培养基种类和甲酸浓度对基质辅助激光解吸电离飞行时间质谱在鉴定白色假丝酵母菌结果时的影响

The influence of medium and formic acid on the identification of Candida albicans by MALDI-TOF-MS

目的探讨在不同培养基和甲酸浓度的选择上MALDI-TOF MS对鉴定白色假丝酵母菌结果的影响。方法哥伦比亚血琼脂、沙氏琼脂和念珠菌显色3种培养基上生长的标准白色念珠菌,通过5种浓度的甲酸破壁处理后进行质谱仪鉴定。结果以2. 0及以上的分值为准确值,3种培养基在各自分别为90%、90%和80%的甲酸浓度下准确值最多;血琼脂培养基中90%与70%、90%与60%的甲酸浓度数值差异有统计学意义(χ~2值分别为4. 269、5. 689,P <0. 05)。沙氏琼脂培养基中以90%与70%、90%与60%的甲酸浓度数值差异有统计学意义(χ~2值分别为5. 169、9. 553,P <0. 05)。念珠菌显色培养基80%的甲酸浓度与其他浓度比较差异均无统计学意义(P> 0. 05)。血琼脂培养基同沙氏琼脂培养基两者的90%甲酸浓度之间差异无统计学意义(χ~2=0. 751,P> 0. 05)。结论血琼脂培养基和沙氏琼脂培养基中90%与70%、90%与60%的甲酸浓度数值之间均有差异,两者90%的甲酸浓度之间无差异。

Objective To investigate the effect of different medium and concentration of formic acid on the identification of Candida albicans by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry( MALDI-TOF-MS).Methods Standard Candida albicans grown on Colombian blood agar,Sabouraud medium and Candida coloration medium were conducted for identification by mass spectrometry after cell breaking in 5 concentrations of formic acid. Results With the scores of 2. 0 and above as the accurate values,the accurate values of the three media were the dominant under the concentrations of90%,90% and 80% formic acid. There was statistical significance on the differences in the concentrations of 90% and 70%,90% and 60% formic acid in blood AGAR medium,with the differences statistically significant( χ~2= 4. 269,χ~2= 5. 689,P <0. 05). There was a significant difference in the concentrations of 90% and 70%,90% and 60% formic acid in the AGAR medium,with the differences statistically significant( χ~2= 5. 169,χ~2= 9. 553,P < 0. 05). There was no statistical significance on the difference between the concentration of 80% formic acid in Candida sp. There was no statistical significance on the difference in the concentration of 90% formic acid between blood AGAR and Sabouraud AGAR medium( χ~2= 0. 751,P > 0. 05). Conclusion There are differences in the concentrations of 90% and 70%,90% and 60% of formic acid between blood AGAR medium and Sabouraud AGAR medium,and no difference in the concentrations of 90% formic acid between the two medium.