Loop-mediated isothermal amplification for paratyphoid fever - a proof-of-principle analysis

Lett Appl Microbiol. 2019 Jun;68(6):509-513. doi: 10.1111/lam.13130. Epub 2019 Apr 25.

Abstract

In-house loop-mediated isothermal amplification (LAMP) procedures for the detection of paratyphoid fever-associated bacteria on serovar level were evaluated. Therefore, LAMP primers for Salmonella genus, for two LAMP schemes for S. Paratyphi A, for S. Paratyphi B and for S. Paratyphi C were tested with DNA from culture isolates from strain collections and spiked blood cultures against published PCR protocols targeting the same micro-organisms. Sensitivity and specificity for DNA from culture isolates verified by LAMP ranged from 80·0 to 100·0% and 96·1 to 100·0% vs 65 to 100% and 98·7 to 100% for the PCR approaches. For the spiked blood culture materials, sensitivity and specificity for LAMP ranged from 87·5 to 100·0% and 96·7 to 100·0% vs from 60 to 100% and 98·2 to 100% for PCR. In conclusion, LAMP for paratyphoid fever shows comparable performance characteristics as PCR. Due to its easy application, the procedure is well suited for surveillance purposes in resource-limited settings. SIGNIFICANCE AND IMPACT OF THE STUDY: The use of easy-to-apply, point-of-care-testing-like loop-mediated isothermal amplification (LAMP) for the diagnosis of paratyphoid fever is evaluated. This approach can contribute to low-threshold availability of surveillance options for resource limited settings. Easy-to-teach and easy-to-apply LAMP schemes with similar performance characteristics as PCR are provided. The described test evaluation is of particular use for surveillance and public health experts.

Keywords: LAMP; Salmonella Paratyphi; enteric fever; loop-mediated isothermal amplification; paratyphoid fever; rapid diagnostics.

MeSH terms

  • Blood Culture
  • DNA Primers / genetics
  • DNA, Bacterial / genetics*
  • Humans
  • Nucleic Acid Amplification Techniques / methods*
  • Paratyphoid Fever / diagnosis*
  • Paratyphoid Fever / microbiology
  • Polymerase Chain Reaction
  • Proof of Concept Study
  • Salmonella / genetics*
  • Salmonella / isolation & purification*
  • Sensitivity and Specificity

Substances

  • DNA Primers
  • DNA, Bacterial