Kennedy H F, Gemmell C G, Bagg J, Gibson B E, Michie J R
Department of Microbiology, Royal Hospital for Sick Children, Yorkhill NHS Trust, Glasgow G3 8SJ, UK.
J Antimicrob Chemother. 2001 May;47(5):693-6. doi: 10.1093/jac/47.5.693.
This study investigated the antibiotic susceptibilities of 67 isolates of viridans streptococci from 61 cases of bacteraemia in immunocompromised paediatric patients with malignancy. The majority of patients (87%) had received prior courses of empirical antibiotic therapy, which consisted of ceftazidime plus amikacin during period 1 and piperacillin/tazobactam plus amikacin during period 2. Susceptibility to vancomycin and quinupristin/dalfopristin was 100%. Susceptibility to beta-lactam antibiotics varied. For period 1, the geometric mean MICs of all beta-lactams tested against blood culture isolates (n = 31) exceeded those against isolates (n = 36) collected from blood after the change in empirical therapy (by 3.3-fold for ceftazidime, 2.8-fold for piperacillin/tazobactam and 1.6-fold for penicillin). The selection of a beta-lactam antibiotic for empirical therapy must be made with care, as repeated courses of certain agents may be more likely to select for viridans streptococci with diminished susceptibility.
本研究调查了61例患有恶性肿瘤的免疫功能低下儿科患者血行感染中分离出的67株草绿色链球菌的抗生素敏感性。大多数患者（87%）之前接受过经验性抗生素治疗，在第1阶段为头孢他啶加阿米卡星，在第2阶段为哌拉西林/他唑巴坦加阿米卡星。对万古霉素和奎奴普丁/达福普汀的敏感性为100%。对β-内酰胺类抗生素的敏感性各不相同。在第1阶段，针对血培养分离株（n = 31）检测的所有β-内酰胺类药物的几何平均最低抑菌浓度超过了经验性治疗改变后从血液中分离出的菌株（n = 36）（头孢他啶为3.3倍，哌拉西林/他唑巴坦为2.8倍，青霉素为1.6倍）。选择β-内酰胺类抗生素进行经验性治疗时必须谨慎，因为重复使用某些药物疗程可能更易选择出敏感性降低的草绿色链球菌。
