Olga L. M. Haenen

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Herpesvirus of eel Herpesvirus anguillae (HVA) was isolated repeatedly from farmed eel of an outwardly healthy stock, but virus isolation was much greater in an experimental group of fish that were injected with dexamethasone. The results suggest that HVA can establish a latent infection in eel. Previous exposure of these eels to HVA virus was shown by(More)
Many of the known fish herpesviruses have important aquaculture species as their natural host, and may cause serious disease and mortality. Anguillid herpesvirus 1 (AngHV-1) causes a hemorrhagic disease in European eel, Anguilla anguilla. Despite their importance, fundamental molecular knowledge on fish herpesviruses is still limited. In this study we(More)
Anguillid herpesvirus (AnHV, also known as Herpesvirus anguillae or HVA) is found in both Japanese and European eels. Based on restriction enzyme analysis a small number of differences were found between AnHV isolated from Japanese eels and from European eels. The total genome size of both is about 245 kb, which is confirmed by alternating-field(More)
We show that European eels infected with the rhabdovirus EVEX (Eel Virus European X) virus, developed hemorrhage and anemia during simulated migration in large swim tunnels, and died after 1000-1500 km. In contrast, virus-negative animals swam 5500 km, the estimated distance to the spawning ground of the European eel in the Sargasso Sea. Virus-positive eels(More)
EVEX (Eel-Virus-European-X), HVA (Herpesvirus anguillae), and EVE (Eel Virus European) were detected in wild and farmed European eels (Anguilla anguilla L.) from the Netherlands, EVEX and EVE from farmed eels from Italy, and EVEX from wild eels from Morocco. EVEX was also isolated from wild New Zealand eel (A. dieffenbachi). Elvers (A.anguilla) collected(More)
Viral interleukin 10 (IL-10) like open reading frames have been identified in several pox- and herpesviruses, including the fish herpesviruses Anguillid herpesvirus 1 (AngHV-1) and Cyprinid herpesvirus 3 (CyHV-3). European eel (Anguilla anguilla) IL-10 was sequenced, in order to compare European eel and common carp (Cyprinus carpio) IL-10 with their(More)
Diseases are an important cause of losses and decreased production rates in freshwater eel farming, and have been suggested to play a contributory role in the worldwide decline in wild freshwater eel stocks. Three commonly detected pathogenic viruses of European eel Anguilla anguilla are the aquabirnavirus eel virus European (EVE), the rhabdovirus eel virus(More)
In a recirculation aquaculture system the drumfilter effluent can be used as substrate for heterotrophic bacterial production, which can be recycled as feed. Because the bacteria might contain pathogens, which could reduce its suitability as feed, it is important to characterize these communities. Bacteria were produced in growth reactors under different(More)
Carbapenems are considered last-resort antibiotics in health care. Increasing reports of carbapenemase-producing bacteria in food-producing animals and in the environment indicate the importance of this phenomenon in public health. Surveillance for carbapenemase genes and carbapenemase-producing bacteria in Dutch food-producing animals, environmental(More)
Aeromonas salmonicida is the causative agent of furunculosis, a disease that affects both salmonid and non-salmonid fish. Detection of A. salmonicida can be labour intensive and time consuming because of the difficulties in distinguishing the bacterium from other species given the wide variety of existing biochemical profiles and the slow growth(More)