Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0033036 (APC)
 10,214 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Reticuloendotheliosis virus (REV) fragments are a common contaminant in some commercial vaccines such as fowl poxvirus (FPV) and Marek's disease virus. However, only those strains integrating or containing a near-intact REV provirus are more likely to cause problems in the field. We confirm here, by PCR assays and animal experiments, that vaccines against FPV and herpes virus of turkeys were contaminated with full genome sequences of REV. Further, we determined the complete proviral sequence of two REV isolates from contaminated vaccines. Two REV isolates (REV-99 and REV-06) present in the vaccines were both replication competent, and their proviral genome was 8286 nucleotides in length with two identical long terminal repeats (LTR). The complete genome in these two REV isolates shared 99.8% identity to APC-566 and fowl poxvirus REV proviral inserts (FPV-REV). REV-99 and REV-06 LTR showed over 99% identity to chicken syncytial virus (CSV), but an identity of only 75.8% and 78.0%, respectively, to SNV. Alignments with other available REV gag, pol, and env sequences revealed high similarity at the nucleotide level. The results further indicated that the prototype CSV may be the most-important REV contaminant in the commercial vaccines, and distinct genotypes of REVs may cocirculate in chicken flocks of China at the present time.
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PMID:Full genome sequences of two reticuloendotheliosis viruses contaminating commercial vaccines. 1984 70

According to the requirements of the Ministry of Agriculture of China, all vaccines must be screened for exogenous virus contamination before commercialization. A freeze-dried vaccine against Marek's disease was used to inoculate specific pathogen-free chickens, from which serum samples were collected after 42 days. The results were positive for reticuloendotheliosis virus antibody, which was indicative of reticuloendotheliosis virus contamination. After neutralization with serum positive for Marek's disease virus, chicken embryo fibroblasts were inoculated with the vaccine. Afterward, viral isolation and identification were performed. One reticuloendotheliosis virus strain (MD-2) was isolated and verified using an immunofluorescence assay. Polymerase chain reaction amplification of the provirus MD-2 genome was performed using seven overlapping fragments as primers. The amplified products were sequenced and spliced to obtain the whole MD-2 genome sequence. The full genome length of MD-2 was 8,284 bp, which had an identity greater than 99% with the prairie chicken isolate APC-566 from the US, the goose-derived isolate 3410/06 from Taiwan, and the chicken-derived reticuloendotheliosis virus isolate HLJR0901 from Heilongjiang Province, China. The MD-2 was phylogenetically close to these isolates. The identity with REV isolate HA9901 from Jiangsu Province of China was 96.7%. The MD-2 had the lowest identity with duck-derived Sin Nombre virus from the United States, with the value of only 93.5%. The main difference lay in the U3 region of the long terminal repeat. The present research indicated that some vaccines produced during specific periods in China might be contaminated by reticuloendotheliosis virus. The reticuloendotheliosis virus strain isolated from the vaccine was phylogenetically close to the prevalent strain, with only minor variations.
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PMID:Isolation, identification, and whole genome sequencing of reticuloendotheliosis virus from a vaccine against Marek's disease. 2572 74