Fatal Fournier’s gangrene caused by Clostridium ramosum in a patient with central diabetes insipidus and insulin-dependent diabetes mellitus: a case report

Noriyoshi Takano, Midori Sasaki Yatabe, Junichi Yatabe, Masaaki Kato, Daisuke Sueoka, Shigekazu Iguchi, Atsushi Yoshida, Yutaka Uzawa, Ken Kikuchi, Kimitaka Tani, Shinpei Ogawa, Michio Itabashi, Masakazu Yamamoto, Daisuke Watanabe, Takashi Ando, Satoshi Morimoto, Atsuhiro Ichihara

Clostridium ramosum is a generally non-pathogenic enteric anaerobe, and Fournier's gangrene is a rare necrotizing soft tissue infection with male predisposition affecting the perineum and the genital area. We report, to our knowledge, the first case of Fournier's gangrene caused by C. ramosum in a female patient with multiple underlying conditions. A 44-year-old woman with a 6-year history of insulin-dependent diabetes mellitus after total pancreatectomy and an 11-year history of central diabetes insipidus developed a pain in the genital area after a month of urinary catheter use. The lower abdominal pain worsened gradually over 2 weeks, and the pain, general fatigue, and loss of appetite prompted the patient's hospital admission. As she had severe edema in her pelvic and bilateral femoral areas, ceftriaxone was started empirically after collecting two sets of blood cultures. On hospital day 2, CT examination revealed the presence of necrotizing faciitis in the genital and pelvic areas, and the antibiotics were changed to a combination of meropenem, vancomycin, and clindamycin. Gram-positive cocci and gram-positive rods were isolated from blood cultures, which were finally identified as Streptococcus constellatus and C. ramosum using superoxide dismutase and 16S rDNA sequencing. An emergent surgery was performed on hospital day 2 to remove the affected tissue. Despite undergoing debridement and receiving combined antimicrobial chemotherapies, the patient's clinical improvement remained limited. The patient's condition continued to deteriorate, and she eventually died on hospital day 8. In the present case, the underlying diabetes mellitus, urinary incontinence due to central diabetes insipidus, undernutrition, and edema served as the predisposing conditions. C. ramosum is a potentially opportunistic pathogen among immunosuppressed persons and a rare cause of necrotizing fasciitis.