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Xanthones, a class of polyketide derivatives characterized by a dibenzo‐γ‐pyrone core structure, are aromatic oxygenated cyclic compounds extensively found in nature. They are known for their diverse biological activities, including anti‐Alzheimer, antitumor, and antidiabetic properties, which have spurred extensive research into their therapeutic potential. One of the most significant challenges facing mankind currently is the development of antibiotic resistance in pathogenic microbes making microbial infections increasingly difficult to treat. The formation of biofilms enhances bacterial resistance to antibiotics, immune defenses, and environmental stresses. In this review, we have categorized xanthones, both of biological origin and synthesized, based on their structure and summarized the recent studies on their ability to inhibit Gram‐positive and ‐negative bacteria as well as the various underlying mechanisms that contribute to their microbicidal activity. These mechanisms include inhibition of virulence factors and biofilm formation, interaction with cell membranes, and interference with cell wall synthesis and DNA replication. In addition, we have listed the various methods involved in biofilm inhibition and the structure‐activity relationship of various xanthone molecules, highlighting how xanthone derivatives exhibit increased antibacterial activity. With the growing concern of antibiotic resistance, exploring natural compounds like xanthones to study their interaction with bacterial cells is crucial for identifying new treatment options. [ABSTRACT FROM AUTHOR]

In this study, five species of Marasmius namely, M. bambusiniformis, M. haematocephalus, M. leveilleanus, M. midnapurensis, and M rotalis, plus Paramarasmius palmivorus are described, based on morphotaxonomic and molecular characters. Sequence data from internal transcribed spacers were used for phylogenetic analyses of the six species, supporting their identification based on macro and micromorphological characters. All of these species are reported for the first time from Puducherry region. [ABSTRACT FROM AUTHOR]

Bacterial populations are routinely characterized based on microscopic examination, colony formation, and biochemical tests. However, in the recent past, bacterial identification, classification, and nomenclature have been strongly influenced by genome sequence information. Advances in bioinformatics and growth in genome databases has placed genome-based metadata analysis in the hands of researchers who will require taxonomic experience to resolve intricacies. To achieve this, different tools are now available to quantitatively measure genome relatedness within members of the same species, and genome-wide average nucleotide identity (gANI) is one such reliable tool to measure genome similarity. A genome assembly with a gANI score of Key words: bacterial taxonomy, bioinformatics, nucleotide identity, nomenclature. De maniere routiniere, les populations bacteriennes sont examinees au microscope, evaluees pour la formation de colonies et font l'objet de tests biochimiques. Cependant, depuis peu, l'identification, la classification etla nomenclature des bacteries ont ete largement influencees par les informations genomiques. Les avancees en bioinformatique et la croissance des bases de donnees genomiques ont fourni aux chercheurs des outils d'analyse de metadonnees genomiques, lesquels pourront faire appel a leur experience en taxonomie pour resoudre des differences subtiles. Pour y arriver, differents outils sont maintenant disponibles pour mesurer de maniere quantitative le degre de proximite entre membres d'une même espece. La moyenne globale d'identite nucleotidique (gANI, pour << genome-wide average nucleotide identity >>) est l'un de ces outils pour mesurer de maniere fiable la similarite des genomes. A l'echelle d'un genome, un score gANI Mots-cles : taxonomie bacterienne, bioinformatique, identite nucleotidique, nomenclature., Introduction Accurate bacterial classification is essential to identify potential genes to understand genetic mechanisms, diagnose disease, and provide better treatment, especially during infectious disease spread, outbreaks, and progression (Fricke and [...]

Eggplant (Solanum melongena L.) is one of the most popular solanaceous vegetable crops cultivated mainly in the tropical and subtropical parts of the world. Eggplant production is challenged by a wide range of pathogens, such as bacteria, fungi, viruses, and nematodes. The fungi cause the most severe economic loss to eggplant farmers due to their widespread incidence and devastating impact on crop yield. The fungal diseases are influenced by several factors, including environmental conditions, physiological and genetic characteristics of the host. Despite the economic implications of fungal diseases in eggplant, a compilation of the current understanding of pathogenesis, disease development and the host-resistance mechanisms remain unavailable. In this article, we comprehensively review common fungal pathogens of eggplant reported worldwide, and the diseases caused by them, including their major symptoms. We also discuss the major environmental factors that favor pathogenesis and summarize the molecular mechanisms underlying the host-pathogen interactions and disease development. Finally, we briefly discuss the prospects for future research to develop modern breeding and agronomic tools for combating the diseases in this important crop. [ABSTRACT FROM AUTHOR]

AbstractPseudomonas aeruginosa (PA), an opportunistic human pathogen that is frequently linked with chronic infections in immunocompromised individuals, is also metabolically versatile, and thrives in diverse environments. Additionally, studies report that PA can interact with other microorganisms, such as bacteria, and fungi, producing unique metabolites that can modulate the host immune response, and contribute to disease pathogenesis. This review summarizes the current knowledge related to the metabolic interactions of PA with other microorganisms (Staphylococcus, Acinetobacter, Klebsiella, Enterococcus, and Candida) and human hosts, and the importance of these interactions in a polymicrobial context. Further, we highlight the potential applications of studying these metabolic interactions toward designing better diagnostic tools, and therapeutic strategies to prevent, and treat infections caused by this pathogen. [ABSTRACT FROM AUTHOR]

Identification and classification of microbes are vital for maintenance of normal and altered state of human health and have applications in pharmaceutical industries, food processing, clinical analysis, and treatment. Development of methods aimed towards achieving these goals must be rapid and reliable. Conventional physiochemical and morphology-based methods of identification are often ambiguous, while newer molecular methods such as flow cytometry and polymerase chain reaction, though reliable, are time and resource intensive. Spectroscopic methods provide advantages over conventional methods as these can be fast, non-destructive, and highly specific. Surface charge of bacteria is an important parameter which can reveal composition of cell wall and is attributed to the presence of carboxyl and phosphoryl groups. Interaction of the cell with the solvent and response to various stresses can hence be measured by the changes in surface charge. In this study, we have obtained auto-fluorescence spectra (tryptophan) and dynamic light scattering (DLS) measurements from common pathogenic strains of Pseudomonas aeruginosa and Staphylococcus aureus. Fluorescence emission spectra were obtained in the range of 300-550 nm at excitation wavelength of 280 nm and DLS measurements comprised zeta potential and size parameters. Both types of measurements were performed in physiological and stress-induced conditions such as heat, sonication, and antibiotic treatment with vancomycin and cetylpyridinium chloride. Effects of these antibiotics on membrane integrity and cell viability, as obtained by DLS measurements, were statistically significant and comparable with conventional methods. Multivariate analysis enabled clustering of 83% of the samples at the genera level, based on variances from auto-fluorescence and DLS measurements. [ABSTRACT FROM AUTHOR]

The genes encoding aminoglycoside resistance in Enterococcus faecalis may promote collateral aminoglycoside resistance in polymicrobial wounds. We studied a total of 100 diabetic foot ulcer samples for infection and found 60 samples to be polymicrobial, 5 to be monomicrobial, and 35 samples to be culture negative. A total of 65 E. faecalis isolates were screened for six genes coding for aminoglycoside resistance, antibiotic resistance patterns, and biofilm production. Infectious Diseases Society of America/International Working Group on the Diabetic Foot system was used to classify the wound ulcers. Majority of the subjects with culture-positive wound were recommended conservative management, while 14 subjects underwent amputation. Enterococcal isolates showed higher resistance for erythromycin, tetracycline, and ciprofloxacin. Isolates from grade 3 ulcer showed higher frequency of aac(6′)-Ie-aph(2″)-Ia, while all the isolates were negative for aph(2″)-Ib, aph(2″)-Ic, and aph(2″)-Id. The isolates from grade 3 ulcers showed higher resistance to aminoglycosides as well as teicoplanin and chloramphenicol. All the 39 biofilm producers were obtained from polymicrobial wound and showed higher resistance when compared to biofilm non-producers. Higher frequency of isolates carrying aac(6′)-Ie-aph(2″)-Ia in polymicrobial community showing resistance to key antibiotics suggests widespread distribution of aminoglycoside-resistant E. faecalis and their role in worsening diabetic foot ulcers. [ABSTRACT FROM AUTHOR]