Search results for "vibrio"

Biochemical and toxigenic properties of Vibrio furnissii isolated from a European eel farm

1995

Abstract The present study describes for the first time the isolation of Vibrio furnissii strains from a European eel culture system which are pathogenic for eels ( Anguilla anguilla ) (LD 50 dose, 10 6 cfu/fish). Biochemical characterization of the isolates was performed by API 20E system and by classical numerical taxonomy. Growth at 4 °C, and with 6–8% (w/v) NaCl in a broth medium were necessary to differentiate Vibrio furnissii from Aeromonas species when the API 20E system was used. Virulence for eels of V. furnissii isolates was demonstrated by intraperitoneal injection of living cells. The extracellular products (ECPs) produced by V. furnissii were lethal to elvers and induced some o…

Toxicity of the extracellular products ofVibrio damsela isolated from diseased fish

1993

In this work we analyzed the pathogenic in vivo and in vitro activities for both fish and mammals of extracellular products (ECP) of several isolates of Vibrio damsela implicated in disease problems in marine culture. The ECP from all the strains were strongly lethal for fish (LD50 ranging from 0.06 to 3.7 μg protein/g fish) and mice (LD50 ranging from 0.02 to 0.43 μg protein/g mouse), causing death between 4 and 72 h after inoculation. These ECP samples possessed low proteolytic activity without production of caseinase, gelatinase, or elastase. However, most of them showed remarkable phospholipase and hemolytic activity for sheep, human, and turbot red blood cells. In addition, all the ECP…

Evaluation of the API 20E system for identification and discrimination of Vibrio vulnificus biotypes 1 and 2

1993

Vibrios isolated from the cultured manila clam (Ruditapes philippinarum): numerical taxonomy and antibacterial activities.

2002

Aims: A numerical taxonomic study of halophilic Vibrio isolated from healthy and brown ring disease (BRD) affected manila clams (Ruditapes philippinarum), harvested from the Atlantic coast of south-western Spain, was performed. Methods and Results: Characterization of 123 presumptive Vibrio spp. was carried out using 94 phenotypic tests. Simple matching and Jaccard similarity coefficients were used for numerical analysis. Cluster analysis by the unweighted pair group method with arithmetic averages yielded 15 phena defined at 0.81 similarity. Large phena corresponded to Vibrio tubiashii, V. splendidus biotype I and V. harveyi (phena 1, 5 and 9, respectively). The species V. splendidus bioty…

Structure of a polysaccharide from the lipopolysaccharide of Vibrio vulnificus clinical isolate YJ016 containing 2-acetimidoylamino-2-deoxy-L-galactu…

2009

Abstract A polysaccharide isolated after mild acid degradation of the lipopolysaccharide of Vibrio vulnificus clinical isolate YJ016 was found to contain l -Fuc, d -GlcpNAc, 2,4-diacetamido-2,4,6-trideoxy- d -glucose (di-N-acetylbacillosamine, d -QuiNAc4NAc), and 2-acetimidoylamino-2-deoxy- l -galacturonic acid ( l -GalNAmA). The last sugar derivative was confirmed by correlations for nitrogen-linked protons in 2D TOCSY and ROESY spectra measured in a H2O–D2O mixture. The following structure of the polysaccharide was established by 1H and 13C NMR spectroscopy, including 2D ROESY and 1H,13C HMBC experiments: Download : Download full-size image where the degree of 6-O-acetylation of the later…

Identification of the membrane penetrating domain of Vibrio cholerae cytolysin as a β-barrel structure

2005

Summary Vibrio cholerae cytolysin (VCC) is an oligomerizing pore-forming toxin that is related to cytolysins of many other Gram-negative organisms. VCC contains six cysteine residues, of which two were found to be present in free sulphydryl form. The positions of two intramolecular disulphide bonds were mapped, and one was shown to be essential for correct folding of protoxin. Mutations were created in which the two free cysteines were deleted, so that single cysteine substitution mutants could be generated for site-specific labelling. Employment of polarity-sensitive fluorophores identified amino acid side-chains that formed part of the pore-forming domain of VCC. The sequence commenced at…

Succinate dehydrogenase functioning by a reverse redox loop mechanism and fumarate reductase in sulphate-reducing bacteria.

2006

Sulphate- or sulphur-reducing bacteria with known or draft genome sequences (Desulfovibrio vulgaris, Desulfovibrio desulfuricans G20, Desulfobacterium autotrophicum [draft], Desulfotalea psychrophila and Geobacter sulfurreducens) all contain sdhCAB or frdCAB gene clusters encoding succinate : quinone oxidoreductases. frdD or sdhD genes are missing. The presence and function of succinate dehydrogenase versus fumarate reductase was studied. Desulfovibrio desulfuricans (strain Essex 6) grew by fumarate respiration or by fumarate disproportionation, and contained fumarate reductase activity. Desulfovibrio vulgaris lacked fumarate respiration and contained succinate dehydrogenase activity. Succi…

Novel host-specific iron acquisition system in the zoonotic pathogenVibrio vulnificus

2015

Summary Vibrio vulnificus is a marine bacterium associated with human and fish (mainly farmed eels) diseases globally known as vibriosis. The ability to infect and overcome eel innate immunity relies on a virulence plasmid (pVvbt2) specific for biotype 2 (Bt2) strains. In the present study, we demonstrated that pVvbt2 encodes a host-specific iron acquisition system that depends on an outer membrane receptor for eel transferrin called Vep20. The inactivation of vep20 did not affect either bacterial growth in human plasma or virulence for mice, while bacterial growth in eel blood/plasma was abolished and virulence for eels was significantly impaired. Furthermore, vep20 is an iron-regulated ge…

Serological and molecular characteristics of Vibrio vulnificus biotype 3: evidence for high clonality.

2007

Vibrio vulnificus biotype 3 has been implicated as the causative pathogen of an ongoing disease outbreak that erupted in Israel in 1996. Recent work based on multi-locus sequence typing (MLST) showed that V. vulnificus biotype 3 is genetically homogeneous. The aim of this study was to investigate the existence of subpopulations within this homogeneous biotype by characterizing the surface antigens and analysing the sequence diversity of selected outer-membrane protein (OMP)-encoding genes. Rabbit antisera were prepared against biotype 1, 2 and 3 strains. The results of the slide-agglutination test, dot-blot assay (using fresh and boiled cells), and immunoblotting of lipopolysaccharides (LPS…

Microbial communities in full-scale woodchip bioreactors treating aquaculture effluents.

2021

Woodchip bioreactors are being successfully applied to remove nitrate from commercial land-based recirculating aquaculture system (RAS) effluents. In order to understand and optimize the overall function of these bioreactors, knowledge on the microbial communities, especially on the microbes with potential for production or mitigation of harmful substances (e.g. hydrogen sulfide; H2S) is needed. In this study, we quantified and characterized bacterial and fungal communities, including potential H2S producers and consumers, using qPCR and high throughput sequencing of 16S rRNA gene. We took water samples from bioreactors and their inlet and outlet, and sampled biofilms growing on woodchips a…