Fig. 1: Development of Agr (QS)-dysfunctional mutants under antibiotic treatment in vitro. | npj Biofilms and Microbiomes

Fig. 1: Development of Agr (QS)-dysfunctional mutants under antibiotic treatment in vitro.

From: Antibiotic treatment can exacerbate biofilm-associated infection by promoting quorum cheater development

Fig. 1

a Experimental setup. For planktonic growth, cultures of S. aureus LAC were inoculated daily into new TSB media at 1/200 volume for 9 days. Levofloxacin (Lev), vancomycin (Van), or clindamycin (Cli) were supplied at ¼× MIC. For biofilm growth, cultures of S. aureus LAC were inoculated at 1/200 volume from pre-cultures into microtiter plate wells containing 200 μl of TSBg each and grown for 48 h to form a biofilm. Then, the supernatant was gently removed, and 200 μl TSBg containing Lev, Van, or Cli was dispensed into the wells at 5× MIC In the following 9 days, every 3 days, the old supernatant was gently removed and replaced with fresh TSBg (200 μl) with the respective antibiotics. b, c Results for planktonic (b) and biofilm (c) growth. Agr dysfunctionality was assessed by hemolysis on sheep agar plates. n = 3/group and time point. Error bars show the mean ± SD. Statistical analysis is done by two-way ANOVAs with Dunnett’s post-tests versus control values.

Back to article page