MULTICENTER STUDY OF THE BURDEN OF MULTIDRUG-RESISTANT BACTERIA IN THE ETIOLOGY OF INFECTED DIABETIC FOOT ULCERS
BackgroundInfected diabetic foot ulcer (IDFU) is a public health issue and a leading cause of non-traumatic limb amputation. Very few published data on IDFU is available in most West African countries. The objective of this study was to investigate the etiological agents of IDFU and the challenge of antibacterial drug resistance in the management of infections.\n\nMethodsThis was a prospective cross-sectional hospital-based study involving three tertiary healthcare facilities. Consecutive eligible patients presenting in the facilities were recruited. Tissue biopsies and/or aspirates were collected and cultured on a set of selective and non-selective media and incubated in appropriate atmospheric conditions for 24 to 72 hours. Isolates were identified by established standard methods. Antibiotic susceptibility testing was performed using modified Kirby-Bauer disc diffusion method. Specific resistance determinants were investigated by polymerase chain reaction-based protocols. Data analysis was done with SPSS version 20.\n\nResultsNinety patients with clinical diagnosis of DFI were studied between July 2016 and April 2017. A total of 218 microorganisms were isolated, comprising 129 (59.2%) Gram-negative bacilli (GNB), 59 (27.1%) Gram-positive cocci (GPC) and 29 (13.2%) anaerobic bacteria. The top five facultative/aerobic bacteria encountered were: Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae and Citrobacter spp. representing 41 (18.8%), 23 (10.5%), 20 (9.2%), 19 (8.7%) and 19 (8.7%) isolates, in that order, respectively. The commonest anaerobes were Bacteroides spp., and Peptostreptococcus anaerobius which accounted for 7 (24.1%) and 6 (20.7%), respectively. Of the 93 IDFU cases, 74 (80%) were infected by multidrug-resistant (MDR) bacteria predominantly methicillin-resistant S. aureus, extended-spectrum {beta}-lactamase-producing GNB, mainly of the CTX-M variety. Only 4 (3.1%) GNB were carbapenemase-producers encoded by blaVIM. Factors associated with presence of MDR bacteria were peripheral neuropathy (r= 4.05, P= 0.042) and duration of foot infection >1 month(r= 7.63, P= 0.015).\n\nConclusionsMDR facultative/aerobic bacteria are overrepresented amongst agents causing IDFU. A relatively low proportion of the etiological agents were anaerobic bacteria. This finding should help formulate empirical therapeutic options for managing IDFU. Furthermore, drastic reduction in inappropriate use of cocktail of antibiotics for IDFUs is advocated to combat infection by MDR bacteria in these patients.