一株从临床分离的奥默儿玉氏酵母的生物学特征及其致病毒力相关特性

Biological characteristics and virulence-related properties of a clinical Kodamaea ohmeri strain

奥默儿玉氏酵母Kodamaea ohmeri已经成为一种重要的新兴人类酵母病原体。本文利用形态学和ITS序列分析鉴定分离自患者腹水的临床菌株3873为K.ohmeri。5-氟胞嘧啶、两性霉素B、氟康唑、伊曲康唑和伏立康对菌株3873的MIC值分别为≤4、≤0.5、≤4、≤0.125和≤0.6 mg/L。菌株3873在血清诱导下发育出假菌丝,无法形成真菌丝,且在微需氧条件下侵入能力强;最适生长温度和pH分别为37℃和7.0,在此条件下细胞表面疏水性也最高;采用试管法和微平板法静置培养48h形成大量生物膜;在体外培养条件下,对刚果红、羟基脲和H2O2具有一定的耐受能力,对NaCl试剂较为敏感。本研究有助于更好地了解K.ohmeri的基本生物学特征和与其毒力相关的特性。

Kodamaea ohmeri has emerged as an important human yeast pathogen.A clinical strain 3873 isolated from ascites of a patient was identified as K.ohmeri based on morphology and ITS sequence analysis.The MIC values of 5-flucytosine,amphotericin B,fluconazole,itraconazole and voriconazole of the strain were≤4,≤0.5,≤4,≤0.125,and≤0.6 mg/L,respectively.The strain could produce pseudohyphae,but was unable to form fungal filaments with the induction of serum and had a strong invasive growth ability under microaerophilic conditions.The optimum growth temperature and pH of the strain were 37°C and 7.0,respectively.Under the optimum conditions the strain exhibited the highest cell surface hydrophobicity.A large amount of biofilm formation was observed within 48 h using the test tube method and the microplate method.In vitro,strain 3873 showed a slight tolerance to Congo red,hydroxy urea(HU)and H2O2,but a relative sensitivity to NaCl.This study contributes to a better understanding of the basic biological characteristics of K.ohmeri and properties related to its virulence.