Rapid high throughput SYBR green assay for identifying the malaria vectors Anopheles arabiensis, Anopheles coluzzii and Anopheles gambiae s.s. Giles

PLoS One. 2019 Apr 19;14(4):e0215669. doi: 10.1371/journal.pone.0215669. eCollection 2019.

Abstract

The Anopheles gambiae sensu lato species complex consists of a number of cryptic species with different habitats and behaviours. These morphologically indistinct species are identified by chromosome banding. Several molecular diagnostic techniques for distinguishing between An. coluzzii and An. gambiae are still under improvement. Although, the current SINE method for identification between An. coluzzii and An. gambiae works reliably, this study describes a refinement of the SINE method to increase sensitivity for identification of An. coluzzii, An. gambiae and An. arabiensis based on amplicon dissociation curve characteristics. Field-collected samples, laboratory-reared colonies and crossed specimens of the two species were used for the design of the protocol. An. gambiae, An. coluzzii, and hybrids of the two species were sampled from Ghana and An. arabiensis from Kenya. Samples were first characterised using conventional SINE PCR method, and further assayed using SYBR green, an intercalating fluorescent dye. The three species and hybrids were clearly differentiated using the melting temperature of the dissociation curves, with derivative peaks at 72°C for An. arabiensis, 75°C for An. gambiae and 86°C for An. coluzzii. The hybrids (An. gambiae / An. coluzzii) showed both peaks. This work is the first to describe a SYBR green real time PCR method for the characterization of An. arabiensis, An. gambiae and An. coluzzii and was purposely designed for basic melt-curve analysis (rather than high-resolution melt-curve) to allow it to be used on a wide range of real-time PCR machines.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Anopheles / classification
  • Anopheles / genetics*
  • Anopheles / parasitology
  • Benzothiazoles
  • DNA / chemistry
  • DNA / genetics
  • Diamines
  • Fluorescent Dyes / chemistry
  • Ghana
  • Kenya
  • Malaria / diagnosis
  • Malaria / genetics*
  • Malaria / parasitology
  • Molecular Diagnostic Techniques / methods*
  • Mosquito Vectors / genetics*
  • Mosquito Vectors / parasitology
  • Organic Chemicals / chemistry
  • Polymerase Chain Reaction / methods*
  • Quinolines
  • Reproducibility of Results
  • Sensitivity and Specificity
  • Species Specificity

Substances

  • Benzothiazoles
  • Diamines
  • Fluorescent Dyes
  • Organic Chemicals
  • Quinolines
  • SYBR Green I
  • DNA