[Plasmid profile typing of Salmonella typhimurium and its distribution in some provinces and cities of China]

[[[ Objective: ]]] To study the relationship between the infection and prevalence of Salmonella typhimurium. [[[ Methods: ]]] From 1980 to 1995, when Salmonella typhimurium infection was prevalent in north and south China, a total of 2,655 isolates of Salmonella typhimurium were collected from 19 provinces, municipalities, and autonomous regions and Hong Kong Special Administrative Region for plasmid profile analysis. The profiles consisting of some small plamids were recorded with capital letters A to J, and the profile which was free from small plasmid was recorded with capital letter O. Large plasmid in molecular weights of 140-20 Mdal showing in profiles was recorded with Arabic numerals 9 to 0 respectively. Having two or more than two large plasmids, the profile was recorded with two or more Arabic numerals. [[[ Results: ]]] The 2,655 strains were divided into 11 plasmid profile groups and 168 plasmid profile types. Of 52 plasmid profile types frequently isolated, plasmid profile type O 4 was distributed extensively in 16 provinces, municipalities, and autonomous rehions and Hong Kong. Plasmid profile type O 5 was isolated in 5 provinces and Hong Kong, mostly in Jiangxi and Hubei. Plasmid profile type J 4 was isolated in 7 provinces, municipalities and autonomous regions, mostly in Jiangxi. Five plasmid profile types of Group A caused a big prevalence of nosocomial infection in Henan. Type A 6 was also isolated in Xinjiang and Anhui. Six plasmid profile types of Group E were prevalent in Xinjiang predominantely, three types caused nosocomial infection in Shanghai, type E 82 caused nosocomial infection and food poisoning in Liaoning. Type F 4 was isolated in 4 provinces, mostly in jiangxi and Fujian. Many plasmid profile types were prevalent local. Types B 5, BCEG 60, BE 6, B’ 0 G 6, G 5 and EG 6 were prevalent in Jiangxi, Types IF’4, IF’H40 and F 9864 were prevalent in Sandong, Type IF’4 was also isolated in Jiangsu and Hubei, Type IF 40 in Anhui, Type BH 6 in Huibei, and Type EH 5 in Fujian. [[[ Conclusion: ]]] Plasmid profile analysis showed the same types in the prevance but different plasmid profiles in different provinces.