The Investigation To The Distribution Of Leptospira In AnHui And The Study On The Representive Strain Of Gu Serogroup, Qin Serovar EG79

AnHui Province has been estimated as a distress area of Leptospirosis because of its special geographic feature, climatop. And it is difficult to prevent and control leptospirosis because of so many kinds of hosts and serotypes. This time, we want to investigate the distribution of Leptospira that area from 2000 to 2005 to analysis and predict the epidemic situation of Laptospirosis in AnHui Province. So, we can offer the theoretical support to prevent and control the Leptospirosis in AnHui. At the same time, we will study the new serotype found in Wannan Mountain Area to evaluate the possibility of epidemity.In this thesis, we take the MAT to type the Leptospira isolated from the blood samples collected from 2000 to 2005, and then analysis the development tendency of the Leptosprosis in AnHui. After typing the Leptospira isolated from the collected blood samples from the inferior centers of disease control and prevention, we find that the Leptospirosis in AnHui has been controlled and the positive rate is 6.14%. But the results also show the slight upgrade of Leptosprosis and the icterohaemorrhagiae which has been found in the south of the AnHui province now has been found in the north.At the sime time we take a series of methods including the serology methods, biological genetic methods and pathology observation to study the representive strain of Gu serogroup, Qin serovar EG79, isolated form Ronan plancyi. The results of the orthodox serological methods to EG79 show: 2,6-DAP can not restrain the growth of EG79, EG79 can grow in 13℃ and the medium adding 8-AG while it can not grow in 37℃, EG79 is sensitive to Gu²⁺ and can react with 1mol/L NaCl. From the patterns of PFGE, we can find the obvious difference of the EG79 and the nonpathogenic Leptospira. The result of injecting the well-grown culture of the EG79 strain into guinea pigs showed that the viabilities of the infected guinea pig declined with rise of body temperature and reduction of body weight. Definite pathological lesions could be demonstrated in the liver and lungs. The PCR showed a positive result It is concluded that this new type of Leptospira interrogens possesses a certain degree of virulence to guinea pigs, but further experimentations are necessary to prove its virulence to human beings.Compare the information of Leptospira epidemic situation in 90s at AnHui Province, we thought that the distribution of Leptospira in AnHui has changed and the icterohaemorrhagiaewhich has been found in the south of the AnHui now has been found in the north. So, it is important to monitor persistently. And it is significant to identify whether a kind of Leptospira belongs to Leptospira intemogans, because only Leptospira interrogans can cause the Leptospirosis. From all of the results of the study to EG79, we prefer to identify the Gu serogroup, Qin serovar Gu serogroup, Qin serovar is a new kind of Leptospira interrogans. So we thought this study has theoretical sense, especially when we found the types of Leptospira carried by Ronan plancyi accord with that carried by local human.