Mutators and Long-Term Molecular Evolution of Pathogenic Escherichia coli O157:H7
1998
Mutation Rates in Pathogenic E. coli O157:H7
Sample size: 12
publication
Evidence: moderate
Author Information
Author(s): Thomas S. Whittam, Sean D. Reid, Robert K. Selander
Primary Institution: Pennsylvania State University
Hypothesis
An increased mutation rate has facilitated the emergence of Escherichia coli O157:H7.
Conclusion
The study found no evidence of a genomewide elevation of the mutation rate in pathogenic E. coli O157:H7.
Supporting Evidence
- More than 1% of O157:H7 strains had spontaneous rates of mutation that were 1,000-fold higher than typical E. coli.
- Two loci showed deviations from expected rates, but most genes did not.
- 11 of the 12 loci did not deviate significantly from a uniform rate of evolution.
Takeaway
Scientists looked at how fast E. coli O157:H7 changes over time and found it doesn't mutate faster than other types of E. coli.
Methodology
The study compared the divergence of 12 genes between E. coli O157:H7, E. coli K-12, and Salmonella enterica.
Limitations
The study does not account for transient mutator states that may not be detectable over long evolutionary times.
Statistical Information
P-Value
p < 0.05 for mdh
Statistical Significance
p > 0.05
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