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

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.

Degradation of bovine complement C3 by trichomonad extracellular proteinase.

Bovine trichomoniasis is a local infection of the reproductive tract making interaction with mucosal host defenses crucial. Since the parasite is susceptible to killing by bovine complement, we investigated the role of the third component of complement (C3) in host parasite interactions. Bovine C3 was purified by anionic and cationic exchange chromatography.

Phylogenetic relationships of human and wildlife piroplasm isolates in the western United States inferred from the 18S nuclear small subunit RNA gene.

The 18S nuclear small subunit ribosomal RNA gene of piroplasms from wildlife and human cases of babesiosis in the western USA were isolated by PCR and sequenced. Phylogenetic analyses of these sequences and comparisons with sequences from other Babesia and Theileria species revealed that piroplasm isolates from the human cases were indistinguishable from some of the isolates from the western wildlife species, most notably the isolates from mule deer (Odocoileus hemionus). These results suggest that large ungulates may serve as reservoirs for human piroplasm infection.

Tritrichomonas foetus extracellular cysteine proteinase cleavage of bovine IgG2 allotypes.

Bovine trichomoniasis is a sexually transmitted disease associated with reproductive failure. Systemic immunization results in protective IgG antibodies in uterine and vaginal secretions. Because bovine IgG2 is a better opsonin than IgG1, it is potentially important in defense.

Clinical, anatomic, and immunopathologic characterization of Babesia gibsoni infection in the domestic dog (Canis familiaris).

The pathology associated with acute, chronic, and recrudescent Babesia gibsoni infections was characterized in a group of 6 naturally or experimentally infected, spleen-intact and splenectomized dogs. All experimentally infected dogs became acutely parasitemic, lethargic, anemic, thrombocytopenic, and hemoglobinuric. Anatomic lesions associated, with the disease included diffuse nonsuppurative periportal and centrilobular hepatitis, multifocal necrotizing arteritis, membranoproliferative glomerulonephritis, reactive lymphadenopathy, diffuse erythrophagocytosis, and extramedullary hematopoiesis.

Characterization of extracellular proteinases of Tritrichomonas foetus.

Proteinases released from Tritrichomonas foetus into a reducing buffer were characterized because we previously showed that they digested host proteins important in defense of the reproductive tract. These proteinases were shown to be extracellular because cell numbers did not decrease and trichomonads remained motile during their 3.5-hr incubation.

Seroprevalence of two Babesia spp. isolates in selected bighorn sheep (Ovis canadensis) and mule deer (Odocoileus hemionus) populations in California.

Sera from 111 bighorn sheep (Ovis canadensis) and 95 mule deer (Odocoileus hemionus) were tested using an indirect immunofluorescence assay for antibodies to two isolates of Babesia spp. recently obtained from these hosts in California (USA). The study populations were from six locations: three areas of real or potential sympatry of bighorn sheep and deer, one area with deer only, and two areas with bighorn sheep only.

Infection with a babesia-like organism in northern California.

Background: Human babesiosis is a tick-transmitted zoonosis associated with two protozoa of the family Piroplasmorida: Babesia microti (in the United States) and B. divergens (in Europe). Recently, infection with an unusual babesia-like piroplasm (designated WA1) was described in a patient from Washington State.

Cultivation and phylogenetic characterization of a newly recognized human pathogenic protozoan.

An intraerythrocytic protozoan (WA1) recently isolated from a patient in Washington State was shown to be morphologically identical to Babesia microti but biologically and genetically distinct. Continuous growth of WA1 was established in stationary erythrocyte cultures. Hybridization of a chemiluminescent Babesia-specific DNA probe to Southern blots of restriction enzyme-digested genomic DNA showed that WA1 could be distinguished from other Babesia species that were antigenically cross-reactive (Babesia gibsoni and babesial parasites from desert bighorn sheep, Ovis canadensis nelsoni) or known to infect humans (B.

Diagnosis of babesiosis: evaluation of a serologic test for the detection of Babesia microti antibody.

To assess the possibility of standardization of a commonly used indirect immunofluorescent antibody (IFA) test for detection of Babesia microti antibody in human sera, the results from four reference laboratories were compared. Patients with babesiosis from southern New England (n = 25) and subjects with no history of babesiosis from southern New England (n = 55) and Iceland (n = 50) were enrolled in the study. Anti-Babesia antibody titers were determined in a blinded fashion by IFA test.

Evaluation of the indirect fluorescent antibody test for diagnosis of Babesia gibsoni infections in dogs.

We determined the extent of the serologic cross-reactivity in the indirect fluorescent antibody (IFA) test for Babesia gibsoni, and the optimal cut-off titer for seropositivity in the test. The lowest titer to B gibsoni detected in a dog with naturally acquired clinical babesiosis was 1,280, and 7 of 12 dogs had titer between 10,240 and 20,480. Two experimentally infected normosplenic dogs developed high titer (40,960 to 81,920) to B gibsoni, and the same sera reacted in IFA tests for B canis (titer < or = 640), Toxoplasma gondii (titer < or = 2,560), and Neospora caninum (titer < or = 10,240).

Babesiosis in Washington State: a new species of Babesia?

Objective: To characterize the etiologic agent (WA1) of the first reported case of babesiosis acquired in Washington State.

Design: Case report, and serologic, molecular, and epizootiologic studies.

Setting: South-central Washington State.

The isolation and partial characterization of a Babesia sp. from desert bighorn sheep (Ovis canadensis nelsoni).

A novel Babesia parasite of desert bighorn sheep was isolated. Its taxonomic description, host range, pathogenicity and antigenic relatedness were investigated. The parasite was infective for black-tailed and white-tailed deer, but with host-specific differences compared to that of bighorn sheep.

Experimental Lyme disease in dogs produces arthritis and persistent infection.

Lyme disease was reproduced in specific pathogen-free beagle dogs by exposure to Borrelia burgdorferi-infected ticks (Ixodes dammini). Seroconversion and disease frequency were higher after exposure to infected adult ticks than to infected nymphs. Young pups developed clinical disease more readily than older dogs.

Isolation and in vitro cultivation of Babesia parasites from free-ranging desert bighorn sheep (Ovis canadensis nelsoni) and mule deer (Odocoileus hemionus) in California.

Protozoal parasites of the genus Babesia were isolated for the first time from free-ranging desert bighorn sheep (Ovis canadensis nelsoni) and mule deer (Odocoileus hemionus) populations in California by in vitro culture of host blood. These naturally infected animals did not have microscopically detectable parasitemia at the time blood was collected for parasite cultivation. Three isolates of small Babesia parasites were cultured from different sample groups of bighorn sheep, and 2 isolates of large Babesia parasites were cultured from a group of bighorn sheep and a group of mule deer, respectively.

Detection of Babesia microti by polymerase chain reaction.

Human babesiosis, which is caused by infection with the intraerythrocytic malarialike protozoan Babesia microti, has recently been diagnosed with increasing frequency in residents of New England. Diagnosis is difficult because of the small size of the parasite and the sparse parasitemia that is characteristic of most infections with this pathogen. We generated B.

Ribosomal DNA probe for differentiation of Babesia microti and B. gibsoni isolates.

The objective of this study was to determine whether different isolates of Babesia microti could be distinguished from morphologically similar isolates of B. gibsoni by using a ribosomal DNA (rDNA) probe. A Babesia-specific rDNA probe was obtained by polymerase chain reaction amplification of sequences from B.

Hemolytic anemia caused by Babesia gibsoni infection in dogs.

Babesia gibsoni caused severe hemolytic anemia in 11 dogs from southern California. The most common clinical signs of B gibsoni infection were lethargy, anorexia, anemia, and thrombocytopenia. Acute infection with B gibsoni may be misdiagnosed as autoimmune hemolytic anemia.

Developmental changes in Hymenolepis citelli and Hymenolepis diminuta during patency.

Stem cell frequency, wet weight, proglottid number, and egg production were measured in Hymenolepis citelli at specific intervals between 20 and 120 days postinfection in an effort to correlate changes in stem cell frequency to other developmental parameters. Considerable variability was seen in wet weight and proglottid number, but differences did not seem to reflect any relation between these parameters and stem cell frequency. Significant differences were observed in egg production at specific postinfection periods.