Babesiosis In Cattle Research Articles

A 50-year-old question: Can imidocarb chemoprophylaxis ensure seroconversion for babesiosis in cattle under field conditions?

Bovine babesiosis, caused by Babesia bovis or Babesia bigemina, is a major tick-borne disease affecting livestock. In regions with limited vaccine availability, imidocarb is widely used as a chemoprophylactic drug. Although it is assumed that chemoprophylaxis allows for the development of immunity shortly after treatment, the extent of seroconversion during the imidocarb administration protocol remains largely unexplored, with most investigations emphasizing symptom prevention. This research endeavors to verify the seroconversion rate (humoral immunity) of cattle undergoing imidocarb chemoprophylaxis while exposed to tick vectors in field conditions. Fifteen tick-naïve heifers were used, with twelve receiving imidocarb (experimental group) on day 0 of the experiment, and the remaining three serving as controls. On day one of the study, all animals were introduced into a tick-infested pasture. Subsequently, at 28-day intervals (days 28, 56, 84, 112, 140, and 168), the experimental group received imidocarb treatments (1.2 mg/Kg). The detection of antibodies against B. bovis and B. bigemina was performed using commercial ELISA kits. Throughout the study, all animals were exposed to natural infestation by Rhipicephalus microplus ticks. By the 56th day, after two imidocarb doses, 25 % of the experimental group had seroconverted for B. bovis, and 41 % for B. bigemina. By the 84th day, 66 % were seropositive for B. bovis and B. bigemina. By the 112th day, 75 % were seropositive for B. bovis. Notably, one heifer (8 %) failed to seroconvert for either species, while 41 % remained seropositive for only one Babesia species. These findings underscore certain limitations of the chemoprophylaxis protocol for bovine babesiosis. While the majority of treated cattle become seropositive for at least one Babesia species after four successive treatments, exposure to the parasite while receiving imidocarb chemoprophylaxis does not guarantee seroconversion for all treated animals.

Analysis of management factors influencing Anaplasma marginale transmission

The aim of this study was to identify factors that play a key role in the epidemiology of bovine anaplasmosis by adapting a model primarily developed for cattle babesiosis. A cross-sectional observational study was conducted to study the proportion of calf herds in endemic stability/instability for A. marginale in a semi-arid area of Argentina. The A. marginale inoculation rate (h) was calculated from age-specific seroprevalence using double-antigen sandwich ELISA in 58 herds of 4.5–8.5-month–old calves. Herds were considered to be in endemic instability (EI) at h < 0.005 and, therefore, at risk of anaplasmosis outbreaks. A generalized linear model was performed to explore husbandry practices associated with differences in A. marginale transmission. Additionally, spatial clustering of herds with the same immunological status was analyzed using spatial scan statistics (SatScan, Bernoulli model). Spearman's correlation was used to explore a possible association between A. marginale h and Babesia bovis and B. bigemina h (data obtained in previous works). Almost half (43 %) of the herds were in the EI zone for A. marginale. Calves raised under forage combinations had a greater risk of being in EI (OR = 5.41, CI95 %OR = 1.43–20.41) than those reared exclusively on permanent pastures, where cattle density is higher (P = 0.01). Moreover, calves from herds treated only with pyrethroids to control ticks had more chances of being in EI (OR = 4.16, CI95 %OR = 1.12–15.38) than calves from herds receiving different acaricide combinations (P = 0.03). Calves from herds subjected to more than two treatments against Haematobia irritans had higher odds for EI (OR = 5.69, CI95 %OR = 1.24–26.11) than those from herds using fewer than two treatments (P = 0.02). The spatial analysis revealed no spatial clustering of the immune status of the herds (P = 0.67 and P = 0.74 for low and high incidence rates, respectively). A significant variation between farms was observed in A. marginale h (CV = 90.38 %). The correlation analysis revealed a strong epidemiological link of A. marginale h with B. bovis h (Rho=0.794, P<0.001) and B. bigemina h (Rho=0.839, P<0.001). Given that R. microplus is the only vector of B. bovis and B. bigemina in the region, the results of this work strongly suggest an active and significant role of R. microplus in the transmission of A. marginale.

Sero epidemiological study on bovine babesiosis in cattle and buffaloes in Sharkia Governorate, Egypt.

Bovine babesiosis represents a serious challenge for animal health, herd production, and profitability. Understanding the epidemiology and risk factors associated with babesiosis is critical to reduce their negative impacts. Investigation of the seroprevalence and risk factors associated with Babesia bigemina (B. bigemina) and Babesia bovis (B. bovis) in five districts in Sharkia governorate using ELISA. Across-sectional research was conducted to determine the seropositivity of babesiosis by collecting a total of 352 blood samples from 250 cattle and 102 buffaloes. A multivariate logistic regression model was implemented to evaluate the strength of the risk factors associated with both Babesia species infection. The seroprevalence of B. bigemina and B. bovis was 42.6% and 17.0 %, respectively. The prevalence of babesiosis in cattle was found to be 48.8% for B. bigemina and 16.8% for B. bovis. Inclusive, in buffaloes, the prevalence was 27.5% for B. bigemina and 17.6% for B. bovis. Adult animals were more vulnerable to infection with babesia than young animals by 3-5 times, respectively. Males were more susceptible to B. bigemina and B. bovis than females by 3.7 and 3.5 times. Similarly, the odds of infection in infested animals with ticks were 2-4 times higher than in animals without ticks. The obtained results revealed that age, sex of the animal, and tick infestation were major risk factors for the seropositivity of both Babesia species. Inclusive, there was no evidence to support the premise that seroprevalence of babesiosis is correlated with the season and species.

Retrospective analysis of laboratory diagnostic data to assess the seasonal and proportional distribution of major tick-borne diseases in cattle from selected smallholder farms, Zambia

Abstract Tick-borne diseases (TBDs) are endemic in Zambia and several other Sub-Saharan countries. They affect livestock production by causing high morbidity and mortality, resulting in increased production losses in terms of live-weight gain, milk production, off-take rates, and draft power. Herein, we applied a facility-based design to assess the proportion and seasonal distribution of theileriosis, babesiosis, anaplasmosis, and heartwater in cattle from selected smallholder farms in Lusaka and Central provinces of Zambia using laboratory records for microscopic examination of haemoparasites. The overall proportions for theileriosis, babesiosis, and anaplasmosis were 33.7% (95% CI: 30.7–38.2%), 8.3% (95% CI: 6.4–10.9%), and 0.5% (95% CI: 0.1–1.4%), respectively. Heartwater was detected in all the six laboratory records reviewed. Lusaka province had the highest proportion of theileriosis at 30.2% (95% CI: 25.5–35.3%), followed by babesiosis, 8.5% (95% CI: 5.8–11.9%), and anaplasmosis, 0.3% (95% CI: 0.01–1.6%). Similarly, Central province had the highest proportion of theileriosis at 39.5% (95% CI: 33.8–45.4%), followed by babesiosis, 8.4% (95% CI: 5.5–12.2%), and anaplasmosis, 0.7% (95% CI: 0.1–2.5%). Among the districts, Rufunsa district had the highest proportion for theileriosis at 70.6% (95% CI: 44.0–89.7%), followed by Kafue, 54.5% (95% CI: 23.4–83.3%), and Shibuyunji, 51.4% (95% CI: 34.0–68.6%). Analysis of seasonal variation revealed no statistical difference between the dry and wet seasons for theileriosis, babesiosis, and anaplasmosis. Furthermore, there was no statistical difference between Central and Lusaka provinces for babesiosis and anaplasmosis except for theileriosis. These data may have implications on farmers’ herd health management strategies with respect to TBDs, and farmers should be sensitized for effective implementation of risk-based disease control.

Diagnostic Accuracy of an Indirect Enzyme Linked Immunosorbent Assay (iELISA) for Screening of Babesia bovis in Cattle from West Africa.

The epidemiology of corresponding tick-borne diseases has changed as a result of the recent introduction of Rhipicephalus (Boophilus) microplus to West Africa. The current study aimed to assess the diagnostic performance of an indirect ELISA for the detection of Babesia bovis infection in cattle. In a cross-section study, using a Bayesian Latent Class Model and iELISA diagnostic test for cattle babesiosis due to Babesia bovis, accuracy has been assessed with RT-PCR as an imperfect reference test. A total of 766 cattle were tested. The optimal diagnostic performances were obtained with 5% percentage of positivity. Sensitivity and specificity were, respectively, 0.94 [Cr. I.: 0.85-0.99] and 0.89 [Cr. I.: 0.87-0.92]. Additional diagnostic characteristics revealed that the Positive Predictive Value (PPV) and Negative Predictive Value (NPV) were 96.6% [Cr. I.: 92.7-100%] and 82.2% [Cr. I.: 72-93%]. Overall, this test well discriminates an infected status from an uninfected status considering the area under the ROC curve (AUC) which was 0.78 [Cr. I: 0.72-0.85] and a Diagnostic Odds Ratio (DOR) of 127.8 [Cr. I.: 10.43-1562.27]. The AUC was significantly higher than 0.5 (p &lt; 10-5). In consequence, this serologic assay could be suitable in moderate to high prevalence assessments.

Tick Diversity and Distribution of Hard (Ixodidae) Cattle Ticks in South Africa

Ticks are amongst the important ectoparasites where livestock are concerned, as they adversely affect the animals through bloodsucking. In tropical and subtropical countries, they transmit pathogens such as babesiosis, theileriosis, ehrlichiosis, and anaplasmosis in cattle, causing a reduction in production rate and significant concomitant economic losses. Ticks affect 80% of the cattle population across the world, with an estimated economic loss of USD 20–30 billion per year. In South Africa, economic losses in the livestock industry caused by ticks and tick-borne diseases are estimated to exceed USD 33 million per year (ZAR 500 million). There are seven major genera of ixodid ticks in Southern Africa (i.e., Amblyomma, Dermacentor, Haemaphysalis, Hyalomma, Ixodes and Rhipicephalus). The environment in which a tick lives is made up of all the various biological and abiotic factors that are either necessary or unnecessary for its life. The areas where various ticks have been found have been documented in many publications. Using these data, maps of possible species’ habitats can be made. Historical records on tick distribution may be incorrect due to identification mistakes or a change in the tick’s name. All the sources used to generate the maps for this review were unpublished and came from a wide range of sources. To identify tick species and the accompanying microbial ecosystems, researchers are increasingly adopting tick identification methods including 16S and 18S rDNA gene sequencing. Indeed, little is known about the genetic alterations that give important traits, including the predilection for tick hosts, transmission, and acaricide resistance. Opportunities for exploring these changes in tick populations and subpopulations are provided by advancements in omics technologies. The literature on the variety of ixodid ticks, their direct and indirect effects, and control methods in South Africa is compiled in this review.

Babesiosis in Cattle

Babesiosis in Cattle

Molecular Prevalence of Babesiosis in Cattle in Southern Rajasthan

Molecular Prevalence of Babesiosis in Cattle in Southern Rajasthan

Identification of novel immune correlates of protection against acute bovine babesiosis by superinfecting cattle with in vitro culture attenuated and virulent Babesia bovis strains.

The apicomplexan tickborne parasites Babesia bovis and B. bigemina are the major causative agents of bovine babesiosis, a disease that negatively affects the cattle industry and food safety around the world. The absence of correlates of protection represents one major impediment for the development of effective and sustainable vaccines against bovine babesiosis. Herein we superinfected cattle with attenuated and virulent strains of B. bovis to investigate immune correlates of protection against acute bovine babesiosis. Three 6-month-old Holstein calves were infected intravenously (IV) with the in vitro culture attenuated Att-S74-T3Bo B. bovis strain (106 infected bovine red blood cells (iRBC)/calf) while three age-matched Holstein calves were inoculated IV with normal RBC as controls (106 RBC/calf). All Att-S74-T3Bo-infected calves showed a significant increase in temperature early after inoculation but recovered without treatment. Att-S74-T3Bo-infected calves also developed: (a) monocytosis, neutropenia, and CD4+ lymphopenia in peripheral blood on days 3 to 7 post-inoculation; (b) significant levels of TNFα, CXCL10, IFNγ, IL-4, and IL-10 in sera at day 6 after infection; and (c) IgM and IgG against B. bovis antigens, starting at days 10 and 30 post-inoculation, respectively. At 46 days post-Att-S74-T3Bo inoculation, all experimental calves were infected IV with the homologous virulent B. bovis strain Vir-S74-T3Bo (107 iRBC/calf). All Att-S74-T3Bo-infected calves survived superinfection with Vir-S74-T3Bo without displaying signs of acute babesiosis. In contrast, control animals showed signs of acute disease, starting at day 10 post-Vir-S74-T3Bo infection, and two of them were humanely euthanized at days 13 and 14 after inoculation due to the severity of their symptoms. Also, control calves showed higher (P<0.05) parasite load in peripheral blood compared to animals previously exposed to Att-S74-T3Bo. No significant alterations in the profile of leukocytes and cytokines were observed in Att-S74-T3Bo-inoculated after Vir-S74-T3Bo infection. In conclusion, data demonstrate novel changes in the profile of blood immune cells and cytokine expression in peripheral blood that are associated with protection against acute bovine babesiosis. These identified immune correlates of protection may be useful for designing effective and sustainable vaccines against babesiosis in cattle.

Incidences of Rhipicephalus (Boophilus) microplus (Canestrini, 1888) Transmitted Pathogens in Cattle in West Africa

Context and PurposeIn a context of recent introduction of Rhipicephalus (Boophilus) microplus tick species in West Africa, the purpose of the authors is to estimate incidence density of cattle babesiosis either caused by Babesia bigemina or Babesia bovis, and cattle anaplasmosis. Incidence density represents how quickly a disease or a condition is occurring amongst a group of individuals at risk.MethodsThe longitudinal and prospective study design took place in south, centre, east, west and north of Côte d’Ivoire. Cattle have been followed for 12 months. At the end of each month, each animal has been RT-PCR tested for new infection by Babesia bovis, Babesia bigemina, and PCR–RFLP tested for new infection by Anaplasma marginale.ResultsFindings show for the study area that incidence densities of Babesia bovis, Babesia bigemina and Anaplasma marginale infections in Côte d’Ivoire are, respectively, 15.3 new infections [95% CI 13.1–17.88] per 100 cattle, 32.2 new infections [95% CI 28.5–36.3] per 100 cattle, and 25.9 new infections [95% CI 22.5–29.6] per 100 cattle.ConclusionFinally, there is increasing of infection incidence density following the region distance from the coast or elevation.

Babesiosis in cattle and ixodid tick distribution in Dasenech and Salamago Districts, southern Ethiopia

Babesiosis, caused by protozoan parasites of the genus Babesia, and ixodid ticks are considered to be one of the most important causes that result in significant economic losses in cattle production worldwide, including in Ethiopia. A cross-sectional study was undertaken in the Dasenech and Salamago Districts of South Omo zone Ethiopia to determine the prevalence and associated risk factors of babesia infection and ixodid ticks of cattle using Giemsa-stained thin and thick film techniques and morphological identification keys for babesia species and tick identification, respectively. Out of 470 examined cattle, 102 (21.7%) were infected by Babesiosis (15.53% Babesia bigemina and 6.17% Babesia bovis). A statistically significant association (p < 0.05) was observed between babesia infection and season and tick infestation. However, cattle that were infected with the Babesia parasite revealed a lower mean PCV value (21.49%) than noninfected cattle (28.29%) and showed a statistically significant (p < 0.05) difference with the occurrence of Babesia infection. The overall prevalence of ixodid ticks was 53.8% (253/470) and revealed a statistically significant association (p < 0.05) between the season and origin of the animal. However, no statistically significant association (p > 0.05) was observed between sex, age, and body condition score of the animal with the occurrence of ixodid tick. A total of 8040 adult ticks belonging to four tick genera, Amblyomma, Rhipicephalus (Boophilus), Hyalomma, and Rhipicephalus, were collected from various body parts and identified. The high prevalence of Babesia infection and ixodid ticks in cattle at the study sites requires seroprevalence and molecular studies to identify the predominant Babesia species and to detect Babesia in tick hemolymph for the identification of tick genera responsible for the occurrence of Babesia infection. Additionally, tailoring suitable and coordinated tick management methods using chemotherapy as well as strategic treatment to overt clinical cases of bovine babesiosis is critical.

Haemato-biochemical alterations associated with babesiosis in cattle

Haemato-biochemical alterations associated with babesiosis in cattle

Evaluation of 5-Aminolevulenic Acid Plus Ferrous Ion for Its Potential to Improve Symptoms of Bovine Babesiosis

5-aminolevulenic acid (ALA), an endogenous, non-proteinogenic, naturally occurring amino acid found in diverse organisms, is a precursor of heme biosynthesis. For apicomplexan protozoan parasites, an ALA and sodium ferrous citrate (SFC) combination was previously evaluated and suggested as a potential drug candidate for Plasmodium falciparum malaria. This study aimed to evaluate the potential of this combination against bovine babesiosis. ALA administration at 100 and 500 µM coupled with 10 µM SFC in culture medium significantly inhibited intraerythrocytic development and growth of Babesia bovis, which causes cerebral babesiosis in cattle, under in vitro culture. However, administration of 10 µM SFC only in the medium did not inhibit parasite growth. ALA/SFC was efficacious in treating babesiosis in an experimental animal model with B. microti, which causes debilitating babesiosis in mice. Female BALB/c mice were infected with B. microti and administered a single oral dose of ALA/SFC combination daily in different concentrations for 30 days. Treatment with ALA/SFC at 4/0.4 mg/kg body weight significantly suppressed parasite development in the mice blood circulation and resulted in significantly lower parasitemia. Moreover, body weight loss in the mice has been improved significantly compared with the control group at the peak of parasitemia. Treated mice showed moderate decreases in red blood cell count, hemoglobin value, and hematocrit compared with those observed in the control group, indicating an effect in moderating progressive anemia. These findings suggested the potential of ALA/SFC to achieve symptomatic improvement against bovine babesiosis.

First Report on Molecular Identification of Babesia bigemina in a Nervous Signs Evident Naturally Infected Holstein-Friesian Cattle from Central India

Background: Bovine babesiosis caused by an intraerythrocytic apicomplexan protozoon responsible for the most prevalent and costly tick borne diseases (TBD’s) of cattle throughout the globe. Cerebral babesiosis of bovine is fatal and mainly caused by Babesia bovis. To the knowledge of author, there is no confirm molecular report of Babeisa bigemina caused cerebral babesiosis in cattle. Therefore, authors want to report Babesia bigemina caused cerebral babesiosis on record. Methods: In the year 2015, a Holstein-Friesian cow aged 3 years and weighing approximately 300 kg, was attended at Jabalpur, (M.P.) with the clinical signs of high rise in temperature (104°F), recumbency, severe dysponea, peculiar sound during open mouth breathing, pale color of eye conjunctiva and mucous membrane of vagina, convulsions, sever anaemia, paddling of legs at frequent interval. After preparation of peripheral thin blood smear from animal at the site of collection and fixation with methanol, blood sample brought to Department of Veterinary Parasitology, College of Veterinary Science and A.H, Jabalpur and stained by standard protocol for Giemsa staining. Genomic DNA was isolated from the collected blood sample using QIAamp® DNA blood mini kit following the manufacturer’s recommendations and PCR was performed. Conclusion: The thin blood smear examination revealed the presence of Babesia parasite. The species of Babesia was confirmed by molecular amplification of genomic DNA as B. bigemina. This might be the first confirmed report of cerebral babesiosis caused by B. bigemina from Central India.

A Comparative Genomic Study of Attenuated and Virulent Strains of Babesia bigemina

Cattle babesiosis is a socio-economically important tick-borne disease caused by Apicomplexa protozoa of the genus Babesia that are obligate intraerythrocytic parasites. The pathogenicity of Babesia parasites for cattle is determined by the interaction with the host immune system and the presence of the parasite’s virulence genes. A Babesia bigemina strain that has been maintained under a microaerophilic stationary phase in in vitro culture conditions for several years in the laboratory lost virulence for the bovine host and the capacity for being transmitted by the tick vector. In this study, we compared the virulome of the in vitro culture attenuated Babesia bigemina strain (S) and the virulent tick transmitted parental Mexican B. bigemina strain (M). Preliminary results obtained by using the Basic Local Alignment Search Tool (BLAST) showed that out of 27 virulence genes described and analyzed in the B. bigemina virulent tick transmitted strain, only five were fully identified in the attenuated laboratory strain. In all cases, the identity and coverture of the identified genes of the wildtype strain were higher than those of the laboratory strain. This finding is putatively associated with the continuous partial loss of virulence genes in the laboratory strain after several passages of the parasite population under optimal in vitro growth conditions. The loss of virulence factors might be reflected in the absence of symptoms of the disease in cattle inoculated with the attenuated strain despite the presence of infection in the bovine host cells.

A report on tick burden and molecular detection of tick-borne pathogens in cattle blood samples collected from four regions in Saudi Arabia

Babesiosis, theileriosis and anaplasmosis are among the most commonly reported tick-borne diseases in cattle and are associated with significant economic losses. Through the present study the researchers aimed to report the presence of various pathogens that cause babesiosis, theileriosis and anaplasmosis in cattle collected from different provinces in Saudi Arabia and to report their phylogenetic relationship. A total of 362 blood samples of cattle along with ticks that were present on the cattle were collected from four regions (Riyadh, Al-Kharj, Al-Hasa and Al-Qassim) of Saudi Arabia. Blood samples were screened by polymerase chain reaction (PCR) for the presence of various Babesia, Theileria and Anaplasma species by amplification of their 18S rRNA and/or 23S rRNA genes. A total of 541 ticks were collected and identified from the cattle. These included Hyalomma anatolicum, Hyalomma dromedarii, Hyalomma impeltatum, Hyalomma excavatum, Rhipicephalus annulatus and Rhipicephalus turanicus. Regarding tick-borne pathogens, the overall prevalence was 1.9 % (7/362) for Theileria annulata, (2/362) 0.6 % for Theileria and (21/362) 5.8 % for Anaplasma ovis. Four of the cattle were found to be co-infected with more than one pathogen (1.1 %). We did not detect any Babesia species in the blood of the studied cattle. Prevalence of the Theileria and Anaplasma species was highest in cattle that resided in Riyadh, followed by cattle from Al-Hasa and Al-Qassim. Representative amplified partial-gene sequences of T. annulata (GenBank accession numbers MK826137-39) and A. ovis (GenBank acc. no. MK 880224) were submitted to GenBank. The presence of ticks on cattle was found to be associated with a high prevalence of Theileria spp. (P = 0.02) and Anaplasma ovis (P < 0.001). We report novel genotypes of T. annulata and A. ovis from cattle in Saudi Arabia and we recommend that molecular surveys are undertaken throughout the country to address the prevalence and geographical distribution of tick-borne infections for their effective diagnosis and treatment.

Babesiosis in Cattle slaughtered at Zango Abattoir Zaria, Kaduna State, Nigeria: A Short Communication

Babesiosis constitutes a major public health threat to cattle rearing in most countries, including Nigeria. This study was designed to determine the prevalence of Babesia sp. in cattle slaughtered at Zango abattoir. Blood samples were collected from 200 Cattle at slaughter in bottles containing EDTA and transported to the laboratory. A thin blood smear was made, air- dried, fixed in absolute methanol for 5 minutes and stained with 10% Giemsa. Slides were examined for Babesia spp. under oil immersion (x100) objective lens. An overall prevalence of 6.5% (13/200) was observed. Prevalence in males and females were 4.35% (3/69) and 7.63% (10/131) respectively and the differences in their prevalence rates were not significant (χ²=0.803, p value=0.370). Females had a higher chance of getting infected (OR=1.818, CI=0.483-6.838) than male (OR=0.550, CI=0.146-2.068). The prevalence in White Fulani 6.63% (12/181) was higher than that of Sokoto Gudali 5.26% (1/19) although not significant (χ²=0.053, P-Value=0.818). White Fulani had a higher chance of getting infected (OR=1.278, CI=0.157- 10.407) than Sokoto Gudali (OR=0.782, CI=0.096-6.371). The prevalence in cattle at &gt; 8.5 years was 4.35% (3/69) as compared to 7.63 % (10/131) of cattle within 5-8.5 years. There was also no association between the age of cattle and the prevalence of Babesia (χ²=0.803, P value=0.370). Other haemoparasites observed were Anaplasma spp 16.5% (33/200), Theileriaspp11.0% (22/200) and Trypanosoma sp0.5% (1/200). This study has detected a low prevalence of Babesia in the study area. There is therefore the need for large scale studies and also studies using ELISA and PCR.

Four-Dimensional Characterization of the Babesia divergens Asexual Life Cycle, from the Trophozoite to the Multiparasite Stage.

Babesia is an apicomplexan parasite of significance that causes the disease known as babesiosis in domestic and wild animals and in humans worldwide. Babesia infects vertebrate hosts and reproduces asexually by a form of binary fission within erythrocytes/red blood cells (RBCs), yielding a complex pleomorphic population of intraerythrocytic parasites. Seven of them, clearly visible in human RBCs infected with Babesia divergens, are considered the main forms and named single, double, and quadruple trophozoites, paired and double paired pyriforms, tetrad or Maltese Cross, and multiparasite stage. However, these main intraerythrocytic forms coexist with RBCs infected with transient parasite combinations of unclear origin and development. In fact, little is understood about how Babesia builds this complex population during its asexual life cycle. By combining cryo-soft X-ray tomography and video microscopy, main and transitory parasites were characterized in a native whole cellular context and at nanometric resolution. The architecture and kinetics of the parasite population was observed in detail and provide additional data to the previous B. divergens asexual life cycle model that was built on light microscopy. Importantly, the process of multiplication by binary fission, involving budding, was visualized in live parasites for the first time, revealing that fundamental changes in cell shape and continuous rounds of multiplication occur as the parasites go through their asexual multiplication cycle. A four-dimensional asexual life cycle model was built highlighting the origin of several transient morphological forms that, surprisingly, intersperse in a chronological order between one main stage and the next in the cycle.IMPORTANCE Babesiosis is a disease caused by intraerythrocytic Babesia parasites, which possess many clinical features that are similar to those of malaria. This worldwide disease is increasing in frequency and geographical range and has a significant impact on human and animal health. Babesia divergens is one of the species responsible for human and cattle babesiosis causing death unless treated promptly. When B. divergens infects its vertebrate hosts, it reproduces asexually within red blood cells. During its asexual life cycle, B. divergens builds a population of numerous intraerythrocytic (IE) parasites of difficult interpretation. This complex population is largely unexplored, and we have therefore combined three- and four-dimensional imaging techniques to elucidate the origin, architecture, and kinetics of IE parasites. Unveiling the nature of these parasites has provided a vision of the B. divergens asexual cycle in unprecedented detail and is a key step to develop control strategies against babesiosis.

EVALUATION OF ANTI-PROTOZOAL ACTIVITY OF PEGANUM HARMALA (HARMAL) AGAINST BABESIOSIS IN CATTLE

Babesia gradually attains resistance against the allopathic medicines due to their frequent use. To overcome the resistance, herbal therapy is getting more attention. The current study was planned to monitor the efficacy of Peganum harmala against babesiosis in cattle. The blood was collected from ear vein of cattle having high infestation of ticks. A thin blood smear was prepared and stained. Through survey 74 animals were found positive for tick-borne pathogens with an overall prevalence of 19.27%. Babesia sp. was the most prevalent (9.38%; 36/384) haemoparasite, followed in order by Theileria sp. (5.20%, 20/384) and Anaplasma sp. (4.69%, 18/384). All blood samples were subjected to PCR and it was found that 40/384 (10.41%) blood samples were harbouring Babesia bovis and Babesia bigemina. From positive animals for Babesia 30 cattles were randomly selected and divided into 3 groups of 10 animals each viz A, B and C, all groups were tested with the water extract of P. harmala @ 7.5 mg kg-1, 10 mg kg-1 and 12.5 mg kg-1 body weight by intramuscular route, at interval of 12, 24 and 36 h. Ten healthy animals were selected as control in group D. Three animals with moderate infection, 8-9 animals of group A, B and C were recovered, during 48 h after treatment. Two animals each from A, B and one from group C were not cured and died. Five animals from group A were not cured till 36 h of the treatment. Group D of healthy untreated animals were well as they were. Results showed that there was a significant increase in WBCs, including increase in leukocytes and neutrophils in animals infected, whereas number of RBCs and HB decreases. This study concluded that infected cattle treated with water extract of P. harmala 12.5 mg kg-1, recovered early (P&lt;0.01) compared to that of 7.5 and 10 mg kg-1.

Novel Babesia bovis exported proteins that modify properties of infected red blood cells.

Babesia bovis causes a pathogenic form of babesiosis in cattle. Following invasion of red blood cells (RBCs) the parasite extensively modifies host cell structural and mechanical properties via the export of numerous proteins. Despite their crucial role in virulence and pathogenesis, such proteins have not been comprehensively characterized in B. bovis. Here we describe the surface biotinylation of infected RBCs (iRBCs), followed by proteomic analysis. We describe a multigene family (mtm) that encodes predicted multi-transmembrane integral membrane proteins which are exported and expressed on the surface of iRBCs. One mtm gene was downregulated in blasticidin-S (BS) resistant parasites, suggesting an association with BS uptake. Induced knockdown of a novel exported protein encoded by BBOV_III004280, named VESA export-associated protein (BbVEAP), resulted in a decreased growth rate, reduced RBC surface ridge numbers, mis-localized VESA1, and abrogated cytoadhesion to endothelial cells, suggesting that BbVEAP is a novel virulence factor for B. bovis.