Abstract

Background:
Diabetic foot infections (DFIs) are often polymicrobial and require accurate microbiological diagnosis for effective management. Superficial cultures may fail to detect deeper pathogens, leading to inadequate therapy. This study aims to highlight the role of deep tissue culture in identifying uncommon pathogens.

Case Description:
We report a single case study of an 82-year-old male with long-standing diabetes mellitus presenting with a non-healing left foot ulcer following a thorn prick injury. Initial pus culture yielded Klebsiella pneumoniae, and empirical therapy failed to produce clinical improvement. Deep tissue culture obtained during surgical debridement revealed polymicrobial infection with Klebsiella pneumoniae and Citrobacter youngae. Identification was confirmed using the VITEK 2 automated system. Antibiotic therapy was modified based on susceptibility testing, resulting in significant clinical recovery.

Conclusion:
This case emphasizes that deep tissue sampling is crucial in non-responding DFIs for accurate pathogen identification and targeted therapy. Detection of rare organisms such as C. youngae can significantly alter clinical management and improve outcomes.

Key words: Antimicrobial susceptibility; Citrobacter youngae; Deep tissue culture; Diabetic foot ulcer; Vitek identification.