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Figure 1 | BMC Microbiology

Figure 1

From: The impact of the competence quorum sensing system on Streptococcus pneumoniaebiofilms varies depending on the experimental model

Figure 1

Characteristics of the biofilm model based on exponentially growing cells. Pneumococcal attachment to 96-well microtiter wells after 1:100 dilution in TSB medium was evaluated by viable counts following detachment of cells by sonication. Prior to sonication 18 hour biofilm was washed three times with medium. Panel A reports the effect of the duration of sonication (2 sec. white; 5 sec. light grey; 10 sec dark grey; 30 sec. black) on detachment and survival of pneumococcal cells. Panel B reports biofilm formation of TIGR4 (open bar), FP184 (mutated for comD response regulator; grey bar) and FP218 (mutant of response regulator of the BLP system; black bar) in media supplemented with CSP2, its allelic variant CSP1, BLPTIGR4 or its allelic variant BLPR6. Panel C shows a time course experiment with simultaneous evaluation of turbidity of the planktonic culture (closed circle; OD values of TIGR plotted on right axis) and biofilm counts using encapsulated TIGR4 (square) and its rough isogenic mutant FP23 (triangle). Experiments were performed in TSB supplemented with CSP2 (open symbols) or plain TSB (closed symbols). Turbidity data are form strain TIGR4. Data are from quadruplicate experiments (the small SD are not visible due to log scale of the graph)

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