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Clinical Microbiology Reviews Jul 2002Babesia and its close relatives are members of a group of organisms called piroplasms, a name which comes from their pear-shaped outlines. Long associated with blood... (Review)
Review
Babesia and its close relatives are members of a group of organisms called piroplasms, a name which comes from their pear-shaped outlines. Long associated with blood diseases of cattle and other mammals, members of the genus Babesia have been recognized since the 1950s as infectious agents in humans. Species of this protozoan blood parasite that have routinely been isolated from mice (B. microti) or cattle (B. divergens) have also been isolated from humans. In addition to these familiar species, new isolates that resist being placed in existing taxonomic categories are the basis for rethinking their phylogenetic relationships based on sequencing data. The parasite represents a threat to the safety of the blood supply in that blood from asymptomatic humans can transmit Babesia to blood recipients. Such transmissions have occurred. The development of methods for cultivation of these organisms represents a significant opportunity to study their biology and disease potential. In addition, in vitro cultivation has provided a basis for studying immune responses of mammals to these infectious agents, with the hope of ultimately producing attenuated strains that could be used for immunizing of cattle and, perhaps, humans who live in areas of endemicity. The microaerophilous stationary phase culture technique, which uses a tissue culture medium base supplemented with appropriate serum and erythrocytes, has made it possible to obtain large numbers of parasitized erythrocytes for studying the biology of this parasite.
Topics: Animals; Babesia; Babesiosis; Cattle; Cells, Cultured; Culture Media; Dogs; Erythrocytes; Humans; Parasitology; Zoonoses
PubMed: 12097245
DOI: 10.1128/CMR.15.3.365-373.2002 -
Parasites & Vectors Aug 2023Bovine babesiosis, caused by different Babesia spp. such as B. bovis, B. bigemina, B. divergens, and B. major, is a global disease that poses a serious threat to... (Review)
Review
Bovine babesiosis, caused by different Babesia spp. such as B. bovis, B. bigemina, B. divergens, and B. major, is a global disease that poses a serious threat to livestock production. Babesia bovis infections are associated with severe disease and increased mortality in adult cattle, making it the most virulent agent of bovine babesiosis. Babesia bovis parasites undergo asexual reproduction within bovine red blood cells, followed by sexual reproduction within their tick vectors, which transmit the parasite transovarially. Current control methods, including therapeutic drugs (i.e., imidocarb) have been found to lead to drug resistance. Moreover, changing environmental factors add complexity to efficient parasite control. Understanding the fundamental biology, host immune responses, and host-parasite interactions of Babesia parasites is critical for developing next-generation vaccines to control acute disease and parasite transmission. This systematic review analyzed available research papers on vaccine development and the associated immune responses to B. bovis. We compiled and consolidated the reported vaccine strategies, considering the study design and rationale of each study, to provide a systematic review of knowledge and insights for further research. Thirteen studies published since 2014 (inclusive) represented various vaccine strategies developed against B. bovis such as subunit, live attenuated, and viral vector vaccines. Such strategies incorporated B. bovis proteins or whole live parasites with the latter providing the most effective prophylaxis against bovine babesiosis. Incorporating novel research approaches, such as "omics" will enhance our understanding of parasite vulnerabilities.
Topics: Animals; Cattle; Babesia bovis; Babesiosis; Cattle Diseases; Babesia; Vaccines
PubMed: 37563668
DOI: 10.1186/s13071-023-05885-z -
Parasites & Vectors Apr 2016The epidemiology of the zoonotic tick-transmitted parasite Babesia spp. and its occurrence in wild reservoir hosts in Sweden is unclear. In European deer, several...
BACKGROUND
The epidemiology of the zoonotic tick-transmitted parasite Babesia spp. and its occurrence in wild reservoir hosts in Sweden is unclear. In European deer, several parasite species, including Babesia capreoli and the zoonotic B. venatorum and B. divergens has been reported previously. The European roe deer, Capreolus capreolus, is an important and common part of the indigenous fauna in Europe, as well as an important host for Ixodes ricinus ticks, the vector of several Babesia spp. in Europe. Here, we aimed to investigate the occurrence of Babesia spp. in roe deer in Sweden.
FINDINGS
Roe deer (n = 77) were caught and sampled for blood. Babesia spp. was detected with a PCR assay targeting the 18S rRNA gene. The prevalence of Babesia spp. was 52%, and two species were detected; B. capreoli and B. venatorum in 44 and 7.8% of the individuals, respectively. Infection occurred both in summer and winter.
CONCLUSIONS
We showed that roe deer in Sweden, close to the edge of their northern inland distributional range, are infected with Babesia spp. The occurrence of B. venatorum in roe deer imply that it is established in Sweden and the zoonotic implication of this finding should be regarded to a greater extent in future.
Topics: Animals; Animals, Wild; Babesia; Babesiosis; Deer; Seasons; Sweden
PubMed: 27094215
DOI: 10.1186/s13071-016-1503-8 -
Veterinary Research 2009Babesia, the causal agent of babesiosis, are tick-borne apicomplexan protozoa. True babesiae (Babesia genus sensu stricto) are biologically characterized by direct... (Review)
Review
Babesia, the causal agent of babesiosis, are tick-borne apicomplexan protozoa. True babesiae (Babesia genus sensu stricto) are biologically characterized by direct development in erythrocytes and by transovarial transmission in the tick. A large number of true Babesia species have been described in various vertebrate and tick hosts. This review presents the genus then discusses specific adaptations of Babesia spp. to their hosts to achieve efficient transmission. The main adaptations lead to long-lasting interactions which result in the induction of two reservoirs: in the vertebrate host during low long-term parasitemia and throughout the life cycle of the tick host as a result of transovarial and transstadial transmission. The molecular bases of these adaptations in vertebrate hosts are partially known but few of the tick-host interaction mechanisms have been elucidated.
Topics: Adaptation, Physiological; Animals; Babesia; Babesiosis; Host-Parasite Interactions; Ticks; Vertebrates
PubMed: 19379662
DOI: 10.1051/vetres/2009020 -
BMC Biology Jul 2022Human babesiosis, caused by parasites of the genus Babesia, is an emerging and re-emerging tick-borne disease that is mainly transmitted by tick bites and infected blood...
BACKGROUND
Human babesiosis, caused by parasites of the genus Babesia, is an emerging and re-emerging tick-borne disease that is mainly transmitted by tick bites and infected blood transfusion. Babesia duncani has caused majority of human babesiosis in Canada; however, limited data are available to correlate its genomic information and biological features.
RESULTS
We generated a B. duncani reference genome using Oxford Nanopore Technology (ONT) and Illumina sequencing technology and uncovered its biological features and phylogenetic relationship with other Apicomplexa parasites. Phylogenetic analyses revealed that B. duncani form a clade distinct from B. microti, Babesia spp. infective to bovine and ovine species, and Theileria spp. infective to bovines. We identified the largest species-specific gene family that could be applied as diagnostic markers for this pathogen. In addition, two gene families show signals of significant expansion and several genes that present signatures of positive selection in B. duncani, suggesting their possible roles in the capability of this parasite to infect humans or tick vectors.
CONCLUSIONS
Using ONT sequencing and Illumina sequencing technologies, we provide the first B. duncani reference genome and confirm that B. duncani forms a phylogenetically distinct clade from other Piroplasm parasites. Comparative genomic analyses show that two gene families are significantly expanded in B. duncani and may play important roles in host cell invasion and virulence of B. duncani. Our study provides basic information for further exploring B. duncani features, such as host-parasite and tick-parasite interactions.
Topics: Animals; Babesia; Babesiosis; Cattle; Genomics; Humans; Phylogeny; Sheep
PubMed: 35790982
DOI: 10.1186/s12915-022-01361-9 -
Parasites & Vectors Aug 2022The recently discovered Babesia sp. Mymensingh, which causes clinical bovine babesiosis, has a wide geographical distribution. We investigated the phylogenetic position...
BACKGROUND
The recently discovered Babesia sp. Mymensingh, which causes clinical bovine babesiosis, has a wide geographical distribution. We investigated the phylogenetic position of Babesia sp. Mymensingh using its mitochondrial, plastid, and nuclear genes. Based on morphological and molecular data, Babesia sp. Mymensingh is a unique species and we named it as Babesia naoakii n. sp.
METHODS
A blood DNA sample from a Babesia sp. Mymensingh-infected cow was subjected to genome sequencing to obtain the sequences of mitochondrial, plastid, and nuclear genes. Six phylogenetic trees were then constructed with (1) concatenated amino acid sequences of cytochrome oxidase subunit I, cytochrome oxidase subunit III, and cytochrome b genes of the mitochondrial genome; (2) 16S rRNA of the plastid genome; (3) nucleotide sequences of the elongation factor Tu gene of the plastid genome; (4) ITS1-5.8S rRNA-ITS2; (5) concatenated nucleotide sequences of 89 nuclear genes; and (6) concatenated amino acid sequences translated from the 89 nuclear genes.
RESULTS
In all six phylogenetic trees, B. naoakii n. sp. formed a sister clade to the common ancestor of Babesia bigemina and B. ovata. The concatenated nuclear genes of B. naoakii n. sp. and their translated amino acid sequences shared lower identity scores with the sequences from B. bigemina (82.7% and 84.7%, respectively) and B. ovata (83.5% and 85.5%, respectively) compared with the identity scores shared between the B. bigemina and B. ovata sequences (86.3% and 87.9%, respectively).
CONCLUSIONS
Our study showed that B. naoakii n. sp. occupies a unique phylogenetic position distinct from existing Babesia species. Our findings, together with morphological differences, identify B. naoakii n. sp. as a distinct parasite species.
Topics: Animals; Babesia; Babesiosis; Cattle; Cattle Diseases; Female; Phylogeny; Plastids; RNA, Ribosomal, 16S
PubMed: 36002908
DOI: 10.1186/s13071-022-05374-9 -
The Korean Journal of Parasitology Aug 2014Babesia gibsoni is an intraerythrocytic apicomplexan parasite that causes piroplasmosis in dogs. B. gibsoni infection is characterized clinically by fever, regenerative... (Review)
Review
Babesia gibsoni is an intraerythrocytic apicomplexan parasite that causes piroplasmosis in dogs. B. gibsoni infection is characterized clinically by fever, regenerative anemia, splenomegaly, and sometimes death. Since no vaccine is available, rapid and accurate diagnosis and prompt treatment of infected animals are required to control this disease. Over the past decade, several candidate molecules have been identified using biomolecular techniques in the authors' laboratory for the development of a serodiagnostic method, vaccine, and drug for B. gibsoni. This review article describes newly identified candidate molecules and their applications for diagnosis, vaccine production, and drug development of B. gibsoni.
Topics: Animals; Antigens, Protozoan; Antiprotozoal Agents; Babesia; Babesiosis; Dogs; Drug Discovery; Protozoan Vaccines
PubMed: 25246713
DOI: 10.3347/kjp.2014.52.4.345 -
Scientific Reports Feb 2023Co-infections with Dirofilaria repens and Babesia canis are rarely reported in the literature and there is very limited knowledge of their impact on canine health....
Co-infections with Dirofilaria repens and Babesia canis are rarely reported in the literature and there is very limited knowledge of their impact on canine health. Central Poland is endemic for both parasites, posing a risk of co-infections in dogs. To evaluate the impact of co-infection with B. canis and D. repens on canine health, four groups of dogs were examined: healthy dogs, dogs infected with B. canis, dogs infected with D. repens and dogs co-infected with both species. Blood parameters indicative of anaemia, kidney and liver damage were analysed statistically. Additionally, expression levels of immune response genes were quantified and compared, to define the type of immune response typically encountered in single- and co-infections. In dogs infected with D. repens, no major alterations in blood parameters were observed. Dogs infected with B. canis suffered from anaemia, kidney and liver insufficiency. In contrast, dogs co-infected with D. repens and B. canis showed milder alternation in blood biochemical parameters associated with liver (ALP activity) and kidney (serum urea and creatinine levels) dysfunction, compared to dogs infected only with B. canis. The expression of genes associated with cellular (Th1-mediated) (STAT4 and INF-γ), humoral (Th2-mediated) (STAT6, GATA3, SOCS3, IL-13) and regulatory (IL-10) responses was quantified. For this analysis, dogs infected with B. canis were divided into two groups-'Babesia 1' (mild babesiosis), 'Babesia 2' (severe babesiosis). All the tested factors, except INF-γ, were found to be expressed in dogs infected with D. repens. In 'Babesia 1' dogs, expression of GATA3 was highest, while in 'Babesia 2'-INF-γ and SOCS3 dominated. IL-13 expression was predominant in dogs infected with D. repens, and STAT6 and IL-10 predominated in dogs with co-infections.
Topics: Dogs; Animals; Babesia; Babesiosis; Dirofilaria repens; Interleukin-10; Coinfection; Interleukin-13; Dog Diseases
PubMed: 36739305
DOI: 10.1038/s41598-023-29011-2 -
PLoS Neglected Tropical Diseases May 2019Chemotherapy is a principle tool for the control and prevention of piroplasmosis. The search for a new chemotherapy against Babesia and Theileria parasites has become...
BACKGROUND
Chemotherapy is a principle tool for the control and prevention of piroplasmosis. The search for a new chemotherapy against Babesia and Theileria parasites has become increasingly urgent due to the toxic side effects of and developed resistance to the current drugs. Chalcones have attracted much attention due to their diverse biological activities. With the aim to discover new drugs and drug targets, in vitro and in vivo antibabesial activity of trans-chalcone (TC) and chalcone 4 hydrate (CH) alone and combined with diminazene aceturate (DA), clofazimine (CF) and atovaquone (AQ) were investigated.
METHODOLOGY/PRINCIPAL FINDINGS
The fluorescence-based assay was used for evaluating the inhibitory effect of TC and CH on four Babesia species, including B. bovis, B. bigemina, B. divergens, B. caballi, and T. equi, the combination with DA, CF, and AQ on in vitro cultures, and on the multiplication of a B. microti-infected mouse model. The cytotoxicity of compounds was tested on Madin-Darby bovine kidney (MDBK), mouse embryonic fibroblast (NIH/3T3), and human foreskin fibroblast (HFF) cell lines. The half maximal inhibitory concentration (IC50) values of TC and CH against B. bovis, B. bigemina, B. divergens, B. caballi, and T. equi were 69.6 ± 2.3, 33.3 ± 1.2, 64.8 ± 2.5, 18.9 ± 1.7, and 14.3 ± 1.6 μM and 138.4 ± 4.4, 60.9 ± 1.1, 82.3 ± 2.3, 27.9 ± 1.2, and 19.2 ± 1.5 μM, respectively. In toxicity assays, TC and CH affected the viability of MDBK, NIH/3T3, and HFF cell lines the with half maximum effective concentration (EC50) values of 293.9 ± 2.9, 434.4 ± 2.7, and 498 ± 3.1 μM and 252.7 ± 1.7, 406.3 ± 9.7, and 466 ± 5.7 μM, respectively. In the mouse experiment, TC reduced the peak parasitemia of B. microti by 71.8% when administered intraperitoneally at 25 mg/kg. Combination therapies of TC-DA and TC-CF were more potent against B. microti infection in mice than their monotherapies.
CONCLUSIONS/SIGNIFICANCE
In conclusion, both TC and CH inhibited the growth of Babesia and Theileria in vitro, and TC inhibited the growth of B. microti in vivo. Therefore, TC and CH could be candidates for the treatment of piroplasmosis after further studies.
Topics: Animals; Antiprotozoal Agents; Babesia; Babesiosis; Cell Line; Chalcones; Drug Evaluation, Preclinical; Female; Humans; Inhibitory Concentration 50; Mice, Inbred BALB C; Theileria; Theileriasis
PubMed: 31125333
DOI: 10.1371/journal.pntd.0007030 -
Parasites & Vectors Jan 2022Canine babesiosis is an important tick-borne disease in endemic regions. One of the relevant subspecies in Europe is Babesia canis, and it can cause severe clinical...
Identification of parameters and formulation of a statistical and machine learning model to identify Babesia canis infections in dogs using available ADVIA hematology analyzer data.
BACKGROUND
Canine babesiosis is an important tick-borne disease in endemic regions. One of the relevant subspecies in Europe is Babesia canis, and it can cause severe clinical signs such as hemolytic anemia. Apart from acute clinical symptoms dogs can also have a more chronic disease development or be asymptomatic carriers. Our objective was to identify readily available ADVIA hematology analyzer parameters suggestive of B. canis parasitemia in dogs and to formulate a predictive model.
METHODS
A historical dataset of complete blood count data from an ADVIA hematology system with blood smear or PCR confirmed parasitemia cases was used to obtain a model by conventional statistics (CS) methods and machine learning (ML) using logistical regression and tree methods.
RESULTS
Both methods identified that important parameters were platelet count, mean platelet volume and percentage large unstained cells. We were able to formulate a CS model and ML model to screen for Babesia parasitemia in dogs with a sensitivity of 84.6% (CS) and 100% (ML), a specificity of 97.7% (CS) and 95.7% (ML) and a positive likelihood ratio (LR+) of 36.78 (CS) and 23.2 (ML).
CONCLUSIONS
This study introduces two methods of screening for B. canis parasitemia on readily available data from ADVIA hematology systems. The algorithms can easily be introduced in laboratories that use these analyzers. When the algorithm marks a sample as 'suggestive' for Babesia parasitemia, the sample is approximately 37 times more likely to show Babesia merozoites on blood smear analysis.
Topics: Animals; Babesia; Babesiosis; Dog Diseases; Dogs; Hematology; Machine Learning; Parasitemia; Reproducibility of Results; Sensitivity and Specificity
PubMed: 35093154
DOI: 10.1186/s13071-022-05163-4