Figure 3

The effect of the combination of PMAP-36 and tetracycline on drug resistance in PCN033. PCN033 (1 × 10⁶ CFU) was incubated with different concentrations of PMAP-36, tetracycline (1/32 MIC), or tetracycline (1/32 MIC) + PMAP-36 (1/32 MIC) for 6 h at 37 °C, after which the mRNA levels of tetB were analysed by qPCR (A, B). PCN033 was exposed to sub-MICs of PMAP-36 and tetracycline at 37 °C for 30 generations, and the change in MIC was determined by normalizing the MIC of the n generation to the MIC of the first generation (C). Statistical significance is indicated by *p < 0.05 and ***p < 0.001 (Student’s t test).