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Journal of clinical microbiology2002; 40(2); 690-693; doi: 10.1128/JCM.40.2.690-693.2002

Molecular analysis of Neorickettsia risticii in adult aquatic insects in Pennsylvania, in horses infected by ingestion of insects, and isolated in cell culture.

Abstract: Upon ingestion of adult aquatic insects, horses developed clinical signs of Potomac horse fever, and Neorickettsia risticii was isolated from the blood. 16S rRNA and 51-kDa antigen gene sequences from blood, isolates, and caddis flies fed to the horses were identical, proving oral transmission of N. risticii from caddis flies to horses.
Publication Date: 2002-02-05 PubMed ID: 11825999PubMed Central: PMC153368DOI: 10.1128/JCM.40.2.690-693.2002Google Scholar: Lookup
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  • Journal Article
  • Research Support
  • Non-U.S. Gov't
  • Research Support
  • U.S. Gov't
  • Non-P.H.S.

Summary

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This research reveals that horses, after ingesting adult aquatic insects, show clinical signs of Potomac horse fever. The bacteria causing the disease, Neorickettsia risticii, is transmitted orally from caddis flies to horses, as proven by identical gene sequences in the blood of the horses, the isolates, and the caddis flies eaten by the horses.

Study on Molecular Analysis of Neorickettsia risticii

The main study of this research paper is based on the molecular analysis of Neorickettsia risticii, a bacterium that causes Potomac horse fever in horses. This analysis was conducted on three different sources:

  • Horses that developed symptoms of Potomac horse fever after ingesting aquatic insects.
  • Adult aquatic insects present around the horses.
  • Neorickettsia risticii isolated in a cell culture.

Finding the Link Between Potomac Horse Fever and Aquatic Insects

The researchers discovered that Potomac horse fever in horses, observed as clinical symptoms, occurred after the horses ingested adult aquatic insects. Particularly, they identified the caddis fly as one of the carriers of the bacteria, Neorickettsia risticii, that causes this disease.

Discovering the Oral Transmission of Neorickettsia risticii

The research established that the bacterium Neorickettsia risticii, responsible for causing Potomac horse fever, is orally transmitted from caddis flies to horses. This was confirmed by comparing gene sequences of the 16S rRNA and the 51-kDa antigen from:

  • The blood of horses showing symptoms of Potomac horse fever.
  • The isolated strains of Neorickettsia risticii obtained via cell culture.
  • The caddis flies that were ingested by the horses.

The researchers found that these gene sequences were identical, providing strong evidence of the oral transmission route.

Cite This Article

APA
Mott J, Muramatsu Y, Seaton E, Martin C, Reed S, Rikihisa Y. (2002). Molecular analysis of Neorickettsia risticii in adult aquatic insects in Pennsylvania, in horses infected by ingestion of insects, and isolated in cell culture. J Clin Microbiol, 40(2), 690-693. https://doi.org/10.1128/JCM.40.2.690-693.2002

Publication

ISSN: 0095-1137
NlmUniqueID: 7505564
Country: United States
Language: English
Volume: 40
Issue: 2
Pages: 690-693

Researcher Affiliations

Mott, Jason
  • Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, Ohio 43210-1092, USA.
Muramatsu, Yasukazu
    Seaton, Elizabeth
      Martin, Carol
        Reed, Stephen
          Rikihisa, Yasuko

            MeSH Terms

            • Animals
            • Antigens, Helminth / genetics
            • Blood / microbiology
            • Culture Media
            • Feeding Behavior
            • Horse Diseases / microbiology
            • Horse Diseases / transmission
            • Horses / physiology
            • Insecta / microbiology
            • Mice
            • Molecular Sequence Data
            • Pennsylvania
            • RNA, Ribosomal, 16S / genetics
            • Rickettsiaceae / classification
            • Rickettsiaceae / genetics
            • Rickettsiaceae Infections / microbiology
            • Rickettsiaceae Infections / transmission
            • Rickettsiaceae Infections / veterinary

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