Babesiosis In Cattle Research Articles

Simulated interactions of white-tailed deer (Odocoileus virginianus), climate variation and habitat heterogeneity on southern cattle tick (Rhipicephalus (Boophilus) microplus) eradication methods in south Texas, USA

White-tailed deer (Odocoileus virginianus) are a host for cattle fever ticks (Rhipicephalus (Boophilus) sp.), which are vectors of the pathogens causing bovine babesiosis and anaplasmosis in cattle. Tick eradication efforts focused on cattle along the U.S.-Mexico border are high priority and the potential role of white-tailed deer in compromising these efforts is of great concern. We developed a spatially-explicit, individual-based model to investigate the interactions of white-tailed deer, climate variation, and habitat heterogeneity on the efficacy of three standard tick eradication protocols: the application of acaricides to cattle every two weeks for (1) nine or (2) 12 consecutive months, or (3) the removal of cattle (“pasture vacation”) for 12 consecutive months. We simulated the application of each of these eradication methods during each of three different annual temporal weather profiles for temperature, saturation deficit, and precipitation. Each of the methods suppressed the number of host-seeking larvae in the system to near zero. However, some host-seeking larvae remained, and white-tailed deer remained infested throughout the treatment period. Within 30–60days after the termination of each treatment, tick infestations began to increase, and within 2 years after the initiation of each treatment, populations of host-seeking larvae had increased to pretreatment levels. Differences in treatment efficacy and tick population recovery rates were influenced by (1) the level of pre-treatment infestation, (2) weather conditions during the treatment year, and (3) weather conditions during the post-treatment recovery period. Treatment efficacy and tick population recovery also were influenced by the habitat heterogeneity since cattle and white-tailed deer have different habitat preferences. During treatment periods, white-tailed deer participated in creating tick refugia by dispersing engorged female ticks into, and collecting host-seeking larvae from, habitats favorable for the survival and development of off-host life stages. These refugia facilitated the recrudescence of infestations following the termination of treatment periods. Future applications to assess tick-host-landscape interactions and to consider alternative tick suppression tactics in integrated tick eradication systems are discussed.

Clinical Management of Babesiosis in Cattle: A Case Report

Clinical Management of Babesiosis in Cattle: A Case Report

A promising new ELISA diagnostic test for cattle babesiosis based on Babesia bigemina Apical Membrane Antigen-1.

Babesiosis due to Babesia bigemina is a relevant tick-borne disease, affecting cattle worldwide. Many surface proteins of the pathogen including the Apical Membrane Antigen 1 (AMA-1) - have been analysed for vaccine and diagnostic purposes. This study focused on B. bigemina AMA-1 and on its use for the assessment of diagnostic tests. After bioinformatic analyses, AMA-1 codifying region was amplified and cloned into an expression vector used to induce protein synthesis in Escherichia coli cells. AMA-1 was purified by affinity chromatography and used to set up the best condition for an ELISA protocol. Bovine field sera positive to B. bigemina were used to evaluate the presence of anti-AMA-1 antibodies. In order to verify the assay specificity, sera positive to Babesia bovis or to the piroplasm Theileria annulata were also included. Significant differences were obtained between sera negative to both B. bigemina and B. bovis and samples positive to B. bigemina, to B. bovis or to both pathogens. No significant reaction was observed with T. annulata positive sera. The results showed that AMA-1 protein is suitable to be used as antigen in diagnostic assays for babesiosis diagnosis in cattle, as it does not show any cross reaction with anti-T. annulata antibodies.

Address the Public Health and Food Security Concerns of Babesiosis Through Molecular Detection of Babesia Bovis in Suspected Carrier Cattle of Selected Localities in Sri Lanka

Emergence of babesiosis in both public health and food security concern in global perspectives cannot be ignored. The dairy farming plays an important role in food industry that, fulfilling the protein requirement through producing both milk and meat. The farming operations may get hampered due to non-infectious and infectious diseases. Infectious diseases also cause huge production losses in all farming operations in time to time. Babesiosis becomes a major concern in public health and animal production specialists in recent years both locally and internationally due to severity of out breaks, carrier animals and zoonotic nature. Babesiosis as an emerging zoonotic disease and also causing heavy production losses due to the both clinical diseases and carrier animals. Babesia parasites, mainly Babesia bovis and B. bigemina, are tick-borne hemoparasites inducing bovine babesiosis in cattle globally. Babesiosis is known to occur in tropical and subtropical regions of the world and it is one of the major constraints to the livestock industry which adversely affects economic return and food security by reducing milk, meat production and if not treated leads to the death of the animal. Babesia parasites are considered to be endemic in central Sri Lanka and the prevalence of babesiosis is high in other areas. Carrier cattle infected with babesiosis have low number of parasites in circulation. Babesiosis is difficult to detect and is a challenge to conventional diagnostic methods. However, diagnosis of carrier animals in herd is important for preventing outbreaks by transmission through vector ticks to healthy animals and for obtaining epidemiological data of the disease. Here, we have conducted nested PCR detection of Babesia bovis in carrier cattle (Jersey crosses, Friesian crosses and Australian milking zebu) of selected localities of Sri Lanka. For this study, 30 blood samples were collected from suspected carrier cattle and analyzed using light microscopy and nested PCR. Screening by light microscope indicated that 47% of the samples to be positive. PCR analysis of samples diagnosed 80% as positive. Hence, 33% of the animals appeared to be healthy through routine light microscope diagnosis were in fact carriers posing a threat for the healthy herd population. The high prevalence of babesiosis in carrier cattle in Sri Lanka emphasized that island-wide control and prevention programs against bovine babesiosis are needed to minimize the financial burden caused by the parasites to reduce to production losses. This preliminary study on molecular detection of Babesia bovis in selected localities offers a rapid and efficient screening method for suspected carrier herds while providing new avenues to minimize losers incurred in milk production due to unidentified carrier animals.

Molecular survey of Babesia infections in cattle from different areas of Myanmar

Cattle babesiosis is one of the most important tick-borne diseases worldwide. The present study reports a molecular survey of Babesia infections in cattle in Myanmar. Nested PCR assays based on the Babesia bigemina apical membrane antigen-1 gene (AMA-1) and B. bovis rhoptry associated protein-1 gene (RAP-1) revealed that the overall percentage of B. bigemina and B. bovis infection were 9.8% (70/713) and 17.1% (122/713), respectively. A mixed infection was detected in 4.6% (33/713) of animals. Animals <1 year (OR=13.66, CI=5.15–36.26) and 1–5 years of age (OR=3.91, CI=1.50–10.17) were identified as potential risk factors for B. bigemina infection. For B. bovis infection, age <1 year (OR=3.06, CI=1.63–5.75) and 1–5 years (OR=2.08, CI=1.21–3.57), Friesian–Zebu crossbreeds (OR=2.04, CI=1.26–3.30) and grazing (OR=1.59, CI=1.06–2.38) were identified as potential risk factors. This is the first report on a nationwide survey of bovine Babesia infections in Myanmar, providing useful information for the management and control of the disease.

Current status of subclinical form of babesiosis and anaplasmosis in cattle at Rangpur district in Bangladesh

Babesiosis and anaplasmosis are important tick borne diseases and they are responsible for significant economic losses for livestock industry worldwide. A cross-sectional survey was conducted in randomly selected 400 cattle at two upazilas of Rangpur district in Bangladesh, to estimate the prevalence and identify the risk factors of Babesia and Anaplasma infections. Microscopic examination of Giemsa’s stained blood films was carried out for the tentative diagnosis of infections. Multiplex PCR was also performed to confirm microscopically positive samples. To identify the risk factors, odds ratio and 95% confidence interval were calculated. The overall prevalence of Babesia and Anaplasma infections were 1.5% and 3.5%, respectively. The prevalence of Babesia infections recorded in Gangachara and Pirgachaupazilas were 1.3% and 1.7%, respectively while it was 3.8% and 3.3%, respectively for Anaplasma infection. Insignificantly higher prevalence of both infections was recorded in crossbred cattle than those of indigenous cattle. Female cattle had insignificantly higher infection (3.8%) with Anaplasma than the male cattle (2.3%) while no infection with Babesia was found in any male cattle. None of the calves (?1 yr) had infection with either organism. However, infection with both organisms was more prevalent in young cattle (&gt;1-2.5 yr) than those of adult cattle (&gt;2.5 yr). The availability of blood sucking ticks was one of the potential risk factors for both infections (OR = 6-7). Age (&gt;1-2.5 yr) was identified as another important risk factor which had significant association with the occurrence of Anaplasma infection (OR = 4.36). The information generated from this study could be useful as basic information for further advanced epidemiological study and formulation of control measures of the tick borne diseases.Progressive Agriculture 26:51-59, 2015

Prevalence of theileriosis and babesiosis in cattle in Sirajganj district of Bangladesh

A study was conducted to investigate the prevalence of theileriosis and babesiosis in cattle in Sirajganj district of Bangladesh during the period of December 2013 to November 2014. During one year study period a total of 395 cattle were examined, 23 and 8 were found to be infected with Theileria spp. and Babesia spp., respectively. On Geimsa stained blood smear examination, it was observed that the overall prevalence of theileriosis and babesiosis in cattle were recorded as 5.82% and 2.27% respectively. The effect of age, sex, breed and season was observed in cattle during this study. The highest prevalence of theileriosis (7.25%) and babesiosis (3.10%) was reported in the older cattle (&gt;3 years of age) and the higher prevalence was observed in female (6.66% and 2.59%, respectively) than male (4.0% and 1.60% respectively). All crossbred cattle was showed higher prevalence than local cattle. The prevalence of theileriosis was noticed as the highest in the rainy season (6.25%) in relation to summer (5.83%) and winter (5.05%) season. But the prevalence of babesiosis was ranked the highest in summer season (2.50%) followed in rainy (2.27%) and winter (2.02%) season that was insignificant. From the study it was evident that cattle were infected with the organisms and caused a heavy economic loss which will assist to take necessary preventive measurements.Res. Agric., Livest. Fish.2(1): 79-86, April 2015

Models of bovine babesiosis including juvenile cattle.

Bovine Babesiosis in cattle is caused by the transmission of protozoa of Babesia spp. by ticks as vectors. Juvenile cattle (<9 months of age) have resistance to Bovine Babesiosis, rarely show symptoms, and acquire immunity upon recovery. Susceptibility to the disease varies between breeds of cattle. Models of the dynamics of Bovine Babesiosis transmitted by the cattle tick that include these factors are formulated as systems of ordinary differential equations. Basic reproduction numbers are calculated, and it is proved that if these numbers are below the threshold value of one, then Bovine Babesiosis dies out. However, above the threshold number of one, the disease may approach an endemic state. In this case, control measures are suggested by determining target reproduction numbers. The percentage of a particular population (for example, the adult bovine population) needed to be controlled to eradicate the disease is evaluated numerically using Columbia data from the literature.

Toxic Effect of Babesiosis in Cattle and Chemotherapiotic Treatment in Egypt

Babesia bigemina plays an important role in causing liver and kidney dysfunction in affected animals. The aim of this study evaluating the toxic effect of babesiosis on liver and kidney by measuring biochemical parameters and pathological tissue changes in infected animals with B. Bigemina and chose the best method of treatment. A total of 40 cattle age 1-3 years 30 were suffered from increase in temperatures, off food, Hemoglobin urea, red water from endemic area with babesia. Take sample from infected animals & examine it with microscopic examination found babesia bigemina and confirm by inoculation of heparinized blood from this animals in rats and found rats death at fifth day from infection and histopathological exam found babesia in piroplasma form in pathological tissue of rat’s liver & kidney. The infected animals were divided into three groups each group 10 animals untreated group use as control positive and treated groups divided into two groups first group treated with imidocarb only and the second group use imidocarb and lincomcyn as antibiotic drug and compare between two groups by measuring liver& kidney function improvement and compare two groups with negative and positive group which method of treatment more effective in treatment of babesia & decrease toxic effect of babesia.

The Babesia bovis gene and promoter model: an update from full-length EST analysis.

BackgroundBabesia bovis is an apicomplexan parasite that causes babesiosis in infected cattle. Genomes of pathogens contain promising information that can facilitate the development of methods for controlling infections. Although the genome of B. bovis is publically available, annotated gene models are not highly reliable prior to experimental validation. Therefore, we validated a preproposed gene model of B. bovis and extended the associated annotations on the basis of experimentally obtained full-length expressed sequence tags (ESTs).ResultsFrom in vitro cultured merozoites, 12,286 clones harboring full-length cDNAs were sequenced from both ends using the Sanger method, and 6,787 full-length cDNAs were assembled. These were then clustered, and a nonredundant referential data set of 2,115 full-length cDNA sequences was constructed. The comparison of the preproposed gene model with our data set identified 310 identical genes, 342 almost identical genes, 1,054 genes with potential structural inconsistencies, and 409 novel genes. The median length of 5' untranslated regions (UTRs) was 152 nt. Subsequently, we identified 4,086 transcription start sites (TSSs) and 2,023 transcriptionally active regions (TARs) by examining 5' ESTs. We identified ATGGGG and CCCCAT sites as consensus motifs in TARs that were distributed around -50 bp from TSSs. In addition, we found ACACA, TGTGT, and TATAT sites, which were distributed periodically around TSSs in cycles of approximately 150 bp. Moreover, related periodical distributions were not observed in mammalian promoter regions.ConclusionsThe observations in this study indicate the utility of integrated bioinformatics and experimental data for improving genome annotations. In particular, full-length cDNAs with one-base resolution for TSSs enabled the identification of consensus motifs in promoter sequences and demonstrated clear distributions of identified motifs. These observations allowed the illustration of a model promoter composition, which supports the differences in transcriptional regulation frameworks between apicomplexan parasites and mammals.Electronic supplementary materialThe online version of this article (doi:10.1186/1471-2164-15-678) contains supplementary material, which is available to authorized users.

Prevalence and phylogenetic analysis of Babesia bigemina and Babesia bovis hemoparasites from cattle in South Africa

IntroductionBabesia parasites, mainly Babesia bovis and B. bigemina, are tick-borne hemoparasites inducing bovine babesiosis in cattle globally. The clinical signs of the disease include anaemia, fever and hemoglobinuria. Babesiosis is known to occur in tropical and subtropical regions. ObjectiveWe aimed at providing information about the occurrence and phylogenetic relationship of B. bigemina and B. bovis species in cattle from different locations in nine provinces of South Africa. MethodsA total of 430 blood samples were randomly collected from healthy animals in different locations. These samples were tested for Babesia parasitic infections using nested PCR assays with species-specific primers. Neighbour-joining trees were constructed to study the phylogenetic relationship between B. bigemina and B. bovis sequences of randomly selected isolates. Results & DiscussionNested PCR assays with Group I primer sets revealed that the overall prevalence of B. bigemina and B. bovis in all bovine samples tested was 64.7% (95% CI = 60.0-69.0) and 35.1% (95% CI = 30.6-39.8), respectively. Only 117/430 (27.2%) animals had a mixed infection. The highest prevalence of 87.5% (95% CI = 77.2–93.5) for B. bigemina was recorded in the Free State province, while North West had the highest number of animals infected with B.bovis (65.5%; 95% CI = 52.7-76.4). Phylograms were inferred based on B. bigemina-specific gp45 and B. bovis-specific rap-1 nucleotide sequences obtained with Group II nested PCR primers. Phylogenetic analysis of gp45 sequences revealed clearly distinct strains in the genotypes of B. bigemina isolates investigated, including those of published in GenBank. A phylogeny based on B. bovis rap-1 sequences indicated a similar trend of clustering among the sequences of B. bovis isolates. ConclusionThis study demonstrates the occurrence of Babesia parasites in cattle from different provinces of South Africa. It was also noted that the situation of Babesia parasitic infection in cattle from certain areas within the provinces had either reached endemic stability or was progressing towards stability.

Evaluation of medicinal turpentine used for the prevention of bovine babesiosis in southern KwaZulu-Natal and the eastern Free State.

Medicinal turpentine has been used extensively in the eastern Free State and KwaZulu-Natal provinces of South Africa with reportedly excellent results. It is believed that it is able to prevent and treat babesiosis (redwater) in cattle. Redwater is an often-fatal disease in cattle and results in losses of large numbers every year in South Africa. This study was initiated in an attempt to investigate the validity of the use of the turpentine as a medicinal agent. Using a semi in vitro screening assay, Babesia caballi grown in primary equine erythrocytes was exposed to various concentrations of turpentine in comparison to diminazene and imidocarb. The turpentine had no parasiticidal effect following direct exposure. During the recovery phase, the previously exposed parasites appeared to grow more slowly than the controls. In comparison, diminazene and imidocarb were 100% effective in killing the parasites. In a subsequent tolerance study in adult cattle (n = 6) at 1x (2 mL), 3x and 5x the recommended dose, the product was non-toxic. Irritation was noted at the injection site with the higher dose. The only major finding on clinical pathology was a general increase in globulins, without a concurrent change in native babesia antibody titres. It was concluded that it is unlikely that medicinal turpentine is an effective treatment against babesiosis.

The effect of 12 successive blood passages on the virulence of Babesia ovis in splenectomized lambs: A preliminary study

Babesia ovis, the primary causative agent of ovine babesiosis, is a tick-borne hemoprotozoan parasite and causes serious losses in small ruminant livestock in tropical and subtropical regions. The current control of ovine babesiosis has been base on chemotherapy and limited tick control measures. Attenuated parasites which are valuable sources of live vaccines have been used to prevent babesiosis in cattle. There is a necessity to the studies about prevention of the disease by means of immunoprophylaxis in sheep. For this purpose, this study was planned to obtain the attenuated derivatives of a virulent B. ovis strain by successive blood passages in splenectomized lambs. A total of seventeen, six-month-old lambs, 13 of which splenectomized, 4 of which spleen intact lambs, known to be negative for the presence of hemoparasites and anti-B. ovis antibodies were used. The splenectomized lambs were used for passaging the virulent B. ovis field strain. Four intact lambs divided into two groups were used to evaluate the pathogenicity of the virulent strain and twelfth passage strain of B. ovis. Blood collected from a clinically evident case of babesiosis in the field was inoculated intravenously into the first splenectomized lamb, and then the acute clinical disease was occurred. The same process was successively applied to the rest of 12 splenectomized lambs to have the attenuated B. ovis strain. The clinical, microscopic and hematological changes after inoculation were recorded in each passage of the lambs. All of the passage lambs were exhibited the severe symptoms of the disease from the 2nd day of inoculation. The same treatment protocol including vitamin B12 and the anti-babesial drug imidocarb dipropionate (IMDP) was applied to all splenectomized lambs on the fourth or fifth day of the inoculation. Although the symptoms of the disease were less severe than those of splenectomized lambs; two intact lambs infected with the virulent strain and two intact lambs infected with the twelfth passage blood were also showed the clinical and hematological findings of the disease on the 2nd and 3rd day after inoculation. Infection-related symptoms in all intact lambs disappeared spontaneously from the 6th day of inoculation without the application of any drug. The results of the study showed that there was no change on the virulence of B. ovis through the 12 successive blood passages. Therefore, the further passages or alternative attenuation methods may be necessary to attenuate the virulent strain of B. ovis.

Diversity of Babesia bovis merozoite surface antigen genes in the Philippines

Babesia bovis is the causative agent of fatal babesiosis in cattle. In the present study, we investigated the genetic diversity of B. bovis among Philippine cattle, based on the genes that encode merozoite surface antigens (MSAs). Forty-one B. bovis-positive blood DNA samples from cattle were used to amplify the msa-1, msa-2b, and msa-2c genes. In phylogenetic analyses, the msa-1, msa-2b, and msa-2c gene sequences generated from Philippine B. bovis-positive DNA samples were found in six, three, and four different clades, respectively. All of the msa-1 and most of the msa-2b sequences were found in clades that were formed only by Philippine msa sequences in the respective phylograms. While all the msa-1 sequences from the Philippines showed similarity to those formed by Australian msa-1 sequences, the msa-2b sequences showed similarity to either Australian or Mexican msa-2b sequences. In contrast, msa-2c sequences from the Philippines were distributed across all the clades of the phylogram, although one clade was formed exclusively by Philippine msa-2c sequences. Similarities among the deduced amino acid sequences of MSA-1, MSA-2b, and MSA-2c from the Philippines were 62.2–100, 73.1–100, and 67.3–100%, respectively. The present findings demonstrate that B. bovis populations are genetically diverse in the Philippines. This information will provide a good foundation for the future design and implementation of improved immunological preventive methodologies against bovine babesiosis in the Philippines. The study has also generated a set of data that will be useful for futher understanding of the global genetic diversity of this important parasite.

Babesiosis and anaplasmosis in dairy cattle in Northeastern Brazil

The goal of this study was to characterize the epidemiological situation and the factors involved in the prevalence of babesiosis and anaplasmosis in cattle in the dairy basin of Parnaíba, Piauí, Brazil. The study was conducted in 22 farms, and collected blood samples from 202 cattle to study serological, molecular and determination of the packed cell volume (PCV). On the farms were applied surveys involving epidemiological aspects. Seroprevalence rates were: Babesia bigemina 52.5%, B. bovis 68.8%, and Anaplasma marginale 89.1%. Of the samples analyzed, 73.3% were reactive for Babesia spp. and A. marginale, showing co-infection. In PCR, B. bigemina and B. bovis were positive in 52.0% and 33.2% respectively, and A. marginale in 76.2%. Of these, 51.5% amplified DNA of Babesia spp. and A. marginale. The semi-intensive management predominated in 68.0% of the farms studied. The clinical history of babesiosis and anaplasmosis, was reported from 73% of the farms. There was no significant difference (p&gt;0.05) between age groups and for the PCV of positive compared with negative animals. The study indicates that in this region is enzootic instability for babesiosis and enzootic stability for anaplasmosis, reinforcing the fact that in Brazil there are areas of enzootic instability, even in tropical regions of the country. The PCR technique was a valuable tool for the diagnosis of these diseases and may be used to characterize a geographic region.

Prevalence of Babesiosis in Cattle and Goats at Zaria Abattoir, Nigeria

Babesiosis is a haemolytic disease caused by intraerythrocytic protozoan of the genus babesia. It is a disease of small and large ruminants, characterized by fever(40-42 0 C) which may be sudden in onset. The animals become listless, anorexic, anaemic and jaundice. moderate to high morbidity and mortality has been observed. This is a cross-sectional study designed to determine the prevalence of babesiosis in cattle and goats slaughtered in Zaria abattoir. A paired blood samples were collected from the jugular vein of the animals at slaughter in bottles containing ethylenediaminetetra acetic acid (EDTA). Of the 223 animals sampled at Zaria abattoir, 168 were cattle and 55 goats. A total of 16 cattle were found to be infected with Babesia bigemina, representing 9.5%, while in the goats none were infected with Babesia sp. giving a zero percent prevalence. Out of the 168 cattle sampled, 96 were males in which 13/96 (13.5%) were positive for Babesia bigemina and of the 72 females sampled, 3/72 (4.17%) were positive for B. bigemina. The mean PCV of males and female infected were 28.69% and 28.67% respectively. Mixed infections with other blood parasites were also observed, Anaplasma marginale 58/168 (34.5%), Theileria mutans 52/168 (30.6%) and Trypanosoma vivax 3/168 (1.8%) in cattle, and in goats Anaplasma ovis 25/55(45.5%) and Theileria ovis 18/55 (32.7%). The overall prevalence of 9.5% of babesiosis in cattle was observed in this study and while in goats no babesia parasite was recorded.

Molecular diagnosis and phylogenetic analysis of Babesia bigemina and Babesia bovis hemoparasites from cattle in South Africa

BackgroundBabesia parasites, mainly Babesia bovis and B. bigemina, are tick-borne hemoparasites inducing bovine babesiosis in cattle globally. The clinical signs of the disease include, among others, anemia, fever and hemoglobinuria. Babesiosis is known to occur in tropical and subtropical regions of the world. In this study, we aim to provide information about the occurrence and phylogenetic relationship of B. bigemina and B. bovis species in cattle from different locations in nine provinces of South Africa.A total of 430 blood samples were randomly collected from apparently healthy cattle. These samples were genetically tested for Babesia parasitic infections using nested PCR assays with species-specific primers.ResultsNested PCR assays with Group I primer sets revealed that the overall prevalence of B. bigemina and B. bovis in all bovine samples tested was 64.7% (95% CI = 60.0-69.0) and 35.1% (95% CI = 30.6-39.8), respectively. Only 117/430 (27.2%) animals had a mixed infection. The highest prevalence of 87.5% (95% CI = 77.2-93.5) for B. bigemina was recorded in the Free State province collection sites (Ficksburg, Philippolis and Botshabelo), while North West collection sites had the highest number of animals infected with B. bovis (65.5%; 95% CI = 52.7-76.4). Phylograms were inferred based on B. bigemina-specific gp45 and B. bovis-specific rap-1 nucleotide sequences obtained with Group II nested PCR primers. Phylogenetic analysis of gp45 sequences revealed significant differences in the genotypes of B. bigemina isolates investigated, including those of strains published in GenBank. On the other hand, a phylogeny based on B. bovis rap-1 sequences indicated a similar trend of clustering among the sequences of B. bovis isolates investigated in this study.ConclusionThis study demonstrates the occurrence of Babesia parasites in cattle from different provinces of South Africa. It was also noted that the situation of Babesia parasitic infection in cattle from certain areas within the surveyed provinces had either reached endemic stability or was progressing towards stability.

Inhibition of &amp;lt;i&amp;gt;Ehrlichia canis&amp;lt;/i&amp;gt;and &amp;lt;i&amp;gt;Babesia canis&amp;lt;/i&amp;gt; transmission among ticks fed together on dogs vaccinated with Bm86 antigen

GAVAC (Heber Biotec S.A, Havana, Cuba) is a commercially available vaccine developed with the Rhipicephalus (Boophilus) microplus Bm86 recombinant antigen. Bm86 is a “concealed” antigen that is present in the plasmatic membrane of tick gut epithelial cells with unknown function so far. It is well known that after vaccination in the last fifteen years in Cuba, there was a significant decrease of babesiosis (Babesia bovis and Babesia bigemina) and anaplasmosis (Anaplasma marginale) in cattle. A reduced transmission capacity of ticks fed on tick-immune animals and humans has been reported for several tick-borne pathogens. Recent experiments have demonstrated that an anti-tick vaccine may contribute to the control of tick-borne pathogens not only by decreasing the exposure of susceptible hosts to ticks, but also by reducing the vector capacity of ticks. In this study, the potential of Bm86 vaccination to interfere with pathogen transmission among ticks was evaluated by using as experimental model the brown dog tick Rhipicephalus sanguineus and the tickborne Babesia canis and Ehrlichia canis pathogens. Dogs, vaccinated and not vaccinated, were infested with pathogen-infected ticks and noninfected nymphs of R. sanguineus. After feeding, the pathogen transmission to newly molted adults from co-feeding uninfected nymphs was studied by conventional PCR and qPCR. Results suggest that the anti-Bm86 antibodies could be able to block the transmission of B. canis and/or E. canis from infected to non-infected ticks.

Analysis of Babesia bovis infection-induced gene expression changes in larvae from the cattle tick, Rhipicephalus (Boophilus) microplus

BackgroundCattle babesiosis is a tick-borne disease of cattle that has severe economic impact on cattle producers throughout the world’s tropical and subtropical countries. The most severe form of the disease is caused by the apicomplexan, Babesia bovis, and transmitted to cattle through the bite of infected cattle ticks of the genus Rhipicephalus, with the most prevalent species being Rhipicephalus (Boophilus) microplus. We studied the reaction of the R. microplus larval transcriptome in response to infection by B. bovis.MethodsTotal RNA was isolated for both uninfected and Babesia bovis-infected larval samples. Subtracted libraries were prepared by subtracting the B. bovis-infected material with the uninfected material, thus enriching for expressed genes in the B. bovis-infected sample. Expressed sequence tags from the subtracted library were generated, assembled, and sequenced. To complement the subtracted library method, differential transcript expression between samples was also measured using custom high-density microarrays. The microarray probes were fabricated using oligonucleotides derived from the Bmi Gene Index database (Version 2). Array results were verified for three target genes by real-time PCR.ResultsTicks were allowed to feed on a B. bovis-infected splenectomized calf and on an uninfected control calf. RNA was purified in duplicate from whole larvae and subtracted cDNA libraries were synthesized from Babesia-infected larval RNA, subtracting with the corresponding uninfected larval RNA. One thousand ESTs were sequenced from the larval library and the transcripts were annotated. We used a R. microplus microarray designed from a R. microplus gene index, BmiGI Version 2, to look for changes in gene expression that were associated with infection of R. microplus larvae. We found 24 transcripts were expressed at a statistically significant higher level in ticks feeding upon a B. bovis-infected calf contrasted to ticks feeding on an uninfected calf. Six transcripts were expressed at a statistically significant lower level in ticks feeding upon a B. bovis-infected calf contrasted to ticks feeding on an uninfected calf.ConclusionOur experimental approaches yielded specific differential gene expression associated with the infection of R. microplus by B. bovis. Overall, an unexpectedly low number of transcripts were found to be differentially expressed in response to B. bovis infection. Although the BmiGI Version 2 gene index (http://compbio.dfci.harvard.edu/tgi/cgi-bin/tgi/gimain.pl?gudb=b_microplus) was a useful database to help assign putative function to some transcripts, a majority of the differentially expressed transcripts did not have annotation that was useful for assignment of function and specialized bioinformatic approaches were necessary to increase the information from these transcriptome experiments.

Gliding Motility of Babesia bovis Merozoites Visualized by Time-Lapse Video Microscopy

Background Babesia bovis is an apicomplexan intraerythrocytic protozoan parasite that induces babesiosis in cattle after transmission by ticks. During specific stages of the apicomplexan parasite lifecycle, such as the sporozoites of Plasmodium falciparum and tachyzoites of Toxoplasma gondii, host cells are targeted for invasion using a unique, active process termed “gliding motility”. However, it is not thoroughly understood how the merozoites of B. bovis target and invade host red blood cells (RBCs), and gliding motility has so far not been observed in the parasite.Methodology/Principal FindingsGliding motility of B. bovis merozoites was revealed by time-lapse video microscopy. The recorded images revealed that the process included egress of the merozoites from the infected RBC, gliding motility, and subsequent invasion into new RBCs. The gliding motility of B. bovis merozoites was similar to the helical gliding of Toxoplasma tachyzoites. The trails left by the merozoites were detected by indirect immunofluorescence assay using antiserum against B. bovis merozoite surface antigen 1. Inhibition of gliding motility by actin filament polymerization or depolymerization indicated that the gliding motility was driven by actomyosin dependent process. In addition, we revealed the timing of breakdown of the parasitophorous vacuole. Time-lapse image analysis of membrane-stained bovine RBCs showed formation and breakdown of the parasitophorous vacuole within ten minutes of invasion.Conclusions/SignificanceThis is the first report of the gliding motility of B. bovis. Since merozoites of Plasmodium parasites do not glide on a substrate, the gliding motility of B. bovis merozoites is a notable finding.