scholarly journals Virus detection methods for different kinds of food and water samples – The importance of molecular techniques

Food Control ◽  
2021 ◽  
pp. 108764
Author(s):  
Hrdy Jakub ◽  
Vasickova Petra
2005 ◽  
Vol 71 (8) ◽  
pp. 4446-4454 ◽  
Author(s):  
Jianlin Jiang ◽  
Kerri A. Alderisio ◽  
Lihua Xiao

ABSTRACT To assess the source and public health significance of Cryptosporidium oocyst contamination in storm runoff, a PCR-restriction fragment length polymorphism technique based on the small-subunit rRNA gene was used in the analysis of 94 storm water samples collected from the Malcolm Brook and N5 stream basins in New York over a 3-year period. The distribution of Cryptosporidium in this study was compared with the data obtained from 27 storm water samples from the Ashokan Brook in a previous study. These three watersheds represented different levels of human activity. Among the total of 121 samples analyzed from the three watersheds, 107 were PCR positive, 101 of which (94.4%) were linked to animal sources. In addition, C. hominis (W14) was detected in six samples collected from the Malcolm Brook over a 2-week period. Altogether, 22 Cryptosporidium species or genotypes were found in storm water samples from these three watersheds, only 11 of which could be attributed to known species/groups of animals. Several Cryptosporidium spp. were commonly found in these three watersheds, including the W1 genotype from an unknown animal source, the W4 genotype from deer, and the W7 genotype from muskrats. Some genotypes were found only in a particular watershed. Aliquots of 113 samples were also analyzed by the Environmental Protection Agency (EPA) Method 1623; 63 samples (55.7%) were positive for Cryptosporidium by microscopy, and 39 (78%) of the 50 microscopy-negative samples were positive by PCR. Results of this study demonstrate that molecular techniques can complement traditional detection methods by providing information on the source of contamination and the human-infective potential of Cryptosporidium oocysts found in water.


2021 ◽  
Vol 9 (7) ◽  
pp. 1519
Author(s):  
Sonia R. Isaacs ◽  
Dylan B. Foskett ◽  
Anna J. Maxwell ◽  
Emily J. Ward ◽  
Clare L. Faulkner ◽  
...  

For over a century, viruses have left a long trail of evidence implicating them as frequent suspects in the development of type 1 diabetes. Through vigorous interrogation of viral infections in individuals with islet autoimmunity and type 1 diabetes using serological and molecular virus detection methods, as well as mechanistic studies of virus-infected human pancreatic β-cells, the prime suspects have been narrowed down to predominantly human enteroviruses. Here, we provide a comprehensive overview of evidence supporting the hypothesised role of enteroviruses in the development of islet autoimmunity and type 1 diabetes. We also discuss concerns over the historical focus and investigation bias toward enteroviruses and summarise current unbiased efforts aimed at characterising the complete population of viruses (the “virome”) contributing early in life to the development of islet autoimmunity and type 1 diabetes. Finally, we review the range of vaccine and antiviral drug candidates currently being evaluated in clinical trials for the prevention and potential treatment of type 1 diabetes.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Claudia Kohl ◽  
Annika Brinkmann ◽  
Aleksandar Radonić ◽  
Piotr Wojtek Dabrowski ◽  
Kristin Mühldorfer ◽  
...  

AbstractBats are known to be reservoirs of several highly pathogenic viruses. Hence, the interest in bat virus discovery has been increasing rapidly over the last decade. So far, most studies have focused on a single type of virus detection method, either PCR, virus isolation or virome sequencing. Here we present a comprehensive approach in virus discovery, using all three discovery methods on samples from the same bats. By family-specific PCR screening we found sequences of paramyxoviruses, adenoviruses, herpesviruses and one coronavirus. By cell culture we isolated a novel bat adenovirus and bat orthoreovirus. Virome sequencing revealed viral sequences of ten different virus families and orders: three bat nairoviruses, three phenuiviruses, one orbivirus, one rotavirus, one orthoreovirus, one mononegavirus, five parvoviruses, seven picornaviruses, three retroviruses, one totivirus and two thymoviruses were discovered. Of all viruses identified by family-specific PCR in the original samples, none was found by metagenomic sequencing. Vice versa, none of the viruses found by the metagenomic virome approach was detected by family-specific PCRs targeting the same family. The discrepancy of detected viruses by different detection approaches suggests that a combined approach using different detection methods is necessary for virus discovery studies.


2019 ◽  
Vol 263 ◽  
pp. 60-67 ◽  
Author(s):  
Vu Duc Canh ◽  
Hideki Osawa ◽  
Kentaro Inoue ◽  
Ikuro Kasuga ◽  
Satoshi Takizawa ◽  
...  

2021 ◽  
Author(s):  
Siyuan Wang ◽  
Xihong Yue ◽  
Alai Shalitanati ◽  
Abulimiti Moming ◽  
Shu Shen ◽  
...  

Abstract Guertu virus (GTV), a novel tick-borne virus with potential pathogenicity, was first isolated from Dermacentor nuttalli in Xinjiang, China, in 2014. GTV has been shown to infect animal and human cell lines and to be pathogenic in mice. The viral nucleoprotein (NP) is the most conserved immunogenic protein. Elucidating the B-cell epitopes (BCEs) in the immunodominant region of the NP is important for the development of virus detection methods and vaccines. In order to identify the minimal motifs of linear BCEs in the NP of the GTV DXM strain, we used an improved biosynthetic peptide (BSP) method to truncate GTV NP into 30 16mer-peptides with 8 overlapping amino acid residues spanning the full length of the protein. The peptides were analyzed by western blot using rabbit anti-GTV NP polyclonal antiserum, and four positive 16mer-peptides were obtained. The 16mer-peptides were then truncated into 31 8mer-peptides with 7 overlapping amino acid residues and 10mer-peptides with 9 overlapping amino acid residues to screen for BCEs that can react with the rabbit anti-GTV NP polyclonal antiserum. The results showed that there were 6 minimal BCE motifs, namely, Enp1, 88EKYGLVER95; Enp2, 88EKYGLVER95; Enp3, 162TTKILMEA169; Enp4, 187GASKAEVY194; Enp5, 191AEVYNSFR198; and Enp6, 236ETAAAAYRNL245. Positive sheep sera could recognize all six BCEs with anti-GTV antibodies. The BCEs were aligned with the sequences of eight representative severe fever with thrombocytopenia syndrome phlebovirus strains from different countries and regions that were evolutionarily closely related to GTV. The sequence identity of the BCEs ranged from 80–100%, thus showing high conservation. The fine epitope mapping of GTV NP can be used to explore the biological and immunological properties of GTV NP antigens and serve as basic data for the development of multi-epitope detection reagents and vaccine design for GTV.


Nutrients ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1784 ◽  
Author(s):  
Lígia Isoni Auad ◽  
Verônica Cortez Ginani ◽  
Elke Stedefeldt ◽  
Eduardo Yoshio Nakano ◽  
Aline Costa Santos Nunes ◽  
...  

This study aimed to (i) compare the food safety knowledge, attitudes, and self-reported practices (KAP) and observed food safety practices of food truck (FT) food handlers, (ii) evaluate the microbiological quality of food and water samples collected from these vehicles, and (iii) establish a score classification for the KAP instrument according to the food contamination probability assessment. This study was conducted in three stages with 40 food truck food handlers conveniently sampled in the Federal District, Brazil, through structured interviews, application of an observational checklist for the assessment of handlers’ practices and the collection of food and water samples for determination of microbiological quality. FTs that are likely to exhibit food contamination and are at a high risk of foodborne diseases if at least one of the following situations occur: (1) if a food handler scores ≤6 in the knowledge section; (2) if a food handler scores ≤5 in the attitudes section; or (3) if a food handler scores ≤6 in the self-reported practices section. On the other hand, FTs in which handlers score higher than the cutoff points in all the sections are unlikely to exhibit food contamination and are at a low risk of foodborne diseases. The findings of this study are the first step to understand food handlers’ point of view and the initial diagnosis to guide educational strategies in the FT sector.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Louise von Gersdorff Jørgensen ◽  
Johan Wedel Nielsen ◽  
Mikkel Kehler Villadsen ◽  
Bent Vismann ◽  
Sussie Dalvin ◽  
...  

Abstract Surveillance and diagnosis of parasitic Bonamia ostreae infections in flat oysters (Ostrea edulis) are prerequisites for protection and management of wild populations. In addition, reliable and non-lethal detection methods are required for selection of healthy brood oysters in aquaculture productions. Here we present a non-lethal diagnostic technique based on environmental DNA (eDNA) from water samples and demonstrate applications in laboratory trials. Forty oysters originating from Limfjorden, Denmark were kept in 30 ppt sea water in individual tanks. Water was sampled 6 days later, after which all oysters were euthanized and examined for infection, applying PCR. Four oysters (10%) were found to be infected with B. ostreae in gill and mantle tissue. eDNA purified from the water surrounding these oysters contained parasite DNA. A subsequent sampling from the field encompassed 20 oysters and 15 water samples from 5 different locations. Only one oyster turned out positive and all water samples proved negative for B. ostreae eDNA. With this new method B. ostreae may be detected by only sampling water from the environment of isolated oysters or isolated oyster populations. This non-lethal diagnostic eDNA method could have potential for future surveys and oyster breeding programs aiming at producing disease-free oysters.


BIOPHYSICS ◽  
2019 ◽  
Vol 64 (6) ◽  
pp. 890-897 ◽  
Author(s):  
O. I. Guliy ◽  
B. D. Zaitsev ◽  
O. S. Larionova ◽  
I. A. Borodina

Plant Disease ◽  
2013 ◽  
Vol 97 (8) ◽  
pp. 1082-1090 ◽  
Author(s):  
B. Gehesquière ◽  
S. D'Haeyer ◽  
K. T. K. Pham ◽  
A. J. Van Kuik ◽  
M. Maes ◽  
...  

Cylindrocladium buxicola (syn. C. pseudonaviculatum; teleomorph Calonectria pseudonaviculata) is an important fungal pathogen of Buxus spp. Although widespread in Western Europe, this pathogen has only recently been introduced into North America, where it represents a significant threat to the U.S. and Canadian boxwood industries. Trade of latently infected nursery stock is an important mode of long-distance dissemination and introduction of this pathogen but no methods for detection of latently infected material are available. Also, the pathways for short-distance dispersal of C. buxicola have not been adequately studied. Improved detection methods of this pathogen in air and water samples would benefit future research in this area. We have developed real-time polymerase chain reaction assays for the detection of C. buxicola based on the ribosomal DNA internal transcribed spacer 1 (ITS) and the β-tubulin 2 gene (TUB). Using a TaqMan probe conjugated with a 3′ minor groove binding group (TaqMan MGB probe), the ITS-based assay could reliably detect as little as 10 fg of genomic DNA or 20 copies of cloned target DNA and was approximately 70 times more sensitive than the SYBR Green TUB-based assay. The ITS-based assay provided good but not complete specificity, and is well suited for epidemiological studies. The TUB-based assay, however, proved to be fully specific and can be used for diagnostics. We developed and optimized sample processing and DNA extraction methods for detection of latently present C. buxicola in boxwood plants and quantification of conidia in water and air samples. C. buxicola could be detected in 20 g of plant material, of which only 1 ppm of the tissue was infected, in 10-ml water samples containing as low as 1 conidium/ml, and on Melinex tape pieces representing 12 h of air sampling containing 10 or more conidia. The applicability of the techniques to plant, water, and air samples of practical size was demonstrated.


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