Rota Ten Ve Ter [UPDATED]
Group A rotaviruses can be further classified into P or G types based on genetic and antigenic similarities of VP4 (protease sensitive protein) and VP7 (glycoprotein) which constitute the outer capsid of the virion and induce anti-viral neutralizing antibody production [25]. Sixteen G types and 27 P types have been reported in domestic animals [25]. Bovine rotaviruses are G1, G6, G8, or G10 types [49,82]. G6 and G10 type are reported to be the most prevalent in cattle [82].
Rota Ten Ve Ter
Bovine rotavirus usually causes diarrhea in calves at 1 to 2 weeks of age. The milk uptaken by calves can provide a good environment for rotavirus survival under a wide range of gastrointestinal pH levels and infection of the intestinal epithelial cells [26]. This may explain why weaning calves are more susceptible to calf diarrhea. The virus has a very short incubation period (1224 h) [129] and induces peracute diarrhea in affected calves. Once infected, the calves shed a large amount of virus via feces for 57 days, thus contaminating the environment and allowing the virus to be transmitted to pen mates. The virus replicates in the cytoplasm of epithelial cells of small intestinal villi. Destruction of mature enterocytes in the villi, activation of the enteric nervous system by vasoactive components from the damaged cells, and secretion of a viral enterotoxin (e.g., NSP4) account for maldigestive/malabsorptive diarrhea promoted by rotavirus infection. Viral infection causes villus atrophy and usually affects the caudal part of the small intestine. Evidence for interspecies transmission along with genetic reassortment between human and animal rotaviruses (e.g., swine, bovine, feline, and canine) has raised concerns about zoonotic rotaviruses [81].
PCR testing is especially useful for detecting viruses that are difficult to isolate in cell culture or bacteria that require a long time to grow [31]. There are numerous commercial PCR reagents available which provide convenience, high sensitivity, and rapid results. PCR testing requires trained and experienced technicians. Inadvertent contamination during sampling in the field or processing at the laboratory can be a source of false positive results due to its high sensitivity. Viruses with a high mutation rate, often RNA viruses (e.g., rotavirus and calicivirus), need to be continuously monitored for sequence changes in the target gene otherwise negative results will be obtained due to primer incompatibility. Fecal samples are known to contain factors that inhibit PCR and can lead to false negative results if appropriate reagents or steps to remove such inhibitory substances are not included in the test procedures. 041b061a72