Comparison of the performance of different extraction and amplification methods for detecting Escherichia coli DNA
Escherichia coli O157∶H7 is a highly hazardous pathogenic foodborne bacterium.In order to a-chieve rapid detection of Escherichia coli O157∶H7,five methods including alkaline thermal lysis,Tri-tonX-100 thermal lysis,lysozyme with SDS lysis,SDS with proteinase K lysis,and thermal lysis were used to extract genomic DNA of Escherichia coli O157∶H7.The detection effects of loop-mediated isothermal amplification(LAMP)and real-time fluorescence quantitative polymerase chain reaction(qPCR)amplifica-tion methods on the extracted DNA were investigated to establish the optimal nucleic acid rapid extraction sample pretreatment method.The results showed that using the extracted Escherichia coli O157∶H7 ge-nomic DNA obtained through alkaline thermal lysis pretreatment as the testing sample,both LAMP and qPCR amplification methods showed the best detection performance,with a detection limit of 101 CFU/mL,consistent with the detection performance of genomic DNA obtained from conventional commercial kits.The established alkaline thermal lysis sample pretreatment method is time-efficient,cost-effective,without com-plex nucleic acid extraction,and simple to operate,which is suitable for rapid detection of Escherichia coli O157∶H7.