3）エルシニア腸炎

Yersinia Enterocolitis

要旨　Y. enterocolitica，Y. pseudotuberculosisは，食中毒起炎菌となる．胃腸炎からの分離頻度は低いが，集団食中毒の原因にもなる．菌の発育至適温度が低く，発育が遅いため，菌の検出は特定して分離する必要がある．エルシニア感染症は症状が多彩で，菌の血清型や患者の年齢，患者型要因により，①胃腸炎・腸間膜リンパ節炎型，②結節性紅斑型，発疹型，③敗血症型などに臨床分類される．自然治癒傾向の軽症例が多いが，回盲部病変が主体では急性虫垂炎の他，発疹を伴う症例では，Crohn病やBeçget病等の慢性再燃性疾患との鑑別も想起される．鑑別には，菌や血清抗体の検出の他，感受性抗生薬（ホスホマイシン，ニューキノロン系，アミノグルコシド系，第3世代セフェム系薬）投与後の内視鏡的経過観察が有用となる．

　Y. enterocolitica (Y. e.) and Y. pseudotuberculosis (Y. p.) are pathogenic bacteria to cause food poisoning. They are infrequently isolated from stool of patients with diarrhea, but it is necessary to isolate them as the pathogen specifically. They grow in lower temperature and more slowly than others. Infection of Y. e. or Y. p. bring various symptoms, which are classified clinically into following types: 1) gastroenteritis, mesenteric lymphadenitis, 2) erythema nodosum, eruption, 3) sepsis.

　Most of Y. enterocolitis are self-limited infection, but some cases with severe symptoms need antibiotics, such as Fosfomysin,Newquinoron, aminoglucocid. For cases with right lower abdominal pain or ileocecal lesion and/or eruption, detection of serum antibody and colonoscopic follow-up after treatment of antibiotics is useful for differential diagnosis between Y. enterocolitis and other chronic or relapsing disease, such as Crohn's disease, Behçet syndrome.