Determinants of Microbial Load in Infected Diabetic Foot Ulcers: A Pilot Study

M Demetriou,M Panopoulou,E Maltezos,N Papanas,K Papatheodorou

doi:10.1155/2013/858206

Abstract

We examined the determinants of microbial load in infected diabetic foot ulcers in 62 patients (38 men and 24 women, mean age: 65.63 ± 12.71 years) with clinically infected diabetic foot ulcers. Tissue cultures were taken from ulcers by 4 mm punches. Ulcer grade (University of Texas classification), neuropathy disability score (NDS), neuropathy symptom score (NSS), ankle-brachial index (ABI), perfusion, extent, depth, infection, and sensation (PEDIS) grade of diabetic foot infection, and laboratory parameters were evaluated in all patients. Total microbial load was positively correlated with the number of isolates on tissue cultures (r s = 0.544, P < 0.001), white blood cell count (WBC) (r s = 0.273, P = 0.032), and platelet count (PLT) (r s = 0.306, P = 0.015). It also exhibited a borderline insignificant positive correlation with PEDIS infection grade (r s = 0.246, P = 0.053). In stepwise linear regression analysis, the number of isolates on tissue cultures and WBC were identified as the only two significant parameters accounting for 38% of the variation in the log of total microbial load (adjusted R 2 = 0.380, P < 0.001). In conclusion, patients with infected diabetic foot ulcer exhibit a positive correlation of total microbial load with the number of isolates on tissue cultures, WBC and PLT.

Highlights

In both epidemiological surveys and everyday clinical practice, the diabetic foot remains a major cause of patient morbidity [1,2,3] and nontraumatic lower extremity amputations [4,5,6]
The present study found a positive correlation between total microbial load and the number of isolates on tissue cultures
The latter was one of the 2 parameters significantly influencing the variation of the former. This is not surprising, given that total microbial load was calculated by adding colony-forming units (CFUs) per g tissue of each isolate

Summary

Introduction

In both epidemiological surveys and everyday clinical practice, the diabetic foot remains a major cause of patient morbidity [1,2,3] and nontraumatic lower extremity amputations [4,5,6]. Characteristics of foot ulcers (chronicity, extension, and depth), prior antibiotic use, and presence of peripheral arterial disease, generally, have a considerable impact on bacterial pathogens in infected foot ulcers [7, 25,26,27,28], but there is no reliable way of predicting types of pathogens and microbial load [7, 13]. This is important because a high number of foot ulcers are nowadays already infected at initial presentation [29]. The aim of the present study is to examine the determinants of microbial load in infected diabetic foot ulcers

Objectives

Methods

Results

Conclusion