Vetere A, Giuliano M, Pantosti A, Panichi G
Boll Ist Sieroter Milan. 1984;63(6):505-9.
The human normal intestinal flora prevents the colonization of exogenous bacteria, maintaining a constant microecology: this property is called "colonization resistance". In leukemia patients antibiotics used for prevention and/or therapy of infectious episodes can alter the intestinal microecology, so that the gut can represent the trigger zone for generalized septicemia. Moreover cytotoxic drugs used in these patients can favour intestinal disturbances. In our study we evaluated the in vitro activity of three commonly used antineoplastic drugs (Daunorubicin, Cytosine arabinoside, Methotrexate) against aerobic and anaerobic intestinal bacteria and Clostridium difficile that is the aetiological agent of pseudomembranous colitis. Daunorubicin proved to be the most active inhibiting, in concentration ranging from 16 to 128 micrograms/ml, 50% of Bacteroides strains and 90% of Clostridium difficile and Enterococci strains tested. Methotrexate showed activity only against some Bacteroides strains, while Cytosine arabinoside had no activity at all. We conclude that in these patients the use of these drugs may represent another factor of risk altering the intestinal flora and so lowering the colonization resistance.
人类正常肠道菌群可防止外源细菌定植，维持恒定的微生态环境：这一特性被称为“定植抗力”。在白血病患者中，用于预防和/或治疗感染性疾病的抗生素会改变肠道微生态，致使肠道成为全身性败血症的触发区域。此外，这些患者使用的细胞毒性药物会加重肠道紊乱。在我们的研究中，我们评估了三种常用抗肿瘤药物（柔红霉素、阿糖胞苷、甲氨蝶呤）对肠道需氧菌、厌氧菌以及伪膜性结肠炎病原体艰难梭菌的体外活性。结果表明，柔红霉素活性最强，在浓度为16至128微克/毫升时，可抑制50%的拟杆菌菌株以及90%的受试艰难梭菌和肠球菌菌株。甲氨蝶呤仅对部分拟杆菌菌株有活性，而阿糖胞苷则完全没有活性。我们得出结论，在这些患者中使用这些药物可能是改变肠道菌群、降低定植抗力的另一个风险因素。
