TABLE 5.

Influence of mexZ on PA5471-dependent antimicrobial resistance

StrainRelevant genotypeMIC (μg/ml)a
AmiGenKanNeoParSpcStrTobEryNorTet
K7674812864256512325120.516
K2415ΔmexZ481281285121,02464512116
K2416ΔmexZ ΔPA5471b481281285121,02464512116
• a Antibiotic abbreviations are defined in Table 3. —, not determined. The loss of PA5471 did not impact the MICs of these agents in K767 (Table 3), and thus the impact of PA5471 loss on the MICs of these agents was not studied here. Agents for which resistance was increased upon loss of mexZ are indicated in bold.

• b In contrast to the lack of any impact of PA5471 loss on resistance of the MexZ strain K2415, the loss of PA5471 in the MexZ+ strain K767 compromised resistance to all agents listed here, except for neomycin and norfloxacin (Table 3, compare K2418 and K767).