Antimicrobial resistance (AMR) is a major global health concern, and its monitoring in wildlife is essential from a One Health perspective. Here, we obtained bacterial isolates and assessed the AMR profiles and extended-spectrum β-lactamase (ESBL) production of Escherichia coli isolated from fecal samples of wild felids in a protected Atlantic Forest area in southeastern Brazil. We collected 22 fecal samples and identified depositor species through trichological analysis (ocelot, Leopardus pardalis = 18; jaguar, Panthera onca = 1; puma, Puma concolor = 1; Leopardus sp. = 1; unidentified felid = 1). Bacterial isolation was performed using EMB agar and MacConkey agar supplemented with ceftriaxone or meropenem, and isolates were identified by MALDI-TOF MS. From these, 11 E. coli isolates (ocelot = 9; jaguar = 1; puma = 1) were selected to assess AMR using a standardized disk diffusion assay with 15 antimicrobials and to test for ESBL production. In addition to E. coli, the detected bacterial assemblage included Achromobacter micicolens, Acinetobacter baumannii, Acinetobacter nosocomialis, Acinetobacter vivianii, Enterococcus faecalis, Ochrobactrum intermedium and Stenotrophomonas maltophilia. All E. coli isolates were susceptible to all tested antimicrobials, and none showed evidence of ESBL production. These findings may suggest low selective pressure for AMR in the study area, reflecting limited circulation of antimicrobial-resistant bacteria. As free-ranging carnivores may act as sentinels of environmental change and integrate microbiota from prey, this study provides a baseline for monitoring AMR shifts across populations.

Extracellular matrices that scaffold microbial biofilms offer a rich source of polymeric materials with a range of potential applications. However, our understanding of these matrices is largely restricted to model organisms that form biofilms with specific architectures. Examining biofilms from understudied niches has the potential to identify extracellular matrices with novel properties. Here, we targeted a resource-rich boundary at the top of the water column known as the air-liquid interface (ALI). ALIs lack a solid substrate for cellular attachment, suggesting that microbes utilize specialized biofilm architectures to persist at this boundary. We used samples from a lake to enrich for microbes that colonize the ALI. Mixed-species pellicle biofilms formed rapidly in these enrichments and displayed a pronounced ecological succession. We isolated 31 members of the genus Pararheinheimera from early stages of pellicle maturation that formed five phylogenetically distinct clades. We used representative isolates to show that only one Pararheinheimera clade formed adherent films resembling classical pellicles. Isolates from the remaining clades formed floating structures that could be categorized either as non-adhesive films or viscous masses (VMs). VM pellicle formation was a polyphyletic trait that correlated with a mucoid appearance on agar plates, suggesting that the process is driven by copious extracellular matrix secretion. Matrices from VM biofilms were largely non-adhesive, contained a mixture of acidic polysaccharides and proteins, and formed thermally stable, shear-thinning hydrogels. Our results demonstrate that ALI colonization strategies vary widely even among closely related aquatic bacteria and identify VM pellicles as a promising platform for biomaterials development.

Dental caries in primary teeth remains a major pediatric health concern driven by Streptococcus mutans, necessitating effective antimicrobial strategies. Therefore, it is of interest to compare the antibacterial efficacy of nano silver, nano-chitosan and silver diamine fluoride against S. mutans isolated from carious primary teeth. Hence, an in vitro design using agar well diffusion, minimum inhibitory concentration and minimum bactericidal concentration assays was conducted on samples from 30 extracted primary molars. Nano silver demonstrated the highest antibacterial activity followed by silver diamine fluoride and nano-chitosan, with the lowest MIC observed for nano silver. Thus, we show that nano silver exhibits superior antibacterial potential and may serve as an effective adjunct in pediatric caries management.

The green synthesis method is a predominant trend as it is an ecofriendly, cleaner, scalable, and cheaper method and viable to form biocompatible NPsrather than the traditional methods. Jojoba plant is a natural and strong antioxidant as it contains phenolic and flavonoids compounds.Since male and female jojoba plants are known to differ in enzymatic and non-enzymatic antioxidant activity and phytochemical composition, this comparison was designed to test whether such sex-linked phytochemical variability translates into measurable differences in the structural, morphological, and antimicrobial properties of the resulting MnO2 nanoparticles. This study focuses on preparation of MnO2 nanoparticles using the extract of male (M-MnO2) and female (F-MnO2) jojoba[']s leavesand to evaluate theirantimicrobialactivity.The prepared samples were characterized using X-ray diffraction (XRD), energy dispersive X-ray (EDX) and Thermal analyses (TGA & DTG) to assess their structural and physicochemical properties. The scanning electron microscopy (SEM) and transmission electron microscopy (TEM) also used to assess the morphology and microstructure evolution. The X-ray diffraction analysis confirmed the cryptomelane-type α-MnO2 phase for both samples distinguished by its characteristic (2 × 2) tunnel framework capable of hosting potassium ions within the crystal lattice. The microstructure analyses also reveal the nanocrystalline nature with flake morphology of MnO2 NPs that enhances the surface reactivity helping in improving the antimicrobial performance.The antimicrobial efficacy of the two samples (M-MnO2 and F-MnO2) was evaluated throughtheCup Diffusion Agar Method and the Colony Forming Unit (CFU) Assay using Four representative microorganisms were selected for testing: Staphylococcus aureus ATCC 6538-P (Gram-positive bacterium), Escherichia coli ATCC 25,933 (Gram-negative bacterium), Candida albicans ATCC 10,231 (yeast), and Aspergillusniger NRRL-A326 (filamentous fungus).The findings of this research highlight sample F-MnO2 as a potential antimicrobial agent with higher percent of the inhibition zones and higher reduction percent of the number of colonies formation.

Frequent outbreaks of bacterial and fungal diseases in aquaculture cause severe economic losses, making biological control using probiotics a crucial strategy. Bacillus velezensis synthesizes diverse antimicrobial secondary metabolites; however, its biocontrol potential is tightly regulated by environmental signals such as cultivation time. In this study, we investigated the effect of growing time on the antifungal activity of B. velezensis GHZJ-1, isolated from an aquatic environment. It was found that GHZJ-1 shows obvious antifungal activity against the aquatic pathogen Metschnikowia bicuspidata upon 48 h growth but no such activity for 24 h via the agar-diffusion method. We further compared the transcriptomes of GHZJ-1 cells collected at 24 h and 48 h through RNA-Seq. Our results revealed that compared with 24 h, 1821 genes were differentially expressed at 48 h, with 903 upregulated and 918 downregulated. Downregulated genes were enriched in primary metabolic pathways (e.g., ribosome assembly and carbon metabolism), whereas upregulated genes were enriched in secondary metabolite biosynthesis and transmembrane transport. Importantly, 35 upregulated genes directly associated with antimicrobial activity were identified, notably including the ones encoding core elements of a large polyketide synthase (e.g., pksN, log2FC = 2.24), the petrobactin siderophore system (highest log2FC = 3.39), and various antimicrobial peptide export systems. Furthermore, the degU gene was activated at 48 h. These data suggest that facing continuously increased environmental stress over time, GHZJ-1 undergoes global transcriptional reprogramming and resource reallocation, downregulating basal metabolism to construct a synergistic antagonistic system coupling chemical defense with nutritional competition. This study elucidates the time-dependent mechanism for antifungal activity in GHZJ-1, providing a molecular theoretical basis for its green biocontrol application in aquaculture diseases caused by fungi.

Crop straw is an abundant lignocellulosic resource, but its efficient bioconversion is hindered by the recalcitrant structure of plant cell walls. This study integrated degradation phenotyping, enzyme activity assays, whole-genome analysis, and comparative transcriptomics to link the wheat-straw degradation performance of strain XH2 with its enzymatic and molecular responses. Strain XH2 was isolated from fully decomposed compost collected in Anhui Province, China, selected based on the formation of a distinct hydrolysis halo on CMC-Congo red agar, and deposited in the China Center for Type Culture Collection (CCTCC) under accession number CCTCC M 2025519. Morphological, cultural, phylogenetic, and genomic analyses identified strain XH2 as Streptomyces thermocarboxydus. Its degradation capacity was evaluated during 28 days of cultivation by measuring straw degradation, lignocellulosic components, scanning electron microscopy (SEM), and extracellular enzyme activities. S. thermocarboxydus XH2 caused marked disruption of the wheat-straw surface and achieved a degradation rate of 31.45%. Cellulose and hemicellulose contents decreased from 41.10% to 28.87% and from 30.72% to 16.85%, respectively, whereas lignin decreased from 8.28% to 6.30%. Endoglucanase activity, filter paper activity (FPase, an indicator of total cellulase activity), and xylanase activity peaked on day 7, reaching 35.99, 17.68, and 37.01 U/mL, respectively. Genome analysis revealed multiple genes encoding cellulases and hemicellulases. Comparative transcriptomic analysis after 72 h of cultivation in wheat-straw medium identified 1614 differentially expressed genes relative to Gause No. 1 medium, with major enrichment in ABC transporters and fructose and mannose metabolism. Most genes associated with polysaccharide degradation were upregulated. These findings link the degradation phenotype of S. thermocarboxydus XH2 to its enzymatic and molecular responses and support its further evaluation as a candidate for wheat-straw bioconversion under greenhouse and field conditions.

Plants and their endophytic microbiota form a functional holobiont, wherein host-dependent endophytes (HDEs) are proposed to serve as persistent microbial components associated with host continuity. Using long-term in vitro grapevine plantlets, we investigated HDE redistribution and reassembly across successive agar-based subcultures and during the transition to soil-based cultivation. Results showed that the initial tissue niche (shoot-tip versus root-base) imprinted a persistent compositional signature on HDE communities, with distinct cultivar-dependent effects. Numerous microbial amplicon sequence variants (ASVs) remained shared across agar-based and soil-based habitats, demonstrating high persistence of HDE-associated lineages. Bacterial communities exhibited marked plasticity, with plant-associated bacterial lineages contributing substantially to soil community assembly. Notably, 204 root-enriched bacterial ASVs, comprising 10.8-14.3% of the soil community, were recovered, revealing a robust "Root-Specific Legacy". Bacterial HDEs showed higher redistribution potential (43.3%), whereas fungal transfer was significantly lower (10.4%). Functional profiling suggested habitat-associated functional patterns, with the anaerobic phenotype enriched in soil and predicted enhancements in membrane transport, nucleotide metabolism, glycan biosynthesis, and biosynthesis of secondary metabolites in roots. Cladosporium and Fusarium remained dominant in the fungal core taxa, and habitat transition altered their predicted trophic profiles. Our findings establish HDEs as a resilient biological reservoir capable of niche-specific expansion, contributing to the ecological reassembly of the plant holobiont.

Acne vulgaris is a highly prevalent inflammatory skin condition involving the interaction between skin microbes and host immunity, which lead with the changes in composition and activities of the skin microbiota disturbing its homeostasis. Several probiotic strains have been tested for their anti-pathogenic activity against the main acne-responsible bacteria, their capacity to contrast pathogenic adhesion to HaCaT cells and the in vitro down-regulation of innate immunity. To investigate whether probiotics have direct effects on the growth of Cutibacterium acnes, Staphyloccoccus aureus, Streptococcus pyogenes and Streptococcus epidermidis, the antimicrobial activity of six probiotics was analyzed by two different methods (modified cross-streak and agar well diffusion). The in vitro blockage of pathogens' adherence by the probiotic strains to HaCaT cells was also investigated, under three possible mechanisms: exclusion by adhered probiotics, displacement of adhered pathogens and competition for receptor sites. The inflammatory response was evaluated by the Luminex approach, targeting a selection of innate immune markers in the HaCaT cell culture media. All probiotic strains showed anti-pathogenic activity against the pathogens tested. The inhibition result on HaCaT cells highlights a significant (p < 0.05) competition of all probiotics against all pathogens. Each pathogenic strain alone led to an up-regulation of innate immune markers, while restoration of the microbiome diversity by probiotics presence may suppress inflammation via down-regulation of innate immunity. The results suggest that the tested probiotics could prevent colonization of the skin by relevant pathogens through barrier and interference mechanisms (mainly exclusion), suggesting a potential use in the future conventional therapies of skin disorders.

Chemolithotrophic denitrifying bacteria Thiobacillus denitrificans and Sulfurimonas denitrificans are model organisms for sulfur and nitrogen cycling and are frequently used as model organisms in biogeochemical and applied research. Their cultivation is considered technically demanding, largely due to the assumption that strict anaerobic equipment is required. Here, we provide a simplified, reproducible cultivation workflow designed for laboratories with limited anaerobic infrastructure, with a special focus on establishing growth under practical pseudo-anoxic conditions. Three media were evaluated (modified DSMZ 113, ATCC 152 Thiobacillus broth, and a commercial Thiobacillus broth) in both liquid and solid formats using anaerobic jars and a sealed-bottle "pseudo-anoxic" approach. Consistent growth of both organisms was achieved exclusively in modified DSMZ 113. Importantly, T. denitrificans grew reproducibly not only under anaerobic jar conditions but also under the sealed-bottle pseudo-anoxic setup, demonstrating that successful cultivation is feasible without specialized anaerobic systems. The S. denitrificans grew successfully, but exclusively under anoxic conditions. Additionally, we describe a simple and novel coverslip-on-agar microscopy method for rapid confirmation of small transparent colonies, supporting reliable isolation and contamination control. Overall, our results provide a practical step-by-step cultivation guide, highlighting that T. denitrificans can be robustly cultured even without complying with strict protocol for anaerobic cultivation.

Aflatoxin contamination of cereal grains represents a serious food safety concern due to the toxic and carcinogenic properties of aflatoxins produced mainly by Aspergillus species. The present study aimed to evaluate the antifungal and antiaflatoxigenic potential of lactic acid bacteria (LAB) cell-free supernatants as a natural approach for controlling aflatoxin-producing fungi in wheat grains. A total of fifty fungal isolates recovered from agricultural samples were screened for their aflatoxigenic potential using phenotypic and molecular approaches. The toxigenic isolates were identified as Aspergillus flavus (AF) and Aspergillus parasiticus (AP), and their aflatoxigenic potential was confirmed by PCR amplification of aflatoxin biosynthesis-related genes (nor-1 and aflR). The antifungal activity of selected LAB strains was evaluated against the identified Aspergillus isolates using the agar diffusion method. The obtained results demonstrated that LAB cell-free supernatants exhibited significant antifungal activity, with variations among strains. Among the tested LAB strains, Lactobacillus plantarum P3 and Lactobacillus acidophilus ATCC 20552 showed the highest inhibitory activity against both fungal species. Furthermore, LAB treatments significantly reduced fungal-induced wheat grain damage and decreased aflatoxin accumulation during storage. Application of 100% LAB supernatants resulted in a remarkable reduction in total aflatoxins, reaching more than 99% reduction compared with untreated controls. The inhibitory effect decreased with increasing dilution of the supernatants, indicating a concentration-dependent antifungal and antiaflatoxigenic activity. The findings demonstrate that LAB-derived metabolites can effectively suppress the growth of aflatoxin-producing Aspergillus species and limit aflatoxin biosynthesis. Therefore, LAB cell-free supernatants represent a promising biological control strategy for improving cereal safety and reducing mycotoxin contamination in food systems.

The increasing demand for alternative protein sources has stimulated interest in fungal biomass as a food ingredient. Although industrial strains of Fusarium venenatum have been extensively investigated, strain-specific information on conidial production, biomass accumulation, and crude protein content remains limited for strains maintained in microbial culture collections. This study evaluated the growth and sporulation of F. venenatum CML3311 in different solid media and investigated biomass and crude protein production under submerged fermentation conditions. Growth and sporulation were assessed on Yeast Malt Agar (YMA), Dichloran Rose Bengal Chloramphenicol Agar (DRBC), Potato Dextrose Agar (PDA), and Sabouraud Dextrose Agar (SDA). Submerged fermentations were conducted using a 3[2] factorial design evaluating temperature (26-30 °C) and agitation (160-200 rpm) over 72 h. Biomass production was determined gravimetrically, and crude protein content was quantified by the Kjeldahl method. DRBC promoted the highest sporulation, reaching 4.63 × 10[6] conidia/mL after 28 days. Biomass production increased during the first 48 h of cultivation, with the highest yields observed at 28-30 °C (6.4-6.5 g/L). Crude protein content ranged from 25.45% to 56.12% (dry basis), with the highest value obtained after 24 h at 28 °C and 200 rpm. These findings provide a strain-specific basis for inoculum preparation and submerged cultivation of F. venenatum CML3311 and identify conditions to be further investigated in process-optimization and safety-assessment studies.