Fig. 4
The effect of B. cenocepacia infection on the integrity of HLCC monolayers. Confluent HLCCs were subjected to Ham’s F-12 complete medium (a and b) or 60 % ASMDM (c and d), infected with B. cenocepacia at MOI 0.3-5 (b and d) or mock-infected with saline (a and c), and incubated at 37 °C (7 % CO2). After 24 h, HLCC monolayers were assessed for damage with an inverted Zeiss axiovert 40 CFL microscope (1000X magnification). HLCC monolayers in both mock-infected wells are confluent with no damage (a and c). HLCC monolayer in Ham’s F-12 complete medium with B. cenocepacia shows no sign of damage, although a dense mass is floating in the well. Because this is seen in infected wells only, we think the aggregations are clouds of bacterial cells floating in the supernatant (arrows) (b). HLCC monolayer in 60 % ASMDM with B. cenocepacia shows damage as indicated by gaps in the monolayer (black stars). Clouds of bacterial cells can be seen as well (arrows) (d)