Colony counts and characterization of bacteria adherent to the rumen wall and desquamated epithelial cells in conventional young lambs.

Abstract

Characterization and enumeration of the adherent epimural community of the rumen wall of young, conventionally reared lambs were carried out from 2 to 21 days after birth. Three hundred strains were isolated by anaerobic procedures from three sites: dorsal, ventral, and caudal sacs, and from the sloughed epithelial cells. The population of epimural bacteria was very dense from the first days of the lamb's life. This population increased slightly with age. During the first week the counts were similar in the dorsal and ventral sacs, but they were 10 to 100 times lower in the caudal sac. Total counts for anaerobic bacteria were higher than the counts for aerobic bacteria. The isolated strains were distributed into 19 groups: 11 groups included aerotolerant strains, and 8 others, strictly anaerobic strains. During the first week the facultative microflora was mainly composed of Escherichia coli and Streptococci. Later, the epimural community was more complex and included Staphyloccus, Micrococcus, and Gaffkya. The strictly anaerobic microflora was mainly composed of Clostridium, Peptostreptococcus, Veillonella, Propionibacterium, and Acidaminococcus. Some of these strains appeared to be similar to those previously isolated from the rumen fluid of young lambs; however, the genera Micrococcus, Veillonella, Gaffkya, and Acidaminococcus, and E. coli seemed to be specific of the rumen wall tissues.