| Cholera is an antiquated infectious disease. Its basal pathological change is excretive diarrhea which is due to cholera toxin generated from vibrio cholerae. It results in a great deal of dehydrate, lost of salt, muscle convulsion and around circulation crock up in a short time. If not treated properly in time, mortality can be 40%. This infectious disease spreaded quickly and leaded to world pandemic, so in 1962 the fifth world health convention established cholera the world quarantine infectious disease. On February 21st 1962 China established cholera type A infectious disease in the new law of infectious diease prevention.Vibrio cholerae leading to the world pandemic can be divided into three types, including Classical biotype, El Tor biotype and serotype O139 (Bengal). Classical biotype leaded to world pandemic 6 times in history. Each time lasted 6~24 years. Mortality ranged from ten to several hundreds million. El Tor biotype vibrio cholerae spreaded to five continents since 1961 and induced the 7th world pandemic. Cholera resulted from O139 serotype vibrio cholerae firstly occurred in east-south India in 1992. This strain spreaded quickly and in 1993 there were 25 Asia country announced had emerged this type cholera case. Because people generally lack immunity to it, this vibrio cholerae has great potential to spread over world. Some experts think vibrio cholerae O139 may lead to the 8th cholera pandemic.At present people presume O139 vibrio cholerae group has three probableorigins: The first point of view considers O139 originated from El Tor biotype vibrio cholerae through gene mutation. The main cholera toxin genes include ctx, zot, ace and cep. Using these four gene probe hybridize genome of vibrio cholerae O139, the result indicated O139 also contains these toxin gene. O139 wild strain is highly similar to El Tor vibrio cholerae in restriction fragment length polymorphism. This indicated these two type vibrio cholerae have intimate genetic relation. So, vibrio cholerae O139 probably originated from 01 vibrio cholerae which had leaded to the world pandemic. The second point of view considers vibrio cholerae O139 originated from other non-Ol vibrio cholerae which obtain the tonxin gene from El Tor vibrio cholerae through gene transfer. The main difference between Ol group and O139 group is the struction of lipopolysaccharide and furthermore O139 strain has capsule polysaccharides. This characterization is similar to non-Ol vibrio cholerae, so maybe some non-Ol vibrio cholerae obtained toxin gene through gene transfer from Ol vibrio cholerae. The third point of view considers O139 vibrio cholerae exits in environment itself. We did not find them before. Recently because the changes of environment it became the predominant strain.In China, cholera breakout resulted from O139 vibrio cholerae was found in KePing county Xinjiang province for the first time in 1993. This study analyzed the difference of standard strain MO45 of vibrio cholerae O139, El Tor biotype vibrio cholerae strain XJ89079 and O139 vibrio cholerae strain XJ93006 from Xinjiang by 16s rDNA finger prints, plasmid map of 16s rDNA clones, 16s rDNA and 16s~23s rDNA intergenic spacer region analysis. This study analyzed the genetic relationship between these three strains, in order to discuss the law of vibrio cholerae evolution and offer referrences to cholera prevention.Method1. Synthesis of VC0309 and 16s rDNA probe: Consulted El Tor vibrio cholerae strain N 16961 genome sequence from Genbank. Designed a pair of primers on VC0309 gene which is at the upriver of the third copy of 16s rDNA and designed a pair of primers which can amplify whole sequence of the third copy of 16s rDNA.DNA probes were synthesized by DIG-dUTP mixture PCR method.2.16s rDNA finger prints of three vibrio cholerae strains MO45, XJ89079, and XJ93006: DNA of the three strains was digested by Bgl I and Pvu I separately at 37癈 for 16 hours. DNA fragments were separated by electrophoresis, and transferred to filter. The filter was baked at 80 癈. Hybridiz...
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