Impact of polymicrobial infection on fitness of Streptococcus gordonii in vivo

Tn-Seq was used to identify S. gordonii genes that confer fitness during cooperative growth with P. gingivalis in a murine abscess model. After generating a saturating Streptococcus gordonii transposon library using EZ-Tn5 based transposon mutagenesis, this library was inoculated either alone (Sg) or in conjunction with Porphyromonas gingivalis (PgSg) subcutaneously into BALB/cJ mice. Bacteria recovered from developed abscesses were inoculated and cultured in vitro anaerobically until turbid and genomic DNA was isolated. Genomic DNA was also isolated from the S. gordonii transposon library (Input) and was not used to infect mice and used as a control.