Gulls (Larus spp.) are key reservoirs and vectors of antimicrobial resistance (AMR). We characterized extended-spectrum β-lactamase (ESBL) and plasmid-mediated AmpCproducing Escherichia coli from Great Black-backed (Larus marinus) and American Herring (Larus smithsonianus) gulls in Nova Scotia, Canada. From 100 fecal samples, 34 cefotaxime-resistant isolates were recovered: 29 ESBL and 5 AmpC producers. Detected, and blaCMY-2 + blaTEM-1C (n = 1).. Additional resistance genes conferred resistance to sulfonamides (sul2/sul3), trimethoprim (dfrA14/dfrA17), tetracyclines (tet(A)/tet(B)), aminoglycosides, chloramphenicol (floR), macrolides (mph(A)), lincosamides (lnu(F)), and quinolones (qnrS), complemented by chromosomal mutations in gyrA, parC, and parE. The isolates represented phylogroups A (n=10), B1 (n=18), and D (n=6), and high-risk sequence types including ST155 (n=12), ST744 (n=7), ST224 (n=4), and ST648 (n=3). Plasmid analysis revealed a high replicon burden (≥3 in 70.6% of isolates), primarily IncFIB (70.6%), Col (58.8%), and IncI (50.0%). Key virulence factors detected were fimH (97.1%), lpfA (73.5%), fyuA (47.1%), and iss (38.2%). These results demonstrate that synanthropic gulls in Atlantic Canada carry multidrug-resistant ESBL/AmpC E. coli from globally significant clones, underscoring their role in the dissemination of antimicrobial resistance within a One Health context.

We now find ourselves in the antimicrobial resistance era, where antibiotic-resistant bacteria are of increasing concern, leading to a need for new and novel antimicrobial agents. Unfortunately, interest in developing new antibiotics in the pharmaceutical industry has dwindled over the decades. Regardless, academic researchers over the past decade have made strides in exploring alternative options, and out of this, we see the field revisiting historical infection control agents. From this, we now see a field of research exploring the efficacy of metal-based antimicrobials (MBAs) and metalloantibiotics. These antimicrobial agents are formulated as metal salts, alloys, metal complexes, organometallics, and nanomaterials. Many effective formulations have been developed for various applications in which metals are used as antimicrobials that are effective against antibiotic-resistant strains. This critical opinion focuses on the use of metal salts as antimicrobial and antibiofilm treatments. The review identifies potential misinterpretations of mechanisms, knowledge gaps, areas that have been overlooked, and potential ideas to move forward. The goal here is to understand the challenges of dissecting the primary and secondary modes of action of MBAs to formulate effective antimicrobials containing metal elements. Finally, parameters that metal formulations must meet to become successful treatments without falling to the same fate as antibiotics are suggested.

Candida albicans is a common commensal yeast and an opportunistic pathogen of global health importance. However, its global geographic and temporal patterns of genetic variation remain poorly understood. Here we analyzed sequence data on seven housekeeping loci from>5000 isolates in the C. albicans PubMLST database representing>60 countries and spanning>70 years. Diploid sequences at each locus were phased into haplotypes to provide higher-resolution insights into diversity, differentiation, and recombination. Our analyses revealed high allelic and genotypic diversities within most geographic and temporal populations. Pairwise FST estimates revealed low but statistically significant differentiation among both geographic and temporal populations, with AMOVA revealing that most genetic variation resides within rather than among subpopulations. STRUCTURE analysis identified two genetic clusters but with extensive admixture within most geographic populations, consistent with frequent gene flow. Phylogenetic and haplotype network analyses revealed evidence of clonal expansion, with globally distributed haplotypes being genetically closer to one another than among more localized haplotypes. Finally, recombination analyses revealed evidence of non-random recombination within populations, including an overall deficiency of heterozygosity, suggesting the importance of parasexuality and/or mitotic recombination in C. albicans populations. Together, these results highlight the global evolutionary dynamics and population structure of C. albicans.

Phallus rubrovolvatus is a valuable edible fungus extensively cultivated in Guizhou Province, China. However, the changes in the soil microbiome throughout its growth cycle remain poorly understood. In this study, we collected 35 casing soil samples across five growth stages covering the entire 120-day cultivation cycle of Phallus rubrovolvatus and conducted metagenomic sequencing to examine alterations in soil microbial composition, diversity, key biomarkers, and functional potential. Our analyses revealed significant stage-dependent shifts in microbial community structure, with alpha diversity reaching its lowest at the primordium stage (Shannon of 5.12) and network complexity peaking at harvest stage (1.8-fold increase in connectivity). Through LEfSe analysis, we identified 37 stage-specific microbial biomarkers primarily affiliated with Actinomycetota and Acidobacteriota. Notably, Acidobacteriota biomarkers dominated at the primordium stage, while Nitrospirota enrichment characterized the harvest stage. Functional analyses revealed that membrane transport and energy metabolism pathways were enriched during early mycelial colonization, whereas secondary metabolite biosynthesis and signaling pathways became prominent during fruiting body maturation. Correlation analyses identified available nitrogen as the primary soil variable associated with microbial community composition. These findings provide foundational knowledge of microbiome dynamics during Phallus rubrovolvatus cultivation and suggest that microbiome-based management strategies may benefit from stage-specific interventions synchronized with fungal developmental transitions.

Hyriopsis cumingii is an important economic freshwater shellfish in China and there is a need to understand changes in the microbial community structure resulting in multidimensional quality degradation when the fish is stored at different temperatures. This study integrated 16S rRNA full-length sequencing with multidimensional quality indicators to investigate the temperature-regulated bacterial community shifts and quality deterioration mechanisms in stored H. cumingii meat. The results showed that bacterial richness (Chao1 index) decreased progressively with both refrigerated (4°C) and room-temperature (25°C) storage. Community composition underwent significant restructuring, with Bacteroidota decreasing at 25°C while Bacillota increased compared to 4°C storage. Additionally, the refrigerated group showed enrichment of Delftia turuhatensis and Chryseobacterium indologenes compared to the room-temperature storage group. Temperature significantly restructured bacterial communities, with notably higher pathogenic bacteria under refrigeration and spoilage bacteria dominance at room temperature. Metagenomic functional profiling revealed temperature-driven metabolic pathway divergence, indicating distinct spoilage mechanism. Predictable quality changes in H. cumingii correlated with temperature-imposed microbial composition.

The genus Trichoderma comprises many common fungi species that are distributed across the ecosystems. Trichoderma species have been successfully used as biofungicides due to their ability to protect plants and produce secondary metabolites (SMs) such as peptaibols, butenolides, pyridines, koninginins, and polyketide compounds. These SMs possess antimicrobial properties that allow the microbe to suppress or eliminate other pathogens, enabling it to secure a competitive nutritional niche. These SMs function as key agents in biocontrol strategies, contributing to crop protection and plant growth promotion, and are increasingly utilized in the development of bio-fertilizers. Trichoderma functions through multiple mechanisms that support plant health by inducing systemic resistance and by activating plant defense pathways. This article aims to review the bioactivity of selected Trichoderma-derived SMs with an emphasis on their beneficial effects, growth promoting attributes, and their effects on fungal prey. Additionally, the article provides a comprehensive overview of SMs in promoting sustainable agriculture and biological control.

Microscopy has always been an important tool in the investigation of the structure and growth of bacteria that possess a developmental life cycle. Prokaryotic predators are no exception. Phase contrast light microscopy and transmission electron microscopy were utilized in the 1960s to describe Bdellovibrio bacteriovorus, the first Bdellovibrio and like organism (BALO). New prokaryotic predators continue to be isolated to the present day. At the same time, new techniques in microscopy have been developed that allow researchers to ask ever more fundamental questions about the periplasmic and epibiotic life cycles of BALOs. This review outlines current methodologies available in light, electron and fluorescence microscopy and provides examples of their use in the study of BALOs. It is our fitting tribute to R.G.E. Murray.

Colletotrichum gloeosporioides is a destructive pathogen that causes significant economic and ecological losses in agricultural and forestry production. In search of effective biocontrol agents, this study isolated an endophytic fungus, Coniochaeta velutina, from healthy Camellia oleifera leaves and investigated its in vitro inhibitory mechanism on Colletotrichum gloeosporioides using transcriptomics and metabolomics analyses. These findings were used to evaluate the differences in gene expression and metabolite content between the treatment (Coniochaeta velutina-treated Colletotrichum gloeosporioides) and control (untreated Colletotrichum gloeosporioides) groups. The transcriptomic analysis detected a total of 15 310 expressed genes, with 3938 showing significant differential expression (p<0.05) (2093 upregulated and 1845 downregulated genes). These genes were enriched primarily in the following pathways: mitogen-activated protein kinase (MAPK) signalling, antibiotic biosynthesis, amino acid metabolism, carbon metabolism, and peroxidase pathways. Metabolomic analysis revealed 452 metabolites in both groups, with 138 showing significant differences. These genes were enriched mainly in secondary metabolite biosynthesis, amino acid biosynthesis, and α-linolenic acid metabolism. Transcriptome and metabolome association analyses, along with qRT-PCR results, revealed that the levels of intracellular pectolinarigenin metabolites significantly increased in the treatment group, leading to disrupted MAPK signalling and reduced amino acid biosynthesis, which are essential for maintaining normal cell growth. Notably, the decrease in terpenoid compounds was the primary reason that Colletotrichum gloeosporioides was inhibited by the biocontrol fungus Coniochaeta velutina. Therefore, these findings provide valuable insights into the biocontrol mechanisms of Coniochaeta velutina against Colletotrichum gloeosporioides and offer a promising foundation for the development of new anthracnose prevention and control strategies.

Coffee plants and beans are prone to fungal contamination that pose health risks to consumers by producing mycotoxins like ochratoxin A (OTA). Thus, the present study aimed to analyze the mycobiota of Costa Rican coffee beans, focusing on potentially ochratoxigenic species and their in vitro susceptibility patterns to antifungal agents. Fungal isolates were obtained from cherry, green, and roasted coffee beans from Costa Rica; they were identified by morphology, MALDI-TOF technology, and sequencing. The isolation frequency (FR) was 33.10% for all the samples analyzed, 49.51% for the cherry fruits, 37.67% for the green coffee beans, and 17.33% for the roasted beans. The cherry beans were mainly contaminated with Geotrichum klebahni (46.34% FR and 90.91% relative density (RD)), while the green and roasted coffee beans were mainly infected with Aspergillus spp. (22.00% FR and 55.23% RD and 13.83% FR and 77.57% RD, respectively). A total of 46.67% of A. westerdijkiae and 20.00% of A. ochraceus produced fluorescence in YES broth related with ochratoxin production. The isolates of the Aspergillus section Circumdati were susceptible to the azole antifungals. Costa Rican coffee beans could be contaminated with mycotoxigenic fungi during storage.

On solid substrates, biofilms develop rich wrinkle morphologies during its growth. Based on the thin film buckling theory, we established a local three-dimensional biofilm/substrate buckling model, and explored the effects of mechanical forces, elastic modulus of the substrate, and biofilm thickness on the wrinkle morphology. We simulated the wrinkle evolution in various patterns of Bacillus subtilis biofilm growing on agar substrates with different stiffness and found that the biofilm wrinkling process is the process of internal energy release. The stiffness of the substrate changes the wrinkling time of the biofilm; The biofilm wrinkle morphology (patterns II, III, and IV) Uinternal and Uinternal/U0 decrease with nutrient consumption, and the biofilm evolves towards lower energy consumption. In the early stages of biofilm growth (patterns I, II, and III), the harder the agar substrate, the larger the Ufriction and Ufriction/U0, which is less conducive to biofilm expansion.