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1.
Cryptococcus neoformans was isolated from 13 patients (7 females and 6 males) suffering from systemic cryptococcosis. Eight patients were suffering from central nervous system cryptococcosis and 5 were suffering from disseminated cryptococcosis. Systemic lupus erythematosus was found to be the common underlying disease in 3 patients. The results of treatment depended on the underlying diseases (7 improved, 6 died). Also, 13 isolates of C. neoformans were obtained from feces of 30 pet birds. All 26 isolates of C. neoformans were cultured in glycine cycloheximide medium and were found to be of serotypes A and D. 相似文献
2.
A central nervous system isolate from an acquired immunodeficiency syndrome (AIDS) patient of 103
Cryptococcus neoformans cells was instilled intranasally into guinea pigs. These were killed to evaluate the fate of the organisms and the response of the olfactory mucosa. Olfactory epithelium prevented the penetration ofCryptococcus neoformans and showed focal hyperplastic responses. The organisms, which manifested an affinity for the olfactory portion of the nasal cavities, were cleared from the olfactory space with no intervention from the immune system cells. By the end of the fifth week almost no organisms could be found and there was no histological evidence of dissemination. In contrast, destruction of the olfactory epithelium with zinc sulfate allowed the invasion of the subepithelial tissues, demonstrating the role of the olfactory mucosa in preventing infection withCryptococcus neoformans through the nasal route. The results and the model described in this report may be useful in clarifying the pathogenic mechanisms of cryptococcosis and the non immune mediated host responses toCryptococcus neoformans. 相似文献
3.
The intraspecific phylogeography of Grant’s gazelles Nanger granti was assessed with mitochondrial DNA control region sequences. Samples of 177 individuals from 17 Kenyan and Tanzanian populations
were analysed. Three highly divergent, reciprocally monophyletic lineages were found, with among group net nucleotide distances
of 8–12%. The three lineages—notata, granti and petersii—grouped populations according to their geographic origin, encompassing populations in the north, southwest, and east, respectively.
The mtDNA lineages reflected distinct evolutionary trajectories, and the data are discussed in reference to the four currently
recognised subspecies. We suggest Grant’s gazelles be raised to the superspecies Nanger (granti) comprising three taxonomic units corresponding to the three mtDNA lineages. There was no evidence of gene flow between the
notata and granti lineages, despite their geographic proximity, suggesting reproductive isolation. These constitute evolutionary significant
units within the adaptive evolutionary framework. Due to its restricted geographic distribution and genetic and morphological
distinctiveness, we suggest the petersii lineage be raised to the species Nanger (granti) petersii within the Grant’s gazelles superspecies. 相似文献
4.
Cryptococcus neoformans was instilled intranasally into mice which were periodically sacrificed to determine the course of infection. Cryptococci persisted within the nasal passages throughout the 90 day study. Extranasal dissemination began 14–28 days after instillation and was still demonstrable 90 days post-exposure. Ten percent mortality was observed in mice receiving 106 cryptococci, while no mortality was observed in mice exposed to 103 or 104 cryptococci. Our research suggests that nasal colonization with C. neoformans can precede pulmonary and systemic cryptococcosis by weeks or months. 相似文献
5.
D. Natarajan N. Nagamurugan A. Ramachandran C. Mohanasundari K. Srinivasan 《World journal of microbiology & biotechnology》2007,23(5):719-721
The present work demonstrates the screening of extracts of the rare medicinal herb Euphorbia fusiformis for antifungal activity. The main aim was to investigate its antifungal properties against Candida albicans and Cryptococcus neoformans, the causative agents of human candidiasis and cryptococcosis, respectively. Aqueous and organic solvent extracts from the
leaves and rootstock of the plant were tested against the fungi by the well-in-agar method. Almost all the organic solvent
extracts exhibited an inhibitory effect against C. albicans and to some extent on C. neoformans, except for the aqueous extracts, which had no effect. The combined formulations of the extracts also had better activity
against C. albicans than C. neoformans. This study thus concludes by demonstrating the antifungal properties of E. fusiformis and also the potential research in identifying the active principles, which may have future therapeutic value. 相似文献
6.
Cryptococcus neoformans and Cryptococcus gattii are pathogenic yeasts that cause cryptococcosis. These fungi were commonly associated with pigeon droppings and plant materials.
The habitat of these pathogens has not been yet studied in Tunisia, although the ecology of these yeasts must be elucidated
in order to establish surveillance programs and to prevent infections. The aim of this survey was to recover C. neoformans and C. gattii environmental isolates from pigeon droppings and plant materials in different areas of Sfax region, Tunisia. Nine hundred
and fifty samples from leaves, wood, flowers, fruits and soil around trunk bases of 40 almond (Prunus dulcis) and 60 eucalyptus trees were collected as well as 250 pigeon droppings samples from different sites: buildings (n = 150), houses (n = 50) and zoo (n = 50). The identification of Cryptococcus neoformans complex was confirmed using the ID32C auxanogram panel (BioMérieux, Marcy l’Etoile, France); species were determined by multiplex
PCR using the CN70 and CN49 primers, and mating type was determined by PCR. C. neoformans was recovered from 26 specimens of pigeon droppings (10.4%). This yeast was obtained more frequently from dry droppings (9.2%)
than from moist droppings (1.2%). The mating type was determined. All the 31 environmental strains of C. neoformans and C. gattii were MATα. Out of 700 samples tested from 100 trees, only 5 isolates of Cryptococcus neoformans species complex were recovered (0.6%), two isolates of C. gattii and one isolate of C. neoformans were recovered from the wood of E. camaldulensis trees, and only two isolates of C. gattii were recovered from the wood of almond trees (Prunus dulcis Mill. var. zaaf and var. achek). These two Tunisian almond tree varieties were recorded for the first time in Africa as hosts for C. gattii. These results add new information to the ecology and epidemiology of C. neoformans species complex in Tunisia. 相似文献
7.
Ronaldo Rozenbaum Adrelirio José Rios Gonçalves Bodo Wanke Maria Julieta Caiuby Hamilton Clemente Marcia dos Santos Lazera Paulo Cesar Fialho Monteiro Alberto Thomaz Londero 《Mycopathologia》1992,119(3):133-136
The study of the clinical isolates of Cryptococcus neoformans from 83 Brazilian patients with disseminated cryptococcosis showed that 75 were C. neoformans var. neoformans and 8 were var. gattii. Twenty-seven isolates were serotyped; all 19 var. neoformans were serotype A and all 8 var. gattii were serotype B. The correlation of the varieties of C. neoformans with the presence or not of hosts predisposing conditions to the mycosis showed that: (1) cryptococcosis caused by gattii variety occurred in 7 (58.3%) of the 12 nonimmunosuppressed patients, and (2) cryptococcosis caused by neoformans variety occurred in 65 (98.5%) of the 66 AIDS patients and in all 5 patients with other immunosuppressive conditions. The comparison of the distribution of the gattii and neoformans varieties between the nonimmunosup-pressed and immunosuppressed patients showed a significant statistical difference (p < 0.01). 相似文献
8.
Three pseudohyphal isolates of Cryptococcus neoformans were inoculated intracranially into mice. Four weeks post-inoculation the animals showed no symptoms of disease and the number of viable cells per brain decreased to zero. Possible roles of pseudohyphal forms of C. neoformans in the immunology and pathogenesis of cryptococcosis are discussed. 相似文献
9.
Forty-five clinical and 55 environmental strains of Cryptococcus neoformans var. neoformans from São Paulo, Brazil, were tested for their susceptibilities to amphotericin B, fluconazole, itraconazole, and flucytosine by the broth microdilution method according to the National Committee of Clinical Laboratory Standards guidelines. Electrophoretic karyotypes analysis by counter-clamped homogeneous electrophoresis was used to compare their genetic relatedness. Molecular typing revealed three clinical profiles very similar to two environmental profiles and an identical environmental and clinical profile. The results showed that human cryptococcosis can be acquired from environmental strains, which had similar minimum inhibitory concentration values to clinical strains, for antifungal agents. 相似文献
10.
J. Cheng T. J. Bull P. Dalton S. Cen C. Finlayson J. Hermon-Taylor 《World journal of microbiology & biotechnology》2005,21(6-7):1175-1179
Summary Mycobacterium avium subspecies paratuberculosis infection in domestic livestock is widespread in many countries throughout the world. Studies in Europe and the USA show
that M. avium subspecies paratuberculosis can be cultured from retail pasteurized cow’s milk and that these organisms are being transmitted to humans by this route.
Most people with chronic inflammation of the intestine of the Crohn’s disease type are infected with these chronic enteric
pathogens. The production and consumption of cow’s milk has increased in China and so also has the incidence of Crohn’s disease.
The present preliminary investigation was carried out to determine whether M. avium subspecies paratuberculosis is present in the intestinal tissues of Chinese patients with Crohn’s disease who have never left China. Archival paraffin-embedded
surgical pathology blocks from patients having surgery for Crohn’s disease (CD) or for cancer (nIBD) in China were studied.
M. avium subspecies paratuberculosis was detected by nested IS900 PCR with Southern blotting and amplicon sequencing. The intestinal tissues of 9 of 13 (69.2%) CD patients and 2 of 14 (14.3%)
nIBD patients were IS900 PCR positive (P = 0.0063; odds ratio = 13.5). These initial studies suggest that people in China are exposed to M. avium subspecies paratuberculosis and that as in other countries, the infection is significantly associated with Crohn’s disease. M. avium subspecies paratuberculosis in dairy herds and retail milk in China needs to be investigated. 相似文献
11.
The chief histopathological features found in patients with cryptococcosis are both a cystic (gelatinous) lesion and a granulomatous
reaction. These two tissue reactions are definitely different from each other, because a cyst is not accompanied with a significant
cellular response, while a granuloma is formed as a result of various cell reactions. Therefore, it is very interesting that
these two types of lesion can be observed in the same patient or in the same animal infected with Cryptococcus neoformans. From our previous paper (II) the authors reach such a thought that two steps may be required for the granuloma formation
against C. neoformans infection: first, of phagocytosis by sessile macrophages of C. neoformans and second is related to T-cell function. This experiment was done to verify that the granulomatous response against C. neoformans infection might occur easily in the organs rich in sessile macrophages as compared with those poor in them and a polysaccharide
capsule surrounding cryptococci may have effects to inhibit a migration of polymorphonuclear leucocytes or monocytes toward
C. neoformans. C. neoformans strain RIB 12 (serological type A, mating type α) was used in this experiment. After a culture of a brain heart infusion glucose agar slant at 37 C for 3 days, yeast cells
of the strain were harvested, and suspended in 1/15 M(pH7.4) sterile phosphate buffered saline solution. Infective inoculum was prepared by adjusting the number of the yeast cells
to 105, 106 or 5×106/0.2 ml in a hemacytometer. Fourty-two male mice strain ddY were divided into 3 groups consisting of 14 each and one group
was allotted to one of the cell suspensions. Each mouse was inoculated with 0.2 ml of the cell suspension into a tail vein
and one mouse from each group was sacrificed at adequate intervals. At necropsies the brain, thymus, lungs, heart, liver,
kidneys, spleen, pancreas, mesenteric lymph nodes, a part of the small intestine, testes and fat tissue were removed. From
these organs histopathological sections, stained with HE or by PAS, were prepared. To investigate effects of a polysaccharide
capsule to a migration of polymorphonuclear leucocytes or monocytes, double infections with C. neoformans and Aspergillus fumigatus, and an observation by the ‘Agar-Implantation method’ were done.
As results, granulomata were formed easily in the organs rich in macrophages or lymphocytes such as the liver, spleen, lymph
nodes, thymus, lungs, small intestine and fat tissue. On the contrary, in organs poor in the macrophages such as the brain,
heart, pancreas, kidneys, adrenal glands and testes, the chief histopathological feature was a cyst formation containing numerous
yeast cells. In the double infection, two types of lesions such as cysts and abscesses were observed in the sections of the
brain. The former occurred against C. neoformans infection and the latter, against A. fumigatus infection. Even though a cyst was very close to an abscess, polymorphonuclear leucocytes or monocytes were never induced
to C. neoformans. In the observation using the ‘Agar-Implantation method’, a severe cellular infiltration occurred to a perfect (teleomorphic)
state of C. neoformans and very weak response, to yeast cells with a polysaccharide capsule. The difference may be due to the existence of the capsule,
because a perfect state of C. neoformans is not surrounded by it. 相似文献
12.
Morera-López Y Torres-Rodríguez JM Jiménez-Cabello T Baró-Tomás T Alía-Aponte C Lázera MS 《Mycopathologia》2005,160(1):9-14
Cryptococcus neoformans var. grubii (serotype A) was isolated from 12 soil samples mixed with pigeon droppings (16.9%) from 71 soil samples in Barcelona and rural areas of Catalonia. C. neoformans was not isolated from indoor dust and Eucalyptus debris. PCR fingerprinting was performed in 22 representative isolates and all of them corresponded to the VNI pattern. Susceptibility testing for the 22 isolates of C. neoformans var. grubii showed that all of them were susceptible to amphotericin B. Three isolates presented MICs (Minimal Inhibitory Concentrations) ≥ 1 μg/ml to Itraconazole, five MICs ≥ 1 μg/ml to ketoconazole and four were fluconazole resistant, (MICs ≥ 64 μg/ml), while three of them were shown to have MICs ≥ 1 μg/ml to voriconazole. In spite that all isolates presented the same DNA fingerprinting pattern, the susceptibility to antifungals is very variable. The possibility of acquiring cryptococcosis infection with primarily resistant environment strains is feasible. 相似文献
13.
Santos JW Silveira ML Santos FP Mathias AC Bertolazi AN Melo CR Oliveira LO Severo LC Oliveira Fde M 《Mycopathologia》2005,159(3):373-376
An unusual case of chronic pulmonary paracoccidiodomycosis and disseminated cryptococcosis in a non-HIV infected patient is reported in a 72-year-old previously healthy man. A chest radiograph disclosed a bilateral diffused interstitial infiltrate involving middle and lower lung fields. Specimen samples taken from the tracheal tube revealed yeast-like organisms suggestive of Cryptococcus neoformans and Paracoccidiodes brasiliensis. Blood and cerebrospinal fluid culture was positive forC. neoformans and the immunodiffusion test against paracoccidiodin revealed a precipitation band. The patient died 24 days after the admission. 相似文献
14.
A modified bootstrapping procedure is described by means of which standard errors and confidence limits may be determined
for the Penrose shape coefficient. This method is then applied to odontometric data derived from four closely related groups
of primates: Cercopithecus aethiops pygerythrus, C. a. sabaeus,St. Kitt’s green monkey (derived from C. a. sabaeus),and C. a. centralis.Although statistically significant distances were found to exist between these groups, one shape coefficient was significantly
greater than the others: that between C. a. pygerythrusand C. a. centralis.Low levels of sexual dimorphism characterized the shape coefficients, with distances based on mandibular teeth being greater
than those derived from maxillary teeth. 相似文献
15.
Predictions from flight mechanical theory concerning optimal flight speeds were tested in the field in two Mediterranean seabirds,
the Cory’s shearwater Calonectris diomedea and the Audouin’s gull Larus audouinii. Both species were commuting off the coast of Isola di San Pietro, 6 km south-west of the coast of Sardinia. Heading and
airspeed were obtained by vector calculation of flight tracks and measured wind. The Cory’s shearwater used a mixture of gliding
and active flight. At low wind speeds the proportion of active flight was large but it decreased with increasing wind speed.
The mean airspeed was 12.0 m s–1, which is not significantly different from minimum power speed (V
mp) in active flight or the speed for best glide (V
bg) used in gliding flight. However, the shearwaters showed a significant response to wind increment/decrement, indicating that
they were not flying at V
mp, which should be unaffected by head and tailwind. Furthermore, shearwaters can potentially reduce induced drag by the ground
effect while flying close to the sea surface at weak winds, which leads to a reduction in characteristic flight speed. We
suspect that the predictions for gliding flight are most valid for shearwaters at moderate to high wind speeds, when they
should be maximising distance by using V
bg. Audouin’s gulls used active flight exclusively, with a mean airspeed of 11.3 m s–1 that was significantly different from the predicted V
mp. Interestingly, though, the gulls did not show any significant wind response, indicating that they were flying close to their
true V
mp when foraging along the coast.
Received: 17 May 2000 / Received in revised form: 21 November 2000 / Accepted: 8 January 2001 相似文献
16.
Blanding’s turtle is a North American freshwater turtle whose main range occurs south of the Great Lakes; disjunct populations
occur east of the Appalachian Mountains from New York to Nova Scotia. The species is listed as threatened or endangered in
most of its range. We employed five variable microsatellites to examine samples of 300 individuals in 12 populations. Estimates
of F
ST based on pairwise comparisons of populations ranged from 0.000 to 0.465. Phylogenetic analysis of these F
ST values reveals that the Appalachian Mountains and the Hudson River appear to present major barriers to gene flow in Blanding’s
turtle. The extent of fine-scale genetic structure previously reported in the Nova Scotian populations was not found in other
parts of the species’ range. We recommend that populations separated by the Appalachian Mountains as well as the highly disjunct
Nova Scotian populations of Blanding’s turtle be recognized as evolutionarily significant units. 相似文献
17.
Serotypes of Cryptococcus neoformans isolated from patients prior to and during the AIDS era in Thailand 总被引:1,自引:1,他引:0
Samaniya Sukroongreung Churairatana Nilakul Orawan Ruangsomboon Wongsatit Chuakul Boonchuay Eampokalap 《Mycopathologia》1996,135(2):75-78
One hundred and eighty-seven strains of Cryptococcus neoformans isolated from patients in Thailand were charcterized by biochemical varieties relating to serogroups. Canavanine-glycine-bromothymol blue (CGB) agar was used for differentiating the varieties of C. neoformans. Slide agglutination tests were performed with Crypto Check (Iatron, Inc., Tokyo) to determine their serotypes. Fifty-five percent (10 out of 18) of the pre-AIDS isolates were serotype B, 28% were serotype A, 5% were serotype D, and an unexpected 11% (2 out of 18) were serotype C. These are the first to be recorded in Asia. In contrast, among the 169 clinical isolates obtained between January 1993 and March 1995 (AIDS epidemic), serotype A was outstandingly predominant-93% (157 out of 169), serotype B was relatively low (3.6%) and both serotypes D and AD were 1.8%. The pattern of serotypes of the 59 isolates from known HIV-positive patients was closely similar to the total isolates during the AIDS epidemic. In determining the varieties of C. neoformans by CGB, only 1 of the 187 isolates gave a false reaction. On the basis of our findings, we believe that in the pre-AIDS era either C. neoformans var. gattii serorype B or serotype C were the common causative agents of cryptococcosis in Thailand. The advent of AIDS changed the pattern of serotypes with serotype A becoming predominant as has been reported world wide. 相似文献
18.
Daphne M. Y. Cheah Yolanda J. Deal Paul F. A. Wright Nicole E. Buck Chung Wo Chow Julian F. B. Mercer Katrina J. Allen 《Biometals》2007,20(5):751-757
Wilson’s disease carriers constitute 1% of the human population. It is unknown whether Wilson’s disease carriers are at increased
susceptibility to copper overload when exposed to chronically high levels of ingested copper. This study investigated the
effect of chronic excess copper in drinking water on the heterozygous form of the Wilson's disease mouse model – the toxic
milk (tx) mouse. Mice were provided with drinking water containing 300 mg/l copper for 4–7, 8–11, 12–15 or 16–20 months. At the completion
of the study liver, spleen, kidney and brain tissue were analyzed by atomic absorption spectroscopy to determine copper concentration.
Plasma ceruloplasmin oxidase activity and liver histology were also assessed. Chronic copper loading resulted in significantly
increased liver copper in both tx heterozygous and tx homozygous mice, while wild type mice were resistant to the effects of copper loading. Copper loading effects were greatest
in tx homozygous mice, with increased extrahepatic copper deposition in spleen and kidney – an effect absent in heterozygote and
wild type mice. Although liver histology in homozygous mice was markedly abnormal, no histological differences were noted
between heterozygous and wild type mice with copper loading. Tx heterozygous mice have a reduced ability to excrete excess copper, indicating that half of the normal liver Atp7b copper
transporter activity is insufficient to deal with large copper intakes. Our results suggest that Wilson’s disease carriers
in the human population may be at increased risk of copper loading if chronically exposed to elevated copper in food or drinking
water. 相似文献
19.
Rubén López-Martínez José Luis Soto-Hernández Luis Ostrosky-Zeichner Laura Rocío Castañón-Olivares Verónica Angeles-Morales Julio Sotelo 《Mycopathologia》1996,134(2):61-64
A retrospective study of 20 patients with cryptococcal meningitis and their isolated strains was performed. Cryptococcus neoformans var. neoformans was recovered from 14 (70%) cases, and var. gattii was recovered from six (30%) patients. Twelve patients had AIDS (all carrying var. neoformans), two had other diseases (one with var. neoformans and one var. gattii) and there was no identifiable underlying disease in six (one var. neoformans and five var. gattii). Fourteen patients (11 var. neoformans and three var. gattii) resided in the Mexico City area, where a temperate climate is prevalent, and there were six cases (three var. neoformans and three var. gattii) from states with a tropical/subtropical climate. Although there was no significant statistical difference between the two varieties, the fatal outcome was higher in patients with var. neoformans. The disease caused by var. gattii strains was characterized by a higher opening pressure, more inflamatory changes of CSF and a longer clinical course (delayed clinical and mycological cure). Cryptococcus neoformans var. gattii is a significant cause of cryptococcal meningitis in patients without underlying diseases in Mexico. 相似文献
20.
Epidemiology of Cryptococcus neoformans 总被引:2,自引:0,他引:2
The concept of the epidemiology of Cryptococcus neoformans as the causative agent of cryptococcosis and as a basidiomycetous yeast is based on the fact that bird manure has been until now its only known habitat but not plant material which likewise harbours various non-pathogenic Cryptococcus species.It could be shown that the possible influence of nutritional factors on the morphology and morphogenesis earns attention not only in view of the epidemiology of C. neoformans but of its perfect states, too. 相似文献