New Delhi metallo-β-lactamase (NDM)–producing bacteria are a challenge in clinical practice because of the limited antibiotic options and high rate of adverse events. Complex skin and soft tissue infections (SSTI), with or without osteomyelitis, caused by these agents require prolonged antibiotic therapy, multidisciplinary care, and there is little scientific evidence on optimal management. The objective of this study is to describe clinical characteristics, treatment and outcomes of hospitalized patients with such infections.

Retrospective, descriptive study of clinical-demographic characteristics, microbiology and evolution for at least six months after starting antibiotics. Data were obtained from electronic medical records of hospitalized patients between September 2023 and January 2025, following laboratory surveillance identification of positive cultures. Outcomes assessed were death, repeat surgery, transfemoral or transtibial amputation and remission at six months.

Seventeen patients had intraoperative bone and/or soft tissue cultures positive for NDM-producing Enterobacterales; most (15/17, 88%) were Enterobacter cloacae, one Klebsiella pneumoniae and one Klebsiella oxytoca. Bone involvement was observed in 11/17 (65%) infections. There was a predominance of male patients (13/17, 76%), median age 65 years; among comorbidities, 88% had diabetes and hypertension, and 47% were smokers. Sixteen (94%) patients had chronic obstructive arterial disease with indication for revascularization. Most cultures were polymicrobial (60%). Regarding susceptibility testing, 16/17 (94%) isolates were susceptible to amikacin, 5/17 (29%) to tigecycline, and all were susceptible to polymyxin. Fifteen (88%) patients received targeted antimicrobial therapy: 3 received amikacin alone, 4 polymyxin, 4 tigecycline, and the remaining 2 received two of these drugs. Only two patients received ceftazidime-avibactam plus aztreonam; the median duration of antibiotics was 14 days. There were 3/17 (17.6%) in-hospital deaths, 6/17 (41%) amputations, 11/17 (65%) surgical reinterventions, and 4/14 (28.5%) patients without remission at six months.

Complex SSTIs due to NDM-producing bacteria have limited therapeutic options and are associated with high risk of surgical reintervention and amputation, as well as a substantial proportion of cases with inadequate infection control.