A loop-mediated isothermal amplification method for rapid detection of the multidrug-resistance gene cfr.

We developed and evaluated the specificity and sensitivity of a loop-mediated isothermal amplification (LAMP) method for rapid detection of the multidrug-resistance gene cfr. A pair of outer primers and a pair of inner primers and one loop primer were specially designed for recognizing seven distinct sequences on the target cfr gene. The amplification reaction was performed within only 35 min under isothermal conditions at 63 °C in a regular water bath with visual measurement. The LAMP assay showed higher sensitivity than the conventional PCR, with a detection limit of 1 pg per tube of chicken Staphylococcus sciuri genomic DNA. The detection rate of cfr gene for 50 Staphylococcus clinical strains by LAMP assays was 16% and appeared 100% consistence with the result by PCR method. The LAMP method reported here demonstrated a potential and valuable means for detection of the multidrug-resistance gene cfr: easy, rapid, visual, specific, accurate and sensitive, especially useful for on-the-spot investigation.