Author/Authors :
Khoshbakht, Reza Antimicrobial Resistance Research Center - Mashhad University of Medical Sciences, Mashhad, Iran - Student Research Committee - Mashhad University of Medical Sciences, Mashhad, Iran , Zare, Hosna Antimicrobial Resistance Research Center - Mashhad University of Medical Sciences, Mashhad, Iran - Student Research Committee - Mashhad University of Medical Sciences, Mashhad, Iran , Kamali Kakhki, Reza Antimicrobial Resistance Research Center - Mashhad University of Medical Sciences, Mashhad, Iran - Student Research Committee - Mashhad University of Medical Sciences, Mashhad, Iran , Neshani, Alireza Student Research Committee - Mashhad University of Medical Sciences, Mashhad, Iran - Department of Laboratory Sciences - School of Paramedical Sciences - Mashhad University of Medical Sciences, Mashhad, Iran , Arfaatabar, Maryam Department of Medical Laboratory Sciences - Kashan Branch - Islamic Azad University, Kashan, Iran
Abstract :
Background: Staphylococcus epidermidis (S. epidermidis) is the most frequently iso-lated pathogen from prostheses infections in the body. Therefore, improving its diag-nostic methods, including rapid Nucleic Acid Amplification Tests (NAAT), seems neces-sary. Since the first step in designing a NAAT is to find a specific sequence and all DNA targets that have been introduced so far are not completely specific, we introduced a new 100% specific DNA target sequence to identify S. epidermidis in this study.
Methods: Modified comparative genomic analysis was used to find the best specific target sequence to detect S. epidermidis. A PCR method was designed for the evalua-tion of this target. To determine the detection limit and analytical specificity, pure genomic DNA of 18 bacteria include 12 standard strains (one S. epidermidis and 11 non-S. epidermidis) and six clinical isolates (five S. epidermidis and one non-S. epi-dermidis) were used.
Results: The 400 bp sequence of S. epidermidis ATCC 14990 was identified as the most specific sequence (Se400), having a 100% sequence similarity to S. epidermidis genomes but not with other bacteria. The detection limit of Se400-PCR was 10 fg, equal to about 4 copies of S. epidermidis genomic DNA/μl. All pure DNA templates from S. epidermidis generated a detectable amplicon by 264 bp length, but the PCR test was negative for the non-S. epidermidis group.
Conclusion: The Se400 sequence can be considered as a specific target for detecting S. epidermidis, based on our findings.
Keywords :
Comparative genomic analysis , Detection , Pathogen , Polymerase chain reaction , Se400 , Staphylococcus epidermidis
