Edlund C, Nord C E
Department of Microbiology, Pathology and Immunology, Huddinge University Hospital, Karolinska Institute, Stockholm, Sweden.
J Antimicrob Chemother. 2000 Sep;46 Suppl 1:41-8; discussion 63-5.
Oral administration of antibiotics for treatment of urinary tract infections (UTIs) can cause ecological disturbances in the normal intestinal microflora. Poorly absorbed drugs can reach the colon in active form, suppress susceptible microorganisms and disturb the ecological balance. Suppression of the normal microflora may lead to reduced colonization resistance with subsequent overgrowth of pre-existing, naturally resistant microorganisms, such as yeasts and Clostridium difficile. New colonization by resistant potential pathogens may also occur and may spread within the body or to other patients and cause severe infections. It is therefore important to learn more about the ecological effects of antibacterial agents on the human microflora. The impact on intestinal microorganisms of oral antibiotics used for the treatment of UTIs is reviewed here. Ampicillin, amoxycillin and co-amoxiclav suppress both the aerobic and anaerobic intestinal microflora with overgrowth of ampicillin-resistant Enterobacteriaceae. Pivmecillinam also affects the intestinal microflora, suppressing Escherichia coli, but does not have a major effect on the anaerobic microflora. Several orally administered cephalosporins, such as cefixime, cefpodoxime, cefprozil and ceftibuten, reduce the number of Enterobacteriaceae and increase the number of enterococci. Colonization with C. difficile has also been observed. Fluoroquinolones eliminate or strongly suppress intestinal Enterobacteriaceae, but affect enterococci and anaerobic bacteria only slightly. When antimicrobial agents are prescribed for the treatment of UTIs, not only the antimicrobial spectrum of the agent but also the potential ecological disturbances, including the risk of emergence of resistant strains, should be considered.
口服抗生素治疗尿路感染（UTIs）可导致正常肠道微生物群落的生态紊乱。吸收不良的药物可以以活性形式到达结肠，抑制敏感微生物并扰乱生态平衡。正常微生物群落的抑制可能导致定植抵抗力降低，随后先前存在的天然耐药微生物（如酵母菌和艰难梭菌）过度生长。具有耐药潜力的病原体也可能发生新的定植，并可能在体内传播或传播给其他患者，从而引起严重感染。因此，更深入了解抗菌药物对人体微生物群落的生态影响非常重要。本文综述了用于治疗UTIs的口服抗生素对肠道微生物的影响。氨苄西林、阿莫西林和阿莫西林克拉维酸钾会抑制需氧和厌氧肠道微生物群落，导致耐氨苄西林肠杆菌科细菌过度生长。匹美西林也会影响肠道微生物群落，抑制大肠杆菌，但对厌氧微生物群落没有重大影响。几种口服头孢菌素，如头孢克肟、头孢泊肟酯、头孢丙烯和头孢布烯，可减少肠杆菌科细菌数量并增加肠球菌数量。也观察到艰难梭菌的定植。氟喹诺酮类药物可消除或强烈抑制肠道肠杆菌科细菌，但对肠球菌和厌氧菌的影响很小。在开抗菌药物治疗UTIs时，不仅应考虑药物的抗菌谱，还应考虑潜在的生态紊乱，包括耐药菌株出现的风险。
