Potential for biocontrol of melanized fungi by actinobacteria isolated from intertidal region of Ilha Do Mel, Paraná, Brazil

Actinobacteria occur in many environments and have the capacity to produce secondary metabolites with antibiotic potential. Identification and taxonomy of actinobacteria that produce antimicrobial substances is essential for the screening of new compounds, and sequencing of the 16S region of ribosomal DNA (rDNA), which is conserved and present in all bacteria, is an important method of identification. Melanized fungi are free-living organisms, which can also be pathogens of clinical importance. This work aimed to evaluate growth inhibition of melanized fungi by actinobacteria and to identify the latter to the species level. In this study, antimicrobial activity of 13 actinobacterial isolates from the genus Streptomyces was evaluated against seven melanized fungi of the genera Exophiala, Cladosporium, and Rhinocladiella. In all tests, all actinobacterial isolates showed inhibitory activity against all isolates of melanized fungi, and only one actinobacterial isolate had less efficient inhibitory activity. The 16S rDNA region of five previously unidentified actinobacterial isolates from Ilha do Mel, Paraná, Brazil, was sequenced; four of the isolates were identified as Streptomyces globisporus subsp. globisporus, and one isolate was identified as Streptomyces aureus. This work highlights the potential of actinobacteria with antifungal activity and their role in the pursuit of novel antimicrobial substances.(AU)

Microbiological quality of water and dialysate from haemodialysis units in Southern Brazil / Qualidade microbiológica da água e dialisato em clínicas de hemodiálise do Sul do Brasil

Infectious diseases in renal patients may be associated with the dialysis water quality, which may be contaminated with microorganisms. In Brazil, the water quality is evaluated by analyzing total coliforms, heterotrophic bacteria, and bacterial endotoxin, but not Pseudomonas sp. and fungi. Water samples from haemodialysis units in Curitiba/PR were investigated on their conformity with the standard established by the Brazilian Health Ministry. Total coliforms, heterotrophic bacteria, P. aeruginosa and fungi counts were performed according to APHA, and LAL methodology for detecting bacterial endotoxin. All of the samples showed the total coliforms counts 1.1 MPN/100 mL,and 95 % of analyzed samples complied with the standards for heterotrophic bacteria counting. P. aeruginosa was recovered from 4 % of samples. In 15 % of samples, bacterial endotoxin was detected in values above the limit established by legislation. Yeasts were isolated from 26 % samples and filamentous fungi from 58 %, being 46 % characterized as melanized fungi. The fungi genera were Cladosporium spp., Penicillium spp., Beauveria spp., Exophiala spp., Fusarium spp., Aspergillus spp., Trichoderma spp, Acremonium spp. and Rinocladiella spp.. The study highlights the significance of P. aeruginosa and fungi detection in those systems, as these microorganisms are potentially pathogenic to immunocompromised patients(AU)

Doenças infecciosas em pacientes renais podem ser associadas à qualidade da água de diálise, que pode apresentar contaminação com microrganismos. Pelos padrões brasileiros, a qualidade da água é avaliada analisando-se coliformes totais, bactérias heterotróficas e endotoxinas bacterianas. Pseudomonas sp. e fungos não são investigados. Amostras de água de clínicas de hemodiálise em Curitiba/PR foram avaliadas quanto à conformidade com os padrões do Ministério da Saúde. Contagens de coliformes totais, bactérias heterotróficas, Pseudomonas aeruginosa e fungos foram realizadas seguindo-se APHA e detecção de endotoxina pela metodologia LAL. Todas as amostras tiveram contagens de coliformes totais abaixo de 1,1 MPN/100 mL e 95 % das amostras apresentaram padrões aceitáveis para bactérias heterotróficas. P. aeruginosa foi encontrada em quatro amostras. Em 15 % das amostras, endotoxinas bacterianas foram detectadas em valores acima dos permitidos pela legislação. Leveduras foram isoladas em 26 % das amostras e fungos filamentosos em 58 %, sendo 46 % melanizados e 27 % hialinos. Os gêneros fúngicos detectados foram Cladosporium spp., Penicillium spp., Beauveria spp., Exophiala spp., Fusarium spp., Aspergillus spp., Trichoderma spp, Acremonium spp. e Rinocladiella spp.. Foi evidenciada a importância da detecção de P. aeruginosa e fungos nestes sistemas, uma vez que estes podem ser potencialmente patogênicos para pacientes imunocomprometidos(AU)