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1.
Cryptococcosis is a lethal fungal infection mainly caused by Cryptococcus neoformans/C. gattii species. Currently, our understanding of cryptococcosis episodes in HIV-negative patients during renal dialysis remains scarce and fragmented. Here, we performed an analysis of pooled cases to systemically summarize the epidemiology and clinical characteristics of cryptococcosis among HIV-negative patients with renal dialysis. Using pooled data from our hospital and studies identified in four medical databases, 18 cases were identified and analyzed. The median duration time of renal dialysis for peritoneal renal dialysis and hemodialysis cases was 8 months and 36 months, respectively. Several non-neoformans/gattii species were identified among the renal dialysis recipients with cryptococcosis, particularly Cryptococcus laurentii and Cryptococcus albidus, which share similar clinical manifestations as those caused by C. neoformans and C. gattii. Our analyses suggest that physicians should consider the possibility of the occurrence of cryptococcosis among renal dialysis recipients even when cryptococcal antigen test result is negative. The timely removal of the catheter is crucial for peritoneal dialysis patients with cryptococcosis. In addition, there is a need for optimized antifungal treatment strategy in renal dialysis recipients with cryptococcal infections.  相似文献   

2.
The lady beetle Thalassa montezumae and the entomopathogenic fungus Isaria fumosorosea (Ifr) were assessed alone and in combination to suppress green croton scale, Phalacrococcus howertoni, populations on croton plants using laboratory bioassays and greenhouse cage studies. The acquisition of Ifr blastospores by beetle larvae (3rd instar) and adults during contamination in well plates was used to simulate exposure to direct spraying and subsequent possible fungal infection was assessed. Spore dispersal by the insects was determined after the blastospore-contaminated T. montezumae life stages roamed on agar plates for 24 h by counting the number of colony-forming units (CFUs) produced in the plates. There were no significant differences in survival times at 14 days post-treatment between beetle larvae and adults exposed to Ifr and those exposed to water only. Mean survival time of larvae exposed to Ifr was 14 days and water 12 days, whereas for adults it was 13 days compared to 13 days, respectively. Plates with Ifr blastospore-contaminated T. montezumae adults roaming on the agar surface displayed significantly more fungal trails as CFUs compared to plates with larvae. In greenhouse cage studies, the mean mortality rates of the scale exposed to beetle larvae, either alone (80.8%) or in combination with Ifr (89.1%), were not significantly different. Scale mortality rates in the fungus-only (60.5%) and beetle larvae-only treatments were statistically similar. The treatment with both biocontrol agents had a significantly higher scale mortality rate compared to the treatment with Ifr only. Therefore, spraying Ifr prior to releasing T. montezumae is an effective and compatible biological control strategy for management of the green croton scale on croton plants.  相似文献   

3.
We report the two first cases of human C. gattii meningoencephalitis acquired on the Canadian east coast, from the province of Quebec. Unlike C. neoformans, C. gattii is not known to have an established ecological niche on the North American east coast. C. gattii has recently been responsible for major outbreaks in British Columbia, Canada, and in the American pacific northwest. However, no human cases acquired in other Canadian provinces have been reported to our knowledge. The source of acquisition remains unclear for both patients but since neither had traveled outside of the province of Quebec, we discuss the possibilities of environmental and animal-associated acquisition, as well as the possible established endemicity in new areas. These cases add to the growing reported human and animal cases in areas previously not thought to be endemic for C. gattii.  相似文献   

4.
Invasive fungal disease represents one of the severe complications in haematopoietic stem cell transplant recipients. We describe a case of a patient treated for relapse of chronic lymphoblastic leukaemia 6 years after HSCT. The patient was treated for invasive pulmonary aspergillosis but died 3 months later from multiple organ failures consisting of haemorrhagic necrotizing fungal pneumonia, refractory chronic hepatic graft versus host disease and cytomegalovirus hepatitis. Autopsy samples revealed histopathological evidence of fungal hyphae and an unusual Aspergillus nidulans-like species was isolated in pure culture. More precise identification was achieved by using scanning electron microscopy of ascospores and sequencing of calmodulin gene, and the isolate was subsequently re-identified as A. sublatus (section Nidulantes) and showed good in vitro susceptibility against all classes of antifungals. Commonly used ITS rDNA region and β-tubulin gene fail to discriminate A. sublatus from related pathogenic species, especially A. quadrilineatus and A. nidulans. Although this is the first case of proven IPA attributed to A. sublatus, we demonstrated that at least some previously reported infections due to A. quadrilineatus were probably caused by this cryptic species.  相似文献   

5.
The pathogenic yeast Cryptococcus gattii was isolated from a tree hollow of a Castanopsis argyrophylla King ex Hook.f. (Fagaceae) in Chiang Mai, Thailand. Molecular characterization with amplified fragment length polymorphism analysis and multi-locus sequence typing showed that this isolate belonged to genotype AFLP4/VGI representing C. gattii sensu stricto. Subsequent comparison of the environmental isolate with those from clinical samples from Thailand showed that they grouped closely together in a single cluster.  相似文献   

6.
7.
Ectomycorrhizal (ECM) and ectendomycorrhizal fungal species associated with Pinus montezumae were recorded in 8 year-old trees established in microcosms and compared with those associated with 2 year-old trees, in order to determine their persistence over the long-term. Mycorrhizal root tips were morphologically and anatomically characterized and sequenced. The extension of extramatrical mycelium of ECM fungi with long exploration strategies was evaluated. In total, 11 mycorrhizal species were registered. Seven mycorrhizal species were detected on both 2 and 8 year-old pines: Atheliaceae sp., Rhizopogon aff. fallax, R. aff. occidentalis, Suillus pseudobrevipes, Tuber separans, Wilcoxina mikolae and Wilcoxina rehmii. One species, Thelephora terrestris, was exclusively associated with two year–old seedlings, while Cenococcum geophilum, Pezizaceae sp. and Pyrenomataceae sp. were exclusively found on 8 year-old trees. Atheliaceae sp. was the ECM fungal species that presented the most abundant mycelium. Finally, we report one new fungal species of Pezizaceae occurring as a symbiont of P. montezumae.  相似文献   

8.
Cryptococcus is the most common fungal respiratory pathogen in Australian horses, manifesting primarily as pulmonary granulomas. Disease severity at presentation is dependent on the athletic use of the horse. The diagnosis and estimation of disease severity are centred around clinical findings, cytological evaluation of respiratory tract secretions, diagnostic imaging, and antigen titre testing. Both the lateral flow assay and the latex cryptococcal antigen titre are used, and important similarities and differences between species are discussed. Cryptococcus gattii occurs with greater frequency than Cryptococcus neoformans in equine pulmonic cryptococcosis and can be successfully treated with enteral fluconazole monotherapy, with disease severity determining treatment length.  相似文献   

9.
10.
We examined differences in fine root morphology, mycorrhizal colonisation and root-inhabiting fungal communities between Picea abies individuals infected by Heterobasidion root-rot compared with healthy individuals in four stands on peat soils in Latvia. We hypothesised that decreased tree vitality and alteration in supply of photosynthates belowground due to root-rot infection might lead to changes in fungal communities of tree roots. Plots were established in places where trees were infected and in places where they were healthy. Within each stand, five replicate soil cores with roots were taken to 20 cm depth in each root-rot infected and uninfected plot. Root morphological parameters, mycorrhizal colonisation and associated fungal communities, and soil chemical properties were analysed. In three stands root morphological parameters and in all stands root mycorrhizal colonisation were similar between root-rot infected and uninfected plots. In one stand, there were significant differences in root morphological parameters between root-rot infected versus uninfected plots, but these were likely due to significant differences in soil chemical properties between the plots. Sequencing of the internal transcribed spacer of fungal nuclear rDNA from ectomycorrhizal (ECM) root morphotypes of P. abies revealed the presence of 42 fungal species, among which ECM basidiomycetes Tylospora asterophora (24.6 % of fine roots examined), Amphinema byssoides (14.5 %) and Russula sapinea (9.7 %) were most common. Within each stand, the richness of fungal species and the composition of fungal communities in root-rot infected versus uninfected plots were similar. In conclusion, Heterobasidion root-rot had little or no effect on fine root morphology, mycorrhizal colonisation and composition of fungal communities in fine roots of P. abies growing on peat soils.  相似文献   

11.
12.
Petrosavia sakuraii (Petrosaviaceae) is a rare, mycoheterotrophic plant species that has a specific symbiotic interaction with a narrow clade of arbuscular mycorrhizal (AM) fungi. In the present study, we tested the hypothesis that the distribution and abundance of mycobionts in two P. sakuraii habitats, Nagiso and Sengenyama (central Honshu, Japan), determine the distribution pattern of this rare plant. Nagiso is a thriving habitat with hundreds of P. sakuraii individuals per 100 m2, whereas Sengenyama is a sparsely populated habitat with fewer than 10 individuals per 100 m2. AM fungal communities associated with tree roots were compared at 20-cm distances from P. sakuraii shoots between the two habitats by molecular identification of AM fungal partial sequences of the small subunit ribosomal RNA gene. The percentage of AM fungal sequences showing over 99 % identity with those of the dominant P. sakuraii mycobionts was high (54.9 %) in Nagiso, but low (13.2 %) in Sengenyama. Accordingly, the abundance of P. sakuraii seems to reflect the proportion of potential mycobionts. It is likely that P. sakuraii mycobionts are not rare in Japanese warm temperate forests since 11.2 % of AM fungal sequences previously obtained from a deciduous broad-leaved forest devoid of P. sakuraii in Mizuho, central Honshu, Japan, were >99 % identical to those of the dominant P. sakuraii mycobionts. Thus, results suggest that the abundant mycobionts may be required for sufficient propagation of P. sakuraii, and this quantitative trait of AM fungal communities required for P. sakuraii may explain the rarity of this plant.  相似文献   

13.
Diaphorina citri (Kuwayama) is a global pest of citrus that transmits the bacteria associated with the disease, Huanglongbing. Entomopathogenic fungi and the parasitoid Tamarixia radiata (Waterston) are important biological control agents of this pest and likely to interact in D. citri populations. As a basis for interaction studies, we determined the susceptibility of nymphs and adults of D. citri and adults of the parasitoid T. radiata to six fungal isolates from the species Beauveria bassiana s.l. (Bals.-Criv.) Vuill. (isolates B1 and B3), Metarhizium anisopliae s.s. (Metsch.) (Ma129 and Ma65) and Isaria fumosorosea Wize (I2 and Pae). We conducted experiments evaluating infection levels in all three insect groups following inoculation with a series of conidial concentrations (1 × 104–1 × 108 conidia mL?1). Results showed that D. citri nymphs and T. radiata were more susceptible to fungal isolates than D. citri adults. Overall, B. bassiana and M. anisopliae isolates caused the greatest infection compared with I. fumosorosea isolates in all three groups of insects. Isolates B1 (B. bassiana) and Ma129 (M. anisopliae) infected a greater proportion of adults and nymphs of D. citri, respectively. Both isolates of B. bassiana caused greater infection in T. radiata compared with isolates of the other fungal species. We propose that isolates B1 and Ma129 are the strongest candidates for control of D. citri. Our results represent the first report of entomopathogenic fungi infecting T. radiata, and the basis for future studies to design a biological control programme that uses both agents more efficiently against D. citri populations.  相似文献   

14.
The thermal sensitivities of organisms regulate a wide range of ecological interactions, including host–parasite dynamics. The effect of temperature on disease ecology can be remarkably complex in disease systems where the hosts are ectothermic and where thermal conditions constrain pathogen reproductive rates. Amphibian chytridiomycosis, caused by the pathogen Batrachochytrium dendrobatidis (Bd), is a lethal fungal disease that is influenced by temperature. However, recent temperature studies have produced contradictory findings, suggesting that our current understanding of thermal effects on Bd may be incomplete. We investigated how temperature affects three different Bd strains to evaluate diversity in thermal responses. We quantified growth across the entire thermal range of Bd, and beyond the known thermal limits (T max and T min). Our results show that all Bd strains remained viable and grew following 24 h freeze (?12 °C) and heat shock (28 °C) treatments. Additionally, we found that two Bd strains had higher logistic growth rates (r) and carrying capacities (K) at the upper and lower extremities of the temperature range, and especially in low temperature conditions (2–3 °C). In contrast, a third strain exhibited relatively lower growth rates and carrying capacities at these same thermal extremes. Overall, our results suggest that there is considerable variation among Bd strains in thermal tolerance, and they establish a new thermal sensitivity profile for Bd. More generally, our findings point toward important questions concerning the mechanisms that dictate fungal thermal tolerances and temperature-dependent pathogenesis in other fungal disease systems.  相似文献   

15.
Myzus persicae (Sulzer) is a polyphagous aphid that causes chlorosis, necrosis, stunting, and reduce growth rate of the host plants. In this research, the effects of Zinc sulfate and vermicompost (30%), Bacillus subtilis, Pseudomonas fluorescens, Glomus intraradices, G. intraradices × B. subtilis, and G. intraradices × P. fluorescens compared to control was investigated on the growth characters of Capsicum annuum L. and biological parameters of M. persicae. Different fertilizers caused a significant effect on growth characters of C. annuum and biological parameters of M. persicae. The highest plant growth was observed on Zinc sulfate and B. subtilis treated plants, and the lowest was on control. Increase in the amount of specific leaf area (SLA) (0.502 mm2 mg?1) was significantly higher in the B. subtilis than other fertilizer treatments. The longest (10.3 days) and the shortest (5.3 days) developmental times of M. persicae nymphs were observed on 30% vermicompost and Zinc sulfate treatments, respectively. The lowest adult longevity periods of M. persicae (11.2 and 11.3 days) were observed on G. intraradices × B. subtilis and 30% vermicompost treatments, respectively, and the longest ones (16.4 days) on Zinc sulfate. The highest rate of nymphal mortality and the lowest amount of nymphal growth index (NGI) were recorded on 30% vermicompost. The nymphs reared on Zinc sulfate treatment had the lowest rate of nymphal mortality and the highest amount of NGI. Thus, amending the soil with 30% vermicompost had a significantly negative effect on the biological parameters of M. persicae that can be used as an ecological control tactic for this pest.  相似文献   

16.

Aims

Cryoballoon pulmonary vein (PV) isolation in patients with atrial fibrillation has proven to be effective in short-term and long-term follow-up. To visualise the PV anatomy, pre-ablation contrast pulmonary venography is commonly performed. Three-dimensional (3D) computed tomography (CT) overlay is a new technique creating a live 3D image of the left atrium by integrating a previously obtained CT scan during fluoroscopy. To evaluate the benefits of 3D CT overlay during cryoballoon ablation, we studied the use of 3D CT overlay versus contrast pulmonary venography in a randomised fashion in patients with paroxysmal atrial fibrillation undergoing cryoballoon PV isolation.

Methods and results

Between October 2012 and June 2013, 30 patients accepted for PV isolation were randomised to cryoballoon PV isolation using either 3D CT overlay or contrast pulmonary venography. All patients underwent a pre-procedural cardiac CT for evaluation of the anatomy of the left atrium (LA) and the PVs. In the 3D CT overlay group, a 3D reconstruction of the LA and PVs was made. An overlay of the CT reconstruction was then projected over live fluoroscopy. Patients in the contrast pulmonary venography group received significantly more contrast agent (77.1 ± 21.2 cc vs 40.1 ± 17.6 cc, p < 0.001) and radiation (43.0 ± 21.9?Gy.cm2 vs 28.41 ± 11.7?Gy.cm2, p = 0.04) than subjects in the 3D CT overlay group. There was no difference in total procedure time, fluoroscopy time and the amount of cryoapplications between the two groups.

Conclusion

The use of 3D CT overlay decreases radiation and contrast dye exposure and can assist in guiding cryoballoon-based PV isolation.
  相似文献   

17.
Powdery mildew caused by Erysiphe euonymi-japonici (Eej) is an increasingly serious fungal disease on Euonymus japonicus that is an important ornamental plant. However, little is currently known about infection and pathogenesis of Eej on E. japonicus. Here, we report plant infection by Eej at the histological and cytological levels. Eej caused severe disease symptoms with white and snow-like colonies on leaf surfaces of E. japonicus. Microscopic observations were conducted continuously to define infection process of Eej on E. japonicus. Eej conidia germinated to produce appressorial germ tubes on leaf surfaces and formed irregular haustoria in plant epidermal cells at 6 h post-inoculation (hpi) and 12 hpi, respectively. After uptaking nutrients from host cells by haustoria, Eej formed numerous hyphae and extensive colonization on leaf surfaces at 96 hpi and finally produced abundant conidiophores and new conidia on leaf surfaces at 168 hpi. In addition, there was consistently a single nucleus in different Eej infection structures and haustorial development could be divided into three major stages, including formation of penetration peg, formation of haustorial neck and initial haustorium, and maturation of haustorium. These results provide useful information for further determination of Eej pathogenesis and finally controlling the disease.  相似文献   

18.
The coccinellid beetle Anovia punica Gordon (Coleoptera: Coccinellidae: Noviini) is an important predator of the Colombian fluted scale, Crypticerya multicicatrices Kondo & Unruh (Hemiptera: Monophlebidae). In order to gather information on the biological traits of A. punica, we conducted a series of studies, including of the developmental time of each life history stage, estimation of life table parameters, and predation rates under laboratory conditions [25.1 ± 1.6°C, with 70.5 ± 7.3% RH, and natural light regime, approx. 12:12 (L:D) h]. Developmental stages of A. punica were categorized as follows: egg stage, four larval instars, prepupal instar, pupal instar, and adult. Developmental time from egg to adult emergence averaged 29.41 ± 1.85 days, and 47.6% of the eggs developed to adulthood. Female and male survival was 94.42 and 90 days, respectively. Life table parameters show that one female of A. punica is replaced by 86 females (R 0), the intrinsic growth rate (r m ) was 0.1115, the average generation time (T) was 40 days, and the doubling time (D t ) was 6.2 days. The life table parameters suggest that A. punica can be used as a potential predator of C. multicicatrices and, more importantly, provided baseline information for a mass-rearing protocol. This is the first detailed study on the biology of A. punica that reports the potential of this predator as a biological control agent for scale insects of the tribe Iceryini.  相似文献   

19.
Galleria mellonella has been described as a cheap and an easy-to-reproduce model for the study of fungal infections. We hypothesized that yeasts with higher virulence potential decrease survival and significantly trigger an immune response in G. mellonella through the regulation of innate immunity-related genes encoding antimicrobial peptides (AMPs) such as gallerimycin and galiomicin. Candida albicans SC5314 and Candida dubliniensis CBS 7987, selected because of their different virulence potential, were used for a killing assay followed by the determination of gene expression using qPCR. In vivo results confirmed a significantly (p?=?0.0321) lower pathogenicity for C. dubliniensis than for C. albicans. Accordingly, the induction of C. dubliniensis AMPs was lower at all the selected time points post-infection (1 h, 24 h, 48 h). Moreover, we observed an extremely high regulation of the galiomicin gene compared to the gallerimycin one, suggesting a different role of the tested AMPs in protecting G. mellonella from candidiasis.  相似文献   

20.
Mycorrhizal symbiosis often displays low specificity, except for mycoheterotrophic plants that obtain carbon from their mycorrhizal fungi and often have higher specificity to certain fungal taxa. Partially mycoheterotrophic (or mixotrophic, MX) plant species tend to have a larger diversity of fungal partners, e.g., in the genus Pyrola (Monotropoideae, Ericaceae). Preliminary evidence however showed that the Japanese Pyrola japonica has preference for russulacean fungi based on direct sequencing of the fungal internal transcribed spacer (ITS) region from a single site. The present study challenges this conclusion using (1) sampling of P. japonica in different Japanese regions and forest types and (2) fungal identification by ITS cloning. Plants were sampled from eight sites in three regions, in one of which the fungal community on tree ectomycorrhizal (ECM) tips surrounding P. japonica was also analyzed. In all, 1512 clone sequences were obtained successfully from 35 P. japonica plants and 137 sequences from ECM communities. These sequences were collectively divided into 74 molecular operational taxonomic units (MOTUs) (51 and 33 MOTUs, respectively). MOTUs from P. japonica involved 36 ECM taxa (96 % of all clones), and 17 of these were Russula spp. (76.2 % of all clones), which colonized 33 of the 35 sampled plants. The MOTU composition significantly differed between P. japonica and ECM tips, although shared species represented 26.3 % of the ECM tips community in abundance. This suggests that P. japonica has a preference for russulacean fungi.  相似文献   

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