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. Author manuscript; available in PMC: 2014 Aug 1.
Published in final edited form as: J Surg Res. 2013 Feb 24;183(2):767–776. doi: 10.1016/j.jss.2013.02.003

Figure 5. In Vitro Biofilm Culture.

Figure 5

Figure 5

Figure 5

P. aeruginosa biomass reductions (i.e. antimicrobial effect) after 22 hours flow compared with baseline were: no antibiotic 9%, azithromycin 32%, ciprofloxacin 10%, tobramycin 68%. Ciprofloxacin (4 mcg/mL) had no statistically significant effect on P. aeruginosa biofilm biomass when compared with no antibiotic exposure. Azithromycin and especially tobramycin (40 mcg/mL) were more effective than no treatment or the other antibiotics tested (*P<0.05, ∞P <0.001).

The addition of azithromycin to ciprofloxacin was significantly more effective at reducing P. aeruginosa biomass than ciprofloxacin alone (*P<0.05). This combined treatment resulted in 34% P. aeruginosa biomass reduction compared with 10% observed with ciprofloxacin alone.

When azithromycin was added to tobramycin, the effective biomass reduction was lost (68% to 28%, P<0.001) and was no longer statistically significant when compared with no treatment or azithromycin alone.