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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 -
Transfusion Oct 2021Human babesiosis is a zoonotic infection caused by an intraerythrocytic parasite. The highest incidence of babesiosis is in the United States, although cases have been...
BACKGROUND
Human babesiosis is a zoonotic infection caused by an intraerythrocytic parasite. The highest incidence of babesiosis is in the United States, although cases have been reported in other parts of the world. Due to concerns of transfusion-transmitted babesiosis, the US Food and Drug Administration (FDA) recommended year-round regional testing for Babesia by nucleic acid testing or use of an FDA-approved device for pathogen reduction. A new molecular test, cobas Babesia (Roche Molecular Systems, Inc.), was evaluated for the detection of the four species that cause human disease, Babesia microti, Babesia duncani, Babesia divergens, and Babesia venatorum.
STUDY DESIGN AND METHODS
Analytical performance was evaluated followed by clinical studies on whole blood samples from US blood donations collected in a special tube containing a chaotropic reagent that lyses the red cells and preserves nucleic acid. Sensitivity and specificity of the test in individual samples (individual donation testing [IDT]) and in pools of six donations were determined.
RESULTS
Based on analytical studies, the claimed limit of detection of cobas Babesia for B. microti is 6.1 infected red blood cells (iRBC)/mL (95% confidence interval [CI]: 5.0, 7.9); B. duncani was 50.2 iRBC/mL (95% CI: 44.2, 58.8); B. divergens was 26.1 (95% CI: 22.3, 31.8); and B. venatorum was 40.0 iRBC/mL (95% CI: 34.1, 48.7). The clinical specificity for IDT was 99.999% (95% CI: 99.996, 100) and 100% (95% CI: 99.987, 100) for pools of six donations.
CONCLUSION
cobas Babesia enables donor screening for Babesia species with high sensitivity and specificity.
Topics: Babesia; Babesia microti; Babesiosis; Blood Donors; DNA, Protozoan; Diagnostic Tests, Routine; Donor Selection; Humans; RNA, Protozoan; Sensitivity and Specificity; United States
PubMed: 34368968
DOI: 10.1111/trf.16617 -
Microbiology Spectrum Aug 2023The intracellular protozoan parasite Babesia gibsoni infects canine erythrocytes and causes babesiosis. The hazards to animal health have increased due to the rise of B....
The intracellular protozoan parasite Babesia gibsoni infects canine erythrocytes and causes babesiosis. The hazards to animal health have increased due to the rise of B. gibsoni infections and medication resistance. However, the lack of high-quality full-genome sequencing sets has expanded the obstacles to the development of pathogeneses, drugs, and vaccines. In this study, the whole genome of was sequenced, assembled, and annotated. The genomic size of was 7.94 Mbp in total. Four chromosomes with the size of 0.69 Mb, 2.10 Mb, 2.77 Mb, and 2.38 Mb, respectively, 1 apicoplast (28.4 Kb), and 1 mitochondrion (5.9 Kb) were confirmed. KEGG analysis revealed 2,641 putative proteins enriched on 316 pathways, and GO analysis showed 7,571 annotations of the nuclear genome in total. Synteny analysis showed a high correlation between and B. bovis. A new divergent point of occurred around 297.7 million years ago, which was earlier than that of , B. ovata, and B. bigemina. Orthology analysis revealed 22 and 32 unique genes compared to several spp. and apicomplexan species. The metabolic pathways of were characterized, pointing to a minimal size of the genome. A species-specific secretory protein SA1 and 19 homologous genes were identified. Selected specific proteins, including apetala 2 (AP2) factor, invasion-related proteins BgAMA-1 and BgRON2, and rhoptry function proteins BgWH_04g00700 were predicted, visualized, and modeled. Overall, whole-genome sequencing provided molecular-level support for the diagnosis, prevention, clinical treatment, and further research of . The whole genome of was first sequenced, annotated, and disclosed. The key part of genome composition, four chromosomes, was comparatively analyzed for the first time. A full-scale phylogeny evolution analysis based on the whole-genome-wide data of was performed, and a new divergent point on the evolutionary path was revealed. In previous reports, molecular studies were often limited by incomplete genomic data, especially in key areas like life cycle regulation, metabolism, and host-pathogen interaction. With the whole-genome sequencing of , we provide useful genetic data to encourage the exploration of new terrain and make it feasible to resolve the theoretical and practical problems of babesiosis.
Topics: Animals; Dogs; Babesia; Babesiosis; Whole Genome Sequencing; Genomics; Genome; Dog Diseases
PubMed: 37432130
DOI: 10.1128/spectrum.00721-23 -
Vector Borne and Zoonotic Diseases... Jan 2017The genera Babesia and Theileria (phylum Apicomplexa, order Piroplasmida) are mainly transmitted by Ixodid ticks in which the sexual part of their life cycle followed by...
The genera Babesia and Theileria (phylum Apicomplexa, order Piroplasmida) are mainly transmitted by Ixodid ticks in which the sexual part of their life cycle followed by sporogony takes place. They include protozoan parasites that infect erythrocytes of a variety of vertebrate hosts, including domestic and wild animals, with some Babesia spp. also infecting humans. Babesia sporozoites transmitted in the tick's saliva during the bloodmeal directly infect erythrocytes, where they asexually multiply to produce pear-shaped merozoites in the process of merogony; whereas a pre-erythrocytic schizogonic life stage in leukocytes is found in Theileria and precedes merogony in the erythrocytes. The wide spectrum of Babesia and Theileria species and their dissimilar characteristics with relation to disease severity, transmission, epidemiology, and drug susceptibility stress the importance of accurate detection of babesiosis and theileriosis and their causative agents. These guidelines review the main methods currently used for the detection of Babesia and Theileria spp. for diagnostic purposes as well as epidemiological studies involving their vertebrate hosts and arthropod vectors. Serological methods were not included once they did not indicate current infection but rather exposure.
Topics: Animals; Arachnid Vectors; Babesia; Babesiosis; DNA, Protozoan; Erythrocytes; Humans; Theileria; Theileriasis; Ticks
PubMed: 28055573
DOI: 10.1089/vbz.2016.1955 -
Vector Borne and Zoonotic Diseases... Dec 2021In the United States, and are considered key vectors for , the causative agent of Rocky Mountain spotted fever. Through regional surveillance, a wide diversity of...
In the United States, and are considered key vectors for , the causative agent of Rocky Mountain spotted fever. Through regional surveillance, a wide diversity of spp. have been documented in , and spp. has been suggested as potential vectors for various other pathogens, including spp. and . To better define the prevalence and diversity of pathogens in spp. across the United States, 848 ticks collected from dogs and cats in 44/50 states in 2018-2019 were tested by PCR for spp.-specific 17 kDa and ompA gene fragments; a subset of spp. was also tested with PCR, targeting fragments of the 18S and large subunit region rRNA genes of spp. and 16S rRNA genes of . spp. was identified in 12.5% (106/848) of ticks. Species detected include ( = 64 ticks), ( = 15 ticks), ( = 13 ticks), ( = 8 ticks), ( = 3 ticks), ( = 1 tick), and unclassified spp. ( = 2 ticks). Ticks with and were submitted from every U.S. region; was predominantly detected in ticks from the southern half of the United States, and all -positive ticks were that originated from the Rocky Mountain states. was not detected in any spp., and was detected in two . Because most ticks had fed on dogs or cats before submission, these findings do not implicate a given sp. as a primary vector of these agents, but in regard to spp., the data do support other published work showing harbors a diversity of species with unknown implications for animal and human health.
Topics: Animals; Babesia; Cat Diseases; Cats; Dermacentor; Dog Diseases; Dogs; RNA, Ribosomal, 16S; Rickettsia; United States
PubMed: 34958266
DOI: 10.1089/vbz.2021.0047 -
Frontiers in Cellular and Infection... 2022Bovine babesiosis caused by and is an economically important disease that affects cattle worldwide. Both and are transovarially transmitted by ticks. However,...
Comparison of high throughput RNA sequences between and revealed consistent differential gene expression that is required for the life cycle in the vertebrate and invertebrate hosts.
Bovine babesiosis caused by and is an economically important disease that affects cattle worldwide. Both and are transovarially transmitted by ticks. However, little is known regarding parasite gene expression during infection of the tick vector or mammalian host, which has limited the development of effective control strategies to alleviate the losses to the cattle industry. To understand gene regulation during tick and mammalian host infection, we performed high throughput RNA-sequencing using samples collected from calves and ticks infected with . We evaluated gene expression between blood-stages and kinetes and compared them with previous RNA-seq data. The results revealed similar patterns of gene regulation between these two tick-borne transovarially transmitted parasites. Like , the transcription of several genes in kinetes exceeded a 1,000-fold change while a few of these genes had a >20,000-fold increase. To identify genes that may have important roles in and transovarial transmission, we searched for genes upregulated in kinetes in the genomic datasets of and non-transovarially transmitted parasites, spp. and . Using this approach, we identify genes that may be potential markers for transovarial transmission by and . The findings presented herein demonstrate common genes linked to infection of the vector or mammalian host and may contribute to elucidating strategies used by the parasite to complete their life cycle.
Topics: Animals; Cattle; Babesia; Babesia bovis; Base Sequence; Life Cycle Stages; Rhipicephalus; Vertebrates; Gene Expression; Cattle Diseases; Mammals
PubMed: 36601308
DOI: 10.3389/fcimb.2022.1093338 -
Parasites & Vectors Sep 2021Canine babesiosis is a disease caused by a parasite of the genus Babesia which destroys red blood cells. Previous studies have shown the presence of Babesia vogeli in...
Canine babesiosis is a disease caused by a parasite of the genus Babesia which destroys red blood cells. Previous studies have shown the presence of Babesia vogeli in rural areas in Costa Rica using molecular techniques. The objective of the present study was to determine the seroprevalence and prevalence of B. vogeli in clinically healthy dogs and their ticks at the national level, both within and outside the Central Valley. Blood samples and ticks from 482 dogs were collected between June 2011 and May 2014, and analyzed by immunofluorescence assay (IFA) and real-time polymerase chain reaction (qPCR); two protocols of endpoint PCR and sequencing were used to confirm qPCR-positive samples. Seroprevalence of canine babesiosis of 5.3% (24/453) was determined at the national level, specifically 2.0% (5/253) within and 9.5% (19/200) outside the Central Valley, respectively. Real-time PCR determined a global prevalence of B. vogeli of 31.3% (125/400): 21.4% (47/220) within the Central Valley and 43.3% (78/180) outside the Central Valley. The endpoint PCR amplified only 10 of the 125 blood samples identified as positive in qPCR. One sample amplified by endpoint PCR was sequenced and identified as B. vogeli. Twelve canines were identified with past infections, seven canines with active infection, and 111 canines with early infection. Two species of ticks were found with B. vogeli: Rhipicephalus sanguineus sensu lato (n = 40) and Amblyomma ovale (n = 1). The prevalence of canine babesiosis at the national level, both within and outside the Central Valley, is reported here for the first time, determining the presence of the piroplasmid throughout the country, with a higher circulation of the agent outside the Central Valley. Only one species, B. vogeli, was detected in the blood of dogs and their ticks. Therefore, veterinarians should consider using qPCR to determine the presence of the parasite in blood donors and before starting treatment of vector-borne disease in dogs.
Topics: Animals; Babesia; Babesiosis; Costa Rica; Dog Diseases; Dogs; Female; Male; Seroepidemiologic Studies; Ticks
PubMed: 34521453
DOI: 10.1186/s13071-021-04936-7 -
Parasites & Vectors May 2019The epidemiology of feline vector-borne pathogens (FeVBPs) has been less investigated in cats than in dogs. The present study assessed the prevalence of Rickettsia spp.,...
BACKGROUND
The epidemiology of feline vector-borne pathogens (FeVBPs) has been less investigated in cats than in dogs. The present study assessed the prevalence of Rickettsia spp., Babesia spp., Cytauxzoon spp. and Leishmania infantum infections in cat populations living in central Italy, by molecular and serological tools.
RESULTS
A total of 286 healthy cats were randomly selected from catteries and colonies in central Italy. Peripheral blood and conjunctival swab (CS) samples were collected during surgical procedures for regional neutering projects. Sera were analysed by IFAT to detect anti-Rickettsia felis, R. conorii, Babesia microti and Leishmania IgG antibodies using commercial and home-made antigens. DNA extracted from buffy coats (BCs) was tested for Rickettsia spp., and Piroplasmida species, including Cytauxzoon spp. and Babesia spp. by PCR. Buffy coats and CS samples were assayed by a nested (n)-PCR for Leishmania spp. Sixty-two cats (21.67%) were seropositive to at least one of the tested pathogens. The serological assay revealed 23 (8.04%) and 18 (6.29%) positive cats for R. felis and R. conorii, respectively, with low titers (1/64-1/128). No antibodies against B. microti were detected. Neither Rickettsia nor Piroplasmida DNA were amplified using the specific PCR assays. Thirty-one cats (10.83%) tested positive to anti-Leishmania IgG, with titers ranging from 1:40 to 1:160 and 45 animals (15.73%) tested positive to Leishmania CS n-PCR, whereas none of the animals tested positive to BC n-PCR. Considering the results obtained by IFAT and CS n-PCR, a moderate agreement between the two tests was detected (κ = 0.27).
CONCLUSIONS
The results of the serological and molecular surveys showed a moderate exposure to Leishmania in the investigated cats and highlighted the limited molecular diagnostic value of BC versus CS samples for this pathogen. Conversely no evidence supported the circulation of Cytauxzoon spp. in domestic cats, in contrast with previous detections in European wild cats in the same areas monitored. The low positive titres for R. felis in association with no DNA BC amplification prevent speculation on the exposure of feline populations to this FeVBP due to the cross-reactivity existing within spotted fever group rickettsiosis (SFGR).
Topics: Animals; Apicomplexa; Babesia; Cat Diseases; Cats; Communicable Diseases, Emerging; Cross-Sectional Studies; Female; Italy; Leishmania infantum; Male; Protozoan Infections, Animal; Rickettsia; Rickettsia Infections
PubMed: 31046822
DOI: 10.1186/s13071-019-3409-8 -
Acta Tropica Dec 2022The emergence of Babesia pathogens novel to the UK is of growing concern; these include Babesia canis and Babesia caballi. However, a better understanding of changes in...
The emergence of Babesia pathogens novel to the UK is of growing concern; these include Babesia canis and Babesia caballi. However, a better understanding of changes in the prevalence of endemic Babesia species such as Babesia venatorum and Babesia divergens is also of importance. Here, the prevalence of Babesia pathogens in both Dermacentor reticulatus and Ixodes ricinus ticks was assessed. Dermacentor reticulatus were collected from six sites known to harbour populations of this species in west Wales and southern England. DNA was extracted from 879 individual ticks and subjected to PCR and sequence analysis. Seven Babesia species were detected in 7.5% of the ticks, including B. caballi (0.68%), B. bovis (1.7%), B. microti (1.02%), B. bigemina (0.34%), B. capreoli (0.34%), and one isolate of B. canis (0.34%). Two of the field sites with grazing equines present had ticks that were positive for B. caballi. For I. ricinus, up to 200 nymphs were collected from each of 24 cattle farms in south-west England. Nymphs were divided into 6 pools of 30 from each farm for DNA extraction, PCR, and sequencing. Samples from seven out of the 24 farms tested positive for Babesia, and most were positive for more than one species. Babesia divergens was identified from five farms, and three of these farms had two pooled samples positive for B. divergens, which given the low overall prevalence rate suggests that B. divergens may be highly clustered within the tick population. Most of the remaining positive samples were Babesia venatorum, demonstrating that this zoonotic pathogen is widespread in livestock habitats. The data suggest that B. canis is not yet widely prevalent in established D. reticulatus populations in the UK, but that there is a need to raise awareness of the risk of equine piroplasmosis in areas with endemic D. reticulatus foci, since B. caballi appears more widely established.
Topics: Animals; Babesia; Cattle; Dermacentor; Horses; Ixodes; Nymph; Prevalence; United Kingdom
PubMed: 36115381
DOI: 10.1016/j.actatropica.2022.106692 -
Journal of Veterinary Internal Medicine Sep 2019Babesiosis is an important cause of thrombocytopenia and hemolytic anemia in dogs. Babesia vulpes, reported in European dogs and North American foxes, rarely has been...
BACKGROUND
Babesiosis is an important cause of thrombocytopenia and hemolytic anemia in dogs. Babesia vulpes, reported in European dogs and North American foxes, rarely has been reported in domestic North American dogs. Newly optimized polymerase chain reaction (PCR) primers facilitate more sensitive amplification of B. vulpes DNA.
OBJECTIVES
To determine the prevalence of Babesia sp. infections in dogs being tested for Babesia infection, and to describe co-infections and clinicopathologic abnormalities in B. vulpes positive dogs.
ANIMALS
Dog blood or tissue samples (n = 9367) submitted to a diagnostic laboratory between June 2015 and June 2018 were tested using an optimized Babesia PCR assay.
METHODS
Comprehensive canine vector-borne disease diagnostic testing was performed on convenience samples.
RESULTS
Babesia sp. DNA was amplified from 269/9367 (2.9%) North American dogs. Babesia sp. infections included B. gibsoni monoinfection (157; 1.7%), B. vulpes monoinfection (19; 0.20%), and B. gibsoni and B. vulpes coinfection (29; 0.31%). Forty-three of the 48 total B. vulpes-infected dogs were American Pit Bull Terrier-type breeds, of which 36 historically were involved with dog fights. Coinfections with Mycoplasma, Dirofilaria immitis, or Wolbachia and coexposures to Bartonella, Ehrlichia, and Rickettsia spp. were documented in B. vulpes-infected dogs. Clinicopathologic data in B. vulpes-infected dogs both with and without coinfections included anemia, thrombocytopenia, hyperglobulinemia, hypoalbuminemia, and proteinuria.
CONCLUSIONS AND CLINICAL IMPORTANCE
Babesia vulpes infection in domestic North American dogs is commonly found in conjunction with other coinfections, including B. gibsoni and hemotropic Mycoplasma. Similar to B. gibsoni, dog-to-dog transmission of B. vulpes may be a frequent mode of transmission.
Topics: Animals; Babesia; Babesiosis; Coinfection; Dog Diseases; Dogs; North America; Polymerase Chain Reaction; Prevalence
PubMed: 31334887
DOI: 10.1111/jvim.15560