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The aim of the study was to use real time RT-PCR for the detection of genetic material of bovine viral diarrhea virus (BVDV) type 1 and type 3 in serum and milk samples. Material tested included the fetal calf serum used for cell culture, serum samples from healthy calves and from calves experimentally inoculated with BVDV type 1 and type 3, and milk samples (pasteurized and treated with ultra high temperature). Sensitivity of the test was 200 copies of RNA per reaction (10⁵ viral RNA copies per ml) for both types of BVDV, using dedicated primers and standards. Detection limit was 10² tissue culture infectious dose 50 (TCID₅₀) and 1 TCID₅₀ for type 1 and type 3, respectively. Diagnostic specificity of the method was 100%. Out of 10 samples of milk, 3 were positive for BVDV type 1, while none was positive for type 3. On the other hand, BVDV type 3 was found in 6 out of 10 samples of fetal calf serum. Real Time RT-PCR for BVDV type 1 and type 3 proved to be a highly sensitive and highly specific technique, enabling the detection of viral genetic material in various samples, even when its detection by virus isolation or antigen ELISA tests is impossible because of virus inactivation by such processes as high temperature, gamma irradiation, or the presence of virus neutralizing antibodies.
Foot-and-mouth disease (FMD) is the most contagious disease of mammals and has great potential for causing severe economic losses in susceptible cloven-hoofed animals. FMD is caused by a virus of the genus Aphthovirus, family Picornaviridae. Serological tests in laboratories have identified seven different serotypes as O, A, C, SAT 1, SAT 2, SAT 3 and Asia 1. FMD is diagnosed by the virus isolation or demonstration of FMD viral antigen or nucleic acid in samples of biological specimens. The purpose of the study was to apply the isolation test in cell culture and a RT-PCR assay for the detection of foot-and-mouth disease virus in biological materials. Out of the total of 14 examined samples, 6 (42.8%) were found positive using these methods. The antigen ELISA was used for the confirmation of specificity of the isolation assay. Primary bovine thyroid cells were found the most sensitive cell culture system for the detection of foot-and-mouth disease virus, followed by secondary lamb kidney and certain IB-RS-2 cells.
Foot-and-mouth disease virus (FMDV) from the family Picornaviridae, genus Aphthovirus, exists in the form of seven different serotypes: O, A, C, Asia 1 and SAT 1-3. Infection with one serotype does not confer immunity against another. Foot-and-mouth disease is one of the greatest threats to animal health in European countries. The rapid and accurate detection of FMDV is of the utmost importance. The RT-PCR assay was used to detect the presence of FMDV in samples. Positive results of the RT-PCR assay were found in all samples and in the positive control, the negative control reacted negatively. No cytopathic effects in primary bovine thyroid cells were observed in 2 samples that had been thawed several times. The reference strains of FMDV was used to determine the sensitivity of the test. The sensitivity of RT-PCR for detection of FMDV (serotype O, A) was 1 TCID₅₀ and 10 TCID₅₀ (serotype C, Asia 1) by gel electrophoresis.
Genetically modified organisms are increasingly used in the production of feed and food, which has met with opposition from consumers. The aim of the study was the use of molecular biology methods with particular emphasis on techniques of real-time PCR in the research in the detection and identification of genetically modified feed. The research materials were samples of feed taken from feed produced and used in animal nutrition in Poland in the years 2004-2015. The applied research methods included PCR and real-time PCR techniques, and consisted in the detection and determination of the DNA content of genetically modified plants. Cascade methods used in this study included the screening method of detection of GMOs, the method of identifying the type of GMO, and methods of quantitative analysis of GMO content. As part of the research task in the years 2004-2015 a total of 1435 samples of feed towards GMOs were examined. A positive result was found in 559 cases (39%). Most frequently the positive samples were found the presence of genetically modified soybeans (531, 37%). Moreover, within the years 2014-2015 an increase in the number of positive GM rape samples was observed (56, 4%). GM maize contained the least positive samples (38, 2.6%). GMO content above the legislative threshold 0.9% was found in the vast majority of samples containing GM soy, while for maize and rapeseed the number of samples containing more than 0.9% GMO was respectively 12 and 8. Analysis of the feed market in Poland indicates that the soybean plant is the most common genetically modified crop. Analysis of the origin of sources of GM rapeseed showed that the reasons for this should be sought in batches of rapeseed imported from third countries. It has been observed with regard to the situation of GM maize for the feed market in Poland that from 2013 the situation changed radically as a result of the Decree of the Ministry of Agriculture issued prohibiting the cultivation of MON810 maize on Polish fields. The result of our study showed that the proportion of genetically modified feed on the feed market in Poland is very similar to other EU countries. The source of GMOs in feed on the Polish market is feed materials imported into Poland as a source of feed protein.
European Union law enforces labeling of products containing above 0.9% of GMO. The aim of this study was detection and quantification of genetically modified rape in feedingstuffs. Both the qualitative and quantitative analysis was based on Real Time PCR method. Amongst 432 examined samples of feed, 56 contained GM rape line GT73. Only in 8 of them did the content of GM rape exceed 0.9%. The source of GT73 rape contamination was rapeseed meal imported to Poland from the eastern countries, mainly Ukraine, which was confirmed in shipping documents attached to the samples. The efficient monitoring of GMO, especially for rape, is very important, because of the high possibility of contamination of traditional crops with GM varieties.
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