Changing Antibiogram Profile of Acinetobacter baumannii in Diabetic and Non-Diabetic Foot Ulcer Infections

Abstract

Introduction: Foot ulcer infection relies on the hosts immune status and pathophysiological condition. The differences between Diabetic Foot Ulcer Infections (DFU) and non-DFU patients may alter the biofilm-forming capabilities of microorganism and thereby, play a key role in regulation of ulcer healing. Extended Spectrum of β-Lactamase (ESBL) and Metallo-β-Lactamase (MBL) producing Acinetobacter baumannii isolates are reported as important causative agents of infection. Aim: To determine the antimicrobial susceptibility, ESBL, MBL production, and biofilm formation in A.baumannii among diabetic and non-diabetic foot ulcer patients. Materials and Methods: This is a hospital based study, done for a period of 10 months. Samples were collected from general surgery outpatients and inpatients suffering from foot ulcer infections and also include wagner grade II to V. Pus/tissue was collected and processed for standard methods of culture, antimicrobial susceptibility, biofilm formation assay, ESBL, MBL, Modified Hodge Test (MHT) and Minimum Inhibitory Concentration (MIC). Results: A total of 70 bacterial isolates were obtained from 400 patients with DFU and non-DFU from pus and tissue specimens. Antibiogram profiles of DFU isolates were sensitive to colistin and resistant to all the major groups of antibiotics classes. Non-DFU isolates were sensitive to amikacin, ceftriaxone, gentamicin piperacillin/tazobactam, imipenem, meropenem, colistin and resistant to ceftazidime, cefotaxime, ciprofloxacin, co-trimoxazole, piperacillin, tetracycline. The result showed that out of 35 DFU isolates 13 (37.14%) produced ESBL, 10 (28.57%) produced MBL and 9 (25.71%) formed strong biofilm. Further in 35 non DFU isolates 8 (22.85%) produced ESBL, 5 (14.28%) produced MBL and 3 (8.57%) formed strong biofilm. Almost all the isolates of Multi-Drug Resistance (MDR) are ESBL and MBL producer as well as biofilm formers. Conclusion: Colistin is the drug of choice for the efficient treatment of multi-drug resistant isolates of foot ulcer patients. The rapid spreading of ESBL, MBL producers, and MDR require the implementation of not just surveillance study but also proper and rational selection of antibiotics, especially for MDR for better clinical outcomes.

Keywords

• antimicrobial susceptibility
• biofilm
• extended spectrum of β-lactamase
• metallo- β-lactamase