bluuebunny/crossref_metadata_2025 huggingface dataset:
Device-Associated Infection Rates for Non–Intensive Care Unit Patients
Authors: Vonberg Ralf-Peter , Behnke M. , Geffers C. , Sohr D. , Rüden H. , Dettenkofer M. , Gastmeier P.
Published: April 2006

Background.

Reference data from intensive care units (ICUs) are not applicable to non-ICU patients because of the differences in device use rates, length of stay, and severity of underlying diseases among the patient populations. In contrast to the huge amount of data available for ICU patients, appropriate surveillance data for non-ICU patients have been missing in Germany.

Objective.

To establish a new module (“DEVICE-KISS”) of the German Nosocomial Infection Surveillance System for generating stratified reference data for non-ICU wards.

Setting.

Non-ICU patients from 42 German hospitals.

Methods.

Monthly patient-days, device-days and nosocomial infections (NIs) (using Centers for Disease Control and Prevention definitions) were counted. Device use rates were calculated, and NI rates were stratified by different medical specialities.

Results.

From July 2002 through June 2004, among the 77 wards, there were a total of 536,955 patient-days and 74,188 device-days (for CVC-associated primary bloodstream infections, there were 181,401 patient-days and 8,317 central vascular catheter [CVC]-days in 29 wards; for urinary catheter–associated urinary tract infections, there were 445,536 patient-days and 65,871 urinary catheter–days in 65 wards) and 483 NIs (36 bloodstream infections and 447 urinary tract infections). The mean device use rates were 4.6 device-days per 100 patient-days for CVCs (29 wards) and 14.8 device-days per 100 patient-days for urinary catheters (65 wards), respectively. Mean device-associated NI rates were 4.3 infections per 1,000 CVC-days for CVC-associated bloodstream infections and 6.8 infections per 1,000 urinary catheter–days for catheter-associated urinary tract infections.

Conclusions

DEVICE-KISS allows non-ICUs to recognize an outlier position with regard to NIs by providing well-founded reference data for non-ICU patients.
Bacterial Contamination of Keyboards: Efficacy and Functional Impact of Disinfectants
Authors: Rutala William A. , White Matthew S. , Gergen Maria F. , Weber David J.
Published: April 2006

Background.

Computers are ubiquitous in the healthcare setting and have been shown to be contaminated with potentially pathogenic microorganisms. This study was performed to determine the degree of microbial contamination, the efficacy of different disinfectants, and the cosmetic and functional effects of the disinfectants on the computer keyboards.

Methods.

We assessed the effectiveness of 6 different disinfectants (1 each containing chlorine, alcohol, or phenol and 3 containing quaternary ammonium) against 3 test organisms (oxacillin-resistant Staphylococcus aureus [ORSA], Pseudomonas aeruginosa, and vancomycin-resistant Enterococcus species) inoculated onto study computer keyboards. We also assessed the computer keyboards for functional and cosmetic damage after disinfectant use.

Results.

Potential pathogens cultured from more than 50% of the computers included coagulase-negative staphylococci (100% of keyboards), diphtheroids (80%), Micrococcus species (72%), and Bacillus species (64%). Other pathogens cultured included ORSA (4% of keyboards), OSSA (4%), vancomycin-susceptible Enterococcus species (12%), and nonfermentative gram-negative rods (36%). All disinfectants, as well as the sterile water control, were effective at removing or inactivating more than 95% of the test bacteria. No functional or cosmetic damage to the computer keyboards was observed after 300 disinfection cycles.

Conclusions.

Our data suggest that microbial contamination of keyboards is prevalent and that keyboards may be successfully decontaminated with disinfectants. Keyboards should be disinfected daily or when visibly soiled or if they become contaminated with blood.
Device-Associated Infection Rate and Mortality in Intensive Care Units of 9 Colombian Hospitals: Findings of the International Nosocomial Infection Control Consortium
Authors: Moreno Carlos Álvarez , Rosenthal Victor D. , Olarte Narda , Gomez Wilmer Villamil , Sussmann Otto , Agudelo Julio Garzon , Rojas Catherine , Osorio Laline , Linares Claudia , Valderrama Alberto , Mercado Patricia Garrido , Bernate Patrick Hernán Arrieta , Vergara Guillermo Ruiz , Pertuz Alberto Marrugo , Mojica Beatriz Eugenia , Navarrete María del Pilar Torres , Romero Ana Sofia Alonso , Henríquez Daibeth
Published: April 2006

Objective.

To perform active targeted prospective surveillance to measure device-associated infection (DAI) rates, attributable mortality due to DAI, and the microbiological and antibiotic resistance profiles of infecting pathogens at 10 intensive care units (ICUs) in 9 hospitals in Colombia, all of which are members of the International Infection Control Consortium.

Methods.

We conducted prospective surveillance of healthcare-associated infection in 9 hospitals by using the definitions of the US Centers for Disease Control and Prevention National Nosocomial Surveillance System (NNIS). DAI rates were calculated as the number of infections per 100 ICU patients and per 1,000 device-days.

Results.

During the 3-year study, 2,172 patients hospitalized in an ICU for an aggregate duration of 14,603 days acquired 266 DAIs, for an overall DAI rate of 12.2%, or 18.2 DAIs per 1,000 patient-days. Central venous catheter (CVC)–related bloodstream infection (BSI) (47.4% of DAIs; 11.3 cases per 1,000 catheter-days) was the most common DAI, followed by ventilator-associated pneumonia (VAP) (32.3% of DAIs; 10.0 cases per 1,000 ventilator-days) and catheter-associated urinary tract infection (CAUTI) (20.3% of DAIs; 4.3 cases per 1,000 catheter-days). Overall, 65.4% of all Staphylococcus aureus infections were caused by methicillin-resistant strains; 40.0% of Enterobacteriaceae isolates were resistant to ceftriaxone and 28.3% were resistant to ceftazidime; and 40.0% of Pseudomonas aeruginosa isolates were resistant to fluoroquinolones, 50.0% were resistant to ceftazidime, 33.3% were resistant to piperacillin-tazobactam, and 19.0% were resistant to imipenem. The crude unadjusted attributable mortality was 16.9% among patients with VAP (relative risk [RR], 1.93; 95% confidence interval [CI], 1.24-3.00; P = .002); 18.5 among those with CVC-associated BSI (RR, 2.02; 95% CI, 1.42-2.87; P<.001); and 10.5% among those with CAUTI (RR, 1.58; 95% CI, 0.78-3.18; P = .19).

Conclusion.

The rates of DAI in the Colombian ICUs were lower than those published in some reports from other Latin American countries and were higher than those reported in US ICUs by the NNIS. These data show the need for more-effective infection control interventions in Colombia.
Sustained Endemicity ofBurkholderia cepaciaComplex in a Pediatric Institution, Associated With Contaminated Ultrasound Gel
Authors: Jacobson Michelle , Wray Rick , Kovach Danuta , Henry Deborah , Speert David , Matlow Anne
Published: April 2006

Objective.

To determine whether contaminated ultrasound gel is the source of intermittent outbreaks of nosocomial infection due toBurkholderia cepaciacomplex in patients without cystic fibrosis since 1992.

Design.

A prospective clinical and in vitro study of all in-use bottles of ultrasound gel, as well as a retrospective analysis of archived bacterial strains, were performed. Handling of gel for clinical purposes throughout the hospital was evaluated. Gel and archived clinical isolates ofB. cepaciacomplex were speciated to genomovar level and characterized by pulsed-field gel electrophoresis, and the pulsed-field gel electrophoresis patterns were compared.

Setting.

The Hospital for Sick Children, a 300-bed, tertiary care, pediatric academic health sciences center in Toronto, Canada.

Patients.

All patients without cystic fibrosis from whomB. cepaciacomplex was recovered at the Hospital for Sick Children since 1992.

Results.

No standardized protocol for storage or handling of ultrasound gel was found. Gel from 39% of bottles grew eitherB. cepacia(genomovar I) orBurkholderia stabilis(genomovar IV). These isolates had pulsed-field gel electrophoresis patterns identical to 2 of the 7 clinical pulsed-field gel electrophoresis types that are responsible for 88% of clinical isolates.

Conclusions.

Contaminated ultrasound gel contributed to nosocomial infection due toB. cepaciacomplex in this institution over the course of 10 years. Suggested guidelines for the handling of ultrasound gel are provided.
Unbiased pattern detection in microarray data series
Authors: Ahnert S. E. , Willbrand K. , Brown F. C. S. , Fink T. M. A.
Published: April 2006

Motivation: Following the advent of microarray technology in recent years, the challenge for biologists is to identify genes of interest from the thousands of genetic expression levels measured in each microarray experiment. In many cases the aim is to identify pattern in the data series generated by successive microarray measurements.

Results: Here we introduce a new method of detecting pattern in microarray data series which is independent of the nature of this pattern. Our approach provides a measure of the algorithmic compressibility of each data series. A series which is significantly compressible is much more likely to result from simple underlying mechanisms than series which are incompressible. Accordingly, the gene associated with a compressible series is more likely to be biologically significant. We test our method on microarray time series of yeast cell cycle and show that it blindly selects genes exhibiting the expected cyclic behaviour as well as detecting other forms of pattern. Our results successfully predict two independent non-microarray experimental studies.

Contact:  sea31@cam.ac.uk
The Significance of C16 Fatty Acids in the sn-2 Positions of Glycerolipids in the Photosynthetic Growth of Synechocystis sp. PCC6803
Authors: Okazaki Kumiko , Sato Norihiro , Tsuji Noriko , Tsuzuki Mikio , Nishida Ikuo
Published: April 2006

Most extant cyanobacteria contain C16 fatty acids in the sn-2 positions of glycerolipids, which are regulated by lysophosphatidic acid acyltransferase (LPAAT; EC 2.3.1.51). Synechocystis sp. PCC6803 contains sll1848, sll1752, and slr2060 as putative acyltransferase genes. sll1848 was recently reported to encode an indispensable palmitoyl-specific LPAAT; however, here we show that each of the three genes is dispensable. Δ1848 and Δ1848 Δ2060 cells had markedly higher contents of stearate (18:0), oleate (18:1), and linoleate (18:2) in place of palmitate (16:0) in the sn-2 positions, suggesting that Δ1848 Δ2060 cells incorporate 18:0 and 18:1 in the sn-2 positions. The levels of sll1752 transcripts increased in Δ1848 Δ2060 cells. This was accompanied by increased LPAAT activity toward 18:0 coenzyme A and its derivative in the membrane fraction. From these findings, together with the activity of a recombinant sll1752 protein and complementation of the Escherichia coli LPAAT mutant plsC, we conclude that sll1752 encodes a second LPAAT that prefers stearoyl and oleoyl substrates. Δ1848 Δ2060 cells grew slowly at 30°C at lower cell density, and exhibited more severe damage at 20°C than wild-type cells. Furthermore, Δ1848 Δ2060 cells exhibited photoinhibition more severely than wild-type cells. A phycobilisome core-membrane linker protein (slr0335) was also found to be susceptible to protein extraction under our conditions; its content decreased in the membrane fractions of Δ1848 Δ2060 cells. We conclude that C16 fatty acids in sn-2 positions are preferred in the photosynthetic growth of this cyanobacterium, despite sll1752 orthologs being conserved in most cyanobacteria. However, no sll1752 ortholog is conserved among photosynthetic eukaryotes including Cyanidioschyzon merolae.
Ascorbate Oxidase-Dependent Changes in the Redox State of the Apoplast Modulate Gene Transcript Accumulation Leading to Modified Hormone Signaling and Orchestration of Defense Processes in Tobacco
Authors: Pignocchi Cristina , Kiddle Guy , Hernández Iker , Foster Simon J. , Asensi Amparo , Taybi Tahar , Barnes Jeremy , Foyer Christine H.
Published: April 2006

The role of the redox state of the apoplast in hormone responses, signaling cascades, and gene expression was studied in transgenic tobacco (Nicotiana tabacum) plants with modified cell wall-localized ascorbate oxidase (AO). High AO activity specifically decreased the ascorbic acid (AA) content of the apoplast and altered plant growth responses triggered by hormones. Auxin stimulated shoot growth only when the apoplastic AA pool was reduced in wild-type or AO antisense lines. Oxidation of apoplastic AA in AO sense lines was associated with loss of the auxin response, higher mitogen-activated protein kinase activities, and susceptibility to a virulent strain of the pathogen Pseudomonas syringae. The total leaf glutathione pool, the ratio of reduced glutathione to glutathione disulfide, and glutathione reductase activities were similar in the leaves of all lines. However, AO sense leaves exhibited significantly lower dehydroascorbate reductase and ascorbate peroxidase activities than wild-type and antisense leaves. The abundance of mRNAs encoding antioxidant enzymes was similar in all lines. However, the day/night rhythms in the abundance of transcripts encoding the three catalase isoforms were changed in response to the AA content of the apoplast. Other transcripts influenced by AO included photorespiratory genes and a plasma membrane Ca2+ channel-associated gene. We conclude that the redox state of the apoplast modulates plant growth and defense responses by regulating signal transduction cascades and gene expression patterns. Hence, AO activity, which modulates the redox state of the apoplastic AA pool, strongly influences the responses of plant cells to external and internal stimuli.
Transcriptomic Footprints Disclose Specificity of Reactive Oxygen Species Signaling in Arabidopsis
Authors: Gadjev Ilya , Vanderauwera Sandy , Gechev Tsanko S. , Laloi Christophe , Minkov Ivan N. , Shulaev Vladimir , Apel Klaus , Inzé Dirk , Mittler Ron , Van Breusegem Frank
Published: April 2006

Reactive oxygen species (ROS) are key players in the regulation of plant development, stress responses, and programmed cell death. Previous studies indicated that depending on the type of ROS (hydrogen peroxide, superoxide, or singlet oxygen) or its subcellular production site (plastidic, cytosolic, peroxisomal, or apoplastic), a different physiological, biochemical, and molecular response is provoked. We used transcriptome data generated from ROS-related microarray experiments to assess the specificity of ROS-driven transcript expression. Data sets obtained by exogenous application of oxidative stress-causing agents (methyl viologen, Alternaria alternata toxin, 3-aminotriazole, and ozone) and from a mutant (fluorescent) and transgenic plants, in which the activity of an individual antioxidant enzyme was perturbed (catalase, cytosolic ascorbate peroxidase, and copper/zinc superoxide dismutase), were compared. In total, the abundance of nearly 26,000 transcripts of Arabidopsis (Arabidopsis thaliana) was monitored in response to different ROS. Overall, 8,056, 5,312, and 3,925 transcripts showed at least a 3-, 4-, or 5-fold change in expression, respectively. In addition to marker transcripts that were specifically regulated by hydrogen peroxide, superoxide, or singlet oxygen, several transcripts were identified as general oxidative stress response markers because their steady-state levels were at least 5-fold elevated in most experiments. We also assessed the expression characteristics of all annotated transcription factors and inferred new candidate regulatory transcripts that could be responsible for orchestrating the specific transcriptomic signatures triggered by different ROS. Our analysis provides a framework that will assist future efforts to address the impact of ROS signals within environmental stress conditions and elucidate the molecular mechanisms of the oxidative stress response in plants.
Description of a new disease condition occurring in farmed coho salmon, Oncorhynchus kisutch (Walbaum), in South America
Authors: BRANSON E. J. , DIAZ‐MUNOZ D. NIETO
Published: April 2006

Abstract. High levels of mortalities have been experienced in farmed coho salmon, Oncorhynchus kisuteh (Walbaum), in the Gulf of Ancud, southern Chile. Most affected fish had similar skin lesions ranging from small areas of raised scales through white raised plaques to shallow ulcers. The fish were also generally dark, lethargic and anorexic. However, some affected fish appeared grossly normal with no skin lesions. Internal pathology consisted of varying degrees of ascites, peritonitis and general pallor. Spleens were generally enlarged. Kidneys and livers were swollen and grey in colour, often with pale focal lesions. Extensive histopathology was present in affected fish with tissue necrosis, intravascular necrotic thrombi, large basophilic cells and basophilic granules, some free in the tissues, some contained within cells. The basophilic granules, known locally as the ‘UA’, or unidentified agent, were thought to be the main aetiological agent, and are likely to be a rickettsia‐like organism.
Clonal analysis of Yersinia ruckeri based on biotypes, serotypes and outer membrane protein‐types
Authors: DAVIES R. L.
Published: April 2006

Abstract. The biotypes, serotypes and outer membrane protein‐types (OMP‐types) of 135 isolates of Yersinia ruckeri were analysed in an attempt to identify clonoal groups and to examine to further detail the relationships between islotes from wide geographic areas. Each isolate could be assigned to one of two biotypes (1 and 2). one of five 0‐serotypes (01, 02, 05, 06 and 07), and one of five OMP‐types (1–5). Outer membrane protein analysis was able to differentiate between isolates within a given serotype. Thus, serotype 01 isolates types 1 and 2. and serotype 07 isolates consisted of OMP‐types 1 and 5. Whereas OMPwith serotype 07, OMP‐types 1 and 2 were associated with serotypes 01, 02, 05, 06 and 07, for the majority of the disease outbreaks in Europe and represented 79% of the European isolates. A combination of biotype, serotype and OMP‐type analysis was demonstrated to be useful in epidemiological studies of Y. ruckeri.
Octopus bimaculoides (Pickford & McConnaughey, 1949): a marine invertebrate host for ectoparasitic protozoans
Authors: FORSYTHE J. W. , HANLON R. T. , BULLIS R. A. , NOGA E. J.
Published: April 2006

Abstract. During the laboratory culture of the California mud‐fiat oetopus. Octopus bimaculoides(Pickford & McConnaughey, 1949), concurrent infestations of ectoparasitic flagellate and ciliate protozoans were discovered when examining sick and dying animals. The flagellates, similar to the bodonid parasite, Ichthyobodo necator (Henneguy, 1883), were small (3–9 μm total length) and infested any surface epithelia exposed to sea water. The larger ciliates (l5–30 μm total length), believed to be ancistrocomids, were found only on the gills. This is the first documented report of ciliate or flagellate ecto‐parasites infesting cephalopod molluscs. Flagellate infestations were first manifest on the dorsal arms and mantle surfaces of O. bimaculoides as white spots visible when the octopuses were in dark colouration. Lesions formed at the centres of the spots and the interspersed lesions eventually connected. Once the parasites damaged the epidermis, secondary bacterial infections caused lesioning. Both parasites heavily infested the gills. Clinical signs first appeared at 2 months post‐hatching (0‐5 g). Octopuses seemed to become refractory to the disease beyond a size of 25 g. No effective treatment was found for these infestations. It was possible to eliminate parasite spread in the laboratory by prefiltering water to l μm. The source of the parasites was the wild octopus population of the southern California coast.
Histopathology of vitamin C deficiency in a cichlid, Cichlasoma urophthalmus (Günther)
Authors: De MARTÍNEZ M. C. CHÁVEZ , RICHARDS R. H.
Published: April 2006

Abstract. This paper describes the histopathological changes observed in the Mexican native cichlid Cichlasoma urophthalmus (Günther) when try with an initial weight of between 160 and 170 mg were fed with diets deficient in vitamin C for 90 days. The epidermis showed an extensive inflammatory response, with spongiosis and also degenerative changes in the basal cells. Muscle showed a range of pathological changes including inflammation, changes in the number and position of the nuclei, vacuolation and necrosis, granular degeneration, and fibre loss. Gills showed thickening of the primary lamellae, oedema, hyperplasia, telangiectasis and atrophy of the bony supporting structures. Ganglia and neurones of nervous tissue were abnormal with changes which ranged from slight inflammation to central chromatolysis. The hepalopanereas was also affected and focal necrosis of the hepatocytes was frequently observed. The pancreas showed major changes with shrinkage of the acinar cells and reduction of zymogen granule content. Fish fed diets containing 0 and 40 mg vitamin C kg‐1 of diet were infected with Mycobacterium sp. and miliary tuberculosis was found affecting kidney, spleen, choroid gland, stomach, heart and muscle. The association between fish tuberculosis and vitamin C deficiency is discussed.
Detection of infectious pancreatic necrosis in a carrier population of rainbow trout, Oncorhynchus mykiss(Richardson), by flow cytometry
Authors: SAINT‐JEAN S. RODRIGUEZ , PILAR VILAS MINONDO Ma. , PALACIOS M. ANGEL , PRIETO S. PEREZ
Published: April 2006

Abstract. A non‐lethal study of the disease status of adult rainbow trout, Oncorhynchus mykiss (Walbaum), suspected of being carriers of infectious pancreatic necrosis virus (IPNV) was carried out using purified leucocytes from pooled blood samples. Leucocytes were stained by indirect immunofluorcscence to detect IPN viral antigen and analysed by flow cytometry. Leucocytes from an IPN free source were also used as controls. Three populations of leucocytes were analysed: (1) leucocytes examined immediately following purification from blood, which gave positive results with 30–58% of fluorescent cells: (2) purified leucocytes cultured for 7 days in medium at 15 °C. which gave a higher number of fluorescent cells, suggesting multiplication of IPNV; and (3) leucocytes co‐cultured on CHSE‐214 cell monolayers for 7 days at 15 °C, which amplified the number of infected leucocytes to more than 90% but delayed the result 7 days. Isolation and serological identification of the pathogen was carried out on CHSE‐214 cells, which confirmed the positive results obtained by flow cytometry analysis. Further experiments are in progress to complete the applications of flow cytometry to salmonid virus studies.
Yersinia ruckeri produces four iron‐regulated outer membrane proteins but does not produce detectable siderophores
Authors: DAVIES R. L.
Published: April 2006

Abstract. The expression of iron‐regulated outer membrane proteins (OMPs) was examined in 36 isolates of Yersinia ruckeri selected to represent a range of biotypes, serotypes and OMP‐types. Iron‐restricted growth was achieved in tryptone soya broth by chelation with 200 μm α,α'‐dipyridyl, although similar results could be achieved with 25 μm transferrin or 280 μM ethylenediaminedihydroxyphenylacetic acid (EDDA). During growth under iron‐restricted conditions, all 36 isolates produced four additional outer membrane proteins of molecular weights 72, 69·5, 68 and 66 kDa. Expression of these proteins was repressed by the addition of 100 μm FeCl3 to the growth medium, confirming that the proteins were iron‐regulated. The facts that all of the isolates examined possessed the same four iron‐regulated OMPs, and that the plasmid content of different serotypes is known to vary indicated that production of these proteins is probably chromosomally mediated and not plasmid‐mediated. Production of siderophores was not detected in low iron media and suggested a direct iron‐uptake mechanism for this organism.
Simultaneous occurrence of Vibrio salmonicida and antibiotic‐resistant bacteria in sediments at abandoned aquaculture sites
Authors: HUSEVÅG B. , LUNESTAD B. T. , JOHANNESSEN P. J. , ENGER Ø. , SAMUELSEN O. B.
Published: April 2006

Abstract. The present authors have examined the survival of the fish pathogenic bacterium Vibrio salmonidda and the occurrence of antibiotic resistant bacteria in sediments from abandoned aquaculture sites. Survival of V. salmonidda was determined by fluorescent monoclonal antibody labelling combined with 4′,6‐diamidino‐2‐phenylindole (DAPI) staining. Using this method, the authors were able to detect V. salmonidda in sediment samples from six out of 12 abandoned fish farm locations. One out of the six positive stations was abandoned in 1982. Vibrio salmonidda was not detected at the three stations not affected by aquaculture (control locations) or in sediment samples taken 200–250m away from aqua‐culture sites. When applying high‐performance liquid chromatography, oxytctracyclinc or furazolidonc residues were not detected in sediment samples from control or abandoned aquaculture sites. Nevertheless, the percentage of bacteria resistant to oxytctracycline was higher in aquaculture sediments, as compared to control sediments. The simultaneous occurrence of fish pathogens and high levels of resistant bacteria in sediments increases the risk of transfer of resistance to the pathogens.
Cellular responses of leucocytes isolated from the gut of rainbow trout, Oncorhynchus mykiss (Walbaum)
Authors: DAVIDSON G. A. , ELLIS A. E. , SECOMBES C. J.
Published: April 2006

Abstract. Leucocytes were isolated from the gut of rainbow trout by collagcnase digestion. They were shown to be capable of producing a chemoattractant(s) for head kidney leucocytes and a macrophagc activating factor, following stimulation with calcium ionophore and T‐cell mitogens, respectively. They also included low but significant numbers of phagocytes, as determined by phagocytosis of fluorescent latex microspheres and oxygen free radical production. However, migration of isolated gut cells in response to head kidney chemo‐attractants was lacking. The significance of these results in relation to mucosal immunity is discussed.
The usage of vaccination and antimicrobial agents for control of Yersinia ruckeri
Authors: RODGERS C. J.
Published: April 2006

Abstract. Selected salmonid fish farms in England and Wales were sent a questionnaire designed to collect data on enteric redmouth disease (ERM) vaccination and the usage of antimicrobial agents. The response to the survey was 41·5%. The results indicated that 22% of responding farms have had ERM diagnosed since 1982, half of them have experienced the disease every year since the initial confirmation and it occurs primarily between April and September; mainly in rainbow trout, Oncorhynchus mykiss (Walbaum), of 222/kg‐200g. Although larger fish were also affceted. The incidence of ERM coincides with a rise or fall in water temperature, over‐crowding, poor water quality or grading. Vaccination against ERM is used on 53% of the responding farms. In addition, 45% of these farms considered immunization to have failed, mainly due to the poor condition of the fish and the low water temperatures at vaccination. On those farms whieh employed vaccination, the commonest ehemotherapeutant used against ERM is oxolinic acid. However, oxytetracycline is the most frequently used antibiotic on farms not employing a vaccine. The use of an antimicrobial agent as a prophylactic or the use of another compound when the first treatment is completed occurred on some farms. The average annual cost for vaccination and treatment has been calculated.
Florfenicol in Atlantic salmon, Salmo salar L., parr: tolerance and assessment of efficacy against furunculosis
Authors: INGLIS V. , RICHARDS R. H. , VARMA K. J. , SUTHERLAND I. H. , BROKKEN E. S.
Published: April 2006

Abstract. The efficacy of florfenicol against laboratory‐induced infection with Aeromonas salmonicida was tested in Atlantic salmon, Salmo salar L., parr. Medication at three dose levels in the feed was started 24 h after bath challenge with A. salmonicida. The specific mortality rate in the unprotected infected control group was 75% compared with 5, 13 and 17% when florfenicol was given at dose levels of 20, 10 and 5 mg per kg body weight per day, respectively. Florfenicol was palatable to the fish at doses in excess of effective therapeutic levels and feeding for 10 days at 100 mg per kg, or for prolonged periods at 50 mg per kg and 10 mg per kg, resulted in no feeding problems or histopathological abnormalities. Florfenicol appears to have a good therapeutic index and considerable potential in the control of furunculosis in salmon.
Antibiotic resistance of Aeromonas salmonicida isolated from Atlantic salmon, Salmo salar L., in Scotland
Authors: INGLIS V. , FRERICHS G. N. , MILLAR S. D. , RICHARDS R. H.
Published: April 2006

Abstract. Antibiotic sensitivity patterns of 304 isolates of Aeromonas salmonicida from 229 outbreaks of furunculosis among salmon in Scotland between 1988 and 1990 were investigated. Fifty‐five per cent were resistant to oxytetracycline and 37% resistant to oxolinic acid. Multiple resistance was common (52%) and 18 out of 19 antibiograms which were found in the first year recurred in the succeeding year. More than a quarter of the outbreaks were associated with two or more A. salmonicida variants distinguishable by their antibiotic sensitivity patterns. The implications of these findings in the control of furunculosis are considered.
Susceptibility of strains of Aeromonas salmonicida to killing by cell‐free generated superoxide anion
Authors: KARCZEWSKI J. M. , SHARP G. J. E. , SECOMBES C. J.
Published: April 2006

Abstract. Superoxide anion was generated in a cell‐free system using photoreduced riboflavin and methionine. This allowed the susceptibility to killing by superoxide of 11 strains of Aeromonas salmonicida to be investigated. A good correlation was found between susceptibility and ‘virulence factors’ of the different strains. In the presence of an inhibitor of superoxide dismutase (sodium nitroprusside), the bactericidal effect of superoxide was increased, particularly in the more resistant strains, suggesting that these strains possess superoxide dismutase (SOD). The use of levels of detoxifying enzymes within bacteria such as SOD as an indicator of virulence is discussed.
A study on Flexibacter columnaris infection in loach, Misgurnus anguillicaudatus (Bleeker, Günther)
Authors: CHOWDHURY M. B. R. , WAKABAYASHI H.
Published: April 2006

Abstract. Infectivity of Flexibator columnaris to loach, Misgurnus anguillicaudatus (Blecker, Günther), was studied with variation conditions and the presence of other bacteria in the water medium. Invasion of fish by the poathogen varied with different water conditions. The highest prevalence of infection was observed in an experimentally formulated water containing 0·03% NaCl 0·01% KCl, 0·002% CaCl22H2O and 0·004% MgCI2 6H2O. The percentage of infection in tap water was similar to that of the formulated water. The infeetion rate was low in the individual salt solutions, and no infection occurred in distilled water. Even in the formulated water, the pathogen failed to infect the fish when Citrobacter freundii, Aeromonas hydrophila or Pseudomonas fluorescens were present at densities 100 times that of F. columnaris. However, in such cases, the numbers of F. columnaris in the mucus of the fish body surface did not increase much throughout the experimental period. In contrast, F. columnaris suceessfully invaded the fish in the presence of either Streptococcus sp., Flavobacterium flavescens or Flavobacterium fuscum, even when the numbers of these bacteria were 1000 times that of F. columnaris. In this ease, F. columnaris gradually increased its numbers on the fish body surface.
Ultrastructural changes associated with carbon tetrachloride hepatotoxicity in channel catfish, Ictalurus punctatus Rafinesque
Authors: AFIFI S. H. , MacMILLAN J. R.
Published: April 2006

Abstract. Ultrastructural changes occurring in juvenile channel catfish, Ictalurus punctatus Ratinesque, hepatocytes were examined following exposure to carbon tetrachloride (CCl4). Juvenile catfish were intraperitoneally injected with a sublethal dose of undiluted CCl4and controls, used for comparisons, received physiological saline. The rough endoplasmic rcticulum (RER) was slightly dilated by 1 h and was significantly dilated by 4 and 24 h post‐CCl4‐exposure. At 4 h, the RER became degranulated, mitochondrial eristae indistinct with electron dense flocculant matrieal deposits, and nuclear membranes indented. Autophagic vacuoles were present in some hepatocytes. Within 48 h post‐exposure, the hepatocytes were indistinguishable from control hepatocytes. CCl4 can induce reversible or irreversible cell damage which appears dose dependent.
Serine protease and glycerophospholipid:cholesterol acyltransferase of Aeromonas salmonicida work in concert in thrombus formation; in vitro the process is counteracted by plasma antithrombin and α2‐macroglobulin
Authors: SALTE R. , NORBERG K. , ARNESEN J. A. , ØDEGAARD O. R. , EGGSET G.
Published: April 2006

Abstract. Intravascular injection of purified 70‐kDa protease or GCAT‐LPS from Aeromonas salmonicida, or both, invariably led to consumptive coagulopathy within 2h in Atlantic salmon, Salmo salar L. By entering the coagulation cascade at two different levels, the two enzymes work in concert in thrombus formation, the significance being that circulatory failure is probably the major cause of death in acute furunculosis. Only intravascular injection of GCAT‐LPS led to consumptive coagulopathy in rainbow trout, Oncorhynchus mykiss (Walbaum), despite the fact that trout received only half the GCAT dose, and/or four times the protease activity administered to salmon. These results indicate that salmon is, by far, the most susceptible to protease and suggest that rainbow trout is the most susceptible to GCAT‐LPS. The substrate profile of the purified protease gave supporting evidence that it works as activated coagulation factor X. The protease is inhibited in vitro by antithrombin and by α2‐macroglobulin and both inhibitors are consumed in vivo in response to intravascular administration of the enzymes, thus showing a potential for AT and α2M to inhibit the protease also in vivo. Provided such plasma antiprotease activities are correlated with resistance to the disease, and the inhibitors show genetic variation they would be promising candidates for indirect selection and hence a means to prevent furunculosis independently of vaccines. Circulating inhibitors of GCAT‐LPS remain to be identified.
The use of Western blot and electroimmunotransfer blot assays to monitor bacterial kidney disease in experimentally challenged Atlantic salmon, Salmo salar L.
Authors: OLIVIER G. , GRIFFITHS S. G. , FILDES J. , LYNCH W. H.
Published: April 2006

Abstract. Western blot (WB) and electroimmunotransfer blot (EITB) methods were used to monitor bacterial soluble antigens and scroconversion profiles, respectively, in Atlantic salmon, Salmo salar L., experimentally challenged with Renibacterium salmoninarum. The two challenged populations exhibited differences in susceptibility to R. salmoninarum permitting an evaluation of the methods in fish populations harbouring different levels of the pathogen, WB detection of R. salmoninarum soluble antigens in serum provided a sensitive method for detecting pathogen presence during the active infection stages. For comparison, results for drop‐plate culture and direct fluorescent antibody techniques were obtained. During the recovery phase, surviving fish were negative for the pathogen by these methods. However, >90% of challenged fish sampled from early infection stages to the end of the experimental period (141 days post‐infection) were scropositive by the EITB assay for Atlantic salmon immunoglobulin reactive with R. salmoninarum soluble antigens. The results suggest that these methods for detecting R. salmoninarum or its soluble antigens may be useful during active infections. However, asymptomatic fish populations exposed to the pathogen, perhaps having recovered from an active infection and representing potential disease carrier sources, may be more readily identified by antigen‐specific antibodies using methods such as the EITB assay.
Isoenzymatic changes in grass carp,Ctenopharyngodon idellusCuvier & Valenciennes, affected with haemorrhagic disease
Authors: CAI W.
Published: April 2006

Abstract.Electrophoretic analysis of six types of tissue (serum, erythrocyte, liver, kidney, muscle and eye) and seven different isoenzymes (LDH, MDH, Est, ADH, IDH, α‐GPDH and SOD) from both healthy grass carp,Ctenopharyngodon idellusCuvier & Valenciennes, and carp affected by haemorrhagic disease was performed. It was found that: (1) Enzymes from diseased grass carp showed the most drastic changes within each tissue. The absolute activity of LDH in serum from the diseased fish increased to approximately twice that of the healthy fish; whereas the relative activity of A4and A3B1, the main components of A sub‐base in both serum and erythrocytes, was accelerated. (2) The isoenzymic changes in the control groups, diseased fish, artificially infected fish and healthy fish from diseased ponds indicated that biochemical changes occurred in the tissues before pathological change.
Reservoir hosts and new clupeoid host records for the myoliquefactive myxosporean parasite Kudoa thyrsites (Gilchrist)
Authors: LANGDON J. S. , THORNE T. , FLETCHER W. J.
Published: April 2006

Abstract. The myxosporean parasite Kudoa thyrsites (Gilchrist) is well recognised as a cause of flesh liquefaction post‐mortem in several fishes from both hemispheres. The observation of this condition in cultured mahi mahi, Coryphaena hippurus L., in Western Australia led us to search for possible reservoirs of infection amongst the abundant clupeoid fishes of the area. Prevalent and severe infections were found in Sardinops sagax neopilchardus (Steindachner), which we consider to be a major reservoir host for K. thyrsites in south‐west Australian coastal waters. The parasite occurred less frequently in Spratelloides robustus Ogilby, Sardinetla lemuru Bleeker and Engraulis austratis (Shaw) from the same waters. Infection was not detected in Hyperlophus vittatus (Castelnau), Etrumeus teres (De Kay) or Nematalosa vlaminghi (Munro), which may reflect differences in range or dietary composition. Engraulis japonicus (Temminck & Sehlegel) imported from Japan were also infected, but a single sample of E. mordax Girard from California contained only an equipolar Kudoa species. These records expand the known host range of K. thyrsites to 20 species in 10 families, and several of these host species appear to be major reservoirs of infection in certain locations. Flesh spoilage due to the liquefactive effects of the parasite could occur in any of these hosts, and was seen here in S. sagax neopilchardus, S. robustus and E. japonicus in association with mature spores. Detection of infection with ultra‐violet light was found to be ineffective because a cellular host response was not mounted by the clupeoids.
Retention of antigenicity by a fragment of Aeromonas salmonicida 70‐kDa serine protease which includes the primary substrate binding site expressed as β‐galactosidase hybrid proteins
Authors: BENNETT A. J. , WHITBY P. W. , COLEMAN G.
Published: April 2006

Abstract. A 587 bp Pvu II restriction fragment from the 70‐kDa Aeromonas salmonicida serine protease gene, containing the‘active serine’ site sequence of the enzyme, has been cloned into the Sma I restriction site of pUEX2 which on expression, in Escherichia coli DH5α, produced a 142‐kDa hybrid protein in high yield. The hybrid consisted of a fusion between an essentially complete β‐galactosidase subunit and approximately one‐third of the serine protease. A further 42‐kDa hybrid was constructed from the same fragment of serine protease fused to a truncated α‐galactosidase subunit. Both fusion proteins were shown to possess recognizable epitopes by dot blotting against rabbit anti‐A. salmonicida 70‐kDa serine protease antibody.
Haematological responses in the European eel, Anguilla anguilla L., to sublethal infestation by Anguillicola crassus in a thermal effluent of the Swedish Baltic
Authors: HÖGLUND J. , ANDERSSON J. , HÄRDIG J.
Published: April 2006

Abstract. Haematological variations were studied in a European eel population, Anguilla anguilla L., naturally infested by the sanguivorous nematode Anguillicola crassus. This occurred off the Swedish Baltic coast in an area receiving heated cooling water from a nuclear power station. The erythrocyte count, haematocrit, leucocrit, haemoglobin concentration, mean corpuscular volume, mean corpuscular haemoglobin and mean corpuscular haemoglobin concentrations, the various cell types in peripheral blood, serum iron concentration, the amount of total serum protein, and scrum protein fractions α1, β1, α2, β2 and γ were all measured. Each variable was correlated to: (1) the intensity of infestation, i.e. number of parasites per host; and (2) a parasitization index, i.e. the weight of parasites per somatic weight of the host. Most variables showed no or only minor reactions to the infestation. However, a marked increase in the γ‐fraction of scrum proteins, reduced lymphocyte numbers and increased granulocyte numbers are indicative of a humoral and cellular immune response.
Experimental infection of eggs and yolk sac larvae of halibut, Hippoglossus hippoglossus L.
Authors: BERGH Ø. , HANSEN G. H. , TAXT R. E.
Published: April 2006

Abstract Scanning electron micrographs of halibut eggs with an epiflora dominated by Flexibacter sp., showed ulcerations colonized by large numbers of bacteria. The chorion was dissolved in most ulcerations and the zona radiata was severely damaged. Infection experiments showed that exposure to these bacteria caused high mortalities at the late egg stage, hatching and the early yolk sac stage. Eggs exposed to three different Vibrio spp. showed different mortality patterns, with low mortality at hatching, followed by a continuous high mortality throughout the yolk sac stage. Mortality in the uninfected control group was low throughout the experiment. Transmission electron microscopy of the Vibrio‐infected larvae showed bacteria present in the gill, heart and frontal yolk sac regions.
Siderophore pattern of fish‐pathogenic Vibrio anguiliarum, Aeromonas spp. and Pseudomonas spp. from the German Baltic coast
Authors: GIERER W. , RABSCH W. , REISSBRODT R.
Published: April 2006

Abstract A Total of 355 strains of fish‐pathogenic bacteria, including Vibrio anguillarum, Aeromonas hydrophila, A. Caviae, Pseudomonas fluorescens and P. putida, were examined for the presence of hydroxamate‐or phenolate‐type siderophores. These strains were isolated from diseased rainbow trout, Oncorhynchus mykiss (Walbaum), from fish farms in the Baltic Sea off the coast of the former German Democratic Republic. The production of siderophores was demonstrated in bioassays and siderophore‐pattern analysed using several indicator strains. All strains tested grew under conditions of iron limitation. The strains of Vibrionacease produced at least a hydorxamate‐type siderophore detected by the bioassay with A. flavercens JG‐9. Only a few V. anguillarum, but 50% of A. hydrophila produced a phenolate‐type siderophore. Seventy percent of V. anguillarum, 33% if A. hydrophila, 40% of A. caviae, 53% of P. fluorescens and 50% of P. putida promoted the growth of the indication strain S. typhimurium SR 1001, which can use iron by 2,3‐dihydroxybenxoic acid. The pseudomonads tested produced either hydroxamate‐ or phenolate‐type siderophores, or both.
Fish mycobacteriosis: morphopathological and immunocytochemical aspects
Authors: GÓMEZ S. , BERNABÉ A. , GÓMEZ M. A. , NAVARRO J. A. , SÁNCHEZ J.
Published: April 2006

Abstract. A morphopathological study of fish tuberculosis was carried out using histological and immunocytochemical techniques. The clinical signs observed were emaciation, lack of movement coordination and body deformation. Macroscopically, small, light‐coloured, visceral nodules were detected. Immunocytochemical techniques were found to be effective in detecting infections where conventional staining methods failed to reveal, or detected only small numbers of bacilli.
Malachite green: a pharmacokinetic study in rainbow trout, Oncorhynchus mykiss (Walbaum)
Authors: ALDERMAN D. J. , CLIFTON‐HADLEY R. S.
Published: April 2006

Abstract. Pharmacokinetic studies on uptake, distribution and climination of malachite green in rainbow trout, Oncorhynchus mykiss (Walbaum), are described. All three processes were found to be temperature‐dependent, with levels and rates increasing with increases in water temperature. Tissues investigated were serum, liver, kidney, muscle and viscera. First‐order kinetics were found to apply and, in particular, kidney was observed to be a deep compartment. The long‐term persistence of kidney residues may explain the efficacy of malachite green for the control of proliferative kidney disease in rainbow trout. Residue levels in muscle were never excessive and an extrapolation from the experimental data suggests that a suitable withholding period might be 600 degree days.
Host‐parasite interface of Caryophyllaeus laticeps (Eucestoda: Caryophyllidae) in three species of fish
Authors: KARANIS P. , TARASCHEWSKI H.
Published: April 2006

Abstract. The host‐parasite interface of Caryophyllaeus laticeps has been investigated in naturally infected bream, Abramis brama (L.), chub, Leuciscus cephalus (L.), and roach, Rutilus rutilus (L.), by light and electron microscopy. The fish were caught in the Ruhr‐lake near Bochum. Bream showed the highest rate of infection and also harboured the largest worms compared to the two other host species. In all three cyprinids, the worms’ scolices caused local compression of the host's intestinal epithelium. At the attachment site of scolices of medium‐ to large‐sized worms, the intestinal epithelial cells were vacuolized and their brush border ruptured. These pathological effects were most pronounced in bream, which also showed conspicuous granulomas in the tunica propria adjacent to the scolices. A heavy infiltration of eosinophilic granulocytes was noted in chub and roach at the worms’ attachment site. In bream, only the smallest worms provoked a slight eosinophilic reaction. It is concluded that the worms within the three host species were of different ages and that the chronic stage of infection, associated with the formation of granulomas, was only reached in bream, the major host.
Immunological responses in Atlantic salmon,Salmo salarL., against purified serine protease and haemolysins fromAeromonas salmonicida
Authors: ARNESEN J. A. , BJØRNSDOTTIR R. , JØRGENSEN T. Ø. , EGGSET G.
Published: April 2006

Abstract.A method for purification of the 70‐KDa extracellular serine protease ofAeromonas salmonicidaby hydrophobic chromatography and ion exchange is described. The purified protease, adsorbed onto mineral particles, was used for immunization of salmon. Other groups of salmon were immunized with particles coated with purified glycerophospholipid:cholesterol acyltransferase (GCAT) or with the acyltransferase complexed with LPS (GCAT‐LPS). Humoral immune responses assayed after 6 weeks by ELISA, showed relatively good responses against GCAT‐LPS, while titres of antisera against the purified protease and GCAT were scarcely above those of control sera. However, the antibody responses to each toxin were shown by Western blotting to be specific and qualitatively similar to responses seen in rabbits. The toxin preparations were also used (in combination with whole bacteria) for vaccination of salmon. On challenge 3 months later, only GCAT‐LPS elicited significant immunological protection. However, a more convincing protection was seen when total extracellular product was present in the vaccine.