The tick-borne encephalitis virus (TBEV) is an RNA-containing enveloped virus, which poses a major threat to the well-being and health of humans. In this study, we describe an approach to the inactivation of TBEV, which involves the degradation of viral RNA by artificial ribonucleases (aRNases, small organic compounds that exhibit ribonuclease activity in vitro). We demonstrate that the incubat...

A plaque technique for the assay of Rickettsia rickettsii is described. The method employs primary chick or green monkey kidney monolayer cell cultures with either an agarose or special Noble agar overlay. Plaques were counted in 6 days and resultant titers correlated well with ld(50) end points obtained by a standard assay in embryonated eggs. Identification of the plaque-forming organisms was...

Coliphage MS2 is used in place of pathogens in many studies and is considered one of the indicators of pathogenetic viruses in wastewater. We developed a quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) assay to quantify MS2 coliphages in treated wastewater samples. The format used was SYBR Green. The assay included an internal control to disclose the presence of PCR-produ...

INTRODUCTION Traditional methods of screening plant extracts and purified components for antiviral activity require up to a week to perform, prompting the need to develop more rapid quantitative methods to measure the ability of plant based preparations to block viral replication. We describe an adaption of an MS2 plaque reduction assay for use in S. aureus. RESULTS MS2 bacteriophage was capa...

BACKGROUND The antiviral effect of anti-influenza drugs such as zanamivir may be demonstrated in patients as an increased rate of decline in viral load over a time course of treatment as compared with placebo. Historically this was measured using plaque assays, or Culture Enhanced Enzyme Linked Immunosorbent Assay (CE-ELISA). OBJECTIVES to develop and characterise real time quantitative PCR (...

UL9, the origin-binding protein of herpes simplex virus type 1, contains six sequence motifs conserved in a large superfamily of RNA and DNA helicases. Single-amino-acid substitution mutations in these motifs inactivate UL9 function in vivo (R. Martinez, L. Shao, and S. K. Weller, J. Virol. 66:6735-6746, 1992). Overexpression of wild-type UL9 is inhibitory to plaque formation in a transfection ...

The coronavirus disease 2019 (COVID-19) has become a serious problem for public health since it was identified in the province of Wuhan (China) and spread around world producing high mortality rates economic losses. Nowadays, WHO recognizes traditional, complementary, alternative medicine treating COVID-19 symptoms. Therefore, we investigated antiviral potential hydroalcoholic extract Uncaria t...

The efficient replication of large DNA viruses requires dNTPs supplied by a viral ribonucleotide reductase. Viral ribonucleotide reductase is an early gene product of both vaccinia and herpes simplex virus. For productive infection, the apoprotein must scavenge iron from the endogenous, labile iron pool(s). The membrane-permeant, intracellular Fe(2+) chelator, 2,2'-bipyridine (bipyridyl, BIP), ...

Viral quantification represents an important step at multiple points in viral-driven recombinant protein production, studies of the mechanisms of viral infection, and vaccine development and manufacturing. Accurate determination of viral concentration allows viral infections to be precisely normalized and viral expansion processes to be monitored, optimized, and altered to give maximum yields. ...