Genbank accession #: 133708

Plant Molecular Biology -     

Screening of Feral Pigeon (Colomba livia), Mallard (Anas platyrhynchos) and Graylag Goose (Anser anser) Populations for Campylobacter spp., Salmonella spp., Avian Influenza Virus and Avian Paramyxovirus

A total of 119 fresh faecal samples were collected from graylag geese migrating northwards in April. Also, cloacal swabs were taken from 100 carcasses of graylag geese shot during the hunting season in August. In addition, samples were taken from 200 feral pigeons and five mallards. The cultivation of bacteria detected Campylobacter jejuni jejuni in six of the pigeons, and in one of the mallards. Salmonella diarizona 14:k:z53 was detected in one graylag goose, while all pigeons and mallards were negative for salmonellae. No avian paramyxovirus was found in any of the samples tested. One mallard, from an Oslo river, was influenza A virus positive, confirmed by RT-PCR and by inoculation of embryonated eggs. The isolate termed A/Duck/Norway/1/03 was found to be of H3N8 type based on sequence analyses of the hemagglutinin and neuraminidase segments, and serological tests. This is the first time an avian influenza virus has been isolated in Norway. The study demonstrates that the wild bird species examined may constitute a reservoir for important bird pathogens and zoonotic agents in Norway.     

Properties of Extracellular Enzymes from Aphanomyces astaci and Their Relevance in the Penetration Process of Crayfish Cuticle

In culture filtrates from the crayfish plague parasite, Aphanomyces astaci, protease and a low level of hyaluronidase activity were found. The hyaluronidase activity was highest at pH 6.5 or above and at about 23°C. The protease activity had a broad pH-optimum, between pH 7 and at least pH 10, and was partially denatured at 30°C. However, when incubated for 30 min with the substrate, casein, the activity increased logarithmically up to about 35–40°C and had an apparent optimum at 45–50°C. The proteases from the parasitic as well as from two less proteolytic, saprophytic Aphanomyces species were predominantly constitutive and were excreted mainly by the older mycelia. Proteases from the parasite and a saprophyte did not reach full activity until 10–30 min after substrate addition. No lipase activity was found in the case of the mycelium of the parasitic species. However, esterase was apparently present inside germinating zoospores. The native enzymes of A. astaci could degrade freeze-dried soft cuticle from crayfish. The relevance of the different enzymes of A. astaci for the penetration process within the cuticle of crayfish is discussed.