Abdominal Wall Abscess Due to Mycobacterium neworleansense: A Case Report

IntroductionNontuberculous mycobacteria are widely distributed in the natural environment and can cause cutaneous infections through traumatic injuries or invasive procedures, leading to nontuberculous mycobacterial skin diseases. However, skin infections caused by Mycobacterium neworleansense are exceedingly rare. This article reports a case of an abdominal wall abscess resulting from this uncommon pathogen, with the aim of enhancing clinical recognition and improving the diagnosis and management of infections associated with Mycobacterium neworleansense.Case presentationA 74-year-old male with diabetes was hospitalized due to an abscess on the left abdominal wall at a site of long-term insulin administration. After admission, surgical incision and drainage of the abscess were performed. Microbiological culture of the intraoperative pus specimen revealed growth of non-tuberculous mycobacteria, which was subsequently identified as Mycobacterium neworleansense using a combination of 16S rRNA gene sequencing and biochemical profiling. Antimicrobial susceptibility testing demonstrated resistance to macrolides and tetracyclines, but susceptibility to trimethoprim-sulfamethoxazole, aminoglycosides, moxifloxacin, and imipenem. Following surgical intervention, the patient received a combined antibiotic regimen of trimethoprim-sulfamethoxazole and moxifloxacin, which led to successful clinical resolution of the infection.ConclusionMycobacterium neworleansense has the potential to cause subcutaneous abscesses following injection-related procedures. Successful management of such infections relies on accurate pathogen identification through molecular and biochemical methods, coupled with targeted antimicrobial therapy guided by susceptibility testing, and supported by appropriate surgical intervention.