Eghtedarnejad Esmaeil, Khajeh Somayeh, Zomorodian Kamiar, Ghasemi Zeinab, Yazdanpanah Somayeh, Motamedi Marjan
Department of Medical Parasitology and Mycology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran.
Basic Sciences in Infectious Diseases Research Center, Shiraz University of Medical Sciences, Shiraz, Iran.
Curr Med Mycol. 2023 Mar;9(1):28-31. doi: 10.18502/CMM.2023.345029.1398.
Species identification of using culture-dependent methods is time-consuming due to their fastidious growth requirements. This study aimed to evaluate a rapid and accurate molecular method in order to diagnose the pityriasis versicolor (PV) and identify species from direct clinical samples.
Skin scraping or tape samples from patients with PV and healthy volunteers as the control group were collected. Diagnosis of PV was confirmed by direct microscopic examination. The DNA extraction was performed according to the steel-bullet beating method. Polymerase chain reaction-restriction fragment length polymorphism assay using I restriction enzyme was applied for the identification and differentiation of species.
The PCR method was able to detect in 92.1% of specimens which were also confirmed with microscopic examination. Statistically, a significant association was observed between the results of the two assays ( < 0.001). Moderate agreement was identified between the two methods to diagnose the PV in both populations (Kappa: 0.55). Considering microscopic examination as the gold standard method for confirmation of PV, the sensitivity, specificity, positive predictive value, and negative predictive value values of the PCR assay for recognition of PV were 85%, 75%, 92%, and 60%, respectively. and were the most prevalent species isolated from patients.
In this study, the two-step molecular method based on the amplification of the D1/D2 domain and digestion of the PCR product by one restriction enzyme was able to diagnose and identify directly from clinical samples. Consequently, it can be said that the molecular-based method provides more facilities to identify fastidious species, such as .
由于其苛刻的生长要求，使用依赖培养的方法进行菌种鉴定非常耗时。本研究旨在评估一种快速准确的分子方法，以诊断花斑糠疹（PV）并从直接临床样本中鉴定菌种。
收集PV患者的皮肤刮屑或胶带样本以及作为对照组的健康志愿者样本。通过直接显微镜检查确诊PV。根据钢珠振荡法进行DNA提取。使用I型限制性内切酶的聚合酶链反应-限制性片段长度多态性分析用于菌种的鉴定和区分。
PCR方法能够在92.1%的标本中检测到菌种，这些标本也经显微镜检查证实。统计学上，两种检测结果之间存在显著关联（P<0.001）。两种方法在两个人群中诊断PV的一致性为中等（Kappa：0.55）。以显微镜检查作为确诊PV的金标准方法，PCR检测识别PV的灵敏度、特异性、阳性预测值和阴性预测值分别为85%、75%、92%和60%。马拉色菌属球形马拉色菌和糠秕马拉色菌是从患者中分离出的最常见菌种。
在本研究中，基于D1/D2结构域扩增和用一种限制性内切酶消化PCR产物的两步分子方法能够直接从临床样本中诊断和鉴定马拉色菌属。因此，可以说基于分子的方法为鉴定如马拉色菌属等苛求菌种提供了更多便利。
