RESUMEN
Toxoplasma gondii infections are common in humans and animals worldwide. Ingestion of raw or undercooked meat containing tissue cysts of T. gondii is one major source of transmission of this parasite. It is important to guarantee the meat quality of China since our pork industry produces about half of the world's pork. In this study, a total of 746 pig samples were collected from Zhejiang and Jiangsu provinces in eastern China, and examined for T. gondii infection by PCR amplification targeting B1 gene. In this study, we found that 57 of 746 (7.6%) pigs were positive for B1 gene, with 8.5% (48/562) in Zhejiang province and 4.9% (9/184) in Jiangsu province, respectively. The positive DNA samples were further genotyped at 11 genetic markers, including SAG1, 5'-and 3'-SAG2, alternative SAG2, SAG3, BTUB, GRA6, L358, PK1, c22-8, c29-2, and an apicoplast locus Apico through PCR-restriction fragment length polymorphism (PCR-RFLP) technology. Two genotypes (ToxoDB 9 and ToxoDB 10) of T. gondii were identified by PCR-RFLP in Zhejiang province. However, both genotypes were not determined from Jiangsu province, which is speculated on the low DNA concentration and the small number of samples. These results indicate that T. gondii infection is endemic in pigs in eastern China and may raise public food safety concerns, suggesting more interventions for T. gondii-related risks are needed in the future.
Asunto(s)
Toxoplasma , Toxoplasmosis Animal , Humanos , Porcinos , Animales , Toxoplasma/genética , Toxoplasmosis Animal/epidemiología , Toxoplasmosis Animal/parasitología , Genotipo , Marcadores Genéticos , Polimorfismo de Longitud del Fragmento de RestricciónRESUMEN
In the early 1970s, the Chinese Equine Infectious Anemia Virus (EIAV) vaccine, EIAV(DLA), was developed through successive passages of a wild-type virulent virus (EIAV(L)) in donkeys in vivo and then in donkey macrophages in vitro. EIAV attenuation and cell tropism adaptation are associated with changes in both envelope and long terminal repeat (LTR). However, specific LTR changes during Chinese EIAV attenuation have not been demonstrated. In this study, we compared LTR sequences from both virulent and attenuated EIAV strains and documented the diversities of LTR sequence from in vivo and in vitro infections. We found that EIAV LTRs of virulent strains were homologous, while EIAV vaccine have variable LTRs. Interestingly, experimental inoculation of EIAV(DLA) into a horse resulted in a restriction of the LTR variation. Furthermore, LTRs from EIAV(DLA) showed higher Tat transactivated activity than LTRs from virulent strains. By using chimeric clones of wild-type LTR and vaccine LTR, the main difference of activity was mapped to the changes of R region, rather than U3 region.
Asunto(s)
Variación Genética , Caballos/virología , Virus de la Anemia Infecciosa Equina/patogenicidad , Macrófagos/virología , Monocitos/virología , Regiones Promotoras Genéticas , Secuencias Repetidas Terminales/genética , Animales , Secuencia de Bases , Células Cultivadas , Equidae , Anemia Infecciosa Equina/fisiopatología , Anemia Infecciosa Equina/virología , Regulación Viral de la Expresión Génica , Genes tat , Enfermedades de los Caballos/fisiopatología , Enfermedades de los Caballos/virología , Virus de la Anemia Infecciosa Equina/genética , Virus de la Anemia Infecciosa Equina/metabolismo , Datos de Secuencia Molecular , Filogenia , Análisis de Secuencia de ADN , Secuencias Repetidas Terminales/fisiología , Activación Transcripcional , Vacunas ViralesRESUMEN
OBJECTIVE: To discuss the reliability of SARS-CoV antibody detection for SARS diagnosis. METHODS: Using SARS-CoV ELISA kit to detect relevant antibody in fresh serum of healthy, fever, probable, and suspect cases. RESULTS: The positive rate is 0%, 40%, and 95% respectively in healthy, probable, and suspect cases. CONCLUSIONS: It is reliable to detect SARS-CoV antibody in late suspect patients, but there will be high false-positive result in ordinary fever cases.
