Search results for "Vibrionaceae"
showing 10 items of 79 documents
Vibrio pelagius: differences of the type strain deposited at various culture collections.
2000
A critical evaluation of published and own taxonomic and phylogenetic studies on Vibrio pelagius showed substantial diversity of strains received as type strains from various Culture Collections. The comparison of data based upon 16S rRNA sequence analyses, earlier genomic DNA-DNA similarity studies as well as physiological investigations and the original description indicate that Vibrio pelagius strains CECT 4202T and ATCC 25916T really represent the originally described type species whereas strains NCIMB 1900T and CIP 102762T highly likely are representatives of Vibrio natriegens.
Transmission to Eels, Portals of Entry, and Putative Reservoirs of Vibrio vulnificus Serovar E (Biotype 2)
2001
ABSTRACT Vibrio vulnificus serovar E (formerly biotype 2) is the etiologic agent that is responsible for the main infectious disease affecting farmed eels. Although the pathogen can theoretically use water as a vehicle for disease transmission, it has not been isolated from tank water during epizootics to date. In this work, the mode of transmission of the disease to healthy eels, the portals of entry of the pathogen into fish, and their putative reservoirs have been investigated by means of laboratory and field experiments. Results of the experiments of direct and indirect host-to-host transmission, patch contact challenges, and oral-anal intubations suggest that water is the prime vehicle…
Toxic and enzymatic activities of Vibrio vulnificus biotype 2 with respect to host specificity
1996
In this work, the enzymatic activities of selected strains of biotypes 1 and 2 of Vabrio vulnificus were analyzed by using conventional methods and the API ZYM system. The toxic activities of extracellular products (ECPs) were further evaluated by in vitro and in vivo experiments. The ECPs of both biotypes (i) showed high-level hydrolytic activities, (ii) displayed cytotoxicity for fish cell lines, and (iii) were lethal for eels. Exotoxins seem to be proteinaceous since heat treatment of ECP samples destroyed their toxicity. Only biotype 2 strains were virulent for cels, suggesting that host specificity must be related to differences in cell surface properties. Infectivity trials with other…
Survival of fish-virulent strains ofPhotobacterium damselaesubsp.damselaein seawater under starvation conditions
1998
The survival of fish-virulent strains of Photobacterium damselae subsp. damselae in seawater microcosms, with and without sediment, was investigated. The strains survived as culturable bacteria at 14 and 22 degrees C for at least 1 year, and infectivity for fish was maintained. At 5 degrees C, cells lost culturability on solid media, but this was recovered when the temperature was increased to 22 degrees C. Finally, morphological changes in the bacterium (rod to coccus), and production of vesicles and extracellular material were observed during the time of starvation. The overall results suggest that seawater and sediment can act as reservoirs for these virulent strains.
Isolation and characterization of Vibrio parahaemolyticus causing infection in Iberian toothcarp Aphanius iberus
1999
High mortality among laboratory cultured Iberian toothcarp Aphanius iberus occurred in February 1997 in Valencia (Spain). The main signs of the disease were external haemorrhage and tail rot. Bacteria isolated from internal organs of infected fish were biochemically homogeneous and identified as Vibrio parahaemolyticus. The bacteria were haemolytic against erythrocytes from eel Anguilla anguilla, amberjack Seriola dumerili, toothcarp A. iberus and humans, and were Kanagawa-phenomenon-negative. Infectivity tests showed that the virulence for A. iberus was dependent on salinity. Finally, all strains were virulent for amberjack and eel.
Utilization of hemin and hemoglobin by Vibrio vulnificus biotype 2
1996
The eel pathogen Vibrio vulnificus biotype 2 is able to use hemoglobin (Hb) and hemin (Hm) to reverse iron limitation. In this stud, the adjuvant effect of both compounds on eel pathogenicity has been evaluated and confirmed. Further, we have studied the heme-iron acquisition mechanism displayed by this bacterium. Whole cells were capable of binding Hb and Hm, independently of (i) iron levels in growth medium and (ii) the presence of polysaccharide capsules on bacterial surface. The Hb- and Hm-binding capacity was retained by the outer membrane protein (OMP) fraction and was abolished after proteolytic digestion of OMP samples. Western blotting (immunoblotting) of denatured OMPs revealed th…
Role of iron in the pathogenicity of Vibrio damsela for fish and mammals.
1994
The ability to obtain iron of 14 isolates of Vibrio damsela with different degrees of virulence for mice and turbot (Scophthalmus maximus) has been evaluated in artificial and natural iron-restricted environments. All strains were capable of utilizing haemoglobin (Hb) and ferric ammonium citrate (FAC) as the sole iron sources in vitro. However, only virulent V. damsela strains were able to resist the bacteriostatic and bactericidal effects of human and turbot sera, their growth being enhanced by the addition of Hb and FAC. The inhibitory effect of these sera on the growth of the non-pathogenic strain (ATCC 35083), however, was reversed by heat treatment (56 degrees C for 60 min). The role o…
Vibrio vulnificus biotype 2 serovar E gne but not galE is essential for lipopolysaccharide biosynthesis and virulence
2008
ABSTRACT This work aimed to establish the role of gne (encoding UDP-GalNAc 4-epimerase activity) and galE (encoding UDP-Gal-4-epimerase activity) in the biosynthesis of surface polysaccharides, as well as in the virulence for eels and humans of the zoonotic serovar of Vibrio vulnificus biotype 2, serovar E. DNA sequence data revealed that gne and galE are quite homologous within this species (≥90% homology). Mutation in gne of strain CECT4999 increased the surface hydrophobicity, produced deep alterations in the outer membrane architecture, and resulted in noticeable increases in the sensitivity to microcidal peptides (MP), to eel and human sera, and to phagocytosis/opsonophagocytosis. Furt…
Serum antibodies to Vibrio vulnificus biotype 3 lipopolysaccharide and susceptibility to disease caused by the homologous V. vulnificus biotype
2011
SUMMARYIn 1996 an outbreak of severe soft tissue infections caused byVibrio vulnificusunexpectedly erupted in fish consumers in Israel with relatively little morbidity in fish farmers. To test the hypothesis that recurrent exposure of fishermen to the virulent strain may have provided protection against severe or symptomatic disease, we investigated the association between the immune response toV. vulnificusbiotype 3 lipopolysaccharide (BT3 LPS) and disease susceptibility in fish farmers and fish consumers. Serum samples were tested for IgA and IgG of anti-BT3 LPS in fishermen and fish consumers who suffered fromV. vulnificusBT3 infections and their matched controls. Pre-existing levels of …
O-Serogrouping and surface components ofAeromonas hydrophilaandAeromonas jandaeipathogenic for eels
1994
The relationship between virulence, O-serogroup, and some cell-surface features (self-pelleting [SP] and precipitation after boiling [PAB], profile of lipopolysaccharides [LPSs] and outer membrane proteins [OMPs]) was investigated in strains of the pathogenic species Aeromonas hydrophila and A. jandaei isolated from eels. Virulent strains of A. hydrophila reacted mostly with O:19 antiserum, and those of A. jandaei reacted with O:4, O:11, O:15 and O:29 antisera (Guinée and Jansen system). Regarding the PAB and LPS profiles two groups could be distinguished; (i) five PAB+ strains of serotype O:19 that possessed a homogeneous O polysaccharide side chain and (ii) thirteen PAB- strains antigenic…