Diagnostic Use of PCR in Carbapenamase-producing Enterobacteriaceae (CPE): An Improved Method to Overcome the presence of inhibitors for DNA Extraction from Blood Cultures

BackgroundCarpanenamase-producing Enterobacteriaceae (CPE) has emerged as a threat to hospitalized patients. Phenotypic test such as Modified hodge test was less sensitive and specific especially to detect blaNDM-1 which is the most predominant genotype in this region. Nucleic acid amplification technology offers improved specificity and sensitivity. However, there is limitation in this method which is failed amplification due to the presence of inhibitors. In this study, we try to use previous method described by Villumseen et al with some modification using another DNA extraction kit.\n\nMethodology/Principle findingsThree confirmed isolates of blaNDM-1 carbapenamase-producing Klebsiella pneumoniae was spiked with 10 mls sterile whole blood in an aerobic Bactec Plus until the growth was detected. The blood specimen was taken and was subjected to DNA extraction method using two commercialized kits followed with multiplex PCR. All the three isolates revealed blaNDM-1 genotypes. Internal control was amplified in all three isolates.\n\nConclusion/significanceThis study proved that we can get a specific and early diagnosis of CPE by using nucleic acid amplification technique directly from blood culture bottle and eliminate the effect of inhibitors.