Visceral myxobacteriosis in the rainbow trout, Salmo­Gairdneri R. : a new clinicat form of the Cytophaga psychrophila cold water disease

Une forme nouvelle de la myxobactériose d’eau froide est apparue en France au cours de ces dernières années chez les alevins et les trui- telles arc-en-ciel. L’agent responsable est Cytophaga psychrophila, qui ne sévissait jusqu’ici qu’en Amérique du Nord chez les salmonidés juvéniles, provoquant surtout des lésions ulcératives cutanées. En France, au contraire, les lésions causées par la bactérie sont essentiellement viscé rales. L’infection clinique est observée en saison froide, et assez souvent associée à d’autres pathologies. Le diagnostic repose essentiellement sur la mise en évidence et la caractérisation de la bactérie responsable. La maladie a été transmise expérimentalement et les essais en laboratoire ont montré l’efficacité thérapeutique du chloramphénicol et de l’oxytétra- cycline.A new form of the cold water myxobacteriosis in rainbow trout fry and Engerlings appeared in France during the last years. So far, the aetiological agent has been Cytophaga psychrophila, a myxobacteria occuring on juveniles of salmonids of North America and mostly inducing cutaneous ulcerative lesions. On the opposite, lesions observed in France have essentially been detected on internal organs. The clinical infection is prevalent during the cold season and is often associated with other pathogens. Diagnosis is mainly made on isolation and characterization of aetiological bacteria. The disease was experimentally transmitted. Trials in laboratory have also demonstrated the therapeutic efficiency of chloram phenicol and Oxytetracycline

Vaccination par voie orale de la truite arc-en-ciel (Oncorhynchus mykiss Walbaum) contre la Yersiniose a Yersinia ruckeri

SIGLEAvailable from INIST (FR), Document Supply Service, under shelf-number : TD 81130 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

Phenology of the flowering plants of Reese's Bog.

http://deepblue.lib.umich.edu/bitstream/2027.42/52428/1/860.pdfDescription of 860.pdf : Access restricted to on-site users at the U-M Biological Station

Effect of vitamins on the experimental enteric redmouth disease of rainbow trout (Sahno gairdneri)

La yersiniose, entéro-septicémie hémorragique à Yersinia ruckeri est transmise expérimentalement à des truites arc-en-ciel ( Salmo gairdneri ). L’apport dans l'aliment de vitamines A (48 500 Ul/kg), E (500 mg/kg) et C (8 650 mg/kg), pendant 5 jours consécutifs, semble augmenter la résis tance des poissons à l’infection, lors d'épreuves effectuées 3 à 8 semaines plus tard.The yersiniosis, hémorragie entero-septicaemia casued by Yersinia ruckeri, is transmitted to rainbow trout (Salmo gairdneri). The food supplementation with vitamins A (48 500 Ul/kg), E (500 mg/kg) and C (8 650 mg/kg), for five consecutive days, seem to increase the resistance of fishes against infection, within challenges 3 to 8 weeks later

Gyrodactylids parasitizing salmonids in Brittany and Western Pyrénées water basins: epidemiological features of infection and species composition

In the first part of a national survey of gyrodactylid parasites, with spécial référence to Gyrodactylus salaris, funded by French administrations, two water basins harbouring Atlantic salmon were sampled : Brittany (7 rivers and 3 restocking farms) and the Adour basin in the Western Pyrénées (6 rivers and 1 restocking farm). 535 salmonids were collected and examined for G. salaris and other gyrodactylid species investigations. Identification procedure was performed by morphological examination and molecular analysis. Both methods led to the same conclusions with a high degree of consistency : Gyrodactylus salaris was declared absent from the examined samples and, therefore, can be considered absent from the sampled water basins with a high level of confidence (over 99.4%). 99.4 % ) . A new Gyrodactylus species was identified first by morphological examination and confirmed by molecular analysis. This new species is named Gyrodactylus teuchis (CUNNINGHAM et al., in prep.). T his result has been confirmed by an independent study performed in t h e same time (Dr. C.O. CUNNINGHAM, personal communication). G. teuchis shares several morphological and molecular characters with G. salaris. The wrong identification of the latter in France by JOHNSTON et al. (1996) probably originates in their similarities . The absence of Gyrodactylus salaris in both sampled régions, displaying optimal conditions for the parasite's maintenance, leads us to deny its current presence in France. Atlantic salmon parr, mainly parasitized by G. derjavini, are not infected by G. salaris in Brittany and Western Pyrénées. Rainbow trout and brown trout, for which prevalence of gyrodactylids is significantly higher than on salmon parr, are suitable hosts for G. teuchis. This wild fish survey will be extended to other parts of France and probably to farmed salmonids. In t he same way, the actual status towards G. salaris in whole continental Europe needs to be clarified. Biological characteristics of G. teuchis, particularly, its specificity, population dynamics and pathogenesis towards the main host species should be investigated. Besides, further work should be carried out to improve the reliability and efficiency of both identification methods

Proliferative capacity of murine hematopoietic stem cells.

The present study demonstrates a decrease in self-renewal capacity with serial transfer of murine hematopoietic stem cells. Production of differentiated cell progeny is maintained longer than stem cell self-renewal. In normal animals the capacity for self-renewal is not decreased with increasing donor age. The stem cell compartment in normal animals, both young and old, appears to be proliferative quiescent. After apparent recovery from the alkylating agent busulfan, the probability of stem cell self-renewal is decreased, there is a permanent defect in the capacity of the bone marrow for serial transplantation, and the stem cells are proliferatively active. These findings support a model of the hematopoietic stem cell compartment as a continuum of cells with decreasing capacities for self-renewal, increasing likelihood for differentiation, and increasing proliferative activity. Cell progress in the continuum in one direction and such progression is not reversible