Related Experiment Videos
Molecular epidemiology of Shigella infection in Central Australia
M J Albert1, K V Singh, B E Murray
1Alice Springs Hospital, Northern Territory, Australia.
Abstract:
Shigellosis is endemic in Central Australia and the infections are predominantly due to Shigella flexneri 6, Shigella flexneri 2a and Shigella sonnei. Plasmid profiles of isolates collected from 1985-9, suggested that infections caused by Shigella flexneri 6 were predominantly due to a single clone, whereas those caused by Shigella flexneri 2a and Shigella sonnei were due to several genetically diverse strains, although strains with identical plasmid profiles were found in widely separated geographical areas and in different years.
Insights
Shigellosis outbreaks in Central Australia are mainly caused by specific Shigella strains. While Shigella flexneri 6 infections stem from a single clone, Shigella flexneri 2a and Shigella sonnei show genetic diversity, with identical strains appearing geographically widespread.
Area of Science:
- Microbiology
- Infectious Diseases
- Epidemiology
Background:
- Shigellosis is a significant public health concern in Central Australia.
- Commonly identified causative agents include Shigella flexneri 6, Shigella flexneri 2a, and Shigella sonnei.
Purpose of the Study:
- To analyze the genetic diversity and clonal origins of Shigella isolates in Central Australia.
- To understand the transmission patterns of different Shigella species in the region.
Main Methods:
- Plasmid profiling of Shigella isolates collected between 1985 and 1999.
- Comparison of plasmid profiles to assess genetic relatedness and clonal expansion.
Main Results:
- Shigella flexneri 6 infections were largely attributed to a single, dominant clone.
- Shigella flexneri 2a and Shigella sonnei exhibited greater genetic diversity, with multiple distinct strains identified.
- Identical plasmid profiles were observed across geographically distant locations and different years, suggesting widespread dissemination.
Conclusions:
- The findings highlight distinct evolutionary and epidemiological patterns for different Shigella species in Central Australia.
- Shigella flexneri 6 appears to be maintained by clonal expansion, while Shigella flexneri 2a and Shigella sonnei are characterized by broader genetic diversity and dissemination.