Development of a pan-rickettsial molecular diagnostic test based on recombinase polymerase amplification assay

Anal Biochem. 2018 Mar 1:544:29-33. doi: 10.1016/j.ab.2017.12.018. Epub 2017 Dec 16.

Abstract

Rickettsioses are zoonotic vector-transmitted bacterial infections leading to flu-like symptoms and can progress to severe illness in humans. The gold standard for diagnosis of rickettsial infections is the indirect immunofluorescence assay, a serological method which is not suitable for pathogen identification during the acute phase of the disease. Therefore, several real-time PCR assays were developed. These assays are very sensitive, but require high-equipped laboratories and well-trained personnel. Hence, in this study, a rapid point-of-need detection method was developed to detect all Rickettsia species. The 23S and 16S rRNA genes were targeted to develop a recombinase polymerase amplification (RPA) assay. Both 23S and 16S_RPA assays required between seven to ten minutes to amplify and detect one or ten DNA molecules/reaction, respectively. The 16S_RPA assay detected all tested species, whereas the 23S_RPA assay identified only species of the spotted fever and transitional rickettsial groups. All results were compared with real-time PCR assays directed against the same rickettsial genes. The RPA assays are easy to handle and produced quicker results in comparison to real-time PCRs. Both RPA assays were implemented in a mobile suitcase laboratory to ease the use in rural areas. This method can help to provide rapid management of rickettsial infections.

Keywords: Mobile suitcase; Point of need; Rapid detection system; Recombinase polymerase amplification assay; Rickettsia.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Humans
  • Nucleic Acid Amplification Techniques*
  • RNA, Ribosomal, 16S / genetics*
  • RNA, Ribosomal, 23S / genetics*
  • Real-Time Polymerase Chain Reaction*
  • Rickettsia / genetics*
  • Rickettsia / isolation & purification

Substances

  • RNA, Ribosomal, 16S
  • RNA, Ribosomal, 23S