Successful treatment of a rare extended retroperitoneal necrotizing soft tissue infection caused by extended-spectrum beta-lactamase-producing Escherichia coli: A case report.

Rationale: Retroperitoneal necrotizing soft tissue infection (NSTI) is a rare but life-threatening disease. Here, we present a case of extended retroperitoneal NSTI caused by extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli (E coli).

Patient Concerns: The patient complained of progressive redness, swelling, and right flank pain for 10 days, extending to the scrotum for 1 day.

Diagnoses: He was admitted with an initial diagnosis of cellulitis.

Interventions: Debridement was performed after the scrotum developed necrosis on day 2 of hospitalization. The source of infection was found to be an idiopathic retroperitoneal abscess, which was confirmed by computed tomography. Two consecutive microbiological cultures (aerobic plus anaerobic) of the tissue revealed the presence of ESBL-producing E coli. With the application of negative pressure wound therapy (NPWT), we sutured the wound after consecutive debridement.

Outcomes: During the 32 months of follow-up, the patient recovered very well and felt extremely satisfied.

Lessons: This case reminds us that ESBL-producing E coli can cause retroperitoneal abscesses, which may induce NSTI. Aggressive debridement and broad-spectrum antibiotics should be administrated immediately when NSTI is suspected, and NPWT is an effective adjuvant therapy for wound closure.