艰难梭菌 毒素

该试验检测新鲜或冷冻粪便标本中是否存在艰难梭菌毒素A和/或B。在多于65%的健康婴儿和3%的健康成年人中，艰难梭菌为胃肠道正常菌群中的一部分。有时在采用广谱抗生素治疗时，结肠的正常菌群的平衡被破坏（菌群失调）。胃肠道中对抗生素敏感的细菌就被抑制，而艰难梭菌对该种抗生素耐药，能够存活下来并且大量繁殖。艰难梭菌可产生两种毒素—毒素A和毒素B。艰难梭菌过度生长可产生大量毒素损伤结肠粘膜，导致严重的结肠炎症、持续腹泻。坏死组织、纤维蛋白及众多白细胞形成伪膜，覆盖在肠内面的炎症部位，即伪膜性肠炎。

艰难梭菌是引起住院患者腹泻症状最常见的病原菌。15-25%的抗生素相关性腹泻患者及大于95%的伪膜性肠炎患者的粪便中可以检测到艰难梭菌毒素。虽然婴儿常常携带艰难梭菌，但在该人群中不常引起腹泻。年龄增加、免疫缺陷、急性或慢性结肠疾病、既往感染过艰难梭菌、或者近期胃肠道手术或化疗，都是艰难梭菌相关腹泻的危险因素。艰难梭菌相关腹泻常发生在使用抗生素治疗数天的患者中，也可以发生在抗生素治疗完成后数周的患者。

艰难梭菌相关腹泻是一系列的疾病，可以从轻微腹泻到严重结肠炎，甚至可导致败血症及死亡的中毒性巨结肠症。症状可包括频繁的稀便、腹痛、腹部绞痛、恶心、发热、脱水、疲劳及白细胞增多。通常治疗方法包括停止使用之前使用的抗生素和给予特殊的抗生素即艰难梭菌敏感的药物治疗。大部分患者正常菌群重新建立后症状得到改善，但12-24%的患者2个月内可能复发。

用无菌容器收集新鲜粪便。粪便标本不能有尿液或其他液体污染。采集后立即送往实验室，或冷冻后尽快送往实验室。

不需要任何试验前准备。

试验: 粪便培养
疾病: 腹泻

Centers for Disease Control and Prevention: General Information about Clostridium difficile Infections
Mayo Clinic: C. difficile
Mayo Clinic: Pseudomembranous colitis

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