Microbiological Profile of Diabetic Foot Ulcer Patients in a Tertiary Care Hospital in Kerala

Abstract

Abstract Introduction: One of the major complications of diabetes mellitus is diabetic foot ulcer (DFU). Fifteen percent of diabetes mellitus patients develop DFUs and 84% of foot amputations. The present study was carried out to determine the aerobic bacterial isolates cultured from diabetic foot infections and their susceptibility to commonly used antibiotics. Aim: The aim of this study was to determine the aerobic bacterial isolates cultured from diabetic foot infections and their susceptibility to commonly used antibiotics. Materials and Methods: We conducted a prospective observational study involving 104 patients with DFUs, who attended the general surgery/endocrinology outpatient department of our institution over 18 months. Results: This study showed that the most common organisms present in diabetic foot infections were Gram-negative aerobes, which accounted for 73.4%, while Gram-positive was 26%. Pseudomonas aeruginosa (20.1%) was the most predominant single organism isolated from the ulcer, followed by Klebsiella pneumonia and Escherichia coli (15.6% each). Staphylococcus aureus (7.8%) was the most common Gram-positive infective bacteria in DFU. Pseudomonas showed high sensitivity towards cefepime (93.3%), amikacin (93.6%), meropenem (89.7%) and piperacillin-tazobactam (83.9%) and low resistance towards ceftazidime (6.9%). In the current study, K. pneumonia showed good sensitivity towards meropenem (81.8%), amikacin and imipenem (70% each). One of the most important observations was the high resistance rate towards ertapenem (63.6%) and cefepime (60%). E. coli showed 100% sensitivity towards amikacin; it also had good sensitivity towards meropenem (89.5%) and imipenem (87.5%). Proteus species showed 100% sensitivity towards piperacillin-tazobactam, amikacin and meropenem, while an alarming rate of resistance towards imipenem (71.4%). Enterococcus spp. was 100% sensitive to amikacin, vancomycin and linezolid. S. aureus was 100% sensitive to cloxacillin, cefuroxime and ceftriaxone, and also showed 66.7% sensitivity to clindamycin. We also found that all the patients with methicillin-resistant S. aureus in diabetic foot infection wound swabs were 100% sensitive to vancomycin, linezolid and teicoplanin. Conclusion: Appropriate management of DFU is of paramount importance as it can prevent limb amputation and even sometimes potentially life-threatening limb complications. Isolation of microbial agents and determination of the sensitivity/resistance of different antimicrobial drugs are vital for the in-hospital management of these patients. The development of multi-drug resistance can be prevented by the institution of an appropriate antibiotic regimen.