Comparative Analysis of Infection by <i>Rickettsia rickettsii</i> Sheila Smith and Taiaçu Strains in a Murine Model
Rocky Mountain spotted fever (RMSF) is a life-threatening tick-borne disease caused by <i>Rickettsia rickettsii</i>, which is widely distributed throughout the Americas. Over 4000 cases of RMSF are recorded annually in the United States, while only around 100 cases are reported in Brazil...
| Main Authors: | , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2020-09-01
|
| Series: | Pathogens |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2076-0817/9/9/744 |
| _version_ | 1797554101787033600 |
|---|---|
| author | Eliane Esteves Chanida Fongsaran Ingeborg M. Langohr Sean P. Riley Marcelo B. Labruna Sirlei Daffre Andréa C. Fogaça Kevin R. Macaluso |
| author_facet | Eliane Esteves Chanida Fongsaran Ingeborg M. Langohr Sean P. Riley Marcelo B. Labruna Sirlei Daffre Andréa C. Fogaça Kevin R. Macaluso |
| author_sort | Eliane Esteves |
| collection | DOAJ |
| description | Rocky Mountain spotted fever (RMSF) is a life-threatening tick-borne disease caused by <i>Rickettsia rickettsii</i>, which is widely distributed throughout the Americas. Over 4000 cases of RMSF are recorded annually in the United States, while only around 100 cases are reported in Brazil. Conversely, while case fatality rates in the United States oscillate around 5%, in Brazil they can surpass 70%, suggesting that differences in tick vectoring capacity, population sensitivity, and/or variability in virulence of the rickettsial strains may exist. In this study, we compared the susceptibility of C3H/HeN mice to two highly virulent strains of <i>R. rickettsii</i>, one from the United States (Sheila Smith) and the other from Brazil (Taiaçu). Animals inoculated with the Taiaçu strain succumbed to infection earlier and exhibited severe histological lesions in both liver and spleen sooner than mice infected with the Sheila Smith strain. These differences in survival and signs of the disease are not related to a greater proliferation of the Taiaçu strain, as there were no significant differences in the rickettsial load in mice tissues inoculated with either strain. The present study is the first step to experimentally assess differences in fatality rates of RMSF in two different regions of the American continent. |
| first_indexed | 2024-03-10T16:26:59Z |
| format | Article |
| id | doaj.art-f8b46e239de54d9eab26d798ab7c9a1e |
| institution | Directory Open Access Journal |
| issn | 2076-0817 |
| language | English |
| last_indexed | 2024-03-10T16:26:59Z |
| publishDate | 2020-09-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Pathogens |
| spelling | doaj.art-f8b46e239de54d9eab26d798ab7c9a1e2023-11-20T13:12:02ZengMDPI AGPathogens2076-08172020-09-019974410.3390/pathogens9090744Comparative Analysis of Infection by <i>Rickettsia rickettsii</i> Sheila Smith and Taiaçu Strains in a Murine ModelEliane Esteves0Chanida Fongsaran1Ingeborg M. Langohr2Sean P. Riley3Marcelo B. Labruna4Sirlei Daffre5Andréa C. Fogaça6Kevin R. Macaluso7Department of Parasitology, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo 05508-900, BrazilDepartment of Pathobiological Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA 70803, USADepartment of Pathobiological Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA 70803, USADepartment of Pathobiological Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA 70803, USADepartment of Preventive Veterinary Medicine and Animal Health, School of Veterinary Medicine and Animal Science, University of Sao Paulo, Sao Paulo 05508-270, BrazilDepartment of Parasitology, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo 05508-900, BrazilDepartment of Parasitology, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo 05508-900, BrazilDepartment of Pathobiological Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA 70803, USARocky Mountain spotted fever (RMSF) is a life-threatening tick-borne disease caused by <i>Rickettsia rickettsii</i>, which is widely distributed throughout the Americas. Over 4000 cases of RMSF are recorded annually in the United States, while only around 100 cases are reported in Brazil. Conversely, while case fatality rates in the United States oscillate around 5%, in Brazil they can surpass 70%, suggesting that differences in tick vectoring capacity, population sensitivity, and/or variability in virulence of the rickettsial strains may exist. In this study, we compared the susceptibility of C3H/HeN mice to two highly virulent strains of <i>R. rickettsii</i>, one from the United States (Sheila Smith) and the other from Brazil (Taiaçu). Animals inoculated with the Taiaçu strain succumbed to infection earlier and exhibited severe histological lesions in both liver and spleen sooner than mice infected with the Sheila Smith strain. These differences in survival and signs of the disease are not related to a greater proliferation of the Taiaçu strain, as there were no significant differences in the rickettsial load in mice tissues inoculated with either strain. The present study is the first step to experimentally assess differences in fatality rates of RMSF in two different regions of the American continent.https://www.mdpi.com/2076-0817/9/9/744<i>Rickettsia rickettsii</i>Taiaçu strainSheila Smith strainRocky Mountain spotted feverVirulenceC3H/HeN mice |
| spellingShingle | Eliane Esteves Chanida Fongsaran Ingeborg M. Langohr Sean P. Riley Marcelo B. Labruna Sirlei Daffre Andréa C. Fogaça Kevin R. Macaluso Comparative Analysis of Infection by <i>Rickettsia rickettsii</i> Sheila Smith and Taiaçu Strains in a Murine Model Pathogens <i>Rickettsia rickettsii</i> Taiaçu strain Sheila Smith strain Rocky Mountain spotted fever Virulence C3H/HeN mice |
| title | Comparative Analysis of Infection by <i>Rickettsia rickettsii</i> Sheila Smith and Taiaçu Strains in a Murine Model |
| title_full | Comparative Analysis of Infection by <i>Rickettsia rickettsii</i> Sheila Smith and Taiaçu Strains in a Murine Model |
| title_fullStr | Comparative Analysis of Infection by <i>Rickettsia rickettsii</i> Sheila Smith and Taiaçu Strains in a Murine Model |
| title_full_unstemmed | Comparative Analysis of Infection by <i>Rickettsia rickettsii</i> Sheila Smith and Taiaçu Strains in a Murine Model |
| title_short | Comparative Analysis of Infection by <i>Rickettsia rickettsii</i> Sheila Smith and Taiaçu Strains in a Murine Model |
| title_sort | comparative analysis of infection by i rickettsia rickettsii i sheila smith and taiacu strains in a murine model |
| topic | <i>Rickettsia rickettsii</i> Taiaçu strain Sheila Smith strain Rocky Mountain spotted fever Virulence C3H/HeN mice |
| url | https://www.mdpi.com/2076-0817/9/9/744 |
| work_keys_str_mv | AT elianeesteves comparativeanalysisofinfectionbyirickettsiarickettsiiisheilasmithandtaiacustrainsinamurinemodel AT chanidafongsaran comparativeanalysisofinfectionbyirickettsiarickettsiiisheilasmithandtaiacustrainsinamurinemodel AT ingeborgmlangohr comparativeanalysisofinfectionbyirickettsiarickettsiiisheilasmithandtaiacustrainsinamurinemodel AT seanpriley comparativeanalysisofinfectionbyirickettsiarickettsiiisheilasmithandtaiacustrainsinamurinemodel AT marceloblabruna comparativeanalysisofinfectionbyirickettsiarickettsiiisheilasmithandtaiacustrainsinamurinemodel AT sirleidaffre comparativeanalysisofinfectionbyirickettsiarickettsiiisheilasmithandtaiacustrainsinamurinemodel AT andreacfogaca comparativeanalysisofinfectionbyirickettsiarickettsiiisheilasmithandtaiacustrainsinamurinemodel AT kevinrmacaluso comparativeanalysisofinfectionbyirickettsiarickettsiiisheilasmithandtaiacustrainsinamurinemodel |