RT-PCR for detection of all seven genotypes of Lyssavirus genus.

The research explores the optimisation of RT-PCR for detecting all seven genotypes of Lyssavirus genus. The new method was found to have an increased sensitivity compared to earlier versions, making it a relevant tool for rabies diagnosis and surveillance.

Methodology

• The research revolved around the Lyssavirus genus, which consists of seven species or genotypes, each having distinct geographical distribution and specific hosts.
• The researchers used primer sequences chosen from conserved regions across all genotypes. This was done to optimise a generic RT-PCR. RT-PCR is a technology used in molecular biology to amplify and simultaneously quantitate a targeted DNA molecule.
• The study compared the sensitivity of the RT-PCR standardised in this study with a previously published RT-PCR, optimised for EBLV1 detection, but capable of amplifying RNA from all seven lyssaviruses.

Findings

• The comparison involved serial dilutions of 12 RNA extracts from all seven Lyssavirus genotypes. It was found that the new version of the test had higher sensitivity in detecting the genotypes than the old version.
• Twenty samples submitted for rabies diagnosis were tested by the new RT-PCR. Of these, eight samples from six dogs, one horse and one bat tested positive. This was in agreement with immune fluorescent results. Additionally, of the eight positive samples, seven were genotype 1 and one was genotype 5.

Conclusion

• The research concluded that the optimised RT-PCR method can complement immunofluorescence for the diagnosis of rabies. With the capability of detecting all seven genotypes of Lyssavirus, RT-PCR stands as a robust tool to detect unexpected lyssaviruses during rabies surveillance.
• The method’s increased sensitivity could help in better detection, improving the overall effectiveness of rabies identification and control efforts.