Table 1.

Association of phenotype, genotype, and MICs of erythromycin and clindamycin

PhenotypeGenotypeNo. of strainsMIC (μg/ml)a
ErythromycinClindamycin
50%90%Range50%90%Range
MLS Cb ermB 7≥16≥162–≥164≥162–≥16
ermTR 84≥162–≥16≥16≥16≥16
MLS I ermB 0
ermTR 13242–40.250.250.25
M mef 44164–≥160.250.250.25
L linB 1NAc NA40.120.120.12
  • a 50% and 90%, MICs at which 50 and 90% of isolates are inhibited, respectively.

  • b One ermB strain showed heteroresistance; one MLS phenotype strain harbored both anermTR/ermA and a mef gene.

  • c NA, not applicable.