[The geographical distribution of ribotypes of Yersinia pestis in China].

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.