Development and validation of an integrated cell culture-qRTPCR assay for simultaneous quantification of coxsackieviruses, echoviruses, and polioviruses in disinfection studies

2010 ◽  
Vol 61 (2) ◽  
pp. 375-387 ◽  
Author(s):  
B. K. Mayer ◽  
H. Ryu ◽  
D. Gerrity ◽  
M. Abbaszadegan

This study demonstrated the applicability of integrated cell culture-quantitative RTPCR (ICC-qRTPCR) for the simultaneous quantification of coxsackievirus, echovirus, and poliovirus in disinfection studies. Buffalo green monkey cells were inoculated with a 10-fold dilution series of mixed enteroviruses and incubated prior to qRTPCR quantification. Optimal assay conditions included three post infection washes and a 24-hour post infection incubation period based on successful differentiation between infectious and noninfectious viruses and significant and consistent viral replication rates. Ultraviolet disinfection studies were performed to validate the ICC-qRTPCR assay. Using the optimized assay, three-log microbial inactivation was achieved at UV doses of 30–44, 28–42, and 28–29 mJ/cm2 for coxsackievirus B6, echovirus 12, and poliovirus 1, respectively. These results compare favorably to side-by-side assessments using conventional cultural techniques and values previously reported in the literature. This indicates that ICC-qRTPCR is a practical alternative for the simultaneous quantification of enteroviruses in disinfection studies.

Mutagenesis ◽  
2019 ◽  
Author(s):  
Masahiko Watanabe ◽  
Masae Toudou ◽  
Taeko Uchida ◽  
Misato Yoshikawa ◽  
Hiroaki Aso ◽  
...  

Abstract Mutations in oncogenes or tumour suppressor genes cause increases in cell growth capacity. In some cases, fully malignant cancer cells develop after additional mutations occur in initially mutated cells. In such instances, the risk of cancer would increase in response to growth of these initially mutated cells. To ascertain whether such a situation might occur in cultured cells, three independent cultures of human lymphoblastoid GM00130 cells were treated with N-ethyl-N-nitrosourea to induce mutations, and the cells were maintained for 12 weeks. Mutant frequencies and spectra of the cells at the MspI and HaeIII restriction sites located at codons 247–250 of the TP53 gene were examined. Mutant frequencies at both sites in the gene exhibited a declining trend during cell culture and reached background levels after 12 weeks; this was also supported by mutation spectra findings. These results indicate that the mutations detected under our assay conditions are disadvantageous to cell growth.


2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S305-S306
Author(s):  
Li-Juan Jiang ◽  
Lisha Xu ◽  
Meng Huang ◽  
Shucha Zhang ◽  
Yang Li ◽  
...  

Abstract Background Respiratory syncytial virus (RSV) infection presents a significant health challenge in young children, elderly and immunocompromised patients. To date, there are no effective treatments available. EDP-938 was designed to meet this unmet medical need and is currently in Phase 2 clinical trials. Herein we report its preclinical pharmacokinetic (PK) and pharmacodynamic (PD) properties. Methods The pharmacokinetics of EDP-938 following single intravenous and oral doses were determined in mice, rats, dogs, and monkeys. In vitro cellular permeability and metabolic stability were assayed using Caco-2 cells and human liver microsomes, respectively. In vivo pharmacodynamic efficacy of EDP-938 was conducted in the African green monkey model, in which animals experimentally challenged with RSV were orally dosed twice daily with 100 mg/kg EDP-938 for 6 days starting 24 hours prior to infection. Results EDP-938 was well absorbed in the preclinical species with oral bioavailability values ranging from 27.1% in dogs, 35.4% in mice, 35.7% in rats, and 39.5% in monkeys, after a single oral dose when formulated in 0.5% methylcellulose. EDP-938 showed a moderate in vitro permeability of 3.6 x 10–6 cm/sec in Caco-2 cells. Based on the outcome of these absorption studies, EDP-938 was projected to have good oral absorption in humans. EDP-938 had low intrinsic clearance of 5 mL/minute/mg in human liver microsomes. Moreover, EDP-938 demonstrated potent antiviral efficacy in an African green monkey model of RSV infection. In untreated monkeys the RSV RNA viral load in the bronchoalveolar lavage fluid peaked at 106 copies/mL on day 5 post-infection, by comparison in animals treated with EDP-938 the viral load was below the limit of detection by day 3 post-infection. The PK/PD modeling suggested that plasma trough concentrations ≥10 × EC90 led to >4-log viral load reduction in EDP-938 treated monkeys. Conclusion The favorable preclinical PK and PD properties of EDP-938 support its further clinical development as a novel treatment for RSV infection. Disclosures All authors: No reported disclosures.


Author(s):  
Bhupesh K. Prusty ◽  
Alexander Karlas ◽  
Thomas F. Meyer ◽  
Thomas Rudel

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