Babesiosis of cattle

Hemopathogens in naturally infected bovine fetuses in Brazil

The transplacental transmission of parasites and hemoparasites is crucial for understanding the epidemiology of diseases. This study aimed to assess the prevalence of hemopathogens in bovine fetuses at various gestational periods. Samples were obtained from a slaughterhouse in the state of Minas Gerais, Brazil, and a total of 236 fetuses were collected. DNA extracted from blood samples (145) and organ samples (a pool of brain and spleen) (236) underwent a nested PCR (nPCR) assay to detect Babesia spp., Theileria spp., Trypanosoma vivax, Anaplasma marginale, Anaplasma bovis, Anaplasma phagocytophilum, Ehrlichia minasensis, and hemotropic Mycoplasma spp. Additionally, serological analysis of 145 plasma samples was conducted using the indirect fluorescent antibody test-IFAT to detect IgG against Babesia bovis, Babesia bigemina, A. marginale, and Trypanosoma vivax. The observed prevalence of transplacental transmission was 19.3 %, 6.2 %, 42.7 % and 2.7 %, for A. marginale, B. bigemina, 'Candidatus M. haemobos', and Mycoplasma wenyonii, respectively. The prevalence of A. marginale by gestational trimester was 16 % (13/81) in the second trimester and 23 % (14/60) in the third trimester, with no positive samples in the first trimester. Regarding the species B. bovis and B. bigemina, all evaluated animals tested negative by nPCR, and no serological evidence for B. bovis was found by the IFAT. Babesia bigemina demonstrated an overall seroprevalence of 6.2 % (9/145), with 4.8 % (7/145) in the last trimester and 1.3 % (2/145) in the second trimester of pregnancy. In total, 42.7 % (62/145) of blood samples were positive for 'Candidatus M. haemobos', with 42 % (34/81) in the middle trimester, and 43 % (26/60) in the final trimester of pregnancy. Mycoplasma wenyonni was detected in 2.7 % (4/145) blood samples, all in coinfection with 'C. M. haemobos'. The prevalence by pregnancy trimester was 25 % (1/4) in the first trimester; 1.2 % (1/81) in the second trimester and 3.3 % (2/60) in the third trimester of pregnancy. Hemopathogen DNA was detected in fetus blood samples but not the brain or spleen samples. All the samples were negative for T. vivax, Theileria spp., Anaplasma spp. and Ehrlichia spp. Overall, in this study, approximately 70 % of fetuses were positive for one or more of the studied parasites. No significant associations were observed between pairs of pathogens, except 'C. M. haemobos' and A. marginale.

Analysis of serum proteomic profiles of endangered Siamese and Burmese Eld's deer infected with subclinical Babesia bovis in Thailand

The endangered Eld's deer is a conserved species in Thailand, where tropical parasitic infections are endemic. Although Eld's deer with babesiosis are generally asymptomatic, they can still harbor the parasite and serve as reservoirs for ticks, spreading the infection to healthy animals within the herd. The present study aimed to investigate potential serum proteome biomarkers of Eld's deer with subclinical Babesia bovis infection. A total of 67 blood samples were collected from captive Siamese and Burmese Eld's deer showing no signs of parasitic infection. The nested polymerase chain reaction (nPCR) of a conserved spherical body protein 2 (sbp-2) gene of B. bovis was utilized to classify Eld's deer groups, with 25.37 % (17/67) testing positive for B. bovis. Additionally, the application of proteomic studies showed that six B. bovis proteins, such as Obg-like ATPase 1 (OLA1) and heat shock protein 90 (HSP90), were significantly upregulated by more than a two-fold change compared with the PCR-negative samples. Of the 55 overexpressed serum proteins in the PCR-positives, alpha 2-HS glycoprotein (AHSG) and immunoglobulin lambda variable 2-8 (IGLV2-8) were notably among the top 10 proteins with the highest area under curve (AUC) values. Hence, they were proposed as potential biomarkers for subclinical B. bovis infection in Eld's deer. Analysis of the protein interaction network revealed interactions between Eld's deer AHSG and B. bovis OLA1 and HSP90, alongside associations with other proteins such as erb-b2 receptor tyrosine kinase 2 (ERBB2) and epidermal growth factor receptor (EGFR). These interactions were involved in the immune system pathway and inflammatory responses. Our findings shed light on subclinical infection of B. bovis in Eld's deer and identify potential biomarkers, contributing to the further effective detection and monitoring of B. bovis infection in this endangered species.

Molecular epidemiology of bovine theileriosis and genetic diversity of Theileria annulata in three governorates of Egypt

Bovine theileriosis is a protozoan disease caused by the intracellular parasite (Theileria spp.) transmitted by ticks and it is considered one of the most significant parasitic diseases, potentially endangering Egyptian cattle herd industry. The present study was conducted for a molecular survey of bovine theileriosis and its associated risk factors (season variations, geographical locations, breeds, age, sex, tick infestation, and acaricide applications) in three Egyptian governorates, Beni-Suef, Al-Faiyum, and Al-Minya for a year extended from December 2021 to November 2022, in addition, genetic diversity of Theileria isolates. A total of 961 cattle were examined for Theileria infection clinically, microscopically, and by Polymerase Chain Reaction (PCR) using 18S rRNA gene for piroplasms DNA detection, Theileria genus-specific primers of the small subunit of rRNA gene, and Theileria annulata specific primers of the Tams-1 gene. The prevalence rate of bovine theileriosis was 9.26%, and 11.86% using Giemsa-stained blood smear and PCR, respectively. All positive samples screened by Theileria genus-specific primers were positive for T. annulata when screened by the specific primers. Based on molecular screening, season, cattle breeds and acaricide applications were considered risk factors for T. annulata infection, while locality, age, sex and tick infestation had insignificant effects with the occurrence of the disease. A potential novel T. annulata haplotype based on the Tam-1 gene was identified with accession numbers OR364144 and OR915851. Therefore, T. annulata was the only Theileria species found and played a significant problem in the cattle population. This study could be the basis for future studies on unexplored regions and different animal species for well-structured prevention and control measures.

Splenic rupture in dairy cattle: Report of 24 cases

Splenic rupture in cattle is scarcely described in the literature. The aim of this work was to report the occurrence of splenic rupture in cattle in southern Brazil as well as to describe the causes of the condition. Between 2013 and 2022, 24 of the 1769 bovine necropsies performed in southern Brazil were due to splenic rupture, accounting for 1.36% of the diagnoses. Animals died due to hemoperitoneum caused by a rupture in the splenic capsule, typically associated with marked splenomegaly and a large hematoma between the capsule and the parenchyma. Clinical signs were described in a subset of cases (11 of 24 cases, 46%) and included apathy, abdominal pain, mucosal pallor, tachycardia, and respiratory distress. However, the majority (13 of 24 cases, 54%) presented as sudden death. The underlying cause of splenic rupture was established as follows: 16 cases (67%) secondary to babesiosis, 4 cases (17%) due to lymphoma, 1 case (4%) due to a thrombus, 1 case (4%) due to external trauma, 1 case due to a ruptured nodular lymphoid hyperplasia (4%), and 1 case of undetermined cause (4%). Hypovolemic shock caused by splenic rupture is an important cause of death of dairy cattle, and babesiosis and bovine leukemia virus-associated lymphoma are among the most common etiologic diagnoses (84% of cases). The description of the causes of this condition is important to clarify the pathogenesis and occurrence of splenic rupture in dairy cattle.

Molecular detection and phylogenetic analysis of tick-borne pathogens in cattle from southern Malawi

INTRODUCTION

Tick-borne diseases (TBDs) pose a major hindrance to livestock production in countries with limited resources. Effective prevention and management of TBDs require a thorough understanding of disease vectors and pathogens. However, there is limited information on studies of bovine tick-borne pathogens (TBPs) using molecular methods in Malawi. This study aimed to detect TBPs of cattle populations in southern Malawi, which has the largest cattle population in the country.

METHODOLOGY

A total of 220 blood samples from apparently healthy cattle were collected in six districts, and were screened for selected TBPs using polymerase chain reaction (PCR).

RESULTS

The overall detection rate of TBPs was 72.3%. Among the detected pathogens, Babesia bigemina had the highest detection rate (34.5%), followed by Anaplasma marginale (23.2%), Anaplasma phagocytophilum (22.3%), Theileria taurotragi (22.3%), Theileria parva (15.5%), Anaplasma bovis (9.6%), Babesia bovis (7.3%), Theileria mutans (4.1%), and Babesia naoakii (2.7%). Among the positive samples, 64.2% were found to be co-infected with two or more TBPs, with the highest number of seven pathogens detected in a single sample. The study documents the existence of A. phagocytophilum, B. bovis, and B. naoakii in Malawian cattle for the first time.

CONCLUSION

The findings herein demonstrate a significant burden of TBPs on cattle in Malawi, which gives a challenge in combating TBDs. The high TBP burden, along with the high co-infection frequencies in Malawian cattle necessitates the urgency to implement effective control strategies to enhance cattle production in the country.

Reproductive Capabilities of Female Nilgai (Boselaphus tragocamelus) in Southern Texas

Free-ranging nilgai antelope (Boselaphus tragocamelus) are an understudied species, both on their native ranges of India, Pakistan, and Nepal and on their introduced ranges in southern Texas. Basic data related to population sizes, survival, reproduction, and recruitment are needed throughout their range to inform management and conservation decisions. We collected nilgai fetuses from 3 ranches in southern Texas, including East Foundation's El Sauz and Santa Rosa ranches, and the Norias Division of the King Ranch® from 2018-2021. We calculated the percentage of individuals that were pregnant in each of the sample years and overall. We determined monthly average, maximum, and minimum fetus length. Of 488 nilgai cows, we found 386 to be pregnant (79%) and 214 to be pregnant with twins (56%). We found nilgai cows as young as 1-year old to have fetuses and therefore to have reached sexual maturity. Sex ratios of fetuses during any sampling year did not differ. We found ample evidence supporting our hypothesis that nilgai are fecund on their introduced range of southern Texas. To prevent nilgai overpopulation and associated problems, harvest management strategies should be implemented, specifically on nilgai cows.

Gapless assembly of Babesia bovis NVSL348

We are reporting a Babesia bovis genome containing four nuclear chromosomes, a mitochondrial genome, and an apicoplast from reference isolate NVSL348. This report includes a gapless assembly consisting of all six genetic molecules.

Antiparasitic Evaluation of Aquiluscidin, a Cathelicidin Obtained from Crotalus aquilus, and the Vcn-23 Derivative Peptide against Babesia bovis, B. bigemina and B. ovata

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.

A small proportion of Zebu genetic background in crossbred calves may not be enough to improve resistance against natural bovine Babesia spp. infections

The main objective of cattle breeders in tropical and subtropical regions is to acquire animals with taurine-productive traits adapted to the broad weather range of these regions. However, one of the main challenges on using taurine genetics in these areas is the high susceptibility of these animals to tick-borne diseases. Consequently, the present study evaluated from 10 November 2021-19 April 2022, the over 13 assessments, the Babesia bovis and Babesia bigemina DNA loads and the IgG anti-B. bovis and anti-B. bigemina levels in Angus (n = 17, 100% Taurine) and Ultrablack (n = 14, ∼82% taurine and 18% Zebu) calves. Data were analyzed using a multivariate mixed model with repeated measures of the same animal including the fixed effects of evaluation, genetic group, sex, Babesia spp., and their interactions. The repeatability values were estimated from the (co)variances matrix and expressed for each species. The correlations between the DNA loads (CNlog) and IgG titers (S/P) values for the two species were also estimated using the same model. Regarding the specific IgG antibody titers for both Babesia spp., no significant differences were observed between the two genetic groups. However, for B. bovis and B. bigemina DNA loads, Ultrablack calves presented significantly higher values than Angus calves. Under the conditions evaluated in this study, our findings suggest that the low percentage of Zebu genetic in the Ultrablack breed was insufficient to improve resistance against babesiosis. Further studies must demonstrate if the low percentages of Zebu genetics in Taurine breeds can modify the susceptibility to babesiosis infections.

Detection of tick-borne pathogens in Rhipicephalus bursa ticks collected from the autochthonous Garrano breed of horses in Portugal

The Garrano is a semi-feral horse breed native to several mountains in the northern Iberian Peninsula. Despite being endangered, this unique breed of pony has managed to survive in the wild and continues to be selectively bred, highlighting their remarkable resilience and adaptability to harsh environments. Wildlife plays a critical role in the survival of tick vectors in their natural habitats and the transfer of tick-borne pathogens, as they can serve as reservoir hosts for many agents and amplifiers for these vectors. The semi-feral lifestyle of the Garrano horses makes them particularly vulnerable to exposure to numerous tick species throughout the year. Therefore, the aim of this study was to investigate the occurrence of Anaplasma, Ehrlichia, Babesia, Theileria, and spotted fever rickettsiae in the Garrano horse ticks to obtain a knowledge of circulating agents in this host population. The collected ticks (n = 455) were identified as Rhipicephalus bursa. DNA specimens were organized in pools of 5 ticks, for molecular screening. Pools PCR results confirmed the presence of Candidatus Rickettsia barbariae (n = 12 for the ompB gene, n = 11 for the ompA gene and n = 6 for the gltA gene), Babesia bigemina (n = 1), Babesia caballi (n = 3), Theileria equi (n = 15) and Theileria haneyi (n = 1).These results confirm the circulation of an emerging rickettsial spotted fever group member, Candidatus R. barbariae, in R. bursa ticks. Our findings demonstrated that Candidatus R. barbariae co-circulates with B. bigemina and T. equi, which are vectored by R. bursa. We are reporting for the first time, the detection of T. haneyi among R. bursa ticks feeding in the Garrano horses in Portugal. Surveillance studies for tick-borne infections are essential to provide information that can facilitate the implementation of preventive and control strategies.

Comparative efficacy of buparvaquone and imidocarb in inhibiting the in vitro growth of Babesia bovis

Introduction

B. bovis is an apicomplexan parasite responsible for bovine babesiosis, a tick-borne disease with a worldwide impact. The disease remains inefficiently controlled, and few effective drugs, including imidocarb dipropionate (ID), are currently available in endemic areas. The objective of this study was to evaluate whether buparvaquone (BPQ), a drug currently used to treat cattle infected with the Babesia-related Theileria spp. parasites, could be active against Babesia parasites. Herein, we compared the effect of ID and BPQ on B. bovis growth in vitro erythrocyte culture.

Methods

We compared the effect of ID and BPQ on the culture-adapted Texas T2Bo strain of B. bovis. In vitro cultured parasites were incubated with ID and BPQ at two starting parasitemia levels (PPE), 0.2% and 1%. In vitro cultured parasites were treated with ID or BPQ at concentrations ranging from 10 to 300 nM, during 4 consecutive days. Parasitemia levels were daily evaluated using microscopic examination. Data was compared using the independent Student's t-test.

Results and discussion

Both ID and BPQ significantly inhibited (p < 0.05) the growth of B. bovis, regardless of the initial parasitemia used. At 1% parasitemia, BPQ had lower calculated inhibitory concentration 50 (IC50: 50.01) values than ID (IC50: 117.3). No parasites were found in wells with 0.2% starting parasitemia, treated previously with 50 nM of BPQ or ID, after 2 days of culture without drugs. At 1% parasitemia, no parasite survival was detected at 150 nM of BPQ or 300 nM of ID, suggesting that both drugs acted as babesiacidals.

Conclusion

Overall, the data suggests that BPQ is effective against B. bovis and shows a residual effect that seems superior to ID, which is currently the first-line drug for treating bovine babesiosis globally.

Molecular detection and characterization of Theileria annulata, Babesia bovis, and Babesia bigemina infecting cattle and buffalo in southern Egypt

Tick-borne diseases have a major adverse effect on livestock worldwide, causing enormous economic losses in meat and milk production as well threatening animal and public health. In this study, we aimed to detect and characterize piroplasms isolated from cattle and buffalo in southern Egypt, using molecular techniques. Three hundred blood samples were collected from cattle and buffalo in two governorates in southern Egypt. All 300 samples (100%) were confirmed to contain DNA, as they exhibited bands of bovine β-actin gene at the expected 227 bp for cattle and buffalo. The samples were analyzed by PCR for the presence of piroplasms, specifically Babesia bovis, Babesia bigemina, and Theileria annulata. Samples positive for the piroplasma 18S ribosomal RNA gene were further examined for two additional genes, spherical body protein 4 gene, to provide an enhanced degree of specificity for the identification of B. bovis and B. bigemina, and the major merozoite surface antigen gene for T. annulata. The infection rate for piroplasma spp. was 60/300 (20%). The positivity rates were 10.7% (32/300) for T. annulata, 5.3% (16/300) for B. bovis, and 4% (12/300) for B. bigemina. By host species, 42/150 (28%) cattle and 18/150 (12%) buffalo were positive for piroplasms. None of the isolates sequenced for the B. bovis isolates from buffalo in this study showed 100% identity with any sequence deposited in GenBank for the small subunit ribosomal RNA gene (maximum identity value = 99.74%). Similarly, no T. annulata small subunit ribosomal RNA gene sequence identified in this study exhibited 100% identity with any sequence deposited in GenBank (maximum identity value = 99.89%). The current study provides a partial sequence of the T. annulata merozoite-piroplasm surface antigen gene, as well as the B. bovis and B. bigemina spherical body protein 4 genes, in cattle and buffalo in southern Egypt, and is the first report on these piroplasma genes in cattle and buffalo in southern Egypt.

Cloning and catalytic profile of Hyalomma dromedarii leucine aminopeptidase

Ticks have harmful impacts on both human and animal health and cause considerable economic losses. Leucine aminopeptidase enzymes (LAP) play important roles during tick infestation to liberate vital amino acids necessary for growth. The aim of the current study is to identify, express and characterize the LAP from the hard tick Hyalomma dromedarii and elucidate its biochemical characteristics. We cloned an open reading frame of 1560 bp encoding a protein of 519 amino acids. The LAP full-length was expressed in Escherichia coli BL21 (DE3) and purified. The recombinant enzyme (H.d rLAP- 6×His) had a predicted molecular mass of approximately 55 kDa. Purification and the enzymatic characteristics of H.d rLAP- 6×His were studied. The purified enzyme showed maximum activity at 37 °C and pH 8.0-8.5 using Leu-p-nitroanilide as a substrate. The activity of H.d rLAP- 6×His was sensitive to β-mercaptoethanol, dl-dithiothreitol, 1,10- phenanthroline, bestatin HCl, and EDTA and completely abolished by 0.05 % SDS. In parallel, the enzymatic activity was enhanced by Ni2+, Mn2+ and Mg2+, partially inhibited by Na+, Cu2+, Ca2+ and completely inhibited by Zn2+.

Epidemiological assessment of Anaplasma marginale, Babesia bigemina, and Babesia bovis infections in Colombian creole cattle breeds: A molecular survey in northeastern Colombia

Anaplasmosis and babesiosis are globally distributed arthropod-borne diseases known for causing substantial economic losses due to their high morbidity and mortality rates. This study aims to assess the frequency and epidemiological features associated with the infection of Anaplasma marginale, Babesia bigemina, and Babesia bovis in three Creole cattle breeds (Chino Santandereano (Chino), Casanareño (CAS), and Sanmartinero (SM)) in northeastern Colombia. Between June 2019 and March 2020, a total of 252 Creole cattle were sampled, with Chino, CAS, and SM accounting for 42.8%, 29.5%, and 29.5% of the samples, respectively. Blood samples were subjected to molecular analysis to detect the DNA of A. marginale, B. bigemina, and B. bovis, using species-specific primers. Additionally, Packed Cell Volume (PCV), total serum proteins, and body condition were evaluated. Molecular analyses revealed the presence of B. bigemina, A. marginale, and B. bovis in 83.7% (211/252; 95% CI = 79.1%-88.3%), 59.9% (151/252; 95% CI = 53.8%-66.1%), and 40.9% (103/252; 95% CI = 34.7%-46.9%) of the samples, respectively, with 69% (174/252; 95% CI = 57.8%-80.3%) exhibiting coinfections. Notably, in infected animals, no significant alterations in PCV, total serum proteins, or body condition were observed. Multivariate analyses indicated a statistically significant association between the frequency of A. marginale infection and the breed and season, with a higher frequency in SM during the rainy season (P < 0.05). To our knowledge, this is the first molecular survey that evaluates multiple arthropod-borne pathogens in Colombian Creole breeds. The results revel a high frequency of B. bigemina and A. marginale infections, coupled with a notable frequency of coinfections, all without significant alteration in the PCV, total serum proteins and body conditions. Our findings enhance the understanding of the epidemiological aspects of arthropod-borne pathogens in Colombian Creole breed and contribute to the improvement of sanitary programs for these animals.

Wide bovine tick-borne pathogen spectrum: Predominancy of Theileria annulata and the first molecular detection of Ehrlichia minasensis in Turkey

Vector-borne diseases indulge in severe economic losses in the livestock industry by adversely affecting cattle breeding in tropical and subtropical zone countries, including Turkey, encompassing a wide land area representing diverse climatic conditions. This study aimed to investigate significant bovine tick-borne piroplasm, rickettsia, and some other bacterial agents by genus- or species-specific PCR and nested PCR techniques in Turkey. A total of 210 cattle blood samples were collected from sixteen provinces in different geographical regions of Turkey. PCR analyses were performed targeting the detection of Babesia/Theileria/Hepatozoon sp. 18S rRNA, Babesia/Theileria sp. 18S rRNA (V4), B. bigemina RAP-1a, B. bovis SBP-4, B. ovata AMA-1, B. naoaki AMA-1, T. annulata Tams-1, T. orientalis MPSP, T. mutans 18S rRNA, Anaplasma/Ehrlichia sp. 16S rRNA, A. marginale MSP4, A. bovis 16S rRNA, A. phagocytophilum 16S rRNA, A. capra 16S rRNA, E. ruminantium pSC20, Mycoplasma sp. 16S rRNA, and Coxiella burnetii 16S rRNA genes. Overall, 133 (63.3%) cattle were found to be infected with at least one of the following protozoan or bacterial pathogens; B. bovis, B. bigemina, B. occultans, T. annulata, T. orientalis, A. marginale, A. phagocytophilum, and Mycoplasma sp. The total prevalence of pathogens was determined as follows; 0.5% B. bovis, 0.5% B. bigemina, 1.4% B. occultans, 41.0% T. annulata, 1.4% T. orientalis, 10.5% A. marginale, 13.8% A. phagocytophilum, 0.5% A. bovis, 2.9% Uncultured Anaplasma sp., 0.5% E. minasensis, 0.5% Uncultured Ehrlichia sp., and 23.3% Mycoplasma sp. Moreover, large part of the total infection (n:133) was composed of single infections (63.9%); however, double (24.8%), triple (7.5%), quadruple (2.3%), and quintuple (1.5%) co-infections were also encountered. In addition to some bovine pathogens such as B. occultans, T. orientalis, A. bovis, M. wenyonii, and Candidatus Mycoplasma haemobos, which were rarely reported in Turkey, sequencing and phylogenetic analysis revealed the first detection of Uncultured Ehrlichia sp. (0.5%), and E. minasensis (0.5%) with 100% nucleotide sequence identities. The study also indicates that the spectrum of pathogens harbored by Turkish cattle is quite wide, and these pathogens cause multiple co-infections with various combinations, and T. annulata stands out as the primary bovine pathogen among them.

Enzootic stability of tick fever in Holstein calves grazing in a tropical region, subjected to strategic cattle tick control with fluralaner

BACKGROUND

In 2022, fluralaner was launched on the market for use in the control of the cattle tick Rhipicephalus microplus after showing 100% efficacy in registration trials against the causative agents of cattle tick fever (TFAs). The aim of the present study was to determine whether a strategic control regimen against R. microplus using fluralaner (FLU) in Holstein calves grazing in a tropical region would alter the enzootic stability status of cattle tick fever, triggering outbreaks in these animals up to 22 months age.

METHODS

In this study, a group of calves treated with FLU was compared with a control group treated with the regimen currently being used on the farm, which consisted of the fipronil + fluazuron formulation (FIFLUA). In the first experiment, the efficacy of the FIFLUA pour-on formulation was evaluated in a field study. In the second experiment, which lasted 550 days, two experimental groups (n = 30/group) of Holstein calves naturally infested with R. microplus were analyzed. Calves aged 4 to 10 months received either a specific treatment regimen with FLU (experimental group) or FIFLUA (control group). During this period, tick counts, animal weight measurement, feces collection (to determine eggs and oocysts per gram of feces), tick fever monitoring, blood smears (to ascertain enzootic stability of the herd), PCR testing for TFAs and serology (indirect enzyme-linked immunosorbent assay [iELISA]) were performed. All calves were evaluated for signs of tick fever between ages 11 and 22 months.

RESULTS

FIFLUA showed an acaricidal efficacy of > 90% from post-treatment days 14 to 35. Regarding treatments against the TFAs, the average number of treatments was similar between groups, but animals treated with FLU had a smaller reduction in packed cell volume on some of the evaluation dates of the second and third treatment against TFAs. In calves aged 10 months in the FLU group, B. bovis was not detected by PCR (0/15 samples), 40% of the samples had antibody titers and 33% (10/30) of the samples had positive blood smears. Regarding B. bigemina, > 86% of the samples in both groups tested positive for B. bigemina DNA and antibodies; there was no difference in the antibody titers between the groups. There were no clinical cases of cattle tick fever in calves aged 11 to 22 months.

CONCLUSIONS

In comparison with the control treatment, the strategic control regimen against R. microplus with FLU that was implemented in the present study did not negatively affect the enzootic stability status of A. marginale and B. bigemina in the herd up to 22 months of age. The enzootic stability status of B. bovis was not reached by either group. These results likely represent a characteristic of the local tick population, so further studies should be performed.

Systematic Review and Meta-Analysis on Piroplasma spp. Infection and Co-infection with Anaplasma marginale in Domestic Ruminants from Algeria

BACKGROUND

Piroplasmosis and anaplasmosis stand out as the primary diseases affecting livestock during periods of tick activity. These vector-borne diseases continue to emerge worldwide, exerting a detrimental impact on both animal health and national economies. The purpose of this study is to assess the prevalence of Piroplasma spp. and its co-occurrence with Anaplasma marginale in domestic ruminants in Algeria.

METHODS

Three databases were systematically reviewed to identify eligible studies for the final meta-analysis, following the PRISMA statement. The 'meta' package in the R software was employed for the meta-analysis with the random effects model chosen for data pooling.

RESULTS

The meta-analysis encompasses 14 research papers spanning a 19-year period (2004-2023). Theileria spp. was identified in all studies, covering 1675 cattle, 190 sheep, and 128 goats, yielding an overall Theileria infection rate of 45% (95% CI 26-65%). Specifically, cattle had a 59% infection rate, while sheep and goats had rates of 18% and 20%, respectively. Babesia spp. was found in nine studies, involving 1183 cattle and 190 sheep, resulting in an overall Babesia infection rate of 7% (95% CI 4-15%), with cattle and sheep having rates of 10% and 3%, respectively. Notably, eight Piroplasma species T. annulata, T. orientalis, T. buffeli, T. equi, Theileria sp., B. bovis, B. bigemina, and B. occultans were detected in cattle, with T. annulata being the most prevalent at 54%. Regional disparities and host factors also impacted infection rates, with higher rates in Northeastern Algeria and among suspected disease cattle. Additionally, gender, age, and breed influenced cattle susceptibility to Theileria infection. Furthermore, six distinct co-infections between Piroplasma spp. and A. marginale were observed, with T. annulata/A. marginale identified in six studies, demonstrating an 8.3% co-infection rate.

CONCLUSION

This analysis offers crucial insights into the current status of Piroplasmosis and its co-infection with A. marginale in Algerian domestic ruminants, providing valuable data for surveillance and prevention strategies.

Detection and quantification of Babesia bovis and Babesia bigemina using different target genes

Molecular assays have been widely used for the detection and quantification of bovine babesiosis due to their high sensitivity and specificity. However, variations in the sensitivity of pathogen detection may occur depending on the selected target gene. Thus, this study aimed to compare the detection sensitivity (DS) of Babesia bovis and B. bigemina infection levels in artificially and naturally infected cattle using quantitative PCR (qPCR) and six target genes. For B. bovis, the merozoite surface antigen genes 2b and 2c (msa-2b and msa-2c), and the mitochondrial cytochrome b gene (cybmt) were used. For B. bigemina, the genes encoding the proteins associated with rhoptry 1c (rap-1c), rap-1a, and cybmt were used. Six bovines, free of babesiosis, were artificially infected with 1 × 10-8 red blood cells infected (iRBC) with B. bovis (n = 3) or 1 × 10-6B. bigemina iRBC (n = 3). The animals were evaluated daily until parasitemia was confirmed (≥ 2.0%). The quantity of iRBC present in each animal was determined by examining blood smears. Blood samples were then subjected to DNA extraction, serial dilution, and qPCR analysis to determine the DS of each target gene. In addition, 30 calves naturally infected by Babesia spp. were also evaluated using the same six target genes. Regarding the artificial infection, B. bovis cybmt showed 25-fold higher sensitivity than the msa-2b and msa-2c genes, while the B. bigemina cybmt exhibited 5-fold and 25-fold higher sensitivity than the rap-1a and rap-1c genes, respectively. The rap-1a gene was found to be 5 times more sensitive than the rap-1c gene, while the B. bovis msa-2b and msa-2c genes exhibited similar DS. The positive frequencies of naturally infected calves for the target cybmt, msa-2b, and msa-2c genes (B. bovis) were: 100%, 33.3% and 50%, while cybmt, rap-1a, and rap-1c genes (B. bigemina) were 90%, 83.3%, and 63.3%, respectively. This study may contribute to the selection of suitable genes for molecular monitoring of bovine babesiosis. Mitochondrial genes could be considered as an alternative to improve the sensitivity of B. bovis and B. bigemina detection using qPCR.

Comparative chemical genomics in Babesia species identifies the alkaline phosphatase PhoD as a determinant of antiparasitic resistance

Babesiosis is an emerging zoonosis and widely distributed veterinary infection caused by 100+ species of Babesia parasites. The diversity of Babesia parasites and the lack of specific drugs necessitate the discovery of broadly effective antibabesials. Here, we describe a comparative chemogenomics (CCG) pipeline for the identification of conserved targets. CCG relies on parallel in vitro evolution of resistance in independent populations of Babesia spp. (B. bovis and B. divergens). We identified a potent antibabesial, MMV019266, from the Malaria Box, and selected for resistance in two species of Babesia. After sequencing of multiple independently derived lines in the two species, we identified mutations in a membrane-bound metallodependent phosphatase (phoD). In both species, the mutations were found in the phoD-like phosphatase domain. Using reverse genetics, we validated that mutations in bdphoD confer resistance to MMV019266 in B. divergens. We have also demonstrated that BdPhoD localizes to the endomembrane system and partially with the apicoplast. Finally, conditional knockdown and constitutive overexpression of BdPhoD alter the sensitivity to MMV019266 in the parasite. Overexpression of BdPhoD results in increased sensitivity to the compound, while knockdown increases resistance, suggesting BdPhoD is a pro-susceptibility factor. Together, we have generated a robust pipeline for identification of resistance loci and identified BdPhoD as a resistance mechanism in Babesia species.

Expression of sex-specific molecular markers by Babesia bovis gametes

BACKGROUND

Bovine babesiosis caused by Babesia bovis is one of the most important tick-borne diseases of cattle in tropical and subtropical regions. Babesia bovis parasites have a complex lifecycle, including development within the mammalian host and tick vector. In the tick midgut, extracellular Babesia parasites transform into gametes that fuse to form zygotes. To date, little is known about genes and proteins expressed by male gametes.

METHODS AND RESULTS

We developed a method to separate male gametes from in vitro induced B. bovis culture. Separation enabled the validation of sex-specific markers. Collected male gametocytes were observed by Giemsa-stained smear and live-cell fluorescence microscopy. Babesia male gametes were used to confirm sex-specific markers by quantitative real-time PCR. Some genes were found to be male gamete specific genes including pka, hap2, α-tubulin II and znfp2. However, α-tubulin I and ABC transporter, trap2-4 and ccp1-3 genes were found to be upregulated in culture depleted of male gametes (female-enriched). Live immunofluorescence analysis using polyclonal antibodies confirmed surface expression of HAP2 by male and TRAP2-4 by female gametes. These results revealed strong markers to distinguish between B. bovis male and female gametes.

CONCLUSIONS

Herein, we describe the identification of sex-specific molecular markers essential for B. bovis sexual reproduction. These tools will enhance our understanding of the biology of sexual stages and, consequently, the development of additional strategies to control bovine babesiosis.

Distribution and prevalence of ixodid tick species (Acari: Ixodidae) infesting cattle in Karamoja region of northeastern Uganda

BACKGROUND

Ticks and tick-borne diseases (TTBDs) are a significant threat to livestock production in sub-Saharan Africa. Transhumance pastoralism practiced in Karamoja region and other factors like cattle trade, communal grazing and the presence of wildlife predispose cattle to TTBDs. Tick species abundance and distribution data can be used as a tool for early disease diagnosis and inform tick control strategies. However, these data for north-eastern Uganda are currently limited; previous surveys were relatively localized and targeted fewer cattle kraals and numbers.

METHODS

We randomly collected tick specimens from 1,534 cattle spread across Karamoja region in both the peak month of the rainy (May 2020) and the dry (February2021) seasons. The ticks were identified using morpho-taxonomic keys and the tick species identities confirmed by the 16 S rRNA gene sequencing and phylogenetic analysis.

RESULTS

A collection of 18,637 ticks was examined and fifteen tick species from three genera (ten Rhipicephalus; three Amblyomma; two Hyalomma species) were identified. Rhipicephalus appendiculatus was the most dominant (37.9%) tick species, followed by Amblyomma variegatum (32.3%); A. lepidum (17.3%); R. evertsi evertsi (7.8%); and R. decoloratus (1.4%). Eight of these tick species were ubiquitous in the study districts while six were found in isolated areas. The peak month of the dry season collection was associated with a higher proportion of tick-infested cattle (91%) compared to the peak month of the rainy season (89.8%); a difference that was not found statistically significant (χ2 = 0.5077, n = 1385, p = 0.476). The overall cattle infestation rate was mainly dominated by five tick species namely: A. variegatum (55%), R. appendiculatus (53%), A. lepidum (41%), R. evertsi (22%), and R. decoloratus (8%). The proportion of tick-infested cattle was highest in Napak District (95.4%) and lowest in Amudat District (80.9%) during the peak month of the rainy season. Napak and Amudat Districts also had the highest and lowest proportion of tick-infested cattle (94.8% and 80.7% respectively) during the peak month of the dry season. Rhipicephalus microplus was confirmed in Amudat, Kaabong and Napak districts.

CONCLUSION

This study demonstrates high tick infestation rates in cattle by a battery of tick species in Karamoja region. We identified both R. microplus and R. decoloratus which indicates that R. microplus has recently been introduced in this region. This calls for effective tick control responses to prevent further spread of this invasive cattle tick specie.

Immunization of cattle with a Rhipicephalus microplus chitinase peptide containing predicted B-cell epitopes reduces tick biological fitness

Rhipicephalus microplus, the cattle fever tick, is the most important ectoparasite impacting the livestock industry worldwide. Overreliance on chemical treatments for tick control has led to the emergence of acaricide-resistant ticks and environmental contamination. An immunological strategy based on vaccines offers an alternative approach to tick control. To develop novel tick vaccines, it is crucial to identify and evaluate antigens capable of generating protection in cattle. Chitinases are enzymes that degrade older chitin at the time of moulting, therefore allowing interstadial metamorphosis. In this study, 1 R. microplus chitinase was identified and its capacity to reduce fitness in ticks fed on immunized cattle was evaluated. First, the predicted amino acid sequence was determined in 4 isolates and their similarity was analysed by bioinformatics. Four peptides containing predicted B-cell epitopes were designed. The immunogenicity of each peptide was assessed by inoculating 2 cattle, 4 times at 21 days intervals, and the antibody response was verified by indirect ELISA. A challenge experiment was conducted with those peptides that were immunogenic. The chitinase gene was successfully amplified and sequenced, enabling comparison with reference strains. Notably, a 99.32% identity and 99.84% similarity were ascertained among the sequences. Furthermore, native protein recognition was demonstrated through western blot assays. Chitinase peptide 3 reduced the weight and oviposition of engorged ticks, as well as larvae viability, exhibiting a 71% efficacy. Therefore, chitinase 3 emerges as a viable vaccine candidate, holding promise for its integration into a multiantigenic vaccine against R. microplus.

First molecular detection of a novel Babesia species from Haemaphysalis hystricis in Taiwan

Newly recorded ticks and emerging tick-borne pathogens have recently been reported in subtropical and tropical East Asia. In this study, a total of 1,615 ticks (259 Haemaphysalis hystricis, 1334 Rhipicephalus microplus, 19 H. flava, and 3 R. haemaphysaloides) were collected by flagging from vegetation in Taiwan during 2019-2021. All 1,615 captured tick samples tested negative for SFTSV and Borrelia, but 12 of 356 tick samples tested positive for PCR amplification of a fragment of the 18S rRNA gene of Babesia spp., with an infection rate of 3.37 % (12/356) and a minimum infection rate of 0.74 % (12/1,615). Among the 12 detected Babesia spp., 11 were identified as Babesia bigemina in R. microplus, and the other one, detected in H. hystricis, was classified as an unnamed novel Babesia sp. Interestingly, the 18S rRNA sequence from the isolate detected in H. hystricis shared 98.79 % to 99.50 % identity with those of recent isolates from Japan, China and Nigeria. The exact origin of the Babesia species is not known, but the findings highlight the importance of international cooperation and the exchange of information on ticks and tick-borne pathogens. This represents a rare report of a Babesia sp. identified in H. hystricis, a tick species that has been proposed as a novel vector for some Babesia spp. This study supports H. hystricis as a possible vector of Babesia spp.

Competitive displacement and acaricide resistance of two Rhipicephalus (Boophilus) species collected on commercial farms in South Africa

Rhipicephalus (Boophilus) microplus, an invasive species to Africa, and the endemic R. (B.) decoloratus are of high economic importance in the cattle industry. Invasion of the alien species in South Africa has mostly been reported for traditional communal grazing areas where it seemed to be rapid and, in some cases, even replaced the native species. The alien species is also assumed to already be resistant to acaricides upon invasion. The presence of R. (B.) microplus on commercial farms was therefore investigated and resistance screening of both species to field concentrations of cypermethrin, amitraz, and chlorfenvinphos was determined by means of the larval immersion test. Results showed that only 3.7% (of 383) tick collections submitted were R. (B.) microplus populations. A further 1.6% (of 383) showed co-existence of the two species. Comparing the level of resistance to the acaricides between the two species indicated a mean phenotypic resistance of 66.2 and 26.5% of R. (B.) decoloratus populations to cypermethrin and amitraz, respectively. This was significantly lower for R. (B.) microplus, with 23.0 and 4.1% of its populations resistant to cypermethrin and amitraz, respectively. Closed commercial farming areas seemed to have a preventative advantage for the invasion of R. (B.) microplus and displacement of R. (B.) decoloratus by R. (B.) microplus. Regular monitoring of these two species may be of high importance to prevent unnecessary financial losses due to insufficient control and increased awareness of the threat of Asiatic babesiosis vectored by R. (B.) microplus.

Prevalence of babesiosis in bovines of India: a meta-analytical approach for 30 years (1990-2019)

BACKGROUND

India has a massive population of bovines, which makes the framework of the economy mainly relying on milk and meat production. Parasitic diseases such as babesiosis are detrimental to bovines by decreasing animal welfare and production efficiency.

AIM

Performing a meta-analysis of the prevalence of babesiosis over 30 years viz 1990 to 2019 within India to pool out individual studies from different country regions.

MATERIAL AND METHODS

The studies were reviewed thoroughly to assess the quality, and it was done by following the preferred reporting items for systematic review and meta-analysis (PRISMA) and MOOSE protocols. The prevalence of babesiosis in cattle and buffaloes was calculated using meta-analysis tools using R-software and Q Statistics.

RESULTS

The systematic review and meta-analysis performed on 47 studies among bovine, 48 studies among cattle, and 13 studies among buffaloes revealed the (pooled) prevalence of babesiosis in India as 10.9% (6.3%-18.2%; Q = 5132.03, d.f. = 46, P < 0.001), 11.9% (6.9%-19.8%; Q = 5060.2, d.f.=47, P < 0.001), and 6.0% (2.6%-13.2%; Q = 500.55, d.f.=12, P < 0.001), respectively, which provides a rather exact scenario of the prevalence of this haemoparasitic disease across the country. In addition, cattle were having higher risk of babesiosis than buffalo.

CONCLUSION

The findings from the meta-analysis showed that the disease is prevalent across the country, and that bovines are highly affected by it.

CLINICAL RELEVANCE

Appropriate prevention and control measures should be taken to mitigate this disease and enhance welfare and production performances of bovines.

Cerebrospinal fluid analysis and haemato-biochemical variations in young buffalo calves with cerebral babesiosis

Present communication aimed to record the clinical signs, cerebrospinal fluid analysis and haemato-biochemical variations in buffalo calves with the cerebral form of babesiosis. The study was carried out on eight buffalo calves presented to the hospital with nervous signs suffering from babesiosis. Confirmation of babesiosis was done by demonstration of pear-shaped intra-erythrocytic piroplasms of Babesia. The appreciable clinical signs were the absence of rumination, anorexia, wobbling gait, hyperthermia, scleral congestion, hyperthermia, tachycardia, hyperexcitability, delirium, achezia and grinding of teeth. Cerebrospinal fluid analysis exhibited the presence of high protein, nucleated cells and red blood cells. The haemato-biochemical study showed mild anaemia, leucopenia, lymphocytosis and neutropenia; elevated serum globulin, aspartate aminotransferase, blood urea nitrogen and creatinine levels. The present study concludes that the changes in the cerebrospinal fluid during the cerebral form of babesiosis in buffalo calves might be a reason for the development of neurological signs which was not documented in previous literature and babesiosis can consider as differential diagnosis in young calves with nervous signs.

An epidemiological survey of vector-borne pathogens infecting cattle in Kyrgyzstan

Cattle production is a major contributor to the national economy of Kyrgyzstan. Most cattle in Kyrgyzstan are managed via extensive systems and graze in communal pastures. As a result, infestations with ectoparasites are widespread, implying that various vector-borne diseases might be common in cattle. However, methods to control such infectious diseases are not available in Kyrgyzstan because the epidemiology of vector-borne pathogens (VBPs) infecting cattle remains unclear. The present study was therefore designed to survey Kyrgyz cattle for VBPs. We prepared blood DNA samples from 319 cattle in Kyrgyzstan and screened them with specific PCR assays for detecting Babesia bovis, Babesia bigemina, Babesia naoakii, Theileria annulata, Theileria orientalis, Trypanosoma evansi, Trypanosoma theileri, and Anaplasma marginale infections. Our findings indicated that the surveyed cattle were infected with six of the eight pathogens targeted, with the exceptions being B. naoakii and Try. evansi. The most common pathogen was T. orientalis (84.3%), followed by B. bigemina (47.6%), T. annulata (16.6%), A. marginale (11.6%), Try. theileri (7.2%), and B. bovis (2.5%). Additional screening of the B. bovis- and B. bigemina-negative samples with a Babesia genus-specific 18S rRNA PCR identified two positive samples, and sequencing analysis confirmed that each of them was infected with either Babesia major or Babesia occultans. To the best of our knowledge, this is the first report of B. bovis, B. bigemina, B. occultans, Try. theileri, and A. marginale infections in cattle in Kyrgyzstan. Our findings suggest that cattle in Kyrgyzstan are at high risk of infectious diseases caused by VBPs.

Analysis of the bacterial community in female Rhipicephalus microplus ticks from selected provinces in Luzon, Philippines, using next-generation sequencing

Analysis of the tick microbiome can help understand tick-symbiont interactions and identify undiscovered pathogens, which may aid in implementing control of ticks and tick-borne diseases. The tropical cattle tick Rhipicephalus microplus is a widespread ectoparasite of cattle in the Philippines, negatively affecting animal productivity and health. This study characterized the bacterial community of R. microplus from Luzon, Philippines, through next-generation sequencing of 16s rRNA. DNA was extracted from 45 partially engorged female ticks from nine provinces. The DNA samples were pooled per province and then sequenced and analyzed using an open-source bioinformatics platform. In total, 667 operational taxonomic units (OTUs) were identified. The ticks in all nine provinces were found to have Coxiella, Corynebacterium, Staphylococcus, and Acinetobacter. Basic local alignment search tool (BLAST) analysis revealed the presence of known pathogens of cattle, such as Bartonella, Ehrlichia minasensis, and Dermatophilus congolensis. The tick samples from Laguna, Quezon, and Batangas had the most diverse bacterial species, whereas the tick samples from Ilocos Norte had the lowest diversity. Similarities in the composition of the bacterial community in ticks from provinces near each other were also observed. This is the first study on metagenomic analysis of cattle ticks in the Philippines, providing new insights that may be useful for controlling ticks and tick-borne diseases.

Tick-Borne Diseases of Humans and Animals in West Africa

Ticks are a significant group of arthropod vectors that transmit a large variety of pathogens responsible for human and animal diseases worldwide. Ticks are the second biggest transmitters of vector-borne diseases, behind mosquitoes. However, in West Africa, there is often only limited knowledge of tick-borne diseases. With the scarcity of appropriate diagnostic services, the prevalence of tick-borne diseases is generally underestimated in humans. In this review, we provide an update on tick-borne pathogens reported in people, animals and ticks in West Africa by microscopic, immunological and molecular methods. A systematic search was conducted in PubMed and Google Scholar. The selection criteria included all studies conducted in West Africa reporting the presence of Rickettsia, Borrelia, Anaplasma, Ehrlichia, Bartonella, Coxiella burnetii, Theileria, Babesia, Hepatozoon and Crimean-Congo haemorrhagic fever viruses in humans, animals or ticks. Our intention is to raise awareness of tick-borne diseases amongst human and animal health workers in West Africa, and also physicians working with tourists who have travelled to the region.

Bibliometric analysis of parasite vaccine research from 1990 to 2019

Bibliometric and bibliographic analyses are popular tools for investigating publication metrics and thematic transitions in an expanding codex of biomedical literature. Bibliometric techniques have been employed in parasitology and vaccinology, with only a few malaria-specific literature analyses being reported specifically on parasite vaccines. The pursuit of parasite prophylactics is an important, global endeavour both medically and economically. As such, a comprehensive understanding of the research topics would be a valuable tool in assessing the current status and future directions of parasite vaccine development. Consequently, this study investigated parasite vaccinology from 1990 to 2019 by analysing literature exported from the Web of Science and Dimensions databases using two, commonly used, bibliometric programs: SciMAT and VOSviewer. The results of this study show the common, emerging, and transient themes within the discipline, and where the future lies as vaccine development moves further into the age of omics and informatics.

Genetic Diversity of Merozoite Surface Antigens in Global Babesia bovis Populations

Cattle can be severely infected with the tick-borne protozoa Babesia bovis, giving rise to serious economic losses. Invasion of the host's RBCs by the parasite merozoite/sporozoites depends largely on the MSA (merozoite surface antigens) gene family, which comprises various fragments, e.g., MSA-1, MSA-2a1, MSA-2a2, MSA-2b and MSA-2c, highlighting the importance of these antigens as vaccine candidates. However, experimental trials documented the failure of some developed MSA-based vaccines to fully protect animals from B. bovis infection. One reason for this failure may be related to the genetic structure of the parasite. In the present study, all MSA-sequenced B. bovis isolates on the GenBank were collected and subjected to various analyses to evaluate their genetic diversity and population structure. The analyses were conducted on 199 MSA-1, 24 MSA-2a1, 193 MSA-2b and 148 MSA-2c isolates from geographically diverse regions. All these fragments displayed high nucleotide and haplotype diversities, but the MSA-1 was the most hypervariable and had the lowest inter- and intra-population gene flow values. This fragment also displayed a strong positive selection when testing its isolates for the natural selection, which suggests the potential occurrence of more genetic variations. On the contrary, the MSA-2c was the most conserved in comparison to the other fragments, and displayed the highest inter- and intra-population gene flow values, which was evidenced by a significantly negative selection and negative neutrality indices (Fu's Fs and Tajima's D). The majority of the MSA-2c tested isolates had two conserved amino acid repeats, and earlier reports have found these repeats to be highly immunogenic, which underlines the importance of this fragment in developing vaccines against B. bovis. Results of the MSA-2a1 analyses were also promising, but many more MSA-2a1 sequenced isolates are required to validating this assumption. The genetic analyses conducted for the MSA-2b fragment displayed borderline values when compared to the other fragments.

Cattle co-infection patterns by hemopathogens and their phylogenetic analysis during the tick season in Constantine and Mila, Northeast Algeria

Tropical theileriosis, babesiosis, and anaplasmosis are the most dominant tick-borne infections in North Africa where they cause significant economic losses in ruminants' industry. The aim of the present work was to study infections and co-infection patterns in 66 cattle with clinical signs of piroplasmosis and/or anaplasmosis in two localities, Beni Hamidene and Grarem Gouga, districts of Constantine and Mila (Northeast of Algeria), respectively. This study was conducted between early May and late September during four years 2017, 2018, 2020, and 2021. PCR showed that the most frequent pathogen in cattle with clinical signs of piroplasmosis and/or anaplasmosis was Theileria annulata (66/66; 100%) followed by Babesia bovis (21/66; 31.8%), Anaplasma marginale (15/66; 22.7%), and Babesia bigemina (3/66; 4.5%) (p < 0.001). Giemsa-stained blood smears examinations revealed that 66.7% (44/66); 10.6% (7/66); and 9.1% (6/66) of cattle were infected by T. annulata, Babesia spp., and A. marginale, respectively (p < 0.001). PCR revealed seven co-infection patterns: T. annulata/A. marginale (15/66; 22.7%), T. annulata/B. bovis (21/66; 31.8%), T. annulata/B. bigemina (3/66; 4.5%), T. annulata/A. marginale/B. bovis (7/66; 10.6%), T. annulata/B. bovis/B. bigemina (2/66; 3%), T. annulata/A. marginale/B. bigemina (1/66; 1.5%), and T. annulata/A. marginale/B. bigemina/B. bovis (1/66; 1.5%). Phylogenetic analyses showed that T. annulata Tams1 and B. bigemina gp45 sequences were identical to isolates from Mauritania and South Africa, respectively. The three A. marginale amplicons obtained herein had 99.63 to 99.88% similarity between them. This study provides data that can be used to improve control programs targeting these cattle hemopathogens.

THE FIRST SURVEY OF BOVINE BABESIA SPECIES INFECTING YAKS (BOS GRUNNIENS) IN MONGOLIA

Yak (Bos grunniens) farming is an important part of Mongolia's livestock industry. Yaks survive in harsh mountain environments; provide meat, milk, and wool; and serve as a mode of transportation. In Mongolia, yaks are frequently raised alongside other livestock animals such as cattle, Bactrian camels, sheep, goats, and horses. Recently, we demonstrated that Babesia bovis, Babesia bigemina, and Babesia naoakii-parasites with the potential to cause clinical bovine babesiosis-infect not only cattle but also Bactrian camels in Mongolia. However, yaks have never been surveyed for Babesia infections in this country. In the present study, we surveyed yaks in 8 Mongolian provinces: Bayankhongor, Bayan-Ulgii, Khovd, Khovsgol, Omnogovi, Ovorkhangai, Uvs, and Zavkhan. Blood samples were taken and deoxyribonucleic acid (DNA) was extracted from 375 yaks. Furthermore, Giemsa-stained thin smears were prepared from 315 of the 375 blood samples and then examined for the microscopic detection of Babesia parasites. Microscopy revealed that 34 (10.8%) of 315 blood smears were positive for Babesia parasites. All 375 DNA samples were then tested for B. bovis, B. bigemina, and B. naoakii infection using specific polymerase chain reaction assays. We observed that 238 (63.5%) yaks in all surveyed provinces and 8 (2.1%) yaks in 3 provinces (Bayankhongor, Bayan-Ulgii, and Omnogovi) were positive for B. bovis and B. bigemina, respectively. However, all yaks tested were negative for B. naoakii. This epidemiological survey, the first to report Babesia infection in Mongolian yaks, suggests that disease management strategies for yaks in this country should further address bovine babesiosis.

Disruption of a DNA fragment that encodes the microneme adhesive repeat domain-containing region of the BBOV_III011730 does not affect the blood stage growth of Babesia bovis in vitro

Babesia bovis, an intraerythrocytic hemoprotozoan parasite, causes the most pathogenic form of bovine babesiosis, negatively impacting the cattle industry. Comprehensive knowledge of B. bovis biology is necessary for developing control methods. In cattle, B. bovis invades the red blood cells (RBCs) and reproduces asexually. Micronemal proteins, which bind to sialic acid of host cells via their microneme adhesive repeat (MAR) domains, are believed to play a key role in host cell invasion by apicomplexan parasites. In this study, we successfully deleted the region encoding MAR domain of the BBOV_III011730 by integrating a fusion gene of enhanced green fluorescent protein-blasticidin-S-deaminase into the genome of B. bovis. The transgenic B. bovis, lacking the MAR domain of the BBOV_III011730, invaded bovine RBCs in vitro and grew at rates similar to the parental line. In conclusion, our study revealed that the MAR domain is non-essential for the intraerythrocytic development of B. bovis in vitro.

Molecular Identification of Piroplasmids in Ticks from Infested Small Ruminants in Konya Province, Turkey

Ticks play a pivotal role in propagating a diverse spectrum of infectious agents that detrimentally affect the health of both humans and animals. In the present study, a molecular survey was executed of piroplasmids in ticks collected from small ruminants in four districts within Konya province, Turkey. Microscopic examination identified 1281 adult ticks, which were categorized into 357 pools based on their species, sexes, host animals, and collection site before DNA extraction. The infection rates were calculated by using a maximum likelihood estimate (MLE) with 95% confidence intervals (CI). Hyalomma detritum, H. excavatum, Rhipicephalus bursa, R. sanguineus, and R. turanicus were identified in this study. Among the five tick species identified here, R. turanicus exhibited the highest infestation rate in both goats and sheep. The presence of Babesia ovis and Theileria ovis based on 18S rRNA was confirmed using molecular assay. The overall MLE of infection rates for B. ovis and T. ovis was 2.49% (CI 1.72-3.46) and 1.46% (CI 0.87-2.23), respectively. The MLE of B. ovis and T. ovis infection rates in R. bursa was 10.80% (CI 7.43-14.90) and 0.33% (CI 0.02-1.42), respectively, while that in R. turanicus was 0.12% (CI 0.01-0.51) and 2.08% (CI 1.25-3.22). This study further confirms that R. turanicus and R. sanguineus can act as vectors for B. ovis, thus advancing our comprehension of tick-borne piroplasmids epidemiology and providing valuable insights for the development of effective control strategies for ticks and tick-borne diseases in Turkey.

Babesia ovis secreted antigen-1 is a diagnostic marker during the active Babesia ovis infections in sheep

Ovine babesiosis caused by Babesia ovis is an economically significant disease. Recently, a few B. ovis-specific proteins, including recombinant B. ovis secreted antigen-1 (rBoSA1), have been identified. Immunological analyses revealed that rBoSA1 resides within the cytoplasm of infected erythrocytes and exhibits robust antigenic properties for detecting anti-B. ovis antibodies. This protein is released into the bloodstream during the parasite's development. It would be possible to diagnose active infections by detecting this secretory protein. For this purpose, a rBoSA1-specific polyclonal antibody-based sandwich ELISA was optimized in this study. Blood samples taken from the naturally (n: 100) and experimentally (n: 15) infected sheep were analyzed for the presence of native BoSA1. The results showed that native BoSA1 was detectable in 98% of naturally infected animals. There was a positive correlation between parasitemia level in microscopy and protein density in sandwich ELISA. Experimentally infected animals showed positive reactions from the first or second day of inoculations. However, experimental infections carried out by Rhipicephalus bursa ticks revealed the native BoSA1 was detectable from the 7th day of tick attachment when the parasite began to be seen microscopically. Sandwich ELISA was sensitive enough to detect rBoSA1 protein at a 1.52 ng/ml concentration. Additionally, no serological cross-reactivity was observed between animals infected with various piroplasm species, including Babesia bovis, B. bigemina, B. caballi, B. canis, B. gibsoni, Theileria equi, and T. annulata. Taken collectively, the findings show that the rBoSA1-specific polyclonal antibody-based sandwich ELISA can be successfully used to diagnose clinical B. ovis infections in sheep at the early stage.

Exploring the landscape of Babesia bovis vaccines: progress, challenges, and opportunities

Bovine babesiosis, caused by different Babesia spp. such as B. bovis, B. bigemina, B. divergens, and B. major, is a global disease that poses a serious threat to livestock production. Babesia bovis infections are associated with severe disease and increased mortality in adult cattle, making it the most virulent agent of bovine babesiosis. Babesia bovis parasites undergo asexual reproduction within bovine red blood cells, followed by sexual reproduction within their tick vectors, which transmit the parasite transovarially. Current control methods, including therapeutic drugs (i.e., imidocarb) have been found to lead to drug resistance. Moreover, changing environmental factors add complexity to efficient parasite control. Understanding the fundamental biology, host immune responses, and host-parasite interactions of Babesia parasites is critical for developing next-generation vaccines to control acute disease and parasite transmission. This systematic review analyzed available research papers on vaccine development and the associated immune responses to B. bovis. We compiled and consolidated the reported vaccine strategies, considering the study design and rationale of each study, to provide a systematic review of knowledge and insights for further research. Thirteen studies published since 2014 (inclusive) represented various vaccine strategies developed against B. bovis such as subunit, live attenuated, and viral vector vaccines. Such strategies incorporated B. bovis proteins or whole live parasites with the latter providing the most effective prophylaxis against bovine babesiosis. Incorporating novel research approaches, such as "omics" will enhance our understanding of parasite vulnerabilities.

Molecular detection and characterization of a novel Theileria genotype in Dama Gazelle (Nanger dama)

Wild animals play a critical role in maintenance and transmission of various tick-borne pathogens. It is essential to identify these wild host species that can serve as important reservoirs of tickborne diseases. In the present study we investigated Dama gazelle (Nanger dama) as a potential novel reservoir of Theileria spp. A total of 53 blood samples collected from Dama gazelle as part of the Al Ain Zoo preventive medicine program were screened for Theileria spp. by qPCR using a commercial assay, followed by additional studies using conventional PCR targeting an approximate 450-base pair (bp) fragment of the V4 hypervariable region of the 18S ribosomal RNA (rRNA) gene. Sequencing and phylogenetic analysis of a subset (20) of PCR amplicons revealed Theileria isolates from gazelles of Al Ain Zoo clustered closely to Theileria sp. Dama Gazelle (AY735115) from USA and were far away or did not cluster with the known Theileria spp. of ruminants namely T. annulata, T. ovis, T. orientalis, T. luwenshuni, T.parva and T.sinensis. Theileria genotypes detected in gazelles of present study were clearly distinct from the other common theileria species of ruminants. The present finding throws light on the critical role of reservoir host in maintenance and transmission of pathogen.

Vaccination with an in vitro culture attenuated Babesia bovis strain safely protects highly susceptible adult cattle against acute bovine babesiosis

Introduction

Live in vivo attenuated Babesia bovis vaccines produced by sequential passages in splenectomized calves have historically been used to control acute bovine babesiosis in endemic areas worldwide. However, several constraints prevent the widespread use of these vaccines, including the need for several splenectomized calves to produce vaccine batches, and potential inconsistent parasite attenuation, which contraindicates their use for highly Babesia-susceptible adult cattle. Thus, the use of vaccines based on well-defined in vitro culture attenuated B. bovis strains emerges as a more sustainable and efficient alternative. Previous work demonstrated that the culture attenuated strain Att-S74-T3Bo is non-tick transmissible and able to safely protect calves against needle challenge with a B. bovis virulent strain.

Methods and results

Herein we evaluated safety and efficacy of Att-S74-T3Bo in preventing acute babesiosis in adult (>1.5 year of age) cattle. Results demonstrated that Att-S74-T3Bo vaccination of adult animals (n=5) induced self-limiting signs of acute infection and protected the vaccinated animals against challenge with the homologous virulent B. bovis strain Vir-S74-T3Bo. Att-S74-T3Bo-vaccinated adult cattle developed significant (P<0.05) monocytosis, with concomitant neutropenia and CD4+ leukopenia, in peripheral blood early after vaccination. Also, vaccinated animals developed a specific signature of pro- and anti-inflammatory cytokine expression in peripheral blood and significant levels of IgM, total IgG, IgG1, and IgG2 against the B. bovis immunodominant antigen RAP-1 CT. Strikingly, none of the vaccinated animals showed any signs of acute babesiosis after challenge with Vir-S74-T3Bo. In contrast, control adult cattle (n=5) showed pathognomonic symptoms of acute babesiosis, and significant decrease (P<0.05) in lymphocytes, monocytes, and neutrophils, starting on day 7 post-challenge. All control animals developed severe acute disease and were euthanized on days 10 through 12 days post-challenge.

Discussion and conclusion

Evidence from this study indicates that Att-S74-T3Bo safely protects highly susceptible adult cattle against challenge with a homologous virulent strain of B. bovis. In conclusion, Att-S74-T3Bo may be considered as a potential efficient and sustainable attenuated candidate vaccine strain to control acute bovine babesiosis in highly susceptible adult cattle. Future studies should focus on increasing the number of animals vaccinated, duration of immunity, and efficacy of this attenuated strain against heterologous virulent parasite strains.

Tick communities of cattle in smallholder rural livestock production systems in sub-Saharan Africa

BACKGROUND

The majority of the African population lives in rural areas and depends on agriculture for their livelihoods. To increase the productivity and sustainability of their farms, they need access to affordable yield-enhancing inputs of which parasite control is of paramount importance. We therefore determined the status of current tick species with the highest economic impact on cattle by sampling representative numbers of animals in each of seven sub-Saharan countries.

METHODS

Data included tick species' half-body counts from approximately 120 cattle at each of two districts per country, collected four times in approximately 1 year (to include seasonality). Study sites were chosen in each country to include high cattle density and tick burden.

RESULTS

East Africa (Ethiopia, Uganda and Tanzania) showed overall a higher diversity and prevalence in tick infestations compared to West African countries (Benin, Burkina Faso, Ghana and Nigeria). In East Africa, Amblyomma variegatum (vector of Ehrlichia ruminantium), Rhipicephalus microplus (Babesia bovis, B. bigemina, Anaplasma marginale), R. evertsi evertsi (A. marginale) and R. appendiculatus (Theileria parva) were the most prevalent tick species of economic importance. While the latter species was absent in West Africa, here both A. variegatum and R. microplus occurred in high numbers. Rhipicephalus microplus had spread to Uganda, infesting half of the cattle sampled. Rhipicephalus appendiculatus is known for its invasive behaviour and displacement of other blue tick species, as observed in other East and West African countries. Individual cattle with higher body weights, as well as males, were more likely to be infested. For six tick species, we found reduced infestation levels when hosts were treated with anti-parasiticides.

CONCLUSIONS

These baseline data allow the determination of possible changes in presence and prevalence of ticks in each of the countries targeted, which is of importance in the light of human-caused climate and habitat alterations or anthropogenic activities. As many of the ticks in this study are vectors of important pathogens, but also, as cattle may act as end hosts for ticks of importance to human health, our study will help a wide range of stakeholders to provide recommendations for tick infestation surveillance and prevention.

A Forty-Year Analysis of the Literature on Babesia Infection (1982-2022): A Systematic Bibliometric Approach

Babesia infection is a tick-borne protozoan disease associated with significant veterinary, economic, and medical importance. This infection affects many hosts, ranging from wild to domestic animals and including man. All vertebrates serve as potential carriers due to the huge diversity of the species. Babesiosis has been associated with severe economic loss in livestock production, especially in cattle farming, and is also a major public health concern in man, which could be fatal. The infection is usually opportunistic, ranging from asymptomatic to symptomatic, usually in immunocompromised subjects or under conditions of stressful management. This study was designed to uncover trends in relation to publication growth and further explore research output regarding babesiosis from data indexed in the WoS. The WoS is the only platform used to map publications on Babesia infection. The search term "babesiosis" or "Babesia infection" was used to extract articles published across the study period from 1982 to 2022. The inclusion criteria were restricted to only articles for the analysis. The results from the search query showed that a total of 3763 articles were published during the study period with an average of 91.70 ± 43.87 articles annually and an average total citation (n = 1874.8). An annual growth rate of 2.5% was recorded during the study period. The year 2021 had the highest number of published articles (n = 193, 5.1%) and citations (n = 7039). The analysis of the most relevant keywords and titles showed that infection (n = 606, 16.1%), babesiosis (n = 444, 11.7%), and Babesia (n = 1302, 16%) were the most relevant keyword plus (ID), author keyword (DE), and title, respectively. The common conceptual framework analysis through K-means clustering showed two clusters comprising 4 and 41 elements, respectively. The United States of America is the top-performing country in terms of article production (n = 707, 20.8%) and the leading funder for babesiosis research, with two of its agencies ranked at the top. These are the Department of Health and Human Services (n = 254, 6.7%) and the National Institute of Health (n= 238,6.3%). Igarashi I. is the top-performing author (n = 231, 6.1%), while Veterinary Parasitology is ranked the top journal (n = 393, 10.4%) in terms of babesiosis publications. Overall, an increase in publications was observed in the study period, with significant output from developed nations.

Comparative chemical genomics in Babesia species identifies the alkaline phosphatase phoD as a novel determinant of resistance

Babesiosis is an emerging zoonosis and widely distributed veterinary infection caused by 100+ species of Babesia parasites. The diversity of Babesia parasites, coupled with the lack of potent inhibitors necessitates the discovery of novel conserved druggable targets for the generation of broadly effective antibabesials. Here, we describe a comparative chemogenomics (CCG) pipeline for the identification of novel and conserved targets. CCG relies on parallel in vitro evolution of resistance in independent populations of evolutionarily-related Babesia spp. ( B. bovis and B. divergens ). We identified a potent antibabesial inhibitor from the Malaria Box, MMV019266. We were able to select for resistance to this compound in two species of Babesia, achieving 10-fold or greater resistance after ten weeks of intermittent selection. After sequencing of multiple independently derived lines in the two species, we identified mutations in a single conserved gene in both species: a membrane-bound metallodependent phosphatase (putatively named PhoD). In both species, the mutations were found in the phoD-like phosphatase domain, proximal to the predicted ligand binding site. Using reverse genetics, we validated that mutations in PhoD confer resistance to MMV019266. We have also demonstrated that PhoD localizes to the endomembrane system and partially with the apicoplast. Finally, conditional knockdown and constitutive overexpression of PhoD alter the sensitivity to MMV019266 in the parasite: overexpression of PhoD results in increased sensitivity to the compound, while knockdown increases resistance, suggesting PhoD is a resistance mechanism. Together, we have generated a robust pipeline for identification of resistance loci, and identified PhoD as a novel determinant of resistance in Babesia species.

Highlights

Use of two species for in vitro evolution identifies a high confidence locus associated with resistance Resistance mutation in phoD was validated using reverse genetics in B. divergens Perturbation of phoD using function genetics results in changes in the level of resistance to MMV019266Epitope tagging reveals localization to the ER/apicoplast, a conserved localization with a similar protein in diatoms Together, phoD is a novel resistance determinant in multiple Babesia spp .

Molecular Detection and Phylogenetic Analyses of Babesia spp. and Theileria spp. in Livestock in Bangladesh

Piroplasmosis, caused by Babesia spp. and Theileria spp., poses significant constraints for livestock production and upgradation in Bangladesh. Besides examining blood smears, few molecular reports are available from some selected areas in the country. Therefore, the actual scenario of piroplasmosis in Bangladesh is deficient. This study aimed to screen the piroplasms in different livestock species by molecular tools. A total of 276 blood samples were collected from cattle (Bos indicus), gayals (Bos frontalis) and goats (Capra hircus) in five geographies of Bangladesh. After that, screening was conducted through a polymerase chain reaction, and species were confirmed by sequencing. The prevalence of Babesia bigemina, B. bovis, B. naoakii, B. ovis, Theileria annulata and T. orientalis was 49.28%, 0.72%, 1.09%, 32.26%, 6.52% and 46.01%, respectively. The highest prevalence (79/109; 72.48%) of co-infections was observed with B. bigemina and T. orientalis. The phylogenetic analyses revealed that the sequences of B. bigemina (BbigRAP-1a), B. bovis (BboSBP-4), B. naoakii (AMA-1), B. ovis (ssu rRNA) and T. annulata (Tams-1) were included in one clade in the respective phylograms. In contrast, T. orientalis (MPSP) sequences were separated into two clades, corresponding to Types 5 and 7. To our knowledge, this is the first molecular report on piroplasms in gayals and goats in Bangladesh.

Epidemiological analysis of cattle ticks and tick-borne pathogens in Gadag district, Karnataka state in India

In the present study, epidemiological analysis on 839 ticks collected from 50 cattle in Gadag district, Karnataka state, tick identification and detection of tick-borne pathogens was conducted by PCR, sequencing, and phylogeny. The morphological identification revealed that Haemaphysalis spp. [48.6%], Rhipicephalus spp. [48.4%], and Hyalomma spp. [3.0%] tick genera in Gadag district. Further, a higher infestation of Haemaphysalis spp. [69.0%] and Rhipicephalus spp. [62.3%] in Shirahatti and Gadag taluk, respectively was observed. Based on the taluk-wise and tick genus-wise analysis, a higher number of ticks was present in the dewlap region of cattle body sites, except for Hyalomma spp., the majority of which was present in the neck. Tick genus prevalence was 45.1, 42.7%, and 12.2 for Haemaphysalis spp., Rhipicephalus spp., and Hyalomma spp., respectively. The mean tick per cattle was 11.6, 11.0, and 2.5 for Rhipicephalus spp., Haemaphysalis spp., and Hyalomma spp., respectively. The prevalence of Anaplasma marginale, Babesia spp., and Rickettsia rickettsii was 8.0, 6.4, and 6.4%, respectively in the tick DNA samples and was negative for Ehrlichia and Theileria spp. The sequencing of the cytochrome oxidase subunit 1 gene revealed the presence of Haemaphysalis bispinosa, Rhipicephalus decoloratus, and Rhipicephalus microplus tick species in the Gadag district. The phylogenetic analysis revealed the tick species have similarities and identity with the isolates from India and neighboring countries. Thus, the study provides knowledge on tick genus distribution and tick-borne pathogens in Gadag district, Karnataka which will help in developing the control and prevention strategies by the policymakers and for profitable dairy farming by farmers.

Transcriptome Profiling of Rhipicephalus annulatus Reveals Differential Gene Expression of Metabolic Detoxifying Enzymes in Response to Acaricide Treatment

Ticks are hematophagous ectoparasites of economic consequence by virtue of being carriers of infectious diseases that affect livestock and other sectors of the agricultural industry. A widely prevalent tick species, Rhipicephalus (Boophilus) annulatus, has been recognized as a prime vector of tick-borne diseases in South Indian regions. Over time, the use of chemical acaricides for tick control has promoted the evolution of resistance to these widely used compounds through metabolic detoxification. Identifying the genes related to this detoxification is extremely important, as it could help detect valid insecticide targets and develop novel strategies for effective insect control. We performed an RNA-sequencing analysis of acaricide-treated and untreated R. (B.) annulatus and mapped the detoxification genes expressed due to acaricide exposure. Our results provided high-quality RNA-sequenced data of untreated and amitraz-treated R. (B.) annulatus, and then the data were assembled into contigs and clustered into 50,591 and 71,711 uni-gene sequences, respectively. The expression levels of the detoxification genes across different developmental stages of R. (B.) annulatu identified 16,635 transcripts as upregulated and 15,539 transcripts as downregulated. The annotations of the differentially expressed genes (DEGs) revealed the significant expression of 70 detoxification genes in response to the amitraz treatment. The qRT-PCR revealed significant differences in the gene expression levels across different life stages of R. (B.) annulatus.

HARD TICKS (ACARI: IXODIDAE) INFESTING ARABIAN CAMELS (CAMELUS DROMEDARIUS) IN MEDINA AND QASSIM, SAUDI ARABIA

Ixodid ticks are hematophagous obligatory ectoparasites that occur worldwide and transmit pathogens to humans and other vertebrates, causing economic livestock losses. The Arabian camel (Camelus dromedarius Linnaeus, 1758) is an important livestock animal in Saudi Arabia that is vulnerable to parasitism by ticks. The diversity and intensity of ticks on Arabian camels in certain localities in the Medina and Qassim regions of Saudi Arabia were determined. One hundred forty camels were examined for ticks, and 106 were infested (98 females, 8 males). A total of 452 ixodid ticks (267 males, 185 females) were collected from the infested Arabian camels. The tick infestation prevalence was 83.1% and 36.4% in female and male camels, respectively (female camels harbored significantly more ticks than did male camels). The recorded tick species were Hyalomma dromedarii Koch, 1844 (84.5%); Hyalomma truncatum Koch, 1844 (11.1%); Hyalomma impeltatum Schulze and Schlottke, 1929 (4.2%); and Hyalomma scupense Schulze, 1919 (0.22%). Hyalomma dromedarii was the predominant tick species in most regions, with a mean intensity of 2.15 ± 0.29 ticks/camel (2.5 ± 0.53 male ticks/camel, 1.8 ± 0.21 female ticks/camel). The proportion of male ticks was higher than that of female ticks (59.1 vs. 40.9%). To the best of our knowledge, this is the first survey of ixodid ticks on Arabian camels in Medina and Qassim, Saudi Arabia.

Advances in the Epidemiological Surveillance of Tick-Borne Pathogens

Ticks are obligate blood-feeding ectoparasites of mammals, birds, and reptiles, which are globally important vectors of pathogens that impact both human and animal health [...].

Acaricidal action of ozone on larvae and engorged females of Rhipicephalus microplus: a dose-dependent relationship

The tick Rhipicephalus microplus is a vector of infectious agents that causes great economic loss in the productivity of cattle herds. Several studies have sought natural compounds with acaricidal activity to control ticks, without allowing the development of resistance, without causing environmental damage, and without presenting toxicity to the hosts. The activity of ozone on the natural biomolecules of living beings has been studied as an alternative to control arthropods and acaricidal effects were shown on ticks. The aim of the present study was to assess the acaricidal effect on larvae and engorged females of R. microplus according to ozone dose. Larvae (n = 377) were distributed in 10 groups and engorged females (n = 284) were distributed in 14 groups. One group was used as control (not exposed to ozone) and the other groups were exposed to ozone gas for 5-105 min. Ozone had a dose-dependent acaricidal effect on both larvae and engorged females. Dosages between 355 and 2130 mg/L min had a delayed acaricidal effect (12-180 h), leading to the death of all engorged females before laying eggs, whereas doses between 3195 and 7455 mg/L min showed immediate acaricidal effect (5 min to 4 h). Doses between 1775 and 6390 mg/L min had an immediate (up to 5 min) acaricidal effect on the larvae of this species. Further studies should consider longer follow-up times during the assessment of the acaricidal activity against ticks.

Tick-borne pathogens and body condition of cattle in smallholder rural livestock production systems in East and West Africa

BACKGROUND

The majority of the African population lives in rural areas where they heavily depend on crop and livestock production for their livelihoods. Given their socio-economic importance, we initiated a standardized multi-country (Benin, Burkina Faso, Ghana, Nigeria, Ethiopia Tanzania and Uganda) surveillance study to assess the current status of important tick-borne haemoparasites (TBHPs) of cattle.

METHODS

We assessed pathogen prevalences (Anaplasma marginale, Anaplasma centrale, Babesia bigemina, Babesia bovis, Ehrlichia ruminantium, and Theileria parva) in the blood of 6447 animals spread over fourteen districts (two districts per country). In addition, we screened for intrinsic (sex, weight, body condition) and extrinsic (husbandry, tick exposure) risk factors as predictors of infections with TBHPs.

RESULTS

There was a large macro-geographic variation observed in A. marginale, B. bigemina, B. bovis and E. ruminantium prevalences. Most correlated with the co-occurrence of their specific sets of vector-competent ticks. Highest numbers of infected cattle were found in Ghana and Benin, and lowest in Burkina Faso. While T. parva was seldomly found (Uganda only: 3.0%), A. marginale was found in each country with a prevalence of at least 40%. Babesia bovis infected individuals had lower body condition scores. Age (as estimated via body weight) was higher in A. marginale infected cattle, but was negatively correlated with B. bigemina and E. ruminantium prevalences. Ehrlichia ruminantium infection was more often found in males, and A. marginale more often in transhumance farming. High levels of co-infection, especially the combination A. marginale × B. bigemina, were observed in all countries, except for Uganda and Burkina Faso. Babesia bigemina was more or less often observed than expected by chance, when cattle were also co-infected with E. ruminantium or A. marginale, respectively.

CONCLUSIONS

Tick-borne pathogens of cattle are ubiquitous in African's smallholder cattle production systems. Our standardized study will help a wide range of stakeholders to provide recommendations for TBHP surveillance and prevention in cattle, especially for B. bovis which heavily impacts production and continues its spread over the African continent via the invasive Rhipicephalus microplus tick.