Development and application of a simple loop-mediated isothermal amplification method on rapid detection of Listeria monocytogenes strains

Abstract

A loop-mediated isothermal amplification (LAMP) method for rapid detection of the food-borne L. monocytogenes strains had been developed and evaluated in this study. The optimal reaction condition was 65 °C for 45 min, with the detection limit as 1 pg DNA/tube and 100 CFU/reaction. Application of the established LAMP assay was performed on 182 food-borne L. monocytogenes strains using a rapid procedure and easy result confirmation, with the sensitivity of LAMP versus PCR assays as 96.7% (176/182) and 91.2% (166/182), respectively; with 100% specificity, positive predictive value (PPV) and negative predictive value (NPV) for both assays.

Role of integrons in antimicrobial resistance: A review

“…Regarded as one of the greatest contributions to medicine and humanity in the 20th century, antibiotics had been used to treat a wide range of infectious diseases caused by bacteria, for both animals and humans. Microorganisms mediated infectious diseases still remain one of the greatest concerns in public health (Wang et al, , 2012Zhao et al, 2010aZhao et al, , b, c, 2011Xu et al, 2011dXu et al, , 2012a. However, the indiscriminate use of existing antibiotics leads to the emergency of antibiotic resistance and poses a dilemma for the future treatment of bacterial infection, with an increasing number of clinical failures in bacterial mediated *Corresponding authors.…”

Loop-Mediated Isothermal Amplification (LAMP) for the Detection of <i>Listeria monocytogenes</i> and Major Pathogenic Serotypes

“…Other authors reported that LAMP is more sensitive and less influenced by components of biological samples than conventional PCR and real time PCR [12] [16] [17]. Although we did not compare herein the LAMP with other technologies, one can expect that our protocol would be successfully applied for biological samples.…”

“…LAMP assays for diagnosing L. monocytogenes infection have previously been reported [12] [16] [17]. Although these techniques are more sensitive than the LAMP we present here, none of them intended species detection with serotypes distinction.…”

“…Even without the optional primers, satisfactory amplification was achieved in as fast as 60 minutes. All reactions were performed at 63˚C, as previous reports have indicated that isothermal conditions between 60˚C -65˚C give similar results in LAMP assays [12].…”

“…To determine the minimum incubation time for visualization of the amplified products, assays were performed at increasing incubation times (15,30,45, 60, 75 and 90 minutes) using a thermocycler (Biometra) and water bath in parallel. All reactions were performed at 63˚C, as satisfactory LAMP can be achieved at isothermal conditions between 60˚C -65˚C [12].…”