Arthropathic and amyloidogenic Enterococcus faecalis infections in brown layers: a study on infection routes

Intravenous, intra-articular and intraperitoneal inoculation of 6-week-old brown-layer pullets with an arthropathic and amyloidogenic strain of Entero coccus faecalis resulted in amyloid arthropathy, while intramuscular, oral and intratracheal inoculation did not. Oral inoculation of 1-day-old chicke ns did not cause any pathology. However, intramuscular inoculation with 10( 6) colony forming units resulted in severe growth retardation and arthritis in 60% of the birds, and amyloid arthropathy in approximately 40%. In egg transmission studies, neither egg dipping nor inoculation of the air chamber with E. faecalis reproduced the condition, although a few chicks b ecame septicaemic. Yolk sac inoculation of 6-day-old embryos caused embryon ic death within 2 days. In contrast, egg albumen inoculation with E. faecal is led to arthritis in one of six of the progeny, indicating the possibilit y that vertical transmission of E. faecalis by the oviductal route could le ad to arthritis. The presence of antibodies to E. faecalis was confirmed by enzyme-linked im munosorbent assay in 14/15 of experimental birds that had developed arthrit is.