RESUMEN
Under conditions of COVID-19 pandemic, considerable amounts of SARS-CoV-2 contained in household, municipal, and medical wastewaters inevitably reach natural water bodies. Possible preservation of virus infectivity in liquid environment is of a paramount epidemiological importance. Experiments demonstrated that SARS-CoV-2 is resistant to multiple freezing/thawing cycles and retains its infectivity in tap and river water for up to 2 days at 20°C and 7 days at 4°C. In natural milk, its viability is preserved in a refrigerator for 6 days. The exposure of aquarium fish to the virus-containing water fails to cause any infection.
Asunto(s)
COVID-19 , Animales , Humanos , Pandemias , SARS-CoV-2 , Aguas Residuales , AguaRESUMEN
Different methods for producing bulk quantities of concentrated and purified SARS-CoV-2 for the use as antigens and for the research into COVID-19 biology were tested.
Asunto(s)
Prueba de COVID-19/métodos , COVID-19/diagnóstico , SARS-CoV-2/inmunología , Carga Viral/inmunología , Virión/inmunología , Animales , Anticuerpos Neutralizantes/aislamiento & purificación , Anticuerpos Neutralizantes/metabolismo , Anticuerpos Antivirales/aislamiento & purificación , Anticuerpos Antivirales/metabolismo , COVID-19/virología , Línea Celular , Chlorocebus aethiops , Convalecencia , Células Epiteliales/virología , Humanos , Sueros Inmunes/química , SARS-CoV-2/genética , SARS-CoV-2/crecimiento & desarrollo , Porcinos , Células Vero , Carga Viral/genética , Proteínas Virales/inmunología , Proteínas Virales/aislamiento & purificación , Proteínas Virales/metabolismo , Virión/genética , Virión/crecimiento & desarrollo , Replicación ViralRESUMEN
The objectives of our study were to survey the prevalence of genetic markers for Rickettsia spp., Ehrlichia spp., Anaplasma spp., Babesia spp., and Theileria spp. in Hyalomma anatolicum ticks collected in southwestern Tajikistan and to perform sequencing and phylogenetic analysis of fragments of the 16S rRNA gene and groESL operon from Ehrlichia spp. and fragments of the 18S rRNA gene of Theileria spp. detected in H. anatolicum ticks. Hyalomma anatolicum ticks collected in the Tursunzade and Rudaki districts of Tajikistan were tested for DNA of Rickettsia spp., Ehrlichia spp., Anaplasma spp., Babesia spp., and Theileria spp. by PCR with specific primers. The amplified fragments were sequenced and analyzed. DNA of Ehrlichia spp. (3.3 %) and Theileria spp. (3.3 %) was detected only in H. anatolicum ticks collected from the Rudaki district, and DNA of Ehrlichia spp. (0.7 %) was found in H. anatolicum ticks from the Tursunzade district. Sequence analysis of fragments of the 16S rRNA gene and groESL operon from Ehrlichia spp. revealed high similarity to Ehrlichia spp. The Tajik isolates of Theileria spp. were genotyped as Theileria annulata based on the analysis of 18S rRNA gene sequences. The phylogenetic analysis demonstrates that Ehrlichia spp. isolates are highly similar to Ehrlichia spp. circulating in China and Brazil. The isolate Tajikistan-5 is closely related to the putative novel species Ehrlichia mineirensis. The Tajik isolates of Theileria spp. were clustered with T. annulata isolates from Turkey, Iran, Pakistan, and China by phylogenetic analyses.
RESUMEN
This study presents the results of laboratory trials of the reagent kit for the rapid detection of RNA of the Crimean-Congo hemorrhagic fever virus (CCHFV) using loop-mediated isothermal amplification with reverse transcription (RT-LAMP). The developed RT-LAMP reagent kit was used to detect the CCHFV and showed a sensitivity of 103 GE/ml of viral RNA, which is sufficient for detection of the CCHFV in the early stage of human infections. The kit showed high specificity and no cross-reactivity with viral panel from the State collection of viruses of the FBRI SRC VB «Vector¼ (arboviruses and hemorrhagic fever viruses). Laboratory trials of the RT-LAMP kit are showed a high analytical and diagnostic sensitivity and specificity for RNA detection of the CCHFV and high speed of the analysis (60-70 min with sample preparation) compared to real-time PCR. Approbation of the kit field version has showed the possibility of setting the RT-LAMP reaction and viral RNA detection without the using of analytical equipments.