ABSTRACT
A Brazilian isolate of Beauveria bassiana (CG425) that shows high virulence against the coffee berry borer (CBB) was examined for the production of subtilisin-like (Pr1) and trypsin-like (Pr2) cuticle-degrading proteases. Fungal growth was either in nitrate-medium or in CBB cuticle-containing medium under both buffered and unbuffered conditions. In unbuffered medium supplemented with cuticle, the pH of cultures dropped and Pr1 and Pr2 activities were detected in high amounts only at a pH of 5.5 or higher. In buffered cultures, Pr1 and Pr2 activities were higher in medium supplemented with cuticle compared to activities with nitrate-medium. The Pr1 and Pr2 activities detected were mostly in the culture supernatant. These data suggest that Pr1 and Pr2 proteases produced by strain CG425 are induced by components of CBB cuticle, and that the culture pH influences the expression of these proteases, indicating the occurrence of an efficient mechanism of protein secretion in this fungus. The results obtained in this study extend the knowledge about protease production in B. bassiana CG425, opening new avenues for studying the role of secreted proteases in virulence against the coffee berry borer during the infection process.
O isolado brasileiro de Beauveria bassiana (CG425) que apresenta alta virulência contra a broca do café (CBB) foi analisado quanto à produção de proteases degradadoras de cutícula, tipo-subtilisina (Pr1) e tipo-tripsina (Pr2). O crescimento fúngico foi realizado em meio contendo nitrato e em meio contendo cutícula da broca em condições de pH tamponado e não tamponado. Em meio não tamponado, suplementado com cutícula, o pH da cultura caiu e as atividades de Pr1 e Pr2 foram detectadas somente em valores de pH igual ou superior a 5,5. Em culturas tamponadas, as atividades Pr1 e Pr2 foram superiores em meio suplementado com cutícula, comparativamente as atividades em meio contendo nitrato. As atividades Pr1 e Pr2 ocorreram predominantemente no sobrenadante de cultivo. Os dados obtidos sugerem que Pr1 e Pr2 produzidas pelo isolado CG425 são induzidas por componentes da cutícula da broca do café (CBB), e que o pH da cultura influencia a expressão destas proteases, indicando a ocorrência de um mecanismo eficiente de secreção por este fungo. Os resultados obtidos neste estudo aumentam o conhecimento a respeito da produção de proteases por B. bassiana CG425, abrindo novos caminhos para o estudo do papel de proteases na virulência contra a broca do café durante o processo de infecção.
Subject(s)
Beauveria/growth & development , Beauveria/isolation & purification , Clinical Enzyme Tests , Culture Media , Environmental Microbiology , Fungi/growth & development , Fungi/isolation & purification , In Vitro Techniques , Peptide Hydrolases/analysis , Coffee , Methods , VirulenceABSTRACT
Os autores relatam um caso raro de compressäo das veias femoral e ilíaca externa esquerda por um cisto sinovial do quadril, simulando trombose venosa profunda. Houve regressäo completa do quadro clínico após ressecçäo cirúrgica do cisto
Subject(s)
Femoral Vein , Iliac Vein , Synovial Cyst , ThrombophlebitisABSTRACT
Escherichia coli strains isolated from 100 urine samples taken from patients with urinary tract infections (UTI) and from 20 normal fecal (NF) samples were examined for serum resistance, mannose-resistant hemagglutination of human erythrocytes (MRHA) and for production of aerobactin, hemolysis and colicin. Among the UTI E. coli strains, 79% produced aerobactin, 69% showed serum resistance, 44% produced MRHA, 32% were beta-hemolytic and 22% were colicinogenic. A greater proportion of UTI E. coli strains produced aerobactin, colicin V, beta-hemolysis and MRHA when compared to NF strains. Production of MR hemagglutins was significant correlated with that of aerobactin and hemolysin. These results suggest that the presence of aerobactin may be a significant etiological factor in UTI, and that the production of MR adhesins and of hemolysin also might contribute to the virulence of these strains