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. 2015 Feb 24;3:e787. doi: 10.7717/peerj.787

Table 1. Comparison of Cq values and calculated number of CFU.

Cq-values (±SEM) obtained with PMA-qPCR and calculated log values of viable P. aeruginosa biofilm cells (using the equation for the linear trendline), after treatment with colistin (200 µg/ml), levofloxacin (100 µg/ml) or tobramycin (200 µg/ml) for 24 h and incubation with PMA. The difference in the calculated number of viable cells after treatment is significantly different between mono- and multispecies biofilms (p < 0.05).

Biofilm type Treatment Cq-value (±SEM) Calculated log viable cells/biofilm Δlog
Multispecies 15.13 ± 0.28 8.27 1.26
Colistin 7.01
20.39 ± 0.64
Monospecies 15.98 ± 0.35 8.07 0.53
Colistin 7.54
18.18 ± 0.23
Multispecies 12.79 ± 0.38 8.85 0.95
Levofloxacin 7.90
16.71 ± 0.38
Monospecies 14.80 ± 0.15 8.36 1.57
Levofloxacin 6.79
21.29 ± 0.46
Multispecies 15.04 ± 0.44 8.30 −0.05
Tobramycin 8.35
14.84 ± 0.43
Monospecies 14.80 ± 0.15 8.36 −0.02
Tobramycin 8.38
14.70 ± 0.18