br Conflict of Interest Statement br Author

Conflict of Interest Statement
Author Contributions N.M., K.N., M.G., R.J.O., and M.K. performed in vitro and in vivo experiments; N.M., H.D., and M.K., performed protein purification, crystallization, data collection, structure determination, and structural analyses; P.C., and J.D.H. carried out the ICP-MS metal content experiments and analyzed the data; N.M., H.D., and M.K. wrote the manuscript; M.K. designed and supervised the study; R.J.O., J.D.H., and M.K. edited the manuscript.
Acknowledgments The authors acknowledge the staff of the 8.3.1 beam line at the Advanced Light Source for their assistance in data collection. Advanced Light Source was supported by Department of Energy contract DE-AC03-76SF00098. The coordinates and structure factors for the AdcR structure have been deposited in the protein data bank (PDB) with the accession codes 5JLS and 5JLU.
Introduction In a person with diabetes a “triad” of factors that include peripheral neuropathy, peripheral vascular disease and trauma (Lipsky et al., 2012), place the foot at risk of developing a wound. Infections of the feet in people with diabetes are the primary pathway to lower extremity amputation (Lavery et al., 2003). The management of diabetes foot infection (DFI) is underpinned by the requirement to identify the pathogen/s of infection and thus direct antimicrobial therapy. Laboratory based methods that are culture-dependent have been utilised to identify planktonic microorganisms that are potential pathogens of infection, in addition to examining their density through qualitative and quantitative measures. This has shown acute ulcers are usually colonised by Staphylococcus aureus and/or Streptococcus agalactiae (Group B Streptococcus), and chronic ulcers have a more diverse microbiome, with purchase methysergide organisms and Pseudomonas aeruginosa becoming more important (Lipsky et al., 2016a,b). Culture-dependent techniques select for species that flourish under the typical conditions of the diagnostic microbiology laboratory, and this may not necessarily reflect the most abundant or clinically important microorganisms in DFIs especially anaerobes and species not detected under standard clinical microbiology laboratory protocols (Grice et al., 2008). Molecular DNA based techniques that are culture-independent have identified the limitations of traditional cultivation based methods when examining the microbiome of wounds. Using amplification and sequence analysis of 16s rDNA, a highly-conserved gene present in all prokaryotes (bacteria) but not eukaryotes (humans), has revealed a vastly more complex array of bacterial communities in non-infected chronic wounds (Dowd et al., 2008a,b; Gardner et al., 2013; Rhoads et al., 2012a,b; Smith et al., 2016). No data exists for acutely infected DFUs using this methodology.
Materials and Methods
Results 39 patients (39 tissue specimens) with newly infected DFUs were recruited over the 12-month study period. Broad demographic, clinical and laboratory data are shown in Table 1. Next generation DNA sequencing generated 1,028,895 sequences, which were clustered and aligned at 97% similarity to reveal 1139 unique OTUs. A total of seven major phyla were identified including Firmicutes (48%), Proteobacteria (26%), Actinobacteria (12%), Bacteroidetes (8%), Fusobacteria (2%) and Cyanobacteria (1%). The clustering of OTUs contributing to greater than 10% within each DFU sample at the genera/species-level is noted in Table 2 and those contributing to <10% are noted in (S2). Staphylococcus spp. was the most commonly sequenced microorganism in infected DFUs. This was followed by Corynebacterium spp., Finegoldia spp., Peptoniphilus spp., Acinetobacter spp., Anaerococcus spp., and Streptococcus spp., We further categorized microorganisms based on their residing niche (environmental, skin, oral and gut) to better define the site of origin of microorganisms that colonize DFUs (S3). Microorganisms commensal to the skin were predominant in half of patients (50.6%) followed by environmental (29.1%), gut (14%) and oral (6.3%) microorganisms.