Acta Dermato-Venereologica 98-10CompleteContent | Page 20

987 A Case of Subcutaneous Infection with Mycobacterium mageritense Identified by Matrix-assisted Laser Desorption/Ionization-time of Flight Mass Spectrometry Tomohiro OIWA 1 , Teruasa MURATA 1 , Tetsuya HONDA 1 , Satoshi NAKANO 2 and Kenji KABASHIMA 1 * Department of Dermatology, and 2 Department of Clinical Laboratory Medicine, Kyoto University Graduate School of Medicine, 54 Shogoin- Kawahara, Sakyo, Kyoto 606-8507, Japan. *E-mail: [email protected] 1 Accepted Jul 5, 2018; Epub ahead of print Jul 6, 2018 Mycobacterium mageritense is a recently identified rapidly growing uncommon mycobacteria (RGM) (1). Only 9 cases of skin and soft-tissue infection with M. mageritense have been reported to date (1–7) (Table I). Although accurate identification of the pathogenic bacteria is mandatory for efficient treatment, using conventional methods for the identification of M. mage- ritense is complex and time-consuming. We report here a case of subcutaneous infection with M. mageritense that was treated successfully with antibiotics, in which matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) (8) enabled rapid identification of the species. CASE REPORT A 70-year-old Japanese man developed subcutaneous abscesses in the periumbilical region within 2 weeks after a laparoscopic cholecystectomy. After unsuccessful treatments with antibiotics (cefamezin and vancomycin) and immunosuppressive agents Table I. Summary of 9 cases of skin and soft tissue infection with M. mageritense reported Surgical Sex/age, inter­ years vention Antibiotics Duration of treatment Outcomes Ref. F/37 M/25 F/43 F/56 M/48 F/59 M/66 M/52 F/85 M/70 DOXY, CFPM AMK, IPM/CS TMP-SMX, LVFX GFLX N/A CPFX, CAM MLFX, CAM CAM, LVFX LVFX, IPM/CS, MINO CAM, LVFX, MINO 9 months N/A 3 months 2 months 12 months 12 months 4 days 6 months 4 months 7 months Yes Yes Yes No Yes Yes Yes Yes Yes No Cured Improved Cured Cured Cured Cured Cured Cured Cured Cured 1 1 2 2 3 4 5 6 7 This case DOXY: doxycycline; CFPM: cefepime; AMK: amikacin; IPM/CS: imipenem/cilastatin; TMP-SMX: trimethoprim/sulfamethoxazole; LVFX: levofloxacin; GFLX: gatifloxacin; CPFX: ciprofloxacin; MLFX: moxifloxacin; CAM: clarithromycin; IPM/CS: imipenem/ cilastatin; MINO: minocycline; N/A: not available; F: female; M: male. (prednisolone and azathioprine) for 1 year, he was referred to our hospital. On examination, a total of 80 reddish nodules intermit- tently excreting pus were observed on the abdomen (Fig. 1a). Histopathologically, the dermis and subcutaneous adipose tissue were prominently infiltrated with neutrophils (Fig. 1b, c). An SHORT COMMUNICATION Fig. 1. Clinical pictures and histopathology. (a) A clinical picture before the treatment, showing reddish nodules on the abdomen. Arrow: scar from the laparoscopic cholecystectomy contiguous to the umbilicus. Histopathology: (b) low-magnification view showing a prominent infiltration of neutrophils in the deep dermis and subcutaneous adipose tissue. (c) High-magnification view of the rectangle in (b). (d) A clinical picture after treatment with antibiotics, showing post-inflammatory pigmentation. This is an open access article under the CC BY-NC license. www.medicaljournals.se/acta Journal Compilation © 2018 Acta Dermato-Venereologica. doi: 10.2340/00015555-3005 Acta Derm Venereol 2018; 98: 987–988