Application of chitosan microparticles against human norovirus

Author(s):  
Candace Barnes ◽  
Rebecca Barber ◽  
Keith R. Schneider ◽  
Michelle D. Danyluk ◽  
Anita C. Wright ◽  
...  

Human norovirus (HuNoV) is the leading causative agent of foodborne outbreaks and is associated with the second most prevalent cause of waterborne infections in the United States. The goal of this research was to investigate the antiviral activity of chitosan microparticles (CM) against HuNoV GII.4 Sydney and its cultivable surrogate, Tulane virus (TuV), in suspensions mimicking fecally-contaminated water. CM was prepared by crosslinking chitosan molecules with sodium sulfate, and then its anti-noroviral activity was assessed using infectivity assay on TuV and RT-qPCR on TuV and HuNoV. A 3% CM suspension in PBS (pH 7.2) showed binding to TuV particles but with a negligible impact on virus infectivity (p>0.05). TuV and HuNoV suspended in fecal suspensions showed a 1.5-log10 reduction in genomic copies per ml following a 10-min contact time (p<0.05). Despite the negligible impact on viral infectivity, CM moderately binds to virus particles and helps purify environmental water by removing infectious virus particles. In this study, TuV served as a suitable surrogate for HuNoV by showing a similar log10 reduction in fecal suspension. Overall, the outcomes of thisresearch highlight the potential application of CM as a novel, natural treatment to minimize the spread of water-transmitted viral pathogens.

2015 ◽  
Vol 81 (8) ◽  
pp. 2727-2734 ◽  
Author(s):  
Erin DiCaprio ◽  
Doug Culbertson ◽  
Jianrong Li

ABSTRACTHuman norovirus (NoV) is the leading cause of foodborne disease in the United States, and epidemiological studies have shown that fresh produce is one of the major vehicles for the transmission of human NoV. However, the mechanisms of norovirus contamination and persistence in fresh produce are poorly understood. The objective of this study is to determine whether human NoV surrogates, murine norovirus (MNV-1) and Tulane virus (TV), can attach and become internalized and disseminated in strawberries grown in soil. The soil of growing strawberry plants was inoculated with MNV-1 and TV at a level of 108PFU/plant. Leaves and berries were harvested over a 14-day period, and the viral titer was determined by plaque assay. Over the course of the study, 31.6% of the strawberries contained internalized MNV-1, with an average titer of 0.81 ± 0.33 log10PFU/g. In comparison, 37.5% of strawberries were positive for infectious TV, with an average titer of 1.83 ± 0.22 log10PFU/g. A higher percentage (78.7%) of strawberries were positive for TV RNA, with an average titer of 3.15 ± 0.51 log10RNA copies/g as determined by real-time reverse transcriptase quantitative PCR (RT-qPCR). In contrast, no or little virus internalization and dissemination were detected when TV was inoculated into bell peppers grown in soil. Collectively, these data demonstrate (i) virally contaminated soils can lead to the internalization of virus via plant roots and subsequent dissemination to the leaf and fruit portions of growing strawberry plants and (ii) the magnitude of internalization is dependent on the type of virus and plant.


Viruses ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 461
Author(s):  
Shu Zhu ◽  
Candace Barnes ◽  
Sutonuka Bhar ◽  
Papa Hoyeck ◽  
Annalise N. Galbraith ◽  
...  

Human noroviruses are the leading cause of foodborne gastroenteritis worldwide and disease outbreaks have been linked to contaminated surface waters as well as to produce consumption. Noroviruses are extremely stable in water and their presence is being detected with increasing frequency, yet there are no viable methods for reducing norovirus contamination in environmental water. Despite this, there is little knowledge regarding the physical and chemical factors that influence the environmental persistence of this pathogen. This study evaluated the impact of common chemical and physical properties of surface water on the stability of murine norovirus and examined the effect of food-safe chitosan microparticles on infectivity of two human norovirus surrogates. While chemical additives had a minor impact on virus survival, chitosan microparticles significantly reduced infectious titers of both murine norovirus and MS2 bacteriophage.


2021 ◽  
Vol 9 (2) ◽  
pp. 224
Author(s):  
Ravleen Virdi ◽  
Melissa E. Lowe ◽  
Grant J. Norton ◽  
Stephanie N. Dawrs ◽  
Nabeeh A. Hasan ◽  
...  

Nontuberculous mycobacteria (NTM) are environmental organisms that can cause opportunistic pulmonary disease with species diversity showing significant regional variation. In the United States, Hawai’i shows the highest rate of NTM pulmonary disease. The need for improved understanding of NTM reservoirs led us to identify NTM from patient respiratory specimens and compare NTM diversity between outdoor and indoor locations in Hawai’i. A total of 545 water biofilm samples were collected from 357 unique locations across Kaua’i (n = 51), O’ahu (n = 202), Maui (n = 159), and Hawai’i Island (n = 133) and divided into outdoor (n = 179) or indoor (n = 366) categories. rpoB sequence analysis was used to determine NTM species and predictive modeling applied to develop NTM risk maps based on geographic characteristics between environments. M. chimaera was frequently identified from respiratory and environmental samples followed by M. chelonae and M. abscessus; yet significantly less NTM were consistently recovered from outdoor compared to indoor biofilms, as exemplified by showerhead biofilm samples. While the frequency of M. chimaera recovery was comparable between outdoor and indoor showerhead biofilms, phylogenetic analyses demonstrate similar rpoB gene sequences between all showerhead and respiratory M. chimaera isolates, supporting outdoor and indoor environments as possible sources for pulmonary M. chimaera infections.


2011 ◽  
Vol 92 (12) ◽  
pp. 2803-2809 ◽  
Author(s):  
Chun-Yu Hung ◽  
Meng-Chieh Tsai ◽  
Yi-Ping Wu ◽  
Robert Y. L. Wang

Five host cellular proteins were identified in the secretion medium from Japanese encephalitis virus (JEV)-infected baby hamster kidney-21 (BHK-21) cells, including three molecular chaperones: Hsp70, GRP78 and Hsp90. Hsp90 isoforms were characterized further. Hsp90α was observed to be retained inside the nuclei, whereas Hsp90β associated with virus particles during assembly and was released into the secretion medium upon JEV infection. The association of Hsp90β and viral E protein was demonstrated by using sucrose-density fractionation and Western blot analysis. Moreover, JEV viral RNA replication was not affected by treatment with geldanamycin, an Hsp90 inhibitor, but impaired virus infectivity that was determined by a plaque-forming assay. Our results show that Hsp90β, not Hsp90α, is present in the JEV-induced secretion medium and is required for JEV infectivity in BHK-21 cells.


Author(s):  
Sumaiya Saifur ◽  
Courtney M. Gardner

Abstract Stormwater is a largely uncontrolled source of pollution in rural and urban environments across the United States. Concern regarding the growing diversity and abundance of pollutants in stormwater as well as their impacts on water quality has grown significantly over the past several decades. In addition to conventional contaminants like nutrients and heavy metals, stormwater is a well-documented source of many contaminants of emerging concern, which can be toxic to both aquatic and terrestrial organisms and remain a barrier to maintaining high quality water resources. Chemical pollutants like pharmaceuticals and personal care products, industrial pollutants such as per- and polyfluoroalkyl substances, and tire wear particles in stormwater are of great concern due to their toxic, genotoxic, mutagenic and carcinogenic properties. Emerging microbial contaminants such as pathogens and antibiotic resistance genes also represent significant threats to environmental water quality and human health. Knowledge regarding the transport, behavior, and the remediation capacity of these pollutants in runoff is key for addressing these pollutants in situ and minimizing ecosystem perturbations. To this end, this review paper will analyze current understanding of these contaminants in stormwater runoff in terms of their transport, behavior, and bioremediation potential.


2020 ◽  
Vol 8 (5) ◽  
pp. 791
Author(s):  
Caitlin E. Karolenko ◽  
Arjun Bhusal ◽  
Jacob L. Nelson ◽  
Peter M. Muriana

In the US, dried beef products (beef jerky) are a popular snack product in which the manufacture often requires the use of a heat lethality step to provide adequate reduction of pathogens of concern (i.e., 5-log reduction of Salmonella as recommended by the United States Department of Agriculture Food Safety and Inspection Service (USDA-FSIS)). Biltong, a South African-style dried beef product, is manufactured with low heat and humidity. Our objectives were to examine processes for the manufacture of biltong that achieves a 5-log reduction of Salmonella without a heat lethality step and with, or without, the use of additional antimicrobials. Beef pieces (1.9 cm × 5.1 cm × 7.6 cm) were inoculated with a 5-serovar mixture of Salmonella (Salmonella Thompson 120, Salmonella Heidelberg F5038BG1, Salmonella Hadar MF60404, Salmonella Enteritidis H3527, and Salmonella Typhimurium H3380), dipped in antimicrobial solutions (lactic acid, acidified calcium sulfate, sodium acid sulfate) or water (no additional antimicrobial), and marinaded while vacuum tumbling and/or while held overnight at 5 °C. After marination, beef pieces were hung in an oven set at 22.2 °C (72 °F), 23.9 °C (75 °F), or 25 °C (77 °F) depending on the process, and maintained at 55% relative humidity. Beef samples were enumerated for Salmonella after inoculation, after dip treatment, after marination, and after 2, 4, 6, and 8 days of drying. Water activity was generally <0.85 by the end of 6–8 days of drying and weight loss was as high as 60%. Trials also examined salt concentration (1.7%, 2.2%, 2.7%) and marinade vinegar composition (2%, 3%, 4%) in the raw formulation. Nearly all approaches achieved 5-log10 reduction of Salmonella and was attributed to the manner of microbial enumeration eliminating the effects of microbial concentration on dried beef due to moisture loss. All trials were run as multiple replications and statistical analysis of treatments were determined by repeated measures analysis of variance (RM-ANOVA) to determine significant differences (p < 0.05). We believe this is the first published report of a biltong process achieving >5.0 log10 reduction of Salmonella which is a process validation requirement of USDA-FSIS for the sale of dried beef in the USA.


2004 ◽  
Vol 69 (3) ◽  
pp. 703-714 ◽  
Author(s):  
Milan Kožíšek ◽  
Jana Prejdová ◽  
Milan Souček ◽  
Ladislav Machala ◽  
Marie Staňková ◽  
...  

HIV protease (PR) specifically cleaves viral polyproteins to yield infectious progeny virus particles. Inactivation of PR leads to loss of virus infectivity and PR thus became an attractive pharmaceutic target. Indeed, seven protease inhibitors (PI) have been approved for clinical use to date. However, emerging resistant viral variants with reduced sensitivity to PIs become a major obstacle to successful control of viral replication. We have previously reported the design, testing and structural analysis of a pseudopeptide inhibitor, QF34, which efficiently inhibits a wide variety of PR variants. In a clinical study, we have monitored more than 100 HIV-positive patients in the Czech Republic undergoing highly active antiretroviral therapy including PI. In this paper we describe kinetic characterisation of two highly resistant PR species isolated from these patients. The mutated proteases accumulated as much as 14 amino acid exchanges and develop resistance to saquinavir, ritonavir, indinavir and nelfinavir with vitality value up to 150. Kinetic analyses revealed that second-generation PI lopinavir and QF34 retained their subnanomolar potency against both multidrug resistant PR variants. These results suggest a route to the design of PIs capable of inhibiting a variety of resistant PR mutants.


2016 ◽  
Vol 4 (5) ◽  
Author(s):  
Zhihui Yang ◽  
Jan Vinjé ◽  
Christopher A. Elkins ◽  
Michael Kulka

Homologous recombination is one of the driving forces contributing to the genetic variation of human norovirus, which is an important cause of sporadic and epidemic acute gastroenteritis globally. We report the near-complete genome of the novel recombinant norovirus strain GII.P7-GII.6, detected in an adult with norovirus gastroenteritis in the United States.


2017 ◽  
Vol 5 (15) ◽  
Author(s):  
Zhihui Yang ◽  
Jan Vinjé ◽  
Michael Kulka

ABSTRACT We report here the first near-complete genome sequence (7,551 nucleotides) of a human norovirus GII.Pe-GII.4 Sydney variant, detected in a stool sample from an outbreak on a cruise ship in 2013.


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