|Rooney, Alejandro - Alex|
|St Amand, Allison|
Submitted to: Journal of Wound Repair and Regeneration
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/30/2008
Publication Date: 3/1/2009
Citation: Frank, D.N., Wysocki, A., Specht-Glick, D., Rooney, A.P., Feldman, R.A., St Amand, A.L., Pace, N.R., Trent, J.D. 2009. Microbial Diversity in Chronic Open Wounds. Journal of Wound Repair and Regeneration. 17(2):163-172. Interpretive Summary: This manuscript describes research on the characterization of microbes that inhabit wounds. A novel molecular phylogenetic approach is described and compared to traditional cultures-based techniques of characterizing the bacterial species that are found in wounds in various stages of healing. Our findings indicate that standard methods of culturing underestimate the microbial diversity in chronic wounds and that the PCR-based 16S rRNA method provides a more accurate assessment. This research has important implications for clinical diagnosis and treatment in both veterinary and human medical settings.
Technical Abstract: Bacterial colonization of chronic skin wounds is routinely monitored clinically by culture methods that determine the presence of specific pathogens. However, these methods do not necessarily reveal the full microbial diversity of wounds. With the accumulating evidence that diverse microbes associated with wounds may have clinical significance, there is a growing need for clinical methods that more adequately monitor microbial diversity. The purpose of this clinical study was to compare standard culture methods for microbial detection with molecular methods based on phylogenetic analysis of bacterial 16S rRNA genes isolated from wound specimens without prior culture. Samples obtained from 18 volunteers at two different institutions were analyzed in parallel by culture and broad-range 16S rRNA PCR. Microbes present in the wound samples were identified by comparison of rRNA sequences to those of previously characterized microorganisms. In total, 2653 rRNA clones representing 93 species-level sequence-related groups were analyzed. Standard culture detected an average of '3 microbial types per patient (range 1-4), while the 16S rRNA PCR method detected an average of '10 microbial types per patient (range 3-26). The microbial groups most frequently detected by PCR included Staphylococcus spp. (25% of rRNA clones), Corynebacterium spp. (20% of clones), Clostridium spp. (18% of clones) and Pseudomonas spp. (12% of clones). We conclude that standard methods of culture underestimate the microbial diversity in chronic wounds and that the PCR-based 16S rRNA method provides a more accurate assessment. The impact of microbial diversity on wound healing is discussed.