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Plant Disease Jun 2024Artemisia argyi is a perennial herb native to East Asia. It is an important traditional Chinese medicinal plant known for its strong flavor and medicinal effects. It is...
Artemisia argyi is a perennial herb native to East Asia. It is an important traditional Chinese medicinal plant known for its strong flavor and medicinal effects. It is rich in active ingredients and has a wide range of biological activities, including anti-inflammatory, antioxidant, and immune regulation properties. From May to July in 2023, a serious leaf rot outbreak occurred on A. argyi in several farms (approximately 200 acres) in Tanghe county (32°46'44" N, 112°43'13" E), Henan Province, China. The incidence rate reached 65% (n=200). Pale yellow spots (1-2 cm in diameter) first appeared on the leaves, then expanded to form irregular yellowish-brown lesions, eventually causing the entire leaves to wither. Diseased leaves (30) were collected and cut into 5 x 5 mm2 pieces in the areas between infected and healthy tissues. The excised plant tissues were sterilized in 75% ethanol and 1% sodium hypochlorite solution for 30 seconds and one minute, respectively. The tissues were then rinsed with sterile water and placed on potato dextrose agar (PDA) followed by incubating at 25 °C for 3 days. The isolated strains belonged to the genera Fusarium and Alternaria. After pathogenicity verification, 25 purified Fusarium strains were obtained. Three representative strains (AC-Q, AC-X, AC-Y) from different regions were used for further studies. Each strain formed abundant aerial mycelium that was initially white and later developed into purple pigments. Aerial conidiophores were sparsely branched, terminating with verticillate phialides. Macroconidia were slender, straight, and measured 21.8 to 47.5 × 3.1 to 4.4 μm, with two to four septa. Microconidia were clavate and measured 8.31 to 11.6 × 2.1 to 3.5 μm. Morphological characteristics were consistent with the species description of Fusarium verticillioides (Sacc.) Nirenberg 1976 (Leslie and Summerell, 2006). The rDNA internal transcribed spacer (ITS), β-tubulin gene (tub2), translation elongation factor 1-alpha gene (tef1), calmodulin (cmdA), RNA polymerase II largest subunit (rpb1) and RNA polymerase II second largest subunit (rpb2) were amplified for molecular identification (O'Donnell et al., 2022). The sequences were deposited in GenBank with accession Nos. OR960548, OR960552, OR960555 (ITS), OR972413, OR972414, OR972415 (tub2), OR797685, OR797686, OR797687 (tef1), OR972410, OR972411, OR972412 (cmdA), PP035106, PP035107, PP035108 (rpb1), and PP035109, PP035110, PP035111 (rpb2). BLASTn analysis of AC-Q sequences exhibited 99 to 100% similarity with F. verticillioides sequences (strains CBS 576.78) MT010888 of cmdA, MT0109566 of rpb1, and MT010972 of rpb2. A phylogenetic tree was constructed with concatenated sequences (tub2, tef1, cmdA, rpb1, rpb2), alongside the sequences of the type strains using the neighbor-joining method. The three strains formed a clade with the type strain CBS 576.78 of F. verticillioides, and were separated from other Fusarium spp. These morphological and molecular identifications indicated that the pathogen was F. verticillioides. Pathogenicity was tested on 10 healthy 2-month-old potted seedlings by spraying them with a conidial suspension (106 conidia ml-1), and 5 seedlings were sprayed with sterilized water as a control. The plants were placed in a climate incubator at 28°C and a relative humidity of approximately 90%. Ten days after seedling inoculation, typical lesions were observed on the treated plants, except in the control group. The reisolated strains were identified as F. verticillioides by morphological and molecular characterization, fulfilling Koch's postulates. F. verticillioides is known to cause Fusarium ear rot on maize, as well as diseases on other plants in China such as Brassica rapa (Akram et al., 2020) and Schizonepeta tenuifolia (Li et al., 2024). This is the first report of F. verticillioides causing leaf rot on A. argyi worldwide. Identification of the pathogen is crucial for implementing management approaches to reduce yield losses.
PubMed: 38932449
DOI: 10.1094/PDIS-03-24-0667-PDN -
Microorganisms Jun 2024Developing new anti-human immunodeficiency virus (HIV) drug candidates that target different sites in HIV-1 replication, with better resistance profiles and lower drug...
Developing new anti-human immunodeficiency virus (HIV) drug candidates that target different sites in HIV-1 replication, with better resistance profiles and lower drug toxicity, is essential to eradicating HIV. This study investigated the potential of fractionated crude extracts of as immunomodulatory or anti-HIV drug candidates. Solid-phase extraction (SPE) was used to fractionate PO4PR2 using three different columns: MAX (Mixed-mode, strong Anion-eXchange), MCX (Mixed-mode, strong Cation-eXchange), and HLB (Hydrophilic-Lipophilic Balance) with methanol gradient methods (5%, 45%, and 95%). An MTT (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) assay was used to assess the cell viability and cytotoxicity of the fractionated crude extract PO4PR2 in the TZM-bl cell lines. This was followed by a luciferase-based antiviral assay to assess the antiviral activity of PO4PR2. A time of addition (TOA) assay was performed to ascertain the mechanism of inhibition employed by the fractionated crude extract of PO4PR2 in the HIV life cycle. The p24 titer was determined using an ELISA, while a luciferase-based antiviral assay was used to evaluate the HIV percentage inhibition for different HIV-1 replication cycles. The TOA assay was established using antiviral drugs that target different sites in the HIV replication cycle. These included maraviroc, azidothymidine, raltegravir, and amprenavir. The immunomodulatory effect of the fractionated crude extracts on CD4+ T cells was measured by a flow cytometric analysis, for which fluorochrome-labelled monoclonal antibodies were used as markers for activation (CD38 and HLA-DR) and exhaustion (PD-1). The MCX fraction demonstrated a more significant anti-HIV inhibition than that of the fractions generated in other columns, with an IC of 0.3619 µg/mL, an HIV inhibition of 77%, 5% HLB (IC: 0.7232 µg/mL; HIV inhibition of 64%), and 5% MAX (IC: 5.240 µg/mL; HIV inhibition of 67%). It was evident from the time of addition data that the crude extract and the 5% MCX fraction inhibited viral binding (68%), reverse transcription (75%), integration (98%), and proteolysis (77%). It was shown that (the MCX fraction) have a significant inhibitory effect on reverse transcription (75% HIV inhibition) and integration (100% HIV inhibition). The 5% MCX ( = 0.0062), 5% HLB ( = 0.0269), and 5% MAX ( = 0.0117) fractionated crude extracts had low levels of CD4+ T cell (CD38 + HLA-DR+) activation compared to those of the AZT treatment, while CD4+ T cell activation was insignificant. The 5% MAX and HLB fractions may possess immunomodulatory compounds with less anti-HIV-1 activity. could be a key source of innovative anti-HIV drugs with immunomodulatory characteristics.
PubMed: 38930532
DOI: 10.3390/microorganisms12061150 -
Microorganisms Jun 2024Wastewater treatment plants (WWTPs) are crucial in the scope of European Commission circular economy implementation. However, bioaerosol production may be a hazard for... (Review)
Review
BACKGROUND
Wastewater treatment plants (WWTPs) are crucial in the scope of European Commission circular economy implementation. However, bioaerosol production may be a hazard for occupational and public health. A scoping review regarding microbial contamination exposure assessment in WWTPs was performed.
METHODS
This study was performed through PRISMA methodology in PubMed, Scopus and Web of Science.
RESULTS
28 papers were selected for data extraction. The WWTPs' most common sampled sites are the aeration tank (42.86%), sludge dewatering basin (21.43%) and grit chamber. Air sampling is the preferred sampling technique and culture-based methods were the most frequently employed assays. sp. (21.43%), sp. (7.14%), sp. (3.57%), sp. (7.14%) and sp. (3.57%) were the most isolated bacteria and sp. (17.86%), sp. (10.71%) and sp. (10.71%) dominated the fungal presence.
CONCLUSIONS
This study allowed the identification of the following needs: (a) common protocol from the field (sampling campaign) to the lab (assays to employ); (b) standardized contextual information to be retrieved allowing a proper risk control and management; (c) the selection of the most suitable microbial targets to serve as indicators of harmful microbial exposure. Filling these gaps with further studies will help to provide robust science to policy makers and stakeholders.
PubMed: 38930526
DOI: 10.3390/microorganisms12061144 -
Foods (Basel, Switzerland) Jun 2024Postharvest diseases, such as black spots caused by , have caused huge economic losses to the tomato industry and seriously restricted its development. In recent years,...
Postharvest diseases, such as black spots caused by , have caused huge economic losses to the tomato industry and seriously restricted its development. In recent years, biological control has become a new method to control postharvest diseases of fruits and vegetables. Our research group screened , a yeast demonstrating a promising control effect on a postharvest black spot disease of tomatoes, and explored its physiological mechanism of prevention and control. Therefore, this study investigated the prevention and control effect of metabolites of on tomato black spot disease and the inhibition effect of main components on . A GC-MS analysis found that isoamyl acetate was the main component of that played an inhibitory role. The results showed that isoamyl acetate could inhibit the growth of and had a certain control effect on postharvest black spots in tomatoes. Our findings suggest that isoamyl acetate could be a promising alternative to fungicides for controlling postharvest black spots in tomatoes.
PubMed: 38928889
DOI: 10.3390/foods13121949 -
Foods (Basel, Switzerland) Jun 2024Filamentous fungi exhibit remarkable adaptability to diverse substrates and can synthesize a plethora of secondary metabolites. These metabolites, produced in response... (Review)
Review
Filamentous fungi exhibit remarkable adaptability to diverse substrates and can synthesize a plethora of secondary metabolites. These metabolites, produced in response to environmental stimuli, not only confer selective advantages but also encompass potentially deleterious mycotoxins. Mycotoxins, exemplified by those originating from , , , and species, represent challenging hazards to both human and animal health, thus warranting stringent regulatory control. Despite regulatory frameworks, mycotoxin contamination remains a pressing global challenge, particularly within cereal-based matrices and their derived by-products, integral components of animal diets. Strategies aimed at mitigating mycotoxin contamination encompass multifaceted approaches, including biological control modalities, detoxification procedures, and innovative interventions like essential oils. However, hurdles persist, underscoring the imperative for innovative interventions. This review elucidated the prevalence, health ramifications, regulatory paradigms, and evolving preventive strategies about two prominent mycotoxins, aflatoxins and ochratoxin A. Furthermore, it explored the emergence of new fungal species, and biocontrol methods using lactic acid bacteria and essential mustard oil, emphasizing their efficacy in mitigating fungal spoilage and mycotoxin production. Through an integrative examination of these facets, this review endeavored to furnish a comprehensive understanding of the multifaceted challenges posed by mycotoxin contamination and the emergent strategies poised to ameliorate its impact on food and feed safety.
PubMed: 38928866
DOI: 10.3390/foods13121920 -
Molecular Diversity Jun 2024Succinate dehydrogenase inhibitors (SDHIs) as one of the fastest-growing fungicide categories for plant protection. In this study, a series of N'-phenyl...
Succinate dehydrogenase inhibitors (SDHIs) as one of the fastest-growing fungicide categories for plant protection. In this study, a series of N'-phenyl pyridylcarbohydrazides as analogues of commercial SDHIs were designed and evaluated for inhibition activity on phytopathogenic fungi to search for potential novel SDHIs. The determination of antifungal activity in vitro and in vivo led to the discovery of a series of compounds with high activity and broad-spectrum property. Especially, N'-(4-fluorophenyl)picolinohydrazide (1c) and N'-(3,4-fluorophenyl)picolinohydrazide (1ae) showed 0.041-1.851 μg/mL of EC values on twelve fungi, superior to positive controls carbendazim and boscalid. In vivo activity, 1c at 50 μg/mL showed 61% of control efficacy at the post-treatment 9th day for the infection of P. piricola on apples, slightly smaller than 70% of carbendazim. In terms of action mechanism, 1c showed strong inhibition activity with IC of 0.107 μg/mL on SDH in Alternaria brassicae, superior to positive SDHI boscalid (IC 0.182 μg/mL). Molecular docking indicated that 1c can well bind with the ubiquinone-binding region of SDH mainly by hydrogen bond, carbon hydrogen bond, π-alkyl, amide-π stacking, F-N and F-H interactions. Furthermore, scanning and transmission electron micrographs showed that 1c was able to obviously change the structure of mycelia and cell membrane. Fluorescence staining analysis showed that 1c could increase both the intracellular reactive oxygen species level and mitochondrial membrane potential. Finally, seed germination test, seedling growth test and cytotoxicity assay showed that 1c had very low toxicity to plant growth and mammalian cells. Thus, N'-phenyl pyridylcarbohydrazides especially 1c and 1ae can be considered promising fungicide alternatives for plant protection.
PubMed: 38926303
DOI: 10.1007/s11030-024-10919-4 -
Journal of Applied Microbiology Jun 2024In this study the antifungal efficacy and phytotoxicity of silica coated porous zinc oxide nanoparticle (SZNP) was analyzed as this nanocomposite was observed to be a...
AIMS
In this study the antifungal efficacy and phytotoxicity of silica coated porous zinc oxide nanoparticle (SZNP) was analyzed as this nanocomposite was observed to be a suitable platform for slow release fungicides and has the promise to bring down the dosage of other agrochemicals as well.
METHODS AND RESULTS
Loading and release kinetics of tricyclazole, a potent fungicide was analyzed by measuring surface area (SBET) using Brunauer-Emmett-Teller (BET) isotherm and LC-MS/MS respectively. The antifungal efficacy of ZnO nanoparticle (ZNP) and SZNP was investigated on two phytopathogenic fungi (Alternaria solani and Aspergillus niger). The morphological changes to the fungal structure due to ZNP and SZNP treatment were studied by field emission-scanning electron microscopy (FESEM). Nanoparticle mediated elevation of reactive oxygen species in fungal samples was detected by analyzing the level of superoxide dismutase, catalase, thiol content, lipid peroxidation and by 2,7-dichlorofluorescin diacetate (DCFH-DA) assay. The phytotoxicity of these two nanostructures was assessed in rice plants by measuring primary plant growth parameters. Further, the translocation of the nanocomposite in the same plant model system was examined by checking the presence of Fluorescein isothiocyanate (FITC) tagged SZNP within the plant tissue.
CONCLUSIONS
ZNP had superior antifungal efficacy than SZNP and caused generation of more reactive oxygen species (ROS) in the fungal samples. Even then SZNP was preferred as an agrochemical delivery vehicle because unlike ZNP alone it was not toxic to plant system. Moreover, as silica in nano form is entomotoxic in nature and nano ZnO has antifungal property, both the cargo (agrochemical) and the carrier system (silica coated porous nano zinc oxide) will have a synergistic effect in crop protection.
PubMed: 38925655
DOI: 10.1093/jambio/lxae153 -
Animal Genetics Jun 2024The African savanna elephant (Loxodonta africana) is the largest terrestrial animal on Earth and is found primarily in Southern and Eastern Africa. It is a hindgut,...
The African savanna elephant (Loxodonta africana) is the largest terrestrial animal on Earth and is found primarily in Southern and Eastern Africa. It is a hindgut, colonic fermenter and subsists on a diet of raw plant materials found in its grazing area. In this study the bacterial, archaeal and fungal populations of seven African savanna elephant fecal metagenomes were first characterized using amplicon sequencing. On the genus level it was observed that the p-1088-a5 gut group in the bacteriome, Methanocorpusulum and Methanobrevibacter in the archaeome and Alternaria, Aurobasidium, Didymella and Preussia in the mycome, predominated. Subsequently, metagenomic shotgun sequencing was employed to identify possible functional pathways and carbohydrate-active enzymes (CAZymes). Carbohydrate catabolic pathways represented the main degradation pathways, and the fecal metagenome was enriched in the glycohydroside (GH) class of CAZymes. Additionally, the top GH families identified - GH43, GH2, GH13 and GH3 - are known to be associated with cellulytic, hemicellulytic and pectolytic activities. Finally, the CAZymes families identified in the African savanna elephant were compared with those found in the Asian elephant and it was demonstrated that there is a unique repository of CAZymes that could be leveraged in the biotechnological context such as the degradation of lignocellulose for the production of second-generation biofuels and energy.
PubMed: 38923598
DOI: 10.1111/age.13458 -
Bioprocess and Biosystems Engineering Jun 2024Surface enhanced Raman spectroscopy (SERS) by using gold nanoparticles (AuNPs) has gained relevance for the identification of biomolecules and some cancer cells....
Surface enhanced Raman spectroscopy (SERS) by using gold nanoparticles (AuNPs) has gained relevance for the identification of biomolecules and some cancer cells. Searching for greener NPs synthesis alternatives, we evaluated the SERS properties of AuNPs produced by using different filamentous fungi. The AuNPs were synthesized utilizing the supernatant of Botrytis cinerea, Trichoderma atroviride, Trichoderma asperellum, Alternaria sp. and Ganoderma sessile. The AuNPs were characterized by ultraviolet-visible spectroscopy (UV-Vis) to identify its characteristic surface plasmon resonance, which was located at 545 nm (B. cinerea), 550 nm (T. atroviride), 540 nm (T. asperellum), 530 nm (Alternaria sp.), and 525 nm (G. sessile). Morphology, size and crystal structure were characterized through transmission electron microscopy (TEM); colloidal stability was assessed by Z-potential measurements. We found that, under specific incubation conditions, it was possible to obtain AuNPs with spherical and quasi-spherical shapes, which mean size range depends on the fungal species supernatant with 92.9 nm (B. cinerea), 24.7 nm (T. atroviride), 16.4 nm (T. asperellum), 9.5 nm (Alternaria sp.), and 13.6 nm (G. sessile). This, as it can be expected, has an effect on Raman amplification. A micro-Raman spectroscopy system operated at a wavelength of 532 nm was used for the evaluation of the SERS features of the AuNPs. We chose methylene blue as our target molecule since it has been widely used for such a purpose in the literature. Our results show that AuNPs synthesized with the supernatant of T. atroviride, T. asperellum and Alternaria sp. produce the stronger SERS effect, with enhancement factor (EF) of 20.9, 28.8 and 35.46, respectively. These results are promising and could serve as the base line for the development of biosensors through a facile, simple, and low-cost green alternative.
PubMed: 38922411
DOI: 10.1007/s00449-024-03053-w -
Toxins May 2024Mycotoxins, secondary metabolites synthesized by various filamentous fungi genera such as , , , , and , are potent toxic compounds. Their production is contingent upon... (Review)
Review
Mycotoxins, secondary metabolites synthesized by various filamentous fungi genera such as , , , , and , are potent toxic compounds. Their production is contingent upon specific environmental conditions during fungal growth. Arising as byproducts of fungal metabolic processes, mycotoxins exhibit significant toxicity, posing risks of acute or chronic health complications. Recognized as highly hazardous food contaminants, mycotoxins present a pervasive threat throughout the agricultural and food processing continuum, from plant cultivation to post-harvest stages. The imperative to adhere to principles of good agricultural and industrial practice is underscored to mitigate the risk of mycotoxin contamination in food production. In the domain of food safety, the rapid and efficient detection of mycotoxins holds paramount significance. This paper delineates conventional and commercial methodologies for mycotoxin detection in ensuring food safety, encompassing techniques like liquid chromatography, immunoassays, and test strips, with a significant emphasis on the role of electrochemiluminescence (ECL) biosensors, which are known for their high sensitivity and specificity. These are categorized into antibody-, and aptamer-based, as well as molecular imprinting methods. This paper examines the latest advancements in biosensors for mycotoxin testing, with a particular focus on their amplification strategies and operating mechanisms.
Topics: Mycotoxins; Biosensing Techniques; Food Safety; Food Contamination; Food Microbiology; Humans; Animals
PubMed: 38922144
DOI: 10.3390/toxins16060249