69 research outputs found
Histo-pathology study of the growth of Trichoderma harzianum, Phaeomoniella chlamydospora and Eutypa lata on grapevine pruning wounds
Protecting grapevine pruning wounds by inoculating them with Trichoderma spp. can preventinfection from trunk disease pathogens. The growth and interactions of both, the biological control agent Trichoderma spp. and the vine pathogens, are not well understood. Green fluorescent protein (GFP)-labelled Trichoderma harzianum and red fluorescent protein (DsRed)-labelled T. harzianum, were dual-inoculatedwith Phaeomoniella chlamydospora (DsRed) or Eutypa lata (GFP) on fresh pruning wounds of one-year-oldCabernet Sauvignon and Sauvignon blanc shoots. The inoculated fungi were recovered from varying depthswithin the shoots at 30-day-intervals for 90 days. Trichoderma harzianum suppressed the pathogens and grew deeper in the presence of the pathogens than when it was singly inoculated; possibly an indication of pathogen recognition and competitive response. Eutypa lata was completely eliminated from Sauvignon blancin dual-inoculated canes after 90 days. The mycelium of P. chlamydospora (DsRed) grew extensively in thexylem vessels and possibly contributed to vessel occlusion. Phaeomoniella chlamydospora and E. lata caused blockage of the vessels and thickening of the vessel walls. Grapevine wood produced both tyloses and gums (gels) that blocked xylem vessels as a result of infection. A thickening of the cell walls of xylem fibres occurredonly in E. lata-inoculated shoots, indicative of a different mode of pathogenesis from P. chlamydospora
Imazalil resistance in Penicillium digitatum and P. italicum causing citrus postharvest green and blue mould : impact and options
Citrus green and blue mould, caused by Penicillium digitatum (PD) and Penicillium italicum (PI),
respectively, are mostly controlled by means of postharvest fungicide applications. Currently, IMZ is
regarded as the most effective fungicide in use. Effective IMZ concentrations that inhibit 50% (EC50)
growth of nine PD and
five PI isolates were assessed in vitro and the various isolates categorized according
to their resistance (R) factors. Effective residue levels that provided 50% curative (ER50C) and protective
(ER50P) control of these isolates were determined in vivo. All the PI isolates were sensitive, having EC50
values of 0.005–0.050 mg mL 1. Three PD isolates were sensitive (0.027–0.038 mg mL 1), while one
resistant isolate was categorized as low resistant (R-factor of 19), one as moderately resistant (R-factor of
33.2), three as resistant (R-factor of 50–57.6) and one as highly resistant (R-factor of 70.7). Sensitive PD
isolates had mean ER50C and ER50P values on Valencia orange fruit of 0.29 and 0.20 mg g 1, and 0.33 and
0.32 mg g 1 on navel fruit, respectively. ER50 values for resistant isolates did not always correlate with
EC50 values and ranged from 1.22 to 4.56 mg g 1 for ER50C and 1.00–6.62 mg g 1 for ER50P values. ER50P
values for resistant isolates could not be obtained on navel orange fruit, but ER50C values (1.42–
1.65 mg g 1) were similar to those obtained on Valencia fruit. The PI isolates all behaved similar to the
sensitive PD isolates with ER50C and ER50P values on navel and Valencia fruit <0.38 mg g 1. Alternative
fungicides were assessed for the control of an IMZ sensitive, resistant and highly resistant PD isolate;
these included sodium ortho-phenylpenate (SOPP), thiabendazole (TBZ), guazatine (GZT), imazalil (IMZ),
pyrimethanil (PYR) and Philabuster1 (PLB; a combination of IMZ and PYR),
fludioxonil (FLU),
azoxystrobin (AZO), Graduate1A+ (GRA; a combination of FLU and AZO) and propiconazole (PPZ).
Multiple fungicide resistance was shown to IMZ, GZT, TBZ and PPZ in both resistant isolates. For the
sensitive isolates, IMZ, SOPP, TBZ, GZT and PLB provided best curative control, while IMZ, GZT and PLB
provided best protective control. For the IMZ-resistant isolates, SOPP, PYR and PLB gave the best curative
control, while none of the fungicides provided adequate protective control.Citrus Research International, Citrus Academy, Postharvest Innovation Fund (PHI)
and Technology and Human Resources for Industry Programme (THRIP).http://www.elsevier.com/locate/postharvbio2016-09-30hb201
Influence of water stress on Botryosphaeriaceae disease expression in grapevines
Several species in Botryosphaeriaceae have been associated with grapevine trunk diseases. To evaluate the effect of water stress on infection of grapevines by Botryosphaeriaceae spp., 1-year-old Shiraz/101-14 Mgt nursery grapevine plants were planted in plastic potting bags and placed outdoors under shade netting. Five weeks after planting, vines were pruned and the pruning wounds inoculated with spore suspensions of Neofusicoccum australe, Neofusicoccum parvum, Lasiodiplodia theobromae or Diplodia seriata. Control treatments consisted of applications of sterile water or a Trichoderma harzianum spore suspension. Stem inoculations were done by inserting a colonised or uncolonised agar plug into a wound made in each stem. Four different irrigation regimes were introduced 12 weeks after planting to simulate varying degrees of water stress. Measurements of stomatal conductance, photosynthetic rate and leaf spectrometry were made to monitor physiological stress. Eight months after inoculation, vines were uprooted and the root, shoot and plant mass of each vine determined. Lesions observed in the inoculated pruning wounds and stems were also measured. Vines subjected to the lowest irrigation regime were significantly smaller than optimally irrigated vines. Water stressed vines also had significantly lower photosynthetic rates and levels of stomatal conductance compared with vines receiving optimal irrigation, indicating that these plants experienced significantly higher levels of physiological stress. The mean lesion length was significantly longer in the pruning wounds and stems of plants subjected to the lowest irrigation regime, with lesion length declining linearly with increasing irrigation volume. These results clearly indicate that when a grapevine is exposed to water stress, colonisation and disease expression by Botryosphaeriaceae spp. are much more severe
Estimation of introduction and transmission rates of SARS-CoV-2 in a prospective household study
Household studies provide an efficient means to study transmission of infectious diseases, enabling estimation of susceptibility and infectivity by person-type. A main inclusion criterion in such studies is usually the presence of an infected person. This precludes estimation of the hazards of pathogen introduction into the household. Here we estimate age- and time-dependent household introduction hazards together with within household transmission rates using data from a prospective household-based study in the Netherlands. A total of 307 households containing 1, 209 persons were included from August 2020 until March 2021. Follow-up of households took place between August 2020 and August 2021 with maximal follow-up per household mostly limited to 161 days. Almost 1 out of 5 households (59/307) had evidence of an introduction of SARS-CoV-2. We estimate introduction hazards and within-household transmission rates in our study population with penalized splines and stochastic epidemic models, respectively. The estimated hazard of introduction of SARS-CoV-2 in the households was lower for children (0-12 years) than for adults (relative hazard: 0.62; 95%CrI: 0.34-1.0). Estimated introduction hazards peaked in mid October 2020, mid December 2020, and mid April 2021, preceding peaks in hospital admissions by 1-2 weeks. Best fitting transmission models included increased infectivity of children relative to adults and adolescents, such that the estimated child-to-child transmission probability (0.62; 95%CrI: 0.40-0.81) was considerably higher than the adult-to-adult transmission probability (0.12; 95%CrI: 0.057-0.19). Scenario analyses indicate that vaccination of adults can strongly reduce household infection attack rates and that adding adolescent vaccination offers limited added benefit
Estimation of introduction and transmission rates of SARS-CoV-2 in a prospective household study
Household studies provide an efficient means to study transmission of infectious diseases, enabling estimation of individual susceptibility and infectivity. A main inclusion criterion in such studies is often the presence of an infected person. This precludes estimation of the hazards of pathogen introduction into the household. Here we use data from a prospective household-based study to estimate SARS-CoV-2 age- and time-dependent household introduction hazards together with within household transmission rates in the Netherlands from August 2020 to August 2021. Introduction hazards and within-household transmission rates are estimated with penalized splines and stochastic epidemic models, respectively. The estimated hazard of introduction of SARS-CoV-2 in the households was lower for children (0-12 years) than for adults (relative hazard: 0.62; 95%CrI: 0.34-1.0). Estimated introduction hazards peaked in mid October 2020, mid December 2020, and mid April 2021, preceding peaks in hospital admissions by 1-2 weeks. The best fitting transmission models include increased infectivity of children relative to adults and adolescents, such that the estimated child-to-child transmission probability (0.62; 95%CrI: 0.40-0.81) was considerably higher than the adult-to-adult transmission probability (0.12; 95%CrI: 0.057-0.19). Scenario analyses show that vaccination of adults could have strongly reduced infection attack rates in households and that adding adolescent vaccination would have offered limited added benefit
Use of beneficial bacteria and their secondary metabolites to control grapevine pathogen diseases
Grapevine is one of the most important economic crops yielding berries, wine products as well as derivates. However, due to the large array of pathogens inducing diseases on this plant, considerable
amounts of pesticides—with possible negative impact on the environment and health—have been used and are currently used in viticulture. To avoid negative impacts of such products and to ensure product quality, a substantial fraction of pesticides needs to be replaced in the near future. One solution can be related to the use of beneficial bacteria inhabiting the rhizo- and/or the endosphere of plants. These biocontrol bacteria and their secondary metabolites can reduce directly or indirectly pathogen diseases by affecting pathogen performance by antibiosis, competition for niches and nutrients, interference with pathogen signaling or by stimulation of host plant defenses. Due to the large demand for biocontrol of grapevine diseases, such biopesticides, their modes of actions and putative consequences of their uses need to be described. Moreover, the current knowledge on new strains from the rhizo- and endosphere and their metabolites that can be used on grapevine plants to counteract pathogen attack needs to be discussed. This is in particular with regard to the control of root rot, grey mould, trunk diseases, powdery and downy mildews, pierce’s disease, grapevine yellows as well as crown gall. Future prospects on specific beneficial microbes and their secondary metabolites that can be used as elicitors of plant defenses and/or as biocontrol agents with potential use in a more sustainable viticulture will be further discussed
Semaglutide and cardiovascular outcomes in patients with obesity and prevalent heart failure: a prespecified analysis of the SELECT trial
Background: Semaglutide, a GLP-1 receptor agonist, reduces the risk of major adverse cardiovascular events (MACE) in people with overweight or obesity, but the effects of this drug on outcomes in patients with atherosclerotic cardiovascular disease and heart failure are unknown. We report a prespecified analysis of the effect of once-weekly subcutaneous semaglutide 2·4 mg on ischaemic and heart failure cardiovascular outcomes. We aimed to investigate if semaglutide was beneficial in patients with atherosclerotic cardiovascular disease with a history of heart failure compared with placebo; if there was a difference in outcome in patients designated as having heart failure with preserved ejection fraction compared with heart failure with reduced ejection fraction; and if the efficacy and safety of semaglutide in patients with heart failure was related to baseline characteristics or subtype of heart failure. Methods: The SELECT trial was a randomised, double-blind, multicentre, placebo-controlled, event-driven phase 3 trial in 41 countries. Adults aged 45 years and older, with a BMI of 27 kg/m2 or greater and established cardiovascular disease were eligible for the study. Patients were randomly assigned (1:1) with a block size of four using an interactive web response system in a double-blind manner to escalating doses of once-weekly subcutaneous semaglutide over 16 weeks to a target dose of 2·4 mg, or placebo. In a prespecified analysis, we examined the effect of semaglutide compared with placebo in patients with and without a history of heart failure at enrolment, subclassified as heart failure with preserved ejection fraction, heart failure with reduced ejection fraction, or unclassified heart failure. Endpoints comprised MACE (a composite of non-fatal myocardial infarction, non-fatal stroke, and cardiovascular death); a composite heart failure outcome (cardiovascular death or hospitalisation or urgent hospital visit for heart failure); cardiovascular death; and all-cause death. The study is registered with ClinicalTrials.gov, NCT03574597. Findings: Between Oct 31, 2018, and March 31, 2021, 17 604 patients with a mean age of 61·6 years (SD 8·9) and a mean BMI of 33·4 kg/m2 (5·0) were randomly assigned to receive semaglutide (8803 [50·0%] patients) or placebo (8801 [50·0%] patients). 4286 (24·3%) of 17 604 patients had a history of investigator-defined heart failure at enrolment: 2273 (53·0%) of 4286 patients had heart failure with preserved ejection fraction, 1347 (31·4%) had heart failure with reduced ejection fraction, and 666 (15·5%) had unclassified heart failure. Baseline characteristics were similar between patients with and without heart failure. Patients with heart failure had a higher incidence of clinical events. Semaglutide improved all outcome measures in patients with heart failure at random assignment compared with those without heart failure (hazard ratio [HR] 0·72, 95% CI 0·60-0·87 for MACE; 0·79, 0·64-0·98 for the heart failure composite endpoint; 0·76, 0·59-0·97 for cardiovascular death; and 0·81, 0·66-1·00 for all-cause death; all pinteraction>0·19). Treatment with semaglutide resulted in improved outcomes in both the heart failure with reduced ejection fraction (HR 0·65, 95% CI 0·49-0·87 for MACE; 0·79, 0·58-1·08 for the composite heart failure endpoint) and heart failure with preserved ejection fraction groups (0·69, 0·51-0·91 for MACE; 0·75, 0·52-1·07 for the composite heart failure endpoint), although patients with heart failure with reduced ejection fraction had higher absolute event rates than those with heart failure with preserved ejection fraction. For MACE and the heart failure composite, there were no significant differences in benefits across baseline age, sex, BMI, New York Heart Association status, and diuretic use. Serious adverse events were less frequent with semaglutide versus placebo, regardless of heart failure subtype. Interpretation: In patients with atherosclerotic cardiovascular diease and overweight or obesity, treatment with semaglutide 2·4 mg reduced MACE and composite heart failure endpoints compared with placebo in those with and without clinical heart failure, regardless of heart failure subtype. Our findings could facilitate prescribing and result in improved clinical outcomes for this patient group. Funding: Novo Nordisk
Fungal Planet description sheets : 320–370
Novel species of fungi described in the present study include the following from Malaysia: Castanediella
eucalypti from Eucalyptus pellita, Codinaea acacia from Acacia mangium, Emarcea eucalyptigena from Eucalyptus
brassiana, Myrtapenidiella eucalyptorum from Eucalyptus pellita, Pilidiella eucalyptigena from Eucalyptus brassiana
and Strelitziana malaysiana from Acacia mangium. Furthermore, Stachybotrys sansevieriicola is described from
Sansevieria ehrenbergii (Tanzania), Phacidium grevilleae from Grevillea robusta (Uganda), Graphium jumulu from
Adansonia gregorii and Ophiostoma eucalyptigena from Eucalyptus marginata (Australia), Pleurophoma ossicola from
bone and Plectosphaerella populi from Populus nigra (Germany), Colletotrichum neosansevieriae from Sansevieria
trifasciata, Elsinoë othonnae from Othonna quinquedentata and Zeloasperisporium cliviae (Zeloasperisporiaceae
fam. nov.) from Clivia sp. (South Africa), Neodevriesia pakbiae, Phaeophleospora hymenocallidis and Phaeophleospora
hymenocallidicola on leaves of a fern (Thailand), Melanconium elaeidicola from Elaeis guineensis (Indonesia),
Hormonema viticola from Vitis vinifera (Canary Islands), Chlorophyllum pseudoglobossum from a grassland (India),
Triadelphia disseminata from an immunocompromised patient (Saudi Arabia), Colletotrichum abscissum from Citrus
(Brazil), Polyschema sclerotigenum and Phialemonium limoniforme from human patients (USA), Cadophora vitícola
from Vitis vinifera (Spain), Entoloma flavovelutinum and Bolbitius aurantiorugosus from soil (Vietnam), Rhizopogon
granuloflavus from soil (Cape Verde Islands), Tulasnella eremophila from Euphorbia officinarum subsp. echinus
(Morocco), Verrucostoma martinicensis from Danaea elliptica (French West Indies), Metschnikowia colchici from
Colchicum autumnale (Bulgaria), Thelebolus microcarpus from soil (Argentina) and Ceratocystis adelpha from
Theobroma cacao (Ecuador). Myrmecridium iridis (Myrmecridiales ord. nov., Myrmecridiaceae fam. nov.) is also
described from Iris sp. (The Netherlands). Novel genera include (Ascomycetes): Budhanggurabania from Cynodon
dactylon (Australia), Soloacrosporiella, Xenocamarosporium, Neostrelitziana and Castanediella from Acacia mangium
and Sabahriopsis from Eucalyptus brassiana (Malaysia), Readerielliopsis from basidiomata of Fuscoporia wahlbergii
(French Guyana), Neoplatysporoides from Aloe ferox (Tanzania), Wojnowiciella, Chrysofolia and Neoeriomycopsis
from Eucalyptus (Colombia), Neophaeomoniella from Eucalyptus globulus (USA), Pseudophaeomoniella from Olea
europaea (Italy), Paraphaeomoniella from Encephalartos altensteinii, Aequabiliella, Celerioriella and Minutiella from
Prunus (South Africa). Tephrocybella (Basidiomycetes) represents a novel genus from wood (Italy). Morphological
and culture characteristics along with ITS DNA barcodes are provided for all taxa.Alina V. Alexandrova was supported by the Russian Science
Foundation (project N 14-50-00029). Ekaterina F. Malysheva, Olga V.
Morozova,
Alexander E. Kovalenko and Eugene S. Popov acknowledge
financial support from the Russian Foundation for Basic Research (project
13-04-00838a and 15-04-04645a). Margarita Dueñas, María P. Martín and
M. Teresa Telleria acknowledge financial support from the Plan Nacional I+D+I
projects No. CGL2009-07231 and CGL2012-3559. Cony Decock gratefully acknowledges the financial support received from
the FNRS / FRFC (convention FRFC 2.4544.10), the CNRS-French Guiana
and the Nouragues staff, which enabled fieldwork in French Guiana, and the
Belgian State – Belgian Federal Science Policy through the BCCMTM research
programme.http://www.ingentaconnect.com/content/nhn/pimjam201
Household, community, sub-national and country-level predictors of primary cooking fuel switching in nine countries from the PURE study
Introduction. Switchingfrom polluting (e.g. wood, crop waste, coal)to clean (e.g. gas, electricity) cooking
fuels can reduce household air pollution exposures and climate-forcing emissions.While studies have
evaluated specific interventions and assessed fuel-switching in repeated cross-sectional surveys, the role
of different multilevel factors in household fuel switching, outside of interventions and across diverse
community settings, is not well understood. Methods.We examined longitudinal survey data from
24 172 households in 177 rural communities across nine countries within the Prospective Urban and
Rural Epidemiology study.We assessed household-level primary cooking fuel switching during a
median of 10 years offollow up (∼2005–2015).We used hierarchical logistic regression models to
examine the relative importance of household, community, sub-national and national-level factors
contributing to primary fuel switching. Results. One-half of study households(12 369)reported
changing their primary cookingfuels between baseline andfollow up surveys. Of these, 61% (7582)
switchedfrom polluting (wood, dung, agricultural waste, charcoal, coal, kerosene)to clean (gas,
electricity)fuels, 26% (3109)switched between different polluting fuels, 10% (1164)switched from clean
to polluting fuels and 3% (522)switched between different clean fuels
- …