Comparison of Two PCR Methods in determining the Methicillin-Resistant Gene in Coagulase-Negative Staphylococci

Aims: It is very important to detect the coagulase-negative Staphylococci, which produce the hospital infections. Being one of the most expensive and time-consuming stages before the polymerase chain reaction (PCR), DNA extraction is one of the primary stages of PCR. Then, it should be noticed that the elimination of the stage might save time and costs. The aim of this study was to compare two PCR methods including the method with the utilization of the extracted DNA with the extraction kit and the direct PCR method in the detection of the methicillin-resistant genes in the coagulase-negative Staphylococci.
In the descriptive cross-sectional study, 135 Staphylococcus epidermidis and 88 Staphylococcus saprophyticus samples were studied, separated from blood, wounds, urinary catheter, and urine samples of patients hospitalized in the treatment centers of Zahedan. The direct PCR was done on the Staphylococcus saprophyticus and Staphylococcus epidermidis colonies. PCR with the extracted DNA was done for mecA and 16srDNA genes using the extraction kit, and the results were compared.
Findings: In both methods, mecA and 16srDNA genes were successfully amplified in 310bp and 420bp related to Staphylococcus bacteria identifying gene and methicillin resistant gene, respectively. In addition, there were approximately the same band qualities.
In order to save time and costs, the direct PCR method can be used to detect methicillin-resistant coagulase-negative Staphylococci.