Loop-Mediated Isothermal Amplification of thesefAGene for Rapid Detection ofSalmonellaEnteritidis andSalmonellaGallinarum in Chickens

Abstract

Salmonella spp. pose a threat to both human and animal health, with more than 2600 serovars having been reported to date. Salmonella serovars are usually identified by slide agglutination tests, which are labor intensive and time consuming. In an attempt to develop a more rapid screening method for the major poultry Salmonella serovars, we developed a loop-mediated isothermal amplification (LAMP) assay, which directly detected the sefA gene, a fimbrial operon gene existing in several specific serovars of Salmonella enterica including the major poultry serovars, namely Salmonella enterica serovar Enteritidis (Salmonella Enteritidis) and Salmonella enterica serovar Gallinarum (Salmonella Gallinarum). With the 177 bacterial strains we tested, positive reactions were only observed with 85 strains of serovar Salmonella Enteritidis and Salmonella Gallinarum. The detection limit of the LAMP assay was 4 CFU/reaction with genomic DNAs of Salmonella Enteritidis (ATCC 13076) from pure culture and 400 CFU/ reaction with DNA extracted from spiked chicken feces. The LAMP assay was more sensitive than conventional culture, especially without enrichment, in detecting Salmonella Enteritidis (CMCC 50041) in the spiked fecal samples. The results show the sefA LAMP method is a rapid, sensitive, specific, and practical method for directly detection of Salmonella Enteritidis and Salmonella Gallinarum in chickens. The sefA LAMP assay can potentially serve as new on-site diagnostics in the poultry industry.

Visual and rapid detection of Plesiomonas shigelloides using loop‐mediated isothermal amplification method

“…b). These results indicated that the sensitivity of the LAMP assay for P. shigelloides detection was 10 times higher than that of conventional PCR, consistent with the results of previous LAMP assays (Wang et al ; Gong et al ). Furthermore, compared to conventional PCR, the LAMP method allowed faster visualization of results by employing calcein or NADA instead of gel electrophoresis.…”

Loop-Mediated Isothermal Amplification forSalmonellaDetection in Food and Feed: Current Applications and Future Directions

“…For instance, sdfI (Yang et al , 2010 ) and prot6E (Hu et al , 2018 ) were used to design two separate LAMP assays for Salmonella enterica serovar Enteritidis, while typh was used to specifically detect Salmonella Typhimurium (Kumar et al , 2014 ). The sefA gene has been explored to design a LAMP assay for both Salmonella Enteritidis and Salmonella Gallinarum (Gong et al , 2016 ). An insertion element IS200/IS1351 gene was used to detect Salmonella O9 serogroup (Okamura et al , 2008 ), prt ( rfbS ) for serogroup D (i.e., O9) (Ravan and Yazdanparast 2012a , b), and rfbJ for O4 serogroup (Okamura et al , 2009 ).…”

Adapting viral safety assurance strategies to continuous processing of biological products

“…For example, emerging technologies have been proposed for rapid viral or bacterial disease diagnoses in the clinical diagnostic field. These include rapid water‐based thermal cyclers (Wong et al, ) or reverse transcription‐loop‐mediated isothermal amplification (RT‐LAMP) (Gong et al, ; Liu et al, ). For clinical samples, these methodologies have proven to be low‐cost, and just as sensitive as traditional QPCR or RT‐PCR methods.…”