Search results for "Aeromonas salmonicida"
showing 5 items of 5 documents
Preliminary Study on the In vitro and In vivo Effects of Asparagopsis taxiformis Bioactive Phycoderivates on Teleosts
2016
Several compounds from marine organisms have been studied for their potential use in aquaculture. Among the red algae, Asparagopsis taxiformis is considered one of the most promising species for the production of bioactive metabolites with numerous proposed applications. Here, the in vitro antibacterial activity, the easy handling and the absence of adverse effects on marine fish species are reported. Depending on the seasonal period of sampling, ethanol extracts of A. taxiformis exhibited significantly different inhibitory activity against fish pathogenic bacteria. The extract obtained in late spring showed strong antibacterial activity against Aeromonas salmonicida subsp. salmonicida, Vib…
Pathogenic Aeromonas hydrophila Serogroup O:14 and O:81 Strains with an S Layer
2004
ABSTRACT Five autoagglutinating Aeromonas hydrophila isolates recovered from eels and humans were assigned to serogroups O:14 and O:81 of the Sakazaki and Shimada (National Institutes of Health) scheme. They had the following properties in common: positive precipitation after boiling, moderate surface hydrophobicity (salt-aggregation-test value around 1.2), pathogenicity for fish and mice (50% lethal dose, 10 4.61 to 10 7.11 ), lipopolysaccharides that contained O-polysaccharide chains of homogeneous chain length, and an external S layer peripheral to the cell wall observed by electron microscopy. A strong cross-reactivity was detected by immunoblotting between the homogeneous O-polysacchar…
Mechanisms of quinolone resistance in Aeromonas species isolated from humans, water and eels.
2009
Mechanisms of resistance were determined in 33 quinolone-resistant isolates of the species Aeromonas hydrophila, Aeromonas caviae, Aeromonas media, Aeromonas salmonicida, Aeromonas popoffii and Aeromonas veronii, recovered from humans, freshwater and eels. The quinolone resistance-determining regions (QRDRs) of gyrA and parC genes were sequenced in these resistant strains, as well as in 8 quinolone-sensitive Aeromonas used as controls. All quinolone-resistant Aeromonas carried point mutations in the gyrA QRDR at codon 83, respectively giving rise to substitutions Ser(83)-->Ile (32 strains) or Ser(83)-->Val (1 strain). Almost half of these isolates (48%) carried additional point mutations in…
Evidence of enhanced bacterial invasion during Diplostomum spathaceum infection in European grayling, Thymallus thymallus (L.)
2006
Farmed grayling, Thymallus thymallus (L.), are susceptible to atypical Aeromonas salmonicida (aAS) infections. Interactions between bacteria and parasites were studied using grayling subjected to concomitant exposure to aAS bacteria and the digenean parasite Diplostomum spathaceum. Atypical AS was detected from fish by a combination of bacterial cultivation and polymerase chain reaction techniques. A detection level of 17 aAS cells per 100 mg intestine tissue sample was obtained. Concomitant bacterial exposure did not enhance the severity of grayling eye rupture and nuclear extrusion induced by D. spathaceum, but D. spathaceum invasion into grayling increased the proportion of fish carrying…
Aeromonas salmonicida in Finland: pathological problems associated with atypical and typical strains
1991
. Aeromonas salmonicida was studied at fish farms producing salmonid smolts in northern and central Finland from 1982 onwards. Aeromonas salmonicida subsp. salmonicida has been causing epizootics in salmon, Salmo salar L., and trout, S. trutta L., at two coastal farms in northern Finland sinee 1986, involving 1–29% mortality in the fish-rearing units affceted. The disease causes more serious losses of sea trout yearlings and brood fish than of salmon. The achromogenic atypical A. salmonicida proved to be the most common bacterial disease in brown and sea trout at one farm in northern Finland throughout the period, causing constant heavy losses, mainly of fingerlings, especially in 1982–1986…