| phenotypic and genomic studies of "cytophaga psychrophila" isolated from diseased rainbow trout (oncorhynchus mykiss) in france. | five strains of gliding bacteria were isolated in france from farmed diseased rainbow trouts reared at low water temperature. the resemblance of these bacteria to the known fish pathogen "cytophaga psychrophila" led to their comparative study with reference strain ncmb 1947 and with an american isolate. morphological, physiological, and biochemical characteristics of the seven strains proved to be similar. comparison of their dna by the s1 nuclease dna-dna hybridization method showed that the se ... | 1989 | 2764577 |
| characteristics of cytophaga psychrophila (borg) isolated during outbreaks of bacterial cold-water disease. | characteristics of 10 strains of cytophaga psychrophila isolated during a number of epizootics of bacterial cold-water disease were compared. morphological, cultural, biochemical, and serological data showed that the organisms were very closely related. the isolates exhibited gliding motility, formed neither fruiting bodies nor microcysts, were actively proteolytic, and grew only at low temperatures. data presented extend the description of c. psychrophila. | 1968 | 4169926 |
| development of techniques for the genetic manipulation of the gliding bacterium cytophaga johnsonae. | cytophaga johnsonae displays many features that make it an excellent model of bacterial gliding motility. unfortunately, genetic analyses of c. johnsonae, or any related gliding bacteria, were not possible because of a complete lack of selectable markers, cloning vectors, transposons, and convenient methods of gene transfer. as a first step toward a molecular analysis of gliding motility of c. johnsonae, we developed these genetic techniques and tools. common broad-host-range plasmids and transp ... | 1996 | 8550486 |
| association of cytophaga psychrophila with mortality among eyed eggs of atlantic salmon (salmo salar). | although pseudomonas fluorescens was the predominant bacterium associated with atlantic salmon (salmo salar) eggs incubated at the white river national fish hatchery (bethel, vermont) during january 1992, the fish pathogen cytophaga psychrophila was isolated only from specific lots of eggs that displayed poor survival (35% eye-up). | 1995 | 8583633 |
| immunization with bacterial antigens: flavobacterium and flexibacter infections. | seven bacterial species belonging to the flavobacterium-cytophaga group are currently considered to be pathogenic for fish. because they were only recently described and/or because the disease they provoke has little economic significance, no study has been performed concerning immunization against chryseobacterium scophthalmum, flavobacterium johnsoniae and flexibacter ovolyticus. immunization with flexibacter maritimus has not been investigated, and fish surviving a natural infection appear to ... | 1997 | 9270847 |
| 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 ... | 1997 | 9270868 |
| development of a polymerase chain reaction assay for identification and detection of the fish pathogen flavobacterium psychrophilum. | a pcr-based method was developed to identify and detect flavobacterium psychrophilum, the causative agent of "cold-water disease" and "rainbow trout fry syndrome" in salmonid fish. two oligonucleotide primers were designed by comparing the 16s rrna sequence of all taxa in the genus flavobacterium and of representative species in most related genera within rrna superfamily v. purified chromosomal dnas from all these bacterial species, from 25 f. psychrophilum isolates and from several other fish- ... | 1998 | 9766203 |
| fingerprinting of flavobacterium psychrophilum isolates by ribotyping and plasmid profiling. | flavobacterium psychrophilum is the agent of cold-water disease and rainbow trout fry syndrome in salmonid fish worldwide. ribosomal rna gene restriction patterns (ribotypes) and plasmid profiles were determined on a collection of 85 strains isolated from different countries and fish species. several ribotypes were obtained by using the restriction endonucleases hinc ii and pvu ii. computer analysis of the ribotypes revealed that some of them were clearly associated with the fish species from wh ... | 1998 | 9841121 |
| histopathological and electron microscopical observations on rainbow trout fry syndrome. | rainbow trout (oncorhynchus mykiss) fry and fingerlings with clinical signs of rainbow trout fry syndrome, and rainbow trout (0.5 to 3.5 g) with experimentally induced infections with flavobacterium psychrophilum, were examined histopathologically and electron microscopically. severe hypertrophy of the spleen and cellular degeneration were consistently observed. distinctive features of the disease were the loss of definition of the splenic border and its replacement by a loosely structured eosin ... | 1999 | 10209816 |
| an improved growth medium for flavobacterium psychrophilum. | supplementing cytophaga agar and broth with 0.5 g l-1 each of d(+) galactose, d(+) glucose, l-rhamnose and skimmed milk gave a dramatic improvement in the isolation of the fish pathogen flavobacterium psychrophilum. by means of spread-plating, approximately double the number of colonies of larger size were obtained on the improved medium compared to cytophaga agar alone. in supplemented cytophaga broth, growth of fl. psychrophilum was more rapid and generated greater biomass. | 1999 | 10212443 |
| reproducible methods for experimental infection with flavobacterium psychrophilum in rainbow trout oncorhynchus mykiss. | experiments were done in order to achieve a reproducible method that can be used to infect rainbow trout oncorhynchus mykiss with flavobacterium psychrophilum, the causal agent of coldwater disease and rainbow trout fry syndrome. the main method investigated was intraperitoneal injection, and this method was tested using isolates with different elastin-degrading profiles and representing different serotypes. injecting trout, average weight 1 g, with 10(4) cfu (colony-forming units) per fish caus ... | 1999 | 10401582 |
| production of viable cultures of flavobacterium psychrophilum: approach and control. | although the fish pathogen flavobacterium psychrophilum is a major source of concern in salmonid hatcheries, few studies have been conducted on its pathogenicity. difficulties are often experienced when trying to control or quantify standard procedures for in vitro culture of the bacterium. plate enumeration and counting chamber enumeration combined with epifluorescent microscopy with fluorescent dyes determined that no more than 25% of the bacterial cells present in the cultures were able to pr ... | 1999 | 10422696 |
| flavobacterium psychrophilum in baltic salmon salmo salar brood fish and their offspring. | baltic salmon brood fish were investigated for the presence of flavobacterium psychrophilum in the kidney, spleen, brain and sexual products (ovarian fluid, unfertilised eggs and milt). samples for bacteriology were taken at capture, when the fish were ascending their native river to spawn, and after a period of captivity in indoor pools, at stripping. during captivity, abnormal wiggling behaviour was recorded in some of the fish. bacterial samples were taken to determine if f. psychrophilum had ... | 1999 | 10546045 |
| detection of flavobacterium psychrophilum from fish tissue and water samples by pcr amplification. | rainbow trout fry syndrome and cold-water disease, caused by flavobacterium psychrophilum, are important diseases in farmed salmonids. some of the presently available techniques for the detection of fl. psychrophilum are either time consuming or lack sufficient sensitivity. in the present investigation, the possible detection of fl. psychrophilum from fish tissue and water samples was examined using nested pcr with dna probes against a sequence of the 16s rrna genes. the dna was extracted using ... | 2000 | 10735999 |
| effect of flavobacterium psychrophilum strains and their metabolites on the oxidative activity of rainbow trout oncorhynchus mykiss phagocytes. | the oxidative activity of rainbow trout phagocytes was studied using a chemiluminescence technique using 12 different flavobacterium psychrophilum strains and their metabolites. phagocytes were obtained from the head kidney of rainbow trout oncorhynchus mykiss. the addition of viable f. psychrophilum or their metabolites to the phagocytes resulted in an immediate chemiluminescence response. the stimulating effects of both the f. psychrophilum and their metabolites on the phagocytes were found to ... | 2000 | 10950179 |
| ultraviolet irradiation inactivates the waterborne infective stages of myxobolus cerebralis: a treatment for hatchery water supplies. | the effects of ultraviolet (uv) irradiation on the viability of the waterborne triactinomyxon stages of myxobolus cerebralis were evaluated by vital staining and the infectivity for juvenile rainbow trout oncorhynchus mykiss. a dose of 1300 mws cm-2 was required to inactivate 100% of the triactinomyxons held under a static collimated beam of uv as determined by vital staining. juvenile rainbow trout were protected from infections with m. cerebralis when exposed to 14,000 or 1400 triactinomyxon s ... | 2000 | 10986645 |
| difficulties in experimental infection studies with flavobacterium psychrophilum in rainbow trout (oncorhynchus mykiss) using immersion, oral and anal challenges. | this study was carried out in order to try to establish an efficacious and reliable experimental infection model for flavobacterium psychrophilum, the causative agent of rainbow trout fry syndrome, using contact, oral and anal challenges. ten f psychrophilum strains of different origin were included. the influence of water temperature, scarification, water quality, stress and growth conditions of the pathogen on the experimental infection was assessed. for each challenge protocol, all strains fa ... | 2000 | 11020369 |
| occurrence of antimicrobial resistance in fish-pathogenic and environmental bacteria associated with four danish rainbow trout farms. | surveillance of bacterial susceptibility to five antimicrobial agents was performed during a 1-year period in and around four freshwater fish farms situated along a stream in western denmark. besides assessing the levels of antibiotic resistance among the culturable fraction of microorganisms in fish, water, and sediment samples, two major fish pathogens (88 flavobacterium psychrophilum isolates and 134 yersinia ruckeri isolates) and 313 motile aeromonas isolates, representing a group of ubiquit ... | 2000 | 11055942 |
| standardization of experimental infection with flavobacterium psychrophilum, the agent of rainbow trout oncorhynchus mykiss fry syndrome. | rainbow trout fry syndrome (rtfs) is a septicaemic infection of young rainbow trout oncorhynchus mykiss occurring at low temperatures and responsible for severe economic losses in european fish farming. the causative agent, flavobacterium psychrophilum, is a gliding bacterium, and difficulties in culturing it have long been an impediment to investigations on pathogenesis and immunity. successful attempts at experimentally inducing the disease have been reported, but no experimental model resulti ... | 2000 | 11104070 |
| flavobacterium psychrophilum, invasion into and shedding by rainbow trout oncorhynchus mykiss. | the infection route of flavobacterium psychrophilum into rainbow trout oncorhynchus mykiss was studied using bath and cohabitation challenges as well as oral challenge with live feed as a vector. additionally, the number of bacterial cells shed by infected fish into the surrounding water was determined in the cohabitation experiment and in challenge experiments at 3 different water temperatures. the experiments showed that skin and skin mucus abrasion dramatically enhanced the invasion of f. psy ... | 2000 | 11129378 |
| antigenic characterization of the fish pathogen flavobacterium psychrophilum. | flavobacteria are a poorly understood and speciated group of commensal bacteria and opportunistic pathogens. the psychrotroph flavobacterium psychrophilum is the etiological agent of rainbow trout fry syndrome and bacterial cold water disease, septicemic diseases that heavily impact salmonids. consequently, two verified but geographically diverse isolates were characterized phenotypically and biochemically. a facile typing system was devised which readily discriminated between closely related sp ... | 2001 | 11157240 |
| the structure of the lipopolysaccharide o-antigen produced by flavobacterium psychrophilum (259-93). | flavobacterium psychrophilum, a gram-negative bacterium, is the etiological agent of rainbow trout fry syndrome and bacterial cold water disease, septicemic infections in reared salmonids. in humans flavobacterium spp. have been associated with neonatal meningitis and septicemia, catheter-associated bacteremia, and pneumonia. recently, several f. psychrophilum surface molecules, including lipopolysaccharide (lps), have been implicated in its pathogenesis and identified as potential vaccine and d ... | 2001 | 11322892 |
| rapid and low-level toxic pcr-based method for routine identification of flavobacterium psychrophilum. | we describe a rapid, low-toxicity and simple method for the detection of the bacterial fish pathogen flavobacterium psychrophilum. the method, based on the polymerase chain reaction (pcr), combined the electrophoresis of pcr products in a vertical agarose gel and a modified methylene blue stain. dna was amplified directly either from bacterial suspensions or from tissues experimentally infected with f. psychrophilum, using different non-toxic commercial dna extraction kits. the protocol allowed ... | 2000 | 11334307 |
| 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 ... | 2001 | 11375147 |
| purification and characterization of a psychrophilic, calcium-induced, growth-phase-dependent metalloprotease from the fish pathogen flavobacterium psychrophilum. | flavobacterium psychrophilum is a fish pathogen that commonly affects salmonids. this bacterium produced an extracellular protease with an estimated molecular mass of 55 kda. this enzyme, designated fpp1 (f. psychrophilum protease 1), was purified to electrophoretic homogeneity from the culture supernatant by using ammonium sulfate precipitation, ion-exchange chromatography, hydrophobic chromatography, and size exclusion chromatography. on the basis of its biochemical characteristics, fpp1 can b ... | 2001 | 11375148 |
| adhesion of the fish pathogen flavobacterium psychrophilum to unfertilized eggs of rainbow trout (oncorhynchus mykiss) and n-hexadecane. | the ability of flavobacterium psychrophilum, the causative agent of rainbow trout fry syndrome (rtfs) in fish, to attach to unfertilized rainbow trout (oncorhynchus mykiss) eggs and to hydrocarbon n-hexadecane was examined in the present study. | 2001 | 11555199 |
| changes in the cell structure of flavobacterium psychrophilum with length of culture. | flavobacterium psychrophilum, the pathogen of bacterial cold-water disease, causes serious problems in ayu plecoglossus altivelis culture. this study investigated the effect of the culture period of f. psychrophilum and on the structure of its cells. from the sds-page of total proteins of cellular components, much difference was found between the 36 hr culture and the 48 and 72 hr cultures. a sem observation of the cells showed many fragments, especially on the cell surface of the 36 hr culture. ... | 2001 | 11838898 |
| development and application of a nested pcr to monitor brood stock salmonid ovarian fluid and spleen for detection of the fish pathogen flavobacterium psychrophilum. | to develop a nested pcr to detect flavobacterium psychrophilum based on the intergenic spacer region 16s-23s rrna and in 16s rrna for analysis of brood stock salmonid fish samples. | 2002 | 11872127 |
| adherence of flavobacterium psychrophilum on the body surface of the ayu plecoglossus altivelis. | bacterial cold water disease in the ayu plecoglossus altivelis caused by flavobacterium psychrophilum is a serious problem in the japanese freshwater culture industry. the distribution and activity of this bacterium on the body surface of the ayu in the infection process was investigated. the survival of f. psychrophilum in tap water showed that this bacterium might sustain its infectivity for 24 h. in an experimental infection, juvenile ayu were immersed in water containing 10(8.9) cfu/ml f. ps ... | 2002 | 11909737 |
| survival of flavobacterium psychrophilum in rainbow trout (oncorhynchus mykiss) serum in vitro. | virulent and non-virulent strains of flavobacterium psychrophilum of different serotypes were examined for survival and growth in non-immune and immune rainbow trout serum, in vitro. a majority of the examined strains consumed complement of non-immune serum, but the complement cascade was not able to cause an immediate (after 3 h incubation) notable reduction in viability of the inoculated cells. after 24 h incubation a more pronounced reduction in the number of viable bacteria was observed in u ... | 2002 | 11911675 |
| the outer membrane fraction of flavobacterium psychrophilum induces protective immunity in rainbow trout and ayu. | flavobacterium psychrophilum is the causative agent of coldwater disease, which is responsible for serious losses in fish aquaculture in several parts of the world. no commercial vaccines are currently available for the prevention of coldwater disease. the present study sought to assess the efficacy of a f. psychrophilum vaccine based on the antigenic outer membrane fraction (omf). this fraction induced significantly higher protection against coldwater disease in both rainbow trout (oncorhynchus ... | 2002 | 11911677 |
| detection and identification of bacterial pathogens of fish in kidney tissue using terminal restriction fragment length polymorphism (t-rflp) analysis of 16s rrna genes. | we report the application of a nucleic acid-based assay that enables direct detection and identification of bacterial pathogens in fish kidney tissue without the need for bacterial culture. the technique, known as terminal restriction fragment length polymorphism (t-rflp), employs the polymerase chain reaction (pcr) using a primer pair that targets 2 highly conserved regions of the gene that encodes for the 16s small subunit of the bacterial ribosome. each primer is 5' labeled with a different f ... | 2002 | 12033704 |
| usefulness of a taqman-based polymerase chain reaction assay for the detection of the fish pathogen flavobacterium psychrophilum. | this study developed a new diagnostic method for the bacterium flavobacterium psychrophilum based on a taqman polymerase chain reaction (pcr) assay. | 2002 | 12067384 |
| a proposed serotyping system for flavobacterium psychrophilum. | to develop a common serological system for rapid and routine identification of the fish pathogen flavobacterium psychrophilum. | 2002 | 12100595 |
| simultaneous detection of aeromonas salmonicida, flavobacterium psychrophilum, and yersinia ruckeri, three major fish pathogens, by multiplex pcr. | a multiplex pcr assay based on the 16s rrna genes was developed for the simultaneous detection of three major fish pathogens, aeromonas salmonicida, flavobacterium psychrophilum, and yersinia ruckeri. the assay proved to be specific and as sensitive as each single pcr assay, with detection limits in the range of 6, 0.6, and 27 cfu for a. salmonicida, f. psychrophilum, and y. ruckeri, respectively. the assay was useful for the detection of the bacteria in artificially infected fish as well as in ... | 2002 | 12324372 |
| detection of the fish pathogen flavobacterium psychrophilum in water from fish farms. | rainbow trout fry syndrome and cold-water disease are serious diseases in farmed salmonid fish. in the present study, three methods were compared, for the detection of the causative pathogen, flavobacterium psychrophilum in water. the methods included traditional agar plate cultivation on tryptone yeast extract salts (tyes) agar, immunofluorescence antibody technique (ifat) and nested pcr. the three methods were subsequently used for the detection of f. psychrophilum from fish farm environments. ... | 2002 | 12353881 |
| occurrence of flavobacterium psychrophilum in fish-farming environments. | occurrence of flavobacterium psychrophilum in fish farms and fish-farming environments was studied using agar plate cultivation, the immunoflourescence antibody technique (ifat) and nested pcr. characteristics of 64 f. psychrophilum isolates from rainbow trout oncorhynchus mykiss, fish farm rearing water, ovarian fluid and wild fish were serotyped, ribotyped and compared biochemically. virulence of f. psychrophilum isolates from different sources was compared by injection into rainbow trout. add ... | 2002 | 12542087 |
| virulence stability in flavobacterium psychrophilum after storage and preservation according to different procedures. | experimental infections and lethal dose 50% (ld 50) evaluation were conducted in rainbow trout fingerlings, using a virulent strain of flavobacterium psychrophilum processed and stored or maintained in different ways; lyophilisation, freezing at -80 degrees c, maintenance in enriched anacker and ordal (eao) medium at 4 degrees c, revival and subsequent in vivo passages in fish. experiments were performed 1, 8 and 23 months after storing the bacteria. out of a total of 12 cultures revived for exp ... | 2003 | 12588689 |
| purification and characterization of a membrane glycoprotein from the fish pathogen flavobacterium psychrophilum. | the cell envelope of the fish pathogen flavobacterium psychrophilum contains more than 50 polypeptides resolved by sodium dodecyl sulphate-polyacrylaminde gel electrophoresis analysis including a major component named p60. here, we have developed a simple and efficient procedure for the purification of p60 and therefore permitting its biochemical characterization. | 2003 | 12752822 |
| nanoinjection as a tool to mimic vertical transmission of flavobacterium psychrophilum in rainbow trout oncorhynchus mykiss. | newly fertilised eggs of rainbow trout oncorhynchus mykiss were nanoinjected with flavobacterium psychrophilum in order to mimic vertical transmission. two bacterial isolates with different elastin-degrading capacity were used. all infected groups (10, 100 and 1000 colony forming units egg(-1)) showed significantly higher cumulative mortalities than the control groups at the end of the experiment, 70 d post-hatching. the total mortalities in the control groups were below 2.5%. in the high-dose g ... | 2003 | 12911056 |
| adhesion of high and low virulence flavobacterium psychrophilum strains to isolated gill arches of rainbow trout oncorhynchus mykiss. | the ability of flavobacterium psychrophilum to adhere to the gill tissue of rainbow trout oncorhynchus mykiss was evaluated. a gill perfusion model was adopted, offering a number of advantages compared to other in vitro as well as in vivo models. a comparison between the adhesion capacity of a high and low virulence f. psychrophilum strain was made. experiments were additionally carried out to assess the influence of water quality (organic material, nitrite) and temperature on the adhesion proce ... | 2003 | 12911057 |
| passive immunization of rainbow trout, oncorhynchus mykiss (walbaum), against flavobacterium psychrophilum, the causative agent of bacterial coldwater disease and rainbow trout fry syndrome. | flavobacterium psychrophilum, the causative agent of bacterial coldwater disease (cwd) and rainbow trout fry syndrome (rtfs), causes high mortality in cultured salmonids. the present study was designed to determine the role antibody plays in conferring protection to rainbow trout fry, oncorhynchus mykiss (walbaum), by passive immunization with convalescent serum or serum from adult rainbow trout immunized with f. psychrophilum, and goat anti-f. psychrophilum serum. in each experiment, rainbow tr ... | 2003 | 12946006 |
| involvement of a sialic acid-binding lectin with hemagglutination and hydrophobicity of flavobacterium psychrophilum. | strains of flavobacterium psychrophilum were studied for their ability to adhere and cause agglutination of erythrocytes and yeast cells. strains of the serotype th showed low or no hemagglutinating (ha) properties toward human, avian, bovine, and rainbow trout erythrocytes, whereas strains of serotype fd and fp(t) exhibited distinct ha properties. none of the strains was able to cause agglutination of yeast cells. greater adherence specificity toward rainbow trout blood cells was seen for the h ... | 2003 | 12957914 |
| efficacy of oral vaccine against bacterial coldwater disease in ayu plecoglossus altivelis. | the development of a practical vaccination method against bacterial coldwater disease (bcwd) in ayu plecoglossus altivelis and the efficacy of oral administration of formalin-killed cells (fkcs) of flavobacterium psychrophilum was investigated. the fkc was administrated at a dose of 0.1-0.2 g kg(-1) body weight to juvenile ayu (0.5 g body weight) every day for 2 wk or on 5 days over 2 wk. experimental immersion challenge at 3 and 7 wk after vaccination showed significantly higher survival rates ... | 2003 | 13677514 |
| association of flavobacterium psychrophilum with rainbow trout (oncorhynchus mykiss) kidney phagocytes in vitro. | the capacity of virulent and non-virulent strains of flavobacterium psychrophilum of different serotypes to associate with isolated rainbow trout (oncorhynchus mykiss, 300-500 g) kidney phagocytes was evaluated in vitro. the results showed that f. psychrophilum was associated with the phagocytes but large differences in association were observed between the different bacterial strains examined. these differences in association with the phagocytes was not clearly related to the serotype or virule ... | 2003 | 14550665 |
| purification and properties of a new psychrophilic metalloprotease (fpp2) in the fish pathogen flavobacterium psychrophilum. | to go further into the characterization of the proteolysis exocellular system of the salmonid pathogen flavobacterium psychrophilum, the purification and characterization of a novel protease designated fpp2 (f. psychrophilum protease 2) was undertaken. a protease (fpp2) hydrolyzing azocasein was purified. the fpp2 can be defined as a metalloprotease, it had an estimated molecular mass of 62 kda with calcium playing an important role in the thermostability of the enzyme. proteolytic activity was ... | 2003 | 14553922 |
| pathology and immunohistochemistry in three species of salmonids after experimental infection with flavobacterium psychrophilum. | rainbow trout, oncorhynchus mykiss (walbaum), sea trout, salmo trutta l., and atlantic salmon, salmo salar l., were experimentally infected with flavobacterium psychrophilum in order to evaluate any species differences in susceptibility to the bacterium. furthermore, differences in pathological changes and distribution of the bacteria in internal organs were studied. the bacteria were injected intraperitoneally in two doses, high dose (hd) 1 x 10(7) colony forming units (cfu) fish(-1) and low do ... | 2003 | 14575371 |
| concomitant exposure of rainbow trout fry to gyrodactylus derjavini and flavobacterium psychrophilum: effects on infection and mortality of host. | although rainbow trout fry mortality syndrome caused by the bacterium flavobacterium psychrophilum is widespread in fish farms it is difficult to reproduce infection of rainbow trout in the laboratory using immersion exposure with bacterial suspensions. it has therefore been speculated that ectoparasites could act as enhancers of bacterial infections under natural conditions. in the present study rainbow trout fry were exposed to infections with f. psychrophilum (immersion for 30 min or 10 h) al ... | 2003 | 14597284 |
| starvation of flavobacterium psychrophilum in broth, stream water and distilled water. | physical changes in flavobacterium psychrophilum, the causative agent of rainbow trout fry syndrome (rtfs), were examined over a 19 wk period of starvation. bacteria were maintained in either cytophaga broth, filtered stream water, or filtered distilled water, or were maintained in broth after disinfection as a negative control for dead bacteria. culturability and viability of the bacterium were assessed using colony-forming units (cfus) and a commercially available live/dead kit. antigenic prof ... | 2003 | 14598987 |
| chloramphenicol and florfenicol susceptibility of fish-pathogenic bacteria isolated in france: comparison of minimum inhibitory concentration, using recommended provisory standards for fish bacteria. | to investigate the distribution of antimicrobial resistance to phenicols in the fish pathogenic bacteria aeromonas salmonicida, motile aeromonas, yersinia ruckeri, lactic bacteria and the nutritionally fastidious flavobacterium psychrophilum. the last species was screened on two media (diluted mueller-hinton and peptone-enriched anacker and ordal), both supplemented with horse serum. | 2003 | 14633029 |
| flavobacterium psychrophilum infections in salmonid fish. | flavobacterium psychrophilum is the causative agent of bacterial cold water disease and rainbow trout fry syndrome, disease entities responsible for substantial economic losses in salmonid aquaculture. problems associated with epizootics include high mortality rate, increased susceptibility to other diseases, high labour costs of treatment and the enormous expenditure on chemotherapy. despite the increasing significance of the disease, the pathogenesis of f. psychrophilum infections has only bee ... | 2003 | 14653314 |
| genotyping of flavobacterium psychrophilum using pcr-rflp analysis. | genetic variability among 242 strains of flavobacterium psychrophilum was characterized using polymerase chain reaction (pcr) followed by restriction fragment length polymorphism (rflp) analysis. universal primers gyr-1 and gyr-1r, which were designed to amplify the gyrase subunit b gene (gyrb), yielded a 1178 bp pcr product encoding gyrb and a 290 bp pcr product of anonymous dna from all f. psychrophilum strains tested. in the rflp analysis of the anonymous 290 bp dna marker, the restriction en ... | 2003 | 14667032 |
| a novel serotype of flavobacterium psychrophilum detected using antiserum against an isolate from amago, oncorhynchus masou rhodurus jordan & gilbert, in japan. | | 2003 | 14710760 |
| development of genetic techniques for the psychrotrophic fish pathogen flavobacterium psychrophilum. | flavobacterium psychrophilum, a member of the cytophaga-flavobacterium-bacteroides group, is an important pathogen of salmonid fish. previous attempts to develop genetic techniques for this fastidious, psychrotrophic bacterium have met with failure. here we describe the development of techniques for the genetic manipulation of f. psychrophilum and the identification of plasmids, selectable markers, a reporter system, and a transposon that function in several isolates of this fish pathogen. the a ... | 2004 | 14711690 |
| lipopolysaccharide o-antigen antibody-based detection of the fish pathogen flavobacterium psychrophilum. | several yellow-pigmented species within the family flavobacteriaceae are commonly associated with diseases in fish and are difficult to speciate due to their fastidious, slow-growing nature and cross-reactive antigens. here we report the development of specific, antibody-diagnostic tests for flavobacterium psychrophilum, the aetiological agent of rainbow trout fry syndrome and bacterial cold water disease. a unique antigen from f. psychrophilum, the lipopolysaccharide (lps) o-polysaccharide (o-p ... | 2003 | 15153771 |
| protective immunity in rainbow trout oncorhynchus mykiss following immunization with distinct molecular mass fractions isolated from flavobacterium psychrophilum. | vaccine development for coldwater disease (cwd), also known as rainbow trout fry syndrome (rtfs), has been based primarily on whole-cell bacterins or outer membrane fractions of flavobacterium psychrophilum. in the present study, immunogenic regions of the bacterium corresponding to 18-28, 41-49, and 70-100 kda were identified by western blot analysis using rainbow trout oncorhynchus mykiss immune sera. following sodium dodecyl sulfate-polyacrylamide gel electrophoresis (sds-page), antigens with ... | 2004 | 15212288 |
| experimental infection of flavobacterium psychrophilum in fins of atlantic salmon salmo salar revealed by scanning electron microscopy. | infections caused by flavobacterium psychrophilum include 'bacterial coldwater disease' (bcwd) and 'rainbow trout fry syndrome' (rtfs), which are severe diseases that can cause high mortality and significant losses in hatchery-reared salmonids worldwide. usually, these conditions start with necrosis along the edge of the fins. as the infection progresses, both the fish surface and the internal organs can be involved. the aetiological agent produces a ca-dependent protease that can be responsible ... | 2004 | 15212296 |
| relationship between gyra mutations and quinolone resistance in flavobacterium psychrophilum isolates. | flavobacterium psychrophilum is the causative agent of the fish diseases called bacterial cold-water disease and rainbow trout fry syndrome. it has been reported that some isolates of f. psychrophilum are resistant to quinolones; however, the mechanism of this quinolone resistance has been unexplained. in this study, we examined the quinolone susceptibility patterns of 27 f. psychrophilum strains isolated in japan and the united states. out of 27 isolates, 14 were resistant to both nalidixic aci ... | 2004 | 15240271 |
| identification of p18, a surface protein produced by the fish pathogen flavobacterium psychrophilum. | this study was focused on the identification of associated outer membrane proteins which may play a role in the specific interactions between flavobacterium psychrophilum (the aetiological agent of cold-water disease and rainbow trout fry syndrome in salmonid fish worldwide) and the fish tissues. | 2004 | 15281938 |
| impact of pcb on resistance to flavobacterium psychrophilum after experimental infection of rainbow trout oncorhynchus mykiss eggs by nanoinjection. | the effects of sublethal exposure of a commercial blend of polychlorinated biphenyls (pcb), i.e. clophen a50, on disease resistance to the aetiological agent of rainbow trout fry syndrome, flavobacterium psychrophilum, were investigated. newly fertilised rainbow trout oncorhynchus mykiss eggs were nanoinjected with 2 doses of clophen a50 (0.4 or 2 microg egg(-1)) and/or 100 colony forming units of f. psychrophilum. the mean cumulative mortality in control groups, and groups exposed to the lower ... | 2004 | 15352522 |
| flavobacterium psychrophilum in rainbow trout, oncorhynchus mykiss (walbaum), hatcheries: studies on broodstock, eggs, fry and environment. | the occurrence of flavobacterium psychrophilum at four rainbow trout hatcheries was investigated to provide more knowledge about the reservoirs and transmission of this bacterium. broodstock were sampled at stripping (including both unfertilized and fertilized eggs), and the offspring were then sampled at the eyed egg and fry stages. water and surface samples (e.g. hatchery trays) were also sampled. flavobacterium psychrophilum was found in ovarian fluid and milt, indicating that broodstock may ... | 2005 | 15660792 |
| early interactions of flavobacterium psychrophilum with macrophages of rainbow trout oncorhynchus mykiss. | the early interactions of a low and a highly virulent flavobacterium psychrophilum strain with head kidney and spleen macrophages of rainbow trout oncorhynchus mykiss were characterized. the highly virulent strain was killed 5.8 to 11 times less frequently than the low virulent strain. the head kidney macrophages showed a microbicidal activity approximately twice as high as that of the spleen macrophages. a 2- to 3-fold higher production of reactive oxygen species (ros) was induced by the highly ... | 2005 | 15900684 |
| combining suppression subtractive hybridization and microarrays to map the intraspecies phylogeny of flavobacterium psychrophilum. | reciprocal subtractive libraries were prepared for two strains of flavobacterium psychrophilum, one virulent and the other avirulent in a trout challenge model. unique clones were sequenced and their distribution assessed among 34 strains. the analysis showed that f. psychrophilum is composed of two genetic lineages, possibly reflecting host specificity. | 2005 | 15908416 |
| characterisation of surface blebbing and membrane vesicles produced by flavobacterium psychrophilum. | the surface of flavobacterium psychrophilum was examined by electron microscopy to determine if previous findings of haemagglutination positive (ha+) and haemagglutination negative (ha-) abilities could be correlated with expression of pili or of a capsular layer. a thin capsular layer was observed in both ha+ and ha- strains but typical pili were absent. however, long, tubular blebs that released membrane vesicles (mvs) into the supernatant were observed on up to 94% of cells within 1 sample. t ... | 2005 | 15997818 |
| quorum sensing signal molecules (acylated homoserine lactones) in gram-negative fish pathogenic bacteria. | the aim of the present study was to investigate the production of quorum sensing signals (specifically acylated homoserine lactones, ahls) among a selection of strains of gram-negative fish bacterial pathogens. these signals are involved in the regulation of virulence factors in some human and plant-pathogenic bacteria. a total of 59 strains, representing 9 different fish pathogenic species, were tested against 2 ahl monitor bacteria (agrobacterium tumefaciens nt1 [pzlr4] and chromobacterium vio ... | 2005 | 16042042 |
| iron acquisition mechanisms of flavobacterium psychrophilum. | forty strains of flavobacterium psychrophilum were tested for the production of siderophores using the universal chrome azurol s (cas) assay. the majority of the strains (85%) were cas positive (cas+) and some (15%) were cas negative (cas-). the cryptic plasmid pcp1 was carried by all positive strains and was lacking from negative strains. while a weak catechol reaction was detectable in cas+ culture supernatants, the cas reaction was, to some extent, heat sensitive, questioning whether the posi ... | 2005 | 16083444 |
| polymorphisms in 16s rrna genes of flavobacterium psychrophilum correlate with elastin hydrolysis and tetracycline resistance. | flavobacterium psychrophilum is the etiological agent of bacterial coldwater disease, which causes significant problems to aquaculture worldwide. a recent study (soule m, cain k, lafrentz s, call dr [2005] infect immun 73:3799-3802) identified two 16s rrna gene sequence variants (6 base differences) within the variable stem-loop region 3 for f. psychrophilum strains atcc 49418 and csf 259-93. that study also hypothesized that f. psychrophilum is composed of at least 2 distinct genetic lineages ( ... | 2005 | 16119889 |
| identification and expression of a host-recognized antigen, fspa, from flavobacterium psychrophilum. | flavobacterium psychrophilum is the aetiological agent of rainbow trout fry syndrome, an economically important disease of immature salmonid fish for which there is no vaccine. convalescent serum from the host, rainbow trout (oncorhynchus mykiss), reacted strongly with a approximately 20 kda, flavobacterium-specific protein antigen (subsequently named fspa) from f. psychrophilum. protein-enriched, detergent-partitioned samples were separated by two-dimensional gel electrophoresis and the protein ... | 2005 | 16151223 |
| detection and identification of flavobacterium psychrophilum from gill washings and benthic diatoms by pcr-based sequencing analysis. | a nested polymerase chain reaction (pcr) amplification technique was used to detect flavobacterium psychrophilum from washings of fish gill surfaces and benthic diatoms as environmental samples. gill washing samples were prepared from kawamutsu, zacco temminckii (temminck & schlegel) and oikawa, z. platypus (temminck & schlegel). benthic diatom samples were collected from stone surfaces. all samples were collected from rivers in wakayama prefecture, japan from november 2003 to january 2004. foll ... | 2005 | 16266329 |
| efficacy of injection vaccines against flavobacterium psychrophilum in rainbow trout, oncorhynchus mykiss (walbaum). | 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 fp(t);th). specific antibody responses against the bacterium in plasma and skin mucus were ... | 2006 | 16351694 |
| association of flavobacterium psychrophilum strains with intestinal explants of rainbow trout oncorhynchus mykiss. | flavobacterium psychrophilum is an important pathogen in rainbow trout oncorhynchus mykiss. the portal of entry for f. psychrophilum is not well known. in this study, the role of the intestine as a colonization site for f. psychrophilum was determined. for this purpose, the ability of a high (dubois) and a low (99/10a) virulence strain of f. psychrophilum to adhere to intestinal explants of rainbow trout was evaluated. after incubation, samples of the gut were examined bacteriologically, histolo ... | 2005 | 16385810 |
| experimental bath infection with flavobacterium psychrophilum, inducing typical signs of rainbow trout oncorhynchus mykiss fry syndrome. | flavobacterium psychrophilum infection in salmonid fish, known as rainbow trout fry syndrome (rtfs) or bacterial coldwater disease (bcwd), is widespread in fish farms and natural waters. despite many studies in which attempts at infection were made, an adequate method of infection has not yet been established. in this study, we evaluated a bath infection method in which we used bacteria at different stages of growth in the infection of rainbow trout oncorhynchus mykiss. rainbow trout with a mean ... | 2005 | 16385811 |
| pathogenesis of experimentally induced bacterial cold water disease in ayu plecoglossus altivelis. | ayu plecoglossus altivelis were experimentally infected with flavobacterium psychrophilum, which is the causative agent of bacterial cold water disease (cwd). the fish infected by immersion usually died within an hour after they became moribund. the blood volume and haematocrit values of moribund fish were low, while those values of many infected fish that were not moribund were in the range of controls. most of the affected fish in the immersion-infected groups had ulcerative lesions on their l ... | 2005 | 16385814 |
| quantitative expression (walbaum) of immunological factors in rainbow trout, oncorhynchus mykiss (walbaum), after infection with either flavobacterium psychrophilum, aeromonas salmonicida, or infectious haematopoietic necrosis virus. | to further enhance our understanding of immunological gene expression in rainbow trout, oncorhynchus mykiss, after infection with naturally occurring pathogens, a series of probes and primers were developed for the quantification of immune factors. separate groups of specific-pathogen-free rainbow trout were infected with either flavobacterium psychrophilum, aeromonas salmonicida or infectious haematopoietic necrosis virus (ihnv). three different concentrations of each pathogen were used and sam ... | 2006 | 16635061 |
| strawberry disease in rainbow trout in scotland: pathology and association with flavobacterium psychrophilum. | | 2006 | 16679482 |
| a new myxozoan from feral goldfish (carassius auratus). | in february 2004, a mass die-off of common goldfish carassius auratus l., presumptively caused by bacterial coldwater disease (flavobacterium psychrophilum), occurred at fern ridge reservoir, oregon. a range of size classes was affected, but all mature fish were female and all fish were infected with a single myxozoan, chloromyxum auratum n. sp. no histological changes were observed associated with the parasite. infection was represented by mictosporic plasmodia and free-floating spores in the g ... | 2006 | 16729695 |
| a mutation in flavobacterium psychrophilum tlpb inhibits gliding motility and induces biofilm formation. | flavobacterium psychrophilum is a psychrotrophic, fish-pathogenic bacterium belonging to the cytophaga-flavobacterium-bacteroides group. tn4351-induced mutants deficient in gliding motility, growth on iron-depleted media, and extracellular proteolytic activity were isolated. some of these mutants were affected in only one of these characteristics, whereas others had defects in two or more. fp523, a mutant deficient in all of these properties, was studied further. fp523 had a tn4351 insertion in ... | 2006 | 16751514 |
| a protective immune response is generated in rainbow trout by an omph-like surface antigen (p18) of flavobacterium psychrophilum. | investigations of the surface characteristics of flavobacterium psychrophilum, an important pathogen of fish, assisted us in identifying a surface protein termed p18. in the current study, we developed a simple and efficient procedure for the purification of this protein by a two-step method. first, p18 was selectively released from flavobacteria by a heat-hepes treatment of the cells and then subjected to anion-exchange high-performance liquid chromatography. de novo sequencing was used to gene ... | 2006 | 16820479 |
| multiple whole bacterial antigens in polyvalent vaccine may result in inhibition of specific responses in rainbow trout (oncorhynchus mykiss). | the goal of fish vaccination today is to protect fish against multiple bacterial fish pathogens simultaneously using polyvalent vaccines. however, many immunological processes such as antigenic cross-reaction, antigenic competition, affinity maturation and antigen-induced suppression may affect the specificity, avidity and level of antibodies. consequently, the biological function of antibodies may be markedly different from that predicted by conventional serologic tests. here, we investigated t ... | 2007 | 16849036 |
| colonization of rainbow trout, oncorhynchus mykiss (walbaum), eggs by flavobacterium psychrophilum, the causative agent of rainbow trout fry syndrome. | | 2006 | 16866929 |
| rapid direct determination using combined separation by prepared immunomagnetic and flow cytometry of flavobacterium psychrophilum. | flavobacterium psychrophilum, the causative agent of bacterial cold-water disease (bcwd), was originally isolated from coho salmon oncorhychus kisutch in the usa. bacterial cold-water disease has since been spreading throughout japan and has caused serious damage to populations of ayu plecoglossus altivel in many farms and rivers. the rapid method of detecting for f. psuchrophilum is requested, however, traditional methods are laborious because of complicated assay procedures. in this study, a r ... | 2007 | 16996256 |
| isolation of flavobacterium psychrophilum from sea lamprey, petromyzon marinus l., with skin lesions in lake ontario. | | 2006 | 17026672 |
| stationary phase culture supernatant containing membrane vesicles induced immunity to rainbow trout oncorhynchus mykiss fry syndrome. | flavobacterium psychrophilum is the causative agent of bacterial cold water disease (bcwd) and rainbow trout (oncorhynchus mykiss) fry syndrome (rtfs). logarithmic phase formalin-killed cells (fkc) of f. psychrophilum induced immunity to bcwd in ayu (plecoglossus altivelis) by using an oral administration. in this study, we investigated the effective antigens of logarithmic phase cells in rainbow trout. rainbow trout fry immunized with logarithmic phase fkc resulted in near complete protection, ... | 2007 | 17095127 |
| detection of the bacterium flavobacterium psychrophilum from a natural infection in rainbow trout, oncorhynchus mykiss (walbaum), using formalin-fixed, wax-embedded fish tissues. | the bacterial pathogen flavobacterium psychrophilum was successfully identified from formalin-fixed, wax-embedded tissue blocks of infected rainbow trout heart and spleen tissues, using a polymerase chain reaction (pcr)-based assay. filamentous bacteria were observed in haematoxylin and eosin and giemsa-stained sections but no bacteria were recovered from the diseased fish using standard bacteriology isolation techniques. all infected fish had histopathological evidence of myocarditis or rainbow ... | 2007 | 17241403 |
| in vitro competitive adhesion and production of antagonistic compounds by lactic acid bacteria against fish pathogens. | the present study describes the screening of five lactic acid bacteria (lab) for use as probiotics based on their competitive adhesion and production of antagonistic substances against some fish pathogens. a reduction of adhesion of all pathogenic strains tested was obtained with three of the lab strains (lactococcus lactis subsp. lactis clfp100, lactococcus lactis subsp. cremoris clfp102 and lactobacillus curvatus clfp150). with the exception of fish pathogens flavobacterium psychrophilum and r ... | 2007 | 17336468 |
| pcr-rflp genotypes associated with quinolone resistance in isolates of flavobacterium psychrophilum. | a novel genotyping method for epizootiological studies of bacterial cold-water disease caused by flavobacterium psychrophilum and associated with quinolone resistance was developed. polymerase chain reaction followed by restriction fragment length polymorphism (pcr-rflp) was performed on 244 f. psychrophilum isolates from various fish species. pcr was performed with primer pair gyra-fp1f and gyra-fp1r amplifying the a subunit of the dna gyrase (gyra) gene, which contained the quinolone resistanc ... | 2007 | 17352789 |
| differentiating 16s rrna alleles of flavobacterium psychrophilum using a simple pcr assay. | | 2007 | 17352793 |
| electrophoretic and western blot analyses of the lipopolysaccharide and glycocalyx of flavobacterium psychrophilum. | flavobacterium psychrophilum is the aetiological agent of bacterial coldwater disease (cwd) and rainbow trout fry syndrome (rtfs) and it has emerged as one of the most significant bacterial pathogens in salmonid aquaculture worldwide. previous studies have suggested that the o-polysaccharide (o-ps) component of the lipopolysaccharide (lps) of f. psychrophilum is highly immunogenic and may be involved in eliciting a protective immune response in rainbow trout (oncorhynchus mykiss walbaum). in the ... | 2007 | 17420143 |
| identification of potential vaccine target antigens by immunoproteomic analysis of a virulent and a non-virulent strain of the fish pathogen flavobacterium psychrophilum. | flavobacterium psychrophilum is the etiological agent of bacterial coldwater disease (cwd) and rainbow trout fry syndrome (rtfs). to identify antigens associated with virulence or host immunity, we compared total and immunogenic proteins of cellular and extracellular products (ecp) between a virulent (csf-259-93) and non-virulent (atcc 49418) strain of f. psychrophilum. one-dimensional sodium dodecyl sulfate polyacrylamide gel electrophoresis of total cellular proteins revealed only minor differ ... | 2007 | 17425262 |
| recovery of flavobacterium psychrophilum viable cells using a charcoal-based solid medium. | flavobacterium psychrophilum is the etiological agent of the cold-water disease in salmonids. this micro-organism is somewhat fastidious being difficult to isolate and culture. the aim of this study was to develop a new solid medium which improves the recovery of viable cells from a sample. | 2007 | 17451527 |
| molecular typing by pulsed-field gel electrophoresis of flavobacterium psychrophilum isolates derived from japanese fish. | sixty-four isolates of flavobacterium psychrophilum from ayu, plecoglossus altivelis altivelis (temminck & schlegel), and other fish (n=16) in japan and the type strain (ncimb 1947(t)) were typed using pulsed-field gel electrophoresis (pfge) with endonuclease blni and xhoi. these isolates were classified into 20 clusters and 42 genotypes by pfge analysis. the most predominant cluster of isolates from ayu was cluster xii (n=20), followed by clusters xvii, xvi, xx, xi, ix, x, xiii and xv; the rema ... | 2007 | 17498178 |
| complete genome sequence of the fish pathogen flavobacterium psychrophilum. | we report here the complete genome sequence of the virulent strain jip02/86 (atcc 49511) of flavobacterium psychrophilum, a widely distributed pathogen of wild and cultured salmonid fish. the genome consists of a 2,861,988-base pair (bp) circular chromosome with 2,432 predicted protein-coding genes. among these predicted proteins, stress response mediators, gliding motility proteins, adhesins and many putative secreted proteases are probably involved in colonization, invasion and destruction of ... | 2007 | 17592475 |
| improved husbandry to control an outbreak of rainbow trout fry syndrome caused by infection with flavobacterium psychrophilum. | a cohort of 35,200, 13-week-old, female rainbow trout at a fish farm was evaluated because of a 2-week history of anorexia and lethargy and a mortality rate of approximately 100 fish/d. | 2007 | 17605674 |
| identification of a ribosomal l10-like protein from flavobacterium psychrophilum as a recombinant vaccine candidate for rainbow trout fry syndrome. | the psychrophilic bacterium flavobacterium psychrophilum is a rapidly emerging, virulent pathogen of a variety of commercially important finfish species, including salmonids. no vaccines against f. psychrophilum are currently available, partly due to its recalcitrant growth in vitro. consequently, we explored the possibility of constructing recombinant vaccines in escherichia coli as a prophylactic biotechnological strategy to counter f. psychrophilum infections. an immunoreactive clone from a f ... | 2007 | 17693713 |
| the flavobacterium psychrophilum ompa, an outer membrane glycoprotein, induces a humoral response in rainbow trout. | the purpose of this study was to characterize ompa, a major glycoprotein isolated from the membrane fraction of flavobacterium psychrophilum, and to evaluate its potential as antigenic unit in a possible vaccine. | 2007 | 17953557 |
| suggestive association of major histocompatibility ib genetic markers with resistance to bacterial cold water disease in rainbow trout (oncorhynchus mykiss). | genes within the major histocompatibility complex (mhc) are important for both innate and adaptive immune responses in mammals; however, much less is known regarding their contribution in teleost fishes. we examined the involvement of four major histocompatibility (mh) genomic regions in rainbow trout in resistance to the causative agent of bacterial coldwater disease (bcwd), flavobacterium psychrophilum. fish from the 2005 ncccwa brood-year (71 full-sib families) were challenged with f. psychro ... | 2008 | 18274824 |
| spleen size predicts resistance of rainbow trout to flavobacterium psychrophilum challenge. | selective breeding of animals for increased innate resistance offers an attractive strategy to control disease in agriculture. however, this approach is limited by an incomplete knowledge of the heritability, duration, and mechanism(s) of resistance, as well as the impact of selection on the immune response to unrelated pathogens. herein, as part of a rainbow trout broodstock improvement program, we evaluated factors involved in resistance against a bacterial disease agent, flavobacterium psychr ... | 2008 | 18322227 |
| a mutant in one of two exbd loci of a tonb system in flavobacterium psychrophilum shows attenuated virulence and confers protection against cold water disease. | flavobacterium psychrophilum is a psychrotrophic fish-pathogenic bacterium that causes cold water disease (cwd) in salmonids. by means of tn4351 mutagenesis a mutant named fp1033, deficient in growth on iron-depleted medium, was previously isolated. fp1033 recovered the parental phenotype in the presence of iron. the gene disrupted by the transposon in this mutant encoded a protein with similarity to exbd proteins, which are members of the tonb complex system involved in iron uptake mediated by ... | 2008 | 18375806 |
| population structure of the fish-pathogenic bacterium flavobacterium psychrophilum. | flavobacterium psychrophilum is currently one of the main bacterial pathogens hampering the productivity of salmonid farming worldwide, and its control mainly relies on antibiotic treatments. to better understand the population structure of this bacterium and its mode of evolution, we have examined the nucleotide polymorphisms at 11 protein-coding loci of the core genome in a set of 50 isolates. these isolates were selected to represent the broadest possible diversity, originating from 10 differ ... | 2008 | 18424537 |
| immunomagnetic separation using carbonyl iron powder and flow cytometry for rapid detection of flavobacterium psychrophilum. | bacterial cold water disease, caused by flavobacterium psychrophilum, is a serious problem in the aquaculture industry worldwide. several methods to prevent and treat cold water disease have been studied. although detection at the early stage of f. psychrophilum infection is very important for the prevention and treatment of cold water disease, an effective detection method has not yet been developed. the use of flow cytometry (fcm) for the rapid determination of bacterial cell numbers with high ... | 2008 | 18438648 |