The cattle tick, Rhipicephalus (Boophilus) microplus is a tick of veterinary and health importance globally, transmitting Babesia bovis and B. bigemina. Tick control is important and needed to prevent livestock diseases caused by tick-transmitted pathogens. Traditionally, tick control methods have resulted in development of acaricide-resistant ticks, environmental pollution and meat and milk contamination. Therefore, there is a need for alternative method and vaccines directed against tick feeding. The aim of this study was to identify proteins involved in tick feeding, tickhost-pathogen interactions and tick reproduction. Consequently, these will help in identification of antigens with the ultimate goal of developing anti-tick vaccines. R. (B.) microplus female ticks were collected at five different feeding stages. RNA was isolated from the salivary gland extracts (SGEs). The cDNA libraries were synthesized and sequenced with the Illumina MiSeq technology. Transcriptome data was analyzed with CLC Genomics Workbench, Trinity and Minia. The SGEs were also used to isolate the fractions: membrane, soluble and pellet protein for proteomic analysis. The proteomics data was analysed with Mascot, X!Tandem and Scaffold. Both the transcriptome and proteome analysis revealed the presence of major secretory protein families such as Kunitz, lipocalins, serpins, cement proteins and metalloproteases, while the majority of transcripts coded for housekeeping genes. / National Research Foundation (South Africa) / Life and Consumer Science / M. Sc. (Life Science)

Invertebrates do not possess an adaptive immune system, but rely on several mechanisms similar to the innate immune system of mammals. The synthesis and release of a host of potent antimicrobial proteins is an important component of this immune response. The antibacterial activity in the hemolymph of Ornithodoros savignyi is specific for Gram-positive bacteria, and the synthesis and release of the antibacterial factors need to be induced by challenging the ticks with heat-killed Gram-negative bacterial suspensions. The induction of the factors is very rapid, leading to a maximal response within one hour following bacterial challenge. The factors are stable at high temperatures, and were found to be protein in nature. By using reverse phase high performance liquid chromatography, four fractions exhibiting antibacterial activity were identified in the hemolymph of immune challenged ticks. Four antibacterial peptides were isolated from these fractions, and the mass analyses of the peptides indicate that there are at least two different antibacterial peptides present in the hemolymph. The N-terminal amino acid sequence of one of the peptides was determined, and the analysis showed that the peptide has high homology with defensin peptides isolated from other tick species. This led to the putative classification of the peptides as part of the invertebrate defensin family. The presence of lysozyme in O. savignyi was studied using molecular biological methods. Vertebrate and invertebrate lysozyme sequences were used to design a lysozyme-specific primer, which was used to amplify specific DNA products from whole tick cDNA using the polymerase chain reaction (PCR). The conditions for the amplification reaction were optimized, the products of the optimized reaction were cloned into a cloning vector and the nucleotide sequences of the products were determined. The nucleotide sequences were used for similarity searches of sequence databases to determine homology with sequences of known proteins. It is deduced the degenerate primer was not specific for lysozyme and did not playa significant role in the amplification of the PCR products. This method is thus not feasible for the investigation of the lysozyme of O. savignyi. / Dissertation (MSc (Biochemistry))--University of Pretoria, 2005. / Biochemistry / unrestricted

The saliva of hematophagous ectoparasites contains a cocktail of vasodilators, anticoagulants and immunosuppressors that maintain blood in a liquid state at the site of the lesion and evade the host's defense mechanisms in suppressing the immune response. Since ticks have evolved to utilize mammals as a source of food, our understanding of the tick material, especially the salivary glands will enhance the control of tick infestation and allow the exploitation of the tick's natural resources. SGE protease activity was determined by measuring the degradation of azocasein. Proteolytic activity was found in the pH range of 3 to 11 with the highest activity at pH 9 followed by pH 7. At pH 3-5 the activity was mainly due to aspartic proteases, whereas at pH 7-9 the activity was due to the action of metallo- and serine proteases. At pH 11, the activity was mainly ascribed to metallo- and aspartic proteinase activity The fibrinogenolytic activity was determined by incubating human fibrinogen in the presence of SGE and monitoring the fibrinogen degradation by SDS-PAGE. SGE degraded the Au-chain of fibrinogen within 2 hours of incubation and even after 24 hours incubation there was no hydrolysis of the Bβ and γ-chains of fibrinogen. Characterization of the fibrinogenolytic activity revealed that metalloprotease activity was present over pH range of 3-9 and at pH 3-5, the cysteine proteases were active. No serine protease activity was found under similar experimental conditions. CE-HPLC separation of the SGE revealed three regions of proteolytic activity. Further characterization of the activity containing fractions using protease inhibitors at various pH values showed that the activity associated with region A is mainly due to the presence of aspartic and cysteine proteases in the lower pH range (< 5). Region B was mainly due to the activity of the metallo- and serine proteases, while the activity in region C was mainly due to the metalloproteinases which were more active in the higher pH range (> 9). CE-HPLC separation of SGE resulted in three regions exhibiting fibrinogenolytic activity at pH 7-9. In region A all four enzyme classes were found while in regions B and C, serine, cysteine and metalloproteinases were found to be responsible for the activity. Region A was further purified on the HIC-column and activity eluted in several peaks which after individual application on SE-HPLC column had similar retention times. The pooled samples were analyzed for purity using C5 RP-HPLC and reducing tricine SDS-PAGE and three bands of relative molecular masses 15, 22 and 12 kDa, respectively were found. In an attempt to purify the proteins in region C, four individual CE-HPLC runs were combined and applied to a fibrinogen affinity column. Reducing SDS-PAGE analysis of bound material showed two bands of relative molecular masses of 31 and 39 kDa, respectively. CE-HPLC region C as well as the SGE control was found to disaggregate platelets aggregated by ADP, epinephrine, collagen as well as TRAP. No disaggregation was observed for the saline negative control. The disaggregation is most probably due to the hydrolysis of the fibrinogen cross-linking platelets by the metalloproteinase activity in region C. Understanding of the proteolytic activities present in the salivary gland and therefore identifying molecules crucial for tick feeding could aid in the development of experimental vaccines. Even though the fibrinogenolytic activity was not purified to homogeneity, this study has laid the groundwork for further experiments in this field. / Dissertation (MSc (Biochemistry))--University of Pretoria, 2006. / Biochemistry / unrestricted

Tick-borne diseases cause in enormous burden on human, livestock, and wildlife health globally and are driven by the increasing abundance and geographic expansion of medically important tick species. More recently, tick-borne disease emergence is occurring in urban landscapes due to complex feedbacks between the environment, humans, wildlife, and ticks. In this dissertation, I focus on the ecological conditions that allow for tick-borne disease emergence in a city. I use a combination of spatial landscape modeling, empirical data collection, wildlife movement tracking to determine drivers of zoonotic hazards in New York City, NY, and employ vector genomics to examine vector dispersal in the northeastern United States. In chapter one, I pair tick collection throughout the five boroughs of New York City with landscape connectivity modeling to examine how green space connectivity and habitat availability affects the density and infection of questing nymphs – an important epidemiological measure of human risk for tick-borne diseases. I found that green spaces that were highly connected for deer had higher nymph density and infection prevalence for Borrelia burgdorferi sensu stricto, the etiologic agent of Lyme disease. In chapter two, I use camera trapping, live trapping, and tick collection on Staten Island, NY, to examine how landscape fragmentation – through changing habitat size and connectivity – shapes the host community available for questing Ixodes scapularis nymphs. Further, I examined whether patterns in host species abundance and activity correlate with the density of nymphs and their infection prevalence with three different pathogens that vary in host-specificity, B. burgdorferi, Babesia microti, and Anaplasma phagocytophilum. I found associations between host species and the size and connectivity of the park habitat, identified host species which amplified and removed ticks in the environment, and determined links between host activity and abundance and the infection prevalence of nymphs with host-specific pathogens. In chapter three, I utilize movement data from 59 white-tailed deer on Staten Island, NY, to assess the drivers of movement and its impact on tick-borne disease hazard across the landscape. I found that white-tailed deer avoid anthropogenic development at fine spatial scales when establishing home ranges but select for anthropogenic resources within their home range, increasing the potential to distribute ticks into environments that interface with humans. Finally in chapter four, I use double digest Restriction Associated DNA sequencing to examine the genetic differentiation of six I. scapularis populations across the Northeast region. I found high levels of gene flow across a spatial scale of 400 km, likely resulting from frequent host-mediated dispersal events combined with large I. scapularis populations. Taken together, this work emphasizes that host movement and ecology are critical determinants of urban tick-borne disease emergence through directing vector and pathogen dispersal, serving as pathogen reservoirs in urban habitats, and interfacing with humans in unique ways that increase human exposure to zoonotic hazards.

Thesis (MTech (Horticulture))--Cape Peninsula University of Technology, 2018. / Ticks and tick-borne diseases are important limiting factors to the attainment of sustainable animal and human health, affecting livelihood of resource poor farming communities in developing countries. Rhipicephalus appendiculatus and Amblyomma variegatum (Ixodidae) are among the most troubling tick species in Africa. While ticks can be controlled by applying chemical acaricides, these chemicals are quite expensive, especially, for small-scale famers in developing countries. Hence, the quest for alternative tick control over the years have revealed that entomopathogenic fungi (EPF) and plant extracts have huge prospects as sustainable alternatives for tick control. Beauveria bassiana (Hypocreales) is a fungal entomopathogen with the ability to colonize plants endophytically and induce secondary metabolite production in plants, and it has been found to be a potential biological control agent against a wide range of arthropods. Several plant species including plant species belonging to the family Alliaceae possess anti-tick activities (repellent and toxic); therefore, integrating the two strategies by inoculating Tulbaghia violacea with B. bassiana could enhance secondary metabolite contents in extracts obtained from the plant and increase medicinal materials. The primary purpose of the present study was to evaluate the effect of indigenous endophytic entomopathogens inoculation of T. violacea on the plant growth, tissue nutrient contents and secondary metabolites, and anti-tick activities of extracts of T. violacea. The specific objectives were: (i) to carry out a study on the effects of inoculating T. violacea with fungal strains of B. bassiana and Clonostachys rosea on plant growth and tissue nutrient contents in extracts of T. violacea with the view of selecting one of the two fungi for further investigation (ii) to compare secondary metabolite profiles of extracts obtained from plants exposed to fungus (EPF) inoculum and control treatment during cultivation, and (iii) to determine whether exposure of T. violacea to an endophytic fungus (B. bassiana) during cultivation affects the repellent and acaricidal activities of extracts of T. violacea on A. variegatum and R. appendiculatus. The study had two experiments, presented in chapters two and three. In the first experiment, eight weeks old potted seedlings of T. violacea were inoculated separately with B. bassiana (strain SM3) and C. rosea (strain SM8) conidia suspended at concentrations of 1 x 106 conidia mL-1. Plant growth parameters, such as number of leaves, plant height (aerial part), fresh weights of aerial parts, and tissue nutrient contents were assessed. Results indicated that B. bassiana induced higher growth of plants than C. rosea. Inoculation with B. bassiana did not significantly (P ˃ 0.05) influence most of the growth parameters, number of leaves, fresht weight of roots and of fresh weight aerial parts (leaves) of T. violacea assessed in the current study. However, mean plant heights and root lengths were significantly (P < 0.05) higher in favour of B. bassiana treated plants compared to those in C. rosea. Fe contents in the roots (1416.3 ± 305.10 mg/kg) were found to be positively influenced (P < 0.05) by the fungal inoculation. There was a significant difference in roots (P < 0.05) on the uptake of Mn in C. rosea treated plants (243 ± 19 mg/kg) compared to the control group (169 ± 16.37 mg/kg) and B. bassiana treated roots (161.3 ± 14.44 mg/kg). Macro nutrients up take did not differ significantly among treatments on both leaves and roots (P > 0.05).

Orientador: Gervásio Henrique Bechara / Banca: Romário Cerqueira Leite / Banca: Rosângela Zacarias Machado / Resumo: No presente estudo avaliou-se o desenvolvimento de resistência a ninfas do ixodídeo Amblyomma cajennense, induzida por infestações controladas, e a possível existência de reatividade cruzada com Amblyomma hebraeum. Para tal, caprinos sem contato prévio com carrapatos, com seis meses de idade, machos ou fêmeas, foram infestados três vezes sucessivamente com ninfas de A. cajennense. Ademais, outro grupo de caprinos foi infestado nas mesmas condições com ninfas de A. hebraeum e colhidos soros para pesquisa de possível reatividade cruzada com A. cajennense. Observou-se que caprinos desenvolveram resistência apenas parcial a ninfas de A. cajennense, como demonstrado pela alteração significativa dos seguintes parâmetros biológicos das ninfas, em relação à primoinfestação: redução de 41,7% e 37,1% no peso de ingurgitamento, respectivamente na 2ª e 3ª infestações; aumento de 20% no período de ecdise e redução de 25,7% na taxa de ecdise, respectivamente nas 3ª e 2ª infestações. Não houve alteração no período de ingurgitamento nem na porcentagem de recuperação de ninfas com as infestações sucessivas. A reação cutânea induzida pelas ninfas de A. cajennense durante as infestações em caprinos caracterizou-se por infiltrado de células inflamatórias, predominantemente neutrófilos e basófilos, estas últimas envolvidas na imunidade a carrapatos por meio de hipersensibilidade basofílica cutânea. Células apresentadoras de antígeno, nomeadamente macrófagos, linfócitos B e células dendríticas foram detectadas por imunoistoquímica em linfonodos drenantes de locais de fixação dos carrapatos, em maior número nos linfonodos dos animais infestados... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: This study evaluated the acquision of resistance against Amblyomma cajennense nymphs in naïve goats, induced by repeated and controlled infestations, and a possible cross-reactivity with A. hebraeum. Ten naive goats, of both sexes, aged six months were used throughout the experiment. Animals were infested artificially thrice, 30 days intervals between infestations. In addition, goats were infested at same conditions with the tick A. hebraeum as well. Sera from these animals were collected looking for possible cross-reactivity between antigens from these ixodids. It was observed that goats developed partially resistance to A. cajennense nymphs from the 1st infestation on as shown by changes in some biological parameters, as follows: increase of 41.7% and 37.1% in engorgement weight, respectively at the 2nd and 3rd infestations, decrease in 25.7% in nymph’s ecdise rate and increase of 20% in ecdise period, respectively at the 3rd and 2nd infestations. It was not observed alterations in engorgement period and percentage of yielded nymphs. Biopsies of tick bite lesions induced by A. cajennense nymphs during infestations in goats were characterized by inflammatory reaction with cellular influx by neutrophils and basophils predominantly, being the last one involved in the well-known cutaneous basophilia. Antigen presenting cells like macrophages, B-lymphocytes and dendritic cells were detected by immunohistochemical analysis of lymph nodes draining tick infested areas. It should be stressed that these cells were found in higher numbers at lymph nodes from infested goats than from the naïve ones. Western blotting analysis of nymphal A. cajennense extracts revealed shared polypeptides (160, 90 and 16kDa) when used sera from goats infested with A. cajennense either A. hebraeum, indicating cross reactivity between these two tick species. / Mestre

M. Tech. Nature Conservation / Ticks are blood feeding external parasites of mammals, birds, and reptiles throughout the world. Tick infestation is considered to be one of the main constraints to successful game ranching in southern Africa. Several blood parasites are transmitted by ticks and have been incriminated as the cause of death in several wildlife species Ticks thus affect wildlife and domestic animal management worldwide, with approximately 850 species of ticks having been described The aim of the thesis is to collect and describe fully the nature and extent of the tick cohort of a semi-intensive and control free game ranch in the Limpopo Province of South Africa farm and to establish the environmental management effects on tick abundances and species.

The main objective oft his dissertation was to identify the causes of the rise of the tick population in KwaZulu-Natal in 1999. After 100 years of intensive chemical tick control, tick numbers remain high and the stock losses caused by tick borne diseases are still significant. In South Africa legislation was introduced to support intensive chemical tick control. Ticks have consistently shown themselves to possess a genetic pool containing the potential to resist a wide range of chemical poisons. The introduction of new chemicals followed by widespread use, has often resulted in the appearance of a tick population resistant to those chemicals. The problem is compounded by the fact that some farmers are also found to be helping ticks to multiply by not following instructions given by the chemical industry on how to use dips. Chemicals which are used to control ticks are also beyond the financial means of many cattle owners especially in resource- poor communities. Apart from the high cost of intensive tick control, the chemicals that are used to destroy ticks are very poisonous, not only to ticks but to the birds which are natural predators of ticks. The negative effects of these chemicals on the environment combined with the high cost of tick control has forced a revision of intensive chemical tick control strategy. There is now a shift to use methods of tick control which are friendly to the environment and affordable to the resource-poor communities. This dissertation provides a historical overview of the problem in KwaZulu-Natal and recommendations on how to deal with the problem in future. / Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 2001.

Made available in DSpace on 2014-06-11T19:27:57Z (GMT). No. of bitstreams: 0 Previous issue date: 2013-11-29Bitstream added on 2014-06-13T18:56:53Z : No. of bitstreams: 1 000749087.pdf: 1190514 bytes, checksum: 2f296befce1a51e83e431b9d970625ef (MD5) / Ao longo das últimas décadas o controle de Rhipicephalus (Boophilus) microplus tem sido dificultado pelo desenvolvimento da resistência à maioria dos grupos químicos utilizados. Algumas moléculas tem se apresentado como alternativas promissoras, mas mesmo assim, apresentam redução de eficácia com o passar do tempo. As lactonas macrocíclicas, moléculas com atividade endectocida, surgiram como uma dessas opções, mas relatos sobre a resistência, especialmente à ivermectina, se tornam cada vez mais frequentes. O presente estudo objetivou determinar a redução de eficácia da ivermectina contra o R. (B.) microplus, e o consequente surgimento da resistência à esse princípio ativo, por meio de resultados encontrados em várias propriedades rurais, frente às diferentes cepas presentes. Foram realizados testes com bovinos naturalmente infestados da região Sudeste do Brasil, utilizando diferentes concentrações de ivermectina (200 μg/kg, 500 μg/kg e 630 μg/kg). Estes experimentos basearam-se na contagem de partenóginas, entre 4,5 e 8 mm de diâmetro, presentes no lado esquerdo dos bovinos. Das doze propriedades avaliadas, três com a utilização de ivermectina 500 μg/kg (0,5% pour-on), três onde foi testada a ivermectina 200 μg/kg (1% injetável) e seis onde avaliou-se a ivermectina 630 μg/kg (3,15% injetável), apenas uma apresentou valores de eficácia média, entre os dias 7 e 14 pós-tratamento, superior à 90%, sendo classificada como sensível. Nenhum dos demais experimentos atingiu este valor, permitindo a classificação de onze dentre as doze cepas (91,67%) avaliadas, como resistentes. Além disso, o presente estudo confirma a eficiência da avaliação in vivo para o diagnóstico da resistência, assim como reforça a necessidade de maior atenção a esse fenòmeno, amplamente disseminado nessa região do Brasil / Throughout the last decades, the control of Rhipicephalus (Boophilus) microplus has become more difficult due to the development of resistance to most of the products used for its control. Some molecules have been presented as promising alternatives, but nonetheless, their efficacy has shown reduction as time passes. The macrocyclic lactones, molecules with endectocidal activity, appeared as one of these options, but resistance to them, especially to ivermectin, are commonly reported in literature. The present study aimed to determine the decrease in acaricidal efficacy of ivermectin against Rhipicephalus (Boophilus) microplus, and the consequent development of resistance to this active component, by means of several results found in several rural properties, with different tick strains present. Tests were conducted in naturally infested animals originated from farms on the Southeast region of Brazil, using different concentrations of ivermectin (200 μg/kg, 500 μg/kg and 630 μg/kg) applied in different administration methods (pour on and injectable). From all twelve properties evaluated, being three with the administration of 500 μg/kg ivermectin (0.5% pouron), three were 200 μg/kg ivermectin (1% injectable) was tested and six were 630 μg/kg ivermectin (3.15% injectable) was evaluated, only one presented mean efficacy values, between days 7 and 14 post-treatment, superior to 90%, being classified as sensible. None of the other experiments reached or surpassed this index, allowing the classification of eleven amongst twelve (91.67%) evaluated R. (B.) microplus strains, as resistant. Besides, the present study confirms the efficiency of in vivo evaluation for the diagnosis of resistance, as well as reinforces the need for a greater attention to this problem, widely spread in this region of Brazil

Orientador: Antônio de Queiroz Neto / Coorientador: Delphim da Graça Macoris / Banca: Adolorata Aparecida Bianco Carvalho / Banca: Estevam Guilherme Lux Hoppe / Banca: Natalino Hajime Yoshinari / Banca: Jairo Jaramillo Cardenas / Resumo: A Borreliose de Lyme é uma doença causada pela espiroqueta Borrelia burgdorferi sensu lato, cosmopolita, transmitida por meio da picada de carrapatos que permanecem aderidos ao hospedeiro por mais de 24 horas. Em humanos, pode provocar doenças articulares, cardíacas e neurológicas. Nos equinos, até o presente momento a doença havia sido descrita por meio de relatos de caso e extrapolações de sua patogenia nos humanos. Por meio do presente estudo, pretende-se pesquisar os sinais clínicos e alterações hematológicas da borreliose de Lyme nos equinos. Além disso, avaliou-se também a viabilidade de se tratar os equinos infectados com ceftriaxona sódica. Para tanto, o experimento foi composto por três principais fases. A primeira fase foi composta por um levantamento epidemiológico da doença no Estado de São Paulo, especificamente nas cidades com casos suspeitos de borreliose de Lyme em humanos. Coletou-se amostras de sangue e histórico clínico de 760 equinos e obteve-se média de 21% de soropositividade no estado. Desta fase, concluiu-se que existe grande relação entre a soropositividade, presença de carrapatos Amblyomma sculptum, presença de capivaras na propriedade, linfopenia, abortamento e retenção de placenta. A segunda fase foi composta por uma infecção experimental de dois equinos adultos com B. burgdorferi cepa G39/40. Os equinos foram avaliados durante 90 dias de infecção e foi possível verificar que os animais apresentaram sinais clínicos e alterações hematológicas inespecíficas somente nos primeiros 11 dias de infecção. Notou-se a presença de anemia normocítica hipocrômica discreta, dores musculares, palidez de mucosas, letargia e aumento de linfonodos, sinais que podem facilmente ser confundidos com a piroplasmose crônica. Durante a fase 3 do experimento, os dois equinos infectados experimentalmente foram submetidos ao tratamento com ceftriaxona... / Abstract: Lyme borreliosis is a disease caused by the spirochete Borrelia burgdorferi sensu lato, cosmopolitan and transmitted by the bite of ticks which remain adhered to the host for more than 24 hours. In humans, it can cause articular, cardiac and neurological diseases. In horses, so far the disease had been described by means of case reports and extrapolations of its pathogenesis in humans. This study aimed to investigate the clinical signs and hematological changes of Lyme disease in horses. Furthermore, it is also assessed the feasibility of treating infected horses with sodium ceftriaxone. To this end, the experiment consisted of three main phases. The first phase consisted of an epidemiological survey of the disease in São Paulo State, specifically in cities with suspected cases of Lyme borreliosis in humans. It was collected blood samples and clinical history of 760 horses that resulted in an average of 21% seropositivity in the state. In this stage, it was concluded that there was a high relationship between seropositivity, Amblyomma sculptum tick presence, the presence of capybaras in the property, lymphopenia, abortion and retained placenta. The second phase consisted of an experimental infection of two adult horses with B. burgdorferi strain G39 / 40. The horses were evaluated for 90 days of infection and we found that the animals showed nonspecific clinical signs and hematologic changes only in the first 11 days of infection. It was noted the presence of mild hypochromic normocytic anemia, muscle pain, pale mucous membranes, lethargy and swollen lymph nodes, signs that can easily be confused with chronic piroplasmosis. During phase 3 of the experiment, the two horses experimentally infected underwent treatment with intravenous sodium ceftriaxone. Already during the first application, both developed an anaphylactoid reaction moderate to severe with colic syndrome as consequence for one ... / Doutor