This Is (Not) the Way: A Rare Case of Mycobacterium Peregrinum

Case 62-year-old male with past medical history significant for hepatitis C status post lepiasvir/sofosbuvir (Harvoni), latent tuberculosis diagnosed ∼1990 (was treated during an incarceration), recent IV drug use, daily pack-a-day smoker, who presented to the hospital Emergency department complaining of 1 week shortness of breath and hemoptysis. Patient stated that one week prior to presentation he developed shortness of breath followed by followed by hemoptysis with associated symptoms of nausea & vomiting and night sweats. Patient denied any recent sick contacts, any recent incarceration or recent travel, and had been self-isolating during COVID-19 pandemic. On presentation, the patient was noted to be febrile to 103.1 °F and new oxygen requirement of 5 L nasal cannula, normotensive, normal heart rate. Physical exam significant for absent breath sounds at left base with scattered crackles bilaterally throughout all fields. Labs significant for leukocyte count 6.3K/mm3 with 90% neutrophils, basic metabolic panel unremarkable, COVID-19 negative. CT chest significant for dense left lower lobe infiltrate with multiple air bronchograms and scattered areas of groundglass attenuation throughout right lung. Patient's was initially started on vancomycin and cefepime, further work-up including sputum acid-fast bacilli x3, Legionella & pneumococcal urinary antigens, MRSA screen, ANA/ANCA/anti-GBM were all negative. After four days without improvement patient was broadened to meropenem with some improvement in symptoms but patient remained persistently hypoxic, therefore underwent bronchoscopy on hospital day 8. Bronchoalveolar lavage cultures subsequently grew Mycobacterium peregrinum. Patient was discharged on ertapenem, once susceptibilities were obtained patient was transitioned to moxifloxacin and Bactrim by infectious disease as an outpatient. At most recent infectious disease clinic visit 6 weeks after initial presentation patient has substantially improved. Discussion: Mycobacterium peregrinum is a rapidly growing mycobacteria (in contrast M. tuberculosis is classified as a slow grower) and is a subset of Mycobacterium fortuitum, a type of nontuberculous mycobacteria (NTM) which are opportunistic pathogens known to cause surgical site infections, catheter-related bloodstream infections, abscesses, osteomyelitis, among others. M. peregrinum is usually associated with surgical site infections, with very few previous cases of pulmonary M. peregrinum reported in the last 20 years. Unfortunately, the exact burden of M. peregrinum and NTM infections overall both nationally and internationally are not known as they are not reportable diseases to either the Centers for Disease Control or World Health Organization. Due to the complexities of NTM infections, we recommend a multidisciplinary approach including pulmonary and infectious disease specialists.