Stein D S, Libertin C R
Department of Medicine, Loyola University Medical Center, Maywood, IL 60153.
Diagn Microbiol Infect Dis. 1988 Jul;10(3):139-44. doi: 10.1016/0732-8893(88)90032-6.
Endocarditis caused by nutritionally deficient streptococci has a high bacteriologic and clinical failure rate, despite appropriate antimicrobial therapy. We investigated by time kill curve methodology nine clinical endocarditis isolates of nutritionally deficient streptococci to determine the in vitro efficacies of vancomycin and rifampin alone and in combination. The combination of vancomycin and rifampin demonstrated synergy and bactericidal activity in five of the strains. In one strain, this combination inhibited growth by greater than 2 log10 CFU/ml when compared to the growth control or either antibiotic alone, but it failed to be bactericidal. Indifference, defined as less than or equal to 2 log10 CFU per milliliter increase in killing of the combination compared to the next most active single agent, was demonstrated with the remaining three isolates. Changing the antibiotic concentrations in the time kill curve studies for these latter strains failed to demonstrate synergistic activity of the antibiotic combination. The vancomycin and rifampin combination may be a promising therapeutic modality for which in vivo correlation is indicated.
尽管采用了适当的抗菌治疗，但营养缺陷型链球菌引起的心内膜炎在细菌学和临床方面的失败率仍很高。我们采用时间杀菌曲线法对9株营养缺陷型链球菌临床心内膜炎分离株进行了研究，以确定万古霉素和利福平单独及联合使用时的体外疗效。万古霉素和利福平联合使用在5株菌株中显示出协同作用和杀菌活性。在1株菌株中，与生长对照或单独使用任何一种抗生素相比，该联合用药抑制生长的幅度大于2个对数10 CFU/ml，但未能杀菌。其余3株分离株表现为无差异，即与次最有效的单一药物相比，联合用药的杀菌效果每毫升增加小于或等于2个对数10 CFU。在这些菌株的时间杀菌曲线研究中改变抗生素浓度，未能证明联合抗生素具有协同活性。万古霉素和利福平联合使用可能是一种有前景的治疗方式，提示其具有体内相关性。
