Moore Matthew R, Perdreau-Remington Françoise, Chambers Henry F
Division of Infectious Diseases, San Francisco General Hospital, California, USA.
Antimicrob Agents Chemother. 2003 Apr;47(4):1262-6. doi: 10.1128/AAC.47.4.1262-1266.2003.
Heterogeneous resistance to vancomycin is thought to precede emergence of intermediate susceptibility to vancomycin in Staphylococcus aureus, but the clinical significance of heterogeneous resistance is unknown. Paired S. aureus isolates from a patient with endocarditis who relapsed after vancomycin treatment were tested for heterogeneous resistance to vancomycin. The pretreatment and the relapse clinical isolates (strains SF1 and SF2, respectively) were genotyped by pulsed-field gel electrophoresis. Susceptibility to vancomycin was assessed by the broth dilution method, population analysis, and time-kill studies and in the rabbit model of endocarditis. Strains SF1 and SF2 had similar genotypes, and the vancomycin MICs for the strains were </=2 micro g/ml. SF2 exhibited heterogeneous resistance to vancomycin. Vancomycin eradicated SF1 in the rabbit model of endocarditis, while SF2 persisted at pretreatment levels. Vancomycin treatment failure in this patient with endocarditis was attributable to heterogeneous resistance to vancomycin.
在金黄色葡萄球菌中，对万古霉素的异质性耐药被认为先于对万古霉素中介敏感性的出现，但异质性耐药的临床意义尚不清楚。对一名患有心内膜炎的患者在万古霉素治疗后复发的成对金黄色葡萄球菌分离株进行了对万古霉素异质性耐药的检测。通过脉冲场凝胶电泳对治疗前和复发时的临床分离株（分别为菌株SF1和SF2）进行基因分型。通过肉汤稀释法、群体分析、时间杀菌研究以及在心内膜炎兔模型中评估对万古霉素的敏感性。菌株SF1和SF2具有相似的基因型，且这些菌株的万古霉素最低抑菌浓度≤2μg/ml。SF2表现出对万古霉素的异质性耐药。在兔心内膜炎模型中，万古霉素根除了SF1，而SF2维持在治疗前水平。该心内膜炎患者万古霉素治疗失败归因于对万古霉素的异质性耐药。
