Identification of porcine reproductive and respiratory syndrome virus inhibitors through an oriented screening on natural products.

Porcine reproductive and respiratory syndrome(PRRS) caused by porcine reproductive and respiratory syndrome virus(PRRSV) is one of the most infectious diseases in the swine industry worldwide, causing big economic losses. Vaccines are major weapons against PRRSV, however, current available vaccines have several limitations. Developing chemical drugs as alternatives is required. On the basis of traditional medical knowledge, we purposely selected 15 natural products originated from Chinese herbs with anti-infectious effects. Their antiviral activities were evaluated by PRRSV-induced cytopathic effect(CPE) on MARC-145 cells and reverse transcription polymerase chain reaction(RT-PCR) assay. Compounds ethoxysanguinarine(EOSG) and atractylodinol were found to be the hits which could significantly reduce PRRSV-associated CPE with 50% inhibited concentration(IC50) values of 7.9 and 39.4 µmol/L, respectively. Meanwhile, compounds ethoxysanguinarine and atractylodinol significantly decreased mRNA expression of ORF7 gene in a dose-dependent manner. Study results suggest that compounds ethoxysanguinarine and atractylodinol may be useful anti-PRRSV drugs for swine industry or the hits for further lead optimization.

Prevalence and Genotyping of Toxoplasma gondii in Cats, Rats, and Chickens in Border Areas of Yunnan Province, China.

The objective of the present study was to determine the characterization of Toxoplasma gondii in cats, rats, and chickens in the border areas of Yunnan Province. A total of 259 samples was collected from 10 border areas in Yunnan Province including 94 cats, 58 rats, and 107 chickens. Samples were screened by a nested polymerase chain reaction (PCR) assay and the positive products were analyzed by multilocus PCR-restriction fragment length polymorphism (RFLP) to determine the genotypes. Toxoplasma gondii deoxyribonucleic acid (DNA) was detected from 15.96% of 94 cats, 15.52% of 58 rats, and 6.54% of 107 chickens, respectively, and the average infection rate is 11.97%. Using the multilocus PCR-RFLP, we found that the genotype of T. gondii in cats and rats was ToxoDB#9. Because of low DNA concentration, no genotype was determined from chickens. These results fill the gaps of knowledge in the prevalence and genotype of T. gondii in the border areas of Yunnan Province and have implications for the better control of T. gondii infection in humans and animals.

First report of Toxoplasma gondii seroprevalence in peafowls in Yunnan Province, Southwestern China.

BACKGROUND: Toxoplasma gondii is an intracellular protozoan parasite infecting almost all warm-blooded animals, including birds, with a worldwide distribution. Surveys of T. gondii infection in wild birds have been reported extensively in the world, but little is known of T. gondii infection in peafowls worldwide. This study was performed to determine the seroprevalence of T. gondii infection in peafowls in Yunnan Province, southwestern China. METHODS: Sera from 277 peafowls, including 272 blue peafowls (Pavo cristatus) and 5 green peafowls (Pavo muticus) originated from two geographic areas in Yunnan Province were assayed for T. gondii antibodies using the modified agglutination test (MAT). RESULTS: Specific T. gondii antibodies were detected in 35 of 277 (12.64%) peafowls (MAT titer ≥ 1:5). Seropositive birds were found in both species, 33 in 272 blue peafowls and 2 in 5 green peafowls. There was no significant difference in T. gondii seroprevalence between the adolescent birds (6.74%) and the adult birds (6.67%) (P > 0.05). The geographical origins of peafowls was found to be highly associated with T. gondii infection in the present study, a statistically significant difference in T. gondii seropositivity was observed between peafowls from Kunming (31.08%) and those from Xishuangbanna Dai Autonomous Prefecture (5.91%) (OR = 10.956, 95% CI = 1.632-73.545, P = 0.014). Statistical analyses showed that there were no significant interactions between ages and geographical origins of peafowls (P > 0.05). CONCLUSIONS: The results of the present survey indicated that infection of peafowls with T. gondii is widespread in Yunnan Province, which has significant public health concerns and implications for prevention and control of toxoplamosis in this province. To our knowledge, this is the first seroprevalence report of T. gondii infection in China's southwestern Yunnan Province.