Alternative Control Strategies Research Articles

A study of knowledge, attitudes, and practices on ticks and tick-borne diseases of cattle among breeders of two bovine Portuguese autochthonous breeds

Beef cattle production in Portugal is an important sector of national agricultural production, with half of the herd being in the Alentejo region. Despite this, animal health is essential for its productivity, which may be compromised by ticks and tick-borne diseases. So far, no study has been conducted in Portugal to assess knowledge, attitudes, and practices (KAP) on ticks and tick-borne diseases in cattle, which the authors are aware of. This type of questionnaire is a very useful tool in the development and application of effective and sustainable prevention and control measures. Therefore, a KAP questionnaire was applied to 44 cattle breeders of autochthonous Portuguese breeds, namely 14 breeders of the Alentejana breed and 30 of the Mertolenga breed, between January 1 and May 9, 2023. Based on the analysis criteria of these surveys, 64% of the Alentejana breeders and 63% of the Mertolenga breeders have an average level of knowledge about ticks and tick-borne diseases, and 21% of the Alentejana breeders and 33% of the Mertolenga breeders have a high level of knowledge. Although only 21.4% of the Alentejana and 36.7% of the Mertolenga breeders consider tick infestation as a major animal health problem, 71.4% of the Alentejana and 63.3% of breeders of the Mertolenga state that one of the main reasons for veterinary consultations on their farm is deworming of animals, and 92.9% of breeders of the Alentejana and 96.7% of breeders of the Mertolenga refer the use of dewormers as a strategy to control tick infestation. The results of this study contribute to highlighting the importance of correcting some identified knowledge gaps and improving knowledge, especially on the life cycle of this parasite, its local distribution and seasonality, resistance to acaricides, and alternative control strategies.

Phenotypic resistance not associated with knockdown mutations (kdr) in Anopheles albimanus exposed to deltamethrin in southern coastal Ecuador

BackgroundDecrease in malaria rates (e.g. incidence and cases) in Latin America maintains this region on track to achieve the goal of elimination. During the last 5 years, three countries have been certified as malaria free. However, the region fails to achieve the goal of 40% reduction on malaria rates and an increase of cases has been reported in some countries, including Ecuador. This scenario has been associated with multiple causes, such as decrease of funding to continue anti-malarial programmes and the development of insecticide resistance of the main malaria vectors. In Ecuador, official reports indicated phenotypic resistance in Aedes aegypti and Anopheles albimanus to deltamethrin and malathion, particularly in the coastal areas of Ecuador, however, information about the mechanisms of resistance have not been yet elucidated. This study aims to evaluate phenotypic response to deltamethrin and its relationship with kdr mutations in An. albimanus from two localities with different agricultural activities in southern coastal Ecuador.MethodsThe CDC bottle assay was carried out to evaluate the phenotypic status of the mosquito’s population. Sequencing the voltage gated sodium channel gene (VGSC) sought knockdown mutations (kdr) in codons 1010, 1013 and 1014 associated with resistance.ResultsPhenotypic resistance was found in Santa Rosa (63.3%) and suspected resistance in Huaquillas (82.1%); with females presenting a higher median of knockdown rate (83.7%) than males (45.6%). No statistical differences were found between the distributions of knockdown rate for the two localities (p = 0.6048) which indicates no influence of agricultural activity. Although phenotypic resistance was confirmed, genetic analysis demonstrate that this resistance was not related with the kdr mechanism of the VGSC gene because no mutations were found in codons 1010 and 1013, while in codon 1014, 90.6% showed the susceptible sequence (TTG) and 7.3% ambiguous nucleotides (TKK and TYG).ConclusionsThese results highlighted the importance of continuous monitoring of resistance in malaria vectors in Ecuador, particularly in areas that have reported outbreaks during the last years. It is also important to elucidate the mechanism involved in the development of the resistance to PYs to propose alternative insecticides or strategies for vector control in areas where resistance is present.

A Virtual Reality-Based Protocol to Determine the Preferred Control Strategy for Hand Neuroprostheses in People With Paralysis.

Hand neuroprostheses restore voluntary movement in people with paralysis through neuromodulation protocols. There are a variety of strategies to control hand neuroprostheses, which can be based on residual body movements or brain activity. There is no universally superior solution, rather the best approach may vary from patient to patient. Here, we propose a protocol based on an immersive virtual reality (VR) environment that simulates the use of a hand neuroprosthesis to allow patients to experience and familiarize themselves with various control schemes in clinically relevant tasks and choose the preferred one. We used our VR environment to compare two alternative control strategies over 5 days of training in four patients with C6 spinal cord injury: (a) control via the ipsilateral wrist, (b) control via the contralateral shoulder. We did not find a one-fits-all solution but rather a subject-specific preference that could not be predicted based only on a general clinical assessment. The main results were that the VR simulation allowed participants to experience the pros and cons of the proposed strategies and make an educated choice, and that there was a longitudinal improvement. This shows that our VR-based protocol is a useful tool for personalization and training of the control strategy of hand neuroprostheses, which could help to promote user comfort and thus acceptance.

Coupled Continuous PID Controllers for the IFAC Benchmark on Vapor Compression Refrigeration on the Behavioural Setting

This paper presents a behavioral-based controllers design, utilizing evolutionary learning of trajectories, applied to the IFAC PID18 benchmark model for a vapor compression refrigeration system. The challenge of tracing both the evaporator outlet temperature (Te,sec,out) and superheat temperature (Tsh) with disturbances and imposed restrictions is addressed. The challenge integrates a preset discrete MIMO control scheme, serving as a basis for comparison with alternative control schemes. The proposed method also allows for direct experimentation on the system, bypassing the need for reference models or mathematical representations. By developing behavioral paths and iteratively adjusting controller variables, satisfactory control objectives are achieved. The evolutionary behavioral approach is tested on the default discrete control scheme and then applied to newly designed coupled continuous PID controllers, which outperform the benchmark strategy. The method is versatile, adaptable to both model-based and data-driven approaches, and offers a direct relationship with the physical system, independent of both its representation and controller structure, thus emulating real-world conditions effectively.

Combination of computational techniques and RNAi reveal targets in Anopheles gambiae for malaria vector control.

Increasing reports of insecticide resistance continue to hamper the gains of vector control strategies in curbing malaria transmission. This makes identifying new insecticide targets or alternative vector control strategies necessary. CLassifier of Essentiality AcRoss EukaRyote (CLEARER), a leave-one-organism-out cross-validation machine learning classifier for essential genes, was used to predict essential genes in Anopheles gambiae and selected predicted genes experimentally validated. The CLEARER algorithm was trained on six model organisms: Caenorhabditis elegans, Drosophila melanogaster, Homo sapiens, Mus musculus, Saccharomyces cerevisiae and Schizosaccharomyces pombe, and employed to identify essential genes in An. gambiae. Of the 10,426 genes in An. gambiae, 1,946 genes (18.7%) were predicted to be Cellular Essential Genes (CEGs), 1716 (16.5%) to be Organism Essential Genes (OEGs), and 852 genes (8.2%) to be essential as both OEGs and CEGs. RNA interference (RNAi) was used to validate the top three highly expressed non-ribosomal predictions as probable vector control targets, by determining the effect of these genes on the survival of An. gambiae G3 mosquitoes. In addition, the effect of knockdown of arginase (AGAP008783) on Plasmodium berghei infection in mosquitoes was evaluated, an enzyme we computationally inferred earlier to be essential based on chokepoint analysis. Arginase and the top three genes, AGAP007406 (Elongation factor 1-alpha, Elf1), AGAP002076 (Heat shock 70kDa protein 1/8, HSP), AGAP009441 (Elongation factor 2, Elf2), had knockdown efficiencies of 91%, 75%, 63%, and 61%, respectively. While knockdown of HSP or Elf2 significantly reduced longevity of the mosquitoes (p<0.0001) compared to control groups, Elf1 or arginase knockdown had no effect on survival. However, arginase knockdown significantly reduced P. berghei oocytes counts in the midgut of mosquitoes when compared to LacZ-injected controls. The study reveals HSP and Elf2 as important contributors to mosquito survival and arginase as important for parasite development, hence placing them as possible targets for vector control.

Grey-box modeling of Air Handling Units for Analysis and Virtual Sensing

The optimization of control sequences in air handling units (AHUs) presents a significant opportunity for energy savings within HVAC systems. However, many building owners and operators require quantifiable estimates of potential energy savings before committing to retrofitting control systems. Valid estimates of energy savings require system models that consider capacity and limitations of the AHU, but in existing systems, scarce information hinders such modeling efforts. This lack of information complicates AHU modeling and the assessment of alternative control strategies. This paper demonstrates an approach that leverages time-series data from a newly constructed Danish AHU, equipped with multiple sensors for temperature, flow, and pressure, to construct a grey-box model of the unit, including component properties. The estimated parameters for the components are validated against data sheet information, and shows that the estimation procedure is accurate for parameter estimation. To analyze the energy-efficiency of the cooling coil, the model is used to estimate the latent cooling in the cooling coil, as Danish conditions rarely require dehumidification of supply air.

Biology, ecology, and management of redbanded stink bug (Hemiptera: Pentatomidae)

Abstract The redbanded stink bug (RBSB), Piezodorus guildinii (Westwood) (Hemiptera: Pentatomidae) is an invasive stink bug species and a polyphagous pest of cultivated crops and non-cultivated wild plants. The increase in soybean cultivation during the 1960s–1970s led to the spread of RBSB as an economic pest of soybean throughout South America, especially in Brazil, Argentina, and Uruguay. In the early 2000s, RBSB became an economic concern to US agriculture and is currently a key species in a stink bug complex that damages soybean in many mid-southern states. RBSB causes extensive damage to soybeans and other economically important leguminous crops by feeding on sap from stems, flowers, and foliage with a preference for pods and seeds, which causes flat pods, reduced seed weight, and germination. Infestation by RBSB may lead to more crop loss per capita than other stink bug species. RBSBs are less susceptible to commonly used agrochemicals than other stink bug species and have developed resistance to many commonly used insecticides. Several alternative control strategies based on a wide variety of methods have been reported in recent years. This review will discuss the distribution, biology, ecology, and various control strategies for integrated management of RBSB in the last 2 decades.

Avaliação de fungicidas e Trichoderma spp. no controle de fungos patogênicos habitantes do solo em meloeiro

ABSTRACT Soil-borne fungal pathogens pose an increasing challenge to melon cultivation globally. The demand for reduced agrochemical use in melon farming, driven by limitations on chemical residues in the fruit, underscores the need for alternative control strategies. This study assesses the effectiveness of various fungicides-difenoconazole, fluazinam, fludioxonil, and procymidone -and Trichoderma spp. strains (T. asperellum, T. harzianum, and two strains of T. longibrachiatum) in combatting Ceratobasidium sp., Fusarium falciforme, Macrophomina phaseolina, and Monosporascus cannonballus. Fluazinam (EC50 from 0.01 to 0.88 mg/L) and fludioxonil (EC50 from 0.01 to 0.07 mg/L) emerged as the most effective fungicides in suppressing the mycelial growth of the pathogens in vitro, whereas procymidone (EC50 from 2.31 to 9.77 mg/L) was the least effective. Fludioxonil demonstrated significant efficacy against Ceratobasidium sp., F. falciforme, M. phaseolina, and M. cannonballus. In vitro assays revealed that all tested Trichoderma spp. strains significantly inhibited mycelial growth, with over 70% reduction for all pathogens examined. Field trials indicated that Trichoderma treatments could decrease disease incidence (28.00 to 69.33%) and severity (0.95 to 2.25) in melon crops. These findings illuminate the potential of various fungicides and Trichoderma spp. in managing soil-borne pathogens in melon cultivation. Such control methods might be employed independently or synergistically with other strategies like grafting onto resistant rootstocks or breeding for resistance to mitigate the threats these pathogens pose to global melon production.

A Study on the Efficacy of Different Botanicals Against Potato Tuber Moth (Phthorimaea Operculella) in Stored Potatoes

The Potato Tuber Moth (Phthorimaea operculella) is a destructive pest that poses a significant threat to stored potato crops, leading to substantial economic losses worldwide. The use of chemical insecticides to control this pest has drawbacks such as environmental pollution and potential harm to human health. As a result, it is critical to investigate alternate control strategies, such as botanical extracts. This study aimed to evaluate the efficacy of different botanicals, Azadirachta indica (Neem), Acorus calamus (sweet flag), Sapindus mukorossi (Soapnut) and their combination against the Potato Tuber Moth in stored potatoes. The research followed a randomized sampling technique, with seven treatments {T1: sweet flag (100%), T2: Neem (100%), T3: neem (50%)+ soapnut(50%), T4: soapnut powder (100%), T5: sweet flag (50%)+ Neem (50%), T6: sweet flag (50%)+ soapnut(50%), T7: control }. The treatments were applied to potatoes and data were observed, recorded, and tabulated. Our results showed that there was not a huge difference in the final result of mortality in all the treatments, all showing similar results. But when observed by counting the time factor, Acorus calamus outsmarted other bio-pesticides by killing 100% of insects in much less time. Further, all the treatments significantly affect the weight loss of potato tuber. Potato tuber treated with T1 showed the least weight loss of 1.88% of total weight followed by T6 and T4 with 2.56% and 2.58% of weight loss respectively. There was also some weight loss in the untreated potatoes due to evaporation and other physical factors. To sum up the overall result of our study, the experiment concluded that Acorus calamus (T1) had given the best result and thus it stood to be the best bio-pesticide among all.

Comparison of Variable Speed Wind Turbine Control Strategies.

Variable speed operation of wind turbines presents certain advantages over constant speed operation. Basically, variable speed wind turbines use the high inertia of the rotating mechanical parts of the system as a flywheel; this helps to smooth power fluctuations and reduces the drive train mechanical stress. Also, variable speed systems could lead to maximise the capture of energy during partial load operation. In this paper alternative control strategies for variable speed operation are considered and compared from the point of view of energy yield and power quality. Control aim is always maximum power generation. Maximum power tracking and power fluctuation will be analysed when exciting the different configurations with a particular wind profile. Also fixed speed wind turbine are considered for the comparison.

Cost effectiveness of spread mitigation strategies for polyphagous shot hole borer Euwallacea fornicatus (Coleoptera: Curculionidae: Scolytinae).

Polyphagous shot hole borer Euwallacea fornicatus Eichhoff was detected in Western Australia in September 2021, and an eradication campaign funded by the Commonwealth government is underway. As part of contingency planning, we examined the cost effectiveness of alternative control strategies that could be used to mitigate urban forest impacts and maintain the benefits of trees to the local communities if eradication was not feasible. At the time this work was undertaken, decision-makers were concerned about the potential need to replace all urban trees susceptible to attack. We considered this strategy alongside less destructive strategies and assessed their cost effectiveness in terms of material and labor costs and the loss of ecosystem services resulting from reduced tree foliage. Using a stochastic simulation model, we found that a strategy that involved pruning necrotic limbs and treating trees biennially with systemic insecticide was almost always more cost effective than removing infested trees and replanting to resistant varieties. We estimated this strategy would cost A$55-110 million over 50 years, while tree removal would cost $105-195 million. A third strategy using a mix of chemical suppression and tree removal was also considered in light of new information about the pest's host preferences. With an estimated cost of $60-110 million, this strategy was only slightly more expensive than using chemical suppression alone and could actually lead to eradication if the host range is as narrow as recent survey data suggests.

The potential for use of haematological and anti-IgE humoral responses as phenotypic markers for tick resistance in cattle

Approximately 80% of the global cattle population is at risk of infestation and infection by ticks and tick-borne diseases (TTBDs). The economic losses from animal mortality, reduced production, vector control costs and animal treatment are very substantial, hence there is an urgent need to develop and deploy alternative vector control strategies. Breeding for host tick resistance has the potential for sustainable large-scale TTBD control especially in cattle. The gold standard method for phenotyping tick resistance in cattle is by counting ticks on the body but is very laborious and subjective. Better methods for phenotyping tick resistance more objectively, faster and at scale, are essential for selecting host genetic resistance to ticks. This study investigated the correlation between haematological cellular profiles and immunological responses (immunoglobulin E, IgE) and full body tick counts in herds of Bos indicus and Bos taurus following artificial tick challenge with Rhipicephalus decoloratus larvae. Fifty-four Friesian and Ayrshire (Bos taurus) and 52 East African Zebu (Bos indicus) calves were each infested with ∼2500 larvae. Near-replete adult female ticks (≥ 4.5 mm) were counted daily from Day 20–25. Blood and serum samples were obtained from each animal on Days 0 and 23 for cellular blood and IgE titre analysis, respectively. The indicine cattle were refractory to R. decoloratus infestation in comparison with the taurine breed (P < 0.0001). Repeated measurements of blood components pre-infestation revealed a significant (P < 0.05) association with tick count in IgE and red blood cells, haematocrit, and haemoglobin post-infestation. There was also a strong positive correlation between the tick counts and red blood cell numbers, haemoglobin, haematocrit, and IgE concentration (P < 0.0001) following tick challenge. The application of this approach to phenotype host resistance needs to be assessed using higher cattle numbers and with different tick species or genera.

Lightweight and compact smart walking cane.

Devices such as canes and wheelchairs, used to assist locomotion, have remained mostly unchanged for centuries. Recent advances in robotics have the potential to develop smart versions of these devices that can offer better support and living conditions to their users. This is the underlying objective of this project. The existing devices, used during recovery and rehabilitation phases where gait stability is key, are often bulky and cannot be easily migrated from hospital to domestic environments, where maneuvering space tends to be restricted. This article discusses a compact, lightweight and minimally invasive, robotic cane to assist locomotion. The device can assist users with mild locomotion disabilities, e.g., in the final stages of rehabilitation, to maintain and recover their balance in standing and walking situations. This extends previous experiments with alternative control strategies, merged with indicators (based on the Gini index) able to recognize differences between users. Several experiments, with a range of users possessing different mobility impairments, confirm the viability of the robotic cane, with users comfortably using the cane after three minutes, on average, proving its ease of use and low intrusiveness, and with constant support offered during the whole movement. Furthermore, the real-time tuning of the controller gains, via the Gini inequality index, enables adjustment to the user's movement.

Molecular and cellular characterization of four putative nucleotide transporters from the shrimp microsporidian Enterocytozoon hepatopenaei (EHP)

Microsporidia are obligate intracellular parasites that lost several enzymes required in energy production. The expansion of transporter families in these organisms enables them to hijack ATP from hosts. In this study, nucleotide transporters of the microsporidian Enterocytozoon hepatopenaei (EHP), which causes slow growth in economically valuable Penaeus shrimp, were characterized. Analysis of the EHP genome suggested the presence of four putative nucleotide transporter genes, namely EhNTT1, EhNTT2, EhNTT3, and EhNTT4. Sequence alignment revealed four charged amino acids that are conserved in previously characterized nucleotide transporters. Phylogenetic analysis suggested that EhNTT1, 3, and 4 were derived from one horizontal gene transfer event, which was independent from that of EhNTT2. Localization of EhNTT1 and EhNTT2 using immunofluorescence analysis revealed positive signals within the envelope of developing plasmodia and on mature spores. Knockdown of EhNTT2 by double administration of sequence specific double-stranded RNA resulted in a significant reduction in EHP copy numbers, suggesting that EhNTT2 is crucial for EHP replication in shrimp. Taken together, the insight into the roles of NTTs in microsporidian proliferation can provide the biological basis for the development of alternative control strategies for microsporidian infection in shrimp.

Biocontrol potential of native entomopathogenic nematodes against Gonioctena fornicata (Brüggemann, 1873) (Coleoptera, Chrysomelidae) in alfalfa

BackgroundGonioctena fornicata (Brüggemann, 1873) (Coleoptera: Chrysomelidae) inflicts substantial crop damage by consuming alfalfa leaves. The main aim of the study was to develop an efficient, sustainable control method against the pest, considering entomopathogenic nematodes (EPNs) as a potential control agent against soil-dwelling insect pests. This study investigated the impact of two native entomopathogenic nematodes (EPNs), Heterorhabditis bacteriophora (isolate Z-1) and Steinernema feltiae (isolate A-16), on mature larvae and adults of G. fornicata. Concentrations of 250, 500, and 1000 IJs/ml were used for adult and larval stages, and mortality rate was determined at the end of 144 h for larvae and 240 h for adults.ResultsThe highest effect was 94.7% at 120 h for isolate Z-1 and 91.0% at 168 h for isolate A-16 at a concentration of 1000 IJs/ml for adult stages. The highest effect on larval stage was 97.6% at 96 h for isolate Z-1 and 85.8% at 120 h for isolate A-16 at the concentration of 1000 IJs/ml. On the adult stage, isolate Z-1 showed 50.0–67.1% effect at concentrations of 250 and 500 IJs/ml, respectively, while isolate A-16 showed an effect ranging from 46.7 to 63.6%. In the larval stage, isolate Z-1 caused 39.7–77.6% mortality at 250 and 500 IJs/ml concentrations, respectively, while the rate was 32.9–63.9% for isolate A-16. In the trial, isolate Z-1 showed a high efficacy in both stages of G. fornicata.ConclusionsThis study represents the first laboratory investigation encompassing both adult and mature larval stages of G. fornicata. The obtained data offer valuable insights for alternative control strategies targeting G. fornicata.

Modeling and Control of a DC-DC Buck–Boost Converter with Non-Linear Power Inductor Operating in Saturation Region Considering Electrical Losses

The present work proposes a nonlinear model of a buck–boost DC-DC power converter considering the nonlinear magnetic characteristics of the power inductor and electrical losses of the system. The Euler–Lagrange formalism is used for formulating the proposed model. Previous research works have reported mathematical models to describe power inductor dynamics. However, a gap in the literature remains regarding modeling this kind of element when it operates within power converters. Also, a linear-based controller scheme is proposed to regulate a non-ideal buck–boost DC-DC power converter. A methodology for tuning the proposed controller is presented, which considers the nonlinear model structure of the power converter, the linearization procedure based on an identification process, and a frequency domain analysis based on the approximated linear model. Finally, the tuned control scheme is tested on the nonlinear model of the power converter under several operational conditions showing excellent performance by effectively regulating the output voltage. The results are compared with those derived from alternative control strategies, and a better performance is generally obtained.

Phase-Driving Hole Spin Qubits.

The spin-orbit interaction in spin qubits enables spin-flip transitions, resulting in Rabi oscillations when an external microwave field is resonant with the qubit frequency. Here, we introduce an alternative driving mechanism mediated by the strong spin-orbit interactions in hole spin qubits, where a far-detuned oscillating field couples to the qubit phase. Phase-driving at radio frequencies, orders of magnitude slower than the microwave qubit frequency, induces highly nontrivial spin dynamics, violating the Rabi resonance condition. By using a qubit integrated in a silicon fin field-effect transistor, we demonstrate a controllable suppression of resonant Rabi oscillations and their revivals at tunable sidebands. These sidebands enable alternative qubit control schemes using global fields and local far-detuned pulses, facilitating the design of dense large-scale qubit architectures with local qubit addressability. Phase-driving also decouples Rabi oscillations from noise, an effect due to a gapped Floquet spectrum and can enable Floquet engineering high-fidelity gates in future quantum processors.

Biological control of postharvest tomato fruit rots using Bacillus spp. and Pseudomonas spp.

BackgroundPostharvest diseases cause a wide loss to tomato fruits during handling and storing from harvest to consumers. Fungicides are mainly used to control postharvest diseases. Biological control is the eco-friendly substitute strategy used for postharvest diseases management as which becoming promise worldwide. Six bacterial bioagent (i.e., Bacillus subtilis, B. amyloliquefaciens, Pseudomonas resinovorans, P. alcaligenes, P. putida and P. stutzeri) were tested to suppress both Geotrichum candidum and Alternaria alternata causal agents of tomato fruit rots during storage.ResultsIn vitro, most of bioagents significantly reduced mycelial growth rate of G. candidum. Both of B. subtilis and P. stutzeri were the most superior bacterial bioagents with values 67.03 and 72.2%, respectively. In addition, B. subtilis and B. amyloliquefaciens resulted in the most superior over all antagonists against A. alternata. The lowest percent of disease incidence and severity of G. candidum were obtained by B. subtilis and P. stutzeri. The maximum reduction percent of it on tomato fruits was recorded by applying B. subtilis and P. stutzeri with values (90 and 87%) and (91, 89%) in both seasons, respectively. Also, the highest reduction of A. alternata was obtained by using B. subtilis, which resulted in 85 and 84% in both seasons, respectively. The application of bioagents against both pathogens was significantly improved fruit quality aspects (weight loss, vitamin C, TSS and acidity %) during storage period compared to infected control fruits.ConclusionThe findings revealed that both of B. subtilis and P. stutzeri could be potential biological control agents against most postharvest pathogens of tomato fruits. This might be an alternative control strategy instead of fungicides which service the sustainable and organic farming.

Application of Fragmented Extracellular Self-DNA (esDNA) Concept as an Alternative Prophylactic Approach against Vibrio parahaemolyticus and Vibrio harveyi Infection in Brine Shrimp Artemia

The purpose of this study was to investigate species specific inhibitory effects of esDNA isolated from two conspecific organisms: Vibrio parahaemolyticus (VP) and Vibrio harveyi (VH), and to assess the functional role of esDNA to enhance the survival rate of Artemia sp. In an in vitro study, nine doses of Extracellular self-DNA of Vibrio parahaemolyticus (esDNAVP) and Vibrio harveyi (esDNAVH) were used as the target for the challenge test with the conspecific bacteria. In an in vivo study, the protective effect of esDNA was then tested in nauplii of the brine shrimp Artemia at various priming times and concentrations of esDNA under gnotobiotic conditions prior to challenge with VP and VH at the concentration of 5 × 105 CFU mL-1. The results from in vitro study showed that the use of esDNAVP at levels of 24.02 and 48.05 ng µl-1 and esDNAVH at concentrations of 13.33 and 26.67 ng µl-1 were able to inhibit the growth of the conspecific species when added to the culture medium at the concentration level of 5 × 105 CFU mL-1. The results from in vivo study showed that the use of 24.02; 48.05 and 72.07 ng µl-1 of esDNAVP as well as the use of 13.33; 26.67 and 40.00 ng µl-1 of esDNAVH inhibited the growth of VP and VH and enhanced the survival rate of Artemia sp compared to the control treatment (P&lt;0.05). Taken together, we confirmed that esDNA obtained from the extraction and random fragmentation from esDNAVP and esDNAVH, produces a species-specific inhibitory effect on the same species and can serve as a potential alternative strategy for disease control to deliver the functionality of esDNA to the fish and shrimp.

Biocontrol Efficacy of Metschnikowia spp. Yeasts in Organic Vineyards against Major Airborne Diseases of Table Grapes in the Field and in Postharvest.

The aim of this work was to evaluate the efficacy of two antagonistic yeasts, Metschnikowia pulcherrima strain MPR3 and M. fructicola strain NRRL Y-27328 (commercial product NOLI), applied in addition to the "on-farm biological treatments" (BIO) carried out during the production season, for the containment of powdery mildew and grey mould diseases on organic table grapes 'Italia'. The yeast strains were applied in the field three times, and their efficacy was evaluated during the production season and under postharvest conditions. Overall, M. pulcherrima MPR3 combined with BIO treatments reduced disease incidence caused by Erysiphe necator and disease incidence and severity caused by Botrytis cinerea with values between 67.8% and 86.2%, showing higher efficacy than BIO treatments applied alone and in combination with NOLI. Field treatments based on BIO+MPR3 maintained their performance also during fruit storage, protecting grape berries from grey mould development to a greater extent than the other treatments (disease reduction of about 98%). Thus, the presence of M. pulcherrima MPR3 seems to improve disease management both in the field and in postharvest environments, without negative impacts on grape microbial communities. These findings highlight the potential of M. pulcherrima MPR3 as a promising alternative strategy for disease control in organic vineyards and in postharvest, providing sustainable solutions to improve food quality and safety.