Pathogen Infestation Research Articles

Microbial Biopreparations and Their Impact on Organic Strawberry (Fragaria x ananassa Duch.) Yields and Fungal Infestation

Growing consumer awareness of the importance of food quality on their health is the main driving force for increasing the market for sustainable agricultural products. This makes sustainable, environmentally friendly production methods into non-chemical plant protection products against pathogens, including microbial biopreparations, increasingly important among farmers. Strawberry fruits (Fragaria x ananassa Duch.) are often negatively affected by fungal pathogens. The aim of this study was to evaluate the impact of five combinations of newly developed microbial biopreparations (from K2 to K6) on fungal pathogens and the yield of three strawberry cultivars. The research was conducted on a certified organic strawberry plantation in Poland in 2020–2021. In the first year of the study, no statistically significant positive impact of tested treatments on strawberry yields have been found. At the same time, yields of ‘Honeoye’ treated with K4 combination showed a tendency (with no statistical significance) to have higher yields than the control object by about 33%. In the second year of the study, yields of ‘Honeoye’ and ‘Rumba’ treated with K4 combination (containing Bacillus sp. Sp116AC*, Bacillus sp. Sp115AD, Bacillus sp. AF75BC and Bacillus subtilis AF75AB2, humic acids, yeast culture effluent, micronized dolomite, and mustard and rapeseed oil) significantly increased by 79% and 49%, respectively. Fruit infestation by fungal pathogens was reduced under some microbial treatments; however, the effect varied between years, cultivars, and tested biopreparations. The K2 combination showed a tendency (with no statistical significance) to limit B. cinerea infestation rate by 23% in 2020 and 21% in 2021, C. acutatum by 16% in 2021, and P. cactorum infestation rate by 30% in 2021. Tested microbial biopreparations showed a positive impact on the yield of strawberries and (to some extent) on disease infestation, with an impact on pathogen infestation strongly dependent on the year, variety, and biopreparation tested.

Self-assembled thymol-betaine co-crystals with controlled release and hygroscopic properties as green preservatives for aflatoxin prevention

Mycotoxins are representative contaminants causing food losses and food safety problems worldwide. Thymol can effectively inhibit pathogen infestation and aflatoxin accumulation during grain storage, but high volatility limits its application. Here, a thymol-betaine co-crystal system was synthesized through grinding-induced self-assembly. The THY-TMG co-crystal exhibited excellent thermal stability with melting point of 91.2 °C owing to abundant intermolecular interactions. Remarkably, after 15 days at 30 °C, the release rate of thymol from co-crystal was only 55%, far surpassing that of pure thymol. Notably, the co-crystal demonstrated the ability to bind H2O in the environment while controlling the release of thymol, essentially acting as a desiccant. Moreover, the co-crystals effectively inhibited the growth of Aspergillus flavus and the biosynthesis of aflatoxin B1. In practical terms, the THY-TMG co-crystal was successful in preventing AFB1 contamination and nutrients loss in peanuts, thereby prolonging their shelf-life under conditions of 28 °C and 70% RH.

Acidic electrolyzed-oxidizing water treatment mitigated the disease progression in Phomopsis longanae Chi-infected longans by modulating ROS and membrane lipid metabolism

Postharvest harmful pathogenic infestation leads to rapid decay in longan fruit. Compared with P. longanae-infected longans, AEOW alleviated fruit disease severity and diminished the O2-. production rate and MDA content. It also increased APX, CAT, and SOD activities, delayed the decrease in the levels of GSH and AsA, as well as the reducing power and DPPH radical scavenging ability, which resulted in a decline in membrane lipid peroxidation in P. longanae-infected longans. Additionally, AEOW reduced LOX, lipase, PI-PLC, PC-PLC, and PLD activities, maintained higher levels of PC, PI, IUFA, USFAs, and U/S, while reducing levels of PA, DAG, SFAs, and CMP. These effects alleviated membrane lipid degradation and peroxidation in P. longanae-infected longans. Consequently, AEOW effectively maintained membrane integrity via improving antioxidant capacity and suppressing membrane lipid peroxidation. This comprehensive coordination of ROS and membrane lipid metabolisms improved fruit resistance and delayed disease development in longans.

Root rot induces a core assemblage of bacterial microbiome to prevent disease infection in Sanqi ginseng

Plants rely on rhizosphere microbes as the first line of defense against pathogen invasion and for maintaining the health of itself. Increasing evidence suggests that plants recruit beneficial microbes to the roots, strengthening their resistance to pathogens. However, the response of the rhizosphere core bacterial microbiome to root rot infection remains largely unclear. In this study, we investigated the rhizosphere and bulk soil core bacterial microbiome of healthy and root rot-diseased Sanqi ginseng in genuine production areas in China. We utilized 16S amplicon sequencing, co-occurrence network analysis, and strain culture approaches to explore whether root rot-induced plant rhizosphere alterations in the bacterial core microbiome could improve disease suppression. Root rot infection had a significant impact on the rhizosphere core bacterial microbiome of Sanqi ginseng. Root rot led to a reduction in the diversity and evenness of the core bacterial microbiome in the rhizosphere, while the variability of the core bacterial community in the rhizosphere increased. In response to fungal root rot pathogen infestation, Sanqi ginseng recruited potentially beneficial bacteria with disease-suppressive functions to the rhizosphere, such as Sphingobium, Pseudoxanthomonas, Pseudomonas, Stenotrophomonas, and Flavobacterium. Function prediction analysis demonstrated a remarkable enrichment of several functional genes involved in antibiotic biosynthesis in the rhizosphere that was infected with root rot. Strain isolation and pot addition experiments further confirmed the effectiveness of root rot rhizosphere-specific enrichment of Operational Taxonomic Units (OTUs) for controlling root rot. Furthermore, co-occurrence network analysis indicated that root rot activated the disease-suppressive functions of the rhizosphere core bacterial microbiome by enhancing complexity and connectivity at the expense of network stability. These findings expand our knowledge of plant-microbe interactions and provides new evidence supporting the “cry for help” strategy for rhizosphere responses to root rot.

Nonpathogenic Pseudomonas syringae derivatives and its metabolites trigger the plant “cry for help” response to assemble disease suppressing and growth promoting rhizomicrobiome

Plants are capable of assembling beneficial rhizomicrobiomes through a “cry for help” mechanism upon pathogen infestation; however, it remains unknown whether we can use nonpathogenic strains to induce plants to assemble a rhizomicrobiome against pathogen invasion. Here, we used a series of derivatives of Pseudomonas syringae pv. tomato DC3000 to elicit different levels of the immune response to Arabidopsis and revealed that two nonpathogenic DC3000 derivatives induced the beneficial soil-borne legacy, demonstrating a similar “cry for help” triggering effect as the wild-type DC3000. In addition, an increase in the abundance of Devosia in the rhizosphere induced by the decreased root exudation of myristic acid was confirmed to be responsible for growth promotion and disease suppression of the soil-borne legacy. Furthermore, the “cry for help” response could be induced by heat-killed DC3000 and flg22 and blocked by an effector triggered immunity (ETI) -eliciting derivative of DC3000. In conclusion, we demonstrate the potential of nonpathogenic bacteria and bacterial elicitors to promote the generation of disease-suppressive soils.

Climate Change Mitigation Potential of Forestry Sector for Sustainability of Agro-Ecosystem: A Review

Ecosystems that are currently struggling are likely faring and pathetic conditions because of climate change. The most pressing problems facing people in the world's developing parts of the world are water scarcity, dwindling biodiversity, and stagnant agricultural output. According to the majority of scientists, global warming can be stopped before it becomes irreversible if temperatures are kept within a range of 1.5 to 2 degrees Celsius. Greenhouse gases, sometimes known as GHGs, are the burning causes of climate change impacts. Accelerated emissions of GHGs could be dependent on the rate of social, economic, and technological development. Forest systems have a crucial impact in mitigating global warming. Clearing forests, setting them on fire, or otherwise destroying those releases massive amounts of other greenhouse gases (GHGs), even if the forests are the planet's greatest terrestrial carbon sink. Forests' source-sink dynamics and the total quantity of carbon they store are profoundly impacted by regional differences in human land use, anthropogenic climate change, and disturbance. Constantly expanding conservation, restoration, reforestation, and afforestation operations will be necessary to keep global warming under control and stop it from exceeding the crucial threshold. Forests are currently being employed as a potential tool for combating climate change, which has been demonstrated to be an effective and long-term strategy. However, the impact of climate change on forests is largely negative. The negative effects of climate change on forests are becoming more pronounced, as evidenced by an increase in the forest fire events and results in a shift in species distribution at higher altitudes, an increase in dieback, an increase in the number of insect and pathogen infestations, drought and flood conditions, and a decrease in the ecosystem services provided by forests. The IPCC has predicted that changes to ecosystems, arctic ice melting, rising sea levels, decreased grain yields, declining fisheries, and the loss of coral reefs will all have significant consequences. Therefore, protecting ecosystem services and biodiversity is crucial to ensuring humanity's survival.

Assessing performance of simplified bioassays for soil-borne pathogens in smallholder systems of western Kenya.

Soil-borne pathogens cause considerable crop losses and food insecurity in smallholder systems of sub-Saharan Africa. Soil and crop testing is critical for estimating pathogen inoculum levels and potential for disease development, understanding pathogen interactions with soil nutrient and water limitations, as well as for developing informed soil health and disease management decisions. However, formal laboratory analyses and diagnostic services for pathogens are often out of reach for smallholder farmers due to the high cost of testing and a lack of local laboratories. To address this challenge, we assessed the performance of a suite of simplified soil bioassays to screen for plant parasitic nematodes (e.g., Meloidogyne, Pratylenchus) and other key soil-borne pathogens (Pythium and Fusarium). We sampled soils from on-farm trials in western Kenya examining the impact of distinct nutrient inputs (organic vs. synthetic) on bean production. Key soil health parameters and common soil-borne pathogens were evaluated using both simple bioassays and formal laboratory methods across eleven farms, each with three nutrient input treatments (66 samples in total). The soil bioassays, which involved counting galls on lettuce roots and lesions on soybean were well correlated with the abundance of gall forming (Meloidogyne) and root lesion nematodes (e.g., Pratylenchus) recovered in standard laboratory-based extractions. Effectiveness of a Fusarium bioassay, involving the counting of lesions on buried bean stems, was verified via sequencing and a pathogenicity test of cultured Fusarium strains. Finally, a Pythium soil bioassay using selective media clearly distinguished pathogen infestation of soils and infected seeds. When examining management impact on nematode communities, soils amended with manure had fewer plant parasites and considerably more bacterivore and fungivore nematodes compared to soils amended with synthetic N and P. Similarly, Pythium presence was 35% lower in soils amended with manure, while the Fusarium assays indicated 23% higher Fusarium infection in plots with amended manure. Our findings suggest that relatively simple bioassays can be used to help farmers assess soil-borne pathogens in a timely manner, with minimal costs, thus enabling them to make informed decisions on soil health and pathogen management.

Pattern recognition receptors as potential therapeutic targets for developing immunological engineered plants.

There is an urgent need to combat pathogen infestations in crop plants to ensure food security worldwide. To counter this, plants have developed innate immunity mediated by Pattern Recognition Receptors (PRRs) that recognize pathogen-associated molecular patterns (PAMPs) and damage- associated molecular patterns (DAMPs). PRRs activate Pattern-Triggered Immunity (PTI), a defence mechanism involving intricate cell-surface and intracellular receptors. The diverse ligand-binding ectodomains of PRRs, including leucine-rich repeats (LRRs) and lectin domains, facilitate the recognition of MAMPs and DAMPs. Pathogen resistance is mediated by a variety of PTI responses, including membrane depolarization, ROS production, and the induction of defence genes. An integral part of intracellular immunity is the Nucleotide-binding Oligomerization Domain, Leucine-rich Repeat proteins (NLRs) which recognize and respond to effectors in a potent manner. Enhanced understanding of PRRs, their ligands, and downstream signalling pathways has contributed to the identification of potential targets for genetically modified plants. By transferring PRRs across plant species, it is possible to create broad-spectrum resistance, potentially offering innovative solutions for plant protection and global food security. The purpose of this chapter is to provide an update on PRRs involved in disease resistance, clarify the mechanisms by which PRRs recognize ligands to form active receptor complexes and present various applications of PRRs and PTI in disease resistance management for plants.

Physiological and autophagy evaluation of different pear varieties (Pyrus spp.) in response to Botryosphaeria dothidea infection.

Ring rot disease is one of the most common diseases in pear orchards. To better understand the physiology, biochemistry and autophagic changes of different pear varieties after Botryosphaeria dothidea (B.dothidea) infection, we evaluated eight different pear varieties for B. dothidea resistance. The susceptible varieties had larger spot diameters, lower chlorophyll contents and higher malondialdehyde contents than the resistant varieties. In disease-resistant varieties, reactive oxygen species (ROS) levels were relatively lower, while the ROS metabolism (antioxidant enzyme activities and the ascorbic acid-glutathione cycle) was also maintained at higher levels, and it induced a significant upregulation of related gene expression. In addition, autophagy, as an important evaluation index, was found to have more autophagic activity in disease-resistant varieties than in susceptible varieties, suggesting that pathogen infestation drives plants to increase autophagy to defend against pathogens. In summary, the results of this study reveal that different resistant pear varieties enhance plant resistance to the disease through a series of physio-biochemical changes and autophagic activity after inoculation with B. dothidea. This study provides clear physiological and biochemical traits for pear disease resistance selection, potential genetic resources and material basis for pear disease control and disease resistance, breeding and points out the direction for research on the mechanism of pear resistance to B. dothidea.

The Underexplored Mechanisms of Wheat Resistance to Leaf Rust

Wheat leaf rust, caused by the obligate biotrophic fungus Puccinia triticina Eriks. (Pt), is one of the most common wheat foliar diseases that continuously threatens global wheat production. Currently, the approaches used to mitigate pathogen infestation include the application of fungicides and the deployment of resistance genes or cultivars. However, the continuous deployment of selected resistant varieties causes host selection pressures that drive Pt evolution and promote the incessant emergence of new virulent races, resulting in the demise of wheat-resistant cultivars after several years of planting. Intriguingly, diploid wheat accessions were found to confer haustorium formation-based resistance to leaf rust, which involves prehaustorial and posthaustorial resistance mechanisms. The prehaustorial resistance in the interaction between einkorn and wheat leaf rust is not influenced by specific races of the pathogen. The induced defense mechanism, known as systemic acquired resistance, also confers durable resistance against a wide array of pathogens. This review summarizes the host range, pathogenic profile, and evolutionary basis of Pt; the molecular basis underlying wheat–Pt interactions; the cloning and characterization of wheat leaf rust resistance genes; prehaustorial and posthaustorial resistance; systemic acquired resistance; and the role of reactive oxygen species. The interplay between climatic factors, genetic features, planting dates, and disease dynamics in imparting resistance is also discussed.

Influence of Sunn Hemp Biomass Incorporation on Organic Strawberry Production

Sunn hemp (Crotalaria juncea L.), a warm season leguminous cover crop, is commonly used in rotation with organic strawberry production in Florida’s subtropical environment. This study was conducted to explore the impacts of sunn hemp on growth and yield performance of the subsequent organic strawberry crop in sandy soils, taking into consideration the nutrient contribution from soil incorporation of sunn hemp biomass. Sunn hemp was seeded during the summer off-season and terminated before flowering, three weeks prior to the fall planting of two strawberry cultivars (‘Strawberry Festival’ and ‘Camino Real’). With sunn hemp residues incorporated into the soil, two application rates of nitrogen (N) through pre-plant organic fertilization for the strawberry season were used, including N at a rate of 84 kg/ha, without consideration of the N credit from sunn hemp, and N at a rate of 19.8 kg/ha, with consideration of the estimated N credit from sunn hemp. A summer fallow without cover crop and with a pre-plant organic fertilizer application at the N rate of 84 kg/ha was included as the control. Overall, the sunn hemp incorporation at three weeks after termination did not benefit the strawberry plant growth or fruit yield in this study, with rather low levels of soilborne pathogen and nematode infestations. Both sunn hemp treatments exhibited a significantly lower level of total soil N compared to the summer fallow plots at the end of the strawberry season. The reduction in the pre-plant N fertilization resulted in lower above-ground plant dry weight and accumulation of N, phosphorus (P), and potassium (K) at the end of the strawberry season, along with fewer leaves and smaller crowns of the strawberry plants during the early season. Both sunn hemp treatments decreased early fruit yields, while the sunn hemp treatment with the reduced N fertilization also led to a significant reduction in the total fruit number and weight, although no significant differences in the whole-season marketable fruit yield were observed among the nutrient management treatments. Overall, ‘Strawberry Festival’ yielded higher than ‘Camino Real’, but the effects of nutrient management did not vary with the strawberry cultivars. Further studies are needed to enhance organic strawberry nutrient management involving rotational cover crops.

COMBINED EFFECT OF TBSV P19 MUTANTS AND HEAVY METALS ON ANTIOXIDANT ENZYME ACTIVITY

Crops of food value are often exposed to viral pathogens. Therefore, crops can noticeably decrease or die completely. For example, in 2021, the tomato brown wrinkle virus was detected in Kazakhstan, the main hosts of which are tomatoes and peppers. At the same time, in farms where the pathogen was detected, yield loss ranged from 30 to 70%. Therefore, it is important to develop methods aimed at increasing plant stress tolerance to viral infection. The scientific novelty of this manuscript is that previously the simultaneous effect of viral pathogens and heavy metals on plants has not been studied. Antioxidant enzymes play an important role in regulating the concentration of reactive oxygen species in plant cells. The enzyme catalase catalyzes the conversion of hydrogen peroxide into water and molecular oxygen, thereby neutralizing superoxide radicals. Thus, antioxidant enzymes prevent tissue damage and necrosis. Molybdenum enzymes can produce reactive oxygen species when exposed to adverse conditions, such as pathogen infestation or drought. Molybdenum is an integral part of the Moco cofactor within molybdoenzymes, but tungsten has the ability to substitute for molybdenum, resulting in a reversible loss of enzyme function. Consequently, tungsten acts as a stressor for plants. Inoculation of plants with tomato bush stunt virus of the wild type leads to their death. At the same time, when infected with TBSV 157, RMJ1 and RMJ2 mutants, the plants recovered after some time. Plants are expected to be more viable when the subject is exposed to heavy metal solutions and inoculated with viruses.

The effect of migratory beekeeping on Indian honey bee (Apis cerana indica) microbiota – a first report

Migratory beekeeping is a widely extended practice aimed at increasing the yield of honey and pollination services. Microbial symbionts that inhabit the honey bee’s gut are essential to their host’s food digestion, immunity, and gut protection. Throughout the honey bee life cycle and at several migratory sites, the taxonomic composition of the gut microbiota changes. However, it is yet unknown how significant changes in migratory locations, such as altered floral supply, parasitism and pathogen infestation, affect the dynamics of the gut microbiota. The goal of this study was to describe the Indian honey bee (Apis cerana indica) gut microbiome at different migratory sites of Puducherry and Tamil Nadu. Our results found that the core bacterial composition of the microbiota was consistent over different migratory sites. Despite this stability, our comparisons of the microbiota of honey bees from the same colony show that there are differences in composition at different migratory sites. Likewise, there is variation in relative abundance between microbiomes of different migratory sites. The four most dominant phyla were Proteobacteria followed by Bacteroidota, Actinobacteriota and Firmicutes. Most of the isolates belonged to families of Xanthomonadaceae, Orbaceae, Weeksellaceae, Bifidobacteriaceae, Rhizobiaceae, Neisseriaceae, Lactobacillaceae, Dysgonomonadaceae, Clostridiaceae and Enterococcaceae. However, several commensal bacteria that proliferate in the hive environment including members of Lactobacillaceae (Lactobacillus kunkeei), Bifidobacteriaceae, Orbaceae and Neisseriaceae were also identified and considered as beneficial gut inhabitants and involved in the maintenance of a healthy microbiota. This is the first report on bee gut microbiota from Puducherry and Tamil Nadu geographically situated at the southeast coast of India.

Delusional infestation: a retrospective cohort study of49patients over a 6-year period.

Delusional infestation (DI) is the fixed false belief of pathogenic infestation of the skin or body despite no supporting medical evidence. It is a relatively rare condition with a reported prevalence of 1.48 per million people. Successful treatment can be challenging as patients are often reluctant to accept referral or involvement of psychiatric services. We report a retrospective cohort study of 49 consecutive patients with a diagnosis of DI, assessed in a regional psychodermatology service over a 6-year period. Low-dose antipsychotics (risperidone or olanzapine) were prescribed in 44 patients. We use our data to explore possible reasons why DI can be challenging to treat. Response to treatment and engagement with services is multifactorial. Our study emphasizes the importance of early assessment and supports the expansion of psychodermatology services in the UK.

Isolation and Identification of the Causal Agent of Top Rot and the Genetic Architecture of Resistance in Maize.

In maize (Zea mays), the disease known as "top rot" causes necrosis of the upper plant, disrupts tassel formation and pollen dispersal, and decreases yield. However, the causal agent, mode of pathogen infestation, and genetic architecture of resistance in maize remain to be explored. Here, to identify the causal agent, we isolated 41 fungal strains from maize plants infected with top rot. We classified these strains into six groups based on their morphological and molecular characteristics. Four species of Fusarium (F. fujikuroi, F. equiseti, F. proliferatum, and F. verticillioides) were able to cause top rot, with F. fujikuroi and F. equiseti being the main causal agents. Microscopic observations of a F. fujikuroi strain labeled with enhanced green fluorescent protein revealed that this pathogen first colonizes the stomata of leaves and then spreads through intercellular spaces, creating an expanding lesion. To dissect the genetic basis of maize resistance to top rot, we performed quantitative trait locus (QTL) mapping using a recombinant inbred line population constructed from the resistant parent LDC-1 and the susceptible parent YS501. Under natural conditions in Yangzhou and Hainan, we detected three and five QTLs, respectively, with qRtr7-1, located on chromosome 7, detected in both environments. Using inoculated seedlings, we detected three QTLs for resistance on chromosomes 1, 5, and 8. These results improve our understanding of maize top rot and provide a theoretical basis for its control.

Identification and Characterization of the BBX Gene Family in Bambusa pervariabilis × Dendrocalamopsis grandis and Their Potential Role under Adverse Environmental Stresses.

Zinc finger protein (ZFP) transcription factors play a pivotal role in regulating plant growth, development, and response to biotic and abiotic stresses. Although extensively characterized in model organisms, these genes have yet to be reported in bamboo plants, and their expression information is lacking. Therefore, we identified 21 B-box (BBX) genes from a transcriptome analysis of Bambusa pervariabilis × Dendrocalamopsis grandis. Consequently, multiple sequence alignments and an analysis of conserved motifs showed that they all had highly similar structures. The BBX genes were divided into four subgroups according to their phylogenetic relationships and conserved domains. A GO analysis predicted multiple functions of the BBX genes in photomorphogenesis, metabolic processes, and biological regulation. We assessed the expression profiles of 21 BBX genes via qRT-PCR under different adversity conditions. Among them, eight genes were significantly up-regulated under water deficit stress (BBX4, BBX10, BBX11, BBX14, BBX15, BBX16, BBX17, and BBX21), nine under salt stress (BBX2, BBX3, BBX7, BBX9, BBX10, BBX12, BBX15, BBX16, and BBX21), twelve under cold stress (BBX1, BBX2, BBX4, BBX7, BBX10, BBX12, BBX14, BBX15, BBX17, BBX18, BBX19, and BBX21), and twelve under pathogen infestation stress (BBX1, BBX2, BBX4, BBX7, BBX10, BBX12, BBX14, BBX15, BBX17, BBX18, BBX19, and BBX21). Three genes (BBX10, BBX15, and BBX21) were significantly up-regulated under both biotic and abiotic stresses. These results suggest that the BBX gene family is integral to plant growth, development, and response to multivariate stresses. In conclusion, we have comprehensively analyzed the BDBBX genes under various adversity stress conditions, thus providing valuable information for further functional studies of this gene family.

Differences in pathogenic community assembly processes and their interactions with bacterial communities in river and lake ecosystems

Pathogenic bacterial infections caused by water quality degradation are one of the most widespread environmental problems. Clarifying the structure of pathogens and their assembly mechanisms in lake ecosystems is vital to prevent the infestation of waterborne pathogens and maintain human health. However, the composition and assembly mechanisms of pathogenic bacterial communities in river and lake ecosystems are still poorly understood. In this study, we collected 17 water and 17 sediment samples from Lake Chaohu and its 11 inflow rivers. Sequencing of 16S rRNA genes was used to study bacterial pathogen communities. The results of the study showed that there was a significant difference (P < 0.05) in the composition of the pathogen community between riverine and lake habitats. Acinetobacter (36.49%) was the dominant bacterium in the river, whereas Flavobacterium (21.6%) was the most abundant bacterium in the lake. Deterministic processes (i.e., environmental filtering and species interaction) drove the assembly of pathogenic bacterial communities in the lake habitat, while stochastic processes shaped river pathogenic bacterial communities. Spearman correlation analysis showed that the α-diversity of bacterial communities was linearly and negatively linked to the relative abundance of pathogens. Having a higher bacterial community diversity had a suppressive effect on pathogen abundance. In addition, co-occurrence network analysis showed that bacterial communities were tightly linked to pathogenic bacteria. Pseudomonas aeruginosa and Salmonella enterica were identified as keystone species in an inflow water sampling network (W_FR), reducing the complexity of the network. These results provide a reference for assessments of water quality safety and pathogenic bacteria posing risks to human health in large freshwater lakes.

Improvement of storage quality of ‘Hayward’ kiwifruit by MeJA combined with SA treatment through activation of phenylpropane metabolism

Kiwifruit are highly susceptible to pathogenic infestation, which can lead to spoilage during postharvest storage. Therefore, there is an urgent need to develop natural and efficient preservation methods. A compound preservative consisting of 10 μM MeJA (methyl jasmonate) and 1 mM SA (salicylic acid) was used to preserve kiwifruit during storage. Sensory, quality, and phenylpropane metabolism-related indicators were assessed at 20 °C during kiwifruit storage in groups treated with sterile water, MeJA, SA, or a combination of MeJA and SA. The results indicated that the hormone treatment groups exhibited varying degrees of efficacy in suppressing spoilage caused by pathogenic infestation. The combination treatment group demonstrated superior efficacy in comparison to the other treatment groups, as evidenced by its ability to suppress hardness reduction, delay decay rate, and disease index increase, retard soluble solids accumulation, activate enzymes PAL, C4H, and 4CL involved in phenylpropane metabolism and enhance total phenol content. The SA treatment group exhibited the second highest efficacy, whereas the MeJA treatment group demonstrated the lowest efficacy. The results showed that at the end of storage, the PAL activity and total phenolic content of kiwifruit in the combination treatment increased by 52.72%, 39.98%, 17.89%, and 98.19%, 22.47%, 14.93% compared to the control, MeJA and SA treatment alone, respectively. The findings of this study may serve as a theoretical foundation and technical guide for the utilization of MeJA in combination with SA during kiwifruit storage and preservation.

Application of Biohumus at different substrate replacement rates in the germination and cultivation of Zea mays

Research objective: This research aims to evaluate the biostimulant potential of biohumus in different substrate replacement rates on the growth of Zea mays seedlings. This is to increase knowledge of the use of biohumus in plant cultivation, which could be used in the formulation of new growing media and organic fertilisers. Materials and Methods: The experiments, which began in January 2023, were conducted in the CREA-OF greenhouses in Pescia (Pt), on seedlings of Zea mays. The experimental groups were: group control, irrigated with water and substrate previously fertilized; group with 10% biohumus, irrigated and fertilised substrate; group with 20% biohumus, irrigated and fertilized substrate; group with 30% biohumus, irrigated and fertilized substrate; group with 40% biohumus, irrigated and fertilized substrate; group with 50% biohumus, irrigated and fertilized substrate; group with 60% biohumus, irrigated and fertilized substrate; group with 70%, irrigated and fertilized substrate; group with 100% biohumus, irrigated and fertilized substrate. On May 18, 2023, plant height, vegetative weight, roots volume and length, the number of microorganisms and pH in the substrate were determined. Results and Discussion: The experiment showed that the use of biohumus enriched with microorganisms can significantly improved the vegetative and root growth of sown Zea mays seedlings. In general, a significant increase in plant height, vegetative and root weight, and root length was observed from 20% substitution of biohumus in the substrate. The theses that show a particularly clear improvement for all agronomic parameters analysed are those with 50% and 60% biohumus, peat substitution. Plants that received biohumus grew better than those that did not, and cereal plants grew better than those that were grown in plain soil. The nutrient content of biohumus stimulates the growth of the following crops: tomatoes, peppers, garlic, sweet corn, aubergines, bananas. Among other things, it stimulates the growth of chrysanthemum, marigold, geranium, petunia, and poinsettia flowers, as well as acacia and eucalyptus. Due to its macro- and micronutrient content, biohumus has a positive effect on plants (leaf area, root volume, root branching), and improves the soil's biological functions. Plants that received biohumus grew better than those that did not, and cereal plants grew better than those that were grown in plain soil. The growth of barley and cereals improved on a maize farm after biohumus was applied. There was a significant improvement in soil porosity on a maize farmland. Among the benefits of using biohumus as a fertiliser are: it eliminates harmful insects, reduces the infestation of harmful insects, reduces pathogen infestation of plants, fertilizes the soil, and improves the soil structure as a soil conditioner. Conclusions: In order to maintain soil health and fertility, farmers need a sustainable alternative that is economically viable and productive. As part of ecological agriculture, the protection of food, agricultural and human ecosystems is emphasized, along with the improvement of soil fertility and the development of secondary income for farmers. The use of biohumus provides the best answer to ecological agriculture, which is synonymous with 'sustainable agriculture'. This article provides a basis for further research

PS07 Delusional infestation: are delays in access to care adversely affecting patient outcomes? A case series

Abstract Delusional infestation (DI) is the fixed, false belief of pathogenic infestation of the skin or body, despite no supporting medical evidence. Patients may be difficult to treat successfully, because of their reluctance to accept referral or involvement of psychiatric services. Research consistently supports assessment of this cohort in multidisciplinary psychodermatology clinics, where integrated medical and psychiatric care can be seamlessly provided. The British Association of Dermatologists (BAD) All Parliamentary Group has recommended increased psychodermatology services across the UK, but provision is still scanty. We report a review of 49 consecutive patients (12 men and 37 women) with a diagnosis of DI assessed in a regional psychodermatology service. Mean patient age was 63 years (range 41–92). Mean duration of symptoms before attending was 4.9 years. Forty-one (84%) patients complained of living creatures, with the other eight (16%) perceiving fibres or other inanimate objects. Perception of nonliving mater­ial was strongly associated with substance misuse. Low-dose antipsychotics were prescribed in 44 (90%) patients. Risperidone (n = 39; 89%) and olanzapine (n = 5; 11%) were the drugs prescribed. Medications were well tolerated, with no significant adverse side-effects reported. Twenty-three (47%) responded to treatment. Four patients developed full-blown psychotic disorders. We were unable to engage 13 (27%) patients in treatment, and in three (6%), the treatment outcomes were unknown. Responders had a mean time to presentation of 3.7 years vs. nonresponders who had symptoms for an average of 5.9 years. Ten (20%) patients admitted to current or previous substance misuse. Twenty-one (43%) had a history of psychiatric disease. Substance misuse and established psychiatric disorders were associated with poorer engagement and response. Response to treatment and engagement with services is multifactorial. This review demonstrated that delays in presentation are associated with poorer outcomes (Romanov DV, Lepping P, Bewley A et al. Longer duration of untreated psychosis is associated with poorer outcomes for patients with delusional infestation. Acta Derm Venereol 2018; 98:848–54). In 2016, early intervention in psychosis services was introduced as a National Institute for Health and Care Excellence standard in the UK. In psychiatry, there is well-established evidence of the relationship between delays in treatment of psychosis and poorer outcomes. The BAD guidelines have recently been published to encourage more widespread prescribing of low-dose antipsychotics to expedite treatment. Our review highlights that all patients with DI face significant delays to treatment, which may adversely impact or increase the complexity of clinical presentations. This review emphasizes the importance of early assessment and supports the expansion of psychodermatology services.