Current Microbiology最新文献

Soil-borne pathogens pose a significant threat to vegetable production in Pakistan, leading to considerable yield reductions and compromising crop quality. Conventional control methods, such as the use of chemical fungicides, are associated with environmental and health risks, highlighting the urgent need for sustainable and eco-friendly alternatives. Vegetable production in Pakistan is severely affected by loss of yields and degradation in quality due to soil-borne pathogens. The widespread use of chemical fungicides suggests the need for safer substitutes and efficient soil health management. The employment of biological approaches is suggested by concerns about soil health and management. Through competition, antibiosis, and systemically induced resistance, the beneficial soil microflora, growth-promoting bacteria (PGPB), plant growth-promoting fungi (PGPF), including arbuscular mycorrhizal fungi (AMF), Trichoderma spp., and other soil microorganisms work in concert to control soil diseases and restore soil health. When combined with crop rotation, biofumigation, and decreased tillage, organic amendments and agronomic techniques, such as compost, biochar, green manure, and cover crops, have been shown to lower soil pathogen loads, microbial diversity, and resilience while increasing crop yields. Integrated soil health management in vegetable crop profitability (e.g., potatoes, tomatoes, okra, and chilies) and sustainability is improved in the long run with the reduction of chemical inputs through the combination of biological, organic, and agronomic strategies. To improve soil health management in the vegetable sector, integrated microbiome-centered organic strategies are a priority. In-line advanced research, extension services, and a supportive policy framework are all aspects of future vegetable soil health management strategies, soil eco health, and vegetable sector transformation to meet expected soil health management in Pakistan. These strategies are meant to improve the resilience of Pakistan's food systems, promote sustainable agriculture, and safeguard the environment.

Cerium oxide nanoparticles (CeO₂ NPs), a few nanometers in diameter, exhibit strong antioxidant and anti-inflammatory activity and are considered promising candidates for the treatment of ocular diseases. This study investigated the impact of CeO₂ NPs, both in their naked form, and formulated as eye drops, on the bacteria inhabiting the ocular surface. The microbiome from healthy eyes was characterized through 16 S rRNA amplicon sequencing. The dominant bacterial genera included Staphylococcus, with lower abundances of Corynebacterium and Streptococcus, varying among the samples. Eye bacteria were isolated and exposed to both forms of CeO₂ NPs to investigate cell growth, viability, and gene expression. Neither naked CeO₂ NPs nor eye drop formulation affected the growth of Staphylococcus aureus and Staphylococcus epidermidis. In S. aureus, CeO₂ caused down-regulation of rho (naked CeO₂ NPs) and recA (eye drop form) genes related to the termination of transcription and DNA damage response, respectively. In S. epidermidis, the expression of lexA, recA, ftsZ, rho and icaC remained comparable between treated and control samples, while DNA damage response genes lexA and recA were up-regulated in C. amycolatum following exposure to CeO₂ eye drops. These gene expression patterns revealed subtle changes in specific bacteria, indicating a short-term adaptive response to eye drop formulations. Overall, these results suggest that CeO₂ NP eye drops have a minimal impact on the isolated bacterial strains. Nonetheless, comprehensive in vivo and clinical studies are necessary to validate these findings, given the inherent limitations of in vitro assays.

The use of agricultural enzymes is a new research direction for addressing soil problems. Microbial community structure and composition during fermentation are influenced by environmental conditions, making them complex to characterize. Here, the bacterial community structure in the middle and late stages of compost fermentation, with and without the addition of enzymes, was analyzed using 16 S rRNA high-throughput sequencing technology. Additionally, the secondary functional traits of microbial communities were identified using the Kyoto Encyclopedia of Genes and Genomes (KEGG) database. In liquid fermentation, the addition of exogenous enzymes reduced the number of microbial species. After an extended period, the dominant bacterial species emerged, with the relative abundance of Proteobacteria reaching 70%. There was a significant difference between the abundance of bacterial species (p = 0.04). However, in compost, as the fermentation duration increased, the bacterial abundance species increased, and the relative abundance of the main bacterial phyla tended to be uniform. Bacterial species abundance did not differ significantly at the phylum (p > 0.05) or genus (p > 0.05) level. According to the KEGG database, the top five most abundant metabolic pathway functional genes were related to the metabolism of substances and the energy required to maintain basic microbial life activities: carbohydrate metabolism, amino acid metabolism, metabolism of cofactors and vitamins, metabolism of terpenoids and polyketides, and metabolism of other amino acids. Exogenous enzyme supplementation alters microbial community succession and metabolic functions during composting and liquid fermentation. The results of this study provide a theoretical reference for the application of enzymes and traditional compost in agricultural production.

Periodontitis is a chronic inflammatory disease driven by bacterial pathogens. This meta-analysis aimed to quantitatively assess the association between nine bacterial strains and periodontitis across 11 studies. We extracted odds ratios (ORs) and 95% confidence intervals (CIs) from studies evaluating Streptococcus mutans, Lactobacillus, Fusobacterium nucleatum, Prevotella intermedia, Staphylococcus aureus, Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Tannerella forsythia, and Treponema denticola. Heterogeneity was evaluated using Cochran's Q and I² tests. We systematically searched PubMed, Scopus, and Web of Science up to March 2024, following PRISMA guidelines, to identify studies investigating the association between oral bacterial species and periodontitis. Porphyromonas gingivalis was identified as a significant risk factor for periodontitis in all eight studies (ORs: 4.17-97, I² = 85.99%). Tannerella forsythia (ORs: 2.75-36.88, I² = 85.39%) and Treponema denticola (ORs: 3.12-24.5, I² = 85.54%) were also significantly associated with periodontitis. Prevotella intermedia showed a significant association in three out of four studies, despite high heterogeneity (I² = 79.82%). Fusobacterium nucleatum and Staphylococcus aureus were not found to be significant risk factors. Porphyromonas gingivalis, Tannerella forsythia, and Treponema denticola are key bacterial risk factors for periodontitis. The findings highlight the importance of microbial screening in clinical practice, while the heterogeneity suggests the need for standardized research. Future studies should focus on longitudinal assessments and microbial interactions.

Rhizobacteria that promote plant growth (PGPR) are a wide range of soil bacteria that inhabit the rhizosphere of plants. In the present study, two plant growth-promoting bacterial strains were isolated from the rhizospheric soil of the Asparagus plant, Namely Enterobacter mori RGK1 and Exiguobacterium acetylicum RGK, which can enhance plant growth. It was shown that both of these bacterial strains were able to synthesize exopolysaccharide, hydrogen cyanide (HCN), indole acetic acid and siderophores. These strains fix atmospheric nitrogen, solubilize phosphate, zinc and potassium. Additionally, has shown antibiotic susceptibility to antibiotics such as Amikacin, Netilin, Co-trimaxazole, Streptomycin, Furazolidone, Kanamycin, Nalidixic acid, Nitrofurantoin, Tobramycin, Oxytetracyclin, Chloramphenicol, Gentamycin and their ability to withstand salt concentration (NaCl) up to 5-6%. Treatment of Asparagus plantlets with separate and co-culture of both strains demonstrated a remarkable favorable change in physicochemical properties of soil, growth parameters and phytocompounds of Asparagus as compared to control. They improved the growth metrics of the plant such as shoot height, rhizome biomass, plant biomass as well as phenolic, flavonoid, saponin content and free-radical (DPPH) scavenging ability. As compared to the untreated plants, PGPR-treated plantlets showed higher amounts of secondary metabolites, primarily Diosgenin. The main focus is on the use of multiple microbial strains in a single formulation, an emerging trend in sustainable agriculture.

The intestinal microbiome of fish at early stages of ontogeny represents a complex and dynamic ecosystem that is critically important for immune system development, physiological resilience, and growth. The yolk-sac stage is of particular significance, as larvae rely exclusively on endogenous nutrient reserves while being colonized by microbes for the first time. During this period, the foundations of microbiota are established, which subsequently influence the development of the digestive system, barrier functions, and pathogen resistance. Recent studies show that microbial communities at this stage are characterized by low alpha diversity and the dominance of Proteobacteria, Firmicutes, and Bacteroidetes. With the transition to exogenous feeding, there is an increase in taxonomic and functional diversity, along with the emergence of probiotic genera (Bacillus, Lactobacillus, Shewanella) that promote enzymatic activity, immune modulation, and increased survival of larvae. This review systematically compiles data from the past 20 years, encompassing both culture-dependent methods and high-throughput sequencing approaches. It has been demonstrated that despite the limitations of culture-based methods, they remain indispensable for isolating probiotic strains. A comparison of methodologies revealed high variability in protocols, complicating the direct comparison of results. The findings underscore the applied significance of studying microbiota for aquaculture during the yolk-sac stage. The management of microbial communities through probiotics, prebiotics, and environmental regulation presents prospects for enhancing the survival, growth, and resilience of fish larvae.

The development of bedaquiline holds promise for treating multidrug-resistant tuberculosis (MDR-TB). Still, the inflation in bedaquiline resistance has alarmed the global public health crisis, indicating the need for a new treatment strategy. Several scientific studies have reported a high incidence of resistance among MDR-TB patients who had prior exposure to bedaquiline for treating Mycobacterium tuberculosis infections. Disparate research findings indicate that individuals previously administered this drug exhibit a remarkable prevalence of resistance. Studies have further demonstrated that prior treatment often correlates with the emergence of resistant Mycobacterium tuberculosis strains. Overall, evidence from multiple investigations highlights a concerning trend of increased resistance in MDR-TB cases with a history of bedaquiline therapy. Moreover, bedaquiline resistance in MDR-TB strains has been linked to mutations in several chromosomal genes, including atpE, Rv0677c, Rv0678, and pepQ. Consequently, it is imperative to mitigate the burden of MDR-TB and bedaquiline resistance. Herein, this article emphasizes structural features, mechanism of action, emergence of underlying resistance mechanisms, pharmacokinetic & pharmacodynamic properties, clinical toxicity, and strategies to combat resistance associated with bedaquiline.

Chromium (Cr) pollution from anthropogenic activities threatens agriculture and food security in developing countries, necessitating sustainable bioremediation strategies to mitigate its effects. In the current study, Aspergillus welwitschiae, a Cr-tolerant fungus, accumulated > 50% Cr from Czapek broth and improved wheat immunity to tolerate up to 75 ppm of chromate in soil. Inoculation with A. welwitschiae significantly improved Triticum aestivum L. (wheat) tolerance to chromate stress (75 ppm) in the growth medium. The fungal association modulated phytohormone levels, increasing endogenous salicylic acid (SA) (68.5%), indole acetic acid (IAA) (97.14%), and gibberellic acid (GA₃) (34.13%). Additionally, inoculated plants exhibited elevated levels of key metabolites, including flavonoids (94.9%), phenols (13.8%), and soluble sugars (21.3%). Oxidative stress markers like malondialdehyde (MDA) and hydrogen peroxide (H₂O₂) declined by 4.28-fold and 2.36-fold, respectively, compared to non-inoculated controls. The strain also enhanced activities of the antioxidative enzyme under Cr stress, with catalase, and peroxidase levels increasing by 3.67-, and 6.26-folds at 75 ppm Cr. Furthermore, A. welwitschiae promoted Cr uptake and translocation in wheat, accumulating ~ 1.6-fold more Cr in aerial tissues, demonstrating its efficacy in soil remediation for chromium-contaminated agricultural systems.

Children who contracted COVID-19 develop antibodies targeting the SARS-CoV-2 spike (S) protein which persist for 4 to 12 months following infection. We sought to analyze the antibody response to SARS-CoV-2 one year after COVID-19 in children under 18 years, vaccinated or unvaccinated. Blood samples were collected during the acute phase, the convalescence stage and one-year post-disease. Vaccinated adults who had COVID-19 during the same timeframe were analyzed for comparison. Serum SARS-CoV-2 S IgG was assessed using immunoassay, and neutralizing activity was evaluated using a SARS-CoV-2 S-pseudotyped lentivirus assay. Seventy-five children were enrolled, with a median age of 8 years (IQR 3-12), and 35% were vaccinated. Forty-nine adults were included, with a median age of 34 years (IQR 29-44). Among unvaccinated children, median SARS-CoV-2 S IgG levels one year after COVID-19 tended to decrease 2-fold compared to convalescent levels. SARS-CoV-2 antibodies were notably elevated in children with two or three COVID-19 vaccine doses compared to unvaccinated individuals. Children who received mRNA vaccines exhibited higher SARS-CoV-2 IgG titers (p = 0.0028) and neutralizing antibodies (p = 0.0120) compared to those who received inactivated vaccines. SARS-CoV-2 IgG showed no correlation with the severity of the initial illness or the presence of comorbidities. SARS-CoV-2 IgG did not significantly differ between vaccinated children and adults with the same vaccination status. Among unvaccinated children, convalescent levels of IL-1 β and IL-4 positively correlated with one-year antibody responses. This work highlights the significance of vaccinating children to sustain a lasting humoral immune response against SARS-CoV-2, even after infection.

Diarrheagenic Escherichia coli (DEC) poses a significant threat to public health due to its potential to induce severe gastrointestinal illnesses and fatalities. This study was conducted to evaluate the in vitro antibacterial properties and mechanisms of action of ethanol extract derived from haskap berries (Lonicera caerulea L.) (LCEE) against 7 important serotypes among DEC. Chemical analysis unveiled the substantial presence of phenols, flavonoids, and anthocyanins in LCEE, with cyanidin emerging as the predominant anthocyanidin. Antioxidant assays confirmed the potent antioxidant capabilities of LCEE. The DEC treated with LCEE led to conspicuous inhibition zones, reduced growth rates, and demonstrated notable efficacy, with low minimum inhibitory concentration and minimum bactericidal concentration values against DEC. LCEE exerted strong antimicrobial abilities on DEC by reducing bacterial motility, disrupting biofilm and pre-formed biofilm. LCEE was observed to induce alterations in cell morphology and internal structure, enhance membrane permeability, and induce cellular dysfunction, including cell membrane hyperpolarization and decreased intracellular ATP concentration. SDS-PAGE analysis demonstrated LCEE interfered with protein synthesis, while quantitative real-time PCR (RT-qPCR) assays revealed that LCEE inhibited biofilm formation possibly by reducing the expression levels of genes (including luxS, fliC, csgA, and fimA) associated with biofilm-formation. Cytotoxicity assessments indicated that LCEE exhibited no cytotoxic effects in vitro. These findings highlight the potential of LCEE as a natural antimicrobial agent for mitigating DEC contamination in food, thereby lowering the risk of DEC infections.