Sabouraudia最新文献

The sequential changes observed during the mycelium to yeast transformation in Paracoccidioides brasiliensis were studied microscopically. The mycelial elements produced terminal and intercalary swellings which, later on, became chlamydospore-like structures. These increased in size, acquired a double contour and, finally, gave rise to multiple budding cells. Transformation was asynchronous. During the observation period, multiple budding cells and chlamydospores remained attached to the parent mycelium.

Several phospholipases are secreted into the culture medium by growing yeast cells of Candida albicans 3125. DEAE-Sephadex column chromatography of concentrated culture filtrate revealed three separable fractions with phospholipase activities. Analysis of products of hydrolysis showed that the enzyme activities were lysophospholipase, lysophospholipase-transacylase and a phospholipase B.

Mice injected with 10(3) cells of a virulent isolate of Candida albicans via the lateral tail vein developed frequent unilateral abnormalities of the right but not the left kidneys. Initially the number of colony forming units in the right and left kidneys were similar but the number of colonies became consistently higher in the right kidneys as the infection progressed. The frequency of unilateral involvement decreased when the inoculum size was increased to 5 X 10(3) cells. These observations indicate that when growth of C. albicans in vivo is monitored over a period of time starting with a low inoculum, it is critical to be consistent in culturing kidneys from the same side.

Cerebrospinal fluid from rabbits with chronic cryptococcal meningitis was tested for its chemotactic activity towards polymorphonuclear cells and monocytes. CSF chemotactic activity was present; it peaked 5-8 days after infection, coinciding with the time when the number of inflammatory cells in CSF was greatest. However, little chemotactic activity could be found in the early stages of infection, during the initial ingress of inflammatory cells. The chemotactic activity appeared to be host-derived, with characteristics consistent with lymphokine(s) or C5a. Treatment with cortisone significantly reduced the CSF chemotactic activity for both cell types; this reduction may contribute to the severe CSF leukopenia observed in cortisone-treated animals, which are unable to eradicate this yeast infection. Modulation of CSF chemotactic activity may be important to the success or failure of the host central nervous system response to Cryptococcus neoformans.

Antigens prepared from P. brasiliensis yeast cells subjected to ultrasonic treatment proved reliable in the serological diagnosis of paracoccidioidomycosis. Detection of antibodies was possible in over 90% from paracoccidioidomycosis patients in tests with agar gel immunodiffusion and counterimmunoelectrophoresis. Specificity was high and only histoplasmosis sera produced cross reactions, albeit at a lower frequency (10%). The new antigens compared favorably to the standard yeast culture filtrate antigen used in the past and they have the advantage of being reproducible. Proper control of proteolysis is required if activity is to be preserved.

Blastomyces dermatitidis is reported for the first time from the liver of Rhinopoma hardwickei hardwickei Gray (the 'lesser rat-tailed bat'); it was cultured from one of 46 samples of the bat captured on December 10, 1982, from the basement of Safdar-Jang Tomb, a historical monument in New Delhi. The fungus was not found in 581 other bats representing R. hardwickei hardwickei, three more insectivorous and one frugivorous species investigated from several sites in Delhi and New Delhi metropolitan areas. The identity of the isolate was based upon its macroscopic and microscopic cultural morphology, dimorphic character and verification of pathogenicity for white mice. It was further confirmed by determining the capacity of the isolate to produce the 'A' exoantigen specific for B. dermatitidis. The infected bat did not manifest any obvious clinical signs and symptoms of illness. Its visceral organs were free from macroscopic lesions, and histopathologically none of them including the liver, revealed any fungal elements or tissue response. B. dermatitidis was not found in any of the 34 samples of bat guano investigated by direct culture or mouse-inoculation technique. The results reinforce the available evidence for the endemic occurrence of B. dermatitidis in India and focus on the possible role of R. hardwickei hardwickei as a natural host or vector for this pathogen.

Protoplast formation from mycelium and microconidia of Trichophyton mentagrophytes was achieved with Novozym 234. Pretreatment procedures with dithiothreitol or urea mercaptoethanol sodium lauryl sulphate before digestion with Novozym 234 greatly reduced protoplast yield from mycelium. Snail gut enzyme did not protoplasts in good yield. Scanning electron microscopy of mycelium protoplasts showed the acquired spherical shape. The plasma membrane appeared finely granular although remnants of cell wall could sometimes be observed. Transmission electron microscopy showed the cell interior of these protoplasts was plasmolysed. Microconidia treated with Novozym 234 displayed a range of cell wall digestion, with intact protoplasts showing distinct cytoplasmic organelles.