The Experts below are selected from a list of 18651 Experts worldwide ranked by ideXlab platform
Jeremiah A Henning - One of the best experts on this subject based on the ideXlab platform.
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Fungal Colonization of plant roots is resistant to nitrogen addition and resilient to dominant species losses
Ecosphere, 2019Co-Authors: Jeremiah A Henning, Quentin D Read, Nathan J Sanders, Aimee T ClassenAbstract:Global change drivers, such as nitrogen (N) deposition and non‐random species extinctions, may shift interactions among aboveground and belowground communities. However, tightly coupled interactions between aboveground and belowground organisms may buffer ecosystems to global change. Here, we test how four years of organic and inorganic N addition and removal of a dominant plant species, Festuca thurberi, independently and interactively influences Fungal Colonization patterns and performance in a co‐dominant plant species, Helianthella quinquenervis. Surprisingly, we found N addition and Festuca removal had no measurable effects on the Colonization of arbuscular mycorrhizal fungi (AMF) and dark septate endophyte (DSE) or the performance of Helianthella seedlings grown with field‐collected inoculum in a companion greenhouse experiment. However, the proximity of Helianthella to Festuca predicted Fungal Colonization: DSE Colonization decreased by 1% for each cm of distance Helianthella was from Festuca, although the differences in Fungal inoculum potential had no effect on Helianthella seedling survival or biomass. Our results suggest that plant–Fungal interactions can be resistant to N addition and resilient to the loss of dominant plant species. Additionally, our results suggest that soil legacies, mediated through surviving symbiont communities or changes in soil properties, can shape ecosystem resistance and resilience to disturbance and perturbations.
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hemiparasitic plants increase alpine plant richness and evenness but reduce arbuscular mycorrhizal Fungal Colonization in dominant plant species
PeerJ, 2018Co-Authors: Jeremiah A Henning, Michael MckibbenAbstract:Hemiparasitic plants increase plant biodiversity by reducing the abundance of dominant plant species, allowing for the establishment of subordinate species. Hemiparasites reduce host resources by directly removing nutrients from hosts, competing for light and space, and may indirectly reduce host resources by disrupting plant associations with symbiotic root fungi, like arbuscular mycorrhizal fungi and dark-septate endophytes. Here, we explored how a generalist hemiparasite, Castilleja, influences plant richness, evenness, community composition, and mycorrhizal Colonization patterns across a ∼1,000 m elevational gradient in the North American Rocky Mountains. We hypothesized that the presence of Castilleja would be associated with increased plant richness and evenness, shaping plant community composition, and would reduce mycorrhizal Colonization within dominant plant taxa. However, the magnitude of the effects would be contingent upon climate contexts, that is, elevation. Overall, we found that the presence of Castilleja was associated with an 11% increase in plant richness and a 5% increase in plant evenness, regardless of elevation. However, we found that the presence of Castilleja influenced plant composition at only two of the five sites and at the remaining three of five sites, plot pairing was the only predictor that influenced composition. Additionally, we found that the presence of Castilleja reduced mycorrhizal Fungal Colonization within dominant plant species by ∼20%, regardless of elevation. Taken together, our results suggest that hemiparasites regulate plant diversity, evenness, and interactions with mycorrhizal fungi independent of abiotic and biotic contexts occurring at the site, although overall effect on community composition is likely driven by site-level factors.
David A Kaufman - One of the best experts on this subject based on the ideXlab platform.
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patterns of Fungal Colonization in preterm infants weighing less than 1000 grams at birth
Pediatric Infectious Disease Journal, 2006Co-Authors: David A Kaufman, Matthew J Gurka, Kevin C Hazen, Robert J Boyle, Melinda Robinson, Leigh B GrossmanAbstract:Background: Colonization with Candida spp. is an important risk factor for systemic infection in very low birth weight (VLBW; <1500 g) and extremely low birth weight (ELBW, <1000 g) infants. ELBW infants are at a higher risk than VLBW infants for Fungal sepsis and its associated mortality, but few studies have examined Fungal Colonization exclusively in ELBW infants. Methods: Fungal Colonization data were analyzed retrospectively in 50 high risk ELBW infants. Weekly surveillance Fungal cultures of the skin, gastrointestinal tract, respiratory tract and umbilicus had been performed from birth through the first 6 weeks of life. Colonization was analyzed for time of initial Colonization, site, species and spread of Candida from one site to another. Results: Candida was isolated from surveillance cultures in 31 of 50 (62%) infants. Colonization was inversely proportional to gestational age. Initial week of both the Fungal Colonization of the skin [1 (0-6) week, median (range)] and gastrointestinal tract [2 (0-6)] preceded Colonization of the respiratory tract [3 (1-6)] (P = 0.0001). Among infants colonized by only 1 of the species, Colonization at 2 or more sites occurred similarly with Candida albicans (77%) and Candida parapsilosis (85%), whereas Colonization at 3 or more sites occurred more frequently with C. albicans (69%) compared with C. parapsilosis (23%) (P = 0.047). Conclusions: Fungal Colonization occurs on the skin and gastrointestinal tract before the respiratory tract. In addition, C. albicans is more likely than C. parapsilosis to colonize multiple sites.
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fluconazole prophylaxis against Fungal Colonization and infection in preterm infants
The New England Journal of Medicine, 2001Co-Authors: David A Kaufman, Kevin C Hazen, Robert J Boyle, Melinda Robinson, James T Patrie, Leigh Goodman DonowitzAbstract:Background Invasive Fungal infection is associated with substantial morbidity and mortality in preterm infants. We evaluated the efficacy of prophylactic fluconazole in preventing Fungal Colonization and invasive infection in extremely-low-birth-weight infants. Methods We conducted a prospective, randomized, double-blind clinical trial over a 30-month period in 100 preterm infants with birth weights of less than 1000 g. The infants were randomly assigned during the first five days of life to receive either intravenous fluconazole or placebo for six weeks. We obtained weekly surveillance cultures from all patients. Results The 50 infants randomly assigned to fluconazole and the 50 control infants were similar in terms of birth weight, gestational age at birth, and base-line risk factors for Fungal infection. During the six-week treatment period, Fungal Colonization was documented in 30 infants in the placebo group (60 percent) and 11 infants in the fluconazole group (22 percent; difference in risk, 0.38; 9...
Guan Jun - One of the best experts on this subject based on the ideXlab platform.
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risk factors and clinical significance of low respiratory tract Fungal Colonization in patients with ventilator associated pneumonia
Journal of Elinical Research, 2003Co-Authors: Guan JunAbstract:ObjectivesTo survey the risk factors and clinical significance of low respiratory tract Fungal Colonization (LRTFC) in ventilator associated pneumonia (VAP).MethodsThe epidemiological data of LRTFC were collected from fifty three VAP patients who were admitted and treated in our ICU during Jan.1999～Dec.2000. They were divided into Fungal Colonization group and non Fungal Colonization group according to results of fungi culture. Risk factors and their effects on the outcome of VAP patients were compared and analyzed between both groups.ResultsForty nine strains of fungi were isolated from the LRT in 30 out of 53 patients, accounting for 56.6% (30/53) of VAP patients ; 98% of the isolates were Candida species, in which 51% belonged to Candida albicans. There was statistically significant difference in whether potent antibiotics with broad spectrum had been used at prior stage between Fungal Colonization group and non Fungal Colonization group (P=0.006), while no statistically significant differences were found in age, sex, APACHE Ⅱ scores, SAPS Ⅱ scores and whether glucocorticosteroid and antiacid were administered previously. No significant difference also existed in hospital mortality and number of days required for respirator application between both groups.ConclusionLRTFC is quite prevalent in VAP patients. Prior administration of potent antibiotics with broad spectrum is one of main risk factors. LRTFC exerts no distinct effect on essential outcomes of the patients. As for VAP patients without immunodeficiency, it is unnecessary to initiate antiFungal therapy based on the results of LRTFC. Judgment made from other risk factors of invasive Fungal infection and clinical manifestation should be emphasized.
Johannes Rousk - One of the best experts on this subject based on the ideXlab platform.
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bacterial and Fungal Colonization and decomposition of submerged plant litter consequences for biogenic silica dissolution
FEMS Microbiology Ecology, 2016Co-Authors: Hanna Alfredsson, Wim Clymans, Johanna Stadmark, Daniel J Conley, Johannes RouskAbstract:We studied bacterial and Fungal Colonization of submerged plant litter, using a known Si-accumulator (Equisetum arvense), in experimental microcosms during one month. We specifically addressed the microbial decomposer role concerning biogenic silica (bSiO2) dissolution from the degrading litter. To vary the rates and level of microbial Colonization, the litter was combined with a range of mineral nitrogen (N) and phosphorous (P) supplements. Overall microbial growth on plant litter increased with higher levels of N and P. There was a tendency for higher bacterial than Fungal stimulation with higher nutrient levels. Differences in microbial Colonization of litter between treatments allowed us to test how Si remineralization from plants was influenced by microbial litter decomposition. Contrary to previous results and expectations, we observed a general reduction in Si release from plant litter colonized by a microbial community, compared with sterile control treatments. This suggested that microbial growth resulted in a reduction in dissolved Si concentrations, and we discuss candidate mechanisms to explain this outcome. Hence, our results imply that the microbial role in plant litter associated Si turnover is different from that commonly assumed based on bSiO2 dissolution studies in aquatic ecosystems. (Less)
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bacterial and Fungal Colonization and decomposition of submerged plant litter consequences for biogenic silica dissolution
FEMS Microbiology Ecology, 2016Co-Authors: Hanna Alfredsson, Wim Clymans, Johanna Stadmark, Daniel J Conley, Johannes RouskAbstract:We studied bacterial and Fungal Colonization of submerged plant litter, using a known Si-accumulator (Equisetum arvense), in experimental microcosms during one month. We specifically addressed the microbial decomposer role concerning biogenic silica (bSiO2) dissolution from the degrading litter. To vary the rates and level of microbial Colonization, the litter was combined with a range of mineral nitrogen (N) and phosphorous (P) supplements. Overall microbial growth on plant litter increased with higher levels of N and P. There was a tendency for higher relative bacterial than Fungal stimulation with higher nutrient levels. Differences in microbial Colonization of litter between treatments allowed us to test how Si remineralization from plants was influenced by microbial litter decomposition. Contrary to previous results and expectations, we observed a general reduction in Si release from plant litter colonized by a microbial community, compared with sterile control treatments. This suggested that microbial growth resulted in a reduction of dissolved Si concentrations, and we discuss candidate mechanisms to explain this outcome. Hence, our results imply that the microbial role in plant litter associated Si turnover is different from that commonly assumed based on bSiO2 dissolution studies in aquatic ecosystems.
Melinda Robinson - One of the best experts on this subject based on the ideXlab platform.
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patterns of Fungal Colonization in preterm infants weighing less than 1000 grams at birth
Pediatric Infectious Disease Journal, 2006Co-Authors: David A Kaufman, Matthew J Gurka, Kevin C Hazen, Robert J Boyle, Melinda Robinson, Leigh B GrossmanAbstract:Background: Colonization with Candida spp. is an important risk factor for systemic infection in very low birth weight (VLBW; <1500 g) and extremely low birth weight (ELBW, <1000 g) infants. ELBW infants are at a higher risk than VLBW infants for Fungal sepsis and its associated mortality, but few studies have examined Fungal Colonization exclusively in ELBW infants. Methods: Fungal Colonization data were analyzed retrospectively in 50 high risk ELBW infants. Weekly surveillance Fungal cultures of the skin, gastrointestinal tract, respiratory tract and umbilicus had been performed from birth through the first 6 weeks of life. Colonization was analyzed for time of initial Colonization, site, species and spread of Candida from one site to another. Results: Candida was isolated from surveillance cultures in 31 of 50 (62%) infants. Colonization was inversely proportional to gestational age. Initial week of both the Fungal Colonization of the skin [1 (0-6) week, median (range)] and gastrointestinal tract [2 (0-6)] preceded Colonization of the respiratory tract [3 (1-6)] (P = 0.0001). Among infants colonized by only 1 of the species, Colonization at 2 or more sites occurred similarly with Candida albicans (77%) and Candida parapsilosis (85%), whereas Colonization at 3 or more sites occurred more frequently with C. albicans (69%) compared with C. parapsilosis (23%) (P = 0.047). Conclusions: Fungal Colonization occurs on the skin and gastrointestinal tract before the respiratory tract. In addition, C. albicans is more likely than C. parapsilosis to colonize multiple sites.
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fluconazole prophylaxis against Fungal Colonization and infection in preterm infants
The New England Journal of Medicine, 2001Co-Authors: David A Kaufman, Kevin C Hazen, Robert J Boyle, Melinda Robinson, James T Patrie, Leigh Goodman DonowitzAbstract:Background Invasive Fungal infection is associated with substantial morbidity and mortality in preterm infants. We evaluated the efficacy of prophylactic fluconazole in preventing Fungal Colonization and invasive infection in extremely-low-birth-weight infants. Methods We conducted a prospective, randomized, double-blind clinical trial over a 30-month period in 100 preterm infants with birth weights of less than 1000 g. The infants were randomly assigned during the first five days of life to receive either intravenous fluconazole or placebo for six weeks. We obtained weekly surveillance cultures from all patients. Results The 50 infants randomly assigned to fluconazole and the 50 control infants were similar in terms of birth weight, gestational age at birth, and base-line risk factors for Fungal infection. During the six-week treatment period, Fungal Colonization was documented in 30 infants in the placebo group (60 percent) and 11 infants in the fluconazole group (22 percent; difference in risk, 0.38; 9...
