Phongsamart Wanatpreeya, Srifeungfung Somporn, Tiensasitorn Chuntima, Vanprapar Nirun, Chearskul Sanay, Chokephaibulkit Kulkunya
Department of Pediatrics Faculty of Medicine Siriraj Hospital,Mahidol University, Bangkok, Thailand.
J Med Assoc Thai. 2005 Nov;88 Suppl 8:S264-8.
Staphylococcus aureus with reduced susceptibility to vancomycin has been reports worldwide. Here we report the first pediatric case of heterogeneous vancomycin intermediate resistance Staphylacoccus aureus (hVISA) causing endocarditis in Thailand. A 4 months old girl with truncus arteriosus type IV and ventricular septal defect developed methicillin-resistant S. aureus (MRSA) bacteremia and endocarditis after total repair operation. The patient did not respond to combination antimicrobial treatment including vancomycin. The strain was susceptible to trimethoprim-sulfamethoxazole and vancomycin by conventional antimicrobial susceptibily test. The vancomycin minimal inhibitory concentration by E-test was 2 microg/ml. The strain was judged to be possible heteroresistant when screening was done by one-point population analysis. The subsequent population analysis and testing for the emergence of mutants with reduced susceptible to vancomycin confirmed that this strain was hVISA. Despite the treatment with vancomycin, amikacin, rifampicin and cotrimoxazole, the patient died. hVISA should be suspected in MRSA infections that were refractory to vancomycin therapy could be due to. The emergence hVISA underscored the importance of the prudent use of antibiotics, the laboratory capacity to identify MRSA and hVISA and proper communication with treating clinicians, and the meticulous infection-control measures to prevent transmission.
对万古霉素敏感性降低的金黄色葡萄球菌已在全球范围内被报道。在此，我们报告泰国首例由异质性万古霉素中介耐药金黄色葡萄球菌（hVISA）引起的心内膜炎儿科病例。一名4个月大患有IV型动脉干和室间隔缺损的女孩在进行完全修复手术后发生了耐甲氧西林金黄色葡萄球菌（MRSA）菌血症和心内膜炎。该患者对包括万古霉素在内的联合抗菌治疗无反应。通过常规抗菌药敏试验，该菌株对甲氧苄啶 - 磺胺甲恶唑和万古霉素敏感。采用E试验测定的万古霉素最低抑菌浓度为2μg/ml。通过单点群体分析进行筛选时，该菌株被判定可能存在异质性耐药。随后的群体分析以及对万古霉素敏感性降低的突变体出现情况的检测证实该菌株为hVISA。尽管使用了万古霉素、阿米卡星、利福平和复方新诺明进行治疗，患者仍死亡。在对万古霉素治疗难治的MRSA感染中应怀疑hVISA的存在。hVISA的出现凸显了谨慎使用抗生素、具备鉴定MRSA和hVISA的实验室能力以及与治疗临床医生进行适当沟通的重要性，以及采取细致的感染控制措施以防止传播的重要性。
