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Microbes and Infection 2023The genus Enterococcus is commonly overpopulated in patients with depression compared to healthy control in the feces. Therefore, we isolated Enterococcus faecalis,...
The genus Enterococcus is commonly overpopulated in patients with depression compared to healthy control in the feces. Therefore, we isolated Enterococcus faecalis, Enterococcus durans, Enterococcus gallinarum, Enterococcus faecium, and Enterococcus mundtii from the feces of patients with comorbid inflammatory bowel disease with depression and examined their roles in depression in vivo and in vitro. Of these Enterococci, E. mundtii NK1516 most potently induced NF-κB-activated TNF-α and IL-6 expression in BV2 microglia cells. NK1516 also caused the most potent depression-like behaviors in the absence of sickness behaviors, neuroinflammation, downregulated brain-derived neurotrophic factor (BDNF), and serotonin (5-HT) levels in the hippocampus of mice. Furthermore, E. mundtii NK1516 reduced the mRNA expression of Htr1a in the hippocampus. Its capsular polysaccharide (CP), but not cytoplasmic components, also caused depression-like behaviors and reduced BDNF and serotonin levels in the hippocampus. Conversely, this was not observed with E. mundtii ATCC882, a well-known probiotic, or its CP. Orally gavaged fluorescence isothiocyanate (FITC)-conjugated NK1516 CP was detected in the hippocampus of mice. The NK1516 genome exhibited unique CP biosynthesis-related genes (capD, wbjC, WecB, vioB), unlike that of ATCC882. These findings suggest that E. mundtii may be a risk factor for depression.
Topics: Animals; Humans; Mice; Brain-Derived Neurotrophic Factor; Depression; Down-Regulation; Enterococcus; NF-kappa B; Serotonin
PubMed: 36758891
DOI: 10.1016/j.micinf.2023.105116 -
International Journal of Environmental... Dec 2020Enterococci are lactic acid bacteria. Most of them can adapt well to the food system due to their salt and acid-tolerance. Moreover, many enterococcal species have been...
Enterococci are lactic acid bacteria. Most of them can adapt well to the food system due to their salt and acid-tolerance. Moreover, many enterococcal species have been found to produce antimicrobial substances of proteinaceous character, i.e., bacteriocins/enterocins. In this study, EM ML2/2 with bacteriocinogenic potential was identified in Slovak raw goat milk. This strain demonstrated inhibition activity against up to 36% of Gram-positive indicator bacteria, and in concentrated form the bacteriocin substance (pH 6.3) showed the highest inhibition activity (1600 AU/mL) against the principal indicator strain EA5. Semi-purified substance (SPS) EM ML2/2 produced inhibition activity up to 3200 AU/mL. Concentrated bacteriocin substance and SPS maintained active (inhibition activity up to 100 AU/mL) for three months under -20 °C storage conditions. The strain showed susceptible antibiotic profile, and it did not form biofilm. No production of damaging enzymes was noted. It was nonhemolytic, as well as DNase, and gelatinase-negative. It grew well in skim milk, and it was salt and acid-tolerant. The bacteriocin potential of species isolated from Slovak raw goat milk has not previously been detected, so this is an original contribution which may stimulate addtitional research and application studies.
Topics: Animals; Enterococcus; Goats; Milk; Slovakia
PubMed: 33352988
DOI: 10.3390/ijerph17249504 -
Frontiers in Microbiology 2022The complex gut microbiome is a malleable microbial community that can undergo remodeling in response to many factors, including the gut environment and microbial...
The complex gut microbiome is a malleable microbial community that can undergo remodeling in response to many factors, including the gut environment and microbial properties. has emerged as one of the predominant gut commensal bacterial and plays a fundamental role in the host physiology and health of the major economic agricultural insect, Although extensive research on gut structure and microbiome diversity has been carried out, how these microbial consortia are established in multifarious niches within the gut has not been well characterized to date. Here, an species that was stably associated with its host, the model organism , was identified in the larval gut. GFP-tagged LX10 was constructed as a model bacterium to track the colonization mechanism in the intestine of . The results revealed that the minimum and optimum colonization results were obtained by feeding at doses of 10 CFU/silkworm and 10 CFU/silkworm, respectively, as confirmed by bioassays and fluorescence-activated cell sorting analyses (FACS). Furthermore, a comprehensive genome-wide exploration of signal sequences provided insight into the relevant colonization properties of LX10. LX10 grew well under alkaline conditions and stably reduced the intestinal pH through lactic acid production. Additionally, the genomic features responsible for lactic acid fermentation were characterized. We further expressed and purified bacteriocin and found that it was particularly effective against other gut bacteria, including , , , In addition, the successful colonization of LX10 led to drastically increased expression of all adhesion genes (, , , , , and ), defense genes (, and ), regulation gene (), secretion gene () and immune evasion genes ( and ), while the expression of iron acquisition genes ( and ) was largely unchanged or decreased. This work establishes an unprecedented conceptual model for understanding -gut microbiota interactions in an ecological context. Moreover, these results shed light on the molecular mechanisms of gut microbiota proliferation and colonization in the intestinal tract of this insect.
PubMed: 35814682
DOI: 10.3389/fmicb.2022.921330 -
Microorganisms Feb 2023is an important vaginosis causative agent, affecting several women worldwide each year. This study reports on two strains of lactic acid bacteria ( CRL35 and ST88Ch)...
is an important vaginosis causative agent, affecting several women worldwide each year. This study reports on two strains of lactic acid bacteria ( CRL35 and ST88Ch) expressing bacteriocin-like inhibitor substances (BLIS) active against 1281. Both strains were γ-hemolytic and not affected by numerous antibiotics, contraceptives, and commercial drugs, suggesting safety for human use. The recorded antimicrobial activity of semi-purified BLIS was 25,600 AU/mL for CRL35 and 800 AU/mL for ST88Ch. Treatment of BLIS with 1 mg/mL proteinase K resulted in complete loss of antimicrobial activity against ATCC 15313 and partial loss of activity against 1281. The killing effect of the semi-purified BLIS on cell suspensions of 1281 after 9 h of contact was dose-dependent: for CRL35, 400 AU/mL to 25,600 AU/mL caused 63.61% to 79.35% lysis, while for ST88Ch, 200 AU/mL to 800 AU/mL caused 29.32% to 31.25% cell lysis. The effects of temperature, pH, and presence of the contraceptive Nordette-28 on the adsorption levels of the BLIS to 1281 were also evaluated. Nordette-28 (10% or 20%) promoted increased adsorption of both studied BLIS to the cells of 1281 at pH 5.0, while a minor effect was observed at pH 3.0. Different levels of aggregation between 1281 and CRL35 or ST88Ch were recorded, and optimal adsorption levels were recorded at 37 °C. Appropriate BLIS-producing strains can effectively contribute to the equilibrium of vaginal microbial and reduce negative consequences from the development of infections.
PubMed: 36985176
DOI: 10.3390/microorganisms11030602 -
Frontiers in Microbiology 2019Microbial strains with a unique combination of technological and bioactive properties are preferred for industrial applications. The present study was conducted to...
Microbial strains with a unique combination of technological and bioactive properties are preferred for industrial applications. The present study was conducted to evaluate the potential use of QAUEM2808 (NCBI Accession Number: LSMC00000000) in milk fermentation. This strain was isolated from Dahi, an indigenous fermented milk product of South-East Asia. The study confirmed the acidification ability as well as the proteolytic, cellulolytic, and amylolytic enzyme activities of this strain. It also produced a substantial amount of the folate in laboratory media and no physiological dysfunctions in laboratory animals was observed in feeding trials. All these properties were confirmed by genome analysis. The QAUEM2808 genome consisted of a single, circular chromosome comprising 2,957,300-bp, 2,587 genes with GC content of 38.5%. Moreover, 16t RNAs, 1, 3 (16S, 23S) rRNAs, 4 ncRNAs, and 91 pseudo genes were also predicted. The majority of genome encode genes for protein, amino acids, carbohydrate, cell wall DNA and RNA metabolisms including all genes required for conversion of lactose to lactic acid. It also exhibited antimicrobial activity against ATCC 10536, ATCC 6538, ATCC 9027, and ATCC 13932 and was found to be sensitive to commonly used antibiotics. The analysis revealed the presence of genes for mundaticin and enterocin production, and CRISPER regions, however, the genes for antibiotic resistance were absent. No genes related to the pathogenicity island and prophages were detected by genome mining. Therefore, it could be inferened that QAUEM2808 has the potential to be used in milk fermentation as adjunct culture.
PubMed: 30972030
DOI: 10.3389/fmicb.2019.00434 -
International Journal of Environmental... Mar 2022Enterococcus species are an emerging group of bacterial pathogens that have a significant role in hospital-associated infections and are associated with higher mortality...
Enterococcus species are an emerging group of bacterial pathogens that have a significant role in hospital-associated infections and are associated with higher mortality and morbidity rates. Among these pathogens, is one of the causative agents of multiple hospital associated infections. Currently, no commercially available licensed vaccine is present, and multi-drug resistant strains of the pathogen are prominent. Due to several limitations of experimental vaccinology, computational vaccine designing proved to be helpful in vaccine designing against several bacterial pathogens. Herein, we designed a multi-epitope-based vaccine against using in silico approaches. After an in-depth analysis of the core genome, three probable antigenic proteins (lytic polysaccharide monooxygenase, siderophore ABC transporter substrate-binding protein, and lytic polysaccharide monooxygenase) were shortlisted for epitope prediction. Among predicted epitopes, ten epitopes-GPADGRIAS, TTINHGGAQA, SERTALSVTT, GDGGNGGGEV, GIKEPDLEK, KQADDRIEA, QAIGGDTSN, EPLDEQTASR, AQWEPQSIEA, QPLKFSDFEL-were selected for multi-epitope vaccine construct designing. The screened B- and T-cell epitopes were joined with each other via specific linkers and linked to the cholera toxin B subunit as an adjuvant to enhance vaccine immune protection efficacy. The designed vaccine construct induced cellular and humoral immune responses. Blind docking with immune cell receptors, followed by molecular dynamic simulation results confirms the good binding potency and stability of the vaccine in providing protection against the pathogen.
Topics: Bacterial Vaccines; Computational Biology; Enterococcus; Epitopes, T-Lymphocyte; Mixed Function Oxygenases; Molecular Docking Simulation; Vaccines
PubMed: 35329417
DOI: 10.3390/ijerph19063729 -
Current Research in Food Science 2022In the current research, SRBG1 newly isolated from Bat guano was encapsulated using spray drying technique to create a probiotic powder using six combinations of...
In the current research, SRBG1 newly isolated from Bat guano was encapsulated using spray drying technique to create a probiotic powder using six combinations of inulin, maltodextrin and sodium alginate. The encapsulation yield, moisture content, physical characteristics, and shape were investigated. Microcapsules yields ranged from 67 to 85 percent, which is consistent with typical B-290 spray-drier yields. The moisture content showed to increase (4 ± 0.15%) with the addition of sodium alginate to inulin and maltodextrin. In the gastrointestinal conditions (simulated gastric juice and bile salts), it was shown that the viability of probiotic cells in capsules was higher than that of free cells. This demonstrated the effectiveness of combining inulin and maltodextrin to encapsulate substances in surviving in gastro-intestinal conditions. Additionally, we evaluated the non-encapsulated and encapsulated SRBG1 by assessing their impact on the rheological parameters of fermented milk. The results showed that in the absence of sodium alginate the viscosity of milk was lower than with the other protectors, which was confirmed by the quick acidification of the fermented milk by microcapsules containing sodium alginate.
PubMed: 36212080
DOI: 10.1016/j.crfs.2022.09.027 -
Scientific Reports May 2022The symbiotic relationship between insects and gut microbes contributes to their fitness by serving immense range of functions viz. nutrition and digestion,...
The symbiotic relationship between insects and gut microbes contributes to their fitness by serving immense range of functions viz. nutrition and digestion, detoxification, communication and reproduction etc. However, this relationship between insect and gut microbes varies from mutualistic to pathogenic. Gut microbes become pathogenic when the healthy normal microbial composition is perturbed leading to the death of insect host. Spodoptera litura (Fab.) is a polyphagous pest that causes significant damage to many agricultural crops. The management of this pest primarily depends upon chemical insecticides which have resulted in development of resistance. Thus in search for alternative strategies, culturable gut bacteria isolated from S. litura were screened for insecticidal potential. Among these Serratia marcescens and Enterococcus mundtii induced higher larval mortality in S. litura. The mortality rate increased from 32 to 58% due to S. marcescens at concentrations ranging from 2.6 × 10 to 5.2 × 10 cfu/ml and 26 to 52% in case of E. mundtii due to increase in concentration from 4.6 × 10 to 6.1 × 10 cfu/ml. Both the bacteria negatively affected the development, nutritional physiology and reproductive potential of insect. The results indicated a change in gut microbial composition as well as damage to the gut epithelial membrane. Invasion of gut bacteria into the haemocoel led to septicaemia and ultimately death of host insect. In conclusion both these gut bacteria may serve as potential biocontrol agents against S. litura.
Topics: Animals; Insecticides; Larva; Serratia marcescens; Spodoptera; Nicotiana; Virulence
PubMed: 35585189
DOI: 10.1038/s41598-022-12319-w -
Identification and production of a bacteriocin from Enterococcus mundtii QU 2 isolated from soybean.Journal of Applied Microbiology 2005Identification of the bacteriocin produced by Enterococcus mundtii QU 2 newly isolated from soybean and fermentative production of the bacteriocin.
AIMS
Identification of the bacteriocin produced by Enterococcus mundtii QU 2 newly isolated from soybean and fermentative production of the bacteriocin.
METHODS AND RESULTS
The bacteriocin produced by Ent. mundtii QU 2 inhibited the growth of various indicator strains, including Enterococcus, Lactobacillus, Leuconostoc, Pediococcus and Listeria. The bacteriocin activity was stable at wide pH range and against heat treatment, but completely abolished by proteolytic enzymes. The bacteriocin was purified from the culture supernatant by the three-step chromatographic procedure. Mass spectrometry, amino acid sequencing and DNA sequencing revealed that the bacteriocin was similar to class IIa bacteriocins produced by other Ent. mundtii strains. The bacteriocin production decreased in the absence of glucose, nitrogen sources, or Tween 80 in MRS medium. Additionally, it was strongly suppressed by addition of Ca(2+) (CaCO(3) or CaCl(2)). In pH-controlled fermentations, the highest bacteriocin production was achieved at pH 6.0, whereas the highest cell growth was obtained at pH 7.0.
CONCLUSIONS
Ent. mundtii QU 2 produced a class IIa bacteriocin. Some growth factors (e.g. Ca(2+) and pH) influenced the bacteriocin production.
SIGNIFICANCE AND IMPACT OF THE STUDY
A new soybean isolate, Ent. mundtii QU 2 was found to be a class IIa bacteriocin producer. Factors influencing the bacteriocin production described herein are valuable for applications of the bacteriocins from Ent. mundtii strains.
Topics: Amino Acid Sequence; Bacteriocins; Calcium; Culture Media; Enterococcus; Fermentation; Food Microbiology; Genes, Bacterial; Glucose; Hot Temperature; Hydrogen-Ion Concentration; Mass Spectrometry; Nitrogen; Peptide Hydrolases; Polysorbates; Glycine max; Surface-Active Agents
PubMed: 16238749
DOI: 10.1111/j.1365-2672.2005.02704.x