TABLE 3.

M. elsdenii strain characteristics

StrainaAnimal or sampleV3 sequence similarityb to RLC-1 (%)Growth on lactate (OD620)MIC (μg/ml)c
TetCtcOtcDox
LC-1TOvine1001.7544-88-161
B159BovineND1.744-88-161
T81OvineND1.7542-48-161-2
2-9Swine cecal contents (farm A)98.21.812825625664
4-13Swine cecal contents (farm A)99.41.7128>25625664
7-11Swine cecal contents (farm A)98.91.8128>25625664
7-12Swine cecal contents (farm A)98.91.6128>25625664
14-14Swine cecal tissues (farm B)99.41.85256>256>25664
15-5Swine cecal tissues (farm B)98.91.812825625664
19-3Swine cecal tissues (farm B)98.91.5512825625664
20-11Swine cecal tissues (farm B)98.91.4128>25625664
Bacillus fragilis ATCC 25285 (TcS)1-248-161
Bacillus thetaiotaomicron ATCC 29741 (Tcr)641286432-64
  • a M. elsdenii strains LC-1T, B159, and T81 were obtained from stock cultures. Additional M. elsdenii strains were isolated in these studies. Bacteroides strains were obtained from the American Type Culture Collection for use as reference strains in tetracycline MIC assays (41).

  • b Percent sequence similarity with M. elsdenii LC-1T (U95027) in the 16S rDNA V3 region. ND, not determined.

  • c Tetracycline (Tet), chlortetracycline (Ctc), oxytetracycline (Otc), and doxycycline (Dox) concentrations expressed per milliliter of medium.