McGarry, John W
There are approximately twenty species of hard (ixodid) ticks worldwide that frequently affect human populations, many of which are associated with serious, sometimes fatal disease(s). When a tick travel souvenir is presented in the clinic, the risk must be immediately assessed by identifying the tick in question, ascertaining its disease vector status and determining if there has been the opportunity for the transfer of potential pathogens. This short review on identification of disease vector ticks and aspects of blood feeding and disease transmission includes the results of an examination of 59 specimens removed from UK domestic travellers and international travellers between 2002 and 2010. Sixteen tick species belonging to six genera were recorded and almost all showed evidence of blood feeding, which appears to contradict the view that because of their size, adult ticks are found early and therefore present an insignificant risk. Copyright © 2011 Elsevier Ltd. All rights reserved.
Berger, Kathryn A.; Ginsberg, Howard S.; Dugas, Katherine D.; Hamel, Lutz H.; Mather, Thomas N.
Background: Lyme borreliosis (LB) is the most commonly reported vector-borne disease in north temperate regions worldwide, affecting an estimated 300,000 people annually in the United States alone. The incidence of LB is correlated with human exposure to its vector, the blacklegged tick (Ixodes scapularis). To date, attempts to model tick encounter risk based on environmental parameters have been equivocal. Previous studies have not considered (1) the differences between relative humidity (RH) in leaf litter and at weather stations, (2) the RH threshold that affects nymphal blacklegged tick survival, and (3) the time required below the threshold to induce mortality. We clarify the association between environmental moisture and tick survival by presenting a significant relationship between the total number of tick adverse moisture events (TAMEs - calculated as microclimatic periods below a RH threshold) and tick abundance each year.Methods: We used a 14-year continuous statewide tick surveillance database and corresponding weather data from Rhode Island (RI), USA, to assess the effects of TAMEs on nymphal populations of I. scapularis. These TAMEs were defined as extended periods of time (>8 h below 82% RH in leaf litter). We fit a sigmoid curve comparing weather station data to those collected by loggers placed in tick habitats to estimate RH experienced by nymphal ticks, and compiled the number of historical TAMEs during the 14-year record.Results: The total number of TAMEs in June of each year was negatively related to total seasonal nymphal tick densities, suggesting that sub-threshold humidity episodes >8 h in duration naturally lowered nymphal blacklegged tick abundance. Furthermore, TAMEs were positively related to the ratio of tick abundance early in the season when compared to late season, suggesting that lower than average tick abundance for a given year resulted from tick mortality and not from other factors.Conclusions: Our results clarify the mechanism
Ginsberg, H.S.; Faulde, M.K.
The most common vector-borne diseases in both Europe and North America are transmitted by ticks. Lyme borreliosis (LB), a tick-borne bacterial zoonosis, is the most highly prevalent. Other important tick-borne diseases include TBE (tick-borne encephalitis) and Crimean-Congo haemorrhagic fever in Europe, Rocky Mountain spotted fever (RMSF) in North America, and numerous less common tick-borne bacterial, viral, and protozoan diseases on both continents. The major etiological agent of LB is Borrelia burgdorferi in North America, while in Europe several related species of Borrelia can also cause human illness. These Borrelia genospecies differ in clinical manifestations, ecology (for example, some have primarily avian and others primarily mammalian reservoirs), and transmission cycles, so the epizootiology of LB is more complex in Europe than in North America. Ticks dwell predominantly in woodlands and meadows, and in association with animal hosts, with only limited colonization of human dwellings by a few species. Therefore, suburbanization has contributed substantially to the increase in tick-borne disease transmission in North America by fostering increased exposure of humans to tick habitat. The current trend toward suburbanization in Europe could potentially result in similar increases in transmission of tick-borne diseases. Incidence of tick-borne diseases can be lowered by active public education campaigns, targeted at the times and places of greatest potential for encounter between humans and infected ticks. Similarly, vaccines (e.g., against TBE) are most effective when made available to people at greatest risk, and for high-prevalence diseases such as LB. Consultation with vector-borne disease experts during the planning stages of new human developments can minimize the potential for residents to encounter infected ticks (e.g., by appropriate dwelling and landscape design). Furthermore, research on tick vectors, pathogens, transmission ecology, and on
Oliveira, Karla A.; Pinter, Adriano; Medina-Sanchez, Aaron; Boppana, Venkata D.; Wikel, Stephen K.; Saito, Tais B.; Shelite, Thomas; Blanton, Lucas; Popov, Vsevolod; Teel, Pete D.; Walker, David H.; Galvao, Marcio A.M.; Mafra, Claudio
Real-time PCR of Amblyomma imitator tick egg masses obtained in Nuevo Leon State, Mexico, identified a Rickettsia species. Sequence analyses of 17-kD common antigen and outer membrane protein A and B gene fragments showed to it to be R. rickettsii, which suggested a potential new vector for this bacterium. PMID:20678325
Demoner, Larissa de Castro; Rubini, Adriano Stefani; Paduan, Karina dos Santos; Metzger, Betina; de Paula Antunes, João Marcelo Azevedo; Martins, Thiago Fenandes; Mathias, Maria Izabel Camargo; O'Dwyer, Lucia Helena
Hepatozoon canis is a common apicomplexan parasite of dogs. In Brazil, in addition to Rhipicephalus sanguineus, Amblyomma ovale, Amblyomma cajennense, and Rhipicephalus (Boophilus) microplus have been suggested to act as vectors. The present study aimed to evaluate, under controlled conditions, the acquisition of H. canis by A. ovale, R. sanguineus, and A. cajennense after feeding on naturally infected dogs. Cytological and histophatological examinations were performed to recover oocysts and other sporogonic stages of the protozoan from the experimentally infected nymphs and adults. None of the R. sanguineus (n=30) or A. cajennense nymphs (n=15) that were dissected after feeding on H. canis naturally infected dogs became infected by the hemoparasite. Likewise, none of the R. sanguineus (n=165) and A. cajennense (n=114) adult ticks that were fed as nymphs on dogs demonstrated infection. Additionally, A. cajennense adult ticks were incapable of acquiring the infection, since no parasite was found in 62 adults that fed on H. canis-infected dogs. With regard to A. ovale ticks, 2 different infestations were carried out. Firstly, a dog with naturally occurring hepatozoonosis was infested with A. ovale adults originating from Rondônia, Brazil. Ticks fed to full engorgement. A total of 31 adults was collected from the dog and dissected on the third day after natural detachment. Oocysts were detected in 13 (42%) of the ticks. The second experimental infestation was carried out using adult ticks originating from São Paulo, Brazil. Surprisingly, of the 103 dissected ticks, only one (1%) contained oocysts in the hemocoel. No other sporogonic stage was found. Results indicate that different strains of A. ovale ticks may exist in Brazil with different susceptibilities to pathogens. Furthermore, it is possible that R. sanguineus and A. cajennense have little or no importance in the transmission of H. canis in rural areas of Brazil. Copyright © 2013 Elsevier GmbH. All rights
Tsuji, Naotoshi; Battsetseg, Badgar; Boldbaatar, Damdinsuren; Miyoshi, Takeharu; Xuan, Xuenan; Oliver, James H; Fujisaki, Kozo
Antimicrobial peptides are major components of host innate immunity, a well-conserved, evolutionarily ancient defensive mechanism. Infectious disease-bearing vector ticks are thought to possess specific defense molecules against the transmitted pathogens that have been acquired during their evolution. We found in the tick Haemaphysalis longicornis a novel parasiticidal peptide named longicin that may have evolved from a common ancestral peptide resembling spider and scorpion toxins. H. longicornis is the primary vector for Babesia sp. parasites in Japan. Longicin also displayed bactericidal and fungicidal properties that resemble those of defensin homologues from invertebrates and vertebrates. Longicin showed a remarkable ability to inhibit the proliferation of merozoites, an erythrocyte blood stage of equine Babesia equi, by killing the parasites. Longicin was localized at the surface of the Babesia sp. parasites, as demonstrated by confocal microscopic analysis. In an in vivo experiment, longicin induced significant reduction of parasitemia in animals infected with the zoonotic and murine B. microti. Moreover, RNA interference data demonstrated that endogenous longicin is able to directly kill the canine B. gibsoni, thus indicating that it may play a role in regulating the vectorial capacity in the vector tick H. longicornis. Theoretically, longicin may serve as a model for the development of chemotherapeutic compounds against tick-borne disease organisms.
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Ogden, Nick H; Lindsay, L Robbin
There has been considerable debate as to whether global risk from vector-borne diseases will be impacted by climate change. This has focussed on important mosquito-borne diseases that are transmitted by the vectors from infected to uninfected humans. However, this debate has mostly ignored the biological diversity of vectors and vector-borne diseases. Here, we review how climate and climate change may impact those most divergent of arthropod disease vector groups: multivoltine insects and hard-bodied (ixodid) ticks. We contrast features of the life cycles and behaviour of these arthropods, and how weather, climate, and climate change may have very different impacts on the spatiotemporal occurrence and abundance of vectors, and the pathogens they transmit. Crown Copyright © 2016. Published by Elsevier Ltd. All rights reserved.
Shannon, Avery B; Rucinsky, Renee; Gaff, Holly D; Brinkerhoff, R Jory
We collected blood and tick samples in eastern Maryland to quantify vector-borne pathogen exposure and infection in healthy cats and to assess occupational disease risk to veterinary professionals and others who regularly interact with household pets. Thirty-six percent of healthy cats parasitized by ticks at time of examination (9/25) were exposed to, and 14% of bloods (7/49) tested PCR-positive for, at least one vector-borne pathogen including several bloods and ticks with Borrelia miyamotoi, a recently recognized tick-borne zoonotic bacterium. There was no indication that high tick burdens were associated with exposure to vector-borne pathogens. Our results underscore the potential importance of cats to human vector-borne disease risk.
Full Text Available Bartonella spp. are facultative intracellular vector-borne bacteria associated with several emerging diseases in humans and animals all over the world. The potential for involvement of ticks in transmission of Bartonella spp. has been heartily debated for many years. However, most of the data supporting bartonellae transmission by ticks come from molecular and serological epidemiological surveys in humans and animals providing only indirect evidences without a direct proof of tick vector competence for transmission of bartonellae. We used a murine model to assess the vector competence of Ixodes ricinus for Bartonella birtlesii. Larval and nymphal I. ricinus were fed on a B. birtlesii-infected mouse. The nymphs successfully transmitted B. birtlesii to naïve mice as bacteria were recovered from both the mouse blood and liver at seven and 16 days after tick bites. The female adults successfully emitted the bacteria into uninfected blood after three or more days of tick attachment, when fed via membrane feeding system. Histochemical staining showed the presence of bacteria in salivary glands and muscle tissues of partially engorged adult ticks, which had molted from the infected nymphs. These results confirm the vector competence of I. ricinus for B. birtlesii and represent the first in vivo demonstration of a Bartonella sp. transmission by ticks. Consequently, bartonelloses should be now included in the differential diagnosis for patients exposed to tick bites.
... ticks that bite humans How ticks spread disease Diseases transmitted by ticks Trends in tickborne diseases Tickborne diseases ... Emerging and Zoonotic Infectious Diseases (NCEZID) Division of Vector-Borne Diseases (DVBD) Email Recommend Tweet YouTube Instagram Listen Watch ...
... ticks that bite humans How ticks spread disease Diseases transmitted by ticks Trends in tickborne diseases Tickborne diseases ... Emerging and Zoonotic Infectious Diseases (NCEZID) Division of Vector-Borne Diseases (DVBD) Email Recommend Tweet YouTube Instagram Listen Watch ...
Demma, Linda J; Traeger, Marc S; Nicholson, William L; Paddock, Christopher D; Blau, Dianna M; Eremeeva, Marina E; Dasch, Gregory A; Levin, Michael L; Singleton, Joseph; Zaki, Sherif R; Cheek, James E; Swerdlow, David L; McQuiston, Jennifer H
Rocky Mountain spotted fever is a life-threatening, tick-borne disease caused by Rickettsia rickettsii. This disease is rarely reported in Arizona, and the principal vectors, Dermacentor species ticks, are uncommon in the state. From 2002 through 2004, a focus of Rocky Mountain spotted fever was investigated in rural eastern Arizona. We obtained blood and tissue specimens from patients with suspected Rocky Mountain spotted fever and ticks from patients' homesites. Serologic, molecular, immunohistochemical, and culture assays were performed to identify the causative agent. On the basis of specific laboratory criteria, patients were classified as having confirmed or probable Rocky Mountain spotted fever infection. A total of 16 patients with Rocky Mountain spotted fever infection (11 with confirmed and 5 with probable infection) were identified. Of these patients, 13 (81 percent) were children 12 years of age or younger, 15 (94 percent) were hospitalized, and 2 (12 percent) died. Dense populations of Rhipicephalus sanguineus ticks were found on dogs and in the yards of patients' homesites. All patients with confirmed Rocky Mountain spotted fever had contact with tick-infested dogs, and four had a reported history of tick bite preceding the illness. R. rickettsii DNA was detected in nonengorged R. sanguineus ticks collected at one home, and R. rickettsii isolates were cultured from these ticks. This investigation documents the presence of Rocky Mountain spotted fever in eastern Arizona, with common brown dog ticks (R. sanguineus) implicated as a vector of R. rickettsii. The broad distribution of this common tick raises concern about its potential to transmit R. rickettsii in other settings. Copyright 2005 Massachusetts Medical Society.
Gulia-Nuss, Monika; Nuss, Andrew B.; Meyer, Jason M.
Ticks transmit more pathogens to humans and animals than any other arthropod. We describe the 2.1 Gbp nuclear genome of the tick, Ixodes scapularis (Say), which vectors pathogens that cause Lyme disease, human granulocytic anaplasmosis, babesiosis and other diseases. The large genome reflects...... proteins associated with the agent of human granulocytic anaplasmosis, an emerging disease, and the encephalitis-causing Langat virus, and a population structure correlated to life-history traits and transmission of the Lyme disease agent....
Delgado, Juan D; Abreu-Yanes, Estefanía; Abreu-Acosta, Néstor; Flor, Manuel D; Foronda, Pilar
Roads fragment vertebrate populations and affect the dynamics and dispersal patterns of vertebrate parasites. We evaluated how vertebrate ticks distribute near roads and road underpasses in human-caused road-fragmented landscapes in Seville, SW Spain. We sampled 49 stations with 93 individualized sampling points and assessed tick abundance. We explored the relationship between tick presence and abundance and distance to the nearest road and underpass (drainage culverts and other passages used by vertebrates), and landscape features through categorical regression and nonparametric statistics. The presence of the tick-borne pathogens Borrelia sp. and Bartonella sp. was also analyzed by PCR. We found preliminary evidence of high relative tick abundance next to roads and in the vicinity of road underpasses. Plant cover type was related to tick presence in this road context. Implications of road permeability and edge effect in patterns of vertebrate-tick relationships in road fragmentation contexts are discussed. Both Borrelia sp. and Bartonella sp. were detected in the ticks analyzed. This is the first report of these bacteria in ticks from Seville. The results confirm the potential risk of acquiring Lyme disease and bartonellosis in this area.
Full Text Available BACKGROUND: The lone star tick Amblyomma americanum is a common pest and vector of infectious diseases for humans and other mammals in the southern and eastern United States. A Coxiella sp. bacterial endosymbiont was highly prevalent in both laboratory-reared and field-collected A. americanum. The Coxiella sp. was demonstrated in all stages of tick and in greatest densities in nymphs and adult females, while a Rickettsia sp. was less prevalent and in lower densities when present. METHODOLOGY/PRINCIPAL FINDINGS: We manipulated the numbers of both bacterial species in laboratory-reared A. americanum by injecting engorged nymphs or engorged, mated females with single doses of an antibiotic (rifampin or tetracycline or buffer alone. Burdens of the bacteria after molting or after oviposition were estimated by quantitative polymerase chain reaction with primers and probes specific for each bacterial species or, as an internal standard, the host tick. Post-molt adult ticks that had been treated with rifampin or tetracycline had lower numbers of the Coxiella sp. and Rickettsia sp. and generally weighed less than ticks that received buffer alone. Similarly, after oviposition, females treated previously with either antibiotic had lower burdens of both bacterial species in comparison to controls. Treatment of engorged females with either antibiotic was associated with prolonged time to oviposition, lower proportions of ticks that hatched, lower proportions of viable larvae among total larvae, and lower numbers of viable larvae per tick. These fitness estimators were associated with reduced numbers of the Coxiella sp. but not the Rickettsia sp. CONCLUSION/SIGNIFICANCE: The findings indicate that the Coxiella sp. is a primary endosymbiont, perhaps provisioning the obligately hematophagous parasites with essential nutrients. The results also suggest that antibiotics could be incorporated into an integrated pest management plan for control of these and other
de la Fuente, J.; Antunes, S.; Bonnet, S.; Cabezas Cruz, Alejandro; Domingos, A.G.; Estrada-Peňa, A.; Johnson, N.; Kocan, K.M.; Mansfield, K. L.; Nijhof, A.M.; Papa, A.; Rudenko, Natalia; Villar, M.; Alberdi, P.; Torina, A.; Ayllón, N.; Vancová, Marie; Golovchenko, Maryna; Grubhoffer, Libor; Caracappa, S.; Fooks, A. R.; Gortazar, C.; Rego, Ryan O. M.
Roč. 7, APR 7 (2017), č. článku 114. ISSN 2235-2988 EU Projects: European Commission(XE) 278976 - ANTIGONE Institutional support: RVO:60077344 Keywords : tick * Anaplasma * flavivirus * Babesia * Borrelia * Microbiome * immunology * vaccine Subject RIV: EB - Genetics ; Molecular Biology OBOR OECD: Biochemistry and molecular biology Impact factor: 4.300, year: 2016
Galindo, Ruth C.; Kocan, Katherine M.; Blouin, Edmour F.; Mitra, Ruchira; Alberdi, Pilar; Villar, Margarita; de la Fuente, José
Background Tick Subolesin and its ortholog in insects and vertebrates, Akirin, have been suggested to play a role in the immune response through regulation of nuclear factor-kappa B (NF-kB)-dependent and independent gene expression via interaction with intermediate proteins that interact with NF-kB and other regulatory proteins, bind DNA or remodel chromatin to regulate gene expression. The objective of this study was to characterize the structure and regulation of subolesin in Ixodes scapularis. I. scapularis is a vector of emerging pathogens such as Borrelia burgdorferi, Anaplasma phagocytophilum and Babesia microti that cause in humans Lyme disease, anaplasmosis and babesiosis, respectively. The genome of I. scapularis was recently sequenced, and this tick serves as a model organism for the study of vector-host-pathogen interactions. However, basic biological questions such as gene organization and regulation are largely unknown in ticks and other arthropod vectors. Principal Findings The results presented here provide evidence that subolesin/akirin are evolutionarily conserved at several levels (primary sequence, gene organization and function), thus supporting their crucial biological function in metazoans. These results showed that NF-kB (Relish) is involved in the regulation of subolesin expression in ticks, suggesting that as in other organisms, different NF-kB integral subunits and/or unknown interacting proteins regulate the specificity of the NF-kB-mediated gene expression. These results suggested a regulatory network involving cross-regulation between NF-kB (Relish) and Subolesin and Subolesin auto-regulation with possible implications in tick immune response to bacterial infection. Significance These results advance our understanding of gene organization and regulation in I. scapularis and have important implications for arthropod vectors genetics and immunology highlighting the possible role of NF-kB and Subolesin/Akirin in vector
Kenney, Joan L; Anishchenko, Michael; Hermance, Meghan; Romo, Hannah; Chen, Ching-I; Thangamani, Saravanan; Brault, Aaron C
The Flavivirus genus comprises a diverse group of viruses that utilize a wide range of vertebrate hosts and arthropod vectors. The genus includes viruses that are transmitted solely by mosquitoes or vertebrate hosts as well as viruses that alternate transmission between mosquitoes or ticks and vertebrates. Nevertheless, the viral genetic determinants that dictate these unique flaviviral host and vector specificities have been poorly characterized. In this report, a cDNA clone of a flavivirus that is transmitted between ticks and vertebrates (Powassan lineage II, deer tick virus [DTV]) was generated and chimeric viruses between the mosquito/vertebrate flavivirus, West Nile virus (WNV), were constructed. These chimeric viruses expressed the prM and E genes of either WNV or DTV in the heterologous nonstructural (NS) backbone. Recombinant chimeric viruses rescued from cDNAs were characterized for their capacity to grow in vertebrate and arthropod (mosquito and tick) cells as well as for in vivo vector competence in mosquitoes and ticks. Results demonstrated that the NS elements were insufficient to impart the complete mosquito or tick growth phenotypes of parental viruses; however, these NS genetic elements did contribute to a 100- and 100,000-fold increase in viral growth in vitro in tick and mosquito cells, respectively. Mosquito competence was observed only with parental WNV, while infection and transmission potential by ticks were observed with both DTV and WNV-prME/DTV chimeric viruses. These data indicate that NS genetic elements play a significant, but not exclusive, role for vector usage of mosquito- and tick-borne flaviviruses.
Malaria and tick-borne borreliosis are the two first causes of morbidity due to vector-borne diseases in a large part of Sudan-sahelian West Africa. They are also the two tropical diseases which have been the most affected by climatic change in recent years. In the case of tick-borne borreliosis it has been shown in Senegal that the persistence of drought since the years 70 has been associated with a considerable extension of the geographic range of diseases and the vector tick A-sonrai, a species that was in the past limited to the Sahara and Sahel. In the case of malaria, drought has strongly reduced in these same regions of Africa the distribution, abundance and infection rate of Anopheline mosquitoes, but without any significant reduction of the burden of malaria for most populations concerned. The emergence and spread of Plasmodium falciparum resistance to antimalarial drugs only explain part of this phenomenon. (A.L.B.)
Kocan, K M
Development in and transmission of hemoparasites by tick vectors are phenomena closely synchronized with the tick feeding cycle. In all known life cycles, initial infection of tick tissues occurs in midgut epithelial cells and transmission is effected as ticks feed after parasites have developed and multiplied in salivary glands. Many factors reviewed affect development and transmission of hemoparasites by ticks including age of ticks, artificial temperature, climate and/or season, tick stage or sex, hemoparasite variation, concurrent infection of ticks with other pathogens, host cell susceptibility, transovarial transmission, effect of hemoparasites on tick biology, and the effect of infecting parasitemia level in cattle on infection rates in ticks. Four hemoparasites of cattle, Anaplasma marginale, Cowdria ruminantium, Theileria parva, and Babesia spp., are all dependent on ticks for biological transmission. Babesia is transmitted transovarially whereas the other three are transmitted transstadially. Mechanical transfer of infective blood via fomites and mouthparts of biting arthropods is also a major means of transmission for Anaplasma marginale but not of the others. Potential control methods for hemoparasites that target parasites as they are developing in their respective tick hosts include tick control, vaccines (against ticks and parasites), and drugs (against ticks and parasites). Successful application of control strategies will be dependent upon thorough understanding of parasite developmental cycles, biology of the tick vectors and the immune response of cattle to ticks and to hemoparasites. The most effective control measures will be those that are targeted against both ticks and the hemoparasites they vector.
Sonenshine, D. E. [Old Dominion College, Norfolk, VA (United States)
the feasibility of mass rearing and long-term survival of radioisotope-tagged immature ticks suggests that it is now possible to apply this radioecological technique to obtain important new knowledge, on the ecology of tick vectors of disease. (author)
Full Text Available Anaplasma phagocytophilum is an emerging tick-borne pathogen causing human granulocytic anaplasmosis (HGA, tick-borne fever (TBF in small ruminants, and other forms of anaplasmosis in different domestic and wild animals. The main vectors of this pathogen are Ixodes tick species, particularly I. scapularis in the United States and I. ricinus in Europe. One of the main limitations for the development of effective vaccines for the prevention and control of A. phagocytophilum infection and transmission is the identification of effective tick protective antigens. The objective of this study was to apply a vaccinomics approach to I. scapularis-A. phagocytophilum interactions for the identification and characterization of candidate tick protective antigens for the control of vector infestations and A. phagocytophilum infection. The vaccinomics pipeline included the use of quantitative transcriptomics and proteomics data from uninfected and A. phagocytophilum-infected I. scapularis ticks for the selection of candidate protective antigens based on the variation in tick mRNA and protein levels in response to infection, their putative biological function, and the effect of antibodies against these proteins on tick cell apoptosis and pathogen infection. The characterization of selected candidate tick protective antigens included the identification and characterization of I. ricinus homologs, functional characterization by different methodologies including RNA interference, immunofluorescence, gene expression profiling, and artificial tick feeding on rabbit antibodies against the recombinant antigens to select the candidates for vaccination trials. The vaccinomics pipeline developed in this study resulted in the identification of two candidate tick protective antigens that could be selected for future vaccination trials. The results showed that I. scapularis lipocalin (ISCW005600 and lectin pathway inhibitor (AAY66632 and I. ricinus homologs constitute
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Gulia-Nuss, Monika; Nuss, Andrew B.; Meyer, Jason M.; Sonenshine, Daniel E.; Roe, R. Michael; Waterhouse, Robert M.; Sattelle, David B.; de la Fuente, José; Ribeiro, Jose M.; Megy, Karine; Thimmapuram, Jyothi; Miller, Jason R.; Walenz, Brian P.; Koren, Sergey; Hostetler, Jessica B.; Thiagarajan, Mathangi; Joardar, Vinita S.; Hannick, Linda I.; Bidwell, Shelby; Hammond, Martin P.; Young, Sarah; Zeng, Qiandong; Abrudan, Jenica L.; Almeida, Francisca C.; Ayllón, Nieves; Bhide, Ketaki; Bissinger, Brooke W.; Bonzon-Kulichenko, Elena; Buckingham, Steven D.; Caffrey, Daniel R.; Caimano, Melissa J.; Croset, Vincent; Driscoll, Timothy; Gilbert, Don; Gillespie, Joseph J.; Giraldo-Calderón, Gloria I.; Grabowski, Jeffrey M.; Jiang, David; Khalil, Sayed M. S.; Kim, Donghun; Kocan, Katherine M.; Koči, Juraj; Kuhn, Richard J.; Kurtti, Timothy J.; Lees, Kristin; Lang, Emma G.; Kennedy, Ryan C.; Kwon, Hyeogsun; Perera, Rushika; Qi, Yumin; Radolf, Justin D.; Sakamoto, Joyce M.; Sánchez-Gracia, Alejandro; Severo, Maiara S.; Silverman, Neal; Šimo, Ladislav; Tojo, Marta; Tornador, Cristian; Van Zee, Janice P.; Vázquez, Jesús; Vieira, Filipe G.; Villar, Margarita; Wespiser, Adam R.; Yang, Yunlong; Zhu, Jiwei; Arensburger, Peter; Pietrantonio, Patricia V.; Barker, Stephen C.; Shao, Renfu; Zdobnov, Evgeny M.; Hauser, Frank; Grimmelikhuijzen, Cornelis J. P.; Park, Yoonseong; Rozas, Julio; Benton, Richard; Pedra, Joao H. F.; Nelson, David R.; Unger, Maria F.; Tubio, Jose M. C.; Tu, Zhijian; Robertson, Hugh M.; Shumway, Martin; Sutton, Granger; Wortman, Jennifer R.; Lawson, Daniel; Wikel, Stephen K.; Nene, Vishvanath M.; Fraser, Claire M.; Collins, Frank H.; Birren, Bruce; Nelson, Karen E.; Caler, Elisabet; Hill, Catherine A.
Ticks transmit more pathogens to humans and animals than any other arthropod. We describe the 2.1 Gbp nuclear genome of the tick, Ixodes scapularis (Say), which vectors pathogens that cause Lyme disease, human granulocytic anaplasmosis, babesiosis and other diseases. The large genome reflects accumulation of repetitive DNA, new lineages of retro-transposons, and gene architecture patterns resembling ancient metazoans rather than pancrustaceans. Annotation of scaffolds representing ∼57% of the genome, reveals 20,486 protein-coding genes and expansions of gene families associated with tick–host interactions. We report insights from genome analyses into parasitic processes unique to ticks, including host ‘questing', prolonged feeding, cuticle synthesis, blood meal concentration, novel methods of haemoglobin digestion, haem detoxification, vitellogenesis and prolonged off-host survival. We identify proteins associated with the agent of human granulocytic anaplasmosis, an emerging disease, and the encephalitis-causing Langat virus, and a population structure correlated to life-history traits and transmission of the Lyme disease agent. PMID:26856261
Gilbert, Lucy; Aungier, Jennifer; Tomkins, Joseph L
Climate warming is changing distributions and phenologies of many organisms and may also impact on vectors of disease-causing pathogens. In Europe, the tick Ixodes ricinus is the primary vector of medically important pathogens (e.g., Borrelia burgdorferi sensu lato, the causative agent of Lyme borreliosis). How might climate change affect I. ricinus host-seeking behavior (questing)? We hypothesize that, in order to maximize survival, I. ricinus have adapted their questing in response to temperature in accordance with local climates. We predicted that ticks from cooler climates quest at cooler temperatures than those from warmer climates. This would suggest that I. ricinus can adapt and therefore have the potential to be resilient to climate change. I. ricinus were collected from a cline of climates using a latitudinal gradient (northeast Scotland, North Wales, South England, and central France). Under laboratory conditions, ticks were subjected to temperature increases of 1°C per day, from 6 to 15°C. The proportion of ticks questing was recorded five times per temperature (i.e., per day). The theoretical potential to quest was then estimated for each population over the year for future climate change projections. As predicted, more ticks from cooler climates quested at lower temperatures than did ticks from warmer climates. The proportion of ticks questing was strongly associated with key climate parameters from each location. Our projections, based on temperature alone, suggested that populations could advance their activity season by a month under climate change, which has implications for exposure periods of hosts to tick-borne pathogens. Our findings suggest that I. ricinus have adapted their behavior in response to climate, implying some potential to adapt to climate change. Predictive models of I. ricinus dynamics and disease risk over continental scales would benefit from knowledge of these differences between populations.
Oldiges, Daiane P.; Laughery, Jacob M.; Tagliari, Nelson Junior; Leite Filho, Ronaldo Viana; Davis, William C.; da Silva Vaz, Itabajara; Termignoni, Carlos; Knowles, Donald P.; Suarez, Carlos E.
The Rhipicephalus microplus tick is a notorious blood-feeding ectoparasite of livestock, especially cattle, responsible for massive losses in animal production. It is the main vector for transmission of pathogenic bacteria and parasites, including Babesia bovis, an intraerythrocytic apicomplexan protozoan parasite responsible for bovine Babesiosis. This study describes the development and testing of a live B. bovis vaccine expressing the protective tick antigen glutathione-S-transferase from Haemaphysalis longicornis (HlGST). The B. bovis S74-T3B parasites were electroporated with a plasmid containing the bidirectional Ef-1α (elongation factor 1 alpha) promoter of B. bovis controlling expression of two independent genes, the selectable marker GFP-BSD (green fluorescent protein–blasticidin deaminase), and HlGST fused to the MSA-1 (merozoite surface antigen 1) signal peptide from B. bovis. Electroporation followed by blasticidin selection resulted in the emergence of a mixed B. bovis transfected line (termed HlGST) in in vitro cultures, containing parasites with distinct patterns of insertion of both exogenous genes, either in or outside the Ef-1α locus. A B. bovis clonal line termed HlGST-Cln expressing intracellular GFP and HlGST in the surface of merozoites was then derived from the mixed parasite line HlGST using a fluorescent activated cell sorter. Two independent calf immunization trials were performed via intravenous inoculation of the HlGST-Cln and a previously described control consisting of an irrelevant transfected clonal line of B. bovis designated GFP-Cln. The control GFP-Cln line contains a copy of the GFP-BSD gene inserted into the Ef-1α locus of B. bovis in an identical fashion as the HIGST-Cln parasites. All animals inoculated with the HlGST-Cln and GFP-Cln transfected parasites developed mild babesiosis. Tick egg fertility and fully engorged female tick weight was reduced significantly in R. microplus feeding on HlGST-Cln-immunized calves
Daiane P Oldiges
Full Text Available The Rhipicephalus microplus tick is a notorious blood-feeding ectoparasite of livestock, especially cattle, responsible for massive losses in animal production. It is the main vector for transmission of pathogenic bacteria and parasites, including Babesia bovis, an intraerythrocytic apicomplexan protozoan parasite responsible for bovine Babesiosis. This study describes the development and testing of a live B. bovis vaccine expressing the protective tick antigen glutathione-S-transferase from Haemaphysalis longicornis (HlGST. The B. bovis S74-T3B parasites were electroporated with a plasmid containing the bidirectional Ef-1α (elongation factor 1 alpha promoter of B. bovis controlling expression of two independent genes, the selectable marker GFP-BSD (green fluorescent protein-blasticidin deaminase, and HlGST fused to the MSA-1 (merozoite surface antigen 1 signal peptide from B. bovis. Electroporation followed by blasticidin selection resulted in the emergence of a mixed B. bovis transfected line (termed HlGST in in vitro cultures, containing parasites with distinct patterns of insertion of both exogenous genes, either in or outside the Ef-1α locus. A B. bovis clonal line termed HlGST-Cln expressing intracellular GFP and HlGST in the surface of merozoites was then derived from the mixed parasite line HlGST using a fluorescent activated cell sorter. Two independent calf immunization trials were performed via intravenous inoculation of the HlGST-Cln and a previously described control consisting of an irrelevant transfected clonal line of B. bovis designated GFP-Cln. The control GFP-Cln line contains a copy of the GFP-BSD gene inserted into the Ef-1α locus of B. bovis in an identical fashion as the HIGST-Cln parasites. All animals inoculated with the HlGST-Cln and GFP-Cln transfected parasites developed mild babesiosis. Tick egg fertility and fully engorged female tick weight was reduced significantly in R. microplus feeding on Hl
Maria Fernanda B M Galletti
Full Text Available Rickettsia rickettsii is an obligate intracellular tick-borne bacterium that causes Rocky Mountain Spotted Fever (RMSF, the most lethal spotted fever rickettsiosis. When an infected starving tick begins blood feeding from a vertebrate host, R. rickettsii is exposed to a temperature elevation and to components in the blood meal. These two environmental stimuli have been previously associated with the reactivation of rickettsial virulence in ticks, but the factors responsible for this phenotype conversion have not been completely elucidated. Using customized oligonucleotide microarrays and high-throughput microfluidic qRT-PCR, we analyzed the effects of a 10°C temperature elevation and of a blood meal on the transcriptional profile of R. rickettsii infecting the tick Amblyomma aureolatum. This is the first study of the transcriptome of a bacterium in the genus Rickettsia infecting a natural tick vector. Although both stimuli significantly increased bacterial load, blood feeding had a greater effect, modulating five-fold more genes than the temperature upshift. Certain components of the Type IV Secretion System (T4SS were up-regulated by blood feeding. This suggests that this important bacterial transport system may be utilized to secrete effectors during the tick vector's blood meal. Blood feeding also up-regulated the expression of antioxidant enzymes, which might correspond to an attempt by R. rickettsii to protect itself against the deleterious effects of free radicals produced by fed ticks. The modulated genes identified in this study, including those encoding hypothetical proteins, require further functional analysis and may have potential as future targets for vaccine development.
Yoder, J A; Benoit, J B; Rellinger, E J; Tank, J L
Recent reports indicate that the common brown dog tick, or kennel tick, Rhipicephalus sanguineus (Latreille) (Acari: Ixodidae) is a competent vector of Rocky Mountain spotted fever in the U.S.A. This tick is of concern to public health because of its high frequency of contact, as it has a unique ability to thrive within human homes. To assess the moisture requirements necessary for survival, water balance characteristics were determined for each developmental stage, from egg to adult. This is the first time that water relations in ticks have been assessed throughout the complete lifecycle. Notably, R. sanguineus is differentially adapted for life in a dry environment, as characterized by a suppressed water loss rate distinctive for each stage that distinguishes it from other ticks. Analysis of its dehydration tolerance limit and percentage body water content provides no evidence to suggest that the various stages of this tick can function more effectively containing less water, indicating that this species is modified for water conservation, not desiccation hardiness. All stages, eggs excepted, absorb water vapour from the air and can drink free water to replenish water stores. Developmentally, a shift in water balance strategies occurs in the transition from the larva, where the emphasis is on water gain (water vapour absorption from drier air), to the adult, where the emphasis is on water retention (low water loss rate). These results on the xerophilic-nature of R. sanguineus identify overhydration as the primary water stress, indicating that this tick is less dependent upon a moisture-rich habitat for survival, which matches its preference for a dry environment. We suggest that the controlled, host-confined conditions of homes and kennels have played a key role in promoting the ubiquitous distribution of R. sanguineus by creating isolated arid environments that enable this tick to establish within regions that are unfavourable for maintaining water balance.
Full Text Available The Arctic is rapidly warming and host-parasite relationships may be modified by such environmental changes. Here, I showed that the average winter temperature in Svalbard, Arctic Norway, explained almost 90% of the average prevalence of ticks in an Arctic seabird, the Brünnich's guillemot Uria lomvia. An increase of 1°C in the average winter temperature at the nesting colony site was associated with a 5% increase in the number of birds infected by these ectoparasites in the subsequent breeding season. Guillemots were generally infested by only a few ticks (≤5 and I found no direct effect of tick presence on their body condition and breeding success. However, the strong effect of average winter temperature described here clearly indicates that tick-seabird relationships in the Arctic may be strongly affected by ongoing climate warming.
Luiz Ricardo Gonçalves
Full Text Available Since dogs presenting several vector borne diseases can show none or nonspecific clinical signs depending on the phase of infection, the assessment of the particular agents involved is mandatory. The present study aimed to investigate the presence of Babesia spp., Ehrlichia spp., Anaplasma spp., Hepatozoon spp. and Leishmania spp. in blood samples and ticks, collected from two dogs from Rio Grande do Norte showing suggestive tick-borne disease by using molecular techniques. DNA of E. canis, H. canis and L. infantum were detected in blood samples and R. sanguineus ticks collected from dogs. Among all samples analyzed, two showed the presence of multiple infections with E. canis, H. canis and L. infantum chagasi. Here we highlighted the need for molecular differential diagnosis in dogs showing nonspecific clinical signs.
Bratton, Robert L; Corey, Ralph
Tick-borne diseases in the United States include Rocky Mountain spotted fever, Lyme disease, ehrlichiosis, tularemia, babesiosis, Colorado tick fever, and relapsing fever. It is important for family physicians to consider these illnesses when patients present with influenza-like symptoms. A petechial rash initially affecting the palms and soles of the feet is associated with Rocky Mountain spotted fever, whereas erythema migrans (annular macule with central clearing) is associated with Lyme disease. Various other rashes or skin lesions accompanied by fever and influenza-like illness also may signal the presence of a tick-borne disease. Early, accurate diagnosis allows treatment that may help prevent significant morbidity and possible mortality. Because 24 to 48 hours of attachment to the host are required for infection to occur, early removal can help prevent disease. Treatment with doxycycline or tetracycline is indicated for Rocky Mountain spotted fever, Lyme disease, ehrlichiosis, and relapsing fever. In patients with clinical findings suggestive of tick-borne disease, treatment should not be delayed for laboratory confirmation. If no symptoms follow exposure to tick bites, empiric treatment is not indicated. The same tick may harbor different infectious pathogens and transmit several with one bite. Advising patients about prevention of tick bites, especially in the summer months, may help prevent exposure to dangerous vector-borne diseases.
Dunlop, Jason A.; Apanaskevich, Dmitry A.; Lehmann, Jens; Hoffmann, René; Fusseis, Florian; Ehlke, Moritz; Zachow, Stefan; Xiao, Xianghui
Background: Fossil ticks are extremely rare, whereby Ixodes succineus Weidner, 1964 from Eocene (ca. 44–49 Ma) Baltic amber is one of the oldest examples of a living hard tick genus (Ixodida: Ixodidae). Previous work suggested it was most closely related to the modern and widespread European sheep tick Ixodes ricinus (Linneaus, 1758). Results: Restudy using phase contrast synchrotron x-ray tomography yielded images of exceptional quality. These confirm the fossil’s referral to Ixodes Latreille, 1795, but the characters resolved here suggest instead affinities with the Asian subgenus Partipalpiger Hoogstraal et al., 1973 and its single living (and medically significant) species Ixodes ovatus Neumann, 1899. We redescribe the amber fossil here as Ixodes (Partipalpiger) succineus. Conclusions: Our data suggest that Ixodes ricinus is unlikely to be directly derived from Weidner’s amber species, but instead reveals that the Partipalpiger lineage was originally more widely distributed across the northern hemisphere. The closeness of Ixodes (P.) succineus to a living vector of a wide range of pathogens offers the potential to correlate its spatial and temporal position (northern Europe, nearly 50 million years ago) with the estimated origination dates of various tick-borne diseases.
The southern cattle tick, Rhipicephalus (Boophilus) microplus, is an economically important pest costing animal agriculture billions of dollars worldwide. This research focuses on a comparison of three different tick DNA extraction methods: phenol-chloroform extraction (method 1), a modified version...
Zemtsova, Galina E; Killmaster, Lindsay F; Montgomery, Merrill; Schumacher, Lauren; Burrows, Matt; Levin, Michael L
Ticks of the genus Dermacentor are known vectors of rickettsial pathogens in both the Old World and New World. In North America, Dermacentor variabilis and D. andersoni are vectors of Rickettsia rickettsii, while in Europe, D. marginatus and D. reticulatus transmit R. slovaca and R. raoultii, respectively. Neither the presence of R. slovaca in the Americas nor the ability of American tick species to maintain this pathogen have been reported. Here we describe detection of Rickettsia genetically identical to R. slovaca in D. variabilis, its molecular characterization, assessment of pathogenicity to guinea pigs, and vector competence of D. variabilis ticks. Ticks from a laboratory colony of D. variabilis, established from wild ticks and maintained on naïve NZW rabbits, tested positive for spotted fever group (SFG) Rickettsia by PCR. Analysis of 17 kDa gltA, rpoB, ompA, ompB, and sca4 genes revealed 100% identity to R. slovaca sequences available in the GenBank. New Zealand white rabbits fed upon by infected ticks seroconverted to SFG Rickettsia. Guinea pigs inoculated with the Rickettsia culture or infested by the infected ticks developed antibodies to SFG Rickettsia. The intensity of clinical signs and immune response were dependent on dose and route of infection. The identified Rickettsia was detected in all life stages of D. variabilis ticks, confirming transstadial and transovarial transmission. Thirty-six percent of uninfected larvae co-fed with infected nymphs on guinea pigs were PCR-positive and able to pass rickettsia to at least 11.7% of molted nymphs. To our knowledge, this is a first report of identification of a European pathogen R. slovaca or a highly similar agent in the American dog tick, D. variabilis. Considering pathogenicity of R. slovaca in humans, further laboratory and field studies are warranted to assess the relevance of the above findings to the public health and epidemiology of SFG rickettsioses in the United States.
Full Text Available Lyme disease in humans is caused by several genospecies of the Borrelia burgdorferi sensu lato (s.l. complex of spirochetal bacteria, including B. burgdorferi, B. afzelii and B. garinii. These bacteria exist in nature as obligate parasites in an enzootic cycle between small vertebrate hosts and Ixodid tick vectors, with humans representing incidental hosts. During the natural enzootic cycle, infected ticks in endemic areas feed not only upon naïve hosts, but also upon seropositive infected hosts. In the current study, we considered this environmental parameter and assessed the impact of the immune status of the blood-meal host on the phenotype of the Lyme disease spirochete within the tick vector. We found that blood from a seropositive host profoundly attenuates the infectivity (>104 fold of homologous spirochetes within the tick vector without killing them. This dramatic neutralization of vector-borne spirochetes was not observed, however, when ticks and blood-meal hosts carried heterologous B. burgdorferi s.l. strains, or when mice lacking humoral immunity replaced wild-type mice as blood-meal hosts in similar experiments. Mechanistically, serum-mediated neutralization does not block induction of host-adapted OspC+ spirochetes during tick feeding, nor require tick midgut components. Significantly, this study demonstrates that strain-specific antibodies elicited by B. burgdorferi s.l. infection neutralize homologous bacteria within feeding ticks, before the Lyme disease spirochetes enter a host. The blood meal ingested from an infected host thereby prevents super-infection by homologous spirochetes, while facilitating transmission of heterologous B. burgdorferi s.l. strains. This finding suggests that Lyme disease spirochete diversity is stably maintained within endemic populations in local geographic regions through frequency-dependent selection of rare alleles of dominant polymorphic surface antigens.
Lempereur, Laetitia; Wirtgen, Marc; Nahayo, Adrien; Caron, Yannick; Shiels, Brian; Saegerman, Claude; Losson, Bertrand; Linden, Annick
Babesiosis is a tick-borne disease caused by different species of intraerythrocytic protozoan parasites within the genus Babesia. Different species of Babesia are described as potentially zoonotic and cause a malaria-like disease mainly in immunocompromised humans. Interest in the zoonotic potential of Babesia is growing and babesiosis has been described by some authors as an emergent zoonotic disease. The role of cervids to maintain tick populations and act as a reservoir host for some Babesia spp. with zoonotic capability is suspected. To investigate the range and infection rate of Babesia species, ticks were collected from wild cervids in southern Belgium during 2008. DNA extraction was performed for individual ticks, and each sample was evaluated for the absence of PCR inhibition using a PCR test. A Babesia spp. genus-specific PCR based on the 18S rRNA gene was applied to validated tick DNA extracts. A total of 1044 Ixodes ricinus ticks were collected and 1023 validated samples were subsequently screened for the presence of Babesia spp. DNA. Twenty-eight tick samples were found to be positive and identified after sequencing as containing DNA representing: Babesia divergens (3), B. divergens-like (5), Babesia sp. EU1 (11), Babesia sp. EU1-like (3), B. capreoli (2), or unknown Babesia sp. (4). This study confirms the presence of potentially zoonotic species and Babesia capreoli in Belgium, with a tick infection rate of 2.7% (95% CI 1.8,3.9%). Knowledge of the most common reservoir source for transmission of zoonotic Babesia spp. will be useful for models assessing the risk potential of this infection to humans.
Lempereur, Laetitia; Wirtgen, Marc; Nahayo, Adrien; Caron, Yannick; Shiels, Brian; Saegerman, Claude; Losson, Bertrand; Linden, Annick
Babesiosis is a tick-borne disease caused by different species of intraerythrocytic protozoan parasites within the genus Babesia. Different species of Babesia are described as potentially zoonotic and cause a malaria-like disease mainly in immunocompromised humans. Interest in the zoonotic potential of Babesia is growing and babesiosis has been described by some authors as an emergent zoonotic disease. The role of cervids to maintain tick populations and act as a reservoir host for some Babes...
Heidi K Goethert
Full Text Available The island of Martha's Vineyard, Massachusetts, is the site of a sustained outbreak of tularemia due to Francisella tularensis tularensis. Dog ticks, Dermacentor variabilis, appear to be critical in the perpetuation of the agent there. Tularemia has long been characterized as an agent of natural focality, stably persisting in characteristic sites of transmission, but this suggestion has never been rigorously tested. Accordingly, we sought to identify a natural focus of transmission of the agent of tularemia by mapping the distribution of PCR-positive ticks. From 2004 to 2007, questing D. variabilis were collected from 85 individual waypoints along a 1.5 km transect in a field site on Martha's Vineyard. The positions of PCR-positive ticks were then mapped using ArcGIS. Cluster analysis identified an area approximately 290 meters in diameter, 9 waypoints, that was significantly more likely to yield PCR-positive ticks (relative risk 3.3, P = 0.001 than the rest of the field site. Genotyping of F. tularensis using variable number tandem repeat (VNTR analysis on PCR-positive ticks yielded 13 different haplotypes, the vast majority of which was one dominant haplotype. Positive ticks collected in the cluster were 3.4 times (relative risk = 3.4, P<0.0001 more likely to have an uncommon haplotype than those collected elsewhere from the transect. We conclude that we have identified a microfocus where the agent of tularemia stably perpetuates and that this area is where genetic diversity is generated.
Disease risk maps are important tools that help ascertain the likelihood of exposure to specific infectious agents. Understanding how climate change may affect the suitability of habitats for ticks will improve the accuracy of risk maps of tick-borne pathogen transmission in humans and domestic anim...
Full Text Available Recent advances in climate research together with a better understanding of tick-pathogen interactions, the distribution of ticks and the diagnosis of tick-borne pathogens raise questions about the impact of environmental factors on tick abundance and spread and the prevalence and transmission of tick-borne pathogens. While undoubtedly climate plays a role in the changes in distribution and seasonal abundance of ticks, it is always difficult to disentangle factors impacting on the abundance of tick hosts from those exerted by human habits. All together, climate, host abundance and social factors may explain the upsurge of epidemics transmitted by ticks to humans. Herein we focused on tick-borne pathogens that affect humans with pandemic potential. Borrelia burgdorferi s.l. (Lyme disease, Anaplasma phagocytophilum (human granulocytic anaplasmosis and tick-borne encephalitis virus (tick-borne encephalitis are transmitted by Ixodes spp. Crimean-Congo hemorrhagic fever virus (Crimean-Congo hemorrhagic fever is transmitted by Hyalomma spp. In this review, we discussed how vector tick species occupy the habitat as a function of different climatic factors, and how these factors impact on tick survival and seasonality. How molecular events at the tick-pathogen interface impact on pathogen transmission is also discussed. Results from statistically and biologically derived models are compared to show that while statistical models are able to outline basic information about tick distributions, biologically derived models are necessary to evaluate pathogen transmission rates and understand the effect of climatic variables and host abundance patterns on pathogen transmission. The results of these studies could be used to build early alert systems able to identify the main factors driving the subtle changes in tick distribution and seasonality and the prevalence of tick-borne pathogens.
Full Text Available Diagnostic study of vector ticks for different pathogens transmitted specifically have been done by Iranian old scientists working on the basis of biological transmission of pathogens. In this study we decided to confirm natural infection of different collected ticks from three different provinces of Iran.Ticks were collected from livestock (sheep, goats and cattle during favorable seasons (April to September 2007 and 2008. Slide preparations were stained by Giemsa and Feulgen and were studied searching for any trace of infection. Positive DNA from infected blood or tissue samples was provided and was used as positive control. First, PCR optimization for positive DNA was done, and then tick samples were subjected to specific PCR.Eleven pairs of primers were designed for detection of Theileria, Babesia and Anaplasma spp. Totally 21 tick samples were detected to be infected with protozoa. Hyalomma anatolicum anatolicum and Rhipicephalus turanicus from Fars Province were infected with T. lestoquardi at two different places. Hyalomma detritum was infected with T. lestoquardi in Lorestan Province and Rh. turanicus was infected to Ba. ovis from Fars Province.Totally 21 tick samples were detected to be infected with protozoa. Every sample is regarded with host-environment related factors. Since there are complex relations of vectors and their relevant protozoa, different procedures are presented for future studies.
Tissot Dupont, H; Raoult, D
Due to their worldwide distribution, from hottest to coldest climates, and due to their behaviour, ticks are capable of transmitting numerous human and animal bacterial viral or parasitous diseases. Depending on the disease, they play the role of biological vector or intermediate host. In France, six tick borne diseases are of epidemiologic importance. Q fever (not often tick-borne), Mediterranean Spotted Fever, Lyme disease, Turalemia (human and animal), Babesiosis and Tick-borne Viral Encephalitis.
Study of the climatic change impact on vector-borne diseases in West Africa: the case of tick-borne borreliosis and malaria; Etude de l'impact du changement climatique sur les maladies a transmission vectorielle en Afrique de l'Ouest: le cas de la borreliose a tiques et du paludisme
Malaria and tick-borne borreliosis are the two first causes of morbidity due to vector-borne diseases in a large part of Sudan-sahelian West Africa. They are also the two tropical diseases which have been the most affected by climatic change in recent years. In the case of tick-borne borreliosis it has been shown in Senegal that the persistence of drought since the years 70 has been associated with a considerable extension of the geographic range of diseases and the vector tick A-sonrai, a species that was in the past limited to the Sahara and Sahel. In the case of malaria, drought has strongly reduced in these same regions of Africa the distribution, abundance and infection rate of Anopheline mosquitoes, but without any significant reduction of the burden of malaria for most populations concerned. The emergence and spread of Plasmodium falciparum resistance to antimalarial drugs only explain part of this phenomenon. (A.L.B.)
Silaghi, Cornelia; Woll, Dietlinde; Hamel, Dietmar; Pfister, Kurt; Mahling, Monia; Pfeffer, Martin
The aims of this study were to evaluate the host-tick-pathogen interface of Babesia spp. and Anaplasma phagocytophilum in restored areas in both questing and host-attached Ixodes ricinus and Dermacentor reticulatus and their small mammalian hosts. Questing ticks were collected from 5 sites within the city of Leipzig, Germany, in 2009. Small mammals were trapped at 3 of the 5 sites during 2010 and 2011. DNA extracts of questing and host-attached I. ricinus and D. reticulatus and of several tissue types of small mammals (the majority bank voles and yellow-necked mice), were investigated by PCR followed by sequencing for the occurrence of DNA of Babesia spp. and by real-time PCR for A. phagocytophilum. A selected number of samples positive for A. phagocytophilum were further investigated for variants of the partial 16S rRNA gene. Co-infection with Rickettsia spp. in the questing ticks was additionally investigated. 4.1% of questing I. ricinus ticks, but no D. reticulatus, were positive for Babesia sp. and 8.7% of I. ricinus for A. phagocytophilum. Sequencing revealed B. microti, B. capreoli and Babesia spp. EU1 in Leipzig and sequence analysis of the partial 16S RNA gene of A. phagocytophilum revealed variants either rarely reported in human cases or associated with cervid hosts. The statistical analysis revealed significantly less ticks infected with A. phagocytophilum in a city park in Leipzig as compared to the other sampling sites. A. phagocytophilum-DNA was detected in 2 bank voles, DNA of B. microti in 1 striped field-mouse and of Babesia sp. EU1 in the skin tissue of a mole. Co-infections were detected. Our results show the involvement of small mammals in the natural endemic cycles of tick-borne pathogens. A more thorough understanding of the interactions of ticks, pathogens and hosts is the essential basis for effective preventive control measures.
Full Text Available Abstract Background The aims of this study were to evaluate the host-tick-pathogen interface of Babesia spp. and Anaplasma phagocytophilum in restored areas in both questing and host-attached Ixodes ricinus and Dermacentor reticulatus and their small mammalian hosts. Methods Questing ticks were collected from 5 sites within the city of Leipzig, Germany, in 2009. Small mammals were trapped at 3 of the 5 sites during 2010 and 2011. DNA extracts of questing and host-attached I. ricinus and D. reticulatus and of several tissue types of small mammals (the majority bank voles and yellow-necked mice, were investigated by PCR followed by sequencing for the occurrence of DNA of Babesia spp. and by real-time PCR for A. phagocytophilum. A selected number of samples positive for A. phagocytophilum were further investigated for variants of the partial 16S rRNA gene. Co-infection with Rickettsia spp. in the questing ticks was additionally investigated. Results 4.1% of questing I. ricinus ticks, but no D. reticulatus, were positive for Babesia sp. and 8.7% of I. ricinus for A. phagocytophilum. Sequencing revealed B. microti, B. capreoli and Babesia spp. EU1 in Leipzig and sequence analysis of the partial 16S RNA gene of A. phagocytophilum revealed variants either rarely reported in human cases or associated with cervid hosts. The statistical analysis revealed significantly less ticks infected with A. phagocytophilum in a city park in Leipzig as compared to the other sampling sites. A. phagocytophilum-DNA was detected in 2 bank voles, DNA of B. microti in 1 striped field-mouse and of Babesia sp. EU1 in the skin tissue of a mole. Co-infections were detected. Conclusion Our results show the involvement of small mammals in the natural endemic cycles of tick-borne pathogens. A more thorough understanding of the interactions of ticks, pathogens and hosts is the essential basis for effective preventive control measures.
Background The aims of this study were to evaluate the host-tick-pathogen interface of Babesia spp. and Anaplasma phagocytophilum in restored areas in both questing and host-attached Ixodes ricinus and Dermacentor reticulatus and their small mammalian hosts. Methods Questing ticks were collected from 5 sites within the city of Leipzig, Germany, in 2009. Small mammals were trapped at 3 of the 5 sites during 2010 and 2011. DNA extracts of questing and host-attached I. ricinus and D. reticulatus and of several tissue types of small mammals (the majority bank voles and yellow-necked mice), were investigated by PCR followed by sequencing for the occurrence of DNA of Babesia spp. and by real-time PCR for A. phagocytophilum. A selected number of samples positive for A. phagocytophilum were further investigated for variants of the partial 16S rRNA gene. Co-infection with Rickettsia spp. in the questing ticks was additionally investigated. Results 4.1% of questing I. ricinus ticks, but no D. reticulatus, were positive for Babesia sp. and 8.7% of I. ricinus for A. phagocytophilum. Sequencing revealed B. microti, B. capreoli and Babesia spp. EU1 in Leipzig and sequence analysis of the partial 16S RNA gene of A. phagocytophilum revealed variants either rarely reported in human cases or associated with cervid hosts. The statistical analysis revealed significantly less ticks infected with A. phagocytophilum in a city park in Leipzig as compared to the other sampling sites. A. phagocytophilum-DNA was detected in 2 bank voles, DNA of B. microti in 1 striped field-mouse and of Babesia sp. EU1 in the skin tissue of a mole. Co-infections were detected. Conclusion Our results show the involvement of small mammals in the natural endemic cycles of tick-borne pathogens. A more thorough understanding of the interactions of ticks, pathogens and hosts is the essential basis for effective preventive control measures. PMID:22950642
Sarah I. Bonnet
Full Text Available Ticks are among the most important vectors of pathogens affecting humans and other animals worldwide. They do not only carry pathogens however, as a diverse group of commensal and symbiotic microorganisms are also present in ticks. Unlike pathogens, their biology and their effect on ticks remain largely unexplored, and are in fact often neglected. Nonetheless, they can confer multiple detrimental, neutral, or beneficial effects to their tick hosts, and can play various roles in fitness, nutritional adaptation, development, reproduction, defense against environmental stress, and immunity. Non-pathogenic microorganisms may also play a role in driving transmission of tick-borne pathogens (TBP, with many potential implications for both human and animal health. In addition, the genetic proximity of some pathogens to mutualistic symbionts hosted by ticks is evident when studying phylogenies of several bacterial genera. The best examples are found within members of the Rickettsia, Francisella, and Coxiella genera: while in medical and veterinary research these bacteria are traditionally recognized as highly virulent vertebrate pathogens, it is now clear to evolutionary ecologists that many (if not most Coxiella, Francisella, and Rickettsia bacteria are actually non-pathogenic microorganisms exhibiting alternative lifestyles as mutualistic ticks symbionts. Consequently, ticks represent a compelling yet challenging system in which to study microbiomes and microbial interactions, and to investigate the composition, functional, and ecological implications of bacterial communities. Ultimately, deciphering the relationships between tick microorganisms as well as tick symbiont interactions will garner invaluable information, which may aid in the future development of arthropod pest and vector-borne pathogen transmission control strategies.
Full Text Available The importance of tick-borne diseases is increasing all over the world, including Turkey. The tick-borne disease outbreaks reported in recent years and the abundance of tick species and the existence of suitable habitats increase the importance of studies related to the epidemiology of ticks and tick-borne pathogens in Turkey. The aim of this study was to investigate the presence of and to determine the infection rates of some tick-borne pathogens, including Babesia spp., Borrelia burgdorferi sensu lato and spotted fever group rickettsiae in the ticks removed from humans in different parts of Ankara.A total of 169 ticks belonging to the genus Haemaphysalis, Hyalomma, Ixodes and Rhipicephalus were collected by removing from humans in different parts of Ankara. Ticks were molecularly screened for Babesia spp., Borrelia burgdorferi sensu lato and spotted fever group rickettsiae by PCR and sequencing analysis. We detected 4 Babesia spp.; B. crassa, B. major, B. occultans and B. rossi, one Borrelia spp.; B. burgdorferi sensu stricto and 3 spotted fever group rickettsiae; R. aeschlimannii, R. slovaca and R. hoogstraalii in the tick specimens analyzed. This is the report showing the presence of B. rossi in a region that is out of Africa and in the host species Ha. parva. In addition, B. crassa, for which limited information is available on its distribution and vector species, and B. occultans, for which no conclusive information is available on its presence in Turkey, were identified in Ha. parva and H. marginatum, respectively. Two human pathogenic rickettsia species (R. aeschlimannii and R. slovaca were detected with a high prevalence in ticks. Additionally, B. burgdorferi sensu stricto was detected in unusual tick species (H. marginatum, H. excavatum, Hyalomma spp. (nymph and Ha. parva.This study investigates both the distribution of several tick-borne pathogens affecting humans and animals, and the presence of new tick-borne pathogens in Turkey
Jeffrey M. Grabowski
Full Text Available Tick-borne flaviviruses (TBFs affect human health globally. Human vaccines provide protection against some TBFs, and antivirals are available, yet TBF-specific control strategies are limited. Advances in genomics offer hope to understand the viral complement transmitted by ticks, and to develop disruptive, data-driven technologies for virus detection, treatment, and control. The genome assemblies of Ixodes scapularis, the North American tick vector of the TBF, Powassan virus, and other tick vectors, are providing insights into tick biology and pathogen transmission and serve as nucleation points for expanded genomic research. Systems biology has yielded insights to the response of tick cells to viral infection at the transcript and protein level, and new protein targets for vaccines to limit virus transmission. Reverse vaccinology approaches have moved candidate tick antigenic epitopes into vaccine development pipelines. Traditional drug and in silico screening have identified candidate antivirals, and target-based approaches have been developed to identify novel acaricides. Yet, additional genomic resources are required to expand TBF research. Priorities include genome assemblies for tick vectors, “omic” studies involving high consequence pathogens and vectors, and emphasizing viral metagenomics, tick-virus metabolomics, and structural genomics of TBF and tick proteins. Also required are resources for forward genetics, including the development of tick strains with quantifiable traits, genetic markers and linkage maps. Here we review the current state of genomic research on ticks and tick-borne viruses with an emphasis on TBFs. We outline an ambitious 10-year roadmap for research in the “omics era,” and explore key milestones needed to accomplish the goal of delivering three new vaccines, antivirals and acaricides for TBF control by 2030.
Papa, Anna; Xanthopoulou, Kyriaki; Kotriotsiou, Tzimoula; Papaioakim, Miltiadis; Sotiraki, Smaragda; Chaligiannis, Ilias; Maltezos, Efstratios
Ticks serve as vectors and reservoirs for a variety of bacterial, viral and protozoan pathogens affecting humans and animals. Unusual increased tick aggressiveness was observed in 2008-2009 in northeastern Greece. The aim of the study was to check ticks removed from persons during 2009 for infection with Rickettsia species. A total of 159 ticks were removed from 147 persons who sought medical advice in a hospital. Tick identification was performed morphologically using taxonomic keys. DNA was extracted from each individual tick and a PCR assay targeting the rickettsial outer membrane protein A gene of Rickettsia spp. was applied. Most of the adult ticks (132/153, 86.3%) were Rhipicephalus sanguineus. Rickettsiae were detected in 23 of the 153 (15.0%) adult ticks. Five Rickettsiae species were identified: R. aeschlimannii, R. africae (n=6), R. massilae (4), R. monacensis (1), and Candidatus R. barbariae (1). To our knowledge, this is the first report of R. africae, R. monacensis, and Candidatus R. barbariae in Greece. Several Rickettsia species were identified in ticks removed from humans in Greece, including those that are prevalent in northern and southern latitudes. © The Author 2016. Published by Oxford University Press on behalf of Royal Society of Tropical Medicine and Hygiene. All rights reserved. For permissions, please e-mail: email@example.com.
Illoldi-Rangel, Patricia; Rivaldi, Chissa-Louise; Sissel, Blake; Trout Fryxell, Rebecca; Gordillo-Pérez, Guadalupe; Rodríguez-Moreno, Angel; Williamson, Phillip; Montiel-Parra, Griselda; Sánchez-Cordero, Víctor; Sarkar, Sahotra
Species distribution models were constructed for ten Ixodes species and Amblyomma cajennense for a region including Mexico and Texas. The model was based on a maximum entropy algorithm that used environmental layers to predict the relative probability of presence for each taxon. For Mexico, species geographic ranges were predicted by restricting the models to cells which have a higher probability than the lowest probability of the cells in which a presence record was located. There was spatial nonconcordance between the distributions of Amblyomma cajennense and the Ixodes group with the former restricted to lowlands and mainly the eastern coast of Mexico and the latter to montane regions with lower temperature. The risk of Lyme disease is, therefore, mainly present in the highlands where some Ixodes species are known vectors; if Amblyomma cajennense turns out to be a competent vector, the area of risk also extends to the lowlands and the east coast.
Full Text Available Species distribution models were constructed for ten Ixodes species and Amblyomma cajennense for a region including Mexico and Texas. The model was based on a maximum entropy algorithm that used environmental layers to predict the relative probability of presence for each taxon. For Mexico, species geographic ranges were predicted by restricting the models to cells which have a higher probability than the lowest probability of the cells in which a presence record was located. There was spatial nonconcordance between the distributions of Amblyomma cajennense and the Ixodes group with the former restricted to lowlands and mainly the eastern coast of Mexico and the latter to montane regions with lower temperature. The risk of Lyme disease is, therefore, mainly present in the highlands where some Ixodes species are known vectors; if Amblyomma cajennense turns out to be a competent vector, the area of risk also extends to the lowlands and the east coast.
Genchi, Marco; Prati, Paola; Vicari, Nadia; Manfredini, Andrea; Sacchi, Luciano; Clementi, Emanuela; Bandi, Claudio; Epis, Sara; Fabbi, Massimo
Background Tularemia is a zoonosis caused by the Francisella tularensis, a highly infectious Gram-negative coccobacillus. Due to easy dissemination, multiple routes of infection, high environmental contamination and morbidity and mortality rates, Francisella is considered a potential bioterrorism threat and classified as a category A select agent by the CDC. Tick bites are among the most prevalent modes of transmission, and ticks have been indicated as a possible reservoir, although their reservoir competence has yet to be defined. Tick-borne transmission of F. tularensis was recognized in 1923, and transstadial transmission has been demonstrated in several tick species. Studies on transovarial transmission, however, have reported conflicting results. Objective The aim of this study was to evaluate the role of ticks as reservoirs for Francisella, assessing the transovarial transmission of F. tularensis subsp. holarctica in ticks, using experimentally-infected females of Dermacentor reticulatus and Ixodes ricinus. Results Transmission electron microscopy and fluorescence in situ hybridization showed F. tularensis within oocytes. However, cultures and bioassays of eggs and larvae were negative; in addition, microscopy techniques revealed bacterial degeneration/death in the oocytes. Conclusions These results suggest that bacterial death might occur in oocytes, preventing the transovarial transmission of Francisella. We can speculate that Francisella does not have a defined reservoir, but that rather various biological niches (e.g. ticks, rodents), that allow the bacterium to persist in the environment. Our results, suggesting that ticks are not competent for the bacterium vertical transmission, are congruent with this view. PMID:26244842
Full Text Available Tularemia is a zoonosis caused by the Francisella tularensis, a highly infectious Gram-negative coccobacillus. Due to easy dissemination, multiple routes of infection, high environmental contamination and morbidity and mortality rates, Francisella is considered a potential bioterrorism threat and classified as a category A select agent by the CDC. Tick bites are among the most prevalent modes of transmission, and ticks have been indicated as a possible reservoir, although their reservoir competence has yet to be defined. Tick-borne transmission of F. tularensis was recognized in 1923, and transstadial transmission has been demonstrated in several tick species. Studies on transovarial transmission, however, have reported conflicting results.The aim of this study was to evaluate the role of ticks as reservoirs for Francisella, assessing the transovarial transmission of F. tularensis subsp. holarctica in ticks, using experimentally-infected females of Dermacentor reticulatus and Ixodes ricinus.Transmission electron microscopy and fluorescence in situ hybridization showed F. tularensis within oocytes. However, cultures and bioassays of eggs and larvae were negative; in addition, microscopy techniques revealed bacterial degeneration/death in the oocytes.These results suggest that bacterial death might occur in oocytes, preventing the transovarial transmission of Francisella. We can speculate that Francisella does not have a defined reservoir, but that rather various biological niches (e.g. ticks, rodents, that allow the bacterium to persist in the environment. Our results, suggesting that ticks are not competent for the bacterium vertical transmission, are congruent with this view.
Estrada-Peña, Agustín; de la Fuente, José; Latapia, Tamara; Ortega, Carmelo
The impact of climate trends during the period 1901-2009 on the life cycle of Hyalomma marginatum in Europe was modeled to assess changes in the physiological processes of this threat to public health. Monthly records of temperature and water vapour at a resolution of 0.5° and equations describing the life cycle processes of the tick were used. The climate in the target region affected the rates of the life cycle processes of H. marginatum: development rates increased, mortality rates in molting stages decreased, and the survival rates of questing ticks decreased in wide territories of the Mediterranean basin. The modeling framework indicated the existence of critical areas in the Balkans, central Europe, and the western coast of France, where the physiological processes of the tick improved to extents that are consistent with the persistence of populations if introduced. A spatially explicit risk assessment was performed to detect candidate areas where active surveys should be performed to monitor changes in tick density or persistence after a hypothetical introduction. We detected areas where the critical abiotic (climate) and biotic (host density) factors overlap, including most of the Iberian peninsula, the Mediterranean coast of France, eastern Turkey, and portions of the western Black Sea region. Wild ungulate densities are unavailable for large regions of the territory, a factor that might affect the outcome of the study. The risk of successfully establishing H. marginatum populations at northern latitudes of its current colonization range seems to be still low, even if the climate has improved the performance of the tick in these areas.
Full Text Available The impact of climate trends during the period 1901-2009 on the life cycle of Hyalomma marginatum in Europe was modeled to assess changes in the physiological processes of this threat to public health. Monthly records of temperature and water vapour at a resolution of 0.5° and equations describing the life cycle processes of the tick were used. The climate in the target region affected the rates of the life cycle processes of H. marginatum: development rates increased, mortality rates in molting stages decreased, and the survival rates of questing ticks decreased in wide territories of the Mediterranean basin. The modeling framework indicated the existence of critical areas in the Balkans, central Europe, and the western coast of France, where the physiological processes of the tick improved to extents that are consistent with the persistence of populations if introduced. A spatially explicit risk assessment was performed to detect candidate areas where active surveys should be performed to monitor changes in tick density or persistence after a hypothetical introduction. We detected areas where the critical abiotic (climate and biotic (host density factors overlap, including most of the Iberian peninsula, the Mediterranean coast of France, eastern Turkey, and portions of the western Black Sea region. Wild ungulate densities are unavailable for large regions of the territory, a factor that might affect the outcome of the study. The risk of successfully establishing H. marginatum populations at northern latitudes of its current colonization range seems to be still low, even if the climate has improved the performance of the tick in these areas.
Economic losses due to ticks and tick-borne disease of livestock fall disproportionately on developing countries. Currently, tick control relies mostly on pesticides and parasite-resistant cattle. Release of a commercial recombinant vaccine against Boophilus microplus in Australia in 1994 showed that anti-tick vaccines are a feasible alternative. For vaccines, it is important to understand the efficacy needed for a beneficial outcome. In this, it is relevant that some tick antigens affect multiple tick species; that existing vaccines could be improved by the inclusion of additional tick antigens; and that vaccination against ticks can have an impact on tick-borne disease. Practically, although recombinant vaccine manufacture involves relatively few steps, issues of intellectual property rights (IPR) and requirements for registration of a product may affect economic viability of manufacture. Hence practical vaccines for the developing world will require both successful science and a creative 'business solution' for delivery in a cost-effective way. (author)
Atkinson, Samuel F; Sarkar, Sahotra; Aviña, Aldo; Schuermann, Jim A; Williamson, Phillip
The spatial distribution of Dermacentor variabilis, the most commonly identified vector of the bacterium Rickettsia rickettsii which causes Rocky Mountain spotted fever (RMSF) in humans, and the spatial distribution of RMSF, have not been previously studied in the south central United States of America, particularly in Texas. From an epidemiological perspective, one would tend to hypothesise that there would be a high degree of spatial concordance between the habitat suitability for the tick and the incidence of the disease. Both maximum-entropy modelling of the tick's habitat suitability and spatially adaptive filters modelling of the human incidence of RMSF disease provide reliable portrayals of the spatial distributions of these phenomenons. Even though rates of human cases of RMSF in Texas and rates of Dermacentor ticks infected with Rickettsia bacteria are both relatively low in Texas, the best data currently available allows a preliminary indication that the assumption of high levels of spatial concordance would not be correct in Texas (Kappa coefficient of agreement = 0.17). It will take substantially more data to provide conclusive findings, and to understand the results reported here, but this study provides an approach to begin understanding the discrepancy.
... Control How to Remove a Tick Deer Tick Ecology Tick-Borne Diseases Anaplasmosis Babesiosis Borrelia miyamotoi infections ... repellents containing the active ingredient DEET can be applied to the skin (be sure to strictly follow ...
Wang, Hsiao-Hsuan; Grant, W E; Teel, P D; Hamer, S A
Tick vector systems are comprised of complex climate-tick-host-landscape interactions that are difficult to identify and estimate from empirical observations alone. We developed a spatially-explicit, individual-based model, parameterized to represent ecological conditions typical of the south-central United States, to examine effects of shifts in the seasonal occurrence of fluctuations of host densities on tick densities. Simulated shifts in the seasonal occurrence of periods of high and low host densities affected both the magnitude of unfed tick densities and the seasonality of tick development. When shifting the seasonal densities of all size classes of hosts (small, medium, and large) synchronously, densities of nymphs were affected more by smaller shifts away from the baseline host seasonality than were densities of larval and adult life stages. When shifting the seasonal densities of only a single size-class of hosts while holding other size classes at their baseline levels, densities of larval, nymph, and adult life stages responded differently. Shifting seasonal densities of any single host-class earlier resulted in a greater increase in adult tick density than when seasonal densities of all host classes were shifted earlier simultaneously. The mean densities of tick life stages associated with shifts in host densities resulted from system-level interactions of host availability with tick phenology. For example, shifting the seasonality of all hosts ten weeks earlier resulted in an approximately 30% increase in the relative degree of temporal co-occurrence of actively host-seeking ticks and hosts compared to baseline, whereas shifting the seasonality of all hosts ten weeks later resulted in an approximately 70% decrease compared to baseline. Differences among scenarios in the overall presence of active host-seeking ticks in the system were due primarily to the degree of co-occurrence of periods of high densities of unfed ticks and periods of high densities
Full Text Available Nowadays, parasitology is facing a number of crucial challenges, including the urgent request of effective control tools against arthropod vectors of medical and veterinary importance. Ticks transmit at least the same amount or even more pathogen species than any other group of blood-feeding arthropods worldwide affecting humans and animals. Besides the development of vaccines against viruses vectored by ticks, integrated pest management practices aimed at reducing tick interactions with livestock, emerging pheromone-based control tools, and few biological control agents have been also proposed. The extensive employ of acaricides and tick repellents still remains the two most effective and ready-to-use strategies. However, the use of synthetic acaricides is limited by the development of resistance in several tick species as well as by heavy environmental concerns. In this scenario, the exploitation of botanicals as cheap and effective sources of tick repellents may represent a valid alternative, and the preservation of ethnobotanical information on the repellent and acaricidal potential of plants is crucial. On the other hand, novel photodynamic acaricides have been recently described, with a toxicity against ticks which far exceed some of the acaricides currently marketed (e.g. tetramethrin. In this brief review, I provide a focus on some hot news in tick control, with special reference to tick repellents of botanical origin and new photodynamic fluorescent acaricides. To my mind, knowledge on both the mentioned research issues may help researchers to build valuable roadmaps to boost tick control programs worldwide.
England, Marion E; Phipps, Paul; Medlock, Jolyon M; Atkinson, Peter M; Atkinson, Barry; Hewson, Roger; Gale, Paul
Crimean-Congo haemorrhagic fever virus (CCHFV) is a zoonotic virus transmitted by Hyalomma ticks, the immature stages of which may be carried by migratory birds. In this study, a total of 12 Hyalomma ticks were recovered from five of 228 migratory birds trapped in Spring, 2012 in southern Spain along the East Atlantic flyway. All collected ticks tested negative for CCHFV. While most birds had zero Hyalomma ticks, two individuals had four and five ticks each and the statistical distribution of Hyalomma tick counts per bird is over-dispersed compared to the Poisson distribution, demonstrating the need for intensive sampling studies to avoid underestimating the total number of ticks. Rates of tick exchange on migratory birds during their northwards migration will affect the probability that a Hyalomma tick entering Great Britain is positive for CCHFV. Drawing on published data, evidence is presented that the latitude of a European country affects the probability of entry of Hyalomma ticks on wild birds. Further data on Hyalomma infestation rates and tick exchange rates are required along the East Atlantic flyway to further our understanding of the origin of Hyalomma ticks (i.e., Africa or southern Europe) and hence the probability of entry of CCHFV into GB. © 2016 The Society for Vector Ecology.
Vector-borne diseases are infections transmitted by the bite of infected arthropod vectors, such as mosquitoes, ticks, fleas, midges and flies. Vector-borne diseases pose an increasingly wider threat to global public health, both in terms of people affected and their geographical spread. Mosquitoes
Stephanie L. Richards
Full Text Available Improvements to risk assessments are needed to enhance our understanding of tick-borne disease epidemiology. We review tick vectors and duration of tick attachment required for pathogen transmission for the following pathogens/toxins and diseases: (1 Anaplasma phagocytophilum (anaplasmosis; (2 Babesia microti (babesiosis; (3 Borrelia burgdorferi (Lyme disease; (4 Southern tick-associated rash illness; (5 Borrelia hermsii (tick-borne relapsing fever; (6 Borrelia parkeri (tick-borne relapsing fever; (7 Borrelia turicatae (tick-borne relapsing fever; (8 Borrelia mayonii; (9 Borrelia miyamotoi; (10 Coxiella burnetii (Query fever; (11 Ehrlichia chaffeensis (ehrlichiosis; (12 Ehrlichia ewingii (ehrlichiosis; (13 Ehrlichia muris; (14 Francisella tularensis (tularemia; (15 Rickettsia 364D; (16 Rickettsia montanensis; (17 Rickettsia parkeri (American boutonneuse fever, American tick bite fever; (18 Rickettsia ricketsii (Rocky Mountain spotted fever; (19 Colorado tick fever virus (Colorado tick fever; (20 Heartland virus; (21 Powassan virus (Powassan disease; (22 tick paralysis neurotoxin; and (23 Galactose-α-1,3-galactose (Mammalian Meat Allergy-alpha-gal syndrome. Published studies for 12 of the 23 pathogens/diseases showed tick attachment times. Reported tick attachment times varied (<1 h to seven days between pathogen/toxin type and tick vector. Not all studies were designed to detect the duration of attachment required for transmission. Knowledge of this important aspect of vector competence is lacking and impairs risk assessment for some tick-borne pathogens.
Because dogs are such loved companion animals, their health and wellbeing is of great importance to their human companions. Moreover, controlling ticks and fleas on dogs is also important in respect of the zoonotic risk that some of these parasites pose to their human companions. Numerous products
Duijvendijk, van Gilian; Andel, van Wouter; Fonville, Manoj; Gort, Gerrit; Hovius, Joppe W.; Sprong, Hein; Takken, Willem
Several microorganisms have been shown to manipulate their host or vector to enhance their own transmission. Here we examined whether an infection with Borrelia afzelii affects its transmission between its bank vole (Myodes glareolus, Schreber, 1780) host and tick vector. Captive-bred bank voles
Full Text Available The abundance and activity of ectoparasites and its hosts are affected by various abiotic factors, such as climate and other organisms (predators, pathogens and competitors presenting thus multiples forms of association (obligate to facultative, permanent to intermittent and superficial to subcutaneous developed during long co-evolving processes. Ticks are ectoparasites widespread globally and its eco epidemiology are closely related to the environmental conditions. They are obligatory hematophagous ectoparasites and responsible as vectors or reservoirs at the transmission of pathogenic fungi, protozoa, viruses, rickettsia and others bacteria during their feeding process on the hosts. Ticks constitute the second vector group that transmit the major number of pathogens to humans and play a role primary for animals in the process of diseases transmission. Many studies on bioecology of ticks, considering the information related to their population dynamics, to the host and the environment, comes possible the application and efficiency of tick control measures in the prevention programs of vector-borne diseases. In this review were considered some taxonomic, morphological, epidemiological and clinical fundamental aspects related to the tick-borne infections that affect human and animal populations.
Khasnatinov, Maxim A; Tuplin, Andrew; Gritsun, Dmitri J; Slovak, Mirko; Kazimirova, Maria; Lickova, Martina; Havlikova, Sabina; Klempa, Boris; Labuda, Milan; Gould, Ernest A; Gritsun, Tamara S
Over 50 million humans live in areas of potential exposure to tick-borne encephalitis virus (TBEV). The disease exhibits an estimated 16,000 cases recorded annually over 30 European and Asian countries. Conventionally, TBEV transmission to Ixodes spp. ticks occurs whilst feeding on viraemic animals. However, an alternative mechanism of non-viraemic transmission (NVT) between infected and uninfected ticks co-feeding on the same transmission-competent host, has also been demonstrated. Here, using laboratory-bred I. ricinus ticks, we demonstrate low and high efficiency NVT for TBEV strains Vasilchenko (Vs) and Hypr, respectively. These virus strains share high sequence similarity but are classified as two TBEV subtypes. The Vs strain is a Siberian subtype, naturally associated with I. persulcatus ticks whilst the Hypr strain is a European subtype, transmitted by I. ricinus ticks. In mammalian cell culture (porcine kidney cell line PS), Vs and Hypr induce low and high cytopathic effects (cpe), respectively. Using reverse genetics, we engineered a range of viable Vs/Hypr chimaeric strains, with substituted genes. No significant differences in replication rate were detected between wild-type and chimaeric viruses in cell culture. However, the chimaeric strain Vs[Hypr str] (Hypr structural and Vs non-structural genomic regions) demonstrated high efficiency NVT in I. ricinus whereas the counterpart Hypr[Vs str] was not transmitted by NVT, indicating that the virion structural proteins largely determine TBEV NVT transmission efficiency between ticks. In contrast, in cell culture, the extent of cpe was largely determined by the non-structural region of the TBEV genome. Chimaeras with Hypr non-structural genes were more cytotoxic for PS cells when compared with Vs genome-based chimaeras.
Maxim A Khasnatinov
Full Text Available Over 50 million humans live in areas of potential exposure to tick-borne encephalitis virus (TBEV. The disease exhibits an estimated 16,000 cases recorded annually over 30 European and Asian countries. Conventionally, TBEV transmission to Ixodes spp. ticks occurs whilst feeding on viraemic animals. However, an alternative mechanism of non-viraemic transmission (NVT between infected and uninfected ticks co-feeding on the same transmission-competent host, has also been demonstrated. Here, using laboratory-bred I. ricinus ticks, we demonstrate low and high efficiency NVT for TBEV strains Vasilchenko (Vs and Hypr, respectively. These virus strains share high sequence similarity but are classified as two TBEV subtypes. The Vs strain is a Siberian subtype, naturally associated with I. persulcatus ticks whilst the Hypr strain is a European subtype, transmitted by I. ricinus ticks. In mammalian cell culture (porcine kidney cell line PS, Vs and Hypr induce low and high cytopathic effects (cpe, respectively. Using reverse genetics, we engineered a range of viable Vs/Hypr chimaeric strains, with substituted genes. No significant differences in replication rate were detected between wild-type and chimaeric viruses in cell culture. However, the chimaeric strain Vs[Hypr str] (Hypr structural and Vs non-structural genomic regions demonstrated high efficiency NVT in I. ricinus whereas the counterpart Hypr[Vs str] was not transmitted by NVT, indicating that the virion structural proteins largely determine TBEV NVT transmission efficiency between ticks. In contrast, in cell culture, the extent of cpe was largely determined by the non-structural region of the TBEV genome. Chimaeras with Hypr non-structural genes were more cytotoxic for PS cells when compared with Vs genome-based chimaeras.
Samuel F. Atkinson
Full Text Available The spatial distribution of Dermacentor variabilis, the most commonly identified vector of the bacterium Rickettsia rickettsii which causes Rocky Mountain spotted fever (RMSF in humans, and the spatial distribution of RMSF, have not been previously studied in the south central United States of America, particularly in Texas. From an epidemiological perspective, one would tend to hypothesise that there would be a high degree of spatial concordance between the habitat suitability for the tick and the incidence of the disease. Both maximum-entropy modelling of the tick’s habitat suitability and spatially adaptive filters modelling of the human incidence of RMSF disease provide reliable portrayals of the spatial distributions of these phenomenons. Even though rates of human cases of RMSF in Texas and rates of Dermacentor ticks infected with Rickettsia bacteria are both relatively low in Texas, the best data currently available allows a preliminary indication that the assumption of high levels of spatial concordance would not be correct in Texas (Kappa coefficient of agreement = 0.17. It will take substantially more data to provide conclusive findings, and to understand the results reported here, but this study provides an approach to begin understanding the discrepancy.
Hönig, Václav; Carolan, H. E.; Vavrušková, Zuzana; Massire, C.; Mosel, M.l R.; Crowder, C. D.; Rounds, M. A.; Ecker, D. J.; Růžek, Daniel; Grubhoffer, Libor; Luft, B. J.; Eshoo, M. W.
Roč. 93, č. 11 (2017), č. článku fix129. ISSN 0168-6496 EU Projects: European Commission(XE) 278976 - ANTIGONE Institutional support: RVO:60077344 Keywords : burgdorferi sensu-lato * tick * Ixodes ricinus * pcr-esi/ms * Borrelia * host * Lyme borreliosis * Babesia * Anaplasma * Rickettsia Subject RIV: EE - Microbiology, Virology OBOR OECD: Microbiology Impact factor: 3.720, year: 2016
Hofmeester, Tim R.
Diseases that are transmitted by arthropod vectors from animal hosts to humans – so called zoonotic vector-borne diseases – have increased in incidence in the last decades. In North America and Europe, tick-borne pathogens cause the majority of vector-borne diseases, including Lyme borreliosis and tick-borne encephalitis. The pathogens causing these diseases are transmitted by tick species within the Ixodes ricinus complex. These are generalist ticks that have a multi-year lifecycle with thre...
Full Text Available Ticks are vectors of pathogens affecting human and animal health worldwide. Nevertheless, the ecological and evolutionary interactions between ticks, hosts, and pathogens are largely unknown. Here, we integrated a framework to evaluate the associations of the tick Ixodes ricinus with its hosts and environmental niches that impact pathogen circulation. The analysis of tick-hosts association suggested that mammals and lizards were the ancestral hosts of this tick species, and that a leap to Aves occurred around 120 M years ago. The signature of the environmental variables over the host's phylogeny revealed the existence of two clades of vertebrates diverging along a temperature and vegetation split. This is a robust proof that the tick probably experienced a colonization of new niches by adapting to a large set of new hosts, Aves. Interestingly, the colonization of Aves as hosts did not increase significantly the ecological niche of I. ricinus, but remarkably Aves are super-spreaders of pathogens. The disparate contribution of Aves to the tick-host-pathogen networks revealed that I. ricinus evolved to maximize habitat overlap with some hosts that are super-spreaders of pathogens. These results supported the hypothesis that large host networks are not a requirement of tick survival but pathogen circulation. The biological cost of tick adaptation to non-optimal environmental conditions might be balanced by molecular mechanisms triggered by the pathogens that we have only begun to understand.
Khoo, Jing-Jing; Chen, Fezshin; Kho, Kai Ling; Ahmad Shanizza, Azzy Iyzati; Lim, Fang-Shiang; Tan, Kim-Kee; Chang, Li-Yen; AbuBakar, Sazaly
Ticks are vectors in the transmission of many important infectious diseases in human and animals. Ticks can be readily found in the semi-forested areas such as the settlements of the indigenous people in Malaysia, the Orang Asli. There is still minimal information available on the bacterial agents associated with ticks found in Malaysia. We performed a survey of the bacterial communities associated with ticks collected from domestic animals found in two Orang Asli villages in Malaysia. We collected 62 ticks, microscopically and molecularly identified as related to Haemaphysalis wellingtoni, Haemaphysalis hystricis and Haemaphysalis bispinosa. Bacterial 16s rRNA hypervariable region (V6) amplicon libraries prepared from the tick samples were sequenced on the Ion Torrent PGM platform. We detected a total of 392 possible bacterial genera after pooling and sequencing 20 samples, indicating a diverse bacterial community profile. Dominant taxa include the potential tick endosymbiont, Coxiella. Other dominant taxa include the tick-associated pathogen, Rickettsia, and environmental bacteria such as Bacillus, Mycobacterium, Sphingomonas and Pseudomonas. Other known tick-associated bacteria were also detected, including Anaplasma, Ehrlichia, Rickettsiella and Wolbachia, albeit at very low abundance. Specific PCR was performed on selected samples to identify Rickettsia and Coxiella. Sequence of Rickettsia felis, which causes spotted fever in human and cats, was identified in one sample. Coxiella endosymbionts were detected in three samples. This study provides the baseline knowledge of the microbiome of ticks in Malaysia, focusing on tick-associated bacteria affecting the Orang Asli communities. The role of the herein found Coxiella and Rickettsia in tick physiology or disease transmission merits further investigation. Copyright © 2016 The Authors. Published by Elsevier GmbH.. All rights reserved.
Carvalho Ferreira, de H.C.; Zúquete, S.T.; Wijnveld, M.; Weesendorp, E.; Jongejan, F.; Stegeman, J.A.; Loeffen, W.L.A.
African swine fever (ASF) is caused by African swine fever virus (ASFV), a tick-borne DNA virus. Soft ticks of the genus Ornithodoros are the only biological vectors of ASFV recognized so far. Although other hard ticks have been tested for vector competence, two commonly found tick species in
de Carvalho Ferreira, Helena C; Tudela Zúquete, Sara; Wijnveld, Michiel; Weesendorp, Eefke; Jongejan, Frans; Stegeman, Arjan; Loeffen, Willie L A
African swine fever (ASF) is caused by African swine fever virus (ASFV), a tick-borne DNA virus. Soft ticks of the genus Ornithodoros are the only biological vectors of ASFV recognized so far. Although other hard ticks have been tested for vector competence, two commonly found tick species in
Full Text Available Abstract The brown dog tick (Rhipicephalus sanguineus is the most widespread tick in the world and a well-recognized vector of many pathogens affecting dogs and occasionally humans. This tick can be found on dogs living in both urban and rural areas, being highly adapted to live within human dwellings and being active throughout the year not only in tropical and subtropical regions, but also in some temperate areas. Depending on factors such as climate and host availability, Rh. sanguineus can complete up to four generations per year. Recent studies have demonstrated that ticks exposed to high temperatures attach and feed on humans and rabbits more rapidly. This observation suggests that the risk of human parasitism by Rh. sanguineus could increase in areas experiencing warmer and/or longer summers, consequently increasing the risk of transmission of zoonotic agents (e.g., Rickettsia conorii and Rickettsia rickettsii. In the present article, some aspects of the biology and ecology of Rh. sanguineus ticks are discussed including the possible impact of current climate changes on populations of this tick around the world.
Full Text Available Ticks are reservoir and transmission vectors of many bacteria, viruses and parasites, which are pathogenic for humans. Early and correct tick removal is crucial as prevention of tick-borne diseases. The aim of the study is an attempt at rationalization of tick-borne disease prevention using a multifunctional container for Tick Twister®. In practice, it should enable people to use Tick Twister® in all circumstances contributing to the improvement of efficiency in tick-borne diseases prevention, and as a result, to a decrease in their frequency and after effects.
Gazyağci, Aycan Nuriye; Aydenızöz, Meral
Ticks which are commonly found all around the world are ectoparasites which are obliged to suck blood from vertebrates such as mammals and birds during all of their periods of develeopment. They may cause toxicities and paralyses in the course of blood sucking through saliva injection and the attachment sites may become ports of entry for secondary agents. Healthy animals that are severely infested by ticks can show a decreased yield and anemia. Young and sick animals can even die. Besides this, ticks are both biological and mechanical vectors for viruses, bacteria, rickettsias, spirochaetas, protozoons and helminths. Ten percent of the ticks identified in the world are associated with 200 diseases. In this review the taxonomy and morphology of ticks, some of the important diseases they carry and the diagnosis and treatment of these diseases are mentioned.
Ticks are important hematophagous arthropod ectoparasites and like mosquitoes, are vectors for a wide variety of human and animal pathogens. Ticks have significant world-wide health and economic impacts. In the U.S., major impacts include the ability of the blacklegged tick, Ixodes scapularis, to tr...
Full Text Available Crimean-Congo hemorrhagic fever virus (CCHFV is transmitted to humans by bite of infected ticks or by direct contact with blood or tissues of viremic patients or animals. It causes to humans a severe disease with fatality up to 30%. The current knowledge about the vector-host-CCHFV interactions is very limited due to the high-level containment required for CCHFV studies. Among ticks, Hyalomma spp. are considered the most competent virus vectors. CCHFV evades the tick immune response, and following its replication in the lining of the tick's midgut, it is disseminated by the hemolymph in the salivary glands and reproductive organs. The introduction of salivary gland secretions into the host cells is the major route via which CCHFV enters the host. Following an initial amplification at the site of inoculation, the virus is spread to the target organs. Apoptosis is induced via both intrinsic and extrinsic pathways. Genetic factors and immune status of the host may affect the release of cytokines which play a major role in disease progression and outcome. It is expected that the use of new technology of metabolomics, transcriptomics and proteomics will lead to improved understanding of CCHFV-host interactions and identify potential targets for blocking the CCHFV transmission.
Full Text Available Testudo graeca tortoises were collected in the northern and southern Golan Heights (Israeli occupied territory of south Syria, and various locations in Israel and Palestine. Hyalomma aegyptium ticks were found only on Golan Height tortoises, and only the tortoises and ticks from the northern Golan Heights were infected with Hemolivia mauritanica. Tortoises became infected after ingesting infected ticks. Male ticks carrying sporocysts, which remain attached to tortoises for extended durations, apparently served as the source for dissemination of new infections among tortoises. Sporogenesis followed the pattern observed in the two other known species of Hemolivia, though there was some evident variation in fine-structural detail. The sutural slit detected in the H. mauritanica mature sporocyst wall was reminiscent of the suture characteristic of Coccidia of heterothermic vertebrate hosts; it could be a common ancestral character for both hemogregarines and Coccidia.
... described in humans following bites of the lone star tick, Amblyomma americanum . The rash may be accompanied ... of Vector-Borne Diseases (DVBD) Email Recommend Tweet YouTube Instagram Listen Watch RSS ABOUT About CDC Jobs ...
Boeriis, Morten; van Leeuwen, Theo
should be taken into account in discussing ‘reactions’, which Kress and van Leeuwen link only to eyeline vectors. Finally, the question can be raised as to whether actions are always realized by vectors. Drawing on a re-reading of Rudolf Arnheim’s account of vectors, these issues are outlined......This article revisits the concept of vectors, which, in Kress and van Leeuwen’s Reading Images (2006), plays a crucial role in distinguishing between ‘narrative’, action-oriented processes and ‘conceptual’, state-oriented processes. The use of this concept in image analysis has usually focused...
Full Text Available Ticks are hematophagous arachnids transmitting a wide variety of pathogens including viruses, bacteria, and protozoans to their vertebrate hosts. The tick vector competence has to be intimately linked to the ability of transmitted pathogens to evade tick defense mechanisms encountered on their route through the tick body comprising midgut, hemolymph, salivary glands or ovaries. Tick innate immunity is, like in other invertebrates, based on an orchestrated action of humoral and cellular immune responses. The direct antimicrobial defense in ticks is accomplished by a variety of small molecules such as defensins, lysozymes or by tick-specific antimicrobial compounds such as microplusin/hebraein or 5.3-kDa family proteins. Phagocytosis of the invading microbes by tick hemocytes seems to be mediated by the primordial complement-like system composed of thioester-containing proteins, fibrinogen-related lectins and convertase-like factors. Moreover, an important role in survival of the ingested microbes seems to be played by host proteins and redox balance maintenance in the tick midgut. Here, we summarize recent knowledge about the major components of tick immune system and focus on their interaction with the relevant tick-transmitted pathogens, represented by spirochetes (Borrelia, rickettsiae (Anaplasma, and protozoans (Babesia. Availability of the tick genomic database and feasibility of functional genomics based on RNA interference greatly contribute to the understanding of molecular and cellular interplay at the tick-pathogen interface and may provide new targets for blocking the transmission of tick pathogens.
Wieren, van S.E.; Braks, Marieta A.H.; Lahr, J.
Ticks are important vectors of a large number of pathogenic organisms. In the Netherlands, Ixodes ricinus is the most abundant tick species and the main vector for several Borrelia species that may cause Lyme borreliosis. Many chemicals have been developed for tick control. In this chapter, a few
Full Text Available Abstract Background A variety of human diseases transmitted by arthropod vectors, including ticks, are emerging around the globe. Birds are known to be hosts of ticks and can disperse exotic ticks and tick-borne pathogens. In Taiwan, previous studies have focused predominantly on mammals, leaving the role of birds in the maintenance of ticks and dissemination of tick-borne pathogens undetermined. Methods Ticks were collected opportunistically when birds were studied from 1995 to 2013. Furthermore, to improve knowledge on the prevalence and mean load of tick infestation on birds in Taiwan, ticks were thoroughly searched for when birds were mist-netted at seven sites between September 2014 and April 2016 in eastern Taiwan. Ticks were identified based on both morphological and molecular information and were screened for potential tick-borne pathogens, including the genera Anaplasma, Babesia, Borrelia, Ehrlichia and Rickettsia. Finally, a list of hard tick species collected from birds in Taiwan was compiled based on past work and the current study. Results Nineteen ticks (all larvae were recovered from four of the 3096 unique mist-netted bird individuals, yielding a mean load of 0.006 ticks/individual and an overall prevalence of 0.13%. A total of 139 ticks from birds, comprising 48 larvae, 35 nymphs, 55 adults and one individual of unknown life stage, were collected from 1995 to 2016, and 11 species of four genera were identified, including three newly recorded species (Haemaphysalis wellingtoni, Ixodes columnae and Ixodes turdus. A total of eight tick-borne pathogens were detected, with five species (Borrelia turdi, Anaplasma sp. clone BJ01, Ehrlichia sp. BL157-9, Rickettsia helvetica and Rickettsia monacensis not previously isolated in Taiwan. Overall, 16 tick species of five genera have been recorded feeding on birds, including nine species first discovered in this study. Conclusion Our study demonstrates the paucity of information on ticks of
Dumpis, U; Crook, D; Oksi, J
Tick-borne encephalitis (TBE) is a zoonotic arbovirus infection endemic to Russia and Eastern and Central Europe. Despite being a common and serious life-threatening disease for which a mass vaccination program was implemented in Austria, there is only limited reference to this disease in the English-language literature. TBE is transmitted to humans usually by the bite of a tick (either Ixodes persulcatus or Ixodes ricinus); occasionally, cases occur following consumption of infected unpasteurized milk. Transmission is seasonal and occurs in spring and summer, particularly in rural areas favored by the vector. TBE is a serious cause of acute central nervous system disease, which may result in death or long-term neurological sequelae. Effective vaccines are available in a few countries. The risk for travelers of acquiring TBE is increasing with the recent rise in tourism to areas of endemicity during spring and summer.
Miller, Matthew J; Esser, Helen J; Loaiza, Jose R; Herre, Edward Allen; Aguilar, Celestino; Quintero, Diomedes; Alvarez, Eric; Bermingham, Eldredge
In the tropics, ticks parasitize many classes of vertebrate hosts. However, because many tropical tick species are only identifiable in the adult stage, and these adults usually parasitize mammals, most attention on the ecology of tick-host interactions has focused on mammalian hosts. In contrast, immature Neotropical ticks are often found on wild birds, yet difficulties in identifying immatures hinder studies of birds' role in tropical tick ecology and tick-borne disease transmission. In Panama, we found immature ticks on 227 out of 3,498 individually-sampled birds representing 93 host species (24% of the bird species sampled, and 13% of the Panamanian land bird fauna). Tick parasitism rates did not vary with rainfall or temperature, but did vary significantly with several host ecological traits. Likewise, Neotropical-Nearctic migratory birds were significantly less likely to be infested than resident species. Using a molecular library developed from morphologically-identified adult ticks specifically for this study, we identified eleven tick species parasitizing birds, indicating that a substantial portion of the Panamanian avian species pool is parasitized by a diversity of tick species. Tick species that most commonly parasitized birds had the widest diversity of avian hosts, suggesting that immature tick species are opportunistic bird parasites. Although certain avian ecological traits are positively associated with parasitism, we found no evidence that individual tick species show specificity to particular avian host ecological traits. Finally, our data suggest that the four principal vectors of Rocky Mountain Spotted Fever in the Neotropics rarely, if ever, parasitize Panamanian birds. However, other tick species that harbor newly-discovered rickettsial parasites of unknown pathogenicity are frequently found on these birds. Given our discovery of broad interaction between Panamanian tick and avian biodiversity, future work on tick ecology and the dynamics of
Matthew J Miller
Full Text Available In the tropics, ticks parasitize many classes of vertebrate hosts. However, because many tropical tick species are only identifiable in the adult stage, and these adults usually parasitize mammals, most attention on the ecology of tick-host interactions has focused on mammalian hosts. In contrast, immature Neotropical ticks are often found on wild birds, yet difficulties in identifying immatures hinder studies of birds' role in tropical tick ecology and tick-borne disease transmission. In Panama, we found immature ticks on 227 out of 3,498 individually-sampled birds representing 93 host species (24% of the bird species sampled, and 13% of the Panamanian land bird fauna. Tick parasitism rates did not vary with rainfall or temperature, but did vary significantly with several host ecological traits. Likewise, Neotropical-Nearctic migratory birds were significantly less likely to be infested than resident species. Using a molecular library developed from morphologically-identified adult ticks specifically for this study, we identified eleven tick species parasitizing birds, indicating that a substantial portion of the Panamanian avian species pool is parasitized by a diversity of tick species. Tick species that most commonly parasitized birds had the widest diversity of avian hosts, suggesting that immature tick species are opportunistic bird parasites. Although certain avian ecological traits are positively associated with parasitism, we found no evidence that individual tick species show specificity to particular avian host ecological traits. Finally, our data suggest that the four principal vectors of Rocky Mountain Spotted Fever in the Neotropics rarely, if ever, parasitize Panamanian birds. However, other tick species that harbor newly-discovered rickettsial parasites of unknown pathogenicity are frequently found on these birds. Given our discovery of broad interaction between Panamanian tick and avian biodiversity, future work on tick ecology
Ginsberg, Howard S.; Edited by Sonenshine, Daniel E.; Roe, R. Michael
Biology of Ticks is the most comprehensive work on tick biology and tick-borne diseases. This second edition is a multi-authored work, featuring the research and analyses of renowned experts across the globe. Spanning two volumes, the book examines the systematics, biology, structure, ecological adaptations, evolution, genomics and the molecular processes that underpin the growth, development and survival of these important disease-transmitting parasites. Also discussed is the remarkable array of diseases transmitted (or caused) by ticks, as well as modern methods for their control. This book should serve as a modern reference for students, scientists, physicians, veterinarians and other specialists. Volume I covers the biology of the tick and features chapters on tick systematics, tick life cycles, external and internal anatomy, and others dedicated to specific organ systems, specifically, the tick integument, mouthparts and digestive system, salivary glands, waste removal, salivary glands, respiratory system, circulatory system and hemolymph, fat body, the nervous and sensory systems and reproductive systems. Volume II includes chapters on the ecology of non-nidicolous and nidicolous ticks, genetics and genomics (including the genome of the Lyme disease vector Ixodes scapularis) and immunity, including host immune responses to tick feeding and tick-host interactions, as well as the tick's innate immune system that prevents and/or controls microbial infections. Six chapters cover in depth the many diseases caused by the major tick-borne pathogens, including tick-borne protozoa, viruses, rickettsiae of all types, other types of bacteria (e.g., the Lyme disease agent) and diseases related to tick paralytic agents and toxins. The remaining chapters are devoted to tick control using vaccines, acaricides, repellents, biocontrol, and, finally, techniques for breeding ticks in order to develop tick colonies for scientific study.
Cabezas-Cruz, A.; Alberdi, P.; Ayllón, N.; Valdés, James J.; Pierce, R.; Villar, M.; de la Fuente, J.
Roč. 11, č. 4 (2016), s. 303-319 ISSN 1559-2294 EU Projects: European Commission(XE) 278976 - ANTIGONE; European Commission(XE) 316304 - MODBIOLIN Institutional support: RVO:60077344 Keywords : Anaplasma * epigenetic s * histone modifying enzyme * histone * pathogen * tick Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine Impact factor: 4.394, year: 2016
In this podcast for kids, the Kidtastics talk about the dangers of ticks and how to protect yourself from them. Created: 4/9/2013 by Centers for Disease Control and Prevention (CDC). Date Released: 4/9/2013.
Full Text Available Abstract Ticks act as vectors of many pathogens of domestic animals and humans. Anaplasma phagocytophilum in Europe is transmitted by the ixodid tick vector Ixodes ricinus. A. phagocytophilum causes a disease with diverse clinical signs in various hosts. A great genetic diversity of the groESL operon of A. phagocytophilum has been found in ticks elsewhere. In Slovenia, the variety of the groESL operon was conducted only on deer samples. In this study, the prevalence of infected ticks was estimated and the diversity of A. phagocytophilum was evaluated. On 8 locations in Slovenia, 1924 and 5049 (6973 I. ricinus ticks were collected from vegetation in the years 2005 and 2006, respectively. All three feeding stages of the tick's life cycle were examined. The prevalence of ticks infected with A. phagocytophilum in the year 2005 and in the year 2006 was 0.31% and 0.63%, respectively, and it did not differ considerably between locations. The similarity among the sequences of groESL ranged from 95.6% to 99.8%. They clustered in two genetic lineages along with A. phagocytophilum from Slovenian deer. One sequence formed a separate cluster. According to our study, the prevalence of A. phagocytophilum in ticks is comparable to the findings in other studies in Europe, and it does not vary considerably between locations and tick stages. According to groESL operon analysis, two genetic lineages have been confirmed and one proposed. Further studies on other genes would be useful to obtain more information on genetic diversity of A. phagocytophilum in ticks in Slovenia.
Dubourg, G; Socolovschi, C; Del Giudice, P; Fournier, P E; Raoult, D
The clinical and epidemiological features of 56 patients with scalp eschar associated with neck lymphadenopathy after a tick bite (SENLAT) syndrome were evaluated at the National French Rickettsial Center. Eschar swabs, crusts, and biopsies as well as ticks and blood samples were acquired for molecular and serological assays. SENLAT predominantly affects children (p < 0.05), followed by 40- to 70-year-olds, and it is found mostly in women (p < 0.05). The seasonal distribution has two peaks: one in the spring (55%) and one in the autumn (30%). The etiological agent was identified in 18 cases, which include Rickettsia slovaca in 13 cases with incidences of two co-infections with Rickettsia raoultii and one case caused by Rickettsia sibirica mongolitimonae. Other possible agents that were found in attached ticks were Candidatus R. rioja, Coxiella burnetii, and Borrelia burgdorferi. The tick vector was Dermacentor marginatus in almost all cases, with the exception of one case, in which Ixodes ricinus was identified as the vector. Our findings show that SENLAT is a clinical entity characterized as a local infection controlled by the immune system and is neither pathogen- nor vector-specific.
Full Text Available Tick-borne encephalitis (TBE is a serious acute neuroinfection of humans caused by a tick-borne flavivirus. The disease is typically seasonal, linked to the host-seeking activity of Ixodes ricinus (predominantly nymphs, the principal European tick vector species. To address the need for accurate risk predictions of contracting TBE, data on 4,044 TBE cases reported in the Czech Republic during 2001–2006 were compared with questing activity of I. ricinus nymphs monitored weekly at a defined location for the same 6-year period. A time shift of 21 days between infected tick bite and recorded disease onset provided the optimal model for comparing the number of cases of TBE with numbers of questing nymphs. Mean annual distribution of TBE cases and tick counts showed a similar bimodal distribution. Significantly, the ratio of TBE cases to questing nymphs was highest in the summer-autumn period even though the number of questing nymphs peaked in the spring-summer period. However, this pattern changed during a period of extreme meteorological events of flooding and abnormally high temperatures, indicating that changes in climate affect the incidence of TBE. Previous studies failed to link human behavior with changes in incidence of TBE but showed extrinsic temperature impacts arbovirus replication. Hence, we hypothesize the apparent discrepancy between peak nymphal tick activity and greatest risk of contracting TBE is due to the effect of temperature on virus replication in the tick vector. Relative proportions of questing nymphs and the numbers of weeks in which they were found were greater in summer-autumn compared with spring-summer at near-ground temperatures >5°C and at standard day and weekly average temperatures of >15°C. Thus, during the summer-autumn period, the virus dose in infected tick bites is likely greater owing to increased virus replication at higher microclimatic temperatures, consequently increasing the relative risk of
Benelli, Giovanni; Romano, Donato; Rocchigiani, Guido; Caselli, Alice; Mancianti, Francesca; Canale, Angelo; Stefanini, Cesare
Ticks are considered among the most dangerous arthropod vectors of disease agents to both humans and animals worldwide. Lateralization contributes to biological fitness in many animals, conferring important functional advantages, therefore studying its role in tick perception would critically improve our knowledge about their host-seeking behavior. In this research, we evaluated if Ixodes ricinus (L.) (Ixodiidae) ticks have a preference in using the right or the left foreleg to climb on a host. We developed a mechatronic device moving a tuft of fox skin with fur as host-mimicking combination of cues. This engineered approach allows to display a realistic combination of both visual and olfactory host-borne stimuli, which is prolonged over the time and standardized for each replicate. In the first experiment, the mechatronic apparatus delivered host-borne cues frontally, to evaluate the leg preference during questing as response to a symmetrical stimulus. In the second experiment, host-borne cues were provided laterally, in an equal proportion to the left and to the right of the tick, to investigate if the host direction affected the questing behavior. In both experiments, the large majority of the tested ticks showed individual-level left-biased questing acts, if compared to the ticks showing right-biased ones. Furthermore, population-level left-biased questing responses were observed post-exposure to host-mimicking cues provided frontally or laterally to the tick. Overall, this is the first report on behavioral asymmetries in ticks of medical and veterinary importance. Moreover, the mechatronic apparatus developed in this research can be exploited to evaluate the impact of repellents on tick questing in highly reproducible standardized conditions. Copyright © 2017 Elsevier B.V. All rights reserved.
Malaisri, Premnika; Hirunkanokpun, Supanee; Baimai, Visut; Trinachartvanit, Wachareeporn; Ahantarig, Arunee
We collected a total of 169 adult hard ticks and 120 nymphs from under the leaves of plants located along tourist nature trails in ten localities. The results present data examining the vector competence of ticks of different genera and the presence of Rickettsia and Anaplasma species. The ticks belonged to three genera, Amblyomma, Dermacentor, and Haemaphysalis, comprising 11 species. Rickettsia bacteria were detected at three collection sites, while Anaplasma bacteria were detected at only one site. Phylogenetic analysis revealed new rickettsia genotypes from Thailand that were closely related to Rickettsia tamurae, Rickettsia monacensis, and Rickettsia montana. This study was also the first to show that Anaplasma bacteria are found in Haemaphysalis shimoga ticks and are closely related evolutionarily to Anaplasma bovis. These results provide additional information for the geographical distribution of tick species and tick-borne bacteria in Thailand and can therefore be applied for ecotourism management. © 2015 The Society for Vector Ecology.
Estrada-Peña, Agustín; de la Fuente, José
A number of tick-borne diseases of humans have increased in incidence and geographic range over the past few decades, and there is concern that they will pose an even greater threat to public health in future. Although global warming is often cited as the underlying mechanism favoring the spread of tick-borne diseases, climate is just one of many factors that determine which tick species are found in a given geographic region, their population density, the likelihood that they will be infected with microbes pathogenic for humans and the frequency of tick-human contact. This article provides basic information needed for microbiologists to understand the many factors that affect the geographic range and population density of ticks and the risk of human exposure to infected ticks. It first briefly summarizes the life cycle and basic ecology of ticks and how ticks and vertebrate hosts interact, then reviews current understanding of the role of climate, sociodemographic factors, agricultural development and changes in human behavior that affect the incidence of tick-borne diseases. These concepts are then illustrated in specific discussions of tick-borne encephalitis and Crimean-Congo hemorrhagic fever. Copyright © 2014 Elsevier B.V. All rights reserved.
Urbanová, Veronika; Hajdušek, Ondřej; Hönig Mondeková, Helena; Šíma, Radek; Kopáček, Petr
Roč. 7, MAR (2017), č. článku 73. ISSN 2235-2988 R&D Projects: GA ČR GJ15-12006Y; GA ČR GA13-11043S; GA ČR GA17-27386S; GA ČR GA17-27393S EU Projects: European Commission(XE) 602272 - ANTIDotE Institutional support: RVO:60077344 Keywords : Borrelia * complement * Ixodes * phagocytosis * thioester-containing proteins Subject RIV: EC - Immunology OBOR OECD: Immunology Impact factor: 4.300, year: 2016
Urbanová, V.; Hajdušek, O.; Hönig Mondeková, Helena; Šíma, R.; Kopáček, P.
Roč. 7, MAR 16 (2017), s. 1-16, č. článku 73. ISSN 2235-2988 Institutional support: RVO:61388971 Keywords : Borrelia * complement * phagocytosis Subject RIV: EE - Microbiology, Virology OBOR OECD: Microbiology Impact factor: 4.300, year: 2016
Dudek, Krzysztof; Skórka, Piotr; Sajkowska, Zofia Anna; Ekner-Grzyb, Anna; Dudek, Monika; Tryjanowski, Piotr
The success of ectoparasites depends primarily on the site of attachment and body condition of their hosts. Ticks usually tend to aggregate on vertebrate hosts in specific areas, but the distribution pattern may depend on host body size and condition, sex, life stage or skin morphology. Here, we studied the distribution of ticks on lizards and tested the following hypothesis: occurrence or high abundance of ticks is confined with body parts with smaller scales and larger interscalar length because such sites should provide ticks with superior attachment conditions. This study was performed in field conditions in central Poland in 2008-2011. In total, 500 lizards (Lacerta agilis) were caught and 839 ticks (Ixodes ricinus, larvae and nymphs) were collected from them. Using generalised linear mixed models, we found that the ticks were most abundant on forelimbs and their axillae, with 90% of ticks attached there. This part of the lizard body and the region behind the hindlimb were covered by the smallest scales with relatively wide gaps between them. This does not fully support our hypothesis that ticks prefer locations with easy access to skin between scales, because it does not explain why so few ticks were in the hindlimb area. We found that the abundance of ticks was positively correlated with lizard body size index (snout-vent length). Tick abundance was also higher in male and mature lizards than in female and young individuals. Autotomy had no effect on tick abundance. We found no correlation between tick size and lizard morphology, sex, autotomy and body size index. The probability of occurrence of dead ticks was positively linked with the total number of ticks on the lizard but there was no relationship between dead tick presence and lizard size, sex or age. Thus lizard body size and sex are the major factors affecting the abundance of ticks, and these parasites are distributed nearly exclusively on the host's forelimbs and their axillae. Copyright © 2015
Gonsioroski, Andressa Varella; Bezerra, Isis Abel; Utiumi, Kiyoko Uemura; Driemeier, David; Farias, Sandra Estrazulas; da Silva Vaz, Itabajara; Masuda, Aoi
The tick Rhipicephalus microplus is an ectoparasite harmful to livestock, a vector of disease agents that affects meat and milk production. However, resistance to acaricides reflects the need for alternative tick control methods, among which vaccines have gained increasing relevance. In this scenario, monoclonal antibodies can be used to identify and characterize antigens that can be used as vaccine immunogens. Capillary tube artificial feeding of partially engorged R. microplus females with monoclonal antibodies against proteins from the gut of tick were used to test the effects of immunoglobulins in the physiology of the parasite. The results of artificial feeding showed that female ticks over 25mg and under 60 mg in weight performed better in the artificial feeding process, with a 94-168% weight increase after 24h of feeding. Results showed that artificial feeding of ticks proved to be a viable technique to study the effects of antibodies or drugs in the physiology of the parasite. One monoclonal antibody (BrBm2) induced decreased oviposition. Moreover, the antigen recognized by BrBm2 was identified as a 27-kDa protein and immunolabeled on digestive vesicles membranes of digestive cells of partially and fully engorged females. Copyright © 2012 Elsevier Inc. All rights reserved.
Clayton, Katie A; Gall, Cory A; Mason, Katheen L; Scoles, Glen A; Brayton, Kelly A
In North America, ticks are the most economically impactful vectors of human and animal pathogens. The Rocky Mountain wood tick, Dermacentor andersoni (Acari: Ixodidae), transmits Rickettsia rickettsii and Anaplasma marginale to humans and cattle, respectively. In recent years, studies have shown that symbiotic organisms are involved in a number of biochemical and physiological functions. Characterizing the bacterial microbiome of D. andersoni is a pivotal step towards understanding symbiont-host interactions. In this study, we have shown by high-throughput sequence analysis that the composition of endosymbionts in the midgut and salivary glands in adult ticks is dynamic over three generations. Four Proteobacteria genera, Rickettsia, Francisella, Arsenophonus, and Acinetobacter, were identified as predominant symbionts in these two tissues. Exposure to therapeutic doses of the broad-spectrum antibiotic, oxytetracycline, affected both proportions of predominant genera and significantly reduced reproductive fitness. Additionally, Acinetobacter, a free-living ubiquitous microbe, invaded the bacterial microbiome at different proportions based on antibiotic treatment status suggesting that microbiome composition may have a role in susceptibility to environmental contaminants. This study characterized the bacterial microbiome in D. andersoni and determined the generational variability within this tick. Furthermore, this study confirmed that microbiome manipulation is associated with tick fitness and may be a potential method for biocontrol.
Fan, Guihong; Thieme, Horst R; Zhu, Huaiping
Ticks play a critical role as vectors in the transmission and spread of Lyme disease, an emerging infectious disease which can cause severe illness in humans or animals. To understand the transmission dynamics of Lyme disease and other tick-borne diseases, it is necessary to investigate the population dynamics of ticks. Here, we formulate a system of delay differential equations which models the stage structure of the tick population. Temperature can alter the length of time delays in each developmental stage, and so the time delays can vary geographically (and seasonally which we do not consider). We define the basic reproduction number [Formula: see text] of stage structured tick populations. The tick population is uniformly persistent if [Formula: see text] and dies out if [Formula: see text]. We present sufficient conditions under which the unique positive equilibrium point is globally asymptotically stable. In general, the positive equilibrium can be unstable and the system show oscillatory behavior. These oscillations are primarily due to negative feedback within the tick system, but can be enhanced by the time delays of the different developmental stages.
Sh Salari Lak
Full Text Available Background: West Azerbaijan is considered as a main region for domestic animal breeding. Due to importance of herd as a main host and ticks as a vector of relapsing fever and CCHF, a comprehensive study was undertaken in the region.Methods: Outdoor, indoor collection as well as ticks stick to the animals' body were collected and identified. The study was conducted during the whole seasons in 2004-2005.Results: During four seasons a total of 2728 ticks of two families (Ixodidae and Argasidae were collected comprising 7 genera of 5 hard ticks and two genera of soft ticks including Haemaphysalis, Hyalomma, Rhipicephalus, Boophilus and Dermacentor. The soft ticks were Ornithodoros and Argas. These 7 genera included 18 species. The main species were Haemaphysalis inermis, H. punctata, H. sulcata, H. numidiana, H. concinna, Hyalomma marginatum, Hy. anatolicum, Hy. detritum, Hy. dromedarii, Hy. asiaticum, Hy. schulzei, H. aegyptium, Rhipicephalus bursa, R. sangiuneus, Dermacentor marginatus, Boophilus annulatus, Ornithodoros lahorensis, and Argas persicus. Frequency of ticks during different seasons was different. A pyrethroid insecticide, cypermethrin, which is widely used for tick control was tested against soft ticks. The test method was based on WHO recommendation. At the LD50 level A. persicus needs more concentration than O. lahorensis.Conclusion: Ornithodoros and Argas are the more prevalent soft ticks in the region. Distribution and prevalence of hard ticks was varied in different seasons. Results of this study will provide a clue for vectors of tick-borne diseases in the region for local authorities for implementation of tick control.
Russart, Nathan M; Dougherty, Michael W; Vaughan, Jefferson A
Ticks were sampled at nine locations throughout North Dakota during early summer of 2010, using flagging techniques and small mammals trapping. In total, 1,762 ticks were collected from eight of the nine locations. The dominant species were Dermacentor variabilis (Say) (82%), found throughout the state, and Ixodes scapularis Say (17%), found in northeastern counties. A few nymphal and adult I. scapularis tested positive for Borrelia burgdorferi (3%) and Anaplasma phagocytophilum (8%). This is the first report of I. scapularis and associated pathogens occurring in North Dakota and provides evidence for continued westward expansion of this important vector tick species in the United States.
Star M Dunham-Ems
Full Text Available While the roles of rpoS(Bb and RpoS-dependent genes have been studied extensively within the mammal, the contribution of the RpoS regulon to the tick-phase of the Borrelia burgdorferi enzootic cycle has not been examined. Herein, we demonstrate that RpoS-dependent gene expression is prerequisite for the transmission of spirochetes by feeding nymphs. RpoS-deficient organisms are confined to the midgut lumen where they transform into an unusual morphotype (round bodies during the later stages of the blood meal. We show that round body formation is rapidly reversible, and in vitro appears to be attributable, in part, to reduced levels of Coenzyme A disulfide reductase, which among other functions, provides NAD+ for glycolysis. Our data suggest that spirochetes default to an RpoS-independent program for round body formation upon sensing that the energetics for transmission are unfavorable.
Eremeeva, Marina E; Dasch, Gregory A
Rickettsiae are obligately intracellular bacteria that are transmitted to vertebrates by a variety of arthropod vectors, primarily by fleas and ticks. Once transmitted or experimentally inoculated into susceptible mammals, some rickettsiae may cause febrile illness of different morbidity and mortality, and which can manifest with different types of exhanthems in humans. However, most rickettsiae circulate in diverse sylvatic or peridomestic reservoirs without having obvious impacts on their vertebrate hosts or affecting humans. We have analyzed the key features of tick-borne maintenance of rickettsiae, which may provide a deeper basis for understanding those complex invertebrate interactions and strategies that have permitted survival and circulation of divergent rickettsiae in nature. Rickettsiae are found in association with a wide range of hard and soft ticks, which feed on very different species of large and small animals. Maintenance of rickettsiae in these vector systems is driven by both vertical and horizontal transmission strategies, but some species of Rickettsia are also known to cause detrimental effects on their arthropod vectors. Contrary to common belief, the role of vertebrate animal hosts in maintenance of rickettsiae is very incompletely understood. Some clearly play only the essential role of providing a blood meal to the tick while other hosts may supply crucial supplemental functions for effective agent transmission by the vectors. This review summarizes the importance of some recent findings with known and new vectors that afford an improved understanding of the eco-epidemiology of rickettsiae; the public health implications of that information for rickettsial diseases are also described. Special attention is paid to the co-circulation of different species and genotypes of rickettsiae within the same endemic areas and how these observations may influence, correctly or incorrectly, trends, and conclusions drawn from the surveillance of
Rathinavelu, Sivaprakash; Broadwater, Anne; de Silva, Aravinda M.
The Lyme disease spirochete, Borrelia burgdorferi, inhabits the gut lumen of the tick vector. At this location the spirochete is exposed to host blood when a tick feeds. We report here on studies that were done with normal and complement-deficient (C3-knockout) mice to determine if the host complement system killed spirochetes within the vector. We found that spirochete numbers within feeding nymphs were not influenced by complement, most likely because host complement was inactivated within ...
Hofmeester, Tim R.
Diseases that are transmitted by arthropod vectors from animal hosts to humans – so called zoonotic vector-borne diseases – have increased in incidence in the last decades. In North America and Europe, tick-borne pathogens cause the majority of vector-borne diseases, including Lyme borreliosis
Full Text Available Abstract The overwhelming majority of animal conservation projects are focused on vertebrates, despite most of the species on Earth being invertebrates. Estimates state that about half of all named species of invertebrates are parasitic in at least one stage of their development. The dilemma of viewing parasites as biodiversity or pest has been discussed by several authors. However, ticks were omitted. The latest taxonomic synopses of non-fossil Ixodidae consider valid 700 species. Though, how many of them are still extant is almost impossible to tell, as many of them are known only from type specimens in museums and were never collected since their original description. Moreover, many hosts are endangered and as part of conservation efforts of threatened vertebrates, a common practice is the removal of, and treatment for external parasites, with devastating impact on tick populations. There are several known cases when the host became extinct with subsequent coextinction of their ectoparasites. For our synoptic approach we have used the IUCN status of the host in order to evaluate the status of specifically associated hard-ticks. As a result, we propose a number of 63 coendangered and one extinct hard-tick species. On the other side of the coin, the most important issue regarding tick-host associations is vectorial transmission of microbial pathogens (i.e. viruses, bacteria, protozoans. Tick-borne diseases of threatened vertebrates are sometimes fatal to their hosts. Mortality associated with pathogens acquired from ticks has been documented in several cases, mostly after translocations. Are ticks a real threat to their coendangered host and should they be eliminated? Up to date, there are no reliable proofs that ticks listed by us as coendangered are competent vectors for pathogens of endangered animals.
Davies, Saran; Abdullah, Swaid; Helps, Chris; Tasker, Séverine; Newbury, Hannah; Wall, Richard
In a study of tick and tick-borne pathogen prevalence, between May and October 2016, 278 veterinary practices in Great Britain examined 1855 cats. Six-hundred and one cats were found to have attached ticks. The most frequently recorded tick species was Ixodes ricinus (57.1%), followed by Ixodes hexagonus (41.4%) and Ixodes trianguliceps (1.5%). Male cats, 4-6 years of age living in rural areas were most likely to be carrying a tick; hair length and tick treatment history had no significant association with attachment. For cats that were parasitized by ticks in large urban areas, I. hexagonus was the most frequent species recorded. Molecular analysis was possible for 541 individual tick samples, others were too damaged for analysis; Babesia spp., and Borrelia burgdorferi sensu lato were identified in 1.1% (n=6) and 1.8% (n=10) of these, respectively. Babesia spp. included Babesia vulpes sp. nov./Babesia microti-like (n=4) in I. hexagonus and Babesia venatorum (n=2) in I. ricinus. Borrelia burgdorferi s.l. species included Borrelia garinii (n=6) and Borrelia afzelii (n=4). The majority of B. burgorferi s.l. cases were found in I. ricinus, with B. afzelii in one I. hexagonus nymph. No Borrelia or Babesia spp. were present in I. trianguliceps. To determine a true prevalence for ticks on cats, practices that only submitted questionnaires from cats with ticks and practices that submitted fewer than 5 returns per week were removed; amongst those considered to have adhered strictly to the collection protocol, feline tick prevalence amongst cats that had access to the outdoors was 6.6%. These results show that ticks can be found on cats throughout Great Britain, which harbour a range of species of Babesia and B. burgdorferi s.l. and that cats, particularly in green spaces within urban areas, may form an important host for I. hexagonus, a known vector of pathogens. Copyright © 2017 Elsevier B.V. All rights reserved.
Kuo, Chi-Chien; Shu, Pei-Yun; Mu, Jung-Jung; Lee, Pei-Lung; Wu, Yin-Wen; Chung, Chien-Kung; Wang, Hsi-Chieh
Ticks are second to mosquitoes as the most important disease vectors, and recent decades have witnessed the emergence of many novel tick-borne rickettsial diseases, but systematic surveys of ticks and tick-borne rickettsioses are generally lacking in Asia. We collected and identified ticks from small mammal hosts between 2006 and 2010 in different parts of Taiwan. Rickettsia spp. infections in ticks were identified by targeting ompB and gltA genes with nested polymerase chain reaction. In total, 2,732 ticks were collected from 1,356 small mammals. Rhipicephalus haemaphysaloides Supino (51.8% of total ticks), Haemaphysalis bandicota Hoogstraal & Kohls (28.0%), and Ixodes granulatus Supino (20.0%) were the most common tick species, and Rattus losea Swinhoe (44.7% of total ticks) and Bandicota indica Bechstein (39.9%) were the primary hosts. The average Rickettsia infective rate in 329 assayed ticks was 31.9% and eight Rickettsia spp. or closely related species were identified. This study shows that rickettsiae-infected ticks are widespread in Taiwan, with a high diversity of Rickettsia spp. circulating in the ticks. Because notifiable rickettsial diseases in Taiwan only include mite-borne scrub typhus and flea-borne murine typhus, more studies are warranted for a better understanding of the real extent of human risks to rickettsioses in Taiwan. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: firstname.lastname@example.org.
E. A. Bessolitsyna
Full Text Available The objects of this study are Ixodes ticks which were collected in different areas of Kirov province. The aim of the study is to determine the proportion of TBEV infected ticks using the reverse transcription and PCR, dependingon time, place, and methods of collection in the Kirov province as well as of ticks specific and sexual identity. The study found that from the two tick species that were tested only taiga tick (Ixodes persulcatus but not the meadow thick (Dermacentor reticulatus was the TBEV vector. Study also has shown that both males and females ticks can be the TBEV vectors. Moreover, it was proved the importance of ticks testing which were gathered not only from human but also from animals, primary from dogs, and from the plants.
Full Text Available Cattle ticks, Rhipicephalus (Boophilus microplus, are a serious threat to animal health and production. Some ticks feed on a single host species while others such as R. microplus infest multiple hosts. White tailed deer (WTD play a role in the maintenance and expansion of cattle tick populations. However, cattle ticks fed on WTD show lower weight and reproductive performance when compared to ticks fed on cattle, suggesting the existence of host factors that affect tick feeding and reproduction. To elucidate these factors, a proteomics approach was used to characterize tick and host proteins in R. microplus ticks fed on cattle and WTD. The results showed that R. microplus ticks fed on cattle have overrepresented tick proteins involved in blood digestion and reproduction when compared to ticks fed on WTD, while host proteins were differentially represented in ticks fed on cattle or WTD. Although a direct connection cannot be made between differentially represented tick and host proteins, these results suggested that differentially represented host proteins together with other host factors could be associated with higher R. microplus tick feeding and reproduction observed in ticks fed on cattle.
Ehlers, Julian; Ganzhorn, Jörg U; Silaghi, Cornelia; Krüger, Andreas; Pothmann, Daniela; Ratovonamana, R Yedidya; Veit, Alexandra; Keller, Christian; Poppert, Sven
Little is known about the role of endemic ticks as vectors for bacterial and protozoan pathogens for animals and humans in Madagascar and their interaction in anthropogenic habitats where humans, their livestock and native Malagasy species (vectors and hosts) come into more frequent contact than in natural forest ecosystems. The aims of the study were (1) to test whether habitat degradation is associated with increased infestation of tortoises by ticks and (2) to investigate whether ticks carried Babesia, Borrelia or Rickettsia species that might be pathogenic for humans and livestock. We studied hard ticks of two endemic Malagasy tortoises, Astrochelys radiata and Pyxis arachnoides in March and April 2013 in southwest Madagascar. Two tortoise habitats were compared, the National Park of Tsimanampetsotsa and the adjacent degraded pasture and agricultural land at the end of the wet season. Ticks were screened for protozoan and bacterial pathogens via PCR on DNA isolated from ticks using genus-specific primers. Only one out of 42 A. radiata collected from both habitats had ticks. The low prevalence did not allow further analyses of the effect of habitat degradation. Forty-two P. arachnoides were found in the anthropogenic habitat and 36 individuals in the national park. Tick infestation rates of P. arachnoides differed significantly between the two study sites. Tortoises inside the park had lower tick prevalence than outside (8 of 36 (22%) versus 32 of 42 individuals (76%)) and infected animals tended to have fewer ticks inside than outside the park. All ticks collected in both habitats were adults of the ixodid tick Amblyomma chabaudi, which is supposed to be a host-specific tick of P. arachnoides. Screening for Borrelia sp. and Babesia sp. was negative in all ticks. But all A. chabaudi ticks were infected with Rickettsia africae, known to cause spotted fever in humans. Thus, habitat degradation seems to be linked to higher infestation of tortoises with ticks with
Samish, M.; Ginsberg, H.; Glazer, I.; Bowman, A.S.; Nuttall, P.
Ticks have numerous natural enemies, but only a few species have been evaluated as tick biocontrol agents (BCAs). Some laboratory results suggest that several bacteria are pathogenic to ticks, but their mode of action and their potential value as biocontrol agents remain to be determined. The most promising entomopathogenic fungi appear to be Metarhizium anisopliae and Beauveria bassiana, strains of which are already commercially available for the control of some pests. Development of effective formulations is critical for tick management. Entomopathogenic nematodes that are pathogenic to ticks can potentially control ticks, but improved formulations and selection of novel nematode strains are needed. Parasitoid wasps of the genus Ixodiphagus do not typically control ticks under natural conditions, but inundative releases show potential value. Most predators of ticks are generalists, with a limited potential for tick management (one possible exception is oxpeckers in Africa). Biological control is likely to play a substantial role in future IPM programmes for ticks because of the diversity of taxa that show high potential as tick BCAs. Considerable research is required to select appropriate strains, develop them as BCAs, establish their effectiveness, and devise production strategies to bring them to practical use.
Kamani, Joshua; Baneth, Gad; Mumcuoglu, Kosta Y.; Waziri, Ndadilnasiya E.; Eyal, Osnat; Guthmann, Yifat; Harrus, Shimon
Background Only limited information is currently available on the prevalence of vector borne and zoonotic pathogens in dogs and ticks in Nigeria. The aim of this study was to use molecular techniques to detect and characterize vector borne pathogens in dogs and ticks from Nigeria. Methodology/Principal Findings Blood samples and ticks (Rhipicephalus sanguineus, Rhipicephalus turanicus and Heamaphysalis leachi) collected from 181 dogs from Nigeria were molecularly screened for human and animal vector-borne pathogens by PCR and sequencing. DNA of Hepatozoon canis (41.4%), Ehrlichia canis (12.7%), Rickettsia spp. (8.8%), Babesia rossi (6.6%), Anaplasma platys (6.6%), Babesia vogeli (0.6%) and Theileria sp. (0.6%) was detected in the blood samples. DNA of E. canis (23.7%), H. canis (21.1%), Rickettsia spp. (10.5%), Candidatus Neoehrlichia mikurensis (5.3%) and A. platys (1.9%) was detected in 258 ticks collected from 42 of the 181 dogs. Co- infections with two pathogens were present in 37% of the dogs examined and one dog was co-infected with 3 pathogens. DNA of Rickettsia conorii israelensis was detected in one dog and Rhipicephalus sanguineus tick. DNA of another human pathogen, Candidatus N. mikurensis was detected in Rhipicephalus sanguineus and Heamaphysalis leachi ticks, and is the first description of Candidatus N. mikurensis in Africa. The Theileria sp. DNA detected in a local dog in this study had 98% sequence identity to Theileria ovis from sheep. Conclusions/Significance The results of this study indicate that human and animal pathogens are abundant in dogs and their ticks in Nigeria and portray the potential high risk of human exposure to infection with these agents. PMID:23505591
Full Text Available BACKGROUND: Only limited information is currently available on the prevalence of vector borne and zoonotic pathogens in dogs and ticks in Nigeria. The aim of this study was to use molecular techniques to detect and characterize vector borne pathogens in dogs and ticks from Nigeria. METHODOLOGY/PRINCIPAL FINDINGS: Blood samples and ticks (Rhipicephalus sanguineus, Rhipicephalus turanicus and Heamaphysalis leachi collected from 181 dogs from Nigeria were molecularly screened for human and animal vector-borne pathogens by PCR and sequencing. DNA of Hepatozoon canis (41.4%, Ehrlichia canis (12.7%, Rickettsia spp. (8.8%, Babesia rossi (6.6%, Anaplasma platys (6.6%, Babesia vogeli (0.6% and Theileria sp. (0.6% was detected in the blood samples. DNA of E. canis (23.7%, H. canis (21.1%, Rickettsia spp. (10.5%, Candidatus Neoehrlichia mikurensis (5.3% and A. platys (1.9% was detected in 258 ticks collected from 42 of the 181 dogs. Co- infections with two pathogens were present in 37% of the dogs examined and one dog was co-infected with 3 pathogens. DNA of Rickettsia conorii israelensis was detected in one dog and Rhipicephalus sanguineus tick. DNA of another human pathogen, Candidatus N. mikurensis was detected in Rhipicephalus sanguineus and Heamaphysalis leachi ticks, and is the first description of Candidatus N. mikurensis in Africa. The Theileria sp. DNA detected in a local dog in this study had 98% sequence identity to Theileria ovis from sheep. CONCLUSIONS/SIGNIFICANCE: The results of this study indicate that human and animal pathogens are abundant in dogs and their ticks in Nigeria and portray the potential high risk of human exposure to infection with these agents.
Asmare, Kassahun; Abayneh, Takele; Sibhat, Berhanu; Shiferaw, Dessie; Szonyi, Barbara; Krontveit, Randi I; Skjerve, Eystein; Wieland, Barbara
five genera, four species of Glossina and 4 genera of biting flies were reported. Despite the evidence on presence of various vectors including ticks, flies, mosquitoes and midges, studies on vector-borne diseases in Ethiopia are surprisingly rare, especially considering risks related to climate change, which is likely to affect distribution of vectors. Thus better evidence on the current situation is urgently needed in order to prevent spread and to model future distribution scenarios. Copyright © 2017 Elsevier B.V. All rights reserved.
Onnela, Jukka-Pekka; Töyli, Juuso; Kaski, Kimmo
Tick size is an important aspect of the micro-structural level organization of financial markets. It is the smallest institutionally allowed price increment, has a direct bearing on the bid-ask spread, influences the strategy of trading order placement in electronic markets, affects the price formation mechanism, and appears to be related to the long-term memory of volatility clustering. In this paper we investigate the impact of tick size on stock returns. We start with a simple simulation to demonstrate how continuous returns become distorted after confining the price to a discrete grid governed by the tick size. We then move on to a novel experimental set-up that combines decimalization pilot programs and cross-listed stocks in New York and Toronto. This allows us to observe a set of stocks traded simultaneously under two different ticks while holding all security-specific characteristics fixed. We then study the normality of the return distributions and carry out fits to the chosen distribution models. Our empirical findings are somewhat mixed and in some cases appear to challenge the simulation results.
Gillet, Laurent; Schroeder, Hélène; Mast, Jan; Thirion, Muriel; Renauld, Jean-Christophe; Dewals, Benjamin; Vanderplasschen, Alain
Tick salivary proteins are promising targets for the development of anti-tick vaccines. Recently, we described two paralogous anti-complement proteins, called Ixodes ricinus anti-complement (IRAC) proteins I and II, that are co-expressed in tick I. ricinus salivary glands. However, our previous attempts to immunize rabbits against IRAC via infection with recombinant Bovine herpesvirus 4 (BoHV-4) vectors invariably failed although both recombinants expressed high levels of functional IRAC proteins in vitro. As IRAC are soluble monovalent antigens, one of the possible explanations is that monovalent ligation of the B-cell receptor induces receptor activation but fails to promote antigen presentation, a phenomenon that is thought to induce a state of B-cell tolerance. In the present study, we tried to increase IRAC immunogenicity by expressing them as oligovalent antigens. To this end, IRAC were fused to membrane anchors and BoHV-4 vectors expressing these recombinant forms were produced. The immunization potentials of recombinant viruses expressing either secreted or transmembrane IRAC proteins were then compared. While the former did not induce a detectable immune response against IRAC, the latter led to high titres of anti-IRAC antibodies that only marginally affected tick blood feeding. All together, the data presented in this study demonstrate that the immunogenicity of a soluble antigen can be greatly improved by anchoring it in membrane.
Kopacek, Petr; Hajdusek, Ondrej; Buresova, Veronika
Ticks are blood feeding parasites transmitting a wide variety of pathogens to their vertebrate hosts. The transmitted pathogens apparently evolved efficient mechanisms enabling them to evade or withstand the cellular or humoral immune responses within the tick vector. Despite its importance, our knowledge of tick innate immunity still lags far beyond other well established invertebrate models, such as drosophila, horseshoe crab or mosquitoes. However, the recent release of the American deer tick, Ixodes scapularis, genome and feasibility of functional analysis based on RNA interference (RNAi) facilitate the development of this organism as a full-value model for deeper studies of vector-pathogen interactions.
Andrea S. Varela-Stokes
Full Text Available Interest in microbial communities, or microbiota, of blood-feeding arthropods such as ticks (order Parasitiformes, suborder Ixodida is increasing. Studies on tick microorganisms historically emphasized pathogens of high medical or veterinary importance. Current techniques allow for simultaneous detection of pathogens of interest, non-pathogenic symbionts, like Coxiella-LE and Francisella-LE, and microorganisms of unknown pathogenic potential. While each generation of ticks begins with a maternally acquired repertoire of microorganisms, microhabitats off and on vertebrate hosts can alter the microbiome during the life cycle. Further, blood-feeding may allow for horizontal exchange of various pathogenic microbiota that may or may not also be capable of vertical transmission. Thus, the tick microbiome may be in constant flux. The geographical spread of tick vector populations has resulted in a broader appreciation of tick-borne diseases and tick-associated microorganisms. Over the last decade, next-generation sequencing technology targeting the 16S rRNA gene led to documented snapshots of bacterial communities among life stages of laboratory and field-collected ticks, ticks in various feeding states, and tick tissues. Characterizing tick bacterial communities at population and individual tissue levels may lead to identification of markers for pathogen maintenance, and thus, indicators of disease “potential” rather than disease state. Defining the role of microbiota within the tick may lead to novel control measures targeting tick-bacterial interactions. Here, we review our current understanding of microbial communities for some vectors in the family Ixodidae (hard ticks in North America, and interpret published findings for audiences in veterinary and medical fields with an appreciation of tick-borne disease.
Bukin, Y. S.; Dzhioev, Y.; Tkachev, S. E.; Kozlova, I.; Paramonov, A. I.; Růžek, Daniel; Qu, Z.; Zlobin, V. I.
Roč. 238, JUN 15 (2017), s. 124-132 ISSN 0168-1702 Institutional support: RVO:60077344 Keywords : tick-borne encephalitis virus * E protein * physicochemical properties amino acid residue * antigen * antibody Subject RIV: EE - Microbiology, Virology OBOR OECD: Virology Impact factor: 2.628, year: 2016
Hall-Mendelin, S; Craig, S B; Hall, R A
Ticks are obligate haematophagous ectoparasites of various animals, including humans, and are abundant in temperate and tropical zones around the world. They are the most important vectors for the pathogens causing disease in livestock and second only to mosquitoes as vectors of pathogens causing...
Arthur M. Spickett
Full Text Available Ticks, as vectors of disease and damage agents, impact directly and indirectly on the economy of the livestock industry in southern Africa. This study surveyed the occurrence and distribution of ticks infesting livestock across the North West province, South Africa. During three phases in consecutive years, officers of the provincial Veterinary Department collected specimens monthly from livestock hosts at specified sites across the province. Data analysis constituted the fourth phase of the study. A total of 1090 collections from 265 sites yielded 42 566 tick specimens, comprising 22 different tick species (18 ixodids, 4 argasids. The specimens represent all of the major tick vectors of disease that occur in South Africa. The major tick-borne diseases (i.e. heartwater, both African and Asiatic bovine babesiosis and anaplasmosis were found to be prevalent mainly in the north-eastern region of the province, which also displayed the highest tick species diversity. The central region appears transitory to some of the major vectors. Although some tick species were contained within specific regions, others were widespread across the province. Associated serology data show that most herds sampled in areas endemic for babesiosis and anaplasmosis in the north-eastern region are endemically unstable and at risk to these tick-borne diseases should vector control measures become ineffective.
Van Treuren, Will; Ponnusamy, Loganathan; Brinkerhoff, R. Jory; Gonzalez, Antonio; Parobek, Christian M.; Juliano, Jonathan J.; Andreadis, Theodore G.; Falco, Richard C.; Ziegler, Lorenza Beati; Hathaway, Nicholas; Keeler, Corinna; Emch, Michael; Bailey, Jeffrey A.; Roe, R. Michael; Apperson, Charles S.; Knight, Rob
Ixodes scapularis is the principal vector of Lyme disease on the East Coast and in the upper Midwest regions of the United States, yet the tick is also present in the Southeast, where Lyme disease is absent or rare. A closely related species, I. affinis, also carries the pathogen in the South but does not seem to transmit it to humans. In order to better understand the geographic diversity of the tick, we analyzed the microbiota of 104 adult I. scapularis and 13 adult I. affinis ticks captured in 19 locations in South Carolina, North Carolina, Virginia, Connecticut, and New York. Initially, ticks from 4 sites were analyzed by 454 pyrosequencing. Subsequently, ticks from these sites plus 15 others were analyzed by sequencing with an Illumina MiSeq machine. By both analyses, the microbiomes of female ticks were significantly less diverse than those of male ticks. The dissimilarity between tick microbiomes increased with distance between sites, and the state in which a tick was collected could be inferred from its microbiota. The genus Rickettsia was prominent in all locations. Borrelia was also present in most locations and was present at especially high levels in one site in western Virginia. In contrast, members of the family Enterobacteriaceae were very common in North Carolina I. scapularis ticks but uncommon in I. scapularis ticks from other sites and in North Carolina I. affinis ticks. These data suggest substantial variations in the Ixodes microbiota in association with geography, species, and sex. PMID:26150449
Lopes, Marcos G; May Junior, Joares; Foster, Rebecca J; Harmsen, Bart J; Sanchez, Emma; Martins, Thiago F; Quigley, Howard; Marcili, Arlei; Labruna, Marcelo B
vector, A. ovale, is recognized as one of the most important human-biting ticks in the Neotropical region.
Jurisic, Aleksandar D; Petrovic, Aleksandra P; Rajkovic, Dragana V; Nicin, Slobodan Dj
In recent years, in urban areas of Novi Sad, unique ecological conditions, specific floristic and faunistic composition and poor habits of citizens in sense of public health, facilitate the development and maintenance of ticks. Regarding the importance of ticks as vectors of severe human and animal diseases, complex and detailed studies are conducted with an aim to find the most efficient methods for tick control. Two tick species, Ixodes ricinus and Dermacentor marginatus, were identified during a 3-year period on the territory of Municipality of Novi Sad. During 2006, the efficacy of the pyrethroid lambda-cyhalothrin in tick control varied from 60.7 to 100%. The highest efficacy recorded in 2007 was 92.3%. The efficacy of lambda-cyhalothrin in 2008 varied from 39.1 to 100%. Lambda-cyhalothrin showed high efficacy in tick control at localities which were improved before the application (mowed, litter removed, abundance control and euthanasia of abandoned cats and dogs). The results of this research indicate that lambda-cyhalothrin has a toxic effect on ticks and could be used as efficient acaricide for tick control, although its efficacy depends on formulation, terrain features and methods of application.
Dabaja, Mayssaa Fawaz; Tempesta, Maria; Bayan, Ali; Vesco, Gesualdo; Vesco, Gesualdo; Greco, Grazia; Torina, Alessandra; Blanda, Valeria; La Russa, Francesco; Scimeca, Salvatore; Ezzedine, Mohamad; Mortada, Hussein; Raoult, Didier; Fournier, Pierre Edouard; Mortada, Mohamad
Ticks (Acari: Ixodidae) are ectoparasites infesting livestock in every geographic area in the world and they are vectors of several viral, bacterial, and protozoan pathogens to animals and humans worldwide. A deep knowledge of the geographical distribution of these arthropods would have a key role in the control of tick-borne diseases. Few data are available about tick presence in domestic ruminants in Lebanon. The study aimed at providing an analysis of tick presence and distribution in Lebanon. Ticks were collected from cattle, sheep, and goats farms distributed in 6 Lebanese provinces between June and September 2014. A total of 272 adult hard ticks were randomly collected from domestic ruminants (cattle, sheep, and goats) located at 37 Lebanese farms, distributed among 30 villages. Ticks belonged to 4 Ixodidae genera: Rhipicephalus (72.4%), Haemaphysalis (11.4%), Dermacentor (8.1%), and Hyalomma (8.1%). They included the following species: Rhipicephalus annulatus (50.7%), Rhipicephalus turanicus (18.8%), Hyalomma anatolicum (8.1%), Haemaphylasis punctata (11.4%), Dermacentor marginatus (8.1%), Rhipicephalus sanguineus (2.5%), and Rhipicephalus bursa (0.4%). Rhipicephalus turanicus and H. anatolicum were found on cattle, sheep, and goats, R. annulatus on cattle and sheep, R. sanguineus, D. marginatus and Hea. punctata on sheep and goats, while R. bursa was collected only on sheep. Tick species involved in pathogen transmission were found and some of the identi ed species were recorded in Lebanon for the rst time.
Bhusri, Benjaporn; Sariya, Ladawan; Mongkolphan, Chalisa; Suksai, Parut; Kaewchot, Supakarn; Changbunjong, Tanasak
Hepatozoon spp. are protozoan parasites that infect a wide range of domestic and wild animals. The infection occurs by ingestion of an infected tick. This study was carried out to detect and characterize Hepatozoon spp. in ticks collected from captive lions ( Panthera leo ) in Thailand based on the partial 18S rRNA gene sequence. A total of 30 ticks were collected and identified as Rhipicephalus sanguineus . The collected ticks were separated into 10 tick pools by sex and life stages. Of the 10 tick pools examined, only one (10%) was found to be infected with the Hepatozoon species. Sequencing and phylogenetic analysis showed a clustering of the partial 18S rRNA gene sequence like that of H. felis from the GenBank database. This is the first report of H. felis in R. sanguineus ticks collected from captive lions in Thailand. Our results indicated that R. sanguineus may be a possible vector of feline Hepatozoon in Thailand.
Integration of a Tick-Borne Encephalitis Virus and Borrelia burgdorferi sensu lato into Mountain Ecosystems, Following a Shift in the Altitudinal Limit of Distribution of Their Vector, Ixodes ricinus (Krkonoše Mountains, Czech Republic)
Danielová, V.; Daniel, M.; Schwarzová, L.; Materna, J.; Rudenko, Natalia; Golovchenko, Maryna; Holubová, J.; Grubhoffer, Libor; Kilian, P.
Roč. 10, č. 3 (2010), s. 223-230 ISSN 1530-3667 Grant - others:GA ČR(CZ) GA310/06/1546 Institutional research plan: CEZ:AV0Z60220518 Keywords : Borrelia burgdorferi genospecies * Climate * Ixodes ricinus tick * Mountain ecosystems * Tick-borne encephalitis virus Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine Impact factor: 2.733, year: 2010
Yurchenko, Oksana O; Dubina, Dmytro O; Vynograd, Nataliya O; Gonzalez, Jean-Paul
Tick-borne encephalitis (TBE) is the most common tick-borne viral infection in Eurasia; thousands of human cases are annually reported from several European countries. Several tick species are vectors of the tick-borne encephalitis virus (TBEV), while TBE appears to be spreading from the Eurasian continent westward to Europe. Fifteen study sites were chosen from five territories of southern Ukraine, including Odessa, Mykolaiv, Kherson Oblast, the Autonomous Republic of Crimea, and Sevastopol. Tick collection was performed in spring season of three consecutive years (1988-1990) using either flagging technique or direct collection of specimens feeding on cattle. A total of 15,243 tick imagoes and nymphs were collected from nine species, including Dermacentor marginatus, D. reticulatus, Haemaphysalis parva, H. punctata, Hyalomma marginatum, Ixodes ricinus, Rhipicephalus bursa, R. rossicus, and R. sanguineus, pooled in 282 monospecific samples. Supernatant of grinded pool was used for inoculation to suckling mice for virus isolation. Eight TBEV isolates were identified from ticks among six study sites. Ticks showed a minimum infection rate from 0.11% to 0.81%. Phylogenetic analysis of the envelope (E) protein gene of seven isolates, assigned all to the European subtype (TBEV-Eu) showing a maximum identity of 97.17% to the "Pan" TBEV-Eu reference strain. Compared to 104 TBEV-Eu isolates they clustered within the same clade as the Pan reference strain and distinguished from other TBEV-Eu isolates. Amino acid sequence analysis of the South Ukrainian TBEV-Eu isolates revealed the presence of four amino acid substitutions 67 (N), 266 (R), 306 (V), and 407 (R), in the ectodomains II and III and in the stem-anchor region of the E protein gene. This study confirmed TBEV-Eu subtype distribution in the southern region of Ukraine, which eventually overlaps with TBEV-FE (Far Eastern subtype) and TBEV-Sib (Siberian subtype) domains, showing the heterogeneity of TBEV circulating in
Hofmeester, Tim R.; Sprong, Hein; Jansen, Patrick A.; Prins, Herbert H.T.; Wieren, Van Sipke E.
Background: Understanding which factors drive population densities of disease vectors is an important step in assessing disease risk. We tested the hypothesis that the density of ticks from the Ixodes ricinus complex, which are important vectors for tick-borne diseases, is determined by the density
Hofmeester, Tim R; Sprong, Hein; Jansen, Patrick A; Prins, Herbert H T; van Wieren, Sipke E
Understanding which factors drive population densities of disease vectors is an important step in assessing disease risk. We tested the hypothesis that the density of ticks from the Ixodes ricinus complex, which are important vectors for tick-borne diseases, is determined by the density of deer, as
Vargas-Sandoval, Margarita; Priego-Santander, Angel G.; Larrazabal de la Via, Alejandra Patricia; Sosa-Gutiérrez, Carolina G.; Lara-Chávez, Blanca; Avila-Val, Teresita
Ticks are regarded as the most relevant vectors of disease-causing pathogens in domestic and wild animals. The diversity of Ixodidae is known for a very small number of genera. Ixodes are repre- sented by 26 species, and in 2007 the first reported ticks vectors in Mexico for the causal agent of Lyme
Kuo, Chi-Chien; Huang, Jing-Lun; Shu, Pei-Yun; Lee, Pei-Lung; Kelt, Douglas A; Wang, Hsi-Chieh
The increase in global travel and trade has facilitated the dissemination of disease vectors. Globalization can also indirectly affect vector-borne diseases through the liberalization of cross-border trade, which has far-reaching, worldwide effects on agricultural practices and may in turn influence vectors through the modification of the ecological landscape. While the cascading effect of economic globalization on vector-borne diseases, sometimes acting synergistically with regional agricultural policy, could be substantial and have significant economic, agricultural, and public health implications, research into this remains very limited. We evaluated how abandonment of rice paddies in Taiwan after joining the World Trade Organization, along with periodic plowing, an agricultural policy to reduce farm pests in abandoned fields can unexpectedly influence risks to diseases transmitted by ticks and chiggers (larval trombiculid mites), which we collected from their small-mammal hosts. Sampling was limited to abandoned (fallow) and plowed fields due to the challenge of trapping small mammals in flooded rice paddies. Striped field mice (Apodemus agrarius) are the main hosts for both vectors. They harbored six times more ticks and three times more chiggers in fallow than in plowed plots. The proportion of ticks infected with Rickettsia spp. (etiologic agent of spotted fever) was three times higher in fallow plots, while that of Orientia tsutsugamushi (scrub typhus) in chiggers was similar in both treatments. Fallow plots had more ground cover and higher vegetation than plowed ones. Moreover, ticks and chiggers in both field types were dominated by species known to infest humans. Because ticks and chiggers should exhibit very low survival in flooded rice paddies, we propose that farm abandonment in Taiwan, driven by globalization, may have inadvertently led to increased risks of spotted fever and scrub typhus. However, periodic plowing can unintentionally mitigate vector
Ham??kov?, Zuzana; Kazim?rov?, M?ria; Haru?tiakov?, Danka; Mahr?kov?, Lenka; Slov?k, Mirko; Berthov?, Lenka; Kocianov?, Elena; Schnittger, Leonhard
Background Babesiosis is an emerging and potentially zoonotic disease caused by tick-borne piroplasmids of the Babesia genus. New genetic variants of piroplasmids with unknown associations to vectors and hosts are recognized. Data on the occurrence of Babesia spp. in ticks and wildlife widen the knowledge on the geographical distribution and circulation of piroplasmids in natural foci. Questing and rodent-attached ticks, rodents, and birds were screened for the presence of Babesia-specific DN...
Lyme disease is transmitted by the bite of blacklegged ticks and affects up to 300,000 Americans each year. This podcast discusses ways to prevent tick bites. Created: 5/14/2015 by MMWR. Date Released: 5/14/2015.
Full Text Available Ticks are obligate blood feeding ectoparasites that transmit a wide variety of pathogenic microorganisms to their vertebrate hosts. Amblyomma sculptum is vector of Rickettsia rickettsii, the causative agent of Rocky Mountain spotted fever (RMSF, the most lethal rickettsiosis that affects humans. It is known that the transmission of pathogens by ticks is mainly associated with the physiology of the feeding process. Pathogens that are acquired with the blood meal must first colonize the tick gut and later the salivary glands (SG in order to be transmitted during a subsequent blood feeding via saliva. Tick saliva contains a complex mixture of bioactive molecules with anticlotting, antiplatelet aggregation, vasodilatory, anti-inflammatory, and immunomodulatory properties to counteract both the hemostasis and defense mechanisms of the host. Besides facilitating tick feeding, the properties of saliva may also benefits survival and establishment of pathogens in the host. In the current study, we compared the sialotranscriptome of unfed A. sculptum ticks and those fed for 72 h on rabbits using next generation RNA sequencing (RNA-seq. The total of reads obtained were assembled in 9,560 coding sequences (CDSs distributed in different functional classes. CDSs encoding secreted proteins, including lipocalins, mucins, protease inhibitors, glycine-rich proteins, metalloproteases, 8.9 kDa superfamily members, and immunity-related proteins were mostly upregulated by blood feeding. Selected CDSs were analyzed by real-time quantitative polymerase chain reaction preceded by reverse transcription (RT-qPCR, corroborating the transcriptional profile obtained by RNA-seq. Finally, high-performance liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS analysis revealed 124 proteins in saliva of ticks fed for 96–120 h. The corresponding CDSs of 59 of these proteins were upregulated in SG of fed ticks. To the best of our knowledge, this is the first
Full Text Available Lyme disease is the most common tick-borne disease in North America and Europe, and on-going surveillance is required to monitor the spread of the tick vectors as their populations expand under the influence of climate change. Active surveillance involves teams of researchers collecting ticks from field locations with the potential to be sites of establishing tick populations. This process is labor- and time-intensive, limiting the number of sites monitored and the frequency of monitoring. Citizen science initiatives are ideally suited to address this logistical problem and generate high-density and complex data from sites of community importance. In 2014, the same region was monitored by academic researchers, public health workers, and citizen scientists, allowing a comparison of the strengths and weaknesses of each type of surveillance effort. Four community members persisted with tick collections over several years, collectively recovering several hundred ticks. Although deviations from standard surveillance protocols and the choice of tick surveillance sites makes the incorporation of community-generated data into conventional surveillance analyses more complex, this citizen science data remains useful in providing high-density longitudinal tick surveillance of a small area in which detailed ecological observations can be made. Most importantly, partnership between community members and researchers has proven a powerful tool in educating communities about of the risk of tick-vectored diseases and in encouraging tick bite prevention.
Papa, Anna; Kontana, Anastasia; Tsioka, Katerina; Chaligiannis, Ilias; Sotiraki, Smaragda
Crimean-Congo hemorrhagic fever virus (CCHFV) is transmitted to humans mainly through the bite of infected ticks. In Greece, only one clinical case has been observed, in 2008, but the seroprevalence in humans is relatively high (4.2%). To have a first insight into the circulation of CCHFV in Greece, 2000 ticks collected from livestock during 2012-2014 were tested. CCHFV was detected in 36 of the 1290 (2.8%) tick pools (1-5 ticks per pool). Two genetic lineages were identified: Europe 1 and Europe 2. Most Europe 1 sequences were obtained from Rhipicephalus sanguineus sensu lato ticks, while most Europe 2 sequences were recovered from Rhipicephalus bursa ticks. The number of collected Hyalomma marginatum ticks (the principal vector of CCHFV) was low (0.5% of ticks) and all were CCHFV negative. Since it is not known how efficient ticks of the Rhipicephalus genus are as vectors of the virus, laboratory studies will be required to explore the role of Rhipicephalus spp. ticks in CCHFV maintenance and transmission.
Yssouf, Amina; Almeras, Lionel; Terras, Jérôme; Socolovschi, Cristina; Raoult, Didier; Parola, Philippe
Background Matrix Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS) has been shown to be an effective tool for the rapid identification of arthropods, including tick vectors of human diseases. Methodology/Principal Findings The objective of the present study was to evaluate the use of MALDI-TOF MS to identify tick species, and to determine the presence of rickettsia pathogens in the infected Ticks. Rhipicephalus sanguineus and Dermacentor marginatus Ticks infected or not by R. conorii conorii or R. slovaca, respectively, were used as experimental models. The MS profiles generated from protein extracts prepared from tick legs exhibited mass peaks that distinguished the infected and uninfected Ticks, and successfully discriminated the Rickettsia spp. A blind test was performed using Ticks that were laboratory-reared, collected in the field or removed from patients and infected or not by Rickettsia spp. A query against our in-lab arthropod MS reference database revealed that the species and infection status of all Ticks were correctly identified at the species and infection status levels. Conclusions/Significance Taken together, the present work demonstrates the utility of MALDI-TOF MS for a dual identification of tick species and intracellular bacteria. Therefore, MALDI-TOF MS is a relevant tool for the accurate detection of Rickettsia spp in Ticks for both field monitoring and entomological diagnosis. The present work offers new perspectives for the monitoring of other vector borne diseases that present public health concerns. PMID:25659152
We have recently shown that repellency of the tick Rhipicephalus sanguineus sensu lato by the tick resistant dog breed Beagle is mediated by volatile organic compounds 2-hexanone and benzaldehyde present in Beagle dog odour. Ectoparasite location on animal hosts is affected by variation in odour com...
Full Text Available The genus Anaplasma (Rickettsiales: Anaplasmataceae includes obligate tick-transmitted intracellular organisms, Anaplasma phagocytophilum and Anaplasma marginale that multiply in both vertebrate and tick host cells. Recently, we showed that A. marginale affects the expression of tick genes that are involved in tick survival and pathogen infection and multiplication. However, the gene expression profile in A. phagocytophilum-infected tick cells is currently poorly characterized. The objectives of this study were to characterize tick gene expression profile in Ixodes scapularis ticks and cultured ISE6 cells in response to infection with A. phagocypthilum and to compare tick gene expression responses in A. phagocytophilum- and A. marginale-infected tick cells by microarray and real-time RT-PCR analyses. The results of these studies demonstrated modulation of tick gene expression by A. phagocytophilum and provided evidence of different gene expression responses in tick cells infected with A. phagocytophilum and A. marginale. These differences in Anaplasma-tick interactions may reflect differences in pathogen life cycle in the tick cells.
The southern cattle tick, Rhipicephalus (Boophilus) microplus (Canestrini), is a key vector of protozoa that causes bovine babesiosis. Largely eradicated from most of the U.S., the cattle tick continues to infest the Cattle Fever Tick Quarantine Zone in south Texas. Management areas of the souther...
Melillo Fenech, Tanya
A vector-borne disease is one in which the pathogenic microorganism is transmitted from an infected individual to another individual by an arthropod or other agent. The transmission depends upon the attributes and requirements of at least three different Iiving organisms : the pathologic agent which is either a virus, protozoa, bacteria or helminth (worm); the vector, which is commonly an arthropod such as ticks or mosquitoes; and the human host.
Full Text Available The economic importance of tick infestation on camels are important as they are important meat and milk producer animals in the less vegetation area of Iran and their health and production are greatly affected by the high tick infestation. In this investigation, tick infestations on camels (Camelus dromedarius were determined in Qeshm Island, Iran. A total number of 912 adult ticks (472 males and 440 females were collected and identified. Hyalomma dromedarii was the predominant tick specie and accounted for 61.9% of the adult ticks. Other hard ticks were H. anatolicum excavatum (22 %, H. asiaticum asiaticum (14.2 %, H. marginatum (1.9 %, H. impeltatum (0.4 % and Ripicephalus bursa (0.4 %. In conclusion, The provision of tick control programs in the Qeshm Island would seem a prerequisite for improving camel meat and milk production.
This thesis describes the results of a study to assess the effect of ethnobotanical products on the behaviour of the brown ear tick Rhipicephalus appendiculatus, the main vector of East Coast fever in sub-Saharan Africa. Ethnoknowledge of the Bukusu people in western Kenya on tick control and
Daniele De Meneghi
Full Text Available Livestock, especially cattle, play a paramount role in agriculture production systems, particularly in poor countries throughout the world. Ticks and tick-borne diseases (TBDs have an important impact on livestock and agriculture production in Sub-Saharan Africa. The authors review the most common methods used for the control of ticks and TBDs. Special emphasis is given to the direct application of acaricides to the host animals. The possible environmental and public health adverse effects (i.e. risks for the workers, residues in the environment, and in food products of animal origin are mentioned. The authors present two case studies, describing different field experiences in controlling ticks in two African countries. In Zambia (Southern Africa, a strategic dipping regime was used to control Rhipicephalus appendiculatus ticks, vectors of theileriosis, a deadly disease affecting cattle in the traditional livestock sector in Southern Province. The dipping regime adopted allowed to reduce the tick challenge and cattle mortally rate, and at the same time, to employ less acaricide as compared to the intensive dipping used so far, without disrupting the building-up of enzootic stability. In Burkina Faso (West Africa, where dipping was never used for tick control, an acaricide footbath was employed as an alternative method to the traditional technique used locally (portable manual sprayers. This was developed from field observations on the invasion/attachment process of the Amblyomma variegatum ticks –vector of cowdriosis- on the animal hosts, leading to a control method aimed to kill ticks temporarily attached to the interdigital areas before their permanent attachment to the predilection sites. This innovative method has been overall accepted by the local farmers. It has the advantage of greatly reducing costs of treatments and has a minimal environmental impact, making footbath a sustainable and replicable method, adoptable also in other West
Ariani, Cristina V; Juneja, Punita; Smith, Sophia; Tinsley, Matthew C; Jiggins, Francis M
Mosquitoes are one of the most important vectors of human disease. The ability of mosquitoes to transmit disease is dependent on the age structure of the population, as mosquitoes must survive long enough for the parasites to complete their development and infect another human. Age could have additional effects due to mortality rates and vector competence changing as mosquitoes senesce, but these are comparatively poorly understood. We have investigated these factors using the mosquito Aedes aegypti and the filarial nematode Brugia malayi. Rather than observing any effects of immune senescence, we found that older mosquitoes were more resistant, but this only occurred if they had previously been maintained on a nutrient-poor diet of fructose. Constant blood feeding reversed this decline in vector competence, meaning that the number of parasites remained relatively unchanged as mosquitoes aged. Old females that had been maintained on fructose also experienced a sharp spike in mortality after an infected blood meal ("refeeding syndrome") and few survived long enough for the parasite to develop. Again, this effect was prevented by frequent blood meals. Our results indicate that old mosquitoes may be inefficient vectors due to low vector competence and high mortality, but that frequent blood meals can prevent these effects of age. Copyright © 2014 Elsevier Inc. All rights reserved.
Full Text Available We have killed wild animals for obtaining food and decimated forests for many reasons. Nowadays, we are burning fossil fuels as never before and even exploring petroleum in deep waters. The impact of these activities on our planet is now visible to the naked eye and the debate on climate change is warming up in scientific meetings and becoming a priority on the agenda of both scientists and policy decision makers. On the occasion of the Impact of Environmental Changes on Infectious Diseases (IECID meeting, held in the 2015 in Sitges, Spain, I was invited to give a keynote talk on climate change, biodiversity, ticks and tick-borne diseases. The aim of the present article is to logically extend my rationale presented on the occasion of the IECID meeting. This article is not intended to be an exhaustive review, but an essay on climate change, biodiversity, ticks and tick-borne diseases. It may be anticipated that warmer winters and extended autumn and spring seasons will continue to drive the expansion of the distribution of some tick species (e.g., Ixodes ricinus to northern latitudes and to higher altitudes. Nonetheless, further studies are advocated to improve our understanding of the complex interactions between landscape, climate, host communities (biodiversity, tick demography, pathogen diversity, human demography, human behaviour, economics, and politics, also considering all ecological processes (e.g., trophic cascades and other possible interacting effects (e.g., mutual effects of increased greenhouse gas emissions and increased deforestation rates. The multitude of variables and interacting factors involved, and their complexity and dynamism, make tick-borne transmission systems beyond (current human comprehension. That is, perhaps, the main reason for our inability to precisely predict new epidemics of vector-borne diseases in general.
Fajs, Luka; Durmiši, Emina; Knap, Nataša; Strle, Franc; Avšič-Županc, Tatjana
Tick-borne encephalitis virus (TBEV) is the most important arboviral agent causing infections of the central nervous system in central Europe. Previous studies have shown that TBEV exhibits pronounced genetic variability, which is often correlated to the geographical origin of TBEV. Genetic variability of TBEV has previously been studied predominantly in rodents and ticks, while information about the variability in patients is scarce. In order to understand the molecular relationships of TBEV between natural hosts, vectors and humans, as well as correlation between phylogenetic and geographical clustering, sequences of TBEV E and NS5 protein genes, were obtained by direct sequencing of RT-PCR products from TBE-confirmed patients as well as from rodents and ticks collected from TBE-endemic regions in Slovenia. A total of 27 partial E protein gene sequences representing 15 human, 4 rodent and 8 tick samples and 30 partial NS5 protein gene sequences representing 17 human, 5 rodent and 8 tick samples were obtained. The complete genome sequence of TBEV strain Ljubljana I was simultaneously obtained. Phylogenetic analysis of the E and NS5 protein gene sequences revealed a high degree of TBEV variability in patients, ticks and rodents. Furthermore, an evident correlation between geographical and phylogenetic clustering was shown that was independent of the TBEV host. Moreover, we show the presence of a possible recombination event in the TBEV genome obtained from a patient sample, which was supported with multiple recombination event detection methods. This is the first study that simultaneously analyzed the genetic relationships of directly sequenced TBEV samples from patients, ticks and rodents and provides the largest set of patient-derived TBEV sequences up to date. In addition, we have confirmed the geographical clustering of TBEV sequences in Slovenia and have provided evidence of a possible recombination event in the TBEV genome, obtained from a patient. PMID
Full Text Available Ticks are tiny crawling bugs in the spider family that feed by sucking blood from animals. They are second only to mosquitoes as vectors of human disease, both infectious and toxic. Infected ticks spread over a hundred diseases, some of which are fatal if undetected. They spread the spirochete (which multiplies in the insect's gut with a subsequent bite to the next host. We describe the only reported cases of peri ocular tick bite from India that presented to us within a span of 3 days and its management. Due suspicion and magnification of the lesions revealed the ticks which otherwise masqueraded as small skin tags/moles on gross examination. The ticks were firmly latched on to the skin and careful removal prevented incarceration of the mouth parts. Rickettsial diseases that were believed to have disappeared from India are reemerging and their presence has recently been documented in at least 11 states in the country. Among vector borne diseases, the most common, Lyme disease, also known as the great mimicker, can present with rheumatoid arthritis, fibromyalgia, depression, attention deficit hyperactivity disorder, multiple sclerosis, chronic fatigue syndrome, cardiac manifestations, encephalitis, and mental illness, to name some of the many associations. Common ocular symptoms and signs include conjunctivitis, keratitis, uveitis, and retinitis. Early detection and treatment of tick borne diseases is important to prevent multi system complications that can develop later in life.
Akimov I. А.
Full Text Available This study presents the results of content analysis of published works on ixodid ticks in urban conditions in order to determine the species diversity, the vectors of research interests at various stages. Information about ticks in the cities up to the 1980s is incidental, to the point of exclusive, after this point there is targeted research in urban landscapes. There are 106 or 15 % of hard ticks of the world fauna registered in the urban territory, 26 species or 3.7 % being the most abundant. Of the urban hard tick species, 23 (88.5 % can attack humans, and 12 species are the most adapted to the urban landscape: Ixodes ricinus, I. persulcatus, Dermacentor reticulatus, D. marginatus, I. pavlovskyi, I. scapularis (dammini, Amblyomma cajennense, Haemaphysalis longicornis, I. hexagonus, Hyalomma marginatum, Am. americanum, and Rhipicephalus sanguineus. It was determined that the most likely causes of the growing number of publications on ixodids urban landscapes are: global accelerating urbanization, the development of recreational areas, the development of green tourism, the growth of the prestige of outdoor recreation, the creation of new, especially of the landscape parks and a tendency to preserve the native landscape in the cities, a significant increase in the density of populations of common species of hard ticks adapted to living in urban environment. The vectors of further work in urban landscapes will be directed to exact planning of monitoring studies of ixodids and associated tick-borne infections.
Růžek, Daniel; Gritsun, T. S.; Forrester, N. L.; Gould, E. A.; Kopecký, Jan; Golovchenko, Maryna; Rudenko, Natalia; Grubhoffer, Libor
Roč. 374, č. 2 (2008), s. 249-255 ISSN 0042-6822 R&D Projects: GA ČR GA524/08/1509; GA ČR(CZ) GA524/06/1479; GA MŠk(CZ) LC06009 Grant - others:European Commission(GB) LSHG-CT-2004-511960 Institutional research plan: CEZ:AV0Z60220518 Keywords : tick-borne encephalitis virus * neuroinvasiveness * viral phenotype Subject RIV: EE - Microbiology, Virology Impact factor: 3.539, year: 2008
Tahmasebi, F; Ghiasi, Seyed Mojtaba; Mostafavi, E
BACKGROUND & OBJECTIVES: Crimean-Congo hemorrhagic fever (CCHF) virus is a tick-borne member of the genus Nairovirus, family Bunyaviridae. CCHFV has been isolated from at least 31 different tick species. The virus is transmitted through the bite of an infected tick, or by direct contact with CCHFV...... to each other. Even though they clustered in the same group with the strain circulating in Iran, they had a closer relationship to the Matin strain. INTERPRETATION & CONCLUSION: Vector control programs should be applied for reducing population density of potential tick vectors in this province. Further...
Full Text Available Rickettsia conorii conorii is the etiological agent of Mediterranean spotted fever, which is transmitted by the brown dog tick, Rhipicephalus sanguineus. The relationship between the Rickettsia and its tick vector are still poorly understood one century after the first description of this disease.An entomological survey was organized in Algeria to collect ticks from the houses of patients with spotted fever signs. Colonies of R. conorii conorii-infected and non-infected ticks were established under laboratory conditions. Gimenez staining and electron microscopy on the ovaries of infected ticks indicated heavy rickettsial infection. The transovarial transmission of R. conorii conorii in naturally infected Rh. sanguineus ticks was 100% at eleven generations, and the filial infection rate was up to 99% according to molecular analyses. No differences in life cycle duration were observed between infected and non-infected ticks held at 25°C, but the average weight of engorged females and eggs was significantly lower in infected ticks than in non-infected ticks. The eggs, larvae and unfed nymphs of infected and non-infected ticks could not tolerate low (4°C or high (37°C temperatures or long starvation periods. R. conorii conorii-infected engorged nymphs that were exposed to a low or high temperature for one month experienced higher mortality when they were transferred to 25°C than non-infected ticks after similar exposure. High mortality was observed in infected adults that were maintained for one month at a low or high temperature after tick-feeding on rabbits.These preliminary results suggest that infected quiescent ticks may not survive the winter and may help explain the low prevalence of infected Rh. sanguineus in nature. Further investigations on the influence of extrinsic factors on diapaused R. conorii-infected and non-infected ticks are required.
Fernández de Mera, Isabel G; Blanda, Valeria; Torina, Alessandra; Dabaja, Mayssaa Fawaz; El Romeh, Ali; Cabezas-Cruz, Alejandro; de la Fuente, José
Tick-borne diseases have become a world health concern, emerging with increasing incidence in recent decades. Spotted fever group (SFG) rickettsiae are tick-borne pathogens recognized as important agents of human tick-borne diseases worldwide. In this study, 88 adult ticks from the species Hyalomma anatolicum, Rhipicephalus annulatus, Rh. bursa, Rh. sanguineus sensu lato, and Rh. turanicus, were collected from farm ruminants in Lebanon, and SFG rickettsiae were molecularly identified and characterized in these ticks. The screening showed a prevalence of 68% for Rickettsia spp., including the species R. aeschlimannii, R. africae, R. massiliae and Candidatus R. barbariae, the latter considered an emerging member of the SFG rickettsiae. These findings contribute to a better knowledge of the distribution of these pathogens and demonstrate that SFG rickettsiae with public health relevance are found in ticks collected in Lebanon, where the widespread distribution of tick vectors and possible livestock animal hosts in contact with humans may favor transmission to humans. Few reports exist for some of the tick species identified here as being infected with SFG Rickettsia. Some of these tick species are proven vectors of the hosted rickettsiae, although this information is unknown for other of these species. Therefore, these results suggested further investigation on the vector competence of the tick species with unknown role in transmission of some of the pathogens identified in this study. Copyright © 2017 Elsevier GmbH. All rights reserved.
Helen J. Esser
Full Text Available Identifying the factors that influence the species diversity and distribution of ticks (Acari: Ixodida across vertebrate host taxa is of fundamental ecological and medical importance. Host body size is considered one of the most important determinants of tick abundance, with larger hosts having higher tick burdens. The species diversity of tick assemblages should also be greater on larger-bodied host species, but empirical studies testing this hypothesis are lacking. Here, we evaluate this relationship using a comparative dataset of feeding associations from Panama between 45 tick species and 171 host species that range in body size by three orders of magnitude. We found that tick species diversity increased with host body size for adult ticks but not for immature ticks. We also found that closely related host species tended to have similar tick species diversity, but correcting for host phylogeny did not alter the relationships between host body size and tick species diversity. The distribution of tick species was highly aggregated, with approximately 20% of the host species harboring 80% of all tick species, following the Pareto principle or 20/80 Rule. Thus, the aggregated pattern commonly observed for tick burdens and disease transmission also holds for patterns of tick species richness. Our finding that the adult ticks in this system preferentially parasitize large-bodied host species suggests that the ongoing anthropogenic loss of large-bodied vertebrates is likely to result in host-tick coextinction events, even when immature stages feed opportunistically. As parasites play critical roles in ecological and evolutionary processes, such losses may profoundly affect ecosystem functioning and services.
Full Text Available Rickettsiosis is a potentially fatal tick borne disease. It is caused by the obligate intracellular bacteria Rickettsia, which is transferred to humans through salivary excretions of ticks during the biting process. Globally, the incidence of tick-borne diseases is increasing; as such, there is a need for a greater understanding of tick–host interactions to create more informed risk management strategies. Flinders Island spotted fever rickettsioses has been identified throughout Australia (Tasmania, South Australia, Queensland and Torres Strait Islands with possible identifications in Thailand, Sri Lanka and Italy. Flinders Island spotted fever is thought to be spread through tick bites and the reptile tick Bothriocroton hydrosauri has been implicated as a vector in this transmission. This study used qPCR to assay Bothriocroton hydrosauri ticks collected from Tiliqua rugosa (sleepy lizard hosts on mainland South Australia near where spotted fever cases have been identified. We report that, although we discovered Rickettsia in all tick samples, it was not Rickettsia honei. This study is the first to use PCR to positively identify Rickettsia from South Australian Bothriocroton hydrosauri ticks collected from Tiliqua rugosa (sleepy lizard hosts. These findings suggest that B. hydrosauri may be a vector of multiple Rickettsia spp. Also as all 41 tested B. hydrosauri ticks were positive for Rickettsia this indicates an extremely high prevalence within the studied area in South Australia.
Full Text Available As evidence of global changes is accumulating, scientists are challenged to detect distribution changes of vectors, reservoirs and pathogens caused by anthropogenic and/or environmental changes. Statistical and mathematical distribution models are emerging for ixodid hard ticks whereas no prediction has ever been developed for argasid ones. These last organisms remain unknown and under-reported; they differ from hard ticks by many structural, biological and ecological properties, which complicate direct adaptation of hard tick models. However, investigations on bibliographic resources concerning these ticks suggest that distribution modelling based on natural niche concept and using environmental factors especially climate is also possible, bearing in mind the scale of prediction and their specificities including their nidicolous lifestyle, an indiscriminate host feeding and a short bloodmeal duration, as well as a flexible development cycle through diapause periods.
Holzer, B R
It is known for many years that tick-borne diseases have worldwide a high economical impact on farming industry and veterinary medicine. But only in the last twenty years the importance of such diseases were notified in human medicine by the medical community and the public with emerging of the tick borne encephalitis virus and the description of Borrelia burgdorferi. It is often forgotten that many other infectious agents as bacteria, virus, Rickettsia or protozoa can be transmitted by ticks. Such diseases are rarely diagnosed in Europe either they are overlooked and misdiagnosed or they are connected with special professional activities. The development of new regions for tourism with different out door activities (adventure trips, trekking, hunting) leads to an exposure to different tick borne diseases, which are often misdiagnosed.
Rubini, A S; Paduan, K S; Martins, T F; Labruna, M B; O'Dwyer, L H
The present study aimed to evaluate under controlled conditions the acquisition of Hepatozoon canis by Amblyomma ovale after feeding on infected dogs, and the subsequent induction of infection in uninfected dogs that ingested the experimentally infected ticks. Two H. canis naturally infected dogs were infested with A. ovale adult ticks derived from an uninfected laboratory tick colony. After feeding, two A. ovale females presented H. canis oocysts in the hemolymph at the first and fourth days after removal of ticks from dogs. The oocysts had an average size of 244.34 microm x 255.46 microm. Three uninfected dogs were fed with ticks previously fed on the infected dogs. Only one dog became infected 32 days after oral inoculation, presenting circulating gametocytes, parasitemia less than 1%, and positive PCR confirmed to be H. canis by DNA sequencing. The results obtained indicated A. ovale ticks as potential vector of H. canis in rural areas of Brazil.
Full Text Available Ticks are distributed worldwide and affect human and animal health by transmitting diverse infectious agents. Effective vaccines against most tick-borne pathogens are not currently available. In this study, we characterized a tick histamine release factor (tHRF from Ixodes scapularis and addressed the vaccine potential of this antigen in the context of tick engorgement and B. burgdorferi transmission. Results from western blotting and quantitative Reverse Transcription-PCR showed that tHRF is secreted in tick saliva, and upregulated in Borrelia burgdorferi-infected ticks. Further, the expression of tHRF was coincident with the rapid feeding phase of the tick, suggesting a role for tHRF in tick engorgement and concomitantly, for efficient B. burgdorferi transmission. Silencing tHRF by RNA interference (RNAi significantly impaired tick feeding and decreased B. burgdorferi burden in mice. Interfering with tHRF by actively immunizing mice with recombinant tHRF, or passively transferring tHRF antiserum, also markedly reduced the efficiency of tick feeding and B. burgdorferi burden in mice. Recombinant tHRF was able to bind to host basophils and stimulate histamine release. Therefore, we speculate that tHRF might function in vivo to modulate vascular permeability and increase blood flow to the tick bite-site, facilitating tick engorgement. These findings suggest that blocking tHRF might offer a viable strategy to complement ongoing efforts to develop vaccines to block tick feeding and transmission of tick-borne pathogens.
Vargová, Blažena; Majláth, Igor; Kurimský, Juraj; Cimbala, Roman; Kosterec, Michal; Tryjanowski, Piotr; Jankowiak, Łukasz; Raši, Tomáš; Majláthová, Viktória
Factors associated with the increased usage of electronic devices, wireless technologies and mobile phones nowadays are present in increasing amounts in our environment. All living organisms are constantly affected by electromagnetic radiation which causes serious environmental pollution. The distribution and density of ticks in natural habitats is influenced by a complex of abiotic and biotic factors. Exposure to radio-frequency electromagnetic field (RF-EMF) constitutes a potential cause altering the presence and distribution of ticks in the environment. Our main objective was to determine the affinity of Dermacentor reticulatus ticks towards RF-EMF exposure. Originally designed and constructed radiation-shielded tube (RST) test was used to test the affinity of ticks under controlled laboratory conditions. All test were performed in an electromagnetic compatibility laboratory in an anechoic chamber. Ticks were irradiated using a Double-Ridged Waveguide Horn Antenna to RF-EMF at 900 and 5000 MHz, 0 MHz was used as control. The RF-EMF exposure to 900 MHz induced a higher concentration of ticks on irradiated arm of RST as opposed to the RF-EMF at 5000 MHz, which caused an escape of ticks to the shielded arm. This study represents the first experimental evidence of RF-EMF preference in D. reticulatus. The projection of obtained results to the natural environment could help assess the risk of tick borne diseases and could be a tool of preventive medicine.
Full Text Available Background: Ixodid ticks (Acari: İxodidae and fleas (Siphonaptera are the major vectors of pathogens threatening animals and human healths. The aim of our study was to detect the infestation rates of East Hedgehogs (Erinaceus concolor with ticks and fleas in Van Province, eastern region of Turkey.Methods: We examined fleas and ticks infestation patterns in 21 hedgehogs, collected from three suburbs with the greater of number gardens. In order to estimate flea and tick infestation of hedgehogs, we immobilized the ectoparasites by treatment the body with a insecticide trichlorphon (Neguvon®-Bayer.Results: On the hedgehogs, 60 ixodid ticks and 125 fleas were detected. All of the ixodid ticks were Rhipicephalus turanicus and all of the fleas were Archaeopsylla erinacei. Infestation rate for ticks and fleas was detected 66.66 % and 100 %, respectively.Conclusion: We detected ticks (R. turanicus and fleas (A. erinacei in hedgehogs at fairly high rates. Since many ticks and fleas species may harbor on hedgehogs and transmit some tick-borne and flea-borne patogens, this results are the important in terms of veterinary and public health.
Climate is one of several causes of disease emergence. Although half or more of infectious diseases are affected by climate it appears to be a relatively infrequent cause of human disease emergence. Climate mostly affects diseases caused by pathogens that spend part of their lifecycle outside of the host, exposed to the environment. The most important routes of transmission of climate sensitive diseases are by arthropod (insect and tick) vectors, in water and in food. Given the sensitivity of many diseases to climate, it is very likely that at least some will respond to future climate change. In the case of vector-borne diseases this response will include spread to new areas. Several vector-borne diseases have emerged in Europe in recent years; these include vivax malaria, West Nile fever, dengue fever, Chikungunya fever, leishmaniasis, Lyme disease and tick-borne encephalitis. The vectors of these diseases are mosquitoes, sand flies and ticks. The UK has endemic mosquito species capable of transmitting malaria and probably other pathogens, and ticks that transmit Lyme disease. The UK is also threatened by invasive mosquito species known to be able to transmit West Nile, dengue, chikungunya and Zika, and sand flies that spread leishmaniasis. Warmer temperatures in the future will increase the suitability of the UK's climate for these invasive species, and increase the risk that they may spread disease. While much attention is on invasive species, it is important to recognize the threat presented by native species too. Proposed actions to reduce the future impact of emerging vector-borne diseases in the UK include insect control activity at points of entry of vehicles and certain goods, wider surveillance for mosquitoes and sand flies, research into the threat posed by native species, increased awareness of the medical profession of the threat posed by specific diseases, regular risk assessments, and increased preparedness for the occurrence of a disease emergency.
Cabezas-Cruz, Alejandro; Alberdi, Pilar; Valdes, James J; Villar, Margarita; de la Fuente, Jose
The obligate intracellular pathogen Anaplasma phagocytophilum infects vertebrate and tick hosts. In this study, a genome-wide search for cytoskeleton components was performed in the tick vector, Ixodes scapularis . The available transcriptomics and proteomics data was then used to characterize the mRNA and protein levels of I. scapularis cytoskeleton components in response to A. phagocytophilum infection. The results showed that cytoskeleton components described in other model organisms were present in the I. scapularis genome. One type of intermediate filaments (lamin), a family of septins that was recently implicated in the cellular response to intracellular pathogens, and several members of motor proteins (kinesins and dyneins) that could be implicated in the cytoplasmic movements of A. phagocytophilum were found. The results showed that levels of tubulin, actin, septin, actin-related proteins and motor proteins were affected by A. phagocytophilum , probably to facilitate infection in I. scapularis . Functional studies demonstrated a role for selected cytoskeleton components in pathogen infection. These results provided a more comprehensive view of the cytoskeletal components involved in the response to A. phagocytophilum infection in ticks.
Kjær, Lene Jung; Korslund, L.; Kjelland, V.; Slettan, A.; Andreassen, Å. K.; Paulsen, K. M.; Christensson, M.; Kjellander, P.; Teräväinen, M.; Soleng, A.; Edgar, K. S.; Lindstedt, H. H.; Schou, Kirstine Klitgaard; Bødker, Rene
Vector-borne diseases such as Lyme disease and tick-borne encephalitis have become more common in recent decades and present a real health problem in many parts of Europe. Risk assessment, control, and prevention of these diseases require a better understanding of vector abundance as well as risk factors determining human exposure to ticks. There is a great need for analyses and models that can predict how vectors and their associated diseases are distributed and how this relates to high risk...
Noé Francisco Rodríguez
Full Text Available Introduction Trypanosoma evansi was first identified in the Canary Islands in 1997, and is still present in a small area of the Archipelago. To date, the disease has exclusively affected camel herds, and has not been detected in any other animal hosts. However potential vectors of Trypanosoma evansi must be identified. Methods One Nzi trap was placed on a camel farm located in the infected area for a period of one year. Results Two thousand five hundred and five insects were trapped, of which Stomoxys calcitrans was the sole hematophagous vector captured. Conclusions Stomoxys calcitrans could be exclusively responsible for the transmission of Trypanosoma evansi among camels in the surveyed area, as other species do not seem to be infected by S. calcitrans in the presence of camels.
Gleim, Elizabeth R; Conner, L Mike; Berghaus, Roy D; Levin, Michael L; Zemtsova, Galina E; Yabsley, Michael J
Some tick populations have increased dramatically in the past several decades leading to an increase in the incidence and emergence of tick-borne diseases. Management strategies that can effectively reduce tick populations while better understanding regional tick phenology is needed. One promising management strategy is prescribed burning. However, the efficacy of prescribed burning as a mechanism for tick control is unclear because past studies have provided conflicting data, likely due to a failure of some studies to simulate operational management scenarios and/or account for other predictors of tick abundance. Therefore, our study was conducted to increase knowledge of tick population dynamics relative to long-term prescribed fire management. Furthermore, we targeted a region, southwestern Georgia and northwestern Florida (USA), in which little is known regarding tick dynamics so that basic phenology could be determined. Twenty-one plots with varying burn regimes (burned surrounded by burned [BB], burned surrounded by unburned [BUB], unburned surrounded by burned [UBB], and unburned surrounded by unburned [UBUB]) were sampled monthly for two years while simultaneously collecting data on variables that can affect tick abundance (e.g., host abundance, vegetation structure, and micro- and macro-climatic conditions). In total, 47,185 ticks were collected, of which, 99% were Amblyomma americanum, 0.7% were Ixodes scapularis, and fewer numbers of Amblyomma maculatum, Ixodes brunneus, and Dermacentor variabilis. Monthly seasonality trends were similar between 2010 and 2011. Long-term prescribed burning consistently and significantly reduced tick counts (overall and specifically for A. americanum and I. scapularis) regardless of the burn regimes and variables evaluated. Tick species composition varied according to burn regime with A. americanum dominating at UBUB, A. maculatum at BB, I. scapularis at UBB, and a more even composition at BUB. These data indicate that
Elizabeth R Gleim
Full Text Available Some tick populations have increased dramatically in the past several decades leading to an increase in the incidence and emergence of tick-borne diseases. Management strategies that can effectively reduce tick populations while better understanding regional tick phenology is needed. One promising management strategy is prescribed burning. However, the efficacy of prescribed burning as a mechanism for tick control is unclear because past studies have provided conflicting data, likely due to a failure of some studies to simulate operational management scenarios and/or account for other predictors of tick abundance. Therefore, our study was conducted to increase knowledge of tick population dynamics relative to long-term prescribed fire management. Furthermore, we targeted a region, southwestern Georgia and northwestern Florida (USA, in which little is known regarding tick dynamics so that basic phenology could be determined. Twenty-one plots with varying burn regimes (burned surrounded by burned [BB], burned surrounded by unburned [BUB], unburned surrounded by burned [UBB], and unburned surrounded by unburned [UBUB] were sampled monthly for two years while simultaneously collecting data on variables that can affect tick abundance (e.g., host abundance, vegetation structure, and micro- and macro-climatic conditions. In total, 47,185 ticks were collected, of which, 99% were Amblyomma americanum, 0.7% were Ixodes scapularis, and fewer numbers of Amblyomma maculatum, Ixodes brunneus, and Dermacentor variabilis. Monthly seasonality trends were similar between 2010 and 2011. Long-term prescribed burning consistently and significantly reduced tick counts (overall and specifically for A. americanum and I. scapularis regardless of the burn regimes and variables evaluated. Tick species composition varied according to burn regime with A. americanum dominating at UBUB, A. maculatum at BB, I. scapularis at UBB, and a more even composition at BUB. These data
Full Text Available Hepatozoon kisrae n. sp. was found infecting a starred lizard at a site in southeastern Samaria, Palestine. These lizards were also hosts to the ixodid tick Hyolomma cf. aegyptium, which was demonstrated to be the vector of this hemogregarine. Hepatozoon and tick infections occurred in lizards within a very restricted locality; at a second site, nearby, ticks occurred without Hepatozoon infection. Micro- and macromeronts occurred mainly in the lungs, while cyst-like merogonic stages, mainly dizoic, occurred in the liver. Mature intraerythrocytic gametocytes were stout and encapsulated. Development from oocysts to sporocysts took place in the tick hemocoel, and was examined by transmission electron microscopy. Lizards were successfully infected when fed on sporocyst-infected ticks or viscera of infected lizards. Ticks become infected when fed on infected lizards; sporogony was complete when the ticks reached adult stage, over 40 days after initial attachment.
Horak, Ivan G; Heyne, Heloise; Halajian, Ali; Booysen, Shalaine; Smit, Willem J
The aim of the study was to determine the species spectrum of ixodid ticks that infest horses and donkeys in South Africa and to identify those species that act as vectors of disease to domestic livestock. Ticks were collected opportunistically from 391 horses countrywide by their owners or grooms, or by veterinary students and staff at the Faculty of Veterinary Science, University of Pretoria. Ticks were also collected from 76 donkeys in Limpopo Province, 2 in Gauteng Province and 1 in North West province. All the ticks were identified by means of a stereoscopic microscope. Horses were infested with 17 tick species, 72.1% with Rhipicephalus evertsi evertsi, 19.4% with Amblyomma hebraeum and 15.6% with Rhipicephalus decoloratus. Rhipicephalus evertsi evertsi was recovered from horses in all nine provinces of South Africa and R. decoloratus in eight provinces. Donkeys were infested with eight tick species, and 81.6% were infested with R. evertsi evertsi, 23.7% with A. hebraeum and 10.5% with R. decoloratus. Several tick species collected from the horses and donkeys are the vectors of economically important diseases of livestock. Rhipicephalus evertsi evertsi is the vector of Theileria equi, the causative organism of equine piroplasmosis. It also transmits Anaplasma marginale, the causative organism of anaplasmosis in cattle. Amblyomma hebraeum is the vector of Ehrlichia ruminantium, the causative organism of heartwater in cattle, sheep and goats, whereas R. decoloratus transmits Babesia bigemina, the causative organism of babesiosis in cattle.
Mihalca, Andrei D; Dumitrache, Mirabela O; Sándor, Attila D; Magdaş, Cristian; Oltean, Miruna; Györke, Adriana; Matei, Ioana A; Ionică, Angela; D'Amico, Gianluca; Cozma, Vasile; Gherman, Călin M
Ticks are among the most important vectors of zoonotic diseases in temperate regions of Europe, with widespread distribution and high densities, posing an important medical risk. Most ticks feed on a variety of progressively larger hosts, with a large number of small mammal species typically harbouring primarily the immature stages. However, there are certain Ixodidae that characteristically attack micromammals also during their adult stage. Rodents are widespread hosts of ticks, important vectors and competent reservoirs of tick-borne pathogens. Micromammal-tick associations have been poorly studied in Romania, and our manuscript shows the results of a large scale study on tick infestation epidemiology in rodents from Romania. Rodents were caught using snap-traps in a variety of habitats in Romania, between May 2010 and November 2011. Ticks were individually collected from these rodents and identified to species and development stage. Frequency, mean intensity, prevalence and its 95% confidence intervals were calculated using the EpiInfo 2000 software. A p value of Romania for the presence of ticks. Each collected tick was identified to species level and the following epidemiological parameters were calculated: prevalence, mean intensity and mean abundance. The total number of ticks collected from rodents was 483, with eight species identified: Ixodes ricinus, I. redikorzevi, I. apronophorus, I. trianguliceps, I. laguri, Dermacentor marginatus, Rhipicephalus sanguineus and Haemaphysalis sulcata. The overall prevalence of tick infestation was 29.55%, with a mean intensity of 3.86 and a mean abundance of 1.14. Only two polyspecific infestations were found: I. ricinus + I. redikorzevi and I. ricinus + D. marginatus. Our study showed a relatively high diversity of ticks parasitizing rodents in Romania. The most common tick in rodents was I. ricinus, followed by I. redikorzevi. Certain rodents seem to host a significantly higher number of tick species than others, the
... this issue Tick Talk Block Tick Bites and Lyme Disease En español Send us your comments When warm ... mainly in the mid-Atlantic and southern states. Lyme disease is the most common tick-borne illness. It’s ...
... virus, Siberian tick-borne encephalitis virus, and Far eastern Tick-borne encephalitis virus (formerly known as Russian ... viruses are closely related to TBEV and Far-eastern TBE, and include Omsk hemorrhagic fever virus in ...
Canine vector-borne diseases (CVBDs) are highly prevalent in Brazil and represent a challenge to veterinarians and public health workers, since some diseases are of great zoonotic potential. Dogs are affected by many protozoa (e.g., Babesia vogeli, Leishmania infantum, and Trypanosoma cruzi), bacteria (e.g., Anaplasma platys and Ehrlichia canis), and helminths (e.g., Dirofilaria immitis and Dipylidium caninum) that are transmitted by a diverse range of arthropod vectors, including ticks, fleas, lice, triatomines, mosquitoes, tabanids, and phlebotomine sand flies. This article focuses on several aspects (etiology, transmission, distribution, prevalence, risk factors, diagnosis, control, prevention, and public health significance) of CVBDs in Brazil and discusses research gaps to be addressed in future studies. PMID:18691408
Full Text Available Abstract Canine vector-borne diseases (CVBDs are highly prevalent in Brazil and represent a challenge to veterinarians and public health workers, since some diseases are of great zoonotic potential. Dogs are affected by many protozoa (e.g., Babesia vogeli, Leishmania infantum, and Trypanosoma cruzi, bacteria (e.g., Anaplasma platys and Ehrlichia canis, and helminths (e.g., Dirofilaria immitis and Dipylidium caninum that are transmitted by a diverse range of arthropod vectors, including ticks, fleas, lice, triatomines, mosquitoes, tabanids, and phlebotomine sand flies. This article focuses on several aspects (etiology, transmission, distribution, prevalence, risk factors, diagnosis, control, prevention, and public health significance of CVBDs in Brazil and discusses research gaps to be addressed in future studies.
Diana Nayibe Polanco Echeverry
Full Text Available Hard ticks are blood-sucking ectoparasites of Ixodidae family. These mites have been always considered disrupting agents of livestock systems, where they are recognized as the cause of economic and production losses. However, their ecological role is important for the dynamic equilibrium of the production systems bovine meat or milk. Knowing their biolog y and ecolog y can shed light on the sanitary decisions made in relation to these organisms. This review article presents issues related to classification, characteristics, and life cycle of hard ticks and relations vector-parasite-host. In addition, it addresses the control of ectoparasites on conventional livestock systems and the implica-tions that these models of intervention might have on agro-ecosystem.
Andrew F. Heckler
Full Text Available In experiments including over 450 university-level students, we studied the effectiveness and time efficiency of several levels of feedback complexity in simple, computer-based training utilizing static question sequences. The learning domain was simple vector math, an essential skill in introductory physics. In a unique full factorial design, we studied the relative effects of “knowledge of correct response” feedback and “elaborated feedback” (i.e., a general explanation both separately and together. A number of other factors were analyzed, including training time, physics course grade, prior knowledge of vector math, and student beliefs about both their proficiency in and the importance of vector math. We hypothesize a simple model predicting how the effectiveness of feedback depends on prior knowledge, and the results confirm this knowledge-by-treatment interaction. Most notably, elaborated feedback is the most effective feedback, especially for students with low prior knowledge and low course grade. In contrast, knowledge of correct response feedback was less effective for low-performing students, and including both kinds of feedback did not significantly improve performance compared to elaborated feedback alone. Further, while elaborated feedback resulted in higher scores, the learning rate was at best only marginally higher because the training time was slightly longer. Training time data revealed that students spent significantly more time on the elaborated feedback after answering a training question incorrectly. Finally, we found that training improved student self-reported proficiency and that belief in the importance of the learned domain improved the effectiveness of training. Overall, we found that computer based training with static question sequences and immediate elaborated feedback in the form of simple and general explanations can be an effective way to improve student performance on a physics essential skill
Nootkatone is a component of grapefruit oil that is toxic to the disease vectoring tick, Ixodes scapularis Say, but unfortunately causes phytotoxicity to treated plants and has a short residual activity due to volatility. We prepared an encapsulated formulation of nootkatone using lignin to compare...
Full Text Available Abstract In Italy, dogs and cats are at risk of becoming infected by different vector-borne pathogens, including protozoa, bacteria, and helminths. Ticks, fleas, phlebotomine sand flies, and mosquitoes are recognized vectors of pathogens affecting cats and dogs, some of which (e.g., Anaplasma phagocytophilum, Borrelia burgdorferi, Dipylidium caninum, Leishmania infantum, Dirofilaria immitis, and Dirofilaria repens are of zoonotic concern. Recent studies have highlighted the potential of fleas as vectors of pathogens of zoonotic relevance (e.g., Rickettsia felis in this country. While some arthropod vectors (e.g., ticks and fleas are present in certain Italian regions throughout the year, others (e.g., phlebotomine sand flies are most active during the summer season. Accordingly, control strategies, such as those relying on the systematic use of acaricides and insecticides, should be planned on the basis of the ecology of both vectors and pathogens in different geographical areas in order to improve their effectiveness in reducing the risk of infection by vector-borne pathogens. This article reviews the current situation and perspectives of canine and feline vector-borne diseases in Italy.
Huntington, Mark K; Allison, Jay
In addition to being a nuisance, ticks can carry disease. This article presents a brief review of ticks and associated tick-borne disease relevant to South Dakota and surrounding regions. Tick-borne diseases of special relevance in South Dakota include tularemia, Rocky Mountain spotted fever, and Lyme disease. A number of others may also be encountered in the state as well. Prompt treatment of suspected cases is important to ensure a successful recovery, and tick-avoidance measures can reduce the risks of acquiring them. Most of these conditions are nationally reportable infectious diseases. Copyright© South Dakota State Medical Association.
Honig, Jessica E.; Osborne, Jane C.; Nichol, Stuart T.
The genus Nairovirus (family Bunyaviridae) contains seven serogroups consisting of 34 predominantly tick-borne viruses, including several associated with severe human and livestock diseases [e.g., Crimean Congo hemorrhagic fever (CCHF) and Nairobi sheep disease (NSD), respectively]. Before this report, no comparative genetic studies or molecular detection assays had been developed for this virus genus. To characterize at least one representative from each of the seven serogroups, reverse transcriptase-polymerase chain reaction (RT-PCR) primers targeting the L polymerase-encoding region of the RNA genome of these viruses were successfully designed based on conserved amino acid motifs present in the predicted catalytic core region. Sequence analysis showed the nairoviruses to be a highly diverse group, exhibiting up to 39.4% and 46.0% nucleotide and amino acid identity differences, respectively. Virus genetic relationships correlated well with serologic groupings and with tick host associations. Hosts of these viruses include both the hard (family Ixodidae) and soft (family Argasidae) ticks. Virus phylogenetic analysis reveals two major monophyletic groups: hard tick and soft tick-vectored viruses. In addition, viruses vectored by Ornithodoros, Carios, and Argas genera ticks also form three separate monophyletic lineages. The striking similarities between tick and nairovirus phylogenies are consistent with possible coevolution of the viruses and their tick hosts. Fossil and phylogenetic data placing the hard tick-soft tick divergence between 120 and 92 million years ago suggest an ancient origin for viruses of the genus Nairovirus
Rolla, G; Heffler, E; Boita, M
Anaphylaxis is a serious systemic allergic reaction with rapid onset and potentially life-threatening. We report in detail a case of severe nocturnal anaphylaxis due to pigeon tick bite showing the diagnostic value of the extract and the recombinant allergen in the diagnostic procedures (basophil...... reagents. Because of the growing number of pigeons in Middle and Southern Europe cities, some cases of idiopathic anaphylaxis could potentially be caused by A. reflexus in those countries. The identification of pigeon ticks as a trigger of anaphylaxis would greatly improve medical care and advice...
Sprong, H.; Wielinga, P.R.; Fonville, M.; Reusken, C.; Brandenburg, A.H.; Borgsteede, F.H.M.
Background - Hard ticks have been identified as important vectors of rickettsiae causing the spotted fever syndrome. Tick-borne rickettsiae are considered to be emerging, but only limited data are available about their presence in Western Europe, their natural life cycle and their reservoir hosts.
Movila, A; Deriabina, T; Morozov, A; Sitnicova, N; Toderas, I; Uspenskaia, I; Alekhnovici, A
The Chernobyl nuclear disaster resulted in contamination of vast areas in Europe. To date, there is little knowledge about the effects of radioactive contamination on tick species. We sampled ticks from vegetation and large-sized wild mammals belonging to orders Carnivora and Artiodactyla at sites with 0.76, 1.91, and 4.50 mSv/hr ionizing radiation background values in the Polesky State Radio-Ecological Reserve of the Chernobyl nuclear disaster zone in spring 2010. Altogether, 122 questing ticks were collected from vegetation. Among collected ticks, Dermacentor reticulatus (Fabricius) was, by far, the most abundant species (99.2%), followed by Ixodes ricnus (L.) (0.8%), which was collected only at the 0.76 mSv/hr site. The average sex ratio female∶male was 2.9∶1.0. In parallel with the present study, we examined 3 Sus scrofa (L.), 2 Nyctereutes procyonoides (Gray), and 1 Alces alces (L.) at the 4.50 mSv/hr site; 96 D. reticulatus ticks were found on 2 N. procyonoides specimens. The mean density and the intensity of infestation were 16 ticks per animal and 48 ticks per infested animal, respectively. Future investigations are warranted to further characterize the role of various tick vectors, vertebrate reservoirs, and diversity of tick-borne pathogens in the Chernobyl exclusion zone.
Van Treuren, Will; Ponnusamy, Loganathan; Brinkerhoff, R Jory; Gonzalez, Antonio; Parobek, Christian M; Juliano, Jonathan J; Andreadis, Theodore G; Falco, Richard C; Ziegler, Lorenza Beati; Hathaway, Nicholas; Keeler, Corinna; Emch, Michael; Bailey, Jeffrey A; Roe, R Michael; Apperson, Charles S; Knight, Rob; Meshnick, Steven R
Ixodes scapularis is the principal vector of Lyme disease on the East Coast and in the upper Midwest regions of the United States, yet the tick is also present in the Southeast, where Lyme disease is absent or rare. A closely related species, I. affinis, also carries the pathogen in the South but does not seem to transmit it to humans. In order to better understand the geographic diversity of the tick, we analyzed the microbiota of 104 adult I. scapularis and 13 adult I. affinis ticks captured in 19 locations in South Carolina, North Carolina, Virginia, Connecticut, and New York. Initially, ticks from 4 sites were analyzed by 454 pyrosequencing. Subsequently, ticks from these sites plus 15 others were analyzed by sequencing with an Illumina MiSeq machine. By both analyses, the microbiomes of female ticks were significantly less diverse than those of male ticks. The dissimilarity between tick microbiomes increased with distance between sites, and the state in which a tick was collected could be inferred from its microbiota. The genus Rickettsia was prominent in all locations. Borrelia was also present in most locations and was present at especially high levels in one site in western Virginia. In contrast, members of the family Enterobacteriaceae were very common in North Carolina I. scapularis ticks but uncommon in I. scapularis ticks from other sites and in North Carolina I. affinis ticks. These data suggest substantial variations in the Ixodes microbiota in association with geography, species, and sex. Copyright © 2015, American Society for Microbiology. All Rights Reserved.
Full Text Available Vaccines that target blood-feeding disease vectors, such as mosquitoes and ticks, have the potential to protect against the many diseases caused by vector-borne pathogens. We tested the ability of an anti-tick vaccine derived from a tick cement protein (64TRP of Rhipicephalus appendiculatus to protect mice against tick-borne encephalitis virus (TBEV transmitted by infected Ixodes ricinus ticks. The vaccine has a "dual action" in immunized animals: when infested with ticks, the inflammatory and immune responses first disrupt the skin feeding site, resulting in impaired blood feeding, and then specific anti-64TRP antibodies cross-react with midgut antigenic epitopes, causing rupture of the tick midgut and death of engorged ticks. Three parameters were measured: "transmission," number of uninfected nymphal ticks that became infected when cofeeding with an infected adult female tick; "support," number of mice supporting virus transmission from the infected tick to cofeeding uninfected nymphs; and "survival," number of mice that survived infection by tick bite and subsequent challenge by intraperitoneal inoculation of a lethal dose of TBEV. We show that one dose of the 64TRP vaccine protects mice against lethal challenge by infected ticks; control animals developed a fatal viral encephalitis. The protective effect of the 64TRP vaccine was comparable to that of a single dose of a commercial TBEV vaccine, while the transmission-blocking effect of 64TRP was better than that of the antiviral vaccine in reducing the number of animals supporting virus transmission. By contrast, the commercial antitick vaccine (TickGARD that targets only the tick's midgut showed transmission-blocking activity but was not protective. The 64TRP vaccine demonstrates the potential to control vector-borne disease by interfering with pathogen transmission, apparently by mediating a local cutaneous inflammatory immune response at the tick-feeding site.
Markeshin, S Ia; Evstaf'ev, I L; Kovin, V V; Evstratov, Iu V
About a hundred of patients with tick-borne encephalitis (TBE) were recorded over the latest decade in the Crimea, and 60 TBE virus strains were isolated from the ticks collected on the peninsula. The results of studies carried out in 1986-1990 helped define the borders of 4 local natural foci of TBE, study their acarifauna, detect the principal TBE vector--Ixodes ricinus (with a mean virophority of 0.6%), and distinguish two foci with a combination of TBE and Crimean-Congo hemorrhagic fever.
Alyssa D. Ammazzalorso
Full Text Available Background. Blacklegged ticks (Ixodes scapularis are important disease vectors in the United States, known to transmit a variety of pathogens to humans, including bacteria, protozoa, and viruses. Their importance as a disease vector necessitates reliable and comparable methods for extracting microbial DNA from ticks. Furthermore, to explore the population genetics or genomics of this tick, appropriate DNA extraction techniques are needed for both the vector and its microbes. Although a few studies have investigated different methods of DNA isolation from ticks, they are limited in the number and types of DNA extraction and lack species-specific quantification of DNA yield.Methods. Here we determined the most efficient and consistent method of DNA extraction from two different developmental stages of I. scapularis—nymph and adult—that are the most important for disease transmission. We used various methods of physical disruption of the hard, chitinous exoskeleton, as well as commercial and non-commercial DNA isolation kits. To gauge the effectiveness of these methods, we quantified the DNA yield and confirmed the DNA quality via PCR of both tick and microbial genetic material.Results. DNA extraction using the Thermo GeneJET Genomic DNA Purification Kit resulted in the highest DNA yields and the most consistent PCR amplification when combined with either cutting or bead beating with select matrices across life stages. DNA isolation methods using ammonium hydroxide as well as the MoBio PowerSoil kit also produced strong and successful PCR amplification, but only for females.Discussion. We contrasted a variety of readily available methods of DNA extraction from single individual blacklegged ticks and presented the results through a quantitative and qualitative assessment.
Cabezas-Cruz, A.; Valdés, James J.
Roč. 11, JUL 2014 (2014), s. 47 ISSN 1742-9994 R&D Projects: GA MŠk(CZ) EE2.3.30.0032 Institutional support: RVO:60077344 Keywords : ticks * venom * secreted proteins * toxicoses * pathogens * convergence Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.051, year: 2014
Kopáček, Petr; Hajdušek, Ondřej; Burešová, Veronika; Daffre, S.
Roč. 708, - (2010), 137-162 ISSN 0065-2598 R&D Projects: GA ČR GAP506/10/2136; GA MŠk(CZ) LC06009 Institutional research plan: CEZ:AV0Z60220518 Keywords : tick * pathogen transmission * innate immunity Subject RIV: EC - Immunology Impact factor: 1.379, year: 2010
Dr. Chris Paddock, a rickettsiologist and infectious disease pathologist discusses a tick-transmitted bacterium, Rickettsia parkeri. Created: 8/18/2011 by National Center for Emerging Zoonotic and Infectious Diseases (NCEZID). Date Released: 8/18/2011.
Abstract' Background For >100 years cattle production in the southern United States has been threatened by cattle fever. It is caused by an invasive parasite-vector complex that includes the protozoan hemoparasites Babesia bovis and B. bigemina, which are transmitted among domestic cattle via Rhipicephalus tick vectors of the subgenus Boophilus. In 1906 an eradication effort was started and by 1943 Boophilus ticks had been confined to a narrow tick eradication quarantine area (TEQA) along the Texas-Mexico border. However, a dramatic increase in tick infestations in areas outside the TEQA over the last decade suggests these tick vectors may be poised to re-invade the southern United States. We investigated historical and potential future distributions of climatic habitats of cattle fever ticks to assess the potential for a range expansion. Methods We built robust spatial predictions of habitat suitability for the vector species Rhipicephalus (Boophilus) microplus and R. (B.) annulatus across the southern United States for three time periods: 1906, present day (2012), and 2050. We used analysis of molecular variance (AMOVA) to identify persistent tick occurrences and analysis of bias in the climate proximate to these occurrences to identify key environmental parameters associated with the ecology of both species. We then used ecological niche modeling algorithms GARP and Maxent to construct models that related known occurrences of ticks in the TEQA during 2001–2011 with geospatial data layers that summarized important climate parameters at all three time periods. Results We identified persistent tick infestations and specific climate parameters that appear to be drivers of ecological niches of the two tick species. Spatial models projected onto climate data representative of climate in 1906 reproduced historical pre-eradication tick distributions. Present-day predictions, although constrained to areas near the TEQA, extrapolated well onto climate projections for
Equine piroplasmosis (EP) is a disease of equidae including horses, donkeys, mules and zebras caused by either of two protozoan parasites, Theileria equi or Babesia caballi. These parasites are biologically transmitted between hosts via tick-vectors and although they have inherent differences, they ...
Full Text Available Argasid ticks include vectors of relapsing fevers caused by Borrelia spp. in humans, and they can transmit arboviruses and other bacterial pathogens. Knowledge about soft ticks (Ixodida: Argasidae in Algeria is incomplete, and distribution data need to be updated. Here we report a series of entomologic investigations that we conducted in five different areas in Algeria between 2012 and 2015. Ticks were identified by entomologic keys and molecular tools (16S rRNA gene. Six distinct species belonging to two genera were identified, including Ornithodoros capensis s.s., Ornithodoros rupestris, Ornithodoros occidentalis, Ornithodoros erraticus, Ornithodoros sonrai and Argas persicus. The present study highlights the distribution of soft ticks, the establishment of an update inventory with nine species and associated pathogens detected in argasid ticks in Algeria. Keywords: Argasid, Borrelia, Ornithodoros, Rickettsia
Lafri, I; Benredjem, W; Neffah-Baaziz, F; Lalout, R; Abdelouahed, K; Gassen, B; Bakhouch, S; Chergui, M; Karakellah, M; Adjmi-Hamoudi, H; Bitam, I
Argasid ticks include vectors of relapsing fevers caused by Borrelia spp. in humans, and they can transmit arboviruses and other bacterial pathogens. Knowledge about soft ticks ( Ixodida: Argasidae ) in Algeria is incomplete, and distribution data need to be updated. Here we report a series of entomologic investigations that we conducted in five different areas in Algeria between 2012 and 2015. Ticks were identified by entomologic keys and molecular tools (16S rRNA gene). Six distinct species belonging to two genera were identified, including Ornithodoros capensis s.s., Ornithodoros rupestris, Ornithodoros occidentalis, Ornithodoros erraticus, Ornithodoros sonrai and Argas persicus. The present study highlights the distribution of soft ticks, the establishment of an update inventory with nine species and associated pathogens detected in argasid ticks in Algeria.
Kate McElroy Horne
Full Text Available The Bunyaviridae family is comprised of more than 350 viruses, of which many within the Hantavirus, Orthobunyavirus, Nairovirus, Tospovirus, and Phlebovirus genera are significant human or agricultural pathogens. The viruses within the Orthobunyavirus, Nairovirus, and Phlebovirus genera are transmitted by hematophagous arthropods, such as mosquitoes, midges, flies, and ticks, and their associated arthropods not only serve as vectors but also as virus reservoirs in many cases. This review presents an overview of several important emerging or re-emerging bunyaviruses and describes what is known about bunyavirus-vector interactions based on epidemiological, ultrastructural, and genetic studies of members of this virus family.
Full Text Available The epidemiology of vector-borne zoonoses depends on the movement of both hosts and vectors, which can differ greatly in intensity across spatial scales. Because of their life history traits and small size, vector dispersal may be frequent, but limited in distance. However, little information is available on vector movement patterns at local spatial scales, and particularly for ticks, transmitting the greatest diversity of recognized infectious agents. To test the degree to which ticks can disperse and disseminate pathogens at local scales, we investigated the temporal dynamics and population structure of the soft tick Ornithodoros maritimus within a colony of its seabird host, the Yellow-legged gull Larus michahellis. Ticks were repeatedly sampled at a series of nests during the host breeding season. In half of the nests, ticks were collected (removal sampling, in the other half, ticks were counted and returned to the nest. A subsample of ticks was screened for known bacteria, viruses and parasites using a high throughput real-time PCR system to examine their distribution within the colony. The results indicate a temporal dynamic in the presence of tick life stages over the season, with the simultaneous appearance of juvenile ticks and hatched chicks, but no among-nest spatial structure in tick abundance. Removal sampling significantly reduced tick numbers, but only from the fourth visit onward. Seven bacterial isolates, one parasite species and one viral isolate were detected but no spatial structure in their presence within the colony was found. These results suggest weak isolation among nests and that tick dispersal is likely frequent enough to quickly recolonize locally-emptied patches and disseminate pathogens across the colony. Vector-mediated movements at local scales may therefore play a key role in pathogen emergence and needs to be considered in conjunction with host movements for predicting pathogen circulation and for establishing
Leydet, Brian F; Liang, Fang-Ting
There are 4 major human-biting tick species in the northeastern United States, which include: Amblyomma americanum, Amblyomma maculatum, Dermacentor variabilis, and Ixodes scapularis. The black bear is a large mammal that has been shown to be parasitized by all the aforementioned ticks. We investigated the bacterial infections in ticks collected from Louisiana black bears (Ursus americanus subspecies luteolus). Eighty-six ticks were collected from 17 black bears in Louisiana from June 2010 to March 2011. All 4 common human-biting tick species were represented. Each tick was subjected to polymerase chain reaction (PCR) targeting select bacterial pathogens and symbionts. Bacterial DNA was detected in 62% of ticks (n=53). Rickettsia parkeri, the causative agent of an emerging spotted fever group rickettsiosis, was identified in 66% of A. maculatum, 28% of D. variabilis, and 11% of I. scapularis. The Lyme disease bacterium, Borrelia burgdorferi, was detected in 2 I. scapularis, while one A. americanum was positive for Borrelia bissettii, a putative human pathogen. The rickettsial endosymbionts Candidatus Rickettsia andeanae, rickettsial endosymbiont of I. scapularis, and Rickettsia amblyommii were detected in their common tick hosts at 21%, 39%, and 60%, respectively. All ticks were PCR-negative for Anaplasma phagocytophilum, Ehrlichia spp., and Babesia microti. This is the first reported detection of R. parkeri in vector ticks in Louisiana; we also report the novel association of R. parkeri with I. scapularis. Detection of both R. parkeri and B. burgdorferi in their respective vectors in Louisiana demands further investigation to determine potential for human exposure to these pathogens. Copyright © 2013 Elsevier GmbH. All rights reserved.
Moutailler, Sara; Valiente Moro, Claire; Vaumourin, Elise; Michelet, Lorraine; Tran, Florence Hélène; Devillers, Elodie; Cosson, Jean-François; Gasqui, Patrick; Van, Van Tran; Mavingui, Patrick; Vourc'h, Gwenaël; Vayssier-Taussat, Muriel
Ticks are the most common arthropod vectors of both human and animal diseases in Europe, and the Ixodes ricinus tick species is able to transmit a large number of bacteria, viruses and parasites. Ticks may also be co-infected with several pathogens, with a subsequent high likelihood of co-transmission to humans or animals. However few data exist regarding co-infection prevalences, and these studies only focus on certain well-known pathogens. In addition to pathogens, ticks also carry symbionts that may play important roles in tick biology, and could interfere with pathogen maintenance and transmission. In this study we evaluated the prevalence of 38 pathogens and four symbionts and their co-infection levels as well as possible interactions between pathogens, or between pathogens and symbionts. A total of 267 Ixodes ricinus female specimens were collected in the French Ardennes and analyzed by high-throughput real-time PCR for the presence of 37 pathogens (bacteria and parasites), by rRT-PCR to detect the presence of Tick-Borne encephalitis virus (TBEV) and by nested PCR to detect four symbionts. Possible multipartite interactions between pathogens, or between pathogens and symbionts were statistically evaluated. Among the infected ticks, 45% were co-infected, and carried up to five different pathogens. When adding symbiont prevalences, all ticks were infected by at least one microorganism, and up to eight microorganisms were identified in the same tick. When considering possible interactions between pathogens, the results suggested a strong association between Borrelia garinii and B. afzelii, whereas there were no significant interactions between symbionts and pathogens. Our study reveals high pathogen co-infection rates in ticks, raising questions about possible co-transmission of these agents to humans or animals, and their consequences to human and animal health. We also demonstrated high prevalence rates of symbionts co-existing with pathogens, opening new
Full Text Available Ticks are the most common arthropod vectors of both human and animal diseases in Europe, and the Ixodes ricinus tick species is able to transmit a large number of bacteria, viruses and parasites. Ticks may also be co-infected with several pathogens, with a subsequent high likelihood of co-transmission to humans or animals. However few data exist regarding co-infection prevalences, and these studies only focus on certain well-known pathogens. In addition to pathogens, ticks also carry symbionts that may play important roles in tick biology, and could interfere with pathogen maintenance and transmission. In this study we evaluated the prevalence of 38 pathogens and four symbionts and their co-infection levels as well as possible interactions between pathogens, or between pathogens and symbionts.A total of 267 Ixodes ricinus female specimens were collected in the French Ardennes and analyzed by high-throughput real-time PCR for the presence of 37 pathogens (bacteria and parasites, by rRT-PCR to detect the presence of Tick-Borne encephalitis virus (TBEV and by nested PCR to detect four symbionts. Possible multipartite interactions between pathogens, or between pathogens and symbionts were statistically evaluated. Among the infected ticks, 45% were co-infected, and carried up to five different pathogens. When adding symbiont prevalences, all ticks were infected by at least one microorganism, and up to eight microorganisms were identified in the same tick. When considering possible interactions between pathogens, the results suggested a strong association between Borrelia garinii and B. afzelii, whereas there were no significant interactions between symbionts and pathogens.Our study reveals high pathogen co-infection rates in ticks, raising questions about possible co-transmission of these agents to humans or animals, and their consequences to human and animal health. We also demonstrated high prevalence rates of symbionts co-existing with pathogens
Full Text Available In North America, the black-legged tick, Ixodes scapularis, an obligate haematophagus arthropod, is a vector of several human pathogens including Borrelia burgdorferi, the Lyme disease agent. In this report, we show that the tick salivary gland transcriptome and proteome is dynamic and changes during the process of engorgement. We demonstrate, using a guinea pig model of I. scapularis feeding and B. burgdorferi transmission, that immunity directed against salivary proteins expressed in the first 24 h of tick attachment - and not later - is sufficient to evoke all the hallmarks of acquired tick-immunity, to thwart tick feeding and also to impair Borrelia transmission. Defining this subset of proteins will promote a mechanistic understanding of novel I. scapularis proteins critical for the initiation of tick feeding and for Borrelia transmission.
Camacho-Nuez, Minerva; Hernández-Silva, Diego Josimar; Castañeda-Ortiz, Elizabeth Jacqueline; Paredes-Martínez, María Elena; Rocha-Martínez, Marisol Karina; Alvarez-Sánchez, María Elizbeth; Mercado-Curiel, Ricardo Francisco; Aguilar-Tipacamu, Gabriela; Mosqueda, Juan
Background Bovine babesiosis is a tick-borne disease caused by the protozoan parasites of the genus Babesia. In their host vector, Babesia spp. undergo sexual reproduction. Therefore, the development of sexual stages and the subsequent formation of the zygote are essential for the parasite to invade the intestinal cells of the vector tick and continue its life-cycle. HAP2/GCS1 is a protein identified in plants, protozoan parasites and other organisms that has an important role during membrane...
For >100 years cattle production in the southern United States has been threatened by cattle fever. It is caused by an invasive parasite-vector complex that includes the protozoan hemoparasites Babesia bovis and B. bigemina, which are transmitted among domestic cattle via Rhipicephalus tick vectors ...
King Roberta S
Full Text Available Abstract Background Ixodes scapularis, commonly known as the blacklegged or deer tick, is the main vector of Lyme disease in the United States. Recent progress in transcriptome research has uncovered hundreds of different proteins expressed in the salivary glands of hard ticks, the majority of which have no known function, and include many novel protein families. We recently identified transcripts coding for two putative cytosolic sulfotransferases in these ticks which recognized phenolic monoamines as their substrates. In this current study, we characterize the genetic expression of these two cytosolic sulfotransferases throughout the tick life cycle as well as the enzymatic properties of the corresponding recombinant proteins. Interestingly, the resultant recombinant proteins showed sulfotransferase activity against both neurotransmitters dopamine and octopamine. Results The two sulfotransferase genes were coded as Ixosc SULT 1 & 2 and corresponding proteins were referred as Ixosc Sult 1 and 2. Using gene-specific primers, the sulfotransferase transcripts were detected throughout the blacklegged tick life cycle, including eggs, larvae, nymphs, adult salivary glands and adult midgut. Notably, the mRNA and protein levels were altered upon feeding during both the larval and nymphal life stages. Quantitative PCR results confirm that Ixosc SULT1 was statistically increased upon blood feeding while Ixosc SULT 2 was decreased. This altered expression led us to further characterize the function of these proteins in the Ixodid tick. The sulfotransferase genes were cloned and expressed in a bacterial expression system, and purified recombinant proteins Ixosc Sult 1(R and 2(R showed sulfotransferase activity against neurotransmitters dopamine and octopamine as well as the common sulfotransferase substrate p-nitrophenol. Thus, dopamine- or octopamine-sulfonation may be involved in altering the biological signal for salivary secretion in I. scapularis
Robin K. Kuriakose
Conclusions and importance: Despite the low risk for Lyme disease, which is endemic to the Adirondack region where the patient was affected, doxycycline was prescribed for prophylaxis. In any case of suspected tick penetration to the ocular surface, immediate ophthalmologic consultation and prompt removal via the method mentioned above is recommended, as well as attention paid to the Infectious Diseases Society of America guidelines regarding prophylaxis.
Kiewra, Dorota; Zaleśny, Grzegorz; Czułowska, Aleksandra
Ticks constitute important vectors of human and animal pathogens. Besides the Lyme borreliosis and tick-borne encephalitis, other pathogens such as Babesia spp., Rickettsia spp., and Anaplasma phagocytophilum, are of increasing public health interest. In Poland, as in other European countries, Ixodes ricinus, the most prevalent tick species responsible for the majority of tick bites in humans, is the main vector of A. phagocytophilum. The aim of the study was to estimate the infection level of I. ricinus with A. phagocytophilum in selected districts, not previously surveyed for the presence of this agent. Sampling of questing ticks was performed in 12 forested sites, located in four districts (Legnica, Milicz, Lubań, and Oława) in SW Poland. Altogether, 792 ticks (151 females, 101 males, and 540 nymphs) representing I. ricinus were checked for the presence of A. phagocytophilum. The average infection level was 4.3%, with higher rate reported for adult ticks. The highest percentage of infected adults was observed in Milicz (17.4%) and the lowest in Oława (6.8%). The abundance of questing I. ricinus in all examined sites as well as the infection with A. phagocytophilum indicate for the first time the risk for HGA transmission in SW Poland.
Lommano, Elena; Bertaiola, Luce; Dupasquier, Christèle
In Europe, Ixodes ricinus is the vector of many pathogens of medical and veterinary relevance, among them Borrelia burgdorferi sensu lato and tick-borne encephalitis virus, which have been the subject of numerous investigations. Less is known about the occurrence of emerging tick-borne pathogens like Rickettsia spp., Babesia spp., “Candidatus Neoehrlichia mikurensis,” and Anaplasma phagocytophilum in questing ticks. In this study, questing nymph and adult I. ricinus ticks were collected at 11 sites located in Western Switzerland. A total of 1,476 ticks were analyzed individually for the simultaneous presence of B. burgdorferi sensu lato, Rickettsia spp., Babesia spp., “Candidatus Neoehrlichia mikurensis,” and A. phagocytophilum. B. burgdorferi sensu lato, Rickettsia spp., and “Candidatus Neoehrlichia mikurensis” were detected in ticks at all sites with global prevalences of 22.5%, 10.2%, and 6.4%, respectively. Babesia- and A. phagocytophilum-infected ticks showed a more restricted geographic distribution, and their prevalences were lower (1.9% and 1.5%, respectively). Species rarely reported in Switzerland, like Borrelia spielmanii, Borrelia lusitaniae, and Rickettsia monacensis, were identified. Infections with more than one pathogenic species, involving mostly Borrelia spp. and Rickettsia helvetica, were detected in 19.6% of infected ticks. Globally, 34.2% of ticks were infected with at least one pathogen. The diversity of tick-borne pathogens detected in I. ricinus in this study and the frequency of coinfections underline the need to take them seriously into consideration when evaluating the risks of infection following a tick bite. PMID:22522688
Haditsch, Martin; Kunze, Ursula
Tick-borne encephalitis (TBE) is a vector-borne disease that is primarily transmitted to humans by infected ticks and causes infection of the central nervous system. Clinical presentations range from meningitis to encephalitis with or without myelitis, and infection may result in death or long-term neurological sequelae. TBE is endemic in regions of at least 27 European as well as in some Asian countries. Infection and disease, however, can be averted successfully by tick-bite prevention and active vaccination. The risk of infection has shifted from daily life and occupational exposure to leisure-time activities, including travelling. Outdoor activities during the tick season with contact with nature increase the risk of tick bites. Although the number of travel-associated cases is unknown, it is certainly under-estimated because there is hardly any awareness of TBE in non-endemic countries. Therefore, the majority of cases remain undiagnosed, also because of the lack of diagnostic serology, as there is no routine screening for TBE in non-endemic regions. Because of the increasing number of travellers from TBE non-endemic to endemic regions, and in view of the fact that TBE was included in the list of notifiable diseases in the European Union in September 2012, this disease needs to become an important issue in travel medicine. Copyright © 2013 Elsevier Ltd. All rights reserved.
Full Text Available In this work has been made a detection and preliminary characterization of some hydrolases in whole extracts from unfed adult males and females of Hyalomma lusitanicum, one of the vectors for Theileria annulata that causes Mediterranean theileriosis in cattle. We have elected as targets, proteases as enzymes implicated in the nutritional processes of ticks, esterases that are usually implicated in resistance to organophosphates and phosphatises often implicated in protein phosphorilation and control of ticks salivary gland. The biological role and physiological significance are discussed in terms of the possibility of use these enzymes as possible in future anti-tick vaccination or acaricide resistance.
Dai, Jianfeng; Wang, Penghua; Adusumilli, Sarojini; Booth, Carmen J.; Narasimhan, Sukanya; Anguita, Juan; Fikrig, Erol
Traditionally, vaccines directly target a pathogen or microbial toxin. Lyme disease, caused by Borrelia burgdorferi, is a tick-borne illness for which a human vaccine is not currently available. B. burgdorferi binds a tick salivary protein, Salp15, during transmission from the vector, and this interaction facilitates infection of mice. We now show that Salp15-antiserum significantly protected mice from B. burgdorferi infection. Salp15-antiserum also markedly enhanced the protective capacity o...
Konto, M; Fufa, G I; Zakaria, A; Tukur, S M; Watanabe, M; Ola-Fadunsin, S D; Khan, M S; Shettima, Y M; Babjee, S M A
The red jungle fowl is generally considered as one of the endangered Asian wild Galleopheasants due to man-made encroachment of their habitats, coupled with the effect of disease and disease causing organisms like ticks and tick-borne infections. This study aimed to determine the tick fauna of the red jungle fowl and their predilection sites based on developmental stages. A total of 33 jungle fowls were sampled for this study from Bangi area of Selangor State, Peninsular Malaysian. The birds were captured using a locally made trap made-up of loops and bites. Ticks present on their bodies were detached using fine forceps and identified morphologically under a dissecting microscope. 91% of the jungle fowls were infested with ticks, all of which belongs to the species Haemaphysalis wellingtoni. The ear region appeared to be the most common predilection site (63%) for all the developmental stages in which the larval stages are solely restricted to that region. Nymphal and adult stages were distributed on the comb, wattle, and facial region in addition to the ear region. This study was the first in its kind and showed a high prevalence of tick infestation among jungle fowls. H. wellingtoni was known to be a vector in transmission of many tick-borne pathogens. Therefore, there is the need for further investigation to identify the various pathogens associated with this tick.
Garcia, Marcos Valério; Silva, Dayana Campelo da; Almeida, Robson Ferreira Cavalcante de; Cunha, Rodrigo Casquero; Matias, Jaqueline; Barros, Jacqueline Cavalcante; Andreotti, Renato; Szabó, Matias Pablo Juan
Herein, we report tick species found on wild and domestic animals and in the environment during a one-year sampling period at the Brazilian Farming Research Company beef cattle unit (Embrapa Beef Cattle), which is located within the urban area of Campo Grande, Mato Grosso do Sul, Brazil. From 55 wild hosts including six different species (Nasua nasua, Cebus spp., Cerdocyon thous, Myrmecophaga tridactyla, Tamandua tetradactyla and Dasyprocta aguti), 323 ticks were collected. Amblyomma ovale ticks were found solely on coatis, and Amblyomma nodosum was identified solely on anteaters. No ticks were found on capuchin monkeys. However, Amblyomma cajennense was found on all parasitized host species with the exception of capuchin monkeys. Giant anteaters displayed the highest infestation abundance, with a mean of 53 ticks∕animal. Environmental sampling yielded 166 adult A. cajennense ticks. The tick species found on domestic animals (Rhipicephalus (Boophilus) microplus, R. sanguineus, Dermacentor nitens and A. cajennense) were those typically found on these hosts in Brazil. The most prevalent tick species, A. cajennense, was found on both wild and domestic animals and was also prevalent in the environment. Thus, this tick species is the primary vector that allows pathogens to bridge wild and domestic animals in the Cerrado.
Full Text Available Ancestral sequence reconstruction has been widely used to test evolution-based hypotheses. The genome of the European tick vector, Ixodes ricinus, encodes for defensin peptides with diverse antimicrobial activities against distantly related pathogens. These pathogens include fungi, Gram-negative and Gram-positive bacteria, i.e., a wide antimicrobial spectrum. Ticks do not transmit these pathogens, suggesting that these defensins may act against a wide range of microbes encountered by ticks during blood feeding or off-host periods. As demonstrated here, these I. ricinus defensins are also effective against the apicomplexan parasite Plasmodium falciparum. To study the general evolution of antimicrobial activity in tick defensins, the ancestral amino acid sequence of chelicerate defensins, which existed approximately 444 million years ago, was reconstructed using publicly available scorpion and tick defensin sequences (named Scorpions-Ticks Defensins Ancestor, STiDA. The activity of STiDA was tested against P. falciparum and the same Gram-negative and Gram-positive bacteria that were used for the I. ricinus defensins. While some extant tick defensins exhibit a wide antimicrobial spectrum, the ancestral defensin showed moderate activity against one of the tested microbes, P. falciparum. This study suggests that amino acid variability and defensin family expansion increased the antimicrobial spectrum of ancestral tick defensins.
Labuda, M; Randolph, S E
Although TBE virus can be transmitted in the laboratory by a wide variety of ixodid tick species to a wide variety of vertebrate host species, nevertheless in nature endemic cycles of TBE virus depend principally on just two tick species, Ixodes ricinus in the western and I. persulcatus in the eastern Palaearctic. A complete transmission cycle, from tick to tick via vertebrates, occurs most efficiently between co-feeding ticks in the absence of a systemic viraemia. This non-systemic route depends on TBE virus replication within particular immunocompetent cells in the skin, and only certain vertebrate species, notably Apodemus mice, are susceptible to this. Amongst the potential tick vectors in Europe, only I. ricinus has the correct host relationships and appropriate natural life cycle to support such non-systemic transmission cycles. Within the wide European distribution of this tick-host relationship, only in certain places do larval and nymphal ticks feed together on the same hosts with sufficient coincidence to ensure TBE virus survival. The environmental factors that determine this seasonal coincidence are being identified with the help of remotely-sensed meteorological satellite imagery to create predictive risk maps of TBE foci.
Strnad, Martin; Hönig, Václav; Růžek, Daniel; Grubhoffer, Libor; Rego, Ryan O M
Lyme borreliosis is the most common zoonotic disease transmitted by ticks in Europe and North America. Despite having multiple tick vectors, the causative agent, Borrelia burgdorferi sensu lato , is vectored mainly by Ixodes ricinus in Europe. In the present study, we aimed to review and summarize the existing data published from 2010 to 2016 concerning the prevalence of B. burgdorferi sensu lato spirochetes in questing I. ricinus ticks. The primary focus was to evaluate the infection rate of these bacteria in ticks, accounting for tick stage, adult tick gender, region, and detection method, as well as to investigate any changes in prevalence over time. The data obtained were compared to the findings of a previous metastudy. The literature search identified data from 23 countries, with 115,028 ticks, in total, inspected for infection with B. burgdorferi sensu lato We showed that the infection rate was significantly higher in adults than in nymphs and in females than in males. We found significant differences between European regions, with the highest infection rates in Central Europe. The most common genospecies were B. afzelii and B. garinii , despite a negative correlation of their prevalence rates. No statistically significant differences were found among the prevalence rates determined by conventional PCR, nested PCR, and real-time PCR. IMPORTANCE Borrelia burgdorferi sensu lato is a pathogenic bacterium whose clinical manifestations are associated with Lyme borreliosis. This vector-borne disease is a major public health concern in Europe and North America and may lead to severe arthritic, cardiovascular, and neurological complications if left untreated. Although pathogen prevalence is considered an important predictor of infection risk, solitary isolated data have only limited value. Here we provide summarized information about the prevalence of B. burgdorferi sensu lato spirochetes among host-seeking Ixodes ricinus ticks, the principal tick vector of
Hlaváčová, Jana; Zimmer, Sara L.; Butenko, Anzhelika; Podešvová, Lucie; Leštinová, Tereza; Lukeš, Julius; Kostygov, Alexei; Votýpka, Jan; Volf, Petr
Background Leishmania virulence factors responsible for the complicated epidemiology of the various leishmaniases remain mainly unidentified. This study is a characterization of a gene previously identified as upregulated in two of three overlapping datasets containing putative factors important for Leishmania’s ability to establish mammalian intracellular infection and to colonize the gut of an insect vector. Methodology/Principal findings The investigated gene encodes ATP/GTP binding motif-containing protein related to Leishmania development 1 (ALD1), a cytosolic protein that contains a cryptic ATP/GTP binding P-loop. We compared differentiation, growth rates, and infective abilities of wild-type and ALD1 null mutant cell lines of L. mexicana. Loss of ALD1 results in retarded growth kinetics but not defects in differentiation in axenic culture. Similarly, when mice and the sand fly vector were infected with the ALD1 null mutant, the primary difference in infection and colonization phenotype relative to wild type was an inability to achieve maximal host pathogenicity. While ability of the ALD1 null mutant cells to infect macrophages in vitro was not affected, replication within macrophages was clearly curtailed. Conclusions/Significance L. mexicana ALD1, encoding a protein with no assigned functional domains or motifs, was identified utilizing multiple comparative analyses with the related and often experimentally overlooked monoxenous flagellates. We found that it plays a role in Leishmania infection and colonization in vitro and in vivo. Results suggest that ALD1 functions in L. mexicana’s general metabolic network, rather than function in specific aspect of virulence as anticipated from the compared datasets. This result validates our comparative genomics approach for finding relevant factors, yet highlights the importance of quality laboratory-based analysis of genes tagged by these methods. PMID:28742133
Matei, Ioana Adriana; Kalmár, Zsuzsa; Magdaş, Cristian; Magdaş, Virginia; Toriay, Hortenzia; Dumitrache, Mirabela Oana; Ionică, Angela Monica; D'Amico, Gianluca; Sándor, Attila D; Mărcuţan, Daniel Ioan; Domşa, Cristian; Gherman, Călin Mircea; Mihalca, Andrei Daniel
Granulocytic anaplasmosis is a common vector-borne disease of humans and animals with natural transmission cycle that involves tick vectors, among which Ixodes ricinus is the most important. The present paper reports the prevalence and geographical distribution of A. phagocytophilum in 10,438 questing Ixodes ricinus ticks collected at 113 locations from 40 counties of Romania. The unfed ticks were examined for the presence of A. phagocytophilum by PCR targeting a portion of ankA gene. The overall prevalence of infection was 3.42%, with local prevalences ranging between 0.29% and 22.45%, with an average prevalence of 5.39% in the infected localities. The infection with A. phagocytophilum was detected in 72 out of 113 localities and in 34 out of 40 counties. The highest prevalence was recorded in females followed by males and nymphs. The results and the distribution model have shown a large distribution of A. phagocytophilum, covering Romania's entire territory. This study is the first large scale survey of the presence of A. phagocytophilum in questing I. ricinus ticks from Romania. Copyright © 2015 Elsevier GmbH. All rights reserved.
Full Text Available Ticks are vectors of some important arthropod-borne diseases in both fields of veterinary and medicine, such as Lyme, tularemia, Rocky Mountain spotted fever, and some types of encephalitis as well as Crimean Congo hemorrhagic fever (CCHF. Iran is known as one of the main foci of CCHF in west of Asia. This study was conducted in DarrehShahr County because of the development of animal husbandry in this area to detect the fauna and viral infection of the hard ticks of livestock. A cross-sectional survey was conducted during 2011-2012 with random sampling in four villages. A sample of ticks was subjected to RT-PCR method for detection of viral infection. During the study period, 592 Ixodidae ticks were collected and identified as seven species of Hyalomma asiaticum, Hy. marginatum, Hy. anatolicum, Hy. dromedarii, Hy. detritum, Rhipicephalus bursa and Rh. sanguineus. More than 20% of these ticks were examined to detect the genome of CCHF virus while 6.6% were positive. All species of Hyalomma were found to be positive. A high rate of livestock was found to be infected with hard ticks, which can act as the vectors of the CCHF disease. Regarding infection of all five Hyalomma species captured in this area, this genus should be considered as the main vector of CCHF. Planning control program can be performed based on the obtained data on seasonal activity of Ixodidae to prevent animal infestation as well as to reduce the risk of CCHF transmission.
Ostfeld, Richard S; Brunner, Jesse L
The evidence that climate warming is changing the distribution of Ixodes ticks and the pathogens they transmit is reviewed and evaluated. The primary approaches are either phenomenological, which typically assume that climate alone limits current and future distributions, or mechanistic, asking which tick-demographic parameters are affected by specific abiotic conditions. Both approaches have promise but are severely limited when applied separately. For instance, phenomenological approaches (e.g. climate envelope models) often select abiotic variables arbitrarily and produce results that can be hard to interpret biologically. On the other hand, although laboratory studies demonstrate strict temperature and humidity thresholds for tick survival, these limits rarely apply to field situations. Similarly, no studies address the influence of abiotic conditions on more than a few life stages, transitions or demographic processes, preventing comprehensive assessments. Nevertheless, despite their divergent approaches, both mechanistic and phenomenological models suggest dramatic range expansions of Ixodes ticks and tick-borne disease as the climate warms. The predicted distributions, however, vary strongly with the models' assumptions, which are rarely tested against reasonable alternatives. These inconsistencies, limited data about key tick-demographic and climatic processes and only limited incorporation of non-climatic processes have weakened the application of this rich area of research to public health policy or actions. We urge further investigation of the influence of climate on vertebrate hosts and tick-borne pathogen dynamics. In addition, testing model assumptions and mechanisms in a range of natural contexts and comparing their relative importance as competing models in a rigorous statistical framework will significantly advance our understanding of how climate change will alter the distribution, dynamics and risk of tick-borne disease.
Rossati, Antonella; Bargiacchi, Olivia; Kroumova, Vesselina; Garavelli, Pietro Luigi
The increase in temperatures recorded since the mid-nineteenth century is unprecedented in the history of mankind. The consequences of climate changes are numerous and can affect human health through direct (extreme events, natural disasters) or indirect (alteration of the ecosystem) mechanisms. Climate changes have repercussions on ecosystems, agriculture, social conditions, migration, conflicts and the transmission mode of infectious diseases. Vector-borne diseases are infections transmitted by the bite of infected arthropods such as mosquitoes, ticks, triatomines, sand flies and flies. Epidemiological cornerstones of vector-borne diseases are: the ecology and behaviour of the host, the ecology and behaviour of the vector, and the population's degree of immunity. Mosquito vectors related to human diseases mainly belong to the genus Culex, Aedes and Mansonia. Climate changes in Europe have increased the spread of new vectors, such as Aedes albopictus, and in some situations have made it possible to sustain the autochthonous transmission of some diseases (outbreak of Chukungunya virus in northern Italy in 2007, cases of dengue in the South of France and in Croatia). Despite the eradication of malaria from Europe, anopheline carriers are still present, and they may allow the transmission of the disease if the climatic conditions favour the development of the vectors and their contacts with plasmodium carriers. The tick Ixodes ricinus is a vector whose expansion has been documented both in latitude and in altitude in relation to the temperature increase; at the same time the related main viral and bacterial infections have increased. In northern Italy and Germany, the appearance of Leishmaniasis has been associated to climatic conditions that favour the development of the vector Phlebotomus papatasi and the maturation of the parasite within the vector, although the increase of cases of visceral leishmaniasis is also related to host immune factors, particularly
Heylen, Dieter; Fonville, Manoj; Docters van Leeuwen, Arieke; Stroo, Arjan; Duisterwinkel, Martin; van Wieren, Sip; Diuk-Wasser, Maria; de Bruin, Arnout; Sprong, Hein
Birds play a major role in the maintenance of enzootic cycles of pathogens transmitted by ticks. Due to their mobility, they affect the spatial distribution and abundance of both ticks and pathogens. In the present study, we aim to identify members of a pathogen community [Borrelia burgdorferi
Cattle play a significant role in the socio-economic life of the people of Ethiopia. ... Different tick species are widely distributed in Ethiopia and a number of re- ... affect the rate of tick population on the ground, host resistance and natural.
Burnard, Delaney; Weaver, Haylee; Gillett, Amber; Loader, Joanne; Flanagan, Cheyne; Polkinghorne, Adam
Members of the order Chlamydiales are known for their potential as human and veterinary bacterial pathogens. Despite this recognition, epidemiological factors such as routes of transmission are yet to be fully defined. Ticks are well known vectors for many other infections with several reports recently describing the presence of bacteria in the order Chlamydiales in these arthropods. Australian wildlife are hosts to an extensive range of tick species. Evidence is also growing that the marsupial hosts these ticks parasitise can also be infected by a number of bacteria in the order Chlamydiales, with at least one species, Chlamydia pecorum, posing a significant conservation threat. In the current study, we investigated the presence and identity of Chlamydiales in 438 ixodid ticks parasitizing wildlife in Australia by screening with a pan-Chlamydiales specific targeting the 16S rRNA gene. Pan-Chlamydiales specific PCR assays confirmed the common presence of Chlamydiales in Australian ticks parasitising a range of native wildlife. Interestingly, we did not detect any Chlamydiaceae, including C. pecorum, the ubiquitous pathogen of the koala. Instead, the Chlamydiales diversity that could be resolved indicated that Australian ticks carry at least six novel Chlamydiales genotypes. Phylogenetic analysis of the 16S rRNA sequences (663 bp) of these novel Chlamydiales suggests that three of these genotypes are associated with the Simkaniaceae and putatively belong to three distinct novel strains of Fritschea spp. and three genotypes are related to the "Ca. Rhabdochlamydiaceae" and putatively belong to a novel genus, Rhabdochlamydia species and strain, respectively. Sequence results suggest Australian wildlife ticks harbour a range of unique Chlamydiales bacteria that belong to families previously identified in a range of arthropod species. The results of this work also suggest that it is unlikely that arthropods act as vectors of pathogenic members of the family
CDCâs tick expert, Dr. Christopher Paddock, discusses ticks found in a new location. Created: 8/4/2016 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID). Date Released: 8/4/2016.
Full Text Available Abstract Background Continuous culture of tick cell lines has proven a valuable asset in isolating and propagating several different vector-borne pathogens, making it possible to study these microorganisms under laboratory conditions and develop serological tests to benefit public health. We describe a method for effective, cost- and labor-efficient isolation and propagation of Rickettsia raoultii using generally available laboratory equipment and Rhipicephalus microplus cells, further demonstrating the usefulness of continuous tick cell lines. R. raoultii is one of the causative agents of tick-borne lymphadenopathy (TIBOLA and is, together with its vector Dermacentor reticulatus, emerging in novel regions of Europe, giving rise to an increased threat to general public health. Methods Dermacentor reticulatus ticks were collected in the Donau-Auen (Lobau national park in Vienna, Austria. The hemolymph of ten collected ticks was screened by PCR-reverse line blot for the presence of rickettsial DNA. A single tick tested positive for R. raoultii DNA and was used to infect Rhipicephalus microplus BME/CTVM2 cells. Results Sixty-five days after infection of the tick-cell line with an extract from a R. raoultii-infected tick, we observed intracellular bacteria in the cultured cells. On the basis of microscopy we suspected that the intracellular bacteria were a species of Rickettsia; this was confirmed by several PCRs targeting different genes. Subsequent sequencing showed 99–100 % identity with R. raoultii. Cryopreservation and resuscitation of R. raoultii was successful. After 28 days identical intracellular bacteria were microscopically observed. Conclusions R. raoultii was successfully isolated and propagated from D. reticulatus ticks using R. microplus BME/CTVM2 cells. The isolated strain shows significant molecular variation compared to currently known sequences. Furthermore we show for the first time the successful cryopreservation and
Wijnveld, Michiel; Schötta, Anna-Margarita; Pintér, Adriano; Stockinger, Hannes; Stanek, Gerold
Continuous culture of tick cell lines has proven a valuable asset in isolating and propagating several different vector-borne pathogens, making it possible to study these microorganisms under laboratory conditions and develop serological tests to benefit public health. We describe a method for effective, cost- and labor-efficient isolation and propagation of Rickettsia raoultii using generally available laboratory equipment and Rhipicephalus microplus cells, further demonstrating the usefulness of continuous tick cell lines. R. raoultii is one of the causative agents of tick-borne lymphadenopathy (TIBOLA) and is, together with its vector Dermacentor reticulatus, emerging in novel regions of Europe, giving rise to an increased threat to general public health. Dermacentor reticulatus ticks were collected in the Donau-Auen (Lobau) national park in Vienna, Austria. The hemolymph of ten collected ticks was screened by PCR-reverse line blot for the presence of rickettsial DNA. A single tick tested positive for R. raoultii DNA and was used to infect Rhipicephalus microplus BME/CTVM2 cells. Sixty-five days after infection of the tick-cell line with an extract from a R. raoultii-infected tick, we observed intracellular bacteria in the cultured cells. On the basis of microscopy we suspected that the intracellular bacteria were a species of Rickettsia; this was confirmed by several PCRs targeting different genes. Subsequent sequencing showed 99-100 % identity with R. raoultii. Cryopreservation and resuscitation of R. raoultii was successful. After 28 days identical intracellular bacteria were microscopically observed. R. raoultii was successfully isolated and propagated from D. reticulatus ticks using R. microplus BME/CTVM2 cells. The isolated strain shows significant molecular variation compared to currently known sequences. Furthermore we show for the first time the successful cryopreservation and resuscitation of R. raoultii.
Full Text Available Abstract Background Ticks are vectors of a wide variety of pathogens causing severe diseases in humans and domestic animals. Intestinal digestion of the host blood is an essential process of tick physiology and also a limiting factor for pathogen transmission since the tick gut represents the primary site for pathogen infection and proliferation. Using the model tick Ixodes ricinus, the European Lyme disease vector, we have previously demonstrated by genetic and biochemical analyses that host blood is degraded in the tick gut by a network of acidic peptidases of the aspartic and cysteine classes. Results This study reveals the digestive machinery of the I. ricinus during the course of blood-feeding on the host. The dynamic profiling of concentrations, activities and mRNA expressions of the major digestive enzymes demonstrates that the de novo synthesis of peptidases triggers the dramatic increase of the hemoglobinolytic activity along the feeding period. Overall hemoglobinolysis, as well as the activity of digestive peptidases are negligible at the early stage of feeding, but increase dramatically towards the end of the slow feeding period, reaching maxima in fully fed ticks. This finding contradicts the established opinion that blood digestion is reduced at the end of engorgement. Furthermore, we show that the digestive proteolysis is localized intracellularly throughout the whole duration of feeding. Conclusions Results suggest that the egressing proteolytic system in the early stage of feeding and digestion is a potential target for efficient impairment, most likely by blocking its components via antibodies present in the host blood. Therefore, digestive enzymes are promising candidates for development of novel 'anti-tick' vaccines capable of tick control and even transmission of tick-borne pathogens.
Full Text Available In a cross sectional survey conducted during the period June 2001 to July 2002, the geographical distribution of ticks on cattle in the Sudan was determined. Seventeen locations were surveyed from Northern, Central, Eastern, Western, Blue Nile and White Nile Provinces. Total body collections of ticks were made from 20 cattle at each location. Four tick genera and 11 species were identified. The tick species collected included Amblyomma lepidum, Amblyomma variegatum, Boophilus decoloratus, Hyalomma anatolicum anatolicum, Hyalomma dromedarii, Hyalomma impeltatum, Hyalomma marginatum rufipes, Hyalomma truncatum, Rhipicephalus evertsi evertsi, Rhipicephalus sanguineus group and Rhipicephalus simus simus. Major ecological changes have occurred due to extensive animal movement, deforestation, desertification and establishment of large mechanized agricultural schemes. These factors have certainly affected the distribution of ticks and tick-borne diseases in the Sudan. The absence of A. variegatum and A. lepidum in northern Sudan was not surprising, since these tick species are known to survive in humid areas and not in the desert and semi-desert areas of northern Sudan. The absence of B. annulatus in northern and central Sudan is in accordance with the finding that this tick species is restricted to the southern parts of the central Sudan. The presence of H. anatolicum anatolicum in Um Benin in relatively high abundance is an interesting finding. The present finding may indicate that the southern limit of this species has changed and moved southwards to latitude 13o N. It is concluded that major changes in tick distribution have taken place in the Sudan
Full Text Available Tick-borne diseases are increasing all over the word, including Turkey. The aim of this study was to determine the bacterial and protozoan vector-borne pathogens in ticks infesting humans in the Corum province of Turkey.From March to November 2014 a total of 322 ticks were collected from patients who attended the local hospitals with tick bites. Ticks were screened by real time-PCR and PCR, and obtained amplicons were sequenced. The dedected tick was belonging to the genus Hyalomma, Haemaphysalis, Rhipicephalus, Dermacentor and Ixodes. A total of 17 microorganism species were identified in ticks. The most prevalent Rickettsia spp. were: R. aeschlimannii (19.5%, R. slovaca (4.5%, R. raoultii (2.2%, R. hoogstraalii (1.9%, R. sibirica subsp. mongolitimonae (1.2%, R. monacensis (0.31%, and Rickettsia spp. (1.2%. In addition, the following pathogens were identified: Borrelia afzelii (0.31%, Anaplasma spp. (0.31%, Ehrlichia spp. (0.93%, Babesia microti (0.93%, Babesia ovis (0.31%, Babesia occultans (3.4%, Theileria spp. (1.6%, Hepatozoon felis (0.31%, Hepatozoon canis (0.31%, and Hemolivia mauritanica (2.1%. All samples were negative for Francisella tularensis, Coxiella burnetii, Bartonella spp., Toxoplasma gondii and Leishmania spp.Ticks in Corum carry a large variety of human and zoonotic pathogens that were detected not only in known vectors, but showed a wider vector diversity. There is an increase in the prevalence of ticks infected with the spotted fever group and lymphangitis-associated rickettsiosis, while Ehrlichia spp. and Anaplasma spp. were reported for the first time from this region. B. microti was detected for the first time in Hyalomma marginatum infesting humans. The detection of B. occultans, B. ovis, Hepatozoon spp., Theileria spp. and Hemolivia mauritanica indicate the importance of these ticks as vectors of pathogens of veterinary importance, therefore patients with a tick infestation should be followed for a variety of pathogens
Ann L. Carr
Full Text Available Ticks are the vector of many human and animal diseases; and host detection is critical to this process. Ticks have a unique sensory structure located exclusively on the 1st pairs of legs; the fore-tarsal Haller’s organ, not found in any other animals, presumed to function like the insect antennae in chemosensation but morphologically very different. The mechanism of tick chemoreception is unknown. Utilizing next-generation sequencing and comparative transcriptomics between the 1st and 4th legs (the latter without the Haller’s organ, we characterized 1st leg specific and putative Haller’s organ specific transcripts from adult American dog ticks, Dermacentor variabilis. The analysis suggested that the Haller’s organ is involved in olfaction, not gustation. No known odorant binding proteins like those found in insects, chemosensory lipocalins or typical insect olfactory mechanisms were identified; with the transcriptomic data only supporting a possible olfactory G-protein coupled receptor (GPCR signal cascade unique to the Haller’s organ. Each component of the olfactory GPCR signal cascade was identified and characterized. The expression of GPCR, Gαo and β-arrestin transcripts identified exclusively in the 1st leg transcriptome, and putatively Haller’s organ specific, were examined in unfed and blood-fed adult female and male D. variabilis. Blood feeding to repletion in adult females down-regulated the expression of all three chemosensory transcripts in females but not in males; consistent with differences in post-feeding tick behavior between sexes and an expected reduced chemosensory function in females as they leave the host. Data are presented for the first time of the potential hormonal regulation of tick chemosensation; behavioral assays confirmed the role of the Haller’s organ in N,N-diethyl-meta-toluamide (DEET repellency but showed no role for the Haller’s organ in host attachment. Further research is needed to understand
Vector-borne diseases are caused by parasites, bacteria, or viruses transmitted by the bites of hematophagous arthropods. In Africa, there has been a recent emergence of new diseases and the re-emergence of existing diseases, usually with changes in disease epidemiology (e.g., geographical distribution, prevalence, and pathogenicity). In Africa, rickettsioses are recognized as important emerging vector-borne infections in humans. Rickettsial diseases are transmitted by different types of arthropods, ticks, fleas, lice, and mites. This review will examine the roles of these different arthropod vectors and their geographical distributions. Copyright © 2012 Elsevier GmbH. All rights reserved.
Coxiella burnetii, as an obligata intracellular bacterium, is the etiologic agent of Q-fever. It is widely distributed in nature and is responsible for infection in various animals (cattle, sheep, goat) and humans. C. burnetii has been isolated from milk, ticks and human patients with acute and chronic Q fever. Ticks are the principal vectors and reservoirs of C. burnetii. Since over 40 species of ticks have been found to be infected with C. burnetii, ticks can serve as indicators of infection in nature. In this study, total of 2472 ticks (1446 female, 1021 male and 5 nymphs) were collected from 38 provinces of Turkey. The ticks were gathered into groups of 1 to 7 ticks as to the provinces, species and gender for DNA extraction. Following DNA extraction, the groups were examined for the presence of C. burtii by using the CB1and CB2. The ticks collected from the province of Denizli (56 in total) were gathered into 13 groups according to the species and gender. From these groups, 6 were positive for C. burnetii. The ticks collected from Ankara province, total of 160 ticks, were grouped into 53 as to their species and gender, only one group was found to be positive for C. burnetii. The specificities of PCR products were evaluated by restriction analysis. The positive PCR products were digested with the enzyme Taq1 and for bands in order of 118, 57, 43 and 39 bp's were appeared such as seen in the positive control DNA (C. burnetii Nine Mile RSA493)
Full Text Available Birds, particularly passerines, can be parasitized by Ixodid ticks, which may be infected with tick-borne pathogens, like Borrelia spp., Babesia spp., Anaplasma, Rickettsia/Coxiella, and tick-borne encephalitis virus. The prevalence of ticks on birds varies over years, season, locality and different bird species. The prevalence of ticks on different species depends mainly on the degree of feeding on the ground. In Europe, the Turdus spp., especially the blackbird, Turdus merula, appears to be most important for harboring ticks. Birds can easily cross barriers, like fences, mountains, glaciers, desserts and oceans, which would stop mammals, and they can move much faster than the wingless hosts. Birds can potentially transport tick-borne pathogens by transporting infected ticks, by being infected with tick-borne pathogens and transmit the pathogens to the ticks, and possibly act as hosts for transfer of pathogens between ticks through co-feeding. Knowledge of the bird migration routes and of the spatial distribution of tick species and tick-borne pathogens is crucial for understanding the possible impact of birds as spreaders of ticks and tick-borne pathogens. Successful colonization of new tick species or introduction of new tick-borne pathogens will depend on suitable climate, vegetation and hosts. Although it has never been demonstrated that a new tick species, or a new tick pathogen, actually has been established in a new locality after being seeded there by birds, evidence strongly suggests that this could occur.
Helena Honig Mondekova
Full Text Available Ticks are important vectors of serious human and animal disease-causing organisms, but their innate immunity can fight invading pathogens and may have the ability to reduce or block transmission to mammalian hosts. Lectins, sugar-binding proteins, can distinguish between self and non-self-oligosaccharide motifs on pathogen surfaces. Although tick hemolymph possesses strong lectin activity, and several lectins have already been isolated and characterized, little is known about the implementation of these molecules in tick immunity. Here, we have described and functionally characterized fibrinogen-related protein (FReP lectins in Ixodes ticks. We have shown that the FReP family contains at least 27 genes (ixoderins, ixo that could, based on phylogenetic and expression analyses, be divided into three groups with differing degrees of expansion. By using RNA interference-mediated gene silencing (RNAi we demonstrated that IXO-A was the main lectin in tick hemolymph. Further, we found that ixoderins were important for phagocytosis of Gram-negative bacteria and yeasts by tick hemocytes and that their expression was upregulated upon injection of microbes, wounding, or after blood feeding. However, although the tick hemocytes could swiftly phagocytose Borrelia afzelii spirochetes, their transmission and burst of infection in mice was not altered. Our results demonstrate that tick ixoderins are crucial immune proteins that work as opsonins in the tick hemolymph, targeting microbes for phagocytosis or lysis.
Niu, Qingli; Liu, Zhijie; Yang, Jifei; Gao, Shandian; Pan, Yuping; Guan, Guiquan; Luo, Jianxun; Yin, Hong
Babesia sp. Xinjiang is a large ovine Babesia species that was recently isolated in China. Compared with other ovine Babesia species, it has different morphological features, pathogenicity and vector tick species. The known transmitting vector is Hyalomma anatolicum. In this study, the distribution and the presence of Babesia sp. Xinjiang in small ruminants and ixodid ticks in China were assessed by specific nested-PCR assay based on the rap-1a gene. A total of 978 blood samples from sheep or goats from 15 provinces and 797 tick specimens from vegetation from 10 provinces were collected and analysed for the presence of the Babesia sp. Xinjiang. Full-length and partial rap-1a of Babesia sp. Xinjiang were amplified from field samples. The PCR results were further confirmed by DNA sequencing. Overall, 38 (3.89%) blood samples and 51 (6.4%) tick samples were positive for Babesia sp. Xinjiang infection. The highest presence (26.92%) was found in blood samples from Yunnan province, while H. qinghaiensis ticks with the highest presence of infection (21.3%) were from Gansu province. This study identified for the first time Babesia sp. Xinjiang infection in H. longicornis tick species. The rap-1a sequences of Babesia sp. Xinjiang from field blood and tick samples indicated 100% identity. The presence of Babesia sp. Xinjiang infection may increase in China. Novel potential transmitting vectors might be more extensive than previously thought. Copyright © 2017. Published by Elsevier B.V.
van Vuuren, M; Penzhorn, B L
The role of African wildlife in the occurrence of vector-borne infections in domestic animals has gained renewed interest as emerging and re-emerging infections occur worldwide at an increasing rate. In Africa, biodiversity conservation and the expansion of livestock production have increased the risk of transmitting vector-borne infections between wildlife and livestock. The indigenous African pathogens with transboundary potential, such as Rift Valley fever virus, African horse sickness virus, bluetongue virus, lumpy skin disease virus, African swine fever virus, and blood-borne parasites have received the most attention. There is no evidence for persistent vector-borne viral infections in African wildlife. For some viral infections, wildlife may act as a reservoir through the inter-epidemic circulation of viruses with mild or subclinical manifestations. Wildlife may also act as introductory or transporting hosts when moved to new regions, e.g. for lumpy skin disease virus, Rift Valley fever virus and West Nile virus. Wildlife may also act as amplifying hosts when exposed to viruses in the early part of the warm season when vectors are active, with spillover to domestic animals later in the season, e.g. with bluetongue and African horse sickness. Some tick species found on domestic animals are more abundant on wildlife hosts; some depend on wildlife hosts to complete their life cycle. Since the endemic stability of a disease depends on a sufficiently large tick population to ensure that domestic animals become infected at an early age, the presence of wildlife hosts that augment tick numbers may be beneficial. Many wild ungulate species are reservoirs of Anaplasma spp., while the role of wildlife in the epidemiology of heartwater (Ehrlichia ruminantium infection) has not been elucidated. Wild ungulates are not usually reservoirs of piroplasms that affect livestock; however, there are two exceptions: zebra, which are reservoirs of Babesia caballi and Theileria
Jessica R Spengler
Full Text Available Crimean-Congo hemorrhagic fever virus (CCHFV is a tick-borne zoonotic agent that is maintained in nature in an enzootic vertebrate-tick-vertebrate cycle. Hyalomma genus ticks have been implicated as the main CCHFV vector and are key in maintaining silent endemic foci. However, what contributes to their central role in CCHFV ecology is unclear. To assess the significance of host preferences of ticks in CCHFV ecology, we performed comparative analyses of hosts exploited by 133 species of ticks; these species represent 5 genera with reported geographical distribution over the range of CCHFV. We found that the composition of vertebrate hosts on which Hyalomma spp. feed is different than for other tick genera. Immatures of the genus Hyalomma feed preferentially on species of the orders Rodentia, Lagomorpha, and the class Aves, while adults concentrate mainly on the family Bovidae. With the exception of Aves, these hosts include the majority of the vertebrates consistently reported to be viremic upon CCHFV infection. While other tick genera also feed on these hosts, Hyalomma spp. almost completely concentrate their populations on them. Hyalomma spp. feed on less phylogenetically diverse hosts than any other tick genus, implying that this network of hosts has a low resilience. Indeed, removing the most prominent hosts quickly collapsed the network of parasitic interactions. These results support the intermittent activity of CCHFV foci: likely, populations of infected Hyalomma spp. ticks exceed the threshold of contact with humans only when these critical hosts reach adequate population density, accounting for the sporadic occurence of clinical tick-transmitted cases. Our data describe the association of vertebrate host preferences with the role of Hyalomma spp. ticks in maintaining endemic CCHFV foci, and highlight the importance of host-tick dynamics in pathogen ecology.
Full Text Available Ticks are one of the most important blood-sucking vectors for infectious microorganisms in humans and animals. When feeding they inject saliva, containing microbes, into the host to facilitate the uptake of blood. An understanding of the microbial populations within their salivary glands would provide a valuable insight when evaluating the vectorial capacity of ticks. Three tick species (Ixodes ovatus, I. persulcatus and Haemaphysalis flava were collected in Shizuoka Prefecture of Japan between 2008 and 2011. Each tick was dissected and the salivary glands removed. Bacterial communities in each salivary gland were characterized by 16S amplicon pyrosequencing using a 454 GS-Junior Next Generation Sequencer. The Ribosomal Database Project (RDP Classifier was used to classify sequence reads at the genus level. The composition of the microbial populations of each tick species were assessed by principal component analysis (PCA using the Metagenomics RAST (MG-RAST metagenomic analysis tool. Rickettsia-specific PCR was used for the characterization of rickettsial species. Almost full length of 16S rDNA was amplified in order to characterize unclassified bacterial sequences obtained in I. persulcatus female samples. The numbers of bacterial genera identified for the tick species were 71 (I. ovatus, 127 (I. persulcatus and 59 (H. flava. Eighteen bacterial genera were commonly detected in all tick species. The predominant bacterial genus observed in all tick species was Coxiella. Spiroplasma was detected in Ixodes, and not in H. flava. PCA revealed that microbial populations in tick salivary glands were different between tick species, indicating that host specificities may play an important role in determining the microbial complement. Four female I. persulcatus samples contained a high abundance of several sequences belonging to Alphaproteobacteria symbionts. This study revealed the microbial populations within the salivary glands of three species of
Full Text Available Abstract Background Ticks of the species Ixodes ricinus are the main vectors of Lyme Borreliosis and Tick-borne Encephalitis – two rapidly emerging diseases in Europe. Repellents provide a practical means of protection against tick bites and can therefore minimize the transmission of tick-borne diseases. We developed and tested seven different dodecanoic acid (DDA-formulations for their efficacy in repelling host-seeking nymphs of I. ricinus by laboratory screening. The ultimately selected formulation was then used for comparative investigations of commercially available tick repellents in humans. Methods Laboratory screening tests were performed using the Moving-object (MO bioassay. All test formulations contained 10% of the naturally occurring active substance DDA and differed only in terms of the quantitative and qualitative composition of inactive ingredients and fragrances. The test procedure used in the human bioassays is a modification of an assay described by the U.S. Environmental Protection Agency and recommended for regulatory affairs. Repellency was computed using the equation: R = 100 - NR/N × 100, where NR is the number of non-repelled ticks, and N is the respective number of control ticks. All investigations were conducted in a controlled laboratory environment offering standardized test conditions. Results All test formulations strongly repelled nymphs of I. ricinus (100-81% protection as shown by the MO-bioassay. The majority of ticks dropped off the treated surface of the heated rotating drum that served as the attractant (1 mg/cm2 repellent applied. The 10% DDA-based formulation, that produced the best results in laboratory screening, was as effective as the coconut oil-based reference product. The mean protection time of both preparations was generally similar and averaged 8 hours. Repellency investigations in humans showed that the most effective 10% DDA-based formulation (~1.67 mg/cm2 applied strongly avoided the
Bezodis, Neil E; North, Jamie S; Razavet, Jane L
A more horizontally oriented ground reaction force vector is related to higher levels of sprint acceleration performance across a range of athletes. However, the effects of acute experimental alterations to the force vector orientation within athletes are unknown. Fifteen male team sports athletes completed maximal effort 10-m accelerations in three conditions following different verbal instructions intended to manipulate the force vector orientation. Ground reaction forces (GRFs) were collected from the step nearest 5-m and stance leg kinematics at touchdown were also analysed to understand specific kinematic features of touchdown technique which may influence the consequent force vector orientation. Magnitude-based inferences were used to compare findings between conditions. There was a likely more horizontally oriented ground reaction force vector and a likely lower peak vertical force in the control condition compared with the experimental conditions. 10-m sprint time was very likely quickest in the control condition which confirmed the importance of force vector orientation for acceleration performance on a within-athlete basis. The stance leg kinematics revealed that a more horizontally oriented force vector during stance was preceded at touchdown by a likely more dorsiflexed ankle, a likely more flexed knee, and a possibly or likely greater hip extension velocity.
Lafri, Ismail; El Hamzaoui, Basma; Bitam, Idir; Leulmi, Hamza; Lalout, Reda; Mediannikov, Oleg; Chergui, Mohamed; Karakellah, Mohamed; Raoult, Didier; Parola, Philippe
Argasid ticks (soft ticks) are blood-feeding arthropods that can parasitize rodents, birds, humans, livestock and companion animals. Ticks of the Ornithodoros genus are known to be vectors of relapsing fever borreliosis in humans. In Algeria, little is known about relapsing fever borreliosis and other bacterial pathogens transmitted by argasid ticks. Between May 2013 and October 2015, we investigated the presence of soft ticks in 20 rodent burrows, 10 yellow-legged gull (Larus michahellis) nests and animal shelters in six locations in two different bioclimatic zones in Algeria. Six species of argasid ticks were identified morphologically and through 16S rRNA gene sequencing. The presence and prevalence of Borrelia spp., Bartonella spp., Rickettsia spp. and Anaplasmataceae was assessed by qPCR template assays in each specimen. All qPCR-positive samples were confirmed by standard PCR, followed by sequencing the amplified fragments. Two Borrelia species were identified: Borrelia hispanica in Ornithodoros occidentalis in Mostaganem, and Borrelia cf. turicatae in Carios capensis in Algiers. One new Bartonella genotype and one new Anaplasmataceae genotype were also identified in Argas persicus. The present study highlights the presence of relapsing fever borreliosis agents, although this disease is rarely diagnosed in Algeria. Other bacteria of unknown pathogenicity detected in argasid ticks which may bite humans deserve further investigation.
Full Text Available Aim: The red jungle fowl is generally considered as one of the endangered Asian wild Galleopheasants due to manmade encroachment of their habitats, coupled with the effect of disease and disease causing organisms like ticks and tickborne infections. This study aimed to determine the tick fauna of the red jungle fowl and their predilection sites based on developmental stages. Materials and Methods: A total of 33 jungle fowls were sampled for this study from Bangi area of Selangor State, Peninsular Malaysian. The birds were captured using a locally made trap made-up of loops and bites. Ticks present on their bodies were detached using fine forceps and identified morphologically under a dissecting microscope. Results: 91% of the jungle fowls were infested with ticks, all of which belongs to the species Haemaphysalis wellingtoni. The ear region appeared to be the most common predilection site (63% for all the developmental stages in which the larval stages are solely restricted to that region. Nymphal and adult stages were distributed on the comb, wattle, and facial region in addition to the ear region. Conclusion: This study was the first in its kind and showed a high prevalence of tick infestation among jungle fowls. H. wellingtoni was known to be a vector in transmission of many tick-borne pathogens. Therefore, there is the need for further investigation to identify the various pathogens associated with this tick.
Toni G Patton
Full Text Available Borrelia burgdorferi, the causative agent of Lyme borreliosis, is transmitted to humans from the bite of Ixodes spp. ticks. During the borrelial tick-to-mammal life cycle, B. burgdorferi must adapt to many environmental changes by regulating several genes, including bba64. Our laboratory recently demonstrated that the bba64 gene product is necessary for mouse infectivity when B. burgdorferi is transmitted by an infected tick bite, but not via needle inoculation. In this study we investigated the phenotypic properties of a bba64 mutant strain, including 1 replication during tick engorgement, 2 migration into the nymphal salivary glands, 3 host transmission, and 4 susceptibility to the MyD88-dependent innate immune response. Results revealed that the bba64 mutant's attenuated infectivity by tick bite was not due to a growth defect inside an actively feeding nymphal tick, or failure to invade the salivary glands. These findings suggested there was either a lack of spirochete transmission to the host dermis or increased susceptibility to the host's innate immune response. Further experiments showed the bba64 mutant was not culturable from mouse skin taken at the nymphal bite site and was unable to establish infection in MyD88-deficient mice via tick infestation. Collectively, the results of this study indicate that BBA64 functions at the salivary gland-to-host delivery interface of vector transmission and is not involved in resistance to MyD88-mediated innate immunity.
Full Text Available Argasid ticks (soft ticks are blood-feeding arthropods that can parasitize rodents, birds, humans, livestock and companion animals. Ticks of the Ornithodoros genus are known to be vectors of relapsing fever borreliosis in humans. In Algeria, little is known about relapsing fever borreliosis and other bacterial pathogens transmitted by argasid ticks.Between May 2013 and October 2015, we investigated the presence of soft ticks in 20 rodent burrows, 10 yellow-legged gull (Larus michahellis nests and animal shelters in six locations in two different bioclimatic zones in Algeria. Six species of argasid ticks were identified morphologically and through 16S rRNA gene sequencing. The presence and prevalence of Borrelia spp., Bartonella spp., Rickettsia spp. and Anaplasmataceae was assessed by qPCR template assays in each specimen. All qPCR-positive samples were confirmed by standard PCR, followed by sequencing the amplified fragments. Two Borrelia species were identified: Borrelia hispanica in Ornithodoros occidentalis in Mostaganem, and Borrelia cf. turicatae in Carios capensis in Algiers. One new Bartonella genotype and one new Anaplasmataceae genotype were also identified in Argas persicus.The present study highlights the presence of relapsing fever borreliosis agents, although this disease is rarely diagnosed in Algeria. Other bacteria of unknown pathogenicity detected in argasid ticks which may bite humans deserve further investigation.
Full Text Available Survival of Borrelia burgdorferi in ticks and mammals is facilitated, at least in part, by the selective expression of lipoproteins. Outer surface protein (Osp A participates in spirochete adherence to the tick gut. As ospB is expressed on a bicistronic operon with ospA, we have now investigated the role of OspB by generating an OspB-deficient B. burgdorferi and examining its phenotype throughout the spirochete life cycle. Similar to wild-type isolates, the OspB-deficient B. burgdorferi were able to readily infect and persist in mice. OspB-deficient B. burgdorferi were capable of migrating to the feeding ticks but had an impaired ability to adhere to the tick gut and survive within the vector. Furthermore, the OspB-deficient B. burgdorferi bound poorly to tick gut extracts. The complementation of the OspB-deficient spirochete in trans, with a wild-type copy of ospB gene, restored its ability to bind tick gut. Taken together, these data suggest that OspB has an important role within Ixodes scapularis and that B. burgdorferi relies upon multiple genes to efficiently persist in ticks.
Full Text Available Cattle ticks are distributed worldwide and affect animal health and livestock production. White tailed deer (WTD sustain and spread cattle tick populations. The aim of this study was to model the efficacy of anti-tick vaccination of WTD to control tick infestations in the absence of cattle vaccination in a territory where both host species coexist and sustain cattle tick populations. Agent-based models that included land cover/landscape properties (patch size, distances to patches and climatic conditions were built in a GIS environment to simulate WTD vaccine effectiveness under conditions where unvaccinated cattle shared the landscape. Published and validated information on tick life cycle was used to build models describing tick mortality and developmental rates. Data from simulations were applied to a large territory in northeastern Mexico where cattle ticks are endemic and WTD and cattle share substantial portions of the habitat. WTD movements were simulated together with tick population dynamics considering the actual landscape and climatic features. The size of the vegetation patches and the distance between patches were critical for the successful control of tick infestations after WTD vaccination. The presence of well-connected, large vegetation patches proved essential for tick control, since the tick could persist in areas of highly fragmented habitat. The continued application of one yearly vaccination on days 1-70 for three years reduced tick abundance/animal/patch by a factor of 40 and 60 for R. annulatus and R. microplus, respectively when compared to non-vaccinated controls. The study showed that vaccination of WTD alone during three consecutive years could result in the reduction of cattle tick populations in northeastern Mexico. Furthermore, the results of the simulations suggested the possibility of using vaccines to prevent the spread and thus the re-introduction of cattle ticks into tick-free areas.
Blanda, Valeria; Torina, Alessandra; La Russa, Francesco; D'Agostino, Rosalia; Randazzo, Kety; Scimeca, Salvatore; Giudice, Elisabetta; Caracappa, Santo; Cascio, Antonio; de la Fuente, José
Rickettsiae (family Rickettsiaceae, order Rickettsiales) are obligate intracellular bacteria transmitted by arthropod vectors. Several Rickettsia species causing vector-borne rickettsioses belong to the spotted fever group (SFG). Traditionally, Rickettsia conorii has been considered as the main etiologic agent of Mediterranean spotted fever. However, the molecular characterization of rickettsiae allowed identifying other species involved in spotted fever in the Mediterranean region. In this study, 42 ticks collected from humans were subjected to morphological identification and molecular characterization of Rickettsia species potentially involved in human rickettsiosis in Sicily. Fourteen ticks positive to at least two Rickettsia spp. molecular markers were used in the study. Identified Rickettsia spp. included R. conorii, found in Rhipicephalus sanguineus sensu lato and Rhipicephalus turanicus, Rickettsia aeschlimannii found in Hyalomma marginatum, Hyalomma lusitanicum, Dermacentor marginatus and Ixodes ricinus, Rickettsia massiliae found in R. turanicus and R. sanguineus s.l., and Rickettsia slovaca found in D. marginatus and R. sanguineus s.l. Our results showed a great variety of zoonotic Rickettsia spp. in ticks collected from humans in Sicily. The Rickettsia spp. reported in this study were identified in previously recognized or new potential tick vectors in Europe, highlighting the risk of infection by different Rickettsia spp. for humans bitten by ticks in Sicily. Copyright © 2017 The Authors. Published by Elsevier GmbH.. All rights reserved.
Killiny, Nabil; Almeida, Rodrigo P P
Vector transmission of bacterial plant pathogens involves three steps: pathogen acquisition from an infected host, retention within the vector, and inoculation of cells into susceptible tissue of an uninfected plant. In this study, a combination of plant and artificial diet systems were used to determine the importance of several genes on the initial adhesion and retention of the bacterium Xylella fastidiosa to an efficient insect vector. Mutant strains included fimbrial (fimA and pilB) and afimbrial (hxfA and hxfB) adhesins and three loci involved in regulatory systems (rpfF, rpfC, and cgsA). Transmission assays with variable retention time indicated that HxfA and HxfB were primarily important for early adhesion to vectors, while FimA was necessary for both adhesion and retention. The long pilus protein PilB was not deficient in initial adhesion but may be important for retention. Genes upregulated under the control of rpfF are important for both initial adhesion and retention, as transmission rates of this mutant strain were initially low and decreased over time, while disruption of rpfC and cgsA yielded trends similar to that shown by the wild-type control. Because induction of an X. fastidiosa transmissible state requires pectin, a series of experiments were used to test the roles of a polygalacturonase (pglA) and the pectin and galacturonic acid carbohydrates on the transmission of X. fastidiosa. Results show that galacturonic acid, or PglA activity breaking pectin into its major subunit (galacturonic acid), is required for X. fastidiosa vector transmission using an artificial diet system. This study shows that early adhesion and retention of X. fastidiosa are mediated by different factors. It also illustrates that the interpretation of results of vector transmission experiments, in the context of vector-pathogen interaction studies, is highly dependent on experimental design.
Prakash, Batah Kunalan; Low, Van Lun; Vinnie-Siow, Wei Yin; Tan, Tiong Kai; Lim, Yvonne Ai-Lian; Morvarid, Akhavan Rezaei; AbuBakar, Sazaly; Sofian-Azirun, Mohd
Canine babesiosis is an emerging tick-borne disease with a worldwide distribution, including Malaysia. While the prevalence of Babesia has been documented from dogs in Malaysia, occurrence of Babesia has been relatively little studied in their tick vectors. Accordingly, a total of 240 dogs and 140 Rhipicephalus sanguineus sensu lato (s.l.) (Acari: Ixodidae) ticks from Malaysia were molecularly screened for the presence of Babesia protozoa in the present study. Babesia gibsoni was only detected in ticks (1.4%), whereas Babesia vogeli was detected in both ticks (1.4%) and dogs (2.1%). This study highlights the detection of B. gibsoni and B. vogeli for the first time, in both adult and nymphal stages of R. sanguineus s.l. in Malaysia, suggesting the potential role of this tick species in transmitting canine babesiosis.
Sumrandee, Chalao; Baimai, Visut; Trinachartvanit, Wachareeporn; Ahantarig, Arunee
We report the detection of Hepatozoon and Theileria in 103 ticks from mammals and snakes in Thailand. By using a genus-specific 18S rRNA PCR, Hepatozoon and Theileria spp. were detected in 8% and 18%, respectively, of ticks (n=79) removed from mammals. Of the ticks removed from snakes (n=24), 96% were infected with Hepatozoon spp., but none were infected with Theileria. Phylogenetic analysis revealed that Hepatozoon spp. detected from Dermacentor astrosignatus and Dermacentor auratus ticks from Wild boar (Sus scrofa) formed a phylogenetic group with many isolates of Hepatozoon felis that were distantly related to a species group containing Hepatozoon canis and Hepatozoon americanum. In contrast, a phylogenetic analysis of the Hepatozoon sequences of snake ticks revealed that Hepatozoon spp. from Amblyomma varanense from King cobra (Ophiophagus hannah) and Amblyomma helvolum ticks from Indochinese rat snake (Ptyas korros), and Asiatic water snake (Xenochrophis piscator) are grouped with Hepatozoon spp. recently isolated from Monocellate cobras, Reticulated pythons and Burmese pythons, all of Thai origin, and with Hepatozoon sp. 774c that has been detected from a tick species obtained from Argus monitors in Australia. A phylogenetic analysis demonstrated that Theileria spp. from Rhipicephalus (Boophilus) microplus, Haemaphysalis obesa, and Haemaphysalis lagrangei ticks from Sambar deer (Cervus unicolor) cluster with the Theileria cervi isolates WU11 and 239, and Theileria sp. Iwate 141. We report for the first time a Hepatozoon species that shares genetic similarity with Hepatozoon felis found in Dermacentor astrosignatus and Dermacentor auratus ticks collected from Wild boars in Thailand. In addition, we found the presence of a Theileria cervi-like sp. which suggests the potential role of Haemaphysalis lagrangei as a Theileria vector in Thailand. Copyright © 2015 Elsevier GmbH. All rights reserved.
Scoles, Glen A; Ueti, Massaro W
The apicomplexan hemoprotozoan parasite Theileria equi is one of the etiologic agents causing equine piroplasmosis, a disease of equines that is endemic throughout large parts of the world. Before 2009 the United States had been considered to be free of this parasite. Occasional cases had occurred but there was no evidence for endemic vector-borne transmission in the U.S. until a 2009 outbreak in Texas in which Dermacentor variabilis and Amblyomma cajennense were implicated as vectors. Although D. variabilis has previously been shown to be a competent laboratory vector, studies suggested A. cajennense was not a competent transstadial vector, even though the presence of this tick species on horses in South American is epidemiologicaly correlated with higher a prevalence of infection. In this study we tested the transstadial and intrastadial vector competence of D. variabilis and A. cajennense for T. equi. A tick passaged T. equi strain from the Texas outbreak and ticks colonized from engorged females collected off horses on the outbreak ranch in Texas were used for these studies. Nymph or adult ticks were fed on infected horses and transmission fed on naïve horses. Infections were tracked with PCR and serology, dissected tick tissues were tested with PCR. A. cajennense transmitted T. equi intrastadially when adult ticks acquired infection by feeding on an infected horse, and transmitted to a naïve host on subsequent reattachment and feeding. D. variabilis failed to transmit in the same experiment. Transstadial transmission was not successful for either tick species. PCR on DNA isolated from eggs of females that had fed on an infected horse suggests that there is no transovarial passage of this parasite by either tick species. This work confirms that ticks from the Texas population of A. cajennense are competent intrastadial vectors of T. equi. We propose that the most likely natural mode of transmission for this parasite/vector combination in the Texas outbreak
Full Text Available Tick-borne rickettsioses are caused by obligate intracellular bacteria belonging to the spotted fever group (SFG rickettsiae. Although Spotted Fever is prevalent in the Middle East, no reports for the presence of tick-borne pathogens are available or any studies on the epidemiology of this disease in the West Bank. We aimed to identify the circulating hard tick vectors and genetically characterize SFG Rickettsia species in ixodid ticks from the West Bank-Palestinian territories.A total of 1,123 ixodid ticks belonging to eight species (Haemaphysalis parva, Haemaphysalis adleri, Rhipicephalus turanicus, Rhipicephalus sanguineus, Rhipicephalus bursa, Hyalomma dromedarii, Hyalomma aegyptium and Hyalomma impeltatum were collected from goats, sheep, camels, dogs, a wolf, a horse and a tortoise in different localities throughout the West Bank during the period of January-April, 2014. A total of 867 ticks were screened for the presence of rickettsiae by PCR targeting a partial sequence of the ompA gene followed by sequence analysis. Two additional genes, 17 kDa and 16SrRNA were also targeted for further characterization of the detected Rickettsia species. Rickettsial DNA was detected in 148 out of the 867 (17% tested ticks. The infection rates in Rh. turanicus, Rh. sanguineus, H. adleri, H. parva, H. dromedarii, and H. impeltatum ticks were 41.7, 11.6, 16.7, 16.2, 11.8 and 20%, respectively. None of the ticks, belonging to the species Rh. bursa and H. aegyptium, were infected. Four SFG rickettsiae were identified: Rickettsia massiliae, Rickettsia africae, Candidatus Rickettsia barbariae and Candidatus Rickettsia goldwasserii.The results of this study demonstrate the geographic distribution of SFG rickettsiae and clearly indicate the presence of at least four of them in collected ticks. Palestinian clinicians should be aware of emerging tick-borne diseases in the West Bank, particularly infections due to R. massiliae and R. africae.
Lv, Jizhou; Fernández de Marco, Maria Del Mar; Goharriz, Hooman; Phipps, L Paul; McElhinney, Lorraine M; Hernández-Triana, Luis M; Wu, Shaoqiang; Lin, Xiangmei; Fooks, Anthony R; Johnson, Nicholas
Ticks host a wide range of zoonotic pathogens and are a significant source of diseases that affect humans and livestock. However, little is known about the pathogens associated with bat ticks. We have collected ectoparasites from bat carcasses over a seven year period. Nucleic acids (DNA and RNA) were extracted from 296 ticks removed from bats and the species designation was confirmed in all ticks as Argas (Carios) vespertilionis. A subset of these samples (n = 120) were tested for the presence of zoonotic pathogens by molecular methods. Babesia species, Rickettsia spp., within the spotted fever group (SFG), and Ehrlichia spp. were detected in ticks removed from 26 bats submitted from 14 counties across England. The prevalence of Rickettsia spp. was found to be highest in Pipistrellus pipistrellus from southern England. This study suggests that the tick species that host B. venatorum may include the genus Argas in addition to the genus Ixodes. As A. vespertilionis has been reported to feed on humans, detection of B. venatorum and SFG Rickettsia spp. could present a risk of disease transmission in England. No evidence for the presence of flaviviruses or Issyk-Kul virus (nairovirus) was found in these tick samples.
Bygbjerg, I.C.; Schioler, K.L.; Konradsen, F.
The predicted changes in climate have raised concerns that vector-borne diseases may emerge or expand in tempered regions. Malaria, leishmaniasis and tick-borne illnesses are discussed in terms of climate change and their endemic potential, especially in Denmark. While climate may play an important...
Raquel SofÃa Salazar Benjumea
Full Text Available Rhipicephalus (Boophilus microplus ticks cause significant economic losses to the Colombian cattle sector: reduction in meat and milk production, blood losses and transmission of blood parasites. The degree of infestation depends on the breed, physiological state and nutrition of the animal and on microclimatic characteristics, which affect the tick life cycle. Diverse studies suggest that given the characteristics of intensive silvopastoral systems (ISS, tick loads within these systems are lower. In this study, the tick loads of grazing animals were monitored for five animal groups: three at an ISS and two at traditional farms located on the Valley of Ibague (Tolima. within the ISS, there were greater tick loads in high production cows (P = 0.026 and a positive relationship (P < 0.05 between milk production and tick load in August sampling. Greater tick counts were also observed in the in San Javier (traditional farm group compared to all other animal groups. We conclude that the dynamics of ticks is a complex phenomenon affected by many factors, whose association determines the observed tick population at any given time.
Raulf, Marie-Kristin; Jordan, Daniela; Fingerle, Volker; Strube, Christina
In recent years, awareness of coinfections has increased as synergistic or antagonistic effects on interacting bacteria have been observed. To date, several reports on coinfections of ticks with Rickettsia and Borrelia spp. are available. However, associations are rarely described and studies are based on rather low sample sizes. In the present study, coinfections of Ixodes ricinus with these pathogens were investigated by determining their association in a meta-analysis. A total of 5079 tick samples examined for Rickettsia and Borrelia spp. via probe-based quantitative real-time PCR in previous prevalence studies or as submitted diagnostic material were included. In Borrelia-positive ticks, genospecies were determined by Reverse Line Blot. Determination of bacterial loads resulted in an increase between developmental tick stages with highest mean bacterial loads in female ticks (7.96×10 4 in Borrelia single-infected, 4.87×10 5 in Rickettsia single-infected and 3.22×10 5 in Borrelia-Rickettsia coinfected females). The determined Borrelia-Rickettsia tick coinfection rate was 12.3% (626/5079) with a significant difference to the expected coinfection rate of 9.0% (457/5079). A significant slight association as well as correlation between Borrelia and Rickettsia were determined. In addition, a significant interrelation of the bacterial load in coinfected ticks was shown. At the level of Borrelia genospecies, significant weak associations with Rickettsia spp. were detected for B. afzelii, B. garinii/bavariensis, B. valaisiana and B. lusitaniae. The positive association provides evidence for interactions between Borrelia and Rickettsia spp. in the tick vector, presumably resulting in higher bacterial replication rates in the tick vector and possibly the reservoir host. However, coinfection may impact the vector negatively as indicated by an absent increase in coinfection rates from nymphs to adults. Future studies are needed to investigate the underlying mechanisms of
Takken, W.; Smallegange, R.C.; Vigneau, A.J.; Johnston, V.; Brown, M.; Mordue-Luntz, A.J.; Billingsley, P.F.
BACKGROUND: Mosquito fitness is determined largely by body size and nutritional reserves. Plasmodium infections in the mosquito and resultant transmission of malaria parasites might be compromised by the vector's nutritional status. We studied the effects of nutritional stress and malaria parasite
Full Text Available Background: Ticks are important vectors and reservoirs of Crimean Congo Hemorrhagic Fever (CCHF virus. Human beings may be infected whenever the normal life cycle of the infected ticks on non- human vertebrate hosts is interrupted by the undesirable presence of humans in the cycle. A total of 26 species of Argasid and Ixodid ticks have been recorded in Iran; including nine Hyalomma, two Rhipicephalus, two Dermacentor, five Haemaphysalis, two Boophilus, one Ixodes and two Argas as well as three Ornithodoros species as blood sucking ectoparasites of livestock and poultries. The present paper reviews tick vectors of CCHF virus in Iran, focusing on the role of ticks in different provinces of Iran using reverse transcription polymerase chain reaction (RT-PCR assay.Methods: During ten years study, 1054 tick specimens; including two species of Argasidae and 17 species of Ixodidae were examined for their infection to CCHF virus genome. The output of all studies as well as related publications were discussed in the current paper.Results: The results show that Rhipicephalus sanguineus, Hyalomma marginatum, H. anatolicum, H. asiaticum and H. dromedarii were known as the most frequent species which were positive for CCHF virus.Conclusion: The status of ticks which were positive for CCHF virus revealed that unlike the most common idea that Hyalomma species are the most important vectors of CCHF virus, other ticks including Rhipicephalus,Haemaphysalis and Dermacentor can be reservoir of this virus; thus, considering geographical distribution, type of host and environmental conditions, different tick control measurements should be carried out in areas with high incidence of CCHF disease.
Telmadarraiy, Zakkyeh; Chinikar, Sadegh; Vatandoost, Hassan; Faghihi, Faezeh; Hosseini-Chegeni, Asadollah
Background: Ticks are important vectors and reservoirs of Crimean Congo Hemorrhagic Fever (CCHF) virus. Human beings may be infected whenever the normal life cycle of the infected ticks on non-human vertebrate hosts is interrupted by the undesirable presence of humans in the cycle. A total of 26 species of Argasid and Ixodid ticks have been recorded in Iran; including nine Hyalomma, two Rhipicephalus, two Dermacentor, five Haemaphysalis, two Boophilus, one Ixodes and two Argas as well as three Ornithodoros species as blood sucking ectoparasites of livestock and poultries. The present paper reviews tick vectors of CCHF virus in Iran, focusing on the role of ticks in different provinces of Iran using reverse transcription polymerase chain reaction (RT-PCR) assay. Methods: During ten years study, 1054 tick specimens; including two species of Argasidae and 17 species of Ixodidae were examined for their infection to CCHF virus genome. The output of all studies as well as related publications were discussed in the current paper. Results: The results show that Rhipicephalus sanguineus, Hyalomma marginatum, H. anatolicum, H. asiaticum and H. dromedarii were known as the most frequent species which were positive for CCHF virus. Conclusion: The status of ticks which were positive for CCHF virus revealed that unlike the most common idea that Hyalomma species are the most important vectors of CCHF virus, other ticks including Rhipicephalus, Haemaphysalis and Dermacentor can be reservoir of this virus; thus, considering geographical distribution, type of host and environmental conditions, different tick control measurements should be carried out in areas with high incidence of CCHF disease. PMID:26623426
Stansly, Philip A; Arevalo, H Alejandro; Qureshi, Jawwad A; Jones, Moneen M; Hendricks, Katherine; Roberts, Pamela D; Roka, Fritz M
Huanglongbing (HLB) or citrus greening is a bacterial disease vectored by the Asian citrus psyllid (ACP) causing tree decline, and yield loss. Vector control and foliar nutrition are used in Florida to slow the spread of HLB and mitigate debilitating effects of the disease. A four year replicated field study was initiated February 2008 in a 5.2-ha commercial block of young 'Valencia' orange trees employing a factorial design to evaluate individual and compound effects of vector management and foliar nutrition. Insecticides were sprayed during tree dormancy and when psyllid populations exceeded a nominal threshold. A mixture consisting primarily of micro- and macro-nutrients was applied three times a year corresponding to the principal foliar flushes. Differences in ACP numbers from five- to 13-fold were maintained in insecticide treated and untreated plots. Incidence of HLB estimated by polymerase chain reaction (PCR), rose from 30% at the beginning of the study to 95% in only 18 months. Highest yields all four years were seen from trees receiving both foliar nutrition and vector control. Production for these trees in the fourth year was close to the pre-HLB regional average for 10 year old 'Valencia' on 'Swingle'. Nevertheless, at current juice prices, the extra revenue generated from the combined insecticide and nutritional treatment did not cover the added treatment costs. This experiment demonstrated that vector control, especially when combined with enhanced foliar nutrition, could significantly increase yields in a citrus orchard with high incidence of HLB. Economic thresholds for both insecticide and nutrient applications are needed under different market and environmental conditions. © 2013 Society of Chemical Industry.
Rathinavelu, Sivaprakash; Broadwater, Anne; de Silva, Aravinda M
The Lyme disease spirochete, Borrelia burgdorferi, inhabits the gut lumen of the tick vector. At this location the spirochete is exposed to host blood when a tick feeds. We report here on studies that were done with normal and complement-deficient (C3-knockout) mice to determine if the host complement system killed spirochetes within the vector. We found that spirochete numbers within feeding nymphs were not influenced by complement, most likely because host complement was inactivated within the vector. The Lyme disease outer surface protein A (OspA) vaccine is a transmission-blocking vaccine that targets spirochetes in the vector. In experiments with mice hyperimmunized with OspA, complement was not required to kill spirochetes within nymphs and to block transmission from nymphs to the vaccinated host. However, host complement did enhance the ability of OspA antibody to block larvae from acquiring spirochetes. Thus, the effects of OspA antibody on nymphal transmission and larval acquisition appear to be based on different mechanisms.
from trochanters, palpal articles 3 with distinct dorsal spine ; palpal articles 2 and 3 not equal. Remarks: According to Harwood and James (1979), humans...Hy. asiaticum parasitize all domestic animals, especially camels, cattle, horses, and sheep. People, hares, boars, and hedgehogs are less frequently...attacked. Immatures feed on hedgehogs , rodents, hares, cats, and dogs. 85 A B Figure 36. Female (a) and male (b) Hyalomma asiaticum. Seasonality: This
Eichenberger, Ramon Marc; Deplazes, Peter; Mathis, Alexander
Changes in the endemic foci of tick populations and invasions of tick species to new areas have become evident in Europe, leading to changes in the epidemiology of tick-transmitted diseases. However, data about tick infestations of pet animals are limited. Following the recent identification of a new focus of canine babesiosis in northeastern Switzerland, we investigated the occurrence of tick vectors in this region by using a pet owner-based sampling strategy. All dog owners in a rural town were sent postal requests to send ticks from their dogs and cats over two consecutive years, beginning in April 2012. In total 3003 ticks were submitted for identification from 249 dogs (approximately 20% of the resident dog population) and from 117 cats. Ixodes ricinus was the most abundant species identified in 96.8% (n=2124) and 74.3% (n=601) of the individual samples submitted from dogs and cats, respectively. Two other tick species, I. hexagonus and Dermacentor reticulatus, were recorded on both host species, with host infestation prevalences below 2%. On cats (but not on dogs), as many as 24.0% (n=194) of the specimens were identified as a fourth tick species, I. trianguliceps. Overall, 93.5% of the ticks were adults (93.8% and 93.0% in dogs and cats), 4.4% nymphs (5.7% in dogs and 1% in cats) and 2% larvae (0.5% and 6.0% in dogs and cats), respectively. The highest infestation intensity was 49 I. ricinus ticks from an individual dog. However, 55.6% of the submissions from dogs and 24.8% from cats contained only one tick. This survey demonstrated that pet owners can contribute to a cost-effective tick surveillance and identified a new tick focus of D. reticulatus. The finding of I. trianguliceps exclusively on cats might be related to behavioural traits of the cats or to a more readily detection of these very small ticks during petting by their owners. Copyright © 2015 Elsevier GmbH. All rights reserved.
Čapek, Miroslav; Literák, I.; Kocianová, E.; Sychra, O.; Najer, T.; Trnka, A.; Kverek, P.
Roč. 5, č. 5 (2014), s. 489-493 ISSN 1877-959X R&D Projects: GA MŠk LC06073 Institutional support: RVO:68081766 Keywords : Ticks * Hyalomma marginatum complex * Vector * Passerines * Migration * Central Europe Subject RIV: EG - Zoology Impact factor: 2.718, year: 2014
None of the examined patients with suspected TBE had the disease confirmed. Hoever, as shown by the results, the relative risk of occurrence of anaplasmosis is higher in people examined for some another vector-borne disease (in this case TBE. Therefore, the performance of screening examinations in patients suspected of having any tick-borne disease is very important.
Belli, A.; Sarr, A.; Rais, O.; Rego, Ryan O. M.; Voordouw, M.J.
Roč. 7, JUL 10 (2017), č. článku 5006. ISSN 2045-2322 Institutional support: RVO:60077344 Keywords : Ixodes ricinus ticks * disease spirochete * borne pathogens * r-0 model * vector * mice * immunity * persistence Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine OBOR OECD: Veterinary science Impact factor: 4.259, year: 2016
Wagemakers, Alex; Coumou, Jeroen; Schuijt, Tim J.; Oei, Anneke; Nijhof, Ard M.; van 't Veer, Cornelis; van der Poll, Tom; Bins, Adriaan D.; Hovius, Joppe W. R.
We previously identified tick salivary lectin pathway inhibitor (TSLPI) in Ixodes scapularis, a vector for Borrelia burgdorferi sensu stricto (s.s.) in North America. TSLPI is a salivary protein facilitating B. burgdorferi s.s. transmission and acquisition by inhibiting the host lectin complement
Oliva Chávez, Adela S; Fairman, James W; Felsheim, Roderick F; Nelson, Curtis M; Herron, Michael J; Higgins, LeeAnn; Burkhardt, Nicole Y; Oliver, Jonathan D; Markowski, Todd W; Kurtti, Timothy J; Edwards, Thomas E; Munderloh, Ulrike G
Anaplasma phagocytophilum, the causative agent of Human Granulocytic Anaplasmosis (HGA), is an obligately intracellular α-proteobacterium that is transmitted by Ixodes spp ticks. However, the pathogen is not transovarially transmitted between tick generations and therefore needs to survive in both a mammalian host and the arthropod vector to complete its life cycle. To adapt to different environments, pathogens rely on differential gene expression as well as the modification of proteins and other molecules. Random transposon mutagenesis of A. phagocytophilum resulted in an insertion within the coding region of an o-methyltransferase (omt) family 3 gene. In wild-type bacteria, expression of omt was up-regulated during binding to tick cells (ISE6) at 2 hr post-inoculation, but nearly absent by 4 hr p.i. Gene disruption reduced bacterial binding to ISE6 cells, and the mutant bacteria that were able to enter the cells were arrested in their replication and development. Analyses of the proteomes of wild-type versus mutant bacteria during binding to ISE6 cells identified Major Surface Protein 4 (Msp4), but also hypothetical protein APH_0406, as the most differentially methylated. Importantly, two glutamic acid residues (the targets of the OMT) were methyl-modified in wild-type Msp4, whereas a single asparagine (not a target of the OMT) was methylated in APH_0406. In vitro methylation assays demonstrated that recombinant OMT specifically methylated Msp4. Towards a greater understanding of the overall structure and catalytic activity of the OMT, we solved the apo (PDB_ID:4OA8), the S-adenosine homocystein-bound (PDB_ID:4OA5), the SAH-Mn2+ bound (PDB_ID:4PCA), and SAM- Mn2+ bound (PDB_ID:4PCL) X-ray crystal structures of the enzyme. Here, we characterized a mutation in A. phagocytophilum that affected the ability of the bacteria to productively infect cells from its natural vector. Nevertheless, due to the lack of complementation, we cannot rule out secondary mutations.
Adela S Oliva Chávez
Full Text Available Anaplasma phagocytophilum, the causative agent of Human Granulocytic Anaplasmosis (HGA, is an obligately intracellular α-proteobacterium that is transmitted by Ixodes spp ticks. However, the pathogen is not transovarially transmitted between tick generations and therefore needs to survive in both a mammalian host and the arthropod vector to complete its life cycle. To adapt to different environments, pathogens rely on differential gene expression as well as the modification of proteins and other molecules. Random transposon mutagenesis of A. phagocytophilum resulted in an insertion within the coding region of an o-methyltransferase (omt family 3 gene. In wild-type bacteria, expression of omt was up-regulated during binding to tick cells (ISE6 at 2 hr post-inoculation, but nearly absent by 4 hr p.i. Gene disruption reduced bacterial binding to ISE6 cells, and the mutant bacteria that were able to enter the cells were arrested in their replication and development. Analyses of the proteomes of wild-type versus mutant bacteria during binding to ISE6 cells identified Major Surface Protein 4 (Msp4, but also hypothetical protein APH_0406, as the most differentially methylated. Importantly, two glutamic acid residues (the targets of the OMT were methyl-modified in wild-type Msp4, whereas a single asparagine (not a target of the OMT was methylated in APH_0406. In vitro methylation assays demonstrated that recombinant OMT specifically methylated Msp4. Towards a greater understanding of the overall structure and catalytic activity of the OMT, we solved the apo (PDB_ID:4OA8, the S-adenosine homocystein-bound (PDB_ID:4OA5, the SAH-Mn2+ bound (PDB_ID:4PCA, and SAM- Mn2+ bound (PDB_ID:4PCL X-ray crystal structures of the enzyme. Here, we characterized a mutation in A. phagocytophilum that affected the ability of the bacteria to productively infect cells from its natural vector. Nevertheless, due to the lack of complementation, we cannot rule out secondary
Andres Iriso Calle
Full Text Available In the past few decades Spain has experienced a resurgence of some vector-transmitted diseases which were thought to be under control and the appearance of new ones. Likewise, the arrival of new vectors and, in some cases, their establishment and expansion is creating to new public health risks. In general, these phenomena have been associated with complex ecological and climate-driven changes which have favored and increased the densities of vectors and their reservoirs, but they have also been affected by processes that have been triggered or accelerated by man such as globalization, urban development, deforestation and land-use changes.Changes in the distribution of vectors and their capacity to transmit pathogens owing to climate change will become more evident in areas that lie within their distribution limits, as is Spain’s case.This is compounded by Spain’s proximity to Africa and the potential entry of new vectors and pathogens from this continent.This scenario necessitates setting up action programs aimed at both identifying risks posed by vectors and preventing vector-borne diseases, and efficiently managing possible outbreaks that could occur in the future.We have reviewed the scenarios which Spain is expected to experience in connection with climate change and its impact on the incidence of diseases transmitted by mosquitoes, phlebotomine sand flies, ticks and other arthropods, and rodents.
Park, Sun-Whan; Song, Bong Gu; Shin, E-Hyun; Yun, Seok-Min; Han, Myung-Guk; Park, Mi Yeoun; Park, Chan; Ryou, Jungsang
Haemaphysalis longicornis a vector that harbors severe fever with thrombocytopenia syndrome virus (SFTSV) is a major species of tick in South Korea. To investigate the existence and prevalence of SFTSV in Korea, we collected ticks from nine provinces in South Korea for detecting SFTSV. In all, we collected 13,053 ticks, and H. longicornis (90.8%, 11,856/13,053) was the most abundant among them. The minimum infection rate (MIR) of SFTSV in H. longicornis was 0.46% (55 pools). SFTSV was detected in ticks during all the developmental stages, showing MIR in larvae (2/350, 0.57%), nymphs (38/10,436, 0.36%), males (2/221, 0.90%), and females (13/849, 1.53%), respectively. Viruses were detected in ticks collected between April and September. A higher MIR was detected in ticks from the southern part of the country. We amplified the M and S segment partial genes from a sample and analyzed the nucleotide sequence. The results showed a 93-98% homology to Chinese and Japanese strains registered in Genbank. In this study, we confirmed the existence of SFTSV for the first time in South Korea. The SFTSV prevalence data from the studies are essential for raising the awareness of SFTS in South Korea. Copyright © 2014 Elsevier GmbH. All rights reserved.
Paulauskas, A; Galdikaitė-Brazienė, E; Radzijevskaja, J; Aleksandravičienė, A; Galdikas, M
Ixodes ricinus (Linnaeus 1758) and Ixodes persulcatus (Schulze 1930) ticks are involved in the transmission of a wide variety of pathogens with considerable impact on human and animal health. The co-distribution zone of these two tick species is situated in the Baltic countries, which provides a special setting for the population studies. In the present study, genetic variability of I. ricinus ticks collected in allopatric and sympatric locations in the Baltic countries has been investigated using a sequence analysis of the mitochondrial DNA control region, 16S rRNA and cytb genes. There were 32 haplotypes (Hd: 0.8551) and 27 haplotypes (Hd:0.8213) of control region sequences from ticks in allopatric and sympatric zones detected, respectively. Out of 47 16S rRNA gene haplotypes, 32 haplotypes (Hd: 0.7213) were found in the allopatric zone and 27 (Hd:0.9572) in the sympatric zone. The Cytb gene was very conserved and monomorphic in ticks from the allopatric zone, whereas three unique haplotypes were observed in the sympatric zone. The higher number of unique haplotypes of the control region was detected in the allopatric zone. Median joining network and Fst analysis did not reveal a clear separation between ticks from the two zones. © 2016 The Society for Vector Ecology.
Lafri, Ismail; Leulmi, Hamza; Baziz-Neffah, Fadhila; Lalout, Reda; Mohamed, Chergui; Mohamed, Karakallah; Parola, Philippe; Bitam, Idir
Argasid ticks are vectors of viral and bacterial agents that can infect humans and animals. In Africa, relapsing fever borreliae are neglected arthropod-borne pathogens that cause mild to deadly septicemia and miscarriage. It would be incredibly beneficial to be able to simultaneous detect and identify other pathogens transmitted by Argasid ticks. From 2012 to 2014, we conducted field surveys in 4 distinct areas of Algeria. We investigated the occurrence of soft ticks in rodent burrows and yellow-legged gull (Larus michahellis) nests in 10 study sites and collected 154 soft ticks. Molecular identification revealed the occurrence of two different soft tick genera and five species, including Carios capensis in yellow-legged gull nests and Ornithodoros occidentalis, Ornithodoros rupestris, Ornithodoros sonrai, Ornithodoros erraticus in rodent burrows. Rickettsial DNA was detected in 41/154, corresponding to a global detection rate of 26.6%. Sequences of the citrate synthase (gltA) gene suggest that this agent is a novel spotted fever group Rickettsia. For the first time in Algeria, we characterize a novel Rickettsia species by molecular means in soft ticks. Copyright © 2015 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.
Full Text Available Risk assessment of tick-borne and zoonotic disease emergence necessitates sound knowledge of the particular microorganisms circulating within the communities of these major vectors. Assessment of pathogens carried by wild ticks must be performed without a priori, to allow for the detection of new or unexpected agents.We evaluated the potential of Next-Generation Sequencing techniques (NGS to produce an inventory of parasites carried by questing ticks. Sequences corresponding to parasites from two distinct genera were recovered in Ixodes ricinus ticks collected in Eastern France: Babesia spp. and Theileria spp. Four Babesia species were identified, three of which were zoonotic: B. divergens, Babesia sp. EU1 and B. microti; and one which infects cattle, B. major. This is the first time that these last two species have been identified in France. This approach also identified new sequences corresponding to as-yet unknown organisms similar to tropical Theileria species.Our findings demonstrate the capability of NGS to produce an inventory of live tick-borne parasites, which could potentially be transmitted by the ticks, and uncovers unexpected parasites in Western Europe.
Medlock Jolyon M
Full Text Available Abstract Many factors are involved in determining the latitudinal and altitudinal spread of the important tick vector Ixodes ricinus (Acari: Ixodidae in Europe, as well as in changes in the distribution within its prior endemic zones. This paper builds on published literature and unpublished expert opinion from the VBORNET network with the aim of reviewing the evidence for these changes in Europe and discusses the many climatic, ecological, landscape and anthropogenic drivers. These can be divided into those directly related to climatic change, contributing to an expansion in the tick’s geographic range at extremes of altitude in central Europe, and at extremes of latitude in Scandinavia; those related to changes in the distribution of tick hosts, particularly roe deer and other cervids; other ecological changes such as habitat connectivity and changes in land management; and finally, anthropogenically induced changes. These factors are strongly interlinked and often not well quantified. Although a change in climate plays an important role in certain geographic regions, for much of Europe it is non-climatic factors that are becoming increasingly important. How we manage habitats on a landscape scale, and the changes in the distribution and abundance of tick hosts are important considerations during our assessment and management of the public health risks associated with ticks and tick-borne disease issues in 21st century Europe. Better understanding and mapping of the spread of I. ricinus (and changes in its abundance is, however, essential to assess the risk of the spread of infections transmitted by this vector species. Enhanced tick surveillance with harmonized approaches for comparison of data enabling the follow-up of trends at EU level will improve the messages on risk related to tick-borne diseases to policy makers, other stake holders and to the general public.
Christopher J Pappas
Full Text Available Borrelia burgdorferi, the spirochetal agent of Lyme disease, is a vector-borne pathogen that cycles between a mammalian host and tick vector. This complex life cycle requires that the spirochete modulate its gene expression program to facilitate growth and maintenance in these diverse milieus. B. burgdorferi contains an operon that is predicted to encode proteins that would mediate the uptake and conversion of glycerol to dihydroxyacetone phosphate. Previous studies indicated that expression of the operon is elevated at 23°C and is repressed in the presence of the alternative sigma factor RpoS, suggesting that glycerol utilization may play an important role during the tick phase. This possibility was further explored in the current study by expression analysis and mutagenesis of glpD, a gene predicted to encode glycerol 3-phosphate dehydrogenase. Transcript levels for glpD were significantly lower in mouse joints relative to their levels in ticks. Expression of GlpD protein was repressed in an RpoS-dependent manner during growth of spirochetes within dialysis membrane chambers implanted in rat peritoneal cavities. In medium supplemented with glycerol as the principal carbohydrate, wild-type B. burgdorferi grew to a significantly higher cell density than glpD mutant spirochetes during growth in vitro at 25°C. glpD mutant spirochetes were fully infectious in mice by either needle or tick inoculation. In contrast, glpD mutants grew to significantly lower densities than wild-type B. burgdorferi in nymphal ticks and displayed a replication defect in feeding nymphs. The findings suggest that B. burgdorferi undergoes a switch in carbohydrate utilization during the mammal to tick transition. Further, the results demonstrate that the ability to utilize glycerol as a carbohydrate source for glycolysis during the tick phase of the infectious cycle is critical for maximal B. burgdorferi fitness.
Tekin, Saban; Dowd, Scot E; Davinic, Marko; Bursali, Ahmet; Keskin, Adem
Ticks continue to be a threat to human and animal health in Turkey, as they are considered important vectors of human and animal diseases. The objectives of this investigation are to characterize the microbial communities of two tick species, Rhipicephalus annulatus and Dermacenter marginatus, analyze patterns of co-occurrence among microbial taxa, identify and compare pathogens contributing human diseases, and determine whether avirulent symbionts could exclude human pathogens from tick communities. Furthermore, this study explores a microbiome of the R. annulatus and D. marginatus via the bacterial 16S tag-encoded FLX-titanium amplicon pyrosequencing (bTEFAP) technique to describe their bacterial diversity. Pyrosequencing was performed on adult males and females isolated from humans from two high-risk Turkish provinces, Sivas and Amasya, during tick outbreaks in 2009. A total of 36,253 sequences were utilized for analyses of the 8 tick samples. Several pathogenic genera such as Francisella, Coxiella, Rickettsia, and Shigella were detected in the ticks tested. The most distinguishable difference between the two species of ticks was the lack of known human pathogen Rickettsia in R. annulatus and in samples 9 and 10 of D. marginatus. These samples had higher relative abundance of Flavobacterium sp., Curvibacter sp., Acidovorax sp., and Bacteroidaceae genera mostly representing symbionts which form a large component of normal tick microbiota. The outcome of this study is consistent with the predictions of the community ecological theory that diversity-rich bacteriomes are more resistant to bacterial invasion (and consequent pathogen dissemination) than diversity-deprived ones.
Bygbjerg, I.C.; Schioler, K.L.; Konradsen, F.
The predicted changes in climate have raised concerns that vector-borne diseases may emerge or expand in tempered regions. Malaria, leishmaniasis and tick-borne illnesses are discussed in terms of climate change and their endemic potential, especially in Denmark. While climate may play an important...... role in disease patterns, it is evident that transmission potential is governed by a complex of factors, including socio-economy, health-care capacity and ecology. In Denmark, malaria and leishmaniasis are unlikely to become public health problems, whereas the potential for tick-borne illnesses may...
Scott, M C; Harmon, J R; Tsao, J I; Jones, C J; Hickling, G J
Determining the host preference of vector ticks is vital to elucidating the eco-epidemiology of the diseases they spread. Detachment of ticks from captured hosts can provide evidence of feeding on those host species, but only for those species that are feasible to capture. Recently developed, highly sensitive molecular assays show great promise in allowing host selection to be determined from minute traces of host DNA that persist in recently molted ticks. Using methods developed in Europe as a starting-point, we designed 12S rDNA mitochondrial gene probes suitable for use in a reverse line blot (RLB) assay of ticks feeding on common host species in the eastern United States. This is the first study to use the 12S mitochondrial gene in a RLB bloodmeal assay in North America. The assay combines conventional PCR with a biotin-labeled primer and reverse line blots that can be stripped and rehybridized up to 20 times, making the method less expensive and more straightforward to interpret than previous methods of tick bloodmeal identification. Probes were designed that target the species, genus, genus group, family, order, or class of eight reptile, 13 birds, and 32 mammal hosts. After optimization, the RLB assay correctly identified the current hostspecies for 99% of ticks [Amblyomma americanum (L.) and eight other ixodid tick species] collected directly from known hosts. The method identified previous-host DNA for approximately half of all questing ticks assayed. Multiple bloodmeal determinations were obtained in some instances from feeding and questing ticks; this pattern is consistent with previous RLB studies but requires further investigation. Development of this probe library, suitable for eastern U.S. ecosystems, opens new avenues for eco-epidemiological investigations of this region's tick-host systems.
Fakoorziba, Mohammad Reza; Golmohammadi, Parvaneh; Moradzadeh, Rahmatollah; Moemenbellah-Fard, Mohammad Djaefar; Azizi, Kourosh; Davari, Behrooz; Alipour, Hamzeh; Ahmadnia, Sara; Chinikar, Sadegh
Crimean-Congo hemorrhagic fever (CCHF) is a potentially fatal viral vector-borne zoonosis which has a mortality rate of up to 30% without treatment in humans. CCHF virus is transmitted to humans by ticks, predominantly from the Hyalomma genus. Following the report of two confirmed and one suspected death due to CCHF virus in Kurdistan province of Iran in 2007, this study was undertaken to determine the fauna of hard ticks on domestic ruminants (cattle, sheep, and goats) and their possible infection with CCHF virus using reverse transcription PCR technique. This is the first detection of CCHF virus in ticks from the Kurdistan province of Iran. Overall, 414 ixodid ticks were collected from two districts in this province. They represented four genera from which 10 separate species were identified. The Hyalomma genus was the most abundant tick genus (70%). It was the only genus shown to be infected with the CCHF virus using RT-PCR technique. The number of ticks positive for CCHF virus was 5 out of 90 (5.6%) adult ticks. The three remaining genera (Haemaphysalis, Rhipicephalus, and Dermacentor) were all negative following molecular survey. Four of the five virally-infected ticks were from cattle mainly in the Sanandaj district. We concluded that CCHF virus is present in the Hyalomma ticks on domestic ruminants (cattle) in Kurdistan province of Iran.
Najm, Nour-Addeen; Meyer-Kayser, Elisabeth; Hoffmann, Lothar; Pfister, Kurt; Silaghi, Cornelia
In this study, the prevalence of Hepatozoon spp. in red foxes (Vulpes vulpes) and their ticks from Germany, as well as molecular characterizations and phylogenetic relationship to other Hepatozoon spp. were investigated. DNA extracts of 261 spleen samples and 1,953 ticks were examined for the presence of Hepatozoon spp. by a conventional polymerase chain reaction (PCR) targeting the 18S rRNA gene. The ticks included four tick species: Ixodes ricinus, Ixodes canisuga, Ixodes hexagonus and Dermacentor reticulatus. A total of 118/261 foxes (45.2%) and 148/1,953 ticks (7.5%) were Hepatozoon PCR-positive. Amplicons from 36 positive foxes and 41 positive ticks were sequenced. All sequences obtained from foxes and 39/41 from ticks had a 99% similarity to Hepatozoon canis, whereas two ticks' sequences had a 99% identity to Hepatozoon sp. The obtained Hepatozoon sequences in this study were phylogenetically related to other Hepatozoon sequences detected in other countries, which may represent strain variants. The high prevalence of H. canis DNA in red foxes in this study supports the suggested role of those animals in distribution of this parasite. Furthermore, detection of DNA of H. canis in foxes and all examined tick species collected from those foxes allows speculating about previously undescribed potential vectors for H. canis and suggests a potential role of the red fox in its natural endemic cycles.
Racelis, A E; Davey, R B; Goolsby, J A; Pérez de León, A A; Varner, K; Duhaime, R
The cattle tick, Rhipicephalus (Boophilus) spp. is a key vector of protozoa that cause bovine babesiosis. Largely eradicated from most of the United States, the cattle tick continues to infest south Texas, and recent outbreaks in this area may signal a resurgence of cattle tick populations despite current management efforts. An improved understanding of the dynamic ecology of cattle fever ticks along the U.S.-Mexico border is required to devise strategies for sustainable eradication efforts. Management areas of the cattle tick overlap considerably with dense, wide infestations of the non-native, invasive grass known as giant reed (Arundo donax L.). Here we show that stands of giant reed are associated with abiotic and biotic conditions that are favorable to tick survival, especially when compared with other nearby habitats (open pastures of buffelgrass (Pennisetum ciliare) and closed canopy native forests). Overhead canopies in giant reed stands and native riparian forests reduce daily high temperature, which was the best abiotic predictor of oviposition by engorged females. In sites where temperatures were extreme, specifically open grasslands, fewer females laid eggs and the resulting egg masses were smaller. Pitfall trap collections of ground dwelling arthropods suggest a low potential for natural suppression of tick populations in giant reed stands. The finding that A. donax infestations present environmental conditions that facilitate the survival and persistence of cattle ticks, as well or better than native riparian habitats and open grasslands, represents an alarming complication for cattle fever tick management in the United States.
Schuijt, Tim J; Coumou, Jeroen; Narasimhan, Sukanya; Dai, Jianfeng; Deponte, Kathleen; Wouters, Diana; Brouwer, Mieke; Oei, Anneke; Roelofs, Joris J T H; van Dam, Alje P; van der Poll, Tom; Van't Veer, Cornelis; Hovius, Joppe W; Fikrig, Erol
The Lyme disease agent Borrelia burgdorferi is primarily transmitted to vertebrates by Ixodes ticks. The classical and alternative complement pathways are important in Borrelia eradication by the vertebrate host. We recently identified a tick salivary protein, designated P8, which reduced complement-mediated killing of Borrelia. We now discover that P8 interferes with the human lectin complement cascade, resulting in impaired neutrophil phagocytosis and chemotaxis and diminished Borrelia lysis. Therefore, P8 was renamed the tick salivary lectin pathway inhibitor (TSLPI). TSLPI-silenced ticks, or ticks exposed to TSLPI-immune mice, were hampered in Borrelia transmission. Moreover, Borrelia acquisition and persistence in tick midguts was impaired in ticks feeding on TSLPI-immunized, B. burgdorferi-infected mice. Together, our findings suggest an essential role for the lectin complement cascade in Borrelia eradication and demonstrate how a vector-borne pathogen co-opts a vector protein to facilitate early mammalian infection and vector colonization. Copyright © 2011 Elsevier Inc. All rights reserved.
Fryxell Rebecca T
Full Text Available Abstract Background In the Eastern and Upper Midwestern regions of North America, Ixodes scapularis (L. is the most abundant tick species encountered by humans and the primary vector of B. burgdorferi, whereas in the southeastern region Amblyomma americanum (Say is the most abundant tick species encountered by humans but cannot transmit B. burgdorferi. Surveys of Borreliae in ticks have been conducted in the southeastern United States and often these surveys identify B. lonestari as the primary Borrelia species, surveys have not included Arkansas ticks, canines, or white-tailed deer and B. lonestari is not considered pathogenic. The objective of this study was to identify Borrelia species within Arkansas by screening ticks (n = 2123, canines (n = 173, and white-tailed deer (n = 228 to determine the identity and locations of Borreliae endemic to Arkansas using PCR amplification of the flagellin (flaB gene. Methods Field collected ticks from canines and from hunter-killed white-tailed were identified to species and life stage. After which, ticks and their hosts were screened for the presence of Borrelia using PCR to amplify the flaB gene. A subset of the positive samples was confirmed with bidirectional sequencing. Results In total 53 (21.2% white-tailed deer, ten (6% canines, and 583 (27.5% Ixodid ticks (252 Ixodes scapularis, 161 A. americanum, 88 Rhipicephalus sanguineus, 50 Amblyomma maculatum, 19 Dermacentor variabilis, and 13 unidentified Amblyomma species produced a Borrelia flaB amplicon. Of the positive ticks, 324 (22.7% were collected from canines (151 A. americanum, 78 R. sanguineus, 43 I. scapularis, 26 A. maculatum, 18 D. variabilis, and 8 Amblyomma species and 259 (37.2% were collected from white-tailed deer (209 I. scapularis, 24 A. maculatum, 10 A. americanum, 10 R. sanguineus, 1 D. variabilis, and 5 Amblyomma species. None of the larvae were PCR positive. A majority of the flaB amplicons were homologous with B
Tokarz, Rafal; Sameroff, Stephen; Leon, Maria Sanchez; Jain, Komal; Lipkin, W Ian
Ticks are implicated as hosts to a wide range of animal and human pathogens. The full range of microbes harbored by ticks has not yet been fully explored. As part of a viral surveillance and discovery project in arthropods, we used unbiased high-throughput sequencing to examine viromes of ticks collected on Long Island, New York in 2013. We detected and sequenced the complete genome of a novel rhabdovirus originating from a pool of Amblyomma americanum ticks. This virus, which we provisionally name Long Island tick rhabdovirus, is distantly related to Moussa virus from Africa. The Long Island tick rhabdovirus may represent a novel species within family Rhabdoviridae.
Swei, Andrea; Bowie, Verna C; Bowie, Rauri C K
Vector-borne pathogens are transmitted between vertebrate hosts and arthropod vectors, two immensely different environments for the pathogen. There is further differentiation among vertebrate hosts that often have complex, species-specific immunological responses to the pathogen. All this presents a heterogeneous environmental and immunological landscape with possible consequences on the population genetic structure of the pathogen. We evaluated the differential genetic diversity of the Lyme disease pathogen, Borrelia burgdorferi, in its vector, the western black-legged tick (Ixodes pacificus), and in its mammal host community using the 5S-23S rRNA intergenic spacer region. We found differences in haplotype distribution of B. burgdorferi in tick populations from two counties in California as well as between a sympatric tick and vertebrate host community. In addition, we found that three closely related haplotypes consistently occurred in high frequency in all sample types. Lastly, our study found lower species diversity of the B. burgdorferi species complex, known as B. burgdorferi sensu lato, in small mammal hosts versus the tick populations in a sympatric study area. Copyright © 2015 Elsevier GmbH. All rights reserved.
Harmon, Jessica R; Hickling, Graham J; Scott, M Cathy; Jones, Carl J
In 1993, four residents of a retirement community in middle Tennessee were hospitalized with symptoms of ehrlichiosis causing community managers to implement mitigation methods to reduce tick numbers. For the past four years, managers have utilized 4-poster acaricide applicators that aim to reduce disease risk to residents by killing ticks that feed on deer. To determine the efficacy of this technique, we assessed Amblyomma americanum abundance in the vicinity of the devices by dragging 400 m vegetation transects once per month while ticks were active. In 2009, adult tick activity peaked in May, nymphal tick activity peaked in June, and larval activity peaked in September. Close to 4-poster devices, larval, nymphal, and adult tick abundances were reduced by 91%, 68%, and 49%, respectively (larval and nymphal p300 m from 4-poster devices, however a ∼90% reduction in larvae was observed to our sampling limit (400 m). At the low density at which these devices are currently being used (average distance between devices = 6.6 km), we conclude that they will have little large-scale effect on the health risk posed by ticks in this community. © 2011 The Society for Vector Ecology.
Kurlovs, Andre H.; Li, Jinze; Cheng, Du; Zhong, Jianmin
Rickettsia is a genus of intracellular bacteria that causes a variety of diseases in humans and other mammals and associates with a diverse group of arthropods. Although Rickettsia appears to be common in ticks, most Rickettsia-tick relationships remain generally uncharacterized. The most intimate of these associations is Rickettsia species phylotype G021, a maternally and transstadially transmitted endosymbiont that resides in 100% of I. pacificus in California. We investigated the effects of this Rickettsia phylotype on I. pacificus reproductive fitness using selective antibiotic treatment. Ciprofloxacin was 10-fold more effective than tetracycline in eliminating Rickettsia from I. pacificus, and quantitative PCR results showed that eggs from the ciprofloxacin-treated ticks contained an average of 0.02 Rickettsia per egg cell as opposed to the average of 0.2 in the tetracycline-treated ticks. Ampicillin did not significantly affect the number of Rickettsia per tick cell in adults or eggs compared to the water-injected control ticks. We found no relationship between tick embryogenesis and rickettsial density in engorged I. pacificus females. Tetracycline treatment significantly delayed oviposition of I. pacificus ticks, but the antibiotic’s effect was unlikely related to Rickettsia. We also demonstrated that Rickettsia-free eggs could successfully develop into larvae without any significant decrease in hatching compared to eggs containing Rickettsia. No significant differences in the incubation period, egg hatching rate, and the number of larvae were found between any of the antibiotic-treated groups and the water-injected tick control. We concluded that Rickettsia species phylotype G021 does not have an apparent effect on embryogenesis, oviposition, and egg hatching of I. pacificus. PMID:25105893
Ginsberg, Howard; Bargar, Timothy A.; Hladik, Michelle L.; Lubelczyk, Charles
Tick and mosquito management is important to public health protection. At the same time, growing concerns about declines of pollinator species raise the question of whether vector control practices might affect pollinator populations. We report the results of a task force of the North American Pollinator Protection Campaign (NAPPC) that examined potential effects of vector management practices on pollinators, and how these programs could be adjusted to minimize negative effects on pollinating species. The main types of vector control practices that might affect pollinators are landscape manipulation, biocontrol, and pesticide applications. Some current practices already minimize effects of vector control on pollinators (e.g., short-lived pesticides and application-targeting technologies). Nontarget effects can be further diminished by taking pollinator protection into account in the planning stages of vector management programs. Effects of vector control on pollinator species often depend on specific local conditions (e.g., proximity of locations with abundant vectors to concentrations of floral resources), so planning is most effective when it includes collaborations of local vector management professionals with local experts on pollinators. Interventions can then be designed to avoid pollinators (e.g., targeting applications to avoid blooming times and pollinator nesting habitats), while still optimizing public health protection. Research on efficient targeting of interventions, and on effects on pollinators of emerging technologies, will help mitigate potential deleterious effects on pollinators in future management programs. In particular, models that can predict effects of integrated pest management on vector-borne pathogen transmission, along with effects on pollinator populations, would be useful for collaborative decision-making.
Coleman Glen T
Full Text Available Abstract Background There are few published reports on canine Babesia, Ehrlichia, Anaplasma, Hepatozoon and haemotropic Mycoplasma infections in India and most describe clinical disease in individual dogs, diagnosed by morphological observation of the microorganisms in stained blood smears. This study investigated the occurrence and distribution of canine tick-borne disease (TBD pathogens using a combination of conventional and molecular diagnostic techniques in four cities in India. Results On microscopy examination, only Hepatozoon gamonts were observed in twelve out of 525 (2.3%; 95% CI: 1.2, 4 blood smears. Using polymerase chain reaction (PCR, a total of 261 from 525 dogs (49.7%; 95% CI: 45.4, 54.1 in this study were infected with one or more canine tick-borne pathogen. Hepatozoon canis (30%; 95% CI: 26.0, 34.0 was the most common TBD pathogen found infecting dogs in India followed by Ehrlichia canis (20.6%; 95% CI: 17.2, 24.3, Mycoplasma haemocanis (12.2%; 95% CI: 9.5, 15.3, Anaplasma platys (6.5%; 95% CI: 4.5, 8.9, Babesia vogeli (5.5%, 95% CI: 3.7, 7.8 and Babesia gibsoni (0.2%, 95% CI: 0.01, 1.06. Concurrent infection with more than one TBD pathogen occurred in 39% of cases. Potential tick vectors, Rhipicephalus (most commonly and/or Haemaphysalis ticks were found on 278 (53% of dogs examined. Conclusions At least 6 species of canine tick-borne pathogens are present in India. Hepatozoon canis was the most common pathogen and ticks belonging to the genus Rhipicephalus were encountered most frequently. Polymerase chain reaction was more sensitive in detecting circulating pathogens compared with peripheral blood smear examination. As co-infections with canine TBD pathogens were common, Indian veterinary practitioners should be cognisant that the discovery of one such pathogen raises the potential for multiple infections which may warrant different clinical management strategies.
Kim, Tae Kwon; Ibelli, Adriana Mércia Guaratini; Mulenga, Albert
In this study we characterized Amblyomma americanum (Aam) tick calreticulin (CRT) homolog in tick feeding physiology. In nature, different tick species can be found feeding on the same animal host. This suggests that different tick species found feeding on the same host can modulate the same host anti-tick defense pathways to successfully feed. From this perspective it's plausible that different tick species can utilize universally conserved proteins such as CRT to regulate and facilitate feeding. CRT is a multi-functional protein found in most taxa that is injected into the vertebrate host during tick feeding. Apart from it's current use as a biomarker for human tick bites, role(s) of this protein in tick feeding physiology have not been elucidated. Here we show that annotated functional CRT amino acid motifs are well conserved in tick CRT. However our data show that despite high amino acid identity levels to functionally characterized CRT homologs in other organisms, AamCRT is apparently functionally different. Pichia pastoris expressed recombinant (r) AamCRT bound C1q, the first component of the classical complement system, but it did not inhibit activation of this pathway. This contrast with reports of other parasite CRT that inhibited activation of the classical complement pathway through sequestration of C1q. Furthermore rAamCRT did not bind factor Xa in contrast to reports of parasite CRT binding factor Xa, an important protease in the blood clotting system. Consistent with this observation, rAamCRT did not affect plasma clotting or platelet aggregation. We discuss our findings in the context of tick feeding physiology.
Dilcher, Meik; Faye, Oumar; Faye, Ousmane; Weber, Franziska; Koch, Andrea; Sadegh, Chinikar; Weidmann, Manfred; Sall, Amadou Alpha
Rhabdoviridae infect a wide range of vertebrates, invertebrates and plants. Their transmission can occur via various arthropod vectors. In recent years, a number of novel rhabdoviruses have been identified from various animal species, but so far only few tick-transmitted rhabdoviruses have been described. We isolated a novel rhabdovirus, provisionally named Zahedan rhabdovirus (ZARV), from Hyalomma anatolicum anatolicum ticks collected in Iran. The full-length genome was determined using 454 next-generation sequencing and the phylogenetic relationship to other rhabdoviruses was analyzed. Inoculation experiments in mammalian Vero cells and mice were conducted and a specific PCR assay was developed. The complete genome of ZARV has a size of 11,230 nucleotides (nt) with the typical genomic organization of Rhabdoviridae. Phylogenetic analysis confirms that ZARV is closely related to Moussa virus (MOUV) from West Africa and Long Island tick rhabdovirus (LITRV) from the U.S., all forming a new monophyletic clade, provisionally designated Zamolirhabdovirus, within the Dimarhabdovirus supergroup. The glycoprotein (G) contains 12 conserved cysteins which are specific for animal rhabdoviruses infecting fish and mammals. In addition, ZARV is able to infect mammalian Vero cells and is lethal for mice when inoculated intracerebrally or subcutaneously. The developed PCR assay can be used to specifically detect ZARV. The novel tick-transmitted rhabdovirus ZARV is closely related to MOUV and LITRV. All three viruses seem to form a new monophyletic clade. ZARV might be pathogenic for mammals, since it can infect Vero cells, is lethal for mice and its glycoprotein contains 12 conserved cysteins only found in animal rhabdoviruses. The mammalian host of ZARV remains to be identified.
Garcia, Marcos Valério; Matias, Jaqueline; Barros, Jacqueline Cavalcante; de Lima, Dênis Pires; Lopes, Rosângela da Silva; Andreotti, Renato
The control of tick species that affect animal production is vital for the economic welfare of the cattle industry. This study focused on testing the acaricidal activity of the essential oil from the leaves and stems of Tagetes minuta against several Brazilian tick species, including Rhipicephalus (Boophilus) microplus, Rhipicephalus sanguineus, Amblyomma cajennense and Argas miniatus. The chemical composition of the essential oil was determined by chromatography and spectroscopy analyses, which revealed the presence of monoterpenes. The adult immersion test (AIT) and the larval packet test (LPT) were used to evaluate the efficacy of T. minuta essential oil in tick management at concentrations of 2.5, 5, 10, 20 and 40%. The results demonstrated that the T. minuta essential oil had over 95% efficacy against four species of ticks at a concentration of 20%. These results suggest that the essential oil of T. minuta could be used as an environmentally friendly acaricide.
Cajimat, Maria N B; Rodriguez, Sergio E; Schuster, Isolde U E; Swetnam, Daniele M; Ksiazek, Thomas G; Habela, Miguel A; Negredo, Ana Isabel; Estrada-Peña, Agustín; Barrett, Alan D T; Bente, Dennis A
Crimean-Congo hemorrhagic fever (CCHF) is a severe tick-borne disease caused by CCHF virus (CCHFV). Ticks in the genus Hyalomma are the main vectors and reservoirs of CCHFV. In Spain, CCHFV was first detected in Hyalomma ticks from Cáceres in 2010. Subsequently, two autochthonous CCHF cases were reported in August 2016. In this study, we describe the characterization of the CCHFV genome directly from Hyalomma lusitanicum collected in Cáceres in 2014. Phylogenetic analyses reveal a close relationship with clade III strains from West Africa, with an estimated divergence time of 50 years. The results of this work suggest that CCHFV has been circulating in Spain for some time, and most likely originated from West Africa.
Andréa C. Fogaça
Full Text Available Rickettsia rickettsii is a tick-borne obligate intracellular bacterium that causes Rocky Mountain Spotted Fever (RMSF. In Brazil, two species of ticks in the genus Amblyomma, A. sculptum and A. aureolatum, are incriminated as vectors of this bacterium. Importantly, these two species present remarkable differences in susceptibility to R. rickettsii infection, where A. aureolatum is more susceptible than A. sculptum. In the current study, A. aureolatum and A. sculptum ticks were fed on suitable hosts previously inoculated with R. rickettsii, mimicking a natural infection. As control, ticks were fed on non-infected animals. Both midgut and salivary glands of all positively infected ticks were colonized by R. rickettsii. We did not observe ticks with infection restricted to midgut, suggesting that important factors for controlling rickettsial colonization were produced in this organ. In order to identify such factors, the total RNA extracted from the midgut (MG was submitted to next generation RNA sequencing (RNA-seq. The majority of the coding sequences (CDSs of A. sculptum differentially expressed by infection were upregulated, whereas most of modulated CDSs of A. aureolatum were downregulated. The functional categories that comprise upregulated CDSs of A. sculptum, for instance, metabolism, signal transduction, protein modification, extracellular matrix, and immunity also include CDSs of A. aureolatum that were downregulated by infection. This is the first study that reports the effects of an experimental infection with the highly virulent R. rickettsii on the gene expression of two natural tick vectors. The distinct transcriptional profiles of MG of A. sculptum and A. aureolatum upon infection stimulus strongly suggest that molecular factors in this organ are responsible for delineating the susceptibility to R. rickettsii. Functional studies to determine the role played by proteins encoded by differentially expressed CDSs in the acquisition of R
Danielle K Offerdahl
Full Text Available Tick-borne flaviviruses (TBFV are sustained in nature through cycling between mammalian and tick hosts. In this study, we used African green monkey kidney cells (Vero and Ixodes scapularis tick cells (ISE6 to compare virus-induced changes in mammalian and arthropod cells. Using confocal microscopy, transmission electron microscopy (TEM, and electron tomography (ET, we examined viral protein distribution and the ultrastructural changes that occur during TBFV infection. Within host cells, flaviviruses cause complex rearrangement of cellular membranes for the purpose of virus replication. Virus infection was accompanied by a marked expansion in endoplasmic reticulum (ER staining and markers for TBFV replication were localized mainly to the ER in both cell lines. TEM of Vero cells showed membrane-bound vesicles enclosed in a network of dilated, anastomosing ER cisternae. Virions were seen within the ER and were sometimes in paracrystalline arrays. Tubular structures or elongated vesicles were occasionally noted. In acutely and persistently infected ISE6 cells, membrane proliferation and vesicles were also noted; however, the extent of membrane expansion and the abundance of vesicles were lower and no viral particles were observed. Tubular profiles were far more prevalent in persistently infected ISE6 cells than in acutely infected cells. By ET, tubular profiles, in persistently infected tick cells, had a cross-sectional diameter of 60-100 nm, reached up to 800 nm in length, were closed at the ends, and were often arranged in fascicle-like bundles, shrouded with ER membrane. Our experiments provide analysis of viral protein localization within the context of both mammalian and arthropod cell lines as well as both acute and persistent arthropod cell infection. Additionally, we show for the first time 3D flavivirus infection in a vector cell line and the first ET of persistent flavivirus infection.
Masood Akhtar*, Faqir Muhammad, Laeeq Akbar Lodhi, Iftikhar Hussain and M. Irfan Anwar1
Full Text Available Tick and tick borne diseases cause many problems to man and domestic animals world wide. These problems are most closely associated with domestic animals in tropical and subtropical areas around the globe. Currently tick control depends largely on the use of different chemicals. But the development of resistance against commonly available acaricides has created problem in this regard and animal population is becoming susceptible to both the ticks and diseases they transmit, with disastrous outcomes. The ability of manipulating organisms on molecular level and recent advancement in immunological procedures has provided alternatives for tick control. The objective of this review is to update/summarize the recent advances in the development of immunity against tick infestation in animals.
Berthová, Lenka; Slobodník, Vladimír; Slobodník, Roman; Olekšák, Milan; Sekeyová, Zuzana; Svitálková, Zuzana; Kazimírová, Mária; Špitalská, Eva
Ixodid ticks (Acari: Ixodidae) are known as primary vectors of many pathogens causing diseases in humans and animals. Ixodes ricinus is a common ectoparasite in Europe and birds are often hosts of subadult stages of the tick. From 2012 to 2013, 347 birds belonging to 43 species were caught and examined for ticks in three sites of Slovakia. Ticks and blood samples from birds were analysed individually for the presence of Rickettsia spp. and Coxiella burnetii by PCR-based methods. Only I. ricinus was found to infest birds. In total 594 specimens of bird-attached ticks were collected (451 larvae, 142 nymphs, 1 female). Altogether 37.2% (16/43) of bird species were infested by ticks and some birds carried more than one tick. The great tit, Parus major (83.8%, 31/37) was the most infested species. In total, 6.6 and 2.7% of bird-attached ticks were infected with Rickettsia spp. and C. burnetii, respectively. Rickettsia helvetica predominated (5.9%), whereas R. monacensis (0.5%) was only sporadically detected. Coxiella burnetii was detected in 0.9%, Rickettsia spp. in 8.9% and R. helvetica in 4.2% of bird blood samples. The great tit was the bird species most infested with I. ricinus, carried R. helvetica and C. burnetti positive tick larvae and nymphs and was found to be rickettsaemic in its blood. Further studies are necessary to define the role of birds in the circulation of rickettsiae and C. burnetii in natural foci.
Eisen, Lars; Eisen, Rebecca J.
The nymphal stage of the blacklegged tick, Ixodes scapularis Say, is considered the primary vector to humans in the eastern United States of the Lyme disease spirochete Borrelia burgdorferi sensu stricto. The abundance of infected host-seeking nymphs is commonly used to estimate the fundamental risk of human exposure to B. burgdorferi, for the purpose of environmental risk assessment and as an outcome measure when evaluating environmentally based tick or pathogen control methods. However, as this tick-based risk measure does not consider the likelihoods of either human encounters with infected ticks or tick bites resulting in pathogen transmission, its linkage to the occurrence of Lyme disease cases is worth evaluating. In this Forum article, we describe different tick-based risk measures, discuss their strengths and weaknesses, and review the evidence for their capacity to predict the occurrence of Lyme disease cases. We conclude that: 1) the linkage between abundance of host-seeking B. burgdorferi-infected nymphs and Lyme disease occurrence is strong at community or county scales but weak at the fine spatial scale of residential properties where most human exposures to infected nymphs occur in Northeast, 2) the combined use of risk measures based on infected nymphs collected from the environment and ticks collected from humans is preferable to either one of these risk measures used singly when assessing the efficacy of environmentally based tick or pathogen control methods aiming to reduce the risk of human exposure to B. burgdorferi, 3) there is a need for improved risk assessment methodology for residential properties that accounts for both the abundance of infected nymphs and the likelihood of human–tick contact, and 4) we need to better understand how specific human activities conducted in defined residential microhabitats relate to risk for nymphal exposures and bites. PMID:27330093
Hemmings, S.; Renneboog, N.; Firsing, S.; Capilouto, E.; Harden, J.; Hyden, R.; Tipre, M.; Zhang, Y.
Lyme disease (LD) accounts for most vector-borne disease reports in the U.S., and although its existence in Alabama remains controversial, other tick-borne illnesses (TBI) such as Southern Tick-Associated Rash Illness (STARI) pose a health concern in the state. Phase One of the Marshall Space Flight Center-UAB DEVELOP study of TBI identified the presence of the chain of infection for LD (Ixodes scapularis ticks carrying Borrelia burgdorferi bacteria) and STARI (Amblyomma americanum ticks and an as-yet-unconfirmed agent) in Alabama. Both LD and STARI are associated with the development of erythema migrans rashes around an infected tick bite, and while treatable with oral antibiotics, a review of educational resources available to state residents revealed low levels of prevention information. To improve prevention, recognition, and treatment of TBI in Alabama, Phase Two builds a health communication campaign based on vector habitat mapping and risk perception assessment. NASA Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) satellite imagery identified likely tick habitats using remotely sensed measurements of vegetation vigor (Normalized Difference Vegetation Index) and soil moisture. Likely tick habitats, identified as those containing both high vegetation density and soil moisture, included Oak Mountain State Park, Bankhead National Forest, and Talladega National Forest. To target a high-risk group -- outdoor recreation program participants at Alabama universities -- the study developed a behavior survey instrument based on existing studies of LD risk factors and theoretical constructs from the Social Ecological Model and Health Belief Model. The survey instrument was amended to include geographic variables in the assessment of TBI knowledge, attitudes, and prevention behaviors, and the vector habitat model will be expanded to incorporate additional environmental variables and in situ data. Remotely sensed environmental data combined with
Williams-Newkirk, Amanda Jo; Rowe, Lori A; Mixson-Hayden, Tonya R; Dasch, Gregory A
The lone star tick (Amblyomma americanum) is an abundant and aggressive biter of humans, domestic animals, and wildlife in the southeastern-central USA and an important vector of several known and suspected zoonotic bacterial pathogens. However, the biological drivers of bacterial community variation in this tick are still poorly defined. Knowing the community context in which tick-borne bacterial pathogens exist and evolve is required to fully understand the ecology and immunobiology of the ticks and to design effective public health and veterinary interventions. We performed a metagenomic survey of the bacterial communities of questing A. americanum and tested 131 individuals (66 nymphs, 24 males, and 41 females) from five sites in three states. Pyrosequencing was performed with barcoded eubacterial primers targeting variable 16S rRNA gene regions 5-3. The bacterial communities were dominated by Rickettsia (likely R. amblyommii) and an obligate Coxiella symbiont, together accounting for 6.7-100% of sequences per tick. DNAs from Midichloria, Borrelia, Wolbachia, Ehrlichia, Pseudomonas, or unidentified Bacillales, Enterobacteriaceae, or Rhizobiales groups were also detected frequently. Wolbachia and Midichloria significantly co-occurred in Georgia (pmales containing more Rickettsia and females containing more Coxiella. Comparisons among adult ticks collected in New York and North Carolina supported the findings from the Georgia collection despite differences in geography, collection date, and sample handling, implying that the differences detected are consistent attributes. The data also suggest that some members of the bacterial community change during the tick life cycle and that some sex-specific attributes may be detectable in nymphs.
Xu, Hongxing; He, Xiaochan; Zheng, Xusong; Yang, Yajun; Tian, Junce; Lu, Zhongxian
Southern rice black-streaked dwarf virus (SRBSDV) is a recently discovered member of the genus Fijivirus and it is transmitted by the rice whitebacked planthopper (WBPH), Sogatella furcifera (Horváth). It was found that SRBSDV infected vectors might contribute negatively to the WBPH population, although the longer nymphal period might benefit viral acquisition, transmission and increase infection rate. The interaction between SRBSDV and its vector need to be further explored to gain better understanding of the dispersal of WBPH and the spread of virus disease, in particular the feeding and reproduction behavior of viruliferous WBPH. Newly hatched nymphs of WBPH were fed on healthy rice plant after feeding on SRBSDV-infected rice plants for 2 h, and newly emerged adults were numbered and tested. Feeding behaviors of WBPH adults were monitored electronically within a Faraday cage using a Giga-4 DC EPG amplifier. The newly emerged adults were paired, and the fecundity and egg hatchability were investigated. WBPH was molecularly identified for SRBSDV when they dead. According to the identification results, data on viruliferous and non-viruliferous WBPH were collected and analyzed. Feeding behavior of viruliferous WBPH was different from those of non-viruliferous WBPH. Frequency of phloem sap ingestion of viruliferous WBPH increased significantly, however the total feeding duration did not increase markedly. When both WBPH parents were infected with SRBSDV, their fecundity and hatchability of the eggs produced were significant lower than those of normal WBPH parents. However, if only one of the parents was viruliferous, fecundity and egg hatchability were only slightly affected. Viruliferous WBPH fed on the phloem more frequently than non-viruliferous WBPH and can thus contribute to virus transmission. When both vector parents are viruliferous fecundity and hatchability of the eggs were significantly reduced. However when only one of the parents WBPH was viruliferous
The risk of vector-borne infections in sled dogs associated with existing and new endemic areas in Poland. Part 2: Occurrence and control of babesiosis in a sled dog kennel during a 13-year-long period.
Bajer, Anna; Mierzejewska, Ewa J; Rodo, Anna; Welc-Falęciak, Renata
The achievements of sled dogs in competitions depend both on their training and on their health. Vector-borne infections may lead to anemia, affect joints or heart muscles or even cause death. Canine babesiosis is an emerging, quickly spreading tick-borne disease in Central Europe. Over a 13-year period (2000-2012) the occurrence of babesiosis cases was analyzed in one sled dog kennel situated in Kury, a village near Tłuszcz (N 52°24'56.78″, E 21°30'37.55″) in Central Poland. Twenty cases/episodes of babesiosis were noted among the 10-12 dogs living in the kennel. In 2000-2004, no cases of babesiosis were noted; the first two cases were noted in April 2005. Since that time, only one dog remained uninfected; 6 dogs were infected once, 3 dogs demonstrated symptoms of babesiosis twice, one dog was infected three times and one dog had it five times. Babesiosis appeared in Spring and Autumn, despite the application of anti-tick treatment. No fatal cases were recorded, but in one case a splenectomy was performed due to splenomegaly and spleen rupture. Additionally, the abundance of the main Babesia canis vector, the Dermacentor reticulatus tick, was estimated and monitored during a 4-year period (2008-2012) close to the dog kennel. The abundance of questing ticks was high in 2008 and 2009, but dropped by 10-fold between 2010 and 2012, when the abandoned meadow was cut and used as horse pasture by the local farmer. The regular occurrence, typical seasonal pattern and identification of B. canis DNA in questing tick from this locality confirmed the establishment of a new hyper enzootic region for canine babesiosis. The effectiveness and schedule of applied preventive measures were discussed. Copyright © 2014 Elsevier B.V. All rights reserved.
Torina, Alessandra; Blanda, Valeria; Blanda, Marcellocalogero; Auteri, Michelangelo; La Russa, Francesco; Scimeca, Salvatore; D'Agostino, Rosalia; Disclafani, Rosaria; Villari, Sara; Currò, Vittoria; Caracappa, Santo
Ticks (Acari: Ixodidae) are bloodsucking arthropods involved in pathogen transmission in animals and humans. Tick activity depends on various ecological factors such as vegetation, hosts, and temperature. The aim of this study was to analyse the spatial/temporal distribution of ticks in six sites within a peri-urban area of Palermo (Natural Reserve of Monte Pellegrino) and correlate it with field data using Geographical Information System (GIS) data. A total of 3092 ticks were gathered via dragging method from June 2012 to May 2014. The species collected were: Ixodes ventalloi (46.09%), Hyalomma lusitanicum (19.99%), Rhipicephalus sanguineus (17.34%), Rhipicephalus pusillus (16.11%), Haemaphisalis sulcata (0.36%), Dermacentor marginatus (0.10%), and Rhipicephalus turanicus (0.03%). GIS analysis revealed environmental characteristics of each site, and abundance of each tick species was analysed in relation to time (monthly trend) and space (site-specific abundance). A relevant presence of I. ventalloi in site 2 and H. lusitanicum in site 5 was observed, suggesting the possible exposure of animals and humans to tick-borne pathogens. Our study shows the importance of surveillance of ticks in peri-urban areas and the useful implementation of GIS analysis in vector ecology; studies on temporal and spatial distribution of ticks correlated to GIS-based ecological analysis represent an integrated strategy for decision support in public health.
Full Text Available Ticks (Acari: Ixodidae are bloodsucking arthropods involved in pathogen transmission in animals and humans. Tick activity depends on various ecological factors such as vegetation, hosts, and temperature. The aim of this study was to analyse the spatial/temporal distribution of ticks in six sites within a peri-urban area of Palermo (Natural Reserve of Monte Pellegrino and correlate it with field data using Geographical Information System (GIS data. A total of 3092 ticks were gathered via dragging method from June 2012 to May 2014. The species collected were: Ixodes ventalloi (46.09%, Hyalomma lusitanicum (19.99%, Rhipicephalus sanguineus (17.34%, Rhipicephalus pusillus (16.11%, Haemaphisalis sulcata (0.36%, Dermacentor marginatus (0.10%, and Rhipicephalus turanicus (0.03%. GIS analysis revealed environmental characteristics of each site, and abundance of each tick species was analysed in relation to time (monthly trend and space (site-specific abundance. A relevant presence of I. ventalloi in site 2 and H. lusitanicum in site 5 was observed, suggesting the possible exposure of animals and humans to tick-borne pathogens. Our study shows the importance of surveillance of ticks in peri-urban areas and the useful implementation of GIS analysis in vector ecology; studies on temporal and spatial distribution of ticks correlated to GIS-based ecological analysis represent an integrated strategy for decision support in public health.
Jaenson Thomas GT
Full Text Available Abstract Background Ixodes ricinus is the main vector in Europe of human-pathogenic Lyme borreliosis (LB spirochaetes, the tick-borne encephalitis virus (TBEV and other pathogens of humans and domesticated mammals. The results of a previous 1994 questionnaire, directed at people living in Central and North Sweden (Svealand and Norrland and aiming to gather information about tick exposure for humans and domestic animals, suggested that Ixodes ricinus ticks had become more widespread in Central Sweden and the southern part of North Sweden from the early 1980s to the early 1990s. To investigate whether the expansion of the tick's northern geographical range and the increasing abundance of ticks in Sweden were still occurring, in 2009 we performed a follow-up survey 16 years after the initial study. Methods A questionnaire similar to the one used in the 1994 study was published in Swedish magazines aimed at dog owners, home owners, and hunters. The questionnaire was published together with a popular science article about the tick's biology and role as a pathogen vector in Sweden. The magazines were selected to get information from people familiar with ticks and who spend time in areas where ticks might be present. Results Analyses of data from both surveys revealed that during the near 30-year period from the early 1980s to 2008, I. ricinus has expanded its distribution range northwards. In the early 1990s ticks were found in new areas along the northern coastline of the Baltic Sea, while in the 2009 study, ticks were reported for the first time from many locations in North Sweden. This included locations as far north as 66°N and places in the interior part of North Sweden. During this 16-year period the tick's range in Sweden was estimated to have increased by 9.9%. Most of the range expansion occurred in North Sweden (north of 60°N where the tick's coverage area doubled from 12.5% in the early 1990s to 26.8% in 2008. Moreover, according to the
Jaenson, Thomas G T; Jaenson, David G E; Eisen, Lars; Petersson, Erik; Lindgren, Elisabet
Ixodes ricinus is the main vector in Europe of human-pathogenic Lyme borreliosis (LB) spirochaetes, the tick-borne encephalitis virus (TBEV) and other pathogens of humans and domesticated mammals. The results of a previous 1994 questionnaire, directed at people living in Central and North Sweden (Svealand and Norrland) and aiming to gather information about tick exposure for humans and domestic animals, suggested that Ixodes ricinus ticks had become more widespread in Central Sweden and the southern part of North Sweden from the early 1980s to the early 1990s. To investigate whether the expansion of the tick's northern geographical range and the increasing abundance of ticks in Sweden were still occurring, in 2009 we performed a follow-up survey 16 years after the initial study. A questionnaire similar to the one used in the 1994 study was published in Swedish magazines aimed at dog owners, home owners, and hunters. The questionnaire was published together with a popular science article about the tick's biology and role as a pathogen vector in Sweden. The magazines were selected to get information from people familiar with ticks and who spend time in areas where ticks might be present. Analyses of data from both surveys revealed that during the near 30-year period from the early 1980s to 2008, I. ricinus has expanded its distribution range northwards. In the early 1990s ticks were found in new areas along the northern coastline of the Baltic Sea, while in the 2009 study, ticks were reported for the first time from many locations in North Sweden. This included locations as far north as 66°N and places in the interior part of North Sweden. During this 16-year period the tick's range in Sweden was estimated to have increased by 9.9%. Most of the range expansion occurred in North Sweden (north of 60°N) where the tick's coverage area doubled from 12.5% in the early 1990s to 26.8% in 2008. Moreover, according to the respondents, the abundance of ticks had increased
Huntington, Mark K; Allison, Jay; Nair, Dilip
Several mosquito-borne viral infections have recently emerged in North America; West Nile virus is the most common in the United States. Although West Nile virus generally causes a self-limited, flulike febrile illness, a serious neuroinvasive form may occur. Dengue is the most common vector-borne viral disease worldwide, and it has been a significant public health threat in the United States since 2009. Known as breakbone fever for its severe myalgias and arthralgias, dengue may cause a hemorrhagic syndrome. Chikungunya also causes flulike febrile illness and disabling arthralgias. Although meningoencephalitis may occur with chikungunya, bleeding is uncommon. Symptoms of Zika virus infection are similar to those of dengue, but milder. Zika virus increases the risk of fetal brain abnormalities, including microcephaly, if a pregnant woman is infected. Zika virus is spread through Aedes albopictus mosquito bites, is transmitted sexually, and may rarely spread nonsexually from person to person. Diagnosis of these vectorborne infections is clinical and serologic, and treatment is supportive. Other, well-established vector-borne diseases are also important. Ehrlichiosis is a tick-borne bacterial disease that presents as a nonspecific syndrome of fever, headache, malaise, and myalgias. It is diagnosed via blood smear testing, with confirmatory serology. Ehrlichiosis is treated with doxycycline. Rickettsial infections are transmitted by fleas, mites, and ticks, and severity ranges from mild to life threatening. Rocky Mountain spotted fever, the most significant rickettsial infection, is primarily a clinical diagnosis that presents as fever, headache, myalgias, petechial rash, and tick exposure. Doxycycline is effective for rickettsial infections if administered promptly. Vector avoidance strategies are critical to the prevention of all of these infections.
Rehman, Abdul; Nijhof, Ard M; Sauter-Louis, Carola; Schauer, Birgit; Staubach, Christoph; Conraths, Franz J
species significantly affected the intensity of tick infestation. This report also describes the presence of R. turanicus in the Punjab Province of Pakistan for the first time. The outcomes of this study will be useful in the planning of integrated control strategies for ticks and tick-borne diseases in Pakistan.
Silvi, Stefania; Verdenelli, M Cristina; Cecchini, Cinzia; Coman, M Magdalena; Bernabei, M Simonetta; Rosati, Jessica; De Leone, Renato; Orpianesi, Carla; Cresci, Alberto
A randomised, double-blind, placebo-controlled, parallel group study assessed in healthy adults how daily consumption of the probiotic combination SYNBIO®, administered in probiotic-enriched foods or in a dietary supplement, affected bowel habits. Primary and secondary outcomes gave the overall assessment of bowel well-being, while a Psychological General Well-Being Index compiled by participants estimated the health-related quality of life as well as the gastrointestinal tolerance determined with the Gastrointestinal Symptom Rating Scale. Support Vector Machine models for classification problems were used to validate the total outcomes on bowel well-being. SYNBIO® consumption improved bowel habits of volunteers consuming the probiotic foods or capsules, while the same effects were not registered in the control groups. The recovery of probiotic bacteria from the faeces of a cohort of 100 subjects for each supplemented group showed the persistence of strains in the gastrointestinal tract.
of group 1. Perhaps with i’,creased age , group 2 nymphs developed a systemic infection. We plan to follow group 1 as it ages , to see if this might be...may facilitate the formation of the unusual forms of Borrelia that we observed. The large swollen forms have been seen in spirochetes in aged cultures...Helminthol. 40:337-342. Lees, A.D. (1948). The sensory phisiology of the sheep Ixodes ricinus L. J. Exp. Biol. 25:145-207. Lemaux, P.G., Herendeen, S.L
Cabezas-Cruz, A.; Valdés, James J.; de la Fuente, J.
Roč. 14, č. 10 (2014), s. 916-917 ISSN 1473-3099 Institutional support: RVO:60077344 Keywords : protective immunity * IgE * responses * mice Subject RIV: EC - Immunology Impact factor: 22.433, year: 2014
Tälleklint, L; Jaenson, T G
Infestation by Ixodes ricinus ticks on rodents, hares and cervids was examined at Bogesund, 10 km north of Stockholm, in south-central Sweden during 1991-1994 and on varying hares (Lepus timidus) at Stora Karlsö and Gotska Sandön in the Baltic Sea during 1992-1993. At Bogesund, there were great differences between two consecutive years in the number of I. ricinus larvae infesting bank voles (Clethrionomys glareolus). The seasonal pattern of infestation by I. ricinus larvae and nymphs on bank voles was unimodal in 1991, with peaks in June-July and bimodal in 1992, with peaks in June and August. Male bank voles, compared to females and older voles, compared to young voles, harboured greater numbers of I. ricinus ticks. Apodemus mice, compared to bank voles, harboured greater numbers of I. ricinus ticks. Ixodes ricinus larvae engorged on Apodemus mice were heavier than larvae engorged on bank voles and resulted in larger nymphs. However, there was no difference in the proportions of viable nymphs resulting from larvae engorged on mice or voles. The ranges in the numbers of I. ricinus ticks infesting individual hosts were 1-451 for rodents, 16-2374 for hares and 428-2072 for roe deer (Capreolus capreolus). These ranges of tick numbers are estimated to represent potential blood losses from individual hosts of approximately 0.2-65% for rodents, 0.2-13% for hares and 0.3-9.0% for roe deer. Within the populations of all host species examined, the distributions of all stages of I. ricinus were clumped, with most host individuals harbouring few ticks and only a few individuals harbouring many ticks. The data suggest that, even though a small proportion of tick hosts may be severely affected, the direct effects of feeding by I. ricinus are unlikely to play an important role on mammal population dynamics.
The Southern cattle tick, Rhipicephalus (Boophilus) microplus, vectors Babesia bovis and B. bigemina, which are the protozoans causing cattle fever, a disease that is responsible for significant production losses to cattle producers in much of Africa, Central and South America, and Australia. We ini...
Flicek, Barbara Fouts
Tick bites are best prevented by people avoiding tick-infested areas. When this is not possible, tick bites may be prevented by the wearing of long trousers that are tucked into boots. The best method to avoid tick bites is twofold: application of a topical deet (N,N-diethyl-m-toluamide) repellent to exposed skin, and treatment of clothing with permethrin. This system is currently used by the US Army to protect soldiers. Ticks can crawl underneath clothing and bite untreated portions of the body; therefore, treating clothing is imperative. Permethrin is nontoxic to humans, and can be used in any age group. Permethrin is commercially available. Checking clothing regularly while in tick-infested areas is highly recommended to back up the few hours of protection provided by the insect repellents. It is also recommended that the entire body be carefully screened for ticks and other parasites by campers and hunters while they are staying in and after leaving infested areas. Any tick found should be removed immediately. Removing ticks may not be easy. It is best to use blunt, rounded forceps, and a magnifying glass to remove ticks, especially when immature ticks are found. The forceps are used to grasp the mouthparts of the tick as close as possible to the skin, and then the tick is pulled upward, perpendicular to the skin, with a continuous and steady action. Usually any mouth parts of the tick retained in the skin are eliminated uneventfully by the body. Other methods of removing ticks, such as using fingers, lighted cigarettes, petroleum jelly, or suntan oil, should be avoided. Killing the tick in situ may increase the risk of regurgitation by the tick and the transmission of infectious agents. Most stick bites are uncomplicated, and result only in benign cutaneous inflammatory reactions that may be pruritic for a few days. As a result of mouthparts being retained at the feeding site, a granuloma may rarely develop. There are no data to indicate that antimicrobial
Giannelli, Alessio; Lia, Riccardo Paolo; Annoscia, Giada; Buonavoglia, Canio; Lorusso, Eleonora; Dantas-Torres, Filipe; Baneth, Gad; Otranto, Domenico
The distribution of Hepatozoon canis mainly encompasses areas where its main tick vector, Rhipicephalus sanguineus sensu lato, is present. However, the detection of this pathogen in dogs, foxes and golden jackals well outside the areas inhabited by this tick species reinforced the hypothesis that additional ixodids are involved in the life cycle and transmission of this protozoon. The present study provides, for the first time, data supporting the sporogonic development of H. canis in specimens of Rhipicephalus turanicus collected from a naturally infected fox from southern Italy. The epidemiological role of R. turanicus as a vector of H. canis is discussed, along with information on the potential use of cell cultures for the experimental infection with H. canis sporozoites. The in vitro infection of canine leucocytes by sporozoites from ticks is proposed as a potential tool for future in-depth studies on the biology of H. canis.
Samish, M; Glazer, I
Entomopathogenic steinemematid and heterorhabditid nematodes are increasingly used to control insect pests of economically important crops. Laboratory and field simulation trials show that ticks are also susceptible to these nematodes. The authors review the potential of entomogenous nematodes for the control of ticks.
This podcast will help health care providers identify patients who are at increased risk of getting tick bites and provide these patients with tick bite prevention and removal tips. Created: 2/14/2012 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID). Date Released: 2/14/2012.
Mar 31, 2015 ... Objective: Ticks play a significant role in the transmission of pathogenic agents to animals. In Côte d'Ivoire, ..... dog, grasscutter constitute the new host for adults of this tick species in ... among West African rodent, Thryonomys.
Ramos, Rafael Antonio Nascimento; Giannelli, Alessio; Carbone, Domenico; Baneth, Gad; Dantas-Torres, Filipe; Otranto, Domenico
Hepatozoon canis (Eucoccidiorida, Hepatozoidae) and the filarioid Cercopithifilaria bainae (Spirurida, Onchocercidae) are tick-transmitted infectious agents of dogs, highly prevalent in the Mediterranean basin in association with Rhipicephalus sanguineus sensu lato. Ticks were collected from the environment every 25±2 days in a confined location in southern Italy where a community of dogs lives, from August 2012 to July 2013. In order to study the occurrence of H. canis and C. bainae, 1091 tick specimens (770 adults; 271 nymphs, and 50 larvae) were dissected, and oocysts of H. canis and larvae of C. bainae were morphologically identified. Out of 1091 dissected ticks, 13.47% (n=147) were positive for H. canis, with the highest prevalence recorded in unfed adults (16.4%; 126/770), followed by nymphs collected as larvae and allowed to moult (14%; 7/50), unfed nymphs dissected immediately after collection (3%; 8/271), and adults collected as nymphs and allowed to moult (2%; 6/271). The highest number of H. canis-positive ticks (35.5%; 43/121; Pcanis and C. bainae infections in the study area seem to be dependent on the seasonality of vector tick populations. Hence, dogs living in these areas are more exposed to both pathogens during the warmer months. These findings provide new insights into the ecology of both H. canis and C. bainae. Copyright © 2014 Elsevier GmbH. All rights reserved.
Keskin, Adem; Bursali, Ahmet; Snow, David E; Dowd, Scot E; Tekin, Saban
Ticks are among the most significant human-biting ectoparasites and they play a major role in transmission of many pathogenic agents to humans. In the present study, three species of Hyalomma ticks, Hyalomma aegyptium, H. marginatum and H. excavatum, were examined for the presence of zoonotic bacteria, both male and female ticks alike. Examination of microbial diversity with tag-encoded pyrosequencing indicates that H. marginatum and H. excavatum were more diversity rich than H. aegyptium. Although numerous pathogenic and non-pathogenic bacterial genera were detected, including Acidovorax, Bacillus, Bacteroides, Bdellovibrio, Clostridium, Curvibacter, Escherichia, Flavobacterium, Limnohabitans, Paenibacillus, Ralstonia, Sarcina, Sediminibacterium, Segetibacter Stenotrophomonas and Variovorax, the predominant zoonotic bacteria represented in these ticks were genera Borrelia, Francisella, and Rickettsia. To the authors' knowledge, this work represents the first detection of Yersinia enterocolitica in the tick H. excavatum, raising questions regarding the vector competency of this tick, as well as associations of different disease representations perhaps through previously unforeseen routes of pathogen introduction. Likewise, similar questions are related to the presence of Legionella pneumophila in one H. excavatum sample.
Villarreal, Zachary; Stephenson, Nicole; Foley, Janet
Increasing rates of Rocky Mountain spotted fever (RMSF) in the southwestern United States and northern Mexico underscore the importance of studying the ecology of the brown dog tick, Rhipicephalus sanguineus, the vector in that region. This species is reported to comprise distinct tropical and temperate lineages that may differ in vectorial capacity for RMSF and are hypothesized to be limited in their geographical range by climatic conditions. In this study, lineage was determined for ticks from 9 locations in California, Arizona, and Mexico by DNA sequencing of 12S, 16S, and D-loop ribosomal RNA. As expected, sites in northern California and eastern Arizona had temperate-lineage ticks, and phylogenetic analysis revealed considerable genetic variability among these temperate-lineage ticks. However, tropical-lineage ticks extended north from Oaxaca, Mexico were well established along the entire border from San Diego, California to western Arizona, and were found as far north as Lytle Creek near Los Angeles, California (a site where both lineages were detected). Far less genetic variability in the tropical lineage despite the large geographical distances is supportive of a hypothesis of rapid northward expansion. Discovery of the tropical lineage north of the identified climatic limitations suggests that more work is needed to characterize this tick's ecology, vectorial capacity, expansion, possible evolution, and response to climate change.
Znazen, Abir; Khrouf, Fatma; Elleuch, Nihel; Lahiani, Dorra; Marrekchi, Chakib; M'Ghirbi, Youmna; Ben Jemaa, Mounir; Bouattour, Ali; Hammami, Adnene
Rickettsioses are important remerging vector born infections. In Tunisia, many species have been described in humans and vectors. Genotyping is important for tracking pathogen movement between hosts and vectors. In this study, we characterized Rickettsia species detected in patients and vectors using multispacer typing (MST), proposed by Founier et al. and based on three intergenic spacers (dksA-xerC, rmpE- tRNA(fMet), mppA-pruC) sequencing. Our study included 25 patients hospitalized during 2009. Ticks and fleas were collected in the vicinity of confirmed cases. Serology was performed on serum samples by microimmunofluorescence using Rickettsia conorii and Rickettsia typhi antigens. To detect and identify Rickettsia species, PCR targeting ompA, ompB and gltA genes followed by sequencing was performed on 18 obtained skin biopsies and on all collected vectors. Rickettsia positive samples were further characterized using primers targeting three intergenic spacers (dksA-xerC, rmpE- tRNA(fMet) and mppA-purC). A rickettsial infection was confirmed in 15 cases (60%). Serology was positive in 13 cases (52%). PCR detected Rickettsia DNA in four biopsies (16%) allowing the identification of R. conorii subsp israelensis in three cases and R. conorii subsp conorii in one case. Among 380 collected ticks, nine presented positive PCR (2.4%) allowing the identification of six R. conorii subsp israelensis, two R. massiliae and one R. conorii subsp conorii. Among 322 collected fleas, only one was positive for R. felis. R. conorii subsp israelensis strains detected in humans and vectors clustered together and showed a new MST genotype. Similarly, R. conorii subsp conorii strains detected in a skin biopsy and a tick were genetically related and presented a new MST genotype. New Rickettsia spotted fever strain genotypes were found in Tunisia. Isolates detected in humans and vectors were genetically homogenous despite location differences in their original isolation suggesting
Rajković Dragana V.
Full Text Available As specific arthropods, ticks in urban environments transmit the agents of dangerous contagious diseases endangering human and animal health. They are vectors of numerous infective agents that cause serious diseases of animals such as babesiosis and ehrlichiosis. Tick populations maintain and transmit an increasing number of different infective agents. In regard to the human population, they transmit the agents of tick encephalitis, Omsk hemorrhagic disease, Crim-Congo hemorrhagic disease, Kyasa-nur forest fever, ixodid fever, Q fever, Rocky Mountain spotted fever, tularemia, Siberian tick typhus and Lyme disease the last of which according to acarological references has become the dominant zoonosis in over 140 of the world's countries. In urban environments ticks represent problem both for their epidemiological significance and as organisms whose presence disturbs people during their work and rest. In Europe, the two most frequent species and Ixodes ricinus and Ixodes persulcatus. Both species have a wide spectrum of hosts.
Apperson, Charles S; Engber, Barry; Nicholson, William L; Mead, Daniel G; Engel, Jeffrey; Yabsley, Michael J; Dail, Kathy; Johnson, Joey; Watson, D Wesley
Cases of Rocky Mountain spotted fever (RMSF) in North Carolina have escalated markedly since 2000. In 2005, we identified a county in the Piedmont region with high case numbers of RMSF. We collected ticks and examined them for bacterial pathogens using molecular methods to determine if a novel tick vector or spotted fever group rickettsiae (SFGR) might be emerging. Amblyomma americanum, the lone star tick, comprised 99.6% of 6,502 specimens collected in suburban landscapes. In contrast, Dermacentor variabilis, the American dog tick, a principal vector of Rickettsia rickettsii, comprised < 1% of the ticks collected. Eleven of 25 lone star tick pools tested were infected with "Rickettsia amblyommii," an informally named SFGR. Sera from patients from the same county who were presumptively diagnosed by local physicians with a tick-borne illness were tested by an indirect immunofluorescence antibody (IFA) assay to confirm clinical diagnoses. Three of six patients classified as probable RMSF cases demonstrated a fourfold or greater rise in IgG class antibody titers between paired acute and convalescent sera to "R. amblyommii" antigens, but not to R. rickettsii antigens. White-tailed deer, Odocoileus virginianus, are preferred hosts of lone star ticks. Blood samples collected from hunter-killed deer from the same county were tested by IFA test for antibodies to Ehrlichia chaffeensis and "R. amblyommii." Twenty-eight (87%) of 32 deer were positive for antibodies to E. chaffeensis, but only 1 (3%) of the deer exhibited antibodies to "R. amblyommii," suggesting that deer are not the source of "R. amblyommii" infection for lone star ticks. We propose that some cases of rickettsiosis reported as RMSF may have been caused by "R. amblyommii" transmitted through the bite of A. americanum.
R T Trout Fryxell
Full Text Available The Lone Star tick, Amblyomma americanum, transmits several bacterial pathogens including species of Anaplasma and Ehrlichia. Amblyomma americanum also hosts a number of non-pathogenic bacterial endosymbionts. Recent studies of other arthropod and insect vectors have documented that commensal microflora can influence transmission of vector-borne pathogens; however, little is known about tick microbiomes and their possible influence on tick-borne diseases. Our objective was to compare bacterial communities associated with A. americanum, comparing Anaplasma/Ehrlichia -infected and uninfected ticks. Field-collected questing specimens (n = 50 were used in the analyses, of which 17 were identified as Anaplasma/Ehrlichia infected based on PCR amplification and sequencing of groEL genes. Bacterial communities from each specimen were characterized using Illumina sequencing of 16S rRNA gene amplicon libraries. There was a broad range in diversity between samples, with inverse Simpson's Diversity indices ranging from 1.28-89.5. There were no statistical differences in the overall microbial community structure between PCR diagnosed Anaplasma/Ehrlichia-positive and negative ticks, but there were differences based on collection method (P < 0.05, collection site (P < 0.05, and sex (P < 0.1 suggesting that environmental factors may structure A. americanum microbiomes. Interestingly, there was not always agreement between Illumina sequencing and PCR diagnostics: Ehrlichia was identified in 16S rRNA gene libraries from three PCR-negative specimens; conversely, Ehrlichia was not found in libraries of six PCR-positive ticks. Illumina sequencing also helped identify co-infections, for example, one specimen had both Ehrlichia and Anaplasma. Other taxa of interest in these specimens included Coxiella, Borrelia, and Rickettsia. Identification of bacterial community differences between specimens of a single tick species from a single geographical site indicates that
Full Text Available Despite being a small country, Kosovo represents one of the few foci of Crimean-Congo hemorrhagic fever (CCHF in Europe. The distribution of Kosovar tick vectors and the evolution of CCHF virus in ticks are both as yet unknown. A better description of the extent and the genetic diversity of CCHFV in ticks from endemic settings is essential, in order to be controlled. We investigated the 2012 distribution of Kosovar ticks alongside the prevalence and the phylogeography of tick-derived CCHFV. Hyalomma marginatum dominated in the endemic municipalities with 90.2% versus 24.3% in the non-endemic regions. Of 1,102 tested ticks, 40 (3.6% were CCHFV-positive, belonging to H. marginatum (29, Rhipicephalus bursa (10, and Ixodes ricinus (1. The virus strains clustered with clade V and VI related sequences. They fell into two lineages: Kosovo I and II. Kosovo I comprised strains recovered exclusively from R. bursa ticks and was closely related to AP92 prototype strain. Kosovo II clustered into Kosovo IIa, including human-derived strains, and IIb including only strains detected in H. marginatum and I. ricinus. Our phylogeographic reconstruction suggests two temporally distinct CCHFV introductions: the most probable location of the most recent common ancestor of Kosovo I lineage was in Greece (63 years ago and that of lineages IIa-b in Turkey (35 years ago. After each CCHFV introduction into Kosovo, subsequent lineage expansions suggest periods of in situ evolution. The study provides the first insight into the genetic variability and the origin of CCHFV in ticks from Kosovo. Our findings indicate the spreading of CCHFV to non-endemic areas, which underlines the importance of further studies in order to monitor and predict future CCHF outbreaks in Kosovo. The AP92-like strains appear to be more widespread than previously thought and may provide a promising target for experimental studies due to their assumed low pathogenicity.
Tokarevich, Nikolay K.; Tronin, Andrey A.; Blinova, Olga V.; Buzinov, Roman V.; Boltenkov, Vitaliy P.; Yurasova, Elena D.; Nurse, Jo
Background The increase in tick-borne encephalitis (TBE) incidence is observed in recent decades in a number of subarctic countries. The reasons of it are widely discussed in scientific publications. The objective of this study was to understand if the climate change in Arkhangelsk Oblast (AO) situated in the north of European subarctic zone of Russia has real impact on the northward expansion of Ixodid ticks and stipulates the increase in TBE incidence. Methods This study analyzes: TBE incidence in AO and throughout Russia, the results of Ixodid ticks collecting in a number of sites in AO, and TBE virus prevalence in those ticks, the data on tick bite incidence in AO, and meteorological data on AO mean annual air temperatures and precipitations. Results It is established that in recent years TBE incidence in AO tended to increase contrary to its apparent decrease nationwide. In last 10 years, there was nearly 50-fold rise in TBE incidence in AO when compared with 1980–1989. Probably, the increase both in mean annual air temperatures and temperatures during tick active season resulted in the northward expansion of Ixodes Persulcatus, main TBE virus vector. The Ixodid ticks expansion is confirmed both by the results of ticks flagging from the surface vegetation and by the tick bite incidence in the population of AO locations earlier free from ticks. Our mathematical (correlation and regression) analysis of available data revealed a distinct correlation between TBE incidence and the growth of mean annual air temperatures in AO in 1990–2009. Conclusion Not ruling out other factors, we conclude that climate change contributed much to the TBE incidence increase in AO. PMID:22028678
Monaghan, A. J.; Beard, C. B.; Eisen, R. J.; Barker, C. M.; Garofalo, J.; Hahn, M.; Hayden, M.; Ogden, N.; Schramm, P.
Vector-borne diseases are illnesses that are transmitted by vectors, which include mosquitoes, ticks, and fleas. The seasonality, distribution, and prevalence of vector-borne diseases are influenced significantly by climate factors, primarily high and low temperature extremes and precipitation patterns. In this presentation we summarize key findings from Chapter 5 ("Vector-borne Diseases") of the recently published USGCRP Scientific Assessment of the Impacts of Climate Change on Human Health in the United States. Climate change is expected to alter geographic and seasonal distributions of vectors and vector-borne diseases, leading to earlier activity and northward range expansion of ticks capable of carrying the bacteria that cause Lyme disease and other pathogens, and influencing the distribution, abundance and prevalence of infection in mosquitoes that transmit West Nile virus and other pathogens. The emergence or reemergence of vector-borne pathogens is also likely.
Newell, Homer E
When employed with skill and understanding, vector analysis can be a practical and powerful tool. This text develops the algebra and calculus of vectors in a manner useful to physicists and engineers. Numerous exercises (with answers) not only provide practice in manipulation but also help establish students' physical and geometric intuition in regard to vectors and vector concepts.Part I, the basic portion of the text, consists of a thorough treatment of vector algebra and the vector calculus. Part II presents the illustrative matter, demonstrating applications to kinematics, mechanics, and e
From his unusual beginning in ""Defining a vector"" to his final comments on ""What then is a vector?"" author Banesh Hoffmann has written a book that is provocative and unconventional. In his emphasis on the unresolved issue of defining a vector, Hoffmann mixes pure and applied mathematics without using calculus. The result is a treatment that can serve as a supplement and corrective to textbooks, as well as collateral reading in all courses that deal with vectors. Major topics include vectors and the parallelogram law; algebraic notation and basic ideas; vector algebra; scalars and scalar p
Cetinic, M.; Diamanti, J.; Szeman, I.; Blacker, S.; Sully, J.
This chapter historicizes four divergent but historically contemporaneous genres of affect theory – romantic, realist, speculative, and materialist. While critics credited with the turn to affect in the 1990s wrote largely in the wake of poststructuralism from the perspective of gender and queer
Wang, Xianzhong; Taub, Daniel R; Jablonski, Leanne M
Reproduction is an important life history trait that strongly affects dynamics of plant populations. Although it has been well documented that elevated carbon dioxide (CO2) in the atmosphere greatly enhances biomass production in plants, the overall effect of elevated CO2 on reproductive allocation (RA), i.e., the proportion of biomass allocated to reproductive structures, is little understood. We combined meta-analysis with graphical vector analysis to examine the overall effect of elevated CO2 on RA and how other environmental factors, such as low nutrients, drought and elevated atmospheric ozone (O3), interacted with elevated CO2 in affecting RA in herbaceous plants. Averaged across all species of different functional groups and environmental conditions, elevated CO2 had little effect on RA (-0.9%). RA in plants of different reproductive strategies and functional groups, however, differed in response to elevated CO2. For example, RA in iteroparous wild species decreased by 8%, while RA in iteroparous crops increased significantly (+14%) at elevated CO2. RA was unaffected by CO2 in plants grown with no stress or in low-nutrient soils. RA decreased at elevated CO2 and elevated O3, but increased in response to elevated CO2 in drought-stressed plants, suggesting that elevated CO2 could ameliorate the adverse effect of drought on crop production to some extent. Our results demonstrate that elevated CO2 and other global environmental changes have the potential to greatly alter plant community composition through differential effects on RA of different plant species and thus affect the dynamics of natural and agricultural ecosystems in the future.
Full Text Available Rocky Mountain spotted fever is an acute illness caused by Rickettsia rickettsii (R. rickettsii and is transmitted by the bite of ticks of the genera Dermacentor, Amblyomma and Rhipicephalus. The illness results in a high mortality rate and may be easily confused with other febrile syndromes. In Yucatan State, Mexico, childhood cases with a high mortality have been reported. In this work we report the isolation of a Mexican R. rickettsii strain from a tick egg mass using an alternative method for Rickettsia isolation with 24-well plates. We also identified a potential vector of R. rickettsii in the southeast of Mexico, which is Amblyomma parvum.
Khrouf, Fatma; M'Ghirbi, Youmna; Znazen, Abir; Ben Jemaa, Mounir; Hammami, Adnene
Ticks (n = 663) and fleas (n = 470) collected from domestic animals from southeastern Tunisia were screened for Rickettsia infection using reverse line blot assay. Evidence of spotted fever group Rickettsia was obtained. We detected Rickettsia felis in fleas, Rickettsia massiliae Bar 29 and the Rickettsia conorii Israeli spotted fever strain in ticks, and Rickettsia conorii subsp. conorii and Rickettsia spp. in both arthropods. The sensitivity of the adopted technique allowed the identification of a new association between fleas and R. conorii subsp. conorii species. The presence of these vector-borne Rickettsia infections should be considered when diagnosing this disease in humans in Tunisia. PMID:24226919
Background Ticks are implicated as hosts to a wide range of animal and human pathogens. The full range of microbes harbored by ticks has not yet been fully explored. Methods As part of a viral surveillance and discovery project in arthropods, we used unbiased high-throughput sequencing to examine viromes of ticks collected on Long Island, New York in 2013. Results We detected and sequenced the complete genome of a novel rhabdovirus originating from a pool of Amblyomma americanum ticks. This virus, which we provisionally name Long Island tick rhabdovirus, is distantly related to Moussa virus from Africa. Conclusions The Long Island tick rhabdovirus may represent a novel species within family Rhabdoviridae. PMID:24517260
Budachetri, K; Kumar, D; Karim, S
The Gulf Coast tick (Amblyomma maculatum) has evolved as a competent vector of the spotted-fever group rickettsia, Rickettsia parkeri. In this study, the functional role of catalase, an enzyme responsible for the degradation of toxic hydrogen peroxide, in the colonization of the tick vector by R. parkeri and transovarial transmission of this pathogen to the next tick generation, was investigated. Catalase gene (CAT) expression in midgut, salivary glands and ovarian tissues exhibited a 2-11-fold increase in transcription level upon R. parkeri infection. Depletion of CAT transcripts using an RNA-interference approach significantly reduced R. parkeri infection levels in midgut and salivary gland tissues by 53-63%. The role of CAT in transovarial transmission of R. parkeri was confirmed by simultaneously blocking the transcript and the enzyme by injecting double-stranded RNA for CAT and a catalase inhibitor (3-amino-1,2,4-triazole) into gravid females. Simultaneous inhibition of the CAT transcript and the enzyme significantly reduced the egg conversion ratio with a 44% reduction of R. parkeri transovarial transmission. These data suggest that catalase is required for rickettsial colonization of the tick vector and transovarial transmission to the next generation. © 2017 The Royal Entomological Society.
McCoy, Karen D; Léger, Elsa; Dietrich, Muriel
Determining patterns of host use, and the frequency at which these patterns change, are of key importance if we are to understand tick population dynamics, the evolution of tick biodiversity, and the circulation and evolution of associated pathogens. The question of whether ticks are typically host specialists or host generalists has been subject to much debate over the last half-century. Indeed, early research proposed that morphological diversity in ticks was linked to host specific adaptations and that most ticks were specialists. Later work disputed this idea and suggested that ticks are largely limited by biogeographic conditions and tend to use all locally available host species. The work presented in this review suggests that the actual answer likely lies somewhere between these two extremes. Although recent observational studies support the view that phylogenetically diverse host species share ticks when found on similar ecological ranges, theory on host range evolution predicts that host specialization should evolve in ticks given their life history characteristics. Contemporary work employing population genetic tools to examine host-associated population structure in several tick systems support this prediction and show that simple species records are not enough to determine whether a parasite is a true host generalist; host specialization does evolve in ticks at local scales, but may not always lead to speciation. Ticks therefore seem to follow a pattern of being global generalists, local specialists. Given this, the notion of host range needs to be modified from an evolutionary perspective, where one simply counts the number of hosts used across the geographic distribution, to a more ecological view, where one considers host use at a local scale, if we are to better understand the circulation of tick-borne pathogens and exposure risks for humans and livestock.
Sonenshine, Daniel E; Macaluso, Kevin R
Ticks transmit a greater variety of pathogenic agents that cause disease in humans and animals than any other haematophagous arthropod, including Lyme disease, Rocky Mountain spotted fever, human granulocytic anaplasmosis, babesiosis, tick-borne encephalitis, Crimean Congo haemorhagic fever, and many others (Gulia-Nuss et al., 2016). Although diverse explanations have been proposed to explain their remarkable vectorial capacity, among the most important are their blood feeding habit, their long term off-host survival, the diverse array of bioactive molecules that disrupt the host's natural hemostatic mechanisms, facilitate blood flow, pain inhibitors, and minimize inflammation to prevent immune rejection (Hajdušek et al., 2013). Moreover, the tick's unique intracellular digestive processes allow the midgut to provide a relatively permissive microenvironment for survival of invading microbes. Although tick-host-pathogen interactions have evolved over more than 300 million years (Barker and Murrell, 2008), few microbes have been able to overcome the tick's innate immune system, comprising both humoral and cellular processes that reject them. Similar to most eukaryotes, the signaling pathways that regulate the innate immune response, i.e., the Toll, IMD (Immunodeficiency) and JAK-STAT (Janus Kinase/ Signal Transducers and Activators of Transcription) also occur in ticks (Gulia-Nuss et al., 2016). Recognition of pathogen-associated molecular patterns (PAMPs) on the microbial surface triggers one or the other of these pathways. Consequently, ticks are able to mount an impressive array of humoral and cellular responses to microbial challenge, including anti-microbial peptides (AMPs), e.g., defensins, lysozymes, microplusins, etc., that directly kill, entrap or inhibit the invaders. Equally important are cellular processes, primarily phagocytosis, that capture, ingest, or encapsulate invading microbes, regulated by a primordial system of thioester-containing proteins
Daniel E. Sonenshine
Full Text Available Ticks transmit a greater variety of pathogenic agents that cause disease in humans and animals than any other haematophagous arthropod, including Lyme disease, Rocky Mountain spotted fever, human granulocytic anaplasmosis, babesiosis, tick-borne encephalitis, Crimean Congo haemorhagic fever, and many others (Gulia-Nuss et al., 2016. Although diverse explanations have been proposed to explain their remarkable vectorial capacity, among the most important are their blood feeding habit, their long term off-host survival, the diverse array of bioactive molecules that disrupt the host's natural hemostatic mechanisms, facilitate blood flow, pain inhibitors, and minimize inflammation to prevent immune rejection (Hajdušek et al., 2013. Moreover, the tick's unique intracellular digestive processes allow the midgut to provide a relatively permissive microenvironment for survival of invading microbes. Although tick-host-pathogen interactions have evolved over more than 300 million years (Barker and Murrell, 2008, few microbes have been able to overcome the tick's innate immune system, comprising both humoral and cellular processes that reject them. Similar to most eukaryotes, the signaling pathways that regulate the innate immune response, i.e., the Toll, IMD (Immunodeficiency and JAK-STAT (Janus Kinase/ Signal Transducers and Activators of Transcription also occur in ticks (Gulia-Nuss et al., 2016. Recognition of pathogen-associated molecular patterns (PAMPs on the microbial surface triggers one or the other of these pathways. Consequently, ticks are able to mount an impressive array of humoral and cellular responses to microbial challenge, including anti-microbial peptides (AMPs, e.g., defensins, lysozymes, microplusins, etc., that directly kill, entrap or inhibit the invaders. Equally important are cellular processes, primarily phagocytosis, that capture, ingest, or encapsulate invading microbes, regulated by a primordial system of thioester
Wolstenholme, E Œ
Elementary Vectors, Third Edition serves as an introductory course in vector analysis and is intended to present the theoretical and application aspects of vectors. The book covers topics that rigorously explain and provide definitions, principles, equations, and methods in vector analysis. Applications of vector methods to simple kinematical and dynamical problems; central forces and orbits; and solutions to geometrical problems are discussed as well. This edition of the text also provides an appendix, intended for students, which the author hopes to bridge the gap between theory and appl
Azagi, Tal; Klement, Eyal; Perlman, Gidon; Lustig, Yaniv; Mumcuoglu, Kosta Y; Apanaskevich, Dmitry A; Gottlieb, Yuval
Hyalomma ticks (Acari: Ixodidae) are hosts for Francisella -like endosymbionts (FLE) and may serve as vectors of zoonotic disease agents. This study aimed to provide an initial characterization of the interaction between Hyalomma and FLE and to determine the prevalence of pathogenic Rickettsia in these ticks. Hyalomma marginatum , Hyalomma rufipes , Hyalomma dromedarii , Hyalomma aegyptium , and Hyalomma excavatum ticks, identified morphologically and molecularly, were collected from different hosts and locations representing the distribution of the genus Hyalomma in Israel, as well as from migratory birds. A high prevalence of FLE was found in all Hyalomma species (90.6%), as well as efficient maternal transmission of FLE (91.8%), and the localization of FLE in Malpighian tubules, ovaries, and salivary glands in H. marginatum Furthermore, we demonstrated strong cophylogeny between FLE and their host species. Contrary to FLE, the prevalence of Rickettsia ranged from 2.4% to 81.3% and was significantly different between Hyalomma species, with a higher prevalence in ticks collected from migratory birds. Using ompA gene sequences, most of the Rickettsia spp. were similar to Rickettsia aeschlimannii , while a few were similar to Rickettsia africae of the spotted fever group (SFG). Given their zoonotic importance, 249 ticks were tested for Crimean Congo hemorrhagic fever virus infection, and all were negative. The results imply that Hyalomma and FLE have obligatory symbiotic interactions, indicating a potential SFG Rickettsia zoonosis risk. A further understanding of the possible influence of FLE on Hyalomma development, as well as on its infection with Rickettsia pathogens, may lead to novel ways to control tick-borne zoonoses. IMPORTANCE This study shows that Francisella -like endosymbionts were ubiquitous in Hyalomma , were maternally transmitted, and cospeciated with their hosts. These findings imply that the interaction between FLE and Hyalomma is of an obligatory
de Oliveira Filho, Jaires Gomes; Ferreira, Lorena Lopes; Sarria, André Lucio Franceschini; Pickett, John A; Birkett, Michael A; Mascarin, Gabriel Moura; de León, Adalberto A Pérez; Borges, Lígia Miranda Ferreira
Domestic dog breeds are hosts for the brown dog tick, Rhipicephalus sanguineus sensu lato, but infestation levels vary among breeds. Beagles are less susceptible to tick infestations than English cocker spaniels due to enhanced production of 2-hexanone and benzaldehyde that act as volatile tick repellents. We report the use of prototype slow-release formulations of these compounds to reduce the burden of R. sanguineus s. l. on English cocker spaniel dogs. Twelve dogs were randomly assigned to two groups with six dogs each. The treated group received collars with slow-release formulations of the compounds attached, while the control group received collars with clean formulations attached. Five environmental infestations were performed, with the number of ticks (at all stages) on the dogs being counted twice a day for 45days. The counts on the number of tick stages found per dog were individually fitted to linear mixed effects models with repeated measures and normal distribution for errors. The mean tick infestation in the treated group was significantly lower than in the control group. For larvae and nymphs, a decrease in tick infestation was observed at the fifth count, and for adults, lower average counts were observed in all counts. The compounds did not interfere with the distribution of the ticks on the body of the dogs, as a similar percentage of ticks was found on the anterior half of the dogs (54.5% for the control group and 56.2% for the treated group). The biological and reproductive parameters of the ticks were not affected by the repellents. This study highlights for the first time the potential use of a novel allomone (repellent)-based formulation for reduction of tick infestation on susceptible dogs. Copyright © 2016 Elsevier GmbH. All rights reserved.
Moemenbellah-Fard, M D; Benafshi, O; Rafinejad, J; Ashraf, H
Tick-borne relapsing fever (TBRF) is a neglected zoonotic disease caused by infection with spirochaetes of the genus Borrelia. Humans usually contract it from the bite of infected soft ticks of the genus Ornithodoros. In Iran, where the disease is endemic in the mountainous north-western provinces, reports of over 200 cases annually probably under-estimate the true incidence. The species, distribution and infection of ticks that are potential vectors of Borrelia and the clinical and epidemiological characteristics of the local TBRF cases were recently investigated in the villages in and around the county town of Bijar, in north-western Iran. A blood sample from each suspected case of TBRF was checked for B. persica by dark-field microscopy, data were collected on the demographics and clinical manifestations of each confirmed case, and the prevalence of tick infection with borreliae and the monthly incidence of TBRF were evaluated. Between 2000 and 2007, 148 cases of TBRF (each with fever, chills and headache) were passively detected in the town. Most (115) of these were confirmed by microscopy, with the other subjects categorized as probable (21) or suspected cases (12) of TBRF. Most (91%) of the 148 subjects were young people, and most came from rural areas and lived in large households in the old mud-and-thatch houses of Bijar. Most (82%) of the cases occurred during the summer or early autumn. Overall, 8543 soft ticks (Ornithodoros tholozani, O. lahorensis, Argas persicus and A. reflexus) were collected by clustered random sampling. When a random sample of the O. tholozani ticks (96 of the 577 collected) was checked for B. persica infection, by being crushed and then inoculated intraperitoneally into a mouse or suckling Syrian hamster, 19 were found infected. Peaks in the monthly incidence of TBRF occurred as the numbers of O. tholozani in the tick collections peaked, and it seems likely that most of the cases were caused by B. persica transmitted by O
Bekloo, Ahmad Jafar; Bakhshi, Hasan; Soufizadeh, Ayoub; Sedaghat, Mohammad Mehdi; Bekloo, Romina Jafar; Ramzgouyan, Maryam Roya; Chegeni, Asadollah Hosseini; Faghihi, Faezeh; Telmadarraiy, Zakkyeh
Ticks serve as important vectors of some pathogens of medical importance all over the world and identification of their rate of infection plays an important role for further control of diseases. In the current study, we investigated on ticks collected from north of Iran where raising and caring livestock are the main task of the people in order to find evidences of infection of Babesia, Theileria, Anaplasma and Ehrlichia microbial agents. Totally, 609 hard tick species from two genera Hyalomma and Rhipicephalus including; Hy. scupense, Hy. dromedarii, Hy. rufipes, Hy. marginatum, Hy. asiaticum, Hy. anatolicum, R. bursa, R. sanguineus and R. turanicus were identified. Molecular analysis revealed the presence of Anaplasma, Ehrlichia, Babesia and Theileria microorganism agents in all collected tick species except Hy. asiaticum and R. turanicus. To the best of our knowledge, this is the first report on identification of B. occultans in Hyalomma anatolicum and B. ovis in Hyalomma sp in Iran. Copyright © 2017 Elsevier B.V. All rights reserved.
Okła, Hubert; Sosnowska, Malwina; Jasik, Krzysztof P; Słodki, Jan; Wojtyczka, Robert D
Ixodes ricinus and other representatives of the order Ixodida are vectors of typical pathogens: Borrelia burgdorferi sensu lato, Anaplasma phagocytophilium, Babesia spp., a tick-borne encephalitis virus, and other microorganisms which are important from a medical and veterinary point of view. The presented study focuses on the verification of nonspecific bacterial flora of I. ricinus. We analyzed ticks collected in a forest region in Silesia, an industrial district in Poland. Methods of classical microbiology and biochemical assays (API 20 NE test, API Staph test and MICRONAUT System) were used for isolation and identification of microorganisms living on the body surface of I. ricinus and inside ticks. The results show the presence of various bacteria on the surface and inside ticks' bodies. During the study, we isolated Acinetobacter lwoffi, Pseudomonas fluorescens, Aeromonas hydrophila, Achromobacter denitrificans, Alcaligenes faecalis, Stenotrophomonas maltophilia, Pseudomonas oryzihabitans, Micrococcus spp., Kocuria varians, Staphylococcus lentus, Kocuria kristinae, Streptococcus pneumoniae, Rhizobium radiobacter, Staphylococcus xylosus. Majority of the isolated species are non-pathogenic environmental microorganisms, but some of the isolated bacterial strains could cause severe infections.
Ivan G. Horak
Full Text Available The distributions of endemic tick vector species as well as the presence of species not endemic to Free State Province, South Africa, were determined during surveys or opportunistic collections from livestock, wildlife and vegetation. Amongst endemic ticks, the presence of Rhipicephalus appendiculatus was confirmed in the north of the province, whilst Rhipicephalus decoloratus was collected at 31 localities mostly in the centre and east, and Ixodes rubicundus at 11 localities in the south, south-west and centre of the province. Amongst the non-endemic species adult Amblyomma hebraeum were collected from white rhinoceroses (Ceratotherium simum on four privately owned farms, whilst the adults of Rhipicephalus microplus were collected from cattle and a larva from vegetation at four localities in the east of the province. The collection of Rhipicephalus evertsi mimeticus from a sheep in the west of the province is the second record of its presence in the Free State, whereas the presence of Haemaphysalis silacea on helmeted guineafowl (Numida meleagris and vegetation in the centre of the province represents a first record for this species in the Free State. The first collection of the argasid tick, Ornithodoros savignyi, in the Free State was made from a domestic cow and from soil in the west of the province. The localities at which the ticks were collected have been plotted and the ticks’ role in the transmission or cause of disease in domestic livestock and wildlife is discussed.
Samish, M; Rot, A; Ment, D; Barel, S; Glazer, I; Gindin, G
High infectivity of entomopathogenic fungi to ticks under laboratory conditions has been demonstrated in many studies. However, the few reports on their use under field conditions demonstrate large variations in their success, often with no clear explanation. The present study evaluated the factors affecting the efficacy of the fungus Metarhizium brunneum against the tick Rhipicephalus (Boophilus) annulatus. It demonstrates how environmental conditions and ground cover affect the efficiency of the fungus under field conditions. During the summer, 93% of tick females exposed to fungus-contaminated ground died within 1 week, whereas during the winter, only 62.2% died within 6 weeks. Nevertheless, the hatchability of their eggs was only 6.1% during the summer and 0.0% during winter. Covering the ground with grass, leaves or gravel improved fungal performance. Aside from killing female ticks, the fungus had a substantial effect on tick fecundity. Fungal infection reduced the proportion of female ticks laying full-size egg masses by up to 91%, and reduced egg hatchability by up to 100%. To reduce the negative effect of outdoor factors on fungal activity, its conidia were mixed with different oils (olive, canola, mineral or paraffin at 10% v/v) and evaluated in both laboratory and field tests for efficacy. All tested oils without conidia sprayed on the sand did not influence tick survival or weight of the laid eggs but significantly reduced egghatchability. Conidia in water with canola or mineral oil spread on agarose and incubated for 18 h showed 57% and 0% germination, respectively. Comparing, under laboratory conditions, the effects of adding each of the four oils to conidia in water on ticks demonstrated no effect on female mortality or weight of the laid egg mass, but the percentage of hatched eggs was reduced. In outdoor trials, female ticks placed on the ground sprayed with conidia in water yielded an average of 175 larvae per female and there was no hatching of
Rothen, Julian; Githaka, Naftaly; Kanduma, Esther G; Olds, Cassandra; Pflüger, Valentin; Mwaura, Stephen; Bishop, Richard P; Daubenberger, Claudia
The tick population of Africa includes several important genera belonging to the family Ixodidae. Many of these ticks are vectors of protozoan and rickettsial pathogens including Theileria parva that causes East Coast fever, a debilitating cattle disease endemic to eastern, central and southern Africa. Effective surveillance of tick-borne pathogens depends on accurate identification and mapping of their tick vectors. A simple and reproducible technique for rapid and reliable differentiation of large numbers of closely related field-collected ticks, which are often difficult and tedious to discriminate purely by morphology, will be an essential component of this strategy. Matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF MS) is increasingly becoming a useful tool in arthropod identification and has the potential to overcome the limitations of classical morphology-based species identification. In this study, we applied MALDI-TOF MS to a collection of laboratory and field ticks found in Eastern Africa. The objective was to determine the utility of this proteomic tool for reliable species identification of closely related afrotropical ticks. A total of 398 ixodid ticks from laboratory maintained colonies, extracted from the hides of animals or systematically collected from vegetation in Kenya, Sudan and Zimbabwe were analyzed in the present investigation. The cytochrome c oxidase I (COI) genes from 33 specimens were sequenced to confirm the tentatively assigned specimen taxa identity on the basis of morphological analyses. Subsequently, the legs of ticks were homogenized and analyzed by MALDI-TOF MS. A collection of reference mass spectra, based on the mass profiles of four individual ticks per species, was developed and deposited in the spectral database SARAMIS™. The ability of these superspectra (SSp.) to identify and reliably validate a set of ticks was demonstrated using the remaining individual 333 ticks. Ultimately, ten
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Full Text Available African swine fever (ASF is a frequently devastating hemorrhagic disease of domestic pigs and wild boar and Ornithodoros erraticus sensu stricto argasid ticks are the only biological vectors of African swine fever virus (ASFV known to occur in Europe. Recently this disease emerged in Eastern Europe and Russian Federation, showing a huge potential for a rapid spread between countries. There is some risk of re-emergence of ASF in the countries where these ticks exist, that can contribute for the persistence of infection and compromise control measures. In this study we aimed to identify factors that determine the probability of infection and its dynamics in the tick vector Ornithodoros erraticus sensu stricto, with two Portuguese strains of ASFV. Our results suggest that these ticks have a high likelihood of excreting the two haemadsorbing ASF viruses of different host origins and that, in field surveys, the analysis of adults and 5th nymphal stage can provide the best chance of detecting virus infection. The results also indicate that infection of pigs with highly virulent ASF viruses will promote higher rates of infection and a higher likelihood for virus excretion by ticks. Nevertheless, there is also a risk, although lower, that ticks can become infected on pigs that have overcome the acute phase of infection, which was simulated in our study by membrane feeding ticks with low titres of virus. We believe these results can be valuable in designing and interpreting the results of ASF control programmes, and future work can also be undertaken as our dataset is released under open access, to perform studies in risk assessment for ASFV persistence in a region where O. erraticus sensu stricto ticks are present.
. Nevertheless, tick cell lines were derived from embryonated eggs and may contain various cell populations with different morphology and behavior that could affect transcriptional response to infection. These results suggested tissue-specific signatures in I. scapularis ISE6 and I. ricinus IRE/CTVM20 tick cell line response to A. phagocytophilum infection that support their use as models for the study of tick-pathogen interactions.
Full Text Available Abstract Background In The Netherlands, the incidence of Lyme borreliosis is on the rise. Besides its causative agent, Borrelia burgdorferi s.l., other potential pathogens like Rickettsia, Babesia and Ehrlichia species are present in Ixodes ricinus ticks. The risk of disease associated with these microorganisms after tick-bites remains, however, largely unclear. A prospective study was performed to investigate how many persons with tick-bites develop localized or systemic symptoms and whether these are associated with tick-borne microorganisms. Results In total, 297 Ixodes ricinus ticks were collected from 246 study participants who consulted a general practitioner on the island of Ameland for tick bites. Ticks were subjected to PCR to detect DNA of Borrelia burgdorferi s.l., Rickettsia spp., Babesia spp. or Ehrlichia/Anaplasma spp.. Sixteen percent of the collected ticks were positive for Borrelia burgdorferi s.l., 19% for Rickettsia spp., 12% for Ehrlichia/Anaplasma spp. and 10% for Babesia spp.. At least six months after the tick bite, study participants were interviewed on symptoms by means of a standard questionnaire. 14 out of 193 participants (8.3% reported reddening at the bite site and 6 participants (4.1% reported systemic symptoms. No association between symptoms and tick-borne microorganisms was found. Attachment duration ≥24 h was positively associated with reddening at the bite site and systemic symptoms. Using logistic regression techniques, reddening was positively correlated with presence of Borrelia afzelii, and having 'any symptoms' was positively associated with attachment duration. Conclusion The risk of contracting acute Lyme borreliosis, rickettsiosis, babesiosis or ehrlichiosis from a single tick bite was
Full Text Available Tick-borne hemorrhagic fever viruses (TBHFV are detected throughout the African and Eurasian continents and are an emerging or re-emerging threat to many nations. Due to the largely sporadic incidences of these severe diseases, information on human cases and research activities in general have been limited. In the past decade, however, novel TBHFVs have emerged and areas of endemicity have expanded. Therefore, the development of countermeasures is of utmost importance in combating TBHFV as elimination of vectors and interrupting enzootic cycles is all but impossible and ecologically questionable. As in vivo models are the only way to test efficacy and safety of countermeasures, understanding of the available animal models and the development and refinement of animal models is critical in negating the detrimental impact of TBHFVs on public and animal health.
Mihalca, Andrei Daniel
It is known that traded exotic animals carry with them an immense number of associated symbionts, including parasites. Reptiles are no exception. Most of the imported reptiles originate from tropical countries and their possibility to carry potentially dangerous pathogens is high. According to CITES, Europe is currently the main reptile importer in the world. Despite this, there is no review or analysis available for the risk related to the importation of tick-borne diseases with traded reptile to the EU. The main aim of the manuscript is to provide a review on the available literature on ticks introduced to and exchanged between European countries via the live reptile trade. So far, the published reports of ticks imported on reptiles are limited to few European countries: Italy, Poland, Spain, Netherlands, Belgium, Slovenia and UK. The following species have been reported: Hyalomma aegyptium, Amblyomma dissimile, Amblyomma exornatum, Amblyomma flavomaculatum, Amblyomma fuscolineatum, Amblyomma latum, Amblyomma quadricavum, Amblyomma marmoreum, Amblyomma nuttalli, Amblyomma sparsum, Amblyomma sphenodonti, Amblyomma transversale and Amblyomma varanense. The majority of species are of African origin, followed by American and Asian species. All groups of reptiles (chelonians, snakes, lizards, crocodiles, tuataras) were involved. However, it seems that certain groups (i.e. tortoises of genus Testudo, monitor lizards of genus Varanus, snakes of genus Python) are more important as host for imported ticks, but this may be related to higher levels of international trade. Even fewer are the reports of tick-borne pathogens associated with imported reptile ticks. Despite the diversity of tick species reported on imported reptiles, the situations of truly invasive species are atypical and are limited in natural environments to maximum two cases where H. aegyptium was involved. Otherwise, the risk associated with reptile trade for introduction of invasive tick to Europe is low
Full Text Available Background/Aim. Despite numerous research of Lyme disease (LD, there are still many concerns about environmental of infectious agent of LD, as well as its prophylaxis, diagnosis and treatment. The aim of this work was to determine the risk of LD in relation to the way of removing ticks and duration of tick attachment. Methods. In the period from 2000 to 2007 a prospective study was conducted including persons with tick bite referred to the Institute of Epidemiology, Military Medical Academy, and followed for the occurrence of early Lyme disease up to six months after a tick bite. Epidemiological questionnaire was used to collect relevant information about the place and time of tick bites, the way of a removing tick, duration of tick attachment, remnants of a tick left in the skin (parts of the mouth device and the signs of clinical manifestations of LD. Duration of tick attachment was determined on the basis of size of engorged tick and epidemiological data. Removed ticks were determined by the key of Pomerancev. Professional removing of attached tick was considered to be removing of tick with mechanical means by healthcare personnel. Fisher's exact test, Chi squares test and calculation of the relative risk (RR were used for data analysis. Results. Of 3 126 patients with tick bite, clinical manifestations of LD were demonstrated in 19 (0.61%. In the group of subjects (n = 829 in which a tick was not removed professionally there were 17 (2.05% cases with LD, while in the group of respondents (n=2 297 in who a tick was removed professionally there were 2 (0.09% cases with LD after tick bite (RR, 23.55; p < 0.0001. The disease was most frequent in the group of respondents with incompletely and unprofessionally removed ticks (2.46%. In the groups of patients with unprofessionally but completely removed ticks LD occurred in 0.89%, while in the group of subjects with a tick removed by an expert, but incompletely in 0.78% cases. The disease occurred
Full Text Available Ticks are vectors for various, including pathogenic, microbes. Tick saliva contains multiple anti-host defense factors that enable ticks their bloodmeals yet also facilitate microbe transmission. Lyme disease-causing borreliae profit specifically from the broadly conserved tick histamine release factor (tHRF, and from cysteine-rich glycoproteins represented by Salp15 from Ixodes scapularis and Iric-1 from Ixodes ricinus ticks which they recruit to their outer surface protein C (OspC. Hence these tick proteins are attractive targets for anti-tick vaccines that simultaneously impair borrelia transmission. Main obstacles are the tick proteins´ immunosuppressive activities, and for Salp15 orthologs, the lack of efficient recombinant expression systems. Here, we exploited the immune-enhancing properties of hepatitis B virus core protein (HBc derived capsid-like particles (CLPs to generate, in E. coli, nanoparticulate vaccines presenting tHRF and, as surrogates for the barely soluble wild-type proteins, cysteine-free Salp15 and Iric-1 variants. The latter CLPs were exclusively accessible in the less sterically constrained SplitCore system. Mice immunized with tHRF CLPs mounted a strong anti-tHRF antibody response. CLPs presenting cysteine-free Salp15 and Iric-1 induced antibodies to wild-type, including glycosylated, Salp15 and Iric-1. The broadly distributed epitopes included the OspC interaction sites. In vitro, the anti-Salp15 antibodies interfered with OspC binding and enhanced human complement-mediated killing of Salp15 decorated borreliae. A mixture of all three CLPs induced high titered antibodies against all three targets, suggesting the feasibility of combination vaccines. These data warrant in vivo validation of the new candidate vaccines´ protective potential against tick infestation and Borrelia transmission.
Kolb, Philipp; Wallich, Reinhard; Nassal, Michael
Ticks are vectors for various, including pathogenic, microbes. Tick saliva contains multiple anti-host defense factors that enable ticks their bloodmeals yet also facilitate microbe transmission. Lyme disease-causing borreliae profit specifically from the broadly conserved tick histamine release factor (tHRF), and from cysteine-rich glycoproteins represented by Salp15 from Ixodes scapularis and Iric-1 from Ixodes ricinus ticks which they recruit to their outer surface protein C (OspC). Hence these tick proteins are attractive targets for anti-tick vaccines that simultaneously impair borrelia transmission. Main obstacles are the tick proteins´ immunosuppressive activities, and for Salp15 orthologs, the lack of efficient recombinant expression systems. Here, we exploited the immune-enhancing properties of hepatitis B virus core protein (HBc) derived capsid-like particles (CLPs) to generate, in E. coli, nanoparticulate vaccines presenting tHRF and, as surrogates for the barely soluble wild-type proteins, cysteine-free Salp15 and Iric-1 variants. The latter CLPs were exclusively accessible in the less sterically constrained SplitCore system. Mice immunized with tHRF CLPs mounted a strong anti-tHRF antibody response. CLPs presenting cysteine-free Salp15 and Iric-1 induced antibodies to wild-type, including glycosylated, Salp15 and Iric-1. The broadly distributed epitopes included the OspC interaction sites. In vitro, the anti-Salp15 antibodies interfered with OspC binding and enhanced human complement-mediated killing of Salp15 decorated borreliae. A mixture of all three CLPs induced high titered antibodies against all three targets, suggesting the feasibility of combination vaccines. These data warrant in vivo validation of the new candidate vaccines´ protective potential against tick infestation and Borrelia transmission. PMID:26352137
Reimerink Johan R
Full Text Available Abstract Background Awareness for flea- and tick-borne infections has grown in recent years and the range of microorganisms associated with these ectoparasites is rising. Bartonella henselae, the causative agent of Cat Scratch Disease, and other Bartonella species have been reported in fleas and ticks. The role of Ixodes ricinus ticks in the natural cycle of Bartonella spp. and the transmission of these bacteria to humans is unclear. Rickettsia spp. have also been reported from as well ticks as also from fleas. However, to date no flea-borne Rickettsia spp. were reported from the Netherlands. Here, the presence of Bartonellaceae and Rickettsiae in ectoparasites was investigated using molecular detection and identification on part of the gltA- and 16S rRNA-genes. Results The zoonotic Bartonella clarridgeiae and Rickettsia felis were detected for the first time in Dutch cat fleas. B. henselae was found in cat fleas and B. schoenbuchensis in ticks and keds feeding on deer. Two Bartonella species, previously identified in rodents, were found in wild mice and their fleas. However, none of these microorganisms were found in 1719 questing Ixodes ricinus ticks. Notably, the gltA gene amplified from DNA lysates of approximately 10% of the questing nymph and adult ticks was similar to that of an uncultured Bartonella-related species found in other hard tick species. The gltA gene of this Bartonella-related species was also detected in questing larvae for which a 16S rRNA gene PCR also tested positive for "Candidatus Midichloria mitochondrii". The gltA-gene of the Bartonella-related species found in I. ricinus may therefore be from this endosymbiont. Conclusions We conclude that the risk of acquiring Cat Scratch Disease or a related bartonellosis from questing ticks in the Netherlands is negligible. On the other hand fleas and deer keds are probable vectors for associated Bartonella species between animals and might also transmit Bartonella spp. to humans.
Full Text Available Abstract Background Hard ticks have been identified as important vectors of rickettsiae causing the spotted fever syndrome. Tick-borne rickettsiae are considered to be emerging, but only limited data are available about their presence in Western Europe, their natural life cycle and their reservoir hosts. Ixodes ricinus, the most prevalent tick species, were collected and tested from different vegetation types and from potential reservoir hosts. In one biotope area, the annual and seasonal variability of rickettsiae infections of the different tick stages were determined for 9 years. Results The DNA of the human pathogen R. conorii as well as R. helvetica, R. sp. IRS and R. bellii-like were found. Unexpectedly, the DNA of the highly pathogenic R. typhi and R. prowazekii and 4 other uncharacterized Rickettsia spp. related to the typhus group were also detected in I. ricinus. The presence of R. helvetica in fleas isolated from small rodents supported our hypothesis that cross-infection can occur under natural conditions, since R. typhi/prowazekii and R. helvetica as well as their vectors share rodents as reservoir hosts. In one biotope, the infection rate with R. helvetica was ~66% for 9 years, and was comparable between larvae, nymphs, and adults. Larvae caught by flagging generally have not yet taken a blood meal from a vertebrate host. The simplest explanation for the comparable prevalence of R. helvetica between the defined tick stages is, that R. helvetica is vertically transmitted through the next generation with high efficiency. The DNA of R. helvetica was also present in whole blood from mice, deer and wild boar. Conclusion Besides R. helvetica, unexpected rickettsiae are found in I. ricinus ticks. We propose that I. ricinus is a major reservoir host for R. helvetica, and that vertebrate hosts play important roles in the further geographical dispersion of rickettsiae.
Razmi, Gholamreza; Pourhosseini, Moslem; Yaghfouri, Saeed; Rashidi, Ahmad; Seidabadi, Mohsen
Theilerioses and babesioses are important diseases in Iranian sheep. The present study was undertaken to identify and classify/specify Theileria spp. and Babesia spp. in sheep and vector ticks. Investigation was carried out from 2009 to 2011 in the Khorasan Razavi Province, Iran. In total, 302 sheep originating from 60 different flocks were clinically examined and their blood collected. In addition, from the same flocks, ixodid ticks were sampled. Stained blood smears were microscopically examined for the presence of Theileria and Babesia organisms, and a semi-nested PCR was used for subsequent molecular specification. From the ticks, salivary glands and uterus were isolated and subsequently analyzed by semi-nested PCR. Piroplasm organisms were observed in 29% of the blood smears with low parasitemia, whereas 65% of the blood samples yielded positive PCR findings. The presence of Theileria ovis (55.6%), Theileria lestoquardi, and mixed infection with Theileria spp. and Babesia ovis were detected by semi-nested PCR in 0.3%, 5.6%, and 0.99%, respectively. In total, 429 ixodid ticks were collected from different areas of the province. The most prevalent ticks were Rhipicephalus turanicus (n = 376; 87.6% of the total), followed by Hyalomma marginatum turanicum (n = 30; 7.0%), Dermacentor raskemensis (n = 12; 2.8%), Hyalomma anatolicum anatolicum (n = 7; 1.6%), Dermacentor marginatus (n = 2; 0.5%), Rhipicephalus bursa (n = 1; 0.2%), and Haemaphysalis sp. (n = 1; 0.2%). Of the positive R. turanicus samples, 5 (5.7%) were infected with T. ovis and 2 (2.9%) with T. lestoquardi. Neither Babesia ovis nor Babesia motasi infection was detected in salivary glands or uterine samples of the ticks. The results also suggest that R. turanicus could be the vector responsible for transmission of the 2 Theileria species.
Sherifi, Kurtesh; Rexhepi, Agim; Berxholi, Kristaq; Mehmedi, Blerta; Gecaj, Rreze M.; Hoxha, Zamira; Joachim, Anja; Duscher, Georg G.
Tick-borne diseases pose a serious threat to human health in South-Eastern Europe, including Kosovo. While Crimean–Congo hemorrhagic fever (CCHF) is a well-known emerging infection in this area, there are no accurate data on Lyme borreliosis and tick-borne encephalitis (TBE). Therefore, we sampled and tested 795 ticks. Ixodes ricinus (n = 218), Dermacentor marginatus (n = 98), and Haemaphysalis spp. (n = 24) were collected from the environment by flagging (all from Kosovo), while Hyalomma marginatum (n = 199 from Kosovo, all from Kosovo) and Rhipicephalus bursa (n = 130, 126 from Albania) could be collected only by removal from animal pasture and domestic ruminants. Ticks were collected in the years 2014/2015 and tested for viral RNA of CCHF and TBE viruses, as well as for DNA of Borrelia burgdorferi sensu lato by real-time PCR. In Kosovo, nine ticks were positive for RNA of Crimean–Congo hemorrhagic fever virus and seven for DNA of B. burgdorferi s. l. None of the ticks tested positive for TBEV. CCHF virus was detected in one H. marginatum male specimen collected while feeding on grazing cattle from the Prizren region and in eight R. bursa specimens (five females and three males collected while feeding on grazing sheep and cattle) from the Prishtina region (Kosovo). B. burgdorferi s. l. was detected in seven questing ticks (four male and one female D. marginatus, two I. ricinus one female and one male) from the Mitrovica region (Kosovo). Our study confirmed that CCHF virus is circulating in Kosovo mainly in H. marginatum and R. bursa in the central areas of the country. B. burgdorferi s. l. was found in its major European host tick, I. ricinus, but also in D. marginatus, in the north of the Kosovo. In order to prevent the spread of these diseases and better control of the tick-borne infections, an improved vector surveillance and testing of ticks for the presence of pathogens needs to be established. PMID:29560357
Full Text Available Tick-borne diseases pose a serious threat to human health in South-Eastern Europe, including Kosovo. While Crimean–Congo hemorrhagic fever (CCHF is a well-known emerging infection in this area, there are no accurate data on Lyme borreliosis and tick-borne encephalitis (TBE. Therefore, we sampled and tested 795 ticks. Ixodes ricinus (n = 218, Dermacentor marginatus (n = 98, and Haemaphysalis spp. (n = 24 were collected from the environment by flagging (all from Kosovo, while Hyalomma marginatum (n = 199 from Kosovo, all from Kosovo and Rhipicephalus bursa (n = 130, 126 from Albania could be collected only by removal from animal pasture and domestic ruminants. Ticks were collected in the years 2014/2015 and tested for viral RNA of CCHF and TBE viruses, as well as for DNA of Borrelia burgdorferi sensu lato by real-time PCR. In Kosovo, nine ticks were positive for RNA of Crimean–Congo hemorrhagic fever virus and seven for DNA of B. burgdorferi s. l. None of the ticks tested positive for TBEV. CCHF virus was detected in one H. marginatum male specimen collected while feeding on grazing cattle from the Prizren region and in eight R. bursa specimens (five females and three males collected while feeding on grazing sheep and cattle from the Prishtina region (Kosovo. B. burgdorferi s. l. was detected in seven questing ticks (four male and one female D. marginatus, two I. ricinus one female and one male from the Mitrovica region (Kosovo. Our study confirmed that CCHF virus is circulating in Kosovo mainly in H. marginatum and R. bursa in the central areas of the country. B. burgdorferi s. l. was found in its major European host tick, I. ricinus, but also in D. marginatus, in the north of the Kosovo. In order to prevent the spread of these diseases and better control of the tick-borne infections, an improved vector surveillance and testing of ticks for the presence of pathogens needs to be established.
Sherifi, Kurtesh; Rexhepi, Agim; Berxholi, Kristaq; Mehmedi, Blerta; Gecaj, Rreze M; Hoxha, Zamira; Joachim, Anja; Duscher, Georg G
Tick-borne diseases pose a serious threat to human health in South-Eastern Europe, including Kosovo. While Crimean-Congo hemorrhagic fever (CCHF) is a well-known emerging infection in this area, there are no accurate data on Lyme borreliosis and tick-borne encephalitis (TBE). Therefore, we sampled and tested 795 ticks. Ixodes ricinus ( n = 218), Dermacentor marginatus ( n = 98), and Haemaphysalis spp. ( n = 24) were collected from the environment by flagging (all from Kosovo), while Hyalomma marginatum ( n = 199 from Kosovo, all from Kosovo) and Rhipicephalus bursa ( n = 130, 126 from Albania) could be collected only by removal from animal pasture and domestic ruminants. Ticks were collected in the years 2014/2015 and tested for viral RNA of CCHF and TBE viruses, as well as for DNA of Borrelia burgdorferi sensu lato by real-time PCR. In Kosovo, nine ticks were positive for RNA of Crimean-Congo hemorrhagic fever virus and seven for DNA of B. burgdorferi s. l. None of the ticks tested positive for TBEV. CCHF virus was detected in one H. marginatum male specimen collected while feeding on grazing cattle from the Prizren region and in eight R. bursa specimens (five females and three males collected while feeding on grazing sheep and cattle) from the Prishtina region (Kosovo). B. burgdorferi s. l. was detected in seven questing ticks (four male and one female D. marginatus , two I. ricinus one female and one male) from the Mitrovica region (Kosovo). Our study confirmed that CCHF virus is circulating in Kosovo mainly in H. marginatum and R. bursa in the central areas of the country. B. burgdorferi s. l. was found in its major European host tick, I. ricinus , but also in D. marginatus , in the north of the Kosovo. In order to prevent the spread of these diseases and better control of the tick-borne infections, an improved vector surveillance and testing of ticks for the presence of pathogens needs to be established.
Santos, Huarrisson A; Thomé, Sandra M G; Baldani, Cristiane D; Silva, Claudia B; Peixoto, Maristela P; Pires, Marcus S; Vitari, Gabriela L V; Costa, Renata L; Santos, Tiago M; Angelo, Isabele C; Santos, Leandro A; Faccini, João L H; Massard, Carlos L
Anaplasma phagocytophilum is an emerging pathogen of humans, dogs and other animals, and it is transmitted by ixodid ticks. The objective of the current study was a) detect A. phagocytophilum in dogs and ixodid ticks using real-time Polymerase Chain Reaction (qPCR); and b) Determine important variables associated to host, environment and potential tick vectors that are related to the presence of A. phagocytophilum in dogs domiciled in Rio de Janeiro, Brazil. We tested blood samples from 398 dogs and samples from 235 ticks, including 194 Rhipicephalus sanguineus sensu lato, 15 Amblyomma cajennense, 8 Amblyomma ovale and 18 pools of Amblyomma sp. nymphs. A semi-structured questionnaire was applied by interviewing each dog owner. Deoxyribonucleic acid obtained from ticks and dog buffy coat samples were amplified by qPCR (msp2 gene). The sequencing of 16S rRNA and groESL heat shock operon genes and a phylogenetic analysis was performed. The multiple logistic regression model was created as a function of testing positive dogs for A. phagocytophilum. Among the 398 blood samples from dogs, 6.03% were positive for A. phagocytophilum. Anaplasma phagocytophilum was detected in one A. cajennense female tick and in five R. sanguineus sensu lato ticks (four males and one female). The partial sequences of the 16S rRNA, and groESL genes obtained were highly similar to strains of A. phagocytophilum isolated from wild birds from Brazil and human pathogenic strains. The tick species collected in positive dogs were R. sanguineus sensu lato and A. cajennense, with A.cajennense being predominant. Tick infestation history (OR = 2.86, CI = 1.98-14.87), dog size (OR = 2.41, IC: 1.51-12.67), the access to forest areas (OR = 3:51, CI: 1.52-16.32), hygiene conditions of the environment in which the dogs lived (OR = 4.35, CI: 1.86-18.63) and Amblyomma sp. infestation (OR = 6.12; CI: 2.11-28.15) were associated with A. phagocytophilum infection in dogs. This is the
Rulison, Eric L; Lebrun, Roger A; Ginsberg, Howard S
Ambient temperature can influence tick development time, and can potentially affect tick interactions with pathogens and with vertebrate hosts. We studied the effect of ambient temperature on duration of attachment of larval blacklegged ticks, Ixodes scapularis Say, to eastern fence lizards, Sceloporus undulatus (Bosc & Daudin). Feeding periods of larvae that attached to lizards under preferred temperature conditions for the lizards (WARM treatment: temperatures averaged 36.6°C at the top of the cage and 25.8°C at the bottom, allowing behavioral thermoregulation) were shorter than for larvae on lizards held under cool conditions (COOL treatment temperatures averaged 28.4°C at top of cage and 24.9°C at the bottom). The lizards were infested with larvae four times at roughly monthly intervals. Larval numbers successfully engorging and dropping declined and feeding period was longer after the first infestation. © 2014 Entomological Society of America.
Fialová, Anna; Cimburek, Zdeněk; Iezzi, G.; Kopecký, Jan
Roč. 12, č. 7 (2010), s. 580-585 ISSN 1286-4579 R&D Projects: GA AV ČR IAA600960811 Institutional research plan: CEZ:AV0Z60220518; CEZ:AV0Z50200510 Keywords : Tick-borne encephalitis virus * Dendritic cell * Tick saliva * Ixodes ricinus Subject RIV: EC - Immunology Impact factor: 2.726, year: 2010
Full Text Available Background: Q fever is a widespread zoonotic disease caused by Coxiella burnetii. Ticks may act as vectors, and many epidemiological studies aim to assess C. burnetii prevalence in ticks. Because ticks may also be infected with Coxiella-like bacteria, screening tools that differentiate between C. burnetii and Coxiella-like bacteria are essential. Methods: In this study, we screened tick specimens from 10 species (Ornithodoros rostratus, O. peruvianus, O. capensis, Ixodes ricinus, Rhipicephalus annulatus, R. decoloratus, R. geigy, O. sonrai, O. occidentalis, and Amblyomma cajennense known to harbor specific Coxiella-like bacteria, by using quantitative PCR primers usually considered to be specific for C. burnetii and targeting, respectively, the IS1111, icd, scvA, p1, and GroEL/htpB genes. Results: We found that some Coxiella-like bacteria, belonging to clades A and C, yield positive PCR results when screened with primers initially believed to be C. burnetii-specific. Conclusions: These results suggest that PCR-based surveys that aim to detect C. burnetii in ticks by using currently available methods must be interpreted with caution if the amplified products cannot be sequenced. Future molecular methods that aim at detecting C. burnetii need to take into account the possibility that cross-reactions may exist with Coxiella-like bacteria.
Full Text Available Objective: To ascertain the prevalence of the Anaplasma/Ehrlichia infections in tick population within four provinces of Iran. Methods: A total of 384 tick specimens were collected from domestic animals inhabiting in four provinces (East Azerbaijan, Gilan, South Khorasan and Yazd. Specimens were identified based on morphological analysis. The detection of Anaplasma spp./Ehrlichia spp. within tick samples was carried out by nested PCR amplification of the 16S ribosomal RNA gene accompanied by DNA sequencing and analysis for verification. Results: A total of 10 tick species were identified as follows: Ornithodoros lahorensis (O. lahorensis (44.8%, Hyalomma dromedarii (15.6%, Dermacentor marginatus (13.5%, Hyalomma anatolicum (11.2%, Hyalomma asiaticum (5.7%, Hyalomma marginatum (4.9%, Rhipicephalus sanguineus (2.3%, Hyalomma detritum (1.0%, Dermacentor niveus (0.5% and Argas persicus (0.3%. The percentage distribution of Anaplasma/Ehrlichia was 55.5% (213 across 384 studied ticks. Conclusions: To the best of our knowledge, this is the first report of Anaplasma ovis infection in O. lahorensis in Iran. We also conjecture the prevalence of Ehrlichia spp. in Yazd Province based on sequencing results; also, it is suggested that O. lahorensis is a potential vector in the studied area. This survey highlights the importance of Argasidae family to verify and correlate their threat in causing anaplasmosis and other diseases in animals.
Romer, Yamila; Nava, Santiago; Govedic, Francisco; Cicuttin, Gabriel; Denison, Amy M.; Singleton, Joseph; Kelly, Aubree J.; Kato, Cecilia Y.; Paddock, Christopher D.
Rickettsia parkeri, a newly recognized tick-borne pathogen of humans in the Americas, is a confirmed cause of spotted fever group rickettsiosis in Argentina. Until recently, almost all cases of R. parkeri rickettsiosis in Argentina have originated from the Paraná River Delta, where entomological surveys have identified populations of R. parkeri-infected Amblyomma triste ticks. In this report, we describe confirmed cases of R. parkeri rickettsiosis from Córdoba and La Rioja provinces, which are located several hundred kilometers inland, and in a more arid ecological region, where A. triste ticks do not occur. Additionally, we identified questing A. tigrinum ticks naturally infected with R. parkeri in Córdoba province. These data provide evidence that another human-biting tick species serves as a potential vector of R. parkeri in Argentina and possibly, other countries of South America. PMID:25349376
Cardoso, Luís; Oliveira, Ana Cristina; Granada, Sara; Nachum-Biala, Yaarit; Gilad, Matan; Lopes, Ana Patrícia; Sousa, Sérgio Ramalho; Vilhena, Hugo; Baneth, Gad
No molecular data have been available on tick-borne pathogens that infect dogs from Angola. The occurrence of agents from the genera Anaplasma, Babesia, Ehrlichia and Hepatozoon was assessed in 103 domestic dogs from Luanda, by means of the polymerase chain reaction (PCR) and DNA sequence analysis. Forty-six dogs (44.7 %) were positive for at least one pathogen. Twenty-one animals (20.4 %) were found infected with Anaplasma platys, 18 (17.5 %) with Hepatozoon canis, six (5.8 %) with Ehrlichia canis, six (5.8 %) with Babesia vogeli, one (1.0 %) with Babesia gibsoni and one (1.0 %) with an unnamed Babesia sp. The molecular frequency of single infections taken together was 37.9 % and that of co-infections with several combinations of two pathogens accounted for 6.8 % of the animals. This is the first report of A. platys, B. vogeli, B. gibsoni, E. canis and H. canis infections diagnosed by PCR in domestic dogs from Angola. The present study provides evidence that dogs in Luanda are widely exposed to, and at risk of becoming infected with, tick-borne pathogens. Further investigation is needed, including a larger number of animals, canine populations from other cities and provinces of the country, as well as potential vector ticks, aiming at better characterizing and controlling canine vector-borne diseases in Angola.
The use of vectors not only simplifies treatments of differential geometry, mechanics, hydrodynamics, and electrodynamics, but also makes mathematical and physical concepts more tangible and easy to grasp. This text for undergraduates was designed as a short introductory course to give students the tools of vector algebra and calculus, as well as a brief glimpse into these subjects' manifold applications. The applications are developed to the extent that the uses of the potential function, both scalar and vector, are fully illustrated. Moreover, the basic postulates of vector analysis are brou
Mulenga, Albert; Kim, Tae Kwon; Ibelli, Adriana Mércia Guaratini
We previously identified a cross-tick species conserved tick feeding stimuli responsive Amblyomma americanum (Aam) AV422 gene. This study demonstrates that AamAV422 belongs to a novel group of arthropod proteins that is characterized by 14 cysteine amino acid residues: C(23)-X7/9-C(33)-X23/24-C(58)-X8-C(67)-X7-C(75)-X23-C(99)-X15-C(115)-X10-C(126)-X24/25/33-C(150)C(151)-X7-C(159)-X8-C(168)-X23/24-C(192)-X9/10-C(202) predicted to form seven disulfide bonds. We show that AamAV422 protein is a ubiquitously expressed protein that is injected into the host within the first 24h of the tick attaching onto the host as revealed by Western blotting analyses of recombinant (r)AamAV422, tick saliva and dissected tick organ protein extracts using antibodies to 24 and 48 h tick saliva proteins. Native AamAV422 is apparently involved with mediating tick anti-hemostasis and anti-complement functions in that rAamAV422 delayed plasma clotting time in a dose responsive manner by up to ≈ 160 s, prevented platelet aggregation by up to ≈ 16% and caused ≈ 24% reduction in production of terminal complement complexes. Target validation analysis revealed that rAamAV422 is a potential candidate for a cocktail or multivalent tick vaccine preparation in that RNA interference (RNAi)-mediated silencing of AamAV422 mRNA caused a statistically significant (≈ 44%) reduction in tick engorgement weights, which is proxy for amounts of ingested blood. We speculate that AamAV422 is a potential target antigen for development of the highly desired universal tick vaccine in that consistent with high conservation among ticks, antibodies to 24h Ixodes scapularis tick saliva proteins specifically bound rAamAV422. We discuss data in this study in the context of advancing the biology of tick feeding physiology and discovery of potential target antigens for tick vaccine development. Copyright © 2013 Australian Society for Parasitology Inc. Published by Elsevier Ltd. All rights reserved.
Full Text Available Cyclic dimeric GMP (c-di-GMP is a bacterial second messenger that modulates many biological processes. Although its role in bacterial pathogenesis during mammalian infection has been documented, the role of c-di-GMP in a pathogen's life cycle within a vector host is less understood. The enzootic cycle of the Lyme disease pathogen Borrelia burgdorferi involves both a mammalian host and an Ixodes tick vector. The B. burgdorferi genome encodes a single copy of the diguanylate cyclase gene (rrp1, which is responsible for c-di-GMP synthesis. To determine the role of c-di-GMP in the life cycle of B. burgdorferi, an Rrp1-deficient B. burgdorferi strain was generated. The rrp1 mutant remains infectious in the mammalian host but cannot survive in the tick vector. Microarray analyses revealed that expression of a four-gene operon involved in glycerol transport and metabolism, bb0240-bb0243, was significantly downregulated by abrogation of Rrp1. In vitro, the rrp1 mutant is impaired in growth in the media containing glycerol as the carbon source (BSK-glycerol. To determine the contribution of the glycerol metabolic pathway to the rrp1 mutant phenotype, a glp mutant, in which the entire bb0240-bb0243 operon is not expressed, was generated. Similar to the rrp1 mutant, the glp mutant has a growth defect in BSK-glycerol medium. In vivo, the glp mutant is also infectious in mice but has reduced survival in ticks. Constitutive expression of the bb0240-bb0243 operon in the rrp1 mutant fully rescues the growth defect in BSK-glycerol medium and partially restores survival of the rrp1 mutant in ticks. Thus, c-di-GMP appears to govern a catabolic switch in B. burgdorferi and plays a vital role in the tick part of the spirochetal enzootic cycle. This work provides the first evidence that c-di-GMP is essential for a pathogen's survival in its vector host.
Fernanda Ferreira Pessoa
chamber and necklace did not affect the cortisol level, although they had prevented grooming. Consequently, animals with the artifacts had more ticks than the ones with no artifacts (34.56% versus 14.9% tick recovery rate, P< 0.05. The last blood sample collection had revealed an increase on the cortisol level, coinciding with the final parasitic life cycle of R. microplus (Table 1. No significant correlation were detected between cortisol levels and the tick recovery rate. Grooming is important to decrease the cattle tick infestation, but its limitation presented in this study, did not elevate the serum cortisol level, related to animal stress.
Ferrell, A Michelle; Brinkerhoff, R Jory
Patterns of vector-borne disease risk are changing globally in space and time and elevated disease risk of vector-borne infection can be driven by anthropogenic modification of the environment. Incidence of Lyme disease, caused by the bacterium Borrelia burgdorferi sensu stricto, has risen in a number of locations in North America and this increase may be driven by spatially or numerically expanding populations of the primary tick vector, Ixodes scapularis . We used a model selection approach to identify habitat fragmentation and land-use/land cover variables to test the hypothesis that the amount and configuration of forest cover at spatial scales relevant to deer, the primary hosts of adult ticks, would be the predominant determinants of tick abundance. We expected that land cover heterogeneity and amount of forest edge, a habitat thought to facilitate deer foraging and survival, would be the strongest driver of tick density and that larger spatial scales (5-10 km) would be more important than smaller scales (1 km). We generated metrics of deciduous and mixed forest fragmentation using Fragstats 4.4 implemented in ArcMap 10.3 and found, after adjusting for multicollinearity, that total forest edge within a 5 km buffer had a significant negative effect on tick density and that the proportion of forested land cover within a 10 km buffer was positively associated with density of I. scapularis nymphs. None of the 1 km fragmentation metrics were found to significantly improve the fit of the model. Elevation, previously associated with increased density of I. scapularis nymphs in Virginia, while significantly predictive in univariate analysis, was not an important driver of nymph density relative to fragmentation metrics. Our results suggest that amount of forest cover (i.e., lack of fragmentation) is the most important driver of I. scapularis density in our study system.
Full Text Available Abstract Background Bovine babesiosis is a tick-borne disease caused by the protozoan parasites of the genus Babesia. In their host vector, Babesia spp. undergo sexual reproduction. Therefore, the development of sexual stages and the subsequent formation of the zygote are essential for the parasite to invade the intestinal cells of the vector tick and continue its life-cycle. HAP2/GCS1 is a protein identified in plants, protozoan parasites and other organisms that has an important role during membrane fusion in fertilization processes. The identification and characterization of HAP-2 protein in Babesia would be very significant to understand the biology of the parasite and to develop a transmission-blocking vaccine in the future. Results To isolate and sequence the hap2 gene DNA from an infected bovine with Babesia bigemina was purified. The hap2 gene was amplified, cloned and sequenced. The sequences of hap2 from four geographically different strains showed high conservation at the amino acid level, including the typical structure with a signal peptide and the HAP2/GSC domain. Antisera anti-HAP2 against the conserved extracellular region of the HAP2 amino acid sequence were obtained from rabbits. The expression of hap2 in the host and vector tissues was analyzed by using semi-quantitative RT-PCR, and the protein was examined by western blot and immunofluorescence. Based on the RT-PCR and WB results, HAP2 is expressed in both, sexual stages induced in vitro, and in infected ticks as well. We did not detect any expression in asexual erythrocytic stages of B. bigemina, relevantly anti-HAP2 specific antibodies were able to block zygotes formation in vitro. Conclusion Babesia bigemina HAP2 is expressed only in tick-infecting stages, and specific antibodies block zygote formation. Further studies regarding the function of HAP2 during tick infection may provide new insights into the molecular mechanisms of sexual reproduction of the parasite.
Full Text Available In this study 308 ticks (Ixodes ariadnae: 26 larvae, 14 nymphs, five females; I. vespertilionis: 89 larvae, 27 nymphs, eight females; I. simplex: 80 larvae, 50 nymphs, nine females have been collected from 200 individuals of 17 bat species in two countries, Hungary and Romania. After DNA extraction these ticks were molecularly analysed for the presence of piroplasm DNA. In Hungary I. ariadnae was most frequently identified from bat species in the family Vespertilionidae, whereas I. vespertilionis was associated with Rhinolophidae. Ixodes ariadnae was not found in Romania. Four, four and one new bat host species of I. ariadnae, I. vespertilionis and I. simplex were identified, respectively. DNA sequences of piroplasms were detected in 20 bat ticks (15 larvae, four nymphs and one female. I. simplex carried piroplasm DNA sequences significantly more frequently than I. vespertilionis. In I. ariadnae only Babesia vesperuginis DNA was detected, whereas in I. vespertilionis sequences of both B. vesperuginis and B. crassa. From I. simplex the DNA of B. canis, Theileria capreoli, T. orientalis and Theileria sp. OT3 were amplified, as well as a shorter sequence of the zoonotic B. venatorum. Bat ticks are not known to infest dogs or ruminants, i.e. typical hosts and reservoirs of piroplasms molecularly identified in I. vespertilionis and I. simplex. Therefore, DNA sequences of piroplasms detected in these bat ticks most likely originated from the blood of their respective bat hosts. This may indicate either that bats are susceptible to a broader range of piroplasms than previously thought, or at least the DNA of piroplasms may pass through the gut barrier of bats during digestion of relevant arthropod vectors. In light of these findings, the role of bats in the epidemiology of piroplasmoses deserves further investigation.
Full Text Available The Asiatic blue tick, Rhipicephalus microplus, a known vector of bovine babesiosis and bovine anaplasmosis, is of great concern in the cattle industry. For this reason, detailed knowledge of the distribution of R. microplus is vital. Currently, R. microplus is believed to be associated mainly with the northern and eastern Savanna and Grassland vegetation in South Africa. The objective of the study was to record the distribution of R. microplus, and the related endemic Rhipicephalus decoloratus, in the central-western region of South Africa that comprises Albany Thicket, Fynbos and Savanna vegetation. In this survey, ticks were collected from 415 cattle in four provinces (Eastern Cape, Northern Cape and Western Cape and Free State provinces and from the vegetation in the Eastern Cape province of South Africa between October 2013 and September 2015. More than 8000 ticks were collected from cattle at 80 localities of which R. microplus was present at 64 localities and R. decoloratus at 47 localities. A total of 7969 tick larvae were recorded from the vegetation at 20 localities of which 6593 were R. microplus and 1131 were R. decoloratus. Rhipicephalus microplus was recorded in each of the regions that were sampled. Rhipicephalus microplus is now present throughout the coastal region of the Eastern Cape province and at multiple localities in the north-eastern region of the Northern Cape province. It was also recorded in the western region of the Western Cape province and one record was made for the Free State province. The observed range changes may be facilitated by the combined effects of environmental adaptability by the tick and the movement of host animals.
Hornok, Sándor; Szőke, Krisztina; Kováts, Dávid; Estók, Péter; Görföl, Tamás; Boldogh, Sándor A; Takács, Nóra; Kontschán, Jenő; Földvári, Gábor; Barti, Levente; Corduneanu, Alexandra; Sándor, Attila D
In this study 308 ticks (Ixodes ariadnae: 26 larvae, 14 nymphs, five females; I. vespertilionis: 89 larvae, 27 nymphs, eight females; I. simplex: 80 larvae, 50 nymphs, nine females) have been collected from 200 individuals of 17 bat species in two countries, Hungary and Romania. After DNA extraction these ticks were molecularly analysed for the presence of piroplasm DNA. In Hungary I. ariadnae was most frequently identified from bat species in the family Vespertilionidae, whereas I. vespertilionis was associated with Rhinolophidae. Ixodes ariadnae was not found in Romania. Four, four and one new bat host species of I. ariadnae, I. vespertilionis and I. simplex were identified, respectively. DNA sequences of piroplasms were detected in 20 bat ticks (15 larvae, four nymphs and one female). I. simplex carried piroplasm DNA sequences significantly more frequently than I. vespertilionis. In I. ariadnae only Babesia vesperuginis DNA was detected, whereas in I. vespertilionis sequences of both B. vesperuginis and B. crassa. From I. simplex the DNA of B. canis, Theileria capreoli, T. orientalis and Theileria sp. OT3 were amplified, as well as a shorter sequence of the zoonotic B. venatorum. Bat ticks are not known to infest dogs or ruminants, i.e. typical hosts and reservoirs of piroplasms molecularly identified in I. vespertilionis and I. simplex. Therefore, DNA sequences of piroplasms detected in these bat ticks most likely originated from the blood of their respective bat hosts. This may indicate either that bats are susceptible to a broader range of piroplasms than previously thought, or at least the DNA of piroplasms may pass through the gut barrier of bats during digestion of relevant arthropod vectors. In light of these findings, the role of bats in the epidemiology of piroplasmoses deserves further investigation.
The present invention relates to a compact, reliable and low-cost vector velocimeter for example for determining velocities of particles suspended in a gas or fluid flow, or for determining velocity, displacement, rotation, or vibration of a solid surface, the vector velocimeter comprising a laser...
Randolph, Sarah E
There is no doubt that all vector-borne diseases are very sensitive to climatic conditions. Many such diseases have shown marked increases in both distribution and incidence during the past few decades, just as human-induced climate change is thought to have exceeded random fluctuations. This coincidence has led to the general perception that climate change has driven disease emergence, but climate change is the inevitable backdrop for all recent events, without implying causality. Coincidence and causality can be disentangled using tick-borne encephalitis (TBE) as a test case, based on the excellent long-term data for this medically significant European disease system. Detailed analysis of climate records since 1970 has revealed abrupt temperature increases just prior to the dramatic upsurge in TBE incidence in many parts of central and eastern Europe. Furthermore, the seasonal patterns of this temperature change are such as might have favoured the transmission of TBE virus between co-feeding ticks. Nevertheless, the pattern of climate change is too uniform to explain the marked heterogeneity in the timing and degree of TBE upsurge, for example in different counties within each of the Baltic countries. Recent decreases as well as increases in TBE incidence must also be taken into account. Instead of a single cause, a network of interacting factors, acting synergistically but with differential force in space and time, would generate this epidemiological heterogeneity. From analysis of past and present events, it appears that human behavioural factors have played a more significant role than purely biological enzootic factors, although there is an explicit causal linkage from one to the other. This includes a range of abiotic and biotic environmental factors, together with human behaviour determined by socio-economic conditions. Many of the abrupt changes followed from the shift from planned to market economies with the fall of Soviet rule. Comparisons between eight
Full Text Available Ticks are unique among hematophagous arthropods by continuous attachment to host skin and blood feeding for days; complexity and diversity of biologically active molecules differentially expressed in saliva of tick species; their ability to modulate the host defenses of pain and itch, hemostasis, inflammation, innate and adaptive immunity, and wound healing; and, the diverse array of infectious agents they transmit. All of these interactions occur at the cutaneous interface in a complex sequence of carefully choreographed host defense responses and tick countermeasures resulting in an environment that facilitates successful blood feeding and establishment of tick-borne infectious agents within the host. Here, we examine diverse patterns of tick attachment to host skin, blood feeding mechanisms, salivary gland transcriptomes, bioactive molecules in tick saliva, timing of pathogen transmission, and host responses to tick bite. Ticks engage and modulate cutaneous and systemic immune defenses involving keratinocytes, natural killer cells, dendritic cells, T cell subpopulations (Th1, Th2, Th17, Treg , B cells, neutrophils, mast cells, basophils, endothelial cells, cytokines, chemokines, complement, and extracellular matrix. A framework is proposed that integrates tick induced changes of skin immune effectors with their ability to respond to tick-borne pathogens. Implications of these changes are addressed. What are the consequences of tick modulation of host cutaneous defenses? Does diversity of salivary gland transcriptomes determine differential modulation of host inflammation and immune defenses and therefore, in part, the clades of pathogens effectively transmitted by different tick species? Do ticks create an immunologically modified cutaneous environment that enhances specific pathogen establishment? Can tick saliva molecules be used to develop vaccines that block pathogen transmission?
Kiffner, C; Lödige, C; Alings, M; Vor, T; Rühe, F
Macroparasites feeding on wildlife hosts follow skewed distributions for which basic statistical approaches are of limited use. To predict Ixodes spp. tick burden on roe deer, we applied Generalized Additive Models for Location, Scale and Shape (GAMLSS) which allow incorporating a variable dispersion. We analysed tick burden of 78 roe deer, sampled in a forest region of Germany over a period of 20 months. Assuming a negative binomial error distribution and controlling for ambient temperature, we analysed whether host sex and body mass affected individual tick burdens. Models for larval and nymphal tick burden included host sex, with male hosts being more heavily infested than female ones. However, the influence of host sex on immature tick burden was associated with wide standard errors (nymphs) or the factor was marginally significant (larvae). Adult tick burden was positively correlated with host body mass. Thus, controlled for host body mass and ambient temperature, there is weak support for sex-biased parasitism in this system. Compared with models which assume linear relationships, GAMLSS provided a better fit. Adding a variable dispersion term improved only one of the four models. Yet, the potential of modelling dispersion as a function of variables appears promising for larger datasets. © 2010 The Authors. Medical and Veterinary Entomology © 2010 The Royal Entomological Society.
Hamšíková, Zuzana; Kazimírová, Mária; Haruštiaková, Danka; Mahríková, Lenka; Slovák, Mirko; Berthová, Lenka; Kocianová, Elena; Schnittger, Leonhard
Babesiosis is an emerging and potentially zoonotic disease caused by tick-borne piroplasmids of the Babesia genus. New genetic variants of piroplasmids with unknown associations to vectors and hosts are recognized. Data on the occurrence of Babesia spp. in ticks and wildlife widen the knowledge on the geographical distribution and circulation of piroplasmids in natural foci. Questing and rodent-attached ticks, rodents, and birds were screened for the presence of Babesia-specific DNA using molecular methods. Spatial and temporal differences of Babesia spp. prevalence in ticks and rodents from two contrasting habitats of Slovakia with sympatric occurrence of Ixodes ricinus and Haemaphysalis concinna ticks and co-infections of Candidatus N. mikurensis and Anaplasma phagocytophilum were investigated. Babesia spp. were detected in 1.5 % and 6.6 % of questing I. ricinus and H. concinna, respectively. Prevalence of Babesia-infected I. ricinus was higher in a natural than an urban/suburban habitat. Phylogenetic analysis showed that Babesia spp. from I. ricinus clustered with Babesia microti, Babesia venatorum, Babesia canis, Babesia capreoli/Babesia divergens, and Babesia odocoilei. Babesia spp. amplified from H. concinna segregated into two monophyletic clades, designated Babesia sp. 1 (Eurasia) and Babesia sp. 2 (Eurasia), each of which represents a yet undescribed novel species. The prevalence of infection in rodents (with Apodemus flavicollis and Myodes glareolus prevailing) with B. microti was 1.3 % in an urban/suburban and 4.2 % in a natural habitat. The majority of infected rodents (81.3 %) were positive for spleen and blood and the remaining for lungs and/or skin. Rodent-attached I. ricinus (accounting for 96.3 %) and H. concinna were infected with B. microti, B. venatorum, B. capreoli/B. divergens, Babesia sp. 1 (Eurasia), and Babesia sp. 2 (Eurasia). All B. microti and B. venatorum isolates were identical to known zoonotic strains from Europe. Less than 1
Six, Robert H; Everett, William R; Young, David R; Carter, Lori; Mahabir, Sean P; Honsberger, Nicole A; Myers, Melanie R; Holzmer, Susan; Chapin, Sara; Rugg, Jady J
The efficacy of a single oral treatment with sarolaner (Simparica™, Zoetis), a novel isoxazoline compound, was evaluated against five tick species known to infest dogs in the United States. A total of 10 laboratory studies, two against each species, were conducted using adult purpose-bred mongrels or Beagle dogs. In each study, 16 dogs were randomly allocated to one of two treatment groups based on pre-treatment host-suitability tick counts. Dogs were infested with approximately 50 unfed adult Amblyomma americanum, Amblyomma maculatum, Dermacentor variabilis, Ixodes scapularis or Rhipicephalus sanguineus ticks on Days -2, 5, 12, 19, 26 and 33. On Day 0, dogs were treated with a placebo or a sarolaner tablet providing a minimum dose of 2 mg/kg. Tick counts were conducted 48h after treatment and after each subsequent weekly re-infestation. There were no treatment-related adverse reactions during any of the studies. Dogs in the placebo-treated group maintained tick infestations throughout the studies. Geometric mean live tick counts were significantly lower (P≤0.0001) in the sarolaner-treated group compared to the tick counts in the placebo group at all timepoints. Treatment with sarolaner resulted in ≥99.6% efficacy against existing infestations of all five tick species within 48h. The efficacy against weekly post-treatment re-infestations of all tick species was ≥96.9% for at least 35 days after treatment. Thus, a single dose of sarolaner administered orally at the minimum dosage of 2mg/kg, resulted in excellent efficacy within 48h against existing tick infestations, and against weekly re-infestations for 35 days after treatment. These studies confirmed that administration of the minimum dose of sarolaner will provide rapid treatment of existing infestations and give at least one month of control against re-infestation by the common tick species affecting dogs in the US. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.
To determine the prevalence and abundance of hard ticks infesting camels, 414 nomadic one - humped camels in Kano State, northwestern Nigeria were selected by random sampling and examined for the presence of ticks on their bodies between January and December 2007. Three species of ticks, Amblyomma ...
Voluntary collections of ticks from domestic dogs and cats by veterinary practitioners across Florida were conducted over a 10 month period. Of the 1,337 ticks submitted, five species of ixodid ticks were identified and included Rhipicephalus sanguineus, Amblyomma americanum, A. maculatum, Dermacen...
The Ixodidae include the most common tick species encountered in Europe. The ticks transmit a variety of bacterial and protozoan agents of medical and veterinary significance. The aim of the current work was to investigate distribution of Ixodes ricinus and Dermacentor reticulatus ticks in Kyiv, the...
Miller, Matthew J.; Esser, Helen J.; Loaiza, Jose R.; Herre, Edward Allen; Aguilar, Celestino; Quintero, Diomedes; Alvarez, Eric; Bermingham, Eldredge
In the tropics, ticks parasitize many classes of vertebrate hosts. However, because many tropical tick species are only identifiable in the adult stage, and these adults usually parasitize mammals, most attention on the ecology of tick-host interactions has focused on mammalian hosts. In
The Python/Boa Family is found in most part of tropics. It is a highly domesticated pet and can easily be handled (Cansdale 1962). Snakes are commonly infected by ticks more importantly the hand bodied ticks (Fowler, 1986).However, under captive condition, ticks usually exert a lot of burden on their hosts being carriers of ...
A. A. Chernikova
Full Text Available The article presents the basic information relating to the clinical and immunological features of ixodes tick-borne borreliosis in children living in the Primorsky region. Research objective: to to analyze the effectiveness of the inclusion to the treatment scheme meglumine acridon acetate (cycloferon in pills for the treatment of children with ixodes tick-borne borreliosis.The study included 55 children with ixodes tick-borne borreliosis at the age of 4–12 years: 25 children of the main group and 30 children of the comparison group who received traditional therapy. In the treatment scheme of children of the main group, the drug meglumine acridon acetate (cycloferon was included. The use of cycloferon in the complex therapy of patients with ixodes tick-borne borreliosis resulted in a reduction in the duration of the manifestation of the main clinical symptoms of the disease, facilitated the synthesis of serum interleukine IL-10 by blood cells and inhibited the production of interleukine-1α and γ-interferon, which led to a faster formation of Th1 / Th2 type Immune response. Positive dynamics during treatment persisted in the study of the catamnesis of the patients observed for 5 years after the disease. There were no cases of chronic ixodes tick-borne borreliosis.
Bush, Larry M; Vazquez-Pertejo, Maria T
Lyme disease is the most commonly reported tick-borneillness in the United States. Thecausative spirochete, Borrelia burgdorferi is transmitted by 4 species of Ixodes tick species. Over 90% of US cases occur in northeasternstates from Maine to Virginia, and in Wisconsin, Minnesota, and Michigan. Infection also takes place in northern California and Oregon. Lyme borreliosis is also diagnosed in parts of Europe, China, and Japan. The white-footed mouse is the primary animal reservoir for B. burgdorferi in the U.S. and the preferred host for nymphal and larval forms of the deer tick. Deer are hosts for the adult ticks but do not carry the spirochete. Signs and symptomsof infection occur in 3 stages; early localized, typified by erythema migrans; early disseminated with a flu-like syndrome, neurologic, and cardiac manifestations; and late, characteristically with arthritis. Although, the term 'Chronic Lyme Disease' has been assigned to many patients with a variety of unexplained symptoms, experts in the field question the validity of this diagnosis and warn against prolonged unproven antimicrobial therapies. Diagnosis relies upon clinical evaluation and is supported by serologic testing using a 2-step process which requires careful interpretation. Treatmentvaries with stage of disease, but normally includes doxycycline, amoxicillin,and ceftriaxone. Currently, no preventative vaccine is available. In some geographic areas, patients may be confected with Babesia, Ehrlichia, and Anaplasma since the same Ixodes ticks transmit these pathogens. Copyright © 2018 Mosby, Inc. All rights reserved.
Hagen, Ralf Matthias; Frickmann, Hagen; Ehlers, Julian; Krüger, Andreas; Margos, Gabriele; Hizo-Teufel, Cecilia; Fingerle, Volker; Rakotozandrindrainy, Raphael; Kalckreuth, Vera von; Im, Justin; Pak, Gi Deok; Jeon, Hyon Jin; Rakotondrainiarivelo, Jean Philibert; Heriniaina, Jean Noël; Razafindrabe, Tsiry; Konings, Frank; May, Jürgen; Hogan, Benedikt; Ganzhorn, Jörg; Panzner, Ursula; Schwarz, Norbert Georg; Dekker, Denise; Marks, Florian; Poppert, Sven
The occurrence of tick-borne relapsing fever and leptospirosis in humans in Madagascar remains unclear despite the presence of their potential vectors and reservoir hosts. We screened 255 Amblyomma variegatum ticks and 148 Rhipicephalus microplus ticks from Zebu cattle in Madagascar for Borrelia-specific DNA. Borrelia spp. DNA was detected in 21 Amblyomma variegatum ticks and 2 Rhipicephalus microplus ticks. One Borrelia found in one Rhipicephalus microplus showed close relationship to Borrelia theileri based on genetic distance and phylogenetic analyses on 16S rRNA and flaB sequences. The borreliae from Amblyomma variegatum could not be identified due to very low quantities of present DNA reflected by high cycle threshold values in real-time-PCR. It is uncertain whether these low numbers of Borrelia spp. are sufficient for transmission of infection from ticks to humans. In order to determine whether spirochaete infections are relevant in humans, blood samples of 1009 patients from the highlands of Madagascar with fever of unknown origin were screened for Borrelia spp. - and in addition for Leptospira spp. - by real-time PCR. No target DNA was detected, indicating a limited relevance of these pathogens for humans in the highlands of Madagascar. Copyright © 2017 Elsevier B.V. All rights reserved.
Guilfoyle, Richard A.; Smith, Lloyd M.
A vector comprising a filamentous phage sequence containing a first copy of filamentous phage gene X and other sequences necessary for the phage to propagate is disclosed. The vector also contains a second copy of filamentous phage gene X downstream from a promoter capable of promoting transcription in a bacterial host. In a preferred form of the present invention, the filamentous phage is M13 and the vector additionally includes a restriction endonuclease site located in such a manner as to substantially inactivate the second gene X when a DNA sequence is inserted into the restriction site.
Guilfoyle, R.A.; Smith, L.M.
A vector comprising a filamentous phage sequence containing a first copy of filamentous phage gene X and other sequences necessary for the phage to propagate is disclosed. The vector also contains a second copy of filamentous phage gene X downstream from a promoter capable of promoting transcription in a bacterial host. In a preferred form of the present invention, the filamentous phage is M13 and the vector additionally includes a restriction endonuclease site located in such a manner as to substantially inactivate the second gene X when a DNA sequence is inserted into the restriction site. 2 figures.
Ergunay, K.; Tkachev, S.; Kozlova, I.; Růžek, Daniel
Roč. 16, č. 1 (2016), s. 4-12 ISSN 1530-3667 R&D Projects: GA ČR GAP502/11/2116 Institutional support: RVO:60077344 Keywords : tick-borne encephalitis * serology * PCR * tick(s) * rodents Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.045, year: 2016
Rodrigo Casquero Cunha
Full Text Available Cattle ticks are responsible for great economic losses in cattle farming worldwide, and their main control method, chemicals, has been showing problems, whether resulting from the development of resistant strains of ticks or environmental contamination. Research studies directed toward developing vaccines against ticks are emerging. One way to evaluate those vaccines is to calculate the percentage of efficacy. The aim of this study was to analyze scientific publications archived in PubMed that used this method of assessment and discuss the main factors that may affect its calculation. Thus, 25 articles addressing this subject were selected. The percentage of efficacy was usually calculated in one of two ways, with one considering the reduced fertility of eggs and the other not. The latter method may underestimate the vaccine efficacy, and the most complete formula for calculating the efficacy reflects how much the vaccine actually affects the infestation. In our view, the use of the complete formula for calculating the percentage of efficacy is broader and more representative of the vaccine effect on the tick population.
The cross-product is a mathematical operation that is performed between two 3-dimensional vectors. The result is a vector that is orthogonal or perpendicular to both of them. Learning about this for the first time while taking Calculus-III, the class was taught that if AxB = AxC, it does not necessarily follow that B = C. This seemed baffling. The…
Detection and genetic characterization of tick-borne encephalitis virus (TBEV) derived from ticks removed from red foxes (Vulpes vulpes) and isolated from spleen samples of red deer (Cervus elaphus) in Croatia.
Jemeršić, Lorena; Dežđek, Danko; Brnić, Dragan; Prpić, Jelena; Janicki, Zdravko; Keros, Tomislav; Roić, Besi; Slavica, Alen; Terzić, Svjetlana; Konjević, Dean; Beck, Relja
Tick-borne encephalitis (TBE) is a growing public health concern in central and northern European countries. Even though TBE is a notifiable disease in Croatia, there is a significant lack of information in regard to vector tick identification, distribution as well as TBE virus prevalence in ticks or animals. The aim of our study was to identify and to investigate the viral prevalence of TBE virus in ticks removed from red fox (Vulpes vulpes) carcasses hunted in endemic areas in northern Croatia and to gain a better insight in the role of wild ungulates, especially red deer (Cervus elaphus) in the maintenance of the TBE virus in the natural cycle. We identified 5 tick species (Ixodes ricinus, Ixodes hexagonus, Haemaphysalis punctata, Dermacentor reticulatus, Rhipicephalus sanguineus) removed from 40 red foxes. However, TBE virus was isolated only from adult I. ricinus and I. hexagonus ticks showing a viral prevalence (1.6%) similar to or higher than reported in endemic areas of other European countries. Furthermore, 2 positive spleen samples from 182 red deer (1.1%) were found. Croatian TBE virus isolates were genetically analyzed, and they were shown to be closely related, all belonging to the European TBE virus subgroup. However, on the basis of nucleotide and amino acid sequence analysis, 2 clusters were identified. Our results show that further investigation is needed to understand the clustering of isolates and to identify the most common TBE virus reservoir hosts in Croatia. Sentinel surveys based on wild animal species would give a better insight in defining TBE virus-endemic and possible risk areas in Croatia. Copyright © 2013. Published by Elsevier GmbH.
Full Text Available Abstract Background Ehrlichia ruminantium is the causal agent of heartwater, a fatal tropical disease affecting ruminants with important economic impacts. This bacterium is transmitted by Amblyomma ticks and is present in sub-Saharan Africa, islands in the Indian Ocean and the Caribbean, where it represents a threat to the American mainland. Methods An automated DNA extraction method was adapted for Amblyomma ticks and a new qPCR targeting the pCS20 region was developed to improve E. ruminantium screening capacity and diagnosis. The first step in the preparation of tick samples, before extraction, was not automated but was considerably improved by using a Tissue Lyser. The new pCS20 Sol1 qPCR and a previously published pCS20 Cow qPCR were evaluated with the OIE standard pCS20 nested PCR. Results pCS20 Sol1 qPCR was found to be more specific than the nested PCR, with a 5-fold increase in sensitivity (3 copies/reaction vs 15 copies/reaction, was less prone to contamination and less time-consuming. As pCS20 Sol1 qPCR did not detect Rickettsia, Anasplasma and Babesia species or closely related species such as Panola Mountain Ehrlichia, E. chaffeensis and E. canis, its specificity was also better than Cow qPCR. In parallel, a tick 16S qPCR was developed for the quality control of DNA extraction that confirmed the good reproducibility of the automated extraction. The whole method, including the automated DNA extraction and pCS20 Sol1 qPCR, was shown to be sensitive, specific and highly reproducible with the same limit of detection as the combined manual DNA extraction and nested PCR, i.e. 6 copies/reaction. Finally, 96 samples can be tested in one day compared to the four days required for manual DNA extraction and nested PCR. Conclusions The adaptation of an automated DNA extraction using a DNA/RNA viral extraction kit for tick samples and the development of a new qPCR increased the accuracy of E. ruminantium epidemiological studies, as well as the
Susana Rueda Pérez
Full Text Available There is medical consensus on the need to remove the tick within 24 hours the mite parasites to the human host, to avoid possible complications. The preferred way is by gently traction the mite, aided by forceps without twisting or chokes with toxic agents, because of the possibility that the mite excretes bacteria mixed with substances. The average time of extraction is estimated between one or three minutes. In children parasitized by ticks this amount of time can be excessive when it’s necessary restraint without the consent of the minor. Using this technique we reduce the time to seconds and the damage caused to the skin is minimal.
Alkadhi, H.; Kollias, S.S.
The tick-borne encephalitis (TBE) virus gives rise to epidemic encephalitis. Mild forms usually manifest as influenza-like episodes or are clinically silent. MRI is usually normal in TBE. We describe severe TBE in a patient who presented with fever and altered mental status after a tick bite and a specific antibody response to TBE. MRI revealed pronounced signal abnormalities in the basal ganglia and thalamus, without contrast enhancement. These findings coincide well with neuropathological studies of severe nerve cell degeneration with inflammatory cell infiltrates, neuronophagia and reactive astrocytosis in the deep grey matter. We review the literature and discuss the relevant differential diagnosis. (orig.)
Randolph Sarah E
Full Text Available Abstract Background The emergence of zoonoses is due both to changes in human activities and to changes in their natural wildlife cycles. One of the most significant vector-borne zoonoses in Europe, tick-borne encephalitis (TBE, doubled in incidence in 1993, largely as a consequence of the socio-economic transition from communism to capitalism and associated environmental changes. Methods To test the effect of the current economic recession, unemployment in 2009 and various socio-economic indices were compared to weather indices (derived from principal component analyses as predictors for the change in TBE case numbers in 2009 relative to 2004-08, for 14 European countries. Results Greatest increases in TBE incidence occurred in Latvia, Lithuania and Poland (91, 79 and 45%, respectively. The weather was rejected as an explanatory variable. Indicators of high background levels of poverty, e.g. percent of household expenditure on food, were significant predictors. The increase in unemployment in 2009 relative to 2008 together with 'in-work risk of poverty' is the only case in which a multivariate model has a second significant term. Conclusion Background socio-economic conditions determine susceptibility to risk of TBE, while increased unemployment triggered a sudden increase in risk. Mechanisms behind this result may include reduced resistance to infection through stress; reduced uptake of costly vaccination; and more exposure of people to infected ticks in their forest habitat as they make greater use of wild forest foods, especially in those countries, Lithuania and Poland, with major marketing opportunities in such products. Recognition of these risk factors could allow more effective protection through education and a vaccination programme targeted at the economically most vulnerable.
Godfrey, Elinor R; Randolph, Sarah E
The emergence of zoonoses is due both to changes in human activities and to changes in their natural wildlife cycles. One of the most significant vector-borne zoonoses in Europe, tick-borne encephalitis (TBE), doubled in incidence in 1993, largely as a consequence of the socio-economic transition from communism to capitalism and associated environmental changes. To test the effect of the current economic recession, unemployment in 2009 and various socio-economic indices were compared to weather indices (derived from principal component analyses) as predictors for the change in TBE case numbers in 2009 relative to 2004-08, for 14 European countries. Greatest increases in TBE incidence occurred in Latvia, Lithuania and Poland (91, 79 and 45%, respectively). The weather was rejected as an explanatory variable. Indicators of high background levels of poverty, e.g. percent of household expenditure on food, were significant predictors. The increase in unemployment in 2009 relative to 2008 together with 'in-work risk of poverty' is the only case in which a multivariate model has a second significant term. Background socio-economic conditions determine susceptibility to risk of TBE, while increased unemployment triggered a sudden increase in risk. Mechanisms behind this result may include reduced resistance to infection through stress; reduced uptake of costly vaccination; and more exposure of people to infected ticks in their forest habitat as they make greater use of wild forest foods, especially in those countries, Lithuania and Poland, with major marketing opportunities in such products. Recognition of these risk factors could allow more effective protection through education and a vaccination programme targeted at the economically most vulnerable.
Behle, Robert W; Flor-Weiler, Lina B; Bharadwaj, Anuja; Stafford, Kirby C
Nootkatone is a component of grapefruit oil that is toxic to the disease-vectoring tick, Ixodes scapularis Say, but unfortunately causes phytotoxicity to treated plants and has a short residual activity due to volatility. We prepared a lignin-encapsulated nootkatone formulation to compare with a previously used emulsifiable formulation for volatility, plant phytotoxicity, and toxicity to unfed nymphs of I. scapularis. Volatility of nootkatone was measured directly by trapping nootkatone vapor in a closed system and indirectly by measuring nootkatone residue on treated filter paper after exposure to simulated sunlight (Xenon). After 24 h in the closed system, traps collected only 15% of the nootkatone applied as the encapsulated formulation compared with 40% applied as the emulsifiable formulation. After a 1-h light exposure, the encapsulated formulation retained 92% of the nootkatone concentration compared with only 26% retained by the emulsifiable formulation. For plant phytotoxicity, cabbage, Brassica oleracea L., leaves treated with the encapsulated formulation expressed less necrosis, retaining greater leaf weight compared with leaves treated with the emusifiable formulation. The nootkatone in the emulsifiable formulation was absorbed by cabbage and oat, Avena sativa L., plants (41 and 60% recovered 2 h after application, respectively), as opposed to 100% recovery from the plants treated with encapsulated nootkatone. Using a treated vial technique, encapsulated nootkatone was significantly more toxic to I. scapularis nymphs (LC50 = 20 ng/cm2) compared with toxicity of the emulsifiable formulation (LC50 = 35 ng/cm2). Thus, the encapsulation of nootkatone improved toxicity for tick control, reduced nootkatone volatility, and reduced plant phytotoxicity.
T. S. Pinegina
Full Text Available The results of the study outcomes of tick-borne encephalitis in adults in the Tomsk Region. Patients conducted a comprehensive clinical and laboratory examination. Revealed the prevalence of autonomic disorders in individuals who have had at different periods of tick-borne encephalitis, which is regarded as the effects of tick-borne infection. Residual effects of tick-borne encephalitis occurs mainly in the form of light paresis after suffering a focal forms. Among the chronic (progredient forms of tick-borne encephalitis often formed hyperkinetic options. Most of the study revealed the presence of precipitating factors that could have an influence on the outcome. Fundamental diffe rences in all-clinical and immunological analyses at patients with various outcomes of tick-borne encephalitis it wasn't noted. KEY WORDS: tick-borne encephalitis, Tomsk Region, the outcomes.
Nebbak, A; El Hamzaoui, B; Berenger, J-M; Bitam, I; Raoult, D; Almeras, L; Parola, P
Ticks and fleas are vectors for numerous human and animal pathogens. Controlling them, which is important in combating such diseases, requires accurate identification, to distinguish between vector and non-vector species. Recently, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) was applied to the rapid identification of arthropods. The growth of this promising tool, however, requires guidelines to be established. To this end, standardization protocols were applied to species of Rhipicephalus sanguineus (Ixodida: Ixodidae) Latreille and Ctenocephalides felis felis (Siphonaptera: Pulicidae) Bouché, including the automation of sample homogenization using two homogenizer devices, and varied sample preservation modes for a period of 1-6 months. The MS spectra were then compared with those obtained from manual pestle grinding, the standard homogenization method. Both automated methods generated intense, reproducible MS spectra from fresh specimens. Frozen storage methods appeared to represent the best preservation mode, for up to 6 months, while storage in ethanol is also possible, with some caveats for tick specimens. Carnoy's buffer, however, was shown to be less compatible with MS analysis for the purpose of identifying ticks or fleas. These standard protocols for MALDI-TOF MS arthropod identification should be complemented by additional MS spectrum quality controls, to generalize their use in monitoring arthropods of medical interest. © 2017 The Royal Entomological Society.
J.nfection and treatment method ofimmunisation has been devised ... providing research and training and in extension work on. TBDs. ... systems, cattle types, level of disease risk, disease control policies ... This paper highlights tick .control,.
Wagemakers, Alex; Coumou, Jeroen; Schuijt, Tim J; Oei, Anneke; Nijhof, Ard M; van 't Veer, Cornelis; van der Poll, Tom; Bins, Adriaan D; Hovius, Joppe W R
We previously identified tick salivary lectin pathway inhibitor (TSLPI) in Ixodes scapularis, a vector for Borrelia burgdorferi sensu stricto (s.s.) in North America. TSLPI is a salivary protein facilitating B. burgdorferi s.s. transmission and acquisition by inhibiting the host lectin complement pathway through interference with mannose binding lectin (MBL) activity. Since Ixodes ricinus is the predominant vector for Lyme borreliosis in Europe and transmits several complement sensitive B. burgdorferi sensu lato (s.l.) strains, we aimed to identify, describe, and characterize the I. ricinus ortholog of TSLPI. We performed (q)PCRs on I. ricinus salivary gland cDNA to identify a TSLPI ortholog. Next, we generated recombinant (r)TSLPI in a Drosophila expression system and examined inhibition of the MBL complement pathway and complement-mediated killing of B. burgdorferi s.l. in vitro. We identified a TSLPI ortholog in I. ricinus salivary glands with 93% homology at the RNA and 89% at the protein level compared to I. scapularis TSLPI, which was upregulated during tick feeding. In silico analysis revealed that TSLPI appears to be part of a larger family of Ixodes salivary proteins among which I. persulcatus basic tail salivary proteins and I. scapularis TSLPI and Salp14. I. ricinus rTSLPI inhibited the MBL complement pathway and protected B. burgdorferi s.s. and Borrelia garinii from complement-mediated killing. We have identified a TSLPI ortholog, which protects B. burgdorferi s.l. from complement-mediated killing in I. ricinus, the major vector for tick-borne diseases in Europe.
Philip P. Adams
Full Text Available Knowledge of the transcriptional responses of vector-borne pathogens at the vector-pathogen interface is critical for understanding disease transmission. Borrelia (Borreliella burgdorferi, the causative agent of Lyme disease in the United States, is transmitted by the bite of infected Ixodes sp. ticks. It is known that B. burgdorferi has altered patterns of gene expression during tick acquisition, persistence and transmission. Recently, we and others have discovered in vitro expression of RNAs found internal, overlapping, and antisense to annotated open reading frames in the B. burgdorferi genome. However, there is a lack of molecular genetic tools for B. burgdorferi for quantitative, strand-specific, comparative analysis of these transcripts in distinct environments such as the arthropod vector. To address this need, we have developed a dual luciferase reporter system to quantify B. burgdorferi promoter activities in a strand-specific manner. We demonstrate that constitutive expression of a B. burgdorferi codon-optimized Renilla reniformis luciferase gene (rlucBb allows normalization of the activity of a promoter of interest when fused to the B. burgdorferi codon-optimized Photinus pyralis luciferase gene (flucBb on the same plasmid. Using the well characterized, differentially regulated, promoters for flagellin (flaBp, outer surface protein A (ospAp and outer surface protein C (ospCp, we document the efficacy of the dual luciferase system for quantitation of promoter activities during in vitro growth and in infected ticks. Cumulatively, the dual luciferase method outlined herein is the first dual reporter system for B. burgdorferi, providing a novel and highly versatile approach for strand-specific molecular genetic analyses.
Baxter, Richard H. G.; Contet, Alicia; Krueger, Kathryn
Arthropods, especially ticks and mosquitoes, are the vectors for a number of parasitic and viral human diseases, including malaria, sleeping sickness, Dengue, and Zika, yet arthropods show tremendous individual variation in their capacity to transmit disease. A key factor in this capacity is the group of genetically encoded immune factors that counteract infection by the pathogen. Arthropod-specific pattern recognition receptors and protease cascades detect and respond to infection. Proteins ...
Eastern, and Siberian subtypes . Several tick-borne flaviviruses can also cause hemorrhagic disease. Important examples of these viruses include...assay. Identical base compositions within a column are the same color. Unique base compositions are shown with white backgrounds. (For interpretation...States, 1999e2005. Vector Borne Zoonotic Dis 2008;8:733e40.  Hofstadler SA, Sampath R, Blyn LB, Eshoo MW, Hall TA, Jiang Y, et al. TIGER : the
Kotál, Jan; Langhansová, H.; Lieskovská, J.; Andersen, J. F.; Francischetti, I.M.B.; Chavakis, T.; Kopecký, J.; Pedra, J. H. F.; Kotsyfakis, Michalis; Chmelař, J.
Roč. 128, OCT 14 2015 (2015), s. 58-68 ISSN 1874-3919 R&D Projects: GA ČR GAP502/12/2409 Institutional support: RVO:60077344 Keywords : Adaptive immunity * Innate immunity * Saliva * Salivary glands * Tick Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.867, year: 2015
Izzard, Leonard; Graves, Stephen; Cox, Erika; Fenwick, Stan; Unsworth, Nathan; Stenos, John
A novel rickettsia was detected in Ixodes tasmani ticks collected from Tasmanian devils. A total of 55% were positive for the citrate synthase gene by quantitative PCR. According to current criteria for rickettsia speciation, this new rickettsia qualifies as Candidatus Rickettsia tasmanensis, named after the location of its detection.
D'Amico, G.; Dumitrache, M.O.; Matei, I.A.; Ionică, A.M.; Gherman, C.M.; Sándor, A.D.; Modrý, David; Mihalca, A. D.
Roč. 71, č. 2 (2017), s. 139-149 ISSN 0168-8162 Institutional support: RVO:60077344 Keywords : Dermacentor spp. * Haemaphysalis spp. * Ixodes spp. * Rhipicephalus spp. * wildlife * tick-host associations Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine OBOR OECD: Veterinary science Impact factor: 1.760, year: 2016
Full Text Available The acaricidal effect of seven essential oils was examined in vitro against the cattle tick (Rhipicephalus microplus. Engorged female ticks were manually collected in farms of Southern Brazil and placed into petri dishes (n = 10 in order to test the following oils: juniper (Juniperus communis, palmarosa (Cymbopogon martinii, cedar (Cedrus atlantica, lemon grass (Cymbopogon citratus, ginger (Zingiber officinale, geranium (Pelargonium graveolens and bergamot (Citrus aurantium var bergamia at concentrations of 1%, 5%, and 10% each. A control group was used to validate the tests containing Triton X-100 only. Treatment effectiveness was measured considering inhibition of tick oviposition (partial or total, egg’s weight, and hatchability. C. martinii, C. citratus and C. atlantica essential oils showed efficacy higher than 99% at all concentrations tested. In addition, J. communis, Z. officinale, P. graveolens, and C. aurantium var bergamia oils showed efficiency ranging from 73% to 95%, depending on the concentration tested, where higher concentrations showed greater efficacy. It was concluded that essential oils can affect tick reproduction in vitro by inhibiting oviposition and hatchability.
Liu, Quan; He, Biao; Huang, Si-Yang; Wei, Feng; Zhu, Xing-Quan
Severe fever with thrombocytopenia syndrome (SFTS) is an emerging haemorrhagic fever that was first described in rural areas of China. The causative agent, SFTS virus (SFTSV), is a novel phlebovirus in the Bunyaviridae family. Since the first report in 2010, SFTS has been found in 11 provinces of China, with about 2500 reported cases, and an average case-fatality rate of 7·3%. The disease was also reported in Japan and Korea in 2012; Heartland virus, another phlebovirus genetically closely related to SFTSV, was isolated from two patients in the USA. The disease has become a substantial risk to public health, not only in China, but also in other parts of the world. The virus could undergo rapid evolution by gene mutation, reassortment, and homologous recombination in tick vectors and vertebrate reservoir hosts. No specific treatment of SFTS is available, and avoiding tick bites is an important measure to prevent the infection and transmission of SFTSV. This Review provides information on the molecular characteristics and ecology of this emerging tick-borne virus and describes the epidemiology, clinical signs, pathogenesis, diagnosis, treatment, and prevention of human infection with SFTSV. Copyright © 2014 Elsevier Ltd. All rights reserved.
Campos-Calderón, Liliana; Ábrego-Sánchez, Leyda; Solórzano-Morales, Antony; Alberti, Alberto; Tore, Gessica; Zobba, Rosanna; Jiménez-Rocha, Ana E; Dolz, Gaby
Although vector-borne diseases are globally widespread with considerable impact on animal production and on public health, few reports document their presence in Central America. This study focuses on the detection and molecular identification of species belonging to selected bacterial genera (Ehrlichia, Anaplasma and Rickettsia) in ticks sampled from dogs in Costa Rica by targeting several genes: 16S rRNA/dsb genes for Ehrlichia; 16S rRNA/groEL genes for Anaplasma, and ompA/gltA/groEL genes for Rickettsia. PCR and sequence analyses provides evidences of Ehrlichia canis, Anaplasma platys, and Anaplasma phagocytophilum infection in Rhipicephalus sanguineus s.l ticks, and allow establishing the presence of Rickettsia monacensis in Ixodes boliviensis. Furthermore, the presence of recently discovered Mediterranean A. platys-like strains is reported for the first time in Central America. Results provide new background on geographical distribution of selected tick-transmitted bacterial pathogens in Costa Rica and on their molecular epidemiology, and are pivotal to the development of effective and reliable diagnostic tools in Central America. Copyright © 2016 Elsevier GmbH. All rights reserved.
Robinson, Gilbert de B
This brief undergraduate-level text by a prominent Cambridge-educated mathematician explores the relationship between algebra and geometry. An elementary course in plane geometry is the sole requirement for Gilbert de B. Robinson's text, which is the result of several years of teaching and learning the most effective methods from discussions with students. Topics include lines and planes, determinants and linear equations, matrices, groups and linear transformations, and vectors and vector spaces. Additional subjects range from conics and quadrics to homogeneous coordinates and projective geom
Nathan Christopher Nieto
Full Text Available Human populations throughout much of the world are experiencing unprecedented changes in their relationship to the environment and their interactions with the animals with which so many humans are intimately dependent upon. These changes result not only from human induced changes in the climate, but also from population demographic changes due to wars, social unrest, behavioral changes resulting from cultural mixing, and large changes in land-use practices. Each of these social shifts can affect the maintenance and emergence of arthropod vectors disease or the pathogenic organisms themselves. A good example is the country of Pakistan, with a large rural population and developing urban economy, it also maintains a wide diversity of entomological disease vectors, including biting flies, mosquitoes, and ticks. Pathogens endemic to the region include the agents of piroplasmosis, rickettsiosis, spirocheteosis, and viral hemorrhagic fevers and encephalitis. The northwestern region of the country, including the Khyber Pakhtunkhwa Province (KPK, formerly the North-West Frontier Provence (NWFP, and the Federally Administered Tribal Areas (FATA are mountainous regions with a high degree of habitat diversity that has recently undergone a massive increase in human population density due to an immigrating refugee population from neighboring war-torn Afghanistan. Vector-borne diseases in people and livestock are common in KPK and FATA regions due to the limited use of vector control measures and access to livestock vaccines. The vast majority of people in this region live in abject poverty with >70% of the population living directly from production gained in animal husbandry. In many instances whole families live directly alongside their animal counterparts. In addition, there is little to no awareness of the threat posed by ticks and transmission of either zoonotic or veterinary pathogens. Recent emergence of Crimean-Congo hemorrhagic fever virus in rural
Bendele Kylie G
Full Text Available Abstract Background Ticks are regarded as the most relevant vectors of disease-causing pathogens in domestic and wild animals. The cattle tick, Rhipicephalus (Boophilus microplus, hinders livestock production in tropical and subtropical parts of the world where it is endemic. Tick microbiomes remain largely unexplored. The objective of this study was to explore the R. microplus microbiome by applying the bacterial 16S tag-encoded FLX-titanium amplicon pyrosequencing (bTEFAP technique to characterize its bacterial diversity. Pyrosequencing was performed on adult males and females, eggs, and gut and ovary tissues from adult females derived from samples of R. microplus collected during outbreaks in southern Texas. Results Raw data from bTEFAP were screened and trimmed based upon quality scores and binned into individual sample collections. Bacteria identified to the species level include Staphylococcus aureus, Staphylococcus chromogenes, Streptococcus dysgalactiae, Staphylococcus sciuri, Serratia marcescens, Corynebacterium glutamicum, and Finegoldia magna. One hundred twenty-one bacterial genera were detected in all the life stages and tissues sampled. The total number of genera identified by tick sample comprised: 53 in adult males, 61 in adult females, 11 in gut tissue, 7 in ovarian tissue, and 54 in the eggs. Notable genera detected in the cattle tick include Wolbachia, Coxiella, and Borrelia. The molecular approach applied in this study allowed us to assess the relative abundance of the microbiota associated with R. microplus. Conclusions This report represents the first survey of the bacteriome in the cattle tick using non-culture based molecular approaches. Comparisons of our results with previous bacterial surveys provide an indication of geographic variation in the assemblages of bacteria associated with R. microplus. Additional reports on the identification of new bacterial species maintained in nature by R. microplus that may be
Background Ticks are regarded as the most relevant vectors of disease-causing pathogens in domestic and wild animals. The cattle tick, Rhipicephalus (Boophilus) microplus, hinders livestock production in tropical and subtropical parts of the world where it is endemic. Tick microbiomes remain largely unexplored. The objective of this study was to explore the R. microplus microbiome by applying the bacterial 16S tag-encoded FLX-titanium amplicon pyrosequencing (bTEFAP) technique to characterize its bacterial diversity. Pyrosequencing was performed on adult males and females, eggs, and gut and ovary tissues from adult females derived from samples of R. microplus collected during outbreaks in southern Texas. Results Raw data from bTEFAP were screened and trimmed based upon quality scores and binned into individual sample collections. Bacteria identified to the species level include Staphylococcus aureus, Staphylococcus chromogenes, Streptococcus dysgalactiae, Staphylococcus sciuri, Serratia marcescens, Corynebacterium glutamicum, and Finegoldia magna. One hundred twenty-one bacterial genera were detected in all the life stages and tissues sampled. The total number of genera identified by tick sample comprised: 53 in adult males, 61 in adult females, 11 in gut tissue, 7 in ovarian tissue, and 54 in the eggs. Notable genera detected in the cattle tick include Wolbachia, Coxiella, and Borrelia. The molecular approach applied in this study allowed us to assess the relative abundance of the microbiota associated with R. microplus. Conclusions This report represents the first survey of the bacteriome in the cattle tick using non-culture based molecular approaches. Comparisons of our results with previous bacterial surveys provide an indication of geographic variation in the assemblages of bacteria associated with R. microplus. Additional reports on the identification of new bacterial species maintained in nature by R. microplus that may be pathogenic to its vertebrate hosts
Maruyama Sandra R
Full Text Available Abstract Background Rhipicephalus sanguineus, known as the brown dog tick, is a common ectoparasite of domestic dogs and can be found worldwide. R.sanguineus is recognized as the primary vector of the etiological agent of canine monocytic ehrlichiosis and canine babesiosis. Here we present the first description of a R. sanguineus salivary gland transcriptome by the production and analysis of 2,034 expressed sequence tags (EST from two cDNA libraries, one consctructed using mRNA from dissected salivary glands from female ticks fed for 3-5 days (early to mid library, RsSGL1 and the another from ticks fed for 5 days (mid library, RsSGL2, identifying 1,024 clusters of related sequences. Results Based on sequence similarities to nine different databases, we identified transcripts of genes that were further categorized according to function. The category of putative housekeeping genes contained ~56% of the sequences and had on average 2.49 ESTs per cluster, the secreted protein category contained 26.6% of the ESTs and had 2.47 EST's/clusters, while 15.3% of the ESTs, mostly singletons, were not classifiable, and were annotated as "unknown function". The secreted category included genes that coded for lipocalins, proteases inhibitors, disintegrins, metalloproteases, immunomodulatory and antiinflammatory proteins, as Evasins and Da-p36, as well as basic-tail and 18.3 kDa proteins, cement proteins, mucins, defensins and antimicrobial peptides. Comparison of the abundance of ESTs from similar contigs of the two salivary gland cDNA libraries allowed the identification of differentially expressed genes, such as genes coding for Evasins and a thrombin inhibitor, which were over expressed in the RsSGL1 (early to mid library versus RsSGL2 (mid library, indicating their role in inhibition of inflammation at the tick feeding site from the very beginning of the blood meal. Conversely, sequences related to cement (64P, which function has been correlated with tick
Samish, M; Alekseev, E; Glazer, I
Entomopathogenic nematodes (EPNs) are lethal to ticks even though they do not use their normal propagation cycle within tick cadavers. The tick Boophilus annulatus was found to be far more susceptible to EPNs than Hyalomma excavatum, Rhipicephalus bursa, or Rhipicephalus sanguineus. Ticks seem to be less susceptible to nematodes when feeding on a host. Preimaginal tick stages were less susceptible to nematodes than adult ticks. The mortality rate of unfed females was highest, followed by unfed males, and engorged females. The virulence of nematodes to ticks varied greatly among different nematode strains. In most cases, the Heterorhabditis sp. strains were the most virulent strains tested in petri dishes. In buckets containing sandy soil sprayed with 50 nematodes/cm2 and engorged B. annulatus females, the LT50 of the ticks was less than five days. The addition of manure to soil or a manure extract to petri dishes reduced nematode virulence. Since ticks spend most of their life cycle in the upper humid layer of the ground, and many nematode strains share this same ecological niche, the use of EPNs for biocontrol of ticks appears promising.
Six major types of malpractice were identified. These include delivery of ... based on exotic, more productive but susceptible stock (De. Castro, 1997). The global ..... First Edition, Central News Agency Ltd., Cape Town,. 298 – 329. MAAIF .
Ybañez, Adrian P; Mingala, Claro N; Ybañez, Rochelle Haidee D
Tick-borne diseases (TBDs) remain to be a global animal health threat. Developing countries like the Philippines is not exempt to this. Despite the potential impact TBDs can give to these countries, local government initiatives and researches remain to be limited. In the Philippines, most epidemiological studies were confined only to specific areas, and predominantly in the Northern Area. Due to its unique geography and limited studies, the current nationwide status of most TBDs could not be clearly established. This review mainly covered published studies and presented challenges in the conduct of TBD research in the Philippines, which may be similar to other Southeast Asian or developing countries. To date, reported livestock TBD pathogens in the Philippines include Anaplasma, Babesia, Theileria, and Mycoplasma spp. With the ubiquitous presence of the Rhipicephalus microplus ticks in the country, it is highly probable that other pathogens transmitted by these vectors could be present. Despite studies on different TBDs in the livestock sector, the Philippine government has not yet heightened its efforts to implement tick control measures as part of the routine animal health program for local farmers. Further studies might be needed to determine the nationwide prevalence of TBDs and the presence of other possible tick species and TBD pathogens. The Philippine scenario may present situations that are similar to other developing countries. Copyright © 2017 Elsevier B.V. All rights reserved.
Brei, Brandon; George, John E.; Pound, J. Mathews; Miller, J. Allen; Daniels, Thomas J.; Falco, Richard C.; Stafford, Kirby C.; Schulze, Terry L.; Mather, Thomas N.; Carroll, John F.; Fish, Durland
Abstract As part of the Northeast Area-wide Tick Control Project (NEATCP), meta-analyses were performed using pooled data on the extent of tick-vector control achieved through seven concurrent studies, conducted within five states, using U.S. Department of Agriculture “4-Poster” devices to deliver targeted-acaricide to white-tailed deer. Although reductions in the abundance of all life-stages of Ixodes scapularis were the measured outcomes, this study focused on metrics associated with I. scapularis nymphal tick densities as this measure has consistently proven to directly correlate with human risk of acquiring Lyme disease. Since independent tick sampling schemes were undertaken at each of the five environmentally distinct study locations, a meta-analytic approach permitted estimation of a single true control-effect size for each treatment year of the NEATCP. The control-effect is expressed as the annual percent I. scapularis nymphal control most consistent with meta-analysis data for each treatment year. Our meta-analyses indicate that by the sixth treatment year, the NEATCP effectively reduced the relative density of I. scapularis nymphs by 71% on the 5.14 km2 treatment sites, corresponding to a 71% lower relative entomologic risk index for acquiring Lyme disease. PMID:19650737
Ixodes ricinus, the most commonly observed tick species in Poland, is known vector of microorganisms pathogenic for humans as TBE virus, Borrelia burgdorferi s.1., Anaplasma phagocytophilum and Babesia sp. in this country. Our study aimed to find out whether this tick can also transmit also rickettsiae of the spotted fever group (SFG). DNA extracts from 560 ticks (28 females, 34 males, and 488 nymphs) collected in different wooded areas in northern Poland were examined by PCR for the detection of Rickettsia sp., using a primer set RpCS.877p and RpCS.1258n designated to amplify a 381-bp fragment of gltA gene. A total of 2.9% ticks was found to be positive. The percentage of infected females and males was comparable (10.5% and 11.8%, respectively) and 6.6-7.6 times higher than in nymphs (1.6%). Sequences of four PCR-derived DNA fragments (acc. no. DQ672603) demonstrated 99% similarity with the sequence of Rickettsia helvetica deposited in GenBank. The results obtained suggest the possible role of I. ricinus as a source of a microorganism, which recently has been identified as an agent of human rickettsioses in Europe.
Venclikova, Kristyna; Mendel, Jan; Betasova, Lenka; Hubalek, Zdenek; Rudolf, Ivo
Ixodes ricinus is the most common tick species occurring in Central Europe and it serves as a principal vector of emerging human pathogens. The aim of this study was to determine the prevalence of Babesia spp. in host-seeking I. ricinus in urban and natural habitats. PCR was applied on samples to assess prevalence of Babesia spp. in questing ixodid ticks. Sequencing was used for Babesia species determination. 1,473 I. ricinus ticks (1,294 nymphs, 99 males and 80 females) were examined for the presence of Babesia spp. at the two study sites. Minimum infection rate for Babesia spp. was found to be 0.5% (infected I. ricinus nymphs were only detected in the natural ecosystem). Two Babesia species were identified by sequencing: B. venatorum (formerly called Babesia sp. EU1) and B. capreoli. The results obtained represent the first evidence of the occurrence of B. venatorum and B. capreoli in host-seeking I. ricinus ticks in the Czech Republic.
Thomas, E. G. F.
This paper deals with the theory of integration of scalar functions with respect to a measure with values in a, not necessarily locally convex, topological vector space. It focuses on the extension of such integrals from bounded measurable functions to the class of integrable functions, proving
Liu, M; Li, T; Yu, Z J; Qiu, Z X; Yan, P; Li, Y; Liu, J
The tick Haemaphysalis tibetensis (Acari: Ixodidae) Hoogstraal is an important arthropod vector widespread in the Qinghai-Tibet Plateau, and knowledge of its seasonal dynamics is still poor. The current study investigated the seasonal dynamics of the parasitic and non-parasitic H. tibetensis over a 2-year period from March 2014 to February 2016 in the Tibetan Plateau, China. During this timeframe, non-parasitic ticks were collected weekly by flag-dragging in grassland and shrubland areas, and parasitic ticks were removed weekly from selected sheep. Plateau pikas were captured using traps and examined for immature ticks between May to September 2014. Results suggest that non-parasitic H. tibetensis were mainly distributed in the grassland, and the parasitic adults and nymphs were found mostly on sheep. Larvae were usually found on Plateau pikas and the prevalence of infestation and mean parasitic intensity were 72.1 and 1.81%, respectively. Adults were observed from March to July with the major peak occurring in mid-April. Nymphs were found from March to August and reached a peak in late June. Larvae were collected from April to September, and their numbers peaked in late May. In the parasitic and non-parasitic period, the overall sex ratio of males to females was 1.62 and 1.30, respectively. Results show that H. tibetensis can complete one generation per year, with a population overlap between stages over the spring-summer months. These findings provide additional information on the biology and ecology of H. tibetensis as well as insights on its control in the environment and on sheep. © 2017 The Royal Entomological Society.
Mărcuţan, Ioan-Daniel; Kalmár, Zsuzsa; Ionică, Angela Monica; D'Amico, Gianluca; Mihalca, Andrei Daniel; Vasile, Cozma; Sándor, Attila D
Birds are important hosts and dispersers of parasitic arthropods and vector-borne zoonotic pathogens. Particularly migratory species may carry these parasites over long distances in short time periods. Migratory hotspots present ideal conditions to get a snapshot of parasite and pathogen diversity of birds migrating between continents. The aim of this study was to investigate the presence and diversity of Rickettsia spp. in ticks collected from birds at a migratory hot-spot in the Danube Delta, Romania, eastern Europe. DNA was extracted from ticks that were collected from migratory birds in the Danube Delta during migratory seasons in 2011-2012. Two 360 bp fragments of the 16S ribosomal RNA gene and a 381 bp fragment Gene gltA were PCR amplified and analyzed by sequence analysis (performed at Macrogen Europe, Amsterdam, The Netherlands). Nucleotide sequences were compared to reference sequences available in the GenBank database, using Basic Local Alignment Search Tool. Four hundred ticks of four different species were found on 11 bird species. The prevalence of Rickettsia spp. infection was 14 % (56/400, CI: 11.7-29.1), with significantly more nymphs hosting rickettsial infection compared to larvae (48 vs 7; P birds migrating through eastern Europe may carry ticks infected with a high diversity of rickettsial pathogens, with four Rickettsia spp. recorded. Migratory direction was important for pathogen burden, with seasonal differences in the occurrence of individual Rickettsia species. Here we report the first individual records of different Rickettsia spp. in H. concinna (R. monacensis), I. arboricola (R. helvetica, R. massiliae) and I. redikorzevi (R. helvetica) and also the first geographical record of occurrence of R. massiliae in Romania, representing the easternmost observation on the continent.
Nercy Virginia Rabelo Furtado
Full Text Available During 2012–2015, an entomological survey was conducted as part of a phlebotomine (Diptera: Psychodidae monitoring program in an area influenced by the Santo Antônio do Jari hydroelectric system (Amapá State, Brazil. The purpose was to study aspects of Amazon/Guianan American cutaneous leishmaniasis (ACL vectors subjected to stresses by anthropogenic environmental changes. For sampling, CDC light traps were positioned 0.5, 1, and 20 m above ground at five capture locations along the Jari River Basin. Fluctuations in phlebotomine numbers were analyzed to determine any correlation with rainfall, dam waterlogging, and/or ACL cases, from May 2012 to March 2015. We captured 2,800 individuals, and among 45 species identified, Bichromomyia flaviscutellata, Nyssomyia umbratilis, and Psychodopygus squamiventris s.l. were determined to be the main putative vectors, based on current knowledge of the Amazon/Guianan ACL scenario. Rainfall, but not complete flooding, was relatively correlated with phlebotomine fluctuation, mainly observed for Ps. squamiventris s.l., as were ACL cases with Ny. umbratilis. Behavioral changes were observed in the unexpected high frequency of Bi. flaviscutellata among CDC captures and the noncanopy dominance of Ny. umbratilis, possibly attributable to environmental stress in the sampled ecotopes. Continuous entomological surveillance is necessary to monitor the outcomes of these findings.
Furtado, Nercy Virginia Rabelo; Galardo, Allan Kardec Ribeiro; Galardo, Clicia Denis; Firmino, Viviane Caetano; Vasconcelos Dos Santos, Thiago
During 2012-2015, an entomological survey was conducted as part of a phlebotomine (Diptera: Psychodidae) monitoring program in an area influenced by the Santo Antônio do Jari hydroelectric system (Amapá State, Brazil). The purpose was to study aspects of Amazon/Guianan American cutaneous leishmaniasis (ACL) vectors subjected to stresses by anthropogenic environmental changes. For sampling, CDC light traps were positioned 0.5, 1, and 20 m above ground at five capture locations along the Jari River Basin. Fluctuations in phlebotomine numbers were analyzed to determine any correlation with rainfall, dam waterlogging, and/or ACL cases, from May 2012 to March 2015. We captured 2,800 individuals, and among 45 species identified, Bichromomyia flaviscutellata , Nyssomyia umbratilis , and Psychodopygus squamiventris s.l. were determined to be the main putative vectors, based on current knowledge of the Amazon/Guianan ACL scenario. Rainfall, but not complete flooding, was relatively correlated with phlebotomine fluctuation, mainly observed for Ps. squamiventris s.l. , as were ACL cases with Ny. umbratilis. Behavioral changes were observed in the unexpected high frequency of Bi. flaviscutellata among CDC captures and the noncanopy dominance of Ny. umbratilis , possibly attributable to environmental stress in the sampled ecotopes. Continuous entomological surveillance is necessary to monitor the outcomes of these findings.
Joag, Pramod S
Ideal for undergraduate and graduate students of science and engineering, this book covers fundamental concepts of vectors and their applications in a single volume. The first unit deals with basic formulation, both conceptual and theoretical. It discusses applications of algebraic operations, Levi-Civita notation, and curvilinear coordinate systems like spherical polar and parabolic systems and structures, and analytical geometry of curves and surfaces. The second unit delves into the algebra of operators and their types and also explains the equivalence between the algebra of vector operators and the algebra of matrices. Formulation of eigen vectors and eigen values of a linear vector operator are elaborated using vector algebra. The third unit deals with vector analysis, discussing vector valued functions of a scalar variable and functions of vector argument (both scalar valued and vector valued), thus covering both the scalar vector fields and vector integration.
Full Text Available Abstract Background Ticks are vectors for a variety of viral, bacterial and parasitic diseases in human and domestic animals. To survive and reproduce ticks feed on host blood, yet our understanding of the intestinal proteolytic machinery used to derive absorbable nutrients from the blood meal is poor. Intestinal digestive processes are limiting factors for pathogen transmission since the tick gut presents the primary site of infection. Moreover, digestive enzymes may find practical application as anti-tick vaccine targets. Results Using the hard tick, Ixodes ricinus, we performed a functional activity scan of the peptidase complement in gut tissue extracts that demonstrated the presence of five types of peptidases of the cysteine and aspartic classes. We followed up with genetic screens of gut-derived cDNA to identify and clone genes encoding the cysteine peptidases cathepsins B, L and C, an asparaginyl endopeptidase (legumain, and the aspartic peptidase, cathepsin D. By RT-PCR, expression of asparaginyl endopeptidase and cathepsins B and D was restricted to gut tissue and to those developmental stages feeding on blood. Conclusion Overall, our results demonstrate the presence of a network of cysteine and aspartic peptidases that conceivably operates to digest host blood proteins in a concerted manner. Significantly, the peptidase components of this digestive network are orthologous to those described in other parasites, including nematodes and flatworms. Accordingly, the present data and those available for other tick species support the notion of an evolutionary conservation of a cysteine/aspartic peptidase system for digestion that includes ticks, but differs from that of insects relying on serine peptidases.
Jafar Bekloo, Ahmad; Ramzgouyan, Maryam Roya; Shirian, Sadegh; Faghihi, Faezeh; Bakhshi, Hassan; Naseri, Fatemeh; Sedaghat, Mehdi; Telmadarraiy, Zakkyeh
Anaplasma/Ehrlichia species are tick-transmitted pathogens that cause infections in humans and numerous domestic and wild animal species. There is no information available on the molecular characteristics and phylogenetic position of Anaplasma/Ehrlichia spp. isolated from tick species from different geographic locations in Iran. The aim of this study was to determine the prevalence, molecular characteristics, and phylogenetic relationship of both Anaplasma spp. and Ehrlichia spp. in tick species isolated from different domestic animals from two different geographical locations of Iran. A total of 930 ticks were collected from 93 cattle, 250 sheep, and 587 goats inhabiting the study areas. The collected ticks were then investigated for the presence of Anaplasma/Ehrlichia spp. using nested PCR based on the 16S rRNA gene, followed by sequencing. Sequence analysis was done based on the data published in the GenBank on Anaplasma/Ehrlichia spp. isolates using bioinformatic tools such as the standard nucleotide BLAST. Genome of Anaplasma or Ehrlichia spp. was detected in 14 ticks collected in Heris, including 5 Dermacentor marginatus, 1 Haemaphysalis erinacei, 3 Hyalomma anatolicum, and 4 Rhipicephalus sanguineus, also in 29 ticks collected in Chabahar, including 14 R. sanguineus, 8 D. marginatus, 3 Hyalomma Anatolicum, and 4 Hyalomma dromedarii. Partial analysis of the 16S rRNA gene sequence of positive samples collected from goats and sheep showed that they were infected with Anaplasma/Ehrlichia spp. that were 94-98% identical to ovine Anaplasma and 91-96% identical to Neoehrlichia and Ehrlichia spp. The various ticks identified in this study suggest the possible emergence of tick-borne diseases in animals and humans in these regions. R. sanguineus and D. marginatus seem to be predominant vectors responsible for anaplasmosis in these regions. Partial sequence analysis of the 16S rRNA gene showed that A. ovis is genetically polymorphic in these regions. Furthermore, an
Offerdahl, Danielle K.; Clancy, Niall G.; Bloom, Marshall E.
The tick-borne flaviviruses (TBFV) occur worldwide and the tick-borne encephalitis virus (TBEV) members of the group often cause severe, debilitating neurological disease in humans. Although the primary route of infection is through the bite of an infected tick, alimentary infection through the consumption of TBEV-contaminated dairy products is also well-documented and is responsible for some disease in endemic areas. Experimental infection of goats, cattle, and sheep with TBEV shows that the...
Zintl, A; McGrath, G; O'Grady, L; Fanning, J; Downing, K; Roche, D; Casey, M; Gray, JS
Bovine babesiosis is caused by the tick-borne blood parasite, Babesia divergens. A survey of veterinary practitioners and farmers in Ireland in the 1980’s revealed an annual incidence of 1.7% associated with considerable economic losses. However, two subsequent surveys in the 1990’s indicated a decline in clinical babesiosis. In order to determine whether any such changes have affected the incidence of bovine babesiosis in Ireland, a questionnaire survey of farmers and veterinarians was carri...
Vollack, Ken; Sodoudi, Sahar; Névir, Peter
November through February affect the questing activity of ticks during their subsequent season of activity. We related the number of host-seeking nymphs to meteorological parameters measured in close proximity at minutely intervals over the period of 6 years (2010-2015) in an urban park in Berlin. We...
Kammlah Diane M
Full Text Available Abstract Background Cattle fever ticks, Rhipicephalus (Boophilus microplus and R. (B. annulatus, vector bovine and equine babesiosis, and have significantly expanded beyond the permanent quarantine zone established in South Texas. Currently, there are no vaccines approved for use within the United States for controlling these vectors. Vaccines developed in Australia and Cuba based on the midgut antigen Bm86 have variable efficacy against cattle fever ticks. A possible explanation for this variation in vaccine efficacy is amino acid sequence divergence between the recombinant Bm86 vaccine component and native Bm86 expressed in ticks from different geographical regions of the world. Results There was 91.8% amino acid sequence identity in Bm86 among R. microplus and R. annulatus sequenced from South Texas infestations. When South Texas isolates were compared to the Australian Yeerongpilly and Cuban Camcord vaccine strains, there was 89.8% and 90.0% identity, respectively. Most of the sequence divergence was focused in one region of the protein, amino acids 206-298. Hydrophilicity profiles revealed that two short regions of Bm86 (amino acids 206-210 and 560-570 appear to be more hydrophilic in South Texas isolates compared to vaccine strains. Only one amino acid difference was found between South Texas and vaccine strains within two previously described B-cell epitopes. A total of 4 amino acid differences were observed within three peptides previously shown to induce protective immune responses in cattle. Conclusions Sequence differences between South Texas isolates and Yeerongpilly and Camcord strains are spread throughout the entire Bm86 sequence, suggesting that geographic variation does exist. Differences within previously described B-cell epitopes between South Texas isolates and vaccine strains are minimal; however, short regions of hydrophilic amino acids found unique to South Texas isolates suggest that additional unique surface exposed
Aurélien eFotso Fotso
Full Text Available In Africa, relapsing fevers caused by ectoparasite-borne Borrelia species are transmitted by ticks, with the exception of Borrelia recurrentis, which is a louse-borne spirochete. These tropical diseases responsible for mild to deadly spirochetemia. Cultured B. crocidurae, B. duttonii and B. hispanica circulate alongside at least six species which have not yet been cultured in vectors. Direct diagnosis is hindered by the use of non-specific laboratory tools. Indeed, microscopic observation of Borrelia spirochaeta in smears of peripheral blood taken from febrile patients lacks sensitivity and specificity. Although best visualised using dark-field microscopy, the organisms can also be detected using Wright-Giemsa or acridine orange stains.. PCR-based detection of specific sequences in total DNA extracted from a specimen can be used to discriminate different relapsing fever Borreliae. In our laboratory, we developed a multiplex real-time PCR assay for the specific detection of B. duttonii/recurrentis and B. crocidurae: Multispacer Sequence Typing accurately identified cultured relapsing fever borreliae and revealed diversity among them. Other molecular typing techniques, such as multilocus sequence analysis of tick-borne relapsing fever borreliae, showed the potential risk of human infection in Africa. Recent efforts to culture and sequence relapsing fever borreliae have provided new information for reassessment of the diversity of these bacteria. Recently, matrix-assisted laser desorption ionization time-of-flight mass spectrometry has been reported as a means of identifying cultured borreliae and of identifying both vectors and vectorised pathogens such as detecting relapsing fever borreliae directly in ticks. The lack of a rapid diagnosis test restricts the management of such diseases. We produced monoclonal antibodies against Borrelia crocidurae in order to develop cheap assays for the rapid detection of relapsing fever borreliae. In this paper
Full Text Available The impact of climate on the vector behaviour of the worldwide dog tick Rhipicephalus sanguineus is a cause of concern. This tick is a vector for life-threatening organisms including Rickettsia rickettsii, the agent of Rocky Mountain spotted fever, R. conorii, the agent of Mediterranean spotted fever, and the ubiquitous emerging pathogen R. massiliae. A focus of spotted fever was investigated in France in May 2007. Blood and tissue samples from two patients were tested. An entomological survey was organised with the study of climatic conditions. An experimental model was designed to test the affinity of Rh. sanguineus for biting humans in variable temperature conditions. Serological and/or molecular tools confirmed that one patient was infected by R. conorii, whereas the other was infected by R. massiliae. Dense populations of Rh. sanguineus were found. They were infected with new genotypes of clonal populations of either R. conorii (24/133; 18% or R. massiliae (13/133; 10%. April 2007 was the warmest since 1950, with summer-like temperatures. We show herein that the human affinity of Rh. sanguineus was increased in warmer temperatures. In addition to the originality of theses cases (ophthalmic involvements, the second reported case of R. massiliae infection, we provide evidence that this cluster of cases was related to a warming-mediated increase in the aggressiveness of Rh. sanguineus, leading to increased human attacks. From a global perspective, we predict that as a result of globalisation and warming, more pathogens transmitted by the brown dog tick may emerge in the future.
Jones, E H; Hinckley, A F; Hook, S A; Meek, J I; Backenson, B; Kugeler, K J; Feldman, K A
We examined whether pet ownership increased the risk for tick encounters and tickborne disease among residents of three Lyme disease-endemic states as a nested cohort within a randomized controlled trial. Information about pet ownership, use of tick control for pets, property characteristics, tick encounters and human tickborne disease were captured through surveys, and associations were assessed using univariate and multivariable analyses. Pet-owning households had 1.83 times the risk (95% CI = 1.53, 2.20) of finding ticks crawling on and 1.49 times the risk (95% CI = 1.20, 1.84) of finding ticks attached to household members compared to households without pets. This large evaluation of pet ownership, human tick encounters and tickborne diseases shows that pet owners, whether of cats or dogs, are at increased risk of encountering ticks and suggests that pet owners are at an increased risk of developing tickborne disease. Pet owners should be made aware of this risk and be reminded to conduct daily tick checks of all household members, including the pets, and to consult their veterinarian regarding effective tick control products. © 2017 Blackwell Verlag GmbH.
Kjær, Lene Jung; Korslund, L.; Kjelland, V.
satellite images to run Boosted Regression Tree machine learning algorithms to predict overall distribution (presence/absence of ticks) and relative tick abundance of nymphs and larvae in southern Scandinavia. For nymphs, the predicted abundance had a positive correlation with observed abundance...... the predicted distribution of larvae was mostly even throughout Denmark, it was primarily around the coastlines in Norway and Sweden. Abundance was fairly low overall except in some fragmented patches corresponding to forested habitats in the region. Machine learning techniques allow us to predict for larger...... the collected ticks for pathogens and using the same machine learning techniques to develop prevalence maps of the ScandTick region....
Figueroa, J V; Buening, G M
An increased number of articles on the use of nucleic acid-based hybridization techniques for diagnostic purposes have been recently published. This article reviews nucleic acid-based hybridization as an assay to detect hemoparasite infections of economic relevance in veterinary medicine. By using recombinant DNA techniques, selected clones containing inserts of Anaplasma, Babesia, Cowdria or Theileria genomic DNA sequences have been obtained, and they are now available to be utilized as specific, highly sensitive DNA or RNA probes to detect the presence of the hemoparasite DNA in an infected animal. Either in an isotopic or non-isotopic detection system, probes have allowed scientists to test for--originally in samples collected from experimentally infected animals and later in samples collected in the field--the presence of hemoparasites during the prepatent, patent, convalescent, and chronic periods of the infection in the host. Nucleic acid probes have given researchers the opportunity to carry out genomic analysis of parasite DNA to differentiate hemoparasite species and to identify genetically distinct populations among and within isolates, strains and clonal populations. Prevalence of parasite infection in the tick vector can now be accomplished more specifically with the nucleic acid probes. Lately, with the advent of the polymerase chain reaction technique, small numbers of hemoparasites can be positively identified in the vertebrate host and tick vector. These techniques can be used to assess the veterinary epidemiological situation in a particular geographical region for the planning of control measures.
Full Text Available Background: Rhipicephalus (Boophilus annulatus tick is one of the most important ectoparasite of cattle. Recently, several laboratories in the world have been concentrated on immunizing cattle against tick using various types of tissue extracts of ticks. The aim of this study was to evaluate the effect of immunization of cattle with tick salivary gland extract on biological parameters of ticks and humoral immune responses of cattle.Methods: Fourteen more dominant protein bands identified as immunogenic by Western-blot analysis were eluted from polyacrylamide gel. Test and control groups were injected three times with eluted proteins and sterile PBS (pH= 7.2 respectively with equivalent amount of adjuvant. After four weeks a tick challenge was performed. Finally, biological parameters of collected engorged female ticks were recorded and humoral immune responses to immunization measured by ELISA.Results: The results indicated immunization of cattle resulted in reduction in mean tick counts, attachment, engorgement weights, feeding index, egg mass weight, hatchability and fertility index (respectively 63.1%, 62.6%, 30.2%, 36.4%, 40%, 78.7% and 13.3% and increased duration of feeding, pre-oviposition and incubation period of eggs (respectively 8.6%, 45 and 31.34%. All changes were statistically significant (P< 0.05. Results showed an increase in antibody production of test group from the first week after immunization. The antibody level was boosted following tick infestation.Conclusion: This investigation indicates that immunization of cattle with these antigens could induce a protective immune response against Rh. (B. annulatus tick that would be expected to provide a safe non-chemical means of tick control.
Muñoz-Leal, Sebastián; Eriksson, Alan; Santos, Carolina Ferreira; Fischer, Erich; de Almeida, Juliana Cardoso; Luz, Hermes R; Labruna, Marcelo B
Ticks associated with bats have been poorly documented in the Neotropical Zoogeographical Region. In this study, a total of 1028 bats were sampled for tick infestations in the southern portion of the Brazilian Pantanal. A total of 368 ticks, morphologically identified as Ornithodoros hasei (n = 364) and O. mimon (n = 4), were collected from the following bat species: Artibeus planirostris, Platyrrhinus lineatus, Phyllostomus hastatus, Mimon crenulatum and Noctilio albiventris. Morphological identification of O. hasei was confirmed by molecular analysis. Regarding the most abundant bat species, only 40 (6.2%) out of 650 A. planirostris were infested by O. hasei, with a mean intensity of 7.2 ticks per infested bat, or a mean abundance of 0.44 ticks per sampled bat. Noteworthy, one single P. hastatus was infested by 55 O. hasei larvae, in contrast to the 2.5-7.2 range of mean intensity values for the whole study. As a complement to the present study, a total of 8 museum bat specimens (6 Noctilio albiventris and 2 N. leporinus), collected in the northern region of Pantanal, were examined for tick infestations. These bats contained 176 ticks, which were all morphologically identified as O. hasei larvae. Mean intensity of infestation was 22, with a range of 1-46 ticks per infested bat. Our results suggest that A. planirostris might play an important role in the natural life cycle of O. hasei in the Pantanal.
Hajdušek, Ondřej; Almazán, C.; Loosová, Gabriela; Villar, M.; Canales, M.; Grubhoffer, L.; Kopáček, Petr; de la Fuente, J.
Roč. 28, č. 17 (2010), s. 2993-2998 ISSN 0264-410X R&D Projects: GA AV ČR IAA600960910; GA MŠk(CZ) LC06009 Institutional research plan: CEZ:AV0Z60220518 Keywords : tick ferritin 2 * tick-protective vaccine Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.572, year: 2010
A case of a heavy tick infestation of dogs in a private kennel that resisted treatment with diazinon is reported. Application is by the conventional acaricidal tick dips and subsequent acaricidal spraying of the premises on three consecutive occasions which yielded no result. However a change of drug from diazinon to ...
Růžek, Daniel; Dobler, G.; Mantke, O. D.
Roč. 8, č. 4 (2010), s. 223-232 ISSN 1477-8939 R&D Projects: GA ČR GPP302/10/P438; GA MŠk(CZ) LC06009 Institutional research plan: CEZ:AV0Z60220518 Keywords : Tick-borne encephalitis * Tick-borne encephalitis virus * Pathogenesis * Clinical data Subject RIV: EE - Microbiology, Virology
Bermudez, S.E.; Esser, H.J.; Miranda, R.; Moreno, R.S.
This study reports ticks collected from wild carnivores from different habitat types in Panama. We examined 94 individual wild carnivores and we found 87 parasitized by ticks: seven coyotes, six crab-eating foxes, 54 coatis, four raccoons, five ocelots, two pumas, two gray foxes, two skunks, and one
A preliminary trial of a cocktail of recombinant RAS-1-2 and RIM 36 antigens was conducted in Uganda to assess the effects of ant-tick vaccines against Rhipicephalus appendiculatus tick feeding on Zebu cattle under both experimental and natural conditions. Under experimental conditions, over a period of 28 days, the ...
The effect of tick control by strategic dipping in synthetic pyrethroids on growth and survival rates of calves in Eastern Tanzania where Theileria parva and other tick borne infections (babesiosis, anaplasmosis and ehrlichiosis) are endemic was measured. One day to five months old Tanganyika short horn zebu (Bos indicus) ...
An assessment of protozoan parasite load in the ticks infesting cattle entering the country by hooves through a major trans-boundary route in Ogun State was carried out using ... This is the first report on protozoan parasites detected in ticks infesting cattle entering Nigeria through a major trans-boundary route in Nigeria.
This thesis focuses on the emergence and establishment of equine tick-borne infections in the Netherlands, with particular attention to their diagnosis, clinical relevance and treatment. Four tick-borne agents (Borrelia burgdorferi, Theileria equi, Babesia caballi and Anaplasma phagocytophilum)
Full Text Available Mosquito-borne diseases are common high-impact diseases in tropical and subtropical areas. However, other non-mosquito vector-borne pathogens (VBPs may share their geographic distribution, seasonality, and clinical manifestations, thereby contributing their share to the morbidity and mortality caused by febrile illnesses in these regions. The purpose of this work was to collect and review existing information and identify knowledge gaps about tick, flea-, and louse-borne diseases of veterinary and public health significance in Nigeria. Full-length articles about VBPs were reviewed and relevant information about the vectors, their hosts, geographic distribution, seasonality, and association(s with human or veterinary diseases was extracted. Specific laboratory tools used for detection and identification of VBPs in Nigeria were also identified. A total of 62 original publications were examined. Substantial information about the prevalence and impacts of ticks and fleas on pet and service dogs (18 articles, and livestock animals (23 articles were available; however, information about their association with and potential for causing human illnesses was largely absent despite the zoonotic nature of many of these peri-domestic veterinary diseases. Recent publications that employed molecular methods of detection demonstrated the occurrence of several classic (Ehrlichia canis, Rickettsia africae, Bartonella sp. and emerging human pathogens (R. aeschlimannii, Neoehrlichia mikurensis in ticks and fleas. However, information about other pathogens often found in association with ticks (R. conorii and fleas (R. typhi, R. felis across the African continent was lacking. Records of louse-borne epidemic typhus in Nigeria date to 1947; however, its current status is not known. This review provides an essential baseline summary of the current knowledge in Nigeria of non-mosquito VBPs, and should stimulate improvements in the surveillance of the veterinary and
Sprong, H.; Trentelman, J.; Seemann, I.; Grubhoffer, Libor; Rego, Ryan O. M.; Hajdušek, Ondřej; Kopáček, Petr; Šíma, Radek; Nijhof, A.M.; Anguita, J.; Winter, P.; Rotter, B.; Havlíková, S.; Klempa, B.; Schetters, T.P.; Hovius, J.W.R.
Roč. 7, FEB 2014 (2014), s. 77 ISSN 1756-3305 Institutional support: RVO:60077344 Keywords : Ixodes ricinus * vaccine * Lyme borreliosis * tick-borne encephalitis * babesiosis * public health Subject RIV: EC - Immunology Impact factor: 3.430, year: 2014
de la Fuente, J.; Kopáček, Petr; Lew-Tabor, A.; Maritz-Olivier, C.
Roč. 38, č. 12 (2016), s. 754-769 ISSN 0141-9838 R&D Projects: GA ČR GA13-11043S EU Projects: European Commission(XE) 278976 - ANTIGONE Institutional support: RVO:60077344 Keywords : interactomics * reverse genetics * systems biology * tick * vaccine * vaccinology Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.493, year: 2016
Richter, Dania; Matuschka, Franz-Rainer; Spielman, Andrew; Mahadevan, L.
The tick Ixodes ricinus uses its mouthparts to penetrate the skin of its host and to remain attached for about a week, during which time Lyme disease spirochaetes may pass from the tick to the host. To understand how the tick achieves both tasks, penetration and attachment, with the same set of implements, we recorded the insertion events by cinematography, interpreted the mouthparts’ function by scanning electron microscopy and identified their points of articulation by confocal microscopy. Our structural dynamic observations suggest that the process of insertion and attachment occurs via a ratchet-like mechanism with two distinct stages. Initially, the two telescoping chelicerae pierce the skin and, by moving alternately, generate a toehold. Subsequently, a breaststroke-like motion, effected by simultaneous flexure and retraction of both chelicerae, pulls in the barbed hypostome. This combination of a flexible, dynamic mechanical ratchet and a static holdfast thus allows the tick to solve the problem of how to penetrate skin and also remain stuck for long periods of time. PMID:24174106
Identify the favorable predilection sites of ticks and to measure the tick burden within breeds, different age groups and ... Study period, tick collection and identification methods. Ticks were collected from half body .... reported in many parts of Ethiopia, such as in Rift Valley Solomon Gebre et al., (2001), Hararghe Gulilat Asrat ...