Comparative study of long, segmented, filamentous organisms in chickens and mice.

No transmission of long, segmented, filamentous organisms (LSFO) from a laboratory mouse strain (Mus musculus) to a domestic broiler chicken strain (Gallus domesticus) occurred by oral dosing with mouse mucosal and fecal preparations, even in hydrocortisone-treated chicks. Transmission of chicken LSFO to laboratory mice was attempted, but the results were confounded by the mice having been already infected with LSFO. However, the morphologic characteristics of the LSFO in the dosed mice suggested that transmission of chick LSFO did not occur. Mouse LSFO, as detected in carbol thionin-stained mucosal smears, are generally wider, longer, and have slightly different morphologic characteristics than chicken LSFO. The results of these studies suggest that the LSFO in mice and chickens may be two distinct species.