Modeling the Impact of Intermittent Preventative Treatment on the Spread of Drug-Resistant Malaria

Background: Signal-Mediated Amplification of RNA Technology (SMART) is an isothermal nucleic acid amplification technology, developed for the detection of specific target sequences, either RNA (for expression) or DNA. Cyanophages are viruses that infect cyanobacteria. Marine cyanophages are ubiquitous in the surface layers of the ocean where they infect members of the globally important genus Synechococcus. Results: Here we report that the SMART assay allowed us to differentiate between infected and non-infected host cultures. Expression of the cyanophage strain S-PM2 portal vertex gene (g20) was detected from infected host Synechococcus sp. WH7803 cells. Using the SMART assay, we demonstrated that g20 mRNA peaked 240 – 360 minutes post-infection, allowing us to characterise this as a mid to late transcript. g20 DNA was also detected, peaking 10 hours post-infection, coinciding with the onset of host lysis. Conclusion: The SMART assay is based on isothermal nucleic acid amplification, allowing the detection of specific sequences of DNA or RNA. It was shown to be suitable for differentiating between virus-infected and non-infected host cultures and for the detection of virus gene expression: the first reported use of this technology for such applications. Background The Signal-Mediated Amplification of RNA Technology (SMART, developed by Cytocell Ltd., Banbury, UK), also referred to as CytAMP® (British BioCell International, Cardiff, UK) was originally developed for the medical diagnostics industry [1]. Public Health Laboratory trials have compared CytAMP® with more conventional methods for the specific detection of MRSA (methicillin-resistant Staphylococcus aureus) [2]. A review, outlining guidelines for the laboratory diagnosis and susceptibility testing of MRSA, reported that the sensitivity and specificity of CytAMP® was comparable to those of PCR for this purpose [3]. The SMART assay, summarised in figure 1, has been described in detail elsewhere [1,4]. Briefly, the assay uses two oligonucleotide probes which hybridise specifically to the target, at adjacent sites, and also to each other to Published: 6 June 2007 Virology Journal 2007, 4:52 doi:10.1186/1743-422X-4-52 Received: 15 March 2007 Accepted: 6 June 2007 This article is available from: http://www.virologyj.com/content/4/1/52 © 2007 Wharam et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.