多育赛多孢菌性鼻窦炎1例——致病菌的鉴定和体外抗真菌药物敏感性研究

目的报告国内首例多育赛多孢菌致鼻窦炎,并探讨致病菌的鉴定及其对抗真菌药物体外敏感性。方法取患者左侧上颌窦分泌物进行真菌培养和形态学鉴定,分离菌株β-球蛋白、rDNAITS序列分析确切鉴定,对分离菌进行7种抗真菌药体外药敏试验。结果根据菌株的形态学特点和基因序列结果鉴定为多育赛多孢菌。体外药敏试验显示该菌对7种抗真菌药物耐药。结论多育赛多孢菌所致的真菌病较少见,其确切鉴定靠形态学特征和基因分析。该菌株对多种抗真菌药物耐药。     

Surface properties,adhesion and biofilm formation on different surfaces by Scedosporium spp. and Lomentospora prolificans

Abstract

In the present work, some surface properties of the fungi Scedosporium apiospermum, S. aurantiacum, S. minutisporum, and Lomentospora prolificans and their capability to adhere to and form a biofilm on diverse surfaces were evaluated. All four species had high conidial surface hydrophobicity and elevated electronegative zeta potentials. Abundant quantities of melanin were detected at the conidial surface, whereas sialic acid was absent. The numbers of non-germinated and germinated conidia adhered to poly-L-lysine-covered slides was higher than on glass after 4?h of fungi–surface contact. Additionally, after 72?h of interaction a typical biofilm structure had formed. Mature biofilms were also observed after 72?h on a nasogastric catheter (made from polyvinyl chloride), a late bladder catheter (siliconized latex), and a nasoenteric catheter (polyurethane). Interestingly, biofilm biomass increased considerably when the catheters had previously been incubated with serum. These results confirm that Scedosporium/Lomentospora spp. are capable of forming biofilms on diverse abiotic surfaces.     

Proteins and Peptidases from Conidia and Mycelia of <Emphasis Type="Italic">Scedosporium apiospermum</Emphasis> Strain HLPB

The conidia–mycelia transformation is an essential step during the life cycle of the fungal human pathogens of the Pseudallescheria boydii complex. In the present study, we have analyzed the protein and peptidase profiles in two distinct morphological stages, conidia and mycelia, of Scedosporium apiospermum sensu stricto. Proteins synthesized by the mycelia, migrating at the ranges of 62–48 and 22–18 kDa, were not detected from the conidial extract. Conidia produced a single cellular peptidase of 28 kDa able to digest copolymerized albumin, while mycelia yielded 6 distinct peptidases ranging from 90 to 28 kDa. All proteolytic enzymes were active at acidic pH and fully inhibited by 1,10-phenanthroline, characterizing these activities as metallo-type peptidases. Quantitative peptidase assay, using soluble albumin, showed a high metallopeptidase production in mycelial cells in comparison with conidia. The regulated expression of proteins and peptidases in different morphological stages of S. apiospermum represents a potential target for isolation of stage-specific markers for biochemical and immunological analysis. Martha Machado Pereira and Bianca Alcantara Silva contributed equally to this work.