Impact of predicted climate change environmental conditions on the growth of Fusarium asiaticum strains and mycotoxins production on a wheat-based matrix

Fusarium asiaticum is a predominant fungal pathogen causing Fusarium Head Blight (FHB) in wheat and barley in China and is associated with approximately £201 million in annual losses due to grains contaminated with mycotoxins. F. asiaticum produces deoxynivalenol and zearalenone whose maximum limits in cereals and cereals-derived products have been established in different countries including the EU. Few studies are available on the ecophysiological behaviour of this fungal pathogen, but nothing is known about the impact of projected climate change scenarios on its growth and mycotoxin production. Therefore, this study aimed to examine the interacting effect of i) current and increased temperature (25 vs 30 °C), ii) drought stress variation (0.98 vs 0.95 water activity; aw) and iii) existing and predicted CO2 concentrations (400 vs 1000 ppm) on fungal growth and mycotoxin production (type B trichothecenes and zearalenone) by three F. asiaticum strains (CH024b, 82, 0982) on a wheat-based matrix after 10 days of incubation. The results showed that, when exposed to increased CO2 concentration (1000 ppm) there was a significant reduction of fungal growth compared to current concentration (400 ppm) both at 25 and 30 °C, especially at 0.95 aw. The multi-mycotoxin analysis performed by LC-MS/MS qTRAP showed a significant increase of deoxynivalenol and 15-acetyldeoxynivalenol production when the CH024b strain was exposed to elevated CO2 compared to current CO2 levels. Zearalenone production by the strain 0982 was significantly stimulated by mild water stress (0.95 aw) and increased CO2 concentration (1000 ppm) regardless of the temperature. Such results highlight that intraspecies variability exist among F. asiaticum strains with some mycotoxins likely to exceed current EU legislative limits under prospected climate change conditions.

Biocontrol activities of yeasts or lactic acid bacteria isolated from Robusta coffee against Aspergillus carbonarius growth and ochratoxin A production in vitro

Biocontrol Agents (BCAs) can be an eco-friendly alternative to fungicides to reduce the contamination with mycotoxigenic fungi on coffee. In the present study, different strains of bacteria and yeasts were isolated from Ivorian Robusta coffee. Their ability to reduce fungal growth and Ochratoxin A (OTA) production during their confrontation against Aspergillus carbonarius was screened on solid media. Some strains were able to reduce growth and OTA production by 85 % and 90 % and were molecularly identified as two yeasts, Rhodosporidiobolus ruineniae and Meyerozyma caribbica. Subsequent tests on liquid media with A. carbonarius or solely with OTA revealed adhesion of R. ruineniae to the mycelium of A. carbonarius through Scanning Electron Microscopy, and an OTA adsorption efficiency of 50 %. For M. caribbica potential degradation of OTA after 24 h incubation was observed. Both yeasts could be potential BCAs good candidates for Ivorian Robusta coffee protection against A. carbonarius and OTA contamination.

Impact of Environmental Conditions on the Concentrations of Trichothecenes, Their Glucosides, and Emerging Fusarium Toxins in Naturally Contaminated, Irradiated, and Fusarium langsethiae Inoculated Oats

Trichothecenes produced by Fusarium species are commonly detected in oats. However, the ratios of the concentrations of free trichothecenes and their conjugates and how they are impacted by different interacting environmental conditions are not well documented. This study aims to examine the effect of water activity (0.95 and 0.98 aw) and temperature (20 and 25 °C) stress on the production of T-2 and HT-2 toxins, deoxynivalenol and their conjugates, as well as diacetoxyscirpenol (DAS). Multiple mycotoxins were detected using liquid chromatography-tandem mass spectrometry from 64 contaminated oat samples. The highest concentrations of HT-2-glucoside (HT-2-Glc) were observed at 0.98 aw and 20 °C, and were higher than other type A trichothecenes in the natural oats' treatments. However, no statistical differences were found between the mean concentrations of HT-2-Glc and HT-2 toxins in all storage conditions analysed. DAS concentrations were generally low and highest at 0.95 aw and 20 °C, while deoxynivalenol-3-glucoside levels were highest at 0.98 aw and 20 °C in the naturally contaminated oats. Emerging mycotoxins such as beauvericin, moniliformin, and enniatins mostly increased with a rise in water activity and temperature in the naturally contaminated oats treatment. This study reinforces the importance of storage aw and temperature conditions in the high risk of free and modified toxin contamination of small cereal grains.

Observation of high-energy neutrinos from the Galactic plane

The origin of high-energy cosmic rays, atomic nuclei that continuously impact Earth's atmosphere, is unknown. Because of deflection by interstellar magnetic fields, cosmic rays produced within the Milky Way arrive at Earth from random directions. However, cosmic rays interact with matter near their sources and during propagation, which produces high-energy neutrinos. We searched for neutrino emission using machine learning techniques applied to 10 years of data from the IceCube Neutrino Observatory. By comparing diffuse emission models to a background-only hypothesis, we identified neutrino emission from the Galactic plane at the 4.5σ level of significance. The signal is consistent with diffuse emission of neutrinos from the Milky Way but could also arise from a population of unresolved point sources.

Acclimatisation of Fusarium langsethiae, F. poae and F. sporotrichioides to elevated CO2: Impact on fungal growth and mycotoxin production on oat-based media

Oats are highly susceptible to infection by Fusarium species, especially F. langsethiae, F. poae and F. sporotrichioides which contaminate the grain with mycotoxins. Climate change is expected to affect fungal colonisation and associated mycotoxin production. The objective of this study was to examine the effect of acclimatisation to elevated CO₂ on the growth and mycotoxin production capacity of these fungal species. Strains of F. langsethiae (FL; seven strains), F. poae (FP; two strains) and F. sporotrichioides (FS; one strain) were acclimatised by sub-culturing for 10 generations at either 400 or 1000 ppm CO₂ under diurnal temperature conditions. At each sub-culturing, the effect of acclimatisation to elevated CO₂ on (a) lag phase prior to growth, (b) growth rate on oat-based media was assessed. Additionally, the production of type A trichothecenes and related toxic secondary metabolites of sub-cultures after 1, 7 and 10 generations were assessed using LC-MS/MS qTRAP. The results showed that Fusarium strains had an increased lag time and growth rate in response to the combined effect of sub-culturing and elevated CO₂ levels. T-2 + HT-2 production was affected by elevated CO₂ in strain FL4 (7.1-fold increase) and a decrease in strain FL1 (2.0-fold decrease) at the first sub-culturing and FS (1.3-fold decrease) after 7 sub-cultures compared to ambient conditions. The effect of sub-culturing on T-2 + HT-2 production varied depending on the fungal strain. For strain FL4, significantly less T-2 + HT-2 toxins were produced after 10 generations (4.4-fold decrease) as compared to that under elevated CO₂ conditions after one sub-culture, and no change was observed under ambient conditions. The FS strain showed significant stimulation of T-2 + HT-2 toxin production after 10 sub-cultured generations (1.1-fold increase) compared to the initial sub-culture of this strain under elevated CO₂ conditions. The production of other toxic secondary metabolites was generally not impacted by elevated CO₂ conditions or by sub-culture for 10 generations, with the exceptions of FL1 and FP1. FL1 produced significantly more neosolaniol after 10 generations, when compared to those after 1 and 7, regardless of the CO₂ conditions. For FP1, elevated CO₂ significantly triggered beauvericin production after an initial sub-culture when compared to ambient conditions at the same sub-culture stage (29-fold). FP1 acclimatisation to elevated CO₂ led to a decrease of beauvericin production after 10 generations when compared to 1 (6-fold). In contrast, sub-culturing for 10 generations compared to 1 under ambient CO₂ conditions resulted in an increase in this toxin (12-fold).

Born into an isolating world: family-centred care for babies born to mothers with COVID-19

BACKGROUND

The benefits of facilitating breastmilk feeding and close contact between mother and neonate (family-centred care; FCC) in the perinatal period are well-established. The aim of this study was to determine how the delivery of FCC practices were impacted for neonates born to mothers with perinatal SARS-CoV-2 infection during the COVID-19 pandemic.

METHODS

Neonates born to mothers with confirmed SARS-CoV-2 infection during pregnancy were identified from the 'EsPnIC Covid paEdiatric NeonaTal REgistry' (EPICENTRE) multinational cohort between 10 March 2020 and 20 October 2021. The EPICENTRE cohort collected prospective data on FCC practices. Rooming-in and breastmilk feeding practice were the main outcomes, and factors influencing each were determined. Other outcomes included mother-baby physical contact prior to separation and the pattern of FCC components relative to time and local site guidelines.

FINDINGS

692 mother-baby dyads (13 sites, 10 countries) were analysed. 27 (5%) neonates were positive for SARS-CoV-2 (14 (52%) asymptomatic). Most sites had policies that encouraged FCC during perinatal SARS-CoV-2 infection for most of the reporting period. 311 (46%) neonates roomed-in with their mother during the admission. Rooming-in increased over time from 23% in March-June 2020 to 74% in January-March 2021 (boreal season). 330 (93%) of the 369 separated neonates had no FCC physical contact with their mother prior, and 319 (86%) were asymptomatic. Maternal breastmilk was used for feeding in 354 (53%) neonates, increasing from 23% to 70% between March-June 2020 and January-March 2021. FCC was most impacted when mothers had symptomatic COVID-19 at birth.

INTERPRETATION

This is the largest report of global FCC practice during the COVID-19 pandemic to date. The COVID-19 pandemic may have impacted FCC despite low perinatal transmission rates. Fortunately, clinicians appear to have adapted to allow more FCC delivery as the COVID-19 pandemic progressed.

FUNDING

The National Health and Medical Research Council (Australia): Grant ID 2008212 (DGT), Royal Children's Hospital Foundation: Grant ID 2019-1155 (EJP), Victorian Government Operational Infrastructure Support Program.

Evidence for neutrino emission from the nearby active galaxy NGC 1068

A supermassive black hole, obscured by cosmic dust, powers the nearby active galaxy NGC 1068. Neutrinos, which rarely interact with matter, could provide information on the galaxy’s active core. We searched for neutrino emission from astrophysical objects using data recorded with the IceCube neutrino detector between 2011 and 2020. The positions of 110 known gamma-ray sources were individually searched for neutrino detections above atmospheric and cosmic backgrounds. We found that NGC 1068 has an excess of 79 − 20 + 22 neutrinos at tera–electron volt energies, with a global significance of 4.2σ, which we interpret as associated with the active galaxy. The flux of high-energy neutrinos that we measured from NGC 1068 is more than an order of magnitude higher than the upper limit on emissions of tera–electron volt gamma rays from this source.

Search for Unstable Sterile Neutrinos with the IceCube Neutrino Observatory

We present a search for an unstable sterile neutrino by looking for a resonant signal in eight years of atmospheric ν_{μ} data collected from 2011 to 2019 at the IceCube Neutrino Observatory. Both the (stable) three-neutrino and the 3+1 sterile neutrino models are disfavored relative to the unstable sterile neutrino model, though with p values of 2.8% and 0.81%, respectively, we do not observe evidence for 3+1 neutrinos with neutrino decay. The best-fit parameters for the sterile neutrino with decay model from this study are Δm_{41}^{2}=6.7_{-2.5}^{+3.9}  eV^{2}, sin^{2}2θ_{24}=0.33_{-0.17}^{+0.20}, and g^{2}=2.5π±1.5π, where g is the decay-mediating coupling. The preferred regions of the 3+1+decay model from short-baseline oscillation searches are excluded at 90% C.L.

SAFETY AND EFFICACY OF THYMIC PEPTIDES IN THE TREATMENT OF HOSPITALIZED COVID-19 PATIENTS IN HONDURAS

Coronavirus disease 2019 (Covid-19) active cases continue to demand the development of safe and effective treatments. This is the first clinical trial to evaluate the safety and efficacy of oral thymic peptides. ; We conducted a nonrandomized phase 2 trial with a historic control group to evaluate the safety and efficacy of a daily 250-mg oral dose of thymic peptides in the treatment of hospitalized Covid-19 patients. Comparisons based on standard care from registry data were performed after propensity score matching. The primary outcomes were survival, time to recovery, and number of participants with treatment-related adverse events or side effects by day 20. ; A total of 44 patients were analyzed in this study: 22 in the thymic peptide group and 22 in the standard care group. There were no deaths in the intervention group compared to 24% mortality in standard care by day 20 (log-rank P=0.02). Kaplan-Meier analysis showed a significantly shorter time to recovery by day 20 in the thymic peptide group than in the standard care group (median, 6 days vs. 12 days; hazard ratio for recovery, 2.75 [95% confidence interval, 1.34 to 5.62]; log-rank P=0.002). No side effects or adverse events were reported. ; In patients hospitalized with Covid-19, the use of thymic peptides resulted in no side effects, adverse events, or deaths by day 20. Compared with the registry data, a significantly shorter time to recovery and mortality reduction were measured.

Strong Constraints on Neutrino Nonstandard Interactions from TeV-Scale ν_{μ} Disappearance at IceCube

We report a search for nonstandard neutrino interactions (NSI) using eight years of TeV-scale atmospheric muon neutrino data from the IceCube Neutrino Observatory. By reconstructing incident energies and zenith angles for atmospheric neutrino events, this analysis presents unified confidence intervals for the NSI parameter ε_{μτ}. The best-fit value is consistent with no NSI at a p value of 25.2%. With a 90% confidence interval of -0.0041≤ε_{μτ}≤0.0031 along the real axis and similar strength in the complex plane, this result is the strongest constraint on any NSI parameter from any oscillation channel to date.

Impacts of Gaseous Ozone (O3) on Germination, Mycelial Growth, and Aflatoxin B1 Production In Vitro and In Situ Contamination of Stored Pistachio Nuts

Pistachio nuts can become colonized by mycotoxigenic fungi, especially Aspergillus flavus, resulting in contamination with aflatoxins (AFs). We examined the effect of gaseous O₃ (50–200 ppm; 30 min; 6 L/min) on (a) in vitro germination, (b) mycelial growth, and (c) aflatoxin B1 (AFB₁) production on a milled pistachio nut-based medium at different water activity (a_w) levels and at 30 °C. This was complimented with in situ studies exposing raw pistachio nuts to 50–200 ppm of O₃. Exposure of conidia to gaseous O₃ initially resulted in lower germination percentages at different a_w levels. However, 12 h after treatment, conidial viability recovered with 100% germination after 24–48 h. Growth rates of mycelial colonies were slightly decreased with the increase of the O₃ dose, with significant inhibition only at 0.98 a_w. The production of AFB₁ after O₃ treatment and storage for 10 days was stimulated in A. flavus colonies at 0.98 a_w. Raw pistachio nuts inoculated with A. flavus conidia prior to O₃ exposure showed a significant decrease in population after 20 days of storage. However, AFB₁ contamination was stimulated in most O₃ treatments. The relationship between exposure concentration, time and prevailing a_w levels on toxin control needs to be better understood for these nuts.

Interacting Environmental Stress Factors Affect Metabolomics Profiles in Stored Naturally Contaminated Maize

There is interest in understanding the relationship between naturally contaminated commodities and the potential for the production of different useful and toxic secondary metabolites (SMs). This study examined the impact of interacting abiotic stress parameters of water availability and temperature of stored naturally contaminated maize on the SM production profiles. Thus, the effect of steady-state storage water activity (aw; 0.80−0.95) and temperature (20−35 °C) conditions on SM production patterns in naturally contaminated maize was examined. The samples were analysed using Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS) to evaluate (a) the total number of known SMs, (b) their concentrations, and (c) changes under two-way interacting environmental stress conditions. A total of 151 metabolites were quantified. These included those produced by species of the Aspergillus, Fusarium and Penicillium genera and other unspecified ones by other fungi or bacteria. There were significant differences in the numbers of SMs produced under different sets of interacting environmental conditions. The highest total number of SMs (80+) were present in maize stored at 20−25 °C and 0.95 aw. In addition, there was a gradation of SM production with the least number of SMs (20−30) produced under the driest conditions of 0.80 aw at 20−30 °C. The only exception was at 35 °C, where different production patterns occurred. There were a total of 38 Aspergillus-related SMs, with most detected at >0.85 aw, regardless of the temperature in the 50−500 ng/g range. For Fusarium-related SMs, the pattern was different, with approx. 10−12 SMs detected under all aw × temperature conditions with >50% produced at 500 ng/g. A total of 40−45 Penicillium-related SMs (50−500 ng/g) were detected in the stored maize but predominantly at 20−25 °C and 0.95 aw. Fewer numbers of SMs were found under marginal interacting abiotic stress storage conditions in naturally contaminated maize. There were approx. eight other known fungal SM present, predominantly in low concentrations (<50 ng/g), regardless of interacting abiotic conditions. Other unspecified SMs present consisted of <20 in low concentrations. The effect of interacting abiotic stress factors for the production of different suites of SMs to take account of the different ecological niches of fungal genera may be beneficial for identifying biotechnologically useful SMs.

Comparison of multiple mycotoxins in harvested maize samples in three years (2018-2020) in four continents

This study has examined the pattern of mycotoxin contamination of maize destined for animal feed in different global regions over a period of 3 years (2018-2020) with up to 1000+ samples analysed in each year. Overall, >75% of samples in each of the survey years were contaminated with multiple mycotoxins regardless of the global region (Europe, Africa, Asia, South Americas countries). Using LC-MS/MS, it was possible to quantify the relative contamination present in the samples in each year from the different regions of eight different mycotoxins including aflatoxin B₁ (AFB₁), ochratoxin A (OTA) deoxynivalenol (DON), fumonisin B₁ (FB₁) and B₂, zearalenone (ZEA), T-2 and HT-2 toxins. The trends in mycotoxin contamination showed that there was a consistent contamination with DON in the 3 sampling years in all four regions. Interestingly, AFB₁ contamination was prevalent in all regions in 2018, but more predominant in Europe and in 2019. In contrast, in 2020 it was found to be the major contaminant in Africa only. However, FB₁ contamination of maize which was prevalent in Europe in 2018, became more prevalent in Asia and LATAM countries in 2019 and even in African maize in 2020. Comparisons of contamination with different mycotoxins in each of the years globally showed significant differences for AFB₁, FB₁, DON and ZEA between the different years. These results are discussed in relation to the trends of contamination of maize with mixtures of mycotoxins and the implication for their control in this key commodity used as an important ingredient in animal feed.

De novo genome assembly and functional annotation for Fusarium langsethiae

Background

Fusarium langsethiae is a T-2 and HT-2 mycotoxins producing species firstly characterised in 2004. It is commonly isolated from oats in Northern Europe. T-2 and HT-2 mycotoxins exhibit immunological and haemotological effects in animal health mainly through inhibition of protein, RNA and DNA synthesis. The development of a high-quality and comprehensively annotated assembly for this species is therefore essential in providing the molecular understanding and the mechanism of T-2 and HT-2 biosynthesis in F. langsethiae to help develop effective control strategies.

Results

The F. langsethiae assembly was produced using PacBio long reads, which were then assembled independently using Canu, SMARTdenovo and Flye. A total of 19,336 coding genes were identified using RNA-Seq informed ab-initio gene prediction. Finally, predicting genes were annotated using the basic local alignment search tool (BLAST) against the NCBI non-redundant (NR) genome database and protein hits were annotated using InterProScan. Genes with blast hits were functionally annotated with Gene Ontology.

Conclusions

We developed a high-quality genome assembly of a total length of 59 Mb and N50 of 3.51 Mb. Raw sequence reads and assembled genome is publicly available and can be downloaded from: GenBank under the accession JAFFKB000000000.

All commands used to generate this assembly are accessible via GitHub: https://github.com/FadyMohareb/fusarium_langsethiae.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12864-022-08368-0.

Search for Relativistic Magnetic Monopoles with Eight Years of IceCube Data

We present an all-sky 90% confidence level upper limit on the cosmic flux of relativistic magnetic monopoles using 2886 days of IceCube data. The analysis was optimized for monopole speeds between 0.750c and 0.995c, without any explicit restriction on the monopole mass. We constrain the flux of relativistic cosmic magnetic monopoles to a level below 2.0×10^{-19}  cm^{-2} s^{-1} sr^{-1} over the majority of the targeted speed range. This result constitutes the most strict upper limit to date for magnetic monopoles with β≳0.8 and up to β∼0.995 and fills the gap between existing limits on the cosmic flux of nonrelativistic and ultrarelativistic magnetic monopoles.

Success versus failure: Efficient heat devices in thermodynamics

Classical equilibrium thermodynamics provides, in a general way, upper Carnot bounds for the performance of energy converters. Nevertheless, to suggest lower bounds is a much more subtle issue, especially when they are related to a definition of convenience. Here, this issue is investigated in a unified way for heat engines, refrigerators, and heat pumps. First, irreversibilities are weighted in the context of heat reservoir stability for irreversible engines by using the thermodynamic distance between minimum energy and maximum entropy steady states. Some stability coefficients can be related to a majorization process and the obtention of Pareto fronts, linking stability and optimization by means of efficiency and entropy due to correlations between system and reservoirs. Second, these findings are interpreted in a very simple context. A region where the heat device is efficient is defined in a general scheme and, below this zone, the heat device is inefficient in the sense that irreversibilities somehow dominate its behavior. These findings allow for a clearer understanding of the role played by some well-known figures of merit in the scope of finite-time and -size optimization. Comparison with experimental results is provided.

Effect of Acclimatization in Elevated CO2 on Growth and Aflatoxin B1 Production by Aspergillus flavus Strains on Pistachio Nuts

There is little knowledge of the effect of acclimatization of Aspergillus flavus strains to climate-related abiotic factors and the subsequent effects on growth and aflatoxin B₁ (AFB₁) production. In this study, two strains of A. flavus (AB3, AB10) were acclimatized for five generations in elevated CO₂ (1000 ppm × 37 °C) on a milled pistachio-based medium. A comparison was made of the effects of non-acclimatized strains and those that were acclimatized when colonizing layers of pistachio nuts exposed to 35 or 37 °C, 400 or 1000 ppm CO₂, and 0.93 or 0.98 water activity (a_w), respectively. Acclimatization influenced the fitness in terms of the growth of one strain, while there was no significant effect on the other strain when colonizing pistachio nuts. AFB₁, production was significantly stimulated after ten days colonization when comparing the non-acclimatized and the acclimatized AB3 strain. However, there was no significant increase when comparing these for strain AB10. This suggests that there may be inter-strain differences in the effects of acclimatization and this could have a differential influence on the mycotoxin contamination of such commodities.

Comparison of growth and aflatoxin B1 production profiles of Aspergillus flavus strains on conventional and isogenic GM-maize-based nutritional matrices

Maize grown in both North and South America are now predominantly genetically modified (GM) cultivars with some resistance to herbicide, pesticide, or both. There is little information on the relative colonisation and aflatoxin B₁ (AFB₁) production with maize meal-based nutritional matrices based on kernels of non-GM maize and isogenic GM-ones by strains of Aspergillus flavus. The objectives were to examine the effect of interacting conditions of temperature (25-35 °C) and water availability (0.99-0.90 water activity, a_w) on (a) mycelial growth, (b) AFB₁ production and (c) develop contour maps of optimum and marginal conditions of these parameters for four strains of A. flavus on three different non-GM and isogenic GM-maize based nutritional media. The growth of the four strains of A. flavus (three aflatoxigenic; one non-aflatoxigenic) was relatively similar in relation to the temperature × a_w conditions examined on both non-GM and GM-based matrices. Optimum growth overall was at 30-35 °C and 0.99 a_w for all four strains. Under water stress (0.90 a_w) growth was optimum at 35 °C. Statistically: non-GM, GM cultivars, temperature and a_w all significantly affected growth rates. For AFB₁ production, all single and interacting factors were statistically significant except for non-GM × GM cultivar. In conclusion, colonisation of GM- and non-GM nutritional sources was similar for the different A. flavus strains examined. The contour maps will be very useful for understanding the ecological niches for both toxigenic and non-toxigenic strains in the context of the competitive exclusion of those producing aflatoxins.

Abiotic factors affect growth and aflatoxin B1 production by Aspergillus flavus strains on chilli powder and red chillies

Chillies and chilli-based products are important spices on a global basis. The production, processing, transport and storage phases of chillies are prone to infection by Aspergillus Section Flavi and contamination with aflatoxins (AFs), especially aflatoxin B1 (AFB1) for which legislative limits exist in many countries. We have examined the effect of the interacting abiotic factors of water availability (water activity, aw; 0.995-0.850 aw) and temperature (15-37 °C) on (a) lag phases prior to growth, (b) growth, (c) AFB1 production and (d) contour maps of optimum and boundary conditions for colonisation and toxin production by three Aspergillus flavus strains on a 10% chilli-based medium. Additional studies with whole red chillies + A. flavus conidial inoculum on AFB1 contamination during storage for 10-20 days at 30 °C were also carried out. In vitro, the lag phases before growth were delayed by lower temperatures (15, 20 °C) and aw levels (0.928-0.901 aw). There was no statistical difference in growth between the three strains. Optimal growth was at 37 °C and 0.982 aw with no growth at 0.85 aw. Optimal temperature × aw conditions for AFB1 production were at 30 °C and 0.982 aw with no statistical difference in production between strains. No AFB1 was produced at 15-20 °C at 0.901 and 0.928 aw levels, respectively. In situ studies with A. flavus inoculated whole red chillies at 0.90 and 0.95 aw found that this species became the major component of the total fungal populations at 30 °C after 10-20 days storage. AFB1 contamination was above the European legislative limits (5 μg/kg) for spices at 0.90 aw after 20 days storage and at 0.95 aw after 10 and 20 days. This suggests that storage conditions of ≥0.90 aw, especially at ≥25-30 °C represents a significant risk of contamination with AFB1 at levels where rejection might occur, even after only 10-20 days storage.

P–039 Sperm chromatin integrity in relation to clinical pregnancy rate in an egg donation program

Study question

Is DNA Fragmentation Index (DFI) determinant in clinical pregnancy rate (CPR) after ICSI?

Summary answer

DFI is determinant in CPR after ICSI

What is known already

Male fertility evaluation often leaves the clinician in uncertainty. Semen analysis is a basic examination, but insufficient. Sperm DNA is in a compact state, and its integrity is observed to be related to reproductive capacity

Study design, size, duration

A retrospective, single center study, in 65 couples underwent egg donation, ICSI and blastocyst transfer, evaluating DFI and its effect on CPR. This study was carried out since September 2017 to March 2020

Participants/materials, setting, methods

DFI was evaluated using Sperm Chromatin Dispersion test (SCD) and considering 20% or below as normal. We performed ICSI in donated eggs, cultured until blastocyst stage and transferred 1 to 3 embryos. CPR was defined as the number of patient with fetal heart beats presents in relation with the number of patients with embryo transfer. We determined CPR in both groups with normal and abnormal DFI. Fisher exact test was used to analyze the differences.

Main results and the role of chance

From these 65 couples, in 29 male partners had normal DFI and 36 abnormal. CPR was 68.97% in the first group and 41.67% in the second (p = 0.0448)

Limitations, reasons for caution

The small number of patients is a limitation

Wider implications of the findings: The results permit us to know more male patients, to consider DFI as an important variable and to prepare better our patients for procedures.

Trial registration number

00012

Intra-species variability in Fusarium langsethiae strains in growth and T-2/HT-2 mycotoxin production in response to climate change abiotic factors

The objective of this study was to evaluate the potential intra-species variability of 3 Fusarium langsethiae strains in response to extreme climate change (CC) conditions on an oat-based matrix. The impact of elevated temperature (25 vs 30-34 °C) coupled with increasing drought stress (0.98 vs 0.95 aw) and elevated CO2 (400 vs 1000 ppm) were examined on lag phases prior to growth, growth rate, and production of the mycotoxins T-2 and HT-2 and their ratio. In comparison to the control conditions (25 °C; 0.98; 400 ppm), exposure to increased temperature (30-34 °C), showed similar reductions in the lag phase and fungal growth rates of all 3 strains. However, with elevated CO2 a reduction in both lag phases prior to growth and growth rate occurred regardless of the aw examined. For T-2 and HT-2 mycotoxin production, T-2 showed the most intra-species variability in response to the interacting abiotic stress factors, with the 3 strains having different environmental conditions for triggering increases in T-2 production: Strain 1 produced higher T-2 toxin at 25 °C, while Strain 2 and the type strain (Fl201059) produced most at 0.98 aw/30 °C. Only Strain 2 showed a reduction in toxin production when exposed to elevated CO2. HT-2 production was higher at 25 °C for the type strain and higher at 30-34 °C for the other two strains, regardless of the aw or CO2 level examined. The HT-2/T-2 ratio showed no significant differences due to the imposed interacting CC abiotic conditions.

Comparative Growth Inhibition of Bread Spoilage Fungi by Different Preservative Concentrations Using a Rapid Turbidimetric Assay System

Bread and intermediate moisture bakery products are mainly spoiled by yeasts and filamentous fungi. The inoculum load and preservation system used determines their shelf life. To extend the shelf life of such commodities, the use of chemical preservatives is the most common way to try and control the initiation of mold spoilage of bread. This study has utilized a rapid turbidimetric assay system (Bioscreen C) to examine the temporal efficacy of calcium propionate (CP) and potassium sorbate (PS) for controlling the growth of important bread spoilage fungi. The objectives were to compare the temporal growth of strains of three important spoilage fungi Hyphopichia burtonii (HB17), Paecilomyces variotii (PV11), and Penicillium roqueforti (PR06) isolated from visibly molded bread to (a) different concentrations of CP and PS (0-128 mM), (b) temperatures (25°C, 30°C), (c) water activity (a_w; 0.95, 0.97), and (d) pH (5.0, 5.5). All three abiotic factors, pH, a_w, and temperature, and preservative concentrations influenced the relative growth of the species examined. In general, PS was more effective than CP in inhibiting the growth of the strains of these three species. In addition, the Time to Detection (TTD) for the efficacy of the preservatives under the interacting abiotic factors was compared. The strain of Paecilomyces variotii (PV10) was the most tolerant to the preservatives, with the shortest TTD values for both preservatives. P. roqueforti was the most sensitive with the longest TTD values under all conditions examined. These results are discussed in the context of the evolution of resistance to food-grade preservatives by such spoilage fungi in bakery products.

Water and temperature relations of Fusarium langsethiae strains and modelling of growth and T-2 and HT-2 mycotoxin production on oat-based matrices

In the UK and Northern Europe, ripening oats can become contaminated with T-2 and HT-2 mycotoxins, produced mainly by Fusarium langsethiae. There are indicative levels related to the maximum limits for oat grain for these toxins. The objectives of this study were to examine the effect of interacting conditions of temperature (10-30 °C) and water activity (a_w, 0.995-0.90) on (a) lag times prior to growth, (b) growth and (c) T-2 and HT-2 toxins by two strains of F. langsethiae isolated from oats in the UK and compare this with the type strain (Fl201059) which has been genomically sequenced, and (d) develop (and validated with published data) a probabilistic models for impacts of temperature × a_w on growth and toxin production. All three strains had an optimum a_w range and temperature of 0.995-0.98 and 25 °C for growth. For T-2 + HT-2 production these were 0.995 a_w and 20 °C. Overall, the type strain produced higher amounts of T-2 + HT-2 with a HT-2/T-2 ratio of up to 76. Using this study data sets and those from the literature, probabilistic models were developed and validated for growth and T-2 + HT-2 toxin production in relation to temperature × a_w conditions. These models, when applied in stored oats, will be beneficial in determining the conditions on the relative level of risk of contamination with these two toxins in the context of the EU indicative maximum levels.

Computational evaluation of rebreathing and effective dead space on a helmet-like interface during the COVID-19 pandemic

The coronavirus disease 2019 (COVID-19) is a potentially severe acute respiratory infection caused by severe acute respiratory syndrome coronavirus 2. The potential for transmission of this disease has led to an important scarcity of health-care resources. Consequently, alternative solutions have been explored by many physicians and researchers. Non-invasive Ventilation has been revealed as one alternative for patients with associated acute respiratory distress syndrome. This technique is being used in combination with helmet-like interfaces because of their versatility and affordability. However, these interfaces could experience important problems of CO2 rebreathing, especially under low flow rate conditions. This work proposes a Computational Fluid Dynamics method to accurately characterize the fluid flow in a pre-design environment of helmet-like interfaces. Parameters as effective dead space, rebreathing, pressure, or temperature field distribution are quantified and analysed in detail in order to study the performance and feasibility of such devices to relieve the effects of respiratory infections.

Strategies to Produce Grapefruit-Like Citrus Varieties With a Low Furanocoumarin Content and Distinctive Flavonoid Profiles

Pummelos and hybrids, such as grapefruits, have high furanocoumarin and low flavonoid contents. Furanocoumarins interact negatively with certain drugs, while flavonoids are antioxidant compounds with health benefits. To obtain new grapefruit-like varieties with low furanocoumarin and high flavonoid contents, diploid and triploid hybrid populations from crosses between diploid and tetraploid "Clemenules" clementine and diploid "Pink" pummelo were recovered and analyzed. With regard to furanocoumarins, triploids produce less bergapten, bergamottin and 6,7-DHB than diploids. Regarding flavonoids, triploids yielded more eriocitrin, narirutin, hesperidin and neohesperidin than diploids, whereas no differences were observed in neoeriocitrin and naringin. These results indicate that, the strategy to recover triploid hybrids by 4x × 2x crosses is more appropriate than the recovery of diploid hybrids by 2x × 2x crosses for obtaining grapefruit-like varieties of citrus with lower furanocoumarin and higher flavonoid contents.

Lactobacillus plantarum strain HT-W104-B1: potential bacterium isolated from Malaysian fermented foods for control of the dermatophyte Trichophyton rubrum

The objective was to screen and evaluate the anti-fungal activity of lactic acid bacteria (LABs) isolated from Malaysian fermented foods against two Trichophyton species. A total of 66 LAB strains were screened using dual culture assays. This showed that four LAB strains were very effective in inhibiting growth of T. rubrum but not T. interdigitale. More detailed studies with Lactobacillus plantarum strain HT-W104-B1 showed that the supernatant was mainly responsible for inhibiting the growth of T. rubrum. The minimum inhibitory concentration (MIC), inhibitory concentration, the 50% growth inhibition (IC₅₀) and minimum fungicide concentration (MFC) were 20 mg/mL, 14 mg/mL and 30 mg/mL, respectively. A total of six metabolites were found in the supernatant, with the two major metabolites being L-lactic acid (19.1 mg/g cell dry weight (CDW)) and acetic acid (2.2 mg/g CDW). A comparative study on keratin agar media showed that the natural mixture in the supernatants predominantly contained L-lactic and acetic acid, and this significantly controlled the growth of T. rubrum. The pure two individual compounds were less effective. Potential exists for application of the natural mixture of compounds for the treatment of skin infection by T. rubrum.

Interacting Abiotic Factors Affect Growth and Aflatoxin B1 Production Profiles of Aspergillus flavus Strains on Pistachio-Based Matrices and Pistachio Nuts

Pistachio nuts are an economically important commodity produced by many countries. They can be colonized by mycotoxigenic fungi, especially Aspergillus flavus, resulting in contamination with aflatoxins (AFs), especially aflatoxin B₁ (AFB₁), a Class 1a carcinogen. The objectives were to examine the effect of interactions between the two key abiotic factors, temperature and water activity (a _w ) on (a) in vitro growth and AFB₁ production by four strains of A. flavus isolated from pistachio nuts, on a milled pistachio nut medium modified ionically (NaCl) and non-ionically (glycerol) in the range 20-35°C and 0.995-0.85 a _w , (b) colonization of layers of raw pistachio nuts stored at different interacting temperature x a _w conditions and on relative AFB₁ production and (c) develop models to produce contour maps of the optimal and marginal boundary conditions for growth and AFB₁ production by up to 4 strains of this species. On pistachio nut-based media, optimum growth of four strains of A. flavus was at 0.98-0.95 a _w and 30-35°C. Optimum AFB₁ production was at 30-35°C and 0.98 a _w . No significant differences in growth was found on ionic and non-ionically modified media. Colonization of layers of raw pistachio nuts was slower and contamination with AFB₁ significantly less than in in vitro studies. Contour maps based on the pooled data for up to four strains (in vitro, in situ) showed the optimum and marginal conditions for growth and AFB₁ production. These data can be used to identify those conditions which represent a high, intermediate or low risk of colonization and AFB₁ contamination in the pistachio nut processing chain. These results are discussed in the context of the development of appropriate intervention strategies to minimize AFB₁ contamination of this economically important commodity.

Granular flow through vertical slots: analysis of a general formula

Currently, very little is known about reliable phenomelogical correlations to estimate the gravity-driven mass flow rate, of dry non-cohesive granular material, outflowing from thin thickness slots in vertical sidewalls of rectangular silos. Here, we validate a simple and general formula that fits pretty well data published elsewhere, including the cases of vertically and horizontally elongated slots.

Collapse of conical granular columns

This paper experimentally analyzes the collapse of conical granular columns made out of non-cohesive granular materials. Dimensionless run-out lengths were found, as a function of the aspect ratio a, similar to those occurring in the collapse of cylindrical columns, although in the case of conical columns of high aspect ration, at the end of the collapse, a layer of grains that rotates around the cone axis appears and it affects the final profiles of the mounds.

Acoustic radiation patterns of the silo music phenomenon

In this work, we apply the theory of radiation and reception of acoustic waves in the analysis of the acoustic contributions of the silo music phenomenon. The length portion of the silo where the silo music phenomenon occurs is considered a continuous line source. The continuous line source modeled as a simple acoustic source permits the analysis of the acoustic far field, interpreting the polar graphics of the beam patterns of the acoustic contributions. We propose to apply this technique in the silo design to diminish adverse acoustic effects during the discharge process of granular materials. Additionally, we present calculations of the sound pressure level of the silo music phenomenon.

Dynamics of solute/matric stress interactions with climate change abiotic factors on growth, gene expression and ochratoxin A production by Penicillium verrucosum on a wheat-based matrix

Penicillium verrucosum contaminates temperate cereals with ochratoxin A (OTA) during harvesting and storage. We examined the effect of temperature (25 vs 30 ^oC), CO₂ (400 vs 1000 ppm) and matric/solute stress (-2.8 vs -7.0 MPa) on (i) growth, (ii) key OTA biosynthetic genes and (iii) OTA production on a milled wheat substrate. Growth was generally faster under matric than solute stress at 25 ^oC, regardless of CO₂ concentrations. At 30 ^oC, growth of P. verrucosum was significantly reduced under solute stress in both CO₂ treatments, with no growth observed at -2.8 MPa (=0.98 water activity, a_w) and 1000 ppm CO₂. Overall, growth patterns under solute stress was slower in elevated CO₂ than under matric stress when compared with existing conditions. The otapksPV gene expression was increased under elevated CO₂ levels in matric stress treatments. There was fewer effects on the otanrpsPV biosynthetic gene. This pattern was paralleled with the production of OTA under these conditions. This suggest that P. verrucosum is able to actively grow and survive in both soil and on crop debris under three way interacting climate-related abiotic factors. This resilience suggests that they would still be able to pose an OTA contamination risk in temperate cereals post-harvest.