FIG 5.

In vitro and in vivo fitness assays. For the in vitro fitness assay, growth assays were conducted in LB broth at 37°C with continuous shaking for the two complemented strains (K56::ZpUC19 and K56::ZpUC19-KPHS_33600) (A) along with the parent strain K56 with and without the ZpUC-19 empty vector, respectively. There were no differences seen between the results determined with the resistant strain and the complemented strain. For the in vivo fitness assay, G. mellonella larvae were infected with approximately 1 × 10⁶ CFU of bacteria. After 4 h of infection, meropenem was injected and the larvae were observed for 4 days. Data represent results of comparisons of percentages of survival between larvae infected by the parent strain (K56) and those infected by strains complemented with (B) KPHS_33600, (C) KPHS_33520, (D) KPHS_33590, and (E) KPHS_35510. MEM, meropenem.