The Gelatinase Biosynthesis ‐Activating Pheromone binds and stabilizes the FsrB membrane protein in Enterococcus faecalis quorum sensing

AbstractQuorum sensing mechanisms regulate gene expression in response to changing cell ‐population density detected through pheromones. InEnterococcus faecalis, Fsr quorum sensing produces and responds to the gelatinase biosynthesis ‐activating pheromone (GBAP). Here, we establish that the enterococcal FsrB membrane protein has a direct role connected with GBAP by showing that GBAP binds to purified FsrB. Far‐UV circular dichroism measurements demonstrated a predominantly α‐helical protein exhibiting a small level of con formational flexibility. Five‐fold (400 µM) GBAP stabilised FsrB (80 µM) secondary structure. FsrB thermal denaturation in the presence and absence of GBAP revealed melting temperatures of 70.1°C and 60.8°C respectively, demonstrating GBAP interactions and increased thermal stability conferred by GBAP. Addition of GBAP also resulted in tertiary structural changes, confirming GBAP binding.
Source: FEBS Letters - Category: Biochemistry Authors: Tags: Communication Source Type: research

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Publication date: Available online 8 November 2019Source: Food Research InternationalAuthor(s): Marco Túlio Pardini Gontijo, Jackson de Sousa Silva, Pedro Marcus Pereira Vidigal, José Guilherme Prado MartinAbstractThe microbiota contributes to artisanal cheese bioprotection and biopreservation through inter and intraspecific competition. This work aimed to investigate the phylogenetic distribution of the repertoire of bacteriocin structural genes of model lactic acid bacteria (LAB) in order to investigate its respective role in the artisanal cheeses microenvironment. A phylogenetic analysis of rRNA 16S gene f...
Source: Food Research International - Category: Food Science Source Type: research
Authors: Okamura T, Tamura M, Suguro H, Ohtsu M, Omagari D, Yoshino A, Ogiso B, Asano M Abstract Sodium hypochlorite (NaOCl) is widely used as an antimicrobial irrigant; however, it has cytotoxic and neurotoxic effects. For these reasons, development of new, safe irrigants other than NaOCl is long overdue. In the present study, the antimicrobial and noxious effects of acid-electrolyzed functional water (FW) were evaluated and compared with those of NaOCl. Enterococcus faecalis, Streptococcus mutans, Porphyromonas gingivalis, or Candida albicans were mixed with each tested solution for 30 s. The mixtures were then p...
Source: Journal of oral science - Category: Dentistry Tags: J Oral Sci Source Type: research
Vancomycin-resistant enterococci are troublesome pathogens in clinical settings because of few treatment options. A VanA/VanM-type vancomycin-resistant Enterococcus faecium clinical isolate was identified in Japan. This strain, named AA708, harbored five plasmids, one of which migrated during agarose gel electrophoresis without S1 nuclease treatment, which is indicative of a linear topology. We named this plasmid pELF1. Whole genome sequencing (WGS) analysis of the AA708 strain revealed that the complete sequence of pELF1 was 143,316 bp long and harbored both the vanA and vanM gene clusters. Furthermore, mfold analysis and...
Source: Frontiers in Microbiology - Category: Microbiology Source Type: research
In this report, a 60 years old woman with a past medical history of significant chronic kidney disease undergoing regular hemodialysis, chronic constipation and hepatitis B was admitted to our neurology clinic because of acute intracerebral hemorrhage. She had confusion and right hemiplegia in her neurological examination and required urinary catheterization due to immobilization. Red coloration was observed in urine on the tenth hospital day. Although this coloration was thought to be hematuria, according to urine examination it was not hematuria. Then urine color turned into purple within two days. The next day, because ...
Source: Mikrobiyoloji Bulteni - Category: Microbiology Tags: Mikrobiyol Bul Source Type: research
This study explored the bacterial diversity of 64 spoiled custard cream desserts manufactured by 2 French companies. B. cereus group bacteria, coagulase negative Staphylococcus, Enterococcus and Leuconostoc spp. were isolated from spoiled products. Thirty-one bacterial isolates representative of the main spoilage species were tested for their spoilage abilities. Significant growth and pH decrease were observed regardless of species. While off-odours were detected with B. cereus group and staphylococci, yoghurt odours were detected with Enterococcus spp. and Leuconostoc spp. B. cereus group bacteria produced various esters ...
Source: Food Microbiology - Category: Food Science Authors: Tags: Food Microbiol Source Type: research
Abstract The presence of eight common structural enterocin genes, singly or in varying combinations, in the genome of 15 antagonistic Enterococcus spp. previously isolated from artisan Greek Graviera and Galotyri retail cheeses was tested and associated with the mode of enterocin (Ent+) antilisterial activity of each isolate in three liquid culture media. The isolates were assigned to nine distinct strain genotypes of E. faecium (4 strains), E. durans (2) and E. faecalis (3). All strains were non-hemolytic, except for a cyl-positive E. faecalis genotype isolated from Galotyri cheese, which was strongly listericida...
Source: Food Microbiology - Category: Food Science Authors: Tags: Food Microbiol Source Type: research
This study aimed to evaluate the inhibitory activity of phenyllactic acid (PLA) against the biofilm formation of Enterococcus faecalis and to explore its potential molecular mechanism. The MIC value of PLA that inhibited the growth of E. faecalis R612-Z1 in BHI broth was 5 mg/mL. PLAs at subinhibitory concentrations of 1.25 and 2.50 mg/mL were found to inhibit biofilm formation by a crystal violet staining assay. The cell swimming and swarming motilities of E. faecalis were reduced in the presence of PLA. An apparent decrease in the thickness of PLA-treated biofilms was observed through confocal laser scanning microsco...
Source: Food Microbiology - Category: Food Science Authors: Tags: Food Microbiol Source Type: research
AbstractMoulds positively contribute to the development of typical characteristic flavour and aroma of dry-fermented sausages. However, some mould species, such asPenicillium nordicum andPenicillium verrucosum, may contaminate this product with ochratoxin A (OTA). For this reason, the control of toxigenic moulds is needed. Strategies based on the use of antifungal microorganisms present in the native microbial population in the dry-fermented sausage processing could be a promising strategy. The aim of this work was to study the effect ofEnterococcus faecium strains onP. nordicum andP. verrucosum growth and OTA production i...
Source: Mycotoxin Research - Category: Toxicology Source Type: research
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Source: European Journal of Obstetrics and Gynecology and Reproductive Biology - Category: OBGYN Source Type: research
J, Pogány Simonová M Abstract The sewage sludges represent a potential health hazard because of the quantity of different microbiota detected in sewages. Among microbiota detected in sewages, also belong representatives of the phylum Firmicutes. In the past, environmental enterococci in addition to coliforms were widely used as indicators of faecal contamination. Regarding the enterococcal strains as potential pathogenic bacteria, their pathogenicity is mainly caused by production of virulence factors. Therefore, the aim of the study was to analyse incidence of virulence factors in enterococci from ...
Source: Biomed Res - Category: Research Authors: Tags: Biomed Res Int Source Type: research
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