Erinevate kasvatustehnoloogiate mõju Fusarium spp. esinemisele ja mükotoksiinide tekkimisele teraviljadel

A Thesis for applying for the degree of Doctor of Philosophy in Agriculture.Microbiological and toxicological purity are important one indicators of the quality of cereals. Albeit the content of fusariosis and mycotoxins in the food cereals is not permitted, the feed grain may contain 0.1% Fusarium spp. grains and the levels of mycotoxins may not exceed the maximum levels established in the European Union. Earlier, in 1973–1992, the monitoring of cereal yields conducted by Lõiveke Heino showed that more than 79% of the samples contained grains infected with Fusarium fungi, and on average 54% of the samples monitored in 1998–2007 were infected with mycotoxins in Estonia. The results of several countries scientific studies show that agronomic techniques such as crop rotation, cultivation technology, fertilization, pesticide use, as well as the type and variety of cereals and weather conditions affect the spread of Fusarium fungi under field conditions and the formation of mycotoxins in grains. Until now, there was a lack of knowledge about the extent to which the cultivation technologies affect the Fusarium infestation and mycotoxin contamination of cereals in the Northern Baltic region. Thus, the following hypotheses were set in this dissertation: 1) that the use of barley-pea intercropping technology would reduce the infestation of Fusarium fungi on grain; 2) that the nitrogen fertilization of spring barley would increase the abundance of moulds, yeasts and Fusarium fungi on the grain; 3) the spraying with fungicide in flowering time reduce the incidence of Fusarium fungi, and the formation of mycotoxins DON, HT-2 and T-2 in the barley grains; 4) that the capacity of Fusarium spp. to produce mycotoxins depend on the available carbon and nitrogen sources and affected by environmental conditions. The results of this dissertation showed that the location of the field, the cultivation technology and the weather had a very strong effect on the occurrence of moulds, including Fusarium fungi, on cereals grains. However, the environment and the structure of carbon and nitrogen affected the formation of mycotoxins in the grains. Thus, the suitable cereal growing technologies enable to reduce the contamination of cereals with Fusarium fungi and mycotoxins in the northern climate conditions.Teraviljade kvaliteedi olulisteks näitajateks on teiste hulgas ka mikrobioloogiline ja toksikoloogiline puhtus. Kui toiduviljas ei ole fusarioossete seente ja mükotoksiinide sisaldus lubatud, siis söödavili võib sisaldada 0,1% fusariooseid teri, kuid mükotoksiinide sisaldus ei tohi ületada Euroopa Liidus kehtestatud maksimaalseid piirmäärasid. Varasemalt, aastatel 1973–1992, Lõiveke Heino poolt Eestis läbi viidud teraviljade saagi monitooring näitas, et üle 79% proovides esines Fusarium seentega nakatunud terasid ning aastatel 1998–2007 monitooritud teraviljast oli mükotoksiinidega saastunud keskmiselt 54% proovidest. Teistes riikides tehtud teadusuuringute tulemused näitavad, et agronoomilised võtted, nagu külvikord, harimistehnoloogia, väetamine, pestitsiidide kasutamine, aga samuti teravilja liik ja sort ning ilmastikutingimused, mõjutavad olulisel määral Fusarium seente levimist ja mükotoksiinide tekkimist teradesse. Siiani puudusid Põhja-Baltikumi piirkonda sobivad teadmised kui olulisel määral meie agroklimaatilistes tingimustes kasvatustehnoloogilised võtted mõjutavad teraviljade Fusarium seentega nakatumist ja mükotoksiinidega saastumist. Seega seati käesolevas doktoritöös järgmised hüpoteesid: 1) odra-herne segukülvi tehnoloogia kasutamine võimaldab vähendada terade Fusarium seentega nakatumist; 2) ilmastik, põllu asukoht ja taimedele antud lämmastiku kogused mõjutavad oluliselt hallitus-, pärmseente ja Fusarium seente arvukust teradel; 3) teravilja õitsemiseaegne pritsimine fungitsiidiga vähendab Fusarium seente esinemist ja vähendab mükotoksiinide DON, HT2 ja T2 tekkimist teradesse; 4) Fusarium seente mükotoksiinide tootmine on mõjutatud keskkonna tingimustest ja süsiniku ning lämmastiku päritolust. Doktoritöö tulemustest selgus, et põllu asukoht, kasvatustehnoloogia ja ilmastik avaldasid väga tugevat mõju hallitusseente, sealhulgas Fusarium spp. esinemisele teradel. Kuid mükotoksiinide tekkimine teradesse oli seotud ilmastikuga, keskkonna happesusega ja selles oleva süsiniku ning lämmastiku struktuuriga. Seega Põhjamaade ilmastikku sobiva teravilja kasvatustehnoloogia valikuga on võimalik vähendada saagi saastumist Fusarium seentega ja mükotoksiinidega.Publication of this thesis is supported by the Estonian University of Life Sciences

Effect of Proteolytic Processing at Two Distinct Sites on Shape and Aggregation of an Anchorless Fusion Protein of Human Respiratory Syncytial Virus and Fate of the Intervening Segment

AbstractWe have examined the consequences of cleaving the fusion glycoprotein (F) of human respiratory syncytial virus (HRSV) at two distinct furin-recognition sites. Purified anchorless F is a mixture of unaggregated cone-shaped molecules and rosettes of lollipop-shaped spikes. The unaggregated molecules contain a proportion of uncleaved F0 and an intermediate, FΔ1–109, cleaved only at site I, residues 106–109. Inhibition of cleavage at site I, by two amino acid changes (R108N/R109N), reduces the proportion of aggregated molecules with a concomitant increase in the amount of unprocessed F0. Inhibition of cleavage at site II, residues 131–136, by deletion of four amino acids (Δ131–134), abrogates aggregation of anchorless F and all molecules are seen as individual cone-shaped rods. In vitro cleavage of anchorless F, or mutant Δ131–134, with trypsin at 4, 20, or 37°C, under conditions in which cleavage at site II is complete in all molecules, leads to their aggregation in rosettes of lollipop-shaped spikes. Thus, cleavage at site II is required for the structural changes in anchorless F that lead to changes in shape and to aggregation. The segment between sites I and II, residues 110–136, is not associated with anchorless F in the supernatant of infected cell cultures, indicating that it is released from the processed protein when cleavage at sites I and II is completed

One-way trip: Influenza virus' adaptation to gallinaceous poultry may limit its pandemic potential

We hypothesise that some influenza virus adaptations to poultry may explain why the barrier for human-to-human transmission is not easily overcome once the virus has crossed from wild birds to chickens. Since the cluster of human infections with H5N1 influenza in Hong Kong in 1997, chickens have been recognized as the major source of avian influenza virus infection in humans. Although often severe, these infections have been limited in their subsequent human-to-human transmission, and the feared H5N1 pandemic has not yet occurred. Here we examine virus adaptations selected for during replication in chickens and other gallinaceous poultry. These include altered receptor binding and increased pH of fusion of the haemagglutinin as well as stalk deletions of the neuraminidase protein. This knowledge could aid the delivery of vaccines and increase our ability to prioritize research efforts on those viruses from the diverse array of avian influenza viruses that have greatest human pandemic potential

Data and product needs for influenza immunization programs in low- and middle-income countries: Rationale and main conclusions of the WHO preferred product characteristics for next-generation influenza vaccines.

In 2017, WHO convened a working group of global experts to develop the Preferred Product Characteristics (PPC) for Next-Generation Influenza Vaccines. PPCs are intended to encourage innovation in vaccine development. They describe WHO preferences for parameters of vaccines, in particular their indications, target groups, implementation strategies, and clinical data needed for assessment of safety and efficacy. PPCs are shaped by the global unmet public health need in a priority disease area for which WHO encourages vaccine development. These preferences reflect WHO's mandate to promote the development of vaccines with high public health impact and suitability in Low- and Middle-Income Countries (LMIC). The target audience is all entities intending to develop or to achieve widespread adoption of a specific influenza vaccine product in these settings. The working group determined that existing influenza vaccines are not well suited for LMIC use. While many developed country manufactures and research funders prioritize influenza vaccine products for use in adults and the elderly, most LMICs do not have sufficiently strong health systems to deliver vaccines to these groups. Policy makers from LMICs are expected to place higher value on vaccines indicated for prevention of severe illness, however the clinical development of influenza vaccines focuses on demonstrating prevention of any influenza illness. Many influenza vaccine products do not meet WHO standards for programmatic suitability of vaccines, which introduces challenges when vaccines are used in low-resource settings. And finally, current vaccines do not integrate well with routine immunization programs in LMICs, given age of vaccine licensure, arbitrary expiration dates timed for temperate country markets, and the need for year-round immunization in countries with prolonged influenza seasonality. While all interested parties should refer to the full PPC document for details, in this article we highlight data needs for new influenza vaccines to better demonstrate the value proposition in LMICs

Evaluation of combined live, attenuated respiratory syncytial virus and parainfluenza 3 virus vaccines in infants and young children

© 2004 by the Infectious Diseases Society of America. All rights reserved.We evaluated a combination respiratory syncytial virus (RSV) and parainfluenza 3 virus (PIV3) live, attenuated intranasal vaccine for safety, viral replication, and immunogenicity in doubly seronegative children 6–18 months old. RSV cpts-248/404 and PIV3-cp45 vaccines were combined in a dose of 105 plaque-forming units of each per 0.5-mL dose and compared with monovalent vaccines or placebo. The virus shedding pattern of RSV was not different between monovalent RSV cpts-248/404 vaccine and combination vaccine. Modest reductions in the shedding of PIV3-cp45 vaccine virus were found after the administration of RSV cpts-248/404 and PIV3-cp45 vaccine, relative to monovalent PIV3 vaccine; 16 (76%) of 21 children given combination vaccine shed PIV3-cp45 versus 11 (92%) of 12 of those given monovalent PIV3 vaccine. Both vaccines were immunogenic, and antibody responses were similar between the monovalent groups and the combination group. Combined RSV/PV3 vaccine is feasible for simultaneous administration, and further studies are warranted.Robert B. Belshe, Frances K. Newman, Edwin L. Anderson, Peter F. Wright, Ruth A. Karron,Sharon Tollefson, Frederick W. Henderson, H. Cody Meissner, Shabir Madhi, Don Roberton, Helen Marshall,Richard Loh, Peter Sly, Brian Murphy, Joanne M. Tatem, Valerie Randolph, Jill Hackell, William Gruber and Theodore F. Tsa

Interspecific Competition for Pollination Lowers Seed Production and Outcrossing in Mimulus Ringens

Sympatric plant species with similar flowering phenologies and floral morphologies may compete for pollination, and as a consequence potentially influence each other\u27s reproductive success and mating system. Two likely competitors are Mimulus ringens and Lobelia siphilitica, which co-occur in wet meadows of central and eastern North America, produce blue zygomorphic flowers, and share several species of bumble bee pollinators. To test for effects of competition for pollination, we planted experimental arrays of Mimulus ringens, each consisting of genets with unique combinations of homozygous marker genotypes. In two arrays we planted mixtures of Mimulus and Lobelia. and in two additional arrays we planted Mimulus without a competitor for pollination. Bumble bee pollinators frequently moved between Mimulus and Lobelia flowers in the mixed-species arrays, with 42% of plant-to-plant movements being interspecific transitions. Pollinator movements between species were associated with a reduction in the amount of conspecific pollen arriving on Mimulus stigmas. The presence of Lobelia led to a significant 37% reduction in the mean number of Mimulus seeds per fruit. In addition, Mimulus had a significantly lower rate of outcrossing in the mixed-species arrays (0.43) than in the pure arrays (0.63). This is the first study to demonstrate that competition for pollination directly influences outcrossing rates. Our work suggests that in self-compatible populations with genetic load, competition for pollination may not only reduce seed quantity, but may also lower seed quality

Assessing a Rare and Serious Adverse Event Following Administration of the Ad26.COV2.S Vaccine

In this issue of JAMA, See and colleagues present a case series of patients with cerebral venous sinus thrombosis (CVST) following vaccination with the Ad26.COV2.S vaccine manufactured by Janssen/Johnson & Johnson. These cases were identified through the Vaccine Adverse Event Reporting System (VAERS), a national vaccine safety surveillance program of the Centers for Disease Control and Prevention (CDC) and the Food and Drug Administration (FDA)

Bronchiolitis: an update on management and prophylaxis.

Bronchiolitis is an acute respiratory illness that is the leading cause of hospitalization in young children less than 2 years of age in the UK. Respiratory syncytial virus is the most common virus associated with bronchiolitis and has the highest disease severity, mortality and cost. Bronchiolitis is generally a self-limiting condition, but can have serious consequences in infants who are very young, premature, or have underlying comorbidities. Management of bronchiolitis in the UK is guided by the National Institute for Health and Care Excellence (2015) guidance. The mainstays of management are largely supportive, consisting of fluid management and respiratory support. Pharmacological interventions including nebulized bronchodilators, steroids and antibiotics generally have limited or no evidence of efficacy and are not advised by National Institute of Health and Care Excellence. Antiviral therapeutics remain in development. As treatments are limited, there have been extensive efforts to develop vaccines, mainly targeting respiratory syncytial virus. At present, the only licensed product is a monoclonal antibody for passive immunisation. Its cost restricts its use to those at highest risk. Vaccines for active immunisation of pregnant women and young infants are also being developed