Cryptococcus neoformans em torres de igrejas da cidade do Rio de Janeiro, RJ, Brasil

Cryptococcosis has been a significant cause of morbidity and mortality in patients with Aids. Many reservoirs of the agent Cryptococcus neoformans have been reported, but the ecology of this yeast must be elucidated in order to establish surveillance programs and to prevent infections. The objective of this study was to evaluate the presence of C. neoformans in Rio de Janeiro City, RJ, Brazil. Ten churches were selected for sampling and detection of the yeast collecting pigeon dropping, air samples from church towers and neighboring areas during one year. The data demonstrated that C. neoformans has been present in every church selected and was present in 37.8% of 219 pigeon dropping samples. As well as, the yeast was isolated from soil, insects, eggs, pigeon nests and feathers. Fifteen air samples (4.9%) were positive. The growth on C.G.B. medium showed that all strains belonged to C. neoformans var. neoformans, with 98.8% of the strains belonging to serotype A.Cryptococcus neoformans é um fungo que ocasiona micose de alta morbidade e mortalidade, especialmente em pacientes com Aids. Muitos reservatórios de C. neoformans têm sido relatados, mas a ecologia desta levedura deve ser ainda elucidada para se estabelecer programas de vigilância e prevenção desta infecção. O objetivo deste estudo foi o de avaliar a presença de C. neoformans no Rio de Janeiro, RJ, Brasil. Dez igrejas foram selecionadas para este estudo, coletando-se fezes de pombo, amostras de ar, das torres das igrejas e de áreas vizinhas, durante um ano. Os resultados revelaram que C. neoformans estava presente em todas as igrejas e em 37,8% das 219 amostras das excretas das aves. Ao mesmo tempo, o fungo foi isolado do solo, insetos, ovos e ninhos de pombos. Quinze (4,9%) do total das amostras de ar foram positivas. O crescimento no meio de CGB revelou que todas as amostras pertenciam a C. neoformans var. neoformans, e 98,8% destas amostras pertenciam ao sorotipo A

Bioconversion of α-chitin into N-acetyl-glucosamine using chitinases produced by marine-derived Aeromonas caviae isolates

11 páginas.-- 5 figuras.-- 3 tablas.-- 57 referenciasbstract: N-Acetyl-d-glucosamine (GlcNAc) is a monosaccharide with great application potential in the food, cosmetic, pharmaceutical, and biomaterial areas. GlcNAc is currently produced by chemical hydrolysis of chitin, but the current processes are environmentally unfriendly, have low yield and high cost. This study demonstrates the potential to produce GlcNAc from α-chitin using chitinases of ten marine-derived Aeromonas isolates as a sustainable alternative to the current chemical process. The isolates were characterized as Aeromonas caviae by multilocus sequence analysis (MLSA) using six housekeeping genes (gltA, groL, gyrB, metG, ppsA, and recA), not presented the virulence genes verified (alt, act, ast, ahh1, aer, aerA, hlyA, ascV and ascFG), but showed hemolytic activity on blood agar. GlcNAc was produced at 37 °C, pH 5.0, 2% (w/v) colloidal chitin and crude chitinase extracts (0.5 U mL−1) by all the isolates with yields from 14 to 85% at 6 h, 17–89% at 12 h and 19–93% after 24 h. The highest yield of GlcNAc was observed by A. caviae CH129 (93%). This study demonstrates one of the most efficient chitin enzymatic hydrolysis procedures and A. caviae isolates with great potential for chitinases expression and GlcNAc production. Graphical abstract: [Figure not available: see fulltext.].The authors also thank the financial support provided from Sao Paulo Research Foundation (FAPESP), Grants 2012/16824-0 and 2013/18773-6.Peer reviewe