Search Results (14,062)

Pasteuria penetrans (Pp) is a mycelial and endospore-forming bacterium that parasitizes Meloidogyne spp. A single Pp population may contain multiple genotypes that differ in their spore-attachment specificity. Consequently, a subpopulation within a Pp isolate, which can attach to one Meloidogyne species, may fail to attach to another. Repeated culturing of that Pp isolate, on different Meloidogyne species, may therefore lead to shifts in host specificity. We tested this hypothesis using M. luci and M. arenaria, both of which are quite poor hosts of the Pp3 isolate maintained on M. javanica. Using relatively high spore concentrations (10⁶ spores/mL), low levels of attachment and infection were obtained, and after three successive selection cycles, Pp3 sub-isolates adapted to M. luci and M. arenaria were generated. This selection process was associated with a fitness cost, expressed as reduced spore attachment on M. javanica. The shift in host specificity proved reversible. When the adapted Pp3 M. arenaria and Pp3 M. luci sub- isolates were subsequently selected on M. javanica, for two generations, they regained the ability to attach on M. javanica but with a corresponding fitness cost, of spore attachment on M. arenaria and M. luci. These results demonstrate that Pp host specificity is plastic and capable of rapid selection-driven changes in attachment patterns, although such shifts are accompanied by fitness trade-offs. Full article

The northward expansion of Dirofilaria spp. is a current medical and veterinary concern. However, it is unclear how far north the parasite has spread in Western Siberia and what species of mosquito can carry and transmit it. This study examined Dirofilaria spp. infection in Aedes mosquitoes in the taiga zone of the Irtysh Basin. The mosquito species were identified based on morphology, and Dirofilaria spp. were identified using PCR. Of the 13 habitats surveyed, 24 of 2205 mosquito samples were infected with D. repens and 1 with Dirofilaria sp. The highest infection rate (~7.6) was recorded in Tobolsk, Tyumen region, at 58.4° N. Mosquito infection was recorded as far north as 61° N in Khanty-Mansiysk. The presence of the infective L3 stage of the parasite was recorded up to 60° N in Bobrovsky. Nine species of mosquitoes were found to be infected with D. repens: Aedes rossicus, Aedes behningi, Aedes cantans, Aedes communis, Aedes cyprius, Aedes euedes, Aedes excrucians, Aedes flavescens, and Aedes sticticus. Two of these species, Ae. behningi and Ae. communis, were competent vectors of the parasite. Thus, D. repens has successfully adapted to the Aedes mosquito in the taiga zone of Siberia. Full article

The pathways governing the transformation of crop residues into humic acid (HA) remain incompletely understood because multiple biochemical routes may operate simultaneously during composting-like humification. In this study, a 30-day solid-state humification experiment was conducted by integrating physicochemical pretreatments, including steam explosion (SE) and ammonification coupled with steam explosion (SE-N), with a multi-fungal inoculation strategy involving Aspergillus niger, Candida spp., and Phanerochaete chrysosporium. Across three representative substrate–pretreatment systems and 81 experimental groups, the contents of lignocellulosic fractions, reducing sugars (RS), a UV-280-based soluble nitrogen-containing precursor index (operationally denoted as SNP), fulvic acid (FA), and HA were compared. The results showed that neither physicochemical pretreatment alone nor single-strain inoculation was sufficient to achieve substantial HA formation. SE mainly improved substrate accessibility and promoted carbon release, whereas ammonification provided essential nitrogen preloading for subsequent precursor coupling. In the saccharification-dominant treatment, RS reached 27.5%, but HA remained negligible. In the Candida-only treatment, the soluble nitrogen-containing precursor index increased markedly, yet HA formation was still minimal. By contrast, the highest HA yield (13.7%) was obtained under multi-fungal co-inoculation, particularly when nitrogen preloading by ammonification was combined with concurrent accumulation of carbon and aromatic precursors. The data suggest that lignin-targeting activity by P. chrysosporium was associated with the likely generation of phenolic and quinone-like intermediates that bridged the condensation of sugar- and nitrogen-derived compounds. Overall, the findings support a synergistic humification framework in which polysaccharide depolymerization, microbial nitrogen transformation, and lignin-derived aromatic precursor formation jointly contribute to HA accumulation, rather than a single linear pathway dominating the process. Full article

This study investigated the extraction and characterization of pectin from the peel and the pulp of Opuntia ficus-indica (OFI) cladodes, aiming to define sustainable and optimized extraction conditions and to evaluate the applicability of the extracted pectin in film development for food packaging. Cladodes were chemically characterized, confirming their richness in sugars, dietary fiber, and bioactive compounds. Different solvents (citric acid, acetic acid, and acidified water) and pH values (1.5–7) were evaluated, with citric acid (1% w/v) selected as the most suitable solvent due to its extraction efficiency and food-grade nature. Process optimization was performed using response surface methodology (RSM), considering liquid-to-solid ratio (5–15 v/w), extraction time (40–60 min), and temperature (70–90 °C). The regression models showed good fit, with R² values of 88.79% for peel and 89.20% for pulp. Extraction yield was mainly influenced by liquid-to-solid ratio, time, and temperature, with optimal conditions defined as 10 v/w, 40 min, and 80 °C. Pectin obtained under optimized conditions was characterized by Fourier-transform infrared (FTIR) spectroscopy, showing functional groups consistent with commercial citrus pectin, while galacturonic acid content and degree of esterification confirmed its purity and classification as low-methoxyl pectin, supporting its suitability for further film production. Additionally, the extracted pectin was successfully incorporated into blended films with commercial pectin, resulting in films with improved water resistance and water vapor barrier performance. Overall, OFI cladodes represent a promising and sustainable source of pectin for biodegradable food packaging applications. Full article

Allium spp. (alliums) are susceptible to rot-diseases caused by pathogenic Fusarium spp., including F. proliferatum (FP) and F. oxysporum (FO), which can cause severe crop losses. A series of pathogenicity tests of four FP isolates from garlic (Allium sativum), four FO isolates from garlic and three FO isolates from onion (Allium cepa var. cepa) were conducted on garlic seedlings and cloves, onion seedlings and bulbs, and shallot (Allium cepa var. aggregatum) bulbs to determine the virulence of the isolates. A combination of PCRs and whole-genome sequencing (WGS), using ONT long-read technology, was used to identify genes encoding putative effectors. The FP isolates caused moderate to severe symptoms in garlic and contained homologues of SIX2, CRX1 and CRX2, and either SIX9 or SIX13. The FOC ex onion isolates caused severe disease symptoms in all allium species tested, while FO from garlic caused moderate to severe disease in garlic but only mild symptoms in onion and shallot. Fusarium oxysporum f. sp. cepae ex onion potentially contained homologues of SIX3, SIX5, SIX7, SIX9, SIX10, SIX12, SIX14, C5, CRX1 and CRX2. The most pathogenic FO isolate to garlic was Fo_VPRI44630 ex garlic, which contained SIX9, SIX13, C5, CRX1 and CRX2. The difference in virulence and putative effector profiles suggests evidence of host-associated differentiation, and as such, the f. sp. or race designation between FO ex garlic and FO ex onion should be investigated further. This is an important finding for future research into best management practices and breeding for disease resistance to FO and FP in garlic. Full article

Spider mites (Oligonychus trichardti) are emerging as a major constraint to Urochloa forage productivity in East Africa; however, knowledge of genotypic variation and tolerance remains limited. Herein, 55 Urochloa genotypes were evaluated under field-infested and non-infested conditions across two seasons using an alpha-lattice design. Agronomic and physiological traits, including plant height (PH), tiller number (TN), the Normalized Difference Vegetation Index (NDVI), total dry weight (TDW), and mite damage indices (visual severity index (VSI) and stress tolerance index (STI)) were assessed. Infestation reduced biomass by 22.4% on average, with reductions of up to 45% in susceptible genotypes. Significant genotypic variation was detected for PH, TN, TDW, and VSI. Heritability estimates under mite infestation were moderate to high for all traits except TDW, suggesting that direct selection of these traits could be effective in breeding programs aimed at improving mite resistance. VSI showed a strong negative correlation with NDVI (r = −0.63), supporting its value as a phenotyping indicator of spider mite response. Additive main effects and multiplicative interaction (AMMI) analysis revealed significant genotype × environment interactions for TDW. The AMMI biplot identified Xaraes, ILRI_13369, and ILRI_14787 as high-yielding and stable genotypes, while the AMMI Stability Value (ASV) and the Weighted Average of Absolute Scores from the Best Linear Unbiased Prediction (WAASB) identified CIAT_16122, CIAT_664, ILRI_14801, ILRI_14787, and ILRI_13266 as the most stable and broadly adapted across environments. STI further highlighted ILRI_13751 (2.71) and ILRI_13531 (2.58) as highly tolerant under stress. Overall, the study reveals substantial exploitable genetic diversity and identifies stable, high-yielding, and mite-tolerant genotypes suitable for breeding to improve Urochloa productivity in East Africa. Full article

Eucalyptus spp. are the most important timber and pulpwood species in southern China. This tree species is frequently and severely damaged by the leaf-eating pest Buzura suppressaria, which significantly impairs photosynthesis and hinders the healthy and sustainable development of the Eucalyptus industry. To investigate the defensive responses of Eucalyptus urophylla × Eucalyptus grandis to pest (B. suppressaria)-feeding and leaf-clipping stress, this study measured the temporal changes in defense enzyme activities and defense compounds in Eucalyptus under conditions of pest-feeding and leaf-clipping stresses, aiming to provide a theoretical basis for resistance breeding in Eucalyptus. The results show that pest-feeding and leaf-clipping stress groups significantly affected the peroxidase (POD), polyphenol oxidase (PPO), and phenylalanine ammonia-lyase (PAL) activities in Eucalyptus leaves. Within a short period after stress (3 h), POD activity was significantly reached 444.83 U by leaf-clipping stress, whereas it was significantly inhibited (34.83 U) by pest-feeding stress. PPO activity was significantly enhanced to 95.25 U under pest-feeding stress within 3 h, while leaf clipping induced a lower level of PPO activity (58.75 U). PAL activity was significantly induced to 474.38 U by leaf-clipping stress at 3 h, whereas pest-feeding stress resulted in a moderate increase to 238.00 U. Both pest-feeding and leaf-clipping stresses had significant effects on the contents of defense compounds in Eucalyptus leaves. Within a short period (3 h), both leaf-clipping and pest-feeding stresses significantly induced the accumulation of salicylic acid (0.226 μg/g and 0.326 μg/g, respectively), jasmonic acid (0.239 μg/g and 0.278 μg/g, respectively), and tannin (0.581 μg/g and 0.657 μg/g, respectively). The POD activity and salicylic acid content were identified as the primary factors in Eucalyptus responses to pest-feeding and leaf-clipping stresses. In conclusion, biotic (pest-feeding) and abiotic (leaf-clipping) stresses can induce higher activities of related defense enzymes while also promoting the synthesis of greater quantities of defensive chemical compounds, thereby enhancing the resilience to biotic and abiotic stresses in Eucalyptus. This study provides important practical guidance for insect-resistant Eucalyptus breeding and implementing integrated pest management strategies. Full article

In recent decades, antibiotic-resistant bacteria have become an increasingly urgent public health concern. The uncontrolled use of antibiotics, along with inadequate implementation of prevention and control measures, is the primary factor contributing to this issue. The hospital environment is a major source of multidrug-resistant bacteria, and in recent years, there has been growing concern about hospital wastewater, which acts as a significant reservoir for these bacteria and their resistance genes. This situation leads to the spread of multidrug-resistant bacteria in the environment. One particular concern is Acinetobacter, especially Acinetobacter baumannii, which has emerged as a pathogenic threat in healthcare-associated infections. This bacterium is found in high densities in hospital wastewater. Most strains of A. baumannii express resistance not only to carbapenems but also to several other classes of antibiotics, including tetracyclines, fluoroquinolones, and aminoglycosides. These strains must be combated through effective measures. Bacteriophages represent a potential mitigation strategy for antibiotic-resistant Acinetobacter spp. originating from hospital wastewater. This review summarizes studies from online databases regarding the identification and characterization of Acinetobacter strains in hospital wastewater worldwide, and presents progress in isolating and characterizing bacteriophages against A. baumannii found in hospital wastewater. Full article

Several species of the genus Acinetobacter are nosocomial pathogens with a well-documented ability to acquire resistance to multiple antibiotics. Although Acinetobacter is one of the most abundant genera in meat processing environments, data on this genus outside of clinical environments remains limited. The objective of this study was to ascertain the prevalence, diversity and antimicrobial resistance profile of Acinetobacter spp. in 200 samples collected from food contact surfaces, non-food contact surfaces, carcasses and final meat cuts across five pork, chicken and beef processing facilities, each comprising physically connected slaughterhouses and meat processing plants. Acinetobacter spp. were detected in 80% (95% CI = 71–87%) and 70% (95% CI = 60–79%) of samples from slaughterhouses and processing plants, respectively. The facilities harboured a wide diversity of Acinetobacter species, with 27 different species identified. Acinetobacter baumannii was the species most frequently detected. Whole-genome sequencing of 18 Acinetobacter spp. isolates revealed the presence of ARGs conferring resistance to beta-lactams, tetracyclines and aminoglycosides, and disclosed phylogenetic relationships with isolates from fresh meat. Phenotypic resistance to beta-lactams, fluoroquinolones, aminoglycosides, folate pathway inhibitors and/or tetracyclines was observed in 77.8% of the sequenced isolates, with 44.4% classified as multidrug-resistant. These findings identify meat processing environments as an important reservoir of Acinetobacter spp. and highlight the need for further investigation to prevent the dissemination of antimicrobial-resistant strains. Full article

Harsh environments and climate change hamper industrial hemp productivity. Under stress conditions, uniform germination and vigorous seedlings are key to sustaining crop establishment and performance. Trichoderma spp. are beneficial micromycetes, able to colonize plant roots and promote plant development even under abiotic stress conditions. Thus, the seed treatment with specifically selected Trichoderma isolates could be a useful strategy to enhance hemp seed germination and plantlet growth. In this view, a preliminary screening was performed with ‘Eletta campana’ cv. Nine out of 20 Trichoderma isolates enhanced the radicle growth (+66–111%); most of them resulted in good root colonization, but only four isolates significantly enhanced the shoot DW (+18–22%). Three isolates were selected for a pot experiment, compared to T. afroharzianum T22, to evaluate the effect on plant growth, root architecture, accumulation of photosynthetic pigments and stress-related compounds, and variation in antioxidant activity in 20-day-old plantlets. T. afroharzianum OR4 significantly promoted plantlet growth (+9% shoot DW and +11% leaf DW). The seed treatment had a low impact on the other variables studied, except in the case of foliar proline content, a marker of stress tolerance, that was greatly increased with T. afroharzianum T22 and T. atrobrunneum X44 (+32% and +17% DW). Full article

Background/Objectives: Cyanobacteria represent a diverse group of microorganisms capable of synthesizing a broad array of biologically active metabolites. Some of these compounds, believed to contribute to the ecological and evolutionary success of cyanobacteria, are increasingly being investigated for potential biomedical and biotechnological applications. They also hold promise in combating the growing threat of antimicrobial resistance (AMR). This screening study aimed to identify Baltic cyanobacterial strains with the potential to produce antibacterial compounds active against streptococci and mycobacteria, as well as quorum sensing inhibitors. Methods/Results: Extracts from forty-four cyanobacterial strains were tested using a broth microdilution assay. The most pronounced activity was observed for extracts derived from two Pseudanabaenaceae strains (KUCC C3 and C4), two Anabaena spp. strains (CCNP 1405 and CCNP 1406), and Aphanizomenon sp. KUCC C1. Inhibition of quorum sensing was the most frequently detected activity, with 30% of the tested extracts inhibiting violacein production in Chromobacterium violaceum ATCC 12472. Growth inhibition of Gram-positive bacteria was less common: 16% of cyanobacterial strains inhibited Streptococcus pyogenes ATCC 12344, and 11% inhibited Mycobacterium smegmatis ATCC 14468. Bioassay-guided fractionation of Aphanizomenon sp. KUCC C1, followed by LC–MS/MS analysis, revealed the presence of glycerolipids and glycolipids, including diacylglycerols (DAGs) and galactosyldiacylglycerols (MGDGs and DGDGs), as major constituents of fractions exhibiting quorum quenching activity. Conclusions: These findings highlight the potential of Baltic cyanobacteria as a source of natural compounds capable of disrupting bacterial communication and growth, offering prospects for the development of novel antimicrobial and anti-virulence agents. Full article

To cope with the increasing pressure from diseases and pests under climate change, the effect of 6 maize sowing dates on the plant health of an ultra-early maize variety (Pyroxenia, FAO 130) was analyzed in studies conducted from 2016 to 2018. The assessment of the response of the ultra-early variety to climate change will contribute to the identification of its predisposition to cultivation in terms of health recognition. The extent of plant damage caused by the frit fly (Oscinella frit L.), the European corn borer (Ostrinia nubilalis Hbn.), and the cereal leaf beetle (Oulema melanopus L.), as well as the severity of plant infection by Fusarium ear rot (Fusarium spp.) and maize smut (Ustilago maydis (D.C.) Corda), was assessed. Air temperature, precipitation, and the length of the growing period at individual sowing dates were also analyzed. The lowest level of insect damage and the highest level of disease infection were recorded in the final year of the study (2018), which was dry and had higher mean air temperature. Precipitation and temperature during the sowing dates ranged between 110.5 and 146.1 mm and 17.5 and 19.9 °C, respectively. The optimal sowing date for reducing maize losses caused by insect pests and diseases was found to be the earliest time points, i.e., between April 12 and 26. Full article

Background: Acute calculous cholangitis is commonly associated with biliary tract infections and is predominantly caused by enteric bacteria. Increasing antimicrobial resistance, particularly among extended-spectrum β-lactamase (ESBL)-producing Gram-negative organisms, has become a major concern in Southeast Asia, including Vietnam. Updated local microbiological data are essential to guide appropriate empirical antibiotic therapy. Methods: This retrospective multicenter study analyzed clinical and microbiological data from patients diagnosed with acute calculous cholangitis. Bacterial culture results were collected from Hanoi Medical University Hospital, Thanh Nhan Hospital, and E Hospital between June 2022 and December 2024. Results: Gram-negative bacteria were predominant (286/366, 78.14%), while Gram-positive bacteria accounted for 80/366 (21.86%). Escherichia coli was the most frequently isolated organism (133/366, 36.34%), of which 77/133 (57.89%) were ESBL producing. Klebsiella spp. accounted for 60/366 (16.39%), with 17/60 (28.33%) ESBL-producing isolates. Enterococcus spp. (n = 80) exhibited high susceptibility to vancomycin (69/80, 86.15%) and complete susceptibility to linezolid (80/80, 100%). Conclusions: This multicenter study highlights evolving pathogen distributions and antimicrobial resistance patterns in acute calculous cholangitis in Vietnam. These findings provide valuable evidence to support the optimization of empirical antibiotic regimens in clinical practice. Full article

Antimicrobial resistance [AMR] is a silent yet intensifying global threat, with particularly severe consequences in tropical and subtropical ecosystems, where high ecological connectivity, extensive antimicrobial use, and inadequate sanitation create ideal conditions for the persistence and spread of antimicrobial resistance genes [ARGs]. Within the One Health framework, migratory birds warrant special attention because they traverse tropical AMR hotspots, linking contaminated aquatic, agricultural, and peri-urban environments along established flyways. Evidence from tropical and subtropical regions indicates that migratory birds frequently carry clinically relevant AMR-associated pathogens, including extended-spectrum β-lactamase-producing Escherichia coli, multidrug-resistant Salmonella enterica, and fluoroquinolone- and macrolide-resistant Campylobacter spp. These findings suggest that migratory birds primarily function as ecological sentinels and geographic redistributors of antimicrobial resistance, reflecting environmental contamination and ecological connectivity between human-dominated and natural ecosystems, while evidence for long-term reservoir status remains context-dependent. Addressing the complex interface among AMR, migratory birds, and ARGs requires integrative surveillance strategies that explicitly incorporate wildlife into existing health systems. Genomic and metagenomic monitoring of migratory bird populations, combined with cross-sectoral data sharing, can provide early warning signals of emerging resistance patterns and inform evidence-based interventions. Understanding the ecological role of migratory birds in tropical ecosystems is therefore essential for designing effective One Health strategies to mitigate transboundary AMR risks and preserve the long-term efficacy of antimicrobial therapies. Full article

Aproceros leucopoda (Hymenoptera: Argidae) is an East-Asian pest of Ulmus spp. that has spread across Europe since the 2000s and, more recently, to North America, causing repeated defoliation of host plants. Laboratory studies have suggested four or five generations per year in Hungary; however, in the field, their number ranges from one to six. In 2012 and 2013, the bionomics of this invasive pest were studied in north-eastern Italy through weekly samplings from April to October, with data related to accumulated degree days (DDs). Although adult captures exhibited five peaks in both years, only in 2012 were eggs of the fifth and last generation of the season. Their apparent absence in 2013 might be due to elm water stress or temperatures much higher than optimal (30 vs. 19.5 °C). From 2013 to today, a progressive decline in A. leucopoda populations has been recorded. The possible reasons for the gradual decline in the sawfly population recorded in the subsequent years are discussed. Several natural enemies were observed. This study can contribute to a better understanding of A. leucopoda population dynamics in newly colonised areas, including the risk to wood production in mixed deciduous plantations if defoliation occurs over many consecutive years. Full article