Vol. 5, Issue 2 (2017)
Improving the diagnosis of dermatophytes in gaza strip by using Nested PCR
Author(s): *Tarek A El-Bashiti, Eyad K Ayesh
Abstract: Dermatophytes are a very related to keratinophilic fungi that can invade keratinized humans and animal tissues such as skin, hair and nails causing dermatophytosis. They are the important cause of superficial fungal infection. Conventional identification methods like potassium hydroxide (KOH) microscopy and fungal culture lacks the ability to make an early and specific diagnosis. In this study it is taken into consideration to evaluate nested polymerase chain reaction (NPCR) using primers targeting dermatophyte specific sequence of chitin synthase 1 (CHS1) gene and compared with conventional method by potassium hydroxide (KOH) microscopy test that carried out in Rimal clinic in Gaza city. A total of ninety nine patients were clinically suspected with dermatophytosis including 16 skin specimens 16 nail specimens and 67 hair specimens. For each specimen KOH, PCR and NPCR tests were carried out. The output results of NPCR sequencing was compared with the wild-type gene which was obtained from the National Center for Biotechnology Information (NCBI). The comparison indicated that the product of NPCR is CHS1 gene. Additionally, it was considered to compare the results of NPCR with KOH for dermatophytes which showed that 41.4% are positive indication based on KOH while 18.18% only was positive indication according to NPCR. After carrying out the statistical analysis using SPSS for both tests, it was found that 30% of the total samples should be included for treatment based on KOH test, although this percent of the sample doesn’t need to undergo treatment according to NPCR test. It is also shown that 6% of the samples are excluded for treatment in KOH method, in spite of the NPCR indicated that this percent must be included in the treatment. The prominent controversy between the test results (KOH and NPCR) was found particularly in the nails diagnosis. The study results approved that the NPCR test should be considered in dermatophytes test in Gaza Strip medical laboratories along with KOH test particularly in nails. Moreover, to improve the quality of test results, it was recommended to conduct training session for lab technicians to develop their capacity in the diagnosis of dermatophytes by KOH test.