Viral Tissue Distribution And Histopathology Of Pregnant Sows And Their Fetuses Infected With Porcine Parvovirus

Porcine parvovirus disease is caused by porcine parvovirus (PPV). It can cause reproductive failure in pregnant sows characterized by embryonic and foetal death. In present PPV is a common etiological agent which interfere the development of pig industry. PPV-BQ strain was isolated successfully, the homology comparison between PPV-BQ strain and Kresse strain were 99.4%, The PPV-BQ strain VP2 gene sequence was the same to Kresse strain. In this study, pregnant sows were infected artificially with PPV-BQ strain, four Duroc breed pregnant sows (first pregnancy) were chosen. two artificially challenged sows and two control sows were housed in individual isolation rooms. The two sows were inoculated with the 10mL PPV viruses by both the intranasal and intramuscular route at day 35 of gestation. Other two sows were inoculated with RPMI 1640 as control. At 40 days post inoculation, all sows were executed, the pig fetuses and major organs of sows were aseptically collected, A Real-time PCR assay with SYBR? Green was developed for detecting PPV NS-1 gene. Viral load of different tissues were detected by Real-time PCR, and viral tissue distributions were analyzed. The pathological sections of major organs for sows and their fetuses were prepared, and were stained by hematoxylin and eosin. Histopathology of pregnant sows and their fetuses infected with porcine parvovirus were detected by pathological sections. The results were as follow:1. The autopsy results of sows showed that control sows and their fetuses were normal, but the endometritis was found in infected sows, and some mummified fetuses and solution fetus were found in infected sow uterus.2. The virus replication was not found in control sows and their fetuses. The virus replication was found mainly in the heart, lungs, spleen, kidney, endometrium for infected sows, and viral load of uterus was to 1012 copies. The virus replication was found mainly in the heart, lungs, spleen for infected fetuses.3. The histopathology results showed that control sows and their fetuses were normal, but some mummified fetuses and solution fetus were found for infected sows, The conspicuous pathohistology changes were found in spleen and lung for the infected sows, and conspicuous pathohistology changes were not found for their fetuses.In summary, the investigation comfirmed that the PPV-BQ strain can infect the first pregnant sows successfully. A Real-time PCR assay with SYBR? Green was developed for detecting the distribution of PPV in the tissues,and observed the histopathology of pregnant sows and their fetuses.this investigation investigated the distribution of PPV in the tissues of sows and their fetuses ,and the histopathology of their tissues from organ and molecular level.we established foundations of theory and practice for the further research of porcine parvovirus.