-Small ruminant lentiviruses (SRLV = maedi-visna in sheep and caprine arthritis encephalitis in goats) are distributed throughout most countries of the world, particularly Europe. Laboratories from 16 European countries established collaborations within the framework of a COST (CO-operation in the field of Scientific and Technical Research) action sponsored by the European Union in order to (i) better organize their research programmes on SRLVs and (ii) to coordinate efforts to combat these two diseases. After five years, a consensus conference -the first one in the veterinary medicine field -concluded the work of this network of laboratories by reviewing the present position and discussing three important questions in the field of SRLVs: routes of transmission, consequences of infection and potential role of eradication programmes at either a European or local level, according to the situation in each country or region. This paper brings together existing information regarding these questions and identifies areas for future research.Maedi-visna / caprine arthritis-encephalitis virus / lentivirus / small ruminants / European consensus conference

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Escherichia coli that are virulent for poultry usually result in a respiratory disease, which is frequently followed by a general infection. Adhesiveness of E. coli to epithelial cells and iron-uptake ability of E. coli could be involved in different steps of the disease. These properties were studied in 59 E. coli strains originating from poultry, with reference to lethality for day-old chicks. Adhesive properties were found in 64% of the lethal strains and in only 23% of the nonlethal strains. The ability to grow in limited iron conditions was strongly correlated with lethality. Fifty-two percent of the lethal E. coli strains, but none of the nonlethal strains, possessed both adhesive and iron-uptake abilities. It is suggested that these two properties play a role in the virulence of E. coli for poultry.

Escherichia coli and Salmonella strains resistant to gentamicin and apramycin were isolated from cattle in France and Belgium and from patients in hospitals. Homology between plasmids of both human and animal origins encoding aminoglycoside 3-N-acetyltransferase was revealed by digestion with several restriction endonucleases and confirmed by hybridization with different replicon-specific probes.

Seventy selected strains of Salmonella typhimurium and S. enteritidis isolated from related poultry flocks in three independent geographical areas were characterized by phenotypic and genotypic methods to compare the usefulness of the methods in epidemiological studies. The 56 S. typhimurium isolates were poorly discriminated by their biotypes, resistance patterns, and plasmid profiles. Nine different ribotypes were obtained after DNA digestion by BglII, PvuII, and SmaI. Seven IS200 types, characterized by six to nine copies of IS200 on the chromosome, were detected after digestion of genomic DNA by PstI. These studies resulted in the definition of 15 clonal lineages distributed in three clusters. The 14 S. enteritidis strains were not discriminated either by ribotyping or by detection of IS200 (IS200 typing), but were separated on the basis of antibiotic resistance and plasmid profiling. The stability of the insertion sequence type was confirmed by inoculation of an S. typhimurium strain to axenic chickens reared for 15 weeks in sterile isolators.