Comparison of Culture and Molecular Identification of Bacteria in Chronic Wounds

Daniel D Rhoads,Yan Sun,Scot E Dowd,Randall D Wolcott

doi:10.3390/ijms13032535

Abstract

Clinical diagnostics of chronic polymicrobial infections, such as those found in chronic wounds, represent a diagnostic challenge for both culture and molecular methods. In the current retrospective study, the results of aerobic bacterial cultures and culture-free bacterial identification using DNA analyses were compared. A total of 168 chronic wounds were studied. The majority of bacteria identified with culture testing were also identified with molecular testing, but the majority of bacteria identified with the molecular testing were not identified with culture testing. Seventeen (17) different bacterial taxa were identified with culture, and 338 different bacterial taxa were identified with molecular testing. This study demonstrates the increased sensitivity that molecular microbial identification can have over culture methodologies, and previous studies suggest that molecular bacterial identification can improve the clinical outcomes of patients with chronic wounds.

Highlights

Subjects were included in the study if they met the following criteria: (1) The presence of a chronic wound (“Chronic wound” is defined as a wound that fails to progress through the normal healing trajectory); (2) Debridement required as part of standard of care wound management; (3) The medical record revealed that parallel samples from the wound were sent for both, culture and molecular testing
When considering all 168 wounds, 338 different bacterial taxa were identified by molecular testing
The majority of bacteria identified with culture were identified with molecular testing, but the vast majority of bacteria identified with molecular methods were not identified with culture methods

Summary

Introduction

Wounds that fail to progress through normal wound healing trajectory, are a large and growing problem for an already burdened healthcare system. Wound care providers treat wounds as if the bioburden is one of the major barriers to wound healing. Debridement, antibiotics, and topical antiseptics are routinely used in managing the microbes that are universally found on chronic wounds. The only microbial diagnostic tool available to wound care providers until recently has been the routine clinical culture. The role of bacteria in chronic wounds and the appropriateness of using antimicrobial agents in the routine management of chronic wounds is a source of continual debate in the wound care community [3,4,5]. It is reasonable to consider that improving the methods of microbial detection and identification may be more successful in helping the clinician deal with this important healthcare problem

Methods

Results

Discussion

Conclusion