The diabetic foot infections: biofilms and antimicrobial resistance

To study the difference in antimicrobial resistance profile among biofilm producing and non-producing microorganisms isolated from diabetic foot ulcer in a tertiary care hospital in North India.

We performed a prospective study on 162 DFU in patients treated in a multidisciplinary based diabetes and endocrinology center of JNMCH, AMU, Aligarh, India during the period of December 2008-March 2011. Detailed history and physical examination was carried out for every subject. Patient's profile, grade of DFU, co-morbidities and complications, laboratory data and final outcome were collected. Standard methods of sample collection and identification of microorganism were adopted. Risk factors for biofilm producing infections were determined by univariate analysis with 95% of CI. P value <0.05 were considered as significant.

The overall biofilm producing infection rate among DFU was 67.9%. On univariate analysis, significant risk factors for biofilm producing infection were male sex [P=0.015, OR 2.35, RR 1.71], duration of diabetes [P<0.006, OR 4.0, RR 2.7], duration of ulcer >1 month [P<0.02, OR 2.26, RR 1.72], size of ulcer >4 cm(2) [P<0.05, OR 2.03, RR 1.54], Grade II ulcer [P<0.06, OR 1.87, RR 1.63], necrotic ulcer [P<0.002, OR 5.79, RR 3.59], previous antibiotic use [P<0.007, OR 4.24, RR 2.74], subcutaneous infection [P<0.06, OR 1.87, RR 1.63], HbA1c >7% [P<0.04, OR 3.19, RR1.87] and polymicrobial infection [P<0.001, OR 6.64, RR 3.21] were significant risk factors.

Treating the DFU by shifting from the planktonic model of microbiology to the biofilm model was recommended. With this new scientific approaches along with coordination of clinical and laboratory efforts, education, and research, it is possible to imagine overcoming much of biofilm disease.