Detection of Theileria equi in spleen and blood of asymptomatic piroplasm carrier horses

Ribeiro, Isabel Bezerra; Câmara, Antônio Carlos Lopes; Bittencourt, Marta Vasconcelos; Marçola, Tatiana Guerrero; Paludo, Giane Regina; Soto-Blanco, Benito

doi:10.2478/s11686-013-0127-9

Cited by 14 publications

(8 citation statements)

References 51 publications

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“…Previous research has demonstrated the presence of T. equi in the spleen of asymptomatic horses at times where it was undetectable in the peripheral blood via multiplex PCR [ 2 ]. Additionally, it is possible that the level of parasitemia was simply lower than the detectable limit, and that the small number of parasites surviving drug treatment was still sufficient to allow continued infection after a period of parasite recovery.…”

Section: Discussionmentioning

confidence: 99%

Theileria equi isolates vary in susceptibility to imidocarb dipropionate but demonstrate uniform in vitro susceptibility to a bumped kinase inhibitor

Hines

Ramsay

Kappmeyer

et al. 2015

Parasites & Vectors

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BackgroundThe apicomplexan hemoparasite Theileria equi is a causative agent of equine piroplasmosis, eradicated from the United States in 1988. However, recent outbreaks have sparked renewed interest in treatment options for infected horses. Imidocarb dipropionate is the current drug of choice, however variation in clinical response to therapy has been observed.MethodsWe quantified the in vitro susceptibility of two T. equi isolates and a lab generated variant to both imidocarb dipropionate and a bumped kinase inhibitor compound 1294. We also evaluated the capacity of in vitro imidocarb dipropionate exposure to decrease susceptibility to that drug. The efficacy of imidocarb dipropionate for clearing infection in four T. equi infected ponies was also assessed.ResultsWe observed an almost four-fold difference in imidocarb dipropionate susceptibility between two distinct isolates of T. equi. Four ponies infected with the less susceptible USDA Florida strain failed to clear the parasite despite two rounds of treatment. Importantly, a further 15-fold decrease in susceptibility was produced in this strain by continuous in vitro imidocarb dipropionate exposure. Despite a demonstrated difference in imidocarb dipropionate susceptibility, there was no difference in the susceptibility of two T. equi isolates to bumped kinase inhibitor 1294.ConclusionsThe observed variation in imidocarb dipropionate susceptibility, further reduction in susceptibility caused by drug exposure in vitro, and failure to clear T. equi infection in vivo, raises concern for the emergence of drug resistance in clinical cases undergoing treatment. Bumped kinase inhibitors may be effective as alternative drugs for the treatment of resistant T. equi parasites.

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Section: Discussionmentioning

confidence: 99%

Theileria equi isolates vary in susceptibility to imidocarb dipropionate but demonstrate uniform in vitro susceptibility to a bumped kinase inhibitor

Hines

Ramsay

Kappmeyer

et al. 2015

Parasites & Vectors

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“…infection in splenectomized dogs [14]. Theileria equi was found in the spleen of asymptomatic horses that did not show parasitemia, which suggested that this might be an important tissue supporting the persistence of the parasite in the host [15]. …”

Section: Introductionmentioning

confidence: 99%

Molecular detection of vector-borne pathogens in blood and splenic samples from dogs with splenic disease

et al. 2017

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BackgroundThe spleen is a highly perfused organ involved in the immunological control and elimination of vector-borne pathogens (VBP), which could have a fundamental role in the pathogenesis of splenic disease. This study aimed to evaluate certain VBP in samples from dogs with splenic lesions.MethodsSeventy-seven EDTA-blood and 64 splenic tissue samples were collected from 78 dogs with splenic disease in a Mediterranean area. Babesia spp., Bartonella spp., Ehrlichia/Anaplasma spp., Hepatozoon canis, Leishmania infantum, hemotropic Mycoplasma spp. and Rickettsia spp. were targeted using PCR assays. Sixty EDTA-blood samples from dogs without evidence of splenic lesions were included as a control group.ResultsMore than half (51.56%) of the biopsies (33/64) were consistent with benign lesions and 48.43% (31/64) with malignancy, mostly hemangiosarcoma (25/31). PCR yielded positive results in 13 dogs with spleen alterations (16.67%), for Babesia canis (n = 3), Babesia gibsoni (n = 2), hemotropic Mycoplasma spp. (n = 2), Rickettsia massiliae (n = 1) and “Babesia vulpes” (n = 1), in blood; and for B. canis, B. gibsoni, Ehrlichia canis and L. infantum (n = 1 each), in spleen. Two control dogs (3.3%) were positive for B. gibsoni and H. canis (n = 1 each). Benign lesions were detected in the 61.54% of infected dogs (8/13); the remaining 38.46% were diagnosed with malignancies (5/13). Infection was significantly associated to the presence of splenic disease (P = 0.013). There was no difference in the prevalence of infection between dogs with benign and malignant splenic lesions (P = 0.69); however B. canis was more prevalent in dogs with hemangiosarcoma (P = 0.006).ConclusionsVBP infection could be involved in the pathogenesis of splenic disease. The immunological role of the spleen could predispose to alterations of this organ in infected dogs. Interestingly, all dogs with B. canis infection were diagnosed with hemangiosarcoma in the present survey. As previously reported, results support that VBP diagnosis could be improved by analysis of samples from different tissues. The sample size included here warrants further investigation.Electronic supplementary materialThe online version of this article (doi:10.1186/s13071-017-2074-z) contains supplementary material, which is available to authorized users.

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“…T. equi infections lead to a carrier state with low parasitemia that is unlikely to be identified in a blood smear or even by PCR testing [ 11 , 26 ]. This highlights the importance of increasing the sensitivity of direct parasite detection by performing repeated blood smears and PCR tests [ 27 ].…”

Section: Discussionmentioning

confidence: 99%

First Case of Autochthonous Equine Theileriosis in Austria

et al. 2021

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A 23-year-old pregnant warmblood mare from Güssing, Eastern Austria, presented with apathy, anemia, fever, tachycardia and tachypnoea, and a severely elevated serum amyloid A concentration. The horse had a poor body condition and showed thoracic and pericardial effusions, and later dependent edema and icteric mucous membranes. Blood smear and molecular analyses revealed an infection with Theileria equi. Upon treatment with imidocarb diproprionate, the mare improved clinically, parasites were undetectable in blood smears, and 19 days after hospitalization the horse was discharged from hospital. However, 89 days after first hospitalization, the mare again presented to the hospital with an abortion, and the spleen of the aborted fetus was also PCR-positive for T. equi. On the pasture, where the horse had grazed, different developmental stages of Dermacentor reticulatus ticks were collected and subjected to PCR, and one engorged specimen was positive for T. equi. All three amplicon sequences were identical (T. equi genotype E). It is suspected that T. equi may repeatedly be transmitted in the area where the infected mare had grazed, and it could be shown that transmission to the fetus had occurred. Due to the chronic nature of equine theileriosis and the possible health implications of infection, it is advised to include this disease in the panel of differential diagnoses in horses with relevant clinical signs, including horses without travel disease, and to be aware of iatrogenic transmission from inapparent carrier animals.

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Detection of Theileria equi in spleen and blood of asymptomatic piroplasm carrier horses

Cited by 14 publications

References 51 publications

Theileria equi isolates vary in susceptibility to imidocarb dipropionate but demonstrate uniform in vitro susceptibility to a bumped kinase inhibitor

Theileria equi isolates vary in susceptibility to imidocarb dipropionate but demonstrate uniform in vitro susceptibility to a bumped kinase inhibitor

Molecular detection of vector-borne pathogens in blood and splenic samples from dogs with splenic disease

First Case of Autochthonous Equine Theileriosis in Austria

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