Cattle Tick Infestations Research Articles

A randomized controlled trial of Tickoff® (Metarhizium anisopliae ICIPE 7) for control of tick infestations and transmission of tick-borne infections in extensively grazed zebu cattle in coastal Kenya

The entomopathogenic fungus Metarhizium anisopliae isolate ICIPE 7 is being developed as an eco-friendly alternative to chemical acaricides in managing natural tick infestation on livestock. Its impact on tick infestation and tick-borne infections in cattle under natural conditions are yet unclear. We conducted a randomized controlled field trial to assess the safety and effects of Tickoff® (a formulation of M. anisopliae isolate ICIPE 7) and the chemical acaricide Triatix® on tick infestation and incidence of Anaplasma marginale and Theileria parva in extensively grazed zebu cattle in coastal Kenya. A total of 217 eligible herds comprising 1459 intent-to-treat zebu cattle were enrolled from 12 villages. The herds were randomly assigned in a 1:1:1 ratio to Tickoff®, Triatix®, or Tickoff® excipients. Tick counts, treatment administrations, and adverse events were registered every two weeks for seven months. The mortality of ticks collected from treated cattle was monitored in vitro. Infections with A. marginale and T. parva were monitored every two months. No adverse events were reported in either treatment group. Tickoff® did not significantly affect tick infestation (p = 0.869) or infection incidence (p > 0.05) compared to excipients. Triatix® significantly reduced tick infestation (p < 0.001) and incidence of T. parva (p = 0.042), but not A. marginale (p = 0.509) compared to the reference Tickoff®. In ticks that were removed from cattle, Tickoff® demonstrated significant pathogenicity in vitro relative to excipients (hazard ratio: 8.50, 95 % CI: 4.67–15.47). Fungus growth and sporulation were also observed on tick cadavers from Tickoff®, but not from excipients. While Tickoff® did not impact tick counts, its delayed, but significant effect on tick mortality may hinder onward pathogen transmission and give rise to indirect (i.e., to untreated animals) epidemiological effects, that were not picked up with this study design. Additionally, adverse environmental conditions resulted in low tick abundance and pathogen circulation towards the end of the study period, reducing the power of the study. This work re-emphasizes the challenges of randomized controlled field trials and the complexity of assessing the impact of vector control products on both direct and indirect impacts on pathogen transmission.

Evaluation of effectiveness and safety of Subolesin anti-tick vaccine in Ugandan multi-site field trial

Vaccines are the most effective and sustainable intervention to control ticks and tick-borne diseases (TBD). Using a personalized vaccine design based on regional tick genotypes, a Rhipicephalus appendiculatus Subolesin protective antigen was used in a field trial evaluating tick vaccine efficacy, effectiveness, and safety in cattle infested with multiple tick species in different Ugandan agro-ecological zones. Vaccination with SUB was safe with a protective capacity against anemia and infection, and reduced the number of infested cattle, tick fitness (feeding and reproduction) with vaccine effectiveness against multiple tick species between 93.2% at 167-196 days post-vaccination (dpv) and 61.4% at 251–327 dpv. Total integrated vaccine efficacy/effectiveness was estimated as 98.8%. The Subolesin-based vaccine is protective against multiple cattle tick infestations under field conditions in Uganda. These results support registration and commercialization of the vaccine to reduce tick populations and associated risks for human and animal TBD and chemical acaracides in Uganda.

Assessment of cattle tick infestation: Molecular insights into Rhipicephalus annulatus and the efficacy of garlic oil and nanoemulsion as acaricidal agents

Ticks, particularly Rhipicephalus annulatus, pose significant threats to livestock, causing economic losses and transmitting various infectious diseases. This study aimed to evaluate the potential acaricidal properties of garlic oil and its nanoemulsion against ticks infesting cattle, Rhipicephalus annulatus through the evaluation of mortality rate and morphological changes of the treated ticks. The study also included prevalence, risk factors, and molecular confirmation of tick species. Genetic characterization confirmed the identity of R. annulatus. Our results revealed a high prevalence of R. annulatus (46.9%) with a higher risk in male cattle (50%) than females (44.9%) and a nonsignificant high infection (49.1%) in animals ≤ 1 year old. The acaricidal efficiency of garlic oil and its nanoemulsion was concentration and time-dependent. The high concentration of garlic oil (20 mg/L) induced complete mortality within 48 hours. The nanoemulsion formulation enhanced efficacy, particularly at 5 mg/L, which exhibited rapid and substantial acaricidal activity. Scanning electron microscopy revealed morphological alterations induced by garlic oil and its nanoemulsion, including changes to the anterior capitulum, dorsal, and ventral cuticles. The study contributes to the exploration of effective, safe, and eco-friendly alternatives for tick control. Further research is warranted to validate their efficacy under diverse conditions and assess practical strategies.

Grazing system and Hyalomma marginatum tick infestation in cattle with high prevalence of SFG Rickettsia spp.

Tick-borne diseases (TBDs) represent a significant portion of infectious diseases of global public health interest. In Italy, knowledge about the occurrence of tick-borne pathogens (TBPs) in ticks parasitizing cattle is scarce. In this research, we focused on ticks infesting Maremmana cattle grazing in open pasture and silvopasture systems. After being morphologically identified, ticks were molecularly tested for the presence of pathogens of the genus Rickettsia. Of the 794 ticks detected, 117 were collected, being the majority Hyalomma marginatum (72.6%), followed by other Hyalomma species (23%), Rhipicephalus turanicus (1.7%), Rh. bursa (0.9%), Hy. lusitanicum (0.9%) and Dermatocentor marginatus (0.9%). All ticks were adults, 58.1% males and 41.8% females. The highest tick prevalence was noted in April for silvopasture system cattle (90%), and in May for open pasture ones (85%). TBPs were detected only in Hy. marginatum, and all belong to Rickettsia spp. of zoonotic interest. In particular, 21/40 (52.5%) ticks scored positive for Rickettsia spp. by gltA gene and of these 15/21 (71.4%) also to spotted fever group (SFG) rickettsiae by ompA gene. Of the total positive specimens, 19 were successfully sequenced and scored Rickettsia aeschilimannii (17/19, 89.5%), R. slovaca (1/19, 5%), and R. massiliae (1/19, 5%). This research highlights the potential impact of grazing systems on cattle parasitization by hard ticks. The molecular investigation of TBPs in ticks collected from Maremmana cattle shed light on the presence of pathogenic bacteria of SFG Rickettsia spp., pointing out the potential risk of TBPs transmission between livestock and humans.

Spatial and Seasonal Patterns of Tick Infestations in Kassena-Nankana Livestock.

The ability of ticks to adapt to different ecological zones, coupled with the spread of infectious pathogens negatively affects livestock production and thus, there is a need for better control strategies. However, control measures within a geographical region can only be effective if there is available information on tick population dynamics and ecology. This study focused on ticks infesting livestock in the Kassena-Nankana Districts of the Upper East Region of Ghana. The ticks were morphologically identified, variables such as season, animal host, and predilection sites were recorded, and the data were analyzed using STATA version 13. Out of 448 livestock examined, tick infestation in cattle was (78.60%), followed by sheep (25%) and goats (5.88%). A total of 1,550 ticks including nymphs (303) and adults (1,247) were collected. Adult ticks were found to be significantly associated with season (p < 0.001), with a high burden in the wet season. The nymph burden and body parts of livestock hosts were significantly associated with more nymphs collected from male animals than females (p < 0.001). Three genera of ticks, Amblyomma (62.97%), Hyalomma (18.71%), and Rhipicephalus (18.32%) were morphologically identified with the most predominant tick species recorded as Amblyomma variegatum (62.97%). Matured A. variegatum was sampled primarily in the wet season with their predilection site as the udder/scrotum (p < 0.001). However, adult Hyalomma truncatum was observed to have a significant association with the anal region (p < 0.001). Findings from this study are essential for formulating tick control measures to prevent the spread of infectious pathogens.

Prevalence and identification of tick infestation in cattle and sheep in Herat, Afghanistan

Objective: This study aimed to assess and outline the prevalence of tick infestation among cattle and sheep in Herat, Afghanistan, utilizing accurate identification and classification methods for tick species. Materials and Methods: A total of 620 animals (315 cattle and 305 sheep) in six villages of the Injil district underwent examination for tick presence, with approximately 450 ticks collected for species identification. Results: The ticks found on cattle and sheep belonged predominantly to two genera: Hyalomma (98.6% in cattle, 1.4% in sheep) and Rhipicephalus (1.4%). Among cattle, five Hyalomma species were identified, notably Hyalomma anatolicum (36.60%), Hyalomma anatolicum excavatum (36.16%), Hyalomma marginatum (15.65%), Hyalomma rufipes (6.69%), and Hyalomma detritum (4.90%). Similarly, in sheep, four Hyalomma species were observed, including H. anatolicum (33.3%), H. anatolicum excavatum (31.1%), H. marginatum (20%), and H. rufipes (15.60%). Conclusion: This study confirms the presence of Hyalomma ticks among both cattle and sheep in Herat province, underscoring the escalated risk of Crimean-Congo Hemorrhagic Fever dissemination. These findings advocate for tailored strategies in tick control and educational initiatives to effectively address this critical concern.

Characterization of cutaneous lesions caused by natural tick infestation in cattle.

Although tick infestation is a significant health problem in livestock, there are limited studies on the dermatopathological aspects of natural tick infestation in cattle. This study aimed to describe the gross and histologic aspects of cutaneous lesions caused by tick infestation in cattle. Thirteen cases were selected based on necropsy data from a 10-year retrospective study. Predispositions were observed in beef cattle (P = .049) and the Angus breed (P = .012), and lesions occurred mainly in the fall (P = .007). Gross lesions included hypotrichosis (13/13; 100%), scales (12/13; 92%), alopecia (11/13; 85%), ulcers (7/13; 54%), crusts (7/13; 54%), and erosions (2/13; 15%). These gross lesions were mainly located in the thorax (12/13; 92%), head (11/13; 85%), abdomen (10/13; 77%), neck (9/13; 69%), limbs (9/13; 69%), and perineum (9/13; 69%). Histologically, all cases had ticks adhered to the epidermis with erosions (13/13; 100%), ulcers (11/13; 85%), orthokeratotic hyperkeratosis (13/13; 100%), irregular acanthosis (13/13; 100%), intraepidermal pustules (13/13; 100%), crusts (10/13; 77%), and ballooning degeneration (4/13; 31%). In the dermis, just below the tick insertion site, there was coagulation necrosis, fibrin deposition, and inflammatory infiltrate composed of mixed cells (neutrophils, lymphocytes, plasma cells, macrophages, and few eosinophils) (9/13; 69%), neutrophils (3/13; 23%), or eosinophils (1/13; 8%). This study reinforces the different patterns of cutaneous lesions caused by tick infestation in cattle, which should be considered as a potential cause of dermatitis in this species.

Participatory and Conventional Investigation of Tick Infestation in Camels and Cattle of Somali Pastoral Areas, Eastern Ethiopia.

Ticks are a common parasite that affect many animals by causing slowed growth, reduced milk output, and financial losses for industries that depend on animal hides and skins. From June to December 2017, participatory and conventional investigations on tick infestation in camels and cattle were conducted in Kebribayah and Afdem districts of Ethiopia's Somali Regional State. The aim of this study was to determine the prevalence and density of ticks in these animals and establish strategic control measures to enhance livestock productivity and livelihoods in pastoral areas. The current study found that the prevalence of tick infestation in Kebribayah and Afdem districts was 83.3% and 86.8%, respectively. Rhipicephalus pulchellus (48.9%) was identified as the most common tick species in camels and cattle, followed by Amblyomma gemma (26.3%), Hyalomma truncatum (11.6%), Amblyomma lepidum (6.7%), and Amblyomma variegatum (6.5%). Among the variables considered, age and body condition score were significant risk factors (p < 0.001). Tick density varied depending on the recorded months and seasons (p < 0.001), with the highest mean tick density occurring in November (32.69 ± 21.750) and during the wet season (28.56 ± 19.750). Livestock owners in Kebribayah and Afdem ranked topical acaricide application as the most effective tick control method, followed by ivermectin injections, with the traditional hand removal method being the least effective. These rankings were consistent across both districts, and there was moderate agreement among livestock keepers from both regions regarding the best method. Afdem livestock keepers had slightly weak agreement on high tick burden in spring (W = 0.475, p = 0.127), and Kebribayah livestock keepers showed slightly strong agreement in tick burden across seasons (W = 0.700, p = 0.038), with spring having a significantly higher burden than winter. Consequently, participatory appraisal indicated that ticks were important and prevalent ectoparasites in the study area. Finally, strategic tick control appropriate for specific management and production environments should be implemented biannually in wet seasons.

Low Genetic Diversity of the Only Clade of the Tick Rhipicephalus microplus in the Neotropics.

This study addresses the variability of the mitochondrial cytochrome oxidase subunit I (COI) and 16S rDNA (16S), and nuclear internal transcriber spacer ITS2 (ITS2) genes in a set of field-collected samples of the cattle tick, Rhipicephalus microplus (Canestrini, 1888), and in geo-referenced sequences obtained from GenBank. Since the tick is currently considered to be a complex of cryptic taxa in several regions of the world, the main aims of the study are (i) to provide evidence of the clades of the tick present in the Neotropics, (ii) to explore if there is an effect of climate traits on the divergence rates of the target genes, and (iii) to check for a relationship between geographical and genetic distance among populations (the closest, the most similar, meaning for slow spread). We included published sequences of Rhipicephalus annulatus (Nearctic, Afrotropical, and Mediterranean) and R. microplus (Afrotropical, Indomalayan) to fully characterize the Neotropical populations (total: 74 16S, 44 COI, and 49 ITS2 sequences included in the analysis). Only the clade A of R. microplus spread in the Nearctic-Neotropics. Both the K and Lambda's statistics, two measures of phylogenetic signal, support low divergence rates of the tested genes in populations of R. microplus in the Neotropics. These tests demonstrate that genetic diversity of the continental populations does not correlate either with the geographic distance among samples or with environmental variables. The low variability of these genes may be due to a combination of factors like (i) the recent introduction of the tick in the Neotropics, (ii) a large, effective, and fast exchange of populations, and (iii) a low effect of climate on the evolution rates of the target genes. These results have implications for the ecological studies and control of cattle tick infestations.

Prevalence of Bovine Tick Infestation and its Associated Risk Factors in Wayu Tuka District Western Ethiopia

Ticks are harmful blood-sucking ectoparasites that are widespread across the world but are more economically significant in tropical and subtropical regions. To determine the prevalence of tick infestation in cattle, a cross-sectional study was carried out in the Wayu Tuka district from October 2022 to July 2023. Three study villages were purposefully chosen, and from this chosen kebele, the study populations were chosen using simple random selection techniques. Ticks were identified by their features under a stereomicroscope. In the current study, adult ticks were collected from 384 local and cross breed cattle and examined, of which 108 (28.1%) were infested with different genera of ticks. Ticks were recorded across the study sites, with the highest and lowest prevalences of 29.9%, 27.0%, and 26.7% in Gida Abalo, Gute Badiya, and Bonaya Molo, respectively. No significant difference in prevalence was observed between the three PAs. The major tick genera identified by this study were Amblyomma variegatum, Rhipicephalus (Boophilus) decoloratus, Amblyomma coherence, and Rhipicephalus evertsi evertsi, with prevalence’s of 17 (15.74%), 20 (18.51%), 11 (10.18%), and 5 (4.63%), respectively. There was statistical significance (p&lt;0.05) between the body conditions of cattle and tick infestations in the study area. The highest prevalence of tick infestations, 53 (41.1%), was found in animals with poor body conditions, while a low prevalence of 24 (20.7%) was recorded in animals with good body conditions. On the other hand, a statistically significant difference was not observed between the age and sex of animals in the current study area (p&gt;0.05). In general, the results of the present study reveal that there was a high tick infestation in the study area. Therefore, appropriate control measures should be implemented.

Tick (Acari: Ixodidae) infestation in cattle from Sleman, Yogyakarta Province, Indonesia

Abstract. Sahara A, Budianto BH, Kunda RM, Firdausy LW. 2023. Tick (Acari: Ixodidae) infestation in cattle from Sleman, Yogyakarta Province, Indonesia. Biodiversitas 24: 4087-4094. Massive attacks of were found Haemaphysalis bispinosa in beef cattle farms in Sleman Regency, Yogyakarta, Indonesia. Besides it makes blood loss, they also have the potential to become vectors of several diseases. The aim of this research is to evaluate the prevalence of infestation, describe the morphology, fecundity, and timing of oviposition, as well as the preferred attachment sites for ticks. The samples were collected manually, and the body of the cattle was divided into four regions to determine the preferred sites of attachment of ticks. The morphology and occurrence of tick attachment sites, egg production, and hatchability were examined macroscopically and microscopically, and the obtained data we assessed descriptively and qualitatively. The findings indicated that, in contrast to the body area and the front and back legs, the tick predilection locations were the head, ears, and neck region. An engorged female may generate an average of 731.5±106 eggs throughout her 10-day oviposition cycle. After 17-30 days, tick eggs hatch into larvae; on average, 626.3±56 eggs per tick female successfully hatch into larvae.

Prevalence of Tick Infestations and Tick-Borne Diseases in Cattle in Cameroon

Prevalence of Tick Infestations and Tick-Borne Diseases in Cattle in Cameroon

Prevalence, Species Identification, and Associated Risk Factor Ixodid Tick Infestation of Cattle in Selamago District Southern Ethiopia.

Ticks are blood-sucking external parasites of livestock and humans; and can transmit pathogens beyond their direct effect during biting. Ticks are distributed in different agro-ecological zones. The study's objectives were to determine the species of ixodid ticks, estimate prevalence, and link the presumptive risk variables. A cross-sectional study was conducted from November 2022 to June 2023 in Selamago district, Southern Ethiopia. A total of 384 cattle managed under extensive grazing systems were selected proportionally based on cattle population, from 3 kebeles, which is the lowest administrative structure of government, and individual animals were selected using systematic random sampling techniques at an interval of 5 animals; as the results, 153, 128, and 103 cattle were selected from Hana, Marsiyo, and Geyo kebeles, respectively. 262 animals (68.2%) were found to be infested with one or more tick species. In this study, there was a statistically significant difference in prevalence between sexes and age groups (P < .05). A higher prevalence was recorded in female and adult cattle than respective group. A total of 579 ticks were collected; 4 genera and 7 tick species were identified. As a result, Ambylomma variegatum, Amblyomma gemma, Amblyomma lepidum, Rhipicephalus (Boophilus) decoloratus, Rhipicephalus pulchellus, Rhipicephalus evertsi evertsi, and Hyalomma truncatum were observed. Among the species identified in the study area, Ambylomma variegatum was the most abundant tick (32.3%) and Hy. truncatum was the least prevalent (4.3%). Ticks on animals' body were recovered more dominantly around the perineum region, udder, scrotum, and dewlap, followed by the belly, head, and neck. Male ticks were more frequently encountered than females. The finding shows a high tick infestation, and adult age groups were more affected and had a serious problem. Hence, prompt control measures are required to rescue the livelihood of the community and economic loss.

Monitoring the Subolesin Vaccine Field Trial for Safer Control of Cattle Ticks Amidst Increasing Acaricide Resistance in Uganda.

A collaboration program was established between the group of Health and Biotechnology (SaBio) of the IREC Institute of Game and Wildlife Research (CSIC-UCLM-JCCM, Spain) and the National Agricultural Research Organization of Uganda (NARO) for the development of vaccines for the control of cattle ticks in Uganda. Controlled pen trials identified a tick protective antigen, Rhipicephalus appendiculatus Subolesin, and a cross-species-effective vaccine formulation. As the next step, a controlled vaccine field trial has been approved by Ugandan state regulatory authorities, the Uganda National Council for Science and Technology (UNCST) and the National Drug Authority (NDA), to evaluate the efficacy and effectiveness of the vaccine formulation for the control of cattle tick infestations under field conditions. The results of this trial may lead to the approval of the vaccine for application in Uganda to improve cattle health and production while reducing the use of acaricides.

Prevalence and Identification of Ticks in Cattle Of Rajshahi, Bangladesh

Ticks, the notorious ectoparasite, are frequently infest cattle and cause various disease conditions and acts as vector of pathogenic organism. To determine the tick infestation in cattle of four Districts of Rajshahi Division, Bangladesh, a total of 1200 cattle (300 from each district) were randomly examined throughout the year. Four hundred ticks (100 from each district) collected from cattle were microscopically identified to determine the prevalence of specific ticks. Among the examined cattle, 433 (36.08%) were found infested with one or more species of ticks. The highest prevalence was recorded in Naogaon District (39.66%) followed by Rajshahi (37.33%), Joypurhat (34.33%) and Natore (33%). Tick infestation rate was higher (p&lt;0.05) in rainy season (43%) followed by summer (37.75%) and winter (27.5%). Adult cattle (&gt;5 years) were significantly (p&lt;0.05) susceptible (41.63%) to tick infestation in comparison to young (&gt;1-&lt;5 years) (29.94%) and calves (&lt;1 year) (34.13%). Significant difference (p&lt;0.05) was observed in sex related infestation. Female were highly susceptible (48.31%) than male (19.92%). Local breed cattle were significantly susceptible (41.97%) compare to North Bengal Gray (37.28%) and cross breed (26.60%) cattle. Ear was the most favorite (72.51%) infestation site of tick whereas least was found in scrotum (5.31%). Microscopic identification revealed 5 different species of ticks. Boophilus/ Rhipicephalus microplus was the most prevalent (33.5%) species followed by Haemaphysalis bispinosa (23.50%), Amblyomma variegatum (17.25%), Rhipicephalus sanguineus (14%) and Hyalomma anatolicum anatolicum (11.75%). Notable tick infestation in cattle indicated the possibility of damaged by ticks and opportunity of transmission of pathogenic organism. Thus, an effective control strategy is warned to overcome the harmful effects of ticks on cattle. Vol. 9, No. 2, August 2022: 171-183

Pathogenicity of Entomopathogenic Fungi Fusarium beomiforme against Rhipicephalus microplus Tick Infestation in Cattle

Background: Tick infestation in cattle is commonly controlled using chemical acaricides producing acaricidal resistance, environmental pollution and hazards to human health. Biological control of ticks using entomopathogenic fungi can be an alternative to chemical acaricides and can be used in conjunction with chemical control in integrated pest management. Methods: The isolation of entomopathogenic fungi was carried out from naturally infected ticks in Durg district of Chhattisgarh. The species confirmation of fungal isolates was conducted by Polymerase chain reaction (PCR) using ITS gene as a molecular marker. In vitro efficacy of entomopathogenic fungi at various concentrations against engorged (adult) female ticks and unfed (Nymphs), egg laying capacity and egg hatchability of treated Rhipicephalus microplus was assessed in laboratory. Result: The entomopathogenic fungi isolated from naturally infected ticks was confirmed as Fusarium beomiforme by morpho- molecular analysis. The efficacy of F. beomiforme against adult female and nymphs of R. microplus at the concentration of n x 108 spores ml-1 showed 100% mortality. The 100% reduction of egg laying capacity of treated female ticks and no hatchability of eggs treated with F. beomiforme at the concentration of n x 107 spores ml-1 and n x 108 spores ml-1 was observed.

Transcriptional changes in the peripheral blood leukocytes from Brangus cattle before and after tick challenge with Rhipicephalus australis

BackgroundDisease emergence and production loss caused by cattle tick infestations have focused attention on genetic selection strategies to breed beef cattle with increased tick resistance. However, the mechanisms behind host responses to tick infestation have not been fully characterised. Hence, this study examined gene expression profiles of peripheral blood leukocytes from tick-naive Brangus steers (Bos taurus x Bos indicus) at 0, 3, and 12 weeks following artificial tick challenge experiments with Rhipicephalus australis larvae. The aim of the study was to investigate the effect of tick infestation on host leukocyte response to explore genes associated with the expression of high and low host resistance to ticks.ResultsAnimals with high (HR, n = 5) and low (LR, n = 5) host resistance were identified after repeated tick challenge. A total of 3644 unique differentially expressed genes (FDR < 0.05) were identified in the comparison of tick-exposed (both HR and LR) and tick-naive steers for the 3-week and 12-week infestation period. Enrichment analyses showed genes were involved in leukocyte chemotaxis, coagulation, and inflammatory response. The IL-17 signalling, and cytokine-cytokine interactions pathways appeared to be relevant in protection and immunopathology to tick challenge. Comparison of HR and LR phenotypes at timepoints of weeks 0, 3, and 12 showed there were 69, 8, and 4 differentially expressed genes, respectively. Most of these genes were related to immune, tissue remodelling, and angiogenesis functions, suggesting this is relevant in the development of resistance or susceptibility to tick challenge.ConclusionsThis study showed the effect of tick infestation on Brangus cattle with variable phenotypes of host resistance to R. australis ticks. Steers responded to infestation by expressing leukocyte genes related to chemotaxis, cytokine secretion, and inflammatory response. The altered expression of genes from the bovine MHC complex in highly resistant animals at pre- and post- infestation stages also supports the relevance of this genomic region for disease resilience. Overall, this study offers a resource of leukocyte gene expression data on matched tick-naive and tick-infested steers relevant for the improvement of tick resistance in composite cattle.

Oral vaccine formulation combining tick Subolesin with heat inactivated mycobacteria provides control of cross-species cattle tick infestations

Tick vaccines are necessary as part of a One Health approach for the control of tick infestations and tick-borne diseases. Subolesin (SUB, also known as 4D8) is a tick protective antigen that has shown efficacy in vaccine formulations for the control of ectoparasite infestations and pathogen infection/transmission. A recent proof-of-concept study reported oral vaccination combining Rhipicephalus microplus SUB with heat inactivated Mycobacterium bovis (IV) as an immunostimulant for the control of cattle tick infestations. Based on the efficacy of Rhipicephalus decoloratus SUB for the control of multiple cattle tick species in Uganda, herein we design a controlled pen trial using an oral formulation combining R. decoloratus SUB with IV for the control of R. decoloratus and Rhipicephalus appendiculatus cattle tick infestations. Vaccine efficacy (E) of SUB + IV on tick life cycle was compared with IV and SUB alone and with PBS as control. The IgG antibody titers against SUB and M. bovis P22 and the serum levels of selected protein immune biomarkers (IL-1beta, TNF-alpha, C3) were determined and analyzed as possible correlates of protection. Oral immunization with IV and SUB alone and in SUB + IV combination were effective for the control of tick infestations (E = 71–96% for R. decoloratus and 87–99% for R. appendiculatus) with highest E (higher than 95%) for SUB + IV. The results demonstrated that oral immunization with the SUB + IV formulation resulted in effective control of cattle tick infestations through the activation of multiple immune mechanisms. These results support the application of oral vaccine formulations with SUB + IV for the control of cattle infestations with Rhipicephalus species towards improving animal health.

Proteomic profiling of plasma-derived small extracellular vesicles: a novel tool for understanding the systemic effects of tick burden in cattle.

Cattle ticks pose a significant threat to the health and profitability of cattle herds globally. The investigation of factors leading to natural tick resistance in cattle is directed toward targeted breeding strategies that may combat cattle tick infestation on the genetic level. Exosomes (EXs), small extracellular vesicles (EVs) of 50 to 150 nm diameter, are released from all cell types into biofluids such as blood plasma and milk, have been successfully used in diagnostic and prognostic studies in humans, and can provide essential information regarding the overall health state of animals. Mass spectrometry (MS) is a highly sensitive proteomics application that can be used to identify proteins in a complex mixture and is particularly useful for biomarker development. In this proof of principle study, EXs were isolated from the blood plasma of cattle (Bos taurus) with high (HTR) and low tick resistance (LTR) (n = 3/group). Cattle were classified as HTR or LTR using a tick scoring system, and EXs isolated from the cattle blood plasma using an established protocol. EXs were subjected to MS analysis in data-dependent acquisition mode and protein search performed using Protein Pilot against the B. taurus proteome. A total of 490 unique proteins were identified across all samples. Of these, proteins present in all replicates from each group were selected for further analysis (HTR = 121; LTR = 130). Gene ontology analysis was performed using PANTHER GO online software tool. Proteins unique to HTR and LTR cattle were divided by protein class, of which 50% were associated with immunity/defense in the HTR group, whereas this protein class was not detected in EXs from LTR cattle. Similarly, unique proteins in HTR cattle were associated with B-cell activation, immunoglobins, immune response, and cellular iron ion homeostasis. In LTR cattle, unique exosomal proteins were associated with actin filament binding, purine nucleotide binding, plasma membrane protein complex, and carbohydrate derivative binding. This is the first study to demonstrate that MS analysis of EXs derived from the blood plasma of HTR and LTR cattle can be successfully applied to profile the systemic effects of tick burden.

Morphological and molecular studies on tick species in Ismailia Governorate in Egypt and Al Gabal Al Akhdar in Libya.

Ticks are obligate blood-sucking ectoparasites of vertebrates that have an impact on both domestic and wild animals, especially in tropical and subtropical areas. The objective of this study is to compare the prevalence and the tick species in both Al Gabal Al Akhder regions in northeastern Libya and Ismailia, Egypt. Tick specimens collected from predilection sites on the hosts were identified by morphological (light microscopy) and molecular methods. In Ismailia, Egypt, 23.9% of the 230 (examined cattle and buffaloes) were infested with one species of hard ticks, Rhipicephalus annulatus. In the Libyan province of Al Gabal Al Akhdar, the prevalence of tick infestation in cattle, sheep, and goats, was 47% and 59%, respectively. R. annulatus is the identified tick species for cattle, Hyalomma marginatum, and Rhipicephalus bursa, are the identified tick species of the infested sheep and goats. The 16S rDNA gene sequencing and phylogenetic analysis of sample species from Egypt and Libya proved instrumental in overcoming the difficulties associated with morphological identification techniques.