Genetic typing of isolates of Rickettsia typhi

Authors

Cecilia Y. Kato, Centers for Disease Control and Prevention
Ida H. Chung, Centers for Disease Control and Prevention
Lauren K. Robinson, Northwestern University Feinberg School of Medicine
Marina Eremeeva, Georgia Southern University, Jiann-Ping Hsu College of Public HealthFollow
Gregory A. Dasch, Centers for Disease Control and PreventionFollow

Document Type

Article

Publication Date

5-31-2022

Abstract

Murine typhus, which is caused by Rickettsia typhi, has a wide range of clinical manifestations. It has a low mortality rate but may result in meningoencephalitis and interstitial pneumonia in severe cases. Comparisons of complete genome sequences of R. typhi isolates from North Carolina, USA (Wilmington), Myanmar (B9991PP), and Thailand (TH1527) identified only 26 single nucleotide polymorphism (SNP) and 7 insertion-deletion (INDEL) sites in these highly syntenic genomes. Assays were developed to further define the distribution of these variant sites among 15 additional isolates of R. typhi with different histories from Asia, the USA, and Africa. Mismatch amplification mutation assays (MAMA) were validated for 22 SNP sites, while the 7 INDEL sites were analyzed directly on agarose gels. Six SNP types, 9 INDEL types, 11 total types were identified among these 18 isolates. Replicate DNA samples as well as comparisons of isolates with different passage and source histories gave consistent genetic typing profiles. Comparison of the SNP and INDEL markers to R. typhi’s nearest neighbor Rickettsia prowazekii demonstrated that the majority of the SNPs represent intra-species variation that arose post divergence of these two species while several INDEL sites also exhibited intraspecies variability among the R. prowazekii genomes that have been completely sequenced. The assays for the presence of these SNP and INDEL sites, particularly the latter, comprise a low technology gel method for consistently distinguishing R. typhi and R. prowazekii as well as for differentiating genetic types of R. typhi.

Comments

Georgia Southern University faculty member, Marina E. Eremeeva co-authored Genetic typing of isolates of Rickettsia typhi.

Recommended Citation

Kato, Cecilia Y., Ida H. Chung, Lauren K. Robinson, Marina Eremeeva, Gregory A. Dasch. 2022. "Genetic typing of isolates of Rickettsia typhi." Department of Biostatistics, Epidemiology, and Environmental Health Sciences Faculty Publications, Paper 408.
https://digitalcommons.georgiasouthern.edu/bee-facpubs/408

Copyright

This is an open access article, free of all copyright, and may be freely reproduced, distributed, transmitted, modified, built upon, or otherwise used by anyone for any lawful purpose. The work is made available under the Creative Commons CC0 public domain dedication.