NDM-Producing Klebsiella pneumoniae and Multidrug-Resistant Enterococcus faecium Bacteremia: A Report of Two Cases

Antimicrobial resistance (AMR) has emerged as a major global healthcare challenge, significantly complicating the management of healthcare-associated infections and limiting available therapeutic options. We present two cases of severe bloodstream infections caused by multidrug-resistant pathogens in patients with prolonged healthcare exposure and multiple comorbidities. The first case involved urinary-source bacteremia caused by NDM (New Delhi metallo-β-lactamase)-producing Klebsiella pneumoniae exhibiting extensive AMR. Despite limited therapeutic options and apparent in vitro resistance, treatment with ceftazidime-avibactam was associated with marked clinical and laboratory improvement, resulting in clinical recovery and hospital discharge. The second case involved urinary-source bacteremia caused by multidrug-resistant Enterococcus faecium in an elderly patient with significant comorbidities and recent broad-spectrum antimicrobial exposure. Despite escalation of antimicrobial therapy and supportive management, the patient experienced progressive clinical deterioration and ultimately died. These cases highlight the substantial therapeutic challenges posed by highly resistant pathogens and emphasize the importance of early microbiological diagnosis, individualized interpretation of antimicrobial susceptibility results, prompt optimization of antimicrobial therapy, and strict infection prevention measures in the management of severe multidrug-resistant infections.