Figure 3.

A. baumannii forms spherical persisters in the host environment. (A) The morphotypes of A. baumannii in the G. mellonella larvae without antibiotic treatment. Bright-field and the corresponding fluorescent images of haemocytes extracted at 1 h, 2 h and 3 h after the larvae being infected by dnaK::msfGFP. The red solid arrows pointing the spherical cells. (B) The morphotypes of A. baumannii in the G. mellonella larvae upon treatment with meropenem. The larvae were infected by dnaK::msfGFP for 1 h, followed by treatment with 6 mg/kg of meropenem (left) or filtered water (control, right) for another 30 min. Haemocytes were then extracted for bright-field and fluorescent imaging. (Scale bar, 5 μm). The red solid arrows pointing the spherical cells. (C) Percentage of spherical and non-spherical bacterial cells in the extracted haemocytes from the infected larvae treated with meropenem or control in (B). BF: Bright field.