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Skin Mucus (skin + mucus)
Selected AbstractsFlavobacterium columnare chemotaxis to channel catfish mucusFEMS MICROBIOLOGY LETTERS, Issue 2 2008Phillip H. Klesius Abstract Flavobacterium columnare is a Gram-negative pathogen of many species of wild and cultured fish. Isolates from diseased channel catfish belong to either genomovar I or II. Genomovar II isolates were found to be more virulent than genomovar I isolates. The objective of the present study was to determine whether differences exist in the chemotactic response of these genomovars to mucus obtained from the skin, gills and intestines of healthy channel catfish using the capillary chemotaxis assay. Mucus from the skin and gill induced a greater chemotactic response by F. columnare than mucus from the intestine. Sixty percent of mucus from the skin of individual catfish yielded a positive chemotactic response from F. columnare. Finally, skin mucus induced a greater chemotactic response in genomovar II F. columnare than in genomovar I F. columnare isolates. The data indicate that mucus from channel catfish results in a chemotactic response by F. columnare. This positive chemotactic response may be an important first step for F. columnare colonization of channel catfish skin or gills. Although the role that chemotaxis plays in the virulence of F. columnare is not fully defined, the chemotactic response of genomovar ll isolates suggests that chemotaxis is associated with virulence. [source] Antibacterial factors in skin mucus of rabbitfishesJOURNAL OF FISH BIOLOGY, Issue 6 2001Y. Nagashima Aqueous extracts from the skin mucus of two species of rabbitfishes Siganus fuscescens and S. guttatus showed antibacterial activity against gram-negative bacteria. Stability tests and chromatographic analyses suggested that the S. fuscescens antibacterial factor is an acidic glycoprotein with a molecular mass of 400 kDa. [source] Purification and characterization of a 630 kDa bacterial killing metalloprotease (KilC) isolated from plaice Pleuronectes platessa (L.), epidermal mucusJOURNAL OF FISH DISEASES, Issue 5 2008T Tvete Abstract Antibacterial chemicals in the mucus of fish such as lysozyme, lectins, peptides and proteases provide an efficient first line of defence against pathogens. This study shows that there are at least three antibacterial proteins in plaice skin mucus in addition to lysozyme. One of these proteins is responsible for approximately 74% of the antibacterial activity and is a 630 kDa protease complex designated KilC (bacterial killing metalloprotease C). Purified KilC kills the bacteria Staphylococcus aureus, Escherichia coli, Bacillus subtilis and Pseudomonas aeruginosa efficiently. The protease activity of KilC is dependent upon the divalent cation Mg2+ and shows pH dual optima of 5.0 and 8.0. The enzyme has a temperature optimum of 25 °C and is made up of at least five different sized peptides. Studies with protease inhibitors show that the catalytic site of KilC may be cysteine- or serine protease-like. KilC may kill bacterial cells by acting directly upon the bacteria or by producing low molecular weight bioactive compounds such as peptides. [source] Efficacy of injection vaccines against Flavobacterium psychrophilum in rainbow trout, Oncorhynchus mykiss (Walbaum)JOURNAL OF FISH DISEASES, Issue 1 2006J Madetoja Abstract Efficacy of mineral oil-based experimental injection vaccines against Flavobacterium psychrophilum were tested in rainbow trout, Oncorhynchus mykiss (Walbaum), under laboratory and field conditions. The vaccines consisted of formalin- or heat-inactivated whole bacterium cell preparations of two different serotypes (Fd and Th) or a combination of serologically different F. psychrophilum (Fd and/or Th and/or FpT;Th). Specific antibody responses against the bacterium in plasma and skin mucus were evaluated post-vaccination with enzyme-linked immunosorbent assay. Efficacy of the vaccinations was determined by challenge trials to F. psychrophilum with the vaccinated rainbow trout. Significantly higher antibody levels in plasma were detected in vaccinated fish compared with mock-vaccinated fish. Injection vaccination did not trigger specific antibody production in the skin mucus. Significantly higher survival of i.p. vaccinated fish compared with non-vaccinated fish was observed during the challenge. The results suggest that mineral oil-based injectable vaccines containing formalin- or heat-inactivated virulent cells of F. psychrophilum effectively triggered specific antibody production and protected the fish against bacterial cold water disease. [source] Effects of the commercial probiotic Lactobacillus casei on the growth, protein content of skin mucus and stress resistance of juveniles of the Porthole livebearer Poecilopsis gracilis (Poecilidae)AQUACULTURE NUTRITION, Issue 4 2010L.H.H. HERNANDEZ Abstract A 11-week feeding trial was carried out to determine the effects of the probiotic bacteria Lactobacillus casei from the commercial product Yakult® on the growth performance, proximal composition, protein content of skin mucus and stress resistance of juvenile Porthole livebearer Poeciliopsis gracilis. Triplicate groups of 15 juveniles per tank with an initial weight of 47 ± 9 mg (mean ± standard deviation) were fed with Artemia nauplii enriched with the probiotic, by using the bacteria cells plus the fermented milk (group ProN) and the other (group ProC) by using only the bacterial cells, eliminating the fermented milk by centrifugation. A control of fish was set up, by feeding non-enriched Artemia nauplii. Growth performance and survival rates did not show significantly differences among the treatments and control group, but a slightly tendency of higher values for body weight, weight gain and specific growth rate was observed in the juveniles of ProC treatment. Whole body proximate composition did not show significant differences among the groups, but higher values of protein and lipid contents were observed in the groups fed with the probiotic. Content of protein in the skin mucus were significantly higher in the ProC treatment than control group. Recovery rates after an air-dive test were significantly higher on the fish fed with the probiotic cells than the control group. These results show that L. casei might be used as a probiotic for fish and would help during the culture of juvenile of the Porthole livebearer P. gracilis. [source] Alternative matrices for cortisol measurement in fishAQUACULTURE RESEARCH, Issue 8 2010Daniela Bertotto Abstract Plasma cortisol is the most commonly used indicator of stress in fish but, as the blood sampling procedure itself can be a source of stress, it would be helpful to measure cortisol using less invasive matrices. It is also necessary to find alternative matrices as stress indicators in dead fish in which blood sampling is impossible. In the present study, we investigated transport stress in three aquaculture species, European sea bass (Dicentrarchus labrax L.), common carp (Cyprinus carpio L.) and rainbow trout (Oncorhynchus mykiss Walbaum), by cortisol determination (radioimmunoassay) in plasma and other matrices (skin mucus, gut content, lateral muscle and caudal fin). Cortisol significantly increased after transport in all species and matrices, except in the sea bass gut content, where it remained unchanged. The three species responded to transport stress by producing different cortisol levels. In conclusion, the significant correlation found between plasma cortisol and most of the other matrices opens up the possibility of using them to evaluate stress in fish: mucus sampling is a less invasive method than blood sampling, and in addition to muscle and fin sampling, it can be used in postmortem fish. [source] | ||||||||||