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vibrio spp. secrete proaerolysin as a folded dimer without the need for disulphide bond formation.proaerolysin is an extracellular dimeric protein that is secreted across the inner and outer membranes of aeromonas spp. in separate steps. to investigate the role of protein folding in the second step, one or more cysteine residues were introduced and the mutant proaerolysins were expressed in aeromonas hydrophila and aeromonas salmonicida, as well as vibrio cholerae. replacing met-41 with cys resulted in expression of a protein that could form a dimer in which the monomers were linked together ...19958594324
aeromonas salmonicida possesses two genes encoding homologs of the major outer membrane protein, ompa.two homologs of the outer membrane protein ompa were identified in aeromonas salmonicida by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, immunoblotting, and amino-terminal sequence analyses. an a. salmonicida genomic dna library was constructed by using lambda gem-11 and recombinant phage carrying both genes ompai and ompaii) selected by immunoscreening. a 5.0-kb bamhi fragment containing the two genes in tandem was subcloned in pbluescript and used for further subcloning and seque ...19968626290
immunotoxic effects of copper and cadmium in the sea bass dicentrarchus labrax.two phagocytes-mediated activities of the sea bass dicentrarchus labrax were examined after exposure to sublethal concentrations of copper and cadmium: (a) phagocytosis (measured by phagocytotic index), and (b) the production of reactive oxygen intermediates (luminol-dependent chemiluminescence) in response to bacteria aeromonas salmonicida. in vivo exposure for 48 h to each metal separately by intraperitoneal injection did not affect the quantity of phagocytes of pronephros and their viability ...19968683034
characterization of atypical aeromonas salmonicida isolates by ribotyping and plasmid profiling.a total of 38 strains of atypical aeromonas salmonicida, three oxidase-negative but otherwise typical aer. salmonicida, three typical aer. salmonicida, and two reference strains, isolated from several countries and fish species were examined with respect to rrna gene restriction patterns (ribotypes) and plasmid profiles. most epidemiologically unrelated strains had different ribotypes, whereas isolates from the same outbreak were identical. all strains, except one, carried one or more large plas ...19968698652
utilization of transferrin and salmon serum as sources of iron by typical and atypical strains of aeromonas salmonicida.the ability of typical and atypical strains of aeromonas salmonicida to utilize non-haem sources of protein-bound iron was evaluated. (i) in a plate bioassay, the suppression of growth imposed on typical and atypical a. salmonicida by addition of the high-affinity iron chelator ethylenediamine-di(o- hydroxyphenylacetic acid) (edda) to the growth medium was reversed by the addition of 30% or 90% iron-saturated bovine or human transferrin (tf) or lactoferrin (lf) to the growth medium. (ii) the mec ...19968704995
cloning and nucleotide sequence of the dna gyrase gyra gene from the fish pathogen aeromonas salmonicida.the dna gyrase gyra gene from the fish pathogen aeromonas salmonicida 2148/89 was cloned, and the nucleotide sequence was determined. an open reading frame of 2,766 nucleotides was identified and was found to encode a protein of 922 amino acids with a calculated molecular mass of 101.1 kda. the derived amino acid sequence shared a high degree of identity with other dna gyrase a proteins, in particular, with other gram-negative gyra sequences. when the amino acid sequence of a. salmonicida gyra w ...19968723452
a live (delta aroa) aeromonas salmonicida vaccine for furunculosis preferentially stimulates t-cell responses relative to b-cell responses in rainbow trout (oncorhynchus mykiss).we have previously described (l. m. vaughan, p. r. smith, and t. j. foster, infect. immun. 61:2172-2181, 1993) the construction of a kanamycin-resistant aromatic-dependent mutant of aeromonas salmonicida, the causative agent of furunculosis, and its use as a live vaccine. here we describe the construction of an unmarked aroa deletion mutant and examine the nature and magnitude of immune responses in rainbow trout (oncorhynchus mykiss) to this vaccine strain. good proliferative and antibody respo ...19968751940
atypical aeromonas salmonicida isolated from diseased turbot (scophtalmus maximus l.).atypical aeromonas salmonicida were isolated from 3 outbreaks of disease among farmed turbot (scophthalmus maximus l.) in 3 different farms, 1 from norway (n1) and 2 from denmark (dk1 and dk2). in all 3 cases, the incidence of disease and mortality was high and the main characteristic pathological finding was skin ulcers and septicaemia. the isolated bacteria were subjected to a thorough phenotypic and genotypic examination and comparison in the laboratory. all 3 isolates belonged to a. salmonic ...19968767692
multiple regulation of carp (cyprinus carpio l.) macrophages and neutrophilic granulocytes by serum factors: influence of infection with atypical aeromonas salmonicida.normal carp serum contains inhibitory and stimulatory factors for macrophage and neutrophilic granulocyte respiratory burst activity. as stimulatory factors were only effective in combination with phorbol myristate actetate (pma) activation, it is concluded that they are probably linked to protein kinase c activation. both the stimulatory and inhibitory factors are heat stable. macrophage- and neutrophilic granulocyte-enriched cell fractions from the pronephros of carp had high respiratory burst ...19968797288
survival of cells and dna of aeromonas salmonicida released into aquatic microcosms.the survival of the bacterial fish pathogen aeromonas salmonicida, and persistence of its dna, were monitored in aquatic microcosms using selective culture and most probable number pcr. bacterial cells and naked dna were released into natural non-sterile microcosms consisting of lake sediment overlayered with lake water. two different types of surface sediment were used. one was sandy in character, taken from the shoreline whilst the other was a littoral loamy surface mud. inoculated cells and n ...19968810058
the role of the capsular polysaccharide of aeromonas salmonicida in the adherence and invasion of fish cell lines.the ability of several aeromonas salmonicida strains grown under different conditions (capsulated and non-capsulated) to adhere to and invade two fish cell lines was compared. the level of adherence was slightly higher when the strains were grown under conditions promoting capsule formation than when the same strains were grown under conditions which did not promote capsule formation. however, the most significant difference among the wild-type strains grown under conditions promoting capsule fo ...19968810501
application of a modified disc diffusion technique to antimicrobial susceptibility testing of vibrio anguillarum and aeromonas salmonicida clinical isolates.two techniques for antimicrobial susceptibility testing of vibrio anguillarum and aeromonas salmonicida strains were compared. the first method was the reference test that determines minimal inhibitory concentrations (mic); the second was a modified diffusion test that measures the inhibitory concentrations in diffusion (icd) by carrying out the diffusion test with five discs of differing contents. icd measurement was not applicable for the susceptibility testing of oxytetracycline and sulfadime ...19968828130
an aeromonas salmonicida gene required for the establishment of infection in rainbow trout (oncorhynchus mykiss).the asob gene of aeromonas salmonicida is located approximately 9 kb downstream of the structural gene (vapa) for the surface layer (a-layer). the nucleotide sequence of asob was determined and found to encode a putative polytopic cytoplasmic membrane protein which exhibited homology to a number of bacterial transport proteins. allele exchange mutagenesis of asob resulted in a mutant (a449-d) which was avirulent when administered by bath immersion. however, when administered by intraperitoneal i ...19968917088
cloning, characterization and expression of the reca gene of aeromonas salmonicida.the aeromonas salmonicida a449 reca gene has been cloned, sequenced and expressed in vitro. the predicted amino acid sequence of a. salmonicida reca was determined and, when compared to other reca, was found to possess a number of domains identical to those characterized in escherichia coli reca. the a. salmonicida reca was mobilized into an e. coli reca mutant strain and was shown to allow increased survival in the presence of the chemical mutagen mms and after ultraviolet (uv) irradiation. the ...19968917089
the cell surface of aeromonas salmonicida determines in vitro survival in cultured brook trout (salvelinus fontinalis) peritoneal macrophages.aeromonas salmonicida strains phenotypically differing in their a-layer, lipopolysaccharide, and macrophage cytotoxicity were tested in vitro for survivability in brook trout (salvelinus fontinalis) serum with or without antibodies, and in vivo following intraperitoneal injection. the ability of brook trout peritoneal macrophages to phagocytize and kill the different phenotypes was investigated in an in vitro assay. the virulent strain, a. salmonicida 80204, which has the full complement of know ...19968971685
acute phase proteins in salmonids: evolutionary analyses and acute phase response.inflammation induces dramatic changes in the biosynthetic profile of the liver, leading to increased serum concentrations of positive acute phase (ap) proteins and decreased concentrations of negative ap proteins. serum amyloid a (saa) and the pentraxins c-reactive protein (crp) and serum amyloid p component (sap) are major ap proteins: their serum levels can rise by 1000-fold, indicating that they play a critical role in defense and/or the restoration of homeostasis. we have cloned saa and a sa ...19978977214
characterization of a stable l-form of the fish pathogen aeromonas salmonicida.a stable l-form of aeromonas salmonicida, which resulted from induction with benzylpenicillin, contained more of an outer membrane protein, with an estimated molecular weight of 40 kda but less of 47.9 and 38 kda proteins, than did parental walled cells. in addition, from western blots, two protein bands reacted strongly with a polyclonal antiserum. the antiserum did not react demonstrably with the band detected in the l-forms on the gels.19968987904
in vivo production of a-protein, lipopolysaccharide, iron-regulated outer membrane proteins and 70-kda serine protease by aeromonas salmonicida subsp. salmonicida.using specific immunostaining of western blots, the in vivo expression of several putative virulence factors of aeromonas salmonicida subsp. salmonicida was demonstrated in infected muscle tissue of atlantic salmon and rainbow trout. three virulent isolates of a. salmonicida were used. one isolate was chosen because in vitro it was apparently a non-producer of the 70-kda serine protease. infected furuncle tissue was centrifuged and samples of the pellet and supernatant probed for evidence that t ...19979141656
the disulfide bond in the aeromonas hydrophila lipase/acyltransferase stabilizes the structure but is not required for secretion or activity.vibrio and aeromonas spp. secrete an unusual 35-kda lipase that shares several properties with mammalian lecithin-cholesterol acyltransferase. the aeromonas hydrophila lipase contains two cysteine residues that form an intramolecular disulfide bridge. here we show that changing either of the cysteines to serine does not reduce enzymatic activity, indicating that the disulfide bond is not required for correct folding. however, when either of the cysteines is replaced, the enzyme is more readily d ...19979150203
[recent knowledge on fish pathogenic bacteria aeromonas salmonicida, listonella anguillara and cytophaga columnaris, and their virulence factors]. 19979155200
the effect of temperature and water quality on antibody response to aeromonas salmonicida in sunshine bass (morone chrysops x morone saxatilis).the kinetics of the antibody response to aeromonas salmonicida were determined in sunshine bass (hybrid striped bass: female morone chrysops x male morone saxatilis) acclimated to 10, 18, 24, 29 degrees c, and to 0.15 mg 1(-1) un-ionized ammonia and 200 mg 1(-1) nitrate levels. temperature and water quality factors affected the immune response of sunshine bass. temperatures of 10 degrees c and 18 degrees c decreased the magnitude and delayed the time of the antibody response to a. salmonicida. t ...19969157680
complement resistance of capsulated strains of aeromonas salmonicida.the complement resistance of aeromonas salmonicida strains grown under conditions promoting capsule formation was investigated using well characterized strains and their isogenic mutants. complement resistance was previously studied using the same strains growing under non-capsulating conditions. the serum resistant strains were found to activate complement, but rapidly degrade c3b preventing productive formation of the lytic complex c5b-9. isogenic lipopolysaccharide rough mutants grown under n ...19979160301
identification of a second endogenous porphyromonas gingivalis insertion element.in this study a second endogenous porphyromonas gingivalis insertion element (is element) that is capable of transposition within p. gingivalis was identified. nucleotide sequence analysis of the tn4351 insertion site in a p. gingivalis tn4351-generated transconjugant showed that a complete copy of the previously unidentified is element, designated pgis2, had inserted into is4351r in tn4351. pgis2 is 1,207 bp in length with 19-bp imperfect terminal inverted repeats, and insertion resulted in a d ...19979171437
molecular and phenotypic methods for the characterization of atypical aeromonas salmonicida.atypical aeromonas salmonicida form a taxonomically diverse group among the psychrophilic a. salmonicida. characteristics of 53 atypical a. salmonicida strains originating from finland, denmark, norway and sweden were studied using 60 phenotypic tests. ribopattern analysis and plasmid profiles were used as genetic methods. the production of brown pigment on the furunculosis agar containing l-tyrosine divided the atypical oxidase-positive strains into two groups: pigment-producing (n = 35) and ac ...19979228690
purification and properties of an aminopeptidase from a protamine-degrading marine bacterium.a protamine-degrading marine bacterium was isolated from marine soil and identified as aeromonas salmonicida subsp. based on its taxonomical characteristics. an alanine-specific aminopeptidase, called aminopeptidase k, from an extract of the strain was purified and characterized. the aminopeptidase k was purified about 80-fold by fractionation with ammonium sulfate and column chromatography on qa-52 cellulose, phenyl superose and superose 12. the purified enzyme is composed of 6 subunits of 86 k ...19979255972
adjuvants and immunostimulants for enhancing vaccine potency in fish.adjuvants combined with immunogens are effective enhancers of the immune response in fish. as in other animals, substances such as freund's complete and incomplete adjuvants, light oils and bacterial lipopolysaccharides have been shown to induce elevated antibody production when added to bacterins and administered to fish. light oil adjuvants are now used successfully with injectable bacterins of aeromonas salmonicida, and in multivalent fish vaccines where a. salmonicida is combined with yersin ...19979270854
vaccinated fish welfare: protection versus side-effects.active immunisation of fish involves a number of potentially harmful procedures like handling, anaesthesia or injection of more or less toxic substances. adjuvanted vaccines may cause inflammation, granuloma and pigmentation at the site of injection. intraperitoneal administration of oil-adjuvanted vaccines to atlantic salmon pre-smolts has occasionally resulted in impaired growth and reduced carcass quality. the consequences of such vaccination for fish welfare may therefore be questioned. with ...19979270866
vaccination strategies in freshwater salmonid aquaculture.the focus of this chapter is antibacterial vaccines. the main salmonid species in freshwater aquaculture is the rainbow trout. other salmonid species are produced on a limited scale. the most important bacterial fish diseases in european freshwater aquaculture are the rainbow trout fry syndrome-rtfs-(flavobacterium psychrophilum) and enteric redmouth disease-erm-(yersinia ruckeri) which are widespread and cause serious epizootics, while furunculosis (aeromonas salmonicida) is endemic, only givin ...19979270868
functions of s-layers.although s-layers are being increasingly identified on bacteria and archaea, it is enigmatic that in most cases s-layer function continues to elude us. in a few instances, s-layers have been shown to be virulence factors on pathogens (e.g. campylobacter fetus ssp. fetus and aeromonas salmonicida), protective against bdellovibrio, a depository for surface-exposed enzymes (e.g. bacillus stearothermophilus), shape-determining agents (e.g. thermoproteus tenax) and nucleation factors for fine-grain m ...19979276929
quorum sensing in aeromonas hydrophila and aeromonas salmonicida: identification of the luxri homologs ahyri and asari and their cognate n-acylhomoserine lactone signal molecules.spent culture supernatants from both aeromonas hydrophila and aeromonas salmonicida activate a range of biosensors responsive to n-acylhomoserine lactones (ahls). the genes for a quorum sensing signal generator and a response regulator were cloned from each aeromonas species and termed ahyri and asari, respectively. protein sequence homology analysis places the gene products within the growing family of luxri homologs. ahyr and asar are transcribed divergently from ahyi and asai, respectively, a ...19979286976
identification and molecular characterization of two tandemly located flagellin genes from aeromonas salmonicida a449.two tandemly located flagellin genes, flaa and flab, with 79% nucleotide sequence identity were identified in aeromonas salmonicida a449. the fla genes are conserved in typical and atypical strains of a. salmonicida, and they display significant divergence at the nucleotide level from the fla genes of the motile species aeromonas hydrophila and aeromonas veronii biotype sobria. flaa and flab encode unprocessed flagellins with predicted mrs of 32,351 and 32,056, respectively. when cloned under th ...19979286979
the synthesis, secretion and role in virulence of the paracrystalline surface protein layers of aeromonas salmonicida and a. hydrophila.the s-layers of the aeromonas spp. studied to date are composed of identical protein subunits which are translocated across the cytoplasmic membrane, periplasm and outer membrane to the cell surface, where they are assembled and tethered to the cell via an interaction with the o-polysaccharide side chains of the lipopolysaccharide. aeromonas s-layers have the ability to bind a number of host factors such as fibronectin, laminin and vitronectin as well as providing resistance to serum killing and ...19979297815
aeromonas popoffii sp. nov., a mesophilic bacterium isolated from drinking water production plants and reservoirs.we examined the taxonomic position of seven aeromonas isolates, recovered from flemish and scottish drinking water production plants and reservoirs, which were previously recognized by numerical analysis of genomic aflp fingerprints as members of an unknown aeromonas taxon that most closely resembled the species aeromonas bestiarum (dna hybridization group [hg] 2). the new phenotypic and dna-dna hybridization data obtained in this study show that the a. bestiarum-like strains constitute a separa ...19979336924
pathogenicity of atypical aeromonas salmonicida in atlantic salmon compared with protease production.the pathogenicity of extracellular products (ecps) from 24 atypical aeromonas salmonicida strains was studied with respect to: lethality in atlantic salmon, pathogenic effect in muscle, haemolytic activity, cytotoxicity in two fish cell lines and proteolytic activities. furthermore, the relationship between lethality of ecps and mortality caused by bacterial challenge was examined. correlation was demonstrated between the pathogenic properties and proteolytic activities of the ecps. cytolytic (g ...19979418019
reappraisal of the effect of temperature on the growth kinetics of aeromonas salmonicida.the effect of temperature (1-34 degrees c) on the maximum specific growth rate of aeromonas salmonicida could not be described by the classical growth models; for some strains, two optimal temperatures at 23 degrees c and 30 degrees c were observed, as well as an unexpected increase in the pseudolag time above 27 degrees c. this could be explained by the presence of two subsets, notably s-layer+ and s-layer- sub-populations. the a- cells had higher growth parameters (topt and mu opt) than the a+ ...19979418073
further characterization of renibacterium salmoninarum extracellular products.renibacterium salmoninarum, the agent of bacterial kidney disease in salmonids, releases high concentrations of extracellular protein in tissues of infected fish. the extracellular protein consists almost entirely of a 57-kda protein and derivatives of degradation and aggregation of the same molecule. the 57-kda protein and its derivatives were fractionated into defined ranges of molecular mass. separated fractions continued to produce degradation and aggregation products. one-dimensional electr ...19979480644
identification of lactococcus garvieae by pcr.lactococcus garvieae junior synonym enterococcus seriolicida) is an emerging zoonotic agent isolated from economically important fish (rainbow trout and yellowtail), from cattle, and from humans. clindamycin susceptibility is the only phenotypic test which can differentiate l. garvieae from lactococcus lactis, another emerging agent in humans. a pcr assay for the identification of l. garvieae was developed and resulted in an amplified fragment of 1,100 bp in size. the pcr assay was shown to be s ...19989542921
defined deletion mutants demonstrate that the major secreted toxins are not essential for the virulence of aeromonas salmonicida.the importance of the two major extracellular enzymes of aeromonas salmonicida, glycerophospholipid: cholesterol acyltransferase (gcat) and a serine protease (aspa), to the pathology and mortality of salmonid fish with furunculosis had been indicated in toxicity studies. in this study, the genes encoding gcat (sata) and aspa (aspa) have been cloned and mutagenized by marker replacement of internal deletions, and the constructs have been used for the creation of isogenic sata and aspa mutants of ...19989573081
immunostimulatory effects of dimerized lysozyme (klp-602) on the nonspecific defense mechanisms and protection against furunculosis in salmonids.utilization of natural immunostimulants in fish culture offers a wide range of attractive methods for inducing and building protection against diseases. lysozyme is an enzyme with bacteriolytic properties and is ubiquitous in its distribution among living organisms. this enzyme has antiviral, antibacterial and anti-inflammatory properties. in nature, lysozyme is found as a monomer. lysozyme dimer is significantly less toxic than its monomer, and its high biological activity has been ascertained ...19989613448
sialic acid-binding lectin with antibacterial activity from the horse mussel: further characterization and immunolocalization.a heterogeneous sialic acid-binding lectin with affinity for bacterial lps was isolated and partially characterized from hemolymph of the horse mussel modiolus modiolus.(1) using two-dimensional electrophoresis with immobilized ph gradients, the lectin revealed three subunits with different molecular weight and isoelectric points (pi); mr14 (pi approximately 5.1 and approximately 5.5), 17.5 (pi approximately 5.5) and 20 (pi approximately 4.9) kda. the affinity purified lectin existed in its nati ...19989639084
molecular cloning, nucleotide sequence, and expression in escherichia coli of a hemolytic toxin (aerolysin) gene from aeromonas trota.aeromonas trota ak2, which was derived from atcc 49659 and produces the extracellular pore-forming hemolytic toxin aerolysin, was mutagenized with the transposon mini-tn5km1 to generate a hemolysin-deficient mutant, designated strain ak253. southern blotting data indicated that an 8.7-kb noti fragment of the genomic dna of strain ak253 contained the kanamycin resistance gene of mini-tn5km1. the 8.7-kb noti dna fragment was cloned into the vector pgem5zf(-) by selecting for kanamycin resistance, ...19989647817
generation and preliminary characterization of monoclonal antibodies directed to glycerophospholipid:cholesterol acyltransferase (gcat) native epitopes of aeromonas salmonicida.four monoclonal antibodies (mabs) directed to native glycerophospholipid:cholesterol acyltransferase (gcat) epitopes of aeromonas salmonicida were isolated using an esterase capture assay. the molecular mass of this mab-defined antigen was estimated to be 26 kda in sds-page. three different epitope specificities of these mabs were demonstrated. it was shown that all 4 mabs recognize gcat in culture filtrates of the strain mt004 excluding the simultaneous trapping of other components. none of the ...19989653461
siderophore production by aeromonas salmonicida subsp. salmonicida. lack of strain specificity.siderophore production, presence of iron-regulated outer membrane proteins and siderophore specificity was determined among 17 isolates of aeromonas salmonicida subsp. salmonicida obtained from spain and scotland. all grew in the presence of ethylenediamine di(o-hydroxyphenylacetic acid) (edda) and siderophore production was detected using chrome azurol s (cas) agar, confirming the presence of a high-affinity siderophore iron-uptake mechanism. the arnow test confirmed that all isolates produced ...19989684314
occurrence and significance of atypical aeromonas salmonicida in non-salmonid and salmonid fish species: a review.bacterial strains of aeromonas salmonicida included in the recognized subsp. acromogenes, subsp. masoucida, and subsp. smithia in addition to the large number of strains not included in any of the described subspecies are referred to as atypical a. salmonicida. the atypical strains form a very heterogeneous group with respect to biochemical characteristics, growth conditions, and production of extracellular proteasess. consequently, the present taxonomy of the species a. salmonicida is rather am ...19989696626
identification of atypical aeromonas salmonicida: inter-laboratory evaluation and harmonization of methods.the atypical isolates of aeromonas salmonicida are becoming increasingly important as the frequency of isolation of bacteria belonging to this group continues to rise. the primary object of this study was to compare and evaluate the results obtained in various laboratories concerning the biochemical identification of atypical aer. salmonicida before and after standardization of media and methods. five laboratories examined 25 isolates of aer. salmonicida from diverse fish species and geographica ...19989717284
physical map of the chromosome of aeromonas salmonicida and genomic comparisons between aeromonas strains.i-ceul and pmel physical maps of the aeromonas salmonicida a449 chromosome were constructed using pfge. the circular chromosome of a. salmonicida a449 was estimated to be 4658 +/- 30 kb. the approximate location of several genes, including those encoding proteins implicated in virulence, were identified. the map showed that the known virulence-factor-encoding genes were not clustered. the i-ceul genomic digestion fingerprints of several typical and atypical strains of a. salmonicida were compare ...19989720035
characterization of atypical aeromonas salmonicida by different methods.fifty two isolates of atypical aeromonas salmonicida, recovered from a wide range of hosts and geographical locations, were heterogeneous in terms of molecular and phenotypic characteristics, and represented taxa which could not be accommodated by the current classification of four subspecies. generally, there was incongruence between the molecular (pcr, rapd and ribotyping) and phenotypic methods in terms of cluster membership. by pcr, 6 groups were described of which group 1 encompassed 12 iso ...19989741110
haemorrhagic septicaemia by aeromonas salmonicida subsp. salmonicida in a black-tip reef shark (carcharhinus melanopterus).one black-tip reef shark (carcharhinus melanopterus) was found dead without previous signs of disease. major lesions consisted in cutaneous erythema, mainly at the base of the fins, focal to diffuse inflammatory lesions in gills and intestinal wall, and discrete haemorrhages in the same organs, liver and kidneys. microcolonies of gram-negative rods were observed in the lamina propia of gills, underneath the intestinal mucosa and randomly distributed in the renal and hepatic parenchymas. also, em ...19989780832
plasma proteins of rainbow trout (oncorhynchus mykiss) isolated by binding to lipopolysaccharide from aeromonas salmonicida.in an attempt to find plasma proteins that might be involved in the constitutive resistance of rainbow trout to furunculosis, a disease caused by aeromonas salmonicida (as), we purified serum and plasma proteins based on their calcium- and carbohydrate-dependent affinity for a. salmonicida lipopolysaccharide (lps) coupled to an epoxy-activated synthetic matrix (toyopearl af epoxy 650m). a multimeric family of high molecular weight (96 to 200-kda) lps-binding proteins exhibiting both calcium and ...19989787816
molecular characterization of plasmid-mediated oxytetracycline resistance in aeromonas salmonicida.using broth conjugation, we found that 19 of 29 (66%) oxytetracycline (ot)-resistant isolates of aeromonas salmonicida transferred the ot resistance phenotype to escherichia coli. the ot resistance phenotype was encoded by high-molecular-weight r-plasmids that were capable of transferring ot resistance to both environmental and clinical isolates of aeromonas spp. the molecular basis for antibiotic resistance in ot-resistant isolates of a. salmonicida was determined. the ot resistance determinant ...19989797265
isolation of aeromonas salmonicida in association with purple-pigmented bacteria in sediment from a scottish loch.aeromonas salmonicida was recovered in close association with an unidentified purple-pigmented organism, which was isolated from sediment in a scottish loch during november (1997) and february (1998). however, there has not been any evidence of a. salmonicida infections, specifically furunculosis, associated with the fish in this loch.19989871353
the effect of diet on aerobic bacterial flora associated with intestine of arctic charr (salvelinus alpinus l.).in order to extend the knowledge on the possible effect of diet on the gastrointestinal microbial community of fish, arctic charr (salvelinus alpinus l.) were fed diets containing high (23.7%) and low (6.4%) levels of carbohydrate. the number of viable aerobic and facultative aerobic bacteria associated with the digestive tract were not influenced by dietary regimen. a wide range of bacterial species was isolated, and the predominant bacterial species of both rearing groups were identified as st ...199910030010
expression and properties of an aerolysin--clostridium septicum alpha toxin hybrid protein.aerolysin is a bilobal channel-forming toxin secreted by aeromonas hydrophila. the alpha toxin produced by clostridium septicum is homologous to the large lobe of aerolysin. however, it does not contain a region corresponding to the small lobe of the aeromonas toxin, leading us to ask what the function of the small lobe is. we fused the small lobe of aerolysin to alpha toxin, producing a hybrid protein that should structurally resemble aerolysin. unlike aerolysin, the hybrid was not secreted whe ...199910048023
ulcerative dermatitis caused by aeromonas salmonicida spp. salmonicida in farmed atlantic salmon in british columbia. 199810051960
identification and characterization of is2404 and is2606: two distinct repeated sequences for detection of mycobacterium ulcerans by pcr.molecular analysis of mycobacterium ulcerans has revealed two new insertion sequences (iss), is2404 and is2606. is2404 was identified by complete sequencing of a previously described repetitive dna segment from m. ulcerans. this element is 1,274 bp long, contains 12-bp inverted repeats and a single open reading frame (orf) potentially encoding a protein of 327 amino acids (aa), and apparently generates 7-bp direct repeats upon transposition. amino acid similarity was found between the putative t ...199910074520
peroxide-inducible catalase in aeromonas salmonicida subsp. salmonicida protects against exogenous hydrogen peroxide and killing by activated rainbow trout, oncorhynchus mykiss l., macrophages.aeromonas salmonicida subsp. salmonicida expresses a single cytoplasmically located catalase which was found to be inducible by exposure to 20 microm hydrogen peroxide in mid-exponential phase resulting in a 4 fold increase in activity. subsequent exposure to 2 mm peroxide in late-exponential/early-stationary phase resulted in further induction of catalase activity which increased to 20 fold higher levels than those found in uninduced cultures. exponentially induced cultures were protected again ...199910089155
small subunit rrna gene sequences of aeromonas salmonicida subsp. smithia and haemophilus piscium reveal pronounced similarities with a. salmonicida subsp. salmonicida.the small subunit ribosomal rna (ssu rrna) encoding genes from reference strains of aeromonas salmonicida subsp. smithia and haemophilus piscium were amplified by polymerase chain reaction and cloned into escherichia coli cells. almost the entire ssu rrna gene sequence (1505 nucleotides) from both organisms was determined. these dna sequences were compared with those previously described from a. salmonicida subsp. salmonicida, subsp. achromogenes and subsp. masoucida. this genetic analysis revea ...199910092980
identification of a pathogen-binding lectin in salmon serum.a mannose-binding lectin was isolated from the blood serum of atlantic salmon (salmo salar). analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis under reducing and non-reducing conditions revealed a multimeric structure composed of 17000 mr subunits. hexosamine analysis and glycosidase digestion showed that the lectin is not glycosylated and amino acid analysis revealed no unusual compositional features. using ruthenium red staining, the lectin was shown to bind ca2+ ions. n-te ...199910390051
enhancement of anti-aeromonas salmonicida activity in atlantic salmon (salmo salar) macrophages by a mannose-binding lectin.we investigated the effects of a calcium-dependent mannose-binding lectin isolated from the serum of atlantic salmon on aeromonas salmonicida viability and the anti-a. salmonicida activity of atlantic salmon macrophages. in the absence of other factors, binding of this lectin at concentrations of 0.8, 4.0 and 20.0 ng ml(-1) to virulent a. salmonicida failed to significantly reduce (p> 0.05) cell viability. however, binding of the lectin to a. salmonicida did result in significant (p < or = 0.05) ...199910390056
a-protein from achromogenic atypical aeromonas salmonicida: molecular cloning, expression, purification, and characterization.achromogenic atypical aeromonas salmonicida is the causative agent of goldfish ulcer disease. virulence of this bacterium is associated with the production of a paracrystalline outer membrane a-layer protein. the species-specific structural gene for the monomeric form of a-protein was cloned into a pet-3d plasmid in order to express and produce a recombinant form of the protein in escherichia coli bl21(de3). the induced protein was isolated from inclusion bodies by a simple solubilization-renatu ...199910425160
efficacy of orally administered oxolinic acid and vetoquinol, an oxolinic acid ester, for the treatment of furunculosis in atlantic salmon salmo salar held in seawater.this study was performed to determine the efficacy of orally administered oxolinic acid and vetoquinol, an oxolinic acid ester, in the treatment of experimental induced furunculosis in atlantic salmon salmo salar held in seawater. two strains of the causative bacterium aeromonas salmonicida subsp. salmonicida, 1 sensitive (vi-88/09/03175) and 1 resistant (3475/90) to oxolinic acid, were used. in 2 trials, cohabitational challenges were performed by introducing 8 fish challenged in advance by an ...199910439903
polymerase chain reaction (pcr)-based typing analysis of atypical isolates of the fish pathogen aeromonas salmonicida.two hundred and five isolates of atypical aeromonas salmonicida, recovered from a wide range of hosts and countries were characterized by polymerase chain reaction (pcr) targeting four genes. the chosen genes were those encoding the extracellular a-layer protein (ap), the serine protease (sprot), the glycerophospholipid:cholestrol acetyltransferase protein (gcat), and the 16s rrna (16s rdna). all the atypical a. salmonicida isolates could be assigned to 4 pcr groups. group 1 comprised 45 strains ...199910553293
carnobacterium inhibens sp. nov., isolated from the intestine of atlantic salmon (salmo salar).strain k1t, isolated from the gastrointestinal tract of atlantic salmon (salmo salar), has the capacity to inhibit the growth of the fish pathogens vibrio anguillarum and aeromonas salmonicida. strain k1t is a motile gram-positive psychrophilic rod that lacks both catalase and oxidase, which does not grow on acetate containing media, but grows at ph 9 and in tsb with up to 6% sodium chloride content. strain k1t is facultatively anaerobic and tryptone as a sole source of nutrient promotes growth. ...199910555373
genetic diversity of atypical aeromonas salmonicida studied by pulsed-field gel electrophoresis.pulsed-field gel electrophoresis (pfge) pattern analysis with xbai restriction enzyme was used to study the genetic heterogeneity of 88 atypical aeromonas salmonicida strains which were earlier or during this study characterized phenotypically, by ribotyping (clai/psti) and by plasmid profile analysis. the strains of certain'ribotypes were also analysed by digestion with spei. the strains represented different geographic locations: finland (72 strains), iceland (5 strains), norway (5 strains), s ...199910579451
monoclonal antibodies against asap1, a major exotoxin of the fish pathogen aeromonas salmonicida subsp. achromogenes, and their application in elisa.two monoclonal antibodies (mabs) binding to a toxic extracellular metallo-proteinase of aeromonas salmonicida subsp. achromogenes, asap1, were produced. both reacted with common epitopes of the native enzyme and recognized this 20 kda antigen on western blots. one of these mabs had an inhibitory effect on the caseinase activity of the exotoxin. a mab-based elisa was set up and evaluated for serological detection of asap1 in bacterial culture filtrates. the exotoxin was identified serologically i ...199910583691
isolation of bacteria other than helicobacter pylori from stomachs of squirrel monkeys (saimiri spp.) with gastritis.gastric biopsy specimens obtained from 12 squirrel monkeys (saimiri spp.) were investigated by culture for the presence of bacteria. the stomachs of two monkeys with gastritis were colonized with gram-negative, urease-positive bacteria, identified as ochrobactrum anthropi by the vitek and api nft methods (biomérieux). a third monkey with gastritis was positive for aeromonas salmonicida and pseudomonas vesicularis (both urease-negative). no helicobacter pylori was isolated from squirrel monkeys. ...200010711437
genetic diversity of the fish pathogen aeromonas salmonicida demonstrated by random amplified polymorphic dna and pulsed-field gel electrophoresis analyses.the current taxonomy of aeromonas salmonicida includes 4 subspecies. a. salmonicida subsp. salmonicida is associated with salmonid furunculosis, and a. salmonicida subsp. achromogenes, a. salmonicida subsp. masoucida, and a. salmonicida subsp. smithia are strains that show variation in some biochemical properties. this classification does not readily encompass isolates from a wide range of fish hosts currently described as atypical a. salmonicida. this study examined 17 typical strains, 39 atypi ...200010715816
a major secreted elastase is essential for pathogenicity of aeromonas hydrophila.aeromonas hydrophila is an opportunistic pathogen and the leading cause of fatal hemorrhagic septicemia in rainbow trout. a gene encoding an elastolytic activity, ahyb, was cloned from aeromonas hydrophila ag2 into puc18 and expressed in escherichia coli and in the nonproteolytic species aeromonas salmonicida subsp. masoucida. nucleotide sequence analysis of the ahyb gene revealed an open reading frame of 1,764 nucleotides with coding capacity for a 588-amino-acid protein with a molecular weight ...200010816468
aeromonas salmonicida subsp. pectinolytica subsp. nov., a new pectinase-positive subspecies isolated from a heavily polluted river.aeromonas strains which phenotypically and genetically belong to the aeromonas salmonicida species but that according to their phenotypic properties constitute a new subspecies have been isolated from the water of a heavily polluted river, the matanza river, situated near the central district of buenos aires city. these strains were ascribed to the a. salmonicida species by using 65 biochemical tests and by dna-dna hybridization. they produce acid from -sorbitol, an unusual biochemical property ...200010843053
host cell invasion and intracellular residence by aeromonas salmonicida: role of the s-layer.virulent strains of the fish pathogen aeromonas salmonicida, which have surface s-layers (s+), efficiently adhere to, enter, and survive within macrophages. here we report that s+ bacteria were 10- to 20-fold more adherent to non-phagocytic fish cell lines than s-layer-negative (s-) mutants. when reconstituted with exogenous s-layers, these s- mutants regained adherence. as well, latex beads coated with purified s-layers were more adherent to fish cell lines than uncoated beads, or beads coated ...200010932360
co-culture of aeromonas salmonicida and host cells in intraperitoneal implants is associated with enhanced bacterial survival.an experimental procedure that we named "in vivo co-culture technology" allowed us to study the interactions between aeromonas salmonicida and host cells, inside semipermeable chambers implanted in the peritoneal cavity of atlantic salmon. intraperitoneal implants containing bacteria and host cells, or bacteria and lysed cells, consistently yielded higher numbers of viable bacteria than implants containing bacteria only. electron microscopy confirmed that 30 min after chamber inoculation, numero ...200010932362
identification of bacteria in water for pharmaceutical use.different systems for the obtention of water used in biopharmaceutical industry were characterized from the bacteriological point of view. determination of aerobic mesophilic microorganisms was performed; as well as the isolation of contaminant microorganisms for what the techniques of membrane filtration was used. for the identification of the more representative species there were made conventional biochemical tests and quick systems: api. the results show that water serving as tap water for p ...199810932743
bath exposure of atlantic halibut (hippoglossus hippoglossus l.) yolk sac larvae to bacterial lipopolysaccharide (lps): absorption and distribution of the lps and effect on fish survival.radiolabelled bacterial lipopolysaccharide (3h-lps) obtained from aeromonas salmonicida subsp. salmonicida was added to the petri dishes containing yolk sac larvae of atlantic halibut (hippoglossus hippoglossus l.). the larvae were exposed either to 6.25, 12.5, 25, 50 or 100 micrograms 3h-lps ml-1. the uptake was both dependent on the lps concentration and the time of exposure. after 5 days of exposure, each larva contained 1.8-7.4 ng 3h-lps dependent on the initial concentration. after 10 days ...200010938728
suppression of the humoral immune response of atlantic salmon, salmo salar l. by the 64 kda serine protease of aeromonas salmonicida.bacteria-free supernatants of broth cultures of aeromonas salmonicida inhibited the humoral immune response, but not the cell-mediated immune response, of atlantic salmon to bacteriophage ms2. the immunosuppressive factor was the 64 kda serine protease secreted by a. salmonicida. the suppressive activity was not due to degradation of epitopes of ms2, and although serine protease degraded the heavy chain of salmon igm in vitro there was no evidence for significant degradation in vivo. the princip ...200010938745
grouping by plasmid profiles of atypical aeromonas salmonicida isolated from fish, with special reference to salmonid fish.plasmid profile analyses were performed for 113 strains of atypical aeromonas salmonicida and the reference strain a. salmonicida subsp. salmonicida atcc 14174. the atypical a. salmonicida strains comprised 98 strains obtained from fish originating from 54 farms and 2 lakes in norway, 10 strains from canada (2), denmark (2), finland (1), iceland (1) and sweden (4), the reference strains ncmb 1109 and atcc 15711 (haemophilus piscium) of a. salmonicida subsp. achromogenes, and the type cultures a. ...200010950178
lactic acid bacteria associated with the digestive tract of atlantic salmon (salmo salar l.).the present study reports the effect of excessive handling stress and starvation on the lactic acid bacteria associated with the digestive tract of atlantic salmon (salmo salar l.). a relatively low population level (approximately 2 x 103 bacteria per gram wet tissue) of viable adherent heterotrophic bacteria was associated with the digestive tract (foregut, midgut and hindgut). of the 752 bacterial isolates isolated from diet, water and the digestive tract, 201 isolates belonged to the carnobac ...200010971765
pulsed-field gel electrophoriesis analyis of aeromonas salmonicida ssp. salmonicida.a total of 133 strains of aeromonas salmonicida ssp. salmonicida, isolated from a wide variety of sources, were characterized by pulsed-field gel electrophoresis patterns. sixteen profiles were demonstrated, with one profile being predominant in samples from all the countries and species of fish. our results suggest a clonal distribution of this subspecies, with a predominant clone being responsible for most of the outbreaks worldwide.200010981708
atypical chryseobacterium meningosepticum and meningitis and sepsis in newborns and the immunocompromised, taiwan.from 1996 to 1999, 17 culture-documented systemic infections due to novel, atypical strains of chryseobacterium meningosepticum occurred in two newborns and 15 immunocompromised patients in a medical center in taiwan. all clinical isolates, which were initially misidentified as aeromonas salmonicida by an automated bacterial identification system, were resistant to a number of antimicrobial agents. the isolates were characterized as atypical strains of c. meningosepticum by complete biochemical ...200010998378
the a-layer influences the susceptibility of aeromonas salmonicida to antibacterial peptides. 200011081441
functional tn5393-like transposon in the r plasmid pras2 from the fish pathogen aeromonas salmonicida subspecies salmonicida isolated in norway.tn5393c containing stra-strb was identified as part of r plasmid pras2 from the fish pathogen aeromonas salmonicida subsp. salmonicida. this is the first time an intact and active transposon in the tn5393 family has been reported in an ecological niche other than an agricultural habitat.200011097945
vaccination influences growth of arctic charr.there is limited knowledge about the effects of oil-based vaccines on the growth of arctic charr salvelinus alpinus, in particular at different rearing temperatures. one-year-old arctic charr were immunized intraperitoneally at 2.9 degrees c with a metabolizable oil-adjuvanted, bivalent vaccine containing killed typical and atypical aeromonas salmonicida bacteria. after vaccination the non-vaccinated (controls) and vaccinated individually marked fish were held for 20 d at 10.0 degrees c and then ...200011129384
toxicity of nitric oxide and peroxynitrite to bacterial pathogens of fish.the inhibitory effect of the nitric oxide (no) donor s-nitroso-acetyl-penicillamine (snap) and the no and o2- donor 3-morpholino-sydnonimine hydrochloride (sin-1) was tested in a cell-free assay. strains of the bacterial fish pathogens aeromonas salmonicida, renibacterium salmoninarum and yersinia ruckeri were exposed to different concentrations of the no donors for 24 h. the results showed that no possesses inhibitory properties, while peroxynitrite had no effect. however, when sin-1 was used i ...200011145451
hatchery-level predictive values for infectious pancreatic necrosis virus and aeromonas salmonicida in ontario, canada.the probability and uncertainty of correctly classifying the ipnv and aeromonas salmonicida status of fish-rearing and natural sites in ontario were estimated through monte carlo simulations. propagating several uncertain inputs showed the extent to which natural variability and our present lack of knowledge affect the probability of site misclassification. for the scenarios investigated, the site-level negative predictive values (snpvs) were high and fairly constant. the site-level positive pre ...200111154785
extended method for discrimination of aeromonas spp. by 16s rdna rflp analysis.a previously described molecular method, based on 16s rdna rflp analysis, for the identification of aeromonas spp. was unable to separate the species aeromonas salmonicida, aeromonas bestiarum and the recently described aeromonas popoffii. in this study, the method has been extended with endonucleases aiwni and psti for the identification of these species. a molecular frame for the identification of all known aeromonas spp. is presented.200011155981
[development of an elisa-system for the assessment of furunculosis vaccines]as an alternative method for challenge experiments in fish a sandwich-elisa has been established for the detection of potentially protective antibody populations. assay specificity depends on monoclonal antibodies (mabs) directed against different antigens of aeromonas salmonicida, the causative agent of furunculosis. comparable levels of salmon antibodies against lps and the a-layer protein were recorded by elisa and antigen binding assay. these studies, together with the first analysis of trou ...199811178550
identification and characterization of carnobacteria associated with the gills of atlantic salmon (salmo salar l.).using the surface plate technique, the population level of aerobic bacteria, occurring in the gills of atlantic salmon (salmo salar l.), was determined to be approximately 3 x 10(4) g(-1). of 100 isolates investigated, 58 were gram-negative. out of the 42 gram-positive isolates, 26 belonged to the carnobacteria, of which ten were further identified on the basis of 16s rdna sequence analysis and aflp fingerprinting. all were identified as carnobacterium piscicola-like. these carnobacteria strains ...200011249022
association between major histocompatibility complex class iib alleles and resistance to aeromonas salmonicida in atlantic salmon.we have tested the importance of genetic variation in the major histocompatibility complex (mhc) class iib in atlantic salmon (salmo salar) for survival after challenge with a highly virulent bacterial pathogen. forty juvenile full siblings from each of 120 families were infected with the bacterium aeromonas salmonicida, which causes high mortality in salmon due to furunculosis. fishes from high-resistance (hr, < 35% mortality) and low-resistance (l,r, > 80% mortality) families were screened for ...200111296859
synergy of histone-derived peptides of coho salmon with lysozyme and flounder pleurocidin.recent research has identified endogenous cationic antimicrobial peptides as important factors in the innate immunity of many organisms, including fish. it is known that antimicrobial activity, as well as lysozyme activity, can be induced in coho salmon (oncorhynchus kisutch) mucus after exposure of the fish to infectious agents. since lysozyme alone does not have antimicrobial activity against vibrio anguillarum and aeromonas salmonicida, a four-step protein purification protocol was used to is ...200111302792
a monoclonal antibody recognising a surface marker on rainbow trout (oncorhynchus mykiss) monocytes.the characterisation of a monoclonal antibody (mab 45) reacting with phagocytic leucocytes isolated from blood and spleen of rainbow trout (oncorhynchus mykiss, walbaum) is described. the surface marker labelled by this mab is expressed at relative low levels on the membrane of large, nearly nongranulated trout leucocytes, and having the typical morphology of monocytes in flow cytometry (kfoury et al., 1999, fish pathology, 34, 1-6). no reaction of mab 45 with granulocytes, lymphocytes or thromb ...200111308075
host factors associated with the detection of aeromonas salmonicida and yersinia ruckeri in ontario, canada government fish hatcheries.this paper presents an epidemiological investigation of ontario ministry of natural resources fish health laboratory data from 1981 to 1997, to determine whether fish species and age were associated with lot-level detection of aeromonas salmonicida and yersinia ruckeri in hatchery fish. in stepwise logistic regression, the species brook trout and back-cross (lake trout crossed with the hybrid "splake") were more likely to test a. salmonicida-positive compared to all other species reared in the h ...200111311951
characterization of the properties of human- and dairy-derived probiotics for prevention of infectious diseases in fish.the present study aimed to investigate the potential probiotic properties of six lactic acid bacteria (lab) intended for human use, lactobacillus rhamnosus atcc 53103, lactobacillus casei shirota, lactobacillus bulgaricus, l. rhamnosus lc 705, bifidobacterium lactis bb12, and lactobacillus johnsonii la1, and one for animal use, enterococcus faecium tehobak, for use as a fish probiotic. the strains for human use were specifically chosen since they are known to be safe for human use, which is of m ...200111375147
characterization of class 1 integrons associated with r-plasmids in clinical aeromonas salmonicida isolates from various geographical areas.class 1 integrons were found in 26 of 40 antibiotic-resistant isolates of the fish pathogen aeromonas salmonicida from northern europe and north america. three different dhfr genes, conferring trimethoprim resistance, and one ant(3")1a aminoglycoside resistance gene were identified as gene inserts. the gene cassettes tended to be conserved among isolates from a particular geographical area. nineteen isolates transferred r-plasmids carrying different tet determinants to escherichia coli in filter ...200111389105
effects of bacteria on the growth of an amoeba infecting the gills of turbot.we analysed the influence of various bacteria on the in vitro growth of trophozoites of a platyamoeba strain isolated from diseased gill tissues of cultured turbot. little or no growth was shown by amoebae cultured in the presence of (1) the turbot-pathogenic bacteria vibrio anguillarum, aeromonas salmonicida or streptococcus sp., (2) pasteurella piscicida or vibrio vulnificus (pathogenic for some fishes but not turbot), or (3) the non-pathogenic 'environmental' bacteria vibrio campbelli, vibrio ...200111411647
simulating the effect of eliminating routine bacterial screening on the negative predictive value of the ontario fish hatchery disease monitoring program.we determined the impact of eliminating routine screening for aeromonas salmonicida and yersinia ruckeri on the efficacy of the ontario ministry of natural resources (omnr) fish disease monitoring program, using monte carlo simulation. because the main purpose of the program is to prevent transferring infected fish among omnr hatcheries, or to wild fish populations through stocking waterways, the hatchery-level negative predictive value (hnpv) was used as an indicator of monitoring efficacy. the ...200111448498
immunoglobulin genes and antibody responses in the spotted wolffish (anarhichas minor olafsen).the spotted wolffish anarhichas minor olafsen is a promising new species in aquaculture in the cold waters of northern norway. in this paper, some basic immunological studies of this marine species are reported. of comparative interest are the cdna sequences of the immunoglobulin transcript and the antibody responses to model antigens. of more practical importance are the humoral immune responses and antibody specificities to potentially pathogenic bacteria. full length cdna clones encoding the ...200111478516
induction of inflammatory cytokines by extracellular products and lps of the fish pathogen aeromonas salmonicida ssp. achromogenes in mice and mouse cell cultures.balb/c mice, injected i.p. with extracellular products (ecp) of aeromonas salmonicida subsp. achromogenes (asa), displayed symptoms similar to toxic shock syndrome. the ld(50) observed was between 1.5 and 2.0 microg g(-1) and the mice died within 19 h. four inflammatory cytokines were measured in mice receiving sublethal ecp doses. tnf-alpha and il-6 showed a sharp peak in the serum while il-1 beta and il-2 were not detected. when peritoneal macrophages were cultivated in the presence of ecp, as ...200111498248
antibody response in salmonids against the 70 kda serine protease of aeromonas salmonicida studied by a monoclonal antibody-based elisa.an antigen-capture enzyme-linked immunosorbent assay (celisa) based on monoclonal antibodies (mab) was set up and evaluated for selective detection of salmonid antibody responses to the antigen p1, which is a weakly immunogenic exoprotease of typical aeromonas salmonicida. this new assay permits a specific determination of anti-protease-antibodies, without antigen purification. serum antibodies induced by the strongly immunogenic lipopolysaccharide could reliably be discriminated from anti-p1-an ...200111557299
type ii secretion by aeromonas salmonicida: evidence for two periplasmic pools of proaerolysin.aeromonas salmonicida containing the cloned gene for proaerolysin secretes the protein via the type ii secretory pathway. here we show that altering a region near the beginning of aera led to a dramatic increase in the amount of proaerolysin that was produced and that a large amount of the protein was cell associated. all of the cell-associated protein had crossed the cytoplasmic membrane, because the signal sequence had been removed, and all of it was accessible to processing by trypsin during ...200111566995
cloning and biochemical characterization of fox-5, an ampc-type plasmid-encoded beta-lactamase from a new york city klebsiella pneumoniae clinical isolate.klebsiella pneumoniae 5064, isolated in new york, carried plasmid-mediated resistance to multiple beta-lactams and was unresponsive to clavulanic acid. the beta-lactamase gene responsible for cephalosporin resistance encoded fox-5, with 96 to 97% amino acid identities to other members of the fox family of beta-lactamases. the bla(fox-5) coding region was located next to a transposase gene from the aeromonas salmonicida insertion element isas2.200111600376
class 1 integrons mediate antibiotic resistance in the fish pathogen aeromonas salmonicida worldwide.the presence of class 1 integrons was investigated in 38 sulfonamide-resistant strains of aeromonas salmonicida subsp. salmonicida, atypical a. salmonicida and escherichia coli conjugants with r plasmids originating from a. salmonicida. the strains originated from finland, france, japan, norway, scotland, switzerland, and the united states. additional resistance determinants in strains with class 1 integrons were also determined. of 21 strains containing a class 1 integron, 19 had a single gene ...200111759088
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