Biomedical subjects

F Staib

Publications and source records attributed to F Staib.

49 records · Page 3Linked to original sources

PubMed1976

Growth of Cryptococcus neoformans on uric acid agar.

Effect of certain low molecular nitrogen substances, namely uric acid, eura and creatinine as sole source of nitrogen was studied on 31 strains of Cryptococcus neoformans as well as on a rough looking isolate recovered from the brain of a mouse inoculated with a mucoid strain of C. neoformans. Uric acid as a nitrogen source caused striking alterations in the morphology of C. neoformans. In view of the facts that uric acid is a common end-product of human and animal metabolism, it is abundantly present in the avian faecal matter and is capable of inducing mucoid growth and capsule formation in dry growing non-encapsulated strains or in an otherwise rough looking hypha forming isolate, its role in studying the phylogenesis of C. neoformans and its pathogenicity seems to be an important proposition.

Animals↗

PubMed1976

Staphylococcus aureus and Candida albicans infection (animal experiments).

During a certain period of the course of infection in white mice inoculated intraperitoneally with the pure culture of a proteolysing strain of Candida albicans, Staphylococcus aureus and C. albicans both, were isolated simultaneously from the peritoneal abscesses, especially those adhering to the stomach, duodenum, pancreas and the upper part of small intestine. This concommitant occurrence of the two pathogens was further corroborated by histopathological examination which revealed large number of staphylococci present in the close neighbourhood of Candida cells, usually in the center of the granulomata caused by the fungus. In view of the facts that the proteolytic end-products of C. albicans can offer a good substratum for the growth of S. aureus and the latter may be isolated from the intestinal tract of apparently healthy mice, possibly as a constituent of the transient microflora, the co-existence of these two important aetiologic agents of endogenous infections as encountered during this study appears to be of great clinical interest. Furthermore, these observations also demonstrate the importance of controlling the bacterial flora of mice for pure mycological studies.

Abscess↗

PubMed1976

[Intraocular cryptococcosis (author's transl)].

A 79-year-old female patient suffered from iridocyclitis of both eyes. In the fundus of the left eye equatorially a preretinal questionable granuloma (size 1/2 d.d.) was found; the first hint of a mycotic involvement. In the enucleated right bulbus, an abscess-like granulomatous focus with a diameter of 10 mm was found. Several round encapsulated cells having a diameter of 7 to 20 mu and looking like with Cryptococcus neoformans were microscopically demonstrable in the pus obtained from this abscess. Since the fungus could not be cultured, it may be assumed that a spontaneous healing occurred. The only known basic disease was a temporary uremia (330 mg0/0 urea and 7.0 mg0/0 creatinin). The role of amphotericin B therapy in this patient is discussed.

Aged↗

PubMed1975

[Cryptococcoma and amphotericin B. Therapy of cryptococcosis - animal experiments. 2nd Communication: Patho-histological results (author's transl)].

Since cryptococcosis is characterized by cryptococcoma formation, the antimycotic effect of amphothericin B was examined in view of such pathological-anatomical conditions. In white mice (NMRI), cryptococcoma formation was induced by intramuscular injection of Cryptococcus neoformans strain W71 into the hind leg (STAIB, 1962), using a suspension (0.2 ml) containing approximately 2.8 times 10-7 cells/ml. The mice were treated daily with 1 mg amphotericin B in 5% dimethyl sulfoxide by gastric intubation. Course of infection and effectivity of therapy were assessed by microbiological and patho-histological examination of the organs. In the present paper (2nd Communication) comparative patho-histological results in mice, treated with amphotericin B either immediately or from the 16th day p.i. or not at all, are reported. In the non-treated animals the course of infection we controlled by sacrificing 2 animals per day from the 2nd to the 25th day. Cryptococcoma found in the muscle, fat, and connective tissue in the hind leg of these animals were characterized by the two different patho-histological alterations: a) Masses of encapsulated cryptococci side by side were filling a paucireactive or non-reactive reticular structure with blood capillaries. b) Non-specific granulomatous tissue. The fungi were less abundantly found as non-encapsulated cells. On the 5th day after infection the first alterations due to dissemination were found in the lungs, then in other parenchymatous organs. Under immediate amphotericin B-therapy, no cryptococcoma was found at the place of infection; after a therapy of 30 days duration, C. neoformans could be detected in small conglomerates of non-encapsulated cells in muscle, fat and connective tissue. Histologically, a septic dissemination of the agent could not be found in this group. After a therapy of 25 days duration a shrinking of cryptococcoma was observed in animals treated from the 15th day after infection. Presumably this was caused by a loss of capsule and formation of non-specific granulomatous tissue. In the surroundings of blood vessels non-encapsulated cells were detectable. After therapy with amphotericin B, single cryptococci e.g. such disseminated into the lungs were increasingly showing morphological alterations which might be explained as forms of degeneration. The animal experiment in connection with microbiological and patho-histological follow-up studies is discussed with a view to the therapy of cryptococcosis in man. Because of the variable virulence of C. neoformans it has to be mentioned that this experiment was carried out with a strain of C. neoformans characterized by its capability to form cryptococcoma in mice.

Amphotericin B↗

PubMed1975

[Contributions to the strain-specific virulence of Cryptococcus neoformans. Animal experiments with two C. neoformans-strains isolated from bird manure. Preliminary report (author's transl)].

The results briefly presented here highlight some of the observations met with during the course of a study aimed at finding out differential pathogenic behavior of the two strains of Cryptococcus neoformans i.e. W71/A117 and W2/A94 with special reference to cryptococcoma formation. Both strains were isolated from bird excreta but differed in their gross and microscopic morphology. Groups of male albino mice NMRI were separately inoculated, intramuscularly, with a comparable dose of the two strains. All the 50 animals challenged with W71/A117 developed macroscopically distinct cryptococcoma of variable size, and fatally progressive disease, involving most of the internal organs, namely, brain, heart, lung, liver, spleen and kidneys. On the contrary, only 34 of the 50 mice infected with the strain W2/A94 showed cryptococcoma formation at the site of inoculation, which were comparatively much smaller in size and gradually diminished. None of the animals, observed over a period of 93 days, died, and showed any sign of metastasis. In another series of experiment, only one instance of mortality was observed in a group of 80 mice inoculated intraperitoneally with about 2 X 10(7) viable cells of this strain. However, the fungus could be recovered, in a majority of cases, only from the brain of animals sacrificed after one month, though most of them showed no sign of sickness. The number of mice yielding positive cultures gradually decreased, and after 87 days the fungus could not be isolated from any organ. The high morbidity and mortality in mice caused by strains W71/A117 was significantly lowered when the animals were infected intramuscularly 3 months ago with the strain W2/A94. After an observation period of 61 days, 91% of the double infected animals were still alive in comparison to 23% survival among the animals challenged with the strain W71/A117 only.

Animals↗

PubMed1975

Selective involvement of the brain in experimental murine cryptococcosis. I. Microbiological observations.

During the course of infection in intraperitoneally infected white mice with a particular strain of Cryptococcus neoformans, it was possible to observe a time-limited and selective presence of the fungus in the brain. The presence of the fungus in the brain without causing clinical symptoms and the rare mortal exacerbation of the brain involvement offers possibilities for comparative studies of experimental and human cryptococcosis. On the basis of these strain-specific results new aspects of the virulence of C. neoformans and the epidemiology of cryptococcosis are discussed.

Animals↗

PubMed1975

[Aspergillus infection in skin transplantation and its therapy].

In a 10 years old girl sustaining a corrosive injury of the lower leg from sulphuric acid, in the region of a skin transplantation colonization with Aspergillus fumigatus (Fresenium) and Aspergillus niger (van Tieghem) took place. This infection endangered the attempt of transplantation and the saving of the foot. Treatment by medication with nystatin (moronal) and canesten (clotrimazol) were ineffective. Pimaricin (pimafucin, natamycin) quickly erradicated the mycotic infection and secured an undisturbed progress for the transplantation. Additionally the epidemiology of infections by Aspergillus is briefly discussed.

Antifungal Agents↗

PubMed1975

Selective involvement of the brain in experimental murine cryptococcosis. II. Histopathological observations.

In the present communication the previously described cultural findings about the selective involvement of the central nervous system by C. neoformans, strain W 2/A 94, have been supplemented by the results of histopathological investigations. Attention has been paid to the organ specific tissue reaction during the course of infection, with special reference to the involvement of the brain. In agreement with former observations concerning the cryptococcoma in the muscle-tissue, the cryptococcal foci in the brain also showed the phenomenon of vascularisation. The results have been compared with those of the C. neoformans, strain W 71/A 117 which does not allow such a prolonged selective involvement of the central nervous system due to its high virulence for the white mice. These observations impressively demonstrate the significance of simultaneous microbiological and histopathological examinations for the detection of infections caused by such facultative pathogens.

Animals↗

PubMedDate not supplied

Extracellular proteolysis by Mucoraceae in serum-albumin agar tested by the agar block method.

In a preliminary study, three strains of Absidia corymbifera (two strains from autopsy material of the lungs and one from the soil of a potted indoor plant in a hospital) and one strain of Rhizopus oryzae (from the soil of a potted plant in a hospital) were tested for secretory proteolytic activity in serum-albumin agar (SAA) with initial pH values of 5.0 and 7.0 by the agar block method and subsequent protein staining. Within an incubation period of 5 d/37 degrees C, complete proteolysis took place in all the SAA blocks with an initial pH value of 7.0. The three strains of Absidia corymbifera and the one strain of Rhizopus oryzae did not fully proteolyse the SAA blocks with an initial pH value of 5.0. On the basis of these observations, it is assumed that there are secretory proteases in the causative agents of mucormycosis (zygomycosis) whose optimal pH is not in the acid but in the neutral, perhaps in the alkaline range.

Agar↗

PubMedDate not supplied

Fungal infections following heart transplantation.

Following heart transplantation (HTx), patients often suffer from mycoses due to the necessary immunosuppressive treatment to prevent rejection episodes. Oropharyngeal Candida infections which mostly occur after HTx under high-dose immunosuppressive therapy can be avoided and treated successfully by prophylactic medication to be started immediately after transplantation, either by using azoles (e.g. fluconazole) or amphotericin B suspension. Contrary to this, invasive aspergillosis, beginning in the upper respiratory tract and the lung and mostly followed by hematogenous dissemination into various organs, is always a serious disease with high mortality. To avoid this infection, specimens from the respiratory tract, serum and urine should be examined mycologically prior to HTx. After HTx, apart from prophylactic avoidance of exposure to airborne fungal spores, close mycological control is mandatory to detect colonizations by aspergilli early. Timely administration of amphotericin B and 5-flucytosine, i.e. as soon as invasive growth is suspected, enables curative treatment of the often lethal course of this disease, even under immunosuppressive therapy.

Aspergillosis↗

PubMedDate not supplied

Pathogenic fungi in human dwellings.

Airborne invasive fungal infections in various risk groups of people suffering from immunodeficiencies are an increasing problem for modern medicine. Because of the acute and rapid course of invasive infections, prevention is of principal significance. Such prevention mainly concerns the control of fungal spores in indoor air. In this connection the immediate environment offering ecological niches for growth and morphogenesis of infective particles of Aspergillus spp., Mucoraceae, Cryptococcus neoformans and some other yeast-like fungi is of main interest. The current problems of indoor air mycology, i.e. the epidemiology and ecology of pathogenic fungi in indoor air, can only be recognized and interpreted by centres routinely performing mycological diagnosis for all the various risk groups of patients. Models of specific surveillance of the most important fungal pathogens (e.g. Aspergillus spp. and Cryptococcus neoformans) in indoor air will be outlined and discussed.

Air Microbiology↗

PubMedDate not supplied

Cerebrospinal fluid indices in cryptococcal and tuberculous meningitis: the spider web coagulum and its diagnostic significance.

The differentiation between a chronic cryptococcal meningitis and a chronic tuberculous meningitis may cause problems for the clinician only if standard microbiological methods are not applied to the diagnosis of both infections. In a male non-AIDS patient (50 y), 11 years after a suggested diagnosis of "tuberculous meningitis", meningoencephalitis with hydrocephalus was diagnosed and treated accordingly without success. Mycobacterium tuberculosis was never found. Because fibrin fibres of a spider web coagulum in the CSF resembled Aspergillus mycelium, the patient was then treated with amphotericin B + flucytosine. Finally, a mycological examination led to the true diagnosis: (1) In the CSF, resembling Aspergillus hyphae were found to be spider web coagulum fibres. (2) Cryptococcal meningoencephalitis based on the detection of Cryptococcus neoformans in CSF and its antigen in serum and CSF. - At post-mortem, cryptococcal meningoencephalitis was established as cause of death. Residual signs of tuberculosis could not be detected in the brain and the meninges. Common clinical similarities of cryptococcal and tuberculous meningitis and the possibility of a double infection are discussed. A comparison of the presence of Cr. neoformans in the meninges of non-AIDS and AIDS patients is made. The formation of spider web coagulum in the CSF is discussed. Proposals for the diagnosis, therapy and prophylaxis of cryptococcal meningitis are made.

Cryptococcosis↗

PubMedDate not supplied

Persistence of Cryptococcus neoformans in seminal fluid and urine under itraconazole treatment. The urogenital tract (prostate) as a niche for Cryptococcus neoformans.

The open questions of the persistence of Cryptococcus neoformans in the urogenital tract under antimycotic treatment can be examined under optimal mycological-diagnostic conditions only. The example of a case of cryptococcosis in an AIDS patient diagnosed and treated with itraconazole in the early secondary stage of cryptococcosis is used to discuss the problems of the persistence of Cr. neoformans involvement in the urogenital tract (prostate). Data from a ten-week follow-up study are presented and discussed. The observations made have shown that itraconazole is effective in all regions of the body, with the exception of the urogenital tract. In addition to clinical examinations, cases treated with itraconazole should be finally subjected to cultural examination of prostatic secretion and/or seminal fluid, to exclude the possible presence of a symptom-free involvement of the prostate by Cr. neoformans.

Acquired Immunodeficiency Syndrome↗