Therefore, this transport method is not intended to replace routine diagnostic submission for outbreak surveillance, since a negative LFD does not necessarily define a negative sample. Regardless of the storage time or temperature, it was possible to detect FMDV genome using rRT-PCR from all sections of the LFDs for all isolates examined. These results are consistent with findings from Bisht et al, and Hofmann et al, who were also able to detect FMDV genome from clinical samples which had been stored for one month at elevated temperatures. However, for temperature and time of storage, the LP had significantly lower rRT-PCR Ct values and thus may be more favourable sections to use for laboratory analysis. This observation is supported by testing serial dilutions of virus applied to the LP, WS and AbB, whereby FMDV genome was still detectable at a higher dilutions for the LP and WS than other sections of the LFD. It was also possible to amplify and sequence VP1 from all sections of the LFDs after one month of storage at RT, and amplify the complete genome from the LP after one month of storage at 37uC. In fact there was no significant difference between Ct values derived from LFD membranes stored at RT when compared to those stored at 37uC. This indicates that the LFD membranes are suitable surfaces to preserve full length RNA for extended periods of time regardless of storage temperatures. It would be of interest to determine whether these observations can be replicated for samples processed and shipped from the field and include a range of different serotypes. A particular focus of this study was to examine whether full length FMDV RNA could be recovered from the lateral flow membranes. Following electroporation, it was possible to CYT 11387 recover infectious FMDV that was correctly typed by antigen ELISA. Although LFDs have not been previously tested, these findings are consistent with published work that describes recovery of infectious FMDV from clinical samples preserved in RNA storage buffers. Electroporation of elution wash one week following development on the device was less successful for the recovery of infectious virus. This observation is consistent with data reported by Hofmann et al,, whereby the ability to recover infectious virus following electroporation of RNA stored in Trizol declined over time. The success of recovering virus was not related to the section used on the lateral flow device and suggests that should this method be adopted for recovery of virus it would be important to electroporate elution washes from multiple LFD sections to optimise recovery of infectious full length RNA. Future studies should extend the storage time and include elevated temperatures to determine the point at which infectious virus can no longer be recovered. Contrary to the findings by Belsham et al, the rRT-PCR Ct values in this study did not appear to correlate with the ability to recover infectious virus. For example we were able to recover infectious virus from TUR 4/2013 and PAK 9/2013 which had average Ct values of 3062 and 2564 respectively, yet we were unable to recover infectious virus from TUR 2/2014 despite average Ct values of 2361. The findings of this study are therefore more consistent with those published by Bisht et al, who also reported varied success in recovery of infectious virus from RNA extracted from clinical samples despite strong multiplex PCR results. Further evaluation is required on a greater number of isolates to determine the optimum method/section of LFD to use for recovery of infectious FMDV RNA. Infectious virus was not recovered following direct passage of the elution wash onto BTY cells.
When inoculated onto susceptible cells for molecular detection methods that are widely used for routine diagnostics
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