Anaerobic Culture of Diabetic Foot Infections: Organisms and Antimicrobial Susceptibilities

Abstract

Introduction: The prevalence of diabetes mellitus is high in Singapore. Infections of the lower limb are significant causes of morbidity in this population. Although the aerobic bacteriology of these infections is well-documented, there is less data available on the anaerobic pathogens involved. This study sets out to describe the anaerobic bacteria associated with diabetic foot infections, and evaluates the susceptibility to 3 antimicrobials with anaerobic activity. Materials and Methods: Anaerobic culture was performed on operative samples taken from diabetic foot infections. Organisms were identified through standard microbiological methods and commercial identification kits. Antimicrobial susceptibility testing to clindamycin, metronidazole and imipenem was performed by agar dilution. Results: One hundred and two strains of strict anaerobic bacteria were isolated from 30 unique specimens. The predominant anaerobic isolates were Peptostreptococcus spp. (46%) and Bacteroides fragilis group (19%). Antibiotic resistance was detected for clindamycin (18%), metronidazole (1%) and imipenem (2%). Conclusion: Multiple anaerobic species can be isolated from diabetic foot infections. A significant proportion of isolates are resistant to clindamycin, while resistance to imipenem and metronidazole remains low. Key words: Anaerobe, Antibiotic resistance, Bacterial

Clinical and bacteriological profile of diabetic foot infections in a tertiary care

“…Piperacillin–Tazobactam, Amikacin and Imipenem were the greatest advantageous antimicrobials against aerobic Gram‐negative bacteria. As for aerobic Gram‐positive cocci and anaerobes, the most effective antimicrobials where Vancomycin and Metronidazole respectively [25]. It is vital to ensure meticulous and thoughtful choices of antimicrobial therapy guided by culture findings in addition to the antimicrobial sensitivity patterns of the specific isolates.…”

Microbiology and Antimicrobial Resistance in Diabetic Foot Infections

“…While various articles have presented evidence suggesting similar clinical presentations and outcomes between MRSA and other pathogens in DFIs, some authors maintain that MRSA detection in DFIs may still be associated with more severe infections [14]. In the realm of DFIs, experts continue to consider anaerobic bacteria as potential contributors to persistent and severe infections, even though their exact role in polymicrobial infections remains a subject of debate [107]. This is supported by studies indicating that anaerobic bacteria are often detected in DFIs characterized by deeper ulcers, chronicity, and associations with ischemia, necrosis, gangrene, or foul odor [108].…”