Increased eDNA in the mixed-species biofilms confirmed by real-time RT PCR. Biofilm matrix was extracted and eDNA was quantitated by real-time RT PCR using genomic DNA as standard. Primers for S. epidermidis genes (lrg A, lrgB and bap) were used to quantify the eDNA (Figure 5A). Staphylococcal eDNA was increased significantly in the mixed species biofilms compared to single species S. epidermidis biofilms (*, ** and ¶, p < 0.05). Candida gene specific primers (RIP, RPP2B and PMA1) were used to assess the contribution of eDNA by Candida in mixed species biofilms (Figure 5B). Candida specific eDNA was present in Candida biofilms, absent in S. epidermidis biofilms and negligible in mixed species biofilms. S. epidermidis biofilms are represented in white bars, mixed species biofilms in gray bars and Candida biofilms in chequered bars.
Pammi et al. BMC Microbiology 2013 13:257 doi:10.1186/1471-2180-13-257