Archives of Microbiology最新文献

Vibrio harveyi is responsible for several shrimp diseases such as luminous vibriosis, hepatopancreas necrosis, red body, and black spot disease, which can cause substantial mortality in shrimp. Due to the increasing prevalence of antibiotic-resistant pathogenic infections, bacteriophage therapy is being considered as a potential alternative for disease treatment. In this study, a Vibrio-infecting bacteriophage VPMCC6 was isolated from an infected shrimp aquaculture pond. VPMCC6 bacteriophage had an icosahedral head (43.51 ± 1.07 nm) and a short tail (14.60 ± 2.13 nm). This bacteriophage produced 24 PFU/cell on its propagation strain V. harveyi S2A and could clearly lyse the host bacteria after 3 h of bacteriophage addition. Whole genome sequence analysis confirmed that the bacteriophage VPMCC6 genome had no tRNA and no virulence or antibiotic resistance genes. Moreover, we evaluated the effectiveness of bacteriophage therapy in controlling vibriosis in Penaeus monodon. After vibriosis induction in P. monodon using 1 × 10⁶ CFU/ mL of V. harveyi S2A in laboratory aquarium, the infected shrimp were treated with Vibrio-infecting bacteriophage VPMCC6 at MOI 1. Results showed that bacteriophage VPMCC6 significantly reduced the mortality of P. monodon (reduction of 54.76% compared to the infected group) and controlled V. harveyi infection in shrimp culture water. Histopathological analysis showed that the treatment group displayed less hepatopancreatic necrosis and reduced tissue damage. These findings suggest that bacteriophage VPMCC6 is a promising biocontrol agent against V. harveyi in P. monodon aquaculture.

Strawberry leaf anthracnose (SLA) is an emerging threat in Vietnam’s primary strawberry-growing region. This study investigated the occurrence, etiology, and cultivar susceptibility in Lam Dong Province. Field surveys across 27 farms in three wards of Da Lat City revealed necrotic leaf spots and stem reddening, with mean incidence reached 6.3% on leaves and 2.8% on petioles, and an average severity of 10.4%. SLA distribution varied by location, with higher leaf infection in ward 7 and greater petiole involvement in ward 3. Statistical analysis indicated that mulch use was associated with a significant increase in leaf disease severity, whereas other agronomic practices showed no consistent effect on SLA incidence. A total of 27 Colletotrichum isolates were recovered from symptomatic tissues, and 7 representative isolates were tested for pathogenicity on detached leaves, of which some produced symptoms, showing variable aggressiveness. Multilocus phylogenetic analysis of two representative isolates (C1P8 and C1P3) using ITS, TUB2, GAPDH, ACT, CHS-1, and HIS3 sequences identified the causal agent as Colletotrichum nymphaeae, representing the first report of this pathogen on strawberry in Vietnam. Screening of seven strawberry cultivars with the most aggressive isolate (C1P8) revealed significant differences in susceptibility: ‘Seolhyang’ and ‘Skyberry’ were highly resistant, whereas ‘Pajaro’ was the most susceptible. These findings highlight the combined roles of pathogen virulence and host genotype in SLA development and support the use of resistant cultivars for integrated disease management. This study contributes to regional pathogen surveillance efforts and supports phytosanitary measures against C. nymphaeae in Southeast Asian strawberry systems.

Rapid expansion of global aquaculture in recent decades has increased production but also amplified risks from pollution, pathogenic microbes, and bacterial infections. These issues have driven widespread antibiotic use, resulting in drug resistance, environmental degradation, and risks to human health. To combat this situation, probiotic bacteria are gaining popularity, and among the diverse group of probiotic candidates, lactic acid bacteria (LAB) have emerged as the most promising ones. Naturally present in fish microbiota, LAB promote health by competitively excluding pathogens, producing antimicrobial compounds (organic acids, hydrogen peroxide, and bacteriocins), strengthening gut barrier integrity, and modulating immune responses. This review establishes the scientific basis for recognizing LAB as safe and effective probiotics in aquaculture. It synthesizes current knowledge on species-specific LAB strains isolated from the gastrointestinal tracts of fish, emphasizing their roles in enhancing growth performance, feed efficiency, and immune responses in both fish and shellfish. The review further highlights the pivotal role of LAB in modern intensive aquaculture systems while identifying existing limitations, key research gaps, and future prospects for their broader application. It compares LAB with other major probiotic groups, outlining their unique advantages, potential risks, and recent technological advancements. By extending insights beyond conventional probiotic use, this review proposes a functional classification framework and explores underexplored mechanisms, demonstrating how the strategic integration of LAB can enhance aquaculture productivity, promote sustainability, and ensure the long-term viability of the industry.

The mammalian cell entry (Mce) proteins are critical for the entry and persistence of Mycobacterium tuberculosis (Mtb) within alveolar macrophages. These proteins assemble into an ATP-binding cassette transporter comprising six substrate-binding proteins (MceA-F), two transmembrane domains (YrbEAB), and two nucleotide-binding domains (MceG₂). Although Mtb harbours four distinct mce operons, the regulatory mechanisms governing differential operon expression remain insufficiently understood. In this study, we analyzed the genetic organization, regulatory features, and functional roles of operons encoding Mce proteins across two bacterial families, utilizing a comparative sequence-based approach. Our results reveal a conserved operonic arrangement, and the gene neighbourhood trends further establish the involvement of Mce proteins in cholesterol uptake. Notably, the presence of transcriptional regulators, translational coupling mechanisms, conserved gene clusters encoding translation machinery and accessory proteins suggests a complex, multi-layered regulatory network controlling mce operon expression. Thus, this study offers key computational insights into the complex regulatory framework of the Mce system while also outlining potential experimental approaches to validate the proposed hypotheses.

Worldwide, aquaculture is among the fastest-growing food-producing sectors. To boost the health and growth of aquaculture organisms, microbial supplements are utilized. In particular, yeasts with desirable amino acid and lipid profiles are appealing options for inclusion in aquaculture feed. Besides Ascomycetous yeasts (mainly Saccharomyces cerevisiae, Debaryomyces hansenii, and Yarrowia lipolytica), two Basidiomycetous genera— Please consider reducing length of dashRhodotorula and Phaffia and their derived products (β-glucans, mannan oligosaccharides, and pigments) are used in the industry. They function as probiotics, feed additives, nutritional supplements, growth promoters, pigment enhancers, immunomodulators, immunostimulants, pathogen protectants, and stress relievers. They also enhance digestion, serum biochemical parameters, antioxidant capacities, meat quality, overall yields, and market value of aquaculture species. Since large quantities of yeast biomass can be produced by cultivating on inexpensive substrates, incorporating them into aquaculture feed offers a sustainable way to meet nutritional needs, increase productivity, and promote the overall health of aquaculture species.

Developing an effective HIV vaccine remains a major challenge in modern medicine. The majority of HIV transmissions occur across mucosal surfaces, yet the mucosal immune protection provided by current systemic vaccination strategies is limited. However, the potential of lipid nanoparticle (LNP)-based messenger RNA (mRNA) vaccines to revolutionize HIV prevention is a source of hope and optimism. Additionally, circular RNA (circRNA) represents an emergent platform that may offer potential for mucosal HIV vaccine development. This review examines the relationship between mRNA–LNP formulation science and mucosal immunology, with a focus on how adjuvant design, device engineering, and delivery methods interact to influence protective outcomes. We summarize the most recent research on mucosal delivery methods, including nasal, vaginal, rectal, and pulmonary routes, as well as formulation techniques to overcome obstacles such as mucus penetration, enzymatic breakdown, and epithelial absorption. We also examine how mRNA design (including nucleoside modification status) and prime–boost regimens influence the desired immunological outcomes, such as the induction of mucosal secretory IgA (SIgA), tissue-resident memory T cells (T_RM), and a balanced systemic–local immune response. The microbiome and mucosal inflammation are examined in relation to safety, tolerability, and regulatory considerations. We stress the importance of future research priorities, including integrated prime–boost schedules, adjuvant tuning, and early human trials, to engage the audience and commit to the advancement of HIV prevention. We also highlight translational roadblocks, such as the lack of standardized mucosal assays, limited preclinical challenge data, and manufacturing challenges. When combined, mucosal delivery of mRNA vaccines made with LNP presents a promising strategy for preventing HIV by focusing immune responses at viral entry points.

This study addresses the environmental challenge posed by the persistence of Acid Red 114 (AR114), a recalcitrant azo dye widely used in textile industries, and explores the potential of Paenibacillus dendritiformis as a promising bioremediation candidate. Among 23 bacterial isolates screened, P. dendritiformis exhibited superior performance, achieving 99% decolorization of AR114 (10 mg/L) within 72 h under optimized conditions (pH 7, 35 °C, static). The UV–Vis spectroscopy results confirmed decolorization through disappearance of the characteristic absorption peak at 507 nm, while FTIR analysis revealed the breakdown of key functional groups, validating dye degradation. SEM analysis revealed stress-induced morphological adaptations, including surface roughness, cell aggregation, and biofilm formation, suggesting a biofilm-mediated degradation mechanism. Enzyme assays depicted dye-induced azoreductase activity, peaking at 109.8 U/mL at 72 h, correlating with maximum decolorization. Phytotoxicity tests using Lens culinaris seeds exhibited that untreated water containing AR114 dye reduced germination up to 70%, while bacterial treatment improved germination to 93%. Growth parameters such as root and shoot length, as well as vigor index, also showed marked improvement with bacterial-treated dye solution as compared to the untreated dye solution. To the best of our knowledge, this is the first report of efficient AR114 degradation by P. dendritiformis under static aerobic conditions. The findings establish P. dendritiformis as a robust, eco-friendly, and scalable biocatalyst for azo dye remediation, offering a cost-effective and sustainable alternative to conventional wastewater treatment approaches.

The goat rumen harbors a dense and diverse microbial community that produces enzymes for degrading plant cell wall polysaccharides, representing a potential source of valuable enzymes for applications. In this study, we explored the diversity of endoglucanases from goat rumen bacterial metagenomes using homology- and motif-based approaches. HMM profiling identified 5,182 endoglucanase-encoding ORFs, whereas KEGG annotation (EC 3.2.1.4) detected 7,368 ORFs, with 2,902 shared between the two methods. Taxonomic assignment revealed Firmicutes and Bacteroidetes as the dominant phyla, followed by Fibrobacteres, Spirochaetes, and Lentisphaerae. At the genus level, Ruminococcus (Firmicutes) and Prevotella (Bacteroidetes) were dominant, followed by Butyrivibrio, Fibrobacter, and Treponema. Pfam domain analysis further revealed that the common endoglucanase domains, GH5 and GH9, exhibited a high degree of overlap (> 80%) between the two approaches. Notably, GH26 and GH8 were more frequently identified by HMM profiling, whereas KEGG-based mining revealed greater domain diversity. A candidate endoglucanase-encoding ORF was subsequently expressed in E. coli, and the recombinant protein was characterized. The enzyme displayed bifunctional activity on both cellulose (CMC, filter paper) and hemicellulose (xylan), with the highest activity toward CMC, and showed optimal activity at 50 °C and pH 4.0. Its activity was differentially affected by metal ions and chemical agents, and kinetic analysis revealed strong substrate affinity and high catalytic efficiency (Km = 0.8 mg/mL, Vmax = 186.12 U/mg). Overall, this study demonstrates complementary strategies for mining functional proteins from metagenomes and highlights the potential of goat rumen-derived endoglucanase for lignocellulose degradation in sustainable industrial applications.

Phytopathogenic fungi are a major threat in tropical agriculture, causing diseases in crops and postharvest fruits that lead to significant economic losses. Although synthetic fungicides are commonly used for their control, their environmental persistence and toxicity have raised the need for safer alternatives. In this study, the antifungal potential of CaZn₂(OH)₆•2H₂O] (CZ), ZnO, and Ca(OH)₂ nanoparticles (NPs) synthesized por sol-gel (SG), hydrothermal (HT), microwave-assisted (MW), and mechanochemical (MC) methods was evaluated. A total of 53 fungal strains were isolated from symptomatic plant material, and their pathogenicity was confirmed in 10 strains, primarily from Colletotrichum and Fusarium, using Koch’s postulates. Susceptibility to conventional fungicides (mancozeb, prochloraz, and benomyl) and antifungal activity of NPs were assessed through microdilution and poisoned plate assays. All NPs exhibited fungicidal effects, with minimum fungicidal concentrations (MFCs) ranging from 0.039 to 5.0 mg·mL^− 1. In poisoned plate assays, SG-derived NPs showed the highest inhibition rates (0.2%–100%) and induced macro- and micromorphological alterations, including the paradoxical effect. CZ NPs were particularly effective in inhibiting conidia germination, while ZnO NPs mainly targeted hyphal growth. The in vitro efficacy of these NPs supports their potential use in integrated disease management programs. Further validation under field conditions and ecotoxicological studies will help consolidate their role in sustainable crop protection.

Periodontitis is a chronic inflammatory disease that progressively destroys the tooth-supporting structures, including the gums, periodontal ligament, and alveolar bone. This destruction is primarily driven not by the bacteria themselves, but by the host’s dysregulated immune response to a dysbiotic subgingival biofilm. Bacterial colonization in periodontal disease (PD) triggers both innate and adaptive immune responses. Furthermore, numerous viruses—including human cytomegalovirus (HCMV), Epstein-Barr virus (EBV), and herpes simplex virus (HSV)—have been linked to periodontal disorders and contribute to the etiopathogenesis of periodontitis alongside bacteria. Since its emergence in 2020, COVID-19 has posed a significant global health threat. SARS-CoV-2 infection within the periodontium may induce local inflammation, potentially exacerbating PDs. Given that viral replication and persistence in tissues are thought to increase with the severity of inflammation, the presence of these viruses may be linked to the development and progression of periodontitis. The current study is unique in its synthesis of data on a wide spectrum of viruses associated with periodontitis. This includes common viruses (EBV, HCMV, HSV, human papillomavirus (HPV), and human immunodeficiency virus (HIV)), emerging viruses (Chikungunya, Dengue), and novel viruses such as SARS-CoV-2. By providing a comprehensive overview of viral co-infections in periodontitis, this review advocates for the development of new antiviral diagnostic and therapeutic strategies that adopt a broad, virus-centric approach. We conducted a literature search across PubMed, Google Scholar, and Web of Science using keywords and Medical Subject Headings (MeSH) terms such as “viral infection,” “periodontitis,” and specific virus names.

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