TY - JOUR
T1 - Inactivation of SARS-CoV-2 virus in saliva using a guanidium based transport medium suitable for RT-PCR diagnostic assays
AU - Banik, Sukalyani
AU - Saibire, Kaheerman
AU - Suryavanshi, Shraddha
AU - Johns, Glenn
AU - Chakravorty, Soumitesh
AU - Kwiatkowski, Robert
AU - Alland, David
AU - Banada, Padmapriya P.
N1 - Publisher Copyright:
© 2021 Banik et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
PY - 2021/6
Y1 - 2021/6
N2 - Background Upper respiratory samples used to test for SARS-CoV-2 virus may be infectious and present a hazard during transport and testing. A buffer with the ability to inactivate SARS-CoV-2 at the time of sample collection could simplify and expand testing for COVID-19 to non-conventional settings. Methods We evaluated a guanidium thiocyanate-based buffer, eNAT™ (Copan) as a possible transport and inactivation medium for downstream Reverse Transcriptase-Polymerase Chain Reaction (RT-PCR) testing to detect SARS-CoV-2. Inactivation of SARS-CoV-2 USA-WA1/ 2020 in eNAT and in diluted saliva was studied at different incubation times. The stability of viral RNA in eNAT was also evaluated for up to 7 days at room temperature (28C), refrigerated conditions (4C) and at 35C. Results SARS-COV-2 virus spiked directly in eNAT could be inactivated at >5.6 log10 PFU/ml within a minute of incubation. When saliva was diluted 1:1 in eNAT, no cytopathic effect (CPE) on VeroE6 cells was observed, although SARS-CoV-2 RNA could be detected even after 30 min incubation and after two cell culture passages. A 1:2 (saliva:eNAT) dilution abrogated both CPE and detectable viral RNA after as little as 5 min incubation in eNAT. SARS-CoV-2 RNA from virus spiked at 5X the limit of detection remained positive up to 7 days of incubation in all tested conditions. Conclusion eNAT and similar guanidinium thiocyanate-based media may be of value for transport, stabilization, and processing of clinical samples for RT-PCR based SARS-CoV-2 detection.
AB - Background Upper respiratory samples used to test for SARS-CoV-2 virus may be infectious and present a hazard during transport and testing. A buffer with the ability to inactivate SARS-CoV-2 at the time of sample collection could simplify and expand testing for COVID-19 to non-conventional settings. Methods We evaluated a guanidium thiocyanate-based buffer, eNAT™ (Copan) as a possible transport and inactivation medium for downstream Reverse Transcriptase-Polymerase Chain Reaction (RT-PCR) testing to detect SARS-CoV-2. Inactivation of SARS-CoV-2 USA-WA1/ 2020 in eNAT and in diluted saliva was studied at different incubation times. The stability of viral RNA in eNAT was also evaluated for up to 7 days at room temperature (28C), refrigerated conditions (4C) and at 35C. Results SARS-COV-2 virus spiked directly in eNAT could be inactivated at >5.6 log10 PFU/ml within a minute of incubation. When saliva was diluted 1:1 in eNAT, no cytopathic effect (CPE) on VeroE6 cells was observed, although SARS-CoV-2 RNA could be detected even after 30 min incubation and after two cell culture passages. A 1:2 (saliva:eNAT) dilution abrogated both CPE and detectable viral RNA after as little as 5 min incubation in eNAT. SARS-CoV-2 RNA from virus spiked at 5X the limit of detection remained positive up to 7 days of incubation in all tested conditions. Conclusion eNAT and similar guanidinium thiocyanate-based media may be of value for transport, stabilization, and processing of clinical samples for RT-PCR based SARS-CoV-2 detection.
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U2 - 10.1371/journal.pone.0252687
DO - 10.1371/journal.pone.0252687
M3 - Article
C2 - 34115762
AN - SCOPUS:85107974293
SN - 1932-6203
VL - 16
JO - PloS one
JF - PloS one
IS - 6 June 2021
M1 - e0252687
ER -