bluuebunny/crossref_metadata_2025 huggingface dataset:
Carbohydrate and lectin interactions withEdwardsiella ictaluriand channel catfish,Ictalurus punctatus(Rafinesque), anterior kidney leucocytes and hepatocytes
Authors: AINSWORTH A. J.
Published: April 2006

Abstract.Seven isolates ofEdwardsiella ictaluriwere evaluated for channel catfish red blood cell and neutrophil agglutination properties and reactivity with lectins and carbohydrates. All isolates were agglutinated by lectin derived fromRicinus communisand the intensity of the agglutination reaction could be lessened or abrogated by premixing the lectin derived fromRicinus communiswith β‐D‐galactose or α‐L‐fructose.Edwardsiella ictaluriisolates also sedimented much more rapidly when mixed with lectin derived fromRicinus communisthan when mixed with other lectins. PremixingRicinus communiswith β‐D‐galactose had the greatest effect on slowing the rate of sedimentation. Two out of the sevenE. ictaluriisolates were capable of agglutinating channel catfish red blood cells and anterior kidney neutrophils, and this agglutination could be prevented by the addition of β‐D‐mannose. Likewise, the per cent phagocytosis ofE. ictaluriisolate 1389 (the most intense neutrophil agglutinator) could be dramatically reduced by the inclusion of mannose in the assay mixture. Anterior kidney leucocytes and hepatocytes primarily reacted with lectins derived fromCanavalia ensiformis, Ricinus communisandTriticum vulgaris.The presence on channel catfish cells of carbohydrate‐lectin receptors similar in function to those found on mammalian cells and the reaction ofE. ictaluriwith specific lectins suggest that bacterial clearance and lectinophagocyotosis may occur in a similar manner in catfish to that in mammals.
Infectious haematopoietic necrosis virus from salmonids cultured in Korea
Authors: PARK M. A. , SOHN S. G. , LEE S. D. , CHUN S. K. , PARK J. W. , FRYER J. L. , HAH Y. C.
Published: April 2006

Abstract. Four isolates of infectious haematopoietic necrosis virus (IHNV) were obtained from rainbow trout, Oncorhynchus mykiss (Walbaum), and masu salmon, Oncorhynchus masou (Walbaum), fry during epizootics at hatcheries in Korea. The four isolates of IHNV were compared with three from salmonids in the USA (SRCV, OSV and RB‐76) by analysis of virion proteins in sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS‐PAGE) and neutralization tests, with two monoclonal antibodies raised against SRCV (MAb SRCV/A4) and RB‐76 (MAb RB/B5). Based on the antigenicity and the size of the structural proteins, one Korean isolate from masu salmon (SCS) is similar to RB‐76 and is an electropherotype 1. The other three isolates from rainbow trout (PRT, YRT and MRT) were identical to each other in the mobilities of their virion proteins in SDS‐PAGE, and although their nucleocapsid (N) proteins comigrated with that of the RB‐76 isolate, they differed from RB‐76 in the smaller matrix 2 (M2) protein they contained. In addition, the three Korean isolates (PRT, YRT and MRT) could be divided into two groups by reactivity with MAb RB/B5. While the YRT isolate was neutralized by this MAb, the PRT and MRT isolates were not, suggesting that there are at least two neutralizing antigenic variants of IHNV in Korea.
Herpesvirus cyprini: a search for viral genome in infected fish by infected fish by in situ hybridization
Authors: SANO N. , MORIWAKE M. , HONDO R. , SANO T.
Published: April 2006

Abstract. Herpesvirus cyprini (CHV) genome was traced in carp, Cyprinus carpio L., after acute infection by the method of in situ hybridization with biotinylated probes. The viral genome was detected in several tissues including cranial nerve ganglia. Subcutaneous tissue and spinal nerves. However, at this stage, viral antigens were not detected and the virus was not isolated. The viral genome was also detected in the same fish tissues when papillomas were present which contained viral antigens and even infective virus particles. After papilloma regression, the viral genome was still detected in these tissues. It is suggested that CHV becomes latently established in cranial nerve ganglia, subcutaneous tissue and spinal nerves, and is associated with the induction and recurrence of papillomas.
Development of a Penaeus monodon‐type baculovirus (MBV) DNA probe by polymerase chain reaction and sequence analysis
Authors: LU C. C. , TANG K. F. J. , KOU G. H. , CHEN S. N.
Published: April 2006

Abstract. Penaeus monodon‐type baculovirus (MBV) was isolated and purified from the hepatopancreases of MBV‐infected Penaeus monodon Fabricius. MBV DNA was extracted and used as a template in a polymerase chain reaction (PCR). The primers were chosen from conserved regions of the polyhedrin gene of Autographa californica nuclear polyhedrosis virus (AcNPV). One DNA fragment (674 base pairs) was amplified after PCR. There was a 65% homology between the predicted amino acid sequence of this PCR product with that of the polyhedrin polypeptide of AcNPV. Nucleotide sequence analysis indicated that the amplified DNA is the open reading frame of the MBV polyhedrin gene. This 674 bp DNA fragment was subsequently used as a probe in a dot blot analysis. The probe was able to hybridize with the DNA extracted from the purified MBV and from the MBV‐infected P. monodon, but not from the MBV uninfected P. monodon.
Mycotic aspects of epizootic ulcerative syndrome (EUS) of Asian fishes
Authors: ROBERTS R. J. , WILLOUGHBY L. G. , CHINABUT S.
Published: April 2006

Abstract A survey of fish affected with epizootic ulcerative syndrome taken from outbreaks in countries throughout South and South‐East Asia showed that a morphologically typical fungus was consistently present within lesions. Although the majority of the fungal mycelium was dead in most lesions it proved possible to isolate a very delicate and culturally demanding Aphanomyces from such lesions in a few cases. It also proved relatively easy to isolate other members of the Saprolegniaceae including Aphanomyces from the surface of lesions, but these were considered saprophytes derived from background spore burdens in the water. Sporangium morphology of the putatively pathogenic isolates of Aphanomyces was different from that of saprophytic Aphanomyces strains and they also had a lower thermal tolerance. When a mycelium from these strains was placed below the dermis of healthy fish, it caused an inflammatory response and proceeded to migrate down into the tissues of the fish, inducing severe myonecrosis with chronic epithelial reaction. The saprophytic isolates induced a local host response followed by healing of the induced lesion, and destruction or expulsion of the mycelium. It is considered that the specific slow‐growing, thermo‐labile Aphanomyces is the pathogenic fungus which causes so much tissue damage in this disease, although it may not be a primary pathogen in its own right.
Cytophaga johnsonae: a putative skin pathogen of juvenile farmed barramundi, Lates calcarifer Bloch
Authors: CARSON J. , SCHMIDTKE L. M. , MUNDAY B. L.
Published: April 2006

Abstract Cytophaga johnsonae, a gliding filamentous Gram‐negative rod, was isolated from diseased farmed juvenile barramundi, Lates calcarifer Bloch. Infected fish had extensive but superficial erosion of the skin, mainly involving the posterior flanks, but also affecting the pectoral fins and lower jaw in some individuals. Minimum inhibitory concentrations of a number of antibacterial agents for C. johnsonae were determined; acriflavine and oxolinic acid inhibited growth between 0.78 and 1.5 μg ml−1, while polymyxin B, trimethoprim and sulphamethazine failed to inhibit growth at 100 μg ml−1.
Successful therapy of furunculosis in Atlantic salmon, Salmo salar L., using the fluoroquinolone antimicrobial agent enrofloxacin
Authors: STOFFREGEN D. A. , CHAKO A. J. , BACKMAN S. , BABISH J. G.
Published: April 2006

Abstract An outbreak of furunculosis was diagnosed in an Atlantic salmon, Salmo salar L., commercial sea‐pen farm and treated with the fluoroquinolone antimicrobial enrofloxacin. The affected post‐smolt, adult fish and broodstock readily consumed pelleted feed impregnated with enrofloxacin at concentrations of 1000, 1300 and 2000ppm, respectively, daily for 10 days. Mortalities of infected post‐smolts were reduced from an average of 5.8% per month for the 2 months preceding therapy to 0.6% per month for the 2 months following therapy. Infected adult fish had a 2 month mean mortality rate of 2.6% prior to enrofloxacin treatment and 0.3% over the 2 months subsequent to therapy. Apparently noninfected (nonclinical) fish in the same farm exhibited an average monthly mortality of 0.4% over the 4‐month study period. Sea water temperatures gradually rose from less than 2°C in March to approximately 12°C in September. Mean antimicrobial tissue concentrations over the 10 complete days of medication were 4.58, 7.32, 4.58, 8.89 and 3.40ppm for muscle, skin plus fat, liver, kidney and gill, respectively. Within 24h of consuming medicated feed, tissue concentrations of antimicrobial were nearly 66% of the average concentrations for the medication period. Half‐lives of elimination for the antimicrobial residues were approximately 2 days for liver, 3 days for kidney, 6 days for gill, 11 days for muscle and 22 days for skin plus fat. The producers reported a successful harvest after a 180‐day medication‐free period.
Retinal and lenticular lesions in vitamin‐C‐deficient juvenile red drum, Sciaenops ocellatus (L.)
Authors: COLLINS B. K. , COLLIER L. L. , COLLINS J. S.
Published: April 2006

Abstract Ocular pathologic findings in eyes of ascorbic acid‐deficient juvenile red drum, Sciaenops ocellatus (L.), are described. Abnormalities in the most severely affected eyes included: reduced globe size and lack of normal globe rigidity; vascular congestion and intraocular haemorrhage; lenticular lesions which included disorganization of posterior cortex, vacuolation of posterior subcapsular cortex and posterior migration of lens epithelium; and severe central retinal degeneration. The authors suspect that retinal degeneration was related to phototoxic injury, to which these fish had increased susceptibility as a result of ascorbic acid deficiency. The cause for lenticular lesions was undetermined, but may have been related directly to ascorbic acid deficiency, indirectly to retinal degeneration, or both.
Enhancement of resistance to bacterial infection in rainbow trout, Oncorhynchus mykiss (Walbaum), by oral administration of bovine lactoferrin
Authors: SAKAI M. , OTUBO T. , ATSUTA S. , KOBAYASHI M.
Published: April 2006

Abstract Bovine lactoferrin was evaluated for its ability to enhance resistance of rainbow trout, Oncorhynchus mykiss (Walbaum), to infection with Vibrio anguillarum. Oral administration of lactoferrin (100 mg kg−1) to fish daily for 3 days prior to an intraperitoneal challenge with V. anguillarum resulted in increased survival rates, and enhanced resistance against Streptococcus sp., although to a lesser extent. In lactoferrin‐treated fish, an increase in phagocytic and chemiluminescent (CL) activities of pronephros cells against V. anguillarum was observed. The phagocytic and CL activities of cells against Streptococcus sp. were also significantly increased. However, no in vitro bactericidal activities of lactoferrin against V. anguillarum or Streptococcus sp. were observed. This suggests that the lactoferrin enhanced the resistance of the rainbow trout against bacterial infection through the activation of phagocytes.
The detection of infectious pancreatic necrosis virus in asymptomatic carrier fish by an integrated cell‐culture and ELISA technique
Authors: DAVIS P. J. , LAIDLER L. A. , PERRY P. W. , ROSSINGTON D. , ALCOCK R.
Published: April 2006

Abstract. The need to accurately, reliably and economically screen large populations of brood salmon for infectious pancreatic necrosis virus (IPNV) prompted a fresh approach to the use of ELISA and cell cultures. The result is an integrated procedure that recognizes the limitations of each method while building upon the strength of both in the way that they are brought together, ELISA tests can never be sensitive enough to detect the very low virus levels typical of carrier fish, but are able to detect virus in infected cell cultures, both specifically and objectively. Cell cultures provide the means to detect very low virus levels, but without specificity and only through subjective observation. Without a suitable ELISA, the need to keep cell monolayers in a condition in which viral effects can be observed imposes strict demands on inoculation and culture procedures. In contrast, the new procedure described in this paper provides a simpler culture method in which the inoculum is retained throughout a single, uninterrupted 14‐day culture cycle. This culture duration allowed maximum opportunity for viral replication in healthy cells, even though the monolayers became disorganized. However, the cultures were tested in the standardized ELISA, eliminating the need for microscopic observation and virus neutralization tests. Thorough validation studies confirmed the system's adequacy in practice.
Multiple‐dose pharmacokinetic and depletion studies of sarafloxacin in Atlantic salmon, Salmo salar L.
Authors: MARTINSEN B. , HORSBERG T. E. , BURKE M.
Published: April 2006

Abstract. Two multiple‐dose pharmacokinetic and depletion studies with sarafloxacin hydrochloride in feed pellets were conducted with Atlantic salmon at 12.1 ± 1.1 †C and 9.3 ± 1.5†C, respectively. The dose regimens used were 10mg sarafloxacin kg‐1 biomass for 10 days, and 20mg sarafloxacin kg‐1 biomass for 5 days. In the 10‐day study, the highest average concentrations of sarafloxacin in plasma, muscle and liver were 0.14, 0.39 and 0.88μgg(ml)‐1, respectively. In the 5‐day study, the highest average concentrations in plasma, muscle, liver and skin were 0.40, 0.61, 1.56 and 0.19μg(ml)‐1, respectively. A comparison between the individual plasma concentrations and the corresponding tissue concentrations revealed significantly higher concentrations in tissue than in plasma during the depletion phase. A similar comparison made in the therapeutic phase from 3 days after first medication to one day after the last medication revealed significantly higher concentrations in liver and muscle than in plasma, and significantly lower concentrations in skin than in plasma. On withdrawal of the drug, sarafloxacin concentrations in plasma and the different tissues declined rapidly, Sarafloxacin was not detected in any plasma sample taken 6 days or more after the end of medication. The corresponding figures for muscle, skin and liver tissues were 14, 20 and 22 days, respectively. The half‐lives of sarafloxacin varied in the different tissues included in the studies. The half‐life was shortest in plasma, and increased in ascending order in muscle, liver and skin.
Immunodiagnosis of virulent strains of Aeromonas hydrophila associated with epizootic ulcerative syndrome (EUS) using a monoclonal antibody
Authors: CARTWRIGHT G. A. , CHEN D. , HANNA P. J. , GUDKOVS N. , TAJIMA K.
Published: April 2006

Abstract. A virulent strain of Aeromonas hydrophila associated with epizootic ulcerative syndrome (EUS) was used to produce monoclonal antibodies that identified virulent strains of A. hydrophila. Antibodies from a clone, designated as F26P5C8, were found to identify the A. hydrophila serotype I isolates associated with EUS fish, and which were found to be virulent after subsequent inoculation studies. Immunodiagnosis of a large number of A. hydrophila from Australia and Japan showed some additional isolates to be identified by F26P5C8, but the status of their virulence is presently unknown.
Pharmacological treatments against Ichthyobodo necator (Henneguy, 1883) in rainbow trout, Oncorhynchus mykiss (Walbaum)
Authors: TOJO J. L. , SANTAMARINA M. T. , LEIRO J. , UBEIRA F. M. , SANMARTIN M. L.
Published: April 2006

Abstract. Various antiparasitic drugs belonging to several pharmacological groups were tested by bath administration for in vivo activity against a natural infestation of rainbow trout. Oncorhynchus mykiss (Walbaum), by he flagellate protozoan Ichthyobodo necator. Fish were also monitored for signs of drug toxicity. Complete elimination of infestation in all fish was achieved only by bithionol (25 mgl‐1 for 3h on two consecutive days). Ketoconazole, toltrazuril, amprolium, sulphaquinoxaline, quinacrine, N‐metylglucamine, chloroquine, 1,3‐di‐6‐quinolylurea, diminazene aceturate and paromomycin were not effective. Diminazene aceturate (100 mgl‐1, 3h) was the only drug which was clearly toxic. The comparison of the response of symptomatic and asymptomatic infested fish to a formaldehyde bath indicates that poor health caused by I. necator may greatly increase the susceptibility of fish to the toxic effects of a drug or chemical.
Growth of the fish‐pathogenic fungus, Ichthyophonus hoferi, measured by conductimetry and microscopy
Authors: SPANGGAARD B. , GRAM L. , OKAMOTO N. , HUSS H. H.
Published: April 2006

Abstract. The influence of pH and glucose on growth of the fish pathogenic fungus Ichthyophonus hoferi was measured by indirect conductimetry and microscopy. Using indirect conductimetry, distinct resistance curves were produced within 3 days at 15 †C, Conductimetric changes were enhanced when the media were supplemented with glucose. Low pH (3–4) was essential to ensure continuous growth of the fungus, which could be further facilitated by supplementation with glucose. At pH 7, growth occurred when the fungus had been pre‐cultured at low pH. Growth of the fungus ceased after three successive transfers at pH 7 and this explains why earlier attempts to subculture have failed. Only vegetative stages of I. hoferi were observed; i.e. no conidia. At pH 7, growth was mainly observed as spherical bodies of varying size, with large numbers of nuclei, and thick‐walled spherical multinucleate bodies. Hyphal growth was abundant at low pH. The alternating pH simulates the natural conditions experienced by the fungus on transfer from the stomach (low pH) to the muscle (neutral pH) and reproducible sub‐culturing is obtained when mimicking this pH cycle or when a low pH is maintained.
Aeromonas salmonicida infection in wrasse (Labridae), used as cleaner fish, on an Atlantic salmon, Salmo salar L., farm
Authors: TREASURER J. W. , LAIDLER L. A.
Published: April 2006

Abstract. Typical Aeromonas salmonicida with similar biochemical characteristics to A. salmonicida from Atlantic salmon, was isolated from wrasse, Ctenolabrus rupestris (L.) and Centrolabrus exoletus (L.), stocked as cleaner fish with these salmon. Although no external clinical signs were apparent, localized bacterial microcolonies were observed in muscle, gills, intestine, kidney and myocardial tissue. Mortalities attributed to A. salmonicida comprised 55% (n = 32) of total mortalities. No carriers of A. salmonicida were found in wild wrasse following stress testing. Although salmon post‐smolts died when challenged with 1 × 105 ml‐1 of a virulent strain, there were no mortalities in challenged wrasse. An oral route of infection is suggested rather than water‐borne transfer as wrasse browsed on salmon mortalities. Wrasse were treated for A. salmonicida infection by injection with antibiotic and were also vaccinated, and in the latter case, elevation of antibody levels was noted.
The development of live vaccines for furunculosis lacking the A‐layer and O‐antigen of Aeromonas salmonicida
Authors: THORNTON J. C. , GARDUÑO R. A. , KAY W. W.
Published: April 2006

Abstract. Mutants of Aeromonas salmonicida strains lacking either the A‐protein, O‐antigen or both of these major surface antigens were tested in rainbow trout, Oncorhynchus mykiss (Walbaum), for their suitability as live vaccines (LV). All of these mutants were shown to be attenuated, as fish receiving ∼5 × 107 of the respective strains showed no clinical signs of furunculosis. Immersion vaccination of fish in 5 × 107 cfu ml‐1 of these strains with an identical immersion dose 14 days later resulted in significant protection by all strains from challenge with a heterologous virulent strain of A. salmonicida 5 weeks later. The levels of protection conferred were all greater than or equal to that provided by an injected bacterin using the same vaccination schedule. With one exception, all LV strains that still possessed a functional O‐antigen provided protective indices (PI) four‐ to seven‐fold greater than the PI for the fish injected with bacterin. When antibody responses of vaccinated fish were compared, it was found that only vaccination by bacterin gave rise to a measurable agglutinating litre. Western immunoblots using the immune fish sera failed to reveal any major differences in antigen recognition in fish that received any of the vaccines tested. These data suggest that the immune response generated by the use of live vaccine strains is different from that generated by a bacterin, and that these useful mutations may be incorporated into existing furunculosis LVs for further attenuation.
Influence of dietary carbohydrate on blood chemistry, immunity and disease resistance in Atlantic salmon, Salmo salar L.
Authors: WAAGBØ R. , GLETTE J. , SANDNES K. , HEMRE G. I.
Published: April 2006

Abstract. The influence of dietary carbohydrate (CHO) on blood chemistry, immunity and disease resistance was studied in two experiments with Atlantic salmon, Salmo salar L. Moist diets with increasing amounts of digestible CHO ranging from 0 to 30% (dry weight) were used. In the first experiment with adult (0.5 kg) fish, blood haemoglobin concentration was negatively correlated with increasing dietary CHO level, while serum glucose and protein did not differ between the groups. Serum cortisol increased linearly in fish fed from 5 to 30% CHO. Serum haemolytic activity was negatively correlated with dietary levels of CHO. Humoral immune responses elicited after vaccination by intraperitoneal injection or by dip immersion with Vibrio salmonicida showed no differences according to diet 10 and 17 weeks post‐vaccination. Mortality after challenge with live Aeromonas salmonicida by intraperitoneal injection was lowest in fish fed 10% CHO. In the second experiment with juvenile Atlantic salmon (3g), there were minor differences in body and organ weights. Plasma glucose, protein and cholesterol were elevated in fish fed the highest CHO levels. Fish exposed to immersion challenge with different water concentrations of Vibrio anguillarum showed no statistical differences in mortality. The studies indicate that varying dietary levels of CHO affected immunity and resistance to bacterial infections to a minor extent in Atlantic salmon at low water temperatures during freshwater and seawater stages.
A detection method for infectious pancreatic necrosis virus (IPNV) based on reverse transcription (RT)‐polymerase chain reaction (PCR)
Authors: LOPEZ‐LASTRA M. , GONZALEZ M. , JASHES M. , SANDINO A. M.
Published: April 2006

Abstract. A rapid, sensitive and highly specific detection method for infectious pancreatic neerosis virus (IPNV), based on reverse transcription (RT) polymerase chain reaction (PCR) has been developed. The specificity of the assay is provided by the oligonucleotide primers selected from the IPNV major capsid polypeptide VP2 gene. For each primer combination only one major product is obtained when amplifieation is performed using IPNV double‐stranded RNA from two different viral strains, Sp and VR‐299, as the initial template. No products were detected when genomie nueleic acids other than IPNV RNA were used as RT‐PCR templates. The specificity of the amplification products were confirmed by Southern hybridization using a specific cDNA probe. To assess the sensitivity of the method, dilutions of purified IPNV dsRNA total genome were amplified and quantities of as little as 1 pg of purified dsRNA were detected when the amplification product was visualized by silver‐stained polyacrylamidc gel electrophoresis. This technique detected IPNV directly in infected coho salmon, Oncorhynchus kisutch (Walbaum), and rainbow trout, Oncorhynchus mykiss (Walbaum), tissues and fish egg samples, avoiding viral propagation in cell culture. The results show that this RT‐PCR amplification method is useful for the direct tissue detection of IPNV.
Serological studies of the rhabdovirus of penaeid shrimp (RPS) and its relationship to three other fish rhabdoviruses
Authors: LU Y. , LOH P. C. , NADALA E. C. B.
Published: April 2006

Abstract. The serological relationship of rhabdovirus of penaeid shrimp (RPS) to three fish rhabdoviruses was determined by plaque‐reduction and neutralization kinetics techniques using polyclonal antiserum against RPS. Although RPS was found to be serologically related to Rhabdovirus carpio (RC), a Vesiculovirus type, the two viruses were clearly distinguishable from one another, RPS was unrelated to two other fish rhabdoviruses of the Lyssavirus type, infectious haematopoietic necrosis virus (IHNV) and viral haemorrhagic septicaemia virus (VHSV). Under single cycle growth conditions, immunofluorescence studies showed the appearance of RPS viral antigens as early as 3h post‐infection (pi). The degree of fluorescence and the number of fluorescing cells progressively increased until 24 h pi when more than 90% of the cells showed viral antigens.
Amoxycillin resistance in Scottish isolates of Aeromonas salmonicida
Authors: BARNES A. C. , HASTINGS T. S. , AMYES S. G. B.
Published: April 2006

Abstract. Eighty isolates of Aeromonas salmonicida, recovered from separate outbreaks of furunculosis in farmed and wild salmon in Scotland during 1988 and 1989, were examined for susceptibility to the β‐lactam antibiotic amoxycillin. Susceptibility was determined in terms of minimum inhibitory concentration (MIC). All of the A. salmonicida subsp. salmonicida isolates investigated were susceptible to amoxycillin, with MICs of 0.30–1.50mg1‐1. All of the A. salmonicida subsp. achromogenes isolates tested were resistant to amoxycillin, with MICs in excess of 500mgl‐1. The A. salmonicida subsp. achromogenes produced a β‐lactamase enzyme with a pI of approximately 8.0. The enzyme was inducible and its production was unaffected by plasmid curing with ethidium bromide, suggesting that resistance was chromosomal rather than plasmid mediated.
Ultrastructural observations on the cellular response of carp, Cyprinus carpio L., to eggs of the blood fluke Sanguinicola inermis Plehn, 1905 (Trematoda: Sanguinicolidae)
Authors: RICHARDS D. T. , HOOLE D. , LEWIS J. W. , EWENS E. , ARME C.
Published: April 2006

Abstract. The cellular response, within the kidney of experimentally infected carp to the presence of eggs of the blood fluke Sanguinicola inermis has been investigated using transmission electron microscopy. Initially, 0–1‐wcck‐old eggs were surrounded by host eosinophils which degranulated and broke down adjaeent to the egg shell. Infiltration by neutrophils and monocytes occurred around 1–2‐week‐old eggs. Eggs at 2–3 weeks of age began to become encapsulated, although the first signs of structural damage appeared when the eggs were 5–6 weeks of age.
Fin erosion in a feral population of goldfish, Carassius auratus (L.), exposed to bleached kraft mill effluent
Authors: SHARPLES A. D. , CAMPIN D. N. , EVANS C. W.
Published: April 2006

Abstract. The prevalence of acute and healed fin erosion in goldfish, Carassius auratus (L.), from the Waikato River, New Zealand, peaked in the vicinity of a pulp and paper mill which utilized a kraft pulping process in association with chlorine bleaching, and decreased down the effluent gradient. About 49% of goldfish sampled from the Kopakorahi Stream. which is part of the effluent treatment system (site 1), displayed pathological signs of fin erosion, whereas about 9% of control fish from a reference site located upstream of the official effluent discharge point were similarly affected. Fin erosion was less prevalent in male than in female goldfish, and occurred with different frequencies on different fins, the pectoral (56%) and caudal fins (33%) being most affected. Both the pectoral and caudal fins also had significantly higher proportions of healed erosion rather than acute erosion. The prevalence of acute and healed fin erosion increased significantly with increasing fish length (age). Physical deformities, predominantly in the form of eroded or otherwise malformed opercula, were found in nearly 5% of fish caught at site 1, but were not observed at the reference site. Changes in processing and bleaching technology at the pulp and paper mill in question have since been carried out, and long‐term studies arc planned to monitor any subsequent improvements in fish health.
Comparison of rhabdoviruses associated with epizootic ulcerative syndrome (EUS) with respect to their structural proteins, cytopathology and serology
Authors: LILLEY J. H. , FRERICHS G. N.
Published: April 2006

Abstract. Seven rhabdoviruses isolated from fish suffering from epizootic ulcerative syndrome (EUS) were compared in terms of their morphology, cytopathogenicity, antigenic relatedness and structural polypeptide composition. All strains exhibited a bullet‐shaped morphology, but the T9204 isolate was found to be longer and more variable in length than the other strains. Sixteen fish cell lines investigated showed some variation in susceptibility to each isolate, but the cytopathic changes induced by T9204 in SSN‐2, RSN, GCP, ONP, FHM, AS and MUL lines were significantly different from the other isolates. Polyclonal antisera raised against the BPV, 20E and SL11 strains neutralized six isolates (BPV, 02, 19, 20E, A4 and SL11), but not T9204. Conversely, anti‐T9204 serum only neutralized homologous virus. Polyacrylamide gel electrophoresis demonstrated that BPV, 02, 19, 20E, A4 and SL11 had virtually identical protein profiles, whereas T9204 differed both in the number of protein bands and in their migration pattern. Western blots of these gels identified the proteins specific to T9204 that reacted with anti‐T9204 serum. Therefore, the isolates represent two distinct species of fish rhabdoviruses, but as yet, no causal relationship with EUS, or any other disease condition, has been established.
Systematic granulomas caused by a rickettsia‐like organism in Nile tilapia, Oreochronuis niloticus (L.), from southern Taiwan
Authors: CHEN S.‐C. , TUNG M.‐C. , CHEN S.‐P. , TSAI J.‐F. , WANG P.‐C. , CHEN R.‐S. , LIN S.‐C. , ADAMS A.
Published: April 2006

Abstract. A rickettsia‐like organism was observed in diseased Nile tilapia, Oreochronuis niloticus (L.), from southern Taiwan. Most affected fish were pale and lethargic with haemorrhages and ulcers on the skin. The most significant gross pathological changes were varying degrees of ascites, and enlargement of the spleen, kidney and liver. Marked white nodules (as ring‐shaped foci), varying in size, were found in these organs. A Gram‐negative, rickettsia‐like organism (RLO) frequently appeared as inclusions or within host cell intra‐cytoplasmic vacuoles. Fibrin thrombi, perivascular necrosis, chronic inflammatory cells with hypertrophy and RLO‐laden cells were characteristic of the disease. White nodules induced in experimental fish were similar to naturally infected cases and RLOs were reisolated in tissue culture using a CHSE‐214 cell line. This provides evidence that the systemic granulomas in Nile tilapia were caused by RLOs.
Infectivity of internal tissues of Atlantic salmon, Salmo salar L., experimentally infected with the aetiological agent of infectious salmon anaemia (ISA)
Authors: DANNEVIG B. H. , FALK K. , SKJERVE E.
Published: April 2006

Abstract. Infectivity of internal organs and cells of Atlantic salmon, Salmo salar L., was studied at various times after infection with the aetiological agent of infectious salmon anaemia (ISA). Experimentally infected salmon smolts developed anaemia just prior to the onset of ISA‐mortality. ISA‐infectivity of preparations made from liver, kidney, spleen, plasma, red blood cells (RBC) and head kidney leucocytes was determined by inoculating Atlantic salmon parr with the respective preparations. ISA‐mortality was observed after inoculation of salmon parr with preparations of kidney and liver, and to a minor degree, with spleen and a fraction of head kidney leucocytes (WBC1) collected 7 days post‐infection. At 11 days post‐infection, the infectivity of these preparations increased and ISA‐infectivity was also observed with a second fraction of head kidney leucocytes (WBC2), red blood cells (RBC) and blood plasma. At this time, the ISA‐infectivity of kidney was not significantly higher (P > 0.05) than that of liver but was significantly higher than all other preparations as judged by Cox‐regression analysis. At days 14 and 18 post‐infection, the infectivity of kidney was significantly higher (P < 0.05) than that of liver, but not at 21 and 25 days post‐infection. Generally, the ISA‐infectivity of kidney was higher than spleen, head kidney leucocytes (WBC1 and WBC2), RBC and plasma, although the difference was not significant at all time points. For example, at day 25 post‐infection, the infectivity of kidney was only significantly higher than that of spleen and plasma. On a per gram basis, head kidney leucocytes proved to contain higher amounts of infectious matter than RBC. ISA‐infective leucocytes present in the kidney tissue may have contributed to a major part of the infectivity recognized in the kidney preparations. Thus, head kidney leucocytes and other kidney leucocytes also may be considered to be among the most important target cells of the aetiological agent of ISA.
Ultrastructural studies on intestinal response of carp, Cyprinus carpio L., to the pseudophyllidean tapeworm, Bothriocephalus acheilognathi Yamaguti, 1934
Authors: HOOLE D. , NISAN H.
Published: April 2006

Abstract. The pathological effects of Bothriocephalus acheilognathi on the gut of experimentally infected carp, Cyprinus carpio L., have been studied. Light and electron microscopical observations revealed that damage to the host gut was not restricted to the area engulfed by the bothria, and loss of gut microvilli and the separation and shedding of enterocytes occurred against the site of attachment. Lymphocytes, macrophages and eosinophils accumulated in the wall of the infected gut and migrated into the lumen where they adhered to the parasite tegument. The role of parasite‐derived and host‐produced factors in leucocyte migration and attachment to the worm are discussed.
Histopathology caused by Caligus epidemicus Hewitt (Copepoda: Caligidae) on captive Acanthopagrus australis (Günther) (Pisces: Sparidae)
Authors: ROUBAL F. R.
Published: April 2006

Abstract. Highest densities of copepodids (≤5.3 cm ‐2), chalimus (≤8.5 cm ‐2) and redundant filaments (≤6.7 cm‐2) of Caligus epidemicus were found on the anterodorsal and anteroventral flanks, head and pectoral fins of Acanthopagrus australis (Günther). Copepodids eroded the epidermis and usually attached their frontal filament to the basement membrane on the inter‐ray region of fins, as well as the fin rays or scales. Chalimus stages were associated with a healed epidermis and little tissue response. The most extensive tissue response was associated with the redundant frontal filament, and was characterized by infiltrating macrophages, multinucleated giant cells, and epidermal and fibroblast proliferation. No significant pathology could be attributed to either pre‐adult or adult copepods.
Infection of the yellow head baculo‐like virus (YBV) in two species of penaeid shrimp, Penaeus stylirostris (Stimpson) and Penaeus vannamei (Boone)
Authors: LU Y. , TAPAY L. M. , BROCK J. A. , LOH P. C.
Published: April 2006

Abstract. Yellow head baculo‐like virus infection and disease were demonstrated experimentally in the two main species of penaeid shrimp cultured in Hawaii and the Western hemisphere. Viral infection was induced by intramuscular inoculation of a 10% suspension of cephalothorax tissue filtrate prepared from two tiger shrimp, Penaeus monodon Fabricius, infected with yellow head disease, into sub‐adult (3–10g) P. stylirostris (Stimpson) and P. vannamei (Boone). Signs of disease appeared as early as 2 days post infection (p.i.), and in most cases mortality reached 100% within 5–7 days p.i. Histopathological examination of the infected animals revealed extensive cellular necrosis in ectodermal and some mesenchymal tissues. Electron microscopical examination of thin sections of the gill and hepatopancreas from the infected shrimp revealed non‐occluded rod‐shaped baculo‐like virus particles measuring 130–197 & 45–58 nm which were primarily localized within the cytoplasm of infected cells. The virus particles were contained within cytoplasmic vacuoles, and occurred singly or in small groups of two or more particles.
Comparison of pathological changes due to deficiency of vitamin C, vitamin E and combinations of vitamins C and E in rainbow trout, Oncorhynchus mykiss Walbaum)
Authors: FRISCHKNECHT R. , WAHLI T. , MEIER W.
Published: April 2006

Abstract. Young rainbow trout were fed diets containing different combinations of ascorbyl‐monophosphatc (vitamin C) and all‐rac‐alpha‐tocopheryl acetate (vitamin E) for 31 weeks. The fish fed a diet deficient in both vitamins exhibited a high mortality and were anaemic after 8–12 weeks. Histopathological examination revealed a severe muscular dystrophy and splenic haemosiderosis. Fish fed a diet deficient in vitamin C but high in vitamin E developed the typical signs of vitamin C deficiency after 16–20 weeks, including reduced growth rate, haemorrhages and gill alterations as well as severe deformations and fractures of the vertebral column. A diet deficient in vitamin E but high in vitamin C led to splenic haemosiderosis after 20 weeks. At the end of the experiment, this group showed significantly decreased haematocrit, haemoglobin content and red blood cell numbers and increased spontaneous erythrocytc haemolysis. In a second experiment, older fish of the same origin were fed diets containing high or low levels of ascorbyl‐monophosphatc and all‐rac‐alpha‐tocopheryl acetate, respectively, for 23 weeks. The results were qualitatively the same as in the first experiment, but the onset of mortality in fish fed the diet deficient in both vitamins occurred later (weeks 18–23) and deformations of the vertebral column were absent. Haematocrit, haemoglobin content and red blood cell numbers were significantly decreased in the group fed the diet deficient in both vitamins and crythrocyte haemolysis was increased in both groups receiving a vitamin E free diet, the diet deficient in both vitamins having a more pronounced effect. The results of these two experiments indicate that there is an interrelation between vitamins C and E in rainbow trout. Possible mechanisms are discussed.
A histopathological disease survey of cultured shrimp in North East Sumatera, Indonesia
Authors: TURNBULL J. F. , LARKINS P. E. , McPADDEN C. , MATONDANG R.
Published: April 2006

Abstract. A disease survey was conducted in North East Sumatera, Indonesia, during June and July 1991. The objeet was to obtain information regarding the diseases present in shrimp culture faeilities. Shrimp were sampled for histopathological examination and details of the farm management and environment were recorded. The stocks sampled included some reported to be suffering from disease problems and some reported to be in good health. Samples were taken from 24 pond farms, five hatcheries and a broodstock fisherman. All farms and hatcheries cultured Penaeus monodon Fabricius, one farm also cultured Penaeus merguiensis de Mann, and two cultured Metapenaeus spp. Several wild caught P. monodon female broodstoek and some wild rice shrimp (Acetes spp.) were also sampled. The disease conditions detected in P. monodon were monodon baculovirus (MBV), hepatopancreatic parvo‐likc virus (HPV), septic hcpatopancreatic necrosis (SHN), bacterial septicaemia (BS), haernocytie enteritis (HE), lymphoid organ pathology (LOP), external fouling organisms (EFO), and a single unconfirmed case of infectious hypodcrmal and haemopoietic necrosis (IHHN). The Acetes spp. from one site had a microsporidean infection in the striated muscle of the abdomen. EFO was the most common disease condition, and was identified in 16 farms and three hatcheries. MBV was detected in 14 farms, three hatcheries and in one broodstoek. SHN was found in 13 farms with one case of concurrent BS and LOP was found in eight farms. HE was found in four farms and HPV was identified in shrimp with MBV on two farms and as the only disease in one broodstoek. The significance and implications of these findings for the developing industry in Indonesia arc discussed.
Relationship between fish growth rate and progression of artificially induced erythrocytic inclusion body syndrome in coho salmon, Oncorhynchus kisutch (Walbaum)
Authors: TAKAHASHI K. , OKAMOTO N. , KUMAGAI A. , MAITA M. , ROHOVEC J. S. , IKEDA Y.
Published: April 2006

Abstract. Studies were conducted to clarify the relationship between growth rate and disease progression of erythrocytic inclusion body syndrome (EIBS) in artificially infected coho salmon, Oncorhynchus kisutch (Walbaum). In the diseased state, the haematocrit values decreased and the number of erythrocytes with inclusions was higher in faster growing fish. Rapid growth was accompanied by an abundance of immature erythrocytes, which had the greatest incidence of inclusion bodies.
Antigenic analysis of Norwegian aquatic birnavirus isolates using monoclonal antibodies—with special reference to fish species, age and health status
Authors: MELBY H. P. , CASWELL‐RENO P. , FALK K.
Published: April 2006

Abstract. A panel of 11 monoclonal antibodies (MAbs) was used in an immunodot assay to investigate the antigenic relationship of a representative selection of aquatic biroaviruses isolated in Norway from different species of both carrier and diseased fish. All the 81 isolates shared a serogroup A‐speeifie epitopc, and 67 of them had a reaction pattern identical to the Sp‐type strain. Of the other 14 isolates, nine resembled the Sp‐type strain, two resembled both the Sp‐ and He‐type strains, two were closest to the Ab‐type strain and one resembled the Te‐type strain. Sp‐related strains were predominant from all nine host groups, including from both Atlantic salmon, Salmo salar L., with infectious pancreatic necrosis (IPN) and healthy. Atlantic salmon. The N1 strain reacted identically to the Sp‐type strain.
Protozoan parasites of gilthead sea bream, Sparus aurata L., from different culture systems in Spain
Authors: ALVAREZ‐PELLITERO P. , ADILLA A. SITJÀ‐BOB , FRANCO‐SIERRA A. , PALENZUELA O.
Published: April 2006

Abstract. In a parasitic survey of gilthead sea bream, Sparus aurata L., cultured in different systems in Spain, eight protozoan species were found. Ectoparasites included two ciliates (Trichodina sp. and a Cryptocaryon‐like species), one dinoflagellate (Amyloodinium sp.) and the zooflagellate Ichthyobodo sp. Endoparasites were represented by members of the Apicomplexa (Eimeria sp.) and Myxosporea (Polysporoplasma sparis. Ceratomyxa sp. and Leptotheca sp.). Ichthyobodo sp., Eimeria sp., Ceratomyxa sp. and Leptotheca sp. are reported for the first time in S. aurata. Amyloodinium sp. and Ichthyobodo sp. were associated with outbreaks of disease in larval and juvenile fish. Data on prevalence and intensity of infection and the location in the host are provided. The potential importance of these protozoan parasites for gilthead sea bream culture is discussed.
Melano‐macrophage centres in the gonads of the swamp eel, Synbranchus marmoratus Bloch, (Pisces, Synbranchidae): histological and histochemical characterization
Authors: RAVAGLIA M. A. , MAGGESE M. C.
Published: April 2006

Abstract. During a study of the gametogenesis of the swamp eel. Synbranchus marmoratus Bloch, conspicuous structures were found randomly distributed among the germinal cells and gonadal stroma. At low magnification, these structures appeared as yellowish to dark spherical bodies. Histological and histochemical examination showed clusters of cells with generally pyknotic nuclei and cytoplasm containing lipofusein‐like substances. A comparison of these structures with the melano‐macrophage centres (MMCs) present in the liver and spleen, showed the same structure and features. Their presence and function in the gonads of S. marmoratus might be related not only with the basic functions of the MMCs, but also with the degradation of atretic and/or non‐ovulated follicules, principally during the post‐spawning period.
A reliable method for the induction of experimental furunculosis
Authors: BRICKNELL I. R.
Published: April 2006

Abstract. A series of experiments were carried out to assess the reproducibility of a bath challenge model to induce experimental furunculosis. The challenge method was shown to reliably induce a control mortality of 78.9 ± 3.8%. Although the method was shown to be robust, some tanks failed to achieve an acceptable control mortality. The reasons for this are unclear; however, the failure of a tank to induce a satisfactory control mortality is related to a rapid disappearance of the initial inoculum. The reason for the disappearance of the inoculum appears to be related to the presence of hydrophobic regions in the challenge tank.
Rickettsia‐like organisms in the blue‐eyed plecostomus, Panaque suttoni (Eigenmann & Eigenmann)
Authors: KHOO L. , DENNIS P. M. , LEWBART G. A.
Published: April 2006

Abstract. Intracytoplasmic organisms resembling rickettsia were observed in tissues of two blue‐eyed plecostoitius, Panaqae suttoni (Eigenmann & Eigenmann), a tropical freshwater fish. Gross lesions were limited to renomegaly and splenomegaly. Cytopathological and histopathological examination of the various tissues revealed numerous small, discrete, coccoid organisms in the cytoplasm of monocytes as well as tissue macrophages of the spleen, heart, kidney and sometimes liver. Transmission electron microscopy confirmed that these organisms were within membrane‐bound vacuoles and had a morphology resembling rickettsia.
Elevation of plasma cortisol and hypertrophic response of inter‐renal and chromaffin tissues of rainbow trout, Oncorhynchus mykiss (Walbaum), to the harmful diatom Chaetoceros concavicornis
Authors: YANG C. Z. , ALBRIGHT L. J.
Published: April 2006

Abstract. Changes in plasma cortisol concentrations and inter‐renal and chromaffin tissues of rainbow trout, Oncorhynchus mykiss (Walbaum), exposed to harmful concentrations of the diatom Chaetoceros concavicornis were investigated. The plasma cortisol level of trout exposed to C. concavicornis was over 10‐fold greater than that of untreated trout. Computer‐assisted feulgen‐microspectrophotometry was employed in order to assess the activity of inter‐renal and chromaffin cells. The total areas of inter‐renal and chromaffin nuclei in trout treated with C. concavicornis significantly increased compared to those of untreated fish. In contrast, the chromatin density of inter‐renal and chromaffin nuclei in treated trout decreased significantly. This decrease of chromatin density in treated fish was caused by an increase in the low‐density components, and a decrease in the middle‐density and high‐density components. Although the hypertrophic changes to the inter‐renal and chromaffin nuclei of treated fish exhibited the same general trend, the extents to which the changes took place were different, occurring more rapidly within inter‐renal tissues. The rainbow trout exposed to harmful concentrations of C. concavicornis were experiencing a severe physiological disturbance to which they tried to adapt.