Evaluation of different target genes for the detection of Salmonella sp. by loop-mediated isothermal amplification

Lett Appl Microbiol. 2021 Apr;72(4):420-426. doi: 10.1111/lam.13409. Epub 2020 Dec 16.

Abstract

The loop-mediated isothermal amplification (LAMP) technique was used to investigate six salmonella-specific sequences for their suitability to serve as targets for the pathogen identification. Sequences selected for designing LAMP primers were genes invA, bcfD, phoP, siiA, gene62181533 and a region within the ttrRSBCA locus. Primers including single nucleotide polymorphisms were configured as degenerate primers. Specificity of the designed primer sets was determined by means of 46 salmonella and 32 other food- and waterborne bacterial reference species and strains. Primers targeting the ttrRSBCA locus showed 100 % inclusivity of target and exclusivity of other test species and strains. Other primer sets revealed deficiencies, especially regarding Salmonella enterica subsp. II-IV and Salmonella bongori. Additionally, primers targeting the siiA gene failed to detect S. enterica subsp. enterica serotypes Newport and Stanley, whereas bcfD primers did not amplify DNA of S. enterica subsp. enterica serotype Schleissheim. TtrRSBCA primers, providing short detection times and constant melting temperatures of amplification products, achieved best overall performance.

Keywords: LAMP; bcfD gene; gene62181533; invA gene; phoP gene; salmonella; siiA gene; ttrRSBCA locus.

MeSH terms

  • Bacterial Proteins / genetics*
  • DNA Primers / genetics*
  • DNA, Bacterial / genetics
  • Molecular Diagnostic Techniques / methods*
  • Nucleic Acid Amplification Techniques / methods*
  • Salmonella / genetics*
  • Salmonella / isolation & purification
  • Salmonella enterica / genetics*
  • Salmonella enterica / isolation & purification
  • Sensitivity and Specificity

Substances

  • Bacterial Proteins
  • DNA Primers
  • DNA, Bacterial

Supplementary concepts

  • LAMP assay
  • Salmonella bongori