Bacterial profile of diabetic foot infections and antibiotic susceptibility in a specialized diabetes centre in Cameroon

Abstract

Introduction: bacterial profile of diabetic foot infections and the antibiotic susceptibility are essential in the prescription of empirical antibiotics before the results of cultures of deep wound samples are available. The aim of this study was to determine the microbiological profile and antibiotic susceptibility of bacteria isolated from infected diabetic foot ulcers in patients attending the Yaoundé Central Hospital, Cameroon.

Methods: we retrospectively analyzed the records of patients hospitalized between 2008 and 2013 for diabetic foot infections. The main outcomes were the bacteriological profile and susceptibility patterns of isolates from positive culture of deep wound sample before antibiotherapy, carried out in the national reference laboratory. Eligible clinical records of patients were retrieved from the hospitalization registry.

Results: a total of 101 patient records were analyzed. The mean age of patients was 57.1 ± 9.1 years. There were more males (64.4%), mostly with type 2 diabetes (99%), with a median duration of 9 years (IQR: 4 - 14 years). Their median blood sugar on admission was 246 mg/dL. Five percent of patients died and 23% had a major amputation. Two hundred and twenty-five (225) germs were isolated, with an average of 2.25 germs per patient. Gram-negative bacteria were more frequent (75.2%). These were mainly Morganella morganii (13.8%), Klebsiella pneumonia (12%), Escherichia coli (11.6%), Proteus spp. (10.7%), and Pseudomonas aeruginosa (8.9%). Gram-positive bacteria (24.8%) were mainly Staphylococcus aureus (9.3%), Streptococcus spp. (7.6%), and Enterococcus spp. (7.1%). Gram-negative bacteria showed a high resistance to amoxicillin-clavulanic acid (78%), fluoroquinolones (55%), and gentamycin (50%). They were susceptible to imipenem (95%), amikacin (88%), and show moderate susceptibility to third generation cephalosporins (62%). Gram-positive bacteria were susceptible to vancomycine (94%), and moderately susceptible to pristinamycine (82%) and fusidic acid (67%).

Conclusion: Gram-negative bacteria were more frequently associated with diabetic foot infections, and were frequently resistant to the usually prescribed antibiotics, but remain susceptible to imipenem and amikacin. Our findings should be considered when prescribing empirical anti-biotherapy for diabetic foot infections in our setting.

Keywords: Diabetic foot infections; antibiotic susceptibility.