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Trends in Parasitology May 2019Although Babesia represents an important worldwide veterinary threat and an emerging risk to humans, this parasite has been poorly studied as compared to Plasmodium, its... (Review)
Review
Although Babesia represents an important worldwide veterinary threat and an emerging risk to humans, this parasite has been poorly studied as compared to Plasmodium, its malaria-causing relative. In fact, Babesia employs highly specific survival strategies during its intraerythrocytic development and its intricate journey through the tick vector. This review introduces a substantially extended molecular phylogeny of the order Piroplasmida, challenging previous taxonomic classifications. The intriguing developmental proficiencies of Babesia are highlighted and compared with those of other haemoparasitic Apicomplexa. Molecular mechanisms associated with distinctive events in the Babesia life cycle are emphasized as potential targets for the development of Babesia-specific treatments.
Topics: Animals; Babesia; Babesiosis; Genes, Protozoan; Humans; Life Cycle Stages; Phylogeny; Piroplasmida
PubMed: 30733093
DOI: 10.1016/j.pt.2019.01.007 -
Veterinary Parasitology May 2006The history of the genus Babesia is briefly outlined. The classical differences with the main other genus of non-pigment-forming hemoparasites, Theileria, are the... (Review)
Review
The history of the genus Babesia is briefly outlined. The classical differences with the main other genus of non-pigment-forming hemoparasites, Theileria, are the absence of extra-erythrocytic multiplication (schizogony) in Babesia and the cycle in the vector tick, which includes transovarial transmission in Babesia but only transstadial transmission in Theileria. Also, the multiplication in the red cell of Babesia, by budding, most often results in two daughter cells (merozoites), while that of Theileria gives four merozoites, often as a Maltese cross. In particular this means that what is still commonly called Babesia microti is not a Babesia and that it would be just as logical to speak of human theileriosis as of babesiosis. The small piroplasm of horses, long known as Babesia equi, is already commonly designated as Theileria equi. However, on molecular grounds, it may be necessary to create a new genus for these parasites. The Babesia species of domestic animals are briefly discussed and presented in a table.
Topics: Animals; Animals, Domestic; Arachnid Vectors; Babesia; Babesiosis; Buffaloes; Cats; Cattle; Dogs; Goats; History, 19th Century; History, 20th Century; History, 21st Century; Horses; Humans; Mammals; Sheep; Swine; Theileria; Ticks
PubMed: 16513280
DOI: 10.1016/j.vetpar.2006.01.035 -
Trends in Parasitology Mar 2024
Topics: Humans; Babesia; Babesiosis; DNA, Protozoan
PubMed: 38104025
DOI: 10.1016/j.pt.2023.11.008 -
Infection, Genetics and Evolution :... Dec 2012Babesia are tick-transmitted hemoprotozooans that infect mammals and birds, and which are acknowledged for their major impact on farm and pet animal health and... (Review)
Review
Babesia are tick-transmitted hemoprotozooans that infect mammals and birds, and which are acknowledged for their major impact on farm and pet animal health and associated economic costs worldwide. Additionally, Babesia infections of wildlife can be fatal if associated with stressful management practices; and human babesiosis, also transmitted by blood transfusion, is an increasing public-health concern. Due to the huge diversity of species reported to serve as Babesia hosts, all vertebrates might be potential carriers, as long as they are adequate hosts for Babesia-vector ticks. We here provide a comprehensive overview of the most relevant Babesia species, and a discussion of the classical taxonomic criteria. Babesia, Cytauxzoon and Theileria parasites are closely related and collectively referred to as piroplasmids. A possible scenario for the history of piroplasmids is presented in the context of recent findings, and its implications for future research avenues are outlined. Phylogenetic trees of all available 18S rRNA and hsp70 genes were generated, based on which we present a thoroughly revised molecular classification, comprising five monophyletic Babesia lineages, one Cytauxzoon clade, and one Theileria clade. Updated 18S rRNA and beta-tubulin gene trees of the B. microti isolates agree with those previously reported. To reconcile estimates of the origin of piroplasmids and ticks (~300 Ma, respectively), and mammalian radiation (60 Ma), we hypothesize that the dixenous piroplasmid life cycle evolved with the origin of ticks. Thus, the observed time gap between tick origin and mammalian radiation indicates the existence of hitherto unknown piroplasmid lineages and/or species in extant vertebrate taxa, including reptiles and possibly amphibians. The development and current status of the molecular taxonomy of Babesia, with emphasis on human-infecting species, is discussed. Finally, recent results from population genetic studies of Babesia parasites, and their implications for the development of pathogenicity, drug resistance and vaccines, are summarized.
Topics: Animals; Arachnid Vectors; Babesia; Babesiosis; Evolution, Molecular; Genetics, Population; Humans; Phylogeny
PubMed: 22871652
DOI: 10.1016/j.meegid.2012.07.004 -
Veterinary Parasitology Oct 2016Babesia ovata, which is transmitted by Haemaphysalis longicornis, is an intraerythrocytic protozoan parasite of cattle. Based on its morphology, B. ovata is classified... (Review)
Review
Babesia ovata, which is transmitted by Haemaphysalis longicornis, is an intraerythrocytic protozoan parasite of cattle. Based on its morphology, B. ovata is classified as a large-type Babesia. The developmental stages of B. ovata have been described both in cattle and the tick vector. In infected adult female ticks, the parasite is transovarially transmitted to the tick eggs. The sexual reproduction of B. ovata has been demonstrated in the tick midgut. The diagnostic tools that are currently available for the specific detection of B. ovata in cattle include microscopy and polymerase chain reaction assays. The development of improved molecular and serological diagnostic tools has been constrained by the limited availability of genetic data. B. ovata has been reported in cattle populations in Japan, Korea, China, Mongolia and Thailand. B. ovata was thought to be a benign parasite; however, infections in immuno compromised or Theileria orientalis-infected animals are clinically significant. Thus, control strategies aimed at minimizing the prevalence of B. ovata are vital. The taxonomy of B. ovata is unclear, and the phylogenetic position has not been well defined. Consequently, non-B. ovata species have sometimes been classified as B. ovata. In this review, we provide an outline of the lifecycle, geographical distribution, and control of B. ovata, and critically discuss the taxonomy and phylogeny of this bovine Babesia.
Topics: Animals; Babesia; Babesiosis; Cattle; Cattle Diseases; Phylogeny; Species Specificity
PubMed: 27809988
DOI: 10.1016/j.vetpar.2016.10.006 -
Molecular Microbiology May 2021Babesia species are tick-borne intracellular parasites that infect the red blood cells of their mammalian host, leading to severe or fatal disease. Babesia spp. infect a... (Review)
Review
Babesia species are tick-borne intracellular parasites that infect the red blood cells of their mammalian host, leading to severe or fatal disease. Babesia spp. infect a wide range of mammalian species and cause a significant economic burden globally, predominantly through disease in cattle. Several Babesia spp. are increasingly being recognized as zoonotic pathogens of humans. Babesia spp. have complex life cycles involving multiple stages in the tick and the mammalian host. The parasite utilizes complex signaling pathways during replication, egress, and invasion in each of these stages. They must also rapidly respond to their environment when switching between the mammalian and tick stages. This review will focus on the signaling pathways and environmental stimuli that Babesia spp. utilize in the bloodstream and for transmission to the tick, with an emphasis on the role of phosphorylation- and calcium-based signaling during egress and invasion. The expanding availability of in vitro and in vivo culture systems, genomes, transcriptomes, and transgenic systems available for a range of Babesia spp. should encourage further biological and translational studies of these ubiquitous parasites.
Topics: Animals; Babesia; Babesiosis; Humans; Life Cycle Stages; Protozoan Proteins; Signal Transduction; Ticks
PubMed: 33274587
DOI: 10.1111/mmi.14650 -
Parasites & Vectors Sep 2021Babesia spp. are protozoan parasites of great medical and veterinary importance, especially in the northern Hemisphere. Ticks are known vectors of Babesia spp., although... (Review)
Review
BACKGROUND
Babesia spp. are protozoan parasites of great medical and veterinary importance, especially in the northern Hemisphere. Ticks are known vectors of Babesia spp., although some Babesia-tick interactions have not been fully elucidated.
METHODS
The present review was performed to investigate the specificity of Babesia-tick species interactions that have been identified using molecular techniques in studies conducted in the last 20 years under field conditions. We aimed to indicate the main vectors of important Babesia species based on published research papers (n = 129) and molecular data derived from the GenBank database.
RESULTS
Repeated observations of certain Babesia species in specific species and genera of ticks in numerous independent studies, carried out in different areas and years, have been considered epidemiological evidence of established Babesia-tick interactions. The best studied species of ticks are Ixodes ricinus, Dermacentor reticulatus and Ixodes scapularis (103 reports, i.e. 80% of total reports). Eco-epidemiological studies have confirmed a specific relationship between Babesia microti and Ixodes ricinus, Ixodes persulcatus, and Ixodes scapularis and also between Babesia canis and D. reticulatus. Additionally, four Babesia species (and one genotype), which have different deer species as reservoir hosts, displayed specificity to the I. ricinus complex. Eco-epidemiological studies do not support interactions between a high number of Babesia spp. and I. ricinus or D. reticulatus. Interestingly, pioneering studies on other species and genera of ticks have revealed the existence of likely new Babesia species, which need more scientific attention. Finally, we discuss the detection of Babesia spp. in feeding ticks and critically evaluate the data on the role of the latter as vectors.
CONCLUSIONS
Epidemiological data have confirmed the specificity of certain Babesia-tick vector interactions. The massive amount of data that has been thus far collected for the most common tick species needs to be complemented by more intensive studies on Babesia infections in underrepresented tick species.
Topics: Animals; Babesia; Babesiosis; Deer; Disease Vectors; Host-Parasite Interactions; Tick Infestations; Ticks
PubMed: 34583754
DOI: 10.1186/s13071-021-05019-3 -
International Journal of Molecular... Mar 2023Bovine babesiosis is caused by the Apicomplexa parasites from the genus . It is one of the most important tick-borne veterinary diseases worldwide; being the species... (Review)
Review
Bovine babesiosis is caused by the Apicomplexa parasites from the genus . It is one of the most important tick-borne veterinary diseases worldwide; being the species associated with the most severe clinical signs of the disease and causing the greatest economic losses. Many limitations related to chemoprophylaxis and the acaricides control of transmitting vectors have led to the adoption of live attenuated vaccine immunisation against as an alternative control strategy. However, whilst this strategy has been effective, several drawbacks related to its production have prompted research into alternative methodologies for producing vaccines. Classical approaches for developing anti- vaccines are thus discussed in this review and are compared to a recent functional approach to highlight the latter's advantages when designing an effective synthetic vaccine targeting this parasite.
Topics: Animals; Cattle; Babesia bovis; Cattle Diseases; Babesia; Vaccines, Attenuated; Tick-Borne Diseases; Vaccines, Synthetic
PubMed: 36982294
DOI: 10.3390/ijms24065219 -
Current Opinion in Hematology May 2012Babesiosis is a zoonosis, a disease communicable from animals to humans and an important blood-borne human parasitic infection. Despite its public health impact, its... (Review)
Review
PURPOSE OF REVIEW
Babesiosis is a zoonosis, a disease communicable from animals to humans and an important blood-borne human parasitic infection. Despite its public health impact, its study has largely been neglected. The objective of this review is to present up-to-date information on both parasite and red blood cell molecules that function at the host-parasite interface to facilitate successful invasion.
RECENT FINDINGS
In the last few years, a number of parasite proteins have been identified from genome projects and from functional red cell-binding assays. However, their cognate receptors as well as the precise function these ligands perform in the cascade of invasive events remain umknown. There also appears to be a significant overlap in the structural and functional aspects of the invasion machinery between malaria and Babesia.
SUMMARY
Recognizing that Babesia is an expanding blood safety threat, there should be rapid progress in the development of viable interventions to detect and halt transmission of these pathogens via blood transfusions. By developing a detailed mechanistic understanding of invasion, we can then exploit the participating molecules to procure much needed reagents for diagnosis, epidemiology, treatment and prevention of human babesiosis.
Topics: Animals; Babesia; Babesiosis; Erythrocytes; Host-Parasite Interactions; Humans; Ligands; Membrane Glycoproteins; Protozoan Proteins
PubMed: 22488304
DOI: 10.1097/MOH.0b013e328352245a -
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