Search results for "vibrio"
showing 10 items of 233 documents
Efficacy of a bivalent vaccine against eel diseases caused by Vibrio vulnificus after its administration by four different routes
2003
Vulnivaccine, a vaccine against vibriosis caused by Vibrio vulnificus serovar E (formerly biotype 2), confers acceptable levels of protection to eels after its administration by prolonged immersion in three doses. Recently, a new pathogenic serovar, named serovar A, has been isolated from vaccinated eels in a Spanish freshwater eel farm. The main objective of this work was to design a bivalent vaccine, and to study its effectiveness against the two pathogenic serovars. With this aim, eels weighing around 20 g were immunised with the bivalent vaccine by oral and anal intubation, intraperitoneal injection (i.p.) and prolonged immersion. The overall results indicated that: (i) the new vaccine …
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…
BIOREMOVAL 0F SULPHATE LAYER FROM A 15TH CENTURY POLYCHROME MARBLE ARTIFACT
2015
This case study shows the application of viable bacterial cells for removing undesired deposits from the surface of a stone polychrome bas-relief, exhibited at the Interdisciplinary Gallery of Sicily Palazzo Abatellis (Palermo). Diagnostic studies carried out during the restoration were aimed at characterizing the technique of execution and understanding the degradation processes. The results of the XRF and FTIR investigations showed that on large areas of the artifact’s surface, stratified deposits with a significant presence of sulfates were present. For bioremoval of the deposits, viable bacterial cells belonging to the species Desulfovibrio vulgaris, were utilized in gelled solution for…
Heterotrophic bacteria community and pollution indicators of mussel--farm impact in the Gulf of Gaeta (Tyrrhenian Sea).
2001
Field studies were carried out to determine and compare the impact of organic loads due to the biodeposition of a mussel farm on the water quality and sediment in a coastal area of the Tyrrhenian Sea (Western Mediterranean). A total of five environmental and five microbial parameters were examined from March, 1997 to February, 1998 on a monthly basis at three stations: the first was located under the mussel farm, the second located at about 40 m away from the mussel farm, while the third designed as a control was at about 1-km. No clear changes in the physical characteristics of the water masses were observed, comparing the three sampling sites and the water column generally showed homogene…
High affinity iron-uptake systems in Vibrio damsela: role in the acquisition of iron from transferrin
1997
In this work, the high affinity iron-acquisition systems displayed by virulent and avirulent strains of Vibrio damsela have been investigated. This species is an autochthonous member of marine ecosystems that can behave as an opportunistic pathogen for fish and mammals. All strains tested (i) were able to grow under the restricted conditions imposed by the iron chelators transferrin (Tf) and EDDHA, (ii) secreted siderophores of hydroxamic type, other than aerobactin and desferal, that were able to stimulate the growth of the auxotroph mutant Arthrobacter flavescens JG9, and (iii) expressed common iron-regulated outer membrane proteins (IROMPs). No change in LPS patterns was observed in resp…
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 …
Iron-binding compounds and related outer membrane proteins in Vibrio cholerae non-O1 strains from aquatic environments
1990
A total of 156 strains of Vibrio cholerae non-O1 from aquatic origins were examined for the presence of iron uptake mechanisms and compared with O1 strains and other Vibrio species. All non-O1 strains were able to grow in iron-limiting conditions, with MICs of ethylenediaminedi (O-hydroxyphenylacetic acid) ranging from 20 microM to 2 mM. The production of siderophores was demonstrated by growth in chrome azurol S agar and cross-feeding assays. All strains produced phenolate-type compounds, as assessed by the chemical tests and by bioassays with Salmonella typhimurium enb-7. Some of the strains also promoted the growth of S. typhimurium enb-1 (which can use only enterobactin as a siderophore…
Siderophores and related outer membrane proteins in Vibrio spp. which are potential pathogens of fish and shellfish
1991
. A total of eight reference strains and 43 environmental isolates of Vibrio species that are potential fish pathogens, were assayed for the production and utilization of siderophores. Chemical and biological assays indicated that all species produced phenolate compounds and only some strains of V. cholerae non-O1, V. parahaemolyticus and V. fluvialis produced hydroxamates. Bioassays indicated that all species produced compounds that stimulated the growth of the homologous and the heterologous species in low-iron media. The catechol-type siderophores produced may be functionally related to enterobactin as demonstrated by bioassays with enterobactin-deficient mutants. However, the chromatogr…