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Scientific reports2020; 10(1); 7208; doi: 10.1038/s41598-020-64328-2

Detection of Neorickettsia risticii, the agent of Potomac horse fever, in horses from Rio de Janeiro, Brazil.

Abstract: This study aims to report the presence of Neorickettsia risticii DNA in blood samples from naturally infected horses in Rio de Janeiro, provide clinicopathological findings related to the infection, and report the phylogenetic diversity of the 16S rDNA of N. risticii in order to evaluate its heterogeneity. Real-time quantitative polymerase chain reaction (qPCR) was performed to investigate the presence of N. risticii in samples collected from horses (n = 187). Five positive samples were found in the molecular screening. Hypoalbuminemia and high levels of creatine kinase and lactate dehydrogenase were the predominant findings in the biochemical analysis. The sequences were similar to those of N. risticii. Phylogenetic analysis revealed genotype segregation based on the geographical distribution in the N. risticii sequence clade. Dendrograms constructed with five hypervariable regions revealed that V4 distinguished Neorickettsia at the species level and produced a phylogeny that best represented the phylogeny obtained with the complete 16S rDNA sequence. This is the first report of N. risticii DNA in the blood of Brazilian horses based on sequences deposited in GenBank. Further studies are necessary to clarify the epidemiological chain of this vector-borne parasite in order to determine and establish appropriate preventive measures in the equine trading market.
Publication Date: 2020-04-29 PubMed ID: 32350359PubMed Central: PMC7190851DOI: 10.1038/s41598-020-64328-2Google Scholar: Lookup
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  • Journal Article
  • Research Support
  • Non-U.S. Gov't

Summary

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The research article outlines the detection of a harmful pathogen, Neorickettsia risticii, in horses in Rio De Janeiro, Brazil. The study aimed to not only identify the presence of the bacteria but also understand its genetic diversity and associated clinical symptoms in infected horses.

Methodology and Objectives

  • The goal of the study was to identify the presence of Neorickettsia risticii DNA in blood samples from horses in Rio de Janeiro. It also aimed to provide information on the clinical signs of the infection in horses.
  • Additionally, the examination of the phylogenetic diversity of the 16S rDNA of Neorickettsia risticii was conducted to assess its heterogeneity. The 16S rDNA is a type of DNA sequence that scientists often use to classify and identify bacteria.
  • The team employed real-time quantitative polymerase chain reaction (qPCR), a technique used to amplify and detect DNA sequences, on samples collected from 187 horses.

Findings

  • Five samples tested positive for N. risticii in the molecular screening. Among these horses, low levels of albumin, and high levels of creatine kinase and lactate dehydrogenase were found, suggesting these could be key indicators of the infection.
  • The sequences identified were similar to those of N. risticii, confirming the presence of this bacteria. Phylogenetic analysis, a method used to study the evolutionary relationships between organisms, revealed a pattern of genotype segregation based on geographical distribution within the sequence clade of N. risticii. A clade is a group of organisms believed to have a common ancestor.
  • Dendrograms were constructed using five hypervariable regions and it was observed that the V4 region was effective in identifying Neorickettsia at the species level, and it displayed a phylogeny that was representative of the one acquired with the full 16S rDNA sequence.

Implications and Recommendations

  • It’s the first time that N. risticii DNA has been reported in the blood of Brazilian horses, a finding that could have significant implications for veterinary care and the horse trading market in the region.
  • The researchers recommended further investigation into the epidemiological chain of this vector-borne parasite. An understanding of how the bacteria spreads and its impact is crucial for establishing effective preventive measures in the equine trading market.

Cite This Article

APA
Paulino PG, Almosny N, Oliveira R, Viscardi V, Müller A, Guimarães A, Baldani C, da Silva C, Peckle M, Massard C, Santos H. (2020). Detection of Neorickettsia risticii, the agent of Potomac horse fever, in horses from Rio de Janeiro, Brazil. Sci Rep, 10(1), 7208. https://doi.org/10.1038/s41598-020-64328-2

Publication

ISSN: 2045-2322
NlmUniqueID: 101563288
Country: England
Language: English
Volume: 10
Issue: 1
Pages: 7208
PII: 7208

Researcher Affiliations

Paulino, Patrícia Gonzaga
  • Department of Epidemiology and Public Health, Federal Rural University of Rio de Janeiro (UFRRJ), BR 465, Km 7, Seropedica, RJ, 23890000, Brazil. patgpaulino@gmail.com.
Almosny, Nádia
  • Department of Veterinary Clinic and Pathology, Federal Fluminense University, Niteroi, Brazil.
Oliveira, Renata
  • Department of Veterinary Clinic and Pathology, Federal Fluminense University, Niteroi, Brazil.
Viscardi, Vanessa
  • Department of Veterinary Clinic and Pathology, Federal Fluminense University, Niteroi, Brazil.
Müller, Ananda
  • Ross University School of Veterinary Medicine, Basseterre, Saint Kitts and Nevis.
  • Instituto de Ciencias Clínicas Veterinarias, Universidad Austral de Chile, Valdivia, Chile.
Guimarães, Andresa
  • Department of Veterinary Medicine and Surgery, Veterinary Institute, Federal Rural University of Rio de Janeiro (UFRRJ), BR 465, Km 7, Seropedica, RJ, 23890000, Brazil.
Baldani, Cristiane
  • Department of Veterinary Medicine and Surgery, Veterinary Institute, Federal Rural University of Rio de Janeiro (UFRRJ), BR 465, Km 7, Seropedica, RJ, 23890000, Brazil.
da Silva, Claudia
  • Department of Animal Parasitology, Federal Rural University of Rio de Janeiro (UFRRJ), BR 465, Km 7, Seropedica, RJ, 23890000, Brazil.
Peckle, Maristela
  • Department of Animal Parasitology, Federal Rural University of Rio de Janeiro (UFRRJ), BR 465, Km 7, Seropedica, RJ, 23890000, Brazil.
Massard, Carlos
  • Department of Animal Parasitology, Federal Rural University of Rio de Janeiro (UFRRJ), BR 465, Km 7, Seropedica, RJ, 23890000, Brazil.
Santos, Huarrisson
  • Department of Epidemiology and Public Health, Federal Rural University of Rio de Janeiro (UFRRJ), BR 465, Km 7, Seropedica, RJ, 23890000, Brazil.

MeSH Terms

  • Anaplasmataceae Infections / diagnosis
  • Anaplasmataceae Infections / genetics
  • Anaplasmataceae Infections / microbiology
  • Anaplasmataceae Infections / veterinary
  • Animals
  • Brazil
  • DNA, Bacterial / genetics
  • DNA, Ribosomal / genetics
  • Horse Diseases / diagnosis
  • Horse Diseases / genetics
  • Horse Diseases / microbiology
  • Horses
  • Neorickettsia risticii / genetics
  • Neorickettsia risticii / isolation & purification
  • Phylogeny
  • RNA, Bacterial / genetics
  • RNA, Ribosomal, 16S / genetics

Conflict of Interest Statement

The authors declare no competing interests.

References

This article includes 31 references
  1. Holland CJ, Ristic M, Cole AI, Johnson P, Baker G, Goetz T. Isolation, experimental transmission, and characterization of causative agent of Potomac horse fever.. Science 1985 Feb 1;227(4686):522-4.
    doi: 10.1126/science.3880925pubmed: 3880925google scholar: lookup
  2. Marutani VHB, Headley SA, Bracarense APFRL. Putative Equine Neorickettsiosis in a Mare from Southern Brazil. Acta Scientiae Veterinariae 2019;47:451.
    doi: 10.22456/1679-9216.97586google scholar: lookup
  3. Xiong Q, Bekebrede H, Sharma P, Arroyo LG, Baird JD, Rikihisa Y. An Ecotype of Neorickettsia risticii Causing Potomac Horse Fever in Canada.. Appl Environ Microbiol 2016 Oct 1;82(19):6030-6.
    doi: 10.1128/AEM.01366-16pmc: PMC5038023pubmed: 27474720google scholar: lookup
  4. Lin M, Zhang C, Gibson K, Rikihisa Y. Analysis of complete genome sequence of Neorickettsia risticii: causative agent of Potomac horse fever.. Nucleic Acids Res 2009 Oct;37(18):6076-91.
    doi: 10.1093/nar/gkp642pmc: PMC2764437pubmed: 19661282google scholar: lookup
  5. Shaw SD, Stämpfli H. Diagnosis and Treatment of Undifferentiated and Infectious Acute Diarrhea in the Adult Horse.. Vet Clin North Am Equine Pract 2018 Apr;34(1):39-53.
    doi: 10.1016/j.cveq.2017.11.002pmc: PMC7134835pubmed: 29426709google scholar: lookup
  6. Bertin FR, Reising A, Slovis NM, Constable PD, Taylor SD. Clinical and clinicopathological factors associated with survival in 44 horses with equine neorickettsiosis (Potomac horse Fever).. J Vet Intern Med 2013 Nov-Dec;27(6):1528-34.
    doi: 10.1111/jvim.12209pubmed: 24118378google scholar: lookup
  7. Coimbra HS, Schuch LFD, Veitenheimer MIL, Meireles MCA. Neorickettsia (Ehrlichia) risticii no Sul do Brasil: Heleobia spp. (Mollusca: Hydrobilidae) e Parapleurolophocecous cercariae (Trematoda: Digenea) como possíveis vetores. Arq. Inst. Biol. 2005;72:325–329.
  8. Dutra F, Schuch LF, Delucchi E, Curcio BR, Coimbra H, Raffi MB, Dellagostin O, Riet-Correa F. Equine monocytic Ehrlichiosis (Potomac horse fever) in horses in Uruguay and southern Brazil.. J Vet Diagn Invest 2001 Sep;13(5):433-7.
    doi: 10.1177/104063870101300514pubmed: 11580069google scholar: lookup
  9. Heller MC, McClure J, Pusterla N, Pusterla JB, Stahel S. Two cases of Neorickettsia (Ehrlichia) risticii infection in horses from Nova Scotia.. Can Vet J 2004 May;45(5):421-3.
    pmc: PMC548627pubmed: 15206592
  10. Cicuttin GL. Molecular detection of Neorickettsia risticii in Brazilian free-tailed bats (Tadarida brasiliensis) from Buenos Aires, Argentina. Pesqui. Vet. Bras. 2013;33:648–650.
  11. Cicuttin GL, De Salvo MN, La Rosa I, Dohmen FEG. Neorickettsia risticii, Rickettsia sp. and Bartonella sp. in Tadarida brasiliensis bats from Buenos Aires, Argentina.. Comp Immunol Microbiol Infect Dis 2017 Jun;52:1-5.
    doi: 10.1016/j.cimid.2017.04.004.pubmed: 28673455google scholar: lookup
  12. Cicuttin GL, Greiman SE. Análisis filogenético de Neorickettsia risticii detectada em murciélagos de Argentina. InVet. 2016;18:341–347.
  13. Coimbra HS. Ehrliquiose Monocítica Equina no Rio Grande do Sul: aspectos clínicos, anatomopatológicos e epidemiológicos. Pesqui. Vet. Bras. 2006;26:97–101.
  14. Ferrão CM. Equine monocytic ehrlichiosis (EME) in Rio de Janeiro State, Brazil. Arq. Bras. Med. Vet. Zootec. 2007;59:1575–1578.
  15. Moreira LMC. Frequency of equine monocytic ehrlichiosis (EME) in Brazil. Pesqui. Vet. Bras. 2013;33:697–699.
  16. Roier ECR. Epidemiological survey of Neorickettsia risticii in equids from the State of Rio de Janeiro, Brazil. Pesqui. Vet. Bras. 2016;36:939–946.
  17. Dumler JS, Barbet AF, Bekker CP, Dasch GA, Palmer GH, Ray SC, Rikihisa Y, Rurangirwa FR. Reorganization of genera in the families Rickettsiaceae and Anaplasmataceae in the order Rickettsiales: unification of some species of Ehrlichia with Anaplasma, Cowdria with Ehrlichia and Ehrlichia with Neorickettsia, descriptions of six new species combinations and designation of Ehrlichia equi and 'HGE agent' as subjective synonyms of Ehrlichia phagocytophila.. Int J Syst Evol Microbiol 2001 Nov;51(Pt 6):2145-2165.
    doi: 10.1099/00207713-51-6-2145pubmed: 11760958google scholar: lookup
  18. Stackebrandt E, Goebel BM. Taxonomic Note: A Place for DNA-DNA Reassociation and 16S rRNA Sequence Analysis in the Present Species Definition in Bacteriology. Int. J. Syst. Evol. Microbiol. 1994;44(4):846–849.
    doi: 10.1099/00207713-44-4-846google scholar: lookup
  19. Marcolongo-Pereira C. Doenças de equinos na região Sul do Rio Grande do Sul. Pesqui. Vet. Bras. 2014;34:205–210.
  20. Kanter M, Mott J, Ohashi N, Fried B, Reed S, Lin YC, Rikihisa Y. Analysis of 16S rRNA and 51-kilodalton antigen gene and transmission in mice of Ehrlichia risticii in virgulate trematodes from Elimia livescens snails in Ohio.. J Clin Microbiol 2000 Sep;38(9):3349-58.
  21. Mott J, Muramatsu Y, Seaton E, Martin C, Reed S, Rikihisa Y. 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 2002 Feb;40(2):690-3.
  22. Chakravorty S, Helb D, Burday M, Connell N, Alland D. A detailed analysis of 16S ribosomal RNA gene segments for the diagnosis of pathogenic bacteria.. J Microbiol Methods 2007 May;69(2):330-9.
    doi: 10.1016/j.mimet.2007.02.005pmc: PMC2562909pubmed: 17391789google scholar: lookup
  23. Huse SM, Dethlefsen L, Huber JA, Mark Welch D, Relman DA, Sogin ML. Exploring microbial diversity and taxonomy using SSU rRNA hypervariable tag sequencing.. PLoS Genet 2008 Nov;4(11):e1000255.
  24. Stackebrandt E, Liesack W, Witt D. Ribosomal RNA and rDNA sequence analyses.. Gene 1992 Jun 15;115(1-2):255-60.
    doi: 10.1016/0378-1119(92)90567-9pubmed: 1612445google scholar: lookup
  25. Yang B, Wang Y, Qian PY. Sensitivity and correlation of hypervariable regions in 16S rRNA genes in phylogenetic analysis.. BMC Bioinformatics 2016 Mar 22;17:135.
    doi: 10.1186/s12859-016-0992-ypmc: PMC4802574pubmed: 27000765google scholar: lookup
  26. Taylor SD. Neorickettsia risticii. .
  27. Pusterla N, Leutenegger CM, Sigrist B, Chae JS, Lutz H, Madigan JE. Detection and quantitation of Ehrlichia risticii genomic DNA in infected horses and snails by real-time PCR.. Vet Parasitol 2000 Jun 10;90(1-2):129-35.
    doi: 10.1016/S0304-4017(00)00227-2pubmed: 10828519google scholar: lookup
  28. Greiman SE, Tkach VV, Pulis E, Fayton TJ, Curran SS. Large scale screening of digeneans for Neorickettsia endosymbionts using real-time PCR reveals new Neorickettsia genotypes, host associations and geographic records.. PLoS One 2014;9(6):e98453.
  29. Kumar S, Stecher G, Li M, Knyaz C, Tamura K. MEGA X: Molecular Evolutionary Genetics Analysis across Computing Platforms.. Mol Biol Evol 2018 Jun 1;35(6):1547-1549.
    doi: 10.1093/molbev/msw054pmc: PMC5967553pubmed: 29722887google scholar: lookup
  30. Kimura M. A simple method for estimating evolutionary rates of base substitutions through comparative studies of nucleotide sequences.. J Mol Evol 1980 Dec;16(2):111-20.
    doi: 10.1007/BF01731581pubmed: 7463489google scholar: lookup
  31. Hall TA. BioEdit: a user-friendly biological sequence alignment editor and analysis program for Windows 95/98/NT. Nucleic Acids Symp. Ser. 1999;41:95–98.

Citations

This article has been cited 2 times.
  1. Perles L, Barreto WTG, Macedo GC, Herrera HM, Machado RZ, André MR. Neorickettsia sp. in coatis (Nasua nasua) in Brazil.. Rev Bras Parasitol Vet 2023;32(3):e006623.
    doi: 10.1590/S1984-29612023042pubmed: 37466626google scholar: lookup
  2. Thirumalapura NR, Livengood J, Beeby J, Wang W, Goodrich EL, Goodman LB, Erol E, Tewari D. Improved molecular detection of Neorickettsia risticii with a duplex real-time PCR assay in the diagnosis of Potomac horse fever.. J Vet Diagn Invest 2023 Jan;35(1):62-66.
    doi: 10.1177/10406387221135184pubmed: 36373552google scholar: lookup