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Scientific Reports Jan 2024Animals are exposed to many microbes in their environment, some of which have been shown to colonize various tissues including the intestine. The composition of the...
Animals are exposed to many microbes in their environment, some of which have been shown to colonize various tissues including the intestine. The composition of the intestinal microbiota affects many aspects of the host's physiology and health. Despite this, very little is known about whether host behavior contributes to the colonization. We approach this question in the nematode C. elegans, which feeds on bacteria and also harbors an intestinal microbiome. We examined the behavior of C. elegans towards CeMbio, a simplified microbiome consisting of twelve strains that represent the bacteria found in the animal's natural environment. We observed that C. elegans raised on E. coli shows a strong preference for three members of CeMbio (Lelliottia amnigena JUb66, Enterobacter hormaechei CEent1, and Pantoea nemavictus BIGb0393) compared to E. coli. Previously, these three bacterial strains have been shown to support faster C. elegans development time than E. coli OP50 and are low colonizers compared to eight other members of CeMbio. We then used gas chromatography coupled to mass spectrometry to identify that these three bacteria release isoamyl alcohol, a previously described C. elegans chemoattractant. We suggest that C. elegans seeks bacteria that release isoamyl alcohol and support faster growth.
Topics: Animals; Caenorhabditis elegans; Escherichia coli; Gas Chromatography-Mass Spectrometry; Bacteria; Microbiota; Pentanols
PubMed: 38228683
DOI: 10.1038/s41598-024-51533-6 -
Species-dependent protoplast enlargement involves different types of vacuole generation in bacteria.Scientific Reports Jun 2020Vacuole generation occurs frequently during the enlargement of bacterial protoplasts and spheroplasts. Gram-positive Enterococcus faecalis protoplasts and gram-negative...
Vacuole generation occurs frequently during the enlargement of bacterial protoplasts and spheroplasts. Gram-positive Enterococcus faecalis protoplasts and gram-negative Lelliottia amnigena spheroplasts had large and small vacuoles inside the cytoplasm, respectively. Although no vacuoles were found at the early stage of cell enlargement, all enlarged cells used in the microinjection procedures had vacuoles. The plasma membrane of L. amnigena was more flexible than that of E. faecalis. In addition, E. faecalis protoplasts had unique discoidal structures as well as spherical structures in the cytoplasm. Our findings showed that the number of vacuoles increased as the L. amnigena plasma membrane expanded and that the size of vacuoles increased as the E. faecalis plasma membrane expanded, suggesting that bacterial cell enlargement involved vacuole generation. Thus, biosynthesis of the plasma and vacuolar membranes was synchronous with the bacterial cell enlargement. Differences in the plasma membrane flexibility might influence the different types of vacuole generation.
Topics: Cell Membrane; Cell Membrane Permeability; Cytoplasm; Enterobacteriaceae; Enterococcus faecalis; Microscopy, Electron, Transmission; Time-Lapse Imaging; Vacuoles
PubMed: 32483175
DOI: 10.1038/s41598-020-65759-7 -
Plants (Basel, Switzerland) Mar 2023Europe's forests, particularly in Ukraine, are highly vulnerable to climate change. The maintenance and improvement of forest health are high-priority issues, and...
Europe's forests, particularly in Ukraine, are highly vulnerable to climate change. The maintenance and improvement of forest health are high-priority issues, and various stakeholders have shown an interest in understanding and utilizing ecological interactions between trees and their associated microorganisms. Endophyte microbes can influence the health of trees either by directly interacting with the damaging agents or modulating host responses to infection. In the framework of this work, ten morphotypes of endophytic bacteria from the tissues of unripe acorns of L. were isolated. Based on the results of the sequenced 16S rRNA genes, four species of endophytic bacteria were identified: , , , and . Determining the activity of pectolytic enzymes showed that the isolates and could not cause maceration of plant tissues. Screening for these isolates revealed their fungistatic effect against phytopathogenic micromycetes, namely , , and . Inoculation of , , and their complex in oak leaves, in contrast to phytopathogenic bacteria, contributed to the complete restoration of the epidermis at the sites of damage. The phytopathogenic bacteria and caused a 2.0 and 2.2 times increase in polyphenol concentration in the plants, respectively, while the ratio of antioxidant activity to total phenolic content decreased. Inoculation of and isolates into oak leaf tissue were accompanied by a decrease in the total pool of phenolic compounds. The ratio of antioxidant activity to total phenolic content increased. This indicates a qualitative improvement in the overall balance of the oak leaf antioxidant system induced by potential PGPB. Thus, endophytic bacteria of the genus isolated from the internal tissues of unripe oak acorns have the ability of growth biocontrol and spread of phytopathogens, indicating their promise for use as biopesticides.
PubMed: 36987039
DOI: 10.3390/plants12061352 -
International Journal of Food... Jul 2022The present work was performed to study the enterobacteria involved in the ripening of the artisanal raw ewe's milk PDO cheeses 'Torta del Casar' and 'Queso de la...
The present work was performed to study the enterobacteria involved in the ripening of the artisanal raw ewe's milk PDO cheeses 'Torta del Casar' and 'Queso de la Serena' produced in Extremadura (Spain). These isolates were strain-typed, safety tested and characterized for some important technological properties. A total of 485 enterobacterial isolates were clustered by RAPD-PCR and subsequently identified by partial sequencing of the 16S rRNA gene. Among the 17 different species identified, Hafnia paralvei was the predominant species; H. alvei and Lelliottia amnigena were present to a lesser extent. Therefore, 55 Hafnia spp. strains, selected according to their genetic profile and dairy origin, were tested for the safe application. Overall, they were able to produce the biogenic amines putrescine and cadaverine under favourable conditions, presented α-haemolytic activity and did not produce cytolytic toxin active against HeLa cells or contain virulence genes. In addition, antibiotic susceptibility profiles showed that 17 Hafnia spp. strains were less resistant to the 33 antibiotics tested; subsequently, they were further technologically characterized. Although they showed differences, in general, they were well adapted to the stress conditions of cheese ripening. Among them, two strains, H. alvei 544 and 1142, are highlighted mainly due to their proteolytic activity at refrigeration temperatures and their low or null gas production. Although further studies are necessary before industrial application, these two strains are proposed for potential use as adjunct cultures to favour the homogeneity of these PDO cheeses, preserving their unique sensory characteristics.
Topics: Animals; Cheese; Female; Hafnia; HeLa Cells; Humans; Milk; RNA, Ribosomal, 16S; Random Amplified Polymorphic DNA Technique; Sheep
PubMed: 35561525
DOI: 10.1016/j.ijfoodmicro.2022.109703 -
Natural selenium stress influences the changes of antibiotic resistome in seleniferous forest soils.Environmental Microbiome May 2022Metal(loid)s can promote the spread and enrichment of antibiotic resistance genes (ARGs) in the environment through a co-selection effect. However, it remains unclear...
BACKGROUND
Metal(loid)s can promote the spread and enrichment of antibiotic resistance genes (ARGs) in the environment through a co-selection effect. However, it remains unclear whether exposure of microorganisms to varying concentrations of selenium (Se), an essential but potentially deleterious metal(loid) to living organisms, can influence the migration and distribution of ARGs in forest soils.
RESULTS
Precisely 235 ARGs conferring resistance to seven classes of antibiotics were detected along a Se gradient (0.06-20.65 mg kg) across 24 forest soils. (flor)/(chlor)/(am)phenicol resistance genes were the most abundant in all samples. The total abundance of ARGs first increased and then decreased with an elevated available Se content threshold of 0.034 mg kg (P = 2E-05). A structural equation model revealed that the dominant mechanism through which Se indirectly influences the vertical migration of ARGs is by regulating the abundance of the bacterial community. In addition, the methylation of Se (mediated by tehB) and the repairing of DNA damages (mediated by ruvB and recG) were the dominant mechanisms involved in Se resistance in the forest soils. The co-occurrence network analysis revealed a significant correlated cluster between Se-resistance genes, MGEs and ARGs, suggesting the co-transfer potential. Lelliottia amnigena YTB01 isolated from the soil was able to tolerate 50 μg mL ampicillin and 1000 mg kg sodium selenite, and harbored both Se resistant genes and ARGs in the genome.
CONCLUSIONS
Our study demonstrated that the spread and enrichment of ARGs are enhanced under moderate Se pressure but inhibited under severe Se pressure in the forest soil (threshold at 0.034 mg kg available Se content). The data generated in this pilot study points to the potential health risk associated with Se contamination and its associated influence on ARGs distribution in soil.
PubMed: 35570296
DOI: 10.1186/s40793-022-00419-z -
Microbiology Resource Announcements May 2024Extended-spectrum beta-lactamase, AmpC, and carbapenemase-producing bacteria were isolated from raw sewage, effluent, oxidation pond water, and sediment from a...
Extended-spectrum beta-lactamase, AmpC, and carbapenemase-producing bacteria were isolated from raw sewage, effluent, oxidation pond water, and sediment from a wastewater treatment plant in Aotearoa New Zealand. Here, we report the assemblies of 17 isolates belonging to the species , , , , , , , , , and .
PubMed: 38564672
DOI: 10.1128/mra.00131-24 -
Foods (Basel, Switzerland) Aug 2023This study investigated changes in the microbial compositions of crayfish tails during storage at 4 °C (for 0-12 days) as measured using high-throughput sequencing...
This study investigated changes in the microbial compositions of crayfish tails during storage at 4 °C (for 0-12 days) as measured using high-throughput sequencing (HTS). The specific spoilage organisms (SSOs) in the crayfish tails were isolated using culture-dependent cultivation methods, and they were identified by 16S rRNA and characterized for their enzymatic spoilage potentials (e.g., protease, lipase, phospholipase, and amylase). The spoilage abilities of the selected strains in the crayfish tails were assessed by inoculating them into real food. Moreover, the microbial growth and the volatile basic nitrogen (TVB-N) changes were monitored during the storage period. The results from the HTS showed that the dominant genus of shrimp tails evolved from (D0) to (D4) and, finally, to (D12) during storage. Seven bacterial species (, , and ) were screened from the spoiled shrimp tails by the culture-dependent method, among which had the strongest spoilage ability.
PubMed: 37628005
DOI: 10.3390/foods12163006 -
Revista Espanola de Quimioterapia :... Dec 2017
Topics: Adenocarcinoma; Aged; Enterobacter; Enterobacteriaceae Infections; Humans; Male; Prostatic Neoplasms; Urinary Tract Infections
PubMed: 29199415
DOI: No ID Found