Effects Of Eperythrozoon Suis On Nonspecific Immunity Of Piglets And Selection Of Effective Immunomodulators

Eperythrozoonosis is a zoonosis that caused by eperythrozoon which parasitizes in surface of akaryocyte, blood plasm and bone marrow. It is characterized by fever, anaemia and icterus. The disease can not only decrease growth velocity,meat/feed of infected livestock and productivity of female livestock, but also induce severe clinical symptome and great perish, causing large economical lose. Relative studies have showed that Eperythrozoon suis could decrease body immunity and cause infected livestock to infect other diseases, which got pathogenetic condition much worse. So, lots of veterinarian suggested that immunomodulators should be used as assistant medicine to cure eperythrozoonosis. But there was no studise about which immunomodulator was better reported yet. So, we made the test for it. In our reseach, effect of Eperythrozoon suis on nonspecific immunity of piglets was studied. Astragalus Polysacharin (APS), Levamisole (LMS) and Polysaccharide of Radix Sileris (PRS) were selected as ready immunomodulators, and their immunomodulatory functions were studied to selecte which can be best to be used as assistant.A total of 20 healthy piglets with similar body weight, aged 40 days, were assigned to 5 treatment groups randomly. The first 3 groups were experimental groups, the 4th positive control and the 5th negative control. Piglets of the first 4 groups were inoculated with porcine blood containing eperythrozoon suis, and piglets of the 5th group were simultaneously treated with saline. Then, piglets of experimental groups were intramuscularly injected with PRS, APS and LMS respectively, and piglets of controls were simultaneously treated with saline for 7 days. Blood was sampled from precaval vein on the 0th, 4th, 7th and 14th day after inoculation. Red blood cell infection, lisozyma activity, total lymphocyte count, total protein level, globulin level and immunosuppressive acid protein (IAP) level were tested. The results showed that the fourth, seventh and fourteenth day after inoculation of whole blood infected by eperythrozoon suis, the red blood cell infection of positive group achieved 9.00%,17.00%,62.75% respectively, which indicated zoogenetic infection successful. Red blood cell infections of three immunomodulator group were lower than postive, and the one of PRS was significantly lower than positive at fourteenth day after inoculation. This indicated that three immunomodulators could decrease red blood infection. Eperythrozoon suis infection significantly decreased total protein level and globulin level, significantly enhanced IAP level, and gently decreased total lymphocyte count of piglets of positive. But there was no significant change of lisozyma activity. APS and PRS could significantly increase and lisozyma activity, and all of the three immunomodulators could significantly increase total protein level, globulin level and decrease IAP level of infectious piglets.In conclusion, Eperythrozoon suis could decrease nonspecific immunity of piglets, which may be the main factor that caused infected pigs opt to be infected other diseases. All the three immunomodulators could alleviate the damage of eperythrozoonosis and increase nonspecific immunity of piglets, and APS was the best.