Bioassay Data Research Articles

Stroke mortality prediction based on ensemble learning and the combination of structured and textual data

For severe cerebrovascular diseases such as stroke, the prediction of short-term mortality of patients has tremendous medical significance. In this study, we combined machine learning models Random Forest classifier (RF), Adaptive Boosting (AdaBoost), Extremely Randomised Trees (ExtraTree) classifier, XGBoost classifier, TabNet, and DistilBERT to construct a multi-level prediction model that used bioassay data and radiology text reports from haemorrhagic and ischaemic stroke patients to predict six-month mortality. The performances of the prediction models were measured using the area under the receiver operating characteristic curve (AUROC), the area under the precision-recall curve (AUPRC), precision, recall, and F1-score. The prediction models were built with the use of data from 19,616 haemorrhagic stroke patients and 50,178 ischaemic stroke patients. Novel six-month mortality prediction models for these patients were developed, which enhanced the performance of the prediction models by combining laboratory test data, structured data, and textual radiology report data. The achieved performances were as follows: AUROC = 0.89, AUPRC = 0.70, precision = 0.52, recall = 0.78, and F1 score = 0.63 for haemorrhagic patients, and AUROC = 0.88, AUPRC = 0.54, precision = 0.34, recall = 0.80, and F1 score = 0.48 for ischaemic patients. Such models could be used for mortality risk assessment and early identification of high-risk stroke patients. This could contribute to more efficient utilisation of healthcare resources for stroke survivors.

PubChem 2023 update.

PubChem (https://pubchem.ncbi.nlm.nih.gov) is a popular chemical information resource that serves a wide range of use cases. In the past two years, a number of changes were made to PubChem. Data from more than 120 data sources was added to PubChem. Some major highlights include: the integration of Google Patents data into PubChem, which greatly expanded the coverage of the PubChem Patent data collection; the creation of the Cell Line and Taxonomydata collections, which provide quick and easy access to chemical information for a given cell line and taxon, respectively; and the update of thebioassay data model. In addition, new functionalities were added to the PubChem programmatic access protocols,PUG-REST and PUG-View, including support for target-centric data download for a given protein, gene, pathway, cell line, and taxon and the addition of the 'standardize' option to PUG-REST, which returns the standardized form of an input chemical structure. A significant update was also made to PubChemRDF. The present paper provides an overview of these changes.

Functional validation of CYP304A1 associated with haedoxan A detoxification in Aedes albopictus by RNAi and transgenic drosophila.

Insect cytochrome P450 monooxygenases play important roles in the detoxification metabolism of endogenous and exogenous compounds. Haedoxan A (HA) from Phryma leptostachya L. is a highly efficient natural pesticide used to control houseflies and mosquitos. CYP4C21 and CYP304A1 were previously demonstrated to be transcriptionally increased in Aedes albopictus in response to HA exposure, but their involvement in HA metabolism is unknown. Our data showed that CYP304A1 expression levels in A. albopictus were highest in third-instar larvae, and the expression level of CYP4C21 decreased significantly with the growth of instars, with the lowest occurring in the pupal stage. Compared with the control, the silencing of CYP304A1 and CYP4C21 genes by chitosan nanoparticle-mediated RNA interference could deplete 58.2% and 54.0% of the expression of corresponding genes, respectively. The bioassay data showed that knocking down the expression of CYP304A1 increased the mortality of A. albopictus when exposed to HA at LC30 and LC50 doses, but did not significantly increase mortality after silencing CYP4C21. Our data demonstrated that CYP304A1, but not CYP4C21, may be involved in HA detoxification. Moreover, the resistance ratio of CYP304A1 overexpressing flies was approximately 2-fold higher than that of the control line. The metabolized product of HA by CYP304A1 needs to be further confirmed by in vitro expression. This finding showed that inducibility was not always linked to detoxifying capabilities, and enhanced our understanding of the molecular basis of HA metabolic detoxification in A. albopictus. © 2022 Society of Chemical Industry.

The role of voltage-gated sodium channel genotypes in pyrethroid resistance in Aedes aegypti in Taiwan.

BackgroundAedes aegypti is the major vector of dengue that threatens public health in tropical and subtropical regions. Pyrethroid-based control strategies effectively control this vector, but the repeated usage of the same insecticides leads to resistance and hampers control efforts. Therefore, efficient and prompt monitoring of insecticide resistance in local mosquito populations is critical for dengue control.Methodology/Principal findingWe collected Ae. aegypti in southern Taiwan in March and October 2016. We analyzed the voltage-gated sodium channel (vgsc) genotypes of parentals (G0) and G1 adults after cypermethrin insecticide bioassay. Our results showed that four VGSC mutations (S989P, V1016G, F1534C, and D1763Y) associated with resistance were commonly detected in field-collected Ae. aegypti. The frequencies of these four mutations in the local mosquito population were significantly higher in October (0.29, 0.4, 0.27 and 0.11) than in March (0.09, 0.16, 0.18 and 0.03). Specific vgsc combined genotypes composed of the one to four such mutations (SGFY/SGFY, SVCD/SVCD, SGFY/PGFD, SVCD/SGFY, PGFD/PGFD, and SVCD/PGFD) shifted towards higher frequencies in October, implying their resistance role. In addition, the cypermethrin exposure bioassay data supported the field observations. Moreover, our study observed an association between the resistance level and the proportion of resistance genotypes in the population.Conclusions/SignificanceThis is the first study to demonstrate the role of four-locus vgsc genotypes in resistance evaluation in a local Ae. aegypti population in Taiwan. This alternative method using resistance-associated genotypes as an indicator of practically insecticide resistance monitoring is a useful tool for providing precise and real-time information for decision makers.

Nutrient limitation of phytoplankton in three tributaries of Chesapeake Bay: Detecting responses following nutrient reductions

Many coastal ecosystems suffer from eutrophication, algal blooms, and dead zones due to excessive anthropogenic inputs of nitrogen (N) and phosphorus (P). This has led to regional restoration efforts that focus on managing watershed loads of N and P. In Chesapeake Bay, the largest estuary in the United States, dual nutrient reductions of N and P have been pursued since the 1980s. However, it remains unclear whether nutrient limitation – an indicator of restriction of algal growth by supplies of N and P – has changed in the tributaries of Chesapeake Bay following decades of reduction efforts. Toward that end, we analyzed historical data from nutrient-addition bioassay experiments and data from the Chesapeake Bay long-term water-quality monitoring program for six stations in three tidal tributaries (i.e., Patuxent, Potomac, and Choptank Rivers). Classification and regression tree (CART) models were developed using concurrent collections of water-quality parameters for each bioassay monitoring location during 1990-2003, which satisfactorily predicted the bioassay-based measures of nutrient limitation (classification accuracy = 96%). Predictions from the CART models using water-quality monitoring data showed enhanced nutrient limitation over the period of 1985-2020 at four of the six stations, including the downstream station in each of these three tributaries. These results indicate detectable, long-term water-quality improvements in the tidal tributaries. Overall, this research provides a new analytical tool for detecting signs of ecosystem recovery following nutrient reductions. More broadly, the approach can be adapted to other waterbodies with long-term bioassays and water-quality data sets to detect ecosystem recovery.

Glucosinolate Sulfatases-Sulfatase-Modifying Factors System Enables a Crucifer-Specialized Moth To Pre-detoxify Defensive Glucosinolate of the Host Plant.

Numerous herbivores orally secrete defense compounds to detoxify plant toxins. However, little is known about the role of orally secreted enzymes by a specialized pest, Plutella xylostella, in the detoxification of plant defense compounds. Three glucosinolate sulfatases (GSSs) or two sulfatase-modifying factors (SUMF1s) mutant strains were established on the basis of CRISPR/Cas9 technology to validate the existence of a species-specific GSSs-SUMF1s system. In comparison to the bioassay data from mutant strains of GSS1/GSS2 or SUMF1a/SUMF1b, GSS3 had a minimal role because no significant change was found in GSS3-/- under different feeding contexts. Antibody-based technologies were used to examine GSSs-related deficient strains, and the results showed that the GSS1 protein was primarily released through larval oral secretion. On the basis of high-performance liquid chromatography, we found that GSS1 was secreted to pre-desulfate the typical plant defensive glucosinolates known as 4-(methylsulfinyl)butyl glucosinolate (4MSOB-GL) to suppress the production of the toxic substance, which is referred to as pre-detoxification strategy. These findings highlighted that the GSSs-SUMF1s system is the key factor for counteradaptation of P. xylostella to cruciferous plants, which strengthens the concept that herbivores deploy pre-detoxification strategies to disrupt the plant chemical defenses to facilitate the colonization process.

Current status of infection with infectious hypodermal and hematopoietic necrosis virus (IHHNV) in the Peruvian and Ecuadorian shrimp industry.

Infection with infectious hypodermal and hematopoietic necrosis virus (IHHNV) is a crustacean disease that caused large-scale mortality in Penaeus stylirostris, deformity and growth retardation in Penaeus vannamei and Penaeus monodon. We surveyed the presence of IHHNV in three major shrimp-producing regions in Ecuador, namely Guayas, El Oro, and Esmeralda. The data show that IHHNV is endemic (3.3–100% prevalence) to shrimp farms in these regions. The whole genome sequences of representative circulating IHHNV genotypes in Ecuador and Peru showed that these genotypes formed a separate cluster within the Type II genotypes and were divergent from other geographical isolates of IHHNV originating in Asia, Africa, Australia, and Brazil. In experimental bioassays using specific pathogen-free (SPF) P. vannamei, P. monodon, and P. stylirostris and representative IHHNV isolates from Ecuador and Peru, the virus did not cause any mortality or induce clinical signs in any of the three penaeid species. Although IHHNV-specific Cowdry type A inclusion bodies were histologically detected in experimentally challenged P. vannamei and P. monodon and confirmed by in situ hybridization, no such inclusions were observed in P. stylirostris. Moreover, P. vannamei had the highest viral load, followed by P. monodon and P. stylirostris. Based on IHHNV surveillance data, we conclude that the currently farmed P. vannamei lines in Ecuador are tolerant to circulating IHHNV genotypes. The genome sequence and experimental bioassay data showed that, although the currently circulating genotypes are infectious, they do not induce clinical lesions in the three commercially important penaeid species. These findings suggest a potentially evolving virus-host relationship where circulating genotypes of IHHNV co-exist in equilibrium with P. vannamei raised in Peru and Ecuador.

Comparison of the lower limit of benchmark dose confidence interval with no-observed-adverse-effect level by applying four different software for tumorigenicity testing of pesticides in Japan

The benchmark dose (BMD) approach is updated to create an international harmonizing process following rapid theoretical sophistication. We calculated the lower limit of BMD confidence interval (BMDL) for carcinogenicity based on 193 tumorigenicity bioassay data published in 50 pesticide risk assessment reports by the Food Safety Commission of Japan (FSCJ) to validate the appropriateness and necessity for the refinement of the FSCJ-established BMD guidance. Three well-known BMD software, PROAST, BMDS, and BBMD were used to compare their BMDLs with no-observed-adverse-effect levels (NOAELs) for carcinogenicity. Recently implemented methodologies such as model averaging or Bayesian inference were also used. Our results indicate that the BMD approach provides a point of departure similar to the NOAEL approach if the data used exhibit a clear dose-response relationship. In some cases, particularly in software with a frequentist approach, the calculation failed to provide BMDL or provided considerably lower BMDLs than NOAELs. However, most of the datasets that resulted in failed calculations or extremely low BMDLs exhibited unclear dose-response relationships, i.e., non-monotonous and sporadic responses. The expert review on the shape of the dose-response plot would help better apply the BMD approach. Furthermore, we observed that Bayesian approaches provided fewer failed or extreme BMD calculations than the frequentist approaches.

Susceptibility and field exposure of Striacosta albicosta (Lepidoptera: Noctuidae) eggs and larvae in Ontario, Canada to four insecticides.

Striacosta albicosta Smith (Lepidoptera: Noctuidae) is a primary pest of corn, Zea mays L., in the Great Lakes region, causing yield loss and exacerbating mycotoxin contamination of grain. Foliar insecticides are currently used to manage S.albicosta; however, the toxicity and residual activity of these insecticides against S.albicosta are unknown. Laboratory and field bioassays were conducted to determine the susceptibility and period of in-field efficacy provided by chlorantraniliprole, lambda-cyhalothrin, spinetoram, and methoxyfenozide against S.albicosta. Bioassay data were used to simulate management scenarios. For all insecticides tested, 1st instars were highly susceptible to the recommended field application rates and were >3-fold more susceptible to insecticides than 3rd instars. Insecticide activity decreased after application for all insecticides, with chlorantraniliprole having the longest residual activity. In simulated management scenarios where an insecticide was applied at or below the recommended 5% egg mass threshold with additional oviposition, methoxyfenozide application resulted in greater larval survival 14 days after application (DAA) than the other insecticides tested. In scenarios where insecticides were applied 7 days before threshold was reached, all insecticides resulted in larval survival. These data demonstrate that chlorantraniliprole, lambda-cyhalothrin and spinetoram, applied in conjunction with monitoring, provide effective control of S.albicosta larvae for 10-14 days, whereas methoxyfenozide provides effective control for less than 7 days. © 2022 Society of Chemical Industry.

Toxicity, antifeedant and physiological effects of trans-anethole against Hyphantria cunea Drury (Lep: Arctiidae)

Plant secondary metabolites are currently known to interfere with basic metabolic, behavioral and physiological processes of insects. In the current study, the biological and physiological effects of trans-anethole were investigated against Hyphantria cunea Drury. The bioassay data demonstrated the high toxicity of trans-anethole against the fourth-instar larvae with the LC30, LC50 and LC90 values of 0.72, 1.41 and 7.20 μL/mL, respectively. Also the concentrations of LC30 and LC50 showed 53 and 87% feeding deterrency against the larvae. The biochemical experiments revealed that oral exposure of trans-anethole decreased the activities of digestive enzymes, acetylcholinesterase and the contents of energy reserves while, it induced the activities of detoxifying and antioxidant enzymes compared to control. In fact, trans-anethole induced the inhibition of digestion and AChE activities accompanied by imbalance in metabolic and oxidative processes so it may be recommended as a potent biopesticide in control of H. cunea populations.

Toxicity of green synthesized TiO2 nanoparticles (TiO2 NPs) on zebra fish

Nanoparticles (NPs) is usually fabricated by physical and chemical methods which, consequently, may have adverse effects for human and environment. Therefore, novel environmentally friendly synthesis methods for are essential and preferred. The purpose of this study was to synthesize TiO2 NPs using Echinophora cinerea extract and evaluate its toxicity on zebra fish. In the work, extraction phase was performed using a water as solvent. FTIR, XRD, SEM, and DLS analyzes were performed to determine the characteristics of synthesized TiO2 NPs. The effect of different parameters such as pH, extract concentration, TiO2 concentration, and temperature were investigated on TiO2 NP and optimized. Then, the acute toxicity of synthesized TiO2 NPs at different concentrations was investigated for 96 h on zebra fish. The bioassay data was analyzed via probit regression technique. Based on the obtained results, the optimal conditions for the synthesized TiO2 NPs were 9, 20 g/L, 0.4 g/L, and 25 °C for pH, extract concentration, TiO2 concentration and temperature, respectively. Both FTIR and XRD analysis confirmed the stability and structure of the synthesized NPs. According to SEM and DLS analysis, the synthesized NPs were spherical in shape and about 244.7 nm in diameter. Based on bioassay, LC50 for green synthesized TiO2 NPs with Echinophora cinerea extract at 48 h was 300 mg/L, which revealed a less hazardous material.

Efficiency of Some Insecticides in Controlling Citrus Leafminer, Phyllocnistis citrella Stainton (Lepidoptera: Gracillariidae)

The toxicity of four commercial insecticides (mineral oil, azadirachtin, phenthoate and abamectin) in addition to mint oil (variety of terpenoids), against the citrus leaf-miner, Phyllocnistis citrella, larvae, was tested under laboratory conditions using the leaf-dipping method. The bioassay data indicated that abamectin was the most toxic insecticide against P. citrella larvae, followed by azadirachtin, phenthoate, mint oil and finally mineral oil. On the other hand, field evaluation showed that the highest larval mortality was 94.79 and 83.87% induced by abamectin and azadirachtin, respectively, five days after the 2nd application. Mineral oil and phenthoate showed a 72.43 and 61.4% mortality respectively, at 11 days after the 2nd application, and finally mint oil, 49.82% three days after the 1st application.

Excretion of Pu-238 during Long-term Chelation Therapy by Repeated DTPA Inhalation.

An individual underwent an extensive diethylenetriaminepentaacetate (DTPA) chelation therapy that started several months after plutonium incorporation, most likely by inhalation of a soluble compound. After receiving multiple intravenous infusions of DTPA, the patient continued the treatment by pulmonary delivery of aerosolized DTPA. The purpose of the present work is to provide and discuss the bioassay data obtained during the DTPA aerosol therapy and compare them with those under the DTPA infusion therapy that have been largely interpreted elsewhere. As with DTPA given intravenously, each delayed DTPA inhalation increased the clearance of plutonium not only in urine but also in feces, thus demonstrating the ability to remove plutonium retained by extrapulmonary tissues. Also, the slow decline of increased plutonium urinary elimination together with enhanced fecal excretion are two features coherent with the contribution of intracellular chelation to overall decorporation. The therapeutic benefit of DTPA inhalation appeared lower than with DTPA infusion, most likely due to a lower amount of DTPA reaching the systemic compartments where plutonium chelation predominates. The results suggest that DTPA administration through aerosol could be an alternative to the invasive procedure using a needle, i.e., intravenous injection/infusion, when protracted decorporation therapy is needed following transuranic internalization. Indeed, the patient may be more inclined to undergo a chelation treatment for a longer period because taking DTPA by inhalation may make it less cumbersome and painful.

Salmon lice in the Pacific Ocean show evidence of evolved resistance to parasiticide treatment

Parasitic salmon lice (Lepeophtheirus salmonis) threaten the economic and ecological sustainability of salmon farming, and their evolved resistance to treatment with emamectin benzoate (EMB) has been a major problem for salmon farming in the Atlantic Ocean. In contrast, the Pacific Ocean, where wild salmon are far more abundant, has not seen widespread evolution of EMB-resistant lice. Here, we use EMB bioassays and counts of lice on farms from the Broughton Archipelago, Canada—a core region of salmon farming in the Pacific—to show that EMB sensitivity has dramatically decreased since 2010, concurrent with marked decrease in the field efficacy of EMB treatments. Notably, these bioassay data were not made available through public reporting by industry or by the federal regulator, but rather through Indigenous-led agreements that created a legal obligation for salmon-farming companies to provide data to First Nations. Our results suggest that salmon lice in the Pacific Ocean have recently evolved substantial resistance to EMB, and that salmon-louse outbreaks on Pacific farms will therefore be more difficult to control in the coming years.

131I Intake and Regulatory Compliance Following Administration of Capsular 131I Sodium Iodide for Treatment of Thyroid Disorders.

Intake of 131I by nuclear medicine technologists and physician Authorized Users was evaluated using bioassay data from administration of 131I sodium iodide in capsular form during a 5-year period. Maximum estimated annual intake of 131I sodium iodide, based on bioassay measurements performed at 24 hours post administration, ranged from 10.9 to 35.6 kBq for all staff. Intake by Authorized Users was higher than that by nuclear medicine technologists due to state requirement for Authorized Users to physically administer therapeutic dosages of radiopharmaceuticals. All intake values were less than 10% of the 131I thyroid ALI of 50 microcurie3 (1,850 kBq), indicating that monitoring may be discontinued for staff participating in routine administration of 131I capsules in which volatilization is not suspected. Elimination of bioassay performance has permitted more flexibility in patient scheduling and improved workflow and efficiency.

Photocatalytic removal of diazinon from aqueous solutions: a quantitative systematic review.

Diazinon is a widely used pesticide that can be effectively degraded in aqueous solutions via photocatalytic oxidation. This quantitative systematic review was conducted to shed light on the various aspects of photocatalytic diazinon removal based on evidence. A systematic search was performed in Scopus, PubMed, Web of Science, Embase, and Ovid databases with keywords including diazinon, photocatalysis, and their equivalents. The search was limited to original articles in English published between January 1, 2010, and March 25, 2021. The results were expressed by descriptive statistics including mean, SD, median, and percentiles, among others. The initial electronic and manual search retrieved 777 articles, among which 41 studies comprising 49 trials were qualified for data synthesis. The reported diazinon degradation rate ranged from 2 to 100%, with a mean ± SD of 59.17 ± 28.03%. Besides, ZnO/UV, WO3/UV, TiO2/UV, and TiO2/Vis, in sequence, were the most widely used processes with the highest efficacies. Solution pH in the range of 5-8, catalyst dose below 600mg/L, diazinon initial concentration below 40mg/L, and contact time of 20-140min could be the optimum conditions. Diazinon degradation obeyed the first-order kinetic model with kobs between 0.0042 and 1.86min-1 and consumed energy of 38.93-350.36 kWh/m3. Diazoxon and IMP were the most detected by-products of diazinon degradation although bioassay data were scarce. Based on the results, photocatalytic processes are very efficient in removing diazinon from aqueous solutions although more elaborate studies are needed to assess the mineralization rate and effluent toxicity.

Radiation Dose to Veterinarians and Veterinary Technicians During Radioiodine Treatment of Felis Catus.

The uptake of radioiodine in veterinarians or veterinary staff when 131I is administered via injection to domesticated cats (Felis catus) with hyperthyroidism has not been well studied. Veterinarians and staff undergo specific training for the handling of radioiodine injection of cats to minimize and prevent an inhalation intake. An in-vivo bioassay is performed post cat injection to determine if 131I was inhaled or absorbed. The frequency of in-vivo bioassays requires dedicated time of the veterinarians and those who must perform the bioassay. Bioassay data from veterinarians and staff at the Colorado State University Veterinary Teaching Hospital administering 131I from the past 20 years were analyzed (n = 168) to ascertain if there is a correlation between the amount of time elapsed between the 131I administration, the bioassay, and the net counts resulting from the bioassay. The amount of 131I administration and the bioassay net counts were also analyzed to determine if there was a correlation. No correlations were found, and out of 168 131I administrations over 20 years, only 3 bioassays resulted in measurable doses of 131I with a committed dose equivalent (CDE) of 0.19 mSv, 0.77 mSv, and 1.6 mSv. The current precautions taken to prevent the inhalation intake of 131I appear sufficient to consider changing the requirements for veterinary bioassay after routine administration of 131I to cats.

NP Analyst: An Open Online Platform for Compound Activity Mapping.

Few tools exist in natural products discovery to integrate biological screening and untargeted mass spectrometry data at the library scale. Previously, we reported Compound Activity Mapping as a strategy for predicting compound bioactivity profiles directly from primary screening results on extract libraries. We now present NP Analyst, an open online platform for Compound Activity Mapping that accepts bioassay data of almost any type, and is compatible with mass spectrometry data from major instrument manufacturers via the mzML format. In addition, NP Analyst will accept processed mass spectrometry data from the MZmine 2 and GNPS open-source platforms, making it a versatile tool for integration with existing discovery workflows. We demonstrate the utility of this new tool for both the dereplication of known compounds and the discovery of novel bioactive natural products using a challenging low-resolution antimicrobial bioassay data set. This new platform is available at www.npanalyst.org.

Potential Characterization and Identification of Indigenous Rhizobacteria Species of Ultisol Soil to Support the Growth of Several Superior Upland Rice Varieties

TG4 and SR2 were isolates of indigenous bacteria from cassava roots from Banyumas Regency, Central Java. Both are local isolates from marginal lands that can be developed as biofertilizers. This study aimed to determine the potential characteristics of bacterial isolates TG4 and SR2 in supporting the growth of superior upland rice and determining species identity based on the molecular analysis of 16S rRNA. Bacterial isolates TG4 and SR2 were determined for their potency of Plant Growth Promoting Rhizobacteria (PGPR) by fixing N2, dissolving phosphate, and producing Indole Acetic acid (IAA). Bioassays were carried out on TG4 and SR2 isolates by application of bacterial isolates (B0 = control, B1 = TG4, B2 = isolates SR2, B3 = isolates TG4 and SR2) on superior upland rice (V1 = INPAGO UNSOED 1, V2 = UNSOED PARIMAS, V3 = INPAGO 8) in sterile ultisol soil. The F test was used for bioassay data analysis, and if there was a significant difference, it was further tested with Duncan's Multiple Range Test (DMRT) with an error rate of 5%. The identity of bacterial species TG4 and SR2 was obtained by analyzing 16S rRNA sequences and genetic relationships through phylogenetic trees. The results showed that the isolates of TG4 were phosphate solubilizing bacteria and producers of IAA, while the isolates of SR2 were nitrogen fixing, phosphate solubilizing, and IAA producers. The application of bacterial isolates TG4 and SR2 significantly affected root length wet and dry weight of upland rice plants, with the highest value obtained from using a consortium of TG4 and SR2 bacteria. Bacterial isolates TG4 were identified as Bacillus albus, while SR2 as B. Paramycoides. Bacterial isolates TG4 and SR2 can be used as biofertilizers to support superior upland rice growth.

The Fungus Metarhizium sp. BCC 4849 Is an Effective and Safe Mycoinsecticide for the Management of Spider Mites and Other Insect Pests.

Simple SummaryThe spider mite is a destructive pest of various crops during warm and dry conditions in tropical countries, including Thailand. The pest is difficult to control despite synthetic acaricide use. In the field, insect populations gradually develop resistance to synthetic pesticides over long-term use. The use of entomopathogenic fungi is more human- and environmentally friendly. We searched and identified a potential fungal isolate from a culture collection, focusing on the genus Metarhizium. Metarhizium sp. BCC 4849 not only controls the spider mite but also plays a significant role as a natural regulator of other insect pests. Here, we investigated its infection process on the mite, optimized a conidial formulation for extended shelf life, and conducted toxicological assays in animals to assess its biosafety in humans. The fungal genome has been sequenced. The genomic data indicated that oxidoreduction proteins; zinc-, heme-, and iron-binding proteins; and transmembrane transporters are abundant in the genome.Five isolates of Metarhizium sp. were evaluated for their pathogenicity against the spider mite (Tetranychus truncatus Ehara) (Acari: Tetranychidae) and Metarhizium sp. BCC 4849 resulted in the highest mortality (82%) on the 5th day post-inoculation (DPI). Subsequent insect bioassay data indicated similar high virulence against five other insects: African red mites (Eutetranychus africanus Tucker) (Acari: Tetranychidae), bean aphid (Aphis craccivora Koch) (Hemiptera: Aphididae), cassava mealybug (Phenacoccus manihoti Matile-Ferrero) (Hemiptera: Pseudococcidae), sweet potato weevil (Cylas formicarius Fabricius) (Coleoptera: Brentidae), and oriental fruit fly (Bactrocera dorsalis Hendel) (Diptera: Tephritidae), at mortalities of 92–99%, on 3rd–6th DPI, and in laboratory conditions. The pathogenicity assay against E. africanus in hemp plants under greenhouse conditions indicated 85–100% insect mortality on 10th DPI using the fungus alone or in combination with synthetic acaricide. Genome sequencing of Metarhizium sp. BCC 4849 revealed the high abundance of proteins associated with zinc-, heme-, and iron-binding; oxidation-reduction; and transmembrane transport, implicating its versatile mode of interaction with the environment and adaptation to various ion homeostasis. The light and scanning electron microscopy indicated that at 24 h post inoculation (PI), adhesion and appressorial formation occurred, notably near the setae. Most infected mites had stopped moving and started dying by 48–72 h PI. Elongated hyphal bodies and oval blastospores were detected in the legs. At 96–120 h PI or longer, dense mycelia and conidial mass had colonized the interior and exterior of dead mites, primarily at the bottom than the upper part. The shelf-life study also indicated that conidial formulation combined with an oxygen-moisture absorber markedly enhanced the viability and germination after storage at 35 °C for four months. The fungus was tested as safe for humans and animals, according to our toxicological assays.