Rapid detection of Proteus mirabilis with loop-mediated isothermal amplification.

[Objective] To develop a loop-mediated isothermal amplification (LAMP) assay for the rapid and specific detection of Proteus mirabilis. [Methods] 4 primers which recognized 6 distinct regions on the ureR gene of Proteus mirabilis were designed and used for LAMP assay. Proteus mirabilis DNA amplified under isothermal conditions (65℃ ) for 60 min, then, LAMP results were judged by electrophoretic analysis and restriction digestion. To evaluate the specificity of the LAMP assay, 1 strain of Proteus mirabilis and 13 strains of non-Proteus mirabilis were tested by LAMP and conventional PCR; In addition, the detection limit of LAMP was compared with that of PCR using the Proteus mirabilis strain, that were 10-fold serially diluted and was amplified by LAMP and PCR. [Results] After LAMP reaction, ladder patterns unique to the LAMP assay were observed with 1 strains of Proteus mirabilis, amplification was not observed when 13 strains of non-Proteus mirabilis were tested. The specificity of LAMP products was confirmed by digestion of LAMP products using restriction enzymes. The specificity of LAMP assay was similar to that of a PCR assay, but the sensitivity of LAMP was 10 times higher than that of conventional PCR assay, The detection limit of Proteus mirabilis was 5 cfu / ml by LAMP within 60 min and that of PCR was 50 cfu / ml within 160 min. [Conclusion] The LAMP assay is a rapid, specific and sensitive detection method for Proteus mirabilis and that requires no specialized equipment. This assay is suitable for rapid diagnosis in Proteus mirabilis infection.