Megha Kirti, Sharma Megha, Gupta Amit, Sehgal Rakesh, Khurana Sumeeta
Department of Medical Parasitology, Postgraduate Institute of Medical Education and Research, Chandigarh, India.
Department of Ophthalmology, Postgraduate Institute of Medical Education and Research, Chandigarh, India.
Parasitol Res. 2018 Mar;117(3):729-736. doi: 10.1007/s00436-017-5743-0. Epub 2018 Jan 17.
Acanthamoeba spp. are ubiquitous in the environment and have the potential to cause severe infections. The different genotypes of Acanthamoeba have been shown to influence the severity of the disease and response to therapy. Characterizing Acanthamoeba spp. upto genotype can aid in infection control practices. Twenty-five Acanthamoeba isolates, characterized by 18S rDNA sequencing, were subjected to MALDI-TOF MS analysis by creating a database for the individual genotypes. The differentiating features of the various spectra were observed; the coded samples were then tested against the created database. The results of identification were compared with sequencing. Five different genotypes were obtained-T3, T4, T5, T10, and T11. Spectral analysis revealed genus-specific and genotype-specific peaks. The peak patterns for individual genotype were discrete and reproducible. Clinical isolates produced different peaks from the environmental isolate of the same genotype. A concordance of 92% was obtained with MALDI-TOF MS in comparison with 18sDNA sequencing. MALDI-TOF MS, once optimized, has the potential to reliably identify the genotype of Acanthamoeba spp. and to differentiate clinical isolate from mere contaminant.
棘阿米巴属在环境中普遍存在，有引发严重感染的可能。已证实棘阿米巴的不同基因型会影响疾病的严重程度及对治疗的反应。对棘阿米巴属进行基因型鉴定有助于感染控制措施。通过对25株经18S rDNA测序鉴定的棘阿米巴分离株，为各个基因型创建数据库后进行基质辅助激光解吸电离飞行时间质谱（MALDI-TOF MS）分析。观察到各种光谱的鉴别特征；然后将编码样本与创建的数据库进行比对测试。将鉴定结果与测序结果进行比较。获得了5种不同的基因型——T3、T4、T5、T10和T11。光谱分析揭示了属特异性和基因型特异性峰。各个基因型的峰型是离散且可重复的。临床分离株产生的峰与相同基因型的环境分离株不同。与18S DNA测序相比，MALDI-TOF MS的一致性为92%。一旦优化，MALDI-TOF MS有潜力可靠地鉴定棘阿米巴属的基因型，并区分临床分离株和单纯污染物。
