Objective: To type and group the Yersinia pestis strains isolated in China to clarify the geographical distribution of ribotypes of Yersinia pestis.
Methods: Genomic DNA of Yersinia pestis were digested with EcoR I, then hybridized with 16s-23s-5s rRNA gene probe.
Results: These tested strains were divided into 3 ribotypes, the profiles obtained were relatively homogeneous, with most of them differed only by the presence or the absence of 1 - 2 restriction fragments. Ribotype A and B were the most common types, which distributed in a large area in China while ribotype C was the least, only limited to a small area. There was certain correlation between the ribotypes and the plague foci, usually only one ribotype was found in one plague foci.
Conclusion: The ribotypes were stable in the plague foci. Correlation between the ribotypes of Yersinia pestis strains and their geographical origins was noticed. All 3 ribotypes had different origins, however ribotype A and ribotype C seemed to be closer related.