Evaluation of selective media for primary isolation of Treponema hyodysenteriae and Treponema innocens

A total of 2450 samples of feces, intestinal contents and colon mucosal scrapings were bacteriologically examined. A total of 53 strains of Treponema sp. were isolated, and 45 strains of Bacteroides sp., 30 strains of E. coli, 30 strains of Micrococcus sp. and 10 strains of Streptococcus D isolates were randomly selected. Growth promoting studies showed statistically significant stimulation of Treponema sp. growth by yeast extract, chicken egg yolk and rumen fluid. Different growth inhibitors were also tested. For selective medium the following inhibitors were selected: spectinomycin, colistin, vancomycin, brilliant green. Optimal concentrations of these inhibitors in the medium were determined. Finally TSA medium supplemented with 0.05% yeast extract, 5% bovine blood, 0.01% DTT, 400 μg spectinomycin, and 250 μg/ml vancomycin, appeared to be optimal selective medium for intestinal Treponema sp. isolation. Quantitative studies showed that the number of Treponema C.F.U. on Songers et al. medium with spectinomycin and on spectinomycin-vancomycin medium, did not differ significantly. The number of overgrowing bacteria was statistically significantly lower on spectinomycin-vancomycin medium, than Songers et al. selective medium with spectinomycin. The TSA supplemented with blood, yeast extract 50 μg/ml of colistin and 1 μg/ml of brilliant green was less selective than spectinomycin-vancomycin medium and inhibited some strains of Treponema sp. In the case of spectinomycin-vancomycin resistant of overgrowing bacteria, colistin-brilliant green medium may be suitable for isolation of Treponema sp. Pour réaliser cette étude ont été examinés 2450 échantillons de féces ou de contenu intestinal et raclages de muqueuse de colon de porcs. 56 souches de Treponema sp., 45 souches de Bacteroides sp., 30 souches de E. coli, 30 souches de Micrococcus sp. et 10 souches de Streptococcus D sp. ont été isolés. On a constaté une stimulation de la croissance de Treponema sp. statistiquement significative pour l'action de: extrait de levure, jaune d'oeuf et liquid ruminal. Par contre les résultats avec DTT ont été statistiquement non significatives. En plus, nous avons examiné la sensitivité de Treponema sp. à 10 inhibiteurs de croissance. Pour les milieux sélectives on a utilisé: Spectinomycin, Colisitin, Vancomycin et vert brillant. Nous avons determiné la concentration optimale des inhibiteurs dans le milieu. Le milieu TSA enrichi avec 0,05% de extrait de levure, 5% du sang, 0,01