aureus. Macrolide antimicrobials have been shown to affect quorum sensing within biofilms, leading to reduced polysaccharide synthesis and instability of the biofilm architecture [41, 42]. Thus, it is possible that FOS may also influence the quorum-sensing signals of these strains. We plan to investigate this further in future studies by examining mRNA expression of agr and or protein levels in response to FOS treatment. Surface coverage and morphological effects of GF120918 cost fosfomycin Monotherapy with concentrations of FOS below the selected

strain’s MIC were also found to reduce adherence and biofilm structure on titanium orthopaedic screws. The percent particulate (clusters of biofilms) on the orthopaedic screw surfaces decreased significantly (P < 0.05) between control and FOS treated samples. In control samples, complicated fibrous structures, biofilm-embedded cells, and colonies of bacteria were noted as early as 4 h with increasing amounts of surface coverage after 24 h of growth (Figure 2A and C). Comparisons between the samples indicated that surface area coverage by MRSP biofilm decreased from 13.9% to 0.8% due to FOS treatment over 4 h and from 18.2% to 0.3% over 24 h (Figure 3). A decreased change GDC-0449 in vivo in extracellular polymeric substance production and the density of adherent bacteria and biofilm structures was also noted at 4 h in samples treated with 0.8 μg/ml of FOS (Figure 2A and

B). There is a significant difference in biofilm coverage between the control and FOS treated samples; biofilm coverage is reduced by treatment, indicating higher efficacy and the potential for preventing MRSP adhesion on clinically relevant surfaces. Further, enumeration (Table 2) of biofilm collected from titanium

PCI-32765 cell line screws confirmed that FOS (at below-MIC levels) significantly decreased biofilm formation (P < 0.05). Figure 2 Characteristic cell morphologies of MRSP biofilms and GNE-0877 its surface coverage on titanium orthopaedic screws. The effect of fosfomycin against MRSP A12 strain on titanium orthopaedic screws was assessed microscopically. Scanning electron micrographs of 4 and 24 h old MRSP biofilms on orthopaedic screws are shown without (A), (C) and treated with fosfomycin (B), (D) respectively. The biofilm cells embedded in biofilm extracellular matrix is indicated by the arrows in the control samples. Figure 3 Percent biofilm coverage on orthopaedic screw surface over 4 and 24 h time periods. Image analysis of particulate coverage of SEM images demonstrates that a significant difference (P < 0.05) exists between treated and untreated samples. Extracellular polymeric substances and adherent and biofilm-embedded cells were highlighted against the background in the same locations across both samples. Table 2 Average number of MRSP bacterial colonies grown from titanium screws treated with and without fosfomycin (n = 3) Dilution factor Average number of bacterial colonies (CFU) Control 0.8 μg/ml FOS 1:10 -1 468 ± 16.7 4.6 ± 0.