It is a public health imperative to have safe food and water across the population. Foodborne infections are one of the primary causes of sickness and mortality in both developed and developing ...countries. An estimated 100 million foodborne diseases and 120 000 foodborne illness-related fatalities occur each year in India. Several factors affect foodborne illness, such as improper farming methods, poor sanitary and hygienic conditions at all levels of the food supply chain, the lack of preventative measures in the food processing industry, the misuse of food additives, as well as improper storage and handling. In addition, chemical and microbiological combinations also play a key role in disease development. But recent disease outbreaks indicated that microbial pathogens played a major role in the development of foodborne diseases. Therefore, prompt, rapid, and accurate detection of high-risk food pathogens is extremely vital to warrant the safety of the food items. Conventional approaches for identifying foodborne pathogens are labor-intensive and cumbersome. As a result, a range of technologies for the rapid detection of foodborne bacterial pathogens have been developed. Presently, many methods are available for the instantaneous detection, identification, and monitoring of foodborne pathogens, such as nucleic acid-based methods, biosensor-based methods, and immunological-based methods. The goal of this review is to provide a complete evaluation of several existing and emerging strategies for detecting food-borne pathogens. Furthermore, this review outlines innovative methodologies and their uses in food testing, along with their existing limits and future possibilities in the detection of live pathogens in food.
Diagnostic techniques for viroids Gucek, T.; Trdan, S.; Jakse, J. ...
Plant pathology,
April 2017, 2017-04-00, 20170401, Letnik:
66, Številka:
3
Journal Article
Recenzirano
Odprti dostop
The fast growth of the human population forces us to produce more food, but higher crop production also leads to the fast spread of diseases. Plant pathology deploys a wide range of methods that do ...not provide an adequate solution to all disease losses. In the case of viroids, therapeutic means of control are not available; therefore control strategies are more focused on the development of reliable detection methods to quickly exclude the infected plant material. Although viroids are the smallest and simplest plant pathogens, their identification and detection is not straightforward. Each viroid–host combination is specific, and for reliable identification, all steps from sampling to final detection must be performed accurately. In this review, several methods for viroid detection in various host plants are discussed, including their advantages and disadvantages. Even though relatively new molecular methods enable fast and sensitive detection of viroids, a combination of different methods gives the most reliable identification. Techniques based on nucleic acids may be the future for viroid detection but they still cannot replace biological indexing, which is usually essential in epidemiological and aetiological studies.
Gelatin is a highly purified animal protein of pig, cow, and fish origins and is extensively used in food, pharmaceuticals, and personal care products. However, the acceptability of gelatin products ...greatly depends on the animal sources of the gelatin. Porcine and bovine gelatins have attractive features but limited acceptance because of religious prohibitions and potential zoonotic threats, whereas fish gelatin is welcomed in all religions and cultures. Thus, source authentication is a must for gelatin products but it is greatly challenging due to the breakdown of both protein and DNA biomarkers in processed gelatins. Therefore, several methods have been proposed for gelatin identification, but a comprehensive and systematic document that includes all of the techniques does not exist. This up-to-date review addresses this research gap and presents, in an accessible format, the major gelatin source authentication techniques, which are primarily nucleic acid and protein based. Instead of presenting these methods in paragraph form which needs much attention in reading, the major methods are schematically depicted, and their comparative features are tabulated. Future technologies are forecasted, and challenges are outlined. Overall, this review paper has the merit to serve as a reference guide for the production and application of gelatin in academia and industry and will act as a platform for the development of improved methods for gelatin authentication.
Background and Objectives An international collaborative study was undertaken to identify a replacement for the World Health Organization (WHO) 1st International Standard for human immunodeficiency ...virus 1 (HIV‐1) RNA for use in nucleic acid‐based techniques (NAT) (code 97/656). In the original study to establish the 1st International Standard, a second candidate material (code 97/650) had been shown to perform well and this was re‐evaluated to establish whether it would be a suitable replacement.
Materials and Methods Eight laboratories from six different countries participated in the collaborative study to evaluate the candidate replacement standard. A total of eight different NATs were used, five in a quantitative format and three qualitative, of which five were commercially available.
Results The results showed that the estimates of RNA copies in the current study were generally in line with those of the original study and there was no evidence of any drift in overall levels expressed in International Units (IU) for the candidate standard between the two studies. Furthermore, it was shown to be stable over long‐term storage at –20°C.
Conclusions The candidate material code 97/650 was established by the WHO as the 2nd International Standard for HIV‐1 RNA for use in NAT and assigned a unitage of 5·56 log10 (363 078) IU/vial.
Human cytomegalovirus (HCMV) is a significant cause of morbidity and mortality in immunocompromised patients. The present study was carried out to determine the frequency of occurrence of multiple ...genotypes of HCMV in immunocompromised patients, to determine if there is any discrepancy in identification of mixed infections by multiple genotypes in paired clinical specimens obtained from patients and to determine the significance of viral load differences between patients infected with single and multiple genotypes. One hundred clinical specimens from 75 patients were included in the study. Real-time PCR; Multiplex PCR and PCR-based RFLP were applied for the determination of viral load and genotyping of HCMV, respectively. Out of the 75 patients, 36 (48%) carried multiple genotypes. Discrepancy with regard to detection of genotypes were found in 17/25 patients whose paired clinical specimens were analyzed. Mixed genotypes were found more often in peripheral blood than urine or intraocular fluids collected from the same patient. There was a statistically significant difference between the median viral loads of clinical specimens carrying single genotypes and multiple genotypes. Mixed infections with multiple genotypes were found predominantly in the leukocyte fraction of peripheral blood specimens. The detection of mixed infections by multiple genotypes in the hypervariable regions of HCMV can be a surrogate marker of an increase in viral load. J. Med. Virol. 81:861-869, 2009.
Twenty-six laboratories from 10 different countries participated in a collaborative study to establish the 1st International Standard for HIV-1 RNA for use in nucleic acid-based techniques (NAT). ...Three candidate preparations were tested all based on genotype B viruses. The candidates were tested by each laboratory at a range of dilutions in four independent assays and the results collated and analysed statistically. All three candidates gave results that were tightly grouped, with little difference between the results from different laboratories or from the use of different assays. Studies of relative potency showed good agreement between laboratories. There were no significant differences between five commercial assay types, except that candidate
XX showed a slightly lower potency compared to
YY and
ZZ with a single commercial assay. The reason for this was not established. Degradation studies showed that the freeze-dried preparations were stable at −20,
4 and 20°C for 26 weeks, the longest period studied, but that they became difficult to reconstitute after 3 weeks at 45°C and 9 weeks at 37°C. As a result of the study, the World Health Organisation (WHO) Expert Committee on Biological Standardisation (ECBS) established the preparation referred to as candidate
YY (NIBSC Code No. 97/656) as the 1st International Standard for HIV-1 RNA for use with NAT with an assigned potency of 100 000 International Units per vial.
La sepsis es una de las principales causas de mortalidad y morbilidad en los hospitales. La detección temprana de los patógenos mediante técnicas basadas en ácidos nucleicos puede facilitar el ...diagnóstico rápido de la bacteriemia y/o fungemia, la rápida adecuación del tratamiento antibiótico, reducir el uso de antibióticos innecesarios y disminuir la mortalidad. Se describen 2 técnicas disponibles comercialmente que ayudan, en un tiempo reducido, a identificar distintas bacterias y hongos productores de sepsis: LightCycler® SeptiFast Test Mgrade (Roche Diagnostic SL) y GenoType Blood Culture (Hain Lifescience). De estas 2 técnicas, mostramos los resultados de un estudio inicial propio con el LightCycler® SeptiFast Test Mgrade. El estudio se realizó con 50 muestras correspondientes a 28 pacientes (1-3 muestras por paciente) con síndrome séptico ingresados en la unidad de cuidados intensivos, comparando la nueva técnica con el hemocultivo convencional. La concordancia entre los resultados del hemocultivo y el SeptiFast fue buena, 79% en el primer ensayo, y 89% en el segundo, después de corregir defectos técnicos. Inicialmente se observó inhibición importante de los controles internos para los bacilos gramnegativos, por la presencia de heparina en la sangre empleada y un exceso de ácido desoxirribonucleico (ADN) debido al número de leucocitos. Con la finalidad de disminuir las inhibiciones, en otro estudio posterior se trabajó con 24 muestras a la mitad de volumen original, llevando el ácido nucleico extraído a dilución 1:4. Con estas modificaciones, se apreciaron reducciones importantes de las inhibiciones. En comparación con el hemocultivo, el SeptiFast diferencia mejor las contaminaciones por estafilococos coagulasa-negativa y especies de estreptococos.
Food fingerprinting approaches are expected to become a very potent tool in authentication processes aiming at a comprehensive characterization of complex food matrices. In this chapter, we provide a ...critical view on emerging molecular fingerprinting techniques, including elemental, foodomics, and microbial fingerprints. Among these, molecular biology approaches focusing on DNA‐based techniques are increasingly being evaluated for use in fingerprinting studies. Recent developments in DNA sequencing, particularly with respect to technical advances in the field of next generation sequencing, should greatly facilitate food authentication and enhance food authenticity in the future.
Conclusions Pollok, Sibyll; Weber, Karina; Bauer, Michael ...
Modern Techniques for Pathogen Detection,
05/2015
Book Chapter
This concluding chapter presents an overview of concepts covered in the preceding chapters of this book Modern Techniques for Pathogen Detection. The book integrates current expert knowledge and ...future trends of pathogen detection, and therefore represents an indispensable tool for the community working on this interdisciplinary topic. It focuses on demonstrating the unique application potential of modern identification techniques for pathogen diagnostics. The illustrated methodologies in pathogen detection vary from common culture‐based identification to molecular‐biological methods and spectroscopic techniques. Nucleic acid‐based techniques, microarrays, mass spectrometry, fluorescence in situ hybridization (FISH) and IR/Raman spectroscopy were discussed to cope with sensitivity or specificity problems and to speed up diagnosis and subsequent therapeutic decisions. A successful example for the transfer of such a method from research to clinical routine diagnostics is represented by polymerase chain reaction (PCR)‐based techniques.
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