Comparison of US and European Babesia divergens Isolates
Principal Investigator: P J Holman
Abstract: DESCRIPTION (provided by the applicant): Babesia divergens is a tick transmitted hemoprotozoan parasite that causes human Babesiosis in Europe. Neither B. divergens nor its vector tick are indigenous to the U.S. However, a recent case of acute Babesiosis in a resident of Kentucky was shown to be caused by a parasite morphologically indistinguishable from European Babesia divergens. The parasite in the Kentucky case was found to differ in the small subunit ribosomal RNA gene sequence at only 3 base positions from that of European B. divergens, providing evidence of conspecifity. Recently a Babesia isolate from cottontail rabbits on Nantucket Island was reported to have an identical gene sequence to that of the Kentucky parasite. Molecular epidemiology has also identified this parasite in Ixodes ticks on Nantucket Island, suggesting that an enzootic situation exists. The identification of another Babesia sp. in the US capable of causing human babesiosis is of major concern. Two other Babesia species that cause human Babesiosis in the US, Babesia microti, occurring mostly in the northeastern U.S., and the WA1 isolate, occurring in Washington state and California, have been implicated in blood transfusion acquired cases of babesiosis. Thus, the finding that another previously unknown human blood pathogen is troublesome. The purpose of this study is to compare the culture requirements and target genes of the Kentucky and Nantucket Babesia isolates with European B. divergens (Purnell strain) to determine if conspecificity exists among these parasites. Specific aims include establishing in vitro cultures of the Nantucket isolate and molecular comparison of ITS, HSP70, and cysteine protease genes from European B. divergens with those of the Kentucky and Nantucket isolates. Cultures of the Nantucket isolate will provide an unlimited source of parasites to complete these goals and for future studies. The molecular aspects may provide information that will be useful in future efforts to devise diagnostic tests.
Funding Period: 2003-04-01 - 2006-03-31
more information: NIH RePORT
- In vitro cultivation of a zoonotic Babesia sp. isolated from eastern cottontail rabbits (Sylvilagus floridanus) on Nantucket Island, MassachusettsPatricia J Holman
Department of Veterinary Pathobiology, Texas A and M University, College Station, TX 77843 4467, USA
J Clin Microbiol 43:3995-4001. 2005..Two continuous lines of the zoonotic Babesia sp. were established and confirmed to share identical SSU rRNA gene sequences with each other and with the Missouri and Kentucky human Babesia isolates...
- Comparative infectivity of Babesia divergens and a zoonotic Babesia divergens-like parasite in cattlePatricia J Holman
Department of Veterinary Pathobiology, College of Veterinary Medicine and Biomedical Sciences, Texas A and M University, College Station, Texas, USA
Am J Trop Med Hyg 73:865-70. 2005..NR831 recipients were fully susceptible upon challenge inoculation with B. divergens. This study confirms that the Nantucket Island Babesia sp. is not conspecific with B. divergens based on host specificity for cattle...
- In vitro host erythrocyte specificity and differential morphology of Babesia divergens and a zoonotic Babesia sp. from eastern cottontail rabbits (Sylvilagus floridanus)Angela M Spencer
Department of Veterinary Pathobiology, College of Veterinary Medicine and Biomedical Sciences, Texas A and M University, College Station, Texas 77843, USA
J Parasitol 92:333-40. 2006..divergens. The erythrocyte specificity and morphological differences reported in this study agree with previous in vivo results and validate the use of in vitro methods for characterization of Babesia species...
- Phylogenetic and biologic evidence that Babesia divergens is not endemic in the United StatesPatricia J Holman
Department of Veterinary Pathobiology, College of Veterinary Medicine and Biomedical Sciences, Texas A and M University, College Station, TX 77843, USA
Ann N Y Acad Sci 1081:518-25. 2006..divergens...