Search Results (57)

This study evaluated the effects of various concentrations of PVP-40 on the in vitro cryopreservation and recovery of Babesia bovis and Babesia bigemina. We also assessed a reduced dose of attenuated Babesia strains to determine its efficacy in preventing clinical disease. A microaerophilic stationary phase blood culture system was used to recover Babesia parasites that were cryopreserved in solutions with various PVP-40 concentrations and Babesia parasites in 20% PVP-40 were used to vaccinate naïve cattle. The animals were vaccinated intramuscularly with frozen parasites cryopreserved in 20% PVP-40, with a dose of either 1 × 10⁸ or 1 × 10⁷ erythrocytes infected with both attenuated B. bigemina and B. bovis produced from blood cultures. The control group received uninfected erythrocytes. During the vaccination, clinical parameters such as rectal temperature and hematocrit levels were unaffected. The animals were relocated to a farm in a Babesia hyperendemic area to test the efficacy of these live vaccines in controlling disease onset. Some vaccinated animals showed mild disease. In the vaccinated groups, parasites were detected in blood smears for only one day during the challenge. In contrast, the control group experienced fever for three consecutive days, a decline in hematocrit levels, and significant health deterioration. In this group, parasites were detected in smears for four consecutive days. All the animals in the control group required treatment to manage their high parasitemia and prevent mortality. In this study, we demonstrated that increasing the concentration of PVP-40 to cryopreserve parasites improved the recovery and proliferation of Babesia spp. in blood culture, and we also showed that when animals were vaccinated with cryopreserved, in vitro cultured, attenuated Babesia parasites in 20% PVP-40, they were effectively protected from severe clinical babesiosis. Full article

Babesia bigemina is one of the most important etiological agents of bovine babesiosis, a tick-borne disease posing a major threat in the livestock industry globally, including South Africa. Despite the huge economic impact of cattle babesiosis in South Africa, antigenic variation observed among B. bigemina strains worldwide has impeded the successful development of a single vaccine with the potential to eliminate the disease. As such, there is still a dearth of information regarding the conservation of B. bigemina genes encoding functionally important proteins that play a crucial role during the invasion of bovine erythrocytes by merozoites. Fifty blood samples previously collected from cattle in eight provinces of South Africa were genetically tested for the presence of B. bigemina DNA fragments using four nested PCR-based assays. The genes targeted coded for SpeI-AvaI restriction fragment, rhoptry-associated protein 1 (BgRAP-1), apical membrane antigen 1 (BgAMA-1) and β-tubulin (BgβTUB). PCR-generated fragments of randomly selected samples were sequenced. BLAST searches in GenBank were performed with newly determined sequences to search for homologous sequences. Neighbor-joining phylogenies were inferred from aligned, contiguous sequences of BgRAP-1, BgAMA-1 and BgβTUB genes. Nested PCR assays generated single fragments of 170 bp, 472 bp, 765 bp and 302 bp for SpeI-AvaI, BgRAP-1, BgAMA-1 and BgβTUB fragments, respectively. Of the 50 bovine samples tested by nested PCR, 82% (42/50; 95% CI = 69.2–90.2%), 68% (34/50; 95% CI = 54.2–79.2%), 50% (25/50; 95% CI = 36.6–63.4%) and 46% (23/50; 95% CI = 33.0–59.6%) possessed B. bigemina-specific SpeI-AvaI, BgRAP-1, BgAMA-1 and BgβTUB DNA fragments, respectively. The BgRAP-1, BgAMA-1 and BgβTUB sequences of South African B. bigemina isolates shared 98–100% similarity with previously reported sequences of strains originating from cattle in countries other than South Africa. The high genetic conservation observed among geographical isolates of B. bigemina suggests the conserved functional role of BgRAP-1 and BgAMA-1 proteins as potential candidates that could be incorporated in recombinant subunit vaccines. Full article

Background/Objectives: B. bigemina is a highly pathogenic and widely distributed tick-borne disease parasite responsible for bovine babesiosis. The development of effective and safe therapies is urgently needed for global disease control. The aim of this study is to compare the effects of endochin-like quinolone (ELQ-316), buparvaquone (BPQ), imidocarb (ID), and the combinations of ID + ELQ-316 and BPQ + ELQ-316, on in vitro survival of B. bigemina. Methods: Parasites at a starting parasitemia level of 2%, were incubated with each single drug and a combination of drugs, ranging from 25 to 1200 nM of concentration over four consecutive days. The inhibitory concentrations, 50% (IC50%) and 99% (IC99%), were estimated. Parasitemia levels were evaluated daily using microscopic examination. Data were statistically compared using the non-parametrical Kruskall–Wallis test. Results: All drugs tested significantly inhibited (p < 0.05) the growth of B. bigemina at 2% parasitemia. The combination of ID + ELQ-316 exhibited a lower mean (IC50%: 9.2; confidence interval 95%: 8.7–9.9) than ID (IC50%: 61.5; confidence interval 95%: 59.54–63.46), ELQ-316 (IC50%: 48.10; confidence interval 95%: 42.76–58.83), BPQ (IC50%: 44.66; confidence interval 95%: 43.56–45.81), and BPQ + ELQ-316 (IC50%: 27.59; confidence interval: N/A). Parasites were no longer viable in cultures treated with the BPQ + ELQ-316 combination, as well as with BPQ alone at a concentration of 1200 nM, on days 2 and 3 of treatment, respectively. Conclusions: BPQ and ID increase the babesiacidal effect of ELQ-316. The efficacy of these combinations deserves to be evaluated in vivo, which could lead to a promising and safer treatment option for B. bigemina. Full article

RNA-seq technology has been widely used for the characterization of the transcriptome profile induced by several diseases in both humans and animals. In the present study, RNA-seq was used to identify the differential expression of genes associated with the immune response in cattle infected with two different strains of Babesia bigemina, both derived from the same Mexican field isolate, which exhibit distinct phenotypic characteristics: the virulent strain, capable of producing acute clinical signs, and the attenuated strain, capable of stimulating a protective immune response when used as an immunogen with an efficacy greater than 80%. The differential gene expression analysis performed revealed a total of 620 differentially expressed genes (DEGs). However, the intersection of the edgeR and DESeq2 programs used in the bioinformatics analysis only identified 247 DEGs, of which 108 genes were enriched to be closely correlated with the bovine immune response based on gene ontology terms; most of the DEGs obtained encode proteins associated with the major histocompatibility complex, immunoglobulins, and T-cell surface receptors. The infection caused by the attenuated strain induced higher transcription of immune response genes compared to the infection caused by the virulent strain; nonetheless, in both infections, a greater down-regulation than up-regulation was observed. Different immunoglobulin-associated genes were found to be up-regulated in the group inoculated with the attenuated strain, whereas these were down-regulated in the virulent strain-inoculated group. In addition, an up-regulation of the HSPA6, CD163, and SLC11a1 genes was observed in the group inoculated with the virulent strain, previously reported in other Apicomplexan infections. The findings provide relevant information that could contribute to clarifying the immune response associated with an acute bovine babesiosis infection by B. bigemina. Full article

Anaplasma marginale and Babesia bigemina are tick-borne pathogens, posing significant threats to the health and productivity of cattle in tropical and subtropical regions worldwide. Currently, detection of Babesia bigemina and Anaplasma marginale in infected animals relies primarily on microscopic examination of Giemsa-stained blood or organ smears, which has limited sensitivity. Molecular methods offer higher sensitivity but are costly and impractical in resource-limited settings. Following the development of a pen-side test for detecting Theileria parva infections in cattle, we have created two additional CRISPR-Cas12a assays targeting Anaplasma marginale and Babesia bigemina. The assays target the major surface protein 5 (MSP5) for A. marginale and rhoptry-associated protein 1a (RAP1a) for B. bigemina. These additional tests involve a 20 min recombinase polymerase amplification (RPA) reaction followed by a 60 min CRISPR-Cas12a detection with a lateral strip readout. Results demonstrate high specificity, with no cross-reactivity against other tick-borne parasites, and a limit of detection down to 10² DNA copies/µL of each target marker. The findings pave the way for sensitive and user-friendly pen-side tests to diagnose A. marginale and B. bigemina infections. Full article

Hedgehogs can act as reservoirs for the transmission of tick-borne pathogens (TBPs) to domestic livestock, wild animals, and humans. Understanding host–tick dynamics is essential to evaluate the impact of TBPs. This study was conducted in Pakistan and aimed to determine the prevalence and species of TBPs in the blood and ticks of Indian long-eared hedgehogs captured from various environments. A total of 64 hedgehogs were captured to check for tick infestation. Tick species were identified morphologically and molecularly including ITS-2 region amplification by PCR and subsequent Sanger sequencing. Moreover, TBPs were identified in both ticks and the blood of hedgehogs through conventional PCR and sequencing, targeting the regions msp1b, 18S rRNA, and cytb for Anaplasma spp., Babesia spp., and Theileria spp., respectively. Out of 64 hedgehogs, 16 (25%) were found to be infested with ticks. Morphological and molecular analysis identified all 109 collected ticks as Rhipicephalus turanicus. Only one hedgehog (6.2%) was infected with A. marginale. From the tick samples, 3.7% tested positive for Theileria lestoquardi, 2.8% for Anaplasma marginale, and another 2.8% for Babesia bigemina. This study provides critical insights into circulating TBPs in this region and what possible role hedgehogs might play in disease maintenance for Anaplasma marginale while identifying multiple pathogens that are of concern to human and animal health. Full article

Background/Objectives: Trypanosomiasis and bovine babesiosis correspond to important diseases that cause great economic losses, but there are still no studies evaluating their occurrence in herds of dairy cattle in Ceará. The aim of this study was to perform molecular diagnosis of the main hemoparasites of dairy cows in the microregion of the central hinterland of Ceará. Methods: For the molecular diagnosis of parasites, genomic material was extracted and polymerase chain reaction directed to the cdCatL-like gene for Trypanossoma vivax and SS rRNA of Babesia bigemina and Babesia. bovis was performed. In addition, the mean corpuscular volume of the samples was evaluated. The data were statistically processed. Results: T. vivax was detected in 0.40% (1/246) of the samples, while B. bigemina and B. bovis were detected in 20.62% (33/160) and 11.87% (19/160) of the samples, respectively. It was found that there was a reduction in mean corpuscular volume in animals that presented with co-infection and those infected by B. bovis only, but not in those hosting B. bigemina alone. The variables “purchase of recent animals” and “tick control” had no association with or influence on B. bovis and/or B. bigemina infection. It was possible to identify epidemiologically important factors that may facilitate the transmission of trypanosoma to healthy animals, such as the recent purchase of animals and use of the same needle and syringe for oxytocin application. Conclusions: The pathogens studied were present in the evaluated population. Daily cow management practices can facilitate the transmission of the diseases they cause. Full article

Bovine trypanosomoses, caused by Trypanosoma vivax, is a disease present in African and South American countries. This haemoflagellate protozoan parasite, as well as Anaplasma marginale and Babesia spp., are microorganisms that have a blood tropism, mainly causing fever and anaemia, which reduces the productive capacity of dairy or meat farms. This study aimed to detect T. vivax and other blood parasites in bovine herds in the Galapagos Islands. A total of 170 blood samples from bovines in 19 farms on Santa Cruz Island (the most populated) were collected and analyzed using different PCR techniques: Da-PCR and CatL-PCR to detect Trypanosoma vivax, CatL-PCR to detect Trypanosoma theileri, ESAG-PCR to detect Trypanosoma evansi, 18S rRNA-PCR to detect Babesia spp., rap-1-PCR to detect Babesia bovis, hyp-PCR to detect Babesia bigemina, and msp5-PCR to detect A. marginale. The prevalence of T. vivax, B. bovis, B. bigemina, and A. marginale was estimated as 14.7%, 11.2%, 14.7%, and 67.1%, respectively. In this study, the presence of four haemotropic agents was evidenced in 26.3% (5/19) of the farms. Coinfected cattle (A. marginale, B. bovis and B. bigemina) had significantly higher body temperatures compared to others (two-sample Wilcoxon rank-sum test; p-value = 0.047). The molecular techniques used in this study demonstrated the presence of T. vivax and B. bovis in cattle from Santa Cruz Island in the Galapagos for the first time. The study also investigates the relationship between T. vivax, A. marginale and Babesia spp., making a significant contribution to the field of veterinary medicine. Full article

Babesiosis is a growing concern due to the increased prevalence of this infectious disease caused by Babesia protozoan parasites, affecting various animals and humans. With rising worries over medication side effects and emerging drug resistance, there is a notable shift towards researching babesiacidal agents. Antimicrobial peptides, specifically cathelicidins known for their broad-spectrum activity and immunomodulatory functions, have emerged as potential candidates. Aquiluscidin, a cathelicidin from Crotalus aquilus, and its derivative Vcn-23, have been of interest due to their previously observed antibacterial effects and non-hemolytic activity. This work aimed to characterize the effect of these peptides against three Babesia species. Results showed Aquiluscidin’s significant antimicrobial effects on Babesia species, reducing the B. bigemina growth rate and exhibiting IC₅₀ values of 14.48 and 20.70 μM against B. ovata and B. bovis, respectively. However, its efficacy was impacted by serum presence in culture, and it showed no inhibition against a B. bovis strain grown in serum-supplemented medium. Conversely, Vcn-23 did not demonstrate babesiacidal activity. In conclusion, Aquiluscidin shows antibabesia activity in vitro and its efficacy is affected by the presence of serum in the culture medium. Nevertheless, this peptide represents a candidate for further investigation of its antiparasitic properties and provides insights into potential alternatives for the treatment of babesiosis. Full article

Over the years, tick-borne pathogens (TBPs) have garnered significant interest due to their medical, veterinary and economic importance. Additionally, TBPs have drawn attention to how these microorganisms interact with their own vectors, increasing the risk to human and animal infection of emerging and reemerging zoonoses. In this sense, ticks, which are obligate hematophagous ectoparasites, have a key role in maintaining and transmitting TBPs among humans and animals. The aim of this study was to assess the prevalence of neglected TBPs in mainland Portugal, namely Anaplasma spp., Babesia spp., Ehrlichia spp. and Neoehrlichia mikurensis. DNA fragments were detected in questing ticks collected from five different ecological areas under investigation. To the best of the authors’ knowledge, this study reports new worldwide findings, including B. bigemina infecting Ixodes frontalis, Ixodes ricinus and Rhipicephalus sanguineus sensu lato. Additionally, it presents new findings in Portugal of N. mikurensis infecting I. ricinus and of presumably Wolbachia endosymbionts being detected in I. ricinus. Overall, there were 208 tick samples that were negative for all screened TBPs. The results herein obtained raise concerns about the circulation of neglected TBPs in mainland Portugal, especially in anthropophilic ticks, highlighting the importance of adopting a One Health perspective. Full article

Bovine babesiosis, caused by the protozoan Babesia bigemina, is one of the most important hemoparasite diseases of cattle in Mexico and the world. An attenuated B. bigemina strain maintained under in vitro culture conditions has been used as a live attenuated vaccine; however, the biological mechanisms involved in attenuation are unknown. The objective of this study was to identify, through a comparative transcriptomics approach, the components of the B. bigemina virulent parasites that are differentially expressed in vivo, as opposed to those expressed by B. bigemina attenuated vaccine parasites when inoculated into naïve cattle. The biological material under study was obtained by inoculating spleen-intact cattle with infected erythrocytes containing either the attenuated strain or a virulent field strain. After RNA extraction, transcriptomic analysis (RNA-seq) was performed, followed by bioinformatic Differential Expression (DE) analysis and Gene Ontology (GO) term enrichment. The high-throughput sequencing results obtained by analyzing three biological replicates for each parasite strain ranged from 9,504,000 to 9,656,000, and 13,400,000 to 15,750,000 reads for the B. bigemina attenuated and virulent strains, respectively. At least 519 differentially expressed genes were identified in the analyzed strains. In addition, GO analysis revealed both similarities and differences across the three categories: cellular components, biological processes, and molecular functions. The attenuated strain of B. bigemina derived from in vitro culture presents global transcriptomic changes when compared to the virulent strain. Moreover, the obtained data provide insights into the potential molecular mechanisms associated with the attenuation or pathogenicity of each analyzed strain, offering molecular markers that might be associated with virulence or potential vaccine candidates. Full article

Bovine babesiosis has substantial economic implications in the cattle industry, emphasizing the need for a thorough understanding of the genetic diversity of the causative apicomplexan pathogen. Although babesiosis has been extensively studied globally, the genetic diversity of Babesia species in Malaysian and Nigerian cattle remains unreported. This study aims to bridge this gap by detecting and characterizing Babesia species in selected cattle herds. Our investigation explores the genetic diversity of Babesia species in cattle from Selangor, Malaysia, and Ribah, Nigeria. Blood samples revealed a 32.9% infection rate via PCR analysis. Further genetic analysis detected variations in Malaysian Babesia bigemina isolates but genetic similarity among Nigerian isolates. Conversely, all Babesia bovis isolates displayed genetic homogeneity. In summary, this research identifies genetic diversity in Babesia species affecting Malaysian and Nigerian cattle, highlighting regional disparities. Full article

The northwestern region of China, known as the Qinghai–Tibet Plateau Area (QTPA), is characterized by unique climate conditions that support the breeding of various highly-adapted livestock species. Tick vectors play a significant role in transmitting Babesia and Theileria species, posing serious risks to animal health as well as the economy of animal husbandry in QTPA. A total of 366 blood samples were collected from Tibetan sheep (n = 51), goats (n = 67), yaks (n = 43), cattle (n = 49), Bactrian camels (n = 50), horses (n = 65), and donkeys (n = 40). These samples were examined using conventional and nested PCR techniques to detect Theileria and Babesia species. The overall infection rates were 0.3% (1/366) for Babesia spp. and 38.2% (140/366) for Theileria spp. Notably, neither Babesia nor Theileria species were detected in donkeys and yaks. The infection rates of Babesia and Theileria species among animals in different prefectures were significantly different (p < 0.05). Furthermore, Babesia bovis, B. bigemina, B. caballi, and B. ovis were not detected in the current study. To our knowledge, this is the first documented detection of Theileria luwenshuni infection in Bactrian camels and goats, as well as T. sinesis in cattle and T. equi in horses on the Qinghai plateau. These novel findings shed light on the distribution of Babesia and Theileria species among livestock species in QTPA. Full article

Molecular assays and capillary electrophoresis sequencing have been used to identify parasites in livestock. The low sample capacity, which increases labor and processing time, is one drawback. Targeted amplicon sequencing (Ampliseq) uses the fast and large sample capacity platform to identify parasites in the target host, overcoming this limitation. DNA was extracted from 162 whole blood samples collected from cattle in three provinces in the Philippines. Using Illumina’s Miseq platform, the V4 hypervariable region of the piroplasma 18S rRNA gene was amplified and sequenced. The AMPtk pipeline was used to obtain distinct amplicon sequence variants (ASVs) and the NCBI BLAST non-redundant database was used to assign taxonomy. In total, 95 (58.64%) samples were positive for piroplasma. Using the AMPTk pipeline, 2179 ASVs were obtained. A total of 79 distinct ASVs were obtained after clustering and filtering, which belonged to genera Babesia (n = 58), Theileria (n = 17), Hepatozoon (n = 2), and Sarcocystis (n = 2). The ASV top hits were composed of 10 species: Babesia bovis, B. bigemina, Theileria orientalis, Babesia sp., Hepatozoon canis, Sarcocystis cruzi, T. annulata, T. equi, T. mutans, and Theileria sp. Thung Song. The results generated in this study demonstrated the applicability of Ampliseq in detecting piroplasmid parasites infecting cattle in the Philippines. Full article

Tick-borne diseases (TBDs) massively impact bovine production. In endemic countries, animals are often subclinically infected, showing no signs of the illness. Anemia is a hallmark of TBDs, but there is inadequate information on its presence in infected Thai cattle. In the present study, 265 cattle from four provinces in Thailand were surveyed to identify tick-borne pathogens (TBPs) and to evaluate the changes in the packed cell volume (PCV) values associated with detection. Microscopy and polymerase chain reaction (PCR) were also compared for TBP detection. Babesia/Theileria/Hepatozoon was detected in 33.58% (89/265) of the cattle samples. Specifically, Babesia bovis (9/265), B. bigemina (12/265), Theileria orientalis (62/265), and Anaplasma marginale (50/265) were identified using species-specific assays. Significant decreases in the mean PCV levels were observed in cattle that were positive for at least one TBP (p < 0.001), Babesia/Theileria/Hepatozoon (p < 0.001), T. orientalis (p < 0.001), and A. marginale (p = 0.049). The results of PCR and microscopy for the detection of TBPs suggested slight and fair agreement between the two detection tools. The present findings contribute to a better understanding of TBDs in the field and shall facilitate the formulation of effective control for TBDs in Thailand. Full article