TABLE 1.

Bordetella pertussis isolates tested for erythromycin susceptibility

StrainErythromycin phenotypeErythromycin MIC(s) (μg/ml)MutationSource (reference)
MN2726Susceptible0.064None (wtd)This study
MN277Susceptible0.064None (wt)This study
MN973Susceptible0.064None (wt)This study
MN1286Susceptible0.032None (wt)This study
MN1699Susceptible0.047None (wt)This study
MN1773Susceptible0.047None (wt)This study
MN1893Susceptible0.047None (wt)This study
MN2531Resistant>256A2047GThis study
A228aResistant>256bA2047GArizona (2, 22)
C310aResistant>256bA2047GCalifornia (14)
C352a,b,cHeterogeneousb0.047, >256A2047RGeorgia
C353a,bResistant>256bA2047GGeorgia
  • a Supplied by the CDC.

  • b MIC originally determined by CDC using methods described previously (7) and retested at MDH for purposes of comparison.

  • c Strain C352 exhibits a heterogeneous phenotype (a mix of sensitive and resistant colonies) with respect to erythromycin resistance (37). Sequencing of the 521-bp PCR fragment resulted in an unresolved base (A or G) at position 2047, indicated by an R in the nucleotide sequence.

  • d wt, wild type.