潰瘍性大腸炎との鑑別を要したプレジオモナス・シゲロイデス感染性腸炎の1例

Colitis Caused by Plesiomonas shigelloides, Report of a case

要旨　患者は25歳，男性．海外渡航歴はない．主訴は約1週間続く下痢，血便．発熱なく，血液検査上炎症反応は陰性．大腸内視鏡検査で横行結腸から下行結腸を中心として，発赤浮腫状の粘膜をびまん性に認めた．発赤は小区様構造に一致し，小区を区切る線状網目状に発赤がなく，一見メラノーシス様であった．発赤粘膜面には通常の陰窩開口部が保たれていた．びらん，潰瘍や膿性白点はみられなかった．便培養，腸粘膜の生検培養でPlesiomonas shigelloidesが分離同定され，プレジオモナス・シゲロイデス感染性腸炎と診断した．全経過約2週間で，抗生物質を使用せずに菌は陰性化し，症状も消失した．

　A 25-year-old man visited our hospital with the complaint of bloody diarrhea.

　He had never been abroad. Colonoscopy showed edematous and reddish mucosa covering the whole colon, especially the transverse colon and the descending colon. The pattern of redness resembled pseudomelanosis and the reddish mucosa was surrounded by a circumferential, fine net-work pattern. In addition to this, close observation revealed normal round pits on the surface of the reddish mucosa without erosion or white spots. These findings were not suggestive of ulcerative colitis. Cultures were made and examined using biopsy specimens and fecal samples, and they grew Plesiomonas shigelloides. A defnite diagnosis of infectious colitis due to Plesiomonas shigelloides was made. The patient's symptoms had disappeared without antibiotics within 2 weeks. Close observation of the reddish mucosa was helpful for differentiating ulcerative colitis from infectious colitis.