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Christian Alvarez Glaucia Gon?alves Barbosa Raquel de Vasconcellos Carvalhaes de Oliveira Bernardina Penarrieta Morales Bodo Wanke Márcia dos Santos Lazéra 《Memórias do Instituto Oswaldo Cruz》2013,108(1):126-129
In this study, we evaluated several techniques for the detection of the yeast form of Cryptococcus in decaying wood and measured the viability of these fungi in environmental samples stored in the laboratory. Samples were collected from a tree known to be positive for Cryptococcus and were each inoculated on 10 Niger seed agar (NSA) plates. The conventional technique (CT) yielded a greater number of positive samples and indicated a higher fungal density [in colony forming units per gram of wood (CFU.g-1) ] compared to the humid swab technique (ST). However, the difference in positive and false negative results between the CT-ST was not significant. The threshold of detection for the CT was 0.05.103 CFU.g-1, while the threshold for the ST was greater than 0.1.103 CFU-1. No colonies were recovered using the dry swab technique. We also determined the viability of Cryptococcus in wood samples stored for 45 days at 25ºC using the CT and ST and found that samples not only continued to yield a positive response, but also exhibited an increase in CFU.g-1, suggesting that Cryptococcus is able to grow in stored environmental samples. The ST.1, in which samples collected with swabs were immediately plated on NSA medium, was more efficient and less laborious than either the CT or ST and required approximately 10 min to perform; however, additional studies are needed to validate this technique. 相似文献
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Announcement
1988 Gordon Conference on Theoretical Biology and Biomathematics Tilton Academy, Tilton, New Hampshire, U.S.A., 13–17 June 1988 相似文献5.
Quinovic acid glycosides from Uncaria guianensis. 总被引:1,自引:0,他引:1
A M Yépez O L de Ugaz C M Alvarez V De Feo R Aquino F De Simone C Pizza 《Phytochemistry》1991,30(5):1635-1637
From the bark of Uncaria guianensis, two new quinovic acid glycosides, quinovic acid 3 beta-O-beta-D-quinovopyranoside and quinovic acid 3 beta-O-beta-D-fucopyranosyl-(27----1)-beta-D-glucopyranosylester, have been isolated, in addition to known quinovic acid 3 beta-O-[beta-D-glucopyranosyl-(1----3)-beta-D-fucopyranosyl]-(27----1)- beta-D-glucopyranosylester and quinovic acid 3 beta-O-beta-D-fucopyranoside. Their structures were elucidated by spectral and chemical studies. 相似文献
6.
Benzene, toluene, and p-xylene (BTX) were degraded by indigenous mixed cultures in sandy aquifer material and by two pure cultures isolated from the same site. Although BTX compounds have a similar chemical structure, the fate of individual BTX compounds differed when the compounds were fed to each pure culture and mixed culture aquifer slurries. The identification of substrate interactions aided the understanding of this behavior. Beneficial substrate interactions included enhanced degradation of benzene and p-xylene by the presence of toluene in Pseudomonas sp. strain CFS-215 incubations, as well as benzene-dependent degradation of toluene and p-xylene by Arthrobacter sp. strain HCB. Detrimental substrate interactions included retardation in benzene and toluene degradation by the presence of p-xylene in both aquifer slurries and Pseudomonas incubations. The catabolic diversity of microbes in the environment precludes generalizations about the capacity of individual BTX compounds to enhance or inhibit the degradation of other BTX compounds. 相似文献
7.
R. M. Alvarez B. Rodríguez J. M. Romano A. O. Díaz E. Gómez D. Miró L. Navarro G. Saura J. L. García 《World journal of microbiology & biotechnology》1992,8(2):214-215
Microbial lipids produced byRhodotorula glutinis grown in continuous culture with molasses under nitrogen-limiting conditions were evaluated and the effects of growth rate on fatty acid composition were studied. As the growth rate decreased, cell biomass, lipid content and lipid yield gradually increased. The maximum lipid content recorded was 39% (w/w) of dry cell biomass at a dilution rate of 0.04 h–1. The growth rate also affected fatty acid composition: oleic acid decreased with decreasing growth rate while stearic acid increased. 相似文献
8.
Tracey C. Bourner Enrique Vargas‐Osuna Trevor Williams Candido Santiago‐Alvarez Jenny S. Cory 《Biocontrol Science and Technology》1992,2(4):315-326
Agrotis segetum nuclear polyhedrosis virus (AsNPV) and granulosis virus (AsGV), propagated in laboratory cultures of A. segetum in England and A. ipsilon in Spain, respectively, were applied to plots of maize plants at the one‐ to four‐leaf stage of growth. Plots were arranged in a 6 x 6 Latin square design and infested with second‐instar A. segetum larvae (the common cutworm). Each virus was applied in separate treatments by two application methods; as an aqueous spray containing 0.1% Agral as a wetting agent, and as a bran bait. The NPV was applied at a rate of 4 X 1012 polyhedra/ha, and the GV at 4 X 1013 granules/ha. Soil and plants were sampled for larvae on three occasions following virus treatment: 24 h, 4 days and 11 days. The larvae were reared on diet in the laboratory, until death or pupation, to examine the rate and level of viral infection. Infection data showed 87.5% and 91% NPV infection and 12.5% and 55% GV infection in spray and bait treatments, respectively, in larvae sampled 24 h after treatment. In larvae sampled 4 days after treatment, the results were 78% and 100% NPV infection, and 13% and 6% GV infection. A total of only six larvae were retrieved on day 11. In both treatments larvae infected with AsNPV died significantly more rapidly and at an earlier instar than those infected with AsGV, indicating that AsNPV appears to have better potential as a control agent for A. segetum. 相似文献
9.
A morphological and morphometrical study has been carried out on glomerular lesions in mink with spontaneous Aleutian disease, using the WHO classification for Systemic Lupus Erytematous Nefritis. 154 renal samples from sick animals and 10 samples from uninfected mink were processed by routine histopathological techniques and metacrylate inclusions. The samples were studied quantitatively with an automatic image analyzer. 5 forms of glomerulonephritis (GN) were identified: mesangial glomerulonephritis (n = 13), focal and segmental GN (n = 10), diffuse GN (n = 99), membranous GN (n = 12) and advanced sclerosing GN (n = 10) and were associated with the degree of interstitial plasmocytosis. Glomerule morphometry was shown to be an excellent method for identifying the type of lesion, while it quantified the participation of various glomerular elements in the lesion. 相似文献
10.
Pb2+ modified the apparent threshold sensitivity to Ca2+ of individual K+ channels with a biphasic time-course. At first, the sensitivity to Ca2+ was lowered with the result of a decrease of the fraction of activated vesicles at a given Ca2+ concentration. Later, Pb2+ increased the sensitivity to Ca2+ and the fraction of activated vesicles. The increase of Pb2+ concentration increased the extent of the initial inhibition but decreased its duration. The inhibitory effect was not observed when the addition of Ca2+ preceded the addition of Pb2+. The presence of Mg2+ in the incubation medium was also required. In the absence of Mg2+, Pb2+ decreased the rate of uptake of 86Rb, but no decrease in the fraction of activated vesicles could be demonstrated. 相似文献