Molecular Epidemiologic Techniques in Analysis of Epidemic and Endemic Shigella dysenteriae Type 1 Strains

Authors

Nancy A. Strockbine, Centers for Disease Control
Julie Parsonnet, Centers for Disease Control
Katherine Greene, Centers for Disease Control
Julia A. Kiehlbauch, Centers for Disease Control
I. Kaye Wachsmuth, Centers for Disease Control

Date of this Version

1991

Citation

The Journal of Infectious Diseases 1991;163:406-409

Abstract

During 1988 the number of Shigella dysenteriae type 1 infections reported in the United States increased fivefold. To determine if recent isolates from Mexico were related to those that caused epidemics of dysentery worldwide, Southern hybridization analysis was done with Shiga toxin and ribosomal RNA gene probes. Western hemisphere and Eastern Hemisphere strains differed by the size of a single EcoRI fragment carrying the Shiga toxin genes. Three ribosomal DNA (rDNA) patterns were observed, which correlated with the strain;s continental origin for 81 of 83 isolates tested. Together the Shiga toxin and rDNA probe results indicated that recent Mexican isolates were chromosomally similar to earlier Central American isolates and distinct from Asian and African strains. This suggests there has been no significant exchange of organisms between continents in recent decades and that the 1988 outbreak in Mexico was caused by strains present in Central America since at least 1962.