MicrobiologyOpen最新文献

Accumulation of synthetic plastics in the biosphere has led to global pollution, provoking serious consequences for the environment and human health. Uncontrolled agricultural plastic landfills have the risk of becoming a source of agrochemicals and microplastics. Biotechnological approaches to solve plastic pollution include the removal of these polymers through biological degradation, which is a friendly environmental method. The microbial communities colonizing plastic debris (plastisphere) are considered as a potential source of plastic-degrading microorganisms. In this study, a bacterial biodiversity analysis, based on 16S rRNA gene-targeted metagenomic sequencing, was achieved in the plastisphere of low-density polyethylene (LDPE) and polypropylene (PP) polymers from an agricultural landfill. The α-diversity analysis did not show significant differences between LDPE and PP plastispheres and the plastic-free bulk soil, while LDPE and PP bacterial communities clustered close, but separately from the bulk soil in a β-diversity analysis. Although the taxonomic composition of both plastispheres was different, they shared a significantly higher proportion of Cyanobacteria and Deinococcota than the bulk soil. Additional analyses showed different indicator families, genera and species that can be associated with plastispheres. A predictive functional analysis suggests that degradation of plastic additives in both plastispheres is probably occurring. In addition, the existence of degradation processes for specific herbicides in each plastisphere is highlighted, and the possible exposure of LDPE to both physical and biological degradation processes is also described. These results will contribute to characterize the soil plastisphere exposed to different environmental conditions, and to understand the specific biological niches where plastic-degrading microorganisms could survive.

The complexities of microbial detection and conventional enumeration necessitates the adoption of pragmatic alternatives. This review expands the boundaries of knowledge for microbial detection and sensing, particularly within the field of water quality analysis. Observed alternatives to conventional techniques for microbial analyses in recent studies include Microarray, Fluorescent in situ hybridization (FISH), loop-mediated isothermal amplification (LAMP), matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) and flow cytometry, while nanosensors stood out as an alternative for microbial detection in real-time. This study presents the limitation of conventional methods of detection in water and presents nanoparticles as a detection agent with possibility of incorporation into point-of-use detection. It is notable that nanosensors are currently emerging in the detection of bacteria, viruses and other pathogens in water and have been used in the detection of bacterial pathogens than viral. Nanosensors are established as good choice for rapid water analysis with application in point-of-use and analytical devices. In the use of nanozymes, the choice over natural enzymes can be linked to their unique and excellent catalytic activities, cost-effectiveness and ease of mass production.

Gut microbiota (GM) plays a pivotal role in human health and disease, and its alterations have been implicated in various neurological disorders, including Parkinson's disease (PD). Growing evidence reveals correlations between the abundance of specific bacterial taxa and the severity of motor symptoms and intestinal dysfunction in PD. Moreover, bacterial metabolites have been shown to influence α-synuclein (α-syn) aggregation and neurodegeneration. This narrative review aims to explore the current understanding of the gut-brain axis in PD, specifically the connection between GM and α-syn function in PD experimental models and patients. Several therapeutic strategies aimed at modulating gut microbiota, such as dietary interventions, fecal microbiota transplantation, and targeted bacterial therapies with the goal of alleviating or preventing PD symptoms, are examined. Understanding the mechanisms through which GM influence neurodegeneration, including inflammation, immune modulation, and microbial metabolite production, offers promising avenues for the development of novel therapeutic strategies targeting the microbiome.

The red color pigment prodigiosin is a potent antioxidant produced by different strains of Serratia marcescens and other bacteria. The bio pigment demonstrates many hopeful impending bioactivities. Prodigiosin is an active proapoptotic agent against various cancer cell lines. In the present study, pigment produced from soil isolate Serratia marcescens VITSD2 was characterized and identified using UV, FTIR, GC-MS and NMR analysis (¹H NMR and ¹³C NMR). The antiproliferative activity of prodigiosin pigment from Serratia marcescens VITSD2 was evaluated on cancer cell lines. The active sites and binding patterns of molecular marker survivin was analyzed on docking against prodigiosin.A strong antioxidant potential was noticed at 5 mg/mL concentration with 70 ± 0.08% scavenging activity (2,2-diphenyl-1-picrylhydrazyl)-DPPH. The dose dependent inhibition of HepG2 cell proliferation was observed maximum with 67 ± 0.08% cytotoxic activity at 50 µg/mL. When compared to other cell lines, A549, HL 60 and MCF-7, prodigiosin had a strong inhibitory activity on HepG2 cells. The Rf value of single band obtained in chromatography showed a value of 0.45. Maximum absorbance was observed at 535 nm. The pigment revealed the characteristic functional properties of the prodigiosin. On docking, the lowest binding energy exhibited was found to be -5.15 kcal/mol. The RMSD analysis indicated that the backbone structure converges at 18 ns before it attains stability. Pigment production from Serratia marcescens VIT SD2 offer a renewable and sustainable alternative to synthetic pigments, reducing dependence on nonrenewable resources. The study outcomes specified that the bio pigment prodigiosin extracted from Serratia marcescens VIT SD2 is a promising drug candidate for therapeutics.

Hexachlorocyclohexane (HCH) was extensively used as a pesticide until the 1990s. It was synthesized by benzene photochlorination, resulting in a mixture of stereoisomers, which included α-, β-, γ-, and δ-HCH, among others. It was later discovered that only the γ-HCH isomer (also called lindane) had insecticidal properties, so it began to be purified from this mixture, while the remaining HCH isomers (representing around 85%–90% of industrial HCH production) were disposed of in dumpsites, generating environmental issues. Several works have studied microbial-driven biodegradation and physiological responses to γ-HCH, but information concerning the other isomers is scarce. Since previous research showed that the cyanobacterium Anabaena sp. PCC 7120 is effective at removing lindane; this study focused on its responses to the α-, β-, and δ-HCH isomers. The results showed that Anabaena tolerates α- and γ-HCH well, with little impact on growth, while β- and δ-HCH are more poorly tolerated and negatively affect growth and cell physiology. It was also found that, in the presence of Anabaena sp. PCC 7120, both α- and γ-HCH are completely eliminated from supernatants while β- and δ-HCH are partially eliminated. Additionally, the linC gene was found to be expressed at twice the normal level in the presence of α- and γ-HCH at 2 mg/mL. Overall, this study reveals how Anabaena responds to key HCH isomers found in contaminated sites and supports its potential use in bioremediation.

The research aimed at investigating the antibacterial potential of dental resin composites when combined with various antimicrobial peptides (AMPs) against Porphyromonas gingivalis heme-binding proteins, which are associated with biofilm-related infections in restorative dentistry. A multistage computational approach was implemented to assess the AMP interactions. Molecular docking analyses demonstrated the promising binding of resin constituents with AMPs, and Pardaxin exhibited the highest binding affinity, followed by Tachystatin and Thermolysin. The best performing AMPs were then docked with P. gingivalis heme-binding proteins, and the complexes were subjected to 100 ns molecular dynamics simulations for stability assessment. The simulations confirmed stable interactions, while MM/PBSA binding energy calculations demonstrated significant binding strengths, particularly for Pardaxin (ΔG = −65.58 kcal/mol) and Tachystatin (ΔG = −48.71 kcal/mol), with Thermolysin also showing promising results (ΔG = −39.92 kcal/mol). The comprehensive analysis indicates the potential of incorporating Pardaxin, Tachystatin, and Thermolysin into dental resin composites to enhance their antibacterial activity against P. gingivalis. However, the study is limited to in silico assessments and relies on static representations of resin monomers that may not accurately represent the biological and clinical environment. Experimental validation through in vitro and in vivo studies, including cytocompatibility testing, peptide release behavior, and long-term mechanical stability, is essential to establish their practical application in restorative dentistry.

Supplementing H. pylori treatment with probiotics like Lactobacillus has become an essential approach due to the possible adverse effects of antibiotic therapy and the need to increase overall eradication rates. Although several types of Lactobacillus strains as probiotics were efficient in treating H. pylori, their relative efficiency in treating H. pylori was uncertain. A survey of databases, including PubMed, Cochrane, Google Scholar, Scopus, and Clinicaltrials.gov, retrieved 52 Randomized Controlled Trials (RCTs), with 14 meeting the criteria for RCTs on Lactobacillus supplementation (LS) as an adjunct therapy compared to placebo in adult H. pylori patients. Analyses were conducted using RevMan5.3, Cochrane Risk of Bias Tool, Comprehensive Meta-Analysis Software, and GRADEpro. Fourteen RCTs, including 2054 patients with more than ten different probiotics, were included in this analysis. The LS group showed significantly higher H. pylori eradication rates [RR = 1.04 (95% CI: 1.01, 1.07; p = 0.009; I² = 0%); (high certainty)], decreased AEs including vomiting [RR = 0.82 (95% CI: 0.48, 1.41; p = 0.48; I² = 19%); (high certainty)], diarrhea [RR = 0.45 (95% CI: 0.26, 0.80; p = 0.007; I² = 55%); (high certainty)], abdominal pain [RR = 0.73 (95% CI: 0.28, 1.93; p = 0.53; I² = 66%); (high certainty)], anorexia [RR = 0.79 (95% CI: 0.23, 2.64; p = 0.70; I² = 0%); (high certainty)], constipation [RR = 1.02 (95% CI: 0.42, 2.50; p = 0.96; I² = 0%); (high certainty)], rash [RR = 1.51 (95% CI: 0.57, 3.98; p = 0.41; I² = 0%); (high certainty)], taste disturbance [RR = 0.64 (95% CI: 0.44, 0.92; p = 0.02; I² = 51%); (moderate certainty)], and reduction of gastrointestinal symptoms including abdominal pain [SMD = −0.19 (95% CI: −0.46, 0.09; p = 0.18; I² = %); (moderate certainty)]. None of the included RCTs depicted a high risk of bias. Lactobacillus added to triple or quadruple therapy increased eradication rates, but improvements in adverse effects and gastrointestinal symptoms were not significant. Multiple different strains limited assessment of individual effectiveness, preventing firm conclusions about the specific impact of each Lactobacillus type.

Campylobacter species, a major cause of gastroenteritis, have been frequently isolated from wild birds. Here we determined the prevalence of Campylobacter in wild birds from Switzerland. Campylobacter isolates were then further characterized by whole genome sequencing. A total of 154 samples from 27 different wild bird species were analyzed and Campylobacter was detected in 23 samples (14.9%). Twenty-one isolates were identified as C. jejuni, one as C. coli and one isolate likely belongs to a novel species. Whole genome analyses revealed that the strains were diverse, belonging to 17 different sequence types. Antimicrobial resistances of the C. jejuni strains included class D ß-lactamase bla_OXA genes in all isolates, T86I mutations in GyrA conferring resistance to quinolones in 7 isolates, and tet(O) in 3 isolates. A comparison to 787 Campylobacter from various sources in Switzerland showed that strains spread between humans, poultry and wild birds. Moreover, plasmid analyses and genome comparison provided a strong indication of horizontal gene transfer between Campylobacter strains. Our results strongly support a One-Health approach that includes wild animals to understand and control epidemiology of Campylobacter.

Activating cryptic secondary metabolic gene clusters is a critical area of research in Streptomyces, and the cultivation-based approach is one of effective ways to induce the expression of cryptic gene clusters. In this study, the oligotrophic medium and modified Gauze's medium were used to culture the marine Streptomyces sp. FJNU027 strain, and a unique secondary metabolite in oligotrophic culture was found by HPLC assay when compared with the modified Gauze's culture. Then the differential product was isolated through large-scale fermentation, solvent extraction, column chromatography over Sephadex LH-20, and HPLC preparation. The pure differential product was analyzed by NMR and LC-MS, and identified as 4,4′,5,5′-tetramethyl-[1,1′- diphenyl]-2,2′-diol. To elucidate the possible biosynthesis mechanism of the differential product, the transcriptome sequencing was performed. It showed the expressions of polyketide synthase gene (FZ01GL006410) and cytochrome P450 gene (FZ01GL006417) were significantly enhanced in the oligotrophic medium, and these two genes might be responsible for the biosynthesis of the differential product. This compound was reported for the first time isolated from a natural source, demonstrating a novel approach for acquiring this type of compound. The results indicate that oligotrophic culture is an effective method for modulating the secondary metabolism of Streptomyces.