Description of Babesia duncani n.sp. (Apicomplexa: Babesiidae) from humans and its differentiation from other piroplasms

Patricia A Conrad, Anne M. Kjemtrup, Ramon A. Carreno, John Thomford, Katlyn Wainwright, Mark Eberhard, Rob Quick, Sam R. Telford, Barbara L. Herwaldt

Research output: Contribution to journalArticle

115 Citations (Scopus)

Abstract

The morphologic, ultrastructural and genotypic characteristics of Babesia duncani n.sp. are described based on the characterization of two isolates (WA1, CA5) obtained from infected human patients in Washington and California. The intraerythrocytic stages of the parasite are morphologically indistinguishable from Babesia microti, which is the most commonly identified cause of human babesiosis in the USA. Intraerythrocytic trophozoites of B. duncani n.sp. are round to oval, with some piriform, ring and ameboid forms. Division occurs by intraerythrocytic schizogony, which results in the formation of merozoites in tetrads (syn. Maltese cross or quadruplet forms). The ultrastructural features of trophozoites and merozoites are similar to those described for B. microti and Theileria spp. However, intralymphocytic schizont stages characteristic of Theileria spp. have not been observed in infected humans. In phylogenetic analyses based on sequence data for the complete18S ribosomal RNA gene, B. duncani n.sp. lies in a distinct clade that includes isolates from humans, dogs and wildlife in the western United States but separate from Babesia sensu stricto, Theileria spp. and B. microti. ITS2 sequence analysis of the B. duncani n.sp. isolates (WA1, CA5) show that they are phylogenetically indistinguishable from each other and from two other human B. duncani-type parasites (CA6, WA2 clone1) but distinct from other Babesia and Theileria species sequenced. This analysis provides robust molecular support that the B. duncani n.sp. isolates are monophyletic and the same species. The morphologic characteristics together with the phylogenetic analysis of two genetic loci support the assertion that B. duncani n.sp. is a distinct species from other known Babesia spp. for which morphologic and sequence information are available.

Original languageEnglish (US)
Pages (from-to)779-789
Number of pages11
JournalInternational Journal for Parasitology
Volume36
Issue number7
DOIs
StatePublished - Jun 2006

Fingerprint

Theileria
Apicomplexa
Babesia
Babesia microti
Merozoites
Trophozoites
Parasites
Babesiosis
Schizonts
Genetic Loci
rRNA Genes
Sequence Analysis
Dogs

Keywords

  • 18S rRNA
  • Babesia
  • Babesiosis
  • ITS2
  • Theileria
  • Ultrastructure

ASJC Scopus subject areas

  • Parasitology
  • Infectious Diseases

Cite this

Description of Babesia duncani n.sp. (Apicomplexa : Babesiidae) from humans and its differentiation from other piroplasms. / Conrad, Patricia A; Kjemtrup, Anne M.; Carreno, Ramon A.; Thomford, John; Wainwright, Katlyn; Eberhard, Mark; Quick, Rob; Telford, Sam R.; Herwaldt, Barbara L.

In: International Journal for Parasitology, Vol. 36, No. 7, 06.2006, p. 779-789.

Research output: Contribution to journalArticle

Conrad, PA, Kjemtrup, AM, Carreno, RA, Thomford, J, Wainwright, K, Eberhard, M, Quick, R, Telford, SR & Herwaldt, BL 2006, 'Description of Babesia duncani n.sp. (Apicomplexa: Babesiidae) from humans and its differentiation from other piroplasms', International Journal for Parasitology, vol. 36, no. 7, pp. 779-789. https://doi.org/10.1016/j.ijpara.2006.03.008
Conrad, Patricia A ; Kjemtrup, Anne M. ; Carreno, Ramon A. ; Thomford, John ; Wainwright, Katlyn ; Eberhard, Mark ; Quick, Rob ; Telford, Sam R. ; Herwaldt, Barbara L. / Description of Babesia duncani n.sp. (Apicomplexa : Babesiidae) from humans and its differentiation from other piroplasms. In: International Journal for Parasitology. 2006 ; Vol. 36, No. 7. pp. 779-789.
@article{8084b98de76b4128b2581a3ccf38eb11,
title = "Description of Babesia duncani n.sp. (Apicomplexa: Babesiidae) from humans and its differentiation from other piroplasms",
abstract = "The morphologic, ultrastructural and genotypic characteristics of Babesia duncani n.sp. are described based on the characterization of two isolates (WA1, CA5) obtained from infected human patients in Washington and California. The intraerythrocytic stages of the parasite are morphologically indistinguishable from Babesia microti, which is the most commonly identified cause of human babesiosis in the USA. Intraerythrocytic trophozoites of B. duncani n.sp. are round to oval, with some piriform, ring and ameboid forms. Division occurs by intraerythrocytic schizogony, which results in the formation of merozoites in tetrads (syn. Maltese cross or quadruplet forms). The ultrastructural features of trophozoites and merozoites are similar to those described for B. microti and Theileria spp. However, intralymphocytic schizont stages characteristic of Theileria spp. have not been observed in infected humans. In phylogenetic analyses based on sequence data for the complete18S ribosomal RNA gene, B. duncani n.sp. lies in a distinct clade that includes isolates from humans, dogs and wildlife in the western United States but separate from Babesia sensu stricto, Theileria spp. and B. microti. ITS2 sequence analysis of the B. duncani n.sp. isolates (WA1, CA5) show that they are phylogenetically indistinguishable from each other and from two other human B. duncani-type parasites (CA6, WA2 clone1) but distinct from other Babesia and Theileria species sequenced. This analysis provides robust molecular support that the B. duncani n.sp. isolates are monophyletic and the same species. The morphologic characteristics together with the phylogenetic analysis of two genetic loci support the assertion that B. duncani n.sp. is a distinct species from other known Babesia spp. for which morphologic and sequence information are available.",
keywords = "18S rRNA, Babesia, Babesiosis, ITS2, Theileria, Ultrastructure",
author = "Conrad, {Patricia A} and Kjemtrup, {Anne M.} and Carreno, {Ramon A.} and John Thomford and Katlyn Wainwright and Mark Eberhard and Rob Quick and Telford, {Sam R.} and Herwaldt, {Barbara L.}",
year = "2006",
month = "6",
doi = "10.1016/j.ijpara.2006.03.008",
language = "English (US)",
volume = "36",
pages = "779--789",
journal = "International Journal for Parasitology",
issn = "0020-7519",
publisher = "Elsevier Limited",
number = "7",

}

TY - JOUR

T1 - Description of Babesia duncani n.sp. (Apicomplexa

T2 - Babesiidae) from humans and its differentiation from other piroplasms

AU - Conrad, Patricia A

AU - Kjemtrup, Anne M.

AU - Carreno, Ramon A.

AU - Thomford, John

AU - Wainwright, Katlyn

AU - Eberhard, Mark

AU - Quick, Rob

AU - Telford, Sam R.

AU - Herwaldt, Barbara L.

PY - 2006/6

Y1 - 2006/6

N2 - The morphologic, ultrastructural and genotypic characteristics of Babesia duncani n.sp. are described based on the characterization of two isolates (WA1, CA5) obtained from infected human patients in Washington and California. The intraerythrocytic stages of the parasite are morphologically indistinguishable from Babesia microti, which is the most commonly identified cause of human babesiosis in the USA. Intraerythrocytic trophozoites of B. duncani n.sp. are round to oval, with some piriform, ring and ameboid forms. Division occurs by intraerythrocytic schizogony, which results in the formation of merozoites in tetrads (syn. Maltese cross or quadruplet forms). The ultrastructural features of trophozoites and merozoites are similar to those described for B. microti and Theileria spp. However, intralymphocytic schizont stages characteristic of Theileria spp. have not been observed in infected humans. In phylogenetic analyses based on sequence data for the complete18S ribosomal RNA gene, B. duncani n.sp. lies in a distinct clade that includes isolates from humans, dogs and wildlife in the western United States but separate from Babesia sensu stricto, Theileria spp. and B. microti. ITS2 sequence analysis of the B. duncani n.sp. isolates (WA1, CA5) show that they are phylogenetically indistinguishable from each other and from two other human B. duncani-type parasites (CA6, WA2 clone1) but distinct from other Babesia and Theileria species sequenced. This analysis provides robust molecular support that the B. duncani n.sp. isolates are monophyletic and the same species. The morphologic characteristics together with the phylogenetic analysis of two genetic loci support the assertion that B. duncani n.sp. is a distinct species from other known Babesia spp. for which morphologic and sequence information are available.

AB - The morphologic, ultrastructural and genotypic characteristics of Babesia duncani n.sp. are described based on the characterization of two isolates (WA1, CA5) obtained from infected human patients in Washington and California. The intraerythrocytic stages of the parasite are morphologically indistinguishable from Babesia microti, which is the most commonly identified cause of human babesiosis in the USA. Intraerythrocytic trophozoites of B. duncani n.sp. are round to oval, with some piriform, ring and ameboid forms. Division occurs by intraerythrocytic schizogony, which results in the formation of merozoites in tetrads (syn. Maltese cross or quadruplet forms). The ultrastructural features of trophozoites and merozoites are similar to those described for B. microti and Theileria spp. However, intralymphocytic schizont stages characteristic of Theileria spp. have not been observed in infected humans. In phylogenetic analyses based on sequence data for the complete18S ribosomal RNA gene, B. duncani n.sp. lies in a distinct clade that includes isolates from humans, dogs and wildlife in the western United States but separate from Babesia sensu stricto, Theileria spp. and B. microti. ITS2 sequence analysis of the B. duncani n.sp. isolates (WA1, CA5) show that they are phylogenetically indistinguishable from each other and from two other human B. duncani-type parasites (CA6, WA2 clone1) but distinct from other Babesia and Theileria species sequenced. This analysis provides robust molecular support that the B. duncani n.sp. isolates are monophyletic and the same species. The morphologic characteristics together with the phylogenetic analysis of two genetic loci support the assertion that B. duncani n.sp. is a distinct species from other known Babesia spp. for which morphologic and sequence information are available.

KW - 18S rRNA

KW - Babesia

KW - Babesiosis

KW - ITS2

KW - Theileria

KW - Ultrastructure

UR - http://www.scopus.com/inward/record.url?scp=33744975016&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=33744975016&partnerID=8YFLogxK

U2 - 10.1016/j.ijpara.2006.03.008

DO - 10.1016/j.ijpara.2006.03.008

M3 - Article

C2 - 16725142

AN - SCOPUS:33744975016

VL - 36

SP - 779

EP - 789

JO - International Journal for Parasitology

JF - International Journal for Parasitology

SN - 0020-7519

IS - 7

ER -