables para anfotericina B, fluconazol e itraconazol. Discusión: La incidencia encontrada fue superior a la de países desarrollados. Candida albicans, constituye la especie más frecuente, con alta sensibilidad in vitro a fluconazol, debiendo ser vigiladas las especies de Candida no albicans. Es fundamental desarrollar nuevas investigaciones para detectar potenciales variaciones epidemiológicas.

Background: Candidemia disease in Chile is not very known, despite being a very common and serious disease. Aim: To analyze incidence and susceptibility profile of species from the genus Candida in Hospital Base Valdivia. Material and Methods: All candidemia cases presented between March 2009 and August 2011 in our institution were identified. Species distribution and susceptibility were studied through the disk diffusion method. Results: Twenty-seven candidemia episodes were studied. Incidence varied from 0.3 to 0.7 by a thousand discharges (according to clinical service). Risk factors were hospitalization, preliminary use of antibiotics, aged people and underlying disease (renal failure, heart and lung disease). The most frequent species was C. albicans, followed by C. tropicalis, C. glabrata and C. krusei. Voriconazole was the antifungal showing the best in vitro performance. Amphotericin B, fluconazole and itraconazole presented variable results. Discussion: Incidence found was superior to that described in developed countries. Candida albicans constitute the most frequent species, with high sensitivity levels to fluconazole; Candida no albicans species must be monitored. Developing new research on the topic appears as fundamental to detect potential epidemiological variations.

[Epidemiology and antifungal susceptibility of species producing candidemia in Valdivia, Chile]. / Epidemiología y susceptibilidad antifúngica de especies causantes de candidemia en la ciudad de Valdivia, Chile.

BACKGROUND: Candidemia disease in Chile is not very known, despite being a very common and serious disease. AIM: To analyze incidence and susceptibility profile of species from the genus Candida in Hospital Base Valdivia. MATERIAL AND METHODS: All candidemia cases presented between March 2009 and August 2011 in our institution were identified. Species distribution and susceptibility were studied through the disk diffusion method. RESULTS: Twenty-seven candidemia episodes were studied. Incidence varied from 0.3 to 0.7 by a thousand discharges (according to clinical service). Risk factors were hospitalization, preliminary use of antibiotics, aged people and underlying disease (renal failure, heart and lung disease). The most frequent species was C. albicans, followed by C. tropicalis, C. glabrata and C. krusei. Voriconazole was the antifungal showing the best in vitro performance. Amphotericin B, fluconazole and itraconazole presented variable results. DISCUSSION: Incidence found was superior to that described in developed countries. Candida albicans constitute the most frequent species, with high sensitivity levels to fluconazole; Candida no albicans species must be monitored. Developing new research on the topic appears as fundamental to detect potential epidemiological variations.

Hongos productores de micotoxinas asociados a hierbas medicinales en la Ciudad de São Paulo, Brasil / Mould and mycotoxins associated in medicinal plants in São Paulo, Brazil

Antecedentes: la fitoterapia es una de las más antiguas prácticas utilizadas por la humanidad. Hasta mediados del siglo XIX, cuando se introdujeron los medicamentos, la formulación de estos generalmente era basada en plantas medicinales. Objetivos: Determinar la micobiota y los niveles de aflatoxinas originadas de Aspergillus sección Flavi aislados de las 50 muestras de medicamentos fitoterápicos comercializados actualmente en la ciudad de São Paulo, Brasil. Métodos: Cincuenta (50) muestras de medicamentos fitoterápicos en la forma de hojas (té-25) y cápsulas (25) fueron colectadas de agosto de 2000 a julio de 2001. Los hongos filamentosos aislados fueron identificados al nivel de género de acuerdo con las características morfológicas y criterios taxonómicos. El análisis de aflatoxinas fue realizada por cromatografía de capa fina (TLC). Resultados: El análisis microbiológico mostró que 41 (82 por ciento) de los medicamentos fitoterápicos presentaron un crecimiento fúngico sobre las 100 UFC/g. Un total de 106 especies de seis diferentes géneros fueron aislados (Aspergillus, Penicillium, Mucor, Rhizopus y Alternaria). El género Aspergillus fue el predominante (60.5 por ciento) seguido por Penicillium (20,0 por ciento). Aspergillus niger (30 por ciento) A. flavus (22 por ciento), A. fumigatus (6,5 por ciento) y A. parasiticus fueron las especies de Aspergillus identificadas. Se observó que 13 (56,5 por ciento), de los 23 A. flavus aislados y dos aislados de A. parasiticus produjeron aflatoxinas. Conclusiones: La contaminación observada en la mayoría de los productos y el alto nivel de cepas productoras de aflatoxinas justifica un análisis más cuidadoso de los medicamentos fitoterápicos comercializados y la aplicación de leyes más rigurosas son necesarias para garantizar la calidad de los productos.

Background: phytotherapy is one of the most ancient practices used by humanity. In Antiquity until the middle of the XIX century, when chemotherapeutic drugs were introduced, formulation of medicines was usually based on medicinal plants. Objective: To determine mycobiota and levels of Aspergillus section Flavi aflatoxins isolated from 50 samples of phytotherapeutic remedies currently commercialized in São Paulo, Brazil. Methods: Fifty (50) samples of phytotherapeutic remedies in the form of leaves (teas-25) and powders (capsules-25) were collected from August 2000 to July 2001. Filamentous fungi isolates were identified at the genera level in accordance with morphological characteristics and taxonomic criteria. Aflatoxins were performed by Thin-layer chromatography (TLC). Results: The microbiological analysis showed that 41 (82 percent) of phytotherapeutic remedies presented a fungal growth over 100 CFU/g. A total of 106 species of six different genera were isolated (Aspergillus, Penicillium, Mucor, Rhizopus and Alternaria). The genus Aspergillus was the predominant (60.5 percent) followed by Penicillium genus (20.0 percent). Aspergillus niger (30 percent) A. flavus (22 percent), A. fumigatus (6.5 percent) and A. parasiticus were the species of Aspergillus identified. It was observed that 13 (56.5 percent) of 23 A. flavus isolates and two A. parasiticus isolates produced aflatoxins. Conclusions: The contamination observed in most products and the high level of aflatoxigenic strains justify the concern regarding the execution of more careful analyzes of the commercialized phytotherapeutic remedies and the application of more rigorous laws that may warrant the quality of these products.

The water supply system as a potential source of fungal infection in paediatric haematopoietic stem cell units.

BACKGROUND: We conducted a prospective study to investigate the presence of microfungal contamination in the water supply system of the Oncology Paediatric Institute, São Paulo-Brazil after the occurrence of one invasive Fusarium solani infection in a patient after Haematopoietic Stem Cell Transplantation (HSCT). During a twelve-month period, we investigated the water supply system of the HSCT unit by monitoring a total of fourteen different collection sites. METHODS: One litre of water was collected in each location, filtered through a 0.45 µm membrane and cultured on SDA to detect the presence of filamentous fungi. Physicochemical analyses of samples were performed to evaluate the temperature, turbidity, pH, and the concentration of free residual chlorine. RESULTS: Over the 12 months of the study, 164 samples were collected from the water supply system of the HSCT unit, and 139 of the samples tested positive for filamentous fungi (84.8%), generating a total of 2,362 colonies. Cladosporium spp., Penicillium spp., Purpureocillium spp. and Aspergillus spp. were ranked as the most commonly found genera of mould in the collected samples. Of note, Fusarium solani complex isolates were obtained from 14 out of the 106 samples that were collected from tap water (mean of 20 CFU/L). There was a positive correlation between the total number of fungal CFU obtained in all cultures and both water turbidity and temperature parameters. Our findings emphasise the need for the establishment of strict measures to limit the exposure of high-risk patients to waterborne fungal propagules. CONCLUSIONS: We were able to isolate a wide variety of filamentous fungi from the water of the HSCT unit where several immunocompromised patients are assisted.

Quality of life in patients with chronic kidney disease.

AIM: To compare the dimensions of quality of life in the stages of chronic kidney disease and the influence of sociodemographic, clinical and laboratory data. INTRODUCTION: The information available on the quality of life of patients on conservative treatment and the relationship between the quality of life and glomerular filtration rate is limited. METHODS: 155 patients in stages 1-5 of chronic kidney disease and 36 in hemodialysis were studied. Quality of life was rated by the Medical Outcomes Study Short Form 36-Item (SF-36) and functional status by the Karnofsky Performance Scale. Clinical, laboratory and sociodemographic variables were investigated. RESULTS: Quality of life decreased in all stages of kidney disease. A reduction in physical functioning, physical role functioning and in the physical component summary was observed progressively in the different stages of kidney disease. Individuals with higher educational level who were professionally active displayed higher physical component summary values, whereas men and those with a higher income presented better mental component summary values. Older patients performed worse on the physical component summary and better on the mental component summary. Hemoglobin levels correlated with higher physical component summary values and the Karnofsky scale. Three or more comorbidities had an impact on the physical dimension. CONCLUSION: Quality of life is decreased in renal patients in the early stages of disease. No association was detected between the stages of the disease and the quality of life. It was possible to establish sociodemographic, clinical and laboratory risk factors for a worse quality of life in this population.

Quality of life in patients with chronic kidney disease

AIM: To compare the dimensions of quality of life in the stages of chronic kidney disease and the influence of sociodemographic, clinical and laboratory data. INTRODUCTION: The information available on the quality of life of patients on conservative treatment and the relationship between the quality of life and glomerular filtration rate is limited. METHODS: 155 patients in stages 1-5 of chronic kidney disease and 36 in hemodialysis were studied. Quality of life was rated by the Medical Outcomes Study Short Form 36-Item (SF-36) and functional status by the Karnofsky Performance Scale. Clinical, laboratory and sociodemographic variables were investigated. RESULTS: Quality of life decreased in all stages of kidney disease. A reduction in physical functioning, physical role functioning and in the physical component summary was observed progressively in the different stages of kidney disease. Individuals with higher educational level who were professionally active displayed higher physical component summary values, whereas men and those with a higher income presented better mental component summary values. Older patients performed worse on the physical component summary and better on the mental component summary. Hemoglobin levels correlated with higher physical component summary values and the Karnofsky scale. Three or more comorbidities had an impact on the physical dimension. CONCLUSION: Quality of life is decreased in renal patients in the early stages of disease. No association was detected between the stages of the disease and the quality of life. It was possible to establish sociodemographic, clinical and laboratory risk factors for a worse quality of life in this population.

Evaluation of depressive symptoms in patients with chronic renal failure.

BACKGROUND: Although depression is the most commonly found psychiatric disorder in patients on chronic dialysis, its prevalence in earlier stages of chronic kidney disease (CKD) is not established. This study aims to investigate the prevalence of depression in patients with different stages of CKD and the factors associated with depressive affect. METHODS: A total of 155 nondialytic patients with CKD on conservative therapy and 36 patients on hemodialysis treatment were studied. Depression was rated using the Beck Depression Inventory (BDI) and the Beck Depression Inventory-Short Form (BDI-SF). Functional capacity was evaluated using the Karnofsky Performance Scale, and clinical and sociodemographic variables were also investigated. RESULTS: Using the BDI, depression was identified in 37.7% of the patients on conservative treatment and in 41.7% of those on hemodialysis (p=NS, not significant). The percentage of patients on conservative therapy with moderate or severe depression was higher when the BDI was used, compared with the BDI-SF (37.7% vs. 12.3%, p<0.001). No association was observed between depression and the stages of kidney disease. Among patients with CKD, depression was more prevalent among females (17.9%), patients of low income (54.2%), patients of social class D or E (47.4%), those living with friends or relatives (41.2%) and patients with poor functional capacity (p<0.001). CONCLUSIONS: We observed a high prevalence of depression in patients with CKD, but no significant difference was found between the stages of the disease. Depression was associated with sociodemographic characteristics and functional capacity.

Onychomycosis in São Paulo, Brazil.

Onychomycosis is a fungal infection of the nails with broad aetiological scope, and it represents 18-40% of all onychopathies and 39% of all superficial mycotic infections. From July 1996 to December 1999, samples of nails were collected from 588 patients with presumptive diagnosis of onychomycosis at the Dermatology and Mycology Divisions EPM\UNIFESP, Brazil, and the diagnosis was confirmed in 247 of these cases. The most common pathogens isolated in this study were yeasts in 52% of positive cultures (Candida albicans 18.3%, Candida parapsilosis 13.8%, other species of Candida 15.4% and other yeasts 4.6%), followed by dermatophytes in 40.6% of positive cultures (the most commonly isolated organisms were Trichophyton rubrum in 33.2%, followed by Trichophyton mentagrophytes in 6.3% and others 1.2%). Non-dermatophyte moulds were isolated in 7.4% of positive cultures (Fusarium spp. 4.5%, Nattrassia mangiferae 2.3% and Aspergillus spp. 0.6%). Distal and lateral subungual onychomycosis (DLSO) was the commonest clinical pattern 44.6% followed by free edge onycholysis (FEO) 38.8% and others. In conclusion, this study demonstrated that T. rubrum is the main agent causing onychomycosis in toenails, and species of genus Candida were the main agents isolated in fingernail onychomycosis in our region.