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Use of air-cleaning devices to create airborne particle-free spaces intended to alleviate allergic rhinitis and asthma during sleep.

UNLABELLED: Comprehensive quantitative experiments were performed to assess the capabilities of several air-cleaning devices to create a particle-free microenvironment as a therapy for sleeping persons affected by allergic rhinitis and asthma. Six devices were evaluated, of which five were portable and intended to provide general air cleaning for bedroom-sized spaces. The sixth was intended for installation in front of the headboard of a bed and was designed to provide clean air focused in a space occupied by a sleeping person. The air-cleaning methods of the selected devices included high-efficiency particulate air (HEPA) filtering and electrostatic precipitation. Particle concentration measurements for six particle-size ranges and sound intensity measurements were made during 8-h, sleep-simulating periods. The effects of four parameters were studied: (i) device location, (ii) controlled air motion in the laboratory, (iii) airflow rate setting of the air-cleaning device, and (iv) controlled disturbances. To ensure a totally objective study, a special laboratory facility was constructed which enabled complete control of the experimental conditions. The measured concentration histories provided comprehensive evidence of the relative capabilities of the various devices for the specific air-cleaning function. It was found that the device designed to focus the cleaned air in the sleeping space fulfilled its goal and, in that regard, was clearly superior to all of the other air-cleaning devices. PRACTICAL IMPLICATIONS: There is evidence that allergic reactions are triggered by the presence of airborne particles and that these reactions can be mitigated by particle removal. This strategy can be implemented by the use of air-cleaning devices which are capable of creating particle-free zones at locations where human activity occurs. In particular, the creation of a particle-free zone which encompasses the breathing space of a sleeping person holds promise of mitigating sleep-disturbing allergic reactions.

Air Movements↗

Training of disaster managers at a masters degree level: from emergency care to managerial control.

The world has faced huge disasters over the last few decades and concerns have been expressed by nearly all international agencies involved that there is a scarcity of managerial skills to deal with the mitigation and management of disasters. Disaster risks are also on the increase throughout Africa and Southern Africa because of changes in the development process, settlement patterns and conflicts in the region. Emergency physicians are but one important resource in dealing with disasters. The need for a comprehensive multisectoral approach to disasters and more importantly to deal with its mitigation is becoming increasingly evident, especially in developing countries. Hence, the need for specially trained professionals in disaster management. In an effort to improve national, regional and continental capacity, and in support of the South African Disaster Management Act, the University of the Witwatersrand, Johannesburg, South Africa, has developed a Master of Public Health degree in Disaster Management. The MPH is aimed at preparing professionals from health and allied fields to play leadership roles in the management, improvement and evaluation of health and the health-care system. Emergency physicians have an important role to play in the development of disaster medicine and disaster management programmes and it is important that they engage in this activity, collaborating with colleagues of various other disciplines as appropriate. The following paper outlines the background to the programme and the current programme.

Biometry↗

The use of wide area computer networks in disaster management and the implications for hospital/medical networks.

Computer-mediated communication in various forms is already being used in all phases of disaster management--preparation, response, recovery, and long-term mitigation. However, to date wide area computer networks--particularly the Internet (the supernetwork of networks)--have been used only to a limited extent in disaster management and prevention. Some of these applications are described in this paper. Nevertheless, the high speed and ease of information transfer by computer network and the vast resources becoming available on the Internet make it inevitable that the use of computer networks to temper disasters will increase enormously in the next decade. The Internet will provide a key means through which networks initially dedicated to solely medical purposes and the individuals who use them will become involved not only in disaster response and mitigation worldwide, but in the global community and consciousness that is the Internet.

Australia↗

Acrylamide: an update on current knowledge in analysis, levels in food, mechanisms of formation, and potential strategies of control.

This review summarizes the research to date on acrylamide levels in food, analytical methods, main sources of dietary exposure, mechanisms of formation, and mitigation research in the major food categories. Significant progress in the research has been made over the past 18 months, as reflected by the numerous publications and national and international workshops on the subject. This rapid pace of developments is mainly attributable to the coordinated and collaborative efforts of all of those concerned: the food industry, academia, private/enforcement laboratories, and national authorities. Most of the information gaps identified since the findings in early 2002 on the occurrence of acrylamide in foods and exposure assessments have been addressed, and public databases have been established by several authorities. Today, the performance of analytical methods, particularly for "difficult" food matrices, is adequate, and any modifications made over the past 12 to 18 months in analytical procedures did not significantly impact the initial exposure calculations. Several avenues into mitigation have been explored in the different food categories, with much emphasis being placed on potato-based products, and empirical trials (mostly pilot studies) have provided better knowledge of the key parameters that influence acrylamide formation. However, despite these intensive efforts, only marginal reductions have been achieved by the food industry, and any further progress will entail long-term studies at the primary production level. Any measures devised to reduce exposure to acrylamide in commercial foods must be carefully assessed in terms of food safety and quality. A hitherto poorly addressed concern is the formation of acrylamide in foods prepared by consumers in the home, and more guidance on this by national authorities is warranted.

Acrylamide↗

Frusemide and weight carriage alter the acid:base responses of horses to incremental and to brief intense exertion.

We speculated that frusemide would attenuate the acidosis associated with intense exertion, and that weight carriage would mitigate this effect. Therefore, in each of 2 experiments we measured pulmonary artery and systemic arterial blood pH, PCO2, PO2 and pulmonary artery temperature in 9 horses during exertion on a treadmill after each of 3 treatments. The treatments were: 1) injection of saline solution (C), 2) injection of frusemide (1 mg/kg bwt, i.v. 4 h before running) (FU) and 3) injection of frusemide (F) as for FU and the horses carried weight equal to that lost in the 4 h after frusemide administration (FL). In Experiment 1 the horses performed an incremental exercise test of 90 s at each of 4, 7 and 9 m/s (4 degrees incline). In Experiment 2, the horses ran on a treadmill inclined at 4 degrees for 3 min at 3 m/s, at approximately 120% VO2max for 2 min, and 3 m/s for 5 min. Blood samples for measurement of blood pH, PCO2 and PO2 were collected into heparinised glass syringes. Values were adjusted for changes in pulmonary artery blood temperature. Data were analysed using a 2 way repeated measures ANOVA. There was a consistent pattern in both experiments characterised by a mild alkalosis or mitigated acidosis, compared to C, at rest and during exercise and recovery after FU (P < 0.05). Weight carriage blunted or inhibited the effect of frusemide during exercise and recovery. In experiment 2, at the end of the sprint, FU treatment resulted in a less severe acidosis than did C or FI: mixed venous pH for C, FU, and FL at the end of the sprint were 6.93, 6.98 and 6.93, respectively (P interaction = 0.038), mixed venous base excess was -12.4, -9.91, and -11.8 mmol/l, respectively, and arterial base excess of -1.44, -12.7 and -14.1 mmol/l (P interaction = 0.006) respectively. These effects persisted into recovery. A similar pattern of responses occurred during the incremental exercise test, with weight carriage offsetting the alkalinizing effect of frusemide. We conclude that frusemide attenuates the acidosis of intense exertion and that carriage of weight prevents this effect.

Acid-Base Equilibrium↗

Incipient ovarian failure and premature ovarian failure show the same immunological profile.

PROBLEM: Incipient ovarian failure (IOF) is characterized by regular menstrual cycles, infertility and a raised early-follicular FSH in women under 40. IOF might be a precursor or a mitigated form of premature ovarian failure (POF). Disturbances in the immune system may play a role in ovarian failure. METHOD OF STUDY: Autoantibodies and lymphocyte subsets were determined in 63 POF patients, 50 IOF patients, and 27 controls. RESULTS: The prevalence of autoantibodies did not differ between the groups. There was a statistically significant difference in lymphocyte subsets between the control group and the POF group, with the IOF group taking an intermediate position. We found a decrease in percentage of T-suppressor cells with a rise in T-helper/T-suppressor cell ratio, a decrease in natural killer cells, and an increase in B lymphocytes and HLA-DR positive T cells. CONCLUSIONS: These data support the concept that IOF is a mitigated form of POF. The question remains whether these changes are the cause or the consequence of the ovarian failure.

Adult↗

Social Isolation and Loneliness Among Older Asian Immigrants Through the Lens of Sense of Coherence: Systematic Review of Qualitative Studies.

AIM: To explore the meaning older Asian immigrants attribute to social isolation and loneliness, their management strategies, utilisation of resources and impact on health. DESIGN: Systematic review of qualitative studies. DATA SOURCES: AgeLine, CINAHL, MEDLINE, ProQuest, PsycINFO, Scopus, and Web of Science databases were searched in September 2024. METHODS: Inclusion criteria: participants were Asian immigrants to Western countries aged 65 and over, community-living and experiencing social isolation and loneliness. Antonovsky's Sense of Coherence was used to frame the thematic analysis. RESULTS: Ten papers were included and analysed deductively using elements of the sense of coherence framework: &#x2022; Comprehensibility: Social isolation and loneliness are viewed as multifaceted, influenced by cultural and environmental dislocation, language barriers, intergenerational conflicts, deteriorating health and mobility, and socioeconomic challenges. &#x2022; Manageability: included engaging in culture-specific community programs, family and ethnic community support and living within ethnic enclaves mitigated isolation and loneliness. &#x2022; Meaningfulness: Strong family ties, active community involvement, spirituality, volunteerism, and cultural practices fostered resilience. However, accepting the changing values of their new world, living independently, and carving their own niche provided meaning to their transformed reality. CONCLUSION: Older Asian immigrants experience social isolation and loneliness through a cultural lens, shaped by migration experiences, language barriers, and shifting family dynamics. Cultural roots, family ties, spirituality, community, acceptance, and independence enhance sense of coherence. Recognising the dynamic interplay between cultural identity, resilience, and adaptation is key to understanding their lived experience. IMPLICATIONS FOR THE PROFESSION AND PATIENT CARE: This review informs culturally sensitive interventions, guiding healthcare, community services, and policy to support social participation, mitigate loneliness through ethno-specific activities, and improve the quality of life for aging immigrant populations in Western countries. REPORTING METHOD: The review was undertaken and reported using the PRISMA guidelines. PATIENT OR PUBLIC INVOLVEMENT: None. PROTOCOL REGISTRATION: PROSPERO (CRD42023425752).

Humans↗

Prospects for quantitative computed tomography imaging in the presence of foreign metal bodies using statistical image reconstruction.

X-ray computed tomography (CT) images of patients bearing metal intracavitary applicators or other metal foreign objects exhibit severe artifacts including streaks and aliasing. We have systematically evaluated via computer simulations the impact of scattered radiation, the polyenergetic spectrum, and measurement noise on the performance of three reconstruction algorithms: conventional filtered backprojection (FBP), deterministic iterative deblurring, and a new iterative algorithm, alternating minimization (AM), based on a CT detector model that includes noise, scatter, and polyenergetic spectra. Contrary to the dominant view of the literature, FBP streaking artifacts are due mostly to mismatches between FBP's simplified model of CT detector response and the physical process of signal acquisition. Artifacts on AM images are significantly mitigated as this algorithm substantially reduces detector-model mismatches. However, metal artifacts are reduced to acceptable levels only when prior knowledge of the metal object in the patient, including its pose, shape, and attenuation map, are used to constrain AM's iterations. AM image reconstruction, in combination with object-constrained CT to estimate the pose of metal objects in the patient, is a promising approach for effectively mitigating metal artifacts and making quantitative estimation of tissue attenuation coefficients a clinical possibility.

Algorithms↗

Economic incentives for rain forest conservation across scales.

Globally, tropical deforestation releases 20 to 30% of anthropogenic greenhouse gases. Conserving forests could reduce emissions, but the cost-effectiveness of this mechanism for mitigation depends on the associated opportunity costs. We estimated these costs from local, national, and global perspectives using a case study from Madagascar. Conservation generated significant benefits over logging and agriculture locally and globally. Nationally, however, financial benefits from industrial logging were larger than conservation benefits. Such differing economic signals across scales may exacerbate tropical deforestation. The Kyoto Protocol could potentially overcome this obstacle to conservation by creating markets for protection of tropical forests to mitigate climate change.

Agriculture↗

Greenhouse gases in intensive agriculture: contributions of individual gases to the radiative forcing of the atmosphere

Agriculture plays a major role in the global fluxes of the greenhouse gases carbon dioxide, nitrous oxide, and methane. From 1991 to 1999, we measured gas fluxes and other sources of global warming potential (GWP) in cropped and nearby unmanaged ecosystems. Net GWP (grams of carbon dioxide equivalents per square meter per year) ranged from 110 in our conventional tillage systems to -211 in early successional communities. None of the annual cropping systems provided net mitigation, although soil carbon accumulation in no-till systems came closest to mitigating all other sources of GWP. In all but one ecosystem, nitrous oxide production was the single greatest source of GWP. In the late successional system, GWP was neutral because of significant methane oxidation. These results suggest additional opportunities for lessening the GWP of agronomic systems.

Journal Article↗

Inhibition of Pseudomonas aeruginosa by hyperbaric oxygen. I. Sulfonamide activity enhancement and reversal.

To elucidate an explanation for in vitro sulfonamide enhancement by high-pressure oxygen (HPO) and the reported absence of enhancement with in vivo therapy, Pseudomonas aeruginosa cultures were exposed to selected antifolate antimicrobials in the presence of 1.87 atm absolute of O(2) and compared with non-HPO treated controls. Under these conditions, HPO alone retarded growth. Trimethoprim, a non-sulfonamide which inhibits dihydrofolate reductase, was not bactericidal, nor did HPO enhance existent bacteriostatic activity. The sulfonamide, sulfisozazole, was not bactericidal, but HPO enhanced bacteriostatic activity twofold; bacteriostasis was mitigated in HPO-treated and control cultures by p-aminobenzoate but not by a mixture of compounds involved in folate-mediated "1-C" biosynthesis. Mafenide, a unique sulfonamide, at high concentrations with HPO, was synergistically bactericidal; non-HPO-treated cultures were bacteriostatically inhibited. Bacteriostatic activity of lower mafenide concentrations was also enhanced at least twofold by HPO. These inhibitory effects of mafenide, acting with or without HPO, were mitigated by the above mixture, but not by p-aminobenzoate. This may explain the lack of in vivo HPO-mafenide enhancement in burn-wound sepsis where exudates would contain such a mixture. Lastly, HPO itself was largely bactericidal at 2.87 atm absolute of O(2). This was reversed to various degrees by the above mixture, or its components, or by folic, folinic, or p-aminobenzoic acids. These in vitro interactions suggest HPO per se may act at the same site as some sulfonamides to inhibit folate synthesis (not primarily at the dihydrofolate reductase level), or coenzyme functions of folate, or both.

Aminobenzoates↗

Pulmonary and hepatic gene expression following cecal ligation and puncture: monophosphoryl lipid A prophylaxis attenuates sepsis-induced cytokine and chemokine expression and neutrophil infiltration.

Polymicrobial sepsis induced by cecal ligation and puncture (CLP) reproduces many of the pathophysiologic features of septic shock. In this study, we demonstrate that mRNA for a broad range of pro- and anti-inflammatory cytokine and chemokine genes are temporally regulated after CLP in the lung and liver. We also assessed whether prophylactic administration of monophosphoryl lipid A (MPL), a nontoxic derivative of lipopolysaccharide (LPS) that induces endotoxin tolerance and attenuates the sepsis syndrome in mice after CLP, would alter tissue-specific gene expression post-CLP. Levels of pulmonary interleukin-6 (IL-6), tumor necrosis factor alpha (TNF-alpha), granulocyte colony-stimulating factor (G-CSF), IL-1 receptor antagonist (IL-1ra), and IL-10 mRNA, as well as hepatic IL-1beta, IL-6, gamma interferon (IFN-gamma), G-CSF, inducible nitric oxide synthase, and IL-10 mRNA, were reduced in MPL-pretreated mice after CLP compared to control mice. Chemokine mRNA expression was also profoundly mitigated in MPL-pretreated mice after CLP. Specifically, levels of pulmonary and hepatic macrophage inflammatory protein 1alpha (MIP-1alpha), MIP-1beta, MIP-2, and monocyte chemoattractant protein-1 (MCP-1) mRNA, as well as hepatic IFN-gamma-inducible protein 10 and KC mRNA, were attenuated in MPL-pretreated mice after CLP. Attenuated levels of IL-6, TNF-alpha, MCP-1, MIP-1alpha, and MIP-2 in serum also were observed in MPL-pretreated mice after CLP. Diminished pulmonary chemokine mRNA production was associated with reduced neutrophil margination and pulmonary myeloperoxidase activity. These data suggest that prophylactic administration of MPL mitigates the sepsis syndrome by reducing chemokine production and the recruitment of inflammatory cells into tissues, thereby attenuating the production of proinflammatory cytokines.

Adjuvants, Immunologic↗

Genome-wide analysis of Enterococcus faecalis genes that facilitate interspecies competition with Lactobacillus crispatus.

Enterococci are opportunistic pathogens notorious for causing a variety of infections. While both Enterococcus faecalis and Lactobacillus crispatus are commensal residents of the vaginal tract, the molecular mechanisms that enable E. faecalis to take advantage of a vaginal biome with lower counts of lactobacilli to colonize the vaginal tract and induce aerobic vaginitis remain unknown. Here, we show that L. crispatus eradicates E. faecalis in a contact-independent manner. Using transposon sequencing to identify E. faecalis OG1RF transposon (Tn) mutants that are either under-represented or over-represented when co-cultured with L. crispatus, we found that Tn mutants with disruption in the dltABCD operon, that encodes the proteins responsible for the D-alanylation of teichoic acids, and OG1RF_11697 encoding for an uncharacterized hypothetical protein are more susceptible to killing by L. crispatus. Inversely, Tn mutants with disruption in ldh1, which encodes for L-lactate dehydrogenase, are more resistant to L. crispatus killing. Using the Galleria mellonella infection model, we show that co-injection of L. crispatus with E. faecalis OG1RF enhances larvae survival while this L. crispatus-mediated protection was lost in larvae co-infected with either L. crispatus and E. faecalis&#x394;ldh1 or &#x394;ldh1&#x394;ldh2 strains. Last, using RNA sequencing to identify E. faecalis genes that are differently expressed in the presence of L. crispatus, we found major changes in the expression of genes associated with glycerophospholipid metabolism, central metabolism, and general stress responses. The findings in this study provide insights into how E. faecalis mitigate assaults by L. crispatus.IMPORTANCEEnterococcus faecalis is an opportunistic pathogen notorious for causing a multitude of infections. As vaginal commensals, E. faecalis must interact with Lactobacillus crispatus, but how E. faecalis overcomes or mitigate assaults by L. crispatus killing remains unknown. We show that L. crispatus eradicates E. faecalis temporally in a contact-independent manner. Using high-throughput molecular approaches, we identified genetic determinants that enable E. faecalis to compete with L. crispatus. This study represents an important first step for the identification of adaptive genetic traits required for enterococci to tolerate assaults by lactobacilli.

Enterococcus faecalis↗

Effect of high oxygen tensions on the growth of selected, aerobic, gram-negative, athogenic bacteria.

The in vitro effects of high O(2) tensions (P(O2)) on aerobic, enteric pathogens were examined at pressures of up to 3 atm absolute. Organisms from the genera Salmonella, Shigella, and Vibrio were usually subjected to 24-hr exposures. Tensions of 0.87, 1.87, and 2.87 atm absolute of O(2) (plus traces of CO(2) and N(2)) became progressively inhibitory for Salmonella and Shigella growth, but were bactericidal only for V. comma strains at tensions greater than 0.87 atm absolute of O(2). Growth inhibition of enteric organisms resulted from increased P(O2), rather than pressure per se, and could be mitigated nutritionally; an appropriate carbohydrate source is at least partially involved. Further studies with vibrios indicated that such mitigation was independent of medium pH. In addition, a synergistic relationship existed between O(2) and sulfisoxazole when tensions from 0.87 to 2.87 atm absolute of O(2) were maintained for 3 to 24 hr. Synergism occurred even under nutritional conditions which negated growth inhibition by O(2) alone. Bactericidal concentrations of sulfisoxazole, in the presence of increased P(O2), were reducible up to 4,000-fold. The combined procedure employed in this investigation, by use of an antimicrobial drug of known action, which also synergizes with O(2), plus nutritional studies, suggests a means for establishing a site of O(2) toxicity. These data support the concept that O(2) inhibition of growth represents a metabolic disturbance and that metabolic pathways involving p-aminobenzoic acid may be O(2)-labile. Such an approach could also guide development of antimicrobial agents as O(2) substitutes for promoting synergism.

Carbohydrate Metabolism↗

Difficult-to-treat resistant Gram-negative bacteria and genomic resemblances between colonization and infection among patients in an intensive care unit of a tertiary care hospital in Bangladesh.

Colonization with difficult-to-treat-resistant Gram-negative bacteria (DTR-GNB) increases the risk of subsequent infections with limited treatment options. This study aimed to assess the burden of DTR-GNB colonization in ICU patients, explore its association with clinical outcomes, and examine genomic similarities. This secondary analysis included patients enrolled within 24 h of ICU admission between July 2023 and January 2024. Rectal swabs were collected at enrollment, on days 3, 7, and weekly during ICU stay to detect colonization. Bacterial isolates grown on selective chromogenic agar media were identified and tested for antimicrobial susceptibility using matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) and automated broth microdilution, respectively. Blood, urine, and/or tracheal aspirate cultures were performed if clinically suspected sepsis. Whole-genome sequencing (WGS) was performed on paired colonization and infection isolates, and genomic relatedness was assessed using FastANI, core-genome single-nucleotide polymorphism (SNP) analysis, and phylogenetic reconstruction. Among 373 patients, 181 (48.5%) were colonized with DTR-GNB; 76 (20.4%) at enrollment, and 105 (53.0%) acquired during hospital stay. Among 52 (13.9%) patients evaluated for suspected infection, 30 (57.7%) had positive cultures, predominantly Acinetobacter baumannii (n = 15) and Klebsiella pneumoniae (n = 11) of DTR-phenotypes. Compared to non-colonized patients, patients colonized with DTR-GNB had higher risks of infections (risk ratio [RR]: 2.18, 95% CI: 1.27-3.76) and longer ICU stays (median 7 vs 2 days, P < 0.001). DTR-GNB-infected patients had a higher risk of death (RR: 1.57, 95% CI: 1.34-1.84) compared to patients without DTR-GNB infection. WGS revealed that 13 of 14 paired colonization-infection isolates were conspecific, with three pairs being highly clonal; whereas the remaining pairs showed greater genomic divergence, consistent with the SNP and phylogenetic analyses. While common, more than half acquired DTR-GNB colonization from the ICU. Its association with subsequent infection and prolonged ICU stays underscores the need for enhanced infection prevention and control measures to mitigate nosocomial transmission and improve patient outcomes.IMPORTANCEThis study underscores the growing threat posed by difficult-to-treat resistant Gram-negative bacteria (DTR-GNB) in intensive care units. Nearly half of critically ill patients were colonized, with a considerable proportion acquiring these multidrug-resistant organisms during their ICU stay. Colonization with these pathogens substantially increased the risk of subsequent infections, even by the same colonizing strain, prolonged ICU stays, and likely worsened clinical outcomes due to the unavailability of susceptible antibiotics. Alarmingly, more than 90% of patients infected with DTR-GNB expired in the hospital. These findings highlight the urgent need for robust infection prevention and control strategies to curb nosocomial transmission and mitigate the impact of DTR-GNB on vulnerable patient populations. Addressing this emerging resistance phenotype is critical to improving patient safety and reducing the burden on healthcare systems.

Humans↗

Identification of an antifungal lipopeptide from Bacillus amyloliquefaciens HAU3 inhibiting the growth of Fusarium graminearum using preparative chromatography and 2D-NMR.

UNLABELLED: The presence of fungal contamination and its mycotoxins in animal feed is pervasive, posing a significant threat to the well-being and performance of animals, as well as the safety of animal-derived food products. In this work, we screened a strain of Bacillus amyloliquefaciens (B. amyloliquefaciens) HAU3 that exhibits efficient antifungal activity against the growth of Fusarium graminearum (F. graminearum). The antifungal activity was detected in the supernatant, with 20% sterile supernatant demonstrating an impressive antifungal rate of 98.46% against F. graminearum. The antifungal activity of the strain was evaluated through spectrum analysis and silage trials, revealing its effective antifungal activity against multiple fungal species. Furthermore, the strain is capable of degrading ZEN and its derivatives. The targeted disruption of fungal mycelial membrane was observed using scanning electron microscopy and transmission electron microscopy. Additionally, staining with the reactive oxygen species (ROS)-sensitive fluorogenic dye DCFH-DA and propidium iodide (PI) revealed that the strain induces accumulation of ROS in fungal mycelia. The active compounds underwent further separation, purification, and detection. The prominent active peak was identified through mass spectrometry and magnetic resonance spectroscopy. The molecular structure of the active compounds was predicted to be lipopeptides composed of 8 amino acids known as fengycin. The whole genome sequencing and informatics analysis unveiled a total of 13 gene clusters responsible for the synthesis of secondary metabolites. The antifungal effects of B. amyloliquefaciens HAU3 are exerted through the synthesis of fengycin, which selectively targets and compromises the integrity of fungal mycelia membranes, thereby making it a potential biocontrol agent for mitigating mycotoxin contamination in feed. IMPORTANCE: Mycotoxin contamination in animal feed, predominantly driven by Fusarium graminearum, represents a persistent threat to livestock health and food chain integrity. Here, we report the isolation of a soil-derived Bacillus amyloliquefaciens HAU3, exhibiting potent and broad-spectrum antifungal activity alongside efficient biodegradation of zearalenone and its derivatives. Mechanistic dissection reveals that fengycin, the principal bioactive metabolite, compromises fungal membrane integrity and elicits intracellular oxidative stress, culminating in hyphal collapse. Genomic profiling uncovers a diverse repertoire of biosynthetic gene clusters underpinning secondary metabolite production. These findings establish strain HAU3 as a promising microbial chassis for the development of next-generation biocontrol strategies aimed at mitigating mycotoxin burden in agroecosystems.

Bacillus amyloliquefaciens↗

Integrative analysis of rumen microbiota activity and host metabolism following methanogenesis inhibition in dairy cattle.

Enteric methane emission from dairy cattle is an environmental challenge. The most efficient mitigation strategies nowadays include the use of methanogenesis inhibitors that specifically target the rumen methanogens. Specific inhibitors, such as 3-nitrooxypropanol (3-NOP), reduce methane emissions without negative effects on the products of fermentation that serve as energy metabolites for the host. However, the concomitant effects of methanogenesis inhibition on rumen microbiota and host metabolism are poorly characterized. Thus, the objective of this study was to explore the association between rumen microbiota and host metabolism when methanogenesis is inhibited. Thirteen dairy cows were used as controls, and 12 were supplemented with 3-NOP for 6 weeks. Rumen microbiota composition and activity were characterized using metagenomics and metatranscriptomics. The host metabolism was assessed in a previous publication by a metabolomic analysis of the plasma. Microbiota data were used as explanatory variables of the metabolome data in a multiblock sparse partial least squares analysis. Overall, the association between rumen microbiota and host metabolism was moderate. Notwithstanding this, a few downregulated transcripts related to glycolysis, hydrogen transfer, and protein synthesis, together with a decrease in the proportion of taxa of the Oscillospirales order, showed a correlation with host one-carbon metabolites (|r| > 0.6). These associations raised novel hypotheses that remain to be elucidated, especially with regard to the effects of dihydrogen on the accumulation of microbial glycolysis and methanogenesis metabolite intermediates.IMPORTANCEDairy cattle produce a substantial amount of methane, a potent greenhouse gas. Several strategies have been designed to reduce methane production by targeting the rumen microbiota. One such strategy specifically inhibits methanogens with a molecule called 3-nitrooxypropanol. This study uses an integrative data analysis approach, combining rumen microbiota and host metabolome information, to explore the consequences of inhibiting methanogenesis on the holobiont. This provides additional holistic insight into the effect of methane mitigation strategies on dairy cattle.

Animals↗

Genomics insight on passion fruit viral disease complexity.

Passion fruit viral diseases pose a significant threat to Kenya's passion fruit industry. To unravel the complexity of these diseases, comprehensive virus surveys were conducted across major passion fruit-growing counties. Passion fruit woodiness disease symptoms, like fruit hardening, chlorotic mottling, and leaf distortion, were prevalent. The study unveiled the first 23 complete genomes of Ugandan passiflora virus (UPV) and two East Asian passiflora distortion virus (EAPDV) in Kenya. UPV showed 99% nucleotide (nt) match to a UPV genome from Uganda and 66% nt identity match to EAPDV. In addition, UPV variants and two partial passion fruit green spot virus sequences and partial (passiflora emaravirus) segment RNA1-5 (novel allexivirus and an emaravirus, respectively) were detected. Phylogenetic analysis revealed distinct lineages (I-III), indicating potential multiple introductions into Kenya. Recombination analysis detected no significant breakpoints. However, the study proposed the renaming of EAPDV to passiflora distortion virus (PDV) and UPV to passiflora virus (PV) for neutral nomenclature, without geographical association. Additionally, the study highlighted the role of coinfections in symptom expression, suggesting a potential synergistic relationship between PV, PDV, and other viruses. The results recommend stringent management strategies and enhanced surveillance to mitigate the economic impact of these viruses on the Kenyan passion fruit industry. The findings from this study underscore the need to strengthen nursery certification programs and pest diagnostic protocols in Kenya. Additionally, enhanced pest surveillance and import regulations are critical to preventing the introduction and spread of emerging plant viral diseases, thereby safeguarding the country's horticultural productivity and biosecurity. To our knowledge, this is the first comprehensive study of viral diseases of passion fruit in Kenya.IMPORTANCEThis study presents the first comprehensive survey of viral pathogens affecting passion fruit in Kenya, identifying Ugandan passiflora virus (UPV) and East Asian passiflora distortion virus (EAPDV) as major contributors. Through genomic sequencing, 23 complete genomes of UPV and two of EAPDV were characterized, revealing a 99% nucleotide (nt) similarity between UPV strains from Uganda and Kenya, and 66% nt match with EAPDV. Phylogenetic analysis identified distinct lineages, suggesting possible multiple viral introductions in Kenya. The study also highlights potential synergistic coinfections between UPV, EAPDV, and other viruses, leading to more severe disease symptoms. In light of these findings, the study proposes renaming EAPDV as passiflora distortion virus and UPV as passiflora virus for a more neutral name classification. The research underscores the urgent need for enhanced surveillance, stringent phytosanitary measures, and improved management strategies to mitigate the threat of viral diseases, to safeguard the Kenyan passion fruit industry, and elsewhere.

Plant Diseases↗