異質性萬古黴素抗藥性金黃色葡萄球菌（hVISA）

Heterogeneous Vancomycin-intermediate Staphylococcus aureus: A Systematic Review

異質性萬古黴素抗藥性金黃色葡萄球菌(heterogeneous vancomycin- intermediate Staphylococcus aureus:hVISA)是一群對萬古黴素以臨床實驗室抗藥性試驗結果雖為具藥物敏感性，卻內含部分較高抗藥性菌落的金黃色葡萄球菌，目前該類菌株在世界各地有已有逐漸流行的趨勢，相當值得臨床醫療工作人員與微生物學者重視，包括台灣。目前，hVISA的篩檢可以透過Etest glycopeptide resistance detection (GRD)、Etest macromethod以及Brain heart infusion (BHI) screen agar plates等方法進行篩檢，接著進行 modified population analysis profile / area under the curve (PAP/AUC)進行確定。“高菌量”的感染症(high-inoculum infection)以及長期使用萬古黴素治療但卻治療失敗的個案與hVISA有關聯性。由於hVISA對萬古黴素有較高的抗藥性，治療選擇受到侷限，目前可使用的藥物包括Linezolid、Daptomycin、Rifampin and fusidic acid、以及新一代cephalosporins (Ceftobiprole、Ceftaroline)；其他glycopeptide類的抗生素(Dalbavancin、Oritavancin和Telavancin)對hVISA是否有效，仍需更進一步研究證明。雖然hVISA目前它的臨床意義不明確，但是它的出現通常暗示對萬古黴素的抗藥性增加，及早偵測抗藥性以及使用適當的抗生素是很重要的。

Heterogeneous vancomycin-intermediate Staphylococcus aureus (hVISA) is a resistant subpopulation of vancomycin-sensitive S. aureus, according to the definition of the Clinical and Laboratory Standards Institute. Currently, hVISA has been detected in many countries, including Taiwan. The screening methods of hVISA include the glycopeptide resistance detection macro-method and brain heart infusion screen agar plates. The confirmation method is a modified population analysis profile/area under the curve. “High-inoculum” infection and vancomycin treatment failure are commonly associated with hVISA infection. Because hVISA is a resistant subpopulation of vancomycin-sensitive S. aureus, the therapeutic options are limited. Vancomycin, linezolid, daptomycin, rifampin, fusidic acid, and new cephalosporins (ceftobiprole, ceftaroline) are antibiotics currently available for treating hVISA. The efficacy of other glycopeptides (dalbavancin, oritavancin, and telavancin) requires further investigation. Although the clinical significance of hVISA is yet to be determined, its existence often implicates a poor response to vancomycin treatment. It is important to identify the strains for early modification of antibiotic treatment.