Analyze Diet
Parasites & vectors2016; 9(1); 499; doi: 10.1186/s13071-016-1784-y

Experimental infection of horses with Rickettsia rickettsii.

Abstract: Rickettsia rickettsii is vectored by ticks, and some vertebrate hosts can be sources of infection to ticks during bacteremic periods. In Brazil, the main vector for R. rickettsii is the tick Amblyomma sculptum, a member of the A. cajennense complex. Horses, in turn, are one of the major hosts for A. sculptum. In this study, horses experimentally infected with R. rickettsii were assessed for clinical changes and their capability to transmit the infection to A. sculptum ticks. Four horses were infected with R. rickettsii through either intraperitoneal injection or infestation with R. rickettsii-infected A. sculptum ticks. Simultaneously, the animals were infested with non-infected A. sculptum ticks. The horses were monitored for 30 days by clinical examination, hematological and biochemical tests, real-time PCR of blood for the detection of Rickettsia, and inoculation of blood in guinea pigs. IgG antibody titers were followed until the horses have shown seronegativity or until the end of the experiment. Uninfected ticks that fed on horses were subjected to real-time PCR and/or were fed on susceptible rabbits. The horses showed no clinical, hematological or blood biochemical alterations, and bacteremia was not detected by real-time PCR or by inoculation of horse blood into guinea pigs. Anti-R. rickettsii antibodies were detected in horses from 10 days to 2 years after infection. Uninfected ticks, after feeding on infected horses, showed 2.1 % positivity in real-time PCR, but failed to transmit the infection to rabbits at a next feeding stage. Rickettsia rickettsii-infected horses did not manifest illness and are not competent amplifier hosts of R. rickettsii for A. sculptum ticks.
Publication Date: 2016-09-13 PubMed ID: 27624315PubMed Central: PMC5022194DOI: 10.1186/s13071-016-1784-yGoogle Scholar: Lookup
The Equine Research Bank provides access to a large database of publicly available scientific literature. Inclusion in the Research Bank does not imply endorsement of study methods or findings by Mad Barn.
  • Journal Article
  • Research Support
  • Non-U.S. Gov't

Summary

This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.

The research article is about a study conducted on horses to assess their response to Rickettsia rickettsii infection and the ability to transmit the infection to ticks. The study found horses do not display symptoms after infection and do not efficiently transfer the bacteria to ticks.

Introduction

  • In this research paper, the focus is on understanding the disease dynamics of Rickettsia rickettsii, a bacteria spread by ticks.
  • The main vector, in terms of transmission, for R. rickettsii in Brazil is the Amblyomma sculptum tick, a type of cajennense tick.
  • The experiment uses horses as a host species for the study, as they are a major host for A. sculptum ticks.

Methodology

  • The experiment involved four horses, infected with R. rickettsii through two methods: direct intraperitoneal injection or exposure to infected A. sculptum ticks.
  • The horses were then exposed to non-infected A. sculptum ticks to see if they would catch the infection.
  • Health monitoring and various tests, including clinical examinations and real-time PCR of blood to detect Rickettsia, were carried out on the horses over a 30-day period.
  • Besides this, their blood was also inoculated in guinea pigs to check for bacteremia.
  • The horses’ IgG antibody levels were noted until they were either no-longer present or until the end of the experiment.

Results

  • The researchers found that the horses showed no clinical signs or changes in blood chemistry associated with disease following infection with R. rickettsii.
  • The presence of R. rickettsii was not detected in the horses’ blood
  • However, antibodies against R. rickettsii were noted from 10 days to 2 years after infection, indicating that the horses’ immune systems had responded to the bacteria.
  • In testing ticks that had fed on the infected horses, only a minor proportion (2.1%) showed the presence of R. rickettsii in real-time PCR tests, and none of these ticks were able to transmit the infection to rabbits in subsequent feedings.

Conclusion

  • From these findings, the researchers determined that horses infected with R. rickettsii did not show any sickness and, importantly, were not an effective source for transmitting the infection to the A. sculptum ticks.

Cite This Article

APA
Ueno TE, Costa FB, Moraes-Filho J, Agostinho WC, Fernandes WR, Labruna MB. (2016). Experimental infection of horses with Rickettsia rickettsii. Parasit Vectors, 9(1), 499. https://doi.org/10.1186/s13071-016-1784-y

Publication

ISSN: 1756-3305
NlmUniqueID: 101462774
Country: England
Language: English
Volume: 9
Issue: 1
Pages: 499
PII: 499

Researcher Affiliations

Ueno, Tatiana Evelyn Hayama
  • Agribusiness Technology Agency of São Paulo State, São José do Rio Preto, Brazil. tatianaueno@apta.sp.gov.br.
Costa, Francisco B
  • Faculty of Veterinary Medicine, University of São Paulo, São Paulo, Brazil.
Moraes-Filho, Jonas
  • Faculty of Veterinary Medicine, University of São Paulo, São Paulo, Brazil.
Agostinho, Washington Carlos
  • Faculty of Veterinary Medicine, University of São Paulo, São Paulo, Brazil.
Fernandes, Wilson Roberto
  • Faculty of Veterinary Medicine, University of São Paulo, São Paulo, Brazil.
Labruna, Marcelo B
  • Faculty of Veterinary Medicine, University of São Paulo, São Paulo, Brazil.

MeSH Terms

  • Animals
  • Antibodies, Bacterial / blood
  • Guinea Pigs
  • Horse Diseases / blood
  • Horse Diseases / microbiology
  • Horses
  • Ixodidae / microbiology
  • Rabbits
  • Rickettsia rickettsii
  • Rocky Mountain Spotted Fever / blood
  • Rocky Mountain Spotted Fever / microbiology
  • Rocky Mountain Spotted Fever / veterinary
  • Time Factors

References

This article includes 40 references
  1. Labruna MB. Ecology of rickettsia in South America.. Ann N Y Acad Sci 2009 May;1166:156-66.
  2. Piza J, Salles-Gomes L, Meyer J, Fleury JP, Castro O, Rodrigues C. Le typhus exanthématique a São Paulo. C R Seances Soc Biol Fil 1931;106:1020–1022.
  3. Ministério da Saúde do Brasil. Sistema de Informação de Agravos de Notificação. Casos confirmados de Febre maculosa. Brasil, Grandes Regiões e Unidades Federadas. 1997 a 2014. http://portalsaude.saude.gov.br/images/pdf/2014/maio/26/anexo-FebreMaculosa.pdf. Accessed 20 Mar 2015.
  4. Estrada-Peña A, Guglielmone AA, Mangold AJ. The distribution and ecological 'preferences' of the tick Amblyomma cajennense (Acari: Ixodidae), an ectoparasite of humans and other mammals in the Americas.. Ann Trop Med Parasitol 2004 Apr;98(3):283-92.
    pubmed: 15119974doi: 10.1179/000349804225003316google scholar: lookup
  5. Nava S, Beati L, Labruna MB, Cáceres AG, Mangold AJ, Guglielmone AA. Reassessment of the taxonomic status of Amblyomma cajennense () with the description of three new species, Amblyomma tonelliae n. sp., Amblyomma interandinum n. sp. and Amblyomma patinoi n. sp., and reinstatement of Amblyomma mixtum, and Amblyomma sculptum (Ixodida: Ixodidae).. Ticks Tick Borne Dis 2014 Apr;5(3):252-76.
    doi: 10.1016/j.ttbdis.2013.11.004pubmed: 24556273google scholar: lookup
  6. Martins TF, Barbieri AR, Costa FB, Terassini FA, Camargo LM, Peterka CR, de C Pacheco R, Dias RA, Nunes PH, Marcili A, Scofield A, Campos AK, Horta MC, Guilloux AG, Benatti HR, Ramirez DG, Barros-Battesti DM, Labruna MB. Geographical distribution of Amblyomma cajennense (sensu lato) ticks (Parasitiformes: Ixodidae) in Brazil, with description of the nymph of A. cajennense (sensu stricto).. Parasit Vectors 2016 Mar 31;9:186.
    doi: 10.1186/s13071-016-1460-2pmc: PMC4818509pubmed: 27036324google scholar: lookup
  7. McDade JE, Newhouse VF. Natural history of Rickettsia rickettsii.. Annu Rev Microbiol 1986;40:287-309.
  8. Soares JF, Soares HS, Barbieri AM, Labruna MB. Experimental infection of the tick Amblyomma cajennense, Cayenne tick, with Rickettsia rickettsii, the agent of Rocky Mountain spotted fever.. Med Vet Entomol 2012 Jun;26(2):139-51.
  9. Ricketts HT. Some aspects of Rocky Mountain spotted fever as shown by recent investigations. 1909.. Rev Infect Dis 1991 Nov-Dec;13(6):1227-40.
    pubmed: 1775857doi: 10.1093/clinids/13.6.1227google scholar: lookup
  10. Burgdorfer W, Friedhoff KT, Lancaster JL Jr. Natural history of tick-borne spotted fever in the USA. Susceptibility of small mammals to virulent Rickettsia rickettsii.. Bull World Health Organ 1966;35(2):149-53.
    pmc: PMC2476118pubmed: 5296999
  11. Gage KL, Burgdorfer W, Hopla CE. Hispid cotton rats (Sigmodon hispidus) as a source for infecting immature Dermacentor variabilis (Acari: Ixodidae) with Rickettsia rickettsii.. J Med Entomol 1990 Jul;27(4):615-9.
    doi: 10.1093/jmedent/27.4.615pubmed: 2117665google scholar: lookup
  12. Souza CE, Moraes-Filho J, Ogrzewalska M, Uchoa FC, Horta MC, Souza SS, Borba RC, Labruna MB. Experimental infection of capybaras Hydrochoerus hydrochaeris by Rickettsia rickettsii and evaluation of the transmission of the infection to ticks Amblyomma cajennense.. Vet Parasitol 2009 Apr 6;161(1-2):116-21.
    doi: 10.1016/j.vetpar.2008.12.010pubmed: 19147293google scholar: lookup
  13. Horta MC, Moraes-Filho J, Casagrande RA, Saito TB, Rosa SC, Ogrzewalska M, Matushima ER, Labruna MB. Experimental infection of opossums Didelphis aurita by Rickettsia rickettsii and evaluation of the transmission of the infection to ticks Amblyomma cajennense.. Vector Borne Zoonotic Dis 2009 Feb;9(1):109-18.
    doi: 10.1089/vbz.2008.0114pubmed: 18945194google scholar: lookup
  14. Labruna MB, Kasai N, Ferreira F, Faccini JL, Gennari SM. Seasonal dynamics of ticks (Acari: Ixodidae) on horses in the state of São Paulo, Brazil.. Vet Parasitol 2002 Apr 19;105(1):65-77.
    doi: 10.1016/S0304-4017(01)00649-5pubmed: 11879967google scholar: lookup
  15. de Lemos ER, Machado RD, Coura JR, Guimarães MA, Chagas N. Epidemiological aspects of the Brazilian spotted fever: serological survey of dogs and horses in an endemic area in the State of São Paulo, Brazil.. Rev Inst Med Trop Sao Paulo 1996 Nov-Dec;38(6):427-30.
  16. Horta MC, Labruna MB, Sangioni LA, Vianna MC, Gennari SM, Galvão MA, Mafra CL, Vidotto O, Schumaker TT, Walker DH. Prevalence of antibodies to spotted fever group rickettsiae in humans and domestic animals in a Brazilian spotted fever-endemic area in the state of São Paulo, Brazil: serologic evidence for infection by Rickettsia rickettsii and another spotted fever group Rickettsia.. Am J Trop Med Hyg 2004 Jul;71(1):93-7.
    pubmed: 15238696
  17. Vianna MC, Horta MC, Sangioni LA, Cortez A, Soares RM, Mafra CL, Galvão MA, Labruna MB, Gennari SM. Rickettsial spotted fever in capoeirão village, Itabira, Minas Gerais, Brazil.. Rev Inst Med Trop Sao Paulo 2008 Sep-Oct;50(5):297-301.
  18. Ricketts HT. The role of the wood-tick (Dermacentor occidentalis) in Rocky Mountain spotted fever, and the susceptibility of local animals to this disease - a preliminary report. JAMA 1907;49(1):24–27.
  19. Heinemann PG, Moore JJ. Experimental therapy of Rocky Mountain spotted fever: the preventive and curative action of a serum for spotted fever, and the inefficiency of sodium cacodylate as a curative agent for this disease in guinea pigs. J Infect Dis 1912;10(3):294–304.
    doi: 10.1093/infdis/10.3.294google scholar: lookup
  20. Pinter A, Labruna MB. Isolation of Rickettsia rickettsii and Rickettsia bellii in cell culture from the tick Amblyomma aureolatum in Brazil.. Ann N Y Acad Sci 2006 Oct;1078:523-9.
    doi: 10.1196/annals.1374.103pubmed: 17114770google scholar: lookup
  21. Labruna MB, Whitworth T, Horta MC, Bouyer DH, McBride JW, Pinter A, Popov V, Gennari SM, Walker DH. Rickettsia species infecting Amblyomma cooperi ticks from an area in the state of São Paulo, Brazil, where Brazilian spotted fever is endemic.. J Clin Microbiol 2004 Jan;42(1):90-8.
    doi: 10.1128/JCM.42.1.90-98.2004pmc: PMC321730pubmed: 14715737google scholar: lookup
  22. Barros-Battesti DM, Arzua M, Bechara GH. Carrapatos de importância médico-veterinária da Região Neotropical: um guia ilustrado para identificação de espécies. São Paulo: Vox/International Consortium on Ticks and Tick-borne Diseases (ICTTD-3)/Butantan; 2006.
  23. Speirs VC, Wrigley RH. Clinical examination of horses. Philadelphia: WB Saunders; 1997.
  24. Feldman BV, Zinkl JG, Jain NC. Schalm’s Veterinary Hematology. 5. Philadelphia: Lippincott Williams & Wilkins; 2000.
  25. Kaneko JJ, Harvey JW, Bruss ML. Clinical biochemistry of domestic animals. 5. San Diego: Academic; 1997.
  26. Meyer DJ, Harvey JW. Veterinary laboratory medicine: interpretation and diagnosis. 3. St. Louis: WB Saunders; 2004.
  27. Hillyer EV, Quesenberry KE. Ferrets, rabbits, and rodents: clinical medicine and surgery. 1. Philadelphia: WB Saunders; 1997.
  28. Regnery RL, Spruill CL, Plikaytis BD. Genotypic identification of rickettsiae and estimation of intraspecies sequence divergence for portions of two rickettsial genes.. J Bacteriol 1991 Mar;173(5):1576-89.
  29. Roux V, Fournier PE, Raoult D. Differentiation of spotted fever group rickettsiae by sequencing and analysis of restriction fragment length polymorphism of PCR-amplified DNA of the gene encoding the protein rOmpA.. J Clin Microbiol 1996 Sep;34(9):2058-65.
  30. Marrero M, Raoult D. Centrifugation-shell vial technique for rapid detection of Mediterranean spotted fever rickettsia in blood culture.. Am J Trop Med Hyg 1989 Feb;40(2):197-9.
    pubmed: 2645804doi: 10.4269/ajtmh.1989.40.197google scholar: lookup
  31. Sangioni LA, Horta MC, Vianna MC, Gennari SM, Soares RM, Galvão MA, Schumaker TT, Ferreira F, Vidotto O, Labruna MB. Rickettsial infection in animals and Brazilian spotted fever endemicity.. Emerg Infect Dis 2005 Feb;11(2):265-70.
    doi: 10.3201/eid1102.040656pmc: PMC3320454pubmed: 15752445google scholar: lookup
  32. Black WC 4th, Piesman J. Phylogeny of hard- and soft-tick taxa (Acari: Ixodida) based on mitochondrial 16S rDNA sequences.. Proc Natl Acad Sci U S A 1994 Oct 11;91(21):10034-8.
    doi: 10.1073/pnas.91.21.10034pmc: PMC44952pubmed: 7937832google scholar: lookup
  33. George F, Brouqui P, Boffa MC, Mutin M, Drancourt M, Brisson C, Raoult D, Sampol J. Demonstration of Rickettsia conorii-induced endothelial injury in vivo by measuring circulating endothelial cells, thrombomodulin, and von Willebrand factor in patients with Mediterranean spotted fever.. Blood 1993 Oct 1;82(7):2109-16.
    pubmed: 7691249
  34. Hafez ESE, Hafez B. Reproduction in farm animals. 7. Philadelphia: Lippincott Williams & Wilkins; 2000.
  35. Ricketts HT, Gomez L. Studies on immunity in Rocky Mountain spotted fever: first communication. J Infect Dis 1908;5(2):221–244.
    doi: 10.1093/infdis/5.2.221google scholar: lookup
  36. Piranda EM, Faccini JL, Pinter A, Saito TB, Pacheco RC, Hagiwara MK, Labruna MB. Experimental infection of dogs with a Brazilian strain of Rickettsia rickettsii: clinical and laboratory findings.. Mem Inst Oswaldo Cruz 2008 Nov;103(7):696-701.
  37. Shirai A, Bozeman FM, Humphries JW, Elisberg BL, Faber JE. Experimental infection of the cotton rat Sigmodon hispidus with Rickettsia rickettsii.. J Bacteriol 1967 Nov;94(5):1334-9.
  38. Lundgren DL, Thorpe BD. Infectious diseases in wild animals in Utah. VII. Experimental infection of rodents with Rickettsia rickettsii.. Am J Trop Med Hyg 1966 Sep;15(5):799-806.
    pubmed: 5917635doi: 10.4269/ajtmh.1966.15.799google scholar: lookup
  39. Krawczak FS, Nieri-Bastos FA, Nunes FP, Soares JF, Moraes-Filho J, Labruna MB. Rickettsial infection in Amblyomma cajennense ticks and capybaras (Hydrochoerus hydrochaeris) in a Brazilian spotted fever-endemic area.. Parasit Vectors 2014 Jan 5;7:7.
    doi: 10.1186/1756-3305-7-7pmc: PMC3892071pubmed: 24387674google scholar: lookup
  40. Jain NC. Essentials of veterinary hematology. Philadelphia: Lea & Febiger; 1993.

Citations

This article has been cited 9 times.
  1. Neves LC, Paula WVF, de Paula LGF, da Silva BBF, Dias SA, Pereira BG, Silva BSA, Sevá ADP, Dantas-Torres F, Labruna MB, Krawczak FDS. Detection of Rickettsia spp. in Animals and Ticks in Midwestern Brazil, Where Human Cases of Rickettsiosis Were Reported.. Animals (Basel) 2023 Apr 9;13(8).
    doi: 10.3390/ani13081288pubmed: 37106851google scholar: lookup
  2. Bonilla-Aldana DK, Castaño-Betancourt KJ, Ortega-Martínez JM, Ulloque-Badaracco JR, Hernandez-Bustamante EA, Benites-Zapata VA, Rodriguez-Morales AJ. Prevalence of zoonotic and non-zoonotic Rickettsia in horses: A systematic review and meta-analysis.. New Microbes New Infect 2023 Jan;51:101068.
    doi: 10.1016/j.nmni.2022.101068pubmed: 36632173google scholar: lookup
  3. Campos JBV, Martins FS, de Oliveira CE, Taveira AA, Oliveira JR, Gonçalves LR, Cordeiro MD, Calchi AC, de Campos Binder L, Serpa MCA, Barbieri ARM, Labruna MB, Machado RZ, de Andrade GB, André MR, Herrera HM. Tick-borne zoonotic agents infecting horses from an urban area in Midwestern Brazil: epidemiological and hematological features.. Trop Anim Health Prod 2021 Sep 22;53(5):475.
    doi: 10.1007/s11250-021-02887-wpubmed: 34553290google scholar: lookup
  4. Durães LS, Bitencourth K, Ramalho FR, Nogueira MC, Nunes EC, Gazêta GS. Biodiversity of Potential Vectors of Rickettsiae and Epidemiological Mosaic of Spotted Fever in the State of Paraná, Brazil.. Front Public Health 2021;9:577789.
    doi: 10.3389/fpubh.2021.577789pubmed: 33777873google scholar: lookup
  5. Luz HR, Costa FB, Benatti HR, Ramos VN, de A Serpa MC, Martins TF, Acosta ICL, Ramirez DG, Muñoz-Leal S, Ramirez-Hernandez A, Binder LC, Carvalho MP, Rocha V, Dias TC, Simeoni CL, Brites-Neto J, Brasil J, Nievas AM, Monticelli PF, Moro MEG, Lopes B, Aguiar DM, Pacheco RC, Souza CE, Piovezan U, Juliano R, Ferraz KMPMB, Szabó MPJ, Labruna MB. Epidemiology of capybara-associated Brazilian spotted fever.. PLoS Negl Trop Dis 2019 Sep;13(9):e0007734.
    doi: 10.1371/journal.pntd.0007734pubmed: 31490924google scholar: lookup
  6. de Oliveira PB, Harvey TV, Fehlberg HF, Rocha JM, Martins TF, da Acosta ICL, Labruna MB, Faccini JLH, Albuquerque GR. Serologic and molecular survey of Rickettsia spp. in dogs, horses and ticks from the Atlantic rainforest of the state of Bahia, Brazil.. Exp Appl Acarol 2019 Jul;78(3):431-442.
    doi: 10.1007/s10493-019-00397-xpubmed: 31270640google scholar: lookup
  7. Ebani VV. Serological Evidence of Anaplasma phagocytophilum and Spotted Fever Group Rickettsia spp. Exposure in Horses from Central Italy.. Pathogens 2019 Jun 26;8(3).
    doi: 10.3390/pathogens8030088pubmed: 31247976google scholar: lookup
  8. Tomassone L, Portillo A, Nováková M, de Sousa R, Oteo JA. Neglected aspects of tick-borne rickettsioses.. Parasit Vectors 2018 Apr 24;11(1):263.
    doi: 10.1186/s13071-018-2856-ypubmed: 29690900google scholar: lookup
  9. Quintero V JC, Paternina T LE, Uribe Y A, Muskus C, Hidalgo M, Gil J, Cienfuegos G AV, Osorio Q L, Rojas A C. Eco-epidemiological analysis of rickettsial seropositivity in rural areas of Colombia: A multilevel approach.. PLoS Negl Trop Dis 2017 Sep;11(9):e0005892.
    doi: 10.1371/journal.pntd.0005892pubmed: 28922404google scholar: lookup