Rapid, sensitive and effective diagnostic tools for foot-and-mouth disease virus in Africa

Abstract

Speed is paramount in the diagnosis of highly infectious diseases, such as foot-and-mouth disease (FMD), as well as for emerging diseases; however, simplicity is required if a test is to be deployed in the field. Recent developments in molecular biology have enabled the specific detection of FMD virus (FMDV) by reverse-transcription loop-mediated isothermal amplification (RT-LAMP), real-time reverse-transcription polymerase chain reaction (RT-qPCR) and sequencing. RT-LAMP enables amplification of the FMDV RNA-dependent RNA polymerase 3D(pol) gene at 63 °C (in the presence of a primer mixture and both reverse transcriptase and Bst DNA polymerase) for 1 h, whilst RT-qPCR amplifies the same gene in approximately 2 h 30 min. In this study, we compared the sensitivity and effectiveness of RT-LAMP against RT-qPCR for the detection of the FMDV 3D(pol) gene in 179 oesophageal-pharyngeal scraping samples (collected by probang) obtained from clinically healthy cattle and buffalo in Malawi, Mozambique and Tanzania in 2010. The FMDV detection rate was higher with RT-LAMP (30.2%; n = 54) than with RT-qPCR (17.3%; n = 31). All samples positive by RT-qPCR (Cq ≤ 32.0) were also positive for the RT-LAMP assay; and both assays proved to be highly specific for the FMDV target sequence. In addition, the VP1 sequences of 10 viruses isolated from positive samples corresponded to the respective FMDV serotypes and genotypes. Our findings indicate that the performance of RT-LAMP is superior to RT-qPCR. Accordingly, we consider this test to have great potential with regard to the specific detection and surveillance of infectious diseases of humans and animals in resource-compromised developing countries.

Field-Deployable Reverse Transcription-Insulated Isothermal PCR (RT-iiPCR) Assay for Rapid and Sensitive Detection of Foot-and-Mouth Disease Virus

“…The instrumentations needed for those assays are relatively inexpensive, less complicated, less delicate and easily decontaminated or disposed of between each use. Recently, a number of RT‐LAMP assays have been developed and validated for detection and typing of FMDV (Dukes et al., ; Chen et al., ,b; Yamazaki et al., ; Ding et al., ; Kasanga et al., ; Ranjan et al., ; Waters et al., ; Farooq et al., ; Howson et al., ). The assays were rapid, highly sensitive and specific, and more resistant to inhibitors than conventional and RRT‐PCR assays.…”

“…FMD outbreaks have to be quickly detected and contained, and therefore, onsite detection tools are highly desirable. To date, a number of field‐deployable molecular assays have been developed and evaluated for their potential to use in the field to support local decision‐making (Dukes et al., ; Chen et al., ,b; Madi et al., ; Abd El Wahed et al., ; Yamazaki et al., ; Kasanga et al., ; Ranjan et al., ; Waters et al., ; Howson et al., ), and some of them have been successfully tested in the field (Madi et al., ; Abd El Wahed et al., ; Howson et al., ). To our knowledge, none of those assays are commercially available yet.…”

Global Foot-and-Mouth Disease Research Update and Gap Analysis: 4 - Diagnostics

“…A number of RNA detection assays targeting the FMDV genome have been developed using reverse transcription loop‐mediated isothermal amplification (RT‐LAMP), with some detecting single serotypes and others multiple (Chen et al., ; Madhanmohan et al., ; Yamazaki et al., ; Ding et al., ; Kasanga et al., ). RT‐LAMP was faster, simpler, more cost‐effective and at least as sensitive and specific as RT‐PCR.…”

Rapid and SensitiveSalmonellaTyphi Detection in Blood and Fecal Samples Using Reverse Transcription Loop-Mediated Isothermal Amplification

“…Bst DNA polymerase ensures highly efficient amplification under a wide range of isothermal reaction conditions within 1 h (Mori and Notomi, 2009). RT-LAMP assays using RNA as a template have been widely developed to detect viruses (Teoh et al, 2013;Kasanga et al, 2014) and bacteria, including Salmonella Enteritidis (Techathuvanan et al, 2012) and Salmonella Typhimurium (Techathuvanan et al, 2011). The sensitivity of RT-LAMP is higher or equivalent to routine RT-PCR (Techathuvanan et al, 2011;Liu et al, 2013).…”