Ticks are prominent parasites and competent vectors of pathogens that affect both humans and animals. This review outlines and illustrates the main features of the morphology of ticks of the families Ixodidae and Argasidae, and summarises the basic components of their life cycles. It focuses mainly on development processes and mortality among tick populations so as to provide an overview of how they are regulated in nature and how pathogens can be transmitted under such a framework. The effects of the weather on these life cycles are reviewed. The author also examines how landscape structure and biotic factors, such as the presence and abundance of hosts, may shape the density of tick populations. The uncertainty inherent in dealing with the transmission of pathogens by ticks is highlighted; this results from the sometimes complex relationships among the vectors, the climate and the presence and density of host populations. The need to obtain reliable field estimations of such relationships before drawing conclusions about the effects of the isolated components of the system is stressed. A section is devoted to addressing the expected (and not yet totally understood) effects of trends in climate on the spread of ticks, and how these can be analysed and tracked.
Urbanová, Veronika; Hajdušek, Ondřej; Hönig Mondeková, Helena; Šíma, Radek; Kopáček, Petr
The present concept of the transmission of Lyme disease from Borrelia-infected Ixodes sp. ticks to the naïve host assumes that a low number of spirochetes that manage to penetrate the midgut epithelium migrate through the hemocoel to the salivary glands and subsequently infect the host with the aid of immunomodulatory compounds present in tick saliva. Therefore, humoral and/or cellular immune reactions within the tick hemocoel may play an important role in tick competence to act as a vector for borreliosis. To test this hypothesis we have examined complement-like reactions in the hemolymph of the hard tick Ixodes ricinus against Borrelia afzelii (the most common vector and causative agent of Lyme disease in Europe). We demonstrate that I. ricinus hemolymph does not exhibit borreliacidal effects comparable to complement-mediated lysis of bovine sera. However, after injection of B. afzelii into the tick hemocoel, the spirochetes were efficiently phagocytosed by tick hemocytes and this cellular defense was completely eliminated by pre-injection of latex beads. As tick thioester-containing proteins (T-TEPs) are components of the tick complement system, we performed RNAi-mediated silencing of all nine genes encoding individual T-TEPs followed by in vitro phagocytosis assays. Silencing of two molecules related to the C3 complement component (IrC3-2 and IrC3-3) significantly suppressed phagocytosis of B. afzelii, while knockdown of IrTep (insect type TEP) led to its stimulation. However, RNAi-mediated silencing of T-TEPs or elimination of phagocytosis by injection of latex beads in B. afzelii-infected I. ricinus nymphs had no obvious impact on the transmission of spirochetes to naïve mice, as determined by B. afzelii infection of murine tissues following tick infestation. This result supports the concept that Borrelia spirochetes are capable of avoiding complement-related reactions within the hemocoel of ticks competent to transmit Lyme disease. PMID:28361038
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
Luo, Li-mei; Zhao, Li; Wen, Hong-Ling; Zhang, Zhen-Tang; Liu, Jian-Wei; Fang, Li-Zhu; Xue, Zai-Feng; Ma, Dong-Qiang; Zhang, Xiao-Shuang; Ding, Shu-Jun; Lei, Xiao-Ying; Yu, Xue-jie
Severe fever with thrombocytopenia syndrome (SFTS) is an emerging hemorrhagic fever in East Asia caused by SFTS virus (SFTSV), a newly discovered phlebovirus. The Haemaphysalis longicornis tick has been suspected to be the vector of SFTSV. To determine whether SFTSV can be transmitted among ticks, from ticks to animals, and from animals to ticks, we conducted transmission studies between developmental stages of H. longicornis ticks and between ticks and mice. Using reverse transcription PCR, ...
Villar, Margarita; Ayllón, Nieves; Alberdi, Pilar; Moreno, Andrés; Moreno, María; Tobes, Raquel; Mateos-Hernández, Lourdes; Weisheit, Sabine; Bell-Sakyi, Lesley; de la Fuente, José
Anaplasma phagocytophilum is an emerging zoonotic pathogen that causes human granulocytic anaplasmosis. These intracellular bacteria establish infection by affecting cell function in both the vertebrate host and the tick vector, Ixodes scapularis. Previous studies have characterized the tick transcriptome and proteome in response to A. phagocytophilum infection. However, in the postgenomic era, the integration of omics datasets through a systems biology approach allows network-based analyses to describe the complexity and functionality of biological systems such as host-pathogen interactions and the discovery of new targets for prevention and control of infectious diseases. This study reports the first systems biology integration of metabolomics, transcriptomics, and proteomics data to characterize essential metabolic pathways involved in the tick response to A. phagocytophilum infection. The ISE6 tick cells used in this study constitute a model for hemocytes involved in pathogen infection and immune response. The results showed that infection affected protein processing in endoplasmic reticulum and glucose metabolic pathways in tick cells. These results supported tick-Anaplasma co-evolution by providing new evidence of how tick cells limit pathogen infection, while the pathogen benefits from the tick cell response to establish infection. Additionally, ticks benefit from A. phagocytophilum infection by increasing survival while pathogens guarantee transmission. The results suggested that A. phagocytophilum induces protein misfolding to limit the tick cell response and facilitate infection but requires protein degradation to prevent ER stress and cell apoptosis to survive in infected cells. Additionally, A. phagocytophilum may benefit from the tick cell's ability to limit bacterial infection through PEPCK inhibition leading to decreased glucose metabolism, which also results in the inhibition of cell apoptosis that increases infection of tick cells. These results
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.
Caimano, Melissa J.; Drecktrah, Dan; Kung, Faith; Samuels, D. Scott
Summary Borrelia burgdorferi , the causative agent of Lyme disease (along with closely related genospecies), is in the deeply branching spirochete phylum. The bacterium is maintained in nature in an enzootic cycle that involves transmission from a tick vector to a vertebrate host and acquisition from a vertebrate host to a tick vector. During its arthropod sojourn, B. burgdorferi faces a variety of stresses, including nutrient deprivation. Here, we review some of the spirochetal factors that promote persistence, maintenance and dissemination of B. burgdorferi in the tick, and then focus on the utilization of available carbohydrates as well as the exquisite regulatory systems invoked to adapt to the austere environment between blood meals and to signal species transitions as the bacteria traverse their enzootic cycle. The spirochetes shift their source of carbon and energy from glucose in the vertebrate to glycerol in the tick. Regulation of survival under limiting nutrients requires the classic stringent response in which RelBbu controls the levels of the alarmones guanosine tetraphosphate and guanosine pentaphosphate (collectively termed (p)ppGpp), while regulation at the tick–vertebrate interface as well as regulation of protective responses to the blood meal require the two-component system Hk1/Rrp1 to activate production of the second messenger cyclic-dimeric-GMP (c-di-GMP). PMID:27147446
Cabezas-Cruz, Alejandro; Alberdi, Pilar; Valdés, James J.; Villar, Margarita; de la Fuente, José
The obligate intracellular pathogen, Anaplasma phagocytophilum, is the causative agent of human, equine, and canine granulocytic anaplasmosis and tick-borne fever (TBF) in ruminants. A. phagocytophilum has become an emerging tick-borne pathogen in the United States, Europe, Africa, and Asia, with increasing numbers of infected people and animals every year. It has been recognized that intracellular pathogens manipulate host cell metabolic pathways to increase infection and transmission in both vertebrate and invertebrate hosts. However, our current knowledge on how A. phagocytophilum affect these processes in the tick vector, Ixodes scapularis is limited. In this study, a genome-wide search for components of major carbohydrate metabolic pathways was performed in I. scapularis ticks for which the genome was recently published. The enzymes involved in the seven major carbohydrate metabolic pathways glycolysis, gluconeogenesis, pentose phosphate, tricarboxylic acid cycle (TCA), glyceroneogenesis, and mitochondrial oxidative phosphorylation and β-oxidation were identified. Then, the available transcriptomics and proteomics data was used to characterize the mRNA and protein levels of I. scapularis major carbohydrate metabolic pathway components in response to A. phagocytophilum infection of tick tissues and cultured cells. The results showed that major carbohydrate metabolic pathways are conserved in ticks. A. phagocytophilum infection inhibits gluconeogenesis and mitochondrial metabolism, but increases the expression of glycolytic genes. A model was proposed to explain how A. phagocytophilum could simultaneously control tick cell glucose metabolism and cytoskeleton organization, which may be achieved in part by up-regulating and stabilizing hypoxia inducible factor 1 alpha in a hypoxia-independent manner. The present work provides a more comprehensive view of the major carbohydrate metabolic pathways involved in the response to A. phagocytophilum infection in ticks
Full Text Available Anaplasma phagocytophilum is an emerging pathogen that causes human granulocytic anaplasmosis. Infection with this zoonotic pathogen affects cell function in both vertebrate host and the tick vector, Ixodes scapularis. Global tissue-specific response and apoptosis signaling pathways were characterized in I. scapularis nymphs and adult female midguts and salivary glands infected with A. phagocytophilum using a systems biology approach combining transcriptomics and proteomics. Apoptosis was selected for pathway-focused analysis due to its role in bacterial infection of tick cells. The results showed tissue-specific differences in tick response to infection and revealed differentiated regulation of apoptosis pathways. The impact of bacterial infection was more pronounced in tick nymphs and midguts than in salivary glands, probably reflecting bacterial developmental cycle. All apoptosis pathways described in other organisms were identified in I. scapularis, except for the absence of the Perforin ortholog. Functional characterization using RNA interference showed that Porin knockdown significantly increases tick colonization by A. phagocytophilum. Infection with A. phagocytophilum produced complex tissue-specific alterations in transcript and protein levels. In tick nymphs, the results suggested a possible effect of bacterial infection on the inhibition of tick immune response. In tick midguts, the results suggested that A. phagocytophilum infection inhibited cell apoptosis to facilitate and establish infection through up-regulation of the JAK/STAT pathway. Bacterial infection inhibited the intrinsic apoptosis pathway in tick salivary glands by down-regulating Porin expression that resulted in the inhibition of Cytochrome c release as the anti-apoptotic mechanism to facilitate bacterial infection. However, tick salivary glands may promote apoptosis to limit bacterial infection through induction of the extrinsic apoptosis pathway. These dynamic
... gov . Recommend on Facebook Tweet Share Compartir Avoiding Ticks Preventing tick bites Preventing ticks on your pets ... ticks in the yard New materials for this tick season: Medscape Expert Commentary â€” Tickborne Rickettsial Diseases: ...
Luo, Li-Mei; Zhao, Li; Wen, Hong-Ling; Zhang, Zhen-Tang; Liu, Jian-Wei; Fang, Li-Zhu; Xue, Zai-Feng; Ma, Dong-Qiang; Zhang, Xiao-Shuang; Ding, Shu-Jun; Lei, Xiao-Ying; Yu, Xue-jie
Severe fever with thrombocytopenia syndrome (SFTS) is an emerging hemorrhagic fever in East Asia caused by SFTS virus (SFTSV), a newly discovered phlebovirus. The Haemaphysalis longicornis tick has been suspected to be the vector of SFTSV. To determine whether SFTSV can be transmitted among ticks, from ticks to animals, and from animals to ticks, we conducted transmission studies between developmental stages of H. longicornis ticks and between ticks and mice. Using reverse transcription PCR, we also analyzed the prevalence of SFTSV infection among H. longicornis ticks collected from vegetation in Shandong Province, China. Our results showed a low prevalence of SFTSV among collected ticks (0.2%, 8/3,300 ticks), and we showed that ticks fed on SFTSV-infected mice could acquire the virus and transstadially and transovarially transmit it to other developmental stages of ticks. Furthermore, SFTSV-infected ticks could transmit the virus to mice during feeding. Our findings indicate ticks could serve as a vector and reservoir of SFTSV.
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.
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.
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...
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 acc...
Chao, Li-Lian; Wu, Wen-Jer; Shih, Chien-Ming
The genetic identity of Ixodes granulatus ticks was determined for the first time in Taiwan. The phylogenetic relationships were analyzed by comparing the sequences of mitochondrial 16S ribosomal DNA gene obtained from 19 strains of ticks representing seven species of Ixodes and two outgroup species (Rhipicephalus sanguineus and Haemaphysalis inermis). Four major clades could be easily distinguished by neighbour-joining analysis and were congruent by maximum-parsimony method. All these I. granulatus ticks of Taiwan were genetically affiliated to a monophyletic group with highly homogeneous sequences (92.2-99.3% similarity), and can be discriminated from other Ixodes species and other genera of ticks with a sequence divergence ranging from 11.7 to 30.8%. Moreover, intraspecific analysis revealed that two distinct lineages are evident between the same species of I. granulatus ticks collected from Taiwan and Malaysia. Our results demonstrate that all these I. granulatus ticks of Taiwan represent a unique lineage distinct from the common vector ticks (I. ricinus complex) for Borrelia burgdorferi spirochetes.
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
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 pro...
Rashidi, Ahmad; Razmi, Gholamreza
A survey was carried in North Khorasan Province, Iran in 2010-2011, designed to identify Theileria spp. infections of both sheep and ticks. The tick species were also examined. Ninety sheep from different flocks were clinically examined, and blood samples and ixodid ticks were collected. Light microscopy of blood smears revealed Theileria spp. infection in 37 (41.1 %), while 74 (82.2 %) of blood samples were positive using semi-nested PCR. Theileria ovis, Theileria lestoquardi, and mixed infection were detected in 63/90 (70 %), 5/90 (5.5 %), and 6/90 (6.6 %) of samples, respectively. Of the 434 ticks that were collected, the most prevalent species was Rhipicephalus turanicus (69.3 %) followed by Hyalomma marginatum turanicum (18.4 %), Dermacentor marginatus (6.4 %), and Rhipicephalus bursa (5.7 %). The ticks were separated into 42 tick pools, and the salivary glands were dissected out in 0.85 % (w/v) saline under a stereomicroscope and examined using semi-nested PCR. Three pools of H. marginatum turanicum salivary glands were infected with T. ovis and T. lestoquardi, and one pool of R. turanicus was infected with T. ovis. Based on these results, it is concluded that the prevalence of T. ovis is higher than T. lestoquardi and that H. marginatum turanicum and R. turanicus are likely vectors of T. lestoquardi and T. ovis in this area.
Sungirai, Marvelous; Moyo, Doreen Zandile; De Clercq, Patrick; Madder, Maxime
Tick borne diseases (TBDs) are responsible for huge economic losses in cattle production in most African countries where the majority of cattle owners are the resource poor communal farmers. Governments have initiated and co-ordinate tick control programs with farmers required to contribute funds for their sustenance. The success of these programs will hinge upon the involvement of communal farmers in their design, implementation and evaluation. To this end, 313 communal farmers (approximately 8.4% response rate) were interviewed and 3 focus group discussions were carried out in the southern low-veld part of Zimbabwe with the objectives of investigating communal farmers' perceptions on TBDs affecting cattle, level of participation in government initiated tick control programs, other tick control methods practiced, types of acaricides used and their perceived effectiveness. There was a general awareness of TBDs with 67.7% (n=212) farmers being able to describe tick diseases with names or clinical and post-mortem signs. The diseases or problems frequently associated with ticks were cowdriosis (38%, n=119), mastitis (36.7%, n=115), anaplasmosis (36.1%, n=113), body damage (28.4%, n=89), babesiosis (24.6%, n=77) and poor body condition (16.6%, n=52). Cattle mortalities due to TBDs were reported by 23.8% (n=74) of the farmers. The plunge dip was consistently used by farmers (70.3%, n=220) to control ticks. Other tick control methods practiced were the hand spraying (67.4%, n=211), hand dressing (16.6%, n=52), traditional methods (5.4%, n=17), use of pour-ons (4.5%, n=14) and smearing (2.2%, n=7). The formamidines were the most common class of acaricide used (59.4%, n=186), followed by synthetic pyrethroids (29.1%, n=91), macro cyclic lactones (12.8%, n=40) and organophosphates (4.5%, n=14). Most farmers (75.2%, n=231) perceived these acaricides to be effective in controlling ticks. The results of focus group discussions showed that a number of factors influenced the
Heylen, D.; Sprong, H.; Van Oers, K.; Fonville, M.; Matthysen, E.
Our study tested whether two European bird-specialized ticks, Ixodes arboricola and I. frontalis, can act as vectors in the transmission cycles of Borrelia burgdorferi s.l. The ticks have contrasting ecologies but share songbird hosts (such as the great tit, Parus major) with the generalist I. ricin
Heylen, D.; Sprong, H.; Oers, van K.; Fonville, M.; Leirs, H.; Matthysen, E.
Our study tested whether two European bird-specialized ticks, Ixodes arboricola and I. frontalis, can act as vectors in the transmission cycles of Borrelia burgdorferi s.l. The ticks have contrasting ecologies but share songbird hosts (such as the great tit, Parus major) with the generalist I. ricin
Zygner, W; Górski, P; Wedrychowicz, H
Dermacentor reticulatus tick is a vector and final host of Babesia canis canis, protozoan parasite of the dog. In Poland and other European countries, endemic regions for canine babesiosis caused by B. canis canis are the same as endemic regions for D. reticulatus. In many of these regions, canine babesiosis is the most prevalent tick-borne disease in dogs. In Europe, increasing range of geographical distribution of D. reticulatus is observed. A consequence of this fact may be increasing range of canine babesiosis. D. reticulatus is one of the most common ticks occurring in Poland, however, it occurs mainly in the north-eastern and eastern part of the country, and there are many areas in which this species has not been reported yet. In this study, D. reticulatus ticks were collected from March 2007 to November 2008 in central and eastern Mazowsze region, and in some localities in Białystok and Lublin regions. Twenty four new sites for D. reticulatus, mainly in central and eastern regions of Mazowsze Province have been found. 18 localities are placed on banks of the fishing ponds or in river valleys and 6 are forests borders or barren lands and meadows, not situated near rivers or other water reservoirs. All tick-rich sites are localized in river valleys or on pond banks. However, statistical analysis showed that there were no differences in the density of ticks between groups of areas. These results show that the occurrence of D. reticulatus in newly detected areas has became endemic. Probably woodless, unregulated river valleys are important migration tracts for this species of tick and enable them to penetrate new territories. It seems likely that geographical range of D. reticulatus is widening from east to west of Poland what can induce an increase in the number of canine babesiosis cases in areas non-endemic for B. canis canis and its vector. Climate change may be also partially responsible for earlier beginning of tick's seasonal activity as well as for
Hornok, Sándor; Kováts, Dávid; Flaisz, Barbara; Csörgő, Tibor; Könczöl, Árpád; Balogh, György Tibor; Csorba, Attila; Hunyadi, Attila
Ecdysteroids are important hormones that regulate moulting in arthropods. Three-host ixodid ticks normally moult to the next stage after finishing their blood meal, in the off-host environment. Presumably, three-host ticks that feed on the blood of insectivorous vertebrate hosts can be exposed to high levels of exogenous ecdysteroids causing them to initiate apolysis (the first step of moulting) on the vertebrate host. The aim of the present study was to investigate whether ticks undergo apolysis on insectivorous song birds, and if this phenomenon is associated with the seasonal variation in the availability of moths and with the presence of naturally acquired ecdysteroids in avian blood. During a triannual survey, 3330 hard tick larvae and nymphs were collected from 1164 insectivorous song birds of 46 species. A noteworthy proportion of ticks, 20.5%, showed apolysis. The occurrence of apolytic ticks on birds was correlated with the known seasonality of lepidopteran caterpillars. In addition, 18 blood samples of tick-infested birds were analysed with liquid chromatography - tandem mass spectrometry. Eight samples contained ecdysteroids or their derivatives, frequently in high concentrations, and the presence of these was associated with tick apolysis. In conclusion, naturally acquired ecdysteroids may reach high levels in the blood of insectivorous passerine birds, and will affect ticks (feeding on such blood) by shortening their parasitism.
Full Text Available Ticks are well-known parasites that affect livestock productivity. This paper reviews the current knowledge regarding the spread of ticks with their impact in animal health and the limitations to achieve effective control measures. The forecasted trends in climate play an obvious role in promoting the spread of ticks in several regions. It appears that climate warming is pivotal in the spread and colonization of new territories by Rhipicephalus microplus in several regions of Africa. The reported increase in altitude of this tick species in the mountainous regions of Central and South America appears to be driven by such general trends in climate change. This factor, however, is not the only single contributor to the spread of ticks. The poor management of farms, uncontrolled movements of domestic animals, abundance of wild animals, and absence of an adequate framework to capture the ecological plasticity of certain ticks may explain the complexity of the control measures. In this paper, we review several details regarding the relationships of ticks with the environment, wild fauna and competition with other species of ticks. Our intention is to highlight these relationships with the aim to produce a coherent framework to explore tick ecology and its relationship with animal production systems.
Bouwknegt, C.; Rijn, van P.A.; Schipper, J.M.J.; Holzel, D.R.; Boonstra, J.; Nijhof, A.; Rooij, van E.M.A.; Jongejan, F.
When the first outbreak of bluetongue virus serotype 8 (BTV8) was recorded in North-West Europe in August 2006 and renewed outbreaks occurred in the summer of 2007 and again in 2008, the question was raised how the virus survived the winter. Since most adult Culicoides vector midges are assumed not
Kovalev, Sergey Y; Mukhacheva, Tatyana A
Tick-borne encephalitis is the most important human arthropod-borne virus disease in Europe and Russia, with an annual incidence of about 13 thousand people. Tick-borne encephalitis virus (TBEV) is distributed in the natural foci of forest and taiga zones of Eurasia, from the Pacific to the Atlantic coast. Currently, there are three mutually exclusive hypotheses about the origin and distribution of TBEV subtypes, although they are based on the same assumption of gradual evolution. Recently, we have described the structure of TBEV populations in terms of a clusteron approach, a clusteron being a structural unit of viral population [Kovalev and Mukhacheva (2013) Infect. Genet. Evol., 14, 22-28]. This approach allowed us to investigate questions of TBEV evolution in a new way and to propose a hypothesis of quantum evolution due to a vector switch. We also consider a possible mechanism for this switch occurring in interspecific hybrids of ticks. It is necessarily accompanied by a rapid accumulation of mutations in the virus genome, which is contrary to the generally accepted view of gradual evolution in assessing the ages of TBEV populations. The proposed hypothesis could explain and predict not only the formation of new subtypes, but also the emergence of new vector-borne viruses.
Ferrolho, Joana; Simpson, Jennifer; Hawes, Philippa; Zweygarth, Erich; Bell-Sakyi, Lesley
Canine monocytic ehrlichiosis is caused by Ehrlichia canis, a small gram-negative coccoid bacterium that infects circulating monocytes. The disease is transmitted by the brown dog tick Rhipicephalus sanguineus s.l. and is acknowledged as an important infectious disease of dogs and other members of the family Canidae worldwide. E. canis is routinely cultured in vitro in the canine monocyte-macrophage cell line DH82 and in non-vector Ixodes scapularis tick cell lines, but not in cells derived from its natural vector. Here we report infection and limited propagation of E. canis in the tick cell line RSE8 derived from the vector R. sanguineus s.l., and successful propagation through six passages in a cell line derived from the experimental vector Dermacentor variabilis. In addition, using bacteria semi-purified from I. scapularis cells we attempted to infect a panel of cell lines derived from non-vector species of the tick genera Amblyomma, Dermacentor, Hyalomma, Ixodes and Rhipicephalus with E. canis and, for comparison, the closely-related Ehrlichia ruminantium, causative agent of heartwater in ruminants. Amblyomma and non-vector Dermacentor spp. cell lines appeared refractory to infection with E. canis but supported growth of E. ruminantium, while some, but not all, cell lines derived from Hyalomma, Ixodes and Rhipicephalus spp. ticks supported growth of both pathogens. We also illustrated and compared the ultrastructural morphology of E. canis in DH82, RSE8 and I. scapularis IDE8 cells. This study confirms that E. canis, like E. ruminantium, is able to grow not only in cell lines derived from natural and experimental tick vectors but also in a wide range of other cell lines derived from tick species not known to transmit this pathogen.
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.
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
Contreras, Marinela; Villar, Margarita; Alberdi, Pilar; de la Fuente, José
Ticks are blood-feeding arthropod ectoparasites that transmit disease-causing pathogens to humans and animals worldwide. Vaccines using tick antigens have proven to be cost-effective and environmental friendly for the control of vector infestations and pathogen infection and transmission. However, new strategies are needed to identify tick protective antigens for development of improved vaccines. These strategies will be greatly enhanced by vaccinomics approaches starting from the study of tick-host-pathogen molecular interactions and ending in the characterization and validation of vaccine formulations. The discovery of tick antigens that affect both tick infestations and pathogen infection/transmission could be used for vaccines targeting human and animal populations at risk and reservoir species to reduce host exposure to ticks while reducing the number of infected ticks and their vector capacity for pathogens that affect human and animal health. In this chapter, we describe methods of the vaccinomics platform using transcriptomics and proteomics for the identification of candidate protective antigens in Ixodes scapularis, the vector for human and animal granulocytic anaplasmosis, tick-borne encephalitis, and Lyme disease.
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.
Full Text Available A molecular survey was performed for identification Theileria spp in sheep and ticks during from 2010-2011 in Fasa and Kazeroun areas, Fars province, Iran. A total of 100 sheep from different flocks were clinically examined and blood samples with ixodid ticks collected. The prepared blood smears from capillary vein of ear were stained with giemsa methods and examined by using light microscope. The collected ticks were separated into tick pools with five ticks according to their species and sex. Then, the salivary glands were dissected out in 0.85% saline solution under stereomicroscope. The boold and tick salivary glands samples were examined by using semi-nested PCR. The Theileria spp infection was observed in 46% of blood smears, while 76 % of blood samples were positive by using semi-nested PCR. T. ovis, T. lestoquardi and mixed infection were detected in 43 (43%, 3 (3% and 30 (30% of positive samples, respectively. Any significant difference was not observed between the frequency of Theileria spp infection in sheep of Kazeroun and Fasa areas. In the present study, the most prevalent ticks were R. turanicus 48.8% and followed by H. a. anatolicum 42.2% and H. marginatum 8.8%. The results were shown that one pool belong to salivary glands of H. turanicus were infected with T. ovis. Based on the obtained results, it is concluded that T. ovis have high prevalence with compared to T. lestoquardi and also, R. turanicus could be the vectors T. ovis in this area
Ticks have always been a part of fauna in and around human settlements, and their significance changed concurrently with the enlargement of settlements and their transformation into towns. The increased rate of urbanization during the last decades has created a new reality for tick existence. Two groups of ticks are of major concern for modern towns: those living under natural conditions of urban surroundings and those well-adapted to urban conditions. During the process of urbanization, encroachment into forested and uncultivated areas as well as protection of existing green spaces create opportunities for ticks living in nature to also exist under urban and suburban conditions. Conditions of modern urban and especially suburban environment in developed European countries adequately meet tick requirements. Tick species having an advantage in urban areas are those that can use one and the same host at all parasitic stages, can starve for a prolonged time, can use either urban pests or domesticated animals as hosts, and can live in man-made buildings. The ticks of the Argas reflexus group (Argasidae) and the brown dog tick Rhipicephalus sanguineus (Ixodidae) comply with practically all conditions necessary for successful survival in urban areas. The ability of ticks to transmit numerous human and animal pathogens and the presence of many reservoir hosts in urban and suburban areas create persistent danger for human populations and domestic animals. Impact on urban ticks should be directed against the two major requirements of tick existence: reducing populations of potential tick hosts (feral pigeons, stray dogs and cats, and urban rodents), and changing other environmental conditions to make them less suitable for ticks. It is especially important that urban inhabitants be properly informed about the danger posed by ticks, the sites of possible tick attacks, and basic self-protection techniques.
Estrada-Peña, Agustín; Gray, Jeremy S; Kahl, Olaf; Lane, Robert S; Nijhof, Ard M
Interest in tick-transmitted pathogens has experienced an upsurge in the past few decades. Routine application of tools for the detection of fragments of foreign DNA in ticks, together with a high degree of interest in the quantification of disease risk for humans, has led to a marked increase in the number of reports on the eco-epidemiology of tick-borne diseases. However, procedural errors continue to accumulate in the scientific literature, resulting in misleading information. For example, unreliable identification of ticks and pathogens, erroneous interpretations of short-term field studies, and the hasty acceptance of some tick species as vectors have led to ambiguities regarding the vector role of these arthropods. In this review, we focus on the ecological features driving the life cycle of ticks and the resulting effects on the eco-epidemiology of tick-transmitted pathogens. We review the factors affecting field collections of ticks, and we describe the biologically and ecologically appropriate procedures for describing tick host-seeking activity and its correlation with environmental traits. We detail the climatic variables that have biological importance on ticks and explain how they should be properly measured and analyzed. We also provide evidence to critically reject the use of some environmental traits that are being increasingly reported as the drivers of the behavior of ticks. With the aim of standardization, we propose unambiguous definitions of the status of hosts and ticks regarding their ability to maintain and spread a given pathogen. We also describe laboratory procedures and standards for evaluating the vectorial capacity of a tick or the reservoir role of a host. This approach should provide a coherent framework for the reporting of research findings concerning ticks and tick-borne diseases.
Full Text Available Interest in tick-transmitted pathogens has experienced an upsurge in the past few decades. Routine application of tools for the detection of fragments of foreign DNA in ticks, together with a high degree of interest in the quantification of disease risk for humans, has led to a marked increase in the number of reports on the eco-epidemiology of tick-borne diseases. However, procedural errors continue to accumulate in the scientific literature, resulting in misleading information. For example, unreliable identification of ticks and pathogens, erroneous interpretations of short-term field studies, and the hasty acceptance of some tick species as vectors have led to ambiguities regarding the vector role of these arthropods. In this review, we focus on the ecological features driving the life cycle of ticks and the resulting effects on the eco-epidemiology of tick-transmitted pathogens. We review the factors affecting field collections of ticks, and we describe the biologically and ecologically appropriate procedures for describing tick host-seeking activity and its correlation with environmental traits. We detail the climatic variables that have biological importance on ticks and explain how they should be properly measured and analyzed. We also provide evidence to critically reject the use of some environmental traits that are being increasingly reported as the drivers of the behavior of ticks. With the aim of standardization, we propose unambiguous definitions of the status of hosts and ticks regarding their ability to maintain and spread a given pathogen. We also describe laboratory procedures and standards for evaluating the vectorial status of a tick or the reservoir role of a host. Such harmonization in protocols and terms should provide a coherent framework for the reporting of research findings concerning ticks and tick-borne diseases.
Evidence for Personal Protective Measures to Reduce Human Contact With Blacklegged Ticks and for Environmentally Based Control Methods to Suppress Host-Seeking Blacklegged Ticks and Reduce Infection with Lyme Disease Spirochetes in Tick Vectors and Rodent Reservoirs.
Eisen, Lars; Dolan, Marc C
In the 1980s, the blacklegged tick, Ixodes scapularis Say, and rodents were recognized as the principal vector and reservoir hosts of the Lyme disease spirochete Borrelia burgdorferi in the eastern United States, and deer were incriminated as principal hosts for I. scapularis adults. These realizations led to pioneering studies aiming to reduce the risk for transmission of B. burgdorferi to humans by attacking host-seeking ticks with acaricides, interrupting the enzootic transmission cycle by killing immatures infesting rodent reservoirs by means of acaricide-treated nesting material, or reducing deer abundance to suppress tick numbers. We review the progress over the past three decades in the fields of: 1) prevention of human-tick contact with repellents and permethrin-treated clothing, and 2) suppression of I. scapularis and disruption of enzootic B. burgdorferi transmission with environmentally based control methods. Personal protective measures include synthetic and natural product-based repellents that can be applied to skin and clothing, permethrin sprays for clothing and gear, and permethrin-treated clothing. A wide variety of approaches and products to suppress I. scapularis or disrupt enzootic B. burgdorferi transmission have emerged and been evaluated in field trials. Application of synthetic chemical acaricides is a robust method to suppress host-seeking I. scapularis ticks within a treated area for at least 6-8 wk. Natural product-based acaricides or entomopathogenic fungi have emerged as alternatives to kill host-seeking ticks for homeowners who are unwilling to use synthetic chemical acaricides. However, as compared with synthetic chemical acaricides, these approaches appear less robust in terms of both their killing efficacy and persistence. Use of rodent-targeted topical acaricides represents an alternative for homeowners opposed to open distribution of acaricides to the ground and vegetation on their properties. This host-targeted approach also
EFSA Panel on Animal Health and Welfare (AHAW
Full Text Available The report provides an update on the role of the tick vectors in the epidemiology of African swine fever (ASF and Crimean and Congo haemorrhagic fever (CCHF in Eurasia, specifically to review of the geographical distribution of the relevant ticks with presentation of maps of their occurrence in Europe and Mediterranean basin; a description of the factors that define the relevant tick population dynamics and identify possible high risk areas in the EU; an update on the role of tick vectors associated with CCHF and ASF in Eurasia; and reviews available methods for the control of the relevant tick vectors. Data were collected through systematic literature review in a database from which maps of geographic distribution of ticks, CCHF virus and ASF virus were issued. The main vectors for CCHF are Hyalomma spp, Increase in the number of fragmented areas and the degradation of agricultural lands to bush lands are the two main factors in the creation of new foci of CCHF in endemic areas. Movement of livestock and wildlife species, which may carry infected ticks, contributes to the spread of the infection. The Middle East and Balkan countries are the most likely sources of introduction of CCHFV into other European countries. All the Ornithodoros species investigated so far can become infective with ASF virus and are perhaps biological vectors. These ticks are important in maintaining the local foci of the ASFV, but do not play an active role in the geographical spread of the virus. Wild boars have never been found infested by Ornithodoros spp. because wild boars normally do not rest inside protected burrows, but above the ground. There is no single ideal solution to the control of ticks relevant for CCHF or ASF. The integrated control approach is probably the most effective.
Full Text Available Abstract Background Ixodiphagus hookeri is a parasitic wasp of ixodid ticks around the world. It has been studied as a potential bio-control agent for several tick species. We suspected that the presence of Wolbachia infected I. hookeri eggs in ticks is responsible for incidental detection of Wolbachia DNA in tick samples. Methods The 28S rRNA and 16S rRNA genes of a specimen of I. hookeri was amplified and sequenced. PCR on part of the 28S rRNA gene was used to detect parasitic wasp DNA in 349 questing Ixodes ricinus ticks from various sampling sites. Furthermore, the wsp gene of Wolbachia was sequenced from the I. hookeri specimen and a subset of ticks was tested using this marker. Results Several sequences from tick specimens were identical to the Wolbachia sequence of the I. hookeri specimen. Ixodiphagus hookeri was detected in 9.5% of all tested ticks, varying between 4% and 26% depending on geographic location. Ten out of eleven sampling sites throughout the Netherlands were positive for I. hookeri. Eighty-seven percent of I. hookeri-positive but only 1.6% of I. hookeri-negative ticks were Wolbachia positive. Detection of I. hookeri DNA was strongly associated with the detection of Wolbachia in ticks. Conclusion This is the first reported case of I. hookeri in the Netherlands. Furthermore I. hookeri harbours Wolbachia species and is broadly distributed in the Netherlands. While detection of Wolbachia DNA in ticks might often be due to parasitism with this wasp, other sources of Wolbachia DNA in ticks might exist as well.
Bontemps-Gallo, Sébastien; Lawrence, Kevin; Gherardini, Frank C.
Lyme disease, caused by Borrelia burgdorferi, is a vector-borne illness that requires the bacteria to adapt to distinctly different environments in its tick vector and various mammalian hosts. Effective colonization (acquisition phase) of a tick requires the bacteria to adapt to tick midgut physiology. Successful transmission (transmission phase) to a mammal requires the bacteria to sense and respond to the midgut environmental cues and up-regulate key virulence factors before transmission to a new host. Data presented here suggest that one environmental signal that appears to affect both phases of the infective cycle is osmolarity. While constant in the blood, interstitial fluid and tissue of a mammalian host (300 mOsm), osmolarity fluctuates in the midgut of feeding Ixodes scapularis. Measured osmolarity of the blood meal isolated from the midgut of a feeding tick fluctuates from an initial osmolarity of 600 mOsm to blood-like osmolarity of 300 mOsm. After feeding, the midgut osmolarity rebounded to 600 mOsm. Remarkably, these changes affect the two independent regulatory networks that promote acquisition (Hk1-Rrp1) and transmission (Rrp2-RpoN-RpoS) of B. burgdorferi. Increased osmolarity affected morphology and motility of wild-type strains, and lysed Hk1 and Rrp1 mutant strains. At low osmolarity, Borrelia cells express increased levels of RpoN-RpoS-dependent virulence factors (OspC, DbpA) required for the mammalian infection. Our results strongly suggest that osmolarity is an important part of the recognized signals that allow the bacteria to adjust gene expression during the acquisition and transmission phases of the infective cycle of B. burgdorferi. PMID:27525653
The lone star tick, Amblyomma americanum, is one of important Ixodid tick species that are known ectoparasites and disease vectors affecting animal and human health in the United States. New pesticides or repellents with novel mode of action would help control resistant ticks and protect humans from...
Cabezas-Cruz, Alejandro; Alberdi, Pilar; Ayllón, Nieves; Valdés, James J; Pierce, Raymond; Villar, Margarita; de la Fuente, José
Epigenetic mechanisms have not been characterized in ticks despite their importance as vectors of human and animal diseases worldwide. The objective of this study was to characterize the histones and histone modifying enzymes (HMEs) of the tick vector Ixodes scapularis and their role during Anaplasma phagocytophilum infection. We first identified 5 histones and 34 HMEs in I. scapularis in comparison with similar proteins in model organisms. Then, we used transcriptomic and proteomic data to analyze the mRNA and protein levels of I. scapularis histones and HMEs in response to A. phagocytophilum infection of tick tissues and cultured cells. Finally, selected HMEs were functionally characterized by pharmacological studies in cultured tick cells. The results suggest that A. phagocytophilum manipulates tick cell epigenetics to increase I. scapularis p300/CBP, histone deacetylase, and Sirtuin levels, resulting in an inhibition of cell apoptosis that in turn facilitates pathogen infection and multiplication. These results also suggest that a compensatory mechanism might exist by which A. phagocytophilum manipulates tick HMEs to regulate transcription and apoptosis in a tissue-specific manner to facilitate infection, but preserving tick fitness to guarantee survival of both pathogens and ticks. Our study also indicates that the pathogen manipulates arthropod and vertebrate cell epigenetics in similar ways to inhibit the host response to infection. Epigenetic regulation of tick biological processes is an essential element of the infection by A. phagocytophilum and the study of the mechanisms and principal actors involved is likely to provide clues for the development of anti-tick drugs and vaccines.
Full Text Available Ticks are ectoparasites of animals and humans that serve as vectors of Anaplasma and other pathogens that affect humans and animals worldwide. Ticks and the pathogens that they transmit have coevolved molecular interactions involving genetic traits of both the tick and the pathogen that mediate their development and survival. In this paper, the expression of heat shock proteins (HSPs and other stress response proteins (SRPs was characterized in ticks and cultured tick cells by proteomics and transcriptomics analyses in response to Anaplasma spp. infection and heat shock. The results of these studies demonstrated that the stress response was activated in ticks and cultured tick cells after Anaplasma spp. infection and heat shock. However, in the natural vector-pathogen relationship, HSPs and other SRPs were not strongly activated, which likely resulted from tick-pathogen coevolution. These results also demonstrated pathogen- and tick-specific differences in the expression of HSPs and other SRPs in ticks and cultured tick cells infected with Anaplasma spp. and suggested the existence of post-transcriptional mechanisms induced by Anaplasma spp. to control tick response to infection. These results illustrated the complexity of the stress response in ticks and suggested a function for the HSPs and other SRPs during Anaplasma spp. infection.
de la Fuente, José; Estrada-Peña, Agustín; Cabezas-Cruz, Alejandro; Brey, Ricardo
Ticks are important vectors of emerging zoonotic diseases affecting human and animal health worldwide. Ticks are often found on wild birds, which have been long recognized as a potential risk factor for dissemination of ticks and tick-borne pathogens (TBP), thus raising societal concerns and prompting research into their biology and ecology. To fully understand the role of birds in disseminating some ticks species and TBP, it is important to consider the evolutionary relationships between birds, ticks and transmitted pathogens. In this paper we reviewed the possible role of birds in the dissemination of TBP as a result of the evolution of host-tick-pathogen associations. Birds are central elements in the ecological networks of ticks, hosts and TBP. The study of host-tick-pathogen associations reveals a prominent role for birds in the dissemination of Borrelia spp. and Anaplasma phagocytophilum, with little contribution to the possible dissemination of other TBP. Birds have played a major role during tick evolution, which explains why they are by far the most important hosts supporting the ecological networks of ticks and several TBP. The immune response of birds to ticks and TBP has been largely overlooked. To implement effective measures for the control of tick-borne diseases, it is necessary to study bird-tick and bird-pathogen molecular interactions including the immune response of birds to tick infestation and pathogen infection.
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.
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.
J. S. Gray
Full Text Available Zoonotic tick-borne diseases are an increasing health burden in Europe and there is speculation that this is partly due to climate change affecting vector biology and disease transmission. Data on the vector tick Ixodes ricinus suggest that an extension of its northern and altitude range has been accompanied by an increased prevalence of tick-borne encephalitis. Climate change may also be partly responsible for the change in distribution of Dermacentor reticulatus. Increased winter activity of I. ricinus is probably due to warmer winters and a retrospective study suggests that hotter summers will change the dynamics and pattern of seasonal activity, resulting in the bulk of the tick population becoming active in the latter part of the year. Climate suitability models predict that eight important tick species are likely to establish more northern permanent populations in a climate-warming scenario. However, the complex ecology and epidemiology of such tick-borne diseases as Lyme borreliosis and tick-borne encephalitis make it difficult to implicate climate change as the main cause of their increasing prevalence. Climate change models are required that take account of the dynamic biological processes involved in vector abundance and pathogen transmission in order to predict future tick-borne disease scenarios.
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.
Marsot, M; Henry, P-Y; Vourc'h, G; Gasqui, P; Ferquel, E; Laignel, J; Grysan, M; Chapuis, J-L
Wild birds are important hosts for vector-borne pathogens, especially those borne by ticks. However, few studies have been conducted on the role of different bird species within a community as hosts of vector-borne pathogens. This study addressed individual and species factors that could explain the burden of Ixodes ricinus on forest birds during the reproductive periods of both vectors and hosts. The goal was to identify which bird species contribute the most to the tick population at the community level. Birds were mist-netted on four plots in 2008 and on seven plots in 2009 in two forests (Sénart and Notre Dame, near Paris, France). The dependence of the tick load per bird upon environmental conditions (questing nymph density, year and plot) and on host species traits (species, age, sex, body size, vertical space use, level of innate and acquired immunity) was analysed. Finally, the relative contribution of each bird species to the local dynamics of ticks was estimated, while accounting for their respective abundance. Tick burden differed markedly between bird species and varied according to questing nymph density. Bird species with a high body mass, those that forage low in the vegetation, and those that had a high innate immune response and a high spleen mass were more likely to have a high tick burden. Four species (the Common Blackbird, Turdus merula, the European Robin, Erithacus rubecula, the Song Thrush, Turdus philomelos, and the Winter Wren, Troglodytes troglodytes) hosted more than 90% of the ticks in the local bird community. These species, and particularly T. merula which was host to a high proportion of the nymphs, are likely to contribute significantly to the circulation of pathogens for which they are competent, such as the agent of Lyme borreliosis.
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.)
Díaz-Martín, Verónica; Manzano-Román, Raúl; Obolo-Mvoulouga, Prosper; Oleaga, Ana; Pérez-Sánchez, Ricardo
Ticks are parasites of great medical and veterinary importance since they are vectors of numerous pathogens that affect humans, livestock and pets. Among the argasids, several species of the genus Ornithodoros transmit serious diseases such as tick-borne human relapsing fever (TBRF) and African Swine Fever (ASF). In particular, Ornithodoros erraticus is the main vector of these two diseases in the Mediterranean while O. moubata is the main vector in Africa. The presence of these Ornithodoros ticks in domestic and peridomestic environments may greatly hinder the eradication of TBRF and ASF from endemic areas. In addition, there is a constant threat of reintroduction and spreading of ASF into countries from where it has been eradicated (Spain and Portugal) or where it was never present (the Caucasus, Russia and Eastern Europe). In these countries, the presence of Ornithodoros vectors could have a tremendous impact on ASF transmission and long-term maintenance. Therefore, elimination of these ticks from at least synanthropic environments would contribute heavily to the prevention and control of the diseases they transmit. Tick control is a difficult task and although several methods for such control have been used, none of them has been fully effective against all ticks and the problems they cause. Nevertheless, immunological control using anti-tick vaccines offers an attractive alternative to the traditional use of acaricides. The aim of the present paper is to offer a brief overview of the current status in control measure development for Ornithodoros soft ticks, paying special attention to the development of vaccines against O. erraticus and O. moubata. Thus, our contribution includes an analysis of the chief attributes that the ideal antigens for an anti-tick vaccine should have, an exhaustive compilation and analysis of the scant anti-soft tick vaccine trials carried out to date using both concealed and salivary antigens and, finally, a brief description of the
... Physician’s Resources Contact About The Foundation Select Page Tick Paralysis Menu What is Tick Paralysis? Where is ... How to Remove a Tick Deer Tick Ecology Tick-Borne Diseases Anaplasmosis Babesiosis Borrelia miyamotoi infections Colorado ...
... ticks Tickborne diseases abroad Borrelia miyamotoi Borrelia mayonii Tick Removal Recommend on Facebook Tweet Share Compartir If ... a tick quite effectively. How to remove a tick Use fine-tipped tweezers to grasp the tick ...
Sobrino, Raquel; Millán, Javier; Oleaga, Alvaro; Gortázar, Christian; de la Fuente, José; Ruiz-Fons, Francisco
Ticks parasitizing wild carnivores and the tick-borne pathogens (TBPs) that they transmit may affect domestic carnivores and humans. Thus, investigating the role of wild carnivores as tick hosts is of relevance for understanding the life cycle of ticks in natural foci and the epidemiology of TBPs shared with domestic animals and humans. Therefore, the main objective of this study was to determine the ixodid tick fauna of wild carnivores in Peninsular Spain and the environmental factors driving the risk of wild carnivores to be parasitized by ixodid ticks. We hypothesized that the adaptation of tick species to differing climatic conditions may be reflected in a similar parasitization risk of wild carnivores by ticks between bioclimatic regions in our study area. To test this, we surveyed ixodid ticks in wild carnivores in oceanic, continental-Mediterranean, and thermo-Mediterranean bioclimatic regions of Peninsular Spain. We analyzed the influence of environmental factors on the risk of wild carnivores to be parasitized by ticks by performing logistic regression models. Models were separately performed for exophilic and endophilic ticks under the expected differing influence of environmental conditions on their life cycle. We found differences in the composition of the tick community parasitizing wild carnivores from different bioclimatic regions. Modelling results partially confirmed our null hypothesis because bioclimatic region was not a relevant factor influencing the risk of wild carnivores to be parasitized by exophilic ticks. Bioclimatic region was however a factor driving the risk of wild carnivores to be parasitized by endophilic ticks. Spanish wild carnivores are hosts to a relevant number of tick species, some of them being potential vectors of pathogens causing serious animal and human diseases. Information provided herein can be of help to understand tick ecology in Spanish wildlife, the epidemiology of tick-borne diseases, and to prevent the risks of
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
Schmitz, Kelly M; Foley, Janet E; Kasten, Rickie W; Chomel, Bruno B; Larsen, R Scott
From June to October 2010, 48 endangered riparian brush rabbits (Sylvilagus bachmani riparius) were trapped at a captive propagation site in central California with the intention of release into re-established habitats. During prerelease examinations, ticks and blood samples were collected for surveillance for Rickettsia spp., Anaplasma phagocytophilum, Borrelia burgdorferi, and Bartonella spp. Ticks were identified, and DNA was extracted for PCR analysis. Serology was performed to detect exposure to Rickettsia spp., B. burgdorferi, and A. phagocytophilum. DNA was extracted from blood samples and analyzed for A. phagocytophilum using PCR assays. Rabbit blood samples were also cultured for Bartonella spp. Haemaphysalis leporispalustris ticks were detected on all rabbits except one. A total of 375 ticks were collected, with 48% of the rabbits (23 rabbits) having a burden ranging from 0 to 5 ticks, 15% (seven rabbits) from 6 to 10 ticks, 25% (12 rabbits) from 11 to 15 ticks, and 12% (six rabbits) with >15 ticks. There was no evidence of B. burgdorferi or R. rickettsii in tick or rabbit samples. There was also no evidence of Bartonella spp. in the rabbit samples. Four tick samples and 14 rabbits were weakly PCR positive for A. phagocytophilum, and six rabbits were antibody positive for A. phagocytophilum. These results suggest that there may be little risk of these tick-borne diseases in riparian brush rabbits or to the people in contact with them.
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.
Jahfari, Setareh; Hofhuis, Agnetha; Fonville, Manoj; van der Giessen, Joke; van Pelt, Wilfrid; Sprong, Hein
Background Tick-borne diseases are the most prevalent vector-borne diseases in Europe. Knowledge on the incidence and clinical presentation of other tick-borne diseases than Lyme borreliosis and tick-borne encephalitis is minimal, despite the high human exposure to these pathogens through tick bites. Using molecular detection techniques, the frequency of tick-borne infections after exposure through tick bites was estimated. Methods Ticks, blood samples and questionnaires on health status were collected from patients that visited their general practitioner with a tick bite or erythema migrans in 2007 and 2008. The presence of several tick-borne pathogens in 314 ticks and 626 blood samples of this cohort were analyzed using PCR-based methods. Using multivariate logistic regression, associations were explored between pathogens detected in blood and self-reported symptoms at enrolment and during a three-month follow-up period. Results Half of the ticks removed from humans tested positive for Borrelia burgdorferi sensu lato, Anaplasma phagocytophilum, Candidatus Neoehrlichia mikurensis, Rickettsia helvetica, Rickettsia monacensis, Borrelia miyamotoi and several Babesia species. Among 92 Borrelia burgdorferi s. l. positive ticks, 33% carried another pathogen from a different genus. In blood of sixteen out of 626 persons with tick bites or erythema migrans, DNA was detected from Candidatus Neoehrlichia mikurensis (n = 7), Anaplasma phagocytophilum (n = 5), Babesia divergens (n = 3), Borrelia miyamotoi (n = 1) and Borrelia burgdorferi s. l. (n = 1). None of these sixteen individuals reported any overt symptoms that would indicate a corresponding illness during the three-month follow-up period. No associations were found between the presence of pathogen DNA in blood and; self-reported symptoms, with pathogen DNA in the corresponding ticks (n = 8), reported tick attachment duration, tick engorgement, or antibiotic treatment at enrolment. Conclusions Based on molecular
RAJPUT Zahid Iqbal; HU Song-hua; CHEN Wan-jun; ARIJO Abdullah G.; XIAO Chen-wen
The medical and economic importance of ticks has long been recognized due to their ability to transmit diseases to humans and animals. Ticks cause great economic losses to livestock, and adversely affect livestock hosts in several ways. Loss of blood is a direct effect of ticks acting as potential vector for haemo-protozoa and helminth parasites. Blood sucking by large numbers of ticks causes reduction in live weight and anemia among domestic animals, while their bites also reduce the quality of hides. However, major losses caused by ticks are due to their ability to transmit protozoan, rickettsial and viral diseases of livestock, which are of great economic importance world-wide. There are quite a few methods for controlling ticks, but every method has certain shortcomings. The present review is focused on ticks importance and their control.
Background: Pathogens dependent upon vectors for transmission to new hosts undergo environment specific changes in gene transcription dependent on whether they are replicating in the vector or the mammalian host. Differential gene transcription, especially of potential vaccine candidates, is of inte...
Full Text Available As the Lyme disease bacterium Borrelia burgdorferi traverses its enzootic cycle, alternating between a tick vector and a vertebrate host, the spirochete must adapt and persist in the tick midgut under prolonged nutrient stress between blood meals. In this study, we examined the role of the stringent response in tick persistence and in regulation of gene expression during nutrient limitation. Nutritionally starving B. burgdorferi in vitro increased the levels of guanosine tetraphosphate (ppGpp and guanosine pentaphosphate (pppGpp, collectively referred to as (pppGpp, products of the bifunctional synthetase/hydrolase RelBbu (RelA/SpoT homolog. Conversely, returning B. burgdorferi to a nutrient-rich medium decreased (pppGpp levels. B. burgdorferi survival in ticks between the larval and nymph blood meals, and during starvation in vitro, was dependent on RelBbu. Furthermore, normal morphological conversion from a flat-wave shape to a condensed round body (RB form during starvation was dependent on RelBbu; relBbu mutants more frequently formed RBs, but their membranes were compromised. By differential RNA sequencing analyses, we found that RelBbu regulates an extensive transcriptome, both dependent and independent of nutrient stress. The RelBbu regulon includes the glp operon, which is important for glycerol utilization and persistence in the tick, virulence factors and the late phage operon of the 32-kb circular plasmid (cp32 family. In summary, our data suggest that RelBbu globally modulates transcription in response to nutrient stress by increasing (pppGpp levels to facilitate B. burgdorferi persistence in the tick.
Koh, Fui Xian; Panchadcharam, Chandrawathani; Tay, Sun Tee
Little data are available on the prevalence and transmission of vector-borne diseases in stray dogs in Peninsular Malaysia. This study was designed to determine the occurrence of vector-borne pathogens in Malaysian stray dogs using serological and molecular approaches. In total, 48 dog blood samples were subjected to serological analysis using SNAP 4Dx kit (IDEXX Laboratories, Westbrook, ME). The presence of Ehrlichia and Anaplasma DNA in the dog blood samples and Rhipicephalus sanguineus (Latreille) ticks was detected using nested polymerase chain reaction assays. Positive serological findings against Ehrlichia canis and Anaplasma phagocytophilum were obtained in 17 (39.5%) and four (9.3%) of 43 dog samples, respectively. None of the dog blood samples were positive for Borrelia burgdorferi and Dirofilaria immitis. DNA of E. canis and A. phagocytophilum was detected in 12 (25.5%) and two (4.3%) of 47 dog blood samples, and 17 (51.5%) and one (3.0%) of 33 R. sanguineus ticks, respectively. Additionally, DNA of Ehrlichia spp. closely related to Ehrlichia chaffeensis was detected in two (6.1%) R. sanguineus ticks. This study highlights the prevalence of anaplasmosis and ehrlichiosis in dogs in Malaysia. Due to the zoonotic potential of Ehrlichia and Anaplasma spp., appropriate measures should be instituted for prevention and control of vector-borne diseases in dogs.
Full Text Available Tick-borne encephalitis virus (TBEV causes one of the most dangerous human neuroinfections in Europe and Asia. To infect neurons it must cross the blood-brain-barrier (BBB, and presumably also cells adjacent to the BBB, such as astrocytes, the most abundant glial cell type. However, the knowledge about the viral infection of glial cells is fragmental. Here we studied whether TBEV infects rat astrocytes. Rats belong to an animal group serving as a TBEV amplifying host. We employed high resolution quantitative fluorescence microscopy to investigate cell entry and cytoplasmic mobility of TBEV particles along with the effect on the cell cytoskeleton and cell survival. We report that infection of astrocytes with TBEV increases with time of exposure to TBEV and that with post-infection time TBEV particles gained higher mobility. After several days of infection actin cytoskeleton was affected, but cell survival was unchanged, indicating that rat astrocytes resist TBEV-mediated cell death, as reported for other mammalian cells. Therefore, astrocytes may present an important pool of dormant TBEV infections and a new target for therapeutic intervention.
Potokar, Maja; Korva, Miša; Jorgačevski, Jernej; Avšič-Županc, Tatjana; Zorec, Robert
Tick-borne encephalitis virus (TBEV) causes one of the most dangerous human neuroinfections in Europe and Asia. To infect neurons it must cross the blood-brain-barrier (BBB), and presumably also cells adjacent to the BBB, such as astrocytes, the most abundant glial cell type. However, the knowledge about the viral infection of glial cells is fragmental. Here we studied whether TBEV infects rat astrocytes. Rats belong to an animal group serving as a TBEV amplifying host. We employed high resolution quantitative fluorescence microscopy to investigate cell entry and cytoplasmic mobility of TBEV particles along with the effect on the cell cytoskeleton and cell survival. We report that infection of astrocytes with TBEV increases with time of exposure to TBEV and that with post-infection time TBEV particles gained higher mobility. After several days of infection actin cytoskeleton was affected, but cell survival was unchanged, indicating that rat astrocytes resist TBEV-mediated cell death, as reported for other mammalian cells. Therefore, astrocytes may present an important pool of dormant TBEV infections and a new target for therapeutic intervention. PMID:24465969
The medical as well as the veterinary importance of parasitic arthropods or ectoparasites in general terms, is characterized by the primary or secondary impact on the health of humans and companion animals alike. The parasitic arthropods addressed here are those ectoparasites belong to the class of insects, such as fleas and sand flies, or the subclass of acarids, such as ticks. These parasitic arthropods interact intensively with their hosts by blood feeding. Fleas, sand flies and ticks hold the vector capacity to transmit pathogens such as virus, bacteria or protozoa to cats, dogs and humans. The diseases caused by these pathogens are summarized under the terms canine vector-borne diseases (CVBD), feline vector-borne diseases (FVBD) or metazoonoses. In small animal practice, it is important to understand that the transmitted pathogen may either lead to a disease with clinical signs, or more often to asymptomatic, clinically healthy, or silent infections. Blocking of the vector-host interactions, the blood feeding and subsequently the transmission of pathogens during blood feeding is a key element of CVBD control. The focus of this review is on the current knowledge of the epidemiology of parasitic vectors and three important CVBDs they transmit; rickettsiosis, tick borreliosis and canine leishmaniosis from a European perspective, and how veterinary medicine may contribute to the challenges of CVBDs and their control. Prevention of CVBDs is fundamentally based on ectoparasite control. Ectoparasite management in cats and dogs is important not only for the health and well-being of the individual companion animal but for public health in general and is therefore a perfect example of the 'One health' approach.
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.
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.
Zamoto-Niikura, Aya; Morikawa, Shigeru; Hanaki, Ken-Ichi; Holman, Patricia J; Ishihara, Chiaki
The U.S. lineage, one of the major clades in the Babesia microti group, is known as a causal agent of human babesiosis mostly in the northeastern and upper midwestern United States. This lineage, however, also is distributed throughout the temperate zone of Eurasia with several reported human cases, although convincing evidence of the identity of the specific vector(s) in this area is lacking. Here, the goal was to demonstrate the presence of infectious parasites directly in salivary glands of Ixodes persulcatus, from which U.S. lineage genetic sequences have been detected in Asia, and to molecularly characterize the isolates. Five PCR-positive specimens were individually inoculated into hamsters, resulting in infections in four; consequently, four strains were newly established. Molecular characterization, including 18S rRNA, β-tubulin, and CCT7 gene sequences, as well as Western blot analysis and indirect fluorescent antibody assay, revealed that all four strains were identical to each other and to the U.S. lineage strains isolated from rodents captured in Japan. The 18S rRNA gene sequence from the isolates was identical to those from I. persulcatus in Russia and China, but the genetic and antigenic profiles of the Japanese parasites differ from those in the United States and Europe. Together with previous epidemiological and transmission studies, we conclude that I. persulcatus is likely the principal vector for the B. microti U.S. lineage in Japan and presumably in northeastern Eurasia.
Merino, Octavio; Alberdi, Pilar; Pérez de la Lastra, José M; de la Fuente, José
Ticks are obligate hematophagous ectoparasites that transmit a wide variety of pathogens to humans and animals. The incidence of tick-borne diseases has increased worldwide in both humans and domestic animals over the past years resulting in greater interest in the study of tick-host-pathogen interactions. Advances in vector and pathogen genomics and proteomics have moved forward our knowledge of the vector-pathogen interactions that take place during the colonization and transmission of arthropod-borne microbes. Tick-borne pathogens adapt from the vector to the mammalian host by differential gene expression thus modulating host processes. In recent years, studies have shown that targeting tick proteins by vaccination can not only reduce tick feeding and reproduction, but also the infection and transmission of pathogens from the tick to the vertebrate host. In this article, we review the tick-protective antigens that have been identified for the formulation of tick vaccines and the effect of these vaccines on the control of tick-borne pathogens.
... that go outdoors, you need to beware of ticks. Ticks are small bloodsucking parasites. Many species transmit diseases ... of the diseases you can get from a tick bite are Lyme disease, ehrlichiosis, Rocky Mountain spotted ...
... this? Submit Button Past Emails CDC Features Stop Ticks Language: English Español (Spanish) Recommend on Facebook Tweet ... What to Do if You Find an Attached Tick Remove the attached tick as soon as you ...
Khasnatinov, Maxim A.; Tuplin, Andrew; Gritsun, Dmitri J.; Slovak, Mirko; Kazimirova, Maria; Lickova, Martina; Havlikova, Sabina; Klempa, Boris; Gould, Ernest A.
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. PMID:27341437
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.
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
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.
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 a
Mediannikov, O; Fenollar, F
Ticks are considered to be second worldwide to mosquitoes as vectors of human diseases and the most important vectors of disease-causing pathogens in domestic and wild animals. A number of emerging tick-borne pathogens are already discovered; however, the proportion of undiagnosed infectious diseases, especially in tropical regions, may suggest that there are still more pathogens associated with ticks. Moreover, the identification of bacteria associated with ticks may provide new tool for the control of ticks and tick-borne diseases. Described here molecular methods of screening of ticks, extensive use of modern culturomics approach, newly developed artificial media and different cell line cultures may significantly improve our knowledge about the ticks as the agents of human and animal pathology.
Ghosh, Srikant; Nagar, Gaurav
Ticks, as vectors of several zoonotic diseases, are ranked second only to mosquitoes as vectors. The diseases spread by ticks are a major constraint to animal productivity while causing morbidity and mortality in both animals and humans. A number of tick species have been recognised since long as vectors of lethal pathogens, viz. Crimean-Congo haemorrhagic fever virus (CCHFV), Kyasanur forest disease virus (KFDV), Babesia spp, Theileria, Rickettsia conorii, Anaplasma marginale, etc. and the damages caused by them are well-recognised. There is a need to reassess the renewed threat posed by the tick vectors and to prioritize the tick control research programme. This review is focused on the major tick-borne human and animal diseases in India and the progress in vector control research with emphasis on acaricide resistance, tick vaccine and the development of potential phytoacaricides as an integral part of integrated tick control programme.
El-Bahy, Nasr M; Bazh, Eman K; Shaheen, Hazem M
Tick infection is considered a cause of major concern as it is a vector for some disease transmission. The use of chemicals to control tick infection is increasing in farm systems. The efficacy of three chemicals was studied on the tick Boophilus annulatus. In vitro and in vivo studies were done. The active ticks were collected from naturally infected cattle for in vitro study. They were incubated with the three chemicals which are commercially used. An in vitro study recorded that the highest effect of the three chemicals was 100% at 3 h postexposure (p.e.) time for deltamethrin and 6 h for diazinon and ivermectin on the adult ticks. Egg batches were less affected. In vivo results showed more plain efficacy. The efficacy of deltamethrin was increased gradually until complete cessation of ticks showed within 3rd day posttreatment (d.p.t.), 100% efficacy. But the tick population begins to reappear gradually within 7 d.p.t., while diazinon showed 100% efficacy at 7 d.p.t. and the ticks reappear again within 14 d.p.t. The most preferred results were obtained with ivermectin which showed 100% efficacy at 7 d.p.t., and the cattle was still free from infection until 21 d.p.t. only. Ticks begin to reappear within 28 d.p.t. in slight few numbers. This concluded that the powerful and safe chemical which is commercially used was ivermectin. Even so, it is used also as an anthelmintic drug.
Harrison, Alan; Bown, Kevin J; Montgomery, W Ian; Birtles, Richard J
Bartonella are hemoparasites exploiting a range of mammals as reservoir hosts. Several species are zoonotic pathogens. Fleas, lice, and other arthropods, such as ticks, have been implicated as vectors. While the competence of ticks as vectors of Bartonella species has recently been demonstrated, the epidemiological significance of ticks as vectors of Bartonella species in wildlife populations remains unknown. We used the presence of deer at study sites to control the presence of Ixodes ricinus ticks, and used this system to determine whether I. ricinus contributes to the epidemiology of Bartonella species infections in small mammals. Ticks were present at all sites with deer, but were absent from all sites without deer; however, the abundance of ticks on small mammals did not affect the probability of wood mice being infected with Bartonella species. Data presented here indicate that I. ricinus is not involved in the transmission of Bartonella in woodland rodents.
Akinyi, Mercy Y; Tung, Jenny; Jeneby, Maamun; Patel, Nilesh B; Altmann, Jeanne; Alberts, Susan C
Nonhuman primate species spend a conspicuous amount of time grooming during social interactions, a behavior that probably serves both social and health-related functions. While the social implications of grooming have been relatively well studied, less attention has been paid to the health benefits, especially the removal of ectoparasites, which may act as vectors in disease transmission. In this study, we examined the relationship between grooming behavior, tick load (number of ticks), and haemoprotozoan infection status in a population of wild free-ranging baboons (Papio cynocephalus). We found that the amount of grooming received was influenced by an individual's age, sex and dominance rank. The amount of grooming received, in turn, affected the tick load of an individual. Baboons with higher tick loads had lower packed red cell volume (PCV or haematocrit), one general measure of health status. We detected a tick-borne haemoprotozoan, Babesia microti, but its low prevalence in the population precluded identifying sources of variance in infection.
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.
de la Fuente, José; Waterhouse, Robert M.; Sonenshine, Daniel E.; Roe, R. Michael; Ribeiro, Jose M.; Sattelle, David B.; Hill, Catherine A.
As tick-borne diseases are on the rise, an international effort resulted in the sequence and assembly of the first genome of a tick vector. This result promotes research on comparative, functional and evolutionary genomics and the study of tick-host-pathogen interactions to improve human, animal and ecosystem health on a global scale. PMID:27695689
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 Europe
Alberdi, Pilar; Ayllón, Nieves; Cabezas-Cruz, Alejandro; Bell-Sakyi, Lesley; Zweygarth, Erich; Stuen, Snorre; de la Fuente, José
Anaplasma phagocytophilum is an intracellular rickettsial pathogen transmitted by Ixodes spp. ticks, which causes granulocytic anaplasmosis in humans, horses and dogs and tick-borne fever (TBF) in ruminants. In the United States, human granulocytic anaplasmosis (HGA) is highly prevalent while TBF has not been reported. However, in Europe the situation is the opposite, with high prevalence for TBF in sheep and low prevalence of HGA. The origin of these differences has not been identified and our hypothesis is that different A. phagocytophilum isolates impact differently on tick vector capacity through inhibition of apoptosis to establish infection of the tick vector. In this study we used three different isolates of A. phagocytophilum of human, canine and ovine origin to infect the Ixodes ricinus-derived cell line IRE/CTVM20 and the Ixodes scapularis-derived cell line ISE6 in order to characterize the effect of infection on the level of tick cell apoptosis. Inhibition of apoptosis was observed by flow cytometry as early as 24h post-infection for both tick cell lines and all three isolates of A. phagocytophilum, suggesting that pathogen infection inhibits apoptotic pathways to facilitate infection independently of the origin of the A. phagocytophilum isolate and tick vector species. However, infection with A. phagocytophilum isolates inhibited the intrinsic apoptosis pathway at different levels in I. scapularis and I. ricinus cells. These results suggested an impact of vector-pathogen co-evolution on the adaptation of A. phagocytophilum isolates to grow in tick cells as each isolate grew better in the tick cell line derived from its natural vector species. These results increase our understanding of the mechanisms of A. phagocytophilum infection and multiplication and suggest that multiple mechanisms may affect disease prevalence in different geographical regions.
Dengue and Zika have quickly become two of the most important vector-borne diseases affecting Public health around the world. This presentation will introduce vector-borne diseases and all the vectors implicated. A focus will be made on the most important arboviral diseases (Zika and dengue) describ...
Lamattina, Daniela; Nava, Santiago
This work presents records of ticks infesting humans in northern Misiones Province, Argentina. Also, notes on potential transmission of tick-borne pathogens are included. A total of 282 ticks attached to researchers were collected and identified by their morphological characters. Eight tick species were found: Amblyomma brasiliense, Amblyomma coelebs, Amblyomma dubitatum, Amblyomma incisum, Amblyomma ovale, Haemaphysalis juxtakochi, Rhipicephalus sanguineus and Rhipicephalus microplus. Some of these species as A. dubitatum, A. ovale and R. sanguineus have been found infected with spotted fever group rickettsiae pathogenic to humans in Brazil and Argentina. The potential role as vectors of humans pathogens of the ticks found attached to humans in this study is discussed.
Rodríguez-Vivas, R I; Apanaskevich, D A; Ojeda-Chi, M M; Trinidad-Martínez, I; Reyes-Novelo, E; Esteve-Gassent, M D; Pérez de León, A A
Domestic animals and wildlife play important roles as reservoirs of zoonotic pathogens that are transmitted to humans by ticks. Besides their role as vectors of several classes of microorganisms of veterinary and public health relevance, ticks also burden human and animal populations through their obligate blood-feeding habit. It is estimated that in Mexico there are around 100 tick species belonging to the Ixodidae and Argasidae families. Information is lacking on tick species that affect humans, domestic animals, and wildlife through their life cycle. This study was conducted to bridge that knowledge gap by inventorying tick species that infest humans, domestic animals and wildlife in the State of Yucatan, Mexico. Amblyomma ticks were observed as euryxenous vertebrate parasites because they were found parasitizing 17 animal species and human. Amblyomma mixtum was the most eryxenous species found in 11 different animal species and humans. Both A. mixtum and A. parvum were found parasitizing humans. Ixodes near affinis was the second most abundant species parasitizing six animal species (dogs, cats, horses, white-nosed coati, white-tail deer and black vulture) and was found widely across the State of Yucatan. Ixodid tick populations may increase in the State of Yucatan with time due to animal production intensification, an increasing wildlife population near rural communities because of natural habitat reduction and fragmentation. The diversity of ticks across host taxa documented here highlights the relevance of ecological information to understand tick-host dynamics. This knowledge is critical to inform public health and veterinary programs for the sustainable control of ticks and tick-borne diseases.
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.
EFSA Panel on Animal Health and Welfare (AHAW
Full Text Available This report is the second of a series of two technical assessments of the role of ticks in transmission of animal diseases and zoonoses in Eurasia. A previous published scientific opinion (EFSA Journal 2010; (88, 1703 focused on two diseases- Crimean-Congo haemorrhagic fever and African swine fever in Eurasia. The aim of this report is to provide an overview of the geographic distribution of tick species which have proven involvement in the transmission of pathogens causing animal diseases and zoonoses in Eurasia. The report provides maps of the region that display the occurrences of ticks and tick-borne pathogens. Systematic literature review of available publications for the last 10 years and other available literature from the experts were used in the retrieval of the geographical reported cases for the presence of ticks and tick borne pathogens. The report includes a description of the factors that influence the dynamics of the relevant tick species and identify possible high-risk areas in the EU for introduction, considering the biological and ecological characteristics of the ticks and their ability to adapt to new areas. Findings from this review have provided evidence of the extent of ticks and tick-borne diseases (TBDs in geographical ranges and the existing risk areas that should be considered as baseline information to assess potential risk of these diseases. The report indicates the validity of using available literature to support the presence of ticks and TBDs without further predication using weather and other environmental factors associated with the ticks‟ survival. The report concluded that animal and human movement play more impact on the spread of the ticks and TBDs. Climate changes and flight pattern of migratory birds can influence the presence and spread of the ticks and TBDs, but have not been determined to be responsible for the widespread distribution of ticks.
Kathryn E Reif
Full Text Available The genetic diversity of pathogens, and interactions between genotypes, can strongly influence pathogen phenotypes such as transmissibility and virulence. For vector-borne pathogens, both mammalian hosts and arthropod vectors may limit pathogen genotypic diversity (number of unique genotypes circulating in an area by preventing infection or transmission of particular genotypes. Mammalian hosts often act as "ecological filters" for pathogen diversity, where novel variants are frequently eliminated because of stochastic events or fitness costs. However, whether vectors can serve a similar role in limiting pathogen diversity is less clear. Here we show using Francisella novicida and a natural tick vector of Francisella spp. (Dermacentor andersoni, that the tick vector acted as a stronger ecological filter for pathogen diversity compared to the mammalian host. When both mice and ticks were exposed to mixtures of F. novicida genotypes, significantly fewer genotypes co-colonized ticks compared to mice. In both ticks and mice, increased genotypic diversity negatively affected the recovery of available genotypes. Competition among genotypes contributed to the reduction of diversity during infection of the tick midgut, as genotypes not recovered from tick midguts during mixed genotype infections were recovered from tick midguts during individual genotype infection. Mediated by stochastic and selective forces, pathogen genotype diversity was markedly reduced in the tick. We incorporated our experimental results into a model to demonstrate how vector population dynamics, especially vector-to-host ratio, strongly affected pathogen genotypic diversity in a population over time. Understanding pathogen genotypic population dynamics will aid in identification of the variables that most strongly affect pathogen transmission and disease ecology.
Norte, A C; Lobato, D N C; Braga, E M; Antonini, Y; Lacorte, G; Gonçalves, M; Lopes de Carvalho, I; Gern, L; Núncio, M S; Ramos, J A
Ticks consume resources from their hosts shaping their life-history traits and are vectors of many zoonotic pathogens. Several studies have focused on the health effects of blood-sucking ectoparasites on avian hosts, but there is limited information on the effects of ticks on adult and sub-adult birds, which may actively avoid ticks and are likely to present low infestation intensities. We evaluated the effects of the presence of feeding ticks and intensity of infestation on health variables of avian hosts. We also evaluated whether these variables were affected by tick infection by Borrelia burgdorferi sensu lato (s.l.) and by the presence of Borrelia infection on the birds' skin. Presence of parasite association among ticks, haemosporidea and Borrelia within the bird-host was also tested. We found that infestation by ticks significantly increased heterophyl/lymphocyte ratio in Turdus merula suggesting increased stress. This was especially evident at high infestation intensities when a significant decrease in body mass and body condition (body mass corrected for size) was also observed. Erithacus rubecula infested with more than 10 larvae tended to have lower haematocrit and blood haemoglobin. Plasma globulin concentration in T. merula tended to be affected by the presence of attached ticks and their infection with Borrelia, but this depended on the age of the bird. No association was detected among ticks, haemosporidea and Borrelia infection. We showed that ticks have detrimental effects on their avian hosts even under natural infestation conditions and that confirmed Borrelia reservoir hosts may also present symptoms of infection, though these may be subtle.
Pavela, Roman; Canale, Angelo; Mehlhorn, Heinz; Benelli, Giovanni
Ticks transmit at least the same number or even more pathogens than any other group of blood-feeding arthropods worldwide affecting humans and animals. The eco-friendly control and management of tick vectors in a constantly changing environment is a crucial challenge. Besides the development of vaccines against ticks, IPM practices aimed at reducing tick interactions with livestock, emerging pheromone-based control tools, and few biological control agents, the extensive employment of acaricides and tick repellents still remain the most effective and ready-to-use strategies. However, the former is limited by the development of growing resistances as well as environmental concerns. Exploiting plants and plant products as sources of effective tick repellents and acaricides represents a promising strategy. In this scenario, the preservation of ethnobotanical information on repellent and acaricidal potential of plants is crucial. Here, we evaluated relevant information published in recent years, focused on plants used as repellents and acaricides against tick vectors in different regions worldwide. We selected a total of 238 plant species, which are traditionally used against ticks by native and local communities of Africa (Kenya, Uganda, Zimbabwe, South Africa), Europe (Serbia, Macedonia, Romania), Asia (Pakistan, India) and America (Brazil, Canada), from 56 families. However, only 7 families (i.e. Asteraceae, Euphorbiaceae, Fabaceae, Lamiaceae, Meliaceae, Apocynaceae and Solanaceae) represent the major quote (46%) of all plant species. We evaluated the differences in acaricidal and repellent efficacy of different formulations used. In the final section, implications arising from the surveyed anti-tick ethnobotanical knowledge and challenges for its future are discussed.
Ticks are of medical and veterinary importance due to their ability to transmit pathogens to humans and animals. The Rocky Mountain wood tick, Dermacentor andersoni, is a vector of a number of pathogens, including Anaplasma marginale, which is the most widespread tick-borne pathogen of livestock. Al...
Vargas-Sandoval, Margarita; Torres, Javier
Tick-borne rickettsial diseases (TBRD) are commonly encountered in medical and veterinary clinical settings. The control of these diseases is difficult, requiring disruption of a complex transmission chain involving a vertebrate host and ticks. The geographical distribution of the diseases is related to distribution of the vector, which is an indicator of risk for the population. A total of 1,107 ticks were collected by tick dragging from forests, ecotourism parks and hosts at 101 sites in 22 of the 32 states of Mexico. Collected ticks were placed in 1.5 mL cryovials containing 70% ethanol and were identified to species. Ticks were pooled according to location/host of collection, date of collection, sex, and stage of development. A total of 51 ticks were assayed by polymerase chain reaction (PCR) to confirm species identification using morphological methods. A total of 477 pools of ticks were assayed using PCR techniques for selected tick-borne pathogens. Anaplasma phagocytophilum was the most commonly detected pathogen (45 pools), followed by, Ehrlichia (E.) canis (42), Rickettsia (R.) rickettsii (11), E. chaffeensis (8), and R. amblyommii (1). Rhipicephalus sanguineus was the tick most frequently positive for selected pathogens. Overall, our results indicate that potential tick vectors positive for rickettsial pathogens are distributed throughout the area surveyed in Mexico. PMID:26726019
Full Text Available Abstract Background Ticks are vectors of pathogens that affect human and animal health worldwide. Proteomics and genomics studies of infected ticks are required to understand tick-pathogen interactions and identify potential vaccine antigens to control pathogen transmission. One of the limitations for proteomics research in ticks is the amount of protein that can be obtained from these organisms. In the work reported here, individual naturally-infected and uninfected Rhipicephalus spp. ticks were processed using a method that permits simultaneous extraction of DNA, RNA and proteins. This approach allowed using DNA to determine pathogen infection, protein for proteomics studies and RNA to characterize mRNA levels for some of the differentially expressed proteins. Differential protein expression in response to natural infection with different pathogens was characterized by two-dimensional (2-D differential in gel electrophoresis (DIGE saturation labeling in combination with mass spectrometry analysis. To our knowledge, this is the first report of the application of DIGE saturation labeling to study tick proteins. Results Questing and feeding Rhipicephalus spp. adult ticks were collected in 27 farms located in different Sicilian regions. From 300 collected ticks, only 16 were found to be infected: R. sanguineus with Rickettsia conorii and Ehrlichia canis; R. bursa with Theileria annulata; and R. turanicus with Anaplasma ovis. The proteomic analysis conducted from a limited amount of proteins allowed the identification of host, pathogen and tick proteins differentially expressed as a consequence of infection. Conclusion These results showed that DIGE saturation labeling is a powerful technology for proteomics studies in small number of ticks and provided new information about the effect of pathogen infection in ticks.
Documento que contiene la explicación sobre las temáticas de Sistemas coordenados, Cantidades vectoriales y escalares, Algunas propiedades de los vectores, Componentes de un vector y vectores unitarios
Ticks cause more vector-borne diseases than any other blood-feeding arthropod in Europe; and their abundance is increasing. Influential US studies show that small mammals are key hosts regulating ticks and tick-borne pathogens (TBP), serving as blood meal hosts and TBP reservoirs. The relevance of these studies to Europe is, however, unknown. Therefore, my aim was the determination of the relative influence of small mammal hosts and environmental factors on the dynamics of ticks and TBPs in BW.
Full Text Available In speech synthesis accurate modeling of prosody is important for producing high quality synthetic speech. One of the main aspects of prosody is phone duration. Robust phone duration modeling is a prerequisite for synthesizing emotional speech with natural sounding. In this work ten phone duration models are evaluated. These models belong to well known and widely used categories of algorithms, such as the decision trees, linear regression, lazy-learning algorithms and meta-learning algorithms. Furthermore, we investigate the effectiveness of Support Vector Regression (SVR in phone duration modeling in the context of emotional speech. The evaluation of the eleven models is performed on a Modern Greek emotional speech database which consists of four categories of emotional speech (anger, fear, joy, sadness plus neutral speech. The experimental results demonstrated that the SVR-based modeling outperforms the other ten models across all the four emotion categories. Specifically, the SVR model achieved an average relative reduction of 8% in terms of root mean square error (RMSE throughout all emotional categories.
Sánchez-Vizcaíno, J M; Mur, L; Bastos, A D S; Penrith, M L
African swine fever (ASF), one of the most important diseases of swine, is present in many African countries, as well as in eastern Europe, Russia and Sardinia. It is caused by a complex virus, ASF virus (ASFV), for which neither vaccine nor treatment is available. ASFV affects swine of all breeds and ages, and also replicates in soft ticks of the genus Ornithodoros, facilitating ASFV persistence and reocurrence of disease. Depending on the involvement of these ticks, and the presence or not of sylvatic asymptomatic animals, several epidemiological cycles have been identified. The disease persists in East and southern African countries in a sylvatic cycle between O. porcinus (of the O. moubata species complex) and common warthogs. In some countries a domestic pig-tick cycle exists, whereas in other regions, notably West Africa, the role of soft ticks has not been demonstrated, and ASFV is transmitted between domestic pigs in the absence of tick vectors. Even in several East and Central African countries which have the sylvatic or domestic cycle, the majority of outbreaks are not associated with ticks or wild suids. In Europe, O. erraticus was detected and identified as a crucial vector for ASF maintenance in outdoor pig production on the Iberian Peninsula. However, in most parts of Europe, there is a lack of information about the distribution and role of Ornithodoros ticks in ASF persistence, particularly in eastern regions. This article reviews ASF epidemiology and its main characteristics, with a special focus on the distribution and role of soft ticks in ASF persistence in different settings. Information abouttick detection, control measures and future directions for research is also included.
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.
Sosa-Gutierrez, Carolina G; Vargas-Sandoval, Margarita; Torres, Javier; Gordillo-Pérez, Guadalupe
Tick-borne rickettsial diseases (TBRD) are commonly encountered in medical and veterinary clinical settings. The control of these diseases is difficult, requiring disruption of a complex transmission chain involving a vertebrate host and ticks. The geographical distribution of the diseases is related to distribution of the vector, which is an indicator of risk for the population. A total of 1107 were collected by tick drag from forests, ecotourism parks and hosts at 101 sites in 22 of the 32 states of Mexico. Collected ticks were placed in 1.5 mL cryovials containing 70% ethanol and were identified to species. Ticks were pooled according to location/host of collection, date of collection, sex, and stage of development. A total of 51 ticks were assayed by polymerase chain reaction (PCR) to confirm species identification using morphological methods. A total of 477 pools of ticks were assayed using PCR techniques for selected tick-borne pathogens. Anaplasma phagocytophilum was the most commonly detected pathogen (45 pools), followed by, Ehrlichia (E.) canis (42), Rickettsia (R.) rickettsii (11), E. chaffeensis (8), and R. amblyommii (1). Rhipicephalus sanguineus was the tick most frequently positive for selected pathogens. Overall, our results indicate that potential tick vectors positive for rickettsial pathogens are distributed throughout the area surveyed in Mexico.
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.
Yun, Seok-Min; Lee, Wook-Gyo; Ryou, Jungsang; Yang, Sung-Chan; Park, Sun-Whan; Roh, Jong Yeol; Lee, Ye-Ji; Park, Chan; Han, Myung Guk
We investigated the infection rate for severe fever with thrombocytopenia syndrome virus (SFTSV) among ticks collected from humans during May-October 2013 in South Korea. Haemaphysalis longicornis ticks have been considered the SFTSV vector. However, we detected the virus in H. longicornis, Amblyomma testudinarium, and Ixodes nipponensis ticks, indicating additional potential SFTSV vectors.
Schnettler, E.; Tykalova, H.; Watson, M.; Sharma, M.; Sterken, M.G.; Obbard, D.J.; Lewis, S.H.; McFarlane, M.; Bell-Sakyi, L.; Barry, G.; Weisheit, S.; Best, S.M.; Kuhn, R.J.; Pijlman, G.P.; Chase-Topping, M.E.; Gould, E.A.; Grubhoffer, L.; Fazakerley, J.K.; Kohl, A.
Arboviruses are transmitted by distantly related arthropod vectors such as mosquitoes (class Insecta) and ticks (class Arachnida). RNA interference (RNAi) is the major antiviral mechanism in arthropods against arboviruses. Unlike in mosquitoes, tick antiviral RNAi is not understood, although this in
Full Text Available BACKGROUND: The majority of vector-borne infections occur in the tropics, including Africa, but molecular eco-epidemiological studies are seldom reported from these regions. In particular, most previously published data on ticks in Ethiopia focus on species distribution, and only a few molecular studies on the occurrence of tick-borne pathogens or on ecological factors influencing these. The present study was undertaken to evaluate, if ticks collected from cattle in different Ethiopian biotopes harbour (had access to different pathogens. METHODS: In South-Western Ethiopia 1032 hard ticks were removed from cattle grazing in three kinds of tick biotopes. DNA was individually extracted from one specimen of both sexes of each tick species per cattle. These samples were molecularly analysed for the presence of tick-borne pathogens. RESULTS: Amblyomma variegatum was significantly more abundant on mid highland, than on moist highland. Rhipicephalus decoloratus was absent from savannah lowland, where virtually only A. cohaerens was found. In the ticks Coxiella burnetii had the highest prevalence on savannah lowland. PCR positivity to Theileria spp. did not appear to depend on the biotope, but some genotypes were unique to certain tick species. Significantly more A. variegatum specimens were rickettsia-positive, than those of other tick species. The presence of rickettsiae (R. africae appeared to be associated with mid highland in case of A. variegatum and A. cohaerens. The low level of haemoplasma positivity seemed to be equally distributed among the tick species, but was restricted to one biotope type. CONCLUSIONS: The tick biotope, in which cattle are grazed, will influence not only the tick burden of these hosts, but also the spectrum of pathogens in their ticks. Thus, the presence of pathogens with alternative (non-tick-borne transmission routes, with transstadial or with transovarial transmission by ticks appeared to be associated with the biotope
Several soft tick species in the genus Ornithodoros are vectors of African swine fever virus (ASFV) in nature, or known to be susceptible to infection. African swine fever (ASF) caused by ASFV is considered one of the most serious transboundary swine diseases because of its high lethality for pigs, ...
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.
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
Boeriis, Morten; van Leeuwen, Theo
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...... on the most salient vectors, and this works well, but many images contain a plethora of vectors, which makes their structure quite different from the linguistic transitivity structures with which Kress and van Leeuwen have compared ‘narrative’ images. It can also be asked whether facial expression vectors...... 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...
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.
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
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.
We identified the first pyrokinin receptor (Rhimi-PK-R) from the Chelicerata and analyzed structure-activity relationships of cognate ligand neuropeptides and their analogs. This receptor, which we cloned from larvae of the tick Rhipicephalus microplus (Acari: Ixodidae), is the ortholog of the inse...
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.
Vilibić-Čavlek, Tatjana; Barbić, Ljubo; Pandak, Nenad; Pem-Novosel, Iva; Stevanović, Vladimir; Kaić, Bernard; Mlinarić-Galinović, Gordana
Tick-borne encephalitis virus (TBEV) is a small, enveloped virus that belongs to the family Flaviviridae, genus Flavivirus, tick-borne encephalitis serocomplex. There are three subtypes of TBEV: European, Far-Eastern and Siberian subtypes, which differ in geographical distribution, tick vector and clinical manifestation of disease in humans. TBEV is endemic in a wide geographic area ranging from Central Europe and the Scandinavian Peninsula to Japan. The virus is maintained in nature in so-called natural foci in cycles involving ticks and wild vertebrate hosts (mainly small rodents). The principal vector for the European subtype is Ixodes (I.) ricinus tick, whereas for Far-Eastern and Siberian subtypes it is I. persulcatus. In the Baltic States and Finland, co-circulation of two or all three subtypes was documented. Several animals, principally small rodents, serve as virus reservoirs. In the tick population, TBEV is transmitted by feeding/co-feed ing on the same host, transovarially (from infected females to their eggs) and trans-stadially (from one development stage to the next). An infected tick remains infected for life. While most TBE infections in humans occur following a tick bite, alimentary routes of TBEV transmission (consumption of unpasteurized milk/milk products from infected livestock) have also been described. All three tick stages can transmit the infection to humans. In the last decade, an increase of TBE incidence has been observed in some endemic areas. This could be due to a number of interacting factors such as changes in the climatic conditions affecting tick habitats, improvements in the quality of epidemiological surveillance systems and diagnostics, in landscape resources and their utilization and more outdoor recreation activity. In addition, the endemic area of TBEV has expanded to higher altitudes (up to 1500 m), apparently influenced by climatic changes. The typical clinical picture of infection with European subtype TBEV is
Vander Velde, N.
Full Text Available Ticks have long been known to be the vectors of diseases, to both humans and animals. Yet very little work has been done regarding tick species found in Micronesia, and much of that is now decades old. Many parts of Micronesia have long undergone considerable change by outside influences and hence the natural and social environments have undergone major upheavals. Ticks as vectors of veterinary disease have long been documented in Micronesia, but ticks connected with human disease are often presumed not to exist. Hence another look would seem justified. This paper provides an initial review of information on tick species reported from Micronesia. Some diseases that such ticks transmit are presented, along with some hypothetical consideration of other diseases potentially associated with ticks of Micronesia. As this information on the ecology of ticks in Micronesia and the environments and circumstances allowing for the possibility of transmission of disease to humans come together, there emerges an intriguing picture of an often-overlooked part of the environment in which humans live in Micronesia.
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.
Background: Rhipicephalus appendiculatus is the primary vector of Theileria parva, the etiologic agent of East Coast fever (ECF), a devastating disease of cattle in sub-Saharan Africa. We hypothesized that a vaccine targeting tick proteins that are involved in attachment and feeding might affect fee...
African Swine Fever (ASF) is an emerging arboviral disease that affects pigs. The causative agent is the double-stranded DNA African Swine Fever Virus (ASFV). Several soft tick species in the genus Ornithodoros are known arthropod vectors of ASFV. Infection with ASFV can result in a hemorrhagic synd...
Araya-Anchetta, Ana; Busch, Joseph D; Scoles, Glen A; Wagner, David M
Population genetic studies provide insights into the basic biology of arthropod disease vectors by estimating dispersal patterns and their potential to spread pathogens. In wingless vectors, such as ticks, gene flow will be defined in large part by the mobility of their hosts. However, tick behaviors and life cycle strategies can limit their dispersal even on highly mobile hosts and lead to an increase in genetic structure. In this review we synthesize the published literature from three decades of tick population genetic studies. Based on studies from 22 tick species (including representatives from Amblyomma, Bothriocroton, Dermacentor, Ixodes, Ornithodoros, and Rhipicephalus), observed levels of population genetic structure in ticks varied from no structure to very high levels. In about half of the species (including representatives from Amblyomma, Bothriocroton, Dermacentor, and Ornithodoros), tick genetic structure appeared to be determined primarily by the movement capacity of hosts, with low gene flow observed in ticks that use smaller bodied less mobile hosts and high gene flow in ticks using highly mobile hosts. In a number of other species (primarily from Ixodes, Ornithodoros, and Rhipicephalus), behavioral limitations to gene flow appeared to result in greater genetic structure than expected based upon host movement capability alone. We also discuss the strengths and limitations of genetic markers and their applicability to ticks and suggest possible analyses when planning population genetic studies for ticks.
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.
... Texas, the Virgin Islands of the United States and vectors of said disease in the Northern Mariana... States and vectors of said disease in the Northern Mariana Islands, the Commonwealth of Puerto Rico and... are vectors of said disease exist in the Northern Mariana Islands, the Commonwealth of Puerto...
Sanders, David M; Parker, Jill E; Walker, Wes W; Buchholz, Matt W; Blount, Keith; Kiel, Johnathan L
We are reporting the first known isolation of the Q-fever agent Coxiella burnetii from field-collected cayenne ticks Amblyomma cajennense in North America. Q-fever affects a number of domestic ungulates where it can lead to abortion in sheep and goats. There is far less known about the disease's effects on wild species, primarily because of the tendency of the disease to self resolve and to provide long-term immunity to subsequent infections. The first recovery of C. burnetii in North America was from the tick species Dermacentor andersoni. Since the original isolation C. burnetii has been recovered from five other North American tick species. The currently accepted mode for the majority of human infections is inhalation. The Centers for Disease Control and Prevention, Division of Viral and Rickettsial Diseases, Rickettsial Zoonoses Branch asserts the Q-fever agent as requiring as few as one organism to cause disease via inhalation in susceptible humans. However, with more and more isolations from ticks, evidence linking C. burnetii and ticks is mounting. The true role of tick species as competent vectors is still unconfirmed. Preemptive field collections of possible vector arthropods, hosts, and reservoirs can provide invaluable baseline environmental data that will prove supportive in follow-up studies and abatement efforts.
图尔荪•萨迪尔; 李佳; 王振宝; 宋瑞其; 巴音查汗
In order to understand the infection situation of equine piroplasma and spread of vector tick spe-cies in Zhaosu county of Xinjiang,the blood smear routine inspection method,molecular biology technology and serological detection method were used to detect 200 horses and 320 vector ticks.The results showed that the infective rate of erythrocytes is 9.23%.Babesia caballi detection rates by PCR and cELISA are re-spectively 28% and 23.5%.Theileria detection rates are respectively 36% and 34%.The 320 ticks collected from horses and surrounding environment were identified as D .nuttalli and D .silvarum .This study provid-ed scientific basis for the prevention of the equine piroplasmosis in the area.%为了解新疆昭苏县马感染梨形虫情况及传播媒介蜱的种类,采用寄生虫病病原常规检查方法、分子生物学技术和血清学检测方法对200匹马进行马梨形虫的检测,对320只传播媒介蜱进行形态学鉴定.结果显示,血液涂片染色镜检红细胞染虫率为9．23％,PCR、cELISA 对驽巴贝斯虫的检出率分别为28％和23．5％,对泰勒虫的检出率分别为36％和34％；对马体表和周边环境采集的320只蜱虫鉴定为草原革蜱和森林革蜱2种.本研究为该地区马梨形虫病的防控提供了科学依据.
Kmieciak, Wioletta; Ciszewski, Marcin; Szewczyk, Eligia M
The article presents an overview of diagnostics of tick-borne diseases in Poland, which form one of the most prevalent group of occupational illnesses in the Polish area. This is a current issue due to a constantly growing number of tick-borne infections, i.e., Lyme borreliosis, tick-borne encephalitis, tularemia, Q fever, human granulocytic anaplasmosis and babesiosis. The scale of the problem is well illustrated by the latest reports of the Polish National Institute of Public Health - National Institute of Hygiene (NIPH - NIH). The article also covers the taxonomy of vectors of etiological factors, as well as their reservoirs and possible transmission to humans. The highest risk of tick-borne infection is particularly connected with people either resting or working in the forest or meadow surroundings (i.e., foresters, farmers, hunters). The article contains up-to-date data on epidemiology, etiopathogenesis, symptomatology, laboratory medicine and factors affecting the credibility of results according to current recommendations of the Polish Society of Epidemiology and Physicians of Infectious Diseases and the Polish National Chamber of Laboratory Diagnosticians. The presented review focuses on modern laboratory techniques used in difficult diagnostics of tick-borne diseases, mainly diagnostics algorithms, pre-analytical phase (type of biological material) and analytical phase of diagnostics (reference methods, efficacy of different techniques, interfering factors, proper diagnostic procedures).
Carin I. Boshoff
Full Text Available African swine fever (ASF is an economically significant haemorrhagic disease of domestic pigs. It is caused by the African swine fever virus (ASFV, a deoxyribonucleic acid (DNAarbovirus. Argasid ticks of the genus Ornithodoros, which are widely distributed throughout southern Africa, play a primary role in virus maintenance and spread within the endemic sylvatic cycle. The ASF status of Swaziland is unknown, but this land-locked country is surrounded by ASF-positive countries, has a burgeoning pig industry and sylvatic cycle hosts present within its borders. In this first assessment of ASF status, warthog burrows in seven nature reserves and game management areas in Swaziland were investigated for tick and virus presence. Tick infestation rates of between 33.3% – 88.8% were recovered for the four Ornithodoros-infested reserves. A total of 562 ticks were screened for virus genome presence using a duplex Polymerase Chain Reaction (PCR that targets the C-terminal end of the p72 gene of the ASFV and confirms DNA integrity through amplification of the 16S rRNA tick host gene. All samples were negative for virus genome presence and positive for the tick genome target. Nucleotide sequencing of the latter confirmed that Ornithodoros ticks from Swaziland are identical to those from the Kruger National Park in South Africa across the gene region characterised. Whilst this first evaluation of ASF presence in Swaziland indicates that the virus does not appear to be present in the key virus vector, the presence of sylvatic cycle hosts, together with the country’s proximity to ASF-affected countries calls for expanded investigations and regular monitoring of the ASF status of Swaziland.
Boshoff, Carin I; Bastos, Armanda D S; Dube, Mzwandi M; Heath, Livio
African swine fever (ASF) is an economically significant haemorrhagic disease of domestic pigs. It is caused by the African swine fever virus (ASFV), a deoxyribonucleic acid (DNA)arbovirus. Argasid ticks of the genus Ornithodoros, which are widely distributed throughout southern Africa, play a primary role in virus maintenance and spread within the endemic sylvatic cycle. The ASF status of Swaziland is unknown, but this land-locked country is surrounded by ASF-positive countries, has a burgeoning pig industry and sylvatic cycle hosts present within its borders. In this first assessment of ASF status, warthog burrows in seven nature reserves and game management areas in Swaziland were investigated for tick and virus presence. Tick infestation rates of between 33.3% - 88.8% were recovered for the four Ornithodoros-infested reserves. A total of 562 ticks were screened for virus genome presence using a duplex Polymerase Chain Reaction (PCR) that targets the C-terminal end of the p72 gene of the ASFV and confirms DNA integrity through amplification of the 16S rRNA tick host gene. All samples were negative for virus genome presence and positive for the tick genome target. Nucleotide sequencing of the latter confirmed that Ornithodoros ticks from Swaziland are identical to those from the Kruger National Park in South Africa across the gene region characterised. Whilst this first evaluation of ASF presence in Swaziland indicates that the virus does not appear to be present in the key virus vector, the presence of sylvatic cycle hosts, together with the country's proximity to ASF-affected countries calls for expanded investigations and regular monitoring of the ASF status of Swaziland.
Oscar Betancur H
Full Text Available The pathogens transmitted by ticks to human beings are a motive of public health concern around the world, such is the case of Lyme disease in the northern hemisphere, Encephalitis virus in Europe, the recurrent fevers and the Rocky Mountains spotted fever, better known in Colombia as “Tobia Fever”. People of all economic and social conditions are prone to develop a zoonotic agent transmitted by these vectors, which could be infected by several pathogens through co-infection mechanisms. The epidemiology and prevalence of these diseases are affected by ecological, climatic and anthropogenic factors. All these factors, affect in a different manner the enzootic cycle between pathogens, ticks and wild hosts. Current molecular diagnostic tools have allowed to progress in pathogen identification, previously unknown or undetermined. The government intervention capacity of each country, and the multidisciplinary professional cooperation, especially from physicians and veterinarians, is fundamental in order to strategically implement control and prevention plans that can deal with this problematic. The present article aims to make a thorough review of the factors which are favoring the transmission of zoonotic agents by ticks, contextualizing the most important aspects that determine their prevalence, and the most relevant control and prevention measures.
Full Text Available African swine fever is a haemorrhagic disease in pig production that can have disastrous financial consequences for farming. No vaccines are currently available and animal slaughtering or area zoning to restrict risk-related movements are the only effective measures to prevent the spread of the disease. Ornithodoros soft ticks are known to transmit the African swine fever virus (ASFV to pigs in farms, following the natural epidemiologic cycle of the virus. Tick saliva has been shown to modulate the host physiological and immunological responses during feeding on skin, thus affecting viral infection. To better understand the interaction between soft tick, ASFV and pig at the bite location and the possible influence of tick saliva on pig infection by ASFV, salivary gland extract (SGE of Ornithodoros porcinus, co-inoculated or not with ASFV, was used for intradermal auricular inoculation. Our results showed that, after the virus triggered the disease, pigs inoculated with virus and SGE presented greater hyperthermia than pigs inoculated with virus alone. The density of Langerhans cells was modulated at the tick bite or inoculation site, either through recruitment by ASFV or inhibition by SGE. Additionally, SGE and virus induced macrophage recruitment each. This effect was enhanced when they were co-inoculated. Finally, the co-inoculation of SGE and virus delayed the early local spread of virus to the first lymph node on the inoculation side. This study has shown that the effect of SGE was powerful enough to be quantified in pig both on the systemic and local immune response. We believe this model should be developed with infected tick and could improve knowledge of both tick vector competence and tick saliva immunomodulation.
Bernard, Jennifer; Hutet, Evelyne; Paboeuf, Frédéric; Randriamparany, Tantely; Holzmuller, Philippe; Lancelot, Renaud; Rodrigues, Valérie; Vial, Laurence; Le Potier, Marie-Frédérique
African swine fever is a haemorrhagic disease in pig production that can have disastrous financial consequences for farming. No vaccines are currently available and animal slaughtering or area zoning to restrict risk-related movements are the only effective measures to prevent the spread of the disease. Ornithodoros soft ticks are known to transmit the African swine fever virus (ASFV) to pigs in farms, following the natural epidemiologic cycle of the virus. Tick saliva has been shown to modulate the host physiological and immunological responses during feeding on skin, thus affecting viral infection. To better understand the interaction between soft tick, ASFV and pig at the bite location and the possible influence of tick saliva on pig infection by ASFV, salivary gland extract (SGE) of Ornithodoros porcinus, co-inoculated or not with ASFV, was used for intradermal auricular inoculation. Our results showed that, after the virus triggered the disease, pigs inoculated with virus and SGE presented greater hyperthermia than pigs inoculated with virus alone. The density of Langerhans cells was modulated at the tick bite or inoculation site, either through recruitment by ASFV or inhibition by SGE. Additionally, SGE and virus induced macrophage recruitment each. This effect was enhanced when they were co-inoculated. Finally, the co-inoculation of SGE and virus delayed the early local spread of virus to the first lymph node on the inoculation side. This study has shown that the effect of SGE was powerful enough to be quantified in pig both on the systemic and local immune response. We believe this model should be developed with infected tick and could improve knowledge of both tick vector competence and tick saliva immunomodulation.
Bernard, Jennifer; Hutet, Evelyne; Paboeuf, Frédéric; Randriamparany, Tantely; Holzmuller, Philippe; Lancelot, Renaud; Rodrigues, Valérie; Vial, Laurence; Le Potier, Marie-Frédérique
African swine fever is a haemorrhagic disease in pig production that can have disastrous financial consequences for farming. No vaccines are currently available and animal slaughtering or area zoning to restrict risk-related movements are the only effective measures to prevent the spread of the disease. Ornithodoros soft ticks are known to transmit the African swine fever virus (ASFV) to pigs in farms, following the natural epidemiologic cycle of the virus. Tick saliva has been shown to modulate the host physiological and immunological responses during feeding on skin, thus affecting viral infection. To better understand the interaction between soft tick, ASFV and pig at the bite location and the possible influence of tick saliva on pig infection by ASFV, salivary gland extract (SGE) of Ornithodoros porcinus, co-inoculated or not with ASFV, was used for intradermal auricular inoculation. Our results showed that, after the virus triggered the disease, pigs inoculated with virus and SGE presented greater hyperthermia than pigs inoculated with virus alone. The density of Langerhans cells was modulated at the tick bite or inoculation site, either through recruitment by ASFV or inhibition by SGE. Additionally, SGE and virus induced macrophage recruitment each. This effect was enhanced when they were co-inoculated. Finally, the co-inoculation of SGE and virus delayed the early local spread of virus to the first lymph node on the inoculation side. This study has shown that the effect of SGE was powerful enough to be quantified in pig both on the systemic and local immune response. We believe this model should be developed with infected tick and could improve knowledge of both tick vector competence and tick saliva immunomodulation. PMID:26828597
Yoder, Jay A; Benoit, Joshua B; Rellinger, Eric J; Telford, Sam R
The capacity of ticks to transmit a fungus was examined by analyzing tick saliva, host tissue from feeding sites, and host blood for presence of Scopulariopsis brevicaulis (Sacc.) Bainier, an internal mycosymbiont of the American dog tick, Dermacentor variabilis (Say), and lone star tick, Amnblyomma americanum (L.). Although >85% of ticks were infected with S. brevicaulis, conidia presence was low (0-5% of samples) in microscopic observations and mycological culturing of saliva expressed from larvae, nymphs, and adults. Additionally, the recovery of S. brevicaulis from blood and tissue feeding sites from a rabbit where S. brevicaulis-positive adult ticks had attached and fed was not increased compared with control tissue where no feeding occurred, indicating that transmission does not occur by the blood-feeding route. Tick mouthparts were found to contain S. brevicaulis in addition to Penicillium glabrum (Wehmer) Westling, but these agents were sparse in isolations from the feeding sites, which makes it unlikely that ticks act frequently as a mechanical fungal vector.
Full Text Available The impairment of immune functions in the elderly (immunosenescence results in post-vaccination antibody titers that are significantly lower than in young individuals. It is, however, a controversial question whether also the quality of antibodies declines with age. In this study, we have therefore investigated the age-dependence of functional characteristics of antibody responses induced by vaccination with an inactivated flavivirus vaccine against tick-borne encephalitis (TBE. For this purpose, we quantified TBE virus-specific IgG and neutralizing antibody titers in post-vaccination sera from groups of young and elderly healthy adults and determined antibody avidities and NT/ELISA titer ratios (functional activity. In contrast to the quantitative impairment of antibody production in the elderly, we found no age-related differences in the avidity and functional activity of antibodies induced by vaccination, which also appeared to be independent of the age at primary immunization. There was no correlation between antibody avidity and NT/ELISA ratios suggesting that additional factors affect the quality of polyclonal responses, independent of age. Our work indicates that healthy elderly people are able to produce antibodies in response to vaccination with similar avidity and functional activity as young individuals, albeit at lower titers.
Full Text Available Tick paralysis (TP occurs worldwide and is caused by a neurotoxin secreted by engorged female ticks that affects the peripheral and central nervous system. The clinical manifestations range from mild or nonspecific symptoms to manifestations similar to Guillain-Barré syndrome, bulbar involvement, and death in 10% of the patients. The diagnosis of TP is clinical. To our knowledge, there are no formal reports of TP in humans in South America, although clusters of TP among hunting dogs in Argentina have been identified recently. In this paper, clinical features of two cases of TP occurring during 1994 in Jujuy Province, Argentina, are described.
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.
Williams-Newkirk, Amanda J; Burroughs, Mark; Changayil, Shankar S; Dasch, Gregory A
Amblyomma americanum is an abundant tick in the southeastern, midwestern, and northeastern United States. It is a vector of multiple diseases, but limited genomic resources are available for it. We sequenced the complete mitochondrial genome of a single female A. americanum collected in Georgia using the Illumina platform. The consensus sequence was 14,709 bp long, and the mean coverage across the assembly was >12,000×. All expected tick genomic features were present, including two "Tick-Box" motifs, and in the expected order for the Metastriata. Heteroplasmy rates were low compared to the most closely related tick for which data are available, Amblyomma cajennense. The phylogeny derived from the concatenated protein coding and rRNA genes from the 33 available tick mitochondrial genomes was consistent with those previously proposed for the Acari. This is the first complete mitochondrial sequence for A. americanum, which provides a useful reference for future studies of A. americanum population genetics and tick phylogeny.
The remarkable genetic diversity of vector-borne pathogens allows for the establishment of superinfection in the mammalian host. To have a long-term impact on population strain structure, the introduced strains must also be transmitted by a vector population that has been exposed to the existing pri...
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.
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 borre
Full Text Available The Eurasian otter, Lutra lutra, hosts several parasites with zoonotic potential. As this semiaquatic mammal has large ranges across terrestrial, freshwater and marine habitats, it has the capacity for wide dispersion of pathogens. Despite this, parasites of otters have received relatively little attention. Here, we examine their ectoparasite load and assess whether this is influenced by abiotic or biotic variables. Climatic phenomena such as the North Atlantic Oscillation (NAO affect weather conditions in northern Europe. Consequently parasite distributions, particularly species with life stages exposed to the external environment, can be affected. We assessed the extent to which inter-annual variations in large-scale weather patterns (specifically the NAO and Central England (CE temperatures and host characteristics influenced tick prevalence and intensity. Ectoparasites consisted of a single species, the nidiculous tick Ixodes hexagonus (prevalence = 24.3%; mean intensity = 7.2; range = 1-122; on n = 820 otter hosts. The prevalence, but not intensity of infestation, was associated with high CE temperatures, while both prevalence and intensity were associated with positive phases of the NAO. Such associations indicate that I. hexagonus are most abundant when weather conditions are warmer and wetter. Ticks were more prevalent on juvenile than sub-adult or adult otters, which probably reflects the length of time the hosts spend in the holt where these ticks quest. High tick number was associated with poor host condition, so either poor condition hosts are more susceptible to ticks, or tick infestations negatively impact on host condition. Otters are clearly an important and common host for I. hexagonus, which has implications for vector-borne diseases. This work is the first to consider the impacts of long-term weather patterns on I. hexagonus and uses wild-animal cadavers to illustrate the importance of abiotic and biotic pressures impacting
Cholewiński, Marcin; Derda, Monika; Hadaś, Edward
Despite the considerable progress of medicine, parasitic diseases still pose a great threat to human health and life. Among parasitic diseases, those transmitted by vectors, mainly arthropods, play a particular role. These diseases occur most frequently in the poorest countries and affect a vast part of the human population. They include malaria, babesiosis, trypanosomiasis, leishmaniasis and filariasis. This study presents those vector-transmitted diseases that are responsible for the greatest incidence and mortality of people on a global scale. Attention is focused primarily on diseases transmitted by mosquitoes, flies, Hemiptera and ticks.
... of 4,000 to 10,500 feet. Transmits: Rocky Mountain spotted fever , Colorado tick fever , and tularemia . Comments: Adult ticks feed primarily on large mammals. Larvae and nymphs feed on small rodents. Adult ...
Experimental Transmission of Karshi (Mammalian Tick-Borne Flavivirus Group Virus by Ornithodoros Ticks >2,900 Days after Initial Virus Exposure Supports the Role of Soft Ticks as a Long-Term Maintenance Mechanism for Certain Flaviviruses.
Michael J Turell
Full Text Available Members of the mammalian tick-borne flavivirus group, including tick-borne encephalitis virus, are responsible for at least 10,000 clinical cases of tick-borne encephalitis each year. To attempt to explain the long-term maintenance of members of this group, we followed Ornithodoros parkeri, O. sonrai, and O. tartakovskyi for >2,900 days after they had been exposed to Karshi virus, a member of the mammalian tick-borne flavivirus group.Ticks were exposed to Karshi virus either by allowing them to feed on viremic suckling mice or by intracoelomic inoculation. The ticks were then allowed to feed individually on suckling mice after various periods of extrinsic incubation to determine their ability to transmit virus by bite and to determine how long the ticks would remain infectious. The ticks remained efficient vectors of Karshi virus, even when tested >2,900 d after their initial exposure to virus, including those ticks exposed to Karshi virus either orally or by inoculation.Ornithodoros spp. ticks were able to transmit Karshi virus for >2,900 days (nearly 8 years after a single exposure to a viremic mouse. Therefore, these ticks may serve as a long-term maintenance mechanism for Karshi virus and potentially other members of the mammalian tick-borne flavivirus group.
Someya, Azusa; Ito, Ryuki; Maeda, Akihiko; Ikenaga, Mitsuhiro
The tick is a well-known vector for arthropod-borne pathogens, such as tick-borne encephalitis, Lyme disease, Japanese spotted fever and severe fever with thrombocytopenia syndrome. It is therefore important to know the tick population and distribution in our environment and wild animals in order to prevent tick-borne diseases. Here, we report the results of tick surveillance from May to September 2011 at 14 geographical points and in 5 wild boars in Kyoto City, Kyoto prefecture, Japan. We collected 3,198 ticks comprising 5 tick species, Haemaphysalis (H.) longicornis, H. flava, H. kitaokai, Amblyomma testudinarium and Dermacentor taiwanensis. Interestingly, the proportion of tick species varied according to geographical region within the city. The ticks collected in the city were reported as potential vectors of pathogens, such as rickettsiosis. We detected rickettsial DNA by PCR in 71.1% of 201 ticks investigated. The ticks that carried rickettsiae were distributed across the whole the city. The sequences of PCR-amplified DNA fragments were determined and showed similarities to spotted fever group rickettsiae. Although their pathogenicity for animals including humans is still unclear, it is important to stay alert and pay attention to tick-borne diseases in order to ensure the safety of the citizens of the city as well as that of visitors.
Wanzala, W; Okanga, S
This artcile describes the results obtained from a tick survey conducted in Haller park along the Kenyan coastline. The survey aimed at evaluating tick-host associations, assessing tick population density, and providing baseline information for planning future tick control and management in the park. Ticks (2,968) were collected by handpicking from eight species of wildlife and by dragging in 14 selected sites within the park. A considerable proportion of ticks were also collected from leaves, stems, and bark of most dominant trees, namely, Casuarina equisetifolia L. (Forst. and Forst.), Cocos nucifera L., Adansonia digitata L., Musa paradisiaca L., and Azadiracta indica Adr. Juss. Dragging was conducted in sites predominantly occupied by Cynodon dactylon L. (Pers.), Cenchrus ciliaris L., Stenotaphrum dimidiatum L. (Kuntze.) Brongn., and Brachiaria xantholeuca Hack. Ex Schinz Stapf. and Loudetia kagerensis K. Schum. Hutch. Eight tick species were identified, and the collection included Rhipicephalus pravus Dönitz 1910, Rhipicephalus pulchellus Gerstäcker 1873, Hyalomma marginatum rufipes Koch 1844, Amblyomma gemma Dönitz 1910, Amblyomma hebraeum Koch 1844, Amblyomma sparsum Neumann 1899, Amblyomma nuttalli Dönitz 1909, and Boophilus decoloratus Koch 1844. Given that the identified tick species are known to parasitize humans as well as livestock, there exist risks of emergence of zoonotic infections mediated by tick vectors. In the recreational environment of Haller park, where tick vectors share habitats with hosts, there is a need to develop sustainable and effective tick control and management strategies to minimize economic losses that tick infestation may cause.
Antunes, S; Ferrolho, J; Domingues, N; Santos, A S; Santos-Silva, M M; Domingos, A
Ticks are ubiquitous arthropods and vectors of several pathogenic agents in animals and humans. Monitoring questing ticks is of great importance to ascertain the occurrence of pathogens and the potential vector species, offering an insight into the risk of disease transmission in a given area. In this study 428 host-seeking ticks, belonging to nine species of Ixodidae and collected from 17 of the 23 Portuguese mainland subregions, were screened for several tick-borne agents with veterinary relevance: Anaplasma marginale, Anaplasma ovis, Anaplasma centrale, Babesia spp., Coxiella burnetii and Theileria spp. Prevalence was assessed by PCR and amplified amplicons sequenced for validation of results. Twenty ticks, in a total of 428, were found positive: one Ixodes ventalloi for Theileria annulata and four Dermacentor marginatus, one Haemaphysalis punctata, five Ixodes ricinus, five I. ventalloi, and four Rhipicephalus sanguineus sensu lato for A. marginale. According to the reviewed literature, this is the first report of A. marginale and T. annulata detection in I. ventalloi. Furthermore, the amplification of A. marginale DNA in several tick species suggests a broad range for this agent in Portugal that might include other uncommon species as R. sanguineus s.l. This work provides new data towards a better understanding of tick-pathogen associations and also contributes to the surveillance of tick-borne agents in geographic areas with limited information.
Valcárcel, F; González, J; Tercero Jaime, J M; Olmeda, A S
Red deer (Cervus elaphus L.) are very valuable in trophy-hunting but also contribute to the preservation of natural areas. They are affected by many parasites and pathogens, including hard ticks that are not only important parasites themselves but can also act as vectors and/or reservoirs of pathogens. Tick phenology is complex insofar as population dynamics depend on environmental conditions, vegetation, host availability and their own intrinsic characteristic. Ticks were collected monthly from January 2007 to December 2014 from red deer on a natural reserve located in a meso-Mediterranean environment in Central Spain. A total of 8978 specimens of ixodid ticks were recovered with a mean Parasitization Index of 65.06 ticks/deer. Red deer were infected the whole year round with a summer-spring pattern and two secondary peaks in February and October. The main species was Hyalomma lusitanicum Koch followed by Rhipicephalus bursa Canestrini and Fanzago, Rhipicephalus pusillus Gil Collado, Dermacentor marginatus Sulzer and Ixodes ricinus L. Hyalomma lusitanicum has a complex life cycle in which several generations initiate their cycle at different times throughout the year, most probably lasting more than 1 year. We also describe the ability of nymphs to feed on large ungulates even though their habitual host is wild rabbit.
Kohl, Alain; Pondeville, Emilie; Schnettler, Esther; Crisanti, Andrea; Supparo, Clelia; Christophides, George K.; Kersey, Paul J.; Maslen, Gareth L.; Takken, Willem; Koenraadt, Constantianus J.M.; Oliva, Clelia F.; Busquets, Núria; Abad, F.X.; Failloux, Anna Bella; Levashina, Elena A.; Wilson, Anthony J.; Veronesi, Eva; Pichard, Maëlle; Arnaud Marsh, Sarah; Simard, Frédéric; Vernick, Kenneth D.
Vector-borne pathogens impact public health, animal production, and animal welfare. Research on arthropod vectors such as mosquitoes, ticks, sandflies, and midges which transmit pathogens to humans and economically important animals is crucial for development of new control measures that target t
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.
Medlock, Jolyon M.; Hansford, Kayleigh M.; Bormane, Antra;
, 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...
Nadolny, Robyn M; Wright, Chelsea L; Sonenshine, Daniel E; Hynes, Wayne L; Gaff, Holly D
The incidence of tick-borne rickettsial disease in the southeastern United States has been rising steadily through the past decade, and the range expansions of tick species and tick-borne infectious agents, new and old, has resulted in an unprecedented mix of vectors and pathogens. The results of an ongoing 4-year surveillance project describe the relative abundance of questing tick populations in southeastern Virginia. Since 2009, more than 66,000 questing ticks of 7 species have been collected from vegetation in a variety of habitats, with Amblyomma americanum constituting over 95% of ticks collected. Other species represented included Ixodes scapularis, Dermacentor variabilis, Amblyomma maculatum, Ixodes affinis, Haemaphysalis leporispalustris, and Ixodes brunneus. We found that 26.9-54.9% of A. americanum ticks tested were positive for Rickettsia amblyommii, a non-pathogenic symbiont of this tick species. We also found no evidence of R. rickettsii in D. variabilis ticks, although they did show low infection rates of R. montanensis (1.5-2.0%). Rickettsia parkeri and Candidatus R. andeanae were found in 41.8-55.7% and 0-1.5% A. maculatum ticks, respectively. The rate of R. parkeri in A. maculatum ticks is among the highest in the literature and has increased in the 2 years since R. parkeri and A. maculatum were first reported in southeastern Virginia. We conclude that tick populations in southeastern Virginia have recently undergone dramatic changes in species and abundance and that these populations support a variety of rickettsial agents with the potential for increased risk to human health.
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.
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.
Tick-borne diseases are transmission diseases belonging to the group of zoonoses but carried by ticks. These diseases are a major public health problem but also a problem for groups occupationally exposed to tick bites. Ixodes ricinus is a species of ticks which is the most common reservoir and the vector of a large number of microorganisms pathogenic to humans. It transfers, among others, bacteria of the species: Anaplasma phagocytophilum and Borrelia burgdorferi. The...
Sambou, Masse; Faye, Ngor; Bassène, Hubert; Diatta, Georges; Raoult, Didier; Mediannikov, Oleg
The spotted fevers, caused by the Rickettsia bacteria, are a group of emerging diseases that are responsible for significant human morbidity. In Africa, the distribution of different species of Rickettsia in their tick vectors is poorly studied. We have collected 1169 hard ticks from 5 different species in the northern Senegal, close to the Saharan border. In a far northern collection site, corresponding to the Rickettsia africae distribution area, we collected three Amblyomma variegatum ticks infected by R. africae. Rickettsia africae was also identified in a Hyalomma marginatum rufipes tick, which may represent the secondary host for the pathogen. Rickettsia aeschlimannii was identified in H. m. rufipes, Rhipicephalus evertsi evertsi, and Hyalomma impeltatum ticks.
Fournier, Pierre-Edouard; Fujita, Hiromi; Takada, Nobuhiro; Raoult, Didier
Following the description in Japan of Japanese spotted fever, caused by Rickettsia japonica, a search for the vector of this disease led to the isolation of several rickettsiae from various tick species. Sixty-three rickettsial isolates were obtained from six different tick species, and six type strains were described by PCR and monoclonal antibody testing. We identified these six strains by amplification and sequencing of the genes encoding 16S rRNA and citrate synthase. We confirmed that the isolates from Dermacentor taiwanensis and Haemaphysalis flava ticks were R. japonica isolates. In Ixodes ovatus, Ixodes persulcatus, and Ixodes monospinosus, we identified a Rickettsia identical or closely related to Rickettsia helvetica, a species that is pathogenic for humans and that to date has only been found in Europe. Finally, we identified a new genotype of unknown pathogenicity, genotype AT, that was isolated from Amblyomma testudinarium ticks and that is closely related to a Slovakian genotype obtained from Ixodes ricinus ticks.
... of ticks in the environment Prevents tickborne disease Cons: Tick bites can cause a painful wound and ... wounds and possible resulting infections Prevents tickborne disease Cons: Will not reduce the number of ticks in ...
Full Text Available Assessment of the microbial diversity residing in arthropod vectors of medical importance is crucial for monitoring endemic infections, for surveillance of newly emerging zoonotic pathogens, and for unraveling the associated bacteria within its host. The tick Ixodes ricinus is recognized as the primary European vector of disease-causing bacteria in humans. Despite I. ricinus being of great public health relevance, its microbial communities remain largely unexplored to date. Here we evaluate the pathogen-load and the microbiome in single adult I. ricinus by using 454- and Illumina-based metagenomic approaches. Genomic DNA-derived sequences were taxonomically profiled using a computational approach based on the BWA algorithm, allowing for the identification of known tick-borne pathogens at the strain level and the putative tick core microbiome. Additionally, we assessed and compared the bacterial taxonomic profile in nymphal and adult I. ricinus pools collected from two distinct geographic regions in Northern Italy by means of V6-16S rRNA amplicon pyrosequencing and community based ecological analysis. A total of 108 genera belonging to representatives of all bacterial phyla were detected and a rapid qualitative assessment for pathogenic bacteria, such as Borrelia, Rickettsia and Candidatus Neoehrlichia, and for other bacteria with mutualistic relationship or undetermined function, such as Wolbachia and Rickettsiella, was possible. Interestingly, the ecological analysis revealed that the bacterial community structure differed between the examined geographic regions and tick life stages. This finding suggests that the environmental context (abiotic and biotic factors and host-selection behaviors affect their microbiome.Our data provide the most complete picture to date of the bacterial communities present within I. ricinus under natural conditions by using high-throughput sequencing technologies. This study further demonstrates a novel detection
Smith, Faith D; Wall, Lauren Ellse Richard
Ticks are important vectors of disease in companion animals and transmit an extensive range of viral, bacterial and protozoan pathogens to dogs and cats. They may also be vectors of zoonotic pathogens which affect the health of in-contact owners. In recent years, babesiosis, and anaplasmosis have all shown signs of increased prevalence and distribution in various parts of Europe. Here, the prevalence of Anaplasma spp. and Babesia spp. pathogens in Ixodes ticks, collected from dogs in the UK in 2009, were evaluated using PCR and sequence analysis of the 16S rDNA or 18S rDNA regions respectively. Species identification was performed by alignment with existing sequences in GenBank. After sequencing, 5 out of 677 tick samples (0.74%) contained rDNA which shared 97-100%% sequence homology with Anaplasma phagocytophilum. Of these, three samples came from Ixodes ricinus and two from Ixodes hexagonus. Sixteen out of 742 ticks (2.4%) were positive for Babesia and of these 11 showed 97-100% homology with B. gibsoni. All of these 11 samples were derived from I. ricinus. One sample, again from I. ricinus, showed 99% homology for B. divergens. Four of the Babesia spp sequences were of the "venatorum" or EU1 type, three of which came from I. ricinus and one from an Ixodes canisuga. This strain has been associated with severe human cases of babeisiosis. A further 246 positive results, which appeared to show the presence of Anaplasma following PCR, were shown by sequence analysis to be derived from the bacterium Candidatus "Midichloria mitochondrii", which to date has been assumed to be non-pathogenic. The results are of interest because the presence of B. gibsoni in the UK further confirms the worldwide distribution of this piroplasm and supports the inference that I. ricinus may act as a vector for Babesia of the gibsoni-complex.
João Carlos Pinto Dias
Full Text Available Following an infestation of dogticks in kennels housing dogs used for long-term studies of the pathogenesis of Chagas disease, we examined the effect of ivermectin treatment on the dogs, ticks, trypanosome parasites, and also on triatomine vectors of Chagas disease. Ivermectin treatment was highly effective in eliminating the ticks, but showed no apparent effect on the dogs nor on their trypanosome infection. Triatominae fed on the dogs soon after ivermectin treatment showed high mortality, but this effect quickly declined for bugs fed at successive intervals after treatment. In conclusion, although ivermectin treatment may have a transient effect on peridomestic populations of Triatominae, it is not the treatment of choice for this situation. The study also showed that although the dogticks could become infected with Trypanosoma cruzi, this only occurred when feeding on dogs in the acute phase of infection, and there was no evidence of subsequent parasite development in the ticks.
Taft, Sarah C; Miller, Melissa K; Wright, Stephen M
Lyme disease is the most commonly reported vector-borne disease in the United States and is transmitted by Borrelia burgdorferi-infected Ixodes species. The disease is typically characterized by an erythema migrans (EM) rash at the site of tick feeding. EM rashes have also been associated with feeding by Amblyomma americanum ticks despite evidence suggesting that they are incompetent vectors for Lyme disease. In 1996, a Borrelia organism only recently cultivated in the laboratory was described in A. americanum ticks and designated B. lonestari. This Borrelia is believed to be the etiologic agent of a novel Lyme-like disease, southern tick associated rash illness (STARI). This study examined ticks collected from eight eastern states to evaluate the epidemiology of B. lonestari, B. burgdorferi, and their tick hosts. Three hundred individual or small pool samples were evaluated from tick genera that included Amblyomma, Ixodes, and Dermacentor. DNA was extracted following tick homogenization and the polymerase chain reaction (PCR) was performed using primers derived from the flagellin gene that amplify sequences from both B. burgdorferi and B. lonestari. Species specific digoxigenin labeled probes were designed and used to differentiate between B. burgdorferi and B. lonestari. Borrelia DNA was detected in approximately 10% of the A. americanum and I. scapularis tick samples, but none was present in any of the Dermacentor samples tested. Positive samples were detected in ticks collected from Kentucky, Maryland, Massachusetts, New Jersey, New York, and Virginia. This is the first known report of B. lonestari from Massachusetts and New York and the first detection in I. scapularis. This suggests that B. lonestari and its putative association with STARI may be more widespread than previously thought.
Cagnacci, F; Bolzoni, L; Rosà, R; Carpi, G; Hauffe, H C; Valent, M; Tagliapietra, V; Kazimirova, M; Koci, J; Stanko, M; Lukan, M; Henttonen, H; Rizzoli, A
Tick borne encephalitis (TBE) is endemic to eastern and central Europe with broad temporal and spatial variation in infection risk. Although many studies have focused on understanding the environmental and socio-economic factors affecting exposure of humans to TBE, comparatively little research has been devoted to assessing the underlying ecological mechanisms of TBE occurrence in enzootic cycles, and therefore TBE hazard. The aim of this study was to evaluate the effect of the main ungulate tick hosts on the pattern of tick infestation in rodents and TBE occurrence in rodents and questing adult ticks. In this empirical study, we considered three areas where endemic human TBE occurs and three control sites having no reported human TBE cases. In these six sites located in Italy and Slovakia, we assessed deer density using the pellet group count-plot sampling technique, collected questing ticks, live-trapped rodents (primarily Apodemus flavicollis and Myodes glareolus) and counted ticks feeding on rodents. Both rodents and questing ticks were screened for TBE infection. TBE infection in ticks and rodents was positively associated with the number of co-feeding ticks on rodents and negatively correlated with deer density. We hypothesise that the negative relationship between deer density and TBE occurrence on a local scale (defined by the minimum overlapping area of host species) could be attributed to deer (incompetent hosts) diverting questing ticks from rodents (competent hosts), know as the 'dilution effect hypothesis'. We observed that, after an initial increase, the number of ticks feeding on rodents reached a peak for an intermediate value of estimated deer density and then decreased. Therefore, while at a regional scale, tick host availability has already been shown to be directly correlated with TBE distribution, our results suggest that the interactions between deer, rodents and ticks are much more complex on a local scale, supporting the possibility of a
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.
Sivakumar, Thillaiampalam; Tattiyapong, Muncharee; Okubo, Kazuhiro; Suganuma, Keisuke; Hayashida, Kyoko; Igarashi, Ikuo; Zakimi, Satoshi; Matsumoto, Kotaro; Inokuma, Hisashi; Yokoyama, Naoaki
Babesia ovata is a tick-transmitted hemoprotozoan parasite of cattle. In the present study, we analyzed tick DNA samples (n=1459) prepared from questing ticks collected from various cattle pastures in Hokkaido (Shibecha, Taiki, Otofuke, Memuro, and Shin-Hidaka districts) and Okinawa (Yonaguni Island) prefectures of Japan for B. ovata. When all the tick DNA samples were screened by a previously described B. ovata-specific apical membrane antigen-1 (AMA-1) gene-based polymerase chain reaction (PCR) assay, none of the DNA samples was positive. Therefore, we developed a PCR assay based on the protozoan beta-tubulin (β-tubulin) gene to detect B. ovata from ticks in Japan. In the specificity test, the PCR assay amplified the expected 444-bp target gene fragment from B. ovata DNA. No PCR products were amplified from DNA samples from other blood pathogens, bovine blood, or ticks. In addition, the PCR assay detected 100 fg of B. ovata-genomic DNA extracted from an in vitro culture of the parasites. Subsequently, when all the tick DNA samples were screened by this new PCR assay, 18 were positive for B. ovata. Positive samples were found only in the Yonaguni and Memuro areas. In Okinawa, where all the ticks were identified as Haemaphysalis longicornis, 9.7% of the samples were PCR-positive, while a single tick (Ixodes ovatus) from Memuro was infected with B. ovata. When the nucleotide sequences of the PCR amplicons were phylogenetically analyzed, they formed a separate clade containing a previously described β-tubulin gene sequence from B. ovata (Miyake strain), confirming that the PCR assay had detected only B. ovata from the tick DNA samples. This is the first report that describes the PCR detection of B. ovata in ticks. The findings warrant transmission experiments to evaluate I. ovatus as a potential vector of B. ovata.
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...
Full Text Available AbstractTicks represent a large group of pathogen vectors that blood feed on a diversity of hosts. In the Americas, the Ixodidae ticks Amblyomma cajennense are responsible for severe impact on livestock and public health. In the present work, we present the isolation and molecular identification of a group of culturable bacteria associated with A. cajennense eggs from females sampled in distinct geographical sites in southeastern Brazil. Additional comparative analysis of the culturable bacteria from Anocentor nitens, Rhipicephalus sanguineus and Ixodes scapularis tick eggs were also performed. 16S rRNA gene sequence analyses identified 17 different bacterial types identified as Serratia marcescens, Stenotrophomonas maltophilia, Pseudomonas fluorescens, Enterobacter spp., Micrococcus luteus, Ochrobactrum anthropi, Bacillus cereus and Staphylococcus spp., distributed in 12 phylogroups. Staphylococcus spp., especially S. sciuri,was the most prevalent bacteria associated with A. cajennenseeggs, occurring in 65% of the samples and also frequently observed infecting A. nitens eggs. S. maltophilia, S. marcescens and B. cereus occurred infecting eggs derived from specific sampling sites, but in all cases rising almost as pure cultures from infected A. cajennense eggs. The potential role of these bacterial associations is discussed and they possibly represent new targets for biological control strategies of ticks and tick borne diseases.
Ramos, Vanessa N; Osava, Carolina F; Piovezan, Ubiratan; Szabó, Matias P J
Information on ticks biting humans in Brazil is very restricted. In fact, many times when human tick-borne diseases are diagnosed, the involved vector tick is not identified, although this may be clinically helpful. Pantanal is one of the world's largest floodplains, has an exuberant wildlife, and is place of extensive cattle ranching, ecotourism, and fishing. We herein report tick species found on humans in a 13-month survey in a region with both cattle and wildlife handling in the Brazilian Pantanal. From February 2012 to February 2013, a total of 280 ticks was collected from humans (n=22), 121 of which were attached. Amblyomma cajennense sensu lato nymphs were the main tick species and stage found attached to humans (n=93) especially during the dry months (winter). In the wet season (summer), Amblyomma parvum adults were the main ticks found attached to humans (n=19) followed by A. cajennense s.l. adults (n=9). Only one unattached nymph of A. parvum was collected in this study. These results reinforce that A. cajennense s.l. nymphs are an important parasite of humans (and vectors) in Brazil and draw also attention to A. parvum adults as frequent human parasites as well.
Pérez de León, Adalberto A; Teel, Pete D; Auclair, Allan N; Messenger, Matthew T; Guerrero, Felix D; Schuster, Greta; Miller, Robert J
The ticks Rhipicephalus (Boophilus) annulatus and R. (B.) microplus, commonly known as cattle and southern cattle tick, respectively, impede the development and sustainability of livestock industries throughout tropical and other world regions. They affect animal productivity and wellbeing directly through their obligate blood-feeding habit and indirectly by serving as vectors of the infectious agents causing bovine babesiosis and anaplasmosis. The monumental scientific discovery of certain arthropod species as vectors of infectious agents is associated with the history of research on bovine babesiosis and R. annulatus. Together, R. microplus and R. annulatus are referred to as cattle fever ticks (CFT). Bovine babesiosis became a regulated foreign animal disease in the United States of America (U.S.) through efforts of the Cattle Fever Tick Eradication Program (CFTEP) established in 1906. The U.S. was declared free of CFT in 1943, with the exception of a permanent quarantine zone in south Texas along the border with Mexico. This achievement contributed greatly to the development and productivity of animal agriculture in the U.S. The permanent quarantine zone buffers CFT incursions from Mexico where both ticks and babesiosis are endemic. Until recently, the elimination of CFT outbreaks relied solely on the use of coumaphos, an organophosphate acaricide, in dipping vats or as a spray to treat livestock, or the vacation of pastures. However, ecological, societal, and economical changes are shifting the paradigm of systematically treating livestock to eradicate CFT. Keeping the U.S. CFT-free is a critical animal health issue affecting the economic stability of livestock and wildlife enterprises. Here, we describe vulnerabilities associated with global change forces challenging the CFTEP. The concept of integrated CFT eradication is discussed in reference to global change.
Adalberto A. Pérez de León
Full Text Available The ticks Rhipicephalus (Boophilus annulatus and R. (B. microplus, commonly known as cattle and southern cattle tick, respectively, impede the development and sustainability of livestock industries throughout tropical and other world regions. They affect animal productivity and wellbeing directly through their obligate blood feeding habit and indirectly by serving as vectors of the infectious agents causing bovine babesiosis and anaplasmosis. The monumental scientific discovery of certain arthropod species as vectors of infectious agents is associated with the history of research on bovine babesiosis and R. annulatus. Together, R. microplus and R. annulatus are referred to as cattle fever ticks (CFT. Bovine babesiosis became a regulated foreign animal disease in the United States of America (U.S. through efforts of the Cattle Fever Tick Eradication Program (CFTEP established in 1906. The U.S. was declared free of CFT in 1943, with the exception of a permanent quarantine zone in south Texas along the border with Mexico. This achievement contributed greatly to the development and productivity of animal agriculture in the U.S. The permanent quarantine zone buffers CFT incursions from Mexico where both ticks and babesiosis are endemic. Until recently, the elimination of CFT outbreaks relied solely on the use of coumaphos, an organophosphate acaricide, in dipping vats or as a spray to treat livestock, or the vacation of pastures. However, ecological, societal, and economical changes are shifting the paradigm of systematically treating livestock to eradicate CFT. Keeping the U.S. CFT-free is a critical animal health issue affecting the economic stability of livestock and wildlife enterprises. Here, we describe vulnerabilities associated with global change forces challenging the CFTEP. The concept of integrated CFT eradication is discussed in reference to global change.
Full Text Available Background: Mosquitoes are the primary vectors of West Nile virus (WNV. Ticks have, however, been suggested to be potential reservoirs of WNV. To investigate their role in the spread of the virus, ticks, which had been collected from birds migrating northward from Africa to Europe, were analyzed for the potential presence of WNV RNA. Methods: On the Mediterranean islands of Capri and Antikythira, a total of 14,824 birds were captured and investigated from which 747 ticks were collected. Results and conclusions: Most of the identified ticks (93% were nymphs and larvae of Hyalomma marginatum sensu lato (s.l., most of which were or appear to be Hyalomma rufipes. Of these ticks, 729 were individually screened for WNV RNA. None of the ticks was found to be WNV positive. Thus, there was no evidence that H. marginatum s.l. ticks play a role in the spread of WNV from Africa to Europe.
Croxatto, Antony; Rieille, Nadia; Kernif, Tahar; Bitam, Idir; Aeby, Sébastien; Péter, Olivier; Greub, Gilbert
The Chlamydiales order includes the Chlamydiaceae, Parachlamydiaceae, Waddliaceae, Simkaniaceae, Criblamydiaceae, Rhabdochlamydiaceae, Clavichlamydiaceae, and Piscichlamydiaceae families. Members of the Chlamydiales order are obligate intracellular bacteria that replicate within eukaryotic cells of different origins including humans, animals, and amoebae. Many of these bacteria are pathogens or emerging pathogens of both humans and animals, but their true diversity is largely underestimated, and their ecology remains to be investigated. Considering their potential threat on human health, it is important to expand our knowledge on the diversity of Chlamydiae, but also to define the host range colonized by these bacteria. Thus, using a new pan-Chlamydiales PCR, we analyzed the prevalence of Chlamydiales DNA in ticks and fleas, which are important vectors of several viral and bacterial infectious diseases. To conduct this study, 1340 Ixodes ricinus ticks prepared in 192 pools were collected in Switzerland and 55 other ticks belonging to different tick species and 97 fleas belonging to different flea species were harvested in Algeria. In Switzerland, the prevalence of Chlamydiales DNA in the 192 pools was equal to 28.1% (54/192) which represents an estimated prevalence in the 1340 individual ticks of between 4.0% and 28.4%. The pan-Chlamydiales qPCR was positive for 45% (25/55) of tick samples collected in Algeria. The sequencing of the positive qPCR amplicons revealed a high diversity of Chlamydiales species. Most of them belonged to the Rhabdochlamydiaceae and Parachlamydiaceae families. Thus, ticks may carry Chlamydiales and should thus be considered as possible vectors for Chlamydiales propagation to both humans and animals.
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.
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...
SR Nourollahi Fard
Results: Three pools, each consisting of five female of Hyalomma anatolicum anatolicum and one pool (6 ticks of Rhipicephalus sanguineus ticks collected from goats and sheep were found to be positive by Trans-PCR. Conclusion: This paper documents the first molecular detection of C. burnetii in ticks, which shows their role as putative vectors and reservoirs for this pathogenic agent.
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 D...
Amanda Jo Williams-Newkirk; 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 ...
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
Vargas-Sandoval, Margarita; Priego-Santander, Angel G.; Larrazábal, Alejandra; 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
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.
Harrus, S; Perlman-Avrahami, A; Mumcuoglu, K Y; Morick, D; Eyal, O; Baneth, G
: Ticks are vectors of important pathogens of human and animals. Therefore, their microbial carriage capacity is constantly being investigated. The aim of this study was to characterize the diversity of domestic animal pathogens in ticks collected from vegetation and the ground, from different parts of Israel. Non-engorged questing adult ticks were collected from 13 localities. A total of 1196 ticks in 131 pools-83 pools of Rhipicephalus turanicus and 48 of Rhipicephalus sanguineus (with two to ten ticks per pool)-were included in this study. In addition, 13 single free-roaming Hyalomma spp. ticks were collected. Screening by molecular techniques revealed the presence of Ehrlichia canis, Anaplasma platys, Anaplasma bovis and Babesia canis vogeli DNA in R. turanicus ticks. E. canis, A. bovis, B. canis vogeli and Candidatus Midichloria mitochondrii DNA sequences were detected in R. sanguineus ticks. Candidatus Midichloria mitochondrii DNA was also detected in Hyalomma spp. ticks. Neither Hepatozoon spp. nor Bartonella spp. DNA was detected in any of the ticks examined. This study describes the first detection of E. canis in the tick R. turanicus, which may serve as a vector of this canine pathogen; E. canis was the most common pathogen detected in the collected questing ticks. It also describes the first detection of A. bovis and Candidatus Midichloria mitochondrii in Israel. To the best of the author's knowledge, this is the first report describing the detection of DNA of the latter two pathogens in R. sanguineus, and of A. bovis in R. turanicus.
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.
Background: Rhipicephalus microplus is a highly-invasive tick that vectors cattle fever parasites (Babesia bovis and B. bigemina). In North America, ticks and Babesia are endemic in Mexico and ticks persist in the United States inside a narrow permanent quarantine zone (PQZ) along the Rio Grande. Th...
Full Text Available Abstract Background Ixodes ricinus ticks transmit Babesia species to vertebrate hosts. Using molecular tools we were able to detect the presence of this piroplasmid in its vector. The aims of this study were to investigate the prevalence and identity of Babesia species in questing ticks collected in various areas of Norway. Methods DNA from questing l. ricinus ticks were examined with a realtime PCR for the presence of Babesia. Positive samples of tick DNA were identified to species using PCR, and sequence analysis. Results From a total of 1908 questing l. ricinus ticks, 17 (0.9% indicated the presence of Babesia spp. after realtime-PCR screening. Ixodes ricinus harbouring Babesia spp. was detected in 9 out of 22 localities. Further molecular analyses of DNA from these positive ticks indicate the presence of Babesia venatorum, B. divergens, B. capreoli and a currently undescribed Babesia in Norwegian ticks. The most prevalent was B. venatorum found in 71% of the positive ticks. Conclusions A total of 17 out of 1908 (0.9% ticks were positive for Babesia. Our data confirm that there are several Babesia species in ticks in Norway. Babesia venatorum was the most prevalent. This species has a zoonotic potential and may cause human babesiosis following a tick bite.
Lewis, Lauren A; Radulović, Željko M; Kim, Tae K; Porter, Lindsay M; Mulenga, Albert
Ixodes scapularis is arguably the most medically important tick species in the United States. This tick transmits 5 of the 14 human tick-borne disease (TBD) agents in the USA: Borrelia burgdorferi, Anaplasma phagocytophilum, B. miyamotoi, Babesia microti, and Powassan virus disease. Except for the Powassan virus disease, I. scapularis-vectored TBD agents require more than 24h post attachment to be transmitted. This study describes identification of 24h immunogenic I. scapularis tick saliva proteins, which could provide opportunities to develop strategies to stop tick feeding before transmission of the majority of pathogens. A 24h fed female I. scapularis phage display cDNA expression library was biopanned using rabbit antibodies to 24h fed I. scapularis female tick saliva proteins, subjected to next generation sequencing, de novo assembly, and bioinformatic analyses. A total of 182 contigs were assembled, of which ∼19% (35/182) are novel and did not show identity to any known proteins in GenBank. The remaining ∼81% (147/182) of contigs were provisionally identified based on matches in GenBank including ∼18% (27/147) that matched protein sequences previously annotated as hypothetical and putative tick saliva proteins. Others include proteases and protease inhibitors (∼3%, 5/147), transporters and/or ligand binding proteins (∼6%, 9/147), immunogenic tick saliva housekeeping enzyme-like (17%, 25/147), ribosomal protein-like (∼31%, 46/147), and those classified as miscellaneous (∼24%, 35/147). Notable among the miscellaneous class include antimicrobial peptides (microplusin and ricinusin), myosin-like proteins that have been previously found in tick saliva, and heat shock tick saliva protein. Data in this study provides the foundation for in-depth analysis of I. scapularis feeding during the first 24h, before the majority of TBD agents can be transmitted.
Kocan, Katherine M; de la Fuente, José; Coburn, Lisa A
Ticks (Acari: Ixodida) are arthropod ectoparasites dependent on a bloodmeal from a vertebrate host at each developmental stage for completion of their life cycle. This tick feeding cycle impacts animal health by causing damage to hides, secondary infections, immune reactions and diseases caused by transmission of pathogens. The genus Ixodes includes several medically important species that vector diseases, including granulocytic anaplasmosis and Lyme disease. I. scapularis, commonly called the black-legged or deer tick, is a medically-important tick species in North America and therefore was the first tick genome to be sequenced, thus serving as an important resource for tick research. This Primer focuses on the normal developmental cycle and laboratory rearing of I. scapularis. Definition of normal morphology, along with a consistent source of laboratory-reared I. scapularis, are fundamental for all aspects of future research, especially the effects of genetic manipulation and the evaluation of tick vaccine efficacy. Recent research important for the advancement of tick research, namely the development of tick cell culture systems for study of ticks and tick-borne pathogens, RNA interference for genetic manipulation of ticks and discovery of candidate antigens for development of tick vaccines, are briefly presented along with areas to target for future research.
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
Acetylcholinesterase (AChE) is the primary target for organophosphate (OP) acaricides. OP resistant strains of the Southern cattle tick Rhipicephalus microplus have been identified and represent a major threat to the control of this important disease vector. R. microplus ticks possess at least three...
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.
Y Salim abadi
Full Text Available Background: Ticks are the main vectors for transmission of different pathogens to human and animals. This survey was performed to find out distribution of ticks, which infested the domestic ruminants in Yazd Province, central Iran during year 2008-2009.Methods: A total number of 30 villages from both mountainous (20% and plateau (80% regions of the province were selected randomly. Ticks were colleted from the body of infested animals and transported to the laboratory of Medical Entomology, School of Public Health, Tehran University of Medical Sciences and then were identified to space level using valid identification key.Results: A total of 583 hard ticks were collected. The ticks were classified into three genera and 7 species including: Hyalomma dromedarii (55.92%, Hy. marginatum (13.20%, Hy. anatolicum (9.78%, Hy. detritum (4.98%, Hy. asiaticum (3.94%, Rhipicephalus sanguineus (11.84%, and Dermacentor marginatus (0.34%. The highest seasonal activities occurred in summer. The prevalence of the Ixodidae ticks was more evident in plateaus area in Yazd Province. Among the hosts including: cow, goat, sheep and camel, the ticks that collected from camel was more prevalent. The ratio of male was more than female ticks. Hyalomma. dromedarii was the predominant tick species and accounted for 55.92% of the ticks.Conclusion: Some of the collected ticks may play an important role for transmission of vector borne disease to human; therefore, the results of this study will provide a clue for vectors of tick-borne diseases in the region for local authorities for implementation of disease control.
Maia, Carla; Ferreira, Andreia; Nunes, Mónica; Vieira, Maria Luísa; Campino, Lenea; Cardoso, Luís
Ticks are important vector arthropods of human and animal pathogens. As information about agents of disease circulating in vectors in Portugal is limited, the aim of the present study was to detect bacteria and parasites with veterinary and zoonotic importance in ticks collected from dogs, cats, and field vegetation. A total of 925 ticks, comprising 888 (96.0%) adults, 8 (0.9%) nymphs, and 29 (3.1%) larvae, were collected in 4 geographic areas (districts) of Portugal. Among those, 620 (67.0%) were removed from naturally infested dogs, 42 (4.5%) from cats, and 263 (28.4%) were questing ticks obtained from field vegetation. Rhipicephalus sanguineus was the predominant tick species, and the only one collected from dogs and vegetation, while all Ixodes ricinus specimens (n=6) were recovered from cats. Rickettsia massiliae and Rickettsia conorii were identified in 35 ticks collected from cats and dogs and in 3 ticks collected from dogs. Among ticks collected from cats or dogs, 4 Rh. sanguineus specimens were detected with Hepatozoon felis, 3 with Anaplasma platys, 2 with Hepatozoon canis, one with Anaplasma phagocytophilum, one with Babesia vogeli, one with Borrelia burgdorferi sensu lato and one with Cercopithifilaria spp. Rickettsia helvetica was detected in one I. ricinus tick collected from a cat. To the best of our knowledge, this was the first time that Cercopithifilaria spp., Ba. vogeli, H. canis, and H. felis have been detected in ticks from Portugal. The wide range of tick-borne pathogens identified, some of zoonotic concern, suggests a risk for the emergence of tick-borne diseases in domestic animals and humans in Portugal. Further studies on these and other tick-borne agents should be performed to better understand their epidemiological and clinical importance, and to support the implementation of effective control measures.
Ginsberg, H.S.; Stafford, K.C.; Goodman, J.L.; Dennis, D.T.; Sonenshine, D .E.
The mainstays of tick management and protection from tick-borne diseases have traditionally been personal precautions and the application of acaricides. These techniques maintain their value, and current innovations hold considerable promise for future improvement in effective targeting of materials for tick control. Furthermore, an explosion of research in the past few decades has resulted in the development and expansion of several novel and potentially valuable approaches to tick control, including vaccination against tick-borne pathogen transmission and against tick attachment, host management, use of natural enemies (especially entomopathogenic fungi), and pheromone-based techniques. The situations that require tick management are diverse, and occur under varied ecological conditions. Therefore, the likelihood of finding a single ?magic bullet? for tick management is low. In practical terms, the approach to tick management or to management of tick-borne disease must be tailored to the specific conditions at hand. One area that needs increased attention is the decision-making process in applying IPM to tick control. Further development of novel tick control measures, and increased efficiency in their integration and application to achieve desired goals, holds great promise for effective future management of ticks and tick-borne diseases.
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.
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.
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.
Heckler, Andrew F.; Mikula, Brendon D.
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…
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.
The increasing resistance of arthropodes to pesticides, their high price, and the growing public demand for safer food and a cleaner environment are obliging animal growers to minimize the use of pesticides by introducing alternative means for tick control. The development of a biological tick control method has been neglected as compared to the control of plant pests or dipterous insects harmful to men and animals. There are abundant observations, but only a few studies have as yet been conducted on pathogens, parasitoides, and predators of ticks. A first attempt at tick biocontrol was made with the introduction of tick-parasitic wasps from France to the USA and Russia. During the past decade, interest in developing antitick biocontrol agents such as birds (Brazil, Kenya, and Zimbabwe), parasitoides (Kenya and USA), entomopathogenic nematodes (Egypt, Israel, Guadeloupe, and USA), entomopathogenic fungi (Brazil, Cuba, Israel, Kenya, and USA), and bacteria (Brazil) has gained momentum. The reintroduction of oxpecker birds in some areas of Zimbabwe remains up to now the only known successful attempt at tick biocontrol.
Raghavan, Ram K; Goodin, Douglas G; Hanzlicek, Gregg A; Zolnerowich, Gregory; Dryden, Michael W; Anderson, Gary A; Ganta, Roman R
The potential distribution of Amblyomma americanum ticks in Kansas was modeled using maximum entropy (MaxEnt) approaches based on museum and field-collected species occurrence data. Various bioclimatic variables were used in the model as potentially influential factors affecting the A. americanum niche. Following reduction of dimensionality among predictor variables using principal components analysis, which revealed that the first two principal axes explain over 87% of the variance, the model indicated that suitable conditions for this medically important tick species cover a larger area in Kansas than currently believed. Soil moisture, temperature, and precipitation were highly correlated with the first two principal components and were influential factors in the A. americanum ecological niche. Assuming that the niche estimated in this study covers the occupied distribution, which needs to be further confirmed by systematic surveys, human exposure to this known disease vector may be considerably under-appreciated in the state.
Mehravaran, Ahmad; Moradi, Maryam; Telmadarraiy, Zakyeh; Mostafavi, Ehsan; Moradi, Ali Reza; Khakifirouz, Sahar; Shah-Hosseini, Nariman; Varaie, Fereshteh Sadat Rasi; Jalali, Tahmineh; Hekmat, Soheila; Ghiasi, Seyed Mojtaba; Chinikar, Sadegh
Crimean-Congo haemorrhagic fever (CCHF) virus is a tick-borne member of the genus Nairovirus, family Bunyaviridae. CCHF virus has been isolated from at least 31 different species of ticks. The virus is transmitted through the bite of an infected tick or by direct contact with CCHF virus-infected patients or the products of infected livestock. This study was conducted to determine the rate of CCHF virus infection in ticks in the district of Zahedan, in the province of Sistan and Baluchistan, southeastern Iran. A total of 140 ticks were collected from Sistan and Baluchistan. Reverse transcriptase-polymerase chain reaction (RT-PCR) was used for the detection of the CCHF virus genome in the tick population. This genome was detected in 4.3% of ticks collected from livestock of different regions of Zahedan. The infected tick genera belonged to Hyalomma and Haemaphysalis. Although in the epidemiology of CCHF virus Hyalomma ticks are considered to be the most important vectors and reservoirs, the virus has also been reported to occur in other genera of ticks, which conforms to the current data in our study from Sistan and Baluchistan. Given that animals are common hosts for Hyalomma and Haemaphysalis, regular monitoring programmes for livestock should be applied for CCHF virus control.
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.
Tick - borne encephalitis is a vector-borne disease primarily transmitted to humans by the bite of infected ticks. Clinical presentations range from mild meningitis to severe encephalitis with or without myelitis and may result in long-term neurological equelae or death. The disease can successfully be prevented through active immunization. BE is endemic in regions of at least 26 European countries. The risk of contracting TBE in the most affected countries has increased in the past 20 to 30 years, between 1974 and 2003, the number of reported clinical TBE cases increased by an appalling 400%, the only exception having been Austria. Because of increasing international travel streams of tourists from non-endemic countries to TBE risk areas, the infection is now becoming a more important issue of travel medicine.The risk depends on both the travelling season and the degree of unprotected outdoor exposure to forest areas (e.g. bicycling, camping, hiking, etc.). Tourists are by no means aware of the actual risk potential, especially when travelling to a knowingly 'safe' Europe. Vaccination against tick-borne encephalitis may be required for some tourists, depending on travel destination and behaviour. Implementing general guidelines for the use of TBE travel vaccination should be put on the agenda for travel medicine.
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
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.
Bell-Sakyi, Lesley; Kohl, Alain; Bente, Dennis A; Fazakerley, John K
Continuous cell lines derived from many of the vectors of tick-borne arboviruses of medical and veterinary importance are now available. Their role as tools in arbovirus research to date is reviewed and their potential application in studies of tick cell responses to virus infection is explored, by comparison with recent progress in understanding mosquito immunity to arbovirus infection. A preliminary study of propagation of the human pathogen Crimean-Congo hemorrhagic fever virus (CCHFV) in tick cell lines is reported; CCHFV replicated in seven cell lines derived from the ticks Hyalomma anatolicum (a known vector), Amblyomma variegatum, Rhipicephalus (Boophilus) decoloratus, Rhipicephalus (Boophilus) microplus, and Ixodes ricinus, but not in three cell lines derived from Rhipicephalus appendiculatus and Ornithodoros moubata. This indicates that tick cell lines can be used to study growth of CCHFV in arthropod cells and that there may be species-specific restriction in permissive CCHFV infection at the cellular level.
Reye, Anna L; Stegniy, Valentina; Mishaeva, Nina P; Velhin, Sviataslau; Hübschen, Judith M; Ignatyev, George; Muller, Claude P
Worldwide, ticks are important vectors of human and animal pathogens. Besides Lyme Borreliosis, a variety of other bacterial and protozoal tick-borne infections are of medical interest in Europe. In this study, 553 questing and feeding Ixodes ricinus (n = 327) and Dermacentor reticulatus ticks (n = 226) were analysed by PCR for Borrelia, Rickettsia, Anaplasma, Coxiella, Francisella and Babesia species. Overall, the pathogen prevalence in ticks was 30.6% for I. ricinus and 45.6% for D. reticulatus. The majority of infections were caused by members of the spotted-fever group rickettsiae (24.4%), 9.4% of ticks were positive for Borrelia burgdorferi sensu lato, with Borrelia afzelii being the most frequently detected species (40.4%). Pathogens with low prevalence rates in ticks were Anaplasma phagocytophilum (2.2%), Coxiella burnetii (0.9%), Francisella tularensis subspecies (0.7%), Bartonella henselae (0.7%), Babesia microti (0.5%) and Babesia venatorum (0.4%). On a regional level, hotspots of pathogens were identified for A. phagocytophilum (12.5-17.2%), F. tularensis ssp. (5.5%) and C. burnetii (9.1%), suggesting established zoonotic cycles of these pathogens at least at these sites. Our survey revealed a high burden of tick-borne pathogens in questing and feeding I. ricinus and D. reticulatus ticks collected in different regions in Belarus, indicating a potential risk for humans and animals. Identified hotspots of infected ticks should be included in future surveillance studies, especially when F. tularensis ssp. and C. burnetii are involved.
Reye, Anna L.; Stegniy, Valentina; Mishaeva, Nina P.; Velhin, Sviataslau; Hübschen, Judith M.; Ignatyev, George; Muller, Claude P.
Worldwide, ticks are important vectors of human and animal pathogens. Besides Lyme Borreliosis, a variety of other bacterial and protozoal tick-borne infections are of medical interest in Europe. In this study, 553 questing and feeding Ixodes ricinus (n = 327) and Dermacentor reticulatus ticks (n = 226) were analysed by PCR for Borrelia, Rickettsia, Anaplasma, Coxiella, Francisella and Babesia species. Overall, the pathogen prevalence in ticks was 30.6% for I. ricinus and 45.6% for D. reticulatus. The majority of infections were caused by members of the spotted-fever group rickettsiae (24.4%), 9.4% of ticks were positive for Borrelia burgdorferi sensu lato, with Borrelia afzelii being the most frequently detected species (40.4%). Pathogens with low prevalence rates in ticks were Anaplasma phagocytophilum (2.2%), Coxiella burnetii (0.9%), Francisella tularensis subspecies (0.7%), Bartonella henselae (0.7%), Babesia microti (0.5%) and Babesia venatorum (0.4%). On a regional level, hotspots of pathogens were identified for A. phagocytophilum (12.5–17.2%), F. tularensis ssp. (5.5%) and C. burnetii (9.1%), suggesting established zoonotic cycles of these pathogens at least at these sites. Our survey revealed a high burden of tick-borne pathogens in questing and feeding I. ricinus and D. reticulatus ticks collected in different regions in Belarus, indicating a potential risk for humans and animals. Identified hotspots of infected ticks should be included in future surveillance studies, especially when F. tularensis ssp. and C. burnetii are involved. PMID:23349900
Anna L Reye
Full Text Available Worldwide, ticks are important vectors of human and animal pathogens. Besides Lyme Borreliosis, a variety of other bacterial and protozoal tick-borne infections are of medical interest in Europe. In this study, 553 questing and feeding Ixodes ricinus (n = 327 and Dermacentor reticulatus ticks (n = 226 were analysed by PCR for Borrelia, Rickettsia, Anaplasma, Coxiella, Francisella and Babesia species. Overall, the pathogen prevalence in ticks was 30.6% for I. ricinus and 45.6% for D. reticulatus. The majority of infections were caused by members of the spotted-fever group rickettsiae (24.4%, 9.4% of ticks were positive for Borrelia burgdorferi sensu lato, with Borrelia afzelii being the most frequently detected species (40.4%. Pathogens with low prevalence rates in ticks were Anaplasma phagocytophilum (2.2%, Coxiella burnetii (0.9%, Francisella tularensis subspecies (0.7%, Bartonella henselae (0.7%, Babesia microti (0.5% and Babesia venatorum (0.4%. On a regional level, hotspots of pathogens were identified for A. phagocytophilum (12.5-17.2%, F. tularensis ssp. (5.5% and C. burnetii (9.1%, suggesting established zoonotic cycles of these pathogens at least at these sites. Our survey revealed a high burden of tick-borne pathogens in questing and feeding I. ricinus and D. reticulatus ticks collected in different regions in Belarus, indicating a potential risk for humans and animals. Identified hotspots of infected ticks should be included in future surveillance studies, especially when F. tularensis ssp. and C. burnetii are involved.
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.
Full Text Available Tick-borne diseases are transmission diseases belonging to the group of zoonoses but carried by ticks. These diseases are a major public health problem but also a problem for groups occupationally exposed to tick bites. Ixodes ricinus is a species of ticks which is the most common reservoir and the vector of a large number of microorganisms pathogenic to humans. It transfers, among others, bacteria of the species: Anaplasma phagocytophilum and Borrelia burgdorferi. The article discusses the mechanisms of infection with Borrelia burgdorferi and Anaplasma phagocytophilum for both ticks as well as for animals and humans. The two microorganisms discussed have developed many characteristics and mechanisms of adaptation to the environment, as well as defense mechanisms against the body's immune response. Understanding the biology of ticks and the function of proteins produced by ticks and pathogenic microorganisms is the key in the development of effective treatments and prevention of Lyme disease and anaplasmosis.
Mihalca Andrei D
Full Text Available Abstract Background 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. Methods 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 Results We examined 423 rodents (12 species collected from six counties in 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. Conclusions Our study showed a relatively high diversity of ticks parasitizing rodents in Romania. The most common tick in rodents
Heckler, Andrew F.; Mikula, Brendon D.
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, especially for less prepared and low
CHEN Jia; LIN Yu-bi; ZENG Chu-qian; YANG Zhen-zhen; LAI Xiao-shu; LU Qi-ji; ZHOU Jing-wen
Background In this study,we aimed to evaluate the impact of abnormal glucose,lipid and Cystatin-C on the virtual P vector characteristics,which haven' t been reported in previous studies.Methods 204 of non-diabetes mellitus (NDM),130 of DM (type 2) and 39 of impaired glucose tolerance (IGT) patients were consecutively and retrospectively recruited.We selected a one-minute length of electrocardiogram at 4AM for analysis.After a series of calculating algorisms,we obtained the virtual planar P vector parameters.Results There were no significant differences in FPV,FPA,RSPV,RSPA,HPV and HPA groups.After adjusting confounding factors,the regression coefficients (RC) were estimated as follow:for FPV,female gender (RC-0.21,P =0.02),triglyceride (RC-0.09,P ＜ 0.01),RVOT (RC 0.03,P =0.02);for RSPV,female gender (RC-0.21,P ＜ 0.01),triglyceride (RC-0.10,P ＜ 0.01),average heart rate (RC 0.01,P =0.02);for HPV,triglyceride (RC-0.08,P ＜ 0.001),LDL (RC-0.19,P ＜ 0.01),Apo B (RC 0.67,P ＜ 0.01);for RSPA,B type of blood (RC-22.06,P =0.02),Cystatin-C (RC-72.79,P =0.02),thickness of interventricular septum (RC 3.70,P =0.01).Cystatin-C was suggested as a cure related to RSPA,and the cut-off point was 1.6 mg/L.There were no significant risk factors associated with FPA and HPA.There was no difference in virtual P vector among DM,IGT and NDM groups.Conclusion Increased levels of lipid and Cystatin-C significantly impact the characteristics of virtual P vector,whereas glucose does not.These changes may come from a higher low voltage atrial area and abnormal orientation of atrial depolarization.
Tagliapietra, V; Rosà, R; Arnoldi, D; Cagnacci, F; Capelli, G; Montarsi, F; Hauffe, H C; Rizzoli, A
The wood tick Ixodes ricinus, one of the most common arthropod-borne disease vectors, is of increasing relevance for human and animal health in Europe. The aim of this study was to determine the relative contribution of several abiotic and biotic factors potentially affecting questing activity and local abundance of I. ricinus in Italy, considering the scale at which these factors interact with the host-seeking ticks. Within EDEN, a large-scale EU collaborative project on eco-epidemiology of vector-borne diseases, we collected questing ticks for three consecutive years using a standard protocol at eleven sites in the Italian Alps and Apennines. A total of 25 447 I. ricinus were collected. All sites showed the same annual pattern of tick activity (bimodal for nymphs and unimodal for larvae and adults), although the abundance of nymphs was statistically different between sites and years. A Generalized Linear Mixed Model and a Linear Mixed Model fitted to data for nymphs, showed that while the principal variables affecting the local abundance of questing ticks were saturation deficit (an index combining temperature and relative humidity) and red deer density, the most important variable affecting questing nymph activity was saturation deficit. As for the timing of seasonal emergence, we confirmed that the threshold temperature at this latitude for larvae is 10°C (mean maximum) while that for nymphs is 8°C.
Meghan E Hermance
Full Text Available Powassan virus (POWV is a tick-borne flavivirus that can result in a severe neuroinvasive disease with 50% of survivors displaying long-term neurological sequelae. Human POWV cases have been documented in Canada, the United States, and Russia. Although the number of reported POWV human cases has increased in the past fifteen years, POWV remains one of the less studied human pathogenic flaviviruses. Ixodes ticks are the vectors for POWV, and the virus is transmitted to a host's skin very early during the tick feeding process. Central to the successful transmission of a tick-borne pathogen are complex interactions between the host immune response and early tick-mediated immunomodulation, all of which initially occur at the skin interface. In our prior work, we examined the cutaneous immune gene expression during the early stages of POWV-infected Ixodes scapularis feeding. The present study serves to further investigate the skin interface by identifying early cell targets of infection at the POWV-infected tick feeding site. An in vivo infection model consisting of POWV-infected ticks feeding on mice for short durations was used in this study. Skin biopsies from the tick feeding sites were harvested at various early time points, enabling us to examine the skin histopathology and detect POWV viral antigen in immune cells present at the tick feeding site. The histopathology from the present study demonstrates that neutrophil and mononuclear cell infiltrates are recruited earlier to the feeding site of a POWV-infected tick versus an uninfected tick. This is the first report demonstrating that macrophages and fibroblasts contain POWV antigens, which suggests that they are early cellular targets of infection at the tick feeding site. These data provide key insights towards defining the complex interactions between the host immune response and early tick-mediated immunomodulation.
It’s Open Season on Ticks Protect yourself from tickborne disease this hunting season Ticks feed on the blood of animals (such as rodents, rabbits, deer, and birds), but will bite humans too. Ticks live in grassy or wooded areas, or on ...
Full Text Available The cattle tick Rhipicephalus (Boophilus microplus is one of the most harmful parasites affecting bovines. Similarly to other hematophagous ectoparasites, R. microplus saliva contains a collection of bioactive compounds that inhibit host defenses against tick feeding activity. Thus, the study of tick salivary components offers opportunities for the development of immunological based tick control methods and medicinal applications. So far, only a few proteins have been identified in cattle tick saliva. The aim of this work was to identify proteins present in R. microplus female tick saliva at different feeding stages. Proteomic analysis of R. microplus saliva allowed identifying peptides corresponding to 187 and 68 tick and bovine proteins, respectively. Our data confirm that (i R. microplus saliva is complex, and (ii that there are remarkable differences in saliva composition between partially engorged and fully engorged female ticks. R. microplus saliva is rich mainly in (i hemelipoproteins and other transporter proteins, (ii secreted cross-tick species conserved proteins, (iii lipocalins, (iv peptidase inhibitors, (v antimicrobial peptides, (vii glycine-rich proteins, (viii housekeeping proteins and (ix host proteins. This investigation represents the first proteomic study about R. microplus saliva, and reports the most comprehensive Ixodidae tick saliva proteome published to date. Our results improve the understanding of tick salivary modulators of host defense to tick feeding, and provide novel information on the tick-host relationship.
Since its discovery approximately 30 years ago, Lyme borreliosis has become the most important vector-borne disease in the Western world. This thesis describes in molecular detail novel tick-host-pathogen interactions in Lyme borreliosis, contributing to the understanding of the pathogenesis of this
Anderson, Alice; Chaney, Elizabeth
According to the Centers for Disease Control and Prevention (CDC), there are eleven tick-associated diseases prevalent in the United States. Most commonly diagnosed are Lyme disease, anaplasmosis (ehrlichiosis) and babeisois, with Lyme disease being the most common vector-borne disease in the country. In southeastern states, studies have shown the…
Full Text Available Abstract Background The studies reported here were conducted to ascertain the efficacy of imidacloprid/flumethrin incorporated in a slow-release matrix collar, against infestations of dogs by fleas, ticks, mites and lice. Efficacy was evaluated against the flea Ctenocephalides felis felis, the ticks Rhipicephalus sanguineus, Ixodes ricinus, Ixodes scapularis, Dermacentor reticulatus and Dermacentor variabilis, the mite Sarcoptes scabiei and the biting louse Trichodectes canis. Methods Groups of collar-treated dogs (n = 7–10 were infested with fleas and/or ticks at monthly intervals at least, over a period of up to 8 months. Efficacy against fleas was evaluated 24 to 48 h after treatment and 24 h after each re-infestation. Efficacy against ticks was evaluated at 48 h (acaricidal, 6 h (repellent and 48 h (sustained after infestation. The effect of regular shampooing or immersion in water on the efficacy of the collars was also tested. Efficacy against flea larvae was assessed by incubating blanket samples after dog contact with viable flea eggs. Effectiveness against lice and mites was evaluated after treatment of naturally infested animals. With the exception of the mites, efficacy was calculated by comparison with untreated negative control groups. Results Efficacy against fleas (24 h generally exceeded 95%, and against flea larvae it exceeded 99% for 8 months. Sustained acaricidal (48 h efficacy, covering a period of 8 months was 100% against I. ricinus, starting 2 days after treatment (in vivo, and 100% against I. scapularis (in vitro, above 97% against R. sanguineus, generally above 97% against D. reticulatus and above 90% for D. variabilis. Repellent (6 h efficacy 2 days after treatment and continuing for 8 months was consistently 100% against I. ricinus, and above 90% against R. sanguineus. Regular shampooing affected efficacy against fleas and ticks to a lesser extent than regular immersion in water. The
Full Text Available In order to evaluate the prevalence rate of Babesia spp. in ticks collected from vegetation at seven localities in northern Serbia, tick samples were subjected to molecular analysis. A total of 132 unfed adult ticks of five different species (Dermacentor marginatus, Dermacentor reticulatus, Ixodes ricinus, Haemaphysalis concinna and Haemaphysalis punctata, were examined by PCR for the presence of Babesia spp. Out of the analyzed ticks, 10.61% (14/132 were positive for babesial DNA. The presence of babesiae was found at the localities Pančevački Rit, Titov Gaj, Makiš, PKB and Kljajićevo. Prevalence in D. reticulatus ticks was 21.57% (11/51 and in H. concinna ticks, 8.57% (3/35. Sequencing and phylogenetic analysis showed a clustering of the obtained sequences with those of B. canis from the GenBank database. These results add to the knowledge of the distribution of babesial pathogens and their vectors in Serbia. [Projekat Ministarstva nauke Republike Srbije, br. ON 173006
Full Text Available Ticks are vectors and reservoirs of many arboviruses pathogenic for humans or domestic animals; in addition, during bloodfeeding they can acquire and harbour pathogenic arboviruses normally transmitted by other arthropods such as mosquitoes. Tick cell and organ cultures provide convenient tools for propagation and study of arboviruses, both tick-borne and insect-borne, enabling elucidation of virus-tick cell interaction and yielding insight into the mechanisms behind vector competence and reservoir potential for different arbovirus species. The mosquito-borne zoonotic alphavirus Semliki Forest virus (SFV, which replicates well in tick cells, has been isolated from Rhipicephalus, Hyalomma, and Amblyomma spp. ticks removed from mammalian hosts in East Africa; however nothing is known about any possible role of ticks in SFV epidemiology. Here we present a light and electron microscopic study of SFV infecting cell lines and organ cultures derived from African Rhipicephalus spp. ticks. As well as demonstrating the applicability of these culture systems for studying virus-vector interactions, we provide preliminary evidence to support the hypothesis that SFV is not normally transmitted by ticks because the virus does not infect midgut cells.
Welc-Faleciak, Renata; Rodo, Anna; Siński, Edward; Bajer, Anna
Vector-borne infections constitute increasing health problem in dogs worldwide, including sled dogs, dramatically decreasing the fitness of working dogs and even leading to death. In the period 2006-2008 eighty-two blood samples were collected from eight sled dog kennels in Central Poland. The prevalence of four vector-borne infections (Babesia canis, Bartonella sp., Anaplasma/Ehrlichia and Borrelia burgdorferi) was estimated in 82 sled dogs using PCR and nested PCR for diagnosis and the same methods were used to identify the vector-borne pathogens in 26 dogs presenting at veterinary clinics with symptoms of vector-borne diseases. None of four studied vector-borne pathogens was detected in samples originating from veterinary clinics. Among the remaining 82 dogs B. canis infections were confirmed in three dogs undergoing treatment for babesiosis. The DNA of tick-borne pathogens was also found among 22 (27.8%) of the 79 apparently healthy dogs, including 20 cases of B. canis infection (25.3%), one case of B. burgdorferi s.l. infection and one case of Anaplasma phagocytophilum infection. No evidence of Bartonella spp. and Ehrlichia canis infections were found in this set of samples. Sequencing of a Babesia fragment of 18S rDNA amplified from acute (n=5) and asymptomatic (n=5) cases revealed that all isolates were identical to the Babesia canis canis sequence, originally isolated from Dermacentor reticulatus ticks in Poland. A range of factors was shown to affect the distribution of babesiosis in sled dogs. The data are also discussed in respect to the health risk factors generated by asymptomatic B. canis infections and the efficiency of chemoprophylaxis measures taken by sled dog owners.
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.
N. K. Tokarevich
Full Text Available Abstract. Results of monitoring of tick-borne encephalitis (TBE and tick borreliosis (TB in the western enclave of Russia in Kaliningrad oblast in 1999-2008 are presented in the article. The number of basic vector of the agents of these infections — I. ricinus during the analyzing period in the territory of Kurshskaya spit increased. The number of tick attacked persons in the oblast also increased. Despite these events the TBE incidence rates remained not so high and have tendency to decrease. At the same time the TB morbidity has moderate trend to increase. The link between increase of average annual air temperature and incidence of "tick" infections was not proved for the studying period of time. The people of pre-pension and pension ages living in cities more often suffer from TBE and TB. The most part of patients are exposed to tick attack during visiting of rest places. It was determined that eastern districts of Kaliningrad oblast are more problematic on "tick" infections.
Telmadarraiy Zakkyeh; Oshaghi Mohammad Ali; Hosseini Vasoukolaei Nasibeh; Yaghoobi Ershadi Mohammad Reza; Babamahmoudi Farhang; Mohtarami Fatemeh
Objective:To determine tick infestation of domestic ruminants and their infection to ovine theileriosis in northern Iran. Methods:About 425 domestic ruminants in Ghaemshahr city in northern Iran were inspected for tick infestations. Twenty tick specimens (13 females and 7 males) of Rhipicephalus sanguineus (R. sanguineus), the most common tick in the study area, were tested by PCR amplification against 18s rRNA genome of Theileria spp using specie specific primers and then the PCR products were sequenced for species identification by comparison with data base available in GenBank. Results:About 323 ticks were collected from 102 animals (88 sheep, 12 goats and 2 cattle). The prevalence of ticks infesting animals was R. sanguineus (82.35%), Rhipicephalus bursa (R. bursa) (0.3%), Ixodes ricinus (I. ricinus) (15.2%), Boophilus annulatus (B. annulatus) (1.2%), Haemaphysalis punctata (H. punctata) (0.3%) and Haemaphysalis numidiana (H. numidiana) (0.6%). Eleven (55%) tick specimens were PCR positive against genome of Theileria ovis (T. ovis). Sequence analysis of the PCR products confirmed presence of T. ovis in one R. sanguinus. Conclusions:This is the first report of tick infection to T. ovis in Iran. Due to dominant prevalence of R. sanguineus as well as its infection to T. ovis, it is postulated this tick is the main vector of ovine theileriosis in northern Iran.
Full Text Available Ticks are vectors of very harmful diseases in humans and animals. Nine arbovirus, two rickettsia, two protozoa and one helminthic diseases are transmitted by ticks in different climatic and geographical zones. Twenty six tick species have been determined in Turkey until now. These tick species transmit tropical theileriosis and babesiosis, which are cause of important economical loses especially in farm animals, and lyme disease and Crimean-Congo Hemorrhagic Fever in humans. The control of ticks is getting more important due to appearance of Crimean-Congo Hemorrhagic Fewer (CCHF in Turkey in recent years. However, the control of ticks is a very difficult and expensive procedure and generally chance of success is very low. The main aims of tick control are acaricidal control of ticks on animals, making different applications for elimination of tick-born diseases in humans and reduction of the contact risk between humans, domestic animals and ticks. The repellent is a common name of the compounds, which are applied on directly skin, clothes and sometimes curtains and nets, and prevent the humans and domestic animals against attacks of harmful organisms such as mosquitoes, flies and ticks. Although repellent compounds are applied for the organisms which annoy and suck blood at outdoor, some products used in indoor areas (houses, offices and animal shelters, such as mosquito nets, coils and thermal vaporised liquid and mat formulations, are also evaluated in this frame. Repellents are very beneficial products for prevent attack by ticks. But, it should be known that these compounds are not completely harmless and sometimes they can cause toxic effects in humans and domestic animals. In this review, definition and history of the repellent compounds, the action mechanisms and features of an ideal repellent, important repellent compounds and their toxicological importance and safety usage principles of repellents were evaluated.
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.
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.
Johansen, Jakob Aaquist; Thybo, Søren
The incident of spotted fever imported to Denmark is unknown. We present a classic case of African Tick Bite Fever (ATBF) to highlight a disease, which frequently infects wildlife enthusiasts and hunters on vacation in South Africa. ATBF has a good prognosis and is easily treated with doxycyclin...
... Health Topics Tick-Borne Disease Hazards to Outdoor Workers Physical Hazards Heat Stress Cold Stress Sun Exposure Noise Biological Hazards Insects ... No Longer Available Lyme Disease Hazards to Outdoor Workers Physical Hazards Heat Stress Cold Stress Sun Exposure Noise Biological Hazards Insects ...
Fernandes, Éverton K K; Bittencourt, Vânia R E P; Roberts, Donald W
Ticks are serious health threats for humans, and both domestic and wild animals. Ticks are controlled mostly by application of chemical products; but these acaricides have several negative side effects, including toxicity to animals, environmental contamination, and induction of chemical resistance in some tick populations. Entomopathogenic fungi infect arthropods in nature and can occur at enzootic or epizootic levels in their host populations. Laboratory studies clearly demonstrate that these fungi can cause high mortality in all developmental stages of several tick species, and also reduce oviposition of infected engorged females. Tick mortality following application of fungi in the field, however, often is less than that suggested by laboratory tests. This is due to many negative biotic and climatic factors. To increase efficacy of fungal agents for biological control of ticks under natural conditions, several points need consideration: (1) select effective isolates (viz., high virulence; and tolerance to high temperature, ultraviolet radiation and desiccation); (2) understand the main factors that affect virulence of fungal isolates to their target arthropods including the role of toxic metabolites of the fungal isolates; and (3) define with more precision the immune response of ticks to infection by entomopathogenic fungi. The current study reviews recent literature on biological control of ticks, and comments on the relevance of these results to advancing the development of fungal biocontrol agents, including improving formulation of fungal spores for use in tick control, and using entomopathogenic fungi in integrated pest (tick) management programs.
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.
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.
Ferreri, Luca; Bajardi, Paolo; Giacobini, Mario
Tick-borne diseases can be transmitted via non-systemic (NS) transmission. This occurs when tick gets the infection by co-feeding with infected ticks on the same host resulting in a direct pathogen transmission between the vectors, without infecting the host. This transmission is peculiar, as it does not require any systemic infection of the host. The NS transmission is the main efficient transmission for the persistence of the tick-borne encephalitis virus in nature. By describing the heterogeneous ticks aggregation on hosts through a bipartite graphs representation, we are able to mathematically define the NS transmission and to depict the epidemiological conditions for the pathogen persistence. Despite the fact that the underlying network is largely fragmented, analytical and computational results show that the larger is the variability of the aggregation, and the easier is for the pathogen to persist in the population.
This is a close-up photograph of a tick embedded in the skin. Ticks are important because they can carry diseases such as Rocky Mountain spotted fever, tularemia, Colorado tick fever, Lyme disease, and others.
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 "nAbstract "nBackground: Ticks are hematophagous arthropod belonging to the Class of Arachnids. Ticks are also one of the major vectors of pathogens to animal and human. This study was conducted to determine tick infestation rate of sheep in Abdanan during 2007–2008. "nMethods: Sampling was performed seasonally in 19 villages during spring 2007 until winter 2008. A total of 1095 sheep were selected and tested for tick infestation. After collection, all ticks were transported to laboratory of Medical Entomology and were identified with appropriate identification keys. "nResults: Totally, 864 hard ticks were collected. The ticks were classified into two genera and 5 species including: Hyalomma marginatum (44.67%, Hy. anatolicum (43.17%, Hy.asiaticum (6.37%, Hy. dromedarii (5.55%, Heamaphysalis sulcata (0.24%. The highest seasonal activity was observed in spring (36.46 % and the lowest seasonal was in winter (11.57%. The rate of tick frequency in mountainous region was 48.15% and it was 51.85% in plateau regions. In this study, tick infestation of sheep was 11.41%. "nConclusion: Hy.marginatum has the more frequent density in the study area. "n "nKeywords: Ticks, sheep, Iran
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
André C. Uys
Full Text Available This survey of ixodid ticks was the first to compare the species composition and population dynamics of free-living ticks in intensive, sable antelope breeding enclosures, now commonplace in commercial wildlife ranching in South Africa, with those of multi-herbivore enclosures. The species composition, abundance and seasonal abundance of questing ixodid ticks on the vegetation in intensive breeding enclosures for sable antelope (Hippotragus niger, on which strategic tick control is practised, were compared with those of ticks in a multi-species herbivore enclosure surrounding the breeding enclosures in which no tick control is practised. A total of eight ixodid tick species were collected by drag-sampling the woodland and grassland habitats in each enclosure type monthly from July 2011 to July 2013. Rhipicephalus decoloratus, a potential vector of fatal tick-borne disease in sable antelopes, was the most abundant, accounting for 65.4% of the total number of ticks collected in the sable enclosures, whilst representing only 25.4% of number of ticks collected in the multi-species herbivore enclosure. Rhipicephalus decoloratus and R. evertsi evertsi were more abundant than R. appendiculatus (both p < 0.05 and Amblyomma hebraeum (p < 0.001 and p < 0.01, respectively. Rhipicephalus decoloratus larvae were collected throughout the year, with peak collections in November 2012 and October to December 2013 in the sable enclosures; and in April/May 2012 and February/April 2013 in the multi-species herbivore enclosure. More R. decoloratus were recovered in the second year than in the first year in the grassland habitat of the sable enclosures (V = 7.0, p < 0.05 possibly as a result of acaricide resistance. The apparent temporal over-abundance of R. decoloratus in sable antelope breeding enclosures, in the face of strategic tick control, is of concern and requires further investigation.
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 ...
Full Text Available Ticks play an important role in disease transmission as vectors for human and animal pathogens, including the Gram-negative pathogen Bartonella. Here, we evaluated the presence of Bartonella in ixodid ticks and domestic animals from Palestine. We tested 633 partly engorged ticks and 139 blood samples from domestic animals (dogs, sheep and camels for Bartonella using ITS-PCR. Bartonella DNA was detected in 3.9% of the tested ticks. None of the ticks collected from sheep and goats were positive for Bartonella. Seventeen R. sanguineus ticks (17/391; 4.3% collected from dogs were infected with B. rochalimae (n=10, B. chomelii (n=6, and B. koehlerae (n=1. Four H. dromedarri ticks (4/63; 6.3% obtained from camels were infected with B. bovis (n=2 and B. rochalimae (n=2. Among canine blood samples (n=110, we found one asymptomatic female dog to be infected with B. rochalimae (0.9%. The detection of zoonotic Bartonella species in this study should raise awareness of these vector-borne diseases among physicians, veterinarians and public health workers and highlight the importance of surveillance and preventive measures in the region.
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 ...
Madhav, Nita K; Brownstein, John S; Tsao, Jean I; Fish, Durland
The blacklegged tick, Ixodes scapularis Say, a vector for the agents of Lyme borreliosis and other diseases, has expanded its range dramatically over the past 20 yr. However, the relative contributions of different vertebrate host species to this expansion have remained largely unexplored. To address this issue, we simulated the expansion of a theoretical tick population across a simple landscape by using a deterministic, spatially explicit, cellular automata model. The model incorporates the ecology of ticks and three vertebrate hosts: white-tailed deer, Odocoileus virginianus Zimmermann; white-footed mouse, Peromyscus leucopus Rafinesque; and American robin, Turdus migratorius L. Host contribution to tick dispersal is modeled as a function of tick burden, home range size, and population density. These parameters were determined using published and unpublished data. Our results suggest that 1) hosts with high tick burdens and large home ranges (e.g., deer) play a critical role in I. scapularis range expansion; 2) hosts with small home ranges (e.g., mice) can limit range expansion if they divert a sufficient number of ticks from feeding on more mobile hosts; and (3) birds that migrate annually (e.g., robins) can play a crucial role in tick range expansion.
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.
Passos,Lygia Maria Friche
Continuous cell lines have been established from several ixodid and argasid tick species, representing an excellent tool suitable for the isolation of pathogens and their subsequent propagation, which in turn allows the production of antigenic material for diagnostic tests, antibody and vaccine production, and also for studies on host-vector-pathogen relationships. This paper reviews the use of tick cells for culture initiation and maintenance of two obligate intracellular bacterial pathogens...
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.
Esteve-Gassent, Maria D; Castro-Arellano, Ivan; Feria-Arroyo, Teresa P; Patino, Ramiro; Li, Andrew Y; Medina, Raul F; de León, Adalberto A Pérez; Rodríguez-Vivas, Roger Iván
Emerging and re-emerging tick-borne diseases threaten public health and the wellbeing of domestic animals and wildlife globally. The adoption of an evolutionary ecology framework aimed to diminish the impact of tick-borne diseases needs to be part of strategies to protect human and animal populations. We present a review of current knowledge on the adaptation of ticks to their environment, and the impact that global change could have on their geographic distribution in North America. Environmental pressures will affect tick population genetics by selecting genotypes able to withstand new and changing environments and by altering the connectivity and isolation of several tick populations. Research in these areas is particularly lacking in the southern United States and most of Mexico with knowledge gaps on the ecology of these diseases, including a void in the identity of reservoir hosts for several tick-borne pathogens. Additionally, the way in which anthropogenic changes to landscapes may influence tick-borne disease ecology remains to be fully understood. Enhanced knowledge in these areas is needed in order to implement effective and sustainable integrated tick management strategies. We propose to refocus ecology studies with emphasis on metacommunity-based approaches to enable a holistic perspective addressing whole pathogen and host assemblages. Network analyses could be used to develop mechanistic models involving multihost-pathogen communities. An increase in our understanding of the ecology of tick-borne diseases across their geographic distribution will aid in the design of effective area-wide tick control strategies aimed to diminish the burden of pathogens transmitted by ticks.
Ginsberg, Howard S.
Ticks are often infected with more than one pathogen, and several field surveys have documented nonrandom levels of coinfection. Levels of coinfection by pathogens in four tick species were analyzed using published infection data. Coinfection patterns of pathogens in field-collected ticks include numerous cases of higher or lower levels of coinfection than would be expected due to chance alone, but the vast majority of these cases can be explained on the basis of vertebrate host associations of the pathogens, without invoking interactions between pathogens within ticks. Nevertheless, some studies have demonstrated antagonistic interactions, and some have suggested potential mutualisms, between pathogens in ticks. Negative or positive interactions between pathogens within ticks can affect pathogen prevalence, and thus transmission patterns. Probabilistic projections suggest that the effect on transmission depends on initial conditions. When the number of tick bites is relatively low (e.g., for ticks biting humans) changes in prevalence in ticks are predicted to have a commensurate effects on pathogen transmission. In contrast, when the number of tick bites is high (e.g., for wild animal hosts) changes in pathogen prevalence in ticks have relatively little effect on levels of transmission to reservoir hosts, and thus on natural transmission cycles.
Duzlu, Onder; Yildirim, Alparslan; Inci, Abdullah; Gumussoy, Kadir Semih; Ciloglu, Arif; Onder, Zuhal
This study was carried out to investigate the molecular prevalence of Francisella-like endosymbionts (FLEs) and Francisella tularensis in ticks (Acari: Ixodidae) and mosquitoes in Turkey. Genomic DNA pools were constructed from a total of 1477 adult hard ticks of Rhipicephalus (Rh.) annulatus, Rh. turanicus, Rh. sanguineus, Rh. bursa, Haemaphysalis (Hae.) parva, Hae. sulcata, Hyalomma marginatum marginatum, H. anatolicum anatolicum, H. anatolicum excavatum, H. detritum detritum, H. dromedarii, Dermacentor marginatus, and Ixodes ricinus species, which were collected from several barns, cattle, and people. Genomic DNA was also extracted from pools consisting of 6203 adult female mosquito species belonging to Aedes vexans, Culex (Cx.) pipiens, Cx. hortensis, Cx. theileri, Culiseta annulata, and Anopheles maculipennis species. Conventional PCR and TaqMan probe-based real- time PCR targeting the 16S rRNA gene for FLEs and the lpnA gene for F. tularensis, respectively, were performed on the DNA isolates obtained. FLEs and F. tularensis were not found in any genomic DNA pools constructed from ixodid ticks and mosquitos. This study represents the first investigation of F. tularensis and FLEs in potential vector ticks and mosquitoes by molecular methods in Turkey. The present study provides useful insights into the molecular epidemiology of F. tularensis and FLEs. One of the major conclusions of the study is that tularemia outbreaks may be essentially due to direct transmission from the environment (especially from water) in Turkey and not to vector-borne transmission.
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
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.
Anderson, B E; Sims, K G; Olson, J G; Childs, J E; Piesman, J F; Happ, C M; Maupin, G O; Johnson, B J
Polymerase chain reaction primers specific for Ehrlichia chaffeensis were used to amplify DNA from extracts of pooled ticks. Amplification was performed on extracts from 140 pools (1,579 total ticks) consisting of three tick genera collected from five states. The characteristic 389-basepair product was observed after amplification of extracts from seven different pools of adult Amblyomma americanum (117 pools, 1,462 ticks), but not from pools of nymphs. No specific product was observed after amplification of 20 pools (105 ticks) of Dermacentor variabilis and three pools of Ixodes scapularis (12 ticks). Ehrlichia chaffeensis was present in A. americanum at a minimum frequency of > or = 0.48%, suggesting that A. americanum may be a vector of human ehrlichiosis.
Full Text Available Abstract Background Malaria was endemic in the Rhône-Alpes area of eastern France in the 19th century and life expectancy was particularly shortened in Alpine valleys. This study was designed to determine how the disease affected people in the area and to identify the factors influencing malaria transmission. Methods Demographic data of the 19th century were collected from death registers of eight villages of the flood-plain of the river Isère. Correlations were performed between these demographic data and reconstructed meteorological data. Archive documents from medical practitioners gave information on symptoms of ill people. Engineer reports provided information on the hydraulic project developments in the Isère valley. Results Description of fevers was highly suggestive of endemic malaria transmission in the parishes neighbouring the river Isère. The current status of anopheline mosquitoes in the area supports this hypothesis. Mean temperature and precipitation were poorly correlated with demographic data, whereas the chronology of hydrological events correlated with fluctuations in death rates in the parishes. Conclusion Nowadays, most of the river development projects involve the creation of wet areas, enabling controlled flooding events. Flood-flow risk and the re-emergence of vector-borne diseases would probably be influenced by the climate change. The message is not to forget that human disturbance of any functioning hydrosystem has often been linked to malaria transmission in the past.
Rodríguez-Planes, L I; Vazquez-Prokopec, G M; Cecere, M C; Canale, D M; Gürtler, R E
The control of nondomiciliated triatomine species adapted to peridomestic habitats represents a challenge because they are connected to sylvatic colonies, and pyrethroid insecticides have limited effects outdoors. The effects of residual insecticide spraying have rarely been assessed on secondary triatomines. Triatoma garciabesi (Carcavallo, Martinez, Cichero, Prosen & Ronderos, 1967) is a nontarget vector that inhabits the dry western Chaco region, and a member of the Triatoma sordida Stål 1859 complex. Little is known on the capacity of T. garciabesi to invade and establish viable domestic or peridomestic colonies, and on its response to residual insecticide sprays directed against Triatoma infestans Klug 1834. The presence and abundance of triatomines were assessed by timed manual collections annually or biannually (spring and fall) during 10 yr after a community-wide insecticide spraying campaign and selective insecticide sprays directed against T. infestans in a rural village of northwestern Argentina. T. garciabesi mainly occupied peridomestic habitats associated with chickens, and was unable to colonize human sleeping quarters. Trees with chickens occurred in nearly all houses and were infested in >25% of the occasions. The abundance of bugs at house-compound level was best explained by a generalized estimating equation model that included selective insecticide sprays during the previous semester (negative effects), chicken abundance (positive effects), seasonality, and their interactions. Our results suggest that insecticide applications targeting T. infestans affected the abundance of T. garciabesi, and reduced the likelihood of future infestation.
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.
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.
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.
Mapholi, N O; Maiwashe, A; Matika, O; Riggio, V; Bishop, S C; MacNeil, M D; Banga, C; Taylor, J F; Dzama, K
Ticks and tick-borne diseases are among the main causes of economic loss in the South African cattle industry through high morbidity and mortality rates. Concerns of the general public regarding chemical residues may tarnish their perceptions of food safety and environmental health when the husbandry of cattle includes frequent use of acaricides to manage ticks. The primary objective of this study was to identify single nucleotide polymorphism (SNP) markers associated with host resistance to ticks in South African Nguni cattle. Tick count data were collected monthly from 586 Nguni cattle reared in four herds under natural grazing conditions over a period of two years. The counts were recorded for six species of ticks attached in eight anatomical locations on the animals and were summed by species and anatomical location. This gave rise to 63 measured phenotypes or traits, with results for 12 of these traits being reported here. Tick count (x) data were transformed using log10(x+1) and the resulting values were examined for normality. DNA was extracted from hair and blood samples and was genotyped using the Illumina BovineSNP50 assay. After quality control (call rate >90%, minor allele frequency >0.02), 40,436 SNPs were retained for analysis. Genetic parameters were estimated and association analysis for tick resistance was carried out using two approaches: a genome-wide association (GWA) analysis using the GenABEL package and a regional heritability mapping (RHM) analysis. The Bonferroni genome-wide (PAmblyomma hebraeum (the vector for Heartwater disease) being the dominant species. Heritability estimates (h(2)) from the fitted animal and sire models ranged from 0.02±0.00 to 0.17±0.04 for the transformed tick count data. Several genomic regions harbouring quantitative trait loci (QTL) were identified for different tick count traits by both the GWA and RHM approaches. Three genome-wide significant regions on chromosomes 7, 10 and 19 were identified for total tick
Blouin Edmour F
Full Text Available Abstract Background Subolesin is an evolutionary conserved protein that was discovered recently in Ixodes scapularis as a tick protective antigen and has a role in tick blood digestion, reproduction and development. In other organisms, subolesin orthologs may be involved in the control of developmental processes. Because of the profound effect of subolesin knockdown in ticks and other organisms, we hypothesized that subolesin plays a role in gene expression, and therefore affects multiple cellular processes. The objective of this study was to provide evidence for the role of subolesin in gene expression. Results Two subolesin-interacting proteins were identified and characterized by yeast two-hybrid screen, co-affinity purification and RNA interference (RNAi. The effect of subolesin knockdown on the tick gene expression pattern was characterized by microarray analysis and demonstrated that subolesin RNAi affects the expression of genes involved in multiple cellular pathways. The analysis of subolesin and interacting protein sequences identified regulatory motifs and predicted the presence of conserved protein kinase C (PKC phosphorylation sites. Conclusion Collectively, these results provide evidence that subolesin plays a role in gene expression in ticks.
Full Text Available The identification of micro-organisms carried by ticks is an important issue for human and animal health. In addition to their role as pathogen vectors, ticks are also the hosts for symbiotic bacteria whose impact on tick biology is poorly known. Among these, the bacterium Wolbachia pipientis has already been reported associated with Ixodes ricinus and other tick species. However, the origins of Wolbachia in ticks and their consequences on tick biology (known to be very diverse in invertebrates, ranging from nutritional symbionts in nematodes to reproductive manipulators in insects are unknown. Here we report that the endoparasitoid wasp Ixodiphagus hookeri (Hymenoptera, Chalcidoidea, Encyrtidae--strictly associated with ticks for their development--infested at almost 100% prevalence by a W. pipientis strain belonging to a Wolbachia supergroup that has already been reported as associated with other hymenopteran parasitoids. In a natural population of I. ricinus that suffers high parasitism rates due to I. hookeri, we used specific PCR primers for both hymenopteran and W. pipientis gene fragments to show that all unfed tick nymphs parasitized by I. hookeri also harbored Wolbachia, while unparasitized ticks were Wolbachia-free. We demonstrated experimentally that unfed nymphs obtained from larvae exposed to I. hookeri while gorging on their vertebrate host also harbor Wolbachia. We hypothesize that previous studies that have reported W. pipientis in ticks are due to the cryptic presence of the endoparasitoid wasp I. hookeri. This association has remained hidden until now because parasitoids within ticks cannot be detected until engorgement of the nymphs brings the wasp eggs out of diapause. Finally, we discuss the consequences of this finding for our understanding of the tick microbiome, and their possible role in horizontal gene transfer among pathogenic and symbiotic bacteria.
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
Flores-Fernández José Miguel; Gutiérrez-Ortega Abel; Padilla-Camberos Eduardo; Rosario-Cruz Rodrigo; Hernández-Gutiérrez Rodolfo; Martínez-Velázquez Moisés
The cattle tick Rhipicephalus (Boophilus) microplus is the most economically important ectoparasite affecting the cattle industry in tropical and subtropical areas around the world. The principal method of tick control has relied mainly on the use of chemical acaricides, including ivermectin; however, cattle tick populations resistant to ivermectin have recently been reported in Brazil, Mexico, and Uruguay. Currently, the molecular basis for ivermectin susceptibility and resistance are not we...
The sand fly Phlebotomus papatasi is an important blood feeder and the main vector of the trypanosomatid protozoa Leishmania major, which causes leishmaniasis in parts of the Afro-Eurasian region. The black- legged tick Ixodes scapularis is the primary tick vector of the bacterium Borrelia burgdorfe...
Kang, Jun-Gu; Ko, Sungjin; Kim, Heung-Chul; Chong, Sung-Tae; Klein, Terry A; Chae, Jeong-Byoung; Jo, Yong-Sun; Choi, Kyoung-Seong; Yu, Do-Hyeon; Park, Bae-Keun; Park, Jinho; Chae, Joon-Seok
Deer serve as reservoirs of tick-borne pathogens that impact on medical and veterinary health worldwide. In the Republic of Korea, the population of Korean water deer (KWD, Hydropotes inermis argyropus) has greatly increased from 1982 to 2011, in part, as a result of reforestation programs established following the Korean War when much of the land was barren of trees. Eighty seven Haemaphysalis flava, 228 Haemaphysalis longicornis, 8 Ixodes nipponensis, and 40 Ixodes persulcatus (21 larvae, 114 nymphs, and 228 adults) were collected from 27 out of 70 KWD. A total of 89/363 ticks (266 pools, 24.5% minimum infection rate) and 5 (1.4%) fed ticks were positive for Anaplasma phagocytophilum using nested PCR targeting the 16S rRNA and groEL genes, respectively. The 16S rRNA gene fragment sequences of 88/89 (98.9%) of positive samples for A. phagocytophilum corresponded to previously described gene sequences from KWD spleen tissues. The 16S rRNA gene fragment sequences of 20/363 (5.5%) of the ticks were positive for A. bovis and were identical to previously reported sequences. Using the ITS specific nested PCR, 11/363 (3.0%) of the ticks were positive for Bartonella spp. This is the first report of Anaplasma and Bartonella spp. detected in ticks collected from KWD, suggesting that ticks are vectors of Anaplasma and Bartonella spp. between reservoir hosts in natural surroundings.
Flores, Fernando Sebastián; Costa, Francisco Borges; Nava, Santiago; Diaz, Luiz Adrián; Labruna, Marcelo Bahia
Several tick-borne Rickettsia species are recognized human pathogens in Argentina. Here we evaluated rickettsial infection in ticks collected on passerine birds during 2011-2012 in two eco-regions of Argentina. The ticks were processed by molecular analysis through polymerase chain reaction (PCR) detection and DNA sequencing of fragments of two rickettsial genes, gltA and ompA. A total of 594 tick specimens (532 larvae and 62 nymphs), representing at least 4 species (Amblyomma tigrinum, Ixodes pararicinus, Haemaphysalis juxtakochi, Haemaphysalis leporispalustris), were evaluated. At least one A. tigrinum larva, collected on Coryphospingus cucullatus in Chaco Seco, was infected with Rickettsia parkeri, whereas at least 12 larvae and 1 nymph of I. pararicinus, collected from Troglodytes aedon, Turdus amaurochalinus, Turdus rufiventris, C. cucullatus and Zonotrichia capensis, were infected with an undescribed Rickettsia agent, genetically related to several rickettsial endosymbionts of ticks of the Ixodes ricinus complex. R. parkeri is a recognized human pathogen in several American countries including Argentina, where a recent study incriminated A. tigrinum as the potential vector of R. parkeri to humans. Birds could play an important role in dispersing R. parkeri-infected A. tigrinum ticks. Additionally, we report for the first time a rickettsial agent infecting I. pararicinus ticks.
Moslem Sarani; Zakkyeh Telmadarraiy; Abdolreza Salahi Moghaddam; Kamal Azam; Mohammad Mehdi Sedaghat
Objective: To determine the prevalence of ticks on cattle in the mountainous areas of Golestan province and their geographical distribution.Methods:collection was carried out during four seasons, twice per season over a period of 12 month from March 2009 through February 2010 in two districts, Azadshahr and Ramian. Meteorological data were obtained from Iran Meteorological Organization. The geographical points recorded using a Garmin eTrex®H GPS.Results:In total, 498 animals from 25 herds were selected to search for ticks in 2009-2010. Tick 63 goats, 99 cows and 13 camels in two districts of the mountainous area of Golestan province, including Azadshahr and Ramian. Five species of ixodid ticks were identified: Rhipicephalussanguineus A total of 255 ticks were collected from a total of 219 ruminants including 44 sheep, anatolicum (6%) and Hyalomma asiaticum (4%). The densities of infestations were calculated for sheep, goats, cows and camels 0.9, 0.79, 0.16 and 0.43 respectively. Seasonal activity of each ixodid tick infesting domestic ruminants was determined. The distribution maps showed ixodid ticks on domestic ruminants, and Rhipicephalus sanguineus were dominant species in the area.Conclusions:Such research provides necessary information for human and animal health (66.5%), Rhipicephalus bursa (4.6%), Hyalomma marginatum (19.9%), Hyalomma service mangers to have a better understanding of prevention and control of vector borne diseases especially during the outbreaks.
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.
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.
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.
Joyce M. Sakamoto
Full Text Available The blacklegged tick Ixodes scapularis is widely distributed in the United States and transmits multiple pathogens to humans, wildlife and domestic animals. Recently, several novel viruses in the family Bunyaviridae (South Bay virus (SBV and Blacklegged tick phlebovirus (BTPV were identified infecting female I. scapularis ticks collected in New York State. We used metagenomic sequencing to investigate the distribution of viruses infecting male and female I. scapularis ticks collected in Centre County, Pennsylvania. We identified both SBV and BTPV in both male and female ticks from all collection locations. The role of male I. scapularis in pathogen epidemiology has been overlooked because they rarely bite and are not considered important pathogen vectors. However, males may act as reservoirs for pathogens that can then be transmitted to females during mating. Our data highlight the importance of examining all potential avenues of pathogen maintenance and transmission throughout the vector-pathogen life cycle in order to understand the epidemiology of tick-borne pathogens.
Tick-borne disease in general is among the most important vector-borne diseases that are emerging as a threat to humans and is currently identified as a major health problem in many countries. Tick-borne encephalitis and lyme borreliosis are the main diseases transmitted by Ixodes ricinus ticks in Europe. Besides TBEV (Tick-borne encephalitis virus) and Borrelia burgdorferi sensu lato, I. ricinus is known to transmit other pathogenic microorganisms like- louping ill virus, Anaplasma phagocyto...
Masala, Giovanna; Chisu, Valentina; Foxi, Cipriano; Socolovschi, Christina; Raoult, Didier; Parola, Philippe
Canine monocytic ehrlichiosis is a common and widespread disease. This disease is present in Sardinia year-round because the temperate weather on the island permits the survival of many types of tick vectors. A total of 35 ticks was collected from goats in south-eastern Sardinia, Italy, and tested for Ehrlichia DNA using polymerase chain reaction and DNA sequencing. This study provides the first evidence of the presence of Ehrlichia canis in Rhipicephalus bursa ticks. The data presented here increase our knowledge of tick-borne diseases in Sardinia and provide a useful contribution toward understanding their epidemiology. The role of R. bursa in the life cycle and transmission of E. canis needs however further investigation.
Ogrzewalska, Maria; Schwarcz, Kaiser; Bajay, Miklos M; Bajay, Stephanie K; Pinheiro, José B; Zucchi, Maria I; Pinter, Adriano; Labruna, Marcelo B
The hard tick Amblyomma aureolatum (Pallas) is a vector of the bacterium Rickettsia rickettsii, the etiologic agent of Brazilian spotted fever (BSF) in parts of Brazil. Despite its wide distribution in southeastern South America and its public health importance, there is no information about genetic variation of this species that might help to understand the epidemiology of BSF. Using data from eight microsatellite markers and ticks from six localities, we used a population genetics approach to test the hypothesis that tick populations from areas with the presence of R. rickettsii are genetically different from ticks from areas without R. rickettsii Contrary to expectations, we found low genetic structure between studied regions. Thus, the presence of R. rickettsii in the specific area is more likely correlated with ecological and the environmental conditions or due to unknown gene coding regions of A. aureolatum genome that would be related to R. rickettsii infection resistance.
Bouattour, A; Darghouth, M A; Daoud, A
Ticks (Ixodidae) play a significant role as vectors of pathogens of domestic animals in Tunisia. The major losses caused by ticks are related to transmission of protozoan parasites. These include agents of tropical theileriosis and babesiosis in ruminants. Since 1991, we conducted research studies on tick population of livestock in Tunisia. This overview reports a synthesis on tick distribution, their biology and their role as vectors of pathogens in domestic animals, particularly cattle. During the whole period of the study about 15,000 tick specimens were collected from different zones of the country. A total of 14 species were identified. Hyalomma detritum detritum was the most abundant and important (vector of Theileria annulata) species infesting cattle. Hyalomma dromedarii and Hyalomma impeltatum were collected on domestic ruminants in the arid and desertic zones. Hyalomma marginatum marginatum and Hyalomma anatolicum excavatum were widespread and found on livestock hosts. Ixodes ricinus, vector of Babesia divergens and Borrelia burgdorferi sl, colonises mainly the humid zone. Boophilus annulatus and Rhipicephalus bursa infesting cattle, sheep and goats were found in the sub-humid and semi-arid zones. Haemaphysalis sulcata and Hae. punctata were collected in humid and sub-humid zones on cattle and sheep. Rhipicephalus turanicus were collected in different regions, on different animal species. Rhipicephalus sanguineus, tick of dogs, were often collected on livestock. Only few specimens of Hyalomma marginatum rufipes and Hyalomma franchinii were collected.
found to have elevated antibody titers to Ehrlichia canis . In addition, 10/12 MWDs on temporary duty (TDY) to the Volant Scorpion training course tested...cases of "canine ehrlichiosis" are indeed caused by Ehrlichia canis is unknown at this time, but cases of suspected E. canis infection have been...disease in dogs is caused by Ehrlichia canis , an obligate intracellar rickettsia that parasitizes leukocytes of wild and domestic Canidae, and the brown
The cattle fever tick, Rhipicephalus (Boophilus) microplus is one of the most significant medical veterinary pests in the world, vectoring several serious livestock diseases negatively impacting agricultural economies of tropical and subtropical countries around the world. We assembled the complete ...
Moniuszko, Anna; Rückert, Claudia; Alberdi, M. Pilar; Barry, Gerald; Stevenson, Brian; Fazakerley, John K.; Kohl, Alain; Bell-Sakyi, Lesley
Ticks transmit various human and animal microbial pathogens and may harbour more than one pathogen simultaneously. Both viruses and bacteria can trigger, and may subsequently suppress, vertebrate host and arthropod vector anti-microbial responses. Microbial coinfection of ticks could lead to an advantage or disadvantage for one or more of the microorganisms. In this preliminary study, cell lines derived from the ticks Ixodes scapularis and Ixodes ricinus were infected sequentially with 2 arthropod-borne pathogens, Borrelia burgdorferi s.s., Ehrlichia ruminantium, or Semliki Forest virus (SFV), and the effect of coinfection on the replication of these pathogens was measured. Prior infection of tick cell cultures with the spirochaete B. burgdorferi enhanced subsequent replication of the rickettsial pathogen E. ruminantium whereas addition of spirochaetes to cells infected with E. ruminantium had no effect on growth of the latter. Both prior and subsequent presence of B. burgdorferi also had a positive effect on SFV replication. Presence of E. ruminantium or SFV had no measurable effect on B. burgdorferi growth. In tick cells infected first with E. ruminantium and then with SFV, virus replication was significantly higher across all time points measured (24, 48, 72 h post infection), while presence of the virus had no detectable effect on bacterial growth. When cells were infected first with SFV and then with E. ruminantium, there was no effect on replication of either pathogen. The results of this preliminary study indicate that interplay does occur between different pathogens during infection of tick cells. Further study is needed to determine if this results from direct pathogen–pathogen interaction or from effects on host cell defences, and to determine if these observations also apply in vivo in ticks. If presence of one pathogen in the tick vector results in increased replication of another, this could have implications for disease transmission and incidence
Moniuszko, Anna; Rückert, Claudia; Alberdi, M Pilar; Barry, Gerald; Stevenson, Brian; Fazakerley, John K; Kohl, Alain; Bell-Sakyi, Lesley
Ticks transmit various human and animal microbial pathogens and may harbour more than one pathogen simultaneously. Both viruses and bacteria can trigger, and may subsequently suppress, vertebrate host and arthropod vector anti-microbial responses. Microbial coinfection of ticks could lead to an advantage or disadvantage for one or more of the microorganisms. In this preliminary study, cell lines derived from the ticks Ixodes scapularis and Ixodes ricinus were infected sequentially with 2 arthropod-borne pathogens, Borrelia burgdorferi s.s., Ehrlichia ruminantium, or Semliki Forest virus (SFV), and the effect of coinfection on the replication of these pathogens was measured. Prior infection of tick cell cultures with the spirochaete B. burgdorferi enhanced subsequent replication of the rickettsial pathogen E. ruminantium whereas addition of spirochaetes to cells infected with E. ruminantium had no effect on growth of the latter. Both prior and subsequent presence of B. burgdorferi also had a positive effect on SFV replication. Presence of E. ruminantium or SFV had no measurable effect on B. burgdorferi growth. In tick cells infected first with E. ruminantium and then with SFV, virus replication was significantly higher across all time points measured (24, 48, 72h post infection), while presence of the virus had no detectable effect on bacterial growth. When cells were infected first with SFV and then with E. ruminantium, there was no effect on replication of either pathogen. The results of this preliminary study indicate that interplay does occur between different pathogens during infection of tick cells. Further study is needed to determine if this results from direct pathogen-pathogen interaction or from effects on host cell defences, and to determine if these observations also apply in vivo in ticks. If presence of one pathogen in the tick vector results in increased replication of another, this could have implications for disease transmission and incidence.
scaled models, TV-egility is an Interdisciplinary subject involving a revolution in engineering and pilot education, References I. Gel -Or, B...er 85-4014. Agility in Demand’, Aerospace America. Vol. 26, Hay 1988, pp. 56-58. 6. HerbaL , W. 8., "Thrust Vectoring - Why and How ?" ISABE-87-7061
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.
Alberdi, M. Pilar; Dalby, Matthew J.; Rodriguez-Andres, Julio; Fazakerley, John K.; Kohl, Alain; Bell-Sakyi, Lesley
As well as being vectors of many viral, bacterial, and protozoan pathogens of medical and veterinary importance, ticks harbour a variety of microorganisms which are not known to be pathogenic for vertebrate hosts. Continuous cell lines established from ixodid and argasid ticks could be infected with such endosymbiotic bacteria and endogenous viruses, but to date very few cell lines have been examined for their presence. DNA and RNA extracted from over 50 tick cell lines deposited in the Roslin Wellcome Trust Tick Cell Biobank (http://tickcells.roslin.ac.uk) were screened for presence of bacteria and RNA viruses, respectively. Sequencing of PCR products amplified using pan-16S rRNA primers revealed the presence of DNA sequences from bacterial endosymbionts in several cell lines derived from Amblyomma and Dermacentor spp. ticks. Identification to species level was attempted using Rickettsia- and Francisella-specific primers. Pan-Nairovirus primers amplified PCR products of uncertain specificity in cell lines derived from Rhipicephalus, Hyalomma, Ixodes, Carios, and Ornithodoros spp. ticks. Further characterisation attempted with primers specific for Crimean-Congo haemorrhagic fever virus segments confirmed the absence of this arbovirus in the cells. A set of pan-Flavivirus primers did not detect endogenous viruses in any of the cell lines. Transmission electron microscopy revealed the presence of endogenous reovirus-like viruses in many of the cell lines; only 4 of these lines gave positive results with primers specific for the tick Orbivirus St Croix River virus, indicating that there may be additional, as yet undescribed ‘tick-only’ viruses inhabiting tick cell lines. PMID:22743047
Alberdi, M Pilar; Dalby, Matthew J; Rodriguez-Andres, Julio; Fazakerley, John K; Kohl, Alain; Bell-Sakyi, Lesley
As well as being vectors of many viral, bacterial, and protozoan pathogens of medical and veterinary importance, ticks harbour a variety of microorganisms which are not known to be pathogenic for vertebrate hosts. Continuous cell lines established from ixodid and argasid ticks could be infected with such endosymbiotic bacteria and endogenous viruses, but to date very few cell lines have been examined for their presence. DNA and RNA extracted from over 50 tick cell lines deposited in the Roslin Wellcome Trust Tick Cell Biobank (http://tickcells.roslin.ac.uk) were screened for presence of bacteria and RNA viruses, respectively. Sequencing of PCR products amplified using pan-16S rRNA primers revealed the presence of DNA sequences from bacterial endosymbionts in several cell lines derived from Amblyomma and Dermacentor spp. ticks. Identification to species level was attempted using Rickettsia- and Francisella-specific primers. Pan-Nairovirus primers amplified PCR products of uncertain specificity in cell lines derived from Rhipicephalus, Hyalomma, Ixodes, Carios, and Ornithodoros spp. ticks. Further characterisation attempted with primers specific for Crimean-Congo haemorrhagic fever virus segments confirmed the absence of this arbovirus in the cells. A set of pan-Flavivirus primers did not detect endogenous viruses in any of the cell lines. Transmission electron microscopy revealed the presence of endogenous reovirus-like viruses in many of the cell lines; only 4 of these lines gave positive results with primers specific for the tick Orbivirus St Croix River virus, indicating that there may be additional, as yet undescribed 'tick-only' viruses inhabiting tick cell lines.
Najm, Nour-Addeen; Meyer-Kayser, Elisabeth; Hoffmann, Lothar; Herb, Ingrid; Fensterer, Veronika; Pfister, Kurt; Silaghi, Cornelia
Wild canines which are closely related to dogs constitute a potential reservoir for haemoparasites by both hosting tick species that infest dogs and harbouring tick-transmitted canine haemoparasites. In this study, the prevalence of Babesia spp. and Theileria spp. was investigated in German red foxes (Vulpes vulpes) and their ticks. DNA extracts of 261 spleen samples and 1953 ticks included 4 tick species: Ixodes ricinus (n=870), I. canisuga (n=585), I. hexagonus (n=485), and Dermacentor reticulatus (n=13) were examined for the presence of Babesia/Theileria spp. by a conventional PCR targeting the 18S rRNA gene. One hundred twenty-one out of 261 foxes (46.4%) were PCR-positive. Out of them, 44 samples were sequenced, and all sequences had 100% similarity to Theileria annae. Similarly, sequencing was carried out for 65 out of 118 PCR-positive ticks. Theileria annae DNA was detected in 61.5% of the sequenced samples, Babesia microti DNA was found in 9.2%, and Babesia venatorum in 7.6% of the sequenced samples. The foxes were most positive in June and October, whereas the peak of tick positivity was in October. Furthermore, the positivity of the ticks was higher for I. canisuga in comparison to the other tick species and for nymphs in comparison to adults. The high prevalence of T. annae DNA in red foxes in this study suggests a reservoir function of those animals for T. annae. To our knowledge, this is the first report of T. annae in foxes from Germany as well as the first detection of T. annae and B. microti in the fox tick I. canisuga. Detection of DNA of T. annae and B. microti in three tick species collected from foxes adds new potential vectors for these two pathogens and suggests a potential role of the red fox in their natural endemic cycles.
Mehlhorn, Heinz; Mehlhorn, Tim; Müller, Melanie; Vogt, Manfred; Rissland, Jürgen
Ixodid ticks are important vectors of human pathogens in Central Europe. Despite this fact, prevalence studies are scarce, especially with regard to much-frequented peri-urban recreation sites. In this pilot study, 4.014 larvae, nymphs and adult ticks sampled monthly during the active seasons in 2011 and 2012 from 14 distinct collection sites in two German states (Saarland and Rhineland-Palatinate) were screened for Borrelia spp., Anaplasma spp. and tick-borne encephalitis virus. Mean prevalence rates were 19.8 % for Borrelia spp., 1.9 % for Anaplasma spp. and 0.1 % for tick-borne encephalitis virus (TBEV), which are in accordance with those reported from other regions in Germany and neighbouring countries. Nevertheless, the detection of TBEV-infected ticks is the first positive result after several unsuccessful efforts over the previous years in official "TBE-risk" zones of Saarland and Rhineland-Palatinate which supports the presumption of the origin of observed local infection. Besides ixodid ticks a non-engorged adult female tick of the invading species Dermacentor reticulatus has been found reflecting the appearance of another vector eventually jeopardising the health of host animals as well as humans.
李娟; 孙铭飞; 姜东续; 吴大成; 吴彩艳; 廖申权; 戚南山; 吕敏娜; 杨丽云; 吴玄光
Tick is an important contributor to vector-borne diseases in China and tick-borne diseases have at-tracted much attention because of their increasing incidence and consequent significant harm to livestock and human health.The special climate,geography resources and dietary habits in Guangdong province provide good conditions for the survival of wildlife as well as increase the chances of people contacting with animals,which is helpful for tick and tick-borne disease spread.The most commonly observed tick species in Guangdong province contain 6 genus and 21 species,and human tick-borne diseases in Guangdong prov-ince include Lyme borreliosis,Q-fever,North-Asia tick-borne spotted fever and human granulocytic ana-plasmosis.Detailed information regarding the current epidemic status of tick and major tick-borne diseases in Guangdong province were reviewed in this paper,which would make efforts in government management and research for the prevention,control,diagnosis,and treatment of tick-borne diseases,as well as for the control of ticks.%蜱在吸食动物血液的同时可传播多种病原体，引发重要的人兽共患蜱传病，给人类健康和畜牧业发展带来严重危害，具有重要的公共卫生意义。近年来不断上升的发病率愈发引起人们的关注。广东省特殊的气候、地理资源环境和饮食习惯不但为野生动植物的生存提供了良好的环境，同时也增加了人与动物接触的机会，为新的蜱种和蜱媒病传播提供了方便。目前广东省分布流行的蜱种主要涉及6属21种，已经证实存在的蜱传病有莱姆病、Q 热、北亚蜱传斑点热和人粒细胞无形体。论文就广东省蜱的种类分布以及蜱传病的流行概况做一综述，为广东省蜱传病的防控措施制定及传播机制研究提供参考。
Wen, Jing; Jiao, Dan; Wang, Jian-Hua; Yao, De-Hai; Liu, Zhi-Xiang; Zhao, Gang; Ju, Wen-Dong; Cheng, Cheng; Li, Yi-Jing; Sun, Yi
Since the year 2000, clinical patterns resembling tick-borne rickettsioses have been noticed in China-Russia border areas. Epidemiological data regarding species of the aetiological agent, tick vector prevalence and distribution as well as incidence of human cases in the areas are still sparse to date. In order to identify Rickettsia species occurring in the areas, we investigated Dermacentor silvarum collected in the selected areas. Rickettsia raoultii was the predominant Rickettsia found in D. silvarum evident with ompA, ompB, gltA and 17 kDa protein genes. The Rickettsia prevalence in D. silvarum appeared to be 32.25 % with no sex difference. The results extend the common knowledge about the geographic distribution of R. raoultii and its candidate vector tick species, which suggest an emerged potential threat of human health in the areas.
Full Text Available Introduction. Tick-borne meningoencephalitis virus is a flavivirus that causes the most important vector-borne central nervous system infection in many countries of Europe and Asia. There are three subtypes of tick-borne encephalitis virus: European, Siberian and the Far-Eastern subtype. Transmission. In endemic areas, the virus remains in transmissive cycles between Ixodes ticks and small rodents. Clinical picture. In most cases (70−98% infection goes asymptomatically. In about one-third of meningitis cases, meningoencephalitis or meningomyelitis is developed. Postencephalytic syndrome may be the complication of the infection, presenting with neurological symptoms. Diagnosis. Etiologic diagnosis of tick-borne meningoencephalitis is only made on basis of laboratory analyses. Reverse transcription-polymerase chain reaction is used for determining the presence of virus in the blood and cerebrospinal fluid. Antibodies in blood and cerebrospinal fluid can be detected by serological tests. Prevention. The most efficient way to control this potentially severe disease with possible serious long-term consequences is vaccination. It should be recommended to persons who live or travel to endemic areas. Conclusion. In Serbia, tick-borne encephalitis virus infection belongs to the list of reportable diseases; however, there are no reported cases because the diagnostics is not performed routinely. We believe that the significance of this zoonosis must be examined in our country and some of its parts because of preliminary positive serological findings found out in Vojvodina as well as because of reported cases in neighboring countries such as Hungary and Croatia and its worldwide distribution.
Nady M. Asmaa
Full Text Available An epidemiological study was conducted at Benisuef district to determine the current situation and associated determinants of tick infestations in ruminants and to assess the efficacy of three different types of insecticides against tick infestation under field conditions. Total of (1082 animals of different species (540 cattle, 230 buffaloes, 108 of each sheep & goats and 96 camels were selected randomly and examined carefully for tick infestation. About (30.1% of total observed animals were found tick infested with highest rate in cattle (60.5% followed by goats (25.9%, buffaloes (17.8%, sheep (14.8% while no tick infestation recorded in camels. The most prevalent tick's species affecting ruminants was Boophilus annulatus (26.5% followed by Hyalomma anatolicum (6.1% then Rhipicephalus turanicus (3.4%. Regarding the associated risk factors, tick infestation was found statistically significant (P 3 years (78.8% followed by at age, ≤2 months (57.8% and during summer months were found highly significant (P < 0.01 in cattle ( 76.5% followed by goats and sheep (33.3% & 22.9% resp., comparing with results in winter. The preferred sites of ticks' attachment to infested animals were udders and external genitalia (70.7% of each then Neck & chest (63.0% of each, inner thighs (61.1%, perineum (41.7%, ears (14.6%, around eyes (11.7%. The obtained results revealed that poor husbandry practices of small holder farmers be a determinant making the animals more prone to tick infestation in this district. Improving the hygienic conditions associated with treatment of infested cattle with Ivermectin (0.2 mg/kg b.wt, S/C and spraying of Deltamethrin (1% for surrounding environment twice every 14 days are recommended for control of tick infestation under field condition.
Full Text Available Abstract Background Neoehrlichia mikurensis s an emerging and vector-borne zoonosis: The first human disease cases were reported in 2010. Limited information is available about the prevalence and distribution of Neoehrlichia mikurensis in Europe, its natural life cycle and reservoir hosts. An Ehrlichia-like schotti variant has been described in questing Ixodes ricinus ticks, which could be identical to Neoehrlichia mikurensis. Methods Three genetic markers, 16S rDNA, gltA and GroEL, of Ehrlichia schotti-positive tick lysates were amplified, sequenced and compared to sequences from Neoehrlichia mikurensis. Based on these DNA sequences, a multiplex real-time PCR was developed to specifically detect Neoehrlichia mikurensis in combination with Anaplasma phagocytophilum in tick lysates. Various tick species from different life-stages, particularly Ixodes ricinus nymphs, were collected from the vegetation or wildlife. Tick lysates and DNA derived from organs of wild rodents were tested by PCR-based methods for the presence of Neoehrlichia mikurensis. Prevalence of Neoehrlichia mikurensis was calculated together with confidence intervals using Fisher's exact test. Results The three genetic markers of Ehrlichia schotti-positive field isolates were similar or identical to Neoehrlichia mikurensis. Neoehrlichia mikurensis was found to be ubiquitously spread in the Netherlands and Belgium, but was not detected in the 401 tick samples from the UK. Neoehrlichia mikurensis was found in nymphs and adult Ixodes ricinus ticks, but neither in their larvae, nor in any other tick species tested. Neoehrlichia mikurensis was detected in diverse organs of some rodent species. Engorging ticks from red deer, European mouflon, wild boar and sheep were found positive for Neoehrlichia mikurensis. Conclusions Ehrlichia schotti is similar, if not identical, to Neoehrlichia mikurensis. Neoehrlichia mikurensis is present in questing Ixodes ricinus ticks throughout the
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
Meng Li; Jian Liu; Shu-Sheng Liu
To better understand the etiology of begomovirus epidemics in regions under invasion we need to know how indigenous and invasive whitefly vectors respond to virus infection.We investigated both direct and indirect effects of infection with Tomato yellow leaf curl virus(TYLCV)on the performance of the invasive Q biotype and the indigenous Asian ZHJ2 biotype of whitefly Bemisia tabaci.The Q biotype performed better than the ZHJ2 biotype on either uninfected or virus-infected tomato plants.However,virus-infection of host plants did not,or only marginally affected,the performance of either biotype of whiteflies m terms of fecundity,longevity,survival,development and population increase.Likewise,association of the vectors with TYLCV did not affect fecundity and longevity of the Q or ZHJ2 biotypes on cotton,a non-host of TYLCV.These results indicate that the alien Q biotype whitefly,but not the indigenous ZHJ2 biotype,is likely to become the major vector of TYLCV in the field and facilitate virus epidemics.
Full Text Available The results of the study of parasitic systems of associated with ixodal ticks infections in the Lviv region for the period 2007-2012 were analyzed. The main vectors and reservoirs, carrying at the present stage a high loimopotential of natural dangerous diseases foci were submitted.
Boophilus ticks are vectors of Babesia bovis, the protozoan causative agent of cattle fever, a disease which is responsible for significant production losses to cattle producers in much of Africa, Central and South America and Australia. We utilized subtractive cDNA library synthesis techniques to o...
Medlock, Jolyon M.; Hansford, Kayleigh M.; Bormane, Antra;
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 opini...
Katargina, Olga; Russakova, Stanislava; Geller, Julia; Kondrusik, Macije; Zajkowska, Joanna; Zygutiene, Milda; Bormane, Antra; Trofimova, Julia; Golovljova, Irina
Ticks were collected from the vegetation in the Baltic countries Estonia, Latvia, Lithuania and eastern Poland and analyzed for the presence of tick-borne encephalitis virus (TBEV) by amplification of the partial E and NS3 genes. In Estonia we found statistically significant differences in the TBEV prevalence between I. persulcatus and I. ricinus ticks (4.23% and 0.42%, respectively). In Latvia, the difference in TBEV prevalence between the two species was not statistically significant (1.02% for I. persulcatus and 1.51% for I. ricinus, respectively). In Lithuania and Poland TBEV was detected in 0.24% and 0.11% of I. ricinus ticks, respectively. Genetic characterization of the partial E and NS3 sequences demonstrated that the TBEV strains belonged to the European subtype in all countries, as well as to the Siberian subtype in Estonia. We also found that in areas where ranges of two tick species overlap, the TBEV subtypes may be detected not only in their natural vector, but also in sympatric tick species. PMID:23650497
Full Text Available BACKGROUND: 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. METHODOLOGY/PRINCIPAL FINDINGS: 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. CONCLUSIONS/SIGNIFICANCE: 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.
Bonilla, Denise; Eremeeva, Marina E.; Glaser, Carol; Lane, Robert S.; Porse, Charsey Cole; Castro, Martin B.; Messenger, Sharon; Espinosa, Alex; Hacker, Jill; Kjemtrup, Anne; Ryan, Bonnie; Scott, Jamesina J.; Hu, Renjie; Yoshimizu, Melissa Hardstone; Dasch, Gregory A.; Kramer, Vicki
Rickettsia philipii (type strain “Rickettsia 364D”), the etiologic agent of Pacific Coast tick fever (PCTF), is transmitted to people by the Pacific Coast tick, Dermacentor occidentalis. Following the first confirmed human case of PCTF in 2008, 13 additional human cases have been reported in California, more than half of which were pediatric cases. The most common features of PCTF are the presence of at least one necrotic lesion known as an eschar (100%), fever (85%), and headache (79%); four case-patients required hospitalization and four had multiple eschars. Findings presented here implicate the nymphal or larval stages of D. occidentalis as the primary vectors of R. philipii to people. Peak transmission risk from ticks to people occurs in late summer. Rickettsia philipii DNA was detected in D. occidentalis ticks from 15 of 37 California counties. Similarly, non-pathogenic Rickettsia rhipicephali DNA was detected in D. occidentalis in 29 of 38 counties with an average prevalence of 12.0% in adult ticks. In total, 5,601 ticks tested from 2009 through 2015 yielded an overall R. philipii infection prevalence of 2.1% in adults, 0.9% in nymphs and a minimum infection prevalence of 0.4% in larval pools. Although most human cases of PCTF have been reported from northern California, acarological surveillance suggests that R. philipii may occur throughout the distribution range of D. occidentalis. PMID:27706171
Wu, Xiaotian; Röst, Gergely; Zou, Xingfu
Many observational studies suggest that seasonal migratory birds play an important role in spreading Ixodes scapularis, a vector of Lyme disease, along their migratory flyways, and they are believed to be responsible for geographic range expansion of I. scapularis in Canada. However, the interplay between the dynamics of I. scapularis on land and migratory birds in the air is not well understood. In this study, we develop a periodic delay meta-population model which takes into consideration the local landscape for tick reproduction within patches and the times needed for ticks to be transported by birds between patches. Assuming that the tick population is endemic in the source region, we find that bird migration may boost an already established tick population at the subsequent region and thus increase the risk to humans, or bird migration may help ticks to establish in a region where the local landscape is not appropriate for ticks to survive in the absence of bird migration, imposing risks to public health. This theoretical study reveals that bird migration plays an important role in the geographic range expansion of I. scapularis, and therefore our findings may suggest some strategies for Lyme disease prevention and control.
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.
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.
Alekseev, A N; Dubinina, H V; Antykova, L P; Dzhivanyan, T I; Rijpkema, S G; Kruif, N V; Cinco, M
Two isolated Baltic seashore populations of Ixodes ticks were studied as vectors of different Borrelia genospecies in Russia by using darkfield microscopy and modified polymerase chain reaction (PCR). In the Kalinigrad region (Kurish Spit, forests near the settlements of Lesnoye and Rybachy), 788 Ixodes ricinus (L.) adults and nymphs were collected by flagging and studied by darkfield microscopy during 1995-1996. There were 88 darkfield microscopy positive specimens (11.2%) of which 69 were also analyzed by PCR. Borrelia afzelii and B. garinii were found individually and together in ticks. In this region, on the Kurish Spit, 7 patients with tick borrelioses were observed: 2 in the Russian part of Spit and 5 in the Lithuanian part. A significant difference was found between Borrelia prevalence during the spring and fall peaks of tick abundance. Specimens that were darkfield microscopy positive prevailed in the fall (25.15%) in comparison with the spring peak (7.3%). The number of specimens with identified genospecies prevailed in the spring: 22 out of 35 versus 4 out of 31 in the fall. Among 29 PCR positive I. ricinus, 21 contained B. afzelii, 3 had B. garinii, and 2 had dual infection. In 1995, only B. afzelii infected specimens were observed. In the vicinity of St. Petersburg (the seashore of the northern Gulf of Finland, in forests near Lisy Nos, Morskaja) during 1992-1996, 31 patients with a tick-borne borrelioses were registered. We collected 487 Ixodes persulcatus Schulze by flagging and studied them by darkfield microscopy in 1995-1996 of which 144 ticks (29.6%) were darkfield microscopy positive. Sixty darkfield-positive specimens were analyzed by PCR, and in 88.3% of cases genospecies were identified. B. afzelii and B. garinii were identified individually and together in ticks. In 1995, I. persulcatus with dual infection prevailed with 11 out of 21 (52.4% positive), whereas in 1996, most I. persulcatus ticks contained B. garinii (81.2%). Dual infection was
Temeyer, Kevin B; Tuckow, Alexander P; Brake, Danett K; Li, Andrew Y; Pérez de León, Adalberto A
Acetylcholinesterase (AChE) is the biochemical target of organophosphate (OP) and carbamate pesticides for invertebrates, vertebrate nerve agents, and AChE inhibitors used to reduce effects of Alzheimer's disease. Organophosphate pesticides (OPs) are widely used to control blood-feeding arthropods, including biting flies and ticks. However, resistance to OPs in pests affecting animal and human health has compromised control efficacy. OP resistance often results from mutations producing an OP-insensitive AChE. Our studies have demonstrated production of OP-insensitive AChEs in biting flies and ticks. Complementary DNA (cDNA) sequences encoding AChEs were obtained for the horn fly, stable fly, sand fly, and the southern cattle tick. The availability of cDNA sequences enables the identification of mutations, expression and characterization of recombinant proteins, gene silencing for functional studies, as well as in vitro screening of novel inhibitors. The southern cattle tick expresses at least three different genes encoding AChE in their synganglion, i.e. brain. Gene amplification for each of the three known cattle tick AChE genes and expression of multiple alleles for each gene may reduce fitness cost associated with OP-resistance. AChE hydrolyzes the neurotransmitter, acetylcholine, but may have additional roles in physiology and development. The three cattle tick AChEs possess significantly different biochemical properties, and are expressed in neural and non-neural tissues, which suggest separation of structure and function. The remarkable complexity of AChEs in ticks suggested by combining genomic data from Ixodes scapularis with our genetic and biochemical data from Rhipicephalus microplus is suggestive of previously unknown gene duplication and diversification. Comparative studies between invertebrate and vertebrate AChEs could enhance our understanding of structure-activity relationships. Research with ticks as a model system offers the opportunity to
Allerdice, Michelle E J; Hecht, Joy A; Karpathy, Sandor E; Paddock, Christopher D
Amblyomma maculatum Koch (the Gulf Coast tick) is an aggressive, human-biting ixodid tick distributed throughout much of the southeastern United States and is the primary vector for Rickettsia parkeri, an emerging human pathogen. Amblyomma maculatum has diverse host preferences that include white-tailed deer, a known reservoir for Ehrlichia and Anaplasma species, including the human pathogens E. ewingii and E. chaffeensis To examine more closely the potential role of A. maculatum in the maintenance of various pathogenic Ehrlichia and Anaplasma species, we screened DNA samples from 493 questing adult A. maculatum collected from six U.S. states using broad-range Anaplasmataceae and Ehrlichia genus-specific PCR assays. Of the samples tested, four (0.8%) were positive for DNA of Ehrlichia ewingii, one (0.2%) was positive for Anaplasma platys, and one (0.2%) was positive for a previously unreported Ehrlichia species closely related to Ehrlichia muris and an uncultivated Ehrlichia species from Haemaphysalis longicornis ticks in Japan. No ticks contained DNA of Ehrlichia chaffeensis, Ehrlichia canis, the Panola Mountain Ehrlichia, or Anaplasma phagocytophilum This is the first identification of E. ewingii, A. platys, and the novel Ehrlichia in questing Gulf Coast ticks; nonetheless the low prevalence of these agents suggests that A. maculatum is not likely an important vector of these zoonotic pathogens.
Hunfeld, K P; Brade, V
The three host-tick Ixodes (I.) ricinus is regarded as an important vector of tick-borne microorganisms pathogenic for humans in central Europe and is primarily known as the main vector of Borrelia (B.) burgdorferi and the virus causing tick-borne encephalitis (TBE), the most clinically relevant tick transmitted pathogens for humans in European countries. Furthermore, it is now well established that I. ricinus also transmits Ehrlichia (E.) phagocytophila, Babesia (Ba.) divergens, and Ba. microti, all agents of zoonotic infections in dear, sheep, cattle, dogs, and horses. In addition to their known zoonotic potential, recent molecular-epidemiological and seroepidemiological surveys as well as increasingly reported clinical cases of infections caused by these tick-borne organisms other than B. burgdorferi (TOBB) also strongly suggest a possible relevance of Babesia, Ehrlichia and Rickettsia for humans at risk in Europe. However, there are few medical microbiological investigations and epidemiological data on the distribution and relevance of Babesia for humans in our part of the northern hemisphere. There is also very little diagnostic and clinical knowledge on human babesiosis in many regions of Europe. Furthermore, sophisticated diagnostic tools designed for the reliable detection of the underlying pathogens, are not yet generally available to the microbiological laboratory. This review aims to provide basic information on human babesiosis and the most relevant causative pathogens of the disease in Europe and to draw attention to this parasitic infection as a possibly emerging and probably under-diagnosed disease in this part of the northern hemisphere.
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.
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.
Full Text Available Background: A molecular survey was conducted to investigate the presence of pathogenic Borrelia persica species causing the tick borne relapsing fever (TBRF in Takistan district Qazvin Province, western Iran. Methods: A number of 1021 soft ticks were collected from 31 villages including previously reported infected and none-infected TBRF cases and individually examined for the presence of B. persica DNA by conventional PCR targeting the 16S rRNA. Results: A total of 1021 soft ticks of three species of Ornithodouros tholozani (120: 11.75%, O. lahorensis (461: 45.15% and Argas persicus (440: 43.1% were collected and tested against Borrelia infection. Soft ticks were more prevalent (67% in infected areas than none infected areas. The rate O. tholozani in infected areas was much greater (29 times than none infected areas. Ninety seven percent of soft ticks in none infected areas were of O. tholozani. Sixteen (16.7% ticks of tested (n=95 O. tholozani were infected with B. persica. Three (1.3% out of 205 soft ticks of O. lahorensis were positive for Borrelia sp., and no infection was observed in A. persicus. TaqI RFLP analysis and sequence analysis of the positive PCR products showed the presence of B. persica. The RFLP analysis showed that the positive ticks of O. lahorensis were infected with unknown Borrelia species. Conclusion: This study showed that although there were no TBRF cases in Takisan, but still infected O. tholozani, the known vector of TBRF, presented in the region. Control measures needs to be fulfilled in Thakisan.
Full Text Available During 2012-2013, a total of 4325 host-seeking adult ticks belonging to the genus Ixodes were collected from various localities of Hokkaido, the northernmost island of Japan. Tick lysates were subjected to real-time PCR assay to detect borrelial infection. The assay was designed for specific detection of the Relapsing fever spirochete Borrelia miyamotoi and for unspecific detection of Lyme disease-related spirochetes. Overall prevalence of B. miyamotoi was 2% (71/3532 in Ixodes persulcatus, 4.3% (5/117 in Ixodes pavlovskyi and 0.1% (1/676 in Ixodes ovatus. The prevalence in I. persulcatus and I. pavlovskyi ticks were significantly higher than in I. ovatus. Co-infections with Lyme disease-related spirochetes were found in all of the tick species. During this investigation, we obtained 6 isolates of B. miyamotoi from I. persulcatus and I. pavlovskyi by culture in BSK-M medium. Phylogenetic trees of B. miyamotoi inferred from each of 3 housekeeping genes (glpQ, 16S rDNA, and flaB demonstrated that the Hokkaido isolates were clustered with Russian B. miyamotoi, but were distinguishable from North American and European B. miyamotoi. A multilocus sequence analysis using 8 genes (clpA, clpX, nifS, pepX, pyrG, recG, rplB, and uvrA suggested that all Japanese B. miyamotoi isolates, including past isolates, were genetically clonal, although these were isolated from different tick and vertebrate sources. From these results, B. miyamotoi-infected ticks are widely distributed throughout Hokkaido. Female I. persulcatus are responsible for most human tick-bites, thereby I. persulcatus is likely the most important vector of indigenous relapsing fever from tick bites in Hokkaido.
Pompo, K; Mays, S; Wesselman, C; Paulsen, D J; Fryxell, R T Trout
Anaplasma marginale is the causative agent for bovine anaplasmosis (BA) and Ehrlichia ruminantium is the causative agent for heartwater, 2 devastating diseases of cattle. BA is common in the United States and frequently reported in western Tennessee cattle; however, cases of heartwater are not yet established in the continental United States. Because both pathogens are transmitted via the bites of infected ticks, the objective of this study was to survey cattle and pastures for ticks and for each pathogen. University of Tennessee AgResearch has 7 research and education centers (REC) located throughout the state at which they manage cattle. Ticks were collected from selected cattle (every fourth to sixth animal) and pastures (via dragging) associated with the herd from each REC during the summer of 2013. A total of 512 ticks were collected from cattle (n = 386) and pastures (n = 126) and were PCR-screened for Anaplasma and Ehrlichia using genus-specific primers. Collections consisted of 398 (77.7%) Amblyomma americanum, 84 (16.4%) Amblyomma maculatum, and 30 (5.9%) Dermacentor variabilis. Ticks were not recovered from pastures or cattle east of the Tennessee Plateau. The North American vectors for An. marginale and E. ruminantium were identified (D. variabilis and A. maculatum, respectively), but neither pathogen was recovered. A large proportion of ticks were collected from cattle and, of these, a majority were attached to their host (compared to questing on their host or engorged on the host). Four A. americanum were positive for Ehrlichia spp. (Ehrlichia ewingii, Ehrlichia chaffeensis, and Panola Mountain Ehrlichia), all in western Tennessee. With the identification of a few Ehrlichia infections in cattle-associated ticks and current A. marginale rates in Tennessee beef cattle nearing 11%, additional research is needed to establish baseline tick, Anaplasma, and Ehrlichia data for future management studies.
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 (p<0.00001), but not in other states. The significance of the Midichloria-Wolbachia co-occurrence is unknown. Among ticks collected in Georgia, nymphs differed from adults in both the composition (p = 0.002) and structure (p = 0.002) of their bacterial communities. Adults differed only in their community structure (p = 0.002) with males 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
Amanda Jo Williams-Newkirk
Full Text Available 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 (p<0.00001, but not in other states. The significance of the Midichloria-Wolbachia co-occurrence is unknown. Among ticks collected in Georgia, nymphs differed from adults in both the composition (p = 0.002 and structure (p = 0.002 of their bacterial communities. Adults differed only in their community structure (p = 0.002 with males 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
Souza, Kathleen R; Ribeiro, Gilmar; Silva dos Santos, Carlos Gustavo; de Lima, Eliaci Couto; Melo, Paulo R S; Reis, Mitermayer G; Blanton, Ronald E; Silva, Luciano K
In order to evaluate subpopulation differentiation, effective population size (Ne) and evidence for population bottlenecks at various geographic levels, Aedes aegypti larvae were collected longitudinally from 2007 to 2009 from four areas in the city of Salvador, Brazil. The DNA from each larva was isolated and genotyped with five independent microsatellite markers. FST and Jost's D revealed significant population structuring (Pcontrol measures did contribute to vector reduction, but this was not enough to decrease A. aegypti population genetic diversity in Salvador. The understanding of A. aegypti population dynamics may be helpful for planning and evaluation of control measures to make them more effective.
Sandra J Raffel
Full Text Available Borrelia hermsii, a causative agent of relapsing fever of humans in western North America, is maintained in enzootic cycles that include small mammals and the tick vector Ornithodoros hermsi. In mammals, the spirochetes repeatedly evade the host's acquired immune response by undergoing antigenic variation of the variable major proteins (Vmps produced on their outer surface. This mechanism prolongs spirochete circulation in blood, which increases the potential for acquisition by fast-feeding ticks and therefore perpetuation of the spirochete in nature. Antigenic variation also underlies the relapsing disease observed when humans are infected. However, most spirochetes switch off the bloodstream Vmp and produce a different outer surface protein, the variable tick protein (Vtp, during persistent infection in the tick salivary glands. Thus the production of Vmps in mammalian blood versus Vtp in ticks is a dominant feature of the spirochete's alternating life cycle. We constructed two mutants, one which was unable to produce a Vmp and the other was unable to produce Vtp. The mutant lacking a Vmp constitutively produced Vtp, was attenuated in mice, produced lower cell densities in blood, and was unable to relapse in animals after its initial spirochetemia. This mutant also colonized ticks and was infectious by tick-bite, but remained attenuated compared to wild-type and reconstituted spirochetes. The mutant lacking Vtp also colonized ticks but produced neither Vtp nor a Vmp in tick salivary glands, which rendered the spirochete noninfectious by tick bite. Thus the ability of B. hermsii to produce Vmps prolonged its survival in blood, while the synthesis of Vtp was essential for mammalian infection by the bite of its tick vector.
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.
Folz, S D; Ash, K A; Conder, G A; Rector, D L
A topical formulation of amitraz (Mitaban Liquid Concentrate, The Upjohn Company, Kalamazoo, Michigan, U.S.A.) was evaluated as a tick repellent and detachment agent, and flea repellent. The diluted liquid concentrate (250 p.p.m. active drug) was topically applied as a single treatment to dogs; the concentration was identical to the rate recommended for treatment of demodicosis and scabies. Brown dog tick (Rhipicephalus sanguineus) and American dog tick (Dermacentor variabilis) populations were eliminated and repelled. Repellent activity (92-95%) was observed against R. sanguineus for 2 weeks post-treatment; the treatment was moderately active (63%) during the third week, and at 4 weeks post-treatment the drug was inactive. Established R. sanguineus populations were also treated, and the diluted liquid concentrate had 100% tick-detachment efficacy. Repellent activity (99%) was also detected against D. variabilis; the activity was monitored for only 7 days. The ectoparasiticide had low to moderate flea (Ctenocephalides felis) repellent activity (42%) for 4 days post-treatment; thereafter the treatment was ineffective. Side-effects were not observed in any of the dogs treated with amitraz, or the placebo.
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.
扁虱是莱姆关节炎的罪魁祸首。研究人员为了弄明白何处扁虱最猖獗, 不惜以身作饵,他们发现:The ticks were all over the log surface。因此告诫人 们:Avoid sitting on logs。
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...
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.
Burgdorfer, W; Friedhoff, K T; Lancaster, J L
In the ecology of spotted fever rickettsiae, one of the as yet unsolved problems concerns the significance of small animals in the distribution of Rickettsia rickettsii in nature. In the Bitter Root Valley of western Montana, a great variety of rodents, rabbits and hares are known to serve as the preferred hosts for the immature stages of the vector tick, Dermacentor andersoni.The authors analyse the susceptibility of various species of small mammals to virulent R. rickettsii and evaluate their efficiency as sources of infection for larval ticks. The results demonstrate that meadow-mice, Columbian ground-squirrels, golden-mantled ground-squirrels, chipmunks and snowshoe hares (the latter to a lesser extent), when bitten by infected ticks, respond with rickettsiaemias of sufficient length and degree to infect normal larval D. andersoni. High infection rates were obtained in ticks that fed during periods of high rickettsial concentrations in the blood.
Monje, Lucas D; Nava, Santiago; Eberhardt, Ayelen T; Correa, Ana I; Guglielmone, Alberto A; Beldomenico, Pablo M
To date, three tick-borne pathogenic Rickettsia species have been reported in different regions of Argentina, namely, R. rickettsii, R. parkeri, and R. massiliae. However, there are no reports available for the presence of tick-borne pathogens from the northeastern region of Argentina. This study evaluated the infection with Rickettsia species of Amblyomma dubitatum ticks collected from vegetation and feeding from capybaras (Hydrochoerus hydrochaeris) in northeastern Argentina. From a total of 374 A. dubitatum ticks collected and evaluated by PCR for the presence of rickettsial DNA, 19 were positive for the presence of Rickettsia bellii DNA, two were positive for Rickettsia sp. strain COOPERI, and one was positive for the pathogenic Rickettsia sp. strain Atlantic rainforest. To our knowledge, this study is the first report of the presence of the human pathogen Rickettsia sp. strain Atlantic rainforest and Rickettsia sp. strain COOPERI in Argentina. Moreover, our findings posit A. dubitatum as a potential vector for this pathogenic strain of Rickettsia.
孙明; 王淑芳; 王多全; 杨永彪; 马超
[目的]了解甘肃省武威市蜱和蜱媒病的种类和分布情况，便于建立牛、羊等草食家畜疫病的科学防控模式。[方法]通过布旗法、家畜体表捕捉法与分子生物学方法，对武威市所辖的4个县（区）进行了蜱传播疫病及其传播媒介的流行病学调查。[结果]在全市41个乡镇均发现有蜱的存在，主要以硬蜱属为主，但也发现有软蜱属；全市各县区均发现有梨形虫的感染。[结论]蜱在武威市分布广泛，该地区的蜱媒病感染情况也比较严重；软蜱属的发现增大了外来动物疫病的感染风险；威武地区需加强对蜱及蜱媒病危害和防控的认识，采取以灭蜱和杀灭病畜体内病原相结合的方法，来控制虫媒病的传播。%s:[Objective] To understand the tick species and tick-borne diseases, as to establish animal disease prevention and control model for herbivores such as cattle and sheep in Wuwei city.[Methods] Epidemiological investigation for tick-borne diseases and the vectors was conducted by methods of cloth flag, capture surface ticks of livestock body, and molecular biology in 41 counties within Wuwei city.[Results] the investigation showed that there were dominant hard ticks and some soft ticks distribution, and infestation of Piroplasmosis in all 41 counties of Wuwei City.[Conclusion] Ticks were widely distributed and infestations of tick-borne diseases were serious; the existed ticks increased the risk of infection of exotic animal diseases; the awareness of the risks and control of ticks and tick-borne diseases should be raised, and the spread of the tick-borne diseases should be controlled by combination of killing ticks and inactivating pathogens within infected animals.
McCooke, John K; Guerrero, Felix D; Barrero, Roberto A; Black, Michael; Hunter, Adam; Bell, Callum; Schilkey, Faye; Miller, Robert J; Bellgard, Matthew I
The cattle fever tick, Rhipicephalus (Boophilus) microplus is one of the most significant medical veterinary pests in the world, vectoring several serious livestock diseases negatively impacting agricultural economies of tropical and subtropical countries around the world. In our study, we assembled the complete R. microplus mitochondrial genome from Illumina and Pac Bio sequencing reads obtained from the ongoing R. microplus (Deutsch strain from Texas, USA) genome sequencing project. We compared the Deutsch strain mitogenome to the mitogenome from a Brazilian R. microplus and from an Australian cattle tick that has recently been taxonomically designated as Rhipicephalus australis after previously being considered R. microplus. The sequence divergence of the Texas and Australia ticks is much higher than the divergence between the Texas and Brazil ticks. This is consistent with the idea that the Australian ticks are distinct from the R. microplus of the Americas.
Huerto-Medina, Edward; Dámaso-Mata, Bernardo
The aim of the study was to determine the frequency and associated factors of Ehrlichia canis infection in dogs. Blood samples from 150 dogs infested with ticks in 10 veterinary clinics in the city of Huanuco in Peru were collected. The dogs were randomly selected without regard to breed, age or sex. Ehrlichia canis antibodies were detected by chromatographic immunoassay.51.3% of dogs were infected with Ehrlichia canis. In the multivariate analysis, factors associated with the presence of Ehrlichia canis were: poor health of the dog (p = 0.049), a higher average of tick infestation (p = 0.018), and adult dogs (p = 0.038). The frequency of Ehrlichia canis in dogs of this city is high. Control of the brown dog tick (Rhipicephalus sanguineus) vector of Ehrlichia canis is recommended.
Gordillo-Pérez, G; Vargas, M; Solórzano-Santos, F; Rivera, A; Polaco, O J; Alvarado, L; Muñóz, O; Torres, J
Borrelia burgdorferisensu lato infection has been confirmed in clinical cases in the northeast of Mexico; however, the bacterium has not been identified as infecting the tick vector Ixodes, Amblyomma and Dermacentor ticks were collected from mammals and plants in northeastern Mexico and examined for Borrelia. Eighteen of 214 ticks were PCR-positive for the fla and 16S rRNA genes and 15 for the ospA gene. Southern blotting with a fla probe and sequencing of ospA genes confirmed infection with B. burgdorferi sensu stricto. These findings, together with reports of indigenous cases, fulfil the criteria that allow northeastern Mexico to be considered as a zone endemic for Lyme disease.
Mosabah, Amira A Abd El-rahman; Morsy, Tosson A
Tick paralysis caused by the secretion of toxin with saliva while taking a blood meal is an important veterinary disease, but is rare in humans. Although it has certain geographical proclivities, it exists worldwide. Tick paralysis was demonstrated for the first time in Egypt among four children living in rural area at Giza Governorate. The clinical pictures were confused with rabies; myasthensia gravis; botulism; diphtheritic polyneuropathy encountered in rural areas. The recovery of tick infesting the four little children and negative clinical and laboratory data of all diseases denoted tick paralysis. The encountered ticks infesting their animals were Rhipicephalus sanguineus on dogs, Hyalomma dromedarii on camels and Hyalomma anatolicum excavatum and Haemaphysalis sp. on goats. The case was recognized as first record of tick paralysis in Egypt.
Kim, Yeong Ho; Lee, Ji Hyun; Park, Young Min
Ticks are parasites that usually suck the blood of wild or domestic animals; rarely, they ingest human blood and spread various febrile infectious diseases along with skin problems. Out of 40 cases of tick bite reported in Korea, only 3 were caused by nymphal ticks, and tick bites by nymphal Amblyomma testudinarium have not been reported previously. Herein, we report a rare case of tick bite by nymphal A. testudinarium. A 57-year-old woman presented with an asymptomatic solitary erythematous nodule on the left thigh that had been present for 6 days. The tick, which the patient removed from the lesion and brought to the hospital, was identified as a nymphal A. testudinarium. Doxycycline (200 mg) was used as treatment, and after seven days of use, the patient improved and no other lesions were detected. PMID:27904278
Bell-Sakyi, Lesley; Attoui, Houssam
While ticks have been known to harbor and transmit pathogenic arboviruses for over 80 years, the application of high-throughput sequencing technologies has revealed that ticks also appear to harbor a diverse range of endogenous tick-only viruses belonging to many different families. Almost nothing is known about these viruses; indeed, it is unclear in most cases whether the identified viral sequences are derived from actual replication-competent viruses or from endogenous virus elements incorporated into the ticks’ genomes. Tick cell lines play an important role in virus discovery and isolation through the identification of novel viruses chronically infecting such cell lines and by acting as host cells to aid in determining whether or not an entire replication-competent, infective virus is present in a sample. Here, we review recent progress in tick-borne virus discovery and comment on the actual and potential applications for tick cell lines in this emerging research area. PMID:27679414
Tick-borne diseases represent a major threat to animal health in the United States. The cattle industry in the United States has benefited greatly from the continued USDA efforts through the Cattle Fever Tick Eradication Program in preventing the re-introduction of cattle ticks and associated pathog...
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.
Hirota, Keisuke; Kurosawa, Yoshinaga; Goto, Keisuke; Adachi, Koji; Yoshida, Yuichi; Yamamoto, Osamu
Tick bite is known as a possible cause of some infectious diseases such as Lyme disease, spotted fever and related illnesses. The reaction to a tick bite may persist for several months to several years and can sometimes cause histopathological granuloma. The long-term reaction to salivary extracts from the tick could be responsible for development of granuloma in our patient. We recommended complete resection as the only sure way to treat formed granuloma.
Kim, Chul-Min; Kim, Ji-Young; Yi, Ying-Hua; Lee, Mi-Jin; Cho, Mae-rim; Shah, Devendra H; Klein, Terry A; Kim, Heung-Chul; Song, Jin-Won; Chong, Sung-Tae; O'Guinn, Monica L; Lee, John S; Lee, In-Yong; Park, Jin-Ho; Chae, Joon-Seok
We investigated the prevalence of Bartonella infections in ticks, mites and small mammals (rodents, insectivores and weasels) collected during 2001 through 2004, from various military installations and training sites in Korea, using PCR and sequence analysis of 16S rRNA, 23S rRNA and groEL heat shock protein genes. The prevalence of Bartonella spp. was 5.2% (n = 1,305 sample pools) in ticks, 19.1% (n = 21) in mesostigmatid mites and 13.7% (n = 424 individuals) in small mammals. The prevalence within the family Ixodidae was, 4.4% (n = 1,173) in Haemaphysalis longicornis (scrub tick), 2.7% (n = 74) in H. flava, 5.0% (n = 20) in Ixodes nipponensis, 11.1% (n = 9) in I. turdus, 33.3% (n = 3) in I. persulcatus and 42.3% (n = 26) in Ixodes spp. ticks. In rodents, the prevalence rate was, 6.7% (n = 373) in Apodemus agrarius (striped field mouse) and 11.1% (n = 9) in Eothenomys regulus (Korean red-backed vole) and in an insectivore,Crocidura lasiura, 12.1% (n = 33). Neither of the two weasels were positive for Bartonella spp. Phylogenetic analysis based on amino acid sequence of a portion of the groEL gene amplified from one A. agrarius spleen was identical to B. elizabethae species. We demonstrated the presence of Bartonella DNA in H. longicornis, H. flava and I. nipponensis ticks, indicating that these ticks should be added to the growing list of potential tick vectors and warrants further detailed investigations to disclose their possible roles in Bartonella infection cycles.
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
Kalsbeek, Vibeke; Frandsen, F.; Steenberg, Tove
The objective of this study was to demonstrate the occurrence of entomopathogenic fungi on Ixodes ricinus ticks in relation to the tick stage, engorgement and season. Ticks were collected from the vegetation, from small rodents and from deer. All entomopathogenic fungi found belonged...... infected with fungi. Thirty-three out of 149 engorged females were infected, whereas males and engorged larvae were not infected. Throughout the season, a significantly higher proportion of ticks collected in autumn were infected. Entomopathogenic fungi may have a significant impact on the size of the I...
Tay, S T; Koh, F X; Kho, K L; Ong, B L
This study was conducted to determine the occurrence of Anaplasma spp. in the blood samples of cattle, goats, deer and ticks in a Malaysian farm. Using polymerase chain reaction (PCR) and sequencing approach, Anaplasma spp. was detected from 81(84.4%) of 96 cattle blood samples. All blood samples from 23 goats and 22 deer tested were negative. Based on the analysis of the Anaplasma partial 16S ribosomal RNA gene, four sequence types (genotypes 1 to 4) were identified in this study. Genotypes 1-3 showed high sequence similarity to those of Anaplasma platys/ Anaplasma phagocytophilum, whilst genotype 4 was identical to those of Anaplasma marginale/ Anaplasma centrale/ Anaplasma ovis. Anaplasma DNA was detected from six (5.5%) of 109 ticks which were identified as Rhipicephalus (formely known as Boophilus) microplus ticks collected from the cattle. This study reported for the first time the detection of four Anaplasma sequence types circulating in the cattle population in a farm in Malaysia. The detection of Anaplasma DNA in R. microplus ticks in this study provides evidence that the ticks are one of the potential vectors for transmission of anaplasmosis in the cattle.
Adham, Fatma K; El-Samie-Abd, Emtithal M; Gabre, Refaat M; El Hussein, Hala
The prevalence of Borrelia burgdorferi sensu lato (s.l.), the etiologic agent of Lyme borrelosis (LB), was determined for the first time in Egypt by using polymerase chain reaction (PCR). Questing 5243 hard and soft ticks were collected from animal farms throughout Giza Governorate. DNA from 500 individual tick species was extracted and PCR was performed. Primers verified from the sequence of German strain Pko of Borrelia afzelii were used. Fragments of 642 bp were generated and sequenced. The prevalence of B. burgdorferi sensu lato (s.l.) was 28% of examined soft and hard ticks. High infection rate (66%) of B. burgdorferi s.l. was observed in both nymph and adult soft ticks Ornithodoros savignyi. Beside, the role of hard ticks as potential vectors of Lyme disease in Egypt, where the infection rate was between 0.0-50.0%. Sequence analysis of PCR product of Borrelia burgdorferi sensu lato shares high degree of similarity in sequence compared to similar species in GenBank.
Palomar, Ana M; Portillo, Aránzazu; Mazuelas, David; Roncero, Lidia; Arizaga, Juan; Crespo, Ariñe; Gutiérrez, Óscar; Márquez, Francisco J; Cuadrado, Juan F; Eiros, José M; Oteo, José A
Crimean-Congo hemorrhagic fever virus (CCHFV) was detected in Spain in 2010. The presence of CCHFV in Hyalomma marginatum ticks from migratory birds passing through Morocco during the spring migration strengthened the hypothesis of the arrival of infected ticks transported by birds to the Iberian Peninsula. Furthermore, Hyalomma species are vectors of bacterial infections such as spotted fever rickettsioses. CCHFV and Rickettsia were screened in Hyalomma ticks from Spain attached to patients (n=12) and birds (n=149). In addition, Rickettsia was investigated in 52 Hyalomma ticks from Morocco (previously reported as CCHFV-infected). No sample collected in Spain showed an infection with CCHFV. Two ticks removed from patients (16.7%), as well as 47 (31.5%) and 4 (7.7%) from birds, collected in Spain and Morocco respectively, were infected with Rickettsia aeschlimannii. Rickettsia sibirica subsp. mongolitimonae was also found in 2 ticks from birds collected in Spain (1.3%). The risk of CCHFV-infected ticks attached to migratory birds to reach the North of Spain is low. This study corroborates the presence of R. aeschlimannii in Spain and Morocco, and supports that H. marginatum can be a potential vector of R. sibirica subsp. mongolitimonae in the Iberian Peninsula.
Suggests an approach to teaching vectors that promotes active learning through challenging questions addressed to the class, as opposed to subtle explanations. Promotes introducing vector graphics with concrete examples, beginning with an explanation of the displacement vector. Also discusses artificial vectors, vector algebra, and unit vectors.…
Quarsten, H; Skarpaas, T; Fajs, L; Noraas, S; Kjelland, V
Ticks are important vectors of human pathogens. The knowledge of disease causing agents harboured by ticks in Norway is limited. The focus of this study was (a) to detect the bacteria of medical importance in ticks collected from the vegetation at locations in the southern part of the country and (b) to evaluate a novel commercially available multiplex PCR based method by comparing results with conventional established real-time PCR protocols. Borrelia burgdorferi sensu lato was confirmed to be the most prevalent pathogen detected (31%) among one hundred individually analysed adult ticks. Borrelia miyamotoi, a spirochete associated with relapsing fever, was detected in one sample. Anaplasma phagocytophilum was found in 4% of the ticks, followed by Rickettsia helvetica which was detected in one sample. Similar pathogen prevalence was also detected in 500 ticks analysed in pools. This is the first report of the spotted fever group Rickettsia in Norway. Francisella tularensis, Bartonella species or Coxiella burnetti was not detected. However, due to the low number of ticks analysed, the possible presence of these pathogens in the region cannot be ruled out. All isolates were screened by at least two different molecular methods for each bacterial target; one commercially available multiplex PCR based tick-borne bacteria flow chip system (Master Diagnostica) and corresponding real-time PCR protocols. The comparison of methods verified that most findings were detected by both methods (71 Borrelia, 15 Anaplasma and 2 Rickettsia), whereas two additional Borrelia and Anaplasma infected samples were detected by the real-time protocols.
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
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.
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.
Lu, Xin; Lin, Xian-Dan; Wang, Jian-Bo; Qin, Xin-Cheng; Tian, Jun-Hua; Guo, Wen-Ping; Fan, Fei-Neng; Shao, Renfu; Xu, Jianguo; Zhang, Yong-Zhen
Over the past several years, there was a substantial increase in the number of cases of known and novel tick-borne infections in humans in China. To better understand the ticks associated with these infections, we collected hard ticks from animals or around livestock shelters in 29 localities in 5 provinces (Beijing, Henan, Hubei, Inner Mongolia, and Zhejiang) where cases of tick-borne illness were reported. We collected 2950 hard ticks representing 7 species of 4 genera (Dermacentor sinicus, Haemaphysalis flava, Haemaphysalis longicornis, Ixodes granulatus, Ixodes persulcatus, Rhipicephalus microplus, and Rhipicephalus sanguineus). These ticks were identified to species using morphological characters initially. We then sequenced the mitochondrial small subunit rRNA (12S rRNA) gene, cytochrome oxidase subunit 1 (COI) gene, and the second internal transcribed spacer (ITS2) gene of these ticks, and conducted phylogenetic analyses. Our analyses showed that the molecular and morphological data are consistent in the identification of the 7 tick species. Furthermore, all these 7 tick species from China were genetically closely related to the same species or related species found outside China. Rapid and accurate identification and long-term monitoring of these ticks will be of significance to the prevention and control of tick-borne diseases in China.
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.
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...
The number of endangered plant species in the United States is significant yet studies aimed towards utilizing these plants are limited. Ticks and mosquitoes are hematophagous vectors for significant pathogenic diseases and key measures to lower their associated morbidity rates include the use of p...
Salim Abadi Yaser; Chinikar Sadegh; Telmadarraiy Zakkyeh; Vatandoost Hassan; Moradi Maryam; Oshaghi Mohammad Ali; Ghiasi Seyed Mojtaba
Objective: To determine the rate of Crimean-Congo hemorrhagic fever virus (CCHFV) infection in hard ticks (Ixodidae) in Yazd province of Iran. Methods: A molecular survey on hard ticks(Ixodidae) was conducted in Yazd province during 2008 -2009. A total of 140 hard ticks (three genera and 7 species) were collected from randomly selected villages and were exanimate for presence of CCHFV reverse transcription-polymerase chain reaction (RT-PCR) method. Results:CCHFV genome was found in 5.71% of hard ticks. All positive ticks were from Hyalomma genus. Positive ticks including: Hyalomma dromedarii, Hyalomma marginatum, Hyalomma anatolicum,Hyalomma detritum, Hyalomma asiaticum . We were not able to find virus in in Rhipicephalus sanguineus and Dermacentor marginatus. Results exhibited that Hyalomma is the main vector in the study area. Conclusions: Due to the presence of virus in 24 provinces' out of 31, we recommend the use of acaricides and repellent to prevent disease transmission among humans. Greta care should be taken by the people who are working in slaughter houses.
Raileanu, Cristian; Moutailler, Sara; Pavel, Ionuţ; Porea, Daniela; Mihalca, Andrei D.; Savuta, Gheorghe; Vayssier-Taussat, Muriel
Identifying Borrelia burgdorferi as the causative agent of Lyme disease in 1981 was a watershed moment in understanding the major impact that tick-borne zoonoses can have on public health worldwide, particularly in Europe and the USA. The medical importance of tick-borne diseases has long since been acknowledged, yet little is known regarding the occurrence of emerging tick-borne pathogens such as Borrelia spp., Anaplasma phagocytophilum, Rickettsia spp., Bartonella spp., “Candidatus Neoehrlichia mikurensis”, and tick-borne encephalitis virus in questing ticks in Romania, a gateway into Europe. The objective of our study was to identify the infection and co-infection rates of different Borrelia genospecies along with other tick-borne pathogens in questing ticks collected from three geographically distinct areas in eastern Romania. We collected 557 questing adult and nymph ticks of three different species (534 Ixodes ricinus, 19 Haemaphysalis punctata, and 4 Dermacentor reticulatus) from three areas in Romania. We analyzed ticks individually for the presence of eight different Borrelia genospecies with high-throughput real-time PCR. Ticks with Borrelia were then tested for possible co-infections with A. phagocytophilum, Rickettsia spp., Bartonella spp., “Candidatus Neoehrlichia mikurensis”, and tick-borne encephalitis virus. Borrelia spp. was detected in I. ricinus ticks from all sampling areas, with global prevalence rates of 25.8%. All eight Borrelia genospecies were detected in I. ricinus ticks: Borrelia garinii (14.8%), B. afzelii (8.8%), B. valaisiana (5.1%), B. lusitaniae (4.9%), B. miyamotoi (0.9%), B. burgdorferi s.s (0.4%), and B. bissettii (0.2%). Regarding pathogen co-infection 64.5% of infected I. ricinus were positive for more than one pathogen. Associations between different Borrelia genospecies were detected in 9.7% of ticks, and 6.9% of I. ricinus ticks tested positive for co-infection of Borrelia spp. with other tick-borne pathogens. The
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...during feeding. J. Parasitol. 68: 100-106. Miller, N.G., and Wilson, .R.B. (1962). In vivo and in vitro observations of Leptospira pomona by electron...et Leptospira au microscope electronique. Ann. Inst. Pateur (Paris), 108:791-804. Pillot, J., Dupouey, P., and Ryter, A. (1964). La signification
Medeiros, Matthew C. I.; Hamer, Gabriel L.; Morrow, Michael E.; Eubanks, Micky D.; Teel, Pete D.
Invasive species may impact pathogen transmission by altering the distributions and interactions among native vertebrate reservoir hosts and arthropod vectors. Here, we examined the direct and indirect effects of the red imported fire ant (Solenopsis invicta) on the native tick, small mammal and pathogen community in southeast Texas. Using a replicated large-scale field manipulation study, we show that small mammals were more abundant on treatment plots where S. invicta populations were experimentally reduced. Our analysis of ticks on small mammal hosts demonstrated a threefold increase in the ticks caught per unit effort on treatment relative to control plots, and elevated tick loads (a 27-fold increase) on one common rodent species. We detected only one known human pathogen (Rickettsia parkeri), present in 1.4% of larvae and 6.7% of nymph on-host Amblyomma maculatum samples but with no significant difference between treatment and control plots. Given that host and vector population dynamics are key drivers of pathogen transmission, the reduced small mammal and tick abundance associated with S. invicta may alter pathogen transmission dynamics over broader spatial scales. PMID:27651533
Castellanos, Adrian A; Medeiros, Matthew C I; Hamer, Gabriel L; Morrow, Michael E; Eubanks, Micky D; Teel, Pete D; Hamer, Sarah A; Light, Jessica E
Invasive species may impact pathogen transmission by altering the distributions and interactions among native vertebrate reservoir hosts and arthropod vectors. Here, we examined the direct and indirect effects of the red imported fire ant (Solenopsis invicta) on the native tick, small mammal and pathogen community in southeast Texas. Using a replicated large-scale field manipulation study, we show that small mammals were more abundant on treatment plots where S. invicta populations were experimentally reduced. Our analysis of ticks on small mammal hosts demonstrated a threefold increase in the ticks caught per unit effort on treatment relative to control plots, and elevated tick loads (a 27-fold increase) on one common rodent species. We detected only one known human pathogen (Rickettsia parkeri), present in 1.4% of larvae and 6.7% of nymph on-host Amblyomma maculatum samples but with no significant difference between treatment and control plots. Given that host and vector population dynamics are key drivers of pathogen transmission, the reduced small mammal and tick abundance associated with S. invicta may alter pathogen transmission dynamics over broader spatial scales.
Trout Fryxell, R. T.; DeBruyn, J. M.
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 intra
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
Sherifi, Kurtesh; Cadar, Daniel; Muji, Skender; Robaj, Avni; Ahmeti, Salih; Jakupi, Xhevat; Emmerich, Petra; Krüger, Andreas
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.
Full Text Available Abstract Background African Swine Fever Virus has devastated more than the half of the domestic pig population in Madagascar since its introduction, probably in 1997-1998. One of the hypotheses to explain its persistence on the island is its establishment in local Ornithodoros soft ticks, whose presence has been reported in the past from the north-western coast to the Central Highlands. The aim of the present study was to verify such hypothesis by conducting tick examinations in three distinct zones of pig production in Madagascar where African Swine Fever outbreaks have been regularly reported over the past decade and then to improve our knowledge on the tick distribution and taxonomy. Results Ornithodoros ticks were only found in one pig farm in the village of Mahitsy, north-west of Antananarivo in the Central Highlands, whereas the tick seemed to be absent from the two other study zones near Ambatondrazaka and Marovoay. Using 16SrDNA PCR amplification and sequencing, it was confirmed that the collected ticks belonged to the O. porcinus species and is closely related to the O. p. domesticus sub-species Walton, 1962. ASFV was detected in 7.14% (13/182 of the field ticks through the amplification of part of the viral VP72 gene, and their ability to maintain long-term infections was confirmed since all the ticks came from a pig building where no pigs or any other potential vertebrate hosts had been introduced for at least four years. Conclusions Considering these results, O. porcinus is a reservoir for ASFV and most likely acts as vector for ASFV in Madagascar, but its apparent restricted distribution may limit its role in the epidemiology of the disease in domestic pigs.
Xu, Xing-Li; Cheng, Tian-Yin; Yang, Hu; Yan, Fen
In this study, we have analyzed the intestinal microbial flora associated with Rhipicephalus microplus ticks using both culture-dependent and independent methods based on PCR and denaturing gradient gel electrophoresis (PCR-DGGE). The R. microplus ticks were collected from cattle and goats in Jiangxi, Hunan and Guizhou Provinces of China. Three distinct strains of bacteria were isolated using culture-dependent methods: Staphylococcus simulans, Bacillus subtilis and Bacillus flexus strain. Nineteen distinct DGGE bands were found using PCR-DGGE analysis, and their search for identity shows that they belonged to Rickettsiaceae, Xanthomonadaceae, Coxiella sp., Ehrlichia sp., Pseudomonas sp., Ehrlichia sp., Orphnebius sp., Rickettsia peacockii, Bacillus flexus. Rickettsia peacockii and Coxiella genus were the dominant strain of the R. microplus ticks from cattle, Pseudomonas sp. and B. flexus strain were the most common species in all tick samples from goats. Ehrlichia canis were detected only in R. microplus ticks from Yongshun area in Hunan Province. The results indicate that the intestinal microbial diversity of R. microplus ticks was influenced by tick hosts and local differences in the sampling location and these two aspects may affect transmission of pathogen to humans and animals.
Sampieri, Bruno Rodrigues; Arnosti, André; Nunes, Pablo Henrique; Furquim, Karim Christina Scopinho; Chierice, Gilberto Orivaldo; Mathias, Maria Izabel Camargo
Rhipicephalus sanguineus is a widely distributed tick species that has adapted to the urban environment, and the dog is its main host. This species is also known as a vector and reservoir of diseases caused by bacteria, protozoa, and viruses. Currently, acaricides of synthetic chemical origin have been widely and indiscriminately used, leading to the development of resistance to these products by ticks and causing damage to the environment. Thus, these issues have made it necessary to seek other forms of controlling these ectoparasites. R. sanguineus was artificially infested in host New Zealand White rabbits, which were divided into four treatment groups: control (CG1 and CG2) and treatment (TG1 and TG2) groups. TG1 and TG2 hosts were provided with feed supplemented with esters of ricinoleic acid from castor oil at a concentration of 5 g/kg of feed for 7 and 15 days. Afterward, the ovaries of the female ticks were removed for analysis by transmission electron microscopy. The results showed ultrastructural changes in the somatic and germ cells of ovaries from TG1 and TG2 females, particularly with respect to chorion deposition, a protective membrane of the oocyte, as well as in the transport process of vitellogenic materials via the hemolymph and pedicel cells. Moreover, the mitochondria were less electron-dense and had cristae that were more disorganized than the mitochondria from CG1 and CG2 individuals. Thus, this study demonstrated the action of esters on the ovaries of R. sanguineus, signaling the prospect of a way to control this ectoparasite without affecting nontarget organisms or the environment.
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.
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.
Jaenson Thomas GT
Full Text Available Abstract The highest annual incidence of human tick-borne encephalitis (TBE in Sweden ever recorded by the Swedish Institute for Communicable Disease Control (SMI occurred last year, 2011. The number of TBE cases recorded during 2012 up to 6th August 2012 indicates that the incidence for 2012 could exceed that of 2011. In this review of the ecology and epidemiology of TBE in Sweden our main aim is to analyse the possible reasons behind the gradually increasing incidence of human TBE during the last 20 years. The main TBE virus (TBEV vector to humans in Sweden is the nymphal stage of the common tick Ixodes ricinus. The main mode of transmission and maintenance of TBEV in the tick population is considered to be when infective nymphs co-feed with uninfected but infectible larvae on rodents. In most locations the roe deer, Capreolus capreolus is the main host for the reproducing adult I. ricinus ticks. The high number of roe deer for more than three decades has resulted in a very large tick population. Deer numbers have, however, gradually declined from the early 1990s to the present. This decline in roe deer numbers most likely made the populations of small rodents, which are reservoir-competent for TBEV, gradually more important as hosts for the immature ticks. Consequently, the abundance of TBEV-infected ticks has increased. Two harsh winters in 2009–2011 caused a more abrupt decline in roe deer numbers. This likely forced a substantial proportion of the “host-seeking” ticks to feed on bank voles (Myodes glareolus, which at that time suddenly had become very numerous, rather than on roe deer. Thus, the bank vole population peak in 2010 most likely caused many tick larvae to feed on reservoir-competent rodents. This presumably resulted in increased transmission of TBEV among ticks and therefore increased the density of infected ticks the following year. The unusually warm, humid weather and the prolonged vegetation period in 2011 permitted
Lieskovská, J; Páleníková, J; Širmarová, J; Elsterová, J; Kotsyfakis, M; Campos Chagas, A; Calvo, E; Růžek, D; Kopecký, J
Type I interferon (IFN), mainly produced by dendritic cells (DCs), is critical in the host defence against tick-transmitted pathogens. Here, we report that salivary cysteine protease inhibitor from the hard tick Ixodes scapularis, sialostatin L2, affects IFN-β mediated immune reactions in mouse dendritic cells. Following IFN receptor ligation, the Janus activated kinases/signal transducer and activator of transcription (JAK/STAT) pathway is activated. We show that sialostatin L2 attenuates phosphorylation of STATs in spleen dendritic cells upon addition of recombinant IFN-β. LPS-stimulated dendritic cells release IFN-β which in turn leads to the induction of IFN-stimulated genes (ISG) through JAK/STAT pathway activation. The induction of two ISG, interferon regulatory factor 7 (IRF-7) and IP-10, was suppressed by sialostatin L2 in LPS-stimulated dendritic cells. Finally, the interference of sialostatin L2 with IFN action led to the enhanced replication of tick-borne encephalitis virus in DC. In summary, we present here that tick salivary cystatin negatively affects IFN-β responses which may consequently increase the pathogen load after transmission via tick saliva.
M Khyrul Islam
Full Text Available Ticks are serious haematophagus arthropod pests and are only second to mosquitoes as vectors of diseases of humans and animals. The salivary glands of the slower feeding hard ticks such as Haemaphysalis longicornis are a rich source of bioactive molecules and are critical to their biologic success, yet distinct molecules that help prolong parasitism on robust mammalian hosts and achieve blood-meals remain unidentified. Here, we report on the molecular and biochemical features and precise functions of a novel Kunitz inhibitor from H. longicornis salivary glands, termed Haemangin, in the modulation of angiogenesis and in persistent blood-feeding. Haemangin was shown to disrupt angiogenesis and wound healing via inhibition of vascular endothelial cell proliferation and induction of apoptosis. Further, this compound potently inactivated trypsin, chymotrypsin, and plasmin, indicating its antiproteolytic potential on angiogenic cascades. Analysis of Haemangin-specific gene expression kinetics at different blood-feeding stages of adult ticks revealed a dramatic up-regulation prior to complete feeding, which appears to be functionally linked to the acquisition of blood-meals. Notably, disruption of Haemangin-specific mRNA by a reverse genetic tool significantly diminished engorgement of adult H. longicornis, while the knock-down ticks failed to impair angiogenesis in vivo. To our knowledge, we have provided the first insights into transcriptional responses of human microvascular endothelial cells to Haemangin. DNA microarray data revealed that Haemangin altered the expression of 3,267 genes, including those of angiogenic significance, further substantiating the antiangiogenic function of Haemangin. We establish the vital roles of Haemangin in the hard tick blood-feeding process. Moreover, our results provide novel insights into the blood-feeding strategies that enable hard ticks to persistently feed and ensure full blood-meals through the modulation of
Hirunkanokpun, Supanee; Kittayapong, Pattamaporn; Cornet, Jean-Paul; Gonzalez, Jean-Paul
Ticks are of considerable medical and veterinary importance because they directly harm the host through their feeding action and indirectly through vectoring many bacterial pathogens. Despite many ticks being known from Thailand, very little is known about the bacteria they may harbor. We report here the results of a survey of tick-associated bacteria in Thailand. A total of 334 individuals representing 14 species of ticks in five genera were collected from 10 locations in Thailand and were examined for the human pathogens, Borrelia, Francisella, Rickettsia, and the common arthropod endosymbionts, Wolbachia, by polymerase chain reaction (PCR) assay using specific primers. Rickettsial DNA was detected in 30% (9/30) of Amblyomma testudinarium (Koch, 1844) collected from Khao Yai National Park, Nakhon Nayok Province and 16.84% (16/95) of Hemaphysalis ornithophila (Hoogstraal and Kohls, 1959) collected from Khao Yai National Park, Nakhon Nayok Province and Khao Ang Rue Nai Wildlife Sanctuary, Chachoengsao Province. Rickettsial DNA was not detected in any of the other tick species and no DNA of Borrelia, Francisella, or Wolbachia was detected in any of 14 tick species. Phylogenetic relationships among the rickettsiae detected in this study and those of other rickettsiae were inferred from comparison of sequences of the 17-kDa antigen gene, the citrate synthase gene (gltA), and the 190-kDa outer membrane protein gene (ompA). Results indicated that the three Thai rickettsiae detected in this study represent new rickettsial genotypes and form a separate cluster among the spotted fever group rickettsiae.
Full Text Available Ixodid ticks are notorious blood-sucking ectoparasites and are completely dependent on blood-meals from hosts. In addition to the direct severe effects on health and productivity, ixodid ticks transmit various deadly diseases to humans and animals. Unlike rapidly feeding vessel-feeder hematophagous insects, the hard ticks feed on hosts for a long time (5-10 days or more, making a large blood pool beneath the skin. Tick's salivary glands produce a vast array of bio-molecules that modulate their complex and persistent feeding processes. However, the specific molecule that functions in the development and maintenance of a blood pool is yet to be identified. Recently, we have reported on longistatin, a 17.8-kDa protein with two functional EF-hand Ca(++-binding domains, from the salivary glands of the disease vector, Haemaphysalis longicornis, that has been shown to be linked to blood-feeding processes. Here, we show that longistatin plays vital roles in the formation of a blood pool and in the acquisition of blood-meals. Data clearly revealed that post-transcriptional silencing of the longistatin-specific gene disrupted ticks' unique ability to create a blood pool, and they consequently failed to feed and replete on blood-meals from hosts. Longistatin completely hydrolyzed α, β and γ chains of fibrinogen and delayed fibrin clot formation. Longistatin was able to bind with fibrin meshwork, and activated fibrin clot-bound plasminogen into its active form plasmin, as comparable to that of tissue-type plasminogen activator (t-PA, and induced lysis of fibrin clot and platelet-rich thrombi. Plasminogen activation potentiality of longistatin was increased up to 4 times by soluble fibrin. Taken together, our results suggest that longistatin may exert potent functions both as a plasminogen activator and as an anticoagulant in the complex scenario of blood pool formation; the latter is critical to the feeding success and survival of ixodid ticks.
Papa, Anna; Kontana, Anastasia; Tsioka, Katerina; Chaligiannis, Ilias; Sotiraki, Smaragda
Since 2009, when severe fever with thrombocytopenia syndrome virus and Heartland virus have been identified and associated with disease in humans, the interest on tick-borne phleboviruses is increasing rapidly. The aim of the present study was to investigate the presence of tick-borne phleboviruses in Greece and compare them with respective ones detected worldwide. Ticks collected from goats and sheep in 60 sites of 13 regional units of Greece were grouped in pools (1-3 ticks per pool) and tested for the presence of phleboviral RNA. Six of 210 pools were positive; they consisted of Rhipicephalus sanguineus ticks collected from sheep in 3 regional units of Greece: Pella (2/30, 6.7%), Imathia (2/21, 9.5%), and Ioannina (2/28, 7.1%). The overall tick minimum infection rate was 2.1%. The sequences of the Greek phlebovirus (provisionally named Antigone virus) form a distinct clade in the tick-borne phleboviruses, differing by >40% from the currently known phleboviruses. Any probable implication of these viruses to public health remains to be elucidated.
Valenzuela Jesus G
Full Text Available Abstract Background In recent years, there have been several sialome projects revealing transcripts expressed in the salivary glands of ticks, which are important vectors of several human diseases. Here, we focused on the sialome of the European vector of Lyme disease, Ixodes ricinus. Results In the attempt to describe expressed genes and their dynamics throughout the feeding period, we constructed cDNA libraries from four different feeding stages of Ixodes ricinus females: unfed, 24 hours after attachment, four (partially fed and seven days (fully engorged after attachment. Approximately 600 randomly selected clones from each cDNA library were sequenced and analyzed. From a total 2304 sequenced clones, 1881 sequences forming 1274 clusters underwent subsequent functional analysis using customized bioinformatics software. Clusters were sorted according to their predicted function and quantitative comparison among the four libraries was made. We found several groups of over-expressed genes associated with feeding that posses a secretion signal and may be involved in tick attachment, feeding or evading the host immune system. Many transcripts clustered into families of related genes with stage-specific expression. Comparison to Ixodes scapularis and I. pacificus transcripts was made. Conclusion In addition to a large number of homologues of the known transcripts, we obtained several novel predicted protein sequences. Our work contributes to the growing list of proteins associated with tick feeding and sheds more light on the dynamics of the gene expression during tick feeding. Additionally, our results corroborate previous evidence of gene duplication in the evolution of ticks.
Shahein, Yasser Ezzat
A full-length cDNA of an immunogenic protein was cloned from a cDNA library of the local Egyptian cattle tick Boophilus annulatus. Antibodies raised against B. annulatus larval proteins were used to screen a cDNA expression library. A 936bp cloned fragment was sequenced and showed an open reading frame of 516bp encoding a protein of 171 amino acids. Comparison of the deduced amino acid sequence with protein data bank revealed that the sequence is related to a sequence isolated from the hard tick Haemaphysalis qinghaiensis (Hq05). Southern blot analysis of B. annulatus genomic DNA showed that the cloned cDNA hybridized to double bands per restriction digest, suggesting that the cloned cDNA is a double copy gene. Amino acid analysis of the cloned gene revealed the presence of two casein kinase II phosphorylation sites in the N-terminal domain suggesting that this molecule may be involved in the signal transduction or gene expression pathways. RT-PCR and northern blotting revealed the presence of two isoforms of the Ba05 gene in salivary glands and in the 3-day-old eggs. The cloned gene without the signal peptide, was expressed in Escherichia coli under T7 promotor of pET-30b vector, and purified under denaturation conditions. The purified protein appeared as a single band on 12% SDS-PAGE with a molecular weight around 22.8kDa including the histidine tag of the vector. Antibodies raised against the purified molecule were used to detect the B. annulatus homologue to the Hq05 gene in whole tick, larvae and gut protein extracts. Immunoblotting revealed the presence of this molecule Ba05 only in whole tick and larval protein extracts and not in the gut protein extract. Using the same antibodies, homologues to the Ba05 gene were detected in other tick species as Hyalomma dromedarii and Rhipicephalus sp. but not in Ornithodoros moubata.
Herrin, Brian; Mahapatra, Saugata; Blouin, Edmour F; Shaw, Edward I
Q fever, a zoonotic disease, is caused by a gram-negative intracellular bacterium, Coxiella burnetii. Although normally transmitted during exposure to infectious aerosols, C. burnetii is also found in arthropod vectors. In the environment, ticks are thought to play a crucial role in bacterial maintenance and transmission by infecting various mammalian species. However, the nature of the pathogen-tick relationship is not well defined. To determine C. burnetii's interactions with a cultured tick cell line, we introduced purified C. burnetii NMII into Ixodes scapularis-derived IDE8 cells and assayed for bacterial presence, replication, gene expression, and subsequent infectivity for mammalian cells. Tick cells were harvested at 24 h, 72 h, 7 days, and 11 days postinfection (PI). C. burnetii uptake and subsequent replication was demonstrated by indirect immunofluorescence assay, electron microscopy, and real-time polymerase chain reaction (PCR). When a genome equivalent multiplicity of infection of 30 was used, 30%-40% of exposed cells were seen to have small, rounded, vacuoles at 72 h PI, whereas at 7 and 11 days PI, 60%-70% of cells contained enlarged vacuoles harboring large numbers of bacteria. Quantitative PCR analysis of total genomic DNA confirmed that C. burnetii genome numbers increased significantly from 24 h to 11 days PI. Expression of C. burnetii type four secretion system homologs at 7 days PI was demonstrated by reverse transcriptase PCR. Finally, indirect immunofluorescence assay demonstrated that C. burnetii propagated within IDE8 cells were infectious for mammalian cells. These studies demonstrate the utility of cultured tick cell lines as a model to investigate C. burnetii's molecular interactions with its arthropod vectors.
A list of the 70 species of Australian ticks; diagnostic guides to and species accounts of Ixodes holocyclus (paralysis tick), Ixodes cornuatus (southern paralysis tick) and Rhipicephalus australis (Australian cattle tick); and consideration of the place of Australia in the evolution of ticks with comments on four controversial ideas.
Barker, Stephen C; Walker, Alan R; Campelo, Dayana
Seventy species of ticks are known from Australia: 14 soft ticks (family Argasidae) and 56 hard ticks (family Ixodidae). Sixteen of the 70 ticks in Australia may feed on humans and domestic animals (Barker and Walker 2014). The other 54 species of ticks in Australia feed only on wild mammals, reptiles and birds. At least 12 of the species of ticks in Australian also occur in Papua New Guinea. We use an image-matching system much like the image-matching systems of field guides to birds and flowers to identify Ixodes holocyclus (paralysis tick), Ixodes cornuatus (southern paralysis tick) and Rhipicephalus (Boophilus) australis (Australian cattle tick). Our species accounts have reviews of the literature on I. holocyclus (paralysis tick) from the first paper on the biology of an Australian tick by Bancroft (1884), on paralysis of dogs by I. holocyclus, to papers published recently, and of I. cornuatus (southern paralysis tick) and Rhipicephalus (Boophilus) australis (Australian cattle tick). We comment on four controversial questions in the evolutionary biology of ticks: (i) were labyrinthodont amphibians in Australia in the Devonian the first hosts of soft, hard and nuttalliellid ticks?; (ii) are the nuttalliellid ticks the sister-group to the hard ticks or the soft ticks?; (iii) is Nuttalliella namaqua the missing link between the soft and hard ticks?; and (iv) the evidence for a lineage of large bodied parasitiform mites (ticks plus the holothyrid mites plus the opiliocarid mites).
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.
Karen Denise Mccoy
Full Text Available 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 specialisation 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 specialisation 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.
Khrouf, Fatma; M'Ghirbi, Youmna; Znazen, Abir; Ben Jemaa, Mounir; Hammami, Adnene; Bouattour, Ali
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.
Samish, M.; Ginsberg, H.S.; Glazer, I.; Bowman, Alan. S.; Nuttall, Patricia A.
Widespread and increasing resistance to most available acaracides threatens both global livestock industries and public health. This necessitates better understanding of ticks and the diseases they transmit in the development of new control strategies. Ticks: Biology, Disease and Control is written by an international collection of experts and covers in-depth information on aspects of the biology of the ticks themselves, various veterinary and medical tick-borne pathogens, and aspects of traditional and potential new control methods. A valuable resource for graduate students, academic researchers and professionals, the book covers the whole gamut of ticks and tick-borne diseases from microsatellites to satellite imagery and from exploiting tick saliva for therapeutic drugs to developing drugs to control tick populations. It encompasses the variety of interconnected fields impinging on the economically important and biologically fascinating phenomenon of ticks, the diseases they transmit and methods of their control.
Nabieva, T N; Mukhin, E I
Thirty-two children suffering from motor and vocal ticks exhibited weakness and distonia of ticks-prone muscles were examined. Based on the results obtained earlier, a complex of physical exercises has been worked out and conducted for 20 days. The patients were divided into 3 groups: 1st (n = 10) group did the exercises daily for training the ticks-prone muscles; the 2nd one (n = 10) exercised only after tick's appearance--negative reinforcement; 3rd group (n = 12) did exercises after tick's appearance as well but on irregular basis--probable negative reinforcement. In the 1st group, the exercising resulted in muscle strengthening and decrease of tick's number. The patients of the 2nd group got rid of ticks for 20 days. The probable tick's reinforcement in children of the 3rd group did not change pathological muscle activity. The central mechanisms of cortical plasticity in behavioral therapy of ticks are discussed.
Full Text Available Heartwater is an economically serious tick-borne disease of ruminants caused by the intracellular bacterium Ehrlichia ruminantium. The disease has traditionally been controlled by four different approaches : controlling the tick vector by dipping, establishing endemic stability, performing immunisation by infection and treatment, and preventing the disease by regular administration of prophylactic antibiotics. The first three of these methods are subject to failure for various epidemiological reasons, and serious disease outbreaks can occur. Prophylaxis is effective, but very expensive, and the logistics are daunting when large herds of animals are involved. The development of a safe, cheap and effective vaccine is the only likely way in which heartwater can be economically controlled, and over the past 15 years three new types of experimental vaccine have been developed: inactivated, attenuated, and recombinant vaccines. These new vaccines have shown varying degrees of promise, but none is as yet sufficiently successful to be marketable. We describe the experimental products, and the various technical and biological difficulties which are being encountered, and report on ways in which new technologies are being used to improve vaccine effectiveness.
Nava, S; Lareschi, M; Rebollo, C; Benítez Usher, C; Beati, L; Robbins, R G; Durden, L A; Mangold, A J; Guglielmone, A A
The ticks reported in Paraguay, which are here reviewed, can be categorized as 'endemic or established' (Argas persicus or a sibling species, Ornithodoros hasei, O. rostratus, O. rudis, O. talaje/O. puertoricensis, Amblyomma aureolatum, Am. auricularium, Am. brasiliense, Am. cajennense, Am. calcaratum, Am. coelebs, Am. dissimile, Am. dubitatum, Am. incisum, Am. longirostre, Am. nodosum, Am. ovale, Am. pacae, Am. parvum, Am. pseudoconcolor, Am. rotundatum, Am. scutatum, Am. tigrinum, Am. triste, Dermacentor nitens, Haemaphysalis juxtakochi, H. leporispalustris, Ixodes loricatus, Rhipicephalus microplus, and Rh. sanguineus), 'probably endemic or established' (Ar. miniatus, Ar. monachus, Am. argentinae, Am. humerale, Am. naponense, Am. oblongoguttatum, Am. pseudoparvum, I. aragaoi/I. pararicinus, I. auritulus, I. luciae), or 'erroneously reported from Paraguay' (O. coriaceus, Am. americanum and Am. maculatum). Most Paraguayan tick collections have been made in the Chaco phyto-geographical domain, in the central part of the country. Argas persicus or a related species, Am. cajennense, D. nitens, Rh. microplus and Rh. sanguineus are important parasites of domestic animals. Ornithodoros rudis, Am. aureolatum, Am. brasiliense, Am. cajennense, Am. coelebs, Am. incisum, Am. ovale and Am. tigrinum have all been collected from humans. In terms of public health, the collections of Am. cajennense and Am. triste from humans may be particularly significant, as these species are potential vectors of Rickettsia rickettsii and Ri. parkeri, respectively.
Shi Liu; Chao Yuan; Yun-Fu Cui; Bai-Xiang Li; Li-Jie Wu; Ying Liu
Objective:To investigate the precise species of tick vector and theBorrelia spirochete pathogen at the Heilongjiang Province international border with Russia.Methods:In this study, ticks were collected from12 Heilongjiang border crossings (including grasslands, shrublands, forests, and plantantions) to determine the rate and species type of spirochete-infected ticks and the most prevalent spirochete genotypes.Results:The ticks represented three genera and four species of the Ixodidae family [Ixodes persulcatus,Dermacentor silvarum,Haemaphysalis concinna and Haemaphysalis japonica].Ixodes persulcatus had the highest amount ofBorrelia burgdorferi sensu lato infection of25.6% and the most common species ofBorreliaisolated from Ixodes persulcatus wasBorrelia garinii, strainPD91.Conclusions: Our results suggest thatBorrelia gariniiPD91-infectedIxodes persulcatus may be the principal cause of Lyme disease in the border crossing areas of Heilongjiang Province.
Alberdi, Pilar; Mansfield, Karen L.; Manzano-Román, Raúl; Cook, Charlotte; Ayllón, Nieves; Villar, Margarita; Johnson, Nicholas; Fooks, Anthony R.; de la Fuente, José
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. PMID:26904518
Alberdi, Pilar; Mansfield, Karen L; Manzano-Román, Raúl; Cook, Charlotte; Ayllón, Nieves; Villar, Margarita; Johnson, Nicholas; Fooks, Anthony R; de la Fuente, José
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.
Pat-Nah, Henry; Rodriguez-Vivas, Roger Ivan; Bolio-Gonzalez, Manuel Emilio; Villegas-Perez, Sandra Luz; Reyes-Novelo, Enrique
Ehrlichia canis is the etiological agent behind canine monocytic ehrlichiosis, and the tick Rhipicephalus sanguineus (Latreille) is its main vector. Blood smear and nested polymerase chain reaction (PCR) techniques were used to identify E. canis infection in dogs and R. sanguineus, and explore factors possibly associated with infection in dogs in Yucatan, Mexico. Blood samples were taken and ticks R. sanguineus collected from 50 dogs (10 house dogs and 40 in an animal control center). Data were collected on dog age, sex, body condition, and signs associated with platelet deficiencies (epistaxis). Blood smears were analyzed to identify E. canis morulae and generate platelet counts. Nested PCR analysis was done on blood samples and 200 ticks. A χ(2) test was done to identify factors associated with the E. canis infection in the tested dogs. The overall prevalence for infection, as determined by PCR, was 36% (18 out of 50). All positive dogs were from samples collected from the animal shelter, representing prevalence, for this sampling site, of 45% (18 out of 40). Morulae in monocytes were identified in only 4% of samples. Dog origin (i.e. animal control center) was the only variable associated with E. canis infection (P canis infection is present in both dogs and the brown dog ticks R. sanguineus in Yucatan, Mexico.
Saito, Y; Konnai, S; Yamada, S; Imamura, S; Nishikado, H; Ito, T; Onuma, M; Ohashi, K
Ixodes persulcatus is the primary vector for human tick-borne diseases in Japan. A cDNA library was constructed from whole body homogenates of fed nymphs of I. persulcatus. From this library, one cDNA encoding defensin-like antimicrobial peptide was identified. The amino-acid sequence showed high similarity to those of the defensins of other ticks and arthropods. I. persulcatus defensin mRNA transcripts were detected at all life cycle stages of fed ticks and found to be predominantly expressed in the midguts of adult female ticks, but not in the salivary glands, a finding corroborated by Western blotting analysis. To investigate the function of I. persulcatus defensin, we examined its antibacterial activity by evaluation of growth of several bacterial strains in the presence of the synthetic peptide. The defensin from I. persulcatus markedly inhibited the growth of Gram-positive bacteria including Staphylococcus aureus, Bacillus subtilis and Corynebacterium renale, but not Gram-negative bacteria except Escherichia coli O157. In conclusion, these results suggest that I. persulcatus defensin may be playing a significant role in the defence against microbes from bloodmeals.
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.
Sumrandee, Chalao; Hirunkanokpun, Supanee; Doornbos, Kathryn; Kitthawee, Sangvorn; Baimai, Visut; Grubhoffer, Libor; Trinachartvanit, Wachareeporn; Ahantarig, Arunee
Some reptile ticks are potential vectors of pathogens such as spotted fever group (SFG) rickettsiae. Here, we report for the first time in detail the molecular evidence, DNA sequences and phylogenetic studies, for the presence of Rickettsia spp. in Amblyomma ticks (Amblyomma helvolum and Amblyomma varanense) from snakes in Thailand. A total of 24 tick samples was collected from 4 snake species and identified. A phylogenetic analysis inferred from the partial sequences of the gltA gene indicated that the Rickettsia spp. from 2 Amblyomma helvolum and 1 Amblyomma varanense belong to the same group as the SFG rickettsiae, which are closely related to Rickettsia raoultii strains. In contrast, there was 1 Rickettsia sp. from Amblyomma helvolum grouped into the same clade with other SFG rickettsiae (Rickettsia tamurae, Rickettsia monacensis, and a Rickettsia endosymbiont of Amblyomma dubitatum from Brazil). However, another Rickettsia sp. from Amblyomma varanense was closely related to Rickettsia bellii and Rickettsia sp. strain RDa420 from Thailand. In addition, from phylogenetic results based on the 16S rRNA gene and a concatenated tree of the 3 genes (gltA, ompA, and ompB), we found what may be a novel SFG rickettsia species closely related to Rickettsia raoultii (from both Amblyomma varanense and Amblyomma helvolum). In conclusion, our findings are the first report on the presence of novel SFG rickettsiae in 2 snake tick species, Amblyomma varanense and Amblyomma helvolum in Thailand and in south-eastern Asia.
Bissinger, B W; Kennedy, M K; Carroll, S P
Mosquitoes and ticks are blood-feeding pests of humans and animals that can vector many important aetiological agents of disease. Previous research demonstrated that TT-4302 (Guardian(®) Wilderness) containing 5% geraniol applied to human subjects gave 5-6 h of repellency against mosquitoes (depending on species) and was repellent to ticks in vitro. This study was conducted to obtain an independent third-party evaluation of TT-4302 against Stegomyia aegypti (= Aedes aegypti) (Diptera: Culicidae) mosquitoes and to test the efficacy of the product in the field against ticks. TT-4302 provided an average of 6.5 h of repellency of ≥ 95% [Weibull mean protection time: 7.4 h, 95% confidence interval (CI) 5.8-11.3 h] for St. aegypti, whereas a 15% DEET formulation provided 4.7 h of repellency (Weibull mean protection time: 5.2 h, 95% CI 3.7-6.9 h). In tick field trials, the efficacy of TT-4302 did not differ significantly from that of a 25% DEET formulation against Amblyomma americanum (Ixodida: Ixodidae). TT-4302 was 81.3% repellent at 2.5 h after application, whereas DEET was 77.2% repellent at the same time-point. Results at 3.5 h after application were 71.4% for TT-4302 and 72.9% for DEET.
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
Hamer, Sarah A; Goldberg, Tony L; Kitron, Uriel D; Brawn, Jeffrey D; Anderson, Tavis K; Loss, Scott R; Walker, Edward D; Hamer, Gabriel L
Bird-facilitated introduction of ticks and associated pathogens is postulated to promote invasion of tick-borne zoonotic diseases into urban areas. Results of a longitudinal study conducted in suburban Chicago, Illinois, USA, during 2005-2010 show that 1.6% of 6,180 wild birds captured in mist nets harbored ticks. Tick species in order of abundance were Haemaphysalis leporispalustris, Ixodes dentatus, and I. scapularis, but 2 neotropical tick species of the genus Amblyomma were sampled during the spring migration. I. scapularis ticks were absent at the beginning of the study but constituted the majority of ticks by study end and were found predominantly on birds captured in areas designated as urban green spaces. Of 120 ticks, 5 were infected with Borrelia burgdorferi, spanning 3 ribotypes, but none were infected with Anaplasma phagocytophilum. Results allow inferences about propagule pressure for introduction of tick-borne diseases and emphasize the large sample sizes required to estimate this pressure.
Ejendal, Karin F K; Meyer, Jason M; Brust, Tarsis F; Avramova, Larisa V; Hill, Catherine A; Watts, Val J
Ticks transmit a wide variety of disease causing pathogens to humans and animals. Considering the global health impact of tick-borne diseases, there is a pressing need to develop new methods for vector control. We are exploring arthropod dopamine receptors as novel targets for insecticide/acaricide development because of their integral roles in neurobiology. Herein, we developed a screening assay for dopamine receptor antagonists to further characterize the pharmacological properties of the two D₁-like dopamine receptors (Isdop1 and Isdop2) identified in the Lyme disease vector, Ixodes scapularis, and develop a screening assay for receptor antagonists. A cell-based, cyclic AMP luciferase reporter assay platform was implemented to screen the LOPAC(1280) small molecule library for Isdop2 receptor antagonists, representing the first reported chemical library screen for any tick G protein-coupled receptor. Screening resulted in the identification of 85 "hit" compounds with antagonist activity at the Isdop2 receptor. Eight of these chemistries were selected for confirmation assays using a direct measurement of cAMP, and the effects on both Isdop1 and Isdop2 were studied for comparison. Each of these eight compounds showed antagonistic activity at both Isdop1 and Isdop2, although differences were observed regarding their relative potencies. Furthermore, comparison of the pharmacological properties of the tick dopamine receptors with that of the AaDOP2 receptor from the yellow fever mosquito and the human dopamine D₁ receptor (hD₁) revealed species-specific pharmacological profiles of these receptors. Compounds influencing dopaminergic functioning, such as the dopamine receptor antagonists discovered here, may provide lead chemistries for discovery of novel acaricides useful for vector control
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 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.
Ribeiro, Rita; Otte, Joachim; Madeira, Sara; Hutchings, Geoff H; Boinas, Fernando
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.
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 (Bose & 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.
Biswa Ranjan Maharana
Full Text Available Immunological interaction at the tick host interface involves both innate and acquired host defenses against infestation and Immunomodulatory countermeasures by thetick. Acquired resistance to tick infestation involves humoral and cellular immlmoregulatory effector pathways. Tick-borne disease-causing agentspr exploit tick suppression of host defenses during transmission and initiation of infection. Because of the public health importance of ticks and tick-borne diseases, it is crucial that we understand these interactions and exploit them in novel immunological control. [Vet. World 2011; 4(3.000: 131-135
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
Yousef eAbu Kwaik
Full Text Available Francisella tularensis is a Gram-negative, intracellular, zoonotic bacterium, and is the causative agent of tularemia in a broad host range. Arthropods such as ticks, mosquitoes, and flies maintain F. tularensis in nature by transmitting the bacteria among small mammals. While the tick is largely believed to be a biological vector of F. tularensis, transmission by mosquitoes and flies is largely believed to be mechanical on the mouthpart through interrupted feedings. However, the mechanism of infection of the vectors by F. tularensis is not well understood. Since F. tularensis has not been localized in the salivary gland of the primary human biting ticks, it is thought that bacterial transmission by ticks is through mechanical inoculation of tick feces containing F. tularensis into the skin wound. D. melanogaster is an established arthropod-vector model of tularemia, where F. tularensis infects hemocytes, and is found in hemolymph, as seen in ticks. In addition, phagosome biogenesis and robust intracellular proliferation of F. tularensis in arthropod-derived cells are similar to that in mammalian macrophages. Furthermore, bacterial factors required for infectivity of mammals are often required for infectivity of the fly by F. tularensis. Several host factors that contribute to F. tularensis intracellular pathogenesis in D. melanogaster have been identified, and F. tularensis targets some of the evolutionarily conserved eukaryotic processes to enable intracellular survival and proliferation in evolutionarily distant hosts
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.
Full Text Available Tudor staphylococcal nuclease (Tudor-SN and Argonaute (Ago are conserved components of the basic RNA interference (RNAi machinery with a variety of functions including immune response and gene regulation. The RNAi machinery has been characterized in tick vectors of human and animal diseases but information is not available on the role of Tudor-SN in tick RNAi and other cellular processes. Our hypothesis is that tick Tudor-SN is part of the RNAi machinery and may be involved in innate immune response and other cellular processes. To address this hypothesis, Ixodes scapularis and I. ricinus ticks and/or cell lines were used to annotate and characterize the role of Tudor-SN in dsRNA-mediated RNAi, immune response to infection with the rickettsia Anaplasma phagocytophilum and the flaviviruses TBEV or LGTV and tick feeding. The results showed that Tudor-SN is conserved in ticks and involved in dsRNA-mediated RNAi and tick feeding but not in defense against infection with the examined viral and rickettsial pathogens. The effect of Tudor-SN gene knockdown on tick feeding could be due to down-regulation of genes that are required for protein processing and blood digestion through a mechanism that may involve selective degradation of dsRNAs enriched in G:U pairs that form as a result of adenosine-to-inosine RNA editing. These results demonstrated that Tudor-SN plays a role in tick RNAi pathway and feeding but no strong evidence for a role in innate immune responses to pathogen infection was found.
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 Aim: Hyalomma anatolicum anatolicum and Hyalomma dromedarii ticks are of major economic importance in the livestock sector as the vector of tropical theileriosis causing huge production loss, mostly in tropical countries. The release of different reactive oxygen and nitrogen species by exogenous and endogenous means can potentially induce oxidative damage to the ticks during their prolonged feeding on their vertebrate hosts. Hence, ticks need an effective free radical scavenging and antioxidant defense system for their successful feeding of a blood meal. Therefore, the present study was undertaken to evaluate the interspecies variations in antioxidant response, free radical scavenging, and anti-inflammatory activities in salivary gland extracts (SGE of the two species as they differ considerably in relation to feeding behavior and host specificity. Materials and Methods: Tick salivary glands were dissected out under ice from semi-fed female ticks of both the species and homogenized at low temperature to prepare SGE. SGE was stored at −40°C for analysis of free radical scavenging activities and antioxidant status. Results: Significant depletion in reduced glutathione concentrations, malondialdehyde level and elevation in free radical scavenging activity, superoxide dismutase, anti-inflammatory activity were found in SGE of engorging female H. dromedarii ticks as compared to H. a. anatolicum. Conclusion: Higher antioxidant status and free radical scavenging activities in H. dromedarii might have enabled these ticks to suck more blood from the host in spite of continuous host’s immune responses. These findings about tick biology will help in improving tick control strategies.
Ndudim Isaac Ogo
Full Text Available Aim: The purpose of this pilot study was to genetically identify and characterize Coxiella burnetii from Amblyommavarigatum ticks collected on cattle in North central Nigeria.Materials and Methods: A total of 40 partially fed ticks morphologically identified as adult A. variegatum ticks collectedfrom cattle owned by Fulani pastoralists were evaluated for the presence of C. burnetii using PCR, cloning, and sequencing ofthe heat shock polypeptide gene htpB.Results: C. burnetii DNAwas detected in 10 (25% of the ticks analyzed. Sequences for the C. burnetii gene htpB detected inour samples had 99-100% identity to all other C. burnetii that have been described and that are deposited in the GenBankdatabase. Phylogenetic analysis using neighbor-joining method indicates the clustering of C. burnetii sequences from ourstudy areas with those collected from Oyo state, South-western Nigeria and Spain.Conclusion: This study shows a high infection rate of C. burnetii in A. variegatum ticks in the study areas. Phylogeneticinferences indicates that the strain of C. burnetii found in the North central states of Plateau and Nasarawa were same as thosepreviously reported in the South western state of Oyo. The presence of this pathogen in naturally occurring A. variegatum tickpopulations could present an additional risk of Q-fever disease to humans, especially to the pastoralists that are closelyassociated with their animals and are easily exposed to tick bites. Therefore, further studies are needed to assess thecompetence of A. variegatum ticks as vectors of C. burnetii pathogens.
A model for the phenomenological description of tick-by-tick share prices in a stock exchange is introduced. It is based on mixtures of compound Poisson processes. Preliminary results based on Monte Carlo simulation show that this model can reproduce various stylized facts.
A model for the phenomenological description of tick-by-tick share prices in a stock exchange is introduced. It is based on mixtures of compound Poisson processes. Preliminary results based on Monte Carlo simulation show that this model can reproduce various stylized facts.
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.
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.
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
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
Shemshad, Khadijeh; Rafinejad, Javad; Kamali, Karim; Piazak, Norayer; Sedaghat, Mohammad Mahdi; Shemshad, Masoomeh; Biglarian, Akbar; Nourolahi, Fathollah; Valad Beigi, Enshallah; Enayati, Ahmad Ali
This report presents the results of the first faunistic study of hard ticks in Qazvin province of Iran. The primary objective was to determine the species diversity and geographic distribution of hard ticks that parasitize domestic ruminants. Information about the abiotic preferences of these species has been provided. A total of 286 cattle, 1,053 goats, and 2,050 sheep were examined in 13 villages in 28 flocks distributed throughout the studied areas. Total direct body collections of ticks were made from each domestic ruminant. A total of 228 Ixodid specimens belonging to nine species in three different genera were recorded in the areas, including Boophilus annulatus (Say, 1821), Hyalomma anatolicum Koch, 1844, Hyalomma asiaticum (Schulze and Schlettke, 1929), Hyalomma detritum Schulze, 1919, Hyalomma dromedarii Koch, 1844, Hyalomma marginatum Koch 1844, Hyalomma schulzei Olenev, 1931, Rhipicephalus bursa Canestrini and Fanz, 1878 and Rhipicephalus sanguineus (Latreille, 1806). The most abundant species on sheep was R. sanguineus (46.92%), while B. annulatus (6.6%) found only on cattle. A finding of great significance was that R. sanguineus, the main vector of babesiosis, is firmly established throughout the counties. A further objective of the study was to compare the abundance of the major tick species on domestic ruminants. This was carried out at 19 sampling sites. The highest number of ticks was collected in July-August during the hot season.
Denise Amaral Gomes Nascimento
Full Text Available Abstract The aims of the present study were to serosurvey dogs, horses, and humans highly exposed to tick bites for anti-Borrelia burgdorferi s.l. antibodies, identify tick species present, and determine risk factors associated with seropositivity in a rural settlement of Paraná State, southern Brazil. Eighty-seven residents were sampled, along with their 83 dogs and 18 horses, and individual questionnaires were administered. Immunofluorescence antibody test (IFAT was performed on serum samples and positive samples were subjected to western blot (WB analysis. Anti-B. burgdorferi antibodies were found in 4/87 (4.6% humans, 26/83 (31.3% dogs, and 7/18 (38.9% horses by IFAT, with 4/4 humans also positive by WB. Ticks identified were mostly from dogs and included 45/67 Rhipicephalus sanguineus, 21/67 Amblyomma ovale, and 1/67 A. cajennense sensu lato. All (34/34 horse ticks were identified as A. cajennense s.l.. No significant association was found when age, gender, or presence of ticks was correlated to seropositivity to Borrelia sp. In conclusion, although anti-Borrelia antibodies have been found in dogs, horses and their owners from the rural settlement, the lack of isolation, molecular characterization, absence of competent vectors and the low specificity of the commercial WB kit used herein may have impaired risk factor analysis.
Lah, Ernieenor Faraliana Che; Yaakop, Salmah; Ahamad, Mariana; George, Ernna; Nor, Shukor Md
Identification of a local species of tick, Ixodes granulatus from the family Ixodidae is essential because it has potential to be vector for spotted fever group (SFG) rickettsia and tick thypus. The aim of this study is to portray the relationships among several populations of I. granulatus collected from different species of animal hosts and localities in Peninsular Malaysia. Polymerase Chain Reaction was conducted by amplifying mitochondrial DNA marker, namely cytochrome oxidase subunit I (COI) sequences from 15 individual ticks that attached to five different hosts caught from three different localities. Confirmation of the species identity was accomplished using BLAST program. Neighbor-joining (NJ) and Maximum Parsimony (MP) tree based on COI sequences were constructed by using PAUP 4.0b10 to identify the relationship among species. The result of this study showed a high genetic heterogeneity between I. granulatus and other species of the same genus (7.2-23.7%). Furthermore, a low intraspecific variation was observed among the species of I. granulatus collected from different localities (0-3.7%). This study produced the first establishment of molecular marker for clarifying genetic species variation and diversity of local I. granulatus tick which contribute to the control of tick-borne infections.
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.
Oh, Joonseok; Bowling, John J; Carroll, John F; Demirci, Betul; Başer, K Hüsnü Can; Leininger, Theodor D; Bernier, Ulrich R; Hamann, Mark T
The number of endangered plant species in the U.S. is significant, yet studies aimed towards utilizing these plants are limited. Ticks and mosquitoes are vectors of significant pathogenic diseases of humans. Repellents are critical means of personal protection against biting arthropods and disease transmission. The essential oil and solvent extracts from Lindera melissifolia (Walt.) Blume (Lauraceae) (pondberry) drupes were gathered and analyzed by GC and GC-MS. The essential oil obtained from this endangered plant showed a significant dose dependent repellency of ticks and a moderate mosquito repellent effect while the subsequent hexanes extract was completely ineffective. Fractional freezing enriched the tick repellent components of the essential oil. Several known tick repellent components were recognized by the GC-MS comparison of the resulting fractions and β-caryophyllene, α-humulene, germacrene D and β-elemene warrant evaluations for tick repellency. Identifying pondberry as a potential renewable source for a broad spectrum repellent supports efforts to conserve similar U.S. endangered or threatened plant species.
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.
Full Text Available Abstract Presently, 45% of the total human population of Europe, as well as their domestic and companion animals, are exposed to the risk of vector-borne helminths (VBH causing diseases. A plethora of intrinsic biological and extrinsic factors affect the relationship among helminths, vectors and animal hosts, in a constantly changing environment. Although canine dirofilarioses by Dirofilaria immitis and Dirofilaria repens are key examples of the success of VBH spreading into non-endemic areas, another example is represented by Thelazia callipaeda eyeworm, an emergent pathogen of dogs, cats and humans in several regions of Europe. The recent finding of Onchocerca lupi causing canine and human infestation in Europe and overseas renders the picture of VBH even more complicated. Similarly, tick-transmitted filarioids of the genus Cercopithifilaria infesting the skin of dogs were recently shown to be widespread in Europe. Although for most of the VBH above there is an increasing accumulation of research data on their distribution at national level, the overall impact of the diseases they cause in dogs and humans is not fully recognised in many aspects. This review investigates the reasons underlying the increasing trend in distribution of VBH in Europe and discusses the diagnostic and control strategies currently available. In addition, this article provides the authors’ opinion on some topics related to VBH that would deserve further scientific investigation.
Passos, Lygia Maria Friche
Continuous cell lines have been established from several ixodid and argasid tick species, representing an excellent tool suitable for the isolation of pathogens and their subsequent propagation, which in turn allows the production of antigenic material for diagnostic tests, antibody and vaccine production, and also for studies on host-vector-pathogen relationships. This paper reviews the use of tick cells for culture initiation and maintenance of two obligate intracellular bacterial pathogens, Anaplasma marginale and Anaplasma phagocytophilum. These in vitro cultivation systems have been used in a wide range of studies, covering morphological ultrastructural analysis, genetics, proteomics and biological differences between strains, including genome transcriptional and protein expression approaches, enabling comparisons between host and vector cells. Thus, such systems open a new window for a better understanding of interactions between pathogens and tick cells. Last but not least, such systems contribute to the reduction in usage of animals for experimental research, as antigenic material can be produced in reasonably large quantities without the use of in vivo species-specific systems.
Pintér, Réka; Madai, Mónika; Vadkerti, Edit; Németh, Viktória; Oldal, Miklós; Kemenesi, Gábor; Dallos, Bianka; Gyuranecz, Miklós; Kiss, Gábor; Bányai, Krisztián; Jakab, Ferenc
Tick-borne encephalitis virus (TBEV) is an arthropod-borne viral pathogen causing infections in Europe and is responsible for most arbovirus central nervous system infections in Hungary. Assessing the TBEV prevalence in ticks through detection of genomic RNA is a broadly accepted approach to estimate the transmission risk from a tick bite. For this purpose, 2731 ticks were collected from the neighboring area of the town of Dévaványa, located in southeastern Hungary, which is considered a low-risk-transmission area for TBEV. Altogether, 2300 ticks were collected from the vegetation, while 431 were collected from rodents. Samples were pooled and then screened for TBEV with a newly designed semi-nested RT-PCR (RT-snPCR) targeting the NS1 genomic region. PCR results were confirmed by direct sequencing of the second round amplicons. Among the 3 different collected tick species (Ixodes ricinus, Haemaphysalis concinna, Dermacentor marginatus), I. ricinus was the only species that tested positive for TBEV. TBEV-positive ticks were collected from small mammals or from the vegetation. One nymphal pool and 4 larval pools tested positive for TBEV. The only positive nymphal pool was unfed and came from vegetation, while ticks of the 4 positive larval pools were collected from rodents. Minimal TBEV prevalence in ticks was 0.08% for unfed nymphs and 0.78% for feeding larvae. Our results indicate that further long-term investigations on the occurrence of TBEV are needed to better describe the geographic distribution and the prevalence of infected ticks in Hungary.
Full Text Available Aim: An investigation on ticks and haemoparasites of dogs that belonged to Maiduguri metropolis (Borno State was conducted. Materials and Methods: Survey of ticks and haemo-parasites on 400 stray dogs was conducted in Maiduguri from December 2009 to November 2011, using a stratified random sampling technique from different locations of the town. The town was divided into 10 districts out of which a total of 40 dogs were sampled at random from each district. Results: Four genera of ticks were identified on the infested dogs 384 (96.0, all of which belonged to the family Ixodidae (hard ticks. The genus Boophilus was predominant with a prevalence of 88.0%, Rhipicephalus 10.8%, Hyalomma 0.9% and Amblyomma 0.3% at (p ˂ 0.05. Dogs within the age-group of 6-12 months were the most infested, while those within the age-group of 24 –120 months were the least infested. Sex appeared to have a less significant influence (p > 0.05 on the prevalence of ticks among the dog population as females were more infested than the males. The perineum and the ear were the most commonly infested areas, with 328 (85.4% and 252 (65.4% respectively, while the scrotal and abdominal regions were the least infested areas 12 (3.1% each. The month of August showed the highest mean tick burden of 462.5±3.2 ranging from 450-475, while the month of February showed the least number of ticks with a mean of 244.5±3.8 ranging from 239-250. Dogs found to be infected with Babesia canis are all harboring ticks of the genus Rhipicephalus. Female dogs were more infected (66.7% with Babesia canis than their male counterparts (33.3% (p ˂ 0.05 and dogs within the age group of 1-6 months were more infected. Conclusion: Prevalence of ticks on dogs in this study area is relatively high and the occurrence of Babesia species is vector dependent, with ticks of the genus Rhipicephalus sanguineous being the most common vector in transmission of the parasite. Seasons also play a vital role in the
Williams-Newkirk, Amanda Jo; Rowe, Lori A; Mixson-Hayden, Tonya R; Dasch, Gregory A
We used next generation sequencing to detect the bacterium "Candidatus Midichloria mitochondrii" for the first time in lone star ticks (Amblyomma americanum) from the eastern United States. 177 individuals and 11 tick pools from seven sites in four states were tested by pyrosequencing with barcoded 16S rRNA gene eubacterial primers targeting variable regions 5-3. Average infection prevalence was 0.15 across all surveyed populations (range 0-0.29) and only the site with the smallest sample size (n = 5) was negative. Three genotypes differing by 2.6-4.1 % in a 271 bp region of 16S rRNA gene were identified. Two variants co-occurred in sites in North Carolina and New York, but were not observed in the same tick at those sites. The third genotype was found only in Georgia. Phylogenetic analysis of this fragment indicated that the three variants are more closely related to "Candidatus Midichloria mitochondrii" genotypes from other tick species than to each other. This variation suggests that multiple independent introductions occurred in A. americanum which may provide insight into bacterial spread within its ecosystem and parasitism on this tick. Whether the presence of this bacterium affects acquisition or maintenance of other pathogens and symbionts in A. americanum or the survival, biology and evolution of the tick itself is unknown.
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.
Špitalská, Eva; Stanko, Michal; Mošanský, Ladislav; Kraljik, Jasna; Miklisová, Dana; Mahríková, Lenka; Bona, Martin; Kazimírová, Mária
Many rickettsiae of the spotted fever group are emerging pathogens causing serious diseases associated with vertebrate hosts. Ixodidae ticks are known as their vectors. Investigation of the relative abundance of questing Ixodes ricinus and their infection with Rickettsia spp. in an agricultural site comprising a game reserve in Slovakia was the aim of this study. In total, 2198 I. ricinus (492 larvae, 1503 nymphs and 203 adults) were collected by flagging the vegetation along 100 m(2) transects in Rozhanovce (eastern Slovakia): 334, 595 and 1269 in 2011, 2012 and 2013, respectively. Considering questing nymphs and adults, the highest relative density of 81 individuals/100 m(2) was observed in May 2013, the lowest of 0.3 individuals/100 m(2) in March 2012. A total of 1056 ticks (853 nymphs, 100 females and 103 males; 2011: n = 329, 2012: n = 509 and 2013: n = 218) were individually screened by PCR-based methods for the presence of Rickettsia spp. The overall prevalences were 7.3% for nymphs, 15% for females, 7.8% for males; 7.0% in 2011, 8.4% in 2012, and 8.7% in 2013. The maximum prevalences were observed in July in nymphs and in May in adults. Sequencing showed infection with R. helvetica in 73 ticks (72.6% nymphs, 16.4% females, 11% males) and with R. monacensis in 11 ticks (8 nymphs, 3 females). The results showed the circulation of pathogenic Rickettsia species in the agricultural site and a potential risk for humans to encounter infected ticks.
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?
Venzal, José M; Estrada-Peña, Agustín; Portillo, Aránzazu; Mangold, Atilio J; Castro, Oscar; De Souza, Carlos G; Félix, María L; Pérez-Martínez, Laura; Santibánez, Sonia; Oteo, José A
At first Rickettsia conorii was implicated as the causative agent of spotted fever in Uruguay diagnosed by serological assays. Later Rickettsia parkeri was detected in human-biting Amblyomma triste ticks using molecular tests. The natural vector of R. conorii, Rhipicephalus sanguineus, has not been studied for the presence of rickettsial organisms in Uruguay. To address this question, 180 R. sanguineus from dogs and 245 A. triste from vegetation (flagging) collected in three endemic localities were screened for spotted fever group (SFG) rickettsiosis in southern Uruguay. Tick extracted DNA pools were subjected to PCR using primers which amplify a fragment of the rickettsial gltA gene. Positive tick DNA pools with these primers were subjected to a second PCR round with primers targeting a fragment of the ompA gene, which is only present in SFG rickettsiae. No rickettsial DNA was detected in R. sanguineus. However, DNA pools of A. triste were found to be positive for a rickettsial organism in two of the three localities, with prevalences of 11.8% to 37.5% positive pools. DNA sequences generated from these PCR-positive ticks corresponded to R. parkeri. These findings, joint with the aggressiveness shown by A. triste towards humans, support previous data on the involvement of A. triste as vector of human infections caused by R. parkeri in Uruguay.
José M. Venzal
Full Text Available At first Rickettsia conorii was implicated as the causative agent of spotted fever in Uruguay diagnosed by serological assays. Later Rickettsia parkeri was detected in human-biting Amblyomma triste ticks using molecular tests. The natural vector of R. conorii, Rhipicephalus sanguineus, has not been studied for the presence of rickettsial organisms in Uruguay. To address this question, 180 R. sanguineus from dogs and 245 A. triste from vegetation (flagging collected in three endemic localities were screened for spotted fever group (SFG rickettsiosis in southern Uruguay. Tick extracted DNA pools were subjected to PCR using primers which amplify a fragment of the rickettsial gltA gene. Positive tick DNA pools with these primers were subjected to a second PCR round with primers targeting a fragment of the ompA gene, which is only present in SFG rickettsiae. No rickettsial DNA was detected in R. sanguineus. However, DNA pools of A. triste were found to be positive for a rickettsial organism in two of the three localities, with prevalences of 11.8% to 37.5% positive pools. DNA sequences generated from these PCR-positive ticks corresponded to R. parkeri. These findings, joint with the aggressiveness shown by A. triste towards humans, support previous data on the involvement of A. triste as vector of human infections caused by R. parkeri in Uruguay.
Zamoto-Niikura, Aya; Tsuji, Masayoshi; Qiang, Wei; Nakao, Minoru; Hirata, Haruyuki; Ishihara, Chiaki
The species Babesia microti, commonly found in rodents, demonstrates a high degree of genetic diversity. Three lineages, U.S., Kobe, and Hobetsu, are known to have zoonotic potential, but their tick vector(s) in Japan remains to be elucidated. We conducted a field investigation at Nemuro on Hokkaido Island and at Sumoto on Awaji Island, where up to two of the three lineages occur with similar frequencies in reservoirs. By flagging vegetation at these spots and surrounding areas, 4,010 ticks, comprising six species, were collected. A nested PCR that detects the 18S rRNA gene of Babesia species revealed that Ixodes ovatus and I. persulcatus alone were positive. Lineage-specific PCR for rRNA-positive samples demonstrated that I. ovatus and I. persulcatus carried, respectively, the Hobetsu and U.S. parasites. No Kobe-specific DNA was detected. Infected I. ovatus ticks were found at multiple sites, including Nemuro and Sumoto, with minimum infection rates (MIR) of ∼12.3%. However, all I. persulcatus ticks collected within the same regions, a total of 535, were negative for the Hobetsu lineage, indicating that I. ovatus, but not I. persulcatus, was the vector for the lineage. At Nemuro, U.S. lineage was detected in 2 of 139 adult I. persulcatus ticks (MIR, 1.4%), for the first time, while 48 of I. ovatus ticks were negative for that lineage. Laboratory experiments confirmed the transmission of Hobetsu and U.S. parasites to hamsters via I. ovatus and I. persulcatus, respectively. Differences in vector capacity shown by MIRs at Nemuro, where the two species were equally likely to acquire either lineage of parasite, may explain the difference in distribution of Hobetsu throughout Japan and U.S. taxa in Nemuro. These findings are of importance in the assessment of the regional risk for babesiosis in humans.
Vector repellent is one element in the prevention of vector-borne diseases. Families that neglect protecting their children against vectors risk their children contracting illnesses such as West Nile virus, eastern equine encephalitis, Lyme disease, malaria, dengue hemorrhagic fever, yellow fever, babesiosis, Crimean-Congo hemorrhagic fever, Rocky Mountain spotted fever, Southern tick-associated rash illness, ehrlichiosis, tick-borne relapsing fever, tularemia, and other insect and arthropod related diseases (CDC, 2011). Identification of families at risk includes screening of the underlying basis for reluctance to apply insect repellent. Nurses and physicians can participate in a positive role by assisting families to determine the proper prophylaxis by recommending insect repellent choices that are economical, safe, and easy to use. A holistic alternative might include the suggestion of clove oil in cases where families might have trepidations regarding the use of DEET on children. This article will explore the safety and effectiveness of clove oil and its use as an insect repellent.
... Old Feeding Your 1- to 2-Year-Old Tick Removal: A Step-by-Step Guide KidsHealth > For Parents > Tick Removal: A Step-by-Step Guide A A ... isn't a freckle at all. It's a tick. What should you do? First, don't panic. ...
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, i
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...
Freundt, Eric C.; Beatty, Douglas C.; Stegall-Faulk, Teresa; Wright, Stephen M.
Enterovirus-specific genetic sequences were isolated from two Amblyomma americanum tick pools. Identical genetic sequences were later obtained from cerebrospinal fluid of a patient with aseptic meningitis and a recent history of tick attachment. These observations suggest the possibility of an emerging tick-borne human enterovirus associated with aseptic meningitis.
Full Text Available Background An increase in tick borne diseases in Australia has seen an interest in appropriate removal of ticks (order Ixodida in order to prevent anaphylaxis, allergy and transmission of tick borne diseases. Aims A systematic review of peer-reviewed literature to determine what method of tick removal should be promoted in terms of preventing future health complications. Methods Thematic synthesis was used in two stages: – tick removal studies conducted on animals and humans were examined and the conclusions from all of these studies were compared, in order to ascertain the best tick removal method in relation to prevention of future medical problems (including tick bite allergy and transmission of infection. Conclusion This systematic review documents the best method of tick removal based on scientific and medical studies between 1985 and 2016. It concludes that the best method is to remove the tick as soon as possible after it is detected, using either fine-tipped tweezers or a reputable commercially produced tick removal tool to pull the tick away from the site of attachment. Some methods of removal, such as applying chemicals like petroleum jelly, alcohol, or nail polish to the tick, have been discredited. Other methods of removal, such as freezing, while promising, have not yet been scientifically validated
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
van der Loo, JCM; Swaney, WP; Grassman, E; Terwilliger, A; Higashimoto, T; Schambach, A; Hacein-Bey-Abina, S; Nordling, DL; Cavazzana-Calvo, M; Thrasher, AJ; Williams, DA; Reeves, L; Malik, P
Patients with X-linked severe combined immunodeficiency (SCID-X1) were successfully cured following gene therapy with a gamma-retroviral vector (gRV) expressing the common gamma chain of the interleukin-2 receptor (IL2RG). However, 5 of 20 patients developed leukemia from activation of cellular proto-oncogenes by viral enhancers in the long-terminal repeats (LTR) of the integrated vector. These events prompted the design of a gRV vector with self-inactivating (SIN) LTRs to enhance vector safety. Herein we report on the production of a clinical-grade SIN IL2RG gRV pseudotyped with the Gibbon Ape Leukemia Virus envelope for a new gene therapy trial for SCID-X1, and highlight variables that were found to be critical for transfection-based large-scale SIN gRV production. Successful clinical production required careful selection of culture medium without pre-added glutamine, reduced exposure of packaging cells to cell-dissociation enzyme, and presence of cations in wash buffer. The clinical vector was high titer; transduced 68–70% normal human CD34 + cells, as determined by colony-forming unit assays and by xenotransplantation in immunodeficient NOD.CB17-Prkdcscid/J (nonobese diabetic/severe combined immunodeficiency (NOD/SCID)) and NOD.Cg-Prkdcscid Il2rgtm1Wjl/SzJ (NOD/SCID gamma (NSG))) mice; and resulted in the production of T cells in vitro from human SCID-X1 CD34 + cells. The vector was certified and released for the treatment of SCID-X1 in a multi-center international phase I/II trial. PMID:22551777
Alberdi, M Pilar; Nijhof, Ard M; Jongejan, Frans; Bell-Sakyi, Lesley
Tick cell lines play an important role in research on ticks and tick-borne pathogenic and symbiotic microorganisms. In an attempt to derive continuous Dermacentor reticulatus cell lines, embryo-derived primary cell cultures were set up from eggs laid by field ticks originally collected as unfed adults in The Netherlands and maintained for up to 16 months. After several months, it became evident that cells in the primary cultures were infected with a Rickettsia-like intracellular organism. Supernatant medium containing some D. reticulatus cells was inoculated into cultures of 2 Rhipicephalus (Boophilus) microplus cell lines, BME/CTVM2 and BME/CTVM23, where abundant growth of the bacteria occurred intracellularly on transfer to both cell lines. Bacterial growth was monitored by light (live, inverted microscope, Giemsa-stained cytocentrifuge smears) and transmission electron microscopy revealing heavy infection with typical intracytoplasmic Rickettsia-like bacteria, not present in uninfected cultures. DNA was extracted from bacteria-infected and uninfected control cultures, and primers specific for Rickettsia 16S rRNA, ompB, and sca4 genes were used to generate PCR products that were subsequently sequenced. D. reticulatus primary cultures and both infected tick cell lines were positive for all 3 Rickettsia genes. Sequencing of PCR products revealed 99-100% identity with published Rickettsia raoultii sequences. The R. raoultii also grew abundantly in the D. nitens cell line ANE58, poorly in the D. albipictus cell line DALBE3, and not at all in the D. andersoni cell line DAE15. In conclusion, primary tick cell cultures and cell lines are useful systems for isolation and propagation of fastidious tick-borne microorganisms. In vitro isolation of R. raoultii from Dutch D. reticulatus confirms previous PCR-based detection in field ticks, and presence of the bacteria in the tick eggs used to initiate the primary cultures confirms that transovarial transmission of this
Paddock, Christopher D; Fournier, Pierre-Edouard; Sumner, John W; Goddard, Jerome; Elshenawy, Yasmin; Metcalfe, Maureen G; Loftis, Amanda D; Varela-Stokes, Andrea
Until recently, Amblyomma maculatum (the Gulf Coast tick) had garnered little attention compared to other species of human-biting ticks in the United States. A. maculatum is now recognized as the principal vector of Rickettsia parkeri, a pathogenic spotted fever group rickettsia (SFGR) that causes an eschar-associated illness in humans that resembles Rocky Mountain spotted fever. A novel SFGR, distinct from other recognized Rickettsia spp., has also been detected recently in A. maculatum specimens collected in several regions of the southeastern United States. In this study, 198 questing adult Gulf Coast ticks were collected at 4 locations in Florida and Mississippi; 28% of these ticks were infected with R. parkeri, and 2% of these were infected with a novel SFGR. Seventeen isolates of R. parkeri from individual specimens of A. maculatum were cultivated in Vero E6 cells; however, all attempts to isolate the novel SFGR were unsuccessful. Partial genetic characterization of the novel SFGR revealed identity with several recently described, incompletely characterized, and noncultivated SFGR, including "Candidatus Rickettsia andeanae" and Rickettsia sp. Argentina detected in several species of Neotropical ticks from Argentina and Peru. These findings suggest that each of these "novel" rickettsiae represent the same species. This study considerably expanded the number of low-passage, A. maculatum-derived isolates of R. parkeri and characterized a second, sympatric Rickettsia sp. found in Gulf Coast ticks.
Khater, Hanem; Hendawy, Nabil; Govindarajan, Marimuthu; Murugan, Kadarkarai; Benelli, Giovanni
Ticks transmit more pathogen species than any other group of blood-feeding arthropods worldwide, affecting humans, livestock, and companion animals. Hyalomma dromedarii is the predominant tick species infesting camels, and its effective control is of pivotal importance. In this research, we compared the phytoefficacy of safranin (SF), a fluorescent dye applied as an acaricide for the first time, to that of tetramethrin (TM) against engorged females of H. dromedarii through in vitro immersion bioassays. Furthermore, the effect of SF exposure was evaluated on the reproductive potential of surviving tick females. Different concentrations of SF (0.03, 0.06, 0.3, 1, and 4 % w:v) and TM (0.03, 0.13, 0.5, 2, and 4 %) were prepared in distilled water and administered to engorged females of H. dromedarii. SF-treated ticks were illuminated with a light source for 30 min post-treatment (PT). Photophysical properties of SF were studied, and the relative efficacy of the used light source and sunlight was calculated. Results showed that the minimum least concentration that causes 100 % acaricidal effect was 4 % PT with SF and TM, for 8 and 48 h, respectively. LC50 values 8 and 24 h PT were 0.08, 0.03 and 0.78, 0.20 %, respectively. Comparing LC50 and LC90 2 h PT, SF was 33 and 22 times more potent than TM. LT50 of 4 % SF and TM were 0.80 and 2.17 h, respectively. Treatment with the lowest concentrations of SF and TM induced reduction of the number of ovipositing females, eggs per female, ticks laying viable eggs, and hatched eggs. Overall, our results highlighted that SF is highly effective if compared to TM, allowing use to candidate it for the development of novel and safer acaricides.
Mohamed W. Ghafar
Full Text Available PCR targeting 16S rRNA gene integrated with sequence analysis were performed to investigate the prevalence and the molecular identity of Anaplasma phagocytophilum in Egyptian Rhipicephalus sanguineus ticks attached to dogs. A total of 413 adult and nymphal R. sanguineus ticks were collected while attached to 72 free-roaming dogs from four locations (Imbaba, Boulaq, Haram, Monib in Giza Governorate, Egypt. DNA was successfully extracted from 401 specimens (133 nymphs and 268 adults. The overall prevalence rate was 13.7% and adult ticks showed a significantly higher infection rate (16.4% compared to nymphs (8.3%. Sequence comparisons of 218-bp showed that detected organism belongs to A. phagocytophilum. The sequence showed 99.1% similarity (2 nucleotide differences with some strains described as human pathogens and with that detected in the established tick vectors. Phylogenetic analysis placed the bacteria on a separate branch with that found in R. annulatus from Egypt (DQ379972 (99.5% similarity. Our variant strain was designated as A. phagocytophilum-Ghafar-EGY (AB608266. This report is the first molecular characterization of A. phagocytophilum in R. sanguineus in Egypt, suggesting that this tick species may act as a competent vector for a variant strain of human granulocytic anaplasmosis agent.
Full Text Available The susceptibility of two commonly occurring species of Ixodid ticks viz., the cattle tick, Hyalomma anatolicum anatolicum Koch and the brown dog tick, Rhipicephalus sanguineus Latr to certain newer insecticdes was investigated under controlled environmental conditions. The repellency of diethyl toluamide (Deet to the two species of ticks was also investigated by a specially devised laboratory technique. It was found that based on LC/sub 50/ values, the two species were most susceptible to pyrethrins followed by carbaryl whereas malathion was found least toxic to the ticks.
The redbay ambrosia beetle (RAB), Xyleborus glabratus (Coleoptera: Curculionidae: Scolytinae) vectors the fungal pathogen, Raffaelea lauricola, which causes laurel wilt (LW), a lethal disease of trees in the family Lauraceae, including the most commercially important crop in this family, avocado, Pe...
Hornok, Sándor; Kartali, Kitti; Takács, Nóra; Hofmann-Lehmann, Regina
It has been reported from cities in Central Europe that clinical cases of canine babesiosis are most frequent in spring time, despite the fact that the peak activity of Dermacentor reticulatus (the vector of Babesia canis) is during autumn. The present study was initiated to evaluate the seasonal distribution of B. canis-infected D. reticulatus ticks in this context. In two habitats of Budapest 852 D. reticulatus adults were collected between August, 2014 and June, 2015. Among the molecularly analysed 413 ticks 8.2% were PCR positive for piroplasms. Both formerly reported 18S rDNA genotypes of B. canis: ("A" and "B") were identified. In habitat-1 B. canis-infected ticks were detected only in spring. Similarly, in habitat-2 B. canis-infected ticks occurred significantly more frequently during winter and spring than in the autumn (24.6% vs. 1.4%), and their monthly distribution showed significant negative correlation with tick size. The prevalence of infected ticks was the highest (43.5%) in late February. In addition, a month-dependent time-shift was noted in the appearance of the two B. canis 18S rDNA genotypes: the less pathogenic "A" predominating earlier, and the more pathogenic "B" later. It is known from literature that D. reticulatus individuals that moult to adult in the spring are smaller in size. Thus, the above results suggest that in urban habitats the occurrence of B. canis-infected ticks (or their questing activity) is more likely, when there are freshly emerged adults in the population, i.e. early in the questing season. It was also observed that the temporal distribution of D. reticulatus ticks carrying different B. canis genotypes was not random.
Idalia A. Rodriguez
Full Text Available At Bezà Mahafaly Special Reserve (BMSR, Madagascar, mouse lemurs (Microcebus griseorufus are parasitized by multiple species of haemaphysaline ticks. At present we know little about the role ticks play in wild lemur populations and how they can alter interspecies relationships within communities or impact host fitness. In order to better understand these dynamics at BMSR, we examined parasite-host interactions as well as the ecology of mouse lemurs and their infesting ticks, Haemaphysalis lemuris and H. sp. cf. simplex. We show that season, host sex, and habitat influence the relative abundance of ticks on mouse lemurs. Specifically, infestations occur only during the dry season (May–October, are higher in males, and are higher at the study site with the most ground cover and with greater density of large-bodied hosts. Microcebus likely experience decreased susceptibility to tick infestations during the wet season because at that time they rarely if ever descend to the ground. Similarly, male mouse lemurs have higher infestation rates than females because of the greater time they spend traveling and foraging on the ground. During the dry season, Microcebus likely serve as hosts for the tenrec tick, H. sp. cf. simplex, when tenrecs hibernate. In turn, during the wet season when mouse lemurs rarely descend to the ground, other small mammals at the reserve may serve as maintenance hosts for populations of immature ticks. The synchronous development of larvae and nymphs could present high risk for vector-borne disease in Microcebus. This study also provides a preliminary description of the ecology and life cycle of the most common lemur tick, H. lemuris.
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.
Billeter, Sarah A; Cáceres, Abraham G; Gonzales-Hidalgo, James; Luna-Caypo, Deysi; Kosoy, Michael Y
A total of 103 ticks, collected from canines, horses, donkeys, and snakes from Peru, were screened for the presence of Bartonella DNA by polymerase chain reaction analysis. Bartonella DNA was detected in two ticks using Bartonella 16S-23S intergenic spacer region primers and in an additional two ticks using Bartonella NADH dehydrogenase gamma subunit gene (nuoG) primers. Bartonella rochalimae Eremeeva et al., B. quintana Schmincke, and B. elizabethae Daly et al. DNA was detected in a Rhipicephalus sanguineus Latreille (Acari: Ixodidae) female tick removed from a dog and B. quintana DNA was present in a Dermacentor nitens Neumann (Acari: Ixodidae) pool of five larvae, one nymph, and one adult male tick collected from donkeys. This is the first study to report the detection of B. rochalimae, B. quintana, and B. elizabethae DNA in ticks from Peru. Further investigations must be performed to decipher the role ticks may play in the transmission of Bartonella species.
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
Castellanos, Adrian A.; Medeiros, Matthew C. I.; Hamer, Gabriel L; Morrow, Michael E.; Eubanks, Micky D.; Teel, Pete D.; Sarah A. Hamer; Light, Jessica E.
Invasive species may impact pathogen transmission by altering the distributions and interactions among native vertebrate reservoir hosts and arthropod vectors. Here, we examined the direct and indirect effects of the red imported fire ant (Solenopsis invicta) on the native tick, small mammal and pathogen community in southeast Texas. Using a replicated large-scale field manipulation study, we show that small mammals were more abundant on treatment plots where S. invicta populations were exper...
刘琪; 王伟利; 孟庆峰
对蜱的种属、生物学特性和传播疾病及诊断方法进行了综述.针对蜱及常见蜱传病的特性,有助于找到切实有效的方法,从根本上消灭蜱所带来的危害.%The genus, biological characteristics of tick and diagnosis methods for tick-borne disease were reviewed. Aiming at characteristics of tick and several common tick-bome diseases, effective methods were easy to found, so as to eliminate damages brought by tick.
St John, Heidi K; Adams, Melissa L; Masuoka, Penny M; Flyer-Adams, Johanna G; Jiang, Ju; Rozmajzl, Patrick J; Stromdahl, Ellen Y; Richards, Allen L
Rickettsia montanensis has long been considered a nonpathogenic member of the spotted fever group rickettsiae. However, the infection potential of R. montanensis is being revisited in light of its recent association with a case of human infection in the United States and the possibility that additional cases may have been misdiagnosed as Rocky Mountain spotted fever. To this end, DNA was extracted from American dog ticks (Dermacentor variabilis) removed from Department of Defense (DoD) personnel and their dependents at DoD medical treatment facilities (MTFs) during 2002-2012 (n = 4792). These 4792 samples were analyzed for the presence of R. montanensis (n = 36; 2.84%) and all vector DNA was confirmed to be of D. variabilis origin using a novel Dermacentor genus-specific quantitative real-time polymerase chain reaction procedure, Derm, and a novel Dermacentor species multilocus sequence typing assay. To assess the risk of R. montanensis infection, the positive and negative samples were geographically mapped utilizing MTF site locations. Tick localities were imported into a geographical information systems (GIS) program, ArcGIS, for mapping and analysis. The ecological niche modeling (ENM) program, Maxent, was used to estimate the probability of tick presence in eastern United States using locations of both R. montanensis-positive and -negative ticks, climate, and elevation data. The ENM for R. montanensis-positive D. variabilis estimated high probabilities of the positive ticks occurring in two main areas, including the northern Midwest and mid-Atlantic portions of the northeastern regions of United States, whereas the R. montanensis-negative D. variabilis tick model showed a wider estimated range. The results suggest that R. montanensis-positive and -negative D. variabilis have different ranges where humans may be at risk and are influenced by similar and different factors.
Teshale, S; Geysen, D; Ameni, G; Asfaw, Y; Berkvens, D
Detection of Ehrlichia and Anaplasma species in animals and tick vectors is crucial for an understanding of the epidemiology of diseases caused by these pathogens. In this study, a pair of primers designated EBR2 and EBR3 was designed from the Anaplasma 16S rDNA sequence and was used along with a previously described primer EHR 16SD for the simultaneous detection of Ehrlichia and Anaplasma species by nested PCR. The primers were used to amplify 925bp of DNA from known species of Ehrlichia and Anaplasma. Restriction with MboII and MspI enzymes allowed Ehrlichia and Anaplasma speciation. Restriction with MboII differentiated between An. marginale, Anaplasma (formerly Ehrlichia) sp. Omatjenne, and An. centrale with An. marginale and Anaplasma (formerly Ehrlichia) sp. Omatjenne yielding 2 distinct fragments each while An. centrale produced 3 distinct bands. Ehrlichia ruminantium and An. phagocytophylum remained undigested. Subsequent restriction with MspI differentiated E. ruminantium from An. phagocytophylum with 2 and 4 fragments, respectively. When used on tick samples from the field, 63 ticks (16.4%) out of 384 collected from cattle and sheep were positive for one or more species of Ehrlichia and Anaplasma. The positivity ranged from 6.3% at Andasa to 36.7% at Habernosa. Higher overall infection rates were found in Amblyomma lepidum than in Amblyomma variegatum ticks (p=0.009). Amblyomma lepidum from Habernosa were more often infected with all detected species of Anaplasma and Ehrlichia than Am. variegatum. At Bako, however, Anaplasma (formerly Ehrlichia) sp. Omatjenne was detected only in Am. variegatum. A significantly higher proportion of ticks collected from cattle (20.6%) was found positive than in those collected from sheep (3.3%) (p=0.003). Simultaneous detection of Ehrlichia and Anaplasma species and correct identification of mixed infections was possible. Since the ticks were collected from animals, the occurrence of the major species of Ehrlichia and
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.
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.
Egyed, László; Elő, Péter; Sréter-Lancz, Zsuzsanna; Széll, Zoltán; Balogh, Zsuzsanna; Sréter, Tamás
Ixodes ricinus is the most important tick species in Europe as it is most widely distributed and transmits the majority of tick-borne zoonotic pathogens. As limited data are available for Hungary, the aim of the present study was to investigate the seasonal timing of questing by I. ricinus and the infection rate of this tick species with all major tick-borne zoonotic pathogens. Monthly collections of I. ricinus were carried out over 3 consecutive years by dragging a blanket in 6 biotopes representing different areas of Hungary. Altogether, 1800 nymphs (300 per collection point) were screened as pooled samples (each of 5 specimens) by PCR-based methods for tick-borne pathogens. I. ricinus larvae, nymphs, and adults had bimodal activity patterns with a major peak in the spring. As newly moulted ticks of all stages are thought to emerge in the autumn of each year, it appears that most newly emerged ticks delayed their questing until the following spring. The minimum prevalence of Borrelia burgdorferi sensu lato was 2.5%. Borr. afzelii, Borr. burgdorferi sensu stricto, Borr. garinii, Borr. lusitaniae, and Borr. valaisiana were identified by hybridization. The minimum infection rate with spotted fever group rickettsiae was 1.9%. Rickettsia helvetica was identified in all biotopes. The minimum prevalence of Anaplasma phagocytophilum, Babesia divergens and Bab. microti was low (0.3-0.5%). Bartonella spp.-, Francisella tularensis-, and TBE virus-specific amplification products were not detected. Relative to the results of comparable studies carried out in the Carpathian Basin, the prevalence of tick-borne pathogens was low in Hungary. This might be attributed to the climatic difference between the lowland areas of Hungary and submountain areas of the surrounding countries involved in the studies.
Barker, Stephen C; Walker, Alan R
The book Australian Ticks by F.H.S. Roberts (1970) is a land-mark in Australian tick biology. But it is time for a new and improved book on the ticks of Australia. The present book has identification guides and accounts of the biology and diseases associated with the 16 species of ticks that may feed on domestic animals and humans in Australia. These comprise five argasid (soft) ticks: Argas persicus (poultry tick), Argas robertsi (Robert's bird tick), Ornithodoros capensis (seabird soft tick), O. gurneyi (kangaroo soft tick), Otobius megnini (spinose ear tick); and 11 ixodid (hard) ticks, Amblyomma triguttatum (ornate kangaroo tick), Bothriocroton auruginans (wombat tick), B. hydrosauri (southern reptile tick), Haemaphysalis bancrofti (wallaby tick), H. longicornis (bush tick), Ixodes cornuatus (southern paralysis tick), I. hirsti (Hirst's marsupial tick), I. holocyclus (paralysis tick), I. tasmani (common marsupial tick), Rhipicephalus (Boophilus) australis (Australian cattle tick) and R. sanguineus (brown dog tick). We use an image-matching system to identify ticks, much like the image-matching systems used in field-guides for birds and flowers. Ticks may be identified by drawings that emphasise unique matrices of uniformly defined morphological characters that, together, allow these 16 ticks to be identified by morphology unequivocally. The species accounts have seven sections: (i) General; (ii) Differential diagnosis; (iii) Hosts; (iv) Life-cycle and seasonality; (v) Disease; (vi) Habitat and geographic distribution; (vii) Genes and genomes; and (viii) Other information. There are 71 figures and tables, including a glossary character matrices, drawings of life-cycles, drawings of genera, species, and colour photographs of tick biology.
Job E Lopez
Full Text Available BACKGROUND: Borrelia turicatae, an agent of tick-borne relapsing fever, is an example of a pathogen that can adapt to disparate conditions found when colonizing the mammalian host and arthropod vector. However, little is known about the genetic factors necessary during the tick-mammalian infectious cycle, therefore we developed a genetic system to transform this species of spirochete. We also identified a plasmid gene that was up-regulated in vitro when B. turicatae was grown in conditions mimicking the tick environment. This 40 kilodalton protein was predicted to be surface localized and designated the Borrelia repeat protein A (brpA due to the redundancy of the amino acid motif Gln-Gly-Asn-Val-Glu. METHODOLOGY/PRINCIPAL FINDINGS: Quantitative reverse-transcriptase polymerase chain reaction using RNA from B. turicatae infected ticks and mice indicated differential regulation of brpA during the tick-mammalian infectious cycle. The surface localization was determined, and production of the protein within the salivary glands of the tick was demonstrated. We then applied a novel genetic system for B. turicatae to inactivate brpA and examined the role of the gene product for vector colonization and the ability to establish murine infection. CONCLUSIONS/SIGNIFICANCE: These results demonstrate the complexity of protein production in a population of spirochetes within the tick. Additionally, the development of a genetic system is important for future studies to evaluate the requirement of specific B. turicatae genes for vector colonization and transmission.
Monzón, Javier D; Atkinson, Elizabeth G; Henn, Brenna M; Benach, Jorge L
The lone star tick, Amblyomma americanum, is an important disease vector and the most frequent tick found attached to humans in the eastern United States. The lone star tick has recently experienced a rapid range expansion into the Northeast and Midwest, but despite this emerging infectious threat to wildlife, livestock, and human health, little is known about the genetic causes and consequences of the geographic expansion. In the first population genomic analysis of any tick species, we characterize the genetic diversity and population structure of A. americanum across its current geographic range, which has recently expanded. Using a high-throughput genotyping-by-sequencing approach, we discovered more than 8,000 single nucleotide polymorphisms in 90 ticks from five locations. Surprisingly, newly established populations in New York (NY) and Oklahoma (OK) are as diverse as historic range populations in North and South Carolina. However, substantial population structure occurs among regions, such that new populations in NY and OK are genetically distinct from historic range populations and from one another. Ticks from a laboratory colony are genetically distinct from wild populations, underscoring the need to account for natural variation when conducting transmission or immunological studies, many of which utilize laboratory-reared ticks. An FST-outlier analysis comparing a recently established population to a long-standing population detected numerous outlier sites, compatible with positive and balancing selection, highlighting the potential for adaptation during the range expansion. This study provides a framework for applying high-throughput DNA sequencing technologies for future investigations of ticks, which are common vectors of diseases.
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.
Pazinato, Rafael; Volpato, Andréia; Baldissera, Matheus D; Santos, Roberto C V; Baretta, Dilmar; Vaucher, Rodrigo A; Giongo, Janice L; Boligon, Aline A; Stefani, Lenita Moura; Da Silva, Aleksandro Schafer
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.
Pazinato, Rafael; Klauck, Vanderlei; Volpato, Andreia; Tonin, Alexandre A; Santos, Roberto C; de Souza, Márcia E; Vaucher, Rodrigo A; Raffin, Renata; Gomes, Patrícia; Felippi, Candice C; Stefani, Lenita M; Da Silva, Aleksandro S
The aim of this study was to verify the influence of tea tree oil (TTO) (Melaleuca alternifolia) tested in its pure and nanostructured (TTO nanoparticles) forms on the reproduction of female Rhipicephalus microplus. For our purpose, female ticks were collected from naturally infected animals and treated in vitro with TTO (1, 5, and 10 %) and TTO nanoparticles (0.075, 0.375, and 0.75 %). In order to validate the tests, they were performed in triplicate using positive (amitraz) and negative (untreated) controls. It was possible to observe that pure TTO (5 and 10 %) and TTO nanoparticles (0.375 and 0.75 %) showed 100 % reproductive inhibition on female ticks. Additionally, pure TTO (1 %) also showed an acaricide effect (70 %), similarly to the positive control (78.3 %). This is the first study demonstrating the activity of pure TTO and TTO nanoparticles on female ticks. Therefore, based on these results, we were able to show that both forms and all concentrations of M. alternifolia affected tick reproduction by inhibiting egg laying and hatching. We were also able to show that TTO nanoparticles potentiated the inhibitor effect of pure TTO on the reproduction of R. microplus.
Muto, Memi; Bazartseren, Boldbaatar; Tsevel, Bazartseren; Dashzevge, Erdenechimeg; Yoshii, Kentaro; Kariwa, Hiroaki
Tick-borne encephalitis virus (TBEV) is a zoonotic virus belonging to the genus Flavivirus, in the family Flaviviridae. The virus, which is endemic in Europe and northern parts of Asia, causes severe encephalitis. Tick-borne encephalitis (TBE) has been reported in Mongolia since the 1980s, but details about the biological characteristics of the endemic virus are lacking. In this study, 680 ticks (Ixodes persulcatus) were collected in Selenge aimag, northern Mongolia, in 2012. Nine Mongolian TBEV strains were isolated from tick homogenates. A sequence analysis of the envelope protein gene revealed that all isolates belonged to the Siberian subtype of TBEV. Two strains showed similar growth properties in cultured cells, but their virulence in mice differed. Whole genome sequencing revealed only thirteen amino acid differences between these Mongolian TBEV strains. Our results suggest that these naturally occurring amino acid mutations affected the pathogenicity of Mongolian TBEV. Our results may be an important platform for monitoring TBEV to evaluate the epidemiological risk in TBE endemic areas of Mongolia.
Amicizia, Daniela; Domnich, Alexander; Panatto, Donatella; Lai, Piero Luigi; Cristina, Maria Luisa; Avio, Ulderico; Gasparini, Roberto
Tick-borne Encephalitis (TBE), which is caused by a Flavivirus, is the most common tick-transmitted disease in Central and Eastern Europe and Russia. Today, TBE is endemic in 27 European countries, and has become an international public health problem. The epidemiology of TBE is changing owing to various factors, such as improvements in diagnosis and case reporting, increased recreational activities in areas populated by ticks, and changes in climatic conditions affecting tick habitats. Vaccination remains the most effective protective measure against TBE for people living in risk zones, occupationally exposed subjects and travelers to endemic areas. The vaccines currently in use are FSME-Immun(®), Encepur(®), EnceVir(®) and TBE vaccine Moscow(®). The numerous studies performed on the efficacy and safety of these vaccines have shown a high level of immunogenicity and an excellent safety profile. Several studies have also shown a high level of cross-protection among strains belonging to different subtypes. In the present paper we attempted to describe the continuously changing epidemiology of TBE in European States and to overview clinical development of available vaccines paying particular attention on cross-protection elicited by the vaccines.
Full Text Available Abstract Background Tick-borne encephalitis (TBE is among the most important vector borne diseases of humans in Europe and is currently identified as a major health problem in many countries. TBE endemic zones have expanded over the past two decades, as well as the number of reported cases within endemic areas. Multiple factors are ascribed for the increased incidence of TBE, including climatic change. The number of TBE cases has also increased in Norway over the past decade, and the human cases cluster along the southern coast of Norway. In Norway the distribution and prevalence of TBE virus (TBEV in tick populations is largely unknown. The objectives of this study were to estimate the TBEV prevalence in Ixodes ricinus from seven locations and to assess the relationship between the TBEV prevalence and site-specific climatic variables. Methods A total of 5630 questing nymphs were collected and analyzed in pools of ten. All pools were screened with an in-house real-time RT-PCR, and the positive pools were pyrosequenced. Two methods, minimum infection rate (MIR and a frequentist method (EPP for pooled prevalence estimations were calculated and compared. Climatic data were descriptively compared to the corresponding EPP of each location in order to explain variations in TBEV prevalence. Results The seven foci of TBEV had an estimated overall prevalence (EPP in pools of nymphs combined, of 0.53% with 95% CI (0.35–0.75, with point prevalence ranging between 0.11%–1.22%. The sites with the highest point prevalences were within the municipalities which had the highest numbers of registered TBE cases. The results indicate that the location with highest point prevalence had the highest relative mean humidity and lowest mean saturation deficit and vice versa for the lowest EPP. Conclusion Our study confirms the existence of TBEV endemic foci in Norway. These results are of importance to increase the awareness of TBEV infections in Norway and could be
de Oliveira Filho, Jaires Gomes; Sarria, André Lucio Franceschini; Ferreira, Lorena Lopes; Caulfield, John C; Powers, Stephen J; Pickett, John A; de León, Adalberto A Pérez; Birkett, Michael A; Borges, Lígia Miranda Ferreira
We have recently shown that repellency of the tick Rhipicephalus sanguineus sensu lato by the tick resistant dog breed, the beagle, is mediated by volatile organic compounds (VOCs) 2-hexanone and benzaldehyde present in beagle odour. Ectoparasite location of animal hosts is affected by variation in these odour components and their ratios. The aim of this study was to quantify the release rate, and the ratio, of 2-hexanone and benzaldehyde from beagles. The odour of three beagles was collected, for four days, over one week (day 0, day 1, day 4 and day 7). The compounds were identified using coupled high-resolution gas chromatography-mass spectrometry (GC-MS), and authentic standards of compounds were used to generate external calibration curves for quantification. Both compounds were found in all dogs on all days. The amount of benzaldehyde was always higher than that of 2-hexanone and so their ratio varied from unity, on average (over time) being 3.128±0.365, 1.902±0.390, 1.670±0.671ngmL(-1) for beagle 1, 2 and 3, respectively. There was no significant (pbenzaldehyde in beagle odour samples covering a 7-day period. This knowledge enables development of repellents to protect dogs from R. sanguineus s. l. infestation.
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.
Di Luca, Marco; Toma, Luciano; Bianchi, Riccardo; Quarchioni, Elisa; Marini, Luca; Mancini, Fabiola; Ciervo, Alessandra; Khoury, Cristina
Regular collections were obtained in the Natural Reserve of the Insugherata of Rome during 2011 in order to obtain the tick speci