bluuebunny/crossref_metadata_2025 huggingface dataset:
Nosocomial Serratia marcescens Outbreak in Osaka, Japan, From 1999 to 2000
Authors: Takahashi Hiroshi , Kramer Michael H. , Yasui Yoshinori , Fujii Hayato , Nakase Katsumi , Ikeda Kazunori , Imai Tatsuya , Okazawa Akiko , Tanaka Tomoyuki , Ohyama Takaaki , Okabe Nobuhiko
Published: April 2006

Objectives:

To investigate and control an outbreak of bloodstream infections (BSIs) caused by Serratia marcescens and to identify risk factors for respiratory colonization or infection with S. marcescens.

Design:

Epidemiologic investigation, including review of medical and laboratory records, procedural investigations, pulsed-field gel electrophoresis (PFGE) typing of environmental and patient isolates, statistical study, and recommendation of control measures.

Patients and Setting:

All patients admitted to a 380-bed, secondary-care hospital in Osaka Prefecture, Japan, from July 1999 through June 2000 (study period).

Results:

Seventy-one patients were colonized or infected with S. marcescens; 3 patients who developed primary BSIs on the same ward within 5 days in June 2000 had isolates with indistinguishable PFGE patterns and indwelling intravenous catheters for more than 5 days. On multivariate analysis, among 36 case-patients with positive sputum specimens and 95 control-patients, being bedridden (odds ratio [OR], 15.91; 95% confidence interval [CI95], 4.17-60.77), receiving mechanical ventilation (OR, 7.86; CI95, 2.27-27.16), being older than 80 years (OR, 3.12; CI95, 1.05-9.27), and receiving oral cleaning care (OR 3.10; CI95, 1-9.58) were significant risk factors. S. marcescens was isolated from the fluid tanks of three nebulizers and a liquid soap dispenser. The hospital did not have written infection control standards, and many infection control practices were found to be inadequate (eg, respiratory equipment was used without disinfection between patients).

Conclusions:

Poor hospital hygiene and the lack of standard infection control measures contributed to infections hospital-wide. Recommendations to the hospital included adoption of written infection control policies.
THE PERSIAN GULF, GLOBAL OIL RESOURCES, AND INTERNATIONAL SECURITY
Authors: CHAPMAN DUANE , KHANNA NEHA
Published: April 2006

This article analyzes the interaction of politics and military security in global oil markets since the 1980s. The authors outline the historical evolution of the pricing structure that maintained a stable world oil market. They argue that the security framework underlying this pricing structure relied on a trade‐off between price stability and military security that has contributed to growing political instability in individual Persian Gulf countries and the rise of Al Qaeda and similar groups. The article concludes with a discussion of the pros and cons of three possible policy approaches to this dilemma—a “hands‐off” approach that is similar to the policy that prevailed between 1973 and 1990, a unilateral security system organized and led by the United States, and an international security framework. (JEL D47, F02, L11, Q32, Q41, Q43, Q48)
Transcriptome Analysis of Cold Acclimation in Barley Albina and Xantha Mutants
Authors: Svensson Jan T. , Crosatti Cristina , Campoli Chiara , Bassi Roberto , Stanca Antonio Michele , Close Timothy J. , Cattivelli Luigi
Published: April 2006

Previously, we have shown that barley (Hordeum vulgare) plants carrying a mutation preventing chloroplast development are completely frost susceptible as well as impaired in the expression of several cold-regulated genes. Here we investigated the transcriptome of barley albina and xantha mutants and the corresponding wild type to assess the effect of the chloroplast on expression of cold-regulated genes. First, by comparing control wild type against cold-hardened wild-type plants 2,735 probe sets with statistically significant changes (P = 0.05; ≥2-fold change) were identified. Expression of these wild-type cold-regulated genes was then analyzed in control and cold-hardened mutants. Only about 11% of the genes cold regulated in wild type were regulated to a similar extent in all genotypes (chloroplast-independent cold-regulated genes); this class includes many genes known to be under C-repeat binding factor control. C-repeat binding factor genes were also equally induced in mutants and wild-type plants. About 67% of wild-type cold-regulated genes were not regulated by cold in any mutant (chloroplast-dependent cold-regulated genes). We found that the lack of cold regulation in the mutants is due to the presence of signaling pathway(s) normally cold activated in wild type but constitutively active in the mutants, as well as to the disruption of low-temperature signaling pathway(s) due to the absence of active chloroplasts. We also found that photooxidative stress signaling pathway is constitutively active in the mutants. These results demonstrate the major role of the chloroplast in the control of the molecular adaptation to cold.
Use of Bacterial Quorum-Sensing Components to Regulate Gene Expression in Plants
Authors: You Young-Sook , Marella Heather , Zentella Rodolfo , Zhou Yiyong , Ulmasov Tim , Ho Tuan-Hua David , Quatrano Ralph S.
Published: April 2006

We describe an efficient inducible system to regulate gene expression in plants based on quorum-sensing components found in Gram-negative bacteria such as Agrobacterium tumefaciens. These bacteria monitor their own population density by utilizing members of the N-acyl homoserine lactone family as inducers and a transcriptional activator as its receptor. In our study, we utilize the components from A. tumefaciens (i.e. 3-oxooctanyl-l-homoserine lactone [OOHL]) synthesized by the TraI protein and its receptor, TraR. When OOHL binds to TraR, it recognizes its specific cis-element, the tra box. We translationally fused the eukaryotic VP16 activation domain to the N terminus of TraR. In the presence of OOHL, the chimeric VP16:TraR transcriptional regulator induces reporter gene expression in moss (Physcomitrella patens), barley (Hordeum vulgare), and carrot (Daucus carota) cells, as well as in transgenic Arabidopsis (Arabidopsis thaliana) seedlings. The inducible system shows a low level of reporter gene expression in the absence of the inducer. Foliar application and a floating-leaf assay in the presence of the inducer shows a 30- and 200-fold induction, respectively. Induction by foliar application of the inducer to whole seedlings is achieved within 8 h. The VP16:TraR activator also shows specificity for binding to its cognate inducer, OOHL. Based on microarray analyses, endogenous gene expression is not significantly affected due to overexpression of the TraR protein or presence of OOHL in either wild-type or lactone-inducible transgenic plants.
Integrating Membrane Transport with Male Gametophyte Development and Function through Transcriptomics
Authors: Bock Kevin W. , Honys David , Ward John M. , Padmanaban Senthilkumar , Nawrocki Eric P. , Hirschi Kendal D. , Twell David , Sze Heven
Published: April 2006

Male fertility depends on the proper development of the male gametophyte, successful pollen germination, tube growth, and delivery of the sperm cells to the ovule. Previous studies have shown that nutrients like boron, and ion gradients or currents of Ca2+, H+, and K+ are critical for pollen tube growth. However, the molecular identities of transporters mediating these fluxes are mostly unknown. As a first step to integrate transport with pollen development and function, a genome-wide analysis of transporter genes expressed in the male gametophyte at four developmental stages was conducted. Approximately 1,269 genes encoding classified transporters were collected from the Arabidopsis (Arabidopsis thaliana) genome. Of 757 transporter genes expressed in pollen, 16% or 124 genes, including AHA6, CNGC18, TIP1.3, and CHX08, are specifically or preferentially expressed relative to sporophytic tissues. Some genes are highly expressed in microspores and bicellular pollen (COPT3, STP2, OPT9), while others are activated only in tricellular or mature pollen (STP11, LHT7). Analyses of entire gene families showed that a subset of genes, including those expressed in sporophytic tissues, was developmentally regulated during pollen maturation. Early and late expression patterns revealed by transcriptome analysis are supported by promoter∷β-glucuronidase analyses of CHX genes and by other methods. Recent genetic studies based on a few transporters, including plasma membrane H+ pump AHA3, Ca2+ pump ACA9, and K+ channel SPIK, further support the expression patterns and the inferred functions revealed by our analyses. Thus, revealing the distinct expression patterns of specific transporters and unknown polytopic proteins during microgametogenesis provides new insights for strategic mutant analyses necessary to integrate the roles of transporters and potential receptors with male gametophyte development.
PH4 of Petunia Is an R2R3 MYB Protein That Activates Vacuolar Acidification through Interactions with Basic-Helix-Loop-Helix Transcription Factors of the Anthocyanin Pathway
Authors: Quattrocchio Francesca , Verweij Walter , Kroon Arthur , Spelt Cornelis , Mol Joseph , Koes Ronald
Published: April 2006

The Petunia hybrida genes ANTHOCYANIN1 (AN1) and AN2 encode transcription factors with a basic-helix-loop-helix (BHLH) and a MYB domain, respectively, that are required for anthocyanin synthesis and acidification of the vacuole in petal cells. Mutation of PH4 results in a bluer flower color, increased pH of petal extracts, and, in certain genetic backgrounds, the disappearance of anthocyanins and fading of the flower color. PH4 encodes a MYB domain protein that is expressed in the petal epidermis and that can interact, like AN2, with AN1 and the related BHLH protein JAF13 in yeast two-hybrid assays. Mutation of PH4 has little or no effect on the expression of structural anthocyanin genes but strongly downregulates the expression of CAC16.5, encoding a protease-like protein of unknown biological function. Constitutive expression of PH4 and AN1 in transgenic plants is sufficient to activate CAC16.5 ectopically. Together with the previous finding that AN1 domains required for anthocyanin synthesis and vacuolar acidification can be partially separated, this suggests that AN1 activates different pathways through interactions with distinct MYB proteins.
Field and experimental studies of hybridization between coral trouts, Plectropomus leopardus and Plectropomus maculatus(Serranidae), on the Great Barrier Reef, Australia
Authors: Frisch A. , Van Herwerden L.
Published: April 2006

Spawning aggregations of closely‐related coral trouts, Plectropomus leopardus and Plectropomus maculatus, were found to overlap in time and space on the Great Barrier Reef, thus providing opportunities for accidental hybridization by juxtaposition of heterospecific gametes. The relative abundance and mating strategy of coral trouts also favoured hybridization, since mates could be either rare in some habitats or monopolized by dominant fishes. In the latter case, sneak spawning may have occurred, even when behavioural barriers to reproduction (e.g. assortative mating) were operational. When heterospecific gametes were experimentally mixed, fertilization occurred and hybrid larvae developed. It was concluded that there was considerable opportunity for natural hybridization between coral trouts of the genus Plectropomus.
Temporal and spatial variation in growth of juvenile Atlantic salmon
Authors: Arnekleiv J. V. , Finstad A. G. , Rønning L.
Published: April 2006

Spatial and temporal variation in length‐at‐age and environmental factors affecting variation in growth rate of juvenile Atlantic salmonSalmo salarwere studied using data from a long‐term study in the River Stjørdalselva, central Norway. Mean annual instantaneous growth rate among 1+ and 2+year juvenile Atlantic salmon varied between 0·59 and 1·50 g g−1 year−1and mean instantaneous daily growth rate of young‐of‐the‐year (YOY) varied between 0·013 and 0·033 g g−1 day−1. Between year variation in growth was larger than the within year intra‐watercourse spatial variation. For YOY and 1+year Atlantic salmon, a major part of the observed between year variation in growth rates was explained by variation in mean daily water discharge and spring temperature. For 2+year juvenile Atlantic salmon, mean daily water discharge and cohort density were the only variables to significantly explain variation in growth rates. A large part of the within water‐course spatial variation could not be explained by temperature variations and juvenile Atlantic salmon in the uppermost areas of the river, experiencing the lowest ambient temperatures during the growth period, displayed the highest growth rates. Within the baselines set by temperature, biotic and abiotic factors connected to water flow regime and variation in food availability are suggested to be a major determinants of the temporal and spatial variation in juvenile Atlantic salmon growth rates.
Feeding habits and gill raker morphology of three planktivorous pelagic fish species off the coast of northern and western Kyushu in summer
Authors: Tanaka H. , Aoki I. , Ohshimo S.
Published: April 2006

Feeding habits and gill raker morphology were examined for the three major planktivorous pelagic fishes, Japanese anchovy Engraulis japonicus, Pacific round herring Etrumeus teres and Japanese jack mackerel Trachurus japonicus, off the northern and western coasts of Kyushu, in the north‐eastern part of the East China Sea in the summer months of 2001. Using fishes in the same size range (80–140 mm, standard length), the stomach contents of the three fish species were compared. The diet of the Japanese anchovy mainly consisted of Oncaeidae copepods, while the diets of the Pacific round herring and Japanese jack mackerel were dominated by calanoid copepods at all stations. Comparisons between prey size in the stomach, zooplankton size in the water and gill raker morphology suggested that the stomach contents of the three species were characterized mainly by the difference in the feeding behaviour between Japanese anchovy (filter‐feeding) and the other two species (particulate‐feeding), rather than by the difference in the morphology of feeding apparatus only. It was concluded that behavioural adaptations in the feeding of these pelagic fishes brought about trophic partitioning to some degree in this pelagic ecosystem in summer. Although the diets of these three species overlapped to some extent, there was still little likelihood of competition between the Japanese anchovy and the other two species. The potential for competition between the Pacific round herring and the Japanese jack mackerel is discussed.
Presence of serum tripartite motif‐containing 21 antibodies in patients with esophageal squamous cell carcinoma
Authors: Kuboshima Mari , Shimada Hideaki , Liu Tian‐Ling , Nomura Fumio , Takiguchi Masaki , Hiwasa Takaki , Ochiai Takenori
Published: April 2006

SEREX has been applied to esophageal SCC, and the TRIM21 gene was identified as a novel SEREX antigen of esophageal SCC. The presence of s‐TRIM21‐Abs was confirmed by Western blotting using bacterially expressed TRIM21 gene product and was evaluated for clinicopathological significance in patients with esophageal SCC. s‐TRIM21‐Abs were detected in 18 (20%) of 91 patients with esophageal SCC but not in 42 healthy donors. The presence of s‐TRIM21‐Abs was partly associated with tumor size (P = 0.063) and poor survival (P = 0.067). To measure serum antibody levels, ELISA using purified recombinant TRIM21 protein was developed. The levels of s‐TRIM21‐Abs were significantly higher in patients with esophageal SCC than in healthy donors (P = 0.013). s‐TRIM21‐Abs may be a useful tumor marker to diagnose and predict disease progression in patients with esophageal SCC. (Cancer Sci 2006; 97: 380–386)
Cell cycle arrest and apoptotic induction in LNCaP cells by MCS‐C2, novel cyclin‐dependent kinase inhibitor, through p53/p21WAF1/CIP1pathway
Authors: Park Hae Young , Kim Min Kyoung , Moon Sang‐Ik , Cho Youl‐Hee , Lee Chul‐Hoon
Published: April 2006

The purpose of the present study was to investigate the mechanisms involved in the antiproliferative and apoptotic effects of MCS‐C2, a novel analog of the pyrrolo[2,3‐d]pyrimidine nucleoside toyocamycin and sangivamycin, in human prostate cancer LNCaP cells. MCS‐C2, a selective inhibitor of cyclin‐dependent kinase, was found to inhibit cell growth in a time‐ and dose‐dependent manner, and inhibit cell cycle progression by inducing the arrest of the G1 phase and apoptosis in LNCaP cells. When treated with 3 µM MCS‐C2, inhibited proliferation associated with apoptotic induction was found in the LNCaP cells in a concentration and time‐dependent manner, and nuclear DAPI staining revealed the typical nuclear features of apoptosis. Furthermore, MCS‐C2 induced cell cycle arrest in the G1 phase through the upregulated phosphorylation of the p53 protein at Ser‐15 and activation of its downstream target gene p21WAF1/CIP1. Accordingly, these results suggest that MCS‐C2 inhibits the proliferation of LNCaP cells by way of G1‐phase arrest and apoptosis in association with the regulation of multiple molecules in the cell cycle progression. (Cancer Sci2006; 97: 430 –436)
Why are there so many small plants? Implications for species coexistence
Authors: AARSSEN LONNIE W. , SCHAMP BRANDON S. , PITHER JASON
Published: April 2006

The prominently right‐skewed distribution of species sizes has been the subject of a large literature in animal ecology, but has received comparatively little attention from plant ecologists. It is evident that not all explanations that have been offered for animals are directly applicable to plants.

We suggest three hypotheses that require further study in the interpretation of size‐dependent species richness in plants.

These hypotheses are all based on mechanisms that have generated, for smaller plants, a greater historical opportunity for speciation: (i) large adult plant size confers significant adaptation primarily in habitat types that have been relatively uncommon in space, across evolutionary time; (ii) relatively small species are more widely differentiated from each other in the environmental qualities defining their niches, many of which are made possible by the mere presence of larger species residing in the same habitat; and (iii) compared with large species, smaller species generally have higher fecundity allocation, i.e. they can produce a greater number of offspring per unit plant size per unit time, which generally confers a higher premium under most circumstances of natural selection, thus generating a potentially greater number of descendant individuals, and derived species.

We discuss the implications of these hypotheses in addressing an underlying paradox in plant competition/coexistence theory, i.e. that large adult size is assumed to be the principal trait that confers competitive ability yet, even in those habitat types where competition is assumed to reach the highest levels of intensity within vegetation, the vast majority of the resident species are, nevertheless, relatively small.
The isolation of a rickettsia‐like organism causing disease and mortality in Chilean salmonids and its confirmation by Koch's postulate
Authors: CVITANICH J. D. , GARATE N. O. , SMITH C. E.
Published: April 2006

Abstract. A rickettsia‐like organism (RLO) was isolated from infected coho salmon, Oncorhynchus kisutch (Walbaum), in cultures from six fish cell lines, but could not be cultured on 41 artificial media. The organism was confirmed by Koch's postulates as the aetiological agent of a systemic disease causing signifieant mortality among coho in Chile. The organism was a Gram‐negative, obligate intracellular pathogen frequently observed within intracyto‐plasmic vacuoles or inclusions of host cells, and appears to belong to the order Rickettsiales, family Rickettsiaceae and possibly the tribe Ehrlichiae. The organism, as well as the clinical signs and pathology it produces, is described. The disease, originally observed only in coho raised in seawater net pens, was reproduced experimentally in fish in both freshwater and seawater aquaria. Horizontal transmission without parasite vectors was observed in fish in both aquaria. The organism was shown, for the first time, to cause disease and mortality in Atlantic, Salmo salar L., and Chinook, O. tshawytscha (Walbaum), salmon and rainbow trout, O. mykiss (Walbaum). Because of the systemic nature of the disease, it is proposed that it be called ‘salmonid rickettsial septicaemia’.
Occurrence and treatment of cracked‐skull disease affecting Clarias spp. in homestead ponds in Nigeria
Authors: AWA J. N. , ALEGBELEYE W. O.
Published: April 2006

Abstract. Cracked‐skull disease, previously unrecorded in Nigeria, affected fish in 80% of the homestead ponds investigated in this study. It was peculiar to mud catfish, Clarias spp., under intensive culture in urban Lagos, Nigeria. Male and female fish that were more than 10cm in length were equally vulnerable. The accessory respiratory structures were involved, but the liver, kidney, heart and the other internal organs were not. At its peak, the infection was characterized by a lateral crack in the skull, which resulted in death. Dip treatment in either 2‐0ppm potassium permanganate or 0‐5ppm formalin (with alcohol) for 30s day 1resulted in 65‐0 and 41‐3% full recovery in 7 days, respectively. The implications of the disease for homestead fish culture are discussed.
Disseminated intravascular coagulation in farmed Atlantic salmon, Salmo salar L: evidence of consumptive coagulopathy
Authors: SALTE R. , NORBERG K.
Published: April 2006

Abstract. Atlantic salmon, Salmo salar L., suffering from ‘Hitra disease’ showed an increase in activated partial thromboplastin time and prothrombin time values, and a decrease to very low levels of plasma fibrinogen when compared to healthy controls. Together with a marked thrombocytopenia, these results present firm evidence of consumptive coagulopathy with disseminated intravascular coagulation in diseased fish. When the control pen was retested after 4 weeks, a consumptive coagulopathy was evident also in this group of fish. The fact that this pen came down with ‘Hitra disease’ about 8 weeks later strongly supports our hypothesis that DIG is a basic pathologic process in this disease.
Pathological effects of repeated doses of malachite green: a preliminary study
Authors: GERUNDO N. , ALDERMAN D. J. , CLIFTON‐HADLEY R. S. , FEIST S. W.
Published: April 2006

Abstract. This study reports the histopathogical observations made upon the livers and gills of rainbow trout exposed to a continuing series of exposures to l·6ppm 40 min baths of malachite green at weekly intervals. After the third week of exposure, sinusoidal congestion and focal necroses were evident on the livers. At the ultrastructural level, consistent mito‐chondrial damage was evident with swelling and disruption of the cristac, together with dilation of the rough endoplasmic reticulum. Nuclear alterations increased in severity in the later periods of exposure. However, these hepatic changes were not severe enough to be reflected in scrum protein changes. In the gills of treated fish, separation of the epithelial lining from both lamellar and interlamellar regions was noted and lamellar cell necrosis and leucocyte infiltration became more frequent with increased exposure.
Herpesvirus cyprini: lethality and oncogenicity
Authors: SANO T. , MORITA N. , SHIMA N. , AKIMOTO M.
Published: April 2006

Abstract. Cyprinid herpesvirus 1 (CHV) or Herpesvirus cyprini was virulent for carp, Cyprinus carpio L., fry following 1 h immersion in water at 20 °C. Cumulative mortality for carp fry was 86–97% in 2‐week‐old common carp, 20% in 4‐week‐old fancy carp, and 0% in both 8‐week‐old common and fancy carp. The virus did not produce mortality in fry of crucian carp, grass carp or other cyprinids. It was also oncogenic in carp, inducing papillomas to the extent of 55% among both common and fancy carp fry. The neoplasms appeared 5–6 months after carp had been exposed to the virus by immersion and recurred at an incidence of 83% in carp 7·5 months post‐desquamation of the tumour. The CHV was reisolated from all moribund fish and from all survivors. It also induced papillomas at an incidence of 13% in adult mirror carp and at 10% in adult fancy carp 5 months after intraperitoneal inoculation of 105 TCID50 ml‐1 fish. The virus was rcisolated only from the ncoplastic tissue and not from internal organs. The neoplasms were normally located on fin, skin or mandible, at the intraperitoneal inoculation site. Specific fluorescence for CHV antigen was frequently detected in the gills, liver, kidneys and intestine of 2‐week‐old fry from 3 to 21 days following challenge with CHV. It was found in greater concentrations in experimentally induced papillomata on 2‐week‐old carp fry survivors examined 24 weeks after challenge than in naturally occurring neoplasms.
Infection of mitogen‐stimulated trout leucocytes with salmonid viruses
Authors: ESTEPA A. , COLL J. M.
Published: April 2006

Abstract. The effects of infection with salmonid viruses on mitogen‐stimulated cells and colonies from rainbow trout, Oncorhynchus imkiss (Richardson), kidney cell cultures have been studied using culture in clots of fibrin. Phytohaemaglutinin, concanavalin A and lypo‐polysaccharides from Escherichia coli have been used as mitogens. The viral haemorrhagic septicaemia (VHS) virus destroyed any mitogen‐induced trout kidney colonies or cells, but the infectious pancreatic necrosis (IPN) virus caused no cell or colony death, and even increased their count in the cultures. The results suggested that the target for IPN virus replication is not any trout leucocyte but that among the possible targets of VHS virus are the different types of leucocytes found in the trout kidney and in their in vitro mitogen‐stimulated colonies.
The in vitro susceptibility of Aeromonas salmonicida and other fish‐pathogenic bacteria to 29 antimicrobial agents
Authors: INGLIS V. , RICHARDS R. H.
Published: April 2006

Abstract. The minimum inhibitory concentrations (MICs) of 29 antimicrobial agents were determined for some representative Aeromonas salmonidda, Yersinia ruckeri and Vibrio isolates. Eleven of them, including three widely used in clinical practice, were further tested against 28–36 recent field isolates of A. salmonidda. The fluoroquinolones were inhibitory at very low concentrations with 50% of A. salmonidda isolates having a MIC of enro‐floxacin ≤0·02μg ml‐1. The distribution of MICs to the fluoroquinolones and to oxolinic acid were similar indicating possible cross resistance. Amoxycillin, florfenicol, minocycline, rifampicin and the potentiated sulphonamides had a single peak MIC distribution with values of ≤1·25μg ml‐1. Minimum inhibitory concentrations of the fluoroquinolones were four or more times greater at 10°C compared with 22°C; this was not so with amoxycillin, florfenicol or the sulphachlorpyridazine‐trimethoprim (S‐TP) combination. A. salmonicida was rapidly killed at 22°C by the fluoroquinolones and S‐TP whereas oxolinic acid and amoxycillin killed within 24h. Florfenicol was bacteriostatic. The therapeutic potential of some of these antibiotics is considered.
Recovery of yellow‐pigmented bacteria from dead and moribund fish during outbreaks of rainbow trout, Oncorhynchus mykiss (Walbaum), fry syndrome in England
Authors: AUSTIN B. , STOBIE M.
Published: April 2006

Abstract. During Autumn 1990, the possible presence of microbial pathogens was investigated in two discrete populations of anaemic (rainbow trout fry syndrome; RTFS) rainbow trout fry. Dense pure culture growth of three types of yellow pigmentcd bacteria were recovered from moribund and dead animals on low nutrient media. The cultures were identified as coryneforms. Cytophaga columnaris and Janthinobacterium sp. All taxa induced clinical disease (with similarities to RTFS) in rainbow trout fry.
Cloning and characterization of the haemolysin determinants from Aeromonas hydrophila
Authors: AOKI T. , HIRONO I.
Published: April 2006

Abstract. Two haemolysin genes (AHH4 and AHH‐2) of Aeromonas hydrophila ATCC7966 were cloned into a plasmid vector in Escherichia coli K‐12. An open reading frame (ORF) of the AHH‐1 haemolysin gene was 1734 base pairs (bp). and corresponded to a protein of 577 amino acid residues. Analysis of the deduced amino sequence indicated a highly hydrophobic N‐terminal region which had the characteristics of a leader peptide. The sequence also included the ‐10 region and the ‐35 region of a promoter, and a ribosome‐ binding site upstream from the ORF. The termination site was located downstream from the ORF. The haemolysin was a thermolabile protein with the predicted molecular mass of 60 kDa. The AHH‐1 gene is distributed in various A. hydrophila and A. salmonicida strains. The nucleotide sequence of a 981 bp ORF of the AHH‐2 gene was encoded with the predicted molecular mass of 377 kDa polypeptides. The homology of the nucleotide sequence was very low between the AHH‐1 and AHH‐2 genes, and also with the aerolysin gene cloned by Howard & Buckley (19S6). No leader peptide was found in the N‐terminal region of the ORF of the AHH2 gene. The AHH‐2 gene was detected in the original strain ATCC7966, but was not detected in other tested strains of A. hydrophila and A. salmonicida.
Differences in resistance of carp, Cyprinus carpio L., to atypical Aeromonas salmonicida
Authors: HOUGHTON G. , WIERGERTJES G. F. , GROENEVELD A. , VAN MUISWINKEL W. B.
Published: April 2006

Abstract. The degree of resistance to an atypical strain of Aeromonas salmonicida, the causative bacterium of carp erythrodermatitis, was examined in two strains of carp, Cyprinus carpio L.: a Polish line. R3, sixth generation of conventional inbreeding (full‐sib matings); and a Hungarian line. R8, fifth generation of conventional inbreeding. Comparisons were made between and within the two strains. Results showed a significant difference (P < 0·001) in the degree of resistance, with the Hungarian carp showing greater resistance than the Polish carp. Differences within each strain were also observed indicating a maternal influence on resistance. Two transferrin genotypes in three genetic combinations were identified (DD, DG, GG) but were not found to influence resistance.
Modified extracellular product antigens of Aeromonas salmonicida as potential vaccines for the control of furunculosis in Atlantic salmon, Salmo salar L.
Authors: TATNER M. F.
Published: April 2006

Abstract. Extracellular product (ECP) antigens of Aeromonas salmonicida were modified in an attempt were tested on an antigen‐induced proliferation assay, for the ability to induce antibodies as measured by dot blot dot assay and as vaccines in vaccination/challenge trials. Modifications tested included particularization on to polystyrene beads, coating on to sheep red blood cells, mixing with BCG vaccine as adjuvant, and attachment to the T‐independent carrier Fieoll. The only modification that resulted in increased protection levels was the particularization on to polystyrene beads.
Immunological response of the Indian major carps to Aeromonas hydrophila vaccine
Authors: KARUNASAGAR I. , ROSALIND G. , KARUNASAGAR I.
Published: April 2006

Abstract. Fingerlings of the three major types of Indian carp, i.e. Catla catla (Hamilton), Labeo rohita (Hamilton) and Cirrhunas mrigala (Hamilton), were immunized using a haemolysin‐negative mutant of Aeromonas hydrophila. Very high titres of antibodies were induced in C. catla, followed by C. mrigala and L. rohita. Immunized fish showed good protection against homologous challenge. Moderate protection against heterologous challenge was observed in C. mrigala and L. rohita.
Antigenic relationships among rotaviruses isolated from fish
Authors: DOPAZO C. P. , TORANZO A. E. , SAMAL S. K. , ROBERSON B. S. , BAYA A. , HETRICK F. M.
Published: April 2006

Abstract. An antigenic comparison of five rotaviruses isolated from fish in Spain, the USA and Canada was carried out using neutralization, immunodot and ELISA tests. The Spanish isolate (turbot rotavirus) was serologically different from the other four rotaviruses, by neutralization and immunodot. By these two techniques, among the four American strains the two isolates from Canada (smelt rolavirus and Atlantic salmon rotavirus) were closely related antigenically, and the two strains from USA (striped bass rotavirus and the Hetrick & Baya rotavirus, isolated from salmon) seemed to be the same scrotype. These results were supported by those obtained in the comparison of the RNA patterns of the five viruses. However, the antigenie relationships among these rotaviruses were very different when employing the ELISA technique.
Inhibition of bacterial fish pathogens by Tetraselmis suecica
Authors: AUSTIN B. , BAUDET E. , STOBIE M.
Published: April 2006

Abstract. Supernatants and extracts derived from a commercial heterotrophically grown spray‐dried preparation of Tetraselmis suecica were observed to inhibit Aeromonas hydrophila, A. salmonicida, Lactobacillus sp., Serratia liquefaciens, Staphylococcus epidermidis, Vibrio anguillariim, V. salmonicida and Yersinia ruckeri type I, but not Planococcus sp., Pseudomonas fluorescens, Streptococcus sp., V. ordalii or Y. ruckeri type II by in vitro methods. When used as a food supplement, the algal cells inhibited laboratory‐induced infections in Atlantic salmon. Moreover, there was a reduction in bacterial numbers in tank water. When used therapcutically, algal cells and their extracts reduced mortalities caused by A, salmonicida, Ser. liquefaciens, V. anguillariim, V. salmonicida and Y. ruckeri type I.
Caudal deformity syndrome (CDS): an autosomal recessive lethal mutation in the tilapia, Oreochromis niloticus (L.)
Authors: MAIR G. C.
Published: April 2006

Abstract. Deformities consisting of an upward curvature of the spine in the caudal region with varying degrees of reduction of the caudal fin were observed in some fry of a laboratory population of Oreochromis niloticus (L.). This spinal deformity was combined with a reduction of the operculum, exposing some gill lamellae. No deformed fry survived for more than 7 days after completion of yolk sac absorption. Breeding tests demonstrate that the mutant phenotype is controlled by a single autosomal recessive gene.
Bacterial inhibitors affecting proteases produced byAeromonas salmonicida, and the occurrence of such inhibitors in furunculosis vaccines
Authors: SANDVIK O. , HVAAL A.‐B.
Published: April 2006

Abstract.Cultures ofAeromonas salmonicida, subspeciessalmonicidaandachromogenes, produced considerable quantities of inhibitors that affected extracellular bacterial proteases (endopeplidases), as well as some animal trypsins (from pig, salmon and trout) included in this study. Electrophoretic separation of these inhibitors revealed a complex of three to four single factors which were similar for the two subspecies. One of the factors only inhibited protease from the homologus subspecies, while another only affected enzyme from the other subspecies (cross‐wise inhibition). Both subspecies produced a factor which inhibited animal trypsins only. Subspeciessalmonicidaalso possessed a factor which inhibited most of the examined proteases unspecifically. In young cultures (2–3 days at 15°C), the inhibitors were demonstrable both in the disintegrated cell material and in cell‐free culture filtrate. The activity of the factor which only inhibited the protease from subspeciessalmonicidacould be increased considerably by moderate heating of the material. The effect of inhibitors produced by other relevant Gram‐negative bacteria on the proteases of theA. salmonicidasubspecies included was more limited. Considerable quantities of inhibitors against proteases of the subspeciessalmonicidaandachromogeneswere demonstrated in cell‐free filtrates of two commercially available vaccines against furunculosis in fish.
The influence of ultraviolet‐B radiation on the mechanism of wound repair in the skin of the Atlantic salmon, Salmo salar L.
Authors: BULLOCK A. M. , ROBERTS R. J.
Published: April 2006

Abstract. Exposure of surgically damaged skin of Atlantic salmon, Salmo salar L., to low levels of ultraviolet‐B radiation in clear water showed that the basic mechanism of superficial wound healing, characterized by epidermal migration, was unaffected. However, the migrating cells were more vulnerable to the necrotizing effects of the irradiation than the surrounding donor epithelium and longer standing effects such as wound contracturc and resolution of epidermal structure failed to occur.
Herpesvirus cyprini: detection of the viral genome by in situ hybridization
Authors: SANO N. , SANO M. , SANO T. , HONDO R.
Published: April 2006

Abstract. A method of in situ hybridization with biotinylated probes is described for the spceific detection of the Herpesvirus cyprini (CHV) genome, both in CHV infected cell cultures and tissue specimens prepared from carp fry infected with the same virus. From molecularly cloned PstI‐fragments of CHV DNA, two fragments were selected as probes for in situ hybridization which had no detectable homology, either with DNA of fathead minnow (FHM) cells used for virus propagation, or with the DNA of several fish herpes‐viruses. The method of in situ hybridization was based on a system using streptavidin‐biotinylated alkaline phosphatase for the detection of hybridization.
Plasmids and antibiotic resistance in Aeromonas hydrophila isolated in Malaysia from healthy and diseased fish
Authors: ANSARY A. , HANEEF R. M. , TORRES J. L. , YADAV M.
Published: April 2006

Abstract. Thirty‐four A. hydrophila strains isolated from various fish species and several geographical locations in Malaysia were examined for their antibiotic resistance pattern and plasmid carriage. All strains were found to possess multiple resisitance, most commonly to ampicillin and carbenicillin. Six different antibiogroups representing 18 different antibiotic patterns were obtained. There were no differences in the resistance patterns of A. hydrophila isolates from healthy and diseased fish with ulcerative syndrome. Rifampicin was found to be the most active antibiotic against these strains. Isolation of plasmid DNA have a plasmid occurrence rate of only 14·7%. The molecular sizes of these plasmids ranged from 2·6 to 6Mda. Multiple carriage of plasmid is more likely with strains having three of four plasmids.
Development of a selective‐differential medium for the isolation of Yersinia ruckeri and its application in epidemiological studies
Authors: RODGERS C. J.
Published: April 2006

Abstract. The development of a selective‐differential medium (ROD) for the isolation of Yersinia ruckeri from carrier and clinically infected rainbow trout, Oncorhynchus mykiss (Walbaum), is described. This medium was a useful aid for the detection of Y. ruckeri in faecal material and allowed the epidemiology of enteric redmouth disease to be studied in greater detail. Regular use of ROD at two fish farms in southern England has demonstrated that isolation of Y. ruckeri from faeces was possible under field conditions up to 4–6 weeks before acute clinical kidney infection occurred.
Toxicity of intraperitoneally injected formalin in Atlantic salmon, Salmo salar L.
Authors: NILSEM H. , LILLEHAUG A. , TAKSDAL T. , NORDMO R.
Published: April 2006

Abstract. Atlantic salmon, Salmo salar L., parr were injected intraperitoneally with different quantities of formalin (37% formaldehyde) following anaesthetization with either benzocaine (ethyl‐p‐aminobenzoate) or chlorbutol (1,1,1,‐trichloro 2‐methyl‐2‐propanol) The LD50 for injected formaldehyde was found to be approximately 50mg kg−1 body weight. The type and concentration of the anaesthetic used did not influence mortality rates. Formalin is commonly used to inactivate microorganisms in vaccines. Doses of formalin which were shown to be toxic in this study are close to those which may be injected into fish as a component of various vaccines against bacterial fish diseases. Hence, the formalin content in fish vaccines may well cause mortality under certain conditions.
Field testing of adjuvanted furunculosis vaccines in Atlantic salmon, Salmo salar L.
Authors: LILLEHAUG A. , LUNDER T. , POPPE T. T.
Published: April 2006

Abstract. Two different commercial vaccines against furunculosis, caused by Aeromonas salmonicida subsp. salmonicida, were tested in Atlantic salmon on seven fish farms. Both vaccines were based on formalin‐inaclivated bacterins containing aluminium salts as adjuvants. The fish were vaccinated by intraperitoneal injection in the spring approximately one month prior to transfer to sea water, and they were challenged by natural outbreaks of furunculosis. During the first year, six of the farms experienced disease outbreaks. The overall mortality was 7·14% in vaccinated fish and 21·7% in unvaccinated controls, giving a relative percentage survival (RPS) of 67%. In the seventh farm, outbreaks of furunculosis more than one year after vaccination revealed that there was still a trend towards lower mortality in vaccinated fish, though the mean RPS fell to 22%. The use of adjuvants in the vaccines resulted in local lesions in the abdominal cavity of vaccinated fish. However, the severity of the lesions declined gradually, and they did not influence fish quality at the time of slaughtering. Vaccination also had a moderately adverse impact on fish weight gain in most cases.
Ichthyophthiriasis in carp, Cyprinus carpio L.: fate of parasites in immunized fish
Authors: CROSS M. L. , MATTHEWS R. A.
Published: April 2006

Abstract. The host‐parasite relationship between O‐group carp and the ciliatc Ichthyophthirius multifiliis Fouquet was investigated, with the specific aim of characterizing the fate of parasites encountering immunized fish. Carp were immunized by repeated controlled infections; immunized fish and control fish naive to I. multifiliis were then infected in the caudal fin epidermis by a single controlled exposure to theronts, which were applied in a droplet suspension to the tail surface. The number of parasites present within the caudal fin was monitored over a subsequent 5‐day period by means of in situ parasite mapping. Results indicated that, contrary to previous reports, theronts penetrated the skin of immunized fish in numbers comparable to those of fish receiving a primary infection. However, the majority of parasites which penetrated immune skin did not complete normal development; 79% of the parasites which had initially penetrated the immune skin were not relocated within 2h of exposure, and since no parasite material was detected at penetration sites, it was concluded that these parasites had prematurely exited the skin rather than been killed in situ. Subsequently, these sites became populated by leucocytes, predominantly macrophages, and the infiltrations continued for up to 5 days after the initial exposure. In contrast, at sites where mature trophonts had exited the skin of fish following a primary infection, more diffuse leucocytic infiltrations were recorded, and these were predominated by neutrophils. Differences in the response to parasite exit from immunized and previously unexposed control fish skin are discussed, with particular reference to the mode of protection and the fate of parasites encountering immune fish.
The occurrence of a 70‐kDa serine protease gene in typical and atypical strains of Aeromonas salmonicida
Authors: WHITBY P. W. , DELANY S. G. , COLEMAN G. , MUNRO A. L. S.
Published: April 2006

Abstract. The typical strains of Aeromonas salmonicida examined secreted a PMSF‐sensitive proteolytic activity, and with few exceptions, gave a positive colony hybridization with a 70‐kDa scrinc protease gene probe. By contrast, atypical strains produced a spectrum of responses with various combinations of (1) secreted/did not secrete PMSF‐inhibited protease, (2) colonies hybridized/did not hybridize with the gene probe, and (3) produced protease not inhibited by PMSF. It is suggested that certain strains might be reassigned as typical or atypical on the basis of the presence or absence of the protease gene.
Experimental selection of mebendazole‐resistant gill monogeneans from the European eel, Anguilla anguilla L.
Authors: BUCHMANN K. , ROEPSTORFF A. , WALLER P. J.
Published: April 2006

Abstract Bath treatments with mebendazolc (MBZ) are commonly used for control of pseudodactylogyrosis in intensive eel eulture systems in Europe. To assess the potential for selection of drug‐resistant gill parasites in these systems, the authors have conducted a number of sub‐therapeutic treatments of an anthelmintic naive population of Pseudodactylogyrus bini (Kikuchi, 1929) Gussev, 1965, and P. anguillae (Yin et Sproson, 1948) Gussev, 1965, with different eoncentrations of MBZ. Parasite populations subtherapeutically treated seven times during a 7‐month period with 0.05 and 0.005 mg MBZI−1 developed a high and low relative resistance to MBZ, respectively. It was shown that low temperatures decreased the effect of MBZ. In addition, the benzimidazoles albendazole and triclabendazole produced a comparatively lower parasiticidal effect, and it is suggested that treatments at low temperatures or with low effect bcnzimidazoles will increase the risk of selection of drug‐resistant gill parasites in eel farms.
The sequential pathology of pancreas disease in Atlantic salmon farms in Ireland
Authors: MURPHY T. M. , RODGER H. D. , DRINAN E. M. , GANNON F. , KRUSE P. , KORTING W.
Published: April 2006

Abstract A description is given of cardiac and skeletal myopathy in Atlantic salmon, Sahno salar L., during pancreas disease. Post‐smous in two farms were sampled weekly from April to Oetober. Panereas disease was diagnosed at 9 and 13 weeks after sea transfer on the two farms, respeetively. Myodegenerative lesions were observed in the hearts of fish with hoth normal and diseased panereas. The prevalenee of heart lesions was highest amongst fish affeetcd with panereas disease. Skeletal myopathy of red fibres was observed only in fish in the recovery and chronic phases of disease, whereas white fibre changes were observed in fish with normal pancreas and fish affeetcd with panereas disease.
Infection of captive Pagrus auratus (Bloch & Schneider) by the monogenean, Anoplodiscus cirrusspiralis Roubal, Armitage & Rohde (Anoplodiscidae) in Australia
Authors: ROUBAL F. R. , QUARTARARO N. , WEST A.
Published: April 2006

Abstract The monogenean Anoplodiscus cirrtisspiralis infects the fins and nares of snapper, Pagrus auratus (Bloch & Schneider). The epidermis beneath the haptor in both microhabitats is eroded and the parasite attaches to the basement membrane by an adhesive secretion. Captive snapper suffered fin damage through high levels of infection by this parasite. Laboratory experiments showed A. cirrusspiralis to be adversely affected by reduced salinity and killed within 1 h by diluted sea water of < 5%0 salinity.
Infectious load of Aeromonas salmonicida subsp. salmonicida during the initial phase of a cohabitant infection experiment with Atlantic salmon, Salmo salar L.
Authors: ENGER Ø. , GUNNLAUGSDOTTIR B. , THORSEN B. K. , HJELTNES B.
Published: April 2006

Abstract The abundances of Aeromonas salmonicida subsp. salmonicida in the water and in the surface microlayer was studied during the initial phase of a cohabitant infection experiment with Atlantic salmon, Salmo salar L., smolt. Aeromonas salmonicida was detected in the water samples only until the intraperitoneally infected smolt were dead and had been removed. In the lipid rich surface microlayer, A. salmonicida was detected in high concentrations from the day of the first fish mortality and throughout the rest of the experiment. The significance of the high cell surface hydrophobicity is discussed as a possible reason for enrichment of A. salmonicida at the air‐water interface.