Microbiology of Pressure Ulcers: A Systematic Review

Area of Science:

• Infectious Diseases
• Wound Care
• Microbiology

Background:

• Pressure ulcers are complex wounds often complicated by infections.
• Understanding the microbial landscape of these ulcers is crucial for effective treatment.
• Current diagnostic and therapeutic strategies face challenges due to the dynamic ulcer microenvironment.

Purpose of the Study:

• To characterize the distribution of microorganisms in pressure ulcers.
• To assess study heterogeneity and compare microbial yields between invasive and noninvasive sampling techniques.
• To inform antimicrobial management strategies for pressure ulcer infections.

Main Methods:

• A systematic review of studies reporting microbiological data from pressure ulcers was conducted.
• Searches were performed in PubMed, Embase, and the Cochrane Library up to January 2025.
• Risk of bias was assessed using established frameworks (ROBINS-I V2, ROBINS-E, RoB 2).

Main Results:

• Twenty-eight studies including 1,473 patients and 1,682 pressure ulcers were analyzed.
• Staphylococcus aureus (39.7%), Corynebacterium spp. (28.8%), and Escherichia coli (23.1%) were the most frequently isolated microorganisms.
• Significant heterogeneity was observed across studies, with variations in microbial yields between swab and biopsy sampling methods.

Conclusions:

• Despite heterogeneity, a core group of recurrent pathogens including Staphylococcus aureus, Enterobacteriaceae, Streptococcus spp., Enterococcus spp., Pseudomonas spp., and Bacteroides spp. dominate pressure ulcer flora.
• Standardized protocols for sampling and reporting are needed to improve interpretation.
• Findings provide a framework for empiric antimicrobial therapy, warranting further investigation through prospective controlled trials.