FIG 1.
The insusceptibility of strain YR7 to meropenem. (A) Bacterial viability of strain YR7 on MHA plates containing various levels of meropenem. To determine the bacterial viability of strain YR7, the mid-log-phase cultures in serial dilution were spotted on MHA plates supplemented with meropenem at various levels (0.5, 1, 2, 4, 8, 16, 32, and 64 μg/mL) and maintained for 18 h at 37°C. The density of strain YR7 suspensions was adjusted to a 0.5 McFarland standard (1 × 108 CFU/mL). Eight microliters of the diluted suspension with approximately 1 × 106, 1 × 105, 1 × 104, 1 × 103, and 1 × 102 CFU/mL was inoculated on prepared MHA plates. The type strain BNCC 354128 of A. junii was used as the negative control. (B) Application of the Etest to compare the MIC values of meropenem in the A. junii strains BNCC 354128 and YR7.