Estudo da citotoxicidade in vitro de corantes azo em Tetrahymena pyriformis

O aumento da poluição ambiental e o contínuo desenvolvimento da síntese de novos químicos desencadeou uma crescente preocupação acerca dos possíveis efeitos desses componentes directa ou indirectamente na saúde humana. No presente trabalho pretendeu-se utilizar o protozoário ciliado Tetrahymena pyriformis como bioindicador no estudo de respostas fisiológicas e bioquímicas à presença de oito corantes azo utilizados na indústria têxtil. Para tal, utilizou-se uma bateria de ensaios toxicofisiológicos, como o crescimento, a mortalidade e a morfometria. Estes ensaios foram realizados numa série de testes miniaturizados usando culturas axénicas de T. pyriformis, inoculadas com soluções dos 8 corantes em diferentes concentrações (5, 25 e 50 ppm), tendo como objectivo final a colecta de dados de forma a comparar respostas quanto à presença de diferentes corantes azo e quanto à presença de diferentes concentrações de um mesmo corante. Pretendeu-se com esta bateria de testes estudar se os corantes com aplicação têxtil utilizados são tóxicos para o bioindicador utilizado e em que concentração produzem tal efeito. Espera-se que com os resultados deste estudo se possa extrapolar a influência destes compostos no meio quático receptor

Toenail onychomycosis in a Portuguese geriatric population

Onychomycosis is a common fungal infection of the nail but few data of mycological features in geriatric Portuguese population are yet available. The aim of this study was to perform a mycological examination and characterization of fungal nail pattern of a geriatric population from the north of Portugal clinically suspected of onychomycosis. A total of 108 patients attending the Podology Service in the Centro Hospitalar do Alto Ave (Portugal) from October 2007 to January 2009 were enrolled. All were suspected of having onychomycosis by the abnormal appearance of their nails. From these, 59.3% were diabetic. Distal and lateral subungual onychomycosis was the more common clinical pattern followed by total dystrophic onychomycosis. In 21.3% cases, every nail in both feet had an abnormal appearance. In 86%, the hallux was involved in at least one foot. Fifty samples were culture positive, and fifty-four isolates were reported regardless of the questionable pathogenicity of the infectious agent. In three cases, clinical feature of the nail, direct microscopy, and culture were consistent with Scopulariopsis infection. Fusarium spp. were identified in three cases; however, only one isolate was preceded by the observation of branching septate filaments by direct microscopy. No mixed infections with dermatophytes were reported. Trichophyton rubrum was the dermatophyte most frequently isolated (83.3%) followed by Trichophyton interdigitale. In Portugal, onychomycosis is still viewed by general population as a cosmetic condition. Health risk is enhanced in geriatrics that only perceived the severity of their condition when experiencing further foot complications that include bacterial infection and pain

Trends in the use of protozoa in the assessment of wastewater treatment

Increasing environmental pollution and the continuous development of new chemicals and drugs has led to ever growing concern about the potential effects of these compounds directly or indirectly on human health. As concerns water pollution, protozoa seem to be an excellent tool to assess both toxicity and pollution: they are regarded as biological indicators of pollution when their presence or absence can be related to particular environmental conditions, and they are considered test organisms when a species or population is used to evaluate the toxicity of relevant toxic compounds. Thus, an integrated approach is being developed to assess how toxic compounds affect the different biological levels of organisation – from the community level to the species level – of ciliated protozoa. The present paper reports and discusses the current state of the art of this approach.Instituto de Biotecnologia e Química Fina (IBQF). Fundação para a Ciência e a Tecnologia - PRAXIS XXI-2/2.1/BIO/1118/95, PRAXIS XXI/BD/5080/95, PRAXIS XXI/BD/20328/99

Silver nanoparticles as an antimicrobial agent of Tricophyton rubrum

Resistance to antimicrobial agents, such as amphotericin B, fluconazole, itraconazole, and voriconazole, by pathogenic bacteria and fungi has been increasing at an alarming rate and has become a serious problem. Microorganisms, such as bacteria, moulds, yeasts, and viruses are often pathogenic to humans. There is a pressing need to search for new antimicrobial agents. Amongst inorganic antimicrobial agents, silver has been employed most widely since ancient times to fight infections. The antimicrobial activities of silver, silver ions, and silver compounds are well known Fungi can be employed for biosynthesis of nanoparticles hence avoiding the use of hazardous chemicals for synthesis. However, the effects of mycological synthesized silver nanoparticles against fungal dermatophytes are not well understod. In this work were used inorganic and biogenic routes for the synthesis of silver nanoparticles. In the biogenic route, extracts from Aspergillus oryzae and Penicillium chrysogenum were used. In the inorganic route glucose was used as the reducing agent and polyvinylpyrrolidone as the stabilizer. The nanoparticles were characterized by various techniques. Biogenic nanoparticles from A. ozyzae and P. chrysogenum showed an average size from 19-51 nm to 51-85 nm, respectively. Nanoparticles synthesized by inorganic route had a mean size of 74 nm as determined by Dynamic Light Scattering. The antimicrobial potential activity was tested against strains of Tricophyton rubrum and the silver nanoparticles from P. chrysogenum had antimicrobial effects against T. rubrum strains. The synthesis parameters in future studies should be studied to take full advantage of the potentail for filamentous fungi to synthesise silver nanoparticles

Aplicação do MALDI-TOF ICMS na abordagem polifásicada da identificação de isolados clínicos de Trichophyton rubrum

Introdução: O dermatófito Trichophyton rubrum tem particular interesse em micologia clínica por ser um fungo exclusivamente antropofílico cuja incidência tem vindo a aumentar nos países industrializados. Uma identificação correcta revela‐se de maior importância quer ao nível da administração adequada da medicação ao paciente, quer ao nível da epidemiologia e/ou da taxonomia. A identificação dos dermatófitos é complexa requerendo uma abordagem polifásica. A nova técnica de identificação baseada no Matrix‐Assisted Laser Desorption/Ionisation Time Of Fight Intact Cell Mass Spectrometry (MALDI‐TOF ICMS) começa a dar os primeiros passos como uma alternativa aos métodos moleculares. O objectivo do presente trabalho foi a identificação de isolados clínicos de T. rubrum baseada numa abordagem polifásica, utilizando métodos morfológicos, moleculares e espectrai