Investigation On The Infections Of Toxoplasma Gondii Of Aquatic Animals In Parts Of China

Toxoplasmosis is one of the more common parasitic zoonoses worldwide. Most persons with toxoplasmosis are asymptomatic, but if a woman is infected during pregnancy, the parasite can cross the placenta and cause congenital toxoplasmosis in the fetus. The severity of congenital toxoplasmosis depends on when in the pregnancy the mother is exposed, but it can cause ocular and central nervous system disease as well as lead to growth failure and hearing and vision abnormalities.At the beginning of this stduty the genetic variation between Toxoplasma gondii RH strain and CN strain were analyzed and then to establish the foundation for further studies on molecular and diagnostics of T.gomdii. The internal transcribed apacer1(ITS-1) from RH strain and CN strain were amplified by means of PCR, and then cloned and sequenced. The results showed that ITS-1sequence of RH strain and CN strain are identical, which were consistent with the sequence of the RH strain registered in GenBank. The results indicated that ITS-1sequence provide useful genetic markers for the identification and differentiation of T.gondii from other relates protozoa, but the sequence are not suitable marker for the genetic variation within T.gondii. For the ends of analysis of freshwater and marine fishery production in southeast China for T.gondii, one specific and sensitive PCR mothod was developed targeting the multicopy internal transcribed spacer1(ITS-1). Tachyzoites DNA of T.gondii was diluted and amplified by means of PCR in the sensitivity assay. In order detect its specificity gDNA extracted from Oyster, Chicken, Fish, E.coli, E.tenela and Hypodermal and Hematopoietic Necrosis Baculovirus (HHNBV) was used as control group and amplificated under the same condition with gDNA which was used as experiment group. The results shows that this PCR assay eatablished a detection limit of500fg. And this PCR assay successfully amplified a single band of the expected size (341bp) from T.gondii DNA. No amplication was generated from the control group.To evaluate if Toxoplasma gondii are present in freshwater and marine fishery product in southeast China under natural conditions by using PCR method,408Crassostrea gigase,426Penaeus monodon,618Procambarus clarkii,309Carassius auratus collected,98Monopterus albus, were collected from the different area in southeast China. Only4Procambarus clarkii samples from Nanchang city were assesses as positive for T.gondii DNA. The results suggest that Procambarus clarkii can filter and retain T.gondii oocysts from freshwater environment, indicate that there may be a considerable health threat involved in eating contaminated raw Procambarus clarkii。...