加州鲈致病性镰刀菌的分离鉴定及其药物敏感性分析

Isolation,identification and drug sensitivity analysis of pathogenic Fusarium sp.from Micropterus salmoides

从加州鲈(Micropterus salmoides)患病部位分离纯化到一株优势菌MY1,采用形态观察和真菌rDNA-ITS序列分析对其进行鉴定,通过回归感染实验确定其致病性,同时采用琼脂稀释法和微量液体稀释法对其进行药物敏感性实验,并通过不同温度、pH值、盐度条件进行生理特性研究。结果显示:MY1鉴定为腐皮镰刀菌(Fusarium solani),对加州鲈有较强的致病性,半数致死量(LD50)为1.03×10^(4)个/mL。药敏实验表明,该菌对两性霉素B、克霉唑、益康唑、制霉菌素4种药物敏感,最小抑菌浓度(MIC)分别为8、16、8、32μg/mL。生理特性研究发现,MY1在10~35℃和pH4.32~11.44时均可生长,最适温度为25~30℃,最适pH为7.85;2%~8%NaCl显著抑制其生长。

A dominant strain MY1 was isolated from the nidus of Micropterus salmoides.The strain MY1 was identified by morphological observation and fungal rDNA-ITS sequence analysis.The pathogenicity was tested by artificial infection test..Agar dilution method and microliquid dilution method were used to test drug sensitivity.The physiological characteristics was studied by different temperature,pH value and salinity conditions.The results showed that strain MY1 was identified as Fusarium solaniand the median lethal dose(LD50)was 1.03×10^(4) CFU/mL.The drug sensitivity test showed that the strain was sensitive to amphotericin B,clotrimazole,preconazole and nystatin,with the MIC of 8,16,8 and 32μg/mL,respectively.Studies on physiological characteristics showed that the strain could grow in the range of 10-35℃and pH 4.32-11.44.The optimal temperature was 25-30℃and the optimal pH was 7.85.2%-8%NaCl significantly inhibited MY1 growth.