Microorganisms最新文献

Fusidic acid resistance in Staphylococcus spp. has historically been confined to Staphylococcus ureilyticus, with limited data on its environmental distribution. This study presents the first detection of the fusidic acid resistance gene fusF in Staphylococcus kloosii recovered from virgin soil at Kampung Batu 16, Dusun Tua, Hulu Langat, Malaysia. A total of ten Staphylococcus isolates were identified using the VITEK^®2 system with high confidence (97-99%), comprising seven S. kloosii and three S. ureilyticus. Sequencing of representative isolates further corroborated the species identification. All isolates displayed phenotypic resistance to fusidic acid, while all S. ureilyticus (3/3) exhibited multi-drug resistant (MDR) traits and S. kloosii (7/7) exhibited non-MDR traits. PCR and sequencing confirmed the presence of fusF gene in S. ureilyticus (3/3) and S. kloosii (3/7). In addition, fusB and fusC genes were not detected in both species. The phylogenetic analysis (Maximum Likelihood, Tamura-Nei model) revealed high sequence conservation and clustering between fusF-positive S. kloosii and S. ureilyticus soil isolates, suggesting recent horizontal gene transfer between these two related species. The first detection of fusF gene in S. kloosii from virgin soil signifies the expansion of the ecological and host range beyond S. ureilyticus, establishes virgin soil as a potential antimicrobial resistance (AMR) reservoir, and underscores the One Health risks of resistance dissemination from environmental staphylococci. This baseline study highlights the importance of early AMR surveillance in tropical environments prior to agricultural development.

Seed endophytic microbiota are crucial for plant early development and stress resistance. Pinus massoniana is a key ecological and economic tree species in China, yet it is severely threatened by pine wilt disease (PWD). However, the community composition of P. massoniana seed endophytic microbiota and the persistent symbiosis formed via vertical transmission in seeds remain unclear. We analyzed the endophytic bacterial and fungal microbiota of P. massoniana seeds from four geographic regions using high-throughput 16S rRNA and ITS sequencing to characterize community structure, diversity, and functional potential, providing a basis for endophytic microbiota-based strategies to enhance resistance to PWD. Results showed that both alpha and beta diversity analyses indicated that seed endophytic microbial communities of P. massoniana differed among regions. Bacterial communities were dominated by Pseudomonadota (phylum), Gammaproteobacteria (class), and the genera Klebsiella, norank_f_Pectobacteriaceae, and Lactobacillus. Fungal communities were primarily composed of Ascomycota and Basidiomycota (phylum), Sordariomycetes (class), and the genera Rosellinia, Aspergillus, and Coniophora. Correlation network analysis revealed that fungal networks were characterized by a higher proportion of positive correlations, whereas bacterial networks were more complex. Notably, several genera detected in seeds, including Pseudomonas, Bacillus, and Trichoderma, have also been reported in mature P. massoniana tissues, indicating a potential for putative vertical transmission from mother plants. Functional prediction further suggested that these taxa were enriched in pathways related to terpenoid and polyketide metabolism and saprotrophic functions, which have been implicated in PWD resistance and have been previously reported to exert nematode-suppressive or plant growth-promoting effects. Overall, this study elucidates the community structure and ecological characteristics of seed endophytic microbiota in P. massoniana and identifies potentially beneficial microbial taxa, providing potential support for the future utilization of P. massoniana endophytic microbiota in PWD research.

Municipal wastewater contains high amounts of nitrogen (N) and phosphorus (P), as well as other compounds that are harmful to the environment; however, it can also be used as an algae growth medium. In this study locally (Lithuania) isolated algae Scenedesmus quadricauda were cultivated in local (Vilnius city) municipal wastewater. Data show that Scenedesmus algae can be grown in municipal wastewater as successfully as in Bold's basal medium for 14 days. Algae cultivation significantly reduced the concentration of organic nitrogen forms and phosphate levels. The nitrogen concentration in wastewater after cultivation was reduced to 8 mg N L^-1 (up to 89% reduction in total nitrogen concentration). Phosphorus concentration was reduced to 5.4 mg P L^-1 (up to 86%). The analysis indicates that the optimal temperature for S. quadricauda cultivation is 25 °C; temperatures higher or lower than this result in a reduction in algal biomass. A higher amount of light leads to higher yields. No statistically significant differences were found comparing cultivation in BB medium and wastewater under different conditions. The analysis showed that the main factors influencing algae biochemical composition were final total nitrogen concentration and available total nitrogen amount per unit of algae biomass produced, as well as molar N:P ratios. Algae biomass cultivated in wastewater contained a consistent lipid concentration (on average 14.94 ± 2.38%), a lower final total nitrogen concentration, and overall lower total nitrogen availability, leading to higher carbohydrate concentrations (up to 51.10%) and a lower protein content (down to 15.52%). Algae biomass that was cultivated in the BB medium biochemical composition was not dependent on environmental factors and remained consistent (on average 22.89 ± 3.85% carbohydrate, 39.32 ± 3.89% protein, and 13.99 ± 2.21% lipid).

Low-density polyethylene (LDPE) and poly (butylene adipate-co-terephthalate) (PBAT) agricultural films are major components of microplastics (MPs) and their contamination in agriculture due to their difficulty to recycle. However, potential degradation mechanisms of MPs from LDPE and PBAT in agricultural soils are still unclear. Here, we isolated a strain of Bacillus cereus L6 from long-term agricultural MP-contaminated soil and analyzed its potential biochemical pathways involved in LDPE and PBAT turnover through functional prediction from shotgun genome sequencing. After 28 days of incubation with MPs, Bacillus cereus L6 caused a net mass loss of 0.99% LDPE-MPs/28 days and 3.58% PBAT-MPs/28 days. The surfaces of LDPE and PBAT degraded in bioassays added with Bacillus cereus L6 showed wrinkles, cracks, and pits, accompanied by an increase in roughness. The crystallinity and thermal stability of both LDPE- and PBAT-MPs were decreased and the hydrophobicity of PBAT-MPs was reduced. Whole-genome sequencing analysis showed that Bacillus cereus L6 potentially encoded genes for enzymes related to the biodeterioration of additives in LDPE and PBAT. Moreover, genomic CAZymes predictive analysis showed that genes related to oxygenases and lyases were annotated in the strain L6 Auxiliary Activities family. These findings offer a theoretical foundation for deeper exploration into the degradation and metabolic processes of MPs from discarded agricultural plastics in the environment.

Background: Antifungal resistance among Candida species and related genera, coupled with the lack of new drugs, poses a significant threat to public health. Several studies have demonstrated a relationship between virulence factors and resistance. Current objectives include identifying new targets and searching for new natural molecules. Carvacrol, a natural phenolic compound, has been shown to have antimicrobial properties; however, its impact on the virulence of species other than Candida albicans and related yeast genera remains underexplored.

Methods: The antifungal activity of carvacrol was evaluated against clinical isolates of Candidozyma auris, Meyerozyma guilliermondii, and Candida dubliniensis, as well as its effect on adhesion, hydrophobicity, biofilm formation and osmotic stress tolerance. In vivo activity was assessed using the Galleria mellonella infection model at MIC concentrations.

Results: Carvacrol inhibited adherence and significantly reduced both early and preformed biofilms in M. guilliermondii and C. dubliniensis. In C. auris, the compound produced a modest reduction in biofilm activity but significantly enhanced larval survival in the in vivo model (~20%, p < 0.01). Carvacrol also induced increased tolerance of C. auris to osmotic stress, suggesting activation of adaptive pathways.

Conclusions: Carvacrol exhibits species-specific effects, acting as an antivirulence modulator in M. guilliermondii and C. dubliniensis and attenuating virulence in vivo in C. auris. These findings support the potential of carvacrol as an adjuvant antifungal strategy, particularly against C. auris, and highlight the relevance of targeting virulence traits to reduce selective pressure and limit antifungal resistance.

Probiotics represent a beneficial approach to boost the welfare, health, and meat quality of poultry. One hundred and twenty one-day-old male Muscovy ducklings were divided among 24 floor pens (five ducklings per pen). The pens were randomly distributed among one of four dietary treatments with six replicates (G-C) without any supplementation of probiotics; (G-A) was supplemented with 0.4 g/kg of Amnil^®; (G-M) was supplemented with 0.5 g/kg of M-Mobilize^®; and (G-A-M) was supplemented with 0.4 g/kg of Amnil^® (1-30 day) and 0.5 g/kg of M-Mobilize^® (31-60 day), respectively. The results indicated that BW at day 60 was improved in (G-A) birds compared with (G-C) ones, IL-6 was decreased in (G-A) and (G-A-M) in liver and spleen in comparison with (G-C) (p < 0.05), but no differences were observed between (G-C) and (G-M) (p > 0.05); IL-10 was decreased in all the probiotic-fed ducklings compared with (G-C) birds in the spleen (p < 0.05), and IL-10 was decreased in the (G-A) birds compared with the other treatments in the liver (p < 0.05). Probiotic-fed birds showed a higher enumeration of Lactobacillus spp. compared to (G-C) group (p < 0.05). In addition, the (G-M) group showed improved breast meat flavor, general acceptability, and water-holding capacity (WHC%) compared to (G-C) group (p < 0.05). These results suggest that the probiotic supplement (G-A), could be a good management tool for improving Muscovy ducks' health and production and further research is needed to improve meat quality traits.

Sclerotinia spp. are globally distributed, devastating plant pathogens with a broad host range, including lettuce, on which they cause lettuce drop disease. To investigate the geographical distribution of lettuce drop incidence and the population structure of Sclerotinia sclerotiorum and S. minor in Serbia, 27 commercial lettuce fields across 12 administrative districts were surveyed. Sclerotinia spp. were confirmed at 10 localities, with S. sclerotiorum occurring more frequently. Co-occurrence of both species within the same field was recorded at only one location. Clear phenotypic and physiological differences were found between Sclerotinia species, as well as among isolates within each species. The two species differed in colony appearance, sclerotia production, virulence, growth rate, oxalic acid production, and tolerance to elevated osmotic pressure. Haplotype analysis of S. minor revealed the existence of 9 haplotypes arranged in a star-shaped network. These findings highlight the importance of considering both inter- and intraspecific variability of Sclerotinia species when evaluating their impact on crops, improving our understanding of Sclerotinia populations in lettuce, and supporting the development of effective management strategies.

Colostrum harbors a highly diverse microbial community, predominantly composed of genera such as Staphylococcus, Streptococcus, Lactobacillus, Bifidobacterium, and Enterococcus. The composition and diversity of this microbiota are influenced by maternal factors-including age, body mass index, lactation activity, stress levels, and gestational diabetes-as well as external factors such as mode of delivery, antibiotic exposure, diet, and geographic location. This microbial community plays a critical role in maternal and neonatal health by contributing to early gut colonization, supporting digestion, promoting immune system development, and protecting against pathogenic microorganisms through mechanisms such as antimicrobial peptide production by lactic acid bacteria. The primary aim of this study was to evaluate the impact of mode of delivery on colostrum microbiota by comparing mothers who delivered vaginally with those who underwent cesarean section. Colostrum samples from 15 mothers were subjected to DNA extraction, high-throughput sequencing, and bioinformatic analyses to characterize microbial composition and predicted functional profiles. Although substantial inter-individual variability was observed, no statistically significant differences were detected in overall microbial diversity or community structure between the two delivery groups. However, distinct bacterial taxa and functional characteristics were identified that were specific to each mode of delivery, suggesting subtle delivery-related influences on colostrum microbiota composition.

Saccharomyces cerevisiae was cultured under the influence of static magnetic fields (SMFs) to assess their impact on the biosynthesis of silver nanoparticles (AgNPs). Cell-free media derived from SMF-exposed cultures facilitated the formation of AgNPs, with a significant reduction in nanoparticle size observed at an optimal field strength of 7 mT. AgNPs synthesized under SMF conditions exhibited smaller crystalline structures than those produced in control media, as evidenced by dynamic light scattering (DLS) and transmission electron microscopy (TEM) measurements. Over a 75-day period, SMF-exposed AgNPs demonstrated enhanced stability, as determined by DLS and polydispersity index (PDI) assessments. Further analysis through sodium dodecyl-sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and Fourier transform infrared spectroscopy (FTIR) suggested the formation of a protein corona on the AgNPs in SMF-treated samples, which likely inhibits agglomeration and enhances long-term stability. These findings indicate that SMF-induced stress in S. cerevisiae triggers the secretion of specific proteins that contribute to the stabilization of AgNPs, providing a novel approach to controlling nanoparticle synthesis and stability through magnetic field exposure.

Hepatitis E virus (HEV) is a zoonotic pathogen that can infect pregnant women and cause adverse pregnancy outcomes, including miscarriage and preterm delivery. The previous study demonstrated that HEV genotype 3 (HEV-3) inhibits complete autophagic flux in both mouse placental tissue and human trophoblast cells (JEG-3), evidenced by reduced expression of ATG proteins (including LC3, Beclin1, ATG4B, ATG5, and ATG9A) and accumulation of p62. However, the specific regulatory pathway involved remains unclear. Thus, eukaryotic expression vectors for HEV open reading frames (ORFs) were constructed, and ORF2 and ORF3 proteins were transiently overexpressed in JEG-3 cells via liposome transfection. While both ORF2 and ORF3 significantly reduced LC3B protein levels (p < 0.01), only ORF2 induced p62 accumulation (p < 0.01), indicative of autophagic inhibition, which indicates that ORF2 was the key viral protein mediating autophagy suppression in JEG-3. The results of WB and RT-qPCR showed that ORF2 suppressed the PI3K/Akt/mTOR pathway while enhancing nuclear translocation of TFEB (p < 0.01) and AMPK phosphorylation (p < 0.01), suggesting paradoxical activation of upstream autophagy regulators. Through co-transfection of mCherry-LC3 with ORF2, co-localization studies, and AlphaFold 3-based intermolecular interaction predictions, we propose that ORF2 directly binds LC3B to block autophagosome formation. Finally, co-immunoprecipitation confirmed physical interaction between HEV ORF2 and LC3B, elucidating the molecular mechanism of HEV-induced autophagy suppression in trophoblasts. These findings reveal the molecular mechanism by which HEV inhibits autophagy leading to miscarriage in mice, providing new insights into HEV-induced reproductive damage.