Rahman M A, Chowdhury O A, Debnath M R, Ahmed S M, Das S, Choudhury R, Akter R, Zaman S, Mahamud F
Dr Md Arifur Rahman, M Phil Student, Department of Microbiology, Sylhet MAG Osmani Medical College, Sylhet, Bangladesh.
Mymensingh Med J. 2018 Jul;27(3):626-630.
Dermatophytes are a group of closely related fungi that have the capacity of invading the keratinized tissue of human to produce infections known as dermatophytosis which is commonly referred to as ringworm. Other than routine microscopy, different culture media are available for the detection of dermatophytes from patient's specimen. This cross sectional study was designed to evaluate the outcome of three different culture media and microscopy for the detection of dermatophytes from clinical samples. Skin, hair and nail samples from 84 clinically suspected cases of dermatophytosis who attended at OPD of Dermatology Department, Sylhet MAG Osmani Medical College Hospital, Sylhet, Bangladesh from July 2014 to June 2015 were screened by direct microscopic examination using potassium hydroxide (KOH) mount. All the samples were inoculated for culture in Sabouraud's Dextrose Agar (SDA), Dermatophytes Test medium (DTM) and Sabouraud's Cycloheximide Chloramphenicol Agar (SCCA). The percentage of samples positive by microscopy was 37.5%, whereas the rate of positivity by culture was 47.6% which showed that culture was more sensitive than microscopy for the diagnosis of dermatophytosis. The efficiency of SDA and SCCA was found to be almost equal. There was no statistically significant difference between SDA and DTM in primary isolation of dermatophytes, though isolation rate was slightly higher in DTM. Though direct examination by microscopy is an efficient screening technique, culture should be done for accurate diagnosis. As DTM is easy to evaluate even without handling the growth of culture in the laboratory, it is recommended to use as screening medium for the detection of dermatophytes.
皮肤癣菌是一组密切相关的真菌，它们能够侵入人体的角化组织，引发被称为皮肤癣菌病（通常称为癣）的感染。除了常规显微镜检查外，还有不同的培养基可用于从患者标本中检测皮肤癣菌。本横断面研究旨在评估三种不同培养基及显微镜检查在从临床样本中检测皮肤癣菌方面的效果。对2014年7月至2015年6月期间在孟加拉国锡尔赫特MAG奥斯曼尼医学院医院皮肤科门诊就诊的84例临床疑似皮肤癣菌病病例的皮肤、毛发和指甲样本，使用氢氧化钾（KOH）涂片进行直接显微镜检查筛选。所有样本均接种于沙保弱葡萄糖琼脂（SDA）、皮肤癣菌测试培养基（DTM）和沙保弱环己酰亚胺氯霉素琼脂（SCCA）中进行培养。显微镜检查阳性样本的百分比为37.5%，而培养阳性率为47.6%，这表明在皮肤癣菌病的诊断中，培养比显微镜检查更敏感。发现SDA和SCCA的效率几乎相等。在皮肤癣菌的初次分离中，SDA和DTM之间没有统计学上的显著差异，尽管DTM中的分离率略高。虽然显微镜直接检查是一种有效的筛查技术，但为了准确诊断仍应进行培养。由于DTM即使在不处理实验室培养生长的情况下也易于评估，因此建议将其用作检测皮肤癣菌的筛查培养基。
