Ascarid Of The Giant Panda From Foping Nature Reserve Epidemiological Investigation And Evolution Analysis

The giant panda, China’s unique rare endangered wildlife, which is the flagship species of wildlife conservation in our country. It is known as a "living fossil", and the existing main habitat of nowadays is the mountains in Sichuan, Shaanxi and Gansu province. This study amplified the the ITS’s and the 5.8S’s sequence of the Baylisascaris schroederi of the giant panda, and researched its evolutionary status in Ascaridia with 18S’s gene. A one-year epidemiological investigation was carried out against the Baylisascaris schroederi of the giant panda in Foping nature reserve, and assessment the impact factors which like temperature, dew point type, elevation, bamboo and other abiotic factors.In 2012,193 samples of giant panda’s feces were collected in Foping nature reserve, Shaanxi province. Floating by the saturated brine, and then collect eggs through the morphological identification method. And successfully amplified the sequences of the ITS-1, the 5.8S and the ITS-2 of the Baylisascaris schroederi of the giant panda. Based on the 5.8S’s and the ITS-2’s gene studies have shown that the ascaris of the giant panda belongs to the Baylisascaris, and shows the closest genetic relationship to the Baylisascaris transfuga.Based on the ITS-1 and 18S gene sequence analysis indicated that there is a close coevolution relationship between the ascaris and host, the evolution of Ascaridia exist two origin point.Fecal samples detected by using Mike MAS counting method. The results show that, the annual infection rate of the Baylisascaris schroederi of the giant panda was 52.3%, the average intensity of infection of whole year was 89.27/g, and the individual infected with strength up to the maximum was 1147/g. Infection intensity and infection rates were began to rise from April, and reached their peak during June and July, and then gradually decline. There were some seasonal and regional differences of the Baylisascaris schroederi in popular:the infection intensity in spring and summer (167.74/g,119.81/g)is significantly higher than it’s in autumn and winter(9.25/g,2.89/g),the infection rates in spring and summer(71.0%,77.4%) is significantly higher than it’s in autumn and winter(22.5%,18.4%),The correlation analysis showed that the temperature and the dew point was positively related to the infection intensity(r=0.328,p<0.01), and a significant difference was found of the infection rates while in different temperatures. Infection intensity and infection rates of the Baylisascaris schroederi were significantly higher when the temperature over 15℃.The elevation is negatively related to the infection intensity(r=-0.224,p<0.01).