Search results for "fish disease"
showing 10 items of 233 documents
Interactions between bacteria and Cryptosporidium molnari in gilthead sea bream (Sparus aurata) under farm and laboratory conditions
2006
The possible interaction of Cryptosporidium molnari and bacteria in gilthead sea bream (Sparus aurata) was studied. Epidemiological data from a pathological survey under farm conditions were analyzed. In addition, parasite and bacteria burdens were studied in experimental models in which naturally and experimentally parasitized fish were challenged with a particular strain of Vibrio harveyi (H57). All the bacteria species present were studied. Under farm conditions, the parasite was more prevalent when mortality or morbidity cases (study C) occurred than in randomly sampled fish (study B). In study C, parasite abundance was significantly higher in bacteria-negative fish, and total bacteria …
Carriage of potentially fish-pathogenic bacteria in Sparus aurata cultured in Mediterranean fish farms.
2003
A bacteriological survey of gilthead sea bream Sparus aurata from different fish farms and culture systems on the Spanish Mediterranean coast was conducted. Three different studies were performed. Study A included hatchery-reared larvae; Study B, periodic examination of randomly sampled growing fish; and Study C, growing fish sampled only during mortality/morbidity events. In Studies B and C, sea cages, earth ponds and indoor tanks were surveyed, and in both cases diseased (showing clinical signs) and non-diseased fish were included. In Study A, a shift from Vibrio spp. (30 d after hatching) to oxidative species (60 d after hatching) was detected, and no mortality events were registered. Th…
Transmission, infectivity and survival of Diplostomum spathaceum cercariae
2003
The transmission dynamics of the cercariae of Diplostomum spathaceum were investigated under laboratory conditions using cercariae collected from naturally infected Lymnaea stagnalis. Cercariae were kept in a constant temperature of 20 °C and the survival and infectivity to naïve young rainbow trout recorded at 3-h intervals until few cercariae were alive. Mortality initially remained constant but increased rapidly after 20 h. While a model of constant mortality fitted the survival data, an age-dependent model provided a better fit and implied that cercariae tended to carry similar quantities of resources and once these were exhausted the cercariae died. Cercarial infectivity also showed an…
Influence of rearing conditions on Flavobacterium columnare infection of rainbow trout, Oncorhynchus mykiss (Walbaum).
2005
The influence of rearing conditions on Flavobacterium columnare infection of rainbow trout, Oncorhynchus mykiss (Walbaum), was studied experimentally in the laboratory and at a fish farm. In experiment I, the effect of parasitic infection on columnaris disease was studied using F. columnare carrier fish. The fish were exposed to Diplostomum spathaceum cercariae and a set of other stressors in order to induce clinical columnaris infection. Parasitic infection and other stressors failed to induce the disease. Disease occurred when the fish were challenged with F. columnare, but D. spathaceum infection did not enhance the severity of the infection. In experiment II, the influence of rearing de…
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 (…
Infection of brown trout with Diphyllobothrium dendriticum procercoids.
1997
The aims of this experimental study were to develop a practical method of controlling the number of Diphyllobothrium dendriticum procercoids delivered to a fish host; to examine the effect of different procercoid doses (3, 7 and 15) on the plerocercoid level in fish; and to examine the potential mortality caused by plerocercoids. The experiment was terminated after 2 months. The prevalence of infection at the lowest dose level, 17.2%, was statistically significantly lower than at medium and high levels, 63.3% and 56.7%, respectively. The mean intensity increased slightly along with the dosage. The contribution of D. dendriticum to the death of a few fish could not be proved. It is concluded…
Numerical Taxonomy of Vibrionaceae Isolated from Cultured Amberjack ( Seriola dumerili ) and Surrounding Water
2003
A numerical taxonomic study was performed on 148 isolates of Gram-negative, heterotrophic, facultative anaerobic bacteria isolated from amberjack (Seriola dumerili) and its surrounding culture water. The study included 30 type and reference strains belonging to genera Vibrio, Listonella, and Photobacterium. The strains were characterized by 109 morphological, biochemical, physiological, and nutritional tests. Cluster analysis of similarity matrices obtained with S(SM) and S(J) coefficients was carried out. UPGMA (unweighted pair group mathematical average) analysis defined 11 phena at S(SM) values > or = 86%. Nine phena were identified as Vibrio alginolyticus, V. fischeri, V. harveyi, V. ca…
Sea bass Dicentrarchus labrax (L.) bacterial infection and confinement stress acts on F-type lectin (DlFBL) serum modulation
2014
The F-lectin, a fucose-binding protein found from invertebrates to ectothermic vertebrates, is the last lectin family to be discovered. Here, we describe effects of two different types of stressors, bacterial infection and confinement stress, on the modulation of European sea bass Dicentrarchus labrax (L.) F-lectin (DlFBL), a well-characterized serum opsonin, using a specific antibody. The infection of the Vibrio alginolyticus bacterial strain increased the total haemagglutinating activity during the 16-day testing period. The DlFBL value showed an upward regulation on the first, second and last days and underwent a slight downward regulation 4 days post-challenge. In contrast, the effect o…
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…
Evidence that water transmits the disease caused by the fish pathogen Photobacterium damselae subsp. damselae
2000
The transmission through water of the disease caused by the fish pathogen, Photobacterium damselae subsp. damselae, as well as the role of the skin mucus in the initial steps of the infection, have been studied. All tested strains resisted the bactericidal activity of the mucus and showed an ability to adhere to it, but only those virulent by the intraperitoneal route were infective through water. Moribund fishes showed the typical signs of the disease: haemorrhaged areas on the body surface and ulcerative lesions with mucus degradation. These results suggest that the pathogen can be transmitted to fish through water and use the skin as a portal of entry.