Clostridium difficile感染症における培養検査・毒素検査の臨床的意義と評価

Clinical significance and evaluation of anaerobic culture and toxin detection tests in Clostridium difficile infection

Clostridium difficileは，抗菌薬関連下痢症や偽膜性大腸炎の原因菌である．本菌の実験室内診断法として，嫌気性培養，細胞毒素検査法，抗原検出法，トキシン検出法，抗原・トキシン同時検出法，遺伝子増幅法などがある．培養法，細胞毒素検査法，遺伝子増幅法は感度，特異度に優れているが，特殊な設備，熟練した技術が必要とされる．抗原検出法およびトキシン検出法はいずれも迅速性に優れるが，それぞれ特異度および感度に劣る．C. difficile感染症の診断には複数の試験法を用いた臨床診断が奨励される．

Clostridium difficile is a causative agent for antibiotics-associated diarrhea and pseudomembranous colitis.　Laboratory diagnostic methods include anaerobic culture, cytotoxicity test, antigen-detection method, toxin-detection method and gene amplification method.　Although culture, cytotoxicity test and gene amplification method have high sensitivity and specificity, specific laboratory apparatus and sophisticated techniques are needed.　Antigen-and toxin-detection methods can be performed easily and rapidly, but sensitivity and specificity are relatively low in these methods.　For laboratory diagnosis of C. difficile infection, multiple diagnostic methods are recommended to be used.