Fig 5. Detection of msfA transcripts in vitro and in vivo.

Left panel: RNA was extracted from PittII grown planktonically and as a biofilm in sBHI medium. Right panel: PittII was inoculated bilaterally into the middle ears of three chinchillas via transbullar injection. Animals were euthanized 3h and 24h post-inoculation. Effusions from the middle-ears were harvested immediately and RNA was extracted. Both panels: RNA samples were reverse transcribed (+) or had reverse transcriptase (RT) omitted from the reactions (-). PCR was then performed on + and - RT samples with a primer pair specific to the msfA genes. Due to sequence similarity multiple alleles are amplified. The two different sizes of the four msfA genes make them easily discernible in the gels (white arrows).