Search results for "Antibiosis"
showing 10 items of 24 documents
Biofilms of Lactobacillus plantarum and Lactobacillus fermentum: Effect on stress responses, antagonistic effects on pathogen growth and immunomodula…
2016
IF 3.682; International audience; Few studies have extensively investigated probiotic functions associated with biofilms. Here, we show that strains of Lactobacillus plantarum and Lactobacillus fermentum are able to grow as biofilm on abiotic surfaces, but the biomass density differs between strains. We performed microtiter plate biofilm assays under growth conditions mimicking to the gastrointestinal environment. Osmolarity and low concentrations of bile significantly enhanced Lactobacillus spatial organization. Two L. plantarum strains were able to form biofilms under high concentrations of bile and mucus. We used the agar well-diffusion method to show that supernatants from all Lactobaci…
Selection of New Probiotics for Endometrial Health
2019
Microbiota is a crucial player in gynecologic health, in which bacteria can shift to a dysbiotic state triggering a pathogenic process. Based on an ecological understanding of the problem, the aim of this study is to select a potential probiotic strain to improve female reproductive tract based on its capacity to initially lower pH and to promote the reduction of pathogenic bacteria. Based on this rationale, strain Lactobacillus rhamnosus BPL005 was initially selected for its capacity to reduce in vitro pH levels and produce organic acids. Subsequently, strain L. rhamnosus BPL005 (CECT 8800) was demonstrated to have a protective role on endometrial infections in an in vitro model of bacteri…
Novel Probiotic Bifidobacterium longum subsp. infantis CECT 7210 Strain Active against Rotavirus Infections
2011
ABSTRACT Rotavirus is the leading cause of severe acute gastroenteritis among children worldwide. It is well known that breast-feeding and vaccination afford infants protection. Since breast-feeding has drastically decreased in developed countries, efforts have been focused on the potential use of probiotics as preventive agents. In this study, a novel Bifidobacterium longum subsp. infantis strain was isolated from infant feces and selected, based on its capacity to inhibit in vitro rotavirus Wa replication (up to 36.05% infectious foci reduction) and also to protect cells from virus infection (up to 48.50% infectious foci reduction) in both MA-104 and HT-29 cell lines. Furthermore, studies…
Novel Probiotic Bifidobacterium bifidum CECT 7366 Strain Active against the Pathogenic Bacterium Helicobacter pylori▿
2010
ABSTRACT Helicobacter pylori is considered one of the major risk factors underlying the development of gastritis and gastric and duodenal ulcers. Moreover, 50% of the population carries this bacterium, and consequently, when it is detected, eradication of H. pylori is strongly recommended. Regarding the use of probiotics as functional agents, several studies have shown that there is a direct relationship between the addition of certain probiotic bacteria and in vitro inhibition of H. pylori ; however, in vivo studies showing bifidobacterial activity against H. pylori remain scarce. In this study, a Bifidobacterium bifidum strain which proved active in vitro against H. pylori has been isolat…
Antifungal peptides produced by Bacillus amyloliquefaciens AG1 active against grapevine fungal pathogens
2012
Abstract Antifungal metabolites produced by Bacillus amyloliquefaciens AG1, previously isolated from wood of grapevine with “esca syndrome”, were studied. The crude protein extract (CPE) obtained from culture supernatant fluid by precipitation with ammonium sulfate was assayed against many grapevine fungal pathogens. B. amyloliquefaciens strain AG1 showed a broad spectrum of antifungal activity, inhibiting mycelial growth in vitro of all tested fungal microorganisms. The metabolites contained in CPE were heat stable and remained active over a wide pH range (2–10). Their activity was not affected by proteolytic or glycolytic enzymes. Tricine- SDS-polyacrylamide gel electrophoresis revealed a…
Isolation, identification and characterisation of three novel probiotic strains (Lactobacillus paracaseiCNCM I-4034,Bifidobacterium breveCNCM I-4035 …
2013
The aim of the present study was to isolate, identify and characterise novel strains of lactic acid bacteria and bifidobacteria with probiotic properties from the faeces of exclusively breast-fed infants. Of the 4680 isolated colonies, 758 exhibited resistance to low pH and tolerance to high concentrations of bile salts; of these, only forty-two exhibited a strong ability to adhere to enterocytesin vitro.The identities of the isolates were confirmed by 16S ribosomal RNA (rRNA) sequencing, which permitted the grouping of the forty-two bacteria into three different strains that showed more than 99 % sequence identity withLactobacillus paracasei,Lactobacillus rhamnosusandBifidobacterium breve,…
Characterisation of the yeast Pichia membranifaciens and its possible use in the biological control of Botrytis cinerea, causing the grey mould disea…
2001
Pichia membranifaciens strain FY-101, isolated from grape skins, was found to be antagonistic to Botrytis cinerea, the causal organism of the grey mould disease of the grapevine. When grown together on solid as well as liquid media, the yeast brings about the inhibition of this parasitic fungus, coagulation and leakage of its cytoplasm, and suppression of its ability to produce the characteristic grey mould symptoms on the grapevine plantlets. In vitro experiments confirm that this yeast can be used as a biological control organism against B. cinerea. An account of the molecular characterisation of P. membranifaciens (complete sequence of the ITS region of its ribosomal DNA, GenBank accessi…
Isolation and partial characterization of antagonistic peptides produced by Paenibacillus sp. strain B2 isolated from the sorghum mycorrhizosphere.
2005
ABSTRACT Paenibacillus sp. strain B2, isolated from the mycorrhizosphere of sorghum colonized by Glomus mosseae , produces an antagonistic factor. This factor has a broad spectrum of activity against gram-positive and gram-negative bacteria and also against fungi. The antagonistic factor was isolated from the bacterial culture medium and purified by cation-exchange, reverse-phase, and size exclusion chromatography. The purified factor could be separated into three active compounds following characterization by amino acid analysis and by combined reverse-phase chromatography and mass spectrometry (liquid chromatography-mass spectrometry and mass spectrometry-mass spectrometry). The first com…
Competitive inhibition of three novel bacteria isolated from faeces of breast milk-fed infants against selected enteropathogens.
2013
Numerousin vitroandin vivostudies conducted using different probiotic micro-organisms have demonstrated their ability to interfere with the growth and virulence of a variety of enteropathogens. The reported beneficial effects of the use of probiotics to complement antibiotic therapy or prevent diarrhoea or gastrointestinal infection in infants have increased in recent years. In the present study, we demonstrated the capacity of supernatants obtained from three novel probiotics (Lactobacillus paracaseiCNCM I-4034,Bifidobacterium breveCNCM I-4035 andLactobacillus rhamnosusCNCM I-4036) isolated from the faeces of breastfed infants to inhibit the growth of enterotoxigenic and enteropathogenic (…
Selection of potential probiotic lactobacilli from pig feces to be used as additives in pelleted feeding
2006
Thirty-five isolates from pig feces were identified as Lactobacillus reuteri (12 strains), Lactobacillus mucosae (7), Lactobacillus plantarum (6), Lactobacillus kitasatonis (3), Lactobacillus rossiae (2), Lactobacillus ultunensis (2), Lactobacillus crispatus (2), and Lactobacillus intestinalis (1) by partial sequence analysis of the 16S rRNA. All isolates were detected at 8-9 log CFU g(-1). Preliminarily, strains were selected based on resistance to heat treatments (ca. 70 degrees C for 10 s). The decrease in viability for some L. reuteri, L. mucosae, L. plantarum, L. kitasatonis, and L. rossiae strains was lower than 1 log cycle. Selected strains were further characterized for acid and bil…