MICs and percentages of bacitracin resistance of <i>C. perfringens</i> isolates.

aNumbers of isolates; the three C. perfringens isolates of chicken origin associated with necrotic enteritis had MIC values of 3, 4 and 256 µg/ml; while the three type E isolates of turkey origin had MIC values of 4, 6 and 12 µg/ml. bConcentration where growth was inhibited in 50% and 90% of the isolates. The vertical line indicates the high level bacitracin resistance breakpoint of >256 µg/ml.