TABLE 4.

MICs of bacitracin for S. mutans strains used in this study

StrainaMICb
Xc4.0 ± 0.0d,f
Xc13 (gtfC)4.0 ± 0.0d,f
Xc26R (rmlD)0.80 ± 0.00c,f
Xc41 (rgpA)0.73 ± 0.09c,f
Xc42 (rgpB)0.73 ± 0.09c,f
Xc43 (rgpC)0.80 ± 0.00c,f
Xc44 (rgpD)0.73 ± 0.09c,f
XcB1 (rgpA)0.73 ± 0.09c,f
XcB2 (mbrD)0.033 ± 0.009c,d
Xc101 (mbrA)0.033 ± 0.009c,d
Xc102 (mbrB)0.033 ± 0.009c,d
Xc103 (mbrC)0.040 ± 0.000c,d
Xc104 (mbrD)0.040 ± 0.000c,d
Xc105 (ORF5)3.3 ± 0.9e,g
Xc106 (mbrA, mbrB, mbrC, and mbrD)0.033 ± 0.009c,d
Xc146 (mbrA, mbrB, mbrC, mbrD, and rgpA)0.020 ± 0.000c,d
  • a For all strains besides Xc, the genes were inactivated.

  • b Results are expressed in international units per milliliter. Each value represents the mean ± standard deviation for assays performed three times.

  • c Differences from strain Xc (P < 0.05 [Welch's t test]).

  • d Differences from strain Xc41 (P < 0.01 [Welch's t test]).

  • e Differences from strain Xc41 (P < 0.05 [Welch's t test]).

  • f Differences from strain Xc106 (P < 0.01 [Welch's t test]).

  • g Differences from strain Xc106 (P < 0.05 [Welch's t test]).