Search results for "vulnificus"
showing 10 items of 99 documents
Field testing of a vaccine against eel diseases caused by Vibrio vulnificus
2001
The field results of a vaccination programme against Vibrio vulnificus serovar E (biotype 2) in a Spanish eel farm are reported. A total of 9.5 million glass eels were vaccinated from January 1998 to March 2000 by prolonged immersion followed by 2 subsequent reimmunisations after 12 to 14 and 24 to 28 d, respectively. The acquired protection and the immune response against serovar E were estimated over a period of 6 mo after vaccination. A similar vaccination schedule was conducted with elvers in a Danish eel farm. In this case, the acquired protection and the immune response against serovar E and the new eel-pathogenic serovars, recently described in Denmark, were evaluated over a short te…
Vibrio vulnificus serovar A: an emerging pathogen in European anguilliculture.
2006
The spread of the emerging pathogen Vibrio vulnificus biotype 2 serovar A in Danish anguilliculture is reported. Serovar A was originally isolated in a Spanish eel farm in 2000 and occurred in Denmark in the summer of 2004, affecting eels of 5-10 g body weight cultured in fresh water. The Danish eels showed clinical signs different from those reported for Spanish eels, such as severe haemorrhages in the head and gill region with necrosis of the soft tissues. Danish isolates were biochemically and serologically identical to Spanish serovar A strains and also highly virulent for eels by both intraperitoneal injection and immersion challenges. Vaccination with Vulnivaccine, a vaccine against V…
Isolation of a new serovar of Vibrio vulnificus pathogenic for eels cultured in freshwater farms
2003
The present work reports the isolation of a new serovar of Vibrio vulnificus pathogenic for eels cultured in freshwater farms. This serovar, named Serovar A, produced two outbreaks of low morbidity and mortality in one Spanish eel farm in September 2000 and March 2001. The vibriosis affected healthy eels, weighting between 10 and 100 g, that had been vaccinated against the serovar E of the species (formerly biotype 2) at least 6 months before. Some of the diseased eels showed symptoms different to those reported for the classical vibriosis due to serovar E. These symptoms included bleeding ventral ulcers together with haemorrhagic intestine. Bath experimental challenges demonstrated that (i…
Siderophore-mediated iron acquisition mechanisms in Vibrio vulnificus biotype 2
1996
Vibrio vulnificus biotype 2 is a primary pathogen for eels and, as has recently been suggested, an opportunistic pathogen for humans. In this study we have investigated the ability of V. vulnificus biotype 2 to obtain iron by siderophore-mediated mechanisms and evaluated the importance of free iron in vibriosis. The virulence degree for eels was dependent on iron availability from host fluids, as was revealed by a reduction in the 50% lethal dose for iron-overloaded eels. This biotype produced both phenolate- and hydroxamate-type siderophores of an unknown nature and two new outer membrane proteins of around 84 and 72 kDa in response to iron starvation. No alterations in lipopolysaccharide …
Effects of salinity and temperature on long-term survival of the eel pathogen Vibrio vulnificus biotype 2 (serovar E)
1999
ABSTRACT Vibrio vulnificus biotype 2 (serovar E) is a primary eel pathogen. In this study, we performed long-term survival experiments to investigate whether the aquatic ecosystem can be a reservoir for this bacterium. We have used microcosms containing water of different salinities (ranging from 0.3 to 3.8%) maintained at three temperatures (12, 25, and 30°C). Temperature and salinity significantly affected long-term survival: (i) the optimal salinity for survival was 1.5%; (ii) lower salinities reduced survival, although they were nonlethal; and (ii) the optimal temperature for survival was dependent on the salinity (25°C for microcosms at 0.3 and 0.5% and 12°C for microcosms at 1.5 to 3.…
MARTX ofVibrio vulnificusbiotype 2 is a virulence and survival factor
2012
Vibrio vulnificus biotype 2 is a polyphyletic group whose virulence for fish relies on a plasmid. This plasmid contains an rtxA gene duplicated in the small chromosome that encodes a MARTX (Multifunctional, Autoprocessing Repeats-in-Toxin) unique within the species in domain structure (MARTX type III). To discover the role of this toxin in the fitness of this biotype in the fish-farming environment, single- and double-knockout mutants were isolated from a zoonotic strain and analysed in a series of in vivo and in vitro experiments with eel, fish cell lines and amoebae isolated from gills. Mice, murine and human cell lines were also assayed for comparative purposes. The results suggest that …
A Method of Transposon Insertion Sequencing in Comprehensively Identifying Vibrio vulnificus Genes Required for Growth in Human Serum
2021
One of the most powerful approaches to detect the loci that enable a pathogen to cause disease is the creation of a high-density transposon mutant library by transposon insertion sequencing (TIS) and the screening of the library using an adequate in vivo and/or ex vivo model of the disease. Here we describe the procedure for detection of the putative loci required for a septicemic pathogen to cause sepsis in humans by using TIS plus an ex vivo model of septicaemia: to grow the pathogen in fresh and inactivated human serum. We selected V. vulnificus because it is a highly invasive pathogen capable of spreading from an infection site to the bloodstream, causing sepsis and death in less than 2…
The effect of metals on condition and pathologies of European eel (Anguilla anguilla): in situ and laboratory experiments.
2011
Forty-nine wild eels (Anguilla anguilla) caught in the Albufera Lake (Spain), measuring 24.0-75.0 cm in length and 25.0-637.7 g in weight, were examined for metals (Cd, Co, Cr, Cu, Fe, Hg, Mn, Pb, Se and Zn), condition (CI and HSI indices), as well as for diseases (Anguillicola infestation; bacterial infections). Total metal load significantly increased in eel liver tissue parallel to total length and body weight (log), while silvering females (W(B) > 200 g; L ≥ 500 mm) exhibited the highest amounts of Co, Cu, Hg, Se and Zn. Diverse effects may be expected in these big eels due to long-term metal exposure. In fact, IMBI (individual mean (multi-metal) bioaccumulation index) and copper load (…
Genetic relatedness among environmental, clinical, and diseased-eel Vibrio vulnificus isolates from different geographic regions by ribotyping and ra…
1998
ABSTRACT Genetic relationships among 132 strains of Vibrio vulnificus (clinical, environmental, and diseased-eel isolates from different geographic origins, as well as seawater and shellfish isolates from the western Mediterranean coast, including reference strains) were analyzed by random amplified polymorphic DNA (RAPD) PCR. Results were validated by ribotyping. For ribotyping, DNAs were digested with Kpn I and hybridized with an oligonucleotide probe complementary to a highly conserved sequence in the 23S rRNA gene. Random amplification of DNA was performed with M13 and T3 universal primers. The comparison between ribotyping and RAPD PCR revealed an overall agreement regarding the high l…
A comparison of strategies for the detection and recovery of Vibrio vulnificus from marine samples of the Western Mediterranean coast
1998
Summary We have compared the effectiveness of culture-based methods and a DNA-based method for the detection, of Vibrio vulnificus from seawater and three types of shellfish collected from the coastal waters of Valencia, Spain. For culture-based method, we used two selective media, thiosulphate-citrate-bile salts-sucrose (TCBS), and cellobiose-polymyxin B-colistin (CPC) agars with and without previous enrichment in alkaline-saline-peptone-water (APWS). Presumptive colonies were confirmed as V. vulnificus by the polymerase chain reaction (PCR) using previously described 23S rRNA V. vulficus -specific sequences as primers (Dvu 9V and Dvu 45R). Direct detection was accomplished by a nested-PCR…