Gallibacterium anatis is a Gram-negative bacterium that is a pathogen and part of the microbiome of both domestic and wild birds. It is also the cause of reproductive infections, primarily when birds are stressed. Its pathogenicity has been associated with the expression of virulence factors. The effect of Epinephrine (Epi) and Norepinephrine (NEpi) hormones on the composition and structure of G. anatis biofilms is evaluated here. Catecholamines induced compaction and fragmentation of biofilms at 24h. Biofilm amount diminishes (50%) by NEpi. At 48h, biofilm fragments are immersed in exopolymer material, and the control biofilm shows a high quantity of filamentous cells, not observed with hormones. Enzymatic digestion of biofilm polymers showed increased protein levels in the presence of Epi at 24 or 48h and NEpi at 24 or 72h. Epi increased carbohydrate quantity, but NEpi diminished, and DNA quantities diminished at 48h by Epi. Epi diminishes the expression of proteins in the 70 to 200 kDa range but increases the expression of secreted proteins. NEpi induces proteolytic activity in the range of 20 to 110 kDa. A 55 kDa protease was induced at 72h by both hormones. G. anatis biofilm changes could be significant in its dispersion and pathogenesis.

Listeria costaricensis was recently isolated from a food-processing facility. However, its pathogenic potential and persistence capacity remain poorly characterized at the phenotypic level, raising concerns about food safety. Therefore, we assessed its pathogenic potential through phenotypic invasion and adhesion assays in HeLa cells, showing that L. costaricensis cannot invade HeLa cells despite displaying a cell adhesion capacity comparable to that of L. monocytogenes and L. innocua reference strains. Given the industrial origin of the strain, we further evaluated its susceptibility to commonly used disinfectants by broth microdilution, finding susceptibility to a mixture of quaternary ammonium compounds (MIC <100 µg/mL), and reduced susceptibility to peracetic acid (MIC >160 µg/mL) and sodium hypochlorite (MIC >500 µg/mL). Considering its demonstrated adhesion capacity, we assessed its ability to form biofilms on polystyrene surfaces, reporting a weak biofilm-forming phenotype comparable to other L. monocytogenes strains. Finally, using the VFanalyzer platform we identified on the L. costaricensis genome 28 virulence-associated gene sequences related to regulatory and structural functions, adherence, and an incomplete invasion gene group compared to L. monocytogenes strains. Collectively, these findings phenotypically support the previously proposed non-pathogenic nature of L. costaricensis, while also revealing a level of persistence comparable to other L. monocytogenes isolates.

Botrytis cinerea is a pathogen infecting Cannabis sativa L. plants, causing economic losses, and can develop resistance to chemical fungicides, the use of which is restricted in cannabis production. Thus, developing biocontrol methods is imperative. Seven bacterial strains were isolated from hemp seed oil, characterized, and examined for the potential to control a B. cinerea isolate from cannabis. Three isolates, Bacillus mojavensis HOB3, Paenibacillus sp. HOB6 and Bacillus subtilis HOB7 exhibited significant inhibition of B. cinerea. These isolates were further evaluated for their biosurfactant activity using two liquid media, Lysogeny Broth (LB) and hydrocarbon-amended Bushnell and Haas (BH). The oil-spreading and drop-collapse assays revealed growth-medium-dependent variation in surface activity associated with biosurfactant presence. The BH cell-free extract (BH-CFE) of B. subtilis HOB7 showed the highest estimated biosurfactant presence and antifungal activity against B. cinerea, but both activities were absent when using the LB cell-free extract (LB-CFE) of B. subtilis HOB7. Thus, a potential relationship between antifungal activity and biosurfactant production was suggested. Genome mining of the strains identified gene clusters encoding compounds with antifungal activity, including the biosurfactants polymyxin B, fusaricidin B, fengycin, and surfactin. To our knowledge, this is the first report of the isolation of hemp seed oil bacteria with potential biocontrol properties against fungal phytopathogens.

Although Citrus aurantium has enormous medicinal and ecological value in southern China, little research has been conducted into the composition and functions of endophytic fungi in it. To better explore the characteristics of the endophytic fungal community in C. aurantium, ITS rRNA gene analyses were used to characterise the endophytic fungal microbiome across 3 plant compartments and 3 regions. The results shown that a total of 12109 OTUs were obtained and further divided into 15 phyla and 768 genera. Ascomycota was the dominant phylum. Fusarium, Alternaria, Mortierella, Plectosphaerella, Cladosporium, Colletotrichum, Trichomerium, Botryotrichum, and Aspergillus were the dominant genera. The endemic and dominant genera of endophytic fungi in C. aurantium exhibited plant compartment specificity. The assembly of endophytic fungal communities was dominated by homogeneous selection of deterministic processes. The endophytic fungal genera of C. aurantium predominantly exhibited positive interactions (with a proportion > 99%). The dominant functions of endophytic fungi in C. aurantium were pathotroph and saprotroph. The composition (niche: R2=0.09, P=0.001; site: R2=0.06, P=0.021) and functional components (niche: R2=0.117, P=0.002; site: R2=0.122, P=0.006) exhibited significant plant compartment and region specificity. The results of this study reveal the characteristics of the endophytic fungal community of C. aurantium, and provide a theoretical reference for the further development and utilization of endophytic fungal resources.

Atherosclerotic Cardiovascular Disease (ASCVD) is a global health concern, leading to higher rates of morbidity and mortality. Gut microbial dysbiosis significantly contributes to obesity related ASCVD. However the interrelation of gut microbiome in driving obesity or overweight mediated ASCVD has not been sufficiently investigated. To unravel this complex interplay, we have compared the gut microbial shotgun metagenome data of ASCVD subjects across normal BMI (Body Mass Index) and overweight/obese (OW/OB) BMI categories. We identified a distinct gut microbial composition and function in normal and OW/OB ASCVD subjects. Using gut microbial abundance, a machine learning model was built to predict ASCVD in the normal and OW/OB samples. The gut microbiome based signature for ASCVD discrimination was achieved with an AUC of 0.87 and 0.83 for distinguishing control and ASCVD in normal and OW/OB BMI groups respectively. In addition, we have also identified that Pseudoflavonifractor capillosus could act as a prognostic organism in identifying OW/OB associated ASCVD. Therefore, an appropriate diet could modifying the ASCVD contributing gut microbiome, hence minimizing the risk of ASCVD in OW/OB individuals.

There is a great divide between the microbes active in natural environments and the organisms that may be grown in a laboratory setting. In this work we set out to cultivate representatives of the marine myxobacterial clade, a highly diverse, largely-uncultured group of Gram-negative bacteria believed to have extensive biosynthetic potential. Sediment samples were collected from the St. Lawrence Estuary and Gulf and the presence of active marine myxobacteria was established through qPCR analysis of 16S rRNA gene and transcript abundances . In the expectation that the marine myxobacteria would exhibit predatory behaviour like their terrestrial counterparts, the sediment samples were then streaked on agar plates that contained common marine bacteria as the sole carbon source. Unexpectedly, in place of myxobacteria we isolated Pseudomonas, Bacillus, and Stenotropomonas spp., among others, revealing a generalized ability for these strains to break down living organic matter and suggesting that "bait" bacteria may be an effective approach for the cultivation of novel marine saprophytes.

Clade 2.3.4.4b Eurasian-origin H5N1 entered North America in late 2021 and spread across the continent. While studies have characterized the antibody response mounted by dabbling ducks following exposure, little data are available for diving ducks. This study sought to identify influenza A virus (IAV) infection and antibodies in Lesser and Greater Scaup captured in Maryland, Illinois, and Rhode Island. In Maryland, IAV seroprevalence increased from the 2021/2022 to 2022/2023 sampling season, with IAV antibody prevalence increasing for juvenile (38% to 80%) and adult (82% to 90%) Lesser Scaup. While adult Lesser Scaup sampled in Illinois in 2021/2022 had IAV antibody prevalence comparable to those sampled in Maryland (76% and 82%, respectively), they had higher antibody prevalence to both H5 (48% and 18%) and N1 (68% and 35%), potentially due to being sampled in March versus December and January. Our data suggest that Lesser Scaup had limited antibodies to highly pathogenic H5 IAV prior to the introduction of clade 2.3.4.4b H5N1 to North America, but relevant antibodies were widely observed in the months and year following. Our more limited data suggest similar trends may have occurred in Greater Scaup as well.

The chicken intestine presents a complex environment for microbial survival due to high interbacterial competition, high bile salt concentrations, a low pH, and microaerophilic conditions. While most probiotics contain members of the Bacillota phylum, members of the Pseudomonadota phylum are known to be more important in competitive exclusion - which may be an important consideration in the formulation of future probiotics. Little is known about commensal Pseudomonadota in healthy chickens, or what benefits members of this phylum may offer the host; most studies on Pseudomonadota focus on aspects of opportunistic pathogenesis and dysbiosis. In this study, we use an in-silico approach to evaluate the pathogenic potential, competition strategies, and potential host benefits of Pseudomonadota isolates from healthy chickens. We analyzed the draft genomes of 29 representative isolates of Pseudomonadota using Bagle4, AntiSMash, SeCreT6, KEGG mapper, and Virsorter2 to identify key interbacterial competition strategies including secondary metabolite biosynthesis, secretion systems, quorum sensing, and prophages. Our results revealed that each isolate exhibits distinct interbacterial competitive strategies, often independent of their taxonomic affiliation. Including Pseudomonadota in future poultry probiotics may be critical to improving colonization resistance in industrially raised poultry.

Between 2022 and 2025, high pathogenicity avian influenza (HPAI) H5N1 clade 2.3.4.4b was detected in poultry and wildlife across most countries in Central and South America. The epizootic peaked in 2023, subsided in 2024, and resurged in 2025. In Central America, outbreaks in wildlife were few and small, and mostly affected pelicans. In contrast, South America experienced unprecedented mass mortality in colonial seabirds and pinnipeds, including endangered and endemic species. Notably, viral adaptation enabled mammal-to-mammal transmission in pinnipeds and rapid viral spread across multiple countries along the Pacific and Atlantic coasts. Subsequent introductions to subantarctic islands and Antarctica stemmed from South American viruses. In February 2025, a novel reassortant virus emerged, recombining HPAI H5N1 B3.2 genotype with South American low pathogenicity avian influenza viruses. In May 2025, HPAI H5N1 viruses re-emerged in Brazil, causing a series of outbreaks in poultry and wild birds. The ongoing circulation and evolution of HPAI H5N1 in this region underscores the need for strengthened surveillance, expanded genomic monitoring, and enhanced integration of wildlife conservation and environmental sectors in regional response frameworks.

Antimicrobial resistance (AMR) is a growing public health threat in Canada. In 2022, rising resistance was reported among key pathogens, yet national coordination remains inconsistent, with strategies varying widely by province and territory. This study explored AMR-related challenges in healthcare and the impact of the COVID-19 pandemic on AMR efforts in Canada. Using a qualitative design, researchers conducted semi-structured interviews with 59 experts from fields such as microbiology, public health, and industry. Participants were identified through environmental scanning and snowball sampling. Thematic analysis of transcripts revealed major barriers to a unified AMR response, including inconsistent surveillance, fragmented stewardship efforts, and decentralized health systems. According to participating AMR experts, COVID-19 disrupted AMR control by diverting resources and potentially increasing resistance but also led to improvements in infection prevention, public awareness, and health infrastructure. Participants emphasized the need for stronger political commitment, improved surveillance, a One Health approach, and better funded, coordinated stewardship programs. With the publication of the Pan-Canadian Action Plan in 2023, the Canadian federal government has announced changes. However, effectively addressing AMR will require a unified, multisectoral strategy that bridges political, health, and societal efforts across jurisdictions.

Tomato (Solanum lycopersicum) is one of the most widely cultivated vegetables worldwide, yet its productivity is severely constrained by Fusarium wilt caused by Fusarium oxysporum f. sp. lycopersici (FOL). The pathogen invades the root system and vascular tissues, leading to systemic wilting, plant collapse, and significant yield losses. Although chemical fungicides have been extensively used for management, their long-term effectiveness is declining due to the emergence of fungicide-resistant strains and the associated environmental and health hazards. This growing challenge underscores the urgent need for sustainable alternatives. In this review, we critically synthesize recent advances in the biological control of FOL, focusing on antagonistic fungi, beneficial bacteria, and the role of organic amendments in creating suppressive soils. Unlike earlier reviews that address these components separately, we emphasize their integration within holistic disease management frameworks. We also highlight promising directions, including microbial consortia, molecular insights into pathogen-antagonist interactions, and the potential of combining biological control with precision agriculture tools. Collectively, these strategies offer a sustainable pathway for mitigating Fusarium wilt and ensuring resilient tomato production systems.

Antimicrobial resistant strains of pathogenic Escherichia coli are a burden on the healthcare system, causing longer hospital stays and increased treatment costs compared to non-resistant strains. With whole genome sequencing almost ubiquitous in the analyses of outbreak and surveillance samples, in silico methods for feature identification can be faster and cheaper than traditional wet-lab methods. In this study, machine learning (ML) classification methods were used to predict antimicrobial resistance and identify novel genomic markers of resistance. A total of 4300 E. coli whole genome sequences with laboratory-derived susceptible, intermediate, or resistant (SIR) data for 34 antimicrobials were collected. Three models, gradient boosted decision trees, support vector machines, and artificial neural networks, were trained using genome sub-sequences (k-mers) of length 11 to classify unknown isolates as SIR for each antimicrobial. The models achieved high average accuracies (93.6%, 92.7%, and 92.8% respectively) for our dataset, outperforming database methods including AMRFinderPlus (63.9%) and ResFinder (75.7%). Tested on two smaller independent datasets, the models' average accuracies were 81.6% (XGB), 79.9% (SVM), and 81.2% (ANN), while ResFinder's average accuracy was 94.7%. An advantage of ML models over database methods is that they can identify novel markers of resistance, which is a key advantage for surveillance and research. As more genomic and antimicrobial resistance (AMR) data become publicly available, these models are expected to further improve in performance and utility.

Antimicrobial resistance has a negative impact on people's health and the economy. New resistance mechanisms are emerging, making the treatment of infections very challenging. Fungi are well known for their production of secondary metabolites during active cell growth. In this study a strain of Penicillium sanguifluum (111-12) was isolated from Manitoba soil and investigated for antimicrobial properties of fungal secondary metabolites against pathogenic bacteria, and two fungal plant pathogens that are known for causing Dutch elm diseases and chestnut blight disease. Penicillium sanguifluum (111-12) produced dehydrocurvularin (C1) and 11-hydroxycurvularin (C2). C1 and C2 were examined for their antimicrobial properties and these compounds were combined with various antibiotics to evaluate their potentiation (adjuvant) properties. Promising results were obtained for C1 that decreased the minimum inhibitory concentrations of cefepime, ceftazidime, tobramycin, and amikacin against a clinical multi drug resistant strain of Pseudomonas aeruginosa (PA82). In addition, C1 and C2 showed no impact on the Galleria mellonella model regarding toxicity.

Understanding the microbial diversity is the first step to monitor the microbial quality of agricultural surface waters. Here we report a study comparing the microbial composition and diversities in agricultural surface waters in Ontario, Canada, including the streams adjacent to dairy cattle production in eastern Ontario and the field runoffs from the manure-impacted experimental farm of south-western Ontario. We also studied the quality of the surface water in the western basin of Lake Erie during a harmful algal bloom (cHAB). In eastern Ontario, we found significantly lower ( < 0.01) abundance of Proteobacteria and Burkholderiales in the streams adjacent to dairy production than the non-agriculture site. Bacteroidetes was more abundant ( < 0.0001) in medium/high order streams and agriculture/urban mixed site. Seasonal peaks of were observed in low order streams but the trend was not in medium/high order streams. In south-western Ontario, the dominant bacterial taxa in field runoffs was , regardless of manure types. We also discovered that the elevated total dissolved nitrogen, total dissolved phosphorus and chlorophyll a associated with the cHAB zone in Lake Erie was further away rather from the agricultural sites. In conclusion, our studies identified unique microbiome patterns associated with agricultural surface waters in Ontario.

is a major foodborne pathogen capable of surviving in low-water-activity (a) foods and retaining the ability to invade intestinal epithelial cells after environmental stress, such as exposure to high salt concentrations. Although multiple serotypes tolerate low a, Tennessee strains have been repeatedly linked to outbreaks in dry foods, suggesting specific adaptations. This study evaluated the effects of NaCl (1%, 4%, and 6%) on growth, biofilm formation, post-biofilm recovery, and internalization capacity (Caco-2 cell assays) of six strains-four Tennessee and two serogroup B isolates-from peanuts, raisins, chocolate, and dehydrated tomatoes. Growth and biofilm formation were monitored over a 7-day exposure to NaCl; post-biofilm recovery and internalization were assessed afterward. While all strains showed reduced internalization after salt exposure, Tennessee isolates generally maintained higher growth and biofilm formation than the ATCC 14028 reference strain. Phenotypic responses varied by strain and NaCl concentration, indicating differences in osmotic stress adaptation. The persistence of internalization capacity, even at reduced levels, highlights a potential food safety risk in NaCl-preserved products. These findings emphasize the need to consider strain-specific traits when developing control measures for in dry food environments.

Coinfection and secondary infection by fungi in patients with viral pulmonary infection, especially SARS-CoV-2, are important factors that worsen the prognosis and are associated to increased death rates. This work aims to report the prevalence of isolates in bronchoalveolar and nasopharyngeal samples from suspected COVID-19 patients in the first-second pandemic waves and their antifungal resistance profile. From 2321 patients, 29.04% were diagnosed with SARS-CoV-2 infection. The yeast isolation rate of 6.97% (47/674) from positive SARS-CoV-2 was statistically higher than 4.43% (73/1647) from negative SARS-CoV-2 patients ( = 0.0177). Among yeasts, the most prevalent species was (63/120), with four being azole-resistant isolates (6.35%); however, other emerging and less susceptible species were also isolated, such as (11), (5), (4), (1), and (1). Here, we highlighted prevalence in respiratory tract, emphasizing the relevance for surveillance in SARS-CoV-2/COVID patients for improvement of management as well as patient outcomes.

The genus constitutes a vast pool of microorganisms living in multiple environmental niches including fish pathogens and species in the fish microbiome. Veterinary reports have identified flavobacteria in fish from Quebec's fish farms, confirming their association with infections. However, these reports have not conducted in-depth characterization, and the diversity of nonpathogenic flavobacteria in Quebec remains unknown. This study is the first step in assessing the diversity of in Quebec's fish farms, without focusing solely on pathogenic strains. Seventeen isolates were collected from different fish farms, from either the water or fish. Microbial species identification was performed using PCR genotyping of the gene, whole-genome sequencing, and phylogenetic analysis. Antimicrobial susceptibility tests for tetracycline and florfenicol, the two most commonly used antibiotics in Quebec aquaculture, along with predictive tools, were employed to assess resistance. This study revealed potential new species among the isolates. No known pathogenic species were detected, and all 17 isolates clustered within CIIIb or CIIIc, recently described phylogenetic clades of found in various environments, and the majority showed resistance to antibiotics. This study highlights the expanding diversity of , particularly among species associated with fish, and underscores the need for further research in Quebec.

Africa's vast geographic and climatic diversity makes it a critical region for the ecology and spread of avian influenza viruses, particularly due to its role as a wintering ground for Palearctic migratory waterbirds. The continent has experienced multiple waves of clade 2.3.4.4b A/H5Nx high pathogenicity avian influenza (HPAI), which has caused widespread outbreaks in poultry and wild birds since 2017. From 2023 to mid-2025, clade 2.3.4.4b A/H5N1 outbreaks were reported across West and Southern Africa, with severe impacts on poultry production and conservation of endangered wild bird species. Concurrently, South Africa and Mozambique battled an unprecedented A/H7N6 HPAI epizootic in 2023, leading to the culling or loss of over 6.8 million chickens. Additionally, the A/H9N2 subtype, particularly G5.5 sublineage strains, continues to circulate in North, West, and East Africa, with reassortant viruses with A/H5Nx viruses reported in Egypt. Underreporting and limited surveillance hamper accurate epidemiological assessment. Despite these challenges, advancements in noninvasive environmental sampling offer promising tools for early detection. Strengthening regional cooperation and surveillance is essential for mitigating future outbreaks and protecting both animal and public health.