Exotic Rickettsiae in Ixodes ricinus: fact or artifact?

NARCIS (Netherlands)

Tijsse-Klasen, E.; Fonville, M.; Overbeek, van L.S.; Reimerink, J.H.J.; Sprong, H.

2010-01-01

Several pathogenic Rickettsia species can be transmitted via Ixodes ricinus ticks to humans and animals. Surveys of I. ricinus for the presence of Rickettsiae using part of its 16S rRNA gene yield a plethora of new and different Rickettsia sequences. Interpreting these data is sometimes difficult

The extensible alloscutal cuticle of the tick, Ixodes ricinus

DEFF Research Database (Denmark)

Andersen, Svend Olav; Roepstorff, Peter

2005-01-01

The proteins in the distensible alloscutal cuticle of the blood-feeding tick, Ixodes ricinus, have been characterized by electrophoresis and chromatography, two of the proteins were purified and their total amino acid sequence determined. They show sequence similarity to cuticular proteins from t...

Borreliae in Ixodes ricinus ticks feeding on humans

Czech Academy of Sciences Publication Activity Database

Hubálek, Zdeněk; Halouzka, Jiří; Juřicová, Zina

2004-01-01

Roč. 18, č. 3 (2004), s. 228-231 ISSN 0269-283X R&D Projects: GA ČR GA206/03/0726; GA AV ČR IBS6093007 Institutional research plan: CEZ:AV0Z6093917 Keywords : Borrelia burgdorferi * Ixodes ricinus * Lyme disease Subject RIV: FN - Epidemiology, Contagious Diseases ; Clinical Immunology Impact factor: 1.405, year: 2004

Comparative Metagenomic Profiling of Symbiotic Bacterial Communities Associated with Ixodes persulcatus, Ixodes pavlovskyi and Dermacentor reticulatus Ticks.

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Alexander Kurilshikov

Full Text Available Ixodes persulcatus, Ixodes pavlovskyi, and Dermacentor reticulatus ticks inhabiting Western Siberia are responsible for the transmission of a number of etiological agents that cause human and animal tick-borne diseases. Because these ticks are abundant in the suburbs of large cities, agricultural areas, and popular tourist sites and frequently attack people and livestock, data regarding the microbiomes of these organisms are required. Using metagenomic 16S profiling, we evaluate bacterial communities associated with I. persulcatus, I. pavlovskyi, and D. reticulatus ticks collected from the Novosibirsk region of Russia. A total of 1214 ticks were used for this study. DNA extracted from the ticks was pooled according to tick species and sex. Sequencing of the V3-V5 domains of 16S rRNA genes was performed using the Illumina Miseq platform. The following bacterial genera were prevalent in the examined communities: Acinetobacter (all three tick species, Rickettsia (I. persulcatus and D. reticulatus and Francisella (D. reticulatus. B. burgdorferi sensu lato and B. miyamotoi sequences were detected in I. persulcatus and I. pavlovskyi but not in D. reticulatus ticks. The pooled samples of all tick species studied contained bacteria from the Anaplasmataceae family, although their occurrence was low. DNA from A. phagocytophilum and Candidatus Neoehrlichia mikurensis was first observed in I. pavlovskyi ticks. Significant inter-species differences in the number of bacterial taxa as well as intra-species diversity related to tick sex were observed. The bacterial communities associated with the I. pavlovskyi ticks displayed a higher biodiversity compared with those of the I. persulcatus and D. reticulatus ticks. Bacterial community structure was also diverse across the studied tick species, as shown by permutational analysis of variance using the Bray-Curtis dissimilarity metric (p = 0.002. Between-sex variation was confirmed by PERMANOVA testing in I

Ixodes scapularis and Ixodes ricinus tick cell lines respond to infection with tick-borne encephalitis virus: transcriptomic and proteomic analysis

Czech Academy of Sciences Publication Activity Database

Weisheit, S.; Villar, M.; Tykalová, Hana; Popara, M.; Loecherbach, J.; Watson, M.; Růžek, Daniel; Grubhoffer, Libor; de la Fuente, J.; Fazakerley, J.K.; Bell-Sakyi, L.

2015-01-01

Roč. 8, NOV 18 2015 (2015), s. 599 ISSN 1756-3305 R&D Projects: GA ČR GA15-03044S; GA ČR GAP502/11/2116 EU Projects: European Commission(XE) 238511 Institutional support: RVO:60077344 Keywords : tisk * Ixodes * flavivirus * tick-borne encephalitis virus * tick cell line * innate immunity * antiviral response Subject RIV: EE - Microbiology, Virology Impact factor: 3.234, year: 2015

Ixodes ricinus defensins attack distantly-related pathogens

Czech Academy of Sciences Publication Activity Database

Tonk, M.; Cabezas-Cruz, A.; Valdés, James J.; Rego, Ryan O. M.; Grubhoffer, Libor; Estrada--Pena, A.; Vilcinskas, A.; Kotsyfakis, Michalis; Rahnamaeian, M.

2015-01-01

Roč. 53, č. 2 (2015), s. 358-365 ISSN 0145-305X R&D Projects: GA MŠk(CZ) EE2.3.30.0032; GA ČR GAP502/12/2409 EU Projects: European Commission(XE) 278976 Institutional support: RVO:60077344 Keywords : Antimicrobial peptide * Defensin * Ixodes ricinus * Listeria monocytogenes * Staphylococcus aureus * Staphylococcus epidermidis * Escherichia coli * Pseudomonas aeruginosa * Fusarium spp Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.620, year: 2015

Rickettsiae in questing Ixodes ricinus ticks in the Czech Republic

Czech Academy of Sciences Publication Activity Database

Venclíková, Kristýna; Rudolf, Ivo; Mendel, Jan; Betášová, Lenka; Hubálek, Zdeněk

2014-01-01

Roč. 5, č. 2 (2014), s. 135-138 ISSN 1877-959X Institutional support: RVO:68081766 Keywords : Ixodes ricinus * Anaplasma phagocytophilum * Rickettsia spp. * Rickettsia helvetica * Rickettsia monacensis * Candidatus Neoehrlichia mikurensis Subject RIV: EE - Microbiology, Virology Impact factor: 2.718, year: 2014

THE ANALYSIS OF IXODES TICKS INFESTATION WITH TBEV IN KIROV REGION

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E. A. Bessolitsyna

2014-01-01

Full Text Available The objects of this study are Ixodes ticks which were collected in different areas of Kirov province. The aim of the study is to determine the proportion of TBEV infected ticks using the reverse transcription and PCR, dependingon time, place, and methods of collection in the Kirov province as well as of ticks specific and sexual identity. The study found that from the two tick species that were tested only taiga tick (Ixodes persulcatus but not the meadow thick (Dermacentor reticulatus was the TBEV vector. Study also has shown that both males and females ticks can be the TBEV vectors. Moreover, it was proved the importance of ticks testing which were gathered not only from human but also from animals, primary from dogs, and from the plants.

Absence of Lyme disease spirochetes in larval ixodes ricinus ticks

Czech Academy of Sciences Publication Activity Database

Richter, D.; Debski, A.; Hubálek, Zdeněk; Matuschka, F.-R.

2012-01-01

Roč. 12, č. 1 (2012), s. 21-27 ISSN 1530-3667 EU Projects: European Commission(XE) 10284 - EDEN Institutional research plan: CEZ:AV0Z60930519 Keywords : blood meal * Borrelia * Ixodes * Lyme disease * Vertical transmission Subject RIV: EE - Microbiology, Virology Impact factor: 2.277, year: 2012

Prevalence of pathogenic bacteria in Ixodes ricinus ticks in Central Bohemia.

Science.gov (United States)

Klubal, Radek; Kopecky, Jan; Nesvorna, Marta; Sparagano, Olivier A E; Thomayerova, Jana; Hubert, Jan

2016-01-01

Bacteria associated with the tick Ixodes ricinus were assessed in specimens unattached or attached to the skin of cats, dogs and humans, collected in the Czech Republic. The bacteria were detected by PCR in 97 of 142 pooled samples including 204 ticks, i.e. 1-7 ticks per sample, collected at the same time from one host. A fragment of the bacterial 16S rRNA gene was amplified, cloned and sequenced from 32 randomly selected samples. The most frequent sequences were those related to Candidatus Midichloria midichlori (71% of cloned sequences), followed by Diplorickettsia (13%), Spiroplasma (3%), Rickettsia (3%), Pasteurella (3%), Morganella (3%), Pseudomonas (2%), Bacillus (1%), Methylobacterium (1%) and Phyllobacterium (1%). The phylogenetic analysis of Spiroplasma 16S rRNA gene sequences showed two groups related to Spiroplasma eriocheiris and Spiroplasma melliferum, respectively. Using group-specific primers, the following potentially pathogenic bacteria were detected: Borellia (in 20% of the 142 samples), Rickettsia (12%), Spiroplasma (5%), Diplorickettsia (5%) and Anaplasma (2%). In total, 68% of I. ricinus samples (97/142) contained detectable bacteria and 13% contained two or more putative pathogenic groups. The prevalence of tick-borne bacteria was similar to the observations in other European countries.

Longitudinal surveillance of the tick Ixodes ricinus for borreliae

Czech Academy of Sciences Publication Activity Database

Hubálek, Zdeněk; Halouzka, Jiří; Juřicová, Zina

2003-01-01

Roč. 17, č. 1 (2003), s. 46-51 ISSN 0269-283X R&D Projects: GA ČR GA206/00/1204; GA AV ČR IBS6093007 Institutional research plan: CEZ:AV0Z6093917 Keywords : Borrelia burgdorferi * Ixodes ricinus * Lyme disease Subject RIV: FN - Epidemiology, Contagious Diseases ; Clinical Immunology Impact factor: 1.040, year: 2003

Modeling the geographic distribution of Ixodes scapularis and Ixodes pacificus (Acari: Ixodidae) in the contiguous United States

Science.gov (United States)

Hahn, Micah; Jarnevich, Catherine S.; Monaghan, Andrew J.; Eisen, Rebecca J.

2016-01-01

In addition to serving as vectors of several other human pathogens, the black-legged tick, Ixodes scapularis Say, and western black-legged tick, Ixodes pacificus Cooley and Kohls, are the primary vectors of the spirochete (Borrelia burgdorferi ) that causes Lyme disease, the most common vector-borne disease in the United States. Over the past two decades, the geographic range of I. pacificus has changed modestly while, in contrast, the I. scapularis range has expanded substantially, which likely contributes to the concurrent expansion in the distribution of human Lyme disease cases in the Northeastern, North-Central and Mid-Atlantic states. Identifying counties that contain suitable habitat for these ticks that have not yet reported established vector populations can aid in targeting limited vector surveillance resources to areas where tick invasion and potential human risk are likely to occur. We used county-level vector distribution information and ensemble modeling to map the potential distribution of I. scapularis and I. pacificus in the contiguous United States as a function of climate, elevation, and forest cover. Results show that I. pacificus is currently present within much of the range classified by our model as suitable for establishment. In contrast, environmental conditions are suitable for I. scapularis to continue expanding its range into northwestern Minnesota, central and northern Michigan, within the Ohio River Valley, and inland from the southeastern and Gulf coasts. Overall, our ensemble models show suitable habitat for I. scapularis in 441 eastern counties and for I. pacificus in 11 western counties where surveillance records have not yet supported classification of the counties as established.

Tissue-specific signatures in the transcriptional response to Anaplasma phagocytophilum infection of Ixodes scapularis and Ixodes ricinus tick cell lines

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Pilar eAlberdi

2016-02-01

Full Text Available Anaplasma phagocytophilum are transmitted by Ixodes spp. ticks and have become one of the most common and relevant tick-borne pathogens due to their impact on human and animal health. Recent results have increased our understanding of the molecular interactions between Ixodes scapularis and A. phagocytophilum through the demonstration of tissue-specific molecular pathways that ensure pathogen infection, development and transmission by ticks. However, little is known about the Ixodes ricinus genes and proteins involved in the response to A. phagocytophilum infection. The tick species I. scapularis and I. ricinus are evolutionarily closely related and therefore similar responses are expected in A. phagocytophilum-infected cells. However, differences may exist between I. scapularis ISE6 and I. ricinus IRE/CTVM20 tick cells associated with tissue-specific signatures of these cell lines. To address this hypothesis, the transcriptional response to A. phagocytophilum infection was characterized by RNA sequencing and compared between I. scapularis ISE6 and I. ricinus IRE/CTVM20 tick cell lines. The transcriptional response to infection of I. scapularis ISE6 cells resembled that of tick hemocytes while the response in I. ricinus IRE/CTVM20 cells was more closely related to that reported previously in infected tick midguts. The inhibition of cell apoptosis by A. phagocytophilum appears to be a key adaptation mechanism to facilitate infection of both vertebrate and tick cells and was used to investigate further the tissue-specific response of tick cell lines to pathogen infection. The results supported a role for the intrinsic pathway in the inhibition of cell apoptosis by A. phagocytophilum infection of I. scapularis ISE6 cells. In contrast, the results in I. ricinus IRE/CTVM20 cells were similar to those obtained in tick midguts and suggested a role for the JAK/STAT pathway in the inhibition of apoptosis in tick cells infected with A. phagocytophilum

Anaplasma phagocytophilum in questing Ixodes ricinus ticks from Romania.

Science.gov (United States)

Matei, Ioana Adriana; Kalmár, Zsuzsa; Magdaş, Cristian; Magdaş, Virginia; Toriay, Hortenzia; Dumitrache, Mirabela Oana; Ionică, Angela Monica; D'Amico, Gianluca; Sándor, Attila D; Mărcuţan, Daniel Ioan; Domşa, Cristian; Gherman, Călin Mircea; Mihalca, Andrei Daniel

2015-04-01

Granulocytic anaplasmosis is a common vector-borne disease of humans and animals with natural transmission cycle that involves tick vectors, among which Ixodes ricinus is the most important. The present paper reports the prevalence and geographical distribution of A. phagocytophilum in 10,438 questing Ixodes ricinus ticks collected at 113 locations from 40 counties of Romania. The unfed ticks were examined for the presence of A. phagocytophilum by PCR targeting a portion of ankA gene. The overall prevalence of infection was 3.42%, with local prevalences ranging between 0.29% and 22.45%, with an average prevalence of 5.39% in the infected localities. The infection with A. phagocytophilum was detected in 72 out of 113 localities and in 34 out of 40 counties. The highest prevalence was recorded in females followed by males and nymphs. The results and the distribution model have shown a large distribution of A. phagocytophilum, covering Romania's entire territory. This study is the first large scale survey of the presence of A. phagocytophilum in questing I. ricinus ticks from Romania. Copyright © 2015 Elsevier GmbH. All rights reserved.

Prevalence of tick-borne pathogens in questing Ixodes ricinus ticks in urban and suburban areas of Switzerland

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Corinne P. Oechslin

2017-11-01

Full Text Available Abstract Background Throughout Europe, Ixodes ricinus transmits numerous pathogens. Its widespread distribution is not limited to rural but also includes urbanized areas. To date, comprehensive data on pathogen carrier rates of I. ricinus ticks in urban areas of Switzerland is lacking. Results Ixodes ricinus ticks sampled at 18 (sub- urban collection sites throughout Switzerland showed carrier rates of 0% for tick-borne encephalitis virus, 18.0% for Borrelia burgdorferi (sensu lato, 2.5% for Borrelia miyamotoi, 13.5% for Rickettsia spp., 1.4% for Anaplasma phagocytophilum, 6.2% for "Candidatus Neoehrlichia mikurensis", and 0.8% for Babesia venatorum (Babesia sp., EU1. Site-specific prevalence at collection sites with n > 45 ticks (n = 9 significantly differed for B. burgdorferi (s.l., Rickettsia spp., and "Ca. N. mikurensis", but were not related to the habitat type. Three hundred fifty eight out of 1078 I. ricinus ticks (33.2% tested positive for at least one pathogen. Thereof, about 20% (71/358 were carrying two or three different potentially disease-causing agents. Using next generation sequencing, we could detect true pathogens, tick symbionts and organisms of environmental or human origin in ten selected samples. Conclusions Our data document the presence of pathogens in the (sub- urban I. ricinus tick population in Switzerland, with carrier rates as high as those in rural regions. Carriage of multiple pathogens was repeatedly observed, demonstrating the risk of acquiring multiple infections as a consequence of a tick bite.

An Assessment for the Presence of Powassan Virus in Ixodes scapularis Nymphs from Locations in Virginia, Maryland, New Jersey, Pennsylvania, New York, and Connecticut

Science.gov (United States)

2013-03-21

1214-7 46. Kislenko GS, Chunikhin SP, Rasnitsyn SP, Kurenkov VB, Izotov VK. 1982. [Reproduction of Powassan and West Nile viruses in Aedes aegypti ...Ixodes scapularis (Say 1821), an aggressive tick that readily bites humans. This study collected I. scapularis from sites along the U.S. East Coast...68 Appendix 3: Sampling times and collection rates (Ticks

Relative humidity and activity patterns of Ixodes scapularis (Acari: Ixodidae)

Science.gov (United States)

Berger, K.A.; Ginsberg, Howard S.; Gonzalez, L.; Mather, T.N.

2014-01-01

Laboratory studies have shown clear relationships between relative humidity (RH) and the activity and survival of Ixodes scapularis Say (blacklegged tick). However, field studies have produced conflicting results. We examined this relationship using weekly tick count totals and hourly RH observations at three field sites, stratified by latitude, within the state of Rhode Island. Records of nymphal tick abundance were compared with several RH-related variables (e.g., RH at time of sampling and mean weekly daytime RH). In total, 825 nymphs were sampled in 2009, a year of greater precipitation, with a weighted average leaf litter RH recorded at time of sampling of 85.22%. Alternatively, 649 nymphs were collected in 2010, a year of relatively low precipitation, and a weighted average RH recorded at time of sampling was 75.51%. Negative binomial regression analysis of tick count totals identified cumulative hours <82% RH threshold as a significant factor observed in both years (2009: P = 0.0037; 2010: P < 0.0001). Mean weekly daytime RH did not significantly predict tick activity in either year. However, mean weekly daytime RH recorded with 1-wk lag before sample date was a significant variable (P = 0.0016) in 2010. These results suggest a lag effect between moisture availability and patterns of tick activity and abundance. Differences in the relative importance of each RH variable between years may have been due to abnormally wet summer conditions in 2009.

The efficacy of repellents against Aedes, Anopheles, Culex and Ixodes spp. - a literature review.

Science.gov (United States)

Lupi, Eleonora; Hatz, Christoph; Schlagenhauf, Patricia

2013-01-01

Travellers are confronted with a variety of vector-borne threats. Is one type of repellent effective against all biting vectors? The aim of this review is to examine the literature, up to December 31st, 2012, regarding repellent efficacy. We searched PubMed for relevant papers. Repellents of interest were DEET, Icaridin as well as other piperidine-derived products (SS220), Insect Repellent (IR) 3535 (ethyl-butylacetyl-amino-propionat, EBAAP) and plant-derived products, including Citriodora (para-menthane-3,8-diol). As vectors, we considered the mosquito species Anopheles, Aedes and Culex as well as the tick species Ixodes. We selected only studies evaluating the protective efficacy of repellents on human skin. We reviewed a total of 102 publications. Repellents were evaluated regarding complete protection time or as percentage efficacy [%] in a time interval. We found no standardized study for tick bite prevention. Regarding Aedes, DEET at concentration of 20% or more, showed the best efficacy providing up to 10 h protection. Citriodora repellency against this mosquito genus was lower compared to the other products. Also between subspecies a difference could be observed: Ae. aegypti proved more difficult to repel than Ae. Albopictus. Fewer studies have been conducted on mosquito species Anopheles and Culex. The repellency profile against Anopheles species was similar for the four principal repellents of interest, providing on average 4-10 h of protection. Culex mosquitoes are easier to repel and all four repellents provided good protection. Few studies have been conducted on the tick species Ixodes. According to our results, the longest protection against Ixodes scapularis was provided by repellents containing IR3535, while DEET and commercial products containing Icaridin or PMD showed a better response than IR3535 against Ixodes ricinus. Many plant-based repellents provide only short duration protection. Adding vanillin 5% to plant-based repellents and to DEET

Ultrastructure and lectin characterization of granular salivary cells from Ixodes ricinus females

Czech Academy of Sciences Publication Activity Database

Vancová, Marie; Zacharovová, Klára; Grubhoffer, Libor; Nebesářová, Jana

2006-01-01

Roč. 92, č. 3 (2006), s. 431-440 ISSN 0022-3395 R&D Projects: GA ČR GA206/03/1323 Institutional research plan: CEZ:AV0Z60220518 Keywords : Ixodes ricinus * salivary glands * lectin labeling Subject RIV: EE - Microbiology, Virology Impact factor: 1.300, year: 2006

First detection of Borrelia miyamotoi in Ixodes ricinus ticks from northern Italy.

NARCIS (Netherlands)

Ravagnan, Silvia; Tomassone, Laura; Montarsi, Fabrizio; Krawczyk, Aleksandra Iwona; Mastrorilli, Eleonora; Sprong, Hein; Milani, Adelaide; Rossi, Luca; Capelli, Gioia

2018-01-01

Borrelia miyamotoi is a spirochete transmitted by several ixodid tick species. It causes a relapsing fever in humans and is currently considered as an emerging pathogen. In Europe, B. miyamotoi seems to occur at low prevalence in Ixodes ricinus ticks but has a wide distribution. Here we report the

Behavioural responses of Ixodes ricinus nymphs to carbon dioxide and rodent odour

NARCIS (Netherlands)

Duijvendijk, van G.; Gort, G.; Sprong, H.; Takken, W.

2017-01-01

Many haematophagous ectoparasites use carbon dioxide (CO2) and host odour to detect and locate their hosts. The tick Ixodes ricinus (Linnaeus) (Ixodida: Ixodidae) walks only small distances and quests in vegetation until it encounters a host. The differential effects of CO2 and host odour on the

Ixodes ricinus as vector and reservoir of Borrelia burgdorferi in an urban environment

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Rajković Dragana V.

2005-01-01

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.

Ixodes ricinus tick lipocalins: identification, cloning, phylogenetic analysis and biochemical characterization.

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Jérôme Beaufays

Full Text Available BACKGROUND: During their blood meal, ticks secrete a wide variety of proteins that interfere with their host's defense mechanisms. Among these proteins, lipocalins play a major role in the modulation of the inflammatory response. METHODOLOGY/PRINCIPAL FINDINGS: Screening a cDNA library in association with RT-PCR and RACE methodologies allowed us to identify 14 new lipocalin genes in the salivary glands of the Ixodes ricinus hard tick. A computational in-depth structural analysis confirmed that LIRs belong to the lipocalin family. These proteins were called LIR for "Lipocalin from I. ricinus" and numbered from 1 to 14 (LIR1 to LIR14. According to their percentage identity/similarity, LIR proteins may be assigned to 6 distinct phylogenetic groups. The mature proteins have calculated pM and pI varying from 21.8 kDa to 37.2 kDa and from 4.45 to 9.57 respectively. In a western blot analysis, all recombinant LIRs appeared as a series of thin bands at 50-70 kDa, suggesting extensive glycosylation, which was experimentally confirmed by treatment with N-glycosidase F. In addition, the in vivo expression analysis of LIRs in I. ricinus, examined by RT-PCR, showed homogeneous expression profiles for certain phylogenetic groups and relatively heterogeneous profiles for other groups. Finally, we demonstrated that LIR6 codes for a protein that specifically binds leukotriene B4. CONCLUSIONS/SIGNIFICANCE: This work confirms that, regarding their biochemical properties, expression profile, and sequence signature, lipocalins in Ixodes hard tick genus, and more specifically in the Ixodes ricinus species, are segregated into distinct phylogenetic groups suggesting potential distinct function. This was particularly demonstrated by the ability of LIR6 to scavenge leukotriene B4. The other LIRs did not bind any of the ligands tested, such as 5-hydroxytryptamine, ADP, norepinephrine, platelet activating factor, prostaglandins D2 and E2, and finally leukotrienes B4 and C

Ixodes scapularis saliva mitigates inflammatory cytokine secretion during Anaplasma phagocytophilum stimulation of immune cells

Czech Academy of Sciences Publication Activity Database

Chen, G.; Severo, M. S.; Sohail, M.; Sakhon, O. S.; Wikel, S. K.; Kotsyfakis, Michalis; Pedra, J. H. F.

2012-01-01

Roč. 5, č. 1 (2012), s. 229 ISSN 1756-3305 Institutional support: RVO:60077344 Keywords : Tick * Ixodes scapularis * Saliva * Anaplasma phagocytophilum * Rickettsial agent Subject RIV: EC - Immunology Impact factor: 3.246, year: 2012 http://www.parasitesandvectors.com/content/5/1/229

Human pathogenic borreliae in Ixodes ricinus ticks in natural and urban ecosystem (Czech Republic)

Czech Academy of Sciences Publication Activity Database

Venclíková, Kristýna; Betášová, Lenka; Šikutová, Silvie; Jedličková, Petra; Hubálek, Zdeněk; Rudolf, Ivo

2014-01-01

Roč. 59, č. 4 (2014), s. 717-720 ISSN 1230-2821 EU Projects: European Commission(XE) 261504 - EDENEXT Institutional support: RVO:68081766 Keywords : Ixodes ricinus * Borrelia burgdorgeri s.l. * genomic species * ixodid ticks Subject RIV: EE - Microbiology, Virology Impact factor: 0.905, year: 2014

Anaplasma phagocytophilum Infection Subverts Carbohydrate Metabolic Pathways in the Tick Vector, Ixodes scapularis

Czech Academy of Sciences Publication Activity Database

Cabezas Cruz, Alejandro; Alberdi, P.; Valdés, James J.; Villar, M.; de la Fuente, J.

2017-01-01

Roč. 7, 7 February (2017), č. článku 23. ISSN 2235-2988 EU Projects: European Commission(XE) 278976 - ANTIGONE Institutional support: RVO:60077344 Keywords : proteomics * transcriptomics * glucose metabolism * Ixodes scapularis * Anaplasma phagocytophilum Subject RIV: EB - Genetics ; Molecular Biology OBOR OECD: Biochemistry and molecular biology Impact factor: 4.300, year: 2016

Ixodes ricinus tick saliva modulates tick-borne encephalitis virus infection of dendritic cells

Czech Academy of Sciences Publication Activity Database

Fialová, Anna; Cimburek, Zdeněk; Iezzi, G.; Kopecký, Jan

2010-01-01

Roč. 12, č. 7 (2010), s. 580-585 ISSN 1286-4579 R&D Projects: GA AV ČR IAA600960811 Institutional research plan: CEZ:AV0Z60220518; CEZ:AV0Z50200510 Keywords : Tick-borne encephalitis virus * Dendritic cell * Tick saliva * Ixodes ricinus Subject RIV: EC - Immunology Impact factor: 2.726, year: 2010

Uptake and incorporation of sialic acid by the tick Ixodes ricinus

Czech Academy of Sciences Publication Activity Database

Vancová, Marie; Štěrba, J.; Dupejová, Jarmila; Simonová, Z.; Nebesářová, Jana; Novotný, M. V.; Grubhoffer, Libor

2012-01-01

Roč. 58, č. 9 (2012), s. 1277-1287 ISSN 0022-1910 R&D Projects: GA AV ČR KJB600960906; GA ČR GA206/09/1782; GA ČR GD206/09/H026; GA MŠk(CZ) LC06009 Institutional research plan: CEZ:AV0Z60220518 Keywords : Tick * Ixodes ricinus * Sialic acid * Basement membrane * Mass spectrometry * Electron microscopy Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.379, year: 2012

Occurrence of multiple infections with different Borrelia burgdorferi genospecies in Danish Ixodes ricinus nymphs

DEFF Research Database (Denmark)

Andersen, Jean Vennestrøm; Egholm, H.; Mikkelsen, Per Jensen

2008-01-01

The pathogen Borrelia burgdorferi causes Lyme Borreliosis in human and animals world-wide. In Europe the pathogen is transmitted to the host by the vector Ixodes ricinus. The nymph is the primary instar for transmission to humans. We here study the infection rate of five Borrelia genospecies: B...

Identification and partial characterisation of new members of the Ixodes ricinus defensin family

Czech Academy of Sciences Publication Activity Database

Tonk, Miray; Cabezas Cruz, Alejandro; Valdés, James J.; Rego, Ryan O. M.; Rudenko, Natalia; Golovchenko, Maryna; Bell-Sakyi, L.; de la Fuente, J.; Grubhoffer, Libor

2014-01-01

Roč. 540, č. 2 (2014), s. 146-152 ISSN 0378-1119 R&D Projects: GA ČR(CZ) GAP302/11/1901; GA MŠk(CZ) EE2.3.30.0032 Institutional support: RVO:60077344 Keywords : antimicrobial peptide * defensin * Ixodes ricinus * tick * tick cell line Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.138, year: 2014

Efficacy of granular deltamethrin against Ixodes scapularis and Amblyomma americanum (Acari: Ixodidade) nymphs.

Science.gov (United States)

Schulze, T L; Jordan, R A; Hung, R W; Taylor, R C; Markowski, D; Chomsky, M S

2001-03-01

A single barrier application of granular deltamethrin to the woodland edges of a forested residential community in late spring significantly reduced the abundance of Ixodes scapularis Say nymphs. The application also suppressed the population of Amblyomma americanum (L.) nymphs, which recently became established in the study area. The efficacy of deltamethrin is compared with other commonly used acaricides.

Genomic insights into the Ixodes scapularis tick vector of Lyme disease

DEFF Research Database (Denmark)

Gulia-Nuss, Monika; Nuss, Andrew B.; Meyer, Jason M.

2016-01-01

Ticks transmit more pathogens to humans and animals than any other arthropod. We describe the 2.1 Gbp nuclear genome of the tick, Ixodes scapularis (Say), which vectors pathogens that cause Lyme disease, human granulocytic anaplasmosis, babesiosis and other diseases. The large genome reflects...... proteins associated with the agent of human granulocytic anaplasmosis, an emerging disease, and the encephalitis-causing Langat virus, and a population structure correlated to life-history traits and transmission of the Lyme disease agent....

Differential expression of Ixodes ricinus tick genes induced by blood feeding or Borrelia burgdorferi infection

Czech Academy of Sciences Publication Activity Database

Rudenko, Natalia; Golovchenko, Maryna; Edwards, M. J.; Grubhoffer, Libor

2005-01-01

Roč. 42, č. 1 (2005), s. 36-41 ISSN 0022-2585 R&D Projects: GA AV ČR IAA6022306 Institutional research plan: CEZ:AV0Z60220518 Keywords : Ixodes ricinus * Borrelia burgdorferi * subtractive hybridization Subject RIV: EE - Microbiology, Virology Impact factor: 1.489, year: 2005

The occurrence of Ixodes ricinus ticks and important tick-borne pathogens in areas with high tick-borne encephalitis prevalence in different altitudinal levels of the Czech Republic. Part I. Ixodes ricinus ticks and tick-borne encephalitis virus

Czech Academy of Sciences Publication Activity Database

Daniel, M.; Danielová, V.; Kříž, B.; Růžek, Daniel; Fialová, A.; Malý, M.; Materna, J.; Pejčoch, M.; Erhart, Jan

2016-01-01

Roč. 65, č. 2 (2016), s. 118-128 ISSN 1210-7913 Institutional support: RVO:60077344 Keywords : Ixodes ricinus * tick-borne encephalitis virus * occurence * altitude * region * season Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine Impact factor: 0.500, year: 2016

An Ehrlichia strain from a llama (Lama glama) and Llama-associated ticks (Ixodes pacificus).

Science.gov (United States)

Barlough, J E; Madigan, J E; Turoff, D R; Clover, J R; Shelly, S M; Dumler, J S

1997-01-01

An ehrlichia was identified in the blood of a diseased llama (lama glama). Sequencing of its 16S rRNA gene showed the ehrlichia to be closely related to members of the Ehrlichia phagocytophila genogroup. The agent was also found in a pool of ticks (Ixodes pacificus) collected at the llama site. PMID:9157118

Climate change and Ixodes tick-borne diseases of humans.

Science.gov (United States)

Ostfeld, Richard S; Brunner, Jesse L

2015-04-05

The evidence that climate warming is changing the distribution of Ixodes ticks and the pathogens they transmit is reviewed and evaluated. The primary approaches are either phenomenological, which typically assume that climate alone limits current and future distributions, or mechanistic, asking which tick-demographic parameters are affected by specific abiotic conditions. Both approaches have promise but are severely limited when applied separately. For instance, phenomenological approaches (e.g. climate envelope models) often select abiotic variables arbitrarily and produce results that can be hard to interpret biologically. On the other hand, although laboratory studies demonstrate strict temperature and humidity thresholds for tick survival, these limits rarely apply to field situations. Similarly, no studies address the influence of abiotic conditions on more than a few life stages, transitions or demographic processes, preventing comprehensive assessments. Nevertheless, despite their divergent approaches, both mechanistic and phenomenological models suggest dramatic range expansions of Ixodes ticks and tick-borne disease as the climate warms. The predicted distributions, however, vary strongly with the models' assumptions, which are rarely tested against reasonable alternatives. These inconsistencies, limited data about key tick-demographic and climatic processes and only limited incorporation of non-climatic processes have weakened the application of this rich area of research to public health policy or actions. We urge further investigation of the influence of climate on vertebrate hosts and tick-borne pathogen dynamics. In addition, testing model assumptions and mechanisms in a range of natural contexts and comparing their relative importance as competing models in a rigorous statistical framework will significantly advance our understanding of how climate change will alter the distribution, dynamics and risk of tick-borne disease.

Arsenophonus nasoniae and Rickettsiae Infection of Ixodes ricinus Due to Parasitic Wasp Ixodiphagus hookeri.

Directory of Open Access Journals (Sweden)

Monika Bohacsova

Full Text Available Arsenophonus nasoniae, a male-killing endosymbiont of chalcid wasps, was recently detected in several hard tick species. Following the hypothesis that its presence in ticks may not be linked to the direct occurrence of bacteria in tick's organs, we identified A. nasoniae in wasps emerging from parasitised nymphs. We confirmed that 28.1% of Ixodiphagus hookeri wasps parasitizing Ixodes ricinus ticks were infected by A. nasoniae. Moreover, in examined I. ricinus nymphs, A. nasoniae was detected only in those, which were parasitized by the wasp. However, in part of the adult wasps as well as in some ticks that contained wasp's DNA, we did not confirm A. nasoniae. We also found, that in spite of reported male-killing, some newly emerged adult wasp males were also infected by A. nasoniae. Additionally, we amplified the DNA of Rickettsia helvetica and Rickettsia monacensis (known to be Ixodes ricinus-associated bacteria in adult parasitoid wasps. This may be related either with the digested bacterial DNA in wasp body lumen or with a role of wasps in circulation of rickettsiae among tick vectors.

An Ixodes ricinus Tick Salivary Lectin Pathway Inhibitor Protects Borrelia burgdorferi sensu lato from Human Complement

NARCIS (Netherlands)

Wagemakers, Alex; Coumou, Jeroen; Schuijt, Tim J.; Oei, Anneke; Nijhof, Ard M.; van 't Veer, Cornelis; van der Poll, Tom; Bins, Adriaan D.; Hovius, Joppe W. R.

2016-01-01

We previously identified tick salivary lectin pathway inhibitor (TSLPI) in Ixodes scapularis, a vector for Borrelia burgdorferi sensu stricto (s.s.) in North America. TSLPI is a salivary protein facilitating B. burgdorferi s.s. transmission and acquisition by inhibiting the host lectin complement

Functional characterization of two defensin isoforms of the hard tick Ixodes ricinus

Czech Academy of Sciences Publication Activity Database

Chrudimská, Tereza; Slaninová, Jiřina; Rudenko, Natalia; Růžek, Daniel; Grubhoffer, Libor

2011-01-01

Roč. 4, č. 1 (2011), e63 ISSN 1756-3305 R&D Projects: GA MŠk(CZ) LC06009; GA ČR GA206/09/1782; GA ČR GD206/09/H026; GA ČR(CZ) GAP302/11/1901 Institutional research plan: CEZ:AV0Z60220518; CEZ:AV0Z40550506 Keywords : defensin * antimicrobial compounds * Ixodes ricinus Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.937, year: 2011

Experimental inoculation of beagle dogs with Ehrlichia species detected from Ixodes ovatus

OpenAIRE

Watanabe, Malaika; Oikawa, T; Hiraoka, Hiroko; Kaneko, N; Itamoto, Kazuhito; Mizuno, Tohru; Okuda, Masaru; Inokuma, Hisashi

2006-01-01

Three beagle dogs were inoculated with mice spleen/liver homogenate infected with Ehrlichia species detected from Ixodes ovatus (EIO) and one dog was used as a control. All three infected dogs did not show clinical signs of disease except for mild pyrexia throughout the 41-day study period. Splenomegaly was observed from Day 7 post-inoculation (p.i.) in two of the dogs. Hematological and biochemical abnormalities included mild thrombocytopenia, hypoproteinaemia, hypoalbuminaemia and increased...

An Ixodes ricinus Tick Salivary Lectin Pathway Inhibitor Protects Borrelia burgdorferi sensu lato from Human Complement.

Science.gov (United States)

Wagemakers, Alex; Coumou, Jeroen; Schuijt, Tim J; Oei, Anneke; Nijhof, Ard M; van 't Veer, Cornelis; van der Poll, Tom; Bins, Adriaan D; Hovius, Joppe W R

2016-04-01

We previously identified tick salivary lectin pathway inhibitor (TSLPI) in Ixodes scapularis, a vector for Borrelia burgdorferi sensu stricto (s.s.) in North America. TSLPI is a salivary protein facilitating B. burgdorferi s.s. transmission and acquisition by inhibiting the host lectin complement pathway through interference with mannose binding lectin (MBL) activity. Since Ixodes ricinus is the predominant vector for Lyme borreliosis in Europe and transmits several complement sensitive B. burgdorferi sensu lato (s.l.) strains, we aimed to identify, describe, and characterize the I. ricinus ortholog of TSLPI. We performed (q)PCRs on I. ricinus salivary gland cDNA to identify a TSLPI ortholog. Next, we generated recombinant (r)TSLPI in a Drosophila expression system and examined inhibition of the MBL complement pathway and complement-mediated killing of B. burgdorferi s.l. in vitro. We identified a TSLPI ortholog in I. ricinus salivary glands with 93% homology at the RNA and 89% at the protein level compared to I. scapularis TSLPI, which was upregulated during tick feeding. In silico analysis revealed that TSLPI appears to be part of a larger family of Ixodes salivary proteins among which I. persulcatus basic tail salivary proteins and I. scapularis TSLPI and Salp14. I. ricinus rTSLPI inhibited the MBL complement pathway and protected B. burgdorferi s.s. and Borrelia garinii from complement-mediated killing. We have identified a TSLPI ortholog, which protects B. burgdorferi s.l. from complement-mediated killing in I. ricinus, the major vector for tick-borne diseases in Europe.

Vaccination against Bm86 Homologues in Rabbits Does Not Impair Ixodes ricinus Feeding or Oviposition

NARCIS (Netherlands)

Coumou, Jeroen; Wagemakers, Alex; Trentelman, Jos J.; Nijhof, Ard M.; Hovius, Joppe W.

2014-01-01

Human tick-borne diseases that are transmitted by Ixodes ricinus, such as Lyme borreliosis and tick borne encephalitis, are on the rise in Europe. Diminishing I. ricinus populations in nature can reduce tick exposure to humans, and one way to do so is by developing an anti-vector vaccine against

Ixodes scapularis Tick Cells Control Anaplasma phagocytophilum Infection by Increasing the Synthesis of Phosphoenolpyruvate from Tyrosine

Czech Academy of Sciences Publication Activity Database

Cabezas Cruz, Alejandro; Espinosa, P. J.; Obregon, D. A.; Alberdi, P.; de la Fuente, J.

2017-01-01

Roč. 7, AUG 17 (2017), č. článku 375. ISSN 2235-2988 Institutional support: RVO:60077344 Keywords : proteomics * transcriptomics * phosphoenolpyruvate * glycerol-3-phosphate * Ixodes scapularis * Anaplasma phagocytophilum Subject RIV: EE - Microbiology, Virology OBOR OECD: Microbiology Impact factor: 4.300, year: 2016

Low prevalence of Borrelia bavariensis in Ixodes ricinus ticks in southeastern Austria.

Science.gov (United States)

Glatz, Martin; Muellegger, Robert R; Hizo-Teufel, Cecilia; Fingerle, Volker

2014-10-01

Borrelia bavariensis was recently described as a distinct genospecies among the B. burgdorferi sensu lato complex. The prevalence of B. bavariensis in Austria, a highly endemic area for tick-transmitted pathogens, is scarcely characterized. To investigate the prevalence of B. bavariensis in Ixodes ricinus ticks we reevaluated the results of a study conducted in 518 ticks from southeastern Austria collected in 2002 and 2003. The presence of B. burgdorferi s.l.-specific DNA in ticks was analyzed by a PCR for the outer surface protein A (ospA) gene. Borrelia species were differentiated by restriction fragment length polymorphism (RFLP) analysis, and samples positive for B. bavariensis were further analyzed by multilocus sequence analysis. Two of 133 (1.5%) B. burgdorferi s.l.-positive I. ricinus ticks were infected with B. bavariensis. Both specimens were coinfected with the OspA serotype 5 of B. garinii. Borrelia bavariensis is present; however, seem to be rare in I. ricinus ticks in southeastern Austria. Copyright © 2014 Elsevier GmbH. All rights reserved.

Babesia microti (Piroplasmida: Babesiidae) in nymphal Ixodes ricinus (Acari: Ixodidae) in the Czech Republic

Czech Academy of Sciences Publication Activity Database

Rudolf, Ivo; Golovchenko, Maryna; Šikutová, Silvie; Rudenko, Natalia; Grubhoffer, Libor; Hubálek, Zdeněk

2005-01-01

Roč. 52, č. 3 (2005), s. 274-276 ISSN 0015-5683 R&D Projects: GA ČR(CZ) GA206/03/0726 Institutional research plan: CEZ:AV0Z60930519; CEZ:AV0Z60220518 Keywords : Babesia microti * Ixodes ricinus Subject RIV: EE - Microbiology, Virology Impact factor: 1.138, year: 2005 http://folia.paru.cas.cz/pdfs/showpdf.php?pdf=20766

'Candidatus Rickettsia mendelii', a novel basal group rickettsia detected in Ixodes ricinus ticks in the Czech Republic

Czech Academy of Sciences Publication Activity Database

Hajdušková, Eva; Literák, I.; Papoušek, I.; Costa, F.B.; Nováková, M.; Labruna, M. B.; Zdražilová-Dubská, L.

2016-01-01

Roč. 7, č. 3 (2016), s. 482-486 ISSN 1877-959X Institutional support: RVO:60077344 Keywords : Rickettsiae * Candidatus Rickettsia mendelii * Ixodes ricinus * basal group rickettsiae * ticks * Czech Republic Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.230, year: 2016

The Ixodes (Acari: Ixodidae) of Mexico: Parasite-Host and Host-Parasite Checklists

Science.gov (United States)

2007-08-20

en Peligro de Extinción. Comisión Nacional para el Cono- cimiento y Uso de la Biodiversidad, Fondo de Cultura Económica, Instituto de Ecología, UNAM...the largest genus of ticks in the world, currently comprising 243 species (Guglielmone et al. 2006), more than one quarter of the global tick fauna ...include it in the Mexican tick fauna . Ixodes bequaerti Cooley and Kohls Previous record CHIAPAS: 1&, Catharinus (sic), 4-V-1942, NA [Cooley & Kohls, 1945

Optimization of the solid-phase microextraction method in the determination of Ixodes ricinus (L.) volatiles

Czech Academy of Sciences Publication Activity Database

Zahradníčková, Helena; Bouman, Edwin Arien Poul

2006-01-01

Roč. 29, č. 2 (2006), s. 236-241 ISSN 1615-9306 R&D Projects: GA ČR(CZ) GA206/04/0751 Institutional research plan: CEZ:AV0Z50070508; CEZ:AV0Z60220518 Keywords : GC/MS * Ixodes ricinus * solid-phase microextraction Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 2.535, year: 2006

Detection of Anaplasma phagocytophilum DNA in Ixodes ticks (Acari: Ixodidae) from Madeira Island and Setubal District, mainland Portugal.

Science.gov (United States)

Santos, Ana Sofia; Santos-Silva, Maria Margarida; Almeida, Victor Carlos; Bacellar, Fátima; Dumler, John Stephen

2004-09-01

A total of 278 Ixodes ticks, collected from Madeira Island and Setubal District, mainland Portugal, were examined by polymerase chain reaction (PCR) for the presence of Anaplasma phagocytophilum. Six (4%) of 142 Ixodes ricinus nymphs collected in Madeira Island and 1 nymph and 1 male (2%) of 93 I. ventalloi collected in Setubal District tested positive for A. phagocytophilum msp2 genes or rrs. Infection was not detected among 43 I. ricinus on mainland Portugal. All PCR products were confirmed by nucleotide sequencing to be identical or to be most closely related to A. phagocytophilum. To our knowledge, this is the first evidence of A. phagocytophilum in ticks from Setubal District, mainland Portugal, and the first documentation of Anaplasma infection in I. ventalloi. Moreover, these findings confirm the persistence of A. phagocytophilum in Madeira Island's I. ricinus.

IrFC - An Ixodes ricinus injury-responsive molecule related to Limulus Factor C

Czech Academy of Sciences Publication Activity Database

Urbanová, Veronika; Hartmann, David; Grunclová, Lenka; Šíma, Radek; Flemming, Tina; Hajdušek, Ondřej; Kopáček, Petr

2014-01-01

Roč. 46, č. 2 (2014), s. 439-447 ISSN 0145-305X R&D Projects: GA ČR GAP506/10/2136; GA ČR GP13-27630P; GA ČR GP13-12816P; GA MŠk(CZ) EE2.3.30.0032 Institutional support: RVO:60077344 Keywords : Complement * Innate immunity * Limulus Clotting Factor C * Phagocytosis * RNA interference * Tick Ixodes ricinus Subject RIV: EC - Immunology Impact factor: 2.815, year: 2014

[Characteristics of the distribution of Ixodes persulcatus in the forest-park area of Novosibirsk].

Science.gov (United States)

Sapegina, V F; Dorontsova, V A; Telegin, V I; Ibleva, N G; Dobrotvorskiĭ, A K

1985-01-01

Only one species of ixodid ticks Ixodes persulcatus occurs in the forest-park zone. Conditions of foliage forests with high grass, where occur hosts of all developmental phases of ticks (elks, hares, rodents, insectivores), are most favourable for I. persulcatus. Preimaginal phases of I. persulcatus feed, in general, on dominant species (common shrew, redbacked and narrow-skulled voles, field mouse and northern birch mouse).

The Genus Ixodes (Acari: Ixodidae) in Mexico: Adult Identification Keys, Diagnoses, Hosts, and Distribution (El genero Ixodes (Acari: Ixodidae) en Mexico: claves de identificacion para adultos, diagnosis, huespedes y distribucion)

Science.gov (United States)

2010-01-01

also from Estado de México (Hoffmann, 1969). Hosts in Mexico. Cricetidae and Hominidae ( Homo sapiens Linnaeus, 1758) (Mammalia) (Hoffmann, 1969...distribution El género Ixodes (Acari: Ixodidae) en México: claves de identifi cación para adultos, diagnosis, huéspedes y distribución Carmen Guzmán...postdoctoral scholarship under the Programa de Formación e Incorporación de Profesores de Carrera en Facultades y Escuelas para el Fortalecimiento de la

´Candidatus Midichloria mitochondrii´, an endosymbiont of the tick Ixodes ricinus with a unique intramitochondrial lifestyle

Czech Academy of Sciences Publication Activity Database

Sassera, D.; Beninati, T.; Bandi, C.; Bouman, Edwin Arien Poul; Sacchi, L.; Fabbi, M.; Lo, N.

2006-01-01

Roč. 56, č. 11 (2006), s. 2535-2540 ISSN 1466-5026 R&D Projects: GA ČR GA206/04/0751 Institutional research plan: CEZ:AV0Z60220518 Keywords : Ixodes ricinus * endosymbiont * intramitochondrial Subject RIV: EH - Ecology, Behaviour Impact factor: 2.662, year: 2006

First evidence of Babesia venatorum and Babesia capreoli in questing Ixodes ricinus ticks in the Czech Republic

Czech Academy of Sciences Publication Activity Database

Venclíková, Kristýna; Mendel, Jan; Betášová, Lenka; Hubálek, Zdeněk; Rudolf, Ivo

2015-01-01

Roč. 22, č. 2 (2015), s. 212-214 ISSN 1232-1966 EU Projects: European Commission(XE) 261504 - EDENEXT Institutional support: RVO:68081766 Keywords : Babesia sp. EU1 * Babesia venatorum * Babesia capreoli * Ixodes ricinus * ixodid ticks Subject RIV: EE - Microbiology, Virology Impact factor: 0.895, year: 2015

Europe-Wide Meta-Analysis of Borrelia burgdorferi Sensu Lato Prevalence in Questing Ixodes ricinus Ticks

Czech Academy of Sciences Publication Activity Database

Strnad, Martin; Hönig, Václav; Růžek, Daniel; Grubhoffer, Libor; Rego, Ryan O. M.

2017-01-01

Roč. 83, č. 15 (2017), č. článku e00609-17. ISSN 0099-2240 EU Projects: European Commission(XE) 278976 - ANTIGONE; European Commission(XE) 602272 - ANTIDotE Institutional support: RVO:60077344 Keywords : Borrelia burgdorferi sensu lato * tick * Ixodes ricinus * genospecies * meta-analysis * Lyme borreliosis * Lyme disease Subject RIV: EE - Microbiology, Virology OBOR OECD: Microbiology Impact factor: 3.807, year: 2016

Susceptibility of Four Tick Species Amblyomma americanum, Dermacentor variabilis, Ixodes scapularis, and Rhipicephalus sanguineus (Acari: Ixodidae) to Nootkatone

Science.gov (United States)

The essential oil nootkatone has shown acaricidal activity on ticks. The toxicity of nootkatone was determined in laboratory assays using a vial coating technique against unfed nymphs of four Ixodid ticks: Amblyomma americanum L., Dermacentor variabilis (Say), Ixodes scapularis Say, and Rhipicepha...

Identification of Borrelia burgdorferi genospecies isolated from Ixodes ricinus ticks in the South Moravian region of the Czech Republic

Czech Academy of Sciences Publication Activity Database

Bonczek, Ondřej; Žákovská, A.; Vargová, L.; Šerý, Omar

2015-01-01

Roč. 22, č. 4 (2015), s. 642-646 ISSN 1232-1966 Institutional support: RVO:67985904 Keywords : Borrelia burgdorferi s. I. * Borrelia spielmanii * Ixodes ricinus Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 0.895, year: 2015

Borrelia burgdorferi genospecies detection by RLB hybridization in Ixodes ricinus ticks from different sites of North-Eastern Poland.

Science.gov (United States)

Dunaj, Justyna; Zajkowska, Joanna Maria; Kondrusik, Maciej; Gern, Lise; Rais, Oliver; Moniuszko, Anna; Pancewicz, Sławomir; Świerzbińska, Renata

2014-01-01

RLB (Reverse Line Blot Hybridization) is a molecular biology technique that might be used for Borrelia burgdorferi sensu lato (sl) DNA detection with genospecies specification. Among B. burgdorferi sl genospecies at least 7 are regarded as pathogenic in Europe. The aim of the study was to evaluate the frequency of different Borrelia genospecies DNA detection in Ixodes ricinus ticks in the endemic area of North-Eastern Poland by using RLB. Ixodes ricinus ticks were collected in May - June, from 6 different sites in North-Eastern Poland (Jakubin, Kolno, Grajewo, Suwałki, Siemiatycze, Białowieża) by flagging. Extracted DNA was amplified by polymerase chain reaction (PCR) targeting the intergenic spacer 5S 23S of B. burgdorferi sl. PCR products were hybridised to 15 different oligonucleotide probes for 9 different Borrelia genospecies (B. burgdorferi sl, B. burgdorferi ss, B. garinii, B. afzelii, B. valaisiana, B. lusitaniae, B. spielmanii, B. bissettii and B. relapsing fever-like spirochetes (B. myamotoi)) by RLB. Borrelia genospecies DNA was detected in 205 Ixodes ricinus ticks. Among 14 infected with Borrelia ticks, 4 were identified as B. garinii and 10 as B. afzelii. Higher numbers of infected ticks were noticed in the eastern part of the research area, where large forest complexes dominate. Nymphs appeared to be the most frequently infected tick stage, which has an epidemiological meaning in the incidence of Lyme borreliosis. The study demonstrated that RLB might be easily used in Borrelia DNA detection with genospecies-identification, and indicated the domination of B. afzelii and B. garinii in ticks from North-Eastern Poland.

Detection of Anaplasma phagocytophilum DNA in Ixodes Ticks (Acari: Ixodidae) from Madeira Island and Setúbal District, Mainland Portugal

Science.gov (United States)

Santos-Silva, Maria Margarida; Almeida, Victor Carlos; Bacellar, Fátima; Dumler, John Stephen

2004-01-01

A total of 278 Ixodes ticks, collected from Madeira Island and Setúbal District, mainland Portugal, were examined by polymerase chain reaction (PCR) for the presence of Anaplasma phagocytophilum. Six (4%) of 142 Ixodes ricinus nymphs collected in Madeira Island and 1 nymph and 1 male (2%) of 93 I. ventalloi collected in Setúbal District tested positive for A. phagocytophilum msp2 genes or rrs. Infection was not detected among 43 I. ricinus on mainland Portugal. All PCR products were confirmed by nucleotide sequencing to be identical or to be most closely related to A. phagocytophilum. To our knowledge, this is the first evidence of A. phagocytophilum in ticks from Setúbal District, mainland Portugal, and the first documentation of Anaplasma infection in I. ventalloi. Moreover, these findings confirm the persistence of A. phagocytophilum in Madeira Island's I. ricinus. PMID:15498168

Identification and characterization of Ixodes scapularis antigens that elicit tick immunity using yeast surface display.

Directory of Open Access Journals (Sweden)

Tim J Schuijt

2011-01-01

Full Text Available Repeated exposure of rabbits and other animals to ticks results in acquired resistance or immunity to subsequent tick bites and is partially elicited by antibodies directed against tick antigens. In this study we demonstrate the utility of a yeast surface display approach to identify tick salivary antigens that react with tick-immune serum. We constructed an Ixodes scapularis nymphal salivary gland yeast surface display library and screened the library with nymph-immune rabbit sera and identified five salivary antigens. Four of these proteins, designated P8, P19, P23 and P32, had a predicted signal sequence. We generated recombinant (r P8, P19 and P23 in a Drosophila expression system for functional and immunization studies. rP8 showed anti-complement activity and rP23 demonstrated anti-coagulant activity. Ixodes scapularis feeding was significantly impaired when nymphs were fed on rabbits immunized with a cocktail of rP8, rP19 and rP23, a hall mark of tick-immunity. These studies also suggest that these antigens may serve as potential vaccine candidates to thwart tick feeding.

Deer presence rather than abundance determines the population density of the sheep tick, Ixodes ricinus, in Dutch forests

NARCIS (Netherlands)

Hofmeester, Tim R.; Sprong, Hein; Jansen, Patrick A.; Prins, Herbert H.T.; Wieren, Van Sipke E.

2017-01-01

Background: Understanding which factors drive population densities of disease vectors is an important step in assessing disease risk. We tested the hypothesis that the density of ticks from the Ixodes ricinus complex, which are important vectors for tick-borne diseases, is determined by the density

Variability and action mechanism of a family of anticomplement proteins in Ixodes ricinus.

Directory of Open Access Journals (Sweden)

Bernard Couvreur

Full Text Available BACKGROUND: Ticks are blood feeding arachnids that characteristically take a long blood meal. They must therefore counteract host defence mechanisms such as hemostasis, inflammation and the immune response. This is achieved by expressing batteries of salivary proteins coded by multigene families. METHODOLOGY/PRINCIPAL FINDINGS: We report the in-depth analysis of a tick multigene family and describe five new anticomplement proteins in Ixodes ricinus. Compared to previously described Ixodes anticomplement proteins, these segregated into a new phylogenetic group or subfamily. These proteins have a novel action mechanism as they specifically bind to properdin, leading to the inhibition of C3 convertase and the alternative complement pathway. An excess of non-synonymous over synonymous changes indicated that coding sequences had undergone diversifying selection. Diversification was not associated with structural, biochemical or functional diversity, adaptation to host species or stage specificity but rather to differences in antigenicity. CONCLUSIONS/SIGNIFICANCE: Anticomplement proteins from I. ricinus are the first inhibitors that specifically target a positive regulator of complement, properdin. They may provide new tools for the investigation of role of properdin in physiological and pathophysiological mechanisms. They may also be useful in disorders affecting the alternative complement pathway. Looking for and detecting the different selection pressures involved will help in understanding the evolution of multigene families and hematophagy in arthropods.

Deer presence rather than abundance determines the population density of the sheep tick, Ixodes ricinus, in Dutch forests.

NARCIS (Netherlands)

Hofmeester, Tim R; Sprong, Hein; Jansen, Patrick A; Prins, Herbert H T; van Wieren, Sipke E

2017-01-01

Understanding which factors drive population densities of disease vectors is an important step in assessing disease risk. We tested the hypothesis that the density of ticks from the Ixodes ricinus complex, which are important vectors for tick-borne diseases, is determined by the density of deer, as

Multi-criteria Decision Analysis to Model Ixodes ricinus Habitat Suitability.

Science.gov (United States)

Rousseau, Raphaël; McGrath, Guy; McMahon, Barry J; Vanwambeke, Sophie O

2017-09-01

Tick-borne diseases present a major threat to both human and livestock health throughout Europe. The risk of infection is directly related to the presence of its vector. Thereby it is important to know their distribution, which is strongly associated with environmental factors: the presence and availability of a suitable habitat, of a suitable climate and of hosts. The present study models the habitat suitability for Ixodes ricinus in Ireland, where data on tick distribution are scarce. Tick habitat suitability was estimated at a coarse scale (10 km) with a multi-criteria decision analysis (MCDA) method according to four different scenarios (depending on the variables used and on the weights granted to each of them). The western part of Ireland and the Wicklow mountains in the East were estimated to be the most suitable areas for I. ricinus in the island. There was a good level of agreement between results from the MCDA and recorded tick presence. The different scenarios did not affect the spatial outputs substantially. The current study suggests that tick habitat suitability can be mapped accurately at a coarse scale in a data-scarce context using knowledge-based methods. It can serve as a guideline for future countrywide sampling that would help to determine local risk of tick presence and refining knowledge on tick habitat suitability in Ireland.

The occurrence of Ixodes ricinus ticks and important tick-borne pathogens in areas with high tick-borne encephalitis prevalence in different altitudinal levels of the Czech Republic Part II. Ixodes ricinus ticks and genospecies of Borrelia burgdorferi sensu lato complex

Czech Academy of Sciences Publication Activity Database

Daniel, M.; Rudenko, Natalia; Golovchenko, Maryna; Danielová, V.; Fialová, A.; Kříž, B.; Malý, M.

2016-01-01

Roč. 65, č. 2 (2016), s. 182-192 ISSN 1210-7913 Institutional support: RVO:60077344 Keywords : Ixodes ricinus * Borrelia afezelii * B. garinii * B. burgdorferi s. s. * B. bavariensis * B. valaisiana * B. spielmanii * B. lusitaniae * B. bissettii * distribution * altitude * season * medical importance Subject RIV: EE - Microbiology, Virology Impact factor: 0.500, year: 2016

Isolation, cultivation and identification of Borrelia burgdorferi genospecies from Ixodes ricinus ticks from the city of Brno, Czech Republic

Czech Academy of Sciences Publication Activity Database

Pejchalová, K.; Žákovská, A.; Mejzlíková, M.; Halouzka, Jiří; Dendis, M.

2007-01-01

Roč. 14, č. 1 (2007), s. 75-79 ISSN 1232-1966 Institutional research plan: CEZ:AV0Z60930519 Keywords : Borrelia burgdorferi * cultivation * DFM method * Ixodes ricinus * Lyme Subject RIV: EE - Microbiology, Virology Impact factor: 1.074, year: 2007 http://www.aaem.pl/pdf/1475.pdf

The Genus Ixodes (Acari: Ixodidae) in Mexico: Adult Identification Keys, Diagnoses, Hosts, and Distribution

Science.gov (United States)

2010-01-01

Cricetidae and Hominidae ( Homo sapiens Linnaeus, 1758) (Mammalia) (Hoffmann, 1969). Note. The tick from Valle de Bravo, Estado de México, was...distribution El género Ixodes (Acari: Ixodidae) en México: claves de identifi cación para adultos, diagnosis, huéspedes y distribución Carmen Guzmán...Incorporación de Profesores de Carrera en Facultades y Escuelas para el Fortalecimiento de la Investigación (PROFIP). Tila María Pérez, Curator of CNAC

Ixodes ricinus and its transmitted pathogens in urban and peri-urban areas in Europe: new hazards and relevance for public health

Czech Academy of Sciences Publication Activity Database

Rizzoli, A.; Silaghi, C.; Obiegala, A.; Rudolf, Ivo; Hubálek, Zdeněk; Földvári, G.; Plantard, O.; Vayssier-Taussat, M.; Bonnet, S.; Špitalská, E.; Kazimírová, M.

2014-01-01

Roč. 2, č. 251 (2014) ISSN 2296-2565 EU Projects: European Commission(XE) 261504 - EDENEXT Institutional support: RVO:68081766 Keywords : ticks * Ixodes ricinus * tick-borne pathogens * urban habitats * Europe Subject RIV: FN - Epidemiology, Contagious Diseases ; Clinical Immunology

[Search for protective antigens in Ixodes persulcatus (ixodidae) salivary gland extracts].

Science.gov (United States)

Shtannikov, A V; Reshetniak, T V; Repolovskaia, T V; Panfertsev, E A; Perovskaia, O N; Gutova, V P; Vasil'eva, I S; Ershova, A S; Prilipov, A G; Biketov, S F; Zeidner, N

2010-01-01

RT-PCR evaluation of the activity of eight Ixodes persulcatus salivary gland genes shows clear distinctions in their expression depending of the stage of tick feeding. Out of them, only Salp 10 and Salp 15 proteins may be regarded as candidates for protective antigens to develop anti-tick and anti-Borrelia vaccines. Firstly they play an important role in feeding a tick and modifying a host's immune response. Secondly, the increasing expression of the salp 10 and salp 10 genes begins at early tick feeding stages. Thirdly, the activity of these genes increases with the beginning of feeding by tens and hundreds times and keeps at this level until the third tick feeding stage is over.

Prevalence of Borrelia burgdorferi sensu lato genospecies in host-seeking Ixodes ricinus ticks in selected South Bohemian locations (Czech Republic)

Czech Academy of Sciences Publication Activity Database

Danielová, V.; Daniel, M.; Rudenko, Natalia; Golovchenko, Maryna

2004-01-01

Roč. 12, č. 3 (2004), s. 151-156 ISSN 1210-7778 R&D Projects: GA ČR GA524/03/1326 Institutional research plan: CEZ:AV0Z6022909 Keywords : Ixodes ricinus * Borrelia * Czech Republic Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine

Transmission differentials for multible pathogens as inferred from their prevalence in larva, nymph and sult of Ixodes ricinus (Acari: Ixodidae)

DEFF Research Database (Denmark)

Jensen, Per M.; Christoffersen, Christian S.; Moutailler, Sara

2017-01-01

Ixodes ricinus serves as vector for a range of microorganisms capable of causing clinical illness in humans. The microorganisms occur in the same vector populations and are generally affected by the same tick-host interactions. Still, the instars have different host preferences which should...

Broad-range survey of vector-borne pathogens and tick host identification of Ixodes ricinus from Southern Czech Republic

Czech Academy of Sciences Publication Activity Database

Hönig, Václav; Carolan, H. E.; Vavrušková, Zuzana; Massire, C.; Mosel, M.l R.; Crowder, C. D.; Rounds, M. A.; Ecker, D. J.; Růžek, Daniel; Grubhoffer, Libor; Luft, B. J.; Eshoo, M. W.

2017-01-01

Roč. 93, č. 11 (2017), č. článku fix129. ISSN 0168-6496 EU Projects: European Commission(XE) 278976 - ANTIGONE Institutional support: RVO:60077344 Keywords : burgdorferi sensu-lato * tick * Ixodes ricinus * pcr-esi/ms * Borrelia * host * Lyme borreliosis * Babesia * Anaplasma * Rickettsia Subject RIV: EE - Microbiology, Virology OBOR OECD: Microbiology Impact factor: 3.720, year: 2016

First evidence of Babesia venatorum and Babesia capreoli in questing Ixodes ricinus ticks in the Czech Republic.

Science.gov (United States)

Venclikova, Kristyna; Mendel, Jan; Betasova, Lenka; Hubalek, Zdenek; Rudolf, Ivo

2015-01-01

Ixodes ricinus is the most common tick species occurring in Central Europe and it serves as a principal vector of emerging human pathogens. The aim of this study was to determine the prevalence of Babesia spp. in host-seeking I. ricinus in urban and natural habitats. PCR was applied on samples to assess prevalence of Babesia spp. in questing ixodid ticks. Sequencing was used for Babesia species determination. 1,473 I. ricinus ticks (1,294 nymphs, 99 males and 80 females) were examined for the presence of Babesia spp. at the two study sites. Minimum infection rate for Babesia spp. was found to be 0.5% (infected I. ricinus nymphs were only detected in the natural ecosystem). Two Babesia species were identified by sequencing: B. venatorum (formerly called Babesia sp. EU1) and B. capreoli. The results obtained represent the first evidence of the occurrence of B. venatorum and B. capreoli in host-seeking I. ricinus ticks in the Czech Republic.

Genetic diversity of Ixodes ricinus (Ixodida: Ixodidae) ticks in sympatric and allopatric zones in Baltic countries.

Science.gov (United States)

Paulauskas, A; Galdikaitė-Brazienė, E; Radzijevskaja, J; Aleksandravičienė, A; Galdikas, M

2016-12-01

Ixodes ricinus (Linnaeus 1758) and Ixodes persulcatus (Schulze 1930) ticks are involved in the transmission of a wide variety of pathogens with considerable impact on human and animal health. The co-distribution zone of these two tick species is situated in the Baltic countries, which provides a special setting for the population studies. In the present study, genetic variability of I. ricinus ticks collected in allopatric and sympatric locations in the Baltic countries has been investigated using a sequence analysis of the mitochondrial DNA control region, 16S rRNA and cytb genes. There were 32 haplotypes (Hd: 0.8551) and 27 haplotypes (Hd:0.8213) of control region sequences from ticks in allopatric and sympatric zones detected, respectively. Out of 47 16S rRNA gene haplotypes, 32 haplotypes (Hd: 0.7213) were found in the allopatric zone and 27 (Hd:0.9572) in the sympatric zone. The Cytb gene was very conserved and monomorphic in ticks from the allopatric zone, whereas three unique haplotypes were observed in the sympatric zone. The higher number of unique haplotypes of the control region was detected in the allopatric zone. Median joining network and Fst analysis did not reveal a clear separation between ticks from the two zones. © 2016 The Society for Vector Ecology.

Presence of potentially pathogenic Babesia sp. for human in Ixodes ricinus in Switzerland.

Science.gov (United States)

Casati, Simona; Sager, Heinz; Gern, Lise; Piffaretti, Jean-Claude

2006-01-01

We have designed and performed a new PCR method based on the 18S rRNA in order to individuate the presence and the identity of Babesia parasites. Out of 1159 Ixodes ricinus (Acari: Ixodidae) ticks collected in four areas of Switzerland, nine were found to contain Babesia DNA. Sequencing of the short amplicon obtained (411-452 bp) allowed the identification of three human pathogenic species: Babesia microti, B. divergens, for the first time in Switzerland, Babesia sp. EU1. We also report coinfections with B. sp. EU1-Borrelia burgdorferi sensu stricto and Babesia sp. EU1-B. afzelii.

Functional expression and characterization of cathepsin B and L from the gut of the tick Ixodes ricinus

Czech Academy of Sciences Publication Activity Database

Franta, Zdeněk; Pěničková, Helena; Dvorak, J.; Schneider, E. I.; Horn, Martin; Mareš, Michael; Sojka, Daniel; McKerrow, J. H.; Caffrey, C. R.; Kopáček, Petr

2009-01-01

Roč. 276, S1 (2009), s. 309-309 ISSN 1742-464X. [34th FEBS Congress: Life's Molecular Interactions. 04.07.2009-09.07.2009, Prague] R&D Projects: GA AV ČR IAA600960910; GA MŠk(CZ) LC06009 Institutional research plan: CEZ:AV0Z60220518; CEZ:AV0Z40550506 Keywords : cathepsin B and L * Ixodes ricinus * functionl expresssion Subject RIV: EB - Genetics ; Molecular Biology

Two ways of experimental infection of Ixodes ricinus ticks (Acari: Ixodidae) with spirochetes of Borrelia burgdorferi sensu lato complex

Czech Academy of Sciences Publication Activity Database

Fišerová, Lenka; Černá, Kateřina; Horká, Helena; Kopecký, Jan

2008-01-01

Roč. 55, č. 2 (2008), s. 150-154 ISSN 0015-5683 R&D Projects: GA ČR GA524/05/0811; GA MŠk(CZ) LC06009 Institutional research plan: CEZ:AV0Z60220518 Keywords : Lyme disease spirochete * Borrelia burgdorferi * Borrelia baronii * Borrelia afzelii * tick * Ixodes ricinus Subject RIV: EC - Immunology Impact factor: 1.307, year: 2008

The prevalence of Anaplasma phagocytophilum in questing Ixodes ricinus ticks in SW Poland.

Science.gov (United States)

Kiewra, Dorota; Zaleśny, Grzegorz; Czułowska, Aleksandra

2014-01-01

Ticks constitute important vectors of human and animal pathogens. Besides the Lyme borreliosis and tick-borne encephalitis, other pathogens such as Babesia spp., Rickettsia spp., and Anaplasma phagocytophilum, are of increasing public health interest. In Poland, as in other European countries, Ixodes ricinus, the most prevalent tick species responsible for the majority of tick bites in humans, is the main vector of A. phagocytophilum. The aim of the study was to estimate the infection level of I. ricinus with A. phagocytophilum in selected districts, not previously surveyed for the presence of this agent. Sampling of questing ticks was performed in 12 forested sites, located in four districts (Legnica, Milicz, Lubań, and Oława) in SW Poland. Altogether, 792 ticks (151 females, 101 males, and 540 nymphs) representing I. ricinus were checked for the presence of A. phagocytophilum. The average infection level was 4.3%, with higher rate reported for adult ticks. The highest percentage of infected adults was observed in Milicz (17.4%) and the lowest in Oława (6.8%). The abundance of questing I. ricinus in all examined sites as well as the infection with A. phagocytophilum indicate for the first time the risk for HGA transmission in SW Poland.

Salivary gland extract from engorged Ixodes ricinus (Acari: Ixodidae) stimulates in vitro growth of Borrelia burgdorferi sensu lato

Czech Academy of Sciences Publication Activity Database

Rudolf, Ivo; Šikutová, Silvie; Kopecký, Jan; Hubálek, Zdeněk

2010-01-01

Roč. 50, č. 3 (2010), s. 294-298 ISSN 0233-111X R&D Projects: GA ČR GA206/03/0726; GA AV ČR IAA600960811 Institutional research plan: CEZ:AV0Z60930519; CEZ:AV0Z60220518 Keywords : salivary gland extract * Ixodes ricinus ticks * Borrelia burgdorferi sensu lato Subject RIV: EE - Microbiology, Virology Impact factor: 1.395, year: 2010

Defensins from the tick Ixodes scapularis are effective against phytopathogenic fungi and the human bacterial pathogen Listeria grayi

Czech Academy of Sciences Publication Activity Database

Tonk, Miray; Cabezas-Cruz, A.; Valdés, James J.; Rego, Ryan O. M.; Chrudimská, Tereza; Strnad, Martin; Šíma, Radek; Bell-Sakyi, L.; Franta, Z.; Vilcinskas, A.; Grubhoffer, Libor; Rahnamaeian, M.

2014-01-01

Roč. 7, DEC 3 2015 (2014), s. 554 ISSN 1756-3305 R&D Projects: GA ČR(CZ) GAP302/11/1901; GA MŠk(CZ) EE2.3.30.0032; GA ČR GP13-12816P Institutional support: RVO:60077344 Keywords : Antimicrobial peptide * Defensin * Listeria grayi * Fusarium spp * Ixodes scapularis * Tick cell line Subject RIV: EE - Microbiology, Virology Impact factor: 3.430, year: 2014

Water absorption through salivary gland type I acini in the blacklegged tick, Ixodes scapularis

Directory of Open Access Journals (Sweden)

Donghun Kim

2017-10-01

Full Text Available Tick salivary glands play critical roles in maintaining water balance for survival, as they eliminate excess water and ions during blood feeding on hosts. In the long duration of fasting in the off-host period, ticks secrete hygroscopic saliva into the mouth cavity to uptake atmospheric water vapor. Type I acini of tick salivary glands are speculated to be involved in secretion of hygroscopic saliva based on ultrastructure studies. However, we recently proposed that type I acini play a role in resorption of water/ions from the primary saliva produced by other salivary acini (i.e., types II and III during the tick blood feeding phase. In this study, we tested the function of type I acini in unfed female Ixodes scapularis. The route of ingested water was tracked after forced feeding of water with fluorescent dye rhodamine123. We found that type-I acini of the salivary glands, but not type II and III, are responsible for water uptake. In addition, the ingestion of water through the midgut was also observed. Injection or feeding of ouabain, a Na/K-ATPase inhibitor, suppressed water absorption in type I acini. When I. scapularis was offered a droplet of water, ticks rarely imbibed water directly (5%, while some approached the water droplet to use the high humidity formed in the vicinity of the droplet (23%. We conclude that during both on- and off-host stages, type I acini in salivary glands of female Ixodes scapularis absorb water and ions.

Variation in the Microbiota of Ixodes Ticks with Regard to Geography, Species, and Sex.

Science.gov (United States)

Van Treuren, Will; Ponnusamy, Loganathan; Brinkerhoff, R Jory; Gonzalez, Antonio; Parobek, Christian M; Juliano, Jonathan J; Andreadis, Theodore G; Falco, Richard C; Ziegler, Lorenza Beati; Hathaway, Nicholas; Keeler, Corinna; Emch, Michael; Bailey, Jeffrey A; Roe, R Michael; Apperson, Charles S; Knight, Rob; Meshnick, Steven R

2015-09-01

Ixodes scapularis is the principal vector of Lyme disease on the East Coast and in the upper Midwest regions of the United States, yet the tick is also present in the Southeast, where Lyme disease is absent or rare. A closely related species, I. affinis, also carries the pathogen in the South but does not seem to transmit it to humans. In order to better understand the geographic diversity of the tick, we analyzed the microbiota of 104 adult I. scapularis and 13 adult I. affinis ticks captured in 19 locations in South Carolina, North Carolina, Virginia, Connecticut, and New York. Initially, ticks from 4 sites were analyzed by 454 pyrosequencing. Subsequently, ticks from these sites plus 15 others were analyzed by sequencing with an Illumina MiSeq machine. By both analyses, the microbiomes of female ticks were significantly less diverse than those of male ticks. The dissimilarity between tick microbiomes increased with distance between sites, and the state in which a tick was collected could be inferred from its microbiota. The genus Rickettsia was prominent in all locations. Borrelia was also present in most locations and was present at especially high levels in one site in western Virginia. In contrast, members of the family Enterobacteriaceae were very common in North Carolina I. scapularis ticks but uncommon in I. scapularis ticks from other sites and in North Carolina I. affinis ticks. These data suggest substantial variations in the Ixodes microbiota in association with geography, species, and sex. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Variation in the Microbiota of Ixodes Ticks with Regard to Geography, Species, and Sex

Science.gov (United States)

Van Treuren, Will; Ponnusamy, Loganathan; Brinkerhoff, R. Jory; Gonzalez, Antonio; Parobek, Christian M.; Juliano, Jonathan J.; Andreadis, Theodore G.; Falco, Richard C.; Ziegler, Lorenza Beati; Hathaway, Nicholas; Keeler, Corinna; Emch, Michael; Bailey, Jeffrey A.; Roe, R. Michael; Apperson, Charles S.; Knight, Rob

2015-01-01

Ixodes scapularis is the principal vector of Lyme disease on the East Coast and in the upper Midwest regions of the United States, yet the tick is also present in the Southeast, where Lyme disease is absent or rare. A closely related species, I. affinis, also carries the pathogen in the South but does not seem to transmit it to humans. In order to better understand the geographic diversity of the tick, we analyzed the microbiota of 104 adult I. scapularis and 13 adult I. affinis ticks captured in 19 locations in South Carolina, North Carolina, Virginia, Connecticut, and New York. Initially, ticks from 4 sites were analyzed by 454 pyrosequencing. Subsequently, ticks from these sites plus 15 others were analyzed by sequencing with an Illumina MiSeq machine. By both analyses, the microbiomes of female ticks were significantly less diverse than those of male ticks. The dissimilarity between tick microbiomes increased with distance between sites, and the state in which a tick was collected could be inferred from its microbiota. The genus Rickettsia was prominent in all locations. Borrelia was also present in most locations and was present at especially high levels in one site in western Virginia. In contrast, members of the family Enterobacteriaceae were very common in North Carolina I. scapularis ticks but uncommon in I. scapularis ticks from other sites and in North Carolina I. affinis ticks. These data suggest substantial variations in the Ixodes microbiota in association with geography, species, and sex. PMID:26150449

Borrelia burgdorferi genospecies detection by RLB hybridization in Ixodes cinus ticks from different sites of North-Eastern Poland

Directory of Open Access Journals (Sweden)

Justyna Dunaj

2014-06-01

Full Text Available Introduction. RLB (Reverse Line Blot Hybridization is a molecular biology technique that might be used for [i]Borrelia burgdorferi [/i]sensu lato (sl DNA detection with genospecies specification. Among[i] B. burgdorferi[/i] sl genospecies at least 7 are regarded as pathogenic in Europe. objective. The aim of the study was to evaluate the frequency of different [i]Borrelia[/i] genospecies DNA detection in Ixodes ricinus ticks in the endemic area of North-Eastern Poland by using RLB. materials and method. Ixodes ricinus ticks were collected in May – June, from 6 different sites in North-Eastern Poland (Jakubin, Kolno, Grajewo, Suwałki, Siemiatycze, Białowieża by flagging. Extracted DNA was amplified by polymerase chain reaction (PCR targeting the intergenic spacer 5S 23S of [i]B. burgdorferi sl.[/i] PCR products were hybridised to 15 different oligonucleotide probes for 9 different [i]Borrelia [/i]genospecies ([i]B. burgdorferi sl, B. burgdorferi ss, B. garinii, B. afzelii, B. valaisiana, B. lusitaniae, B. spielmanii, B. bissettii and B. relapsing[/i] fever-like spirochetes (B. myamotoi by RLB. results. [i]Borrelia [/i]genospecies DNA was detected in 205 Ixodes ricinus ticks. Among 14 infected with [i]Borrelia[/i] ticks, 4 were identified as B. garinii and 10 as B. afzelii. Higher numbers of infected ticks were noticed in the eastern part of the research area, where large forest complexes dominate. Nymphs appeared to be the most frequently infected tick stage, which has an epidemiological meaning in the incidence of Lyme borreliosis. conclusions. The study demonstrated that RLB might be easily used in [i]Borrelia[/i] DNA detection with genospecies-identification, and indicated the domination of [i]B. afzelii and B. garinii [/i]in ticks from North-Eastern Poland.

High degree of mitochondrial gene heterogeneity in the bat tick species Ixodes vespertilionis, I. ariadnae and I. simplex from Eurasia.

Science.gov (United States)

Hornok, Sándor; Estrada-Peña, Agustín; Kontschán, Jenő; Plantard, Olivier; Kunz, Bernd; Mihalca, Andrei D; Thabah, Adora; Tomanović, Snežana; Burazerović, Jelena; Takács, Nóra; Görföl, Tamás; Estók, Péter; Tu, Vuong Tan; Szőke, Krisztina; Fernández de Mera, Isabel G; de la Fuente, José; Takahashi, Mamoru; Yamauchi, Takeo; Takano, Ai

2015-09-17

Phylogeographical studies allow precise genetic comparison of specimens, which were collected over large geographical ranges and belong to the same or closely related animal species. These methods have also been used to compare ticks of veterinary-medical importance. However, relevant data are missing in the case of ixodid ticks of bats, despite (1) the vast geographical range of both Ixodes vespertilionis and Ixodes simplex, and (2) the considerable uncertainty in their taxonomy, which is currently unresolvable by morphological clues. In the present study 21 ticks were selected from collections or were freshly removed from bats or cave walls in six European and four Asian countries. The DNA was extracted and PCRs were performed to amplify part of the cytochrome oxidase I (COI), 16S and 12S rDNA genes, followed by sequencing for identification and molecular-phylogenetic comparison. No morphological differences were observed between Ixodes vespertilionis specimens from Spain and from other parts of Europe, but corresponding genotypes had only 94.6 % COI sequence identity. An I. vespertilionis specimen collected in Vietnam was different both morphologically and genetically (i.e. with only 84.1 % COI sequence identity in comparison with I. vespertilionis from Europe). Two ticks (collected in Vietnam and in Japan) formed a monophyletic clade and shared morphological features with I. ariadnae, recently described and hitherto only reported in Europe. In addition, two Asiatic specimens of I. simplex were shown to differ markedly from European genotypes of the same species. Phylogenetic relationships of ticks showed similar clustering patterns with those of their associated bat host species. Although all three ixodid bat tick species evaluated in the present study appear to be widespread in Eurasia, they exhibit pronounced genetic differences. Data of this study also reflect that I. vespertilionis may represent a species complex.

Effect of forest clearing on the abundance of Ixodes ricinus ticks and the prevalence of Borrelia burgdorferi s.l

Czech Academy of Sciences Publication Activity Database

Hubálek, Zdeněk; Halouzka, Jiří; Juřicová, Zina; Šikutová, Silvie; Rudolf, Ivo

2006-01-01

Roč. 20, č. 2 (2006), s. 166-172 ISSN 0269-283X R&D Projects: GA ČR GA206/03/0726 EU Projects: European Commission(XE) 10284 - EDEN Institutional research plan: CEZ:AV0Z60930519 Keywords : Ixodes ricinus * Borrelia burgdorferi sensu lato * Lyme borreliosis risk Subject RIV: FN - Epidemiology, Contagious Diseases ; Clinical Immunology Impact factor: 2.033, year: 2006

Characterization of Ixodes ricinus fibrinogen-related proteins (Ixoderins) discloses their function in the tick innate immunity

Czech Academy of Sciences Publication Activity Database

Hönig Mondeková, Helena; Šíma, Radek; Urbanová, Veronika; Kovář, Vojtěch; Rego, Ryan O. M.; Grubhoffer, Libor; Kopáček, Petr; Hajdušek, Ondřej

2017-01-01

Roč. 7, DEC (2017), č. článku 509. ISSN 2235-2988 R&D Projects: GA ČR GA17-27386S; GA ČR GA17-27393S; GA ČR GJ15-12006Y; GA ČR GA13-11043S EU Projects: European Commission(XE) 602272 - ANTIDotE Institutional support: RVO:60077344 Keywords : Fibrinogen-related protein * Ixoderin * Ixodes * Lectin * RNAi * Tick Subject RIV: EC - Immunology OBOR OECD: Biochemistry and molecular biology Impact factor: 4.300, year: 2016

Efficacy and environmental persistence of nootkatone for the control of the blacklegged tick, Ixodes scapularis (Acari: Ixodidae) in the residential landscape

Science.gov (United States)

We evaluated the ability of the plant-derived compound nootkatone to control nymphs of the blacklegged tick, Ixodes scapularis Say, applied to the perimeter of lawns around homes in Lyme disease endemic areas of Connecticut. Three formulations of nootkatone ranging from 0.05 to 0.84% (0.06 to 1.03 g...

Prevalence of Borrelia burgdorferi (Spirochaetales: Spirochaetaceae) in Ixodes scapularis (Acari: Ixodidae) adults in New Jersey, 2000-2001.

Science.gov (United States)

Schulze, Terry L; Jordan, Robert A; Hung, Robert W; Puelle, Rose S; Markowski, Daniel; Chomsky, Martin S

2003-07-01

Using polymerase chain reaction, we analyzed 529 Ixodes scapularis Say adults collected from 16 of New Jersey's 21 counties for the presence of Borrelia burgdorferi, the etiological agent of Lyme disease. Overall, 261 (49.3%) were positive. B. burgdorferi was detected in ticks obtained from each county and from 53 of the 58 (93.1%) municipalities surveyed. The observed statewide prevalence in New Jersey is similar to those reported from other northeastern and mid-Atlantic states.

The majority of sialylated glycoproteins in adult Ixodes ricinus ticks originate in the host, not the tick

Czech Academy of Sciences Publication Activity Database

Štěrba, Ján; Vancová, Marie; Štěrbová, Jarmila; Bell-Sakyi, L.; Grubhoffer, Libor

2014-01-01

Roč. 389, MAY 2014 (2014), s. 93-99 ISSN 0008-6215 R&D Projects: GA ČR(CZ) GAP302/11/1901; GA ČR GAP302/12/2490; GA MŠk(CZ) LC06009; GA MŠk(CZ) EE2.3.30.0032; GA ČR GA206/09/1782 Institutional support: RVO:60077344 Keywords : tick * Ixodes ricinus * sialic acid * tick cell line Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.929, year: 2014

Infestation of mammals by Ixodes ricinus ticks (Acari: Ixodidae) in south-central Sweden.

Science.gov (United States)

Tälleklint, L; Jaenson, T G

1997-12-01

Infestation by Ixodes ricinus ticks on rodents, hares and cervids was examined at Bogesund, 10 km north of Stockholm, in south-central Sweden during 1991-1994 and on varying hares (Lepus timidus) at Stora Karlsö and Gotska Sandön in the Baltic Sea during 1992-1993. At Bogesund, there were great differences between two consecutive years in the number of I. ricinus larvae infesting bank voles (Clethrionomys glareolus). The seasonal pattern of infestation by I. ricinus larvae and nymphs on bank voles was unimodal in 1991, with peaks in June-July and bimodal in 1992, with peaks in June and August. Male bank voles, compared to females and older voles, compared to young voles, harboured greater numbers of I. ricinus ticks. Apodemus mice, compared to bank voles, harboured greater numbers of I. ricinus ticks. Ixodes ricinus larvae engorged on Apodemus mice were heavier than larvae engorged on bank voles and resulted in larger nymphs. However, there was no difference in the proportions of viable nymphs resulting from larvae engorged on mice or voles. The ranges in the numbers of I. ricinus ticks infesting individual hosts were 1-451 for rodents, 16-2374 for hares and 428-2072 for roe deer (Capreolus capreolus). These ranges of tick numbers are estimated to represent potential blood losses from individual hosts of approximately 0.2-65% for rodents, 0.2-13% for hares and 0.3-9.0% for roe deer. Within the populations of all host species examined, the distributions of all stages of I. ricinus were clumped, with most host individuals harbouring few ticks and only a few individuals harbouring many ticks. The data suggest that, even though a small proportion of tick hosts may be severely affected, the direct effects of feeding by I. ricinus are unlikely to play an important role on mammal population dynamics.

'Candidatus Rickettsia mendelii', a novel basal group rickettsia detected in Ixodes ricinus ticks in the Czech Republic.

Science.gov (United States)

Hajduskova, Eva; Literak, Ivan; Papousek, Ivo; Costa, Francisco B; Novakova, Marketa; Labruna, Marcelo B; Zdrazilova-Dubska, Lenka

2016-04-01

A novel rickettsial sequence in the citrate synthase gltA gene indicating a novel Rickettsia species has been detected in 7 out of 4524 Ixodes ricinus ticks examined within several surveys performed in the Czech Republic from 2005 to 2009. This new Candidatus Rickettsia sp. sequence has been found in 2 nymphs feeding on wild birds (Luscinia megarhynchos and Erithacus rubecula), in a male tick from vegetation, and 4 ticks feeding on a dog (3 males, 1 female tick). Portions of the ompA, ompB, sca4, and htrA genes were not amplifiable in these samples. A maximum likelihood tree of rickettsiae based on comparisons of partial amino acid sequences of citrate synthase and nucleotide sequences of 16S rDNA genes and phylogenetic analysis revealed a basal position of the novel species in the proximity of R. bellii and R. canadensis. The novel species has been named 'Candidatus Rickettsia mendelii' after the founder of genetics, Gregor Mendel. Copyright © 2016 Elsevier GmbH. All rights reserved.

Description of the immature stages and redescription of the female of Ixodes schulzei Aragão & Fonseca, 1951 (Acari: Ixodidae), an endemic tick species of Brazil.

Science.gov (United States)

Barros-Battesti, Darci M; Onofrio, Valeria C; Faccini, João L H; Labruna, Marcelo B; Arruda-Santos, Ana D; Giacomin, Flávia G

2007-11-01

Ixodes schulzei Aragão & Fonseca, 1951 is a tick endemic to Brazil, where nine species of Ixodes Latreille, 1796 are currently known to occur. Larvae, nymphs and females of I. schulzei were obtained from a laboratory colony originating from an engorged female collected on a free-living water rat Nectomys squamipes from the Santa Branca municipality, São Paulo State. Only female ticks were obtained from engorged nymphs. Unfed immature and female adult specimens were measured and the descriptions were based on optical and scanning electron microscopy, as were drawings of some features of the larva. Both immature stages present the very long palpi and basis capituli, and the female has large, contiguous porose areas. However, the basis capituli is triangular, with a slight central elevation in the larva and nymph, whereas in the female this area is depressed. The I. schulzei types deposited at the FIOCRUZ (Instituto Oswaldo Cruz) were also examined, as was other material from collections, such as the IBSP (Coleção Acarológica do Instituto Butantan), CNC-FMVZ/USP (Coleção Nacional de Carrapatos da Faculdade de Medicina Veterinária e Zootecnia da USP) and USNTC (United States National Tick Collection). In addition, the relationship between I. schulzei and other immature neotropical species of Ixodes is discussed.

Crowdsourcing-based nationwide tick collection reveals the distribution of Ixodes ricinus and I. persulcatus and associated pathogens in Finland.

Science.gov (United States)

Laaksonen, Maija; Sajanti, Eeva; Sormunen, Jani J; Penttinen, Ritva; Hänninen, Jari; Ruohomäki, Kai; Sääksjärvi, Ilari; Vesterinen, Eero J; Vuorinen, Ilppo; Hytönen, Jukka; Klemola, Tero

2017-05-10

A national crowdsourcing-based tick collection campaign was organized in 2015 with the objective of producing novel data on tick distribution and tick-borne pathogens in Finland. Nearly 20 000 Ixodes ticks were collected. The collected material revealed the nationwide distribution of I. persulcatus for the first time and a shift northwards in the distribution of I. ricinus in Finland. A subset of 2038 tick samples containing both species was screened for Borrelia burgdorferi sensu lato (the prevalence was 14.2% for I. ricinus and 19.8% for I. persulcatus), B. miyamotoi (0.2% and 0.4%, respectively) and tick-borne encephalitis virus (TBEV; 0.2% and 3.0%, respectively). We also report new risk areas for TBEV in Finland and, for the first time, the presence of B. miyamotoi in ticks from mainland Finland. Most importantly, our study demonstrates the overwhelming power of citizen science in accomplishing a collection effort that would have been impossible with the scientific community alone.

Effect of salivary gland extract from Ixodes ricinus ticks on the proliferation of Borrelia burgdorferi sensu stricto in vivo

Czech Academy of Sciences Publication Activity Database

Macháčková, Martina; Oborník, Miroslav; Kopecký, Jan

2006-01-01

Roč. 53, č. 2 (2006), s. 153-158 ISSN 0015-5683 R&D Projects: GA ČR GA524/05/0811 Grant - others:Studentská grantová agentura, Biologická fakulta Jihočeské univerzity(CZ) SGA2004/009 Institutional research plan: CEZ:AV0Z60220518 Keywords : Borrelia burgdorferi * Ixodes ricinus * saliva-activated transmission Subject RIV: EC - Immunology Impact factor: 1.511, year: 2006

The role of rodents in the ecology of Ixodes ricinus and associated pathogens in Central and Eastern Europe.

Science.gov (United States)

Mihalca, Andrei D; Sándor, Attila D

2013-01-01

Rodents comprise more species than any other mammal order. Most rodents are considered keystone species in their ecological communities, hence the survival of many other species in the ecosystem depend on them. From medical point of view, this is particularly important for rodent-dependent pathogens. In the particular case of tick-borne diseases, rodents are important as hosts for vector ticks and as reservoir hosts (Lyme borreliosis, human granulocytic anaplasmosis, Crimean-Congo hemorrhagic fever, Tick-borne relapsing fevers, tick-borne rickettsioses, babesiosis). Community and population ecology of rodents was shown to be correlated with disease ecology in the case of many tick-borne diseases. In Eastern Europe, several adult hard-tick species use rodents as their principal hosts: Ixodes apronophorus, I. crenulatus, I. laguri, I. redikorzevi, I. trianguliceps. However, the majority of ticks feeding on rodents are immature stages of ticks which as adults are parasitic on larger mammals. Larvae and nymphs of Ixodes ricinus, the most abundant and medically important tick from Europe, are commonly found on rodents. This is particularly important, as many rodents are synanthropic and, together with other micromammals and birds are often the only available natural hosts for ticks in urban environments. This work reviews the correlated ecology of rodents and I. ricinus.

Arthropod repellency, especially tick (Ixodes ricinus), exerted by extract from Artemisia abrotanum and essential oil from flowers of Dianthus caryophyllum.

Science.gov (United States)

Tunón, H; Thorsell, W; Mikiver, A; Malander, I

2006-06-01

A toluene extract of southernwood (Artemisia abrotanum) and the essential oil from flowers of carnation (Dianthus caryophyllum ) exerted pronounced a repellent effect both against ticks (nymphs of Ixodes ricinus) and yellow fever mosquitoes (Aedes aegypti). The most potent repellents found were coumarin and thujyl alcohol from A. abrotanum and phenylethanol from D. caryophyllum where coumarin and thujyl alcohol were also detected.

Rickettsia vini n. sp. (Rickettsiaceae) infecting the tick Ixodes arboricola (Acari: Ixodidae).

Science.gov (United States)

Novakova, Marketa; Costa, Francisco B; Krause, Frantisek; Literak, Ivan; Labruna, Marcelo B

2016-08-26

Recently, a new rickettsia named 'Candidatus Rickettsia vini' belonging to the spotted fever group has been molecularly detected in Ixodes arboricola ticks in Spain, the Czech Republic, Slovakia and Turkey, with prevalence reaching up to 100 %. The aim of this study was to isolate this rickettsia in pure culture, and to describe it as a new Rickettsia species. A total of 148 ornitophilic nidicolous ticks Ixodes arboricola were collected in a forest near Breclav (Czech Republic) and examined for rickettsiae. Shell vial technique was applied to isolate rickettsiae in Vero cells. Rickettsial isolation was confirmed by optical microscopy and sequencing of partial sequences of the rickettsial genes gltA, ompA, ompB, and htrA. Laboratory guinea pigs and chickens were used for experimental infestations and infections. Animal blood sera were tested by immunofluorescence assay employing crude antigens of various rickettsiae. Rickettsia vini n. sp. was successfully isolated from three males of I. arboricola. Phylogenetic analysis of fragments of 1092, 590, 800, and 497 nucleotides of the gltA, ompA, ompB, and htrA genes, respectively, showed closest proximity of R. vini n. sp. to Rickettsia japonica and Rickettsia heilongjiangensis belonging to the spotted fever group. Experimental infection of guinea pigs and chickens with R. vini led to various levels of cross-reactions of R. vini-homologous antibodies with Rickettsia rickettsii, Rickettsia parkeri, 'Candidatus Rickettsia amblyommii', Rickettsia rhipicephali, Rickettsia bellii, and Rickettsia felis. Laboratory infestations by R. vini-infected I. arboricola larvae on chickens led to no seroconversion to R. vini n. sp., nor cross-reactions with R. rickettsii, R. parkeri, 'Ca. R. amblyommii', R. rhipicephali, R. bellii or R. felis. Our results suggest that R. vini n. sp. is possibly a tick endosymbiont, not pathogenic for guinea pigs and chickens. Regarding specific phenotypic characters and significant differences of DNA

Habitat properties are key drivers of Borrelia burgdorferi (s.l.) prevalence in Ixodes ricinus populations of deciduous forest fragments

OpenAIRE

Ehrmann, Steffen; Ruyts, Sanne C.; Scherer-Lorenzen, Michael; Bauhus, Jürgen; Brunet, Jörg; Cousins, Sara A. O.; Deconchat, Marc; Decocq, Guillaume; De Frenne, Pieter; De Smedt, Pallieter; Diekmann, Martin; Gallet-Moron, Emilie; Gärtner, Stefanie; Hansen, Karin; Kolb, Annette

2018-01-01

Background The tick Ixodes ricinus has considerable impact on the health of humans and other terrestrial animals because it transmits several tick-borne pathogens (TBPs) such as B. burgdorferi (sensu lato), which causes Lyme borreliosis (LB). Small forest patches of agricultural landscapes provide many ecosystem services and also the disservice of LB risk. Biotic interactions and environmental filtering shape tick host communities distinctively between specific regions of Europe, which makes ...

Description of a new tick species, Ixodes collaris n. sp. (Acari: Ixodidae), from bats (Chiroptera: Hipposideridae, Rhinolophidae) in Vietnam.

Science.gov (United States)

Hornok, Sándor; Görföl, Tamás; Estók, Péter; Tu, Vuong Tan; Kontschán, Jenő

2016-06-10

In a recent study on ixodid bat ticks from Eurasia, a high genetic difference was found between Ixodes vespertilionis from Europe and Vietnam. Accordingly, it was proposed that I. vespertilionis is a species complex, with at least one additional, hitherto undescribed species. The aim of the present study was to investigate the morphology of bat ticks from Vietnam and to assess their taxonomic status in comparison with those collected in Europe. Ixodid bat ticks (two females and two nymphs) collected from the pomona leaf-nosed bat (Hipposideros pomona) (Hipposideridae) and intermediate horseshoe bat (Rhinolophus affinis) (Rhinolophidae) in Vietnam showed major morphological differences from European isolates of I. vespertilionis, including the shape of the scutum, the enclosure and shape of porose areas, the presence of a caudo-lateral collar-like ridge ventrally on the basis capituli, polytrich coxae with short setae, and grouped (non-linear) arrangement of anterior pit sensillae in Haller's organ. In this study the female and the nymph of an ixodid bat tick species from Vietnam are described for the first time. The genetic and morphological differences between I. vespertilionis Koch, 1844 and these bat ticks from Vietnam justify the status of the latter as a distinct species, Ixodes collaris Hornok n. sp.

IrML – a gene encoding a new member of the ML protein family from the hard tick, Ixodes ricinus

Czech Academy of Sciences Publication Activity Database

Horáčková, J.; Rudenko, Natalia; Golovchenko, Maryna; Havlíková, S.; Grubhoffer, Libor

2010-01-01

Roč. 35, č. 2 (2010), s. 410-418 ISSN 1081-1710 R&D Projects: GA ČR(CZ) GA524/06/1479; GA MŠk(CZ) LC06009 Institutional research plan: CEZ:AV0Z60220518 Keywords : Ixodes ricinus * tick * ML-domain containing protein * in situ hybridization * gene expression * ML (MD-2-related lipid-recognition) domain Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine Impact factor: 1.256, year: 2010

Field and laboratory responses of adult Ixodes scapularis (Acari: Ixodidae) to kairomones produced by white-tailed deer.

Science.gov (United States)

Carroll, J F; Mills, G D; Schmidtmann, E T

1996-07-01

In a field test, adult blacklegged ticks, Ixodes scapularis Say, of both sexes exhibited an arrestant response to substances associated with external glands on the legs of white-tailed deer, Odocoileus virginianus (Zimmermann), their principal host. Substances rubbed from the pelage covering tarsal and interdigital glands were applied to artificial vantage points simulating vegetation on which I. scapularis adults wait for host contact. A combination of tarsal substances (applied to the apex of the simulated vantage point) and interdigital gland substances (applied to the horizontal base) elicited a greater response than either treatment alone. A minimal response was observed on untreated vantage points. In laboratory bioassays using glass tubing as vantage points, substances associated with preorbital glands of deer elicited a strong arrestant response among I. scapularis females, whereas samples rubbed from the forehead, back, and a nonglandular area on deer tarsi evoked weak arrestant responses. These results support the hypothesis that the kairomonal properties of host-generated residues, either in conjunction with or in lieu of the effects of carbon dioxide, help account for the prevalence of host-seeking ticks along animal trails.

Genomic insights into the Ixodes scapularis tick vector of Lyme disease

Science.gov (United States)

Gulia-Nuss, Monika; Nuss, Andrew B.; Meyer, Jason M.; Sonenshine, Daniel E.; Roe, R. Michael; Waterhouse, Robert M.; Sattelle, David B.; de la Fuente, José; Ribeiro, Jose M.; Megy, Karine; Thimmapuram, Jyothi; Miller, Jason R.; Walenz, Brian P.; Koren, Sergey; Hostetler, Jessica B.; Thiagarajan, Mathangi; Joardar, Vinita S.; Hannick, Linda I.; Bidwell, Shelby; Hammond, Martin P.; Young, Sarah; Zeng, Qiandong; Abrudan, Jenica L.; Almeida, Francisca C.; Ayllón, Nieves; Bhide, Ketaki; Bissinger, Brooke W.; Bonzon-Kulichenko, Elena; Buckingham, Steven D.; Caffrey, Daniel R.; Caimano, Melissa J.; Croset, Vincent; Driscoll, Timothy; Gilbert, Don; Gillespie, Joseph J.; Giraldo-Calderón, Gloria I.; Grabowski, Jeffrey M.; Jiang, David; Khalil, Sayed M. S.; Kim, Donghun; Kocan, Katherine M.; Koči, Juraj; Kuhn, Richard J.; Kurtti, Timothy J.; Lees, Kristin; Lang, Emma G.; Kennedy, Ryan C.; Kwon, Hyeogsun; Perera, Rushika; Qi, Yumin; Radolf, Justin D.; Sakamoto, Joyce M.; Sánchez-Gracia, Alejandro; Severo, Maiara S.; Silverman, Neal; Šimo, Ladislav; Tojo, Marta; Tornador, Cristian; Van Zee, Janice P.; Vázquez, Jesús; Vieira, Filipe G.; Villar, Margarita; Wespiser, Adam R.; Yang, Yunlong; Zhu, Jiwei; Arensburger, Peter; Pietrantonio, Patricia V.; Barker, Stephen C.; Shao, Renfu; Zdobnov, Evgeny M.; Hauser, Frank; Grimmelikhuijzen, Cornelis J. P.; Park, Yoonseong; Rozas, Julio; Benton, Richard; Pedra, Joao H. F.; Nelson, David R.; Unger, Maria F.; Tubio, Jose M. C.; Tu, Zhijian; Robertson, Hugh M.; Shumway, Martin; Sutton, Granger; Wortman, Jennifer R.; Lawson, Daniel; Wikel, Stephen K.; Nene, Vishvanath M.; Fraser, Claire M.; Collins, Frank H.; Birren, Bruce; Nelson, Karen E.; Caler, Elisabet; Hill, Catherine A.

2016-01-01

Ticks transmit more pathogens to humans and animals than any other arthropod. We describe the 2.1 Gbp nuclear genome of the tick, Ixodes scapularis (Say), which vectors pathogens that cause Lyme disease, human granulocytic anaplasmosis, babesiosis and other diseases. The large genome reflects accumulation of repetitive DNA, new lineages of retro-transposons, and gene architecture patterns resembling ancient metazoans rather than pancrustaceans. Annotation of scaffolds representing ∼57% of the genome, reveals 20,486 protein-coding genes and expansions of gene families associated with tick–host interactions. We report insights from genome analyses into parasitic processes unique to ticks, including host ‘questing', prolonged feeding, cuticle synthesis, blood meal concentration, novel methods of haemoglobin digestion, haem detoxification, vitellogenesis and prolonged off-host survival. We identify proteins associated with the agent of human granulocytic anaplasmosis, an emerging disease, and the encephalitis-causing Langat virus, and a population structure correlated to life-history traits and transmission of the Lyme disease agent. PMID:26856261

Experimental evidence against transmission of Hepatozoon canis by Ixodes ricinus.

Science.gov (United States)

Giannelli, Alessio; Ramos, Rafael Antonio Nascimento; Dantas-Torres, Filipe; Mencke, Norbert; Baneth, Gad; Otranto, Domenico

2013-09-01

Hepatozoon canis is among the most widespread tick-borne protozoa infecting domestic and wild carnivores. Its distribution is related to the occurrence of its major vector, the brown dog tick Rhipicephalus sanguineus. However, the role of Ixodes ricinus as a vector of H. canis has been hypothesized. In the present study, the development of H. canis was investigated in I. ricinus and R. sanguineus nymphs collected from a naturally infested dog. All I. ricinus ticks examined (n=133) were negative by cytological examination at days 20, 30, and 90 post collection, although H. canis DNA was detected in one nymph at day 20 and in 2 nymphs at day 30 post collection. On the other hand, H. canis sporogony was documented by cytology, and H. canis DNA was detected by PCR in R. sanguineus at day 30 post collection. These results indicate that H. canis sporogony does not occur in I. ricinus, but in R. sanguineus, suggesting that I. ricinus does not act as a vector of H. canis. Copyright © 2013 Elsevier GmbH. All rights reserved.

Efficacy of Plant-Derived and Synthetic Compounds on Clothing as Repellents Against Ixodes scapularis and Amblyomma americanum (Acari: Ixodidae)

Science.gov (United States)

2012-01-01

efÞcacy of the repellent deet against Aedes aegypti . J. Am. Mosq. Control Assoc. 14: 178Ð182. Robbins, P. J., and M. G. Cherniack. 1986. Review of...number of reported Lyme disease cases reached an all- time high of35,000 in 2008 (CDC 2010). The blacklegged tick, Ixodes scapularis Say, the principal...Paddock 2003, Mixson et al. 2006, Apperson et al. 2008). Repellents remain the primary method of personal protection against tick bites (Piesman and

Tick thioester-containing proteins and phagocytosis do not affect transmission of Borrelia afzelii from the competent vector ixodes ricinus

Czech Academy of Sciences Publication Activity Database

Urbanová, Veronika; Hajdušek, Ondřej; Hönig Mondeková, Helena; Šíma, Radek; Kopáček, Petr

2017-01-01

Roč. 7, MAR (2017), č. článku 73. ISSN 2235-2988 R&D Projects: GA ČR GJ15-12006Y; GA ČR GA13-11043S; GA ČR GA17-27386S; GA ČR GA17-27393S EU Projects: European Commission(XE) 602272 - ANTIDotE Institutional support: RVO:60077344 Keywords : Borrelia * complement * Ixodes * phagocytosis * thioester-containing proteins Subject RIV: EC - Immunology OBOR OECD: Immunology Impact factor: 4.300, year: 2016

The Ixodes scapularis Salivary Protein, Salp15, Prevents the Association of HIV-1 gp120 and CD4

OpenAIRE

Juncadella, Ignacio J.; Garg, Renu; Bates, Tonya C.; Olivera, Elias R.; Anguita, Juan

2007-01-01

Ixodes scapularis salivary protein, Salp15, inhibits CD4+ T cell activation by binding to the most-extracellular domains of the CD4 molecule, potentially overlapping with the gp120-binding region. We now show that Salp15 inhibits the interaction of gp120 and CD4. Furthermore, Salp15 prevents syncytia formation between HL2/3 (a stable HeLa cell line expressing the envelope protein) and CD4-expressing cells. Salp15 prevented gp120-CD4 interaction at least partially through its direct interactio...

Preliminary survey for entomopathogenic fungi associated with Ixodes scapularis>/i> (Acari: Ixodidae) in southern New York and New England, USA

Science.gov (United States)

Zhioua, Elyes; Ginsberg, Howard S.; Humber, Richard A.; LeBrun, Roger A.

1999-01-01

Free-living larval, nymphal, and adult Ixodes scapularis Say were collected from scattered locales in southern New England and New York to determine infection rates with entomopathogenic fungi. Infection rates of larvae, nymphs, males, and females were 0% (571), 0% (272), 0% (57), and 4.3% (47), respectively. Two entomopathogenic fungi were isolated from field-collected I. scapularis females from Fire Island, NY. Isolates were identified as Verticillium lecanii (Zimmermann) Viegas and Verticillium sp. (a member of the Verticillium lecanii species complex).Ixodes scapularis Say is the principal vector of Borrelia burgdorferi Johnson, Schmid, Hyde, Steigerwalt & Brenner (Burgdorfer et al. 1982, Johnson et al. 1984), the etiologic agent of Lyme disease in the northeastern and upper-midwestern United States. Control of I. scapularis is based on chemical treatment (Mather et al. 1987b; Schulze et al. 1987, 1991), environmental management (Wilson et al. 1988, Schulze et al. 1995), and habitat modification (Wilson 1986). These methods have shown variable success, and some potentially have negative environmental effects (Wilson and Deblinger 1993, Ginsberg 1994).Studies concerning natural predators, parasitoids, and pathogens of I. scapularis are rare. The use of ground-dwelling birds as tick predators has had only limited success (Duffy et al. 1992). Nymphal I. scapularis are often infected with the parasitic wasp Ixodiphagus hookeri (Howard) (Mather et al. 1987a, Hu et al. 1993, Stafford et al. 1996, Hu and Hyland 1997), but this wasp does not effectively control I. scapularis populations (Stafford et al. 1996). The entomopathogenic nematodes Steinernema carpocapsae (Weiser) and S. glaseri (Steiner) are pathogenic only to engorged female I. scapularis, and thus have limited applicability (Zhioua et al. 1995). In contrast, the entomogenous fungus Metarhizium anisopliae (Metschnikoff) Sorokin is highly pathogenic to all stages of I. scapularis, unfed as well as engorged

Borrelia burgdorferi genospecies detection by RLB hybridization in Ixodes cinus ticks from different sites of North-Eastern Poland

OpenAIRE

Justyna Dunaj; Joanna Maria Zajkowska; Maciej Kondrusik; Lise Gern; Oliver Rais; Anna Moniuszko; Sławomir Pancewicz; Renata Świerzbińska

2014-01-01

Introduction. RLB (Reverse Line Blot Hybridization) is a molecular biology technique that might be used for [i]Borrelia burgdorferi [/i]sensu lato (sl) DNA detection with genospecies specification. Among[i] B. burgdorferi[/i] sl genospecies at least 7 are regarded as pathogenic in Europe. objective. The aim of the study was to evaluate the frequency of different [i]Borrelia[/i] genospecies DNA detection in Ixodes ricinus ticks in the endemic area of North-Eastern Poland by using RLB. ...

Experimental in vitro transmission of Babesia sp. (EU1) by Ixodes ricinus.

Science.gov (United States)

Bonnet, Sarah; Brisseau, Nadine; Hermouet, Axelle; Jouglin, Maggy; Chauvin, Alain

2009-01-01

Babesia sp. (EU1), first characterized in 2003, has been implicated in human cases of babesiosis in Italy, Austria and Germany. It has been identified in roe deer and in its suspected tick vector, Ixodes ricinus, in several European countries. The aim of the present study was to validate the competence of I. ricinus as a vector of Babesia sp. (EU1) via experimental infections. For this purpose, a parasite strain isolated from roe deer was cloned in sheep erythrocytes. After experimental infections, parasite DNA was successfully amplified by PCR in both eggs and larvae originating from infected I. ricinus females and in the salivary glands of females exposed to Babesia sp. (EU1) as nymphs. We also demonstrate that infected females were able to transmit parasite DNA during a new blood meal. Together with previous epidemiological studies, these results validate I. ricinus as a competent vector for Babesia sp. (EU1).

Vertical distribution of the tick Ixodes ricinus and tick-borne pathogens in the Northern Moravian mountaines correlated with climate warming (Jeseníky mts., Czech Republic)

Czech Academy of Sciences Publication Activity Database

Daniel, M.; Materna, J.; Hönig, Václav; Metelka, L.; Danielová, V.; Harčarik, J.; Kliegrová, S.; Grubhoffer, Libor

2009-01-01

Roč. 17, č. 3 (2009), s. 139-145 ISSN 1210-7778 R&D Projects: GA MŠk(CZ) LC06009 Institutional research plan: CEZ:AV0Z60220518 Keywords : Ixodes ricinus * Borrelia burgdorferi genospecies * tick-borne encephalitis virus * vertical distribution * climate warming Subject RIV: FN - Epidemiology, Contagious Diseases ; Clinical Immunology

First molecular evidence of potentially zoonotic Babesia microti and Babesia sp. EU1 in Ixodes ricinus ticks in Belgium

OpenAIRE

Lempereur, L.; De Cat, A.; Caron, Y.; Madder, M.; Claerebout, E.; Saegerman, C.; Losson, B.

2011-01-01

We report the first molecular evidence of the presence of Babesia sp. EU1 and Babesia microti in Ixodes ricinus ticks in Belgium. A 1-year national survey collected 1005 ticks from cats and dogs. A polymerase chain reaction technique amplifying a part of the 18S rRNA gene detected Babesia spp. in 11 out of 841 selected and validated tick extracts. Subsequent sequencing identified Ba. microti (n = 3) and Babesia sp. EU1 (n = 6). This study has demonstrated a low infection rate (1.31% with 95% ...

Pathogenicity of Metarhizium anisopliae (Deuteromycetes) and permethrin to Ixodes scapularis (Acari: Ixodidae) nymphs

Science.gov (United States)

Hornbostel, V.L.; Zhioua, Elyes; Benjamin, Michael A.; Ginsberg, Howard S.; Ostfeld, Richard S.

2005-01-01

Effectiveness of the entomopathogenic fungus Metarhizium anisopliae, for controlling nymphal Ixodes scapularis, was tested in laboratory and field trials. In the laboratory, M. anisopliae (Metschnikoff) Sorokin strain ESC1 was moderately pathogenic, with an LC50 of 107 spores/ml and induced 70% mortality at 109 spores/ml. In a field study, however, 109 spores/ml M. anisopliae did not effectively control questing I. scapularis nymphs, and significant differences were not detected in pre- and post-treatment densities. For nymphs collected and returned to the laboratory for observation, mortality was low in treatment groups, ranging from 20 to 36%. To assess whether a chemical acaricide would synergistically enhance pathogenicity of the fungus, we challenged unfed nymphal I. scapularis with combinations of M. anisopliae and permethrin, a relatively safe pyrethroid acaricide, in two separate bioassays. Significant interactions between M. anisopliae and permethrin were not observed, supporting neither synergism nor antagonism.

Association of Borrelia and Rickettsia spp. and bacterial loads in Ixodes ricinus ticks.

Science.gov (United States)

Raulf, Marie-Kristin; Jordan, Daniela; Fingerle, Volker; Strube, Christina

2018-01-01

In recent years, awareness of coinfections has increased as synergistic or antagonistic effects on interacting bacteria have been observed. To date, several reports on coinfections of ticks with Rickettsia and Borrelia spp. are available. However, associations are rarely described and studies are based on rather low sample sizes. In the present study, coinfections of Ixodes ricinus with these pathogens were investigated by determining their association in a meta-analysis. A total of 5079 tick samples examined for Rickettsia and Borrelia spp. via probe-based quantitative real-time PCR in previous prevalence studies or as submitted diagnostic material were included. In Borrelia-positive ticks, genospecies were determined by Reverse Line Blot. Determination of bacterial loads resulted in an increase between developmental tick stages with highest mean bacterial loads in female ticks (7.96×10 4 in Borrelia single-infected, 4.87×10 5 in Rickettsia single-infected and 3.22×10 5 in Borrelia-Rickettsia coinfected females). The determined Borrelia-Rickettsia tick coinfection rate was 12.3% (626/5079) with a significant difference to the expected coinfection rate of 9.0% (457/5079). A significant slight association as well as correlation between Borrelia and Rickettsia were determined. In addition, a significant interrelation of the bacterial load in coinfected ticks was shown. At the level of Borrelia genospecies, significant weak associations with Rickettsia spp. were detected for B. afzelii, B. garinii/bavariensis, B. valaisiana and B. lusitaniae. The positive association provides evidence for interactions between Borrelia and Rickettsia spp. in the tick vector, presumably resulting in higher bacterial replication rates in the tick vector and possibly the reservoir host. However, coinfection may impact the vector negatively as indicated by an absent increase in coinfection rates from nymphs to adults. Future studies are needed to investigate the underlying mechanisms of

Europe-Wide Meta-Analysis of Borrelia burgdorferi Sensu Lato Prevalence in Questing Ixodes ricinus Ticks.

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Strnad, Martin; Hönig, Václav; Růžek, Daniel; Grubhoffer, Libor; Rego, Ryan O M

2017-08-01

Lyme borreliosis is the most common zoonotic disease transmitted by ticks in Europe and North America. Despite having multiple tick vectors, the causative agent, Borrelia burgdorferi sensu lato , is vectored mainly by Ixodes ricinus in Europe. In the present study, we aimed to review and summarize the existing data published from 2010 to 2016 concerning the prevalence of B. burgdorferi sensu lato spirochetes in questing I. ricinus ticks. The primary focus was to evaluate the infection rate of these bacteria in ticks, accounting for tick stage, adult tick gender, region, and detection method, as well as to investigate any changes in prevalence over time. The data obtained were compared to the findings of a previous metastudy. The literature search identified data from 23 countries, with 115,028 ticks, in total, inspected for infection with B. burgdorferi sensu lato We showed that the infection rate was significantly higher in adults than in nymphs and in females than in males. We found significant differences between European regions, with the highest infection rates in Central Europe. The most common genospecies were B. afzelii and B. garinii , despite a negative correlation of their prevalence rates. No statistically significant differences were found among the prevalence rates determined by conventional PCR, nested PCR, and real-time PCR. IMPORTANCE Borrelia burgdorferi sensu lato is a pathogenic bacterium whose clinical manifestations are associated with Lyme borreliosis. This vector-borne disease is a major public health concern in Europe and North America and may lead to severe arthritic, cardiovascular, and neurological complications if left untreated. Although pathogen prevalence is considered an important predictor of infection risk, solitary isolated data have only limited value. Here we provide summarized information about the prevalence of B. burgdorferi sensu lato spirochetes among host-seeking Ixodes ricinus ticks, the principal tick vector of

Ixodid Ticks (Acari, Ixodidae in Urban Landscapes. A review

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Akimov I. А.

2016-04-01

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.

Large scale spatial risk and comparative prevalence of Borrelia miyamotoi and Borrelia burgdorferi sensu lato in Ixodes pacificus.

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Kerry Padgett

Full Text Available Borrelia miyamotoi is a newly described emerging pathogen transmitted to people by Ixodes species ticks and found in temperate regions of North America, Europe, and Asia. There is limited understanding of large scale entomological risk patterns of B. miyamotoi and of Borreila burgdorferi sensu stricto (ss, the agent of Lyme disease, in western North America. In this study, B. miyamotoi, a relapsing fever spirochete, was detected in adult (n=70 and nymphal (n=36 Ixodes pacificus ticks collected from 24 of 48 California counties that were surveyed over a 13 year period. Statewide prevalence of B. burgdorferi sensu lato (sl, which includes B. burgdorferi ss, and B. miyamotoi were similar in adult I. pacificus (0.6% and 0.8%, respectively. In contrast, the prevalence of B. burgdorferi sl was almost 2.5 times higher than B. miyamotoi in nymphal I. pacificus (3.2% versus 1.4%. These results suggest similar risk of exposure to B. burgdorferi sl and B. miyamotoi from adult I. pacificus tick bites in California, but a higher risk of contracting B. burgdorferi sl than B. miyamotoi from nymphal tick bites. While regional risk of exposure to these two spirochetes varies, the highest risk for both species is found in north and central coastal California and the Sierra Nevada foothill region, and the lowest risk is in southern California; nevertheless, tick-bite avoidance measures should be implemented in all regions of California. This is the first study to comprehensively evaluate entomologic risk for B. miyamotoi and B. burgdorferi for both adult and nymphal I. pacificus, an important human biting tick in western North America.

Effect of the salivary gland and midgut extracts from Ixodes ricinus and Dermacentor reticulatus (Acari : Ixodidae) on the growth of Borrelia garinii in vitro

Czech Academy of Sciences Publication Activity Database

Rudolf, Ivo; Hubálek, Zdeněk

2003-01-01

Roč. 50, č. 2 (2003), s. 159-160 ISSN 0015-5683 R&D Projects: GA AV ČR IAA6022001; GA ČR GA206/00/1204; GA ČR GA206/03/0726 Institutional research plan: CEZ:AV0Z6093917 Keywords : Ixodes ricinus * Dermacentor reticulatus Subject RIV: EE - Microbiology, Virology Impact factor: 0.469, year: 2003 http://folia.paru.cas.cz/pdfs/showpdf.php?pdf=20661

Characterization of the early local immune response to Ixodes ricinus tick bites in human skin.

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Glatz, Martin; Means, Terry; Haas, Josef; Steere, Allen C; Müllegger, Robert R

2017-03-01

Little is known about the immunomodulation by tick saliva during a natural tick bite in human skin, the site of the tick-host interaction. We examined the expression of chemokines, cytokines and leucocyte markers on the mRNA levels and histopathologic changes in human skin biopsies of tick bites (n=37) compared to unaffected skin (n=9). Early tick-bite skin lesions (skin. With longer tick attachment (>24 hours), the numbers of innate immune cells and mediators (not significantly) declined, whereas the numbers of lymphocytes (not significantly) increased. Natural tick bites by Ixodes ricinus ticks initially elicit a strong local innate immune response in human skin. Beyond 24 hours of tick attachment, this response usually becomes less, perhaps because of immunomodulation by tick saliva. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Detection of Borrelia lusitaniae, Rickettsia sp. IRS3, Rickettsia monacensis, and Anaplasma phagocytophilum in Ixodes ricinus collected in Madeira Island, Portugal.

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de Carvalho, Isabel Lopes; Milhano, Natacha; Santos, Ana Sofia; Almeida, Victor; Barros, Silvia C; De Sousa, Rita; Núncio, Maria Sofia

2008-08-01

A total of 300 Ixodes ricinus ticks were tested by polymerase chain reaction (PCR) for the presence of Borrelia spp., Rickettsia spp., and Anaplasma phagocytophilum. Sequence analysis demonstrated 8 (2.7%) ticks infected with B. lusitaniae, 60 (20%) with Rickettsia spp., and 1 (0.3%) with A. phagocytophilum. Seven (2.3%) ticks were coinfected with B. lusitaniae and Rickettsia spp., 2 (0.6%) with R. monacensis, and 5 (1.7%) with Rickettsia sp. IRS3. The results of this study suggest simultaneous transmission of multiple tick-borne agents on Madeira Island, Portugal.

Abundance of Ixodes ricinus and prevalence of Borrelia burgdorferi s.l. in the nature reserve Siebengebirge, Germany, in comparison to three former studies from 1978 onwards

Czech Academy of Sciences Publication Activity Database

Schwarz, Alexandra; Hönig, Václav; Vavrušková, Zuzana; Grubhoffer, Libor; Balczun, C.; Albring, A.; Schaub, G. A.

2012-01-01

Roč. 5, NOV 21 (2012) ISSN 1756-3305 R&D Projects: GA ČR GD206/09/H026; GA MŠk(CZ) LC06009 Institutional research plan: CEZ:AV0Z60220518 Keywords : Ixodes ricinus * Tick density * Borrelia prevalence * Borrelia lusitaniae * Multiple infections * Siebengebirge Subject RIV: EC - Immunology Impact factor: 3.246, year: 2012 http://www.parasitesandvectors.com/content/5/1/268

Der-p2 (Dermatophagoides pteronyssinus) allergen-like protein from the hard tick Ixodes ricinus - a novel member of ML (MD-2-related lipid-recognition) domain protein family

Czech Academy of Sciences Publication Activity Database

Horáčková, Jana; Rudenko, Natalia; Golovchenko, Maryna; Grubhoffer, Libor

2010-01-01

Roč. 137, č. 7 (2010), s. 1139-1149 ISSN 0031-1820 R&D Projects: GA ČR(CZ) GA524/06/1479 Institutional research plan: CEZ:AV0Z60220518 Keywords : Der-p2 allergen-like protein * Ixodes ricinus * tick, * ML protein family * IgE-binding activity Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine Impact factor: 2.522, year: 2010

The paralogous salivary anti-complement proteins IRAC I and IRAC II encoded by Ixodes ricinus ticks have broad and complementary inhibitory activities against the complement of different host species.

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Schroeder, Hélène; Daix, Virginie; Gillet, Laurent; Renauld, Jean-Christophe; Vanderplasschen, Alain

2007-02-01

Several observations suggest that inhibition of the host complement alternative pathway by Ixodes tick saliva is crucial to achieve blood feeding. We recently described two paralogous anti-complement proteins called Ixodes ricinus anti-complement (IRAC) proteins I and II co-expressed in I. ricinus salivary glands. Phylogenetic analyses suggested that these sequences were diversifying by a process of positive Darwinian selection, possibly leading to molecules with different biological properties. In the present study, we tested the hypothesis that each paralogue may have different inhibitory activities against the complement of different natural host species, thereby contributing to broaden the host range of I. ricinus ticks. IRAC I and IRAC II were tested against the complement of eight I. ricinus natural host species (six mammals and two birds). The results demonstrate that IRAC I and IRAC II have broad and complementary inhibition activities against the complement of different host species. This report is the first description of paralogous anti-complement molecules encoded by a pathogen with broad and complementary inhibitory activities against the complement of different host species.

Nonspecific Bacterial Flora Isolated from the Body Surface and Inside Ixodes ricinus Ticks.

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Okła, Hubert; Sosnowska, Malwina; Jasik, Krzysztof P; Słodki, Jan; Wojtyczka, Robert D

2012-09-28

Ixodes ricinus and other representatives of the order Ixodida are vectors of typical pathogens: Borrelia burgdorferi sensu lato, Anaplasma phagocytophilium, Babesia spp., a tick-borne encephalitis virus, and other microorganisms which are important from a medical and veterinary point of view. The presented study focuses on the verification of nonspecific bacterial flora of I. ricinus. We analyzed ticks collected in a forest region in Silesia, an industrial district in Poland. Methods of classical microbiology and biochemical assays (API 20 NE test, API Staph test and MICRONAUT System) were used for isolation and identification of microorganisms living on the body surface of I. ricinus and inside ticks. The results show the presence of various bacteria on the surface and inside ticks' bodies. During the study, we isolated Acinetobacter lwoffi, Pseudomonas fluorescens, Aeromonas hydrophila, Achromobacter denitrificans, Alcaligenes faecalis, Stenotrophomonas maltophilia, Pseudomonas oryzihabitans, Micrococcus spp., Kocuria varians, Staphylococcus lentus, Kocuria kristinae, Streptococcus pneumoniae, Rhizobium radiobacter, Staphylococcus xylosus. Majority of the isolated species are non-pathogenic environmental microorganisms, but some of the isolated bacterial strains could cause severe infections.

A Novel Rickettsia Species Detected in Vole Ticks (Ixodes angustus) from Western Canada

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Anstead, Clare A.

2013-01-01

The genomic DNA of ixodid ticks from western Canada was tested by PCR for the presence of Rickettsia. No rickettsiae were detected in Ixodes sculptus, whereas 18% of the I. angustus and 42% of the Dermacentor andersoni organisms examined were PCR positive for Rickettsia. The rickettsiae from each tick species were characterized genetically using multiple genes. Rickettsiae within the D. andersoni organisms had sequences at four genes that matched those of R. peacockii. In contrast, the Rickettsia present within the larvae, nymphs, and adults of I. angustus had novel DNA sequences at four of the genes characterized compared to the sequences available from GenBank for all recognized species of Rickettsia and all other putative species within the genus. Phylogenetic analyses of the sequence data revealed that the rickettsiae in I. angustus do not belong to the spotted fever, transitional, or typhus groups of rickettsiae but are most closely related to “Candidatus Rickettsia kingi” and belong to a clade that also includes R. canadensis, “Candidatus Rickettsia tarasevichiae,” and “Candidatus Rickettsia monteiroi.” PMID:24077705

Exon variability of gene encoding glycerol-3-phosphate dehydrogenase of Ixodes ricinus ticks*

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Radulović Ž.

2010-12-01

Full Text Available We have previously found apparent differences in Gpdh allele frequences between borrelia infected and uninfected Ixodes ricinus as revealed by native gel electrophoresis of allozyme polymorphisms. The present study deals with the genetic basis of the observed allozyme polymorphism. Multiple sequence alignment of 36 Gpdh open reading frames identified a total of 40 polymorphic nucleotide sites. Of the 40 polymorphic nucleotide sites, 34 were silent (did not result in amino acid residue change, while six were active causing a change in the amino acid chain. All polymorphic amino acid sites were situated within the N-terminal NAD-binding domain, whereas the C-terminal substrate-binding domain was highly conserved. Analysis of the obtained Gpdh sequences and GPDH allozyme polymorphisms for individual ticks pointed to amino acid changes at positions 61 (glycine-to-glutamic acid, 64 (serineto- cysteine and 102 (glycine-to-arginine as a key for differential mobility of GPDH allozymes in an electric field. Our findings are discussed in the context of the molecular basis of I. ricinus host finding behavior.

Molecular Survey on Rickettsia spp., Anaplasma phagocytophilum, Borrelia burgdorferi Sensu Lato, and Babesia spp. in Ixodes ricinus Ticks Infesting Dogs in Central Italy.

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Morganti, Giulia; Gavaudan, Stefano; Canonico, Cristina; Ravagnan, Silvia; Olivieri, Emanuela; Diaferia, Manuela; Marenzoni, Maria Luisa; Antognoni, Maria Teresa; Capelli, Gioia; Silaghi, Cornelia; Veronesi, Fabrizia

2017-11-01

Dogs are a common feeding hosts for Ixodes ricinus and may act as reservoir hosts for zoonotic tick-borne pathogens (TBPs) and as carriers of infected ticks into human settings. The aim of this work was to evaluate the presence of several selected TBPs of significant public health concern by molecular methods in I. ricinus recovered from dogs living in urban and suburban settings in central Italy. A total of 212 I. ricinus specimens were collected from the coat of domestic dogs. DNA was extracted from each specimen individually and tested for Rickettsia spp., Borrelia burgdorferi sensu lato, Babesia spp., and Anaplasma phagocytophilum, using real-time and conventional PCR protocols, followed by sequencing. Sixty-one ticks (28.8%) tested positive for TBPs; 57 samples were infected by one pathogen, while four showed coinfections. Rickettsia spp. was detected in 39 specimens (18.4%), of which 32 were identified as Rickettsia monacensis and seven as Rickettsia helvetica. Twenty-two samples (10.4%) tested positive for A. phagocytophilum; Borrelia lusitaniae and Borrelia afzelii were detected in two specimens and one specimen, respectively. One tick (0.5%) was found to be positive for Babesia venatorum (EU1). Our findings reveal the significant exposure of dogs to TBPs of public health concern and provide data on the role of dogs in the circulation of I. ricinus-borne pathogens in central Italy.

Repellent activity of fractioned compounds from Chamaecyparis nootkatensis essential oil against nymphal Ixodes scapularis (Acari: Ixodidae).

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Dietrich, Gabrielle; Dolan, Marc C; Peralta-Cruz, Javier; Schmidt, Jason; Piesman, Joseph; Eisen, Rebecca J; Karchesy, Joseph J

2006-09-01

Preliminary repellent activity of 14 natural products isolated from essential oil components extracted from the heartwood of Alaska yellow cedar, Chamaecyparis nootkatensis (D. Don) Spach., were evaluated against nymphal Ixodes scapularis Say in a laboratory bioassay and compared with technical grade N,N-diethyl-3-methylbenzamide (deet). Four hours after treatment, nootkatone and valencene-13-ol had repellent concentration (RC)50 values of 0.0458 and 0.0712% (wt:vol), respectively; two additional Alaska yellow cedar compounds, nootkatone 1 --> 10 epoxide and carvacrol had reported RC50 values of 0.0858 and 0.112%, respectively. The observed RC50 value for deet was 0.0728% (wt:vol). Although not statistically significantly more active than deet, the ability of these natural products to repel ticks at relatively low concentrations may represent a potential alternative to synthetic commercial repellents.

The Presence of Borrelia miyamotoi, A Relapsing Fever Spirochaete, in Questing Ixodes ricinus in Belgium and in The Netherlands.

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Cochez, C; Heyman, P; Heylen, D; Fonville, M; Hengeveld, P; Takken, W; Simons, L; Sprong, H

2015-08-01

Borrelia miyamotoi is a tick-borne bacterium that may cause relapsing fever in humans. As this pathogen has been discovered in Europe only recently, only little is known about its local impact on human health and its spatial distribution. In this study, we show the results of PCR screenings for B. miyamotoi in flagged Ixodes ricinus from Belgium and the Netherlands. B. miyamotoi was detected in nine of thirteen, and three of five locations from the Netherlands and Belgium, respectively. These outcomes indicate that B. miyamotoi is more spread than previously thought. The mean infection rate B. miyamotoi was 1.14% for Belgium and 3.84% for the Netherlands. © 2014 Blackwell Verlag GmbH.

Effects of Japanese barberry (Ranunculales: Berberidaceae) removal and resulting microclimatic changes on Ixodes scapularis (Acari: Ixodidae) abundances in Connecticut, USA.

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Williams, Scott C; Ward, Jeffrey S

2010-12-01

Japanese barberry (Berberis thunbergii de Candolle) is a thorny, perennial, exotic, invasive shrub that is well established throughout much of the eastern United States. It can form dense thickets that limit native herbaceous and woody regeneration, alter soil structure and function, and harbor increased blacklegged tick (Ixodes scapularis Say) populations. This study examined a potential causal mechanism for the link between Japanese barberry and blacklegged ticks to determine if eliminating Japanese barberry could reduce tick abundance and associated prevalence of Borrelia burgdorferi (Johnson, Schmid, Hyde, Steigerwalt, and Brenner). Japanese barberry was controlled at five study areas throughout Connecticut; adult ticks were sampled over three years. Each area had three habitat plots: areas where barberry was controlled, areas where barberry remained intact, and areas where barberry was minimal or absent. Sampled ticks were retained and tested for B. burgdorferi presence. At two study areas, temperature and relative humidity data loggers were deployed in each of the three habitat plots over two growing seasons. Intact barberry stands had 280 ± 51 B. burgdorferi-infected adult ticks/ha, which was significantly higher than for controlled (121 ± 17/ha) and no barberry (30 ± 10/ha) areas. Microclimatic conditions where Japanese barberry was controlled were similar to areas without barberry. Japanese barberry infestations are favorable habitat for ticks, as they provide a buffered microclimate that limits desiccation-induced tick mortality. Control of Japanese barberry reduced the number of ticks infected with B. burgdorferi by nearly 60% by reverting microclimatic conditions to those more typical of native northeastern forests. © 2010 Entomological Society of America

First evidence of [i]Babesia venatorum[/i] and [i]Babesia capreoli[/i] in questing Ixodes ricinus ticks in the Czech Republic

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Kristyna Venclikova

2015-05-01

Full Text Available Introduction and objective. [i]Ixodes ricinus[/i] is the most common tick species occurring in Central Europe and it serves as a principal vector of emerging human pathogens. The aim of this study was to determine the prevalence of [i]Babesia spp[/i]. in host-seeking [i]I. ricinus[/i] in urban and natural habitats. Materials and methods. PCR was applied on samples to assess prevalence of [i]Babesia spp.[/i] in questing ixodid ticks. Sequencing was used for [i]Babesia[/i] species determination. Results. 1,473 [i]I. ricinus[/i] ticks (1,294 nymphs, 99 males and 80 females were examined for the presence of [i]Babesia spp[/i]. at the two study sites. Minimum infection rate for [i]Babesia[/i] spp. was found to be 0.5% (infected I. ricinus nymphs were only detected in the natural ecosystem. Two[i] Babesia[/i] species were identified by sequencing: [i]B. venatorum[/i] (formerly called[i] Babesia[/i] sp. EU1 and [i]B. capreoli. [/i] Conclusions. The results obtained represent the first evidence of the occurrence of [i]B. venatorum[/i] and [i]B. capreoli[/i] in host-seeking[i] I. ricinus[/i] ticks in the Czech Republic.

Thioester-containing proteins of the tick Ixodes ricinus: Gene expression, response to microbial challenge and their role in phagocytosis of the yeast Candida albicans

Czech Academy of Sciences Publication Activity Database

Urbanová, Veronika; Šíma, Radek; Šauman, Ivo; Hajdušek, Ondřej; Kopáček, Petr

2015-01-01

Roč. 48, č. 1 (2015), s. 55-64 ISSN 0145-305X R&D Projects: GA ČR GAP506/10/2136; GA ČR GA13-11043S; GA ČR GP13-27630P; GA ČR GP13-12816P; GA MŠk(CZ) EE2.3.30.0032 EU Projects: European Commission(XE) 316304 - MODBIOLIN Institutional support: RVO:60077344 Keywords : Candida albicans * Complement * Innate immunity * Phagocytosis * Thioester-containing proteins * Tick Ixodes ricinus Subject RIV: EC - Immunology Impact factor: 3.620, year: 2015

Diversity of Babesia in Ixodes ricinus ticks in Poland.

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Welc-Falęciak, R; Bajer, A; Paziewska-Harris, A; Baumann-Popczyk, A; Siński, E

2012-01-01

The aims of this study were: (1) to estimate Babesia prevalence in the most common species of tick in Poland, Ixodes ricinus, in two recreational areas (Urwitałt in the Mazury Lake District and Bielański Forest in Warsaw), and (2) to evaluate the molecular diversity of Babesia isolates in questing I. ricinus in Poland. Questing ticks were collected from vegetation in forest areas in Urwitałt near Mikołajki and in Bielański Forest (Warsaw). Purified genomic DNA was used with specific primers to amplify a fragment of the Babesia spp. 18S rRNA gene. Tick-drag indices for I. ricinus were high in both study areas, reaching somewhat higher values in Urwitałt than in Bielański Forest. The overall prevalence of Babesia spp. in examined ticks was 1.6%. In Urwitałt, two strains of B. microti were identified using rRNA sequences: the enzootic Munich strain and an isolate close to the zoonotic Jena strain. The proportion of infections due to these two strains in questing ticks reversed over a six-year period. During 3 years of study in Bielański Forest, all Babesia isolates obtained from I. ricinus were identical to Babesia sp. EU1 (B. venatorum), previously recognized as an agent of human babesiosis. This study has confirmed the presence of enzoonotic and zoonotic Babesia species/strains in the abundant human-biting tick I. ricinus in recreational areas in Poland. It has also shown that the distribution of different genotypes has changed over time, however the reasons for these fluctuations still remain to be investigated.

Identification of host blood-meal sources and Borrelia in field-collected Ixodes ricinus ticks in north-western Poland

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Beata Wodecka

2015-12-01

Full Text Available Forest animals play fundamental roles in the maintenance of [i]Ixodes ricinus[/i] and [i]Borrelia[/i] species in the forest biotope. To identify the forest vertebrate species that are host for I. ricinus and for the recognition of the reservoirs of [i]Borrelia[/i] species, the blood-meal of 325 [i]I. ricinus[/i] ticks collected at two forest sites in north-western Poland were analysed. Nested PCR was used to detect polymorphisms in a fragment of the mitochondrial 12S rRNA gene for the identification of the hosts species. The products were digested with the restriction enzymes, a combination that allows the identification of 60 vertebrate species, comprising 17 bird, 4 reptile and 39 mammalian species. Host DNA was detected in 244 (75%[i] I. ricinus[/i] individuals, with the species being detected and classified for 210 (86% samples. The restriction patterns resulted in the identification of 14 vertebrate species, including 2 species of birds, lizard, badger, rabbit, deer; most of the samples contained DNA from wild boar ([i]Sus scrofa[/i], red fox ([i]Vulpes vulpes[/i], red deer ([i]Cervus elaphus[/i] and roe deer ([i]Capreolus capreolus[/i]. Identification of Borrelia species was based on the flaB gene using nested PCR coupled to RFLP. This method allows the identification of all [i]Borrelia[/i] species transmitted by [i]I. ricinus [/i]in Europe, including [i]B. miyamotoi[/i] and 3 genetic variants of [i]B. garinii[/i]. In the studied isolates, 2 species belonging to [i]B. burgdorferi[/i] sensu lato were identified – B. [i]garinii [/i]and B. [i]afzelii[/i], and B. [i]miyamotoi,[/i] which are related to relapsing fever borreliae.

Babesia microti, human babesiosis, and Borrelia burgdorferi in Connecticut.

Science.gov (United States)

Anderson, J F; Mintz, E D; Gadbaw, J J; Magnarelli, L A

1991-12-01

Babesia microti was isolated from a white-footed mouse (Peromyscus leucopus) that was captured in southeastern Connecticut in 1988, when the first human case of babesiosis acquired in Connecticut was recognized. To date, 13 cases of babesiosis have been reported in Connecticut, the largest number of human cases reported on the mainland United States. Two of nine patients quiried remembered a prior tick bite. Since Babesia parasites are known to be vectored only by ticks, we surmise that 12 of these infections were acquired via tick bites; 1 was obtained by blood transfusion (the patient was 46 years of age) from an endemically infected donor. The ages of the patients with tick-acquired babesiosis ranged from 61 to 95 years. Two patients died with active infections, and one patient died from chronic obstructive pulmonary disease soon after treatment with clindamycin and quinine. Indirect fluorescent-antibody titers of blood samples drawn at the time of hospitalization for 11 patients and at the time of active infection for 1 asymptomatic person ranged from 1:1,024 to 1:4,096. Five of eight patients with babesiosis also had significant immunoglobulin G or immunoglobulin M titers (1:640 to 1:5,120) to Borrelia burgdorferi. B. microti was isolated in Syrian hamsters inoculated with blood from 7 of 12 patients tested and was also isolated from mice captured in six towns. The peridomestic nature of the disease was demonstrated by isolating the parasite from white-footed mice captured in or near the yards of eight different patients. Of 59 mice tested, 27 were positive and 25 were coinfected with B. burgdorferi. The isolation of B. microti from a white-footed mouse captured in north-central Connecticut (West Hartford), away from the focus of human infections in southeastern Connecticut, suggests that this pathogen may spread into other areas where Ixodes dammini, the tick vector, becomes established.

[Changes in the expression of salivary gland genes in Ixodes persulcatus (Ixodidae) depending on the stage of tick feeding].

Science.gov (United States)

Shtannikov, A V; Perovskaia, O N; Reshetniak, T V; Repolovskaia, T V; Panfertsev, E A; Sergeeva, E E; Gutova, V P; Vasil'eva, I S; Ershova, A S; Prilipov, A G; Biketov, S F; Zeidner, N

2009-01-01

By using the guanidine-isothiocyanate test, the authors isolated a summary RNA preparation from Ixodes persulcatus salivary gland extracts. Activity products of the genes responsible for the expression of some salivary proteins were first identified using the RT-PCR. It has been shown that, firstly, I. persulcatus synthesizes at least 3 transcripts homologous to the respective salivary components of the related species I. scapularis, the translation product of which is likely to be immunodominant antigens; secondly, the number of each of these transcripts, as in I. scapularis, depends on the stage of tick feeding. The changes in the expression of each transcript are specific: monotonously increasing changes in Salp 17 and cyclic ones in Salp 16, and synthesis, only when the ticks are fully ingested, in Salp 25.

Immunity against Ixodes scapularis salivary proteins expressed within 24 hours of attachment thwarts tick feeding and impairs Borrelia transmission.

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Sukanya Narasimhan

2007-05-01

Full Text Available In North America, the black-legged tick, Ixodes scapularis, an obligate haematophagus arthropod, is a vector of several human pathogens including Borrelia burgdorferi, the Lyme disease agent. In this report, we show that the tick salivary gland transcriptome and proteome is dynamic and changes during the process of engorgement. We demonstrate, using a guinea pig model of I. scapularis feeding and B. burgdorferi transmission, that immunity directed against salivary proteins expressed in the first 24 h of tick attachment - and not later - is sufficient to evoke all the hallmarks of acquired tick-immunity, to thwart tick feeding and also to impair Borrelia transmission. Defining this subset of proteins will promote a mechanistic understanding of novel I. scapularis proteins critical for the initiation of tick feeding and for Borrelia transmission.

Vector competence of the tick Ixodes ricinus for transmission of Bartonella birtlesii.

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Caroline Reis

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.

From Chemistry to Behavior. Molecular Structure and Bioactivity of Repellents against Ixodes ricinus Ticks.

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Simone Del Fabbro

Full Text Available Tick-borne zoonoses are considered as emerging diseases. Tick repellents represent an effective tool for reducing the risk of tick bite and pathogens transmission. Previous work demonstrated the repellent activity of the phenylpropanoid eugenol against Ixodes ricinus; here we investigate the relationship between molecular structure and repellency in a group of substances related to that compound. We report the biological activity of 18 compounds varying for the presence/number of several moieties, including hydroxyl and methoxy groups and carbon side-chain. Each compound was tested at different doses with a bioassay designed to measure repellency against individual tick nymphs. Both vapor pressure and chemical features of the tested compounds appeared to be related to repellency. In particular, the hydroxyl and methoxy groups as well as the side-chain on the benzene ring seem to play a role. These results are discussed in light of available data on chemical perception in ticks. In the course of the study new repellent compounds were identified; the biological activity of some of them (at least as effective as the "gold standard" repellent DEET appears to be very promising from a practical point of view.

Detection of Rickettsia helvetica in Ixodes ricinus infesting wild and domestic animals and in a botfly larva (Cephenemyia stimulator) infesting roe deer in Germany.

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Scheid, Patrick; Speck, Stephanie; Schwarzenberger, Rafael; Litzinger, Mark; Balczun, Carsten; Dobler, Gerhard

2016-10-01

Ixodes ricinus is a well-known vector of different human pathogens including Rickettsia helvetica. The role of wild mammals in the distribution and probable maintenance of Rickettsia in nature is still to be determined. We therefore investigated various parasites from different wild mammals as well as companion animals for the presence of Rickettsia. A total of 606 I. ricinus, 38 Cephenemyia stimulator (botfly larvae), one Dermacentor reticulatus, 24 Haematopinus suis (hog lice) and 30 Lipoptena cervi (deer flies) were collected from free-ranging animals during seasonal hunting, and from companion animals. Sample sites included hunting leases at three main sampling areas and five additional areas in West and Central Germany. All collected parasites were screened for Rickettsia spp. and I. ricinus were investigated for tick-borne encephalitis virus (TBEV) in addition. While no TBEV was detected, the minimum infection rate (MIR) of I. ricinus with Rickettsia was 4.1% referring to all sampling sites and up to 6.9% at the main sampling site in Koblenz area. Sequencing of a fragment of the ompB gene identified R. helvetica. Approximately one third (29.5%) of the animals carried Rickettsia-positive ticks and the MIR in ticks infesting wild mammals ranged from 4.1% (roe deer) to 9.5%. These data affirm the widespread distribution of R. helvetica in Germany. One botfly larva from roe deer also harboured R. helvetica. Botfly larvae are obligate parasites of the nasal cavity, pharynx and throat of cervids and feed on cell fragments and blood. Based on this one might hypothesise that R. helvetica likely induces rickettsemia in cervids thus possibly contributing to maintenance and distribution of this rickettsia in the field. Copyright © 2016 Elsevier GmbH. All rights reserved.

Integration of a Tick-Borne Encephalitis Virus and Borrelia burgdorferi sensu lato into Mountain Ecosystems, Following a Shift in the Altitudinal Limit of Distribution of Their Vector, Ixodes ricinus (Krkonoše Mountains, Czech Republic)

Czech Academy of Sciences Publication Activity Database

Danielová, V.; Daniel, M.; Schwarzová, L.; Materna, J.; Rudenko, Natalia; Golovchenko, Maryna; Holubová, J.; Grubhoffer, Libor; Kilian, P.

2010-01-01

Roč. 10, č. 3 (2010), s. 223-230 ISSN 1530-3667 Grant - others:GA ČR(CZ) GA310/06/1546 Institutional research plan: CEZ:AV0Z60220518 Keywords : Borrelia burgdorferi genospecies * Climate * Ixodes ricinus tick * Mountain ecosystems * Tick-borne encephalitis virus Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine Impact factor: 2.733, year: 2010

How ticks get under your skin: insertion mechanics of the feeding apparatus of Ixodes ricinus ticks

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Richter, Dania; Matuschka, Franz-Rainer; Spielman, Andrew; Mahadevan, L.

2013-01-01

The tick Ixodes ricinus uses its mouthparts to penetrate the skin of its host and to remain attached for about a week, during which time Lyme disease spirochaetes may pass from the tick to the host. To understand how the tick achieves both tasks, penetration and attachment, with the same set of implements, we recorded the insertion events by cinematography, interpreted the mouthparts’ function by scanning electron microscopy and identified their points of articulation by confocal microscopy. Our structural dynamic observations suggest that the process of insertion and attachment occurs via a ratchet-like mechanism with two distinct stages. Initially, the two telescoping chelicerae pierce the skin and, by moving alternately, generate a toehold. Subsequently, a breaststroke-like motion, effected by simultaneous flexure and retraction of both chelicerae, pulls in the barbed hypostome. This combination of a flexible, dynamic mechanical ratchet and a static holdfast thus allows the tick to solve the problem of how to penetrate skin and also remain stuck for long periods of time. PMID:24174106

Crystallization and diffraction analysis of the serpin IRS-2 from the hard tick Ixodes ricinus

International Nuclear Information System (INIS)

Kovářová, Zuzana; Chmelař, Jindřich; Šanda, Miloslav; Brynda, Jiří; Mareš, Michael; Řezáčová, Pavlína

2010-01-01

Cleavage of the serpin IRS-2 from the hard tick I. ricinus by contaminating proteolytic activity mimicked the specific processing of the serpin by its target protease and resulted in a more stable form of the serpin which produced crystals that diffracted to 1.8 Å resolution. IRS-2 from the hard tick Ixodes ricinus belongs to the serpin family of protease inhibitors. It is produced in the salivary glands of the tick and its anti-inflammatory activity suggests that it plays a role in parasite–host interaction. Recombinant IRS-2 prepared by heterologous expression in a bacterial system was crystallized using the hanging-drop vapour-diffusion method. The crystals belonged to the primitive tetragonal space group P4 3 and diffracted to 1.8 Å resolution. Mass-spectrometric and electrophoretic analyses revealed that IRS-2 was cleaved by contaminating proteases during crystallization. This processing of IRS-2 mimicked the specific cleavage of the serpin by its target protease and resulted in a more stable form (the so-called relaxed conformation), which produced well diffracting crystals. Activity profiling with specific substrates and inhibitors demonstrated traces of serine and cysteine proteases in the protein stock solution

Outer surface protein B is critical for Borrelia burgdorferi adherence and survival within Ixodes ticks.

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Girish Neelakanta

2007-03-01

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.

Aggregation in the tick Ixodes ricinus (Acari: Ixodidae): use and reuse of questing vantage points.

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Healy, John A E; Bourke, Patrick

2008-03-01

Ongoing work in oak woods in Killarney National Park in southwestern Ireland is focusing on the factors influencing the fine-scale aggregated distribution of Ixodes ricinus L. (Acari: Ixodidae) on the ground. The extent of reuse of stems of vegetation as questing points by adult ticks was determined by paint-marking stems on which ticks were found, counting and removing these ticks, and subsequently reexamining the same stems for ticks on two further occasions. Overall, an estimated 2,967 stems in 123 separate rush plants (Juncus effusus L.) were examined. Statistical analysis of the data demonstrated a highly significant reoccupancy by ticks of stems previously and recently used. Furthermore, it is shown that the extent of stem reuse by ticks is significantly and positively correlated with the numbers of ticks originally observed on those stems. Although other factors may be involved in generating clumping of ticks, the results are compatible with the proposition that aggregation of I. ricinus on the ground is pheromone-mediated. The findings are discussed in relation to what is known about the powers of lateral movement of I. ricinus on the ground and the possible implications for the performance of tick traps.

Combining public participatory surveillance and occupancy modelling to predict the distributional response of Ixodes scapularis to climate change.

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Lieske, David J; Lloyd, Vett K

2018-03-01

Ixodes scapularis, a known vector of Borrelia burgdorferi sensu stricto (Bbss), is undergoing range expansion in many parts of Canada. The province of New Brunswick, which borders jurisdictions with established populations of I. scapularis, constitutes a range expansion zone for this species. To better understand the current and potential future distribution of this tick under climate change projections, this study applied occupancy modelling to distributional records of adult ticks that successfully overwintered, obtained through passive surveillance. This study indicates that I. scapularis occurs throughout the southern-most portion of the province, in close proximity to coastlines and major waterways. Milder winter conditions, as indicated by the number of degree days model with a predictive accuracy of 0.845 (range: 0.828-0.893). Both RCP 4.5 and RCP 8.5 climate projections predict that a significant proportion of the province (roughly a quarter to a third) will be highly suitable for I. scapularis by the 2080s. Comparison with cases of canine infection show good spatial agreement with baseline model predictions, but the presence of canine Borrelia infections beyond the climate envelope, defined by the highest probabilities of tick occurrence, suggest the presence of Bbss-carrying ticks distributed by long-range dispersal events. This research demonstrates that predictive statistical modelling of multi-year surveillance information is an efficient way to identify areas where I. scapularis is most likely to occur, and can be used to guide subsequent active sampling efforts in order to better understand fine scale species distributional patterns. Copyright © 2018 The Authors. Published by Elsevier GmbH.. All rights reserved.

Spotted fever Rickettsia species in Hyalomma and Ixodes ticks infesting migratory birds in the European Mediterranean area

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2014-01-01

Background A few billion birds migrate annually between their breeding grounds in Europe and their wintering grounds in Africa. Many bird species are tick-infested, and as a result of their innate migratory behavior, they contribute significantly to the geographic distribution of pathogens, including spotted fever rickettsiae. The aim of the present study was to characterize, in samples from two consecutive years, the potential role of migrant birds captured in Europe as disseminators of Rickettsia-infected ticks. Methods Ticks were collected from a total of 14,789 birds during their seasonal migration northwards in spring 2009 and 2010 at bird observatories on two Mediterranean islands: Capri and Antikythira. All ticks were subjected to RNA extraction followed by cDNA synthesis and individually assayed with a real-time PCR targeting the citrate synthase (gltA) gene. For species identification of Rickettsia, multiple genes were sequenced. Results Three hundred and ninety-eight (2.7%) of all captured birds were tick-infested; some birds carried more than one tick. A total number of 734 ticks were analysed of which 353 ± 1 (48%) were Rickettsia-positive; 96% were infected with Rickettsia aeschlimannii and 4% with Rickettsia africae or unidentified Rickettsia species. The predominant tick taxon, Hyalomma marginatum sensu lato constituted 90% (n = 658) of the ticks collected. The remaining ticks were Ixodes frontalis, Amblyomma sp., Haemaphysalis sp., Rhipicephalus sp. and unidentified ixodids. Most ticks were nymphs (66%) followed by larvae (27%) and adult female ticks (0.5%). The majority (65%) of ticks was engorged and nearly all ticks contained visible blood. Conclusions Migratory birds appear to have a great impact on the dissemination of Rickettsia-infected ticks, some of which may originate from distant locations. The potential ecological, medical and veterinary implications of such Rickettsia infections need further examination. PMID:25011617

First molecular evidence of potentially zoonotic Babesia microti and Babesia sp. EU1 in Ixodes ricinus ticks in Belgium.

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Lempereur, Laetitia; De Cat, Ann; Caron, Yannick; Madder, Maxime; Claerebout, Edwin; Saegerman, Claude; Losson, Bertrand

2011-02-01

We report the first molecular evidence of the presence of Babesia sp. EU1 and Babesia microti in Ixodes ricinus ticks in Belgium. A 1-year national survey collected 1005 ticks from cats and dogs. A polymerase chain reaction technique amplifying a part of the 18S rRNA gene detected Babesia spp. in 11 out of 841 selected and validated tick extracts. Subsequent sequencing identified Ba. microti (n=3) and Babesia sp. EU1 (n=6). This study has demonstrated a low infection rate (1.31% with 95% CI: 0.65-2.33) of Babesia spp. carriage in I. ricinus ticks in Belgium but, for the first time, reports two potentially zoonotic species belonging to this genus. Coinfection with Ba. microti and Borrelia burgdorferi sensu stricto also was demonstrated. In addition, this study clearly demonstrates that inhibitors of polymerase chain reaction amplification are present in engorged ticks.

Infection of Ixodes ricinus by Borrelia burgdorferi sensu lato in peri-urban forests of France.

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Axelle Marchant

Full Text Available Lyme borreliosis is the most common tick-borne disease in the northern hemisphere. In Europe, it is transmitted by Ixodes ticks that carry bacteria belonging to the Borrelia burgdorferi sensu lato complex. The objective of this work was to explore eco-epidemiological factors of Lyme borreliosis in peri-urban forests of France (Sénart, Notre-Dame and Rambouillet. We investigated whether the introduction of Tamias sibiricus in Sénart could alter the density of infected ticks. Moreover, the density and tick infection were investigated according to the tree species found in various patches of Sénart forest. For this purpose, ticks were sampled during 3 years. In the Sénart forest, the density of nymph and adult ticks showed no significant difference between 2008, 2009 and 2011. The nymph density varied significantly as a function of the month of collection. Regarding the nymphs, a higher rate of infection and infected density were found in 2009. Plots with chipmunks (C presented a lower density of both nymphs and adult ticks than plots without chipmunks (NC did. A higher rate of infection of nymphs with Borrelia was seen in C plots. The prevalence of the various species of Borrelia was also found to vary between C and NC plots with the year of the collect. The presence of chestnut trees positively influenced the density of both nymphs and adults. The infected nymph density showed a significant difference depending on the peri-urban forest studied, Sénart being higher than Rambouillet. The prevalence of Borrelia species also differed between the various forests studied. Concerning the putative role that Tamias sibiricus may play in the transmission of Borrelia, our results suggest that its presence is correlated with a higher rate of infection of questing ticks by Borrelia genospecies and if its population increases, it could play a significant role in the risk of transmission of Lyme borreliosis.

Experimental use of two standard tick collection methods to evaluate the relative effectiveness of several plant-derived and synthetic repellents against Ixodes scapularis and Amblyomma americanum (Acari: Ixodidae).

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Schulze, Terry L; Jordan, Robert A; Dolan, Marc C

2011-12-01

We used two standard tick collection methods to test the relative effectiveness of two natural product compounds (nootkatone and carvacrol, classified as an eremophilene sesquiterpene and a monoterpene, respectively, that are derived from botanical sources) with commercially-available plant-derived (EcoSMART Organic Insect Repellent, comprised of plant essential oils) and permethrin-based (Repel Permanone) repellents against Ixodes scapularis Say and Amblyomma americanum (L.). Cloth drags were equally effective in sampling both species of host-seeking nymphs, whereas CO, traps attracted primarily A. americanum. All four repellents performed well on drags, with nootkatone and Permanone Repel (100% repelled through 14 d) slightly more effective than carvacrol and EcoSMART (90.7% and 97.7% repelled at 14 d, respectively) at repelling I. scapularis nymphs. Although the same trend in percent repellency was noted in the CO2 trap trial against both A. americanum nymphs and adults, EcoSMART outperformed Permanone in repelling A. Americanum nymphs after 14 d in the drag trial. Generally, the effectiveness of all repellents tested declined over time. The use of tick drags and CO2 traps was rapid, inexpensive, and easy to use in determining the relative effectiveness of repellents in the field.

Chemical composition and repellency of essential oils from four medicinal plants against Ixodes ricinus nymphs (Acari: Ixodidae).

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El-Seedi, Hesham R; Khalil, Nasr S; Azeem, Muhammad; Taher, Eman A; Göransson, Ulf; Pålsson, Katinka; Borg-Karlson, Anna-Karin

2012-09-01

In our search for effective tick repellents from plant origin, we investigated the effect of essential oils of four medicinal and culinary plants belonging to the family Lamiaceae on nymphs of the tick Ixodes ricinus (L.). The essential oils of the dry leaves of Rosmarinus officinalis (Rosemary) (L.), Mentha spicata (Spearmint) (L.), Origanum majorana (Majoram) (L.), and Ocimum basilicum (Basil) (L.) were isolated by steam distillation and 15 microg/cm2 concentration of oils was tested against ticks in a laboratory bioassay. The oils of R. officinalis, M. spicata, and O. majorana showed strong repellency against the ticks 100, 93.2, and 84.3%, respectively, whereas O. basilicum only showed 64.5% repellency. When tested in the field, the oils of R. officinalis and M. spicata showed 68.3 and 59.4% repellency at a concentration of 6.5 microg/cm2 on the test cloths. The oils were analyzed by gas chromatography mass spectrometry and the major compounds from the most repellent oils were 1,8-cineole, camphor, linalool, 4-terpineol, borneol, and carvone.

Bat ticks revisited: Ixodes ariadnae sp. nov. and allopatric genotypes of I. vespertilionis in caves of Hungary.

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Hornok, Sándor; Kontschán, Jenő; Kováts, Dávid; Kovács, Richárd; Angyal, Dorottya; Görföl, Tamás; Polacsek, Zsolt; Kalmár, Zsuzsa; Mihalca, Andrei D

2014-04-27

In Europe two ixodid bat tick species, Ixodes vespertilionis and I. simplex were hitherto known to occur. Bat ticks were collected from cave walls and bats in Hungary. Their morphology and genotypes were compared with microscopy and conventional PCR (followed by sequencing), respectively. A year-round activity of I. vespertilionis was observed. Molecular analysis of the cytochrome oxidase subunit I (COI) gene of twenty ticks from different caves showed that the occurrence of the most common genotype was associated with the caves close to each other. A few specimens of a morphologically different tick variant were also found and their COI analysis revealed only 86-88% sequence homology with I. simplex and I. vespertilionis, respectively. The microenvironment of caves (well separated from each other) appears to support the existence of allopatric I. vespertilionis COI genotypes, most likely related to the distance between caves and to bat migration over-bridging certain caves. The name I. ariadnae sp. nov. is given to the new tick species described here for the first time.

On the complexity of measuring forests microclimate and interpreting its relevance in habitat ecology: the example of Ixodes ricinus ticks

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Denise Boehnke

2017-11-01

Full Text Available Abstract Background Ecological field research on the influence of meteorological parameters on a forest inhabiting species is confronted with the complex relations between measured data and the real conditions the species is exposed to. This study highlights this complexity for the example of Ixodes ricinus. This species lives mainly in forest habitats near the ground, but field research on impacts of meteorological conditions on population dynamics is often based on data from nearby official weather stations or occasional in situ measurements. In addition, studies use very different data approaches to analyze comparable research questions. This study is an extensive examination of the methodology used to analyze the impact of meteorological parameters on Ixodes ricinus and proposes a methodological approach that tackles the underlying complexity. Methods Our specifically developed measurement concept was implemented at 25 forest study sites across Baden-Württemberg, Germany. Meteorological weather stations recorded data in situ and continuously between summer 2012 and autumn 2015, including relative humidity measures in the litter layer and different heights above it (50 cm, 2 m. Hourly averages of relative humidity were calculated and compared with data from the nearest official weather station. Results Data measured directly in the forest can differ dramatically from conditions recorded at official weather stations. In general, data indicate a remarkable relative humidity decrease from inside to outside the forest and from ground to atmosphere. Relative humidity measured in the litter layer were, on average, 24% higher than the official data and were much more balanced, especially in summer. Conclusions The results illustrate the need for, and benefit of, continuous in situ measurements to grasp the complex relative humidity conditions in forests. Data from official weather stations do not accurately represent actual humidity conditions in

On the complexity of measuring forests microclimate and interpreting its relevance in habitat ecology: the example of Ixodes ricinus ticks.

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Boehnke, Denise; Gebhardt, Reiner; Petney, Trevor; Norra, Stefan

2017-11-06

Ecological field research on the influence of meteorological parameters on a forest inhabiting species is confronted with the complex relations between measured data and the real conditions the species is exposed to. This study highlights this complexity for the example of Ixodes ricinus. This species lives mainly in forest habitats near the ground, but field research on impacts of meteorological conditions on population dynamics is often based on data from nearby official weather stations or occasional in situ measurements. In addition, studies use very different data approaches to analyze comparable research questions. This study is an extensive examination of the methodology used to analyze the impact of meteorological parameters on Ixodes ricinus and proposes a methodological approach that tackles the underlying complexity. Our specifically developed measurement concept was implemented at 25 forest study sites across Baden-Württemberg, Germany. Meteorological weather stations recorded data in situ and continuously between summer 2012 and autumn 2015, including relative humidity measures in the litter layer and different heights above it (50 cm, 2 m). Hourly averages of relative humidity were calculated and compared with data from the nearest official weather station. Data measured directly in the forest can differ dramatically from conditions recorded at official weather stations. In general, data indicate a remarkable relative humidity decrease from inside to outside the forest and from ground to atmosphere. Relative humidity measured in the litter layer were, on average, 24% higher than the official data and were much more balanced, especially in summer. The results illustrate the need for, and benefit of, continuous in situ measurements to grasp the complex relative humidity conditions in forests. Data from official weather stations do not accurately represent actual humidity conditions in forest stands and the explanatory power of short period and

Efficacy of plant-derived and synthetic compounds on clothing as repellents against Ixodes scapularis and Amblyomma americanum (Acari: Ixodidae).

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Jordan, Robert A; Schulze, Terry L; Dolan, Marc C

2012-01-01

We conducted field trials to compare the relative repellent activity of two natural product compounds (nootkatone and carvacrol) with commercially available plant-derived (EcoSMART organic insect repellent) and permethrin-based (Repel Permanone) repellents against adult Ixodes scapularis Say and Amblyomma americanum (L.) (Acari: Ixodidae) by using treated coveralls. One day after treatment, nootkatone and carvacrol provided 100% repellency of I. scapularis adults, with nootkatone maintaining complete protection through 3 d, whereas carvacrol showed steadily declining repellency against I. scapularis during the 7-d course of the trials. Nootkatone was at least as effective against host-seeking A. americanum as against I. scapularis through 3 d. Carvacrol provided little protection against A. americanum adults. Both natural compounds performed well initially in comparison with the commercial products. After 7 d, nootkatone was the most effective against both species followed in order of activity by Permanone, EcoSMART, and carvacrol. Nootkatone seems to have offer considerable potential as a clothing repellent against both I. scapularis and A. americanum.

Molecular characterization of novel sulfotransferases from the tick, Ixodes scapularis

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King Roberta S

2011-06-01

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

Prevalence of infection with Rickettsia helvetica in Ixodes ricinus ticks feeding on non-rickettsiemic rodent hosts in sylvatic habitats of west-central Poland.

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Biernat, Beata; Stańczak, Joanna; Michalik, Jerzy; Sikora, Bożena; Wierzbicka, Anna

2016-02-01

Ixodes ricinus is the most prevalent and widely distributed tick species in European countries and plays a principal role in transmission of a wide range of microbial pathogens. It is also a main vector and reservoir of Rickettsia spp. of the spotted fever group with the infection level ranging in Poland from 1.3% to 11.4%. Nevertheless, little research has been conducted so far to identify reservoir hosts for these pathogens. A survey was undertaken to investigate the presence of Rickettsia spp. in wild small rodents and detached I. ricinus. Rodents, Apodemus flavicollis mice and Myodes glareolus voles were captured in typically sylvatic habitats of west-central Poland. Blood samples and collected ticks were analyzed by conventional, semi-nested and nested PCRs. Rickettsial species were determined by sequence analysis of obtained fragments of gltA and 16S rRNA genes. A total of 2339 immature I. ricinus (mostly larvae) were collected from 158 animals. Proportion of hosts carrying ticks was 84%, being higher for A. flavicollis than for M. glareolus. Rickettsia helvetica, the only species identified, was detected in 8% of 12 nymphs and in at least 10.7% (MIR) of 804 larvae investigated. Prevalence of infected ticks on both rodent species was comparable (10.8 vs. 9%). None of blood samples tested was positive for Rickettsia spp. The results showed that in sylvatic habitats the level of infestation with larval I. ricinus was higher in A. flavicollis mice in comparison with M. glareolus voles. They show that R. helvetica frequently occurred in ticks feeding on rodents. Positive immature ticks were collected from non-rickettsiemic hosts what might suggest a vertical route of their infection (transovarial and/or transstadial) or a very short-lasting rickettsiemia in rodents. A natural vertebrate reservoir host for R. helvetica remains to be determined. Copyright © 2015 Elsevier GmbH. All rights reserved.

Gene organization of a novel defensin of Ixodes ricinus: first annotation of an intron/exon structure in a hard tick defensin gene and first evidence of the occurrence of two isoforms of one member of the arthropod defensin family

Czech Academy of Sciences Publication Activity Database

Rudenko, Natalia; Golovchenko, Maryna; Grubhoffer, Libor

2007-01-01

Roč. 16, č. 4 (2007), s. 501-507 ISSN 0962-1075 R&D Projects: GA MŠk(CZ) LC06009; GA ČR(CZ) GA524/06/1479 Institutional research plan: CEZ:AV0Z60220518 Keywords : defensin * Ixodes ricinus * intron/exon structure * immune response * antimicrobial activity Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine Impact factor: 2.787, year: 2007

Characterization of Ixophilin, a thrombin inhibitor from the gut of Ixodes scapularis.

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Sukanya Narasimhan

Full Text Available Ixodes scapularis, the black-legged tick, vectors several human pathogens including Borrelia burgdorferi, the agent of Lyme disease in North America. Pathogen transmission to the vertebrate host occurs when infected ticks feed on the mammalian host to obtain a blood meal. Efforts to understand how the tick confronts host hemostatic mechanisms and imbibes a fluid blood meal have largely focused on the anticoagulation strategies of tick saliva. The blood meal that enters the tick gut remains in a fluid state for several days during the process of feeding, and the role of the tick gut in maintaining the blood-meal fluid is not understood. We now demonstrate that the tick gut produces a potent inhibitor of thrombin, a key enzyme in the mammalian coagulation cascade. Chromatographic fractionation of engorged tick gut proteins identified one predominant thrombin inhibitory activity associated with an approximately 18 kDa protein, henceforth referred to as Ixophilin. The ixophilin gene was preferentially transcribed in the guts of feeding nymphs. Expression began after 24 hours of feeding, coincident with the flow of host blood into the tick gut. Immunity against Ixophilin delayed tick feeding, and decreased feeding efficiency significantly. Surprisingly, immunity against Ixophilin resulted in increased Borrelia burgdorferi transmission to the host, possibly due to delayed feeding and increased transmission opportunity. These observations illuminate the potential drawbacks of targeting individual tick proteins in a functional suite. They also underscore the need to identify the "anticoagulome" of the tick gut, and to prioritize a critical subset of anticoagulants that could be targeted to efficiently thwart tick feeding, and block pathogen transmission to the vertebrate host.

Lyme disease in Wisconsin: epidemiologic, clinical, serologic, and entomologic findings.

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Davis, J P; Schell, W L; Amundson, T E; Godsey, M S; Spielman, A; Burgdorfer, W; Barbour, A G; LaVenture, M; Kaslow, R A

1984-01-01

In 1980-82, 80 individuals (71 Wisconsin residents) had confirmed Lyme disease (LD-c) reported; 39 additional patients had probable or possible LD. All cases of LD-c occurred during May-November; 73 percent occurred during June-July; 54 (68 percent) occurred in males. The mean age was 38.7 years (range, 7-77 years). Among LD-c patients, likely exposure to the presumed vector Ixodes dammini (ID) occurred in 22 different Wisconsin counties. Antibodies to the ID spirochete that causes LD occurred in 33 of 49 LD-c cases versus 0 of 18 in ill controls (p less than .001) and in 13 of 26 LD-c cases treated with penicillin or tetracycline versus 16 of 19 LD-c cases not treated. Early antibiotic therapy appears to blunt the antibody response to the ID spirochete. Regional tick surveys conducted in Wisconsin during each November in 1979-82 have demonstrated regions of greater density of ID. Utilizing comparable tick collection in these surveys, increases were noted in the percentage of deer with ID from 24 percent (31/128) in 1979 to 38 percent (58/152) in 1981, in the standardized mean value of ID/deer from 1.0 in 1979 to 2.2 in 1981, in the percentage of ID of the total ticks collected from 13 percent in 1979 to 71 percent in 1981, or in the ratio of ID to Dermacentor albipictus ticks from 0.14 in 1979 to 2.44 in 1981. However, a reduction in the density of ID/deer was noted generally throughout Wisconsin in 1982 when compared to 1981. LD is widespread in Wisconsin, with ecologic and clinical features similar to those occurring along the eastern seaboard.

The occurrence of Spotted Fever Group (SFG) Rickettsiae in Ixodes ricinus ticks (Acari: Ixodidae) in northern Poland.

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Stańczak, Joanna

2006-10-01

Ixodes ricinus, the most commonly observed tick species in Poland, is known vector of microorganisms pathogenic for humans as TBE virus, Borrelia burgdorferi s.1., Anaplasma phagocytophilum and Babesia sp. in this country. Our study aimed to find out whether this tick can also transmit also rickettsiae of the spotted fever group (SFG). DNA extracts from 560 ticks (28 females, 34 males, and 488 nymphs) collected in different wooded areas in northern Poland were examined by PCR for the detection of Rickettsia sp., using a primer set RpCS.877p and RpCS.1258n designated to amplify a 381-bp fragment of gltA gene. A total of 2.9% ticks was found to be positive. The percentage of infected females and males was comparable (10.5% and 11.8%, respectively) and 6.6-7.6 times higher than in nymphs (1.6%). Sequences of four PCR-derived DNA fragments (acc. no. DQ672603) demonstrated 99% similarity with the sequence of Rickettsia helvetica deposited in GenBank. The results obtained suggest the possible role of I. ricinus as a source of a microorganism, which recently has been identified as an agent of human rickettsioses in Europe.

Identification of Novel Viruses in Amblyomma americanum, Dermacentor variabilis, and Ixodes scapularis Ticks

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Sameroff, Stephen; Tagliafierro, Teresa; Jain, Komal; Williams, Simon H.; Cucura, D. Moses; Rochlin, Ilia; Monzon, Javier; Carpi, Giovanna; Tufts, Danielle; Diuk-Wasser, Maria; Brinkerhoff, Jory; Lipkin, W. Ian

2018-01-01

ABSTRACT Ticks carry a wide range of known human and animal pathogens and are postulated to carry others with the potential to cause disease. Here we report a discovery effort wherein unbiased high-throughput sequencing was used to characterize the virome of 2,021 ticks, including Ixodes scapularis (n = 1,138), Amblyomma americanum (n = 720), and Dermacentor variabilis (n = 163), collected in New York, Connecticut, and Virginia in 2015 and 2016. We identified 33 viruses, including 24 putative novel viral species. The most frequently detected viruses were phylogenetically related to members of the Bunyaviridae and Rhabdoviridae families, as well as the recently proposed Chuviridae. Our work expands our understanding of tick viromes and underscores the high viral diversity that is present in ticks. IMPORTANCE The incidence of tick-borne disease is increasing, driven by rapid geographical expansion of ticks and the discovery of new tick-associated pathogens. The examination of the tick microbiome is essential in order to understand the relationship between microbes and their tick hosts and to facilitate the identification of new tick-borne pathogens. Genomic analyses using unbiased high-throughput sequencing platforms have proven valuable for investigations of tick bacterial diversity, but the examination of tick viromes has historically not been well explored. By performing a comprehensive virome analysis of the three primary tick species associated with human disease in the United States, we gained substantial insight into tick virome diversity and can begin to assess a potential role of these viruses in the tick life cycle. PMID:29564401

Diversity of Babesia and Rickettsia species in questing Ixodes ricinus: a longitudinal study in urban, pasture, and natural habitats.

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Overzier, Evelyn; Pfister, Kurt; Thiel, Claudia; Herb, Ingrid; Mahling, Monia; Silaghi, Cornelia

2013-08-01

In a previous study, our group investigated the Babesia spp. prevalence in questing Ixodes ricinus ticks from nine city parks in South Germany in the years 2009 and 2010. We showed predominant prevalence of B. venatorum (in previous literature also known as Babesia sp. EU1), especially in those parks in a more natural condition and with occurrence of large wild animals, such as roe deer. To obtain longitudinal data and to broaden the knowledge about this pathogen, further investigations were carried out in 2011 and 2012 in four of those city parks. Two additional habitat types were chosen for comparison of prevalence data and species analysis focusing on occurrence of potential reservoir hosts. A total of 10,303 questing I. ricinus were collected in four city parks, a pasture, and a natural area in Bavaria, and a representative number of samples were investigated for prevalence of DNA of Babesia spp. (n=4381) and Rickettsia spp. (n=2186) by PCR. In the natural and pasture area, a significantly higher Babesia spp. prevalence compared to the urban area was detected. The natural area revealed sequences of B. microti, B. venatorum, and B. capreoli. In the pasture and urban habitat, predominantly B. venatorum was found, whereas B. capreoli was less frequent and only one B. microti-infected tick was found. All B. microti sequences were 100% identical to the zoonotic Jena/Germany strain. For Rickettsia spp., the significantly highest prevalence was also detected in the natural and pasture areas, whereas lower prevalence was found in the urban area. Sequence analysis revealed R. helvetica (98%) and R. monacensis (2%). Prevalence rates and occurrence of Babesia spp. and Rickettsia spp. differed in urban, pasture and natural sites, most likely depending on the habitat structure (natural or cultivated) and therefore on the appearance and availability of reservoir hosts like roe deer or small mammals.

Molecular analysis of Ixodes rugicollis, Candidatus Neoehrlichia sp. (FU98) and a novel Babesia genotype from a European badger (Meles meles).

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Hornok, Sándor; Trauttwein, Klaudia; Takács, Nóra; Hodžić, Adnan; Duscher, Georg Gerhard; Kontschán, Jenő

2017-01-01

The European badger (Meles meles) is a widespread mammal in most countries of the European continent, with increasingly recognized veterinary/medical importance owing to its preferred habitats (including pastures and urban environments), broad spectrum of food items, and role as a game hunting target. However, ticks and tick-borne pathogens associated with badgers are only partly known, and most of them have not yet been analysed with molecular biological methods The aim of this study was to perform molecular taxonomic analysis of ticks collected from a road-killed European badger, as well as to molecularly investigate its ticks and blood sample for the presence of Anaplasmataceae and piroplasms. Ticks from the badger were morphologically identified as females of Ixodes rugicollis. Based on its cytochrome oxidase subunit I (COI) and 16S rRNA sequences, I. rugicollis phylogenetically clustered together with I. lividus and I. arboricola, i.e. other members of the subgenus Pholeoixodes. The blood sample of the badger contained the DNA of Candidatus Neoehrlichia sp. (FU98) recently identified in red fox in Austria and the Czech Republic. This genotype is most closely related to Ca. N. lotoris (from raccoons in North America), and has lower sequence identity with the I. ricinus-transmitted zoonotic agent, Ca. N. mikurensis found in Eurasia. In the blood of the badger and in one female I. rugicollis, the DNA of a new Babesia genotype was also present, which differed from a piroplasm detected in M. meles in Spain, and clustered phylogenetically in the B. microti clade. Phylogenetic analysis of I. rugicollis (based on two genetic markers) confirms its status in subgenus Pholeoixodes. Ca. Neoehrlichia sp. (FU98) was identified for the first time in M. meles and in Hungary. In addition, a molecularly previously not yet characterized Babesia genotype occurs in badgers in Central Europe. Copyright © 2016 Elsevier GmbH. All rights reserved.

Variable strength of forest stand attributes and weather conditions on the questing activity of Ixodes ricinus ticks over years in managed forests.

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Ralf Lauterbach

Full Text Available Given the ever-increasing human impact through land use and climate change on the environment, we crucially need to achieve a better understanding of those factors that influence the questing activity of ixodid ticks, a major disease-transmitting vector in temperate forests. We investigated variation in the relative questing nymph densities of Ixodes ricinus in differently managed forest types for three years (2008-2010 in SW Germany by drag sampling. We used a hierarchical Bayesian modeling approach to examine the relative effects of habitat and weather and to consider possible nested structures of habitat and climate forces. The questing activity of nymphs was considerably larger in young forest successional stages of thicket compared with pole wood and timber stages. Questing nymph density increased markedly with milder winter temperatures. Generally, the relative strength of the various environmental forces on questing nymph density differed across years. In particular, winter temperature had a negative effect on tick activity across sites in 2008 in contrast to the overall effect of temperature across years. Our results suggest that forest management practices have important impacts on questing nymph density. Variable weather conditions, however, might override the effects of forest management practices on the fluctuations and dynamics of tick populations and activity over years, in particular, the preceding winter temperatures. Therefore, robust predictions and the detection of possible interactions and nested structures of habitat and climate forces can only be quantified through the collection of long-term data. Such data are particularly important with regard to future scenarios of forest management and climate warming.

Essential oils of aromatic Egyptian plants repel nymphs of the tick Ixodes ricinus (Acari: Ixodidae).

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El-Seedi, Hesham R; Azeem, Muhammad; Khalil, Nasr S; Sakr, Hanem H; Khalifa, Shaden A M; Awang, Khalijah; Saeed, Aamer; Farag, Mohamed A; AlAjmi, Mohamed F; Pålsson, Katinka; Borg-Karlson, Anna-Karin

2017-09-01

Due to the role of Ixodes ricinus (L.) (Acari: Ixodidae) in the transmission of many serious pathogens, personal protection against bites of this tick is essential. In the present study the essential oils from 11 aromatic Egyptian plants were isolated and their repellent activity against I. ricinus nymphs was evaluated Three oils (i.e. Conyza dioscoridis L., Artemisia herba-alba Asso and Calendula officinalis L.) elicited high repellent activity in vitro of 94, 84.2 and 82%, respectively. The most active essential oil (C. dioscoridis) was applied in the field at a concentration of 6.5 µg/cm 2 and elicited a significant repellent activity against I. ricinus nymphs by 61.1%. The most repellent plants C. dioscoridis, C. officinalis and A. herba-alba yielded essential oils by 0.17, 0.11 and 0.14%, respectively. These oils were further investigated using gas chromatography-mass spectrometry analysis. α-Cadinol (10.7%) and hexadecanoic acid (10.5%) were the major components of C. dioscoridis whereas in C. officinalis, α-cadinol (21.2%) and carvone (18.2%) were major components. Artemisia herba-alba contained piperitone (26.5%), ethyl cinnamate (9.5%), camphor (7.7%) and hexadecanoic acid (6.9%). Essential oils of these three plants have a potential to be used for personal protection against tick bites.

Long-Term Effects of Berberis thunbergii (Ranunculales: Berberidaceae) Management on Ixodes scapularis (Acari: Ixodidae) Abundance and Borrelia burgdorferi (Spirochaetales: Spirochaetaceae) Prevalence in Connecticut, USA.

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Williams, Scott C; Linske, Megan A; Ward, Jeffrey S

2017-12-08

Japanese barberry (Berberis thunbergii de Candolle; Ranunculales: Berberidaceae) is an exotic invasive shrub that escaped cultivation in the United States and is now permanently established in many eastern and midwestern states. This study examined the long-term impacts of Japanese barberry management on blacklegged tick (Ixodes scapularis Say; Acari: Ixodidae) abundances and associated prevalence of Borrelia burgdorferi (Johnson, Schmid, Hyde, Steigerwalt, and Brenner; Spirochaetales: Spirochaetaceae), the etiologic agent of Lyme disease. At six locations across Connecticut, adult I. scapularis were sampled for up to 10 yr. At each location, we sampled an area where barberry infestations were unmanipulated, adjacent areas where barberry was virtually nonexistent, and areas where barberry was managed utilizing a variety of techniques. Barberry management reduced B. burgdorferi-infected adult I. scapularis (BBIAIS) abundances (191/ha ± 64 SE) over 6 yr to statistically indifferent from that of no barberry areas (140/ha ± 47 SE; P = 0.080) and significantly less than intact barberry stands (458/ha ± 80 SE; P = 0.026). Over 9 yr, BBIAIS abundances in managed barberry remained lower than intact barberry stands (P = 0.037), but increased to be significantly greater than no barberry areas (P = 0.007) as cover increased over time. Longer-term data further document that Japanese barberry infestations are favorable habitat for I. scapularis. Control of Japanese barberry and other invasives should be at least on a 5-yr rotation to maintain low levels of invasive cover and eliminate humidity refugia to expose juvenile I. scapularis to more hostile environmental conditions in the interest of public health. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Ticks and tick-borne pathogens in South Bohemia (Czech Republic) – Spatial variability in Ixodes ricinus abundance, Borrelia burgdorferi and tick-borne encephalitis virus prevalence

Czech Academy of Sciences Publication Activity Database

Hönig, Václav; Švec, P.; Halas, Petr; Vavrušková, Zuzana; Tykalová, Hana; Kilian, Patrik; Vetišková, Vendula; Dorňáková, Veronika; Štěrbová, Jarmila; Šimonová, Zuzana; Erhart, Jan; Štěrba, Ján; Golovchenko, Maryna; Rudenko, Natalia; Grubhoffer, Libor

2015-01-01

Roč. 6, č. 5 (2015), s. 559-567 ISSN 1877-959X R&D Projects: GA ČR GD206/09/H026; GA MŠk(CZ) EE2.3.30.0032 Institutional support: RVO:68145535 ; RVO:60077344 Keywords : tick * tick-borne encephalitis * ixodes ricinus * environmental factors * lyme borreliosis Subject RIV: FN - Epidemiology, Contagious Diseases ; Clinical Immunology; EB - Genetics ; Molecular Biology (BC-A) Impact factor: 2.690, year: 2015 http://ac.els-cdn.com/S1877959X15000783/1-s2.0-S1877959X15000783-main.pdf?_tid=8785a702-8de3-11e5-bd28-00000aacb35f&acdnat=1447844587_a91b4e4d404a70fda98b06e4950edb11

Detection of Rickettsia helvetica and Candidatus R. tarasevichiae DNA in Ixodes persulcatus ticks collected in Northeastern European Russia (Komi Republic).

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Kartashov, Mikhail Yu; Glushkova, Ludmila I; Mikryukova, Tamara P; Korabelnikov, Igor V; Egorova, Yulia I; Tupota, Natalia L; Protopopova, Elena V; Konovalova, Svetlana N; Ternovoi, Vladimir A; Loktev, Valery B

2017-06-01

The number of tick-borne infections in the northern European regions of Russia has increased considerably in the last years. In the present study, 676 unfed adult Ixodes persulcatus ticks were collected in the Komi Republic from 2011 to 2013 to study tick-borne rickettsioses. Rickettsia spp. DNA was detected by PCR in 51 (7.6%) ticks. The nucleotide sequence analysis of gltA fragments (765bp) from 51 ticks indicated that 60.8% and 39.2% of the ticks were infected with Rickettsia helvetica and Candidatus R. tarasevichiae, respectively. The gltA fragments showed 100% identity with those of Candidatus R. tarasevichiae previously discovered in Siberia and China, whereas R. helvetica showed 99.9% sequence identity with European isolates. The ompB had 8 nucleotide substitutions, 6 of which resulted in amino acid substitutions. In the sca9 gene, 3 nucleotide substitutions were detected, and only one resulted in amino acid substitution. The smpA, ompW, and β-lactamase genes of R. helvetica also showed a high level of sequence identity. Copyright © 2017 Elsevier GmbH. All rights reserved.

Characterization of Ixodes ricinus Fibrinogen-Related Proteins (Ixoderins Discloses Their Function in the Tick Innate Immunity

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Helena Honig Mondekova

2017-12-01

Full Text Available Ticks are important vectors of serious human and animal disease-causing organisms, but their innate immunity can fight invading pathogens and may have the ability to reduce or block transmission to mammalian hosts. Lectins, sugar-binding proteins, can distinguish between self and non-self-oligosaccharide motifs on pathogen surfaces. Although tick hemolymph possesses strong lectin activity, and several lectins have already been isolated and characterized, little is known about the implementation of these molecules in tick immunity. Here, we have described and functionally characterized fibrinogen-related protein (FReP lectins in Ixodes ticks. We have shown that the FReP family contains at least 27 genes (ixoderins, ixo that could, based on phylogenetic and expression analyses, be divided into three groups with differing degrees of expansion. By using RNA interference-mediated gene silencing (RNAi we demonstrated that IXO-A was the main lectin in tick hemolymph. Further, we found that ixoderins were important for phagocytosis of Gram-negative bacteria and yeasts by tick hemocytes and that their expression was upregulated upon injection of microbes, wounding, or after blood feeding. However, although the tick hemocytes could swiftly phagocytose Borrelia afzelii spirochetes, their transmission and burst of infection in mice was not altered. Our results demonstrate that tick ixoderins are crucial immune proteins that work as opsonins in the tick hemolymph, targeting microbes for phagocytosis or lysis.

An ELISA to Detect Serum Antibodies to the Salivary Gland Toxin of Ixodes holocyclus Neumann in Dogs and Rodents

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S. Hall-Mendelin

2011-01-01

Full Text Available The Ixodes holocyclus tick causes paralysis in up to 10,000 companion and domestic animals each year in Australia. Treatment requires the removal of the parasite and the administration of a commercial tick antiserum that is prepared from hyperimmune dogs. Each batch of this serum is initially tested for toxin-neutralising potency in a mouse bioassay that is expensive, time consuming, and subjective. With the aim of developing a rapid in vitro assay to replace the bioassay, we used a partially purified antigen prepared from I. holocyclus salivary glands to develop an ELISA to detect toxin-reactive antibodies in hyperimmune dog sera. The optimised ELISA reliably detected antibodies reactive to I. holocyclus salivary gland antigens. Parallel testing of sera with a negative control antigen prepared from the salivary glands of the nontoxic tick Rhipicephalus (Boophilus microplus provided further evidence that we were detecting toxin-specific antibodies in the assay. Using the ELISA, we could also detect antibodies induced in rats after experimental infestation with I. holocyclus. This assay shows promise as an alternative means of assessing the potency of batches of hyperimmune dog serum and to screen for toxin-reactive monoclonal antibodies produced from immunised rodents.

Driving forces for changes in geographical distribution of Ixodes ricinus ticks in Europe

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Medlock Jolyon M

2013-01-01

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.

Dynamics of digestive proteolytic system during blood feeding of the hard tick Ixodes ricinus

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Sojka Daniel

2010-12-01

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.

Infections and Coinfections of Questing Ixodes ricinus Ticks by Emerging Zoonotic Pathogens in Western Switzerland

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Lommano, Elena; Bertaiola, Luce; Dupasquier, Christèle

2012-01-01

In Europe, Ixodes ricinus is the vector of many pathogens of medical and veterinary relevance, among them Borrelia burgdorferi sensu lato and tick-borne encephalitis virus, which have been the subject of numerous investigations. Less is known about the occurrence of emerging tick-borne pathogens like Rickettsia spp., Babesia spp., “Candidatus Neoehrlichia mikurensis,” and Anaplasma phagocytophilum in questing ticks. In this study, questing nymph and adult I. ricinus ticks were collected at 11 sites located in Western Switzerland. A total of 1,476 ticks were analyzed individually for the simultaneous presence of B. burgdorferi sensu lato, Rickettsia spp., Babesia spp., “Candidatus Neoehrlichia mikurensis,” and A. phagocytophilum. B. burgdorferi sensu lato, Rickettsia spp., and “Candidatus Neoehrlichia mikurensis” were detected in ticks at all sites with global prevalences of 22.5%, 10.2%, and 6.4%, respectively. Babesia- and A. phagocytophilum-infected ticks showed a more restricted geographic distribution, and their prevalences were lower (1.9% and 1.5%, respectively). Species rarely reported in Switzerland, like Borrelia spielmanii, Borrelia lusitaniae, and Rickettsia monacensis, were identified. Infections with more than one pathogenic species, involving mostly Borrelia spp. and Rickettsia helvetica, were detected in 19.6% of infected ticks. Globally, 34.2% of ticks were infected with at least one pathogen. The diversity of tick-borne pathogens detected in I. ricinus in this study and the frequency of coinfections underline the need to take them seriously into consideration when evaluating the risks of infection following a tick bite. PMID:22522688

Diversity of viruses in Ixodes ricinus, and characterization of a neurotropic strain of Eyach virus

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S. Moutailler

2016-05-01

Full Text Available Ticks transmit more pathogens—including bacteria, parasites and viruses—than any other arthropod vector. Although the epidemiological status of many tick-borne bacteria is very well characterized, tick-borne viruses are still relatively under-studied. Recently, several novel tick-borne viruses have been isolated from human febrile illnesses following tick bites, indicating the existence of other potential new and unknown tick-borne viruses. We used high-throughput sequencing to analyse the virome of Ixodes ricinus, the main vector of tick-borne pathogens in Europe. The majority of collected viral sequences were assigned to two potentially novel Nairovirus and Phlebovirus viruses, with prevalence rates ranging from 3.95% to 23.88% in adults and estimated to be between 0.14% and 72.16% in nymphs. These viruses could not be isolated from the brains of inoculated immunocompromised mice, perhaps indicating that they are unable to infect vertebrates. Within the I. ricinus virome, we also identified contigs with >90% identity to the known Eyach virus. Initially isolated in the 1980s, this virus was indirectly associated with human disease, but had never been extensively studied. Eyach virus prevalence varied between 0.07% and 5.26% in ticks from the French Ardennes and Alsace regions. Eyach virus was successfully isolated following intracerebral inoculation of immunocompromised mice with Eyach virus-positive tick extracts. This virus was also able to multiply and persist in the blood of immunocompetent mice inoculated by intraperitoneal injection, and caused brain infections in three of nine juveniles, without any obvious deleterious effects.

Diversity of viruses in Ixodes ricinus, and characterization of a neurotropic strain of Eyach virus.

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Moutailler, S; Popovici, I; Devillers, E; Vayssier-Taussat, M; Eloit, M

2016-05-01

Ticks transmit more pathogens-including bacteria, parasites and viruses-than any other arthropod vector. Although the epidemiological status of many tick-borne bacteria is very well characterized, tick-borne viruses are still relatively under-studied. Recently, several novel tick-borne viruses have been isolated from human febrile illnesses following tick bites, indicating the existence of other potential new and unknown tick-borne viruses. We used high-throughput sequencing to analyse the virome of Ixodes ricinus, the main vector of tick-borne pathogens in Europe. The majority of collected viral sequences were assigned to two potentially novel Nairovirus and Phlebovirus viruses, with prevalence rates ranging from 3.95% to 23.88% in adults and estimated to be between 0.14% and 72.16% in nymphs. These viruses could not be isolated from the brains of inoculated immunocompromised mice, perhaps indicating that they are unable to infect vertebrates. Within the I. ricinus virome, we also identified contigs with >90% identity to the known Eyach virus. Initially isolated in the 1980s, this virus was indirectly associated with human disease, but had never been extensively studied. Eyach virus prevalence varied between 0.07% and 5.26% in ticks from the French Ardennes and Alsace regions. Eyach virus was successfully isolated following intracerebral inoculation of immunocompromised mice with Eyach virus-positive tick extracts. This virus was also able to multiply and persist in the blood of immunocompetent mice inoculated by intraperitoneal injection, and caused brain infections in three of nine juveniles, without any obvious deleterious effects.

Ir-LBP, an ixodes ricinus tick salivary LTB4-binding lipocalin, interferes with host neutrophil function.

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Jérôme Beaufays

Full Text Available BACKGROUND: During their blood meal, ticks secrete a wide variety of proteins that can interfere with their host's defense mechanisms. Among these proteins, lipocalins play a major role in the modulation of the inflammatory response. METHODOLOGY/PRINCIPAL FINDINGS: We previously identified 14 new lipocalin genes in the tick Ixodes ricinus. One of them codes for a protein that specifically binds leukotriene B4 with a very high affinity (Kd: +/-1 nM, similar to that of the neutrophil transmembrane receptor BLT1. By in silico approaches, we modeled the 3D structure of the protein and the binding of LTB4 into the ligand pocket. This protein, called Ir-LBP, inhibits neutrophil chemotaxis in vitro and delays LTB4-induced apoptosis. Ir-LBP also inhibits the host inflammatory response in vivo by decreasing the number and activation of neutrophils located at the tick bite site. Thus, Ir-LBP participates in the tick's ability to interfere with proper neutrophil function in inflammation. CONCLUSIONS/SIGNIFICANCE: These elements suggest that Ir-LBP is a "scavenger" of LTB4, which, in combination with other factors, such as histamine-binding proteins or proteins inhibiting the classical or alternative complement pathways, permits the tick to properly manage its blood meal. Moreover, with regard to its properties, Ir-LBP could possibly be used as a therapeutic tool for illnesses associated with an increased LTB4 production.

Notas de Ixodologia: II - uma nova espécie do gênero Amblyomma e uma nova espécie do gênero Ixodes (Acari Ixodidae

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Flavio da Fonseca

1952-03-01

Full Text Available A new tick, Amblyomma parkeri, n. sp., is described as a parasite of Coendu sp. from S. Paulo, Brazil. Female holotype, nymph and larva are described (Figs. 2 e 3. The n. sp. differs completly from Koch's species Amblyomma longirostre, the common parasite of the Erethizotidae. Standard data for measures of the female dorsal scutum ixodidae are proposed as follows (fig. 1: PA = Antero-posterior; PB = Postero-basal; PM = Postero-median; TT = Transversal; OO = Inter-ocular; OT= Occulo-transversal; SS = Inter-scapular; CC = Cervical; PT = Postero-transversal; ST = Scapulo-transversal; NPT = Normal to the postero-transversal; NST = Normal to the scapulo-transversal. In the female holotype the standard data are as follows: PA = 2.00 mm; PB = 2.26 mm; PM = 1.10 mm; TT = 2.20 mm; OO = 2.26 mm; SS = 0,84 mm; CC = 0.63 mm; SC = 0.12 mm; NPT = 0.20mm; STN = 0.1 mm. Peritrema 0.80 x 0.42 mm with a narrow postero-internal angle and a large, elongated macula. Coxa I with two short spines and all other coxae with only one shorter spine, shortest in coxa IV. Hypostoma spatulated with formula 3/3. Gnathosoma 1.42 mm long and basis 0.63 mm long by 0.84 greatest wide. Palpi with smoth external surface, 1.00 mm long. Type lot No. 4458 from Cotia, S. Paulo, Brazil; in the acarological collection of the Escola Paulista de Medicina, S. Paulo. Ixodes didelphidis, n. sp., differing from Ixodes loricatus Neumann by the shape of the peritremata (figs. 4 a 5 of the male and female and by the number of the punctations in this organ is described form Didelphidae, Muridae and Cavidae. Twenty eight lots were obtained from Anápolis, Goiás, Brasil, where I. loricatus is subtituded by the n. sp. under description. Comparison with NEUMANN'S types of I. loricatus was possible through the courtesy of Prof. A. BRIZARD from Toulouse, who kindly loaned NEUMANN'S material. Female cotypes N° 40 and male allotype N° 531 in the Collection of Ixodidae of the Oswaldo Cruz Institute.

Tick histamine release factor is critical for Ixodes scapularis engorgement and transmission of the lyme disease agent.

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Jianfeng Dai

2010-11-01

Full Text Available Ticks are distributed worldwide and affect human and animal health by transmitting diverse infectious agents. Effective vaccines against most tick-borne pathogens are not currently available. In this study, we characterized a tick histamine release factor (tHRF from Ixodes scapularis and addressed the vaccine potential of this antigen in the context of tick engorgement and B. burgdorferi transmission. Results from western blotting and quantitative Reverse Transcription-PCR showed that tHRF is secreted in tick saliva, and upregulated in Borrelia burgdorferi-infected ticks. Further, the expression of tHRF was coincident with the rapid feeding phase of the tick, suggesting a role for tHRF in tick engorgement and concomitantly, for efficient B. burgdorferi transmission. Silencing tHRF by RNA interference (RNAi significantly impaired tick feeding and decreased B. burgdorferi burden in mice. Interfering with tHRF by actively immunizing mice with recombinant tHRF, or passively transferring tHRF antiserum, also markedly reduced the efficiency of tick feeding and B. burgdorferi burden in mice. Recombinant tHRF was able to bind to host basophils and stimulate histamine release. Therefore, we speculate that tHRF might function in vivo to modulate vascular permeability and increase blood flow to the tick bite-site, facilitating tick engorgement. These findings suggest that blocking tHRF might offer a viable strategy to complement ongoing efforts to develop vaccines to block tick feeding and transmission of tick-borne pathogens.

Francisella tularensis: No Evidence for Transovarial Transmission in the Tularemia Tick Vectors Dermacentor reticulatus and Ixodes ricinus

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Genchi, Marco; Prati, Paola; Vicari, Nadia; Manfredini, Andrea; Sacchi, Luciano; Clementi, Emanuela; Bandi, Claudio; Epis, Sara; Fabbi, Massimo

2015-01-01

Background Tularemia is a zoonosis caused by the Francisella tularensis, a highly infectious Gram-negative coccobacillus. Due to easy dissemination, multiple routes of infection, high environmental contamination and morbidity and mortality rates, Francisella is considered a potential bioterrorism threat and classified as a category A select agent by the CDC. Tick bites are among the most prevalent modes of transmission, and ticks have been indicated as a possible reservoir, although their reservoir competence has yet to be defined. Tick-borne transmission of F. tularensis was recognized in 1923, and transstadial transmission has been demonstrated in several tick species. Studies on transovarial transmission, however, have reported conflicting results. Objective The aim of this study was to evaluate the role of ticks as reservoirs for Francisella, assessing the transovarial transmission of F. tularensis subsp. holarctica in ticks, using experimentally-infected females of Dermacentor reticulatus and Ixodes ricinus. Results Transmission electron microscopy and fluorescence in situ hybridization showed F. tularensis within oocytes. However, cultures and bioassays of eggs and larvae were negative; in addition, microscopy techniques revealed bacterial degeneration/death in the oocytes. Conclusions These results suggest that bacterial death might occur in oocytes, preventing the transovarial transmission of Francisella. We can speculate that Francisella does not have a defined reservoir, but that rather various biological niches (e.g. ticks, rodents), that allow the bacterium to persist in the environment. Our results, suggesting that ticks are not competent for the bacterium vertical transmission, are congruent with this view. PMID:26244842

Francisella tularensis: No Evidence for Transovarial Transmission in the Tularemia Tick Vectors Dermacentor reticulatus and Ixodes ricinus.

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Marco Genchi

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.

Expansion of the Lyme Disease Vector Ixodes scapularis in Canada inferred from CMIP5 Climate Projections

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McPherson, Michelle Yvonne; García-García, Almudena; José Cuesta-Valero, Francisco; Beltrami, Hugo; Hansen-Ketchum, Patti; MacDougall, Donna; Hume Ogden, Nicholas

2017-04-01

A number of studies have assessed possible climate change impacts on the Lyme disease vector, Ixodes scapularis. However, most have used surface air temperature from only one climate model simulation and/or one emission scenario, representing only one possible climate future. We quantified effects of different Representative Concentration Pathway (RCP) and climate model outputs on the projected future changes in the basic reproduction number (R0) of I. scapularis to explore uncertainties in future R0 estimates. We used surface air temperature generated by a complete set of General Circulation Models from the Coupled Model Intercomparison Project Phase 5 (CMIP5) to hindcast historical and forecast future effects of climate change on the R0 of I. scapularis. As in previous studies, R0 of I. scapularis increased with a warming climate under future projected climate. Increases in the multi-model mean R0 values showed significant changes over time under all RCP scenarios, however; only the estimated R0 mean values between RCP6.0 and RCP8.5 showed statistically significant differences. Our results highlight the potential for climate change to have an effect on future Lyme disease risk in Canada even if the Paris Agreement's goal to keep global warming below 2°C is achieved, although mitigation reducing emissions from RCP8.5 levels to those of RCP6.0 or less would be expected to slow tick invasion after the 2030s. On-going planning is needed to inform and guide adaptation in light of the projected range of possible futures.

Comparative efficacy of a new spot-on combination product containing selamectin and sarolaner (Stronghold®Plus) versus fluralaner (Bravecto®) against induced infestations with Ixodes ricinus ticks on cats.

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Geurden, Thomas; Borowski, Stasia; Wozniakiewicz, Magda; King, Vickie; Fourie, Josephus; Liebenberg, Julian

2017-06-29

Ticks are increasingly reported on cats worldwide, with Ixodes ricinus being a relevant species across Europe and in near by areas of North Africa and the Middle East. Yet there are few acaracidal products with proven efficacy approved for use in cats. The objective of this study was to compare the efficacy of a new spot-on formulation containing selamectin and sarolaner with a topical application of fluralaner (Bravecto®) against Ixodes ricinus ticks on cats. To that end, twenty-four (24) cats were randomly allocated to one of three treatment groups. The cats in the control group remained untreated. Cats in group 2 were treated with selamectin/sarolaner (Stronghold®Plus; Zoetis) at the minimum recommended dose of 1.0 mg/kg sarolaner and 6.0 mg/kg selamectin on Days 0, 30 and 60. The cats in group 3 received a fluralaner treatment (Bravecto®spot-on solution for cats, MSD) at the minimum recommended dose of 40.0 mg/kg on Day 0. Cats were infested with 50 (± 4) viable, adult, unfed I. ricinus ticks on Days 26, 54, 82 and 89 and ticks were removed for counting 48 h (± 2 h) later. Three monthly treatments with selamectin/sarolaner provided high and consistent efficacy against I. ricinus for the entire duration of the study period. In contrast, the efficacy of fluralaner declined in the second month after treatment and was below the efficacy threshold of 90% on Days 56, 84 and 91. The percentage efficacy against I. ricinus was numerically higher in the selemectin/sarolaner treated group than in the fluralaner-treated group on Days 56, 84 and 91. Furthermore, greasiness and spiking of the hair, as well as white deposits were frequently observed in the fluralaner-treated cats. The results of the present study confirm the high and consistent efficacy of a new spot-on combination product containing selamectin and sarolaner against I. ricinus in cats, and indicate a decline in fluralaner efficacy during the 91 day period after treatment.

Environmental drivers of Ixodes ricinus abundance in forest fragments of rural European landscapes.

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Ehrmann, Steffen; Liira, Jaan; Gärtner, Stefanie; Hansen, Karin; Brunet, Jörg; Cousins, Sara A O; Deconchat, Marc; Decocq, Guillaume; De Frenne, Pieter; De Smedt, Pallieter; Diekmann, Martin; Gallet-Moron, Emilie; Kolb, Annette; Lenoir, Jonathan; Lindgren, Jessica; Naaf, Tobias; Paal, Taavi; Valdés, Alicia; Verheyen, Kris; Wulf, Monika; Scherer-Lorenzen, Michael

2017-09-06

The castor bean tick (Ixodes ricinus) transmits infectious diseases such as Lyme borreliosis, which constitutes an important ecosystem disservice. Despite many local studies, a comprehensive understanding of the key drivers of tick abundance at the continental scale is still lacking. We analyze a large set of environmental factors as potential drivers of I. ricinus abundance. Our multi-scale study was carried out in deciduous forest fragments dispersed within two contrasting rural landscapes of eight regions, along a macroclimatic gradient stretching from southern France to central Sweden and Estonia. We surveyed the abundance of I. ricinus, plant community composition, forest structure and soil properties and compiled data on landscape structure, macroclimate and habitat properties. We used linear mixed models to analyze patterns and derived the relative importance of the significant drivers. Many drivers had, on their own, either a moderate or small explanatory value for the abundance of I. ricinus, but combined they explained a substantial part of variation. This emphasizes the complex ecology of I. ricinus and the relevance of environmental factors for tick abundance. Macroclimate only explained a small fraction of variation, while properties of macro- and microhabitat, which buffer macroclimate, had a considerable impact on tick abundance. The amount of forest and the composition of the surrounding rural landscape were additionally important drivers of tick abundance. Functional (dispersules) and structural (density of tree and shrub layers) properties of the habitat patch played an important role. Various diversity metrics had only a small relative importance. Ontogenetic tick stages showed pronounced differences in their response. The abundance of nymphs and adults is explained by the preceding stage with a positive relationship, indicating a cumulative effect of drivers. Our findings suggest that the ecosystem disservices of tick-borne diseases, via the

Approaches for Reverse Line Blot-Based Detection of Microbial Pathogens in Ixodes ricinus Ticks Collected in Austria and Impact of the Chosen Method.

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Schötta, Anna-Margarita; Wijnveld, Michiel; Stockinger, Hannes; Stanek, Gerold

2017-07-01

Ticks transmit a large number of pathogens capable of causing human disease. In this study, the PCR-reverse line blot (RLB) method was used to screen for pathogens in a total of 554 Ixodes ricinus ticks collected from all provinces of Austria. These pathogens belong to the genera Borrelia , Rickettsiae , Anaplasma / Ehrlichia (including " Candidatus Neoehrlichia"), Babesia , and Coxiella The pathogens with the highest detected prevalence were spirochetes of the Borrelia burgdorferi sensu lato complex, in 142 ticks (25.6%). Borrelia afzelii (80/142) was the most frequently detected species, followed by Borrelia burgdorferi sensu stricto (38/142) and Borrelia valaisiana (36/142). Borrelia garinii/Borrelia bavariensis , Borrelia lusitaniae , and Borrelia spielmanii were found in 28 ticks, 5 ticks, and 1 tick, respectively. Rickettsia spp. were detected in 93 ticks (16.8%): R. helvetica (39/93), R. raoultii (38/93), R. monacensis (2/93), and R. slovaca (1/93). Thirteen Rickettsia samples remain uncharacterized. " Candidatus Neoehrlichia mikurensis," Babesia spp. ( B. venatorum , B. divergens , B. microti ), and Anaplasma phagocytophilum were found in 4.5%, 2.7%, and 0.7%, respectively. Coxiella burnetii was not detected. Multiple microorganisms were detected in 40 ticks (7.2%), and the cooccurrence of Babesia spp. and " Candidatus Neoehrlichia mikurensis" showed a significant positive correlation. We also compared different PCR-RLBs for detection of Borrelia burgdorferi sensu lato and Rickettsia spp. and showed that different detection approaches provide highly diverse results, indicating that analysis of environmental samples remains challenging. IMPORTANCE This study determined the wide spectrum of tick-borne bacterial and protozoal pathogens that can be encountered in Austria. Surveillance of (putative) pathogenic microorganisms occurring in the environment is of medical importance, especially when those agents can be transmitted by ticks and cause disease. The

No Observed Effect of Landscape Fragmentation on Pathogen Infection Prevalence in Blacklegged Ticks (Ixodes scapularis in the Northeastern United States.

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Christine P Zolnik

Full Text Available Pathogen prevalence within blacklegged ticks (Ixodes scapularis Say, 1821 tends to vary across sites and geographic regions, but the underlying causes of this variation are not well understood. Efforts to understand the ecology of Lyme disease have led to the proposition that sites with higher host diversity will result in lower disease risk due to an increase in the abundance of inefficient reservoir species relative to the abundance of species that are highly competent reservoirs. Although the Lyme disease transmission cycle is often cited as a model for this "dilution effect hypothesis", little empirical evidence exists to support that claim. Here we tested the dilution effect hypothesis for two pathogens transmitted by the blacklegged tick along an urban-to-rural gradient in the northeastern United States using landscape fragmentation as a proxy for host biodiversity. Percent impervious surface and habitat fragment size around each site were determined to assess the effect of landscape fragmentation on nymphal blacklegged tick infection with Borrelia burgdorferi and Anaplasma phagocytophilum. Our results do not support the dilution effect hypothesis for either pathogen and are in agreement with the few studies to date that have tested this idea using either a landscape proxy or direct measures of host biodiversity.

Contributions to the phylogeny of Ixodes (Pholeoixodes canisuga, I. (Ph. kaiseri, I. (Ph. hexagonus and a simple pictorial key for the identification of their females

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Sándor Hornok

2017-11-01

Full Text Available Abstract Background In Europe, hard ticks of the subgenus Pholeoixodes (Ixodidae: Ixodes are usually associated with burrow-dwelling mammals and terrestrial birds. Reports of Pholeoixodes spp. from carnivores are frequently contradictory, and their identification is not based on key diagnostic characters. Therefore, the aims of the present study were to identify ticks collected from dogs, foxes and badgers in several European countries, and to reassess their systematic status with molecular analyses using two mitochondrial markers. Results Between 2003 and 2017, 144 Pholeoixodes spp. ticks were collected in nine European countries. From accurate descriptions and comparison with type-materials, a simple illustrated identification key was compiled for adult females, by focusing on the shape of the anterior surface of basis capituli. Based on this key, 71 female ticks were identified as I. canisuga, 21 as I. kaiseri and 21 as I. hexagonus. DNA was extracted from these 113 female ticks, and from further 31 specimens. Fragments of two mitochondrial genes, cox1 (cytochrome c oxidase subunit 1 and 16S rRNA, were amplified and sequenced. Ixodes kaiseri had nine unique cox1 haplotypes, which showed 99.2–100% sequence identity, whereas I. canisuga and I. hexagonus had eleven and five cox1 haplotypes, respectively, with 99.5–100% sequence identity. The distribution of cox1 haplotypes reflected a geographical pattern. Pholeoixodes spp. ticks had fewer 16S rRNA haplotypes, with a lower degree of intraspecific divergence (99.5–100% sequence identity and no geographical clustering. Phylogenetic analyses were in agreement with morphology: I. kaiseri and I. hexagonus (with the similar shape of the anterior surface of basis capituli were genetically more closely related to each other than to I. canisuga. Phylogenetic analyses also showed that the subgenus Eschatocephalus (bat ticks clustered within the subgenus Pholeoixodes. Conclusions A simple

The Rickettsia Endosymbiont of Ixodes pacificus Contains All the Genes of De Novo Folate Biosynthesis

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Bodnar, James; Mortazavi, Bobak; Laurent, Timothy; Deason, Jeff; Thephavongsa, Khanhkeo; Zhong, Jianmin

2015-01-01

Ticks and other arthropods often are hosts to nutrient providing bacterial endosymbionts, which contribute to their host’s fitness by supplying nutrients such as vitamins and amino acids. It has been detected, in our lab, that Ixodes pacificus is host to Rickettsia species phylotype G021. This endosymbiont is predominantly present, and 100% maternally transmitted in I. pacificus. To study roles of phylotype G021 in I. pacificus, bioinformatic and molecular approaches were carried out. MUMmer genome alignments of whole genome sequence of I. scapularis, a close relative to I. pacificus, against completely sequenced genomes of R. bellii OSU85-389, R. conorii, and R. felis, identified 8,190 unique sequences that are homologous to Rickettsia sequences in the NCBI Trace Archive. MetaCyc metabolic reconstructions revealed that all folate gene orthologues (folA, folC, folE, folKP, ptpS) required for de novo folate biosynthesis are present in the genome of Rickettsia buchneri in I. scapularis. To examine the metabolic capability of phylotype G021 in I. pacificus, genes of the folate biosynthesis pathway of the bacterium were PCR amplified using degenerate primers. BLAST searches identified that nucleotide sequences of the folA, folC, folE, folKP, and ptpS genes possess 98.6%, 98.8%, 98.9%, 98.5% and 99.0% identity respectively to the corresponding genes of Rickettsia buchneri. Phylogenetic tree constructions show that the folate genes of phylotype G021 and homologous genes from various Rickettsia species are monophyletic. This study has shown that all folate genes exist in the genome of Rickettsia species phylotype G021 and that this bacterium has the genetic capability for de novo folate synthesis. PMID:26650541

Reciprocal Regulation of NF-kB (Relish) and Subolesin in the Tick Vector, Ixodes scapularis

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Galindo, Ruth C.; Kocan, Katherine M.; Blouin, Edmour F.; Mitra, Ruchira; Alberdi, Pilar; Villar, Margarita; de la Fuente, José

2013-01-01

Background Tick Subolesin and its ortholog in insects and vertebrates, Akirin, have been suggested to play a role in the immune response through regulation of nuclear factor-kappa B (NF-kB)-dependent and independent gene expression via interaction with intermediate proteins that interact with NF-kB and other regulatory proteins, bind DNA or remodel chromatin to regulate gene expression. The objective of this study was to characterize the structure and regulation of subolesin in Ixodes scapularis. I. scapularis is a vector of emerging pathogens such as Borrelia burgdorferi, Anaplasma phagocytophilum and Babesia microti that cause in humans Lyme disease, anaplasmosis and babesiosis, respectively. The genome of I. scapularis was recently sequenced, and this tick serves as a model organism for the study of vector-host-pathogen interactions. However, basic biological questions such as gene organization and regulation are largely unknown in ticks and other arthropod vectors. Principal Findings The results presented here provide evidence that subolesin/akirin are evolutionarily conserved at several levels (primary sequence, gene organization and function), thus supporting their crucial biological function in metazoans. These results showed that NF-kB (Relish) is involved in the regulation of subolesin expression in ticks, suggesting that as in other organisms, different NF-kB integral subunits and/or unknown interacting proteins regulate the specificity of the NF-kB-mediated gene expression. These results suggested a regulatory network involving cross-regulation between NF-kB (Relish) and Subolesin and Subolesin auto-regulation with possible implications in tick immune response to bacterial infection. Significance These results advance our understanding of gene organization and regulation in I. scapularis and have important implications for arthropod vectors genetics and immunology highlighting the possible role of NF-kB and Subolesin/Akirin in vector

Ixodes scapularis tick serine proteinase inhibitor (serpin gene family; annotation and transcriptional analysis

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Chalaire Katelyn C

2009-05-01

Full Text Available Abstract Background Serine proteinase inhibitors (Serpins are a large superfamily of structurally related, but functionally diverse proteins that control essential proteolytic pathways in most branches of life. Given their importance in the biology of many organisms, the concept that ticks might utilize serpins to evade host defenses and immunizing against or disrupting their functions as targets for tick control is an appealing option. Results A sequence homology search strategy has allowed us to identify at least 45 tick serpin genes in the Ixodes scapularis genome that are structurally segregated into 32 intronless and 13 intron-containing genes. Nine of the intron-containing serpins occur in a cluster of 11 genes that span 170 kb of DNA sequence. Based on consensus amino acid residues in the reactive center loop (RCL and signal peptide scanning, 93% are putatively inhibitory while 82% are putatively extracellular. Among the 11 different amino acid residues that are predicted at the P1 sites, 16 sequences possess basic amino acid (R/K residues. Temporal and spatial expression analyses revealed that 40 of the 45 serpins are differentially expressed in salivary glands (SG and/or midguts (MG of unfed and partially fed ticks. Ten of the 38 serpin genes were expressed from six to 24 hrs of feeding while six and fives genes each are predominantly or exclusively expressed in either MG and SG respectively. Conclusion Given the diversity among tick species, sizes of tick serpin families are likely to be variable. However this study provides insight on the potential sizes of serpin protein families in ticks. Ticks must overcome inflammation, complement activation and blood coagulation to complete feeding. Since these pathways are regulated by serpins that have basic residues at their P1 sites, we speculate that I. scapularis may utilize some of the serpins reported in this study to manipulate host defense. We have discussed our data in the context of

Adverse moisture events predict seasonal abundance of Lyme disease vector ticks (Ixodes scapularis)

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Berger, Kathryn A.; Ginsberg, Howard S.; Dugas, Katherine D.; Hamel, Lutz H.; Mather, Thomas N.

2014-01-01

Background: Lyme borreliosis (LB) is the most commonly reported vector-borne disease in north temperate regions worldwide, affecting an estimated 300,000 people annually in the United States alone. The incidence of LB is correlated with human exposure to its vector, the blacklegged tick (Ixodes scapularis). To date, attempts to model tick encounter risk based on environmental parameters have been equivocal. Previous studies have not considered (1) the differences between relative humidity (RH) in leaf litter and at weather stations, (2) the RH threshold that affects nymphal blacklegged tick survival, and (3) the time required below the threshold to induce mortality. We clarify the association between environmental moisture and tick survival by presenting a significant relationship between the total number of tick adverse moisture events (TAMEs - calculated as microclimatic periods below a RH threshold) and tick abundance each year.Methods: We used a 14-year continuous statewide tick surveillance database and corresponding weather data from Rhode Island (RI), USA, to assess the effects of TAMEs on nymphal populations of I. scapularis. These TAMEs were defined as extended periods of time (>8 h below 82% RH in leaf litter). We fit a sigmoid curve comparing weather station data to those collected by loggers placed in tick habitats to estimate RH experienced by nymphal ticks, and compiled the number of historical TAMEs during the 14-year record.Results: The total number of TAMEs in June of each year was negatively related to total seasonal nymphal tick densities, suggesting that sub-threshold humidity episodes >8 h in duration naturally lowered nymphal blacklegged tick abundance. Furthermore, TAMEs were positively related to the ratio of tick abundance early in the season when compared to late season, suggesting that lower than average tick abundance for a given year resulted from tick mortality and not from other factors.Conclusions: Our results clarify the mechanism

Modelling the Phenological Relationships of Questing Immature Ixodes Ricinus (Ixodidae) Using Temperature and NDVI Data.

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Alonso-Carné, J; García-Martín, A; Estrada-Peña, A

2016-02-01

All active stages of the tick Ixodes ricinus were collected monthly at two sites in northern Spain between the years 2000 and 2007. We used percentile accumulation of the active stage in the environment to evaluate simple and coherent correlations between accumulation of the active stages of larvae and nymphs and medium-resolution MODIS satellite-derived information on the climate, including monthly and accumulated temperature and the Normalized Difference Vegetation Index (NDVI). This framework is not intended to predict the actual abundance of ticks in the field as a measure of the hazard to humans, but to provide a basic structure for addressing the phenology of the tick in its geographic range. We demonstrated that the accumulation of larval ticks in the active stage is a sigmoid function of the accumulated temperature from the beginning of the calendar year. We also demonstrated that the accumulated temperature necessary to recruit nymphs from the questing larval stage is a function of the changes in accumulated larvae and nymphs and the accumulated temperature and NDVI recorded by the Aqua sensor. The low p-values obtained in the regressions confirmed that such recruitment can be calculated using time intervals to estimate, for example, the beginning of the questing period or the time of the year when a population peak can be expected. The comparison among predicted and actual accumulated temperatures between larvae and nymph recruitment had an averaged error of ±20 days in one complete year. The use of accumulated temperature and NDVI proposed in this study opens up the re-evaluation of reports on the phenology of the tick in Europe. This framework is intended to evaluate the same correlations along the tick's range and predict its phenological patterns in areas of pathogen transmission risk for humans. © 2015 Blackwell Verlag GmbH.

Ixodes ricinus ticks are reservoir hosts for Rickettsia helvetica and potentially carry flea-borne Rickettsia species

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Gaasenbeek Cor

2009-09-01

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.

To beat or not to beat a tick: comparison of DNA extraction methods for ticks (Ixodes scapularis

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Alyssa D. Ammazzalorso

2015-08-01

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.

Behavioral asymmetries in ticks - Lateralized questing of Ixodes ricinus to a mechatronic apparatus delivering host-borne cues.

Science.gov (United States)

Benelli, Giovanni; Romano, Donato; Rocchigiani, Guido; Caselli, Alice; Mancianti, Francesca; Canale, Angelo; Stefanini, Cesare

2018-02-01

Ticks are considered among the most dangerous arthropod vectors of disease agents to both humans and animals worldwide. Lateralization contributes to biological fitness in many animals, conferring important functional advantages, therefore studying its role in tick perception would critically improve our knowledge about their host-seeking behavior. In this research, we evaluated if Ixodes ricinus (L.) (Ixodiidae) ticks have a preference in using the right or the left foreleg to climb on a host. We developed a mechatronic device moving a tuft of fox skin with fur as host-mimicking combination of cues. This engineered approach allows to display a realistic combination of both visual and olfactory host-borne stimuli, which is prolonged over the time and standardized for each replicate. In the first experiment, the mechatronic apparatus delivered host-borne cues frontally, to evaluate the leg preference during questing as response to a symmetrical stimulus. In the second experiment, host-borne cues were provided laterally, in an equal proportion to the left and to the right of the tick, to investigate if the host direction affected the questing behavior. In both experiments, the large majority of the tested ticks showed individual-level left-biased questing acts, if compared to the ticks showing right-biased ones. Furthermore, population-level left-biased questing responses were observed post-exposure to host-mimicking cues provided frontally or laterally to the tick. Overall, this is the first report on behavioral asymmetries in ticks of medical and veterinary importance. Moreover, the mechatronic apparatus developed in this research can be exploited to evaluate the impact of repellents on tick questing in highly reproducible standardized conditions. Copyright © 2017 Elsevier B.V. All rights reserved.

A Risk Model for the Lyme Disease Vector Ixodes scapularis (Acari: Ixodidae) in the Prairie Provinces of Canada.

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Gabriele-Rivet, Vanessa; Koffi, Jules K; Pelcat, Yann; Arsenault, Julie; Cheng, Angela; Lindsay, L Robbin; Lysyk, Timothy J; Rochon, Kateryn; Ogden, Nicholas H

2017-07-01

Lyme disease is emerging in Canada due to geographic range expansion of the tick vector Ixodes scapularis Say. Recent areas of emergence include parts of the southeastern Canadian Prairie region. We developed a map of potential risk areas for future I. scapularis establishment in the Canadian Prairie Provinces. Six I. scapularis risk algorithms were developed using different formulations of three indices for environmental suitability: temperature using annual cumulative degree-days > 0 °C (DD > 0 °C; obtained from Moderate Resolution Imaging Spectroradiometer satellite data as an index of conditions that allow I. scapularis to complete its life cycle), habitat as a combined geolayer of forest cover and agricultural land use, and rainfall. The relative performance of these risk algorithms was assessed using receiver-operating characteristic (ROC) area under the curve (AUC) analysis with data on presence-absence of I. scapularis obtained from recent field surveillance in the Prairie Provinces accumulated from a number of sources. The ROC AUC values for the risk algorithms were significantly different (P  0 °C, habitat as a simple dichotomous variable of presence or absence of forest, and normalized rainfall had the highest AUC of 0.74, representing "fair to good" performance of the risk algorithm. This algorithm had good (>80%) sensitivity in predicting positive I. scapularis surveillance sites, but low (50%) specificity as expected in this region where not all environmentally suitable habitats are expected to be occupied. Further prospective studies are needed to validate and perhaps improve the risk algorithm. © Crown copyright 2017.

Bacteria of the genus Rickettsia in ticks (Acari: Ixodidae) collected from birds in Costa Rica.

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Ogrzewalska, Maria; Literák, Ivan; Capek, Miroslav; Sychra, Oldřich; Calderón, Víctor Álvarez; Rodríguez, Bernardo Calvo; Prudencio, Carlos; Martins, Thiago F; Labruna, Marcelo B

2015-06-01

The aim of this study was to document the presence of Rickettsia spp. in ticks parasitizing wild birds in Costa Rica. Birds were trapped at seven locations in Costa Rica during 2004, 2009, and 2010; then visually examined for the presence of ticks. Ticks were identified, and part of them was tested individually for the presence of Rickettsia spp. by polymerase chain reaction (PCR) using primers targeting fragments of the rickettsial genes gltA and ompA. PCR products were DNA-sequenced and analyzed in BLAST to determine similarities with previously reported rickettsial agents. A total of 1878 birds were examined, from which 163 birds (9%) were infested with 388 ticks of the genera Amblyomma and Ixodes. The following Amblyomma (in decreasing order of abundance) were found in immature stages (larvae and nymphs): Amblyomma longirostre, Amblyomma calcaratum, Amblyomma coelebs, Amblyomma sabanerae, Amblyomma varium, Amblyomma maculatum, and Amblyomma ovale. Ixodes ticks were represented by Ixodes minor and two unclassified species, designated here as Ixodes sp. genotype I, and Ixodes sp. genotype II. Twelve of 24 tested A. longirostre ticks were found to be infected with 'Candidatus Rickettsia amblyommii', and 2 of 4 A. sabanerae were found to be infected with Rickettsia bellii. Eight of 10 larval Ixodes minor were infected with an endosymbiont (a novel Rickettsia sp. agent) genetically related to the Ixodes scapularis endosymbiont. No rickettsial DNA was found in A. calcaratum, A. coelebs, A. maculatum, A. ovale, A. varium, Ixodes sp. I, and Ixodes sp. II. We report the occurrence of I. minor in Costa Rica for the first time and a number of new bird host-tick associations. Moreover, 'Candidatus R. amblyommii' and R. bellii were found in A. longirostre and A. sabanerae, respectively, in Costa Rica for the first time. Copyright © 2015 Elsevier GmbH. All rights reserved.

Habitat properties are key drivers of Borrelia burgdorferi (s.l.) prevalence in Ixodes ricinus populations of deciduous forest fragments.

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Ehrmann, Steffen; Ruyts, Sanne C; Scherer-Lorenzen, Michael; Bauhus, Jürgen; Brunet, Jörg; Cousins, Sara A O; Deconchat, Marc; Decocq, Guillaume; De Frenne, Pieter; De Smedt, Pallieter; Diekmann, Martin; Gallet-Moron, Emilie; Gärtner, Stefanie; Hansen, Karin; Kolb, Annette; Lenoir, Jonathan; Lindgren, Jessica; Naaf, Tobias; Paal, Taavi; Panning, Marcus; Prinz, Maren; Valdés, Alicia; Verheyen, Kris; Wulf, Monika; Liira, Jaan

2018-01-08

The tick Ixodes ricinus has considerable impact on the health of humans and other terrestrial animals because it transmits several tick-borne pathogens (TBPs) such as B. burgdorferi (sensu lato), which causes Lyme borreliosis (LB). Small forest patches of agricultural landscapes provide many ecosystem services and also the disservice of LB risk. Biotic interactions and environmental filtering shape tick host communities distinctively between specific regions of Europe, which makes evaluating the dilution effect hypothesis and its influence across various scales challenging. Latitude, macroclimate, landscape and habitat properties drive both hosts and ticks and are comparable metrics across Europe. Therefore, we instead assess these environmental drivers as indicators and determine their respective roles for the prevalence of B. burgdorferi in I. ricinus. We sampled I. ricinus and measured environmental properties of macroclimate, landscape and habitat quality of forest patches in agricultural landscapes along a European macroclimatic gradient. We used linear mixed models to determine significant drivers and their relative importance for nymphal and adult B. burgdorferi prevalence. We suggest a new prevalence index, which is pool-size independent. During summer months, our prevalence index varied between 0 and 0.4 per forest patch, indicating a low to moderate disservice. Habitat properties exerted a fourfold larger influence on B. burgdorferi prevalence than macroclimate and landscape properties combined. Increasingly available ecotone habitat of focal forest patches diluted and edge density at landscape scale amplified B. burgdorferi prevalence. Indicators of habitat attractiveness for tick hosts (food resources and shelter) were the most important predictors within habitat patches. More diverse and abundant macro- and microhabitat had a diluting effect, as it presumably diversifies the niches for tick-hosts and decreases the probability of contact between ticks

Potential of Tenebrio molitor (Coleoptera: Tenebrionidae) as a bioassay probe for Metarhizium brunneum (Hypocreales: Clavicipitaceae) activity against Ixodes scapularis (Acari: Ixodidae).

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Bharadwaj, Anuja; Stafford, Kirby C

2011-12-01

The yellow mealworm, Tenebrio molitor L., has been used to indicate qualitatively the presence of entomopathogenic fungi in the soil or as a model for evaluating stress and other factors on fungal activity. Although this beetle appears highly susceptible to many of these fungi, little quantitative information is available on the sensitivity of T. molitor to a specific fungus and, therefore, fungal presence or as an indicator for pathogenicity to other species. The purpose of this study was to establish the suitability of T. molitor larvae as a bioassay probe for Metarhizium brunneum for comparison against the blacklegged tick, Ixodes scapularis. Nine concentrations of M. brunneum strain F52 ranging from 1.0 x 10(1) to 8.4 x 10(8) conidial/ml were simultaneously tested against T. molitor larvae and I. scapularis adults. Larvae of yellow mealworm were less sensitive to M. brunneum than I. scapularis adults (LC50's 4.4 x 10(7) and 1.7 x 10(5) conidia/ml, respectively, 4-wk post-treatment). The greater sensitivity of I. scapularis to the fungus suggests that the detection of fungal mycosis in mealworms would indicate sufficient inoculum to be pathogenic to I. scapularis and make this insect a suitable probe for evaluation of the presence and activity of M. brunneum against the blacklegged tick in field applications.

Detection and genetic characterization of tick-borne encephalitis virus (TBEV) derived from ticks removed from red foxes (Vulpes vulpes) and isolated from spleen samples of red deer (Cervus elaphus) in Croatia.

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Jemeršić, Lorena; Dežđek, Danko; Brnić, Dragan; Prpić, Jelena; Janicki, Zdravko; Keros, Tomislav; Roić, Besi; Slavica, Alen; Terzić, Svjetlana; Konjević, Dean; Beck, Relja

2014-02-01

Tick-borne encephalitis (TBE) is a growing public health concern in central and northern European countries. Even though TBE is a notifiable disease in Croatia, there is a significant lack of information in regard to vector tick identification, distribution as well as TBE virus prevalence in ticks or animals. The aim of our study was to identify and to investigate the viral prevalence of TBE virus in ticks removed from red fox (Vulpes vulpes) carcasses hunted in endemic areas in northern Croatia and to gain a better insight in the role of wild ungulates, especially red deer (Cervus elaphus) in the maintenance of the TBE virus in the natural cycle. We identified 5 tick species (Ixodes ricinus, Ixodes hexagonus, Haemaphysalis punctata, Dermacentor reticulatus, Rhipicephalus sanguineus) removed from 40 red foxes. However, TBE virus was isolated only from adult I. ricinus and I. hexagonus ticks showing a viral prevalence (1.6%) similar to or higher than reported in endemic areas of other European countries. Furthermore, 2 positive spleen samples from 182 red deer (1.1%) were found. Croatian TBE virus isolates were genetically analyzed, and they were shown to be closely related, all belonging to the European TBE virus subgroup. However, on the basis of nucleotide and amino acid sequence analysis, 2 clusters were identified. Our results show that further investigation is needed to understand the clustering of isolates and to identify the most common TBE virus reservoir hosts in Croatia. Sentinel surveys based on wild animal species would give a better insight in defining TBE virus-endemic and possible risk areas in Croatia. Copyright © 2013. Published by Elsevier GmbH.

Is sarcoidosis a rickettsiosis? An archival study

DEFF Research Database (Denmark)

Svendsen, Claus Bo; Milman, Nils; Andersen, Claus B

2011-01-01

Based on earlier research, Rickettsia helvetica could possibly be involved in the pathogenesis of sarcoidosis. Rickettsiae are transmitted to humans by a tick vector, Ixodes ricinus; this tick is highly prevalent in Northern Europe. We aimed to investigate the association between evidence...... of rickettsiae and sarcoidosis in histological samples....

The integration of multiple independent data reveals an unusual response to Pleistocene climatic changes in the hard tick Ixodes ricinus.

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Porretta, Daniele; Mastrantonio, Valentina; Mona, Stefano; Epis, Sara; Montagna, Matteo; Sassera, Davide; Bandi, Claudio; Urbanelli, Sandra

2013-03-01

In the last few years, improved analytical tools and the integration of genetic data with multiple sources of information have shown that temperate species exhibited more complex responses to ice ages than previously thought. In this study, we investigated how Pleistocene climatic changes affected the current distribution and genetic diversity of European populations of the tick Ixodes ricinus, an ectoparasite with high ecological plasticity. We first used mitochondrial and nuclear genetic markers to investigate the phylogeographic structure of the species and its Pleistocene history using coalescent-based methods; then we used species distribution modelling to infer the climatic niche of the species at last glacial maximum; finally, we reviewed the literature on the I. ricinus hosts to identify the locations of their glacial refugia. Our results support the scenario that during the last glacial phase, I. ricinus never experienced a prolonged allopatric divergence in separate glacial refugia, but persisted with interconnected populations across Southern and Central Europe. The generalist behaviour in host choice of I. ricinus would have played a major role in maintaining connections between its populations. Although most of the hosts persisted in separate refugia, from the point of view of I. ricinus, they represented a continuity of 'bridges' among populations. Our study highlights the importance of species-specific ecology in affecting responses to Pleistocene glacial-interglacial cycles. Together with other cases in Europe and elsewhere, it contributes to setting new hypotheses on how species with wide ecological plasticity coped with Pleistocene climatic changes. © 2013 Blackwell Publishing Ltd.

Changes in the geographical distribution and abundance of the tick Ixodes ricinus during the past 30 years in Sweden

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Jaenson Thomas GT

2012-01-01

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

Changes in the geographical distribution and abundance of the tick Ixodes ricinus during the past 30 years in Sweden.

Science.gov (United States)

Jaenson, Thomas G T; Jaenson, David G E; Eisen, Lars; Petersson, Erik; Lindgren, Elisabet

2012-01-10

Ixodes ricinus is the main vector in Europe of human-pathogenic Lyme borreliosis (LB) spirochaetes, the tick-borne encephalitis virus (TBEV) and other pathogens of humans and domesticated mammals. The results of a previous 1994 questionnaire, directed at people living in Central and North Sweden (Svealand and Norrland) and aiming to gather information about tick exposure for humans and domestic animals, suggested that Ixodes ricinus ticks had become more widespread in Central Sweden and the southern part of North Sweden from the early 1980s to the early 1990s. To investigate whether the expansion of the tick's northern geographical range and the increasing abundance of ticks in Sweden were still occurring, in 2009 we performed a follow-up survey 16 years after the initial study. A questionnaire similar to the one used in the 1994 study was published in Swedish magazines aimed at dog owners, home owners, and hunters. The questionnaire was published together with a popular science article about the tick's biology and role as a pathogen vector in Sweden. The magazines were selected to get information from people familiar with ticks and who spend time in areas where ticks might be present. Analyses of data from both surveys revealed that during the near 30-year period from the early 1980s to 2008, I. ricinus has expanded its distribution range northwards. In the early 1990s ticks were found in new areas along the northern coastline of the Baltic Sea, while in the 2009 study, ticks were reported for the first time from many locations in North Sweden. This included locations as far north as 66°N and places in the interior part of North Sweden. During this 16-year period the tick's range in Sweden was estimated to have increased by 9.9%. Most of the range expansion occurred in North Sweden (north of 60°N) where the tick's coverage area doubled from 12.5% in the early 1990s to 26.8% in 2008. Moreover, according to the respondents, the abundance of ticks had increased

Occurrence of Babesia spp., Rickettsia spp. and Bartonella spp. in Ixodes ricinus in Bavarian public parks, Germany

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Mahling Monia

2011-07-01

Full Text Available Abstract Background Only limited information is available about the occurrence of ticks and tick-borne pathogens in public parks, which are areas strongly influenced by human beings. For this reason, Ixodes ricinus were collected in public parks of different Bavarian cities in a 2-year survey (2009 and 2010 and screened for DNA of Babesia spp., Rickettsia spp. and Bartonella spp. by PCR. Species identification was performed by sequence analysis and alignment with existing sequences in GenBank. Additionally, coinfections with Anaplasma phagocytophilum were investigated. Results The following prevalences were detected: Babesia spp.: 0.4% (n = 17, including one pool of two larvae in 2009 and 0.5 to 0.7% (n = 11, including one pool of five larvae in 2010; Rickettsia spp.: 6.4 to 7.7% (n = 285, including 16 pools of 76 larvae in 2009. DNA of Bartonella spp. in I. ricinus in Bavarian public parks could not be identified. Sequence analysis revealed the following species: Babesia sp. EU1 (n = 25, B. divergens (n = 1, B. divergens/capreoli (n = 1, B. gibsoni-like (n = 1, R. helvetica (n = 272, R. monacensis IrR/Munich (n = 12 and unspecified R. monacensis (n = 1. The majority of coinfections were R. helvetica with A. phagocytophilum (n = 27, but coinfections between Babesia spp. and A. phagocytophilum, or Babesia spp. and R. helvetica were also detected. Conclusions I. ricinus ticks in urban areas of Germany harbor several tick-borne pathogens and coinfections were also observed. Public parks are of particularly great interest regarding the epidemiology of tick-borne pathogens, because of differences in both the prevalence of pathogens in ticks as well as a varying species arrangement when compared to woodland areas. The record of DNA of a Babesia gibsoni-like pathogen detected in I. ricinus suggests that I. ricinus may harbor and transmit more Babesia spp. than previously known. Because of their high recreational value for human beings, urban green

Occurrence of Babesia spp., Rickettsia spp. and Bartonella spp. in Ixodes ricinus in Bavarian public parks, Germany.

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Schorn, Sabine; Pfister, Kurt; Reulen, Holger; Mahling, Monia; Silaghi, Cornelia

2011-07-15

Only limited information is available about the occurrence of ticks and tick-borne pathogens in public parks, which are areas strongly influenced by human beings. For this reason, Ixodes ricinus were collected in public parks of different Bavarian cities in a 2-year survey (2009 and 2010) and screened for DNA of Babesia spp., Rickettsia spp. and Bartonella spp. by PCR. Species identification was performed by sequence analysis and alignment with existing sequences in GenBank. Additionally, coinfections with Anaplasma phagocytophilum were investigated. The following prevalences were detected: Babesia spp.: 0.4% (n = 17, including one pool of two larvae) in 2009 and 0.5 to 0.7% (n = 11, including one pool of five larvae) in 2010; Rickettsia spp.: 6.4 to 7.7% (n = 285, including 16 pools of 76 larvae) in 2009. DNA of Bartonella spp. in I. ricinus in Bavarian public parks could not be identified. Sequence analysis revealed the following species: Babesia sp. EU1 (n = 25), B. divergens (n = 1), B. divergens/capreoli (n = 1), B. gibsoni-like (n = 1), R. helvetica (n = 272), R. monacensis IrR/Munich (n = 12) and unspecified R. monacensis (n = 1). The majority of coinfections were R. helvetica with A. phagocytophilum (n = 27), but coinfections between Babesia spp. and A. phagocytophilum, or Babesia spp. and R. helvetica were also detected. I. ricinus ticks in urban areas of Germany harbor several tick-borne pathogens and coinfections were also observed. Public parks are of particularly great interest regarding the epidemiology of tick-borne pathogens, because of differences in both the prevalence of pathogens in ticks as well as a varying species arrangement when compared to woodland areas. The record of DNA of a Babesia gibsoni-like pathogen detected in I. ricinus suggests that I. ricinus may harbor and transmit more Babesia spp. than previously known. Because of their high recreational value for human beings, urban green areas are likely to remain in the research focus on

Genetic variability of Rickettsia spp. in Ixodes persulcatus ticks from continental and island areas of the Russian Far East.

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Igolkina, Y; Bondarenko, E; Rar, V; Epikhina, T; Vysochina, N; Pukhovskaya, N; Tikunov, A; Ivanov, L; Golovljova, I; Ivanov, М; Tikunova, N

2016-10-01

Rickettsia spp. are intracellular Gram-negative bacteria transmitted by arthropods. Two potentially pathogenic rickettsiae, Candidatus Rickettsia tarasevichiae and Rickettsia helvetica, have been found in unfed adult Ixodes persulcatus ticks. The aim of this study was to assess the prevalence and genetic variability of Rickettsia spp. in I. persulcatus ticks collected from different locations in the Russian Far East. In total, 604 adult I. persulcatus ticks collected from four sites in the Khabarovsk Territory (continental area) and one site in Sakhalin Island were examined for the presence of Rickettsia spp. by real-time PCR. Nested PCR with species-specific primers and sequencing were used for genotyping of revealed rickettsiae. The overall prevalence of Rickettsia spp. in ticks collected in different sites varied from 67.9 to 90.7%. However, the proportion of different Rickettsia species observed in ticks from Sakhalin Island significantly differed from that in ticks from the Khabarovsk Territory. In Sakhalin Island, R. helvetica prevailed in examined ticks, while Candidatus R. tarasevichiae was predominant in the Khabarovsk Territory. For gltA and ompB gene fragments, the sequences obtained for Candidatus R. tarasevichiae from all studied sites were identical to each other and to the known sequences of this species. According to sequence analysis of gltA, оmpB and sca4 genes, R. helvetica isolates from Sakhalin Island and the Khabarovsk Territory were identical to each other, but they differed from R. helvetica from other regions and from those found in other tick species. For the first time, DNA of pathogenic Rickettsia heilongjiangensis was detected in I. persulcatus ticks in two sites from the Khabarovsk Territory. The gltA, ompA and оmpB gene sequences of R. heilongjiangensis were identical to or had solitary mismatches with the corresponding sequences of R. heilongjiangensis found in other tick species. Copyright © 2016 Elsevier GmbH. All rights

Genomic Resources Notes accepted 1 April 2014 – 31 May 2014

Czech Academy of Sciences Publication Activity Database

Contreras, M.; de la Fuente, J.; Estrada-Pena, A.; Grubhoffer, Libor; Tobes, R.

2014-01-01

Roč. 14, č. 5 (2014), s. 1095-1095 ISSN 1755-098X Institutional support: RVO:60077344 Keywords : global transcriptome comparison * Ixodes scapularis * Ixodes ricinus Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.712, year: 2014

Efficacy of sarolaner in the prevention of Borrelia burgdorferi and Anaplasma phagocytophilum transmission from infected Ixodes scapularis to dogs.

Science.gov (United States)

Honsberger, Nicole A; Six, Robert H; Heinz, Thomas J; Weber, Angela; Mahabir, Sean P; Berg, Thomas C

2016-05-30

The efficacy of sarolaner (Simparica™, Zoetis) to prevent transmission primarily of Borrelia burgdorferi and secondarily of Anaplasma phagocytophilum from infected wild-caught Ixodes scapularis to dogs was evaluated in a placebo-controlled laboratory study. Twenty-four purpose-bred laboratory Beagles seronegative for B. burgdorferi and A. phagocytophilum antibodies were allocated randomly to one of three treatment groups: placebo administered orally on Days 0 and 7, or sarolaner at 2mg/kg administered orally on Day 0 (28 days prior to tick infestation) or on Day 7 (21 days prior to tick infestation). On Day 28, each dog was infested with approximately 25 female and 25 male wild caught adult I. scapularis that were determined to have prevalence of 57% for B. burgdorferi and 6.7% for A. phagocytophilum by PCR. In situ tick counts were conducted on Days 29 and 30. On Day 33, all ticks were counted and removed. Acaricidal efficacy was calculated based on the reduction of geometric mean live tick counts in the sarolaner-treated groups compared to the placebo-treated group for each tick count. Blood samples collected from each dog on Days 27, 49, 63, 77, 91 and 104 were tested for the presence of B. burgdorferi and A. phagocytophilum antibodies using the SNAP(®) 4Dx(®) Plus Test, and quantitatively assayed for B. burgdorferi antibodies using an ELISA test. Skin biopsies collected on Day 104 were tested for the presence of B. burgdorferi by bacterial culture and PCR. Geometric mean live tick counts for placebo-treated dogs were 14.8, 12.8, and 19.1 on Days 29, 30, and 33, respectively. The percent reductions in mean live tick counts at 1, 2, and 5 days after infestation were 86.3%, 100%, and 100% for the group treated with sarolaner 21 days prior to infestation, and 90.9%, 97.1%, and 100% for the group treated with sarolaner 28 days prior to infestation. Geometric mean live tick counts for both sarolaner-treated groups were significantly lower than those for the

NCBI nr-aa BLAST: CBRC-MDOM-02-0026 [SEVENS

Lifescience Database Archive (English)

Full Text Available CBRC-MDOM-02-0026 ref|XP_002416287.1| glycine rich secreted cement protein, putativ...e [Ixodes scapularis] gb|EEC19954.1| glycine rich secreted cement protein, putative [Ixodes scapularis] XP_002416287.1 5e-51 48% ...

NCBI nr-aa BLAST: CBRC-PVAM-01-1566 [SEVENS

Lifescience Database Archive (English)

Full Text Available CBRC-PVAM-01-1566 ref|XP_002416287.1| glycine rich secreted cement protein, putativ...e [Ixodes scapularis] gb|EEC19954.1| glycine rich secreted cement protein, putative [Ixodes scapularis] XP_002416287.1 4e-13 42% ...

NCBI nr-aa BLAST: CBRC-GGOR-01-1493 [SEVENS

Lifescience Database Archive (English)

Full Text Available CBRC-GGOR-01-1493 ref|XP_002416287.1| glycine rich secreted cement protein, putativ...e [Ixodes scapularis] gb|EEC19954.1| glycine rich secreted cement protein, putative [Ixodes scapularis] XP_002416287.1 7e-28 46% ...

The parasitism of Ixodes luciae (Acari: Ixodidae on marsupials and rodents in Peruvian Amazon O parasitismo do Ixodes luciae (Acari: ixodidae em marsupiais e em roedores na Amazônia Peruana

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María Mónica Díaz

2009-01-01

Full Text Available In this work the infestation with I. luciae on Didelphimorphia and Rodentia in different environments of Peruvian Amazon was studied. Didelphimorphia was represented by the family Didelphidae. Specimens belonging to Caluromys lanatus, Didelphis marsupialis, Marmosops sp.2, Metachirus nudicaudatus, Philander andersoni and Philander opossum were infested with adults I. luciae and one Micoureus sp. was infested with larvae. In Rodentia, the infestation with I. luciae nymphs was restricted to Hylaeamys perenensis, Hylaeamys yunganus and Oligoryzomys microtis, while one Oecomys bicolor (all Cricetidae was infested with larvae of this species. The few larvae were found on rodents captured in primary forest. The only significant difference (P No presente trabalho, infestações por Ixodes luciae em Didelphimorphia e Rodentia em diferentes ambientes da Amazônia peruana foram estudadas. Didelphimorphia foi representada pela família Didelphidae. Espécimes pertencentes a Caluromys lanatus, Didelphis marsupialis, Marmosops sp., Metachirus nudicaudatus, Philander andersoni e Philander opossum foram encontrados infestadas por adultos de I. luciae; um Micoureus sp. foi encontrado infestado por larvas. Em Rodentia, a infestação por ninfas de I. luciae estiveram restritas a Hylaeamys perenensis, Hylaeamys yunganus e Oligoryzomys microtis, enquanto que um Oecomys bicolor (todos Cricetidae esteve infestado por larvas de I. luciae. As poucas larvas foram encontradas em roedores capturados na floresta primária. A única diferença significante (P < 0.05 na prevalência de carrapatos adultos em Didelphimorphia foi entre P. andersoni e M. nudicaudatus (distribuição chi-quadrado. A distribuição de carrapatos adultos foi significativamente diferente em P. andersoni quando comparado com M. nudicaudatus, P. opossum e D. marsupialis (teste Kruskal-Wallis. Nenhum efeito significante do mês ou ambiente foi observado em relação à infestação por carrapato

Profiling of proteolytic enzymes in the gut of the tick Ixodes ricinus reveals an evolutionarily conserved network of aspartic and cysteine peptidases

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Mareš Michael

2008-03-01

Full Text Available Abstract Background Ticks are vectors for a variety of viral, bacterial and parasitic diseases in human and domestic animals. To survive and reproduce ticks feed on host blood, yet our understanding of the intestinal proteolytic machinery used to derive absorbable nutrients from the blood meal is poor. Intestinal digestive processes are limiting factors for pathogen transmission since the tick gut presents the primary site of infection. Moreover, digestive enzymes may find practical application as anti-tick vaccine targets. Results Using the hard tick, Ixodes ricinus, we performed a functional activity scan of the peptidase complement in gut tissue extracts that demonstrated the presence of five types of peptidases of the cysteine and aspartic classes. We followed up with genetic screens of gut-derived cDNA to identify and clone genes encoding the cysteine peptidases cathepsins B, L and C, an asparaginyl endopeptidase (legumain, and the aspartic peptidase, cathepsin D. By RT-PCR, expression of asparaginyl endopeptidase and cathepsins B and D was restricted to gut tissue and to those developmental stages feeding on blood. Conclusion Overall, our results demonstrate the presence of a network of cysteine and aspartic peptidases that conceivably operates to digest host blood proteins in a concerted manner. Significantly, the peptidase components of this digestive network are orthologous to those described in other parasites, including nematodes and flatworms. Accordingly, the present data and those available for other tick species support the notion of an evolutionary conservation of a cysteine/aspartic peptidase system for digestion that includes ticks, but differs from that of insects relying on serine peptidases.

Suppression of host-seeking Ixodes scapularis and Amblyomma americanum (Acari: Ixodidae) nymphs after dual applications of plant-derived acaricides in New Jersey.

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Jordan, Robert A; Dolan, Marc C; Piesman, Joseph; Schulze, Terry L

2011-04-01

We evaluated the ability of dual applications of natural, plant-derived acaricides to suppress nymphal Ixodes scapularis Say and Amblyomma americanum (L.) (Acari: Ixodidae) in a Lyme disease endemic area of New Jersey. An aqueous formulation of 2% nootkatone provided >90% control of I. scapularis through 7 d. Control declined to 80.9% at 14 d, and a second application was made that provided >95% control through the remaining 4 wk of the nymphal season. Nootkatone provided >90% control of A. americanum through 35 d postapplication. Applications of 2% carvacrol and EcoTrol T&O resulted in rapid knockdown of both tick species, but control declined significantly to 76.7 and 73.7%, respectively, after 14 d when a second application was made that extended control of both tick species to between 86.2 and 94.8% at 21 d. Subsequently, control declined steadily in all plots by 42 d postapplication except for I. scapularis in carvacrol-treated plots, where levels of control >90% were observed through 35 d. Of the three compounds tested, 2% nootkatone provided the most consistent results, with 96.5 and 91.9% control of I. scapularis and A. americanum through 42 and 35 d, respectively. The ability of plant-derived natural products to quickly suppress and maintain significant control of populations of these medically important ticks may represent a future alternative to the use of conventional synthetic acaricides. In addition, the demonstrated efficacy of properly-timed backpack sprayer application may enable homeowner access to these minimal-risk acaricides.

Effects of global changes on the climatic niche of the tick Ixodes ricinus inferred by species distribution modelling.

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Porretta, Daniele; Mastrantonio, Valentina; Amendolia, Sara; Gaiarsa, Stefano; Epis, Sara; Genchi, Claudio; Bandi, Claudio; Otranto, Domenico; Urbanelli, Sandra

2013-09-19

Global climate change can seriously impact on the epidemiological dynamics of vector-borne diseases. In this study we investigated how future climatic changes could affect the climatic niche of Ixodes ricinus (Acari, Ixodida), among the most important vectors of pathogens of medical and veterinary concern in Europe. Species Distribution Modelling (SDM) was used to reconstruct the climatic niche of I. ricinus, and to project it into the future conditions for 2050 and 2080, under two scenarios: a continuous human demographic growth and a severe increase of gas emissions (scenario A2), and a scenario that proposes lower human demographic growth than A2, and a more sustainable gas emissions (scenario B2). Models were reconstructed using the algorithm of "maximum entropy", as implemented in the software Maxent 3.3.3e; 4,544 occurrence points and 15 bioclimatic variables were used. In both scenarios an increase of climatic niche of about two times greater than the current area was predicted as well as a higher climatic suitability under the scenario B2 than A2. Such an increase occurred both in a latitudinal and longitudinal way, including northern Eurasian regions (e.g. Sweden and Russia), that were previously unsuitable for the species. Our models are congruent with the predictions of range expansion already observed in I. ricinus at a regional scale and provide a qualitative and quantitative assessment of the future climatically suitable areas for I. ricinus at a continental scale. Although the use of SDM at a higher resolution should be integrated by a more refined analysis of further abiotic and biotic data, the results presented here suggest that under future climatic scenarios most of the current distribution area of I. ricinus could remain suitable and significantly increase at a continental geographic scale. Therefore disease outbreaks of pathogens transmitted by this tick species could emerge in previous non-endemic geographic areas. Further studies will

Multi-source analysis reveals latitudinal and altitudinal shifts in range of Ixodes ricinus at its northern distribution limit

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Kristoffersen Anja B

2011-05-01

Full Text Available Abstract Background There is increasing evidence for a latitudinal and altitudinal shift in the distribution range of Ixodes ricinus. The reported incidence of tick-borne disease in humans is on the rise in many European countries and has raised political concern and attracted media attention. It is disputed which factors are responsible for these trends, though many ascribe shifts in distribution range to climate changes. Any possible climate effect would be most easily noticeable close to the tick's geographical distribution limits. In Norway- being the northern limit of this species in Europe- no documentation of changes in range has been published. The objectives of this study were to describe the distribution of I. ricinus in Norway and to evaluate if any range shifts have occurred relative to historical descriptions. Methods Multiple data sources - such as tick-sighting reports from veterinarians, hunters, and the general public - and surveillance of human and animal tick-borne diseases were compared to describe the present distribution of I. ricinus in Norway. Correlation between data sources and visual comparison of maps revealed spatial consistency. In order to identify the main spatial pattern of tick abundance, a principal component analysis (PCA was used to obtain a weighted mean of four data sources. The weighted mean explained 67% of the variation of the data sources covering Norway's 430 municipalities and was used to depict the present distribution of I. ricinus. To evaluate if any geographical range shift has occurred in recent decades, the present distribution was compared to historical data from 1943 and 1983. Results Tick-borne disease and/or observations of I. ricinus was reported in municipalities up to an altitude of 583 metres above sea level (MASL and is now present in coastal municipalities north to approximately 69°N. Conclusion I. ricinus is currently found further north and at higher altitudes than described in

Hepatozoon canis in German red foxes (Vulpes vulpes) and their ticks: molecular characterization and the phylogenetic relationship to other Hepatozoon spp.

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Najm, Nour-Addeen; Meyer-Kayser, Elisabeth; Hoffmann, Lothar; Pfister, Kurt; Silaghi, Cornelia

2014-07-01

In this study, the prevalence of Hepatozoon spp. in red foxes (Vulpes vulpes) and their ticks from Germany, as well as molecular characterizations and phylogenetic relationship to other Hepatozoon spp. were investigated. DNA extracts of 261 spleen samples and 1,953 ticks were examined for the presence of Hepatozoon spp. by a conventional polymerase chain reaction (PCR) targeting the 18S rRNA gene. The ticks included four tick species: Ixodes ricinus, Ixodes canisuga, Ixodes hexagonus and Dermacentor reticulatus. A total of 118/261 foxes (45.2%) and 148/1,953 ticks (7.5%) were Hepatozoon PCR-positive. Amplicons from 36 positive foxes and 41 positive ticks were sequenced. All sequences obtained from foxes and 39/41 from ticks had a 99% similarity to Hepatozoon canis, whereas two ticks' sequences had a 99% identity to Hepatozoon sp. The obtained Hepatozoon sequences in this study were phylogenetically related to other Hepatozoon sequences detected in other countries, which may represent strain variants. The high prevalence of H. canis DNA in red foxes in this study supports the suggested role of those animals in distribution of this parasite. Furthermore, detection of DNA of H. canis in foxes and all examined tick species collected from those foxes allows speculating about previously undescribed potential vectors for H. canis and suggests a potential role of the red fox in its natural endemic cycles.

Molecular detection and phylogenetic analysis of Hepatozoon spp. in questing Ixodes ricinus ticks and rodents from Slovakia and Czech Republic.

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Hamšíková, Zuzana; Silaghi, Cornelia; Rudolf, Ivo; Venclíková, Kristýna; Mahríková, Lenka; Slovák, Mirko; Mendel, Jan; Blažejová, Hana; Berthová, Lenka; Kocianová, Elena; Hubálek, Zdeněk; Schnittger, Leonhard; Kazimírová, Mária

2016-10-01

By amplification and sequencing of 18S rRNA gene fragments, Hepatozoon spp. DNA was detected in 0.08 % (4/5057) and 0.04 % (1/2473) of questing Ixodes ricinus ticks from Slovakia and Czech Republic, respectively. Hepatozoon spp. DNA was also detected in spleen and/or lungs of 4.45 % (27/606) of rodents from Slovakia. Prevalence of infection was significantly higher in Myodes glareolus (11.45 %) than in Apodemus spp. (0.28 %) (P Hepatozoon spp. gene amplicons from I. ricinus showed 100 % identity with Hepatozoon canis isolates from red foxes or dogs in Europe. Phylogenetic analysis showed that at least two H. canis 18S rRNA genotypes exist in Slovakia of which one was identified also in the Czech Republic. The finding of H. canis in questing I. ricinus suggests the geographical spread of the parasite and a potential role of other ticks as its vectors in areas where Rhipicephalus sanguineus is not endemic. Sequencing of 18S rRNA gene amplicons from M. glareolus revealed the presence of two closely related genetic variants, Hepatozoon sp. SK1 and Hepatozoon sp. SK2, showing 99-100 % identity with isolates from M. glareolus from other European countries. Phylogenetic analysis demonstrates that 18S rRNA variants SK1 and SK2 correspond to previously described genotypes UR1 and UR2 of H. erhardovae, respectively. The isolate from Apodemus flavicollis (Hepatozoon sp. SK3b) was 99 % identical with isolates from reptiles in Africa and Asia. Further studies are necessary to identify the taxonomic status of Hepatozoon spp. parasitizing rodents in Europe and the host-parasite interactions in natural foci.

Climate of origin affects tick (Ixodes ricinus) host-seeking behavior in response to temperature: implications for resilience to climate change?

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Gilbert, Lucy; Aungier, Jennifer; Tomkins, Joseph L

2014-04-01

Climate warming is changing distributions and phenologies of many organisms and may also impact on vectors of disease-causing pathogens. In Europe, the tick Ixodes ricinus is the primary vector of medically important pathogens (e.g., Borrelia burgdorferi sensu lato, the causative agent of Lyme borreliosis). How might climate change affect I. ricinus host-seeking behavior (questing)? We hypothesize that, in order to maximize survival, I. ricinus have adapted their questing in response to temperature in accordance with local climates. We predicted that ticks from cooler climates quest at cooler temperatures than those from warmer climates. This would suggest that I. ricinus can adapt and therefore have the potential to be resilient to climate change. I. ricinus were collected from a cline of climates using a latitudinal gradient (northeast Scotland, North Wales, South England, and central France). Under laboratory conditions, ticks were subjected to temperature increases of 1°C per day, from 6 to 15°C. The proportion of ticks questing was recorded five times per temperature (i.e., per day). The theoretical potential to quest was then estimated for each population over the year for future climate change projections. As predicted, more ticks from cooler climates quested at lower temperatures than did ticks from warmer climates. The proportion of ticks questing was strongly associated with key climate parameters from each location. Our projections, based on temperature alone, suggested that populations could advance their activity season by a month under climate change, which has implications for exposure periods of hosts to tick-borne pathogens. Our findings suggest that I. ricinus have adapted their behavior in response to climate, implying some potential to adapt to climate change. Predictive models of I. ricinus dynamics and disease risk over continental scales would benefit from knowledge of these differences between populations.

The crystal structures of two salivary cystatins from the tick Ixodes scapularis and the effect of these inhibitors on the establishment of Borrelia burgdorferi infection in a murine model

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Kotsyfakis, Michalis; Horka, Helena; Salat, Jiri; Andersen, John F. (South Bohemia); (ASCR-ICP); (NIAID)

2010-11-17

We have previously demonstrated that two salivary cysteine protease inhibitors from the Borrelia burgdorferi (Lyme disease) vector Ixodes scapularis - namely sialostatins L and L2 - play an important role in tick biology, as demonstrated by the fact that silencing of both sialostatins in tandem results in severe feeding defects. Here we show that sialostatin L2 - but not sialostatin L - facilitates the growth of B. burgdorferi in murine skin. To examine the structural basis underlying these differential effects of the two sialostatins, we have determined the crystal structures of both sialostatin L and L2. This is the first structural analysis of cystatins from an invertebrate source. Sialostatin L2 crystallizes as a monomer with an 'unusual' conformation of the N-terminus, while sialostatin L crystallizes as a domain-swapped dimer with an N-terminal conformation similar to other cystatins. Deletion of the 'unusual' N-terminal five residues of sialostatin L2 results in marked changes in its selectivity, suggesting that this region is a particularly important determinant of the biochemical activity of sialostatin L2. Collectively, our results reveal the structure of two tick salivary components that facilitate vector blood feeding and that one of them also supports pathogen transmission to the vertebrate host.

Susceptibility of four tick species, Amblyomma americanum, Dermacentor variabilis, Ixodes scapularis, and Rhipicephalus sanguineus (Acari: Ixodidae), to nootkatone from essential oil of grapefruit.

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Flor-Weiler, Lina B; Behle, Robert W; Stafford, Kirby C

2011-03-01

Toxicity of nootkatone was determined in laboratory assays against unfed nymphs of Amblyomma americanum L., Dermacentor variabilis (Say), Ixodes scapularis Say, and Rhipicephalus sanguineus Latreille. We determined the 50% lethal concentration (LC50) and 90% lethal concentration (LC90) of nootkatone by recording tick mortality 24 h after exposure in treated glass vials. Nymphs were susceptible to nootkatone with LC50 values of 0.352, 0.233, 0.169, and 0.197 microg/cm2, and LC90 values of 1.001, 0.644, 0.549, and 0.485 microg/cm2 for A. americanum, D. variabilis, I. scapularis, and R. sanguineus, respectively. The LC50 value for R. sanquineus was not significantly different from D. variabilis or I. scapularis. Other LC50 comparisons were significantly different. The LC90 for A. americanum was higher when compared with the three other tick species, which were not significantly different. Because nootkatone is volatile, we measured the amount of nootkatone recovered from duplicate-treated vials before tick exposure and from vials after tick exposure. Nootkatone recovered from vials before exposure ranged from 82 to 112% of the expected amounts. The nootkatone recovered after the 24-h exposure period ranged from 89% from vials coated with higher concentrations of nootkatone, down to 29% from vials coated with low nootkatone concentrations. Determination of the nootkatone residue after vial coating demonstrated loss of the active compound while verifying the levels of tick exposure. Toxicity of low concentrations of nootkatone to the active questing stage of ticks reported in this study provides a reference point for future formulation research to exploit nootkatone as a safe and environment-friendly tick control.

Prevalence of Borrelia burgdorferi sensu lato in Ixodes ricinus ticks and assessment of entomological risk index at localities in Belgrade

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Krstić Milena

2016-01-01

Full Text Available Background/Aim. The first case of human Lyme borreliosis (LB in Serbia was recorded in 1987. The number of reported LB cases has increased in the past decade. The aim of this study was to estimate the density of Ixodes ricinus (I. ricinus ticks, the prevalence of Borrelia burgdorferi sensu lato (B. burgdorferi in them, and entomological risk index (ERI at 19 Belgrade localities which were grouped into three categories (forests, parkforests, parks. The values of ERI were compared with the number of tick bites in humans. Methods. Ticks were collected monthly by using the flag hours method and the infection rate was determined by using dark field microscopy. The ERI value was calculated for each locality where the ticks were collected. The related data about tick bites was obtained from the patient protocol of the Institute of Epidemiology, Military Medical Academy, Belgrade. Results. The total number of collected ticks, the number of nymphs and the infection rates of the nymphs were significantly higher in forests (p < 0.05 than park-forests and parks. Statistically, the ERI value was significantly higher in forests than parks of Belgrade (χ2 = 7.78, p < 0.01. In March and July, the ERI value was also significantly higher in forests, than park-forests (p < 0.01 and parks (p < 0.01. May was the month with the highest ERI value in each ecological category (forests p < 0.05; park-forests p < 0.01; parks p < 0.001. However, the number of tick bites in humans did not correlate with ERI values. Conclusion. The obtained results indicate that the risk of tick bite and human exposure to B. burgdorferi sensu lato is present at all selected localities in Belgrade. For a more comprehensive Lyme disease risk assessment the method of entomological risk index assessment should be combined with other methods, taking into consideration all tick stages and the behaviour and habits of people who may get infected B. burgdorferi sensu lato.

A preliminary field survey of ectoparasites of rodents in urban park, Sarawak, Malaysian Borneo.

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Madinah, A; Mariana, A; Fatimah, A; Abdullah, M T

2013-09-01

A survey of ectoparasites was carried out during Eco-Zoonoses Expedition in Bukit Aup Jubilee Park (BAJP), Sibu, Sarawak, Malaysian Borneo from 5(th) to 9(th) June 2008. A total of nine individuals comprising two species of rodents were captured. The species of rodents screened for ectoparasites were Sundamys muelleri and Callosciurus notatus. Four genera and six species of ectoparasites were collected, namely, Ixodes granulatus, Ixodes sp., Laelaps sedlaceki, Laelaps nuttalli, Hoplopleura dissicula and Listrophoroides sp. Three species of the ectoparasites are known to have potential health risk. The species were Ixodes granulatus, Laelaps nuttalli and Hoplopleura dissicula. This survey produced the first list of ectoparasites in Bukit Aup Jubilee Park, Sarawak, Malaysia.

High-throughput screening of tick-borne pathogens in Europe

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Michelet, Lorraine; Delannoy, Sabine; Devillers, Elodie

2014-01-01

was conducted on 7050 Ixodes ricinus nymphs collected from France, Denmark, and the Netherlands using a powerful new high-throughput approach. This advanced methodology permitted the simultaneous detection of 25 bacterial, and 12 parasitic species (including; Borrelia, Anaplasma, Ehrlichia, Rickettsia......, Bartonella, Candidatus Neoehrlichia, Coxiella, Francisella, Babesia, and Theileria genus) across 94 samples. We successfully determined the prevalence of expected (Borrelia burgdorferi sensu lato, Anaplasma phagocytophilum, Rickettsia helvetica, Candidatus Neoehrlichia mikurensis, Babesia divergens, Babesia...

The risk of exposure to Anaplasma phagocytophilum, Borrelia burgdorferi sensu lato, Babesia sp. and co-infections in Ixodes ricinus ticks on the territory of Niepołomice forest (southern Poland).

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Asman, Marek; Nowak, Magdalena; Cuber, Piotr; Strzelczyk, Joanna; Szilman, Ewa; Szilman, Piotr; Trapp, Gizela; Siuda, Krzysztof; Solarz, Krzysztof; Wiczkowski, Andrzej

2013-01-01

Niepołomice Forest is located about 20 kilometers east of Cracow (Malopolska province, southern Poland). Its natural and touristic values, as well as wide range of hosts occurring within indicate this to be an area of high risk of exposure to Ixodes ricinus and tick-borne diseases it transfers. I. ricinus is a common species in Poland and Europe. Its seasonal activity begins in Poland in the early spring, and ends with late autumn. A total number of 129 specimens of I. ricinus was collected by flagging in Niepołomice Forest. DNA was isolated by ammonia method from 30 randomly-selected individuals. PCR was used to detect tick-borne pathogens with primers specific for Anaplasma phagocytophilum, Borrelia burgdorferi sensu lato and Babesia sp. Molecular studies confirmed the presence of all three pathogens in I. ricinus. A. phagocytophilum was found in 76.7%, Babesia sp., 60%, B. burgdorferi s. l., in 3.3% of studied ticks. A. phagocytophilum co-infection with Babesia sp., was found in 46.7% of the specimens. A co-infection of all three tested pathogens was recorded in one case (3.3%). In Poland the problem of tick-borne diseases is a growing issue, therefore people residing in southern Polish touristic areas should be informed about the prevention and protection against ticks.

The impact of climate change on the expansion of Ixodes persulcatus habitat and the incidence of tick-borne encephalitis in the north of European Russia

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Tokarevich, Nikolay K.; Tronin, Andrey A.; Blinova, Olga V.; Buzinov, Roman V.; Boltenkov, Vitaliy P.; Yurasova, Elena D.; Nurse, Jo

2011-01-01

Background The increase in tick-borne encephalitis (TBE) incidence is observed in recent decades in a number of subarctic countries. The reasons of it are widely discussed in scientific publications. The objective of this study was to understand if the climate change in Arkhangelsk Oblast (AO) situated in the north of European subarctic zone of Russia has real impact on the northward expansion of Ixodid ticks and stipulates the increase in TBE incidence. Methods This study analyzes: TBE incidence in AO and throughout Russia, the results of Ixodid ticks collecting in a number of sites in AO, and TBE virus prevalence in those ticks, the data on tick bite incidence in AO, and meteorological data on AO mean annual air temperatures and precipitations. Results It is established that in recent years TBE incidence in AO tended to increase contrary to its apparent decrease nationwide. In last 10 years, there was nearly 50-fold rise in TBE incidence in AO when compared with 1980–1989. Probably, the increase both in mean annual air temperatures and temperatures during tick active season resulted in the northward expansion of Ixodes Persulcatus, main TBE virus vector. The Ixodid ticks expansion is confirmed both by the results of ticks flagging from the surface vegetation and by the tick bite incidence in the population of AO locations earlier free from ticks. Our mathematical (correlation and regression) analysis of available data revealed a distinct correlation between TBE incidence and the growth of mean annual air temperatures in AO in 1990–2009. Conclusion Not ruling out other factors, we conclude that climate change contributed much to the TBE incidence increase in AO. PMID:22028678

Infections and mixed infections with the selected species of Borrelia burgdorferi sensu lato complex in Ixodes ricinus ticks collected in eastern Poland: a significant increase in the course of 5 years.

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Wójcik-Fatla, Angelina; Zając, Violetta; Sawczyn, Anna; Sroka, Jacek; Cisak, Ewa; Dutkiewicz, Jacek

2016-02-01

In the years 2008-2009 and 2013-2014, 1620 and 1500 questing Ixodes ricinus ticks, respectively, were examined on the territory of the Lublin province (eastern Poland). The presence of three pathogenic species causing Lyme disease was investigated: Borrelia burgdorferi sensu stricto, B. afzelii and B. garinii. The proportion of I. ricinus ticks infected with B. burgdorferi sensu lato showed a highly significant increase between 2008-2009 and 2013-2014, from 6.0 to 15.3%. A significant increase was noted with regard to all types of infections with individual species: single (4.7-7.8%), dual (1.2-6.6%), and triple (0.1-0.9%). When expressed as the percent of all infections, the frequency of mixed infections increased from 21.4 to 49.2%. Statistical analysis performed with two methods (by calculating of odds ratios and by Fisher's exact test) showed that the frequencies of mixed infections in most cases proved to be significantly greater than expected. The strongest associations were found between B. burgdorferi s. s. and B. afzelii, and between B. burgdorferi s. s. and B. garinii. They appeared to be highly significant (P eastern Poland, and dramatic enhancement of mixed infections with individual species, which may result in mixed infections of humans and exacerbation of the clinical course of Lyme disease cases on the studied area.

Effects of tick control by acaricide self-treatment of white-tailed deer on host-seeking tick infection prevalence and entomologic risk for Ixodes scapularis-borne pathogens.

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Hoen, Anne Gatewood; Rollend, Lindsay G; Papero, Michele A; Carroll, John F; Daniels, Thomas J; Mather, Thomas N; Schulze, Terry L; Stafford, Kirby C; Fish, Durland

2009-08-01

We evaluated the effects of tick control by acaricide self-treatment of white-tailed deer on the infection prevalence and entomologic risk for three Ixodes scapularis-borne bacteria in host-seeking ticks. Ticks were collected from vegetation in areas treated with the "4-Poster" device and from control areas over a 6-year period in five geographically diverse study locations in the Northeastern United States and tested for infection with two known agents of human disease, Borrelia burgdorferi and Anaplasma phagocytophilum, and for a novel relapsing fever-group spirochete related to Borrelia miyamotoi. Overall, 38.2% of adults and 12.5% of nymphs were infected with B. burgdorferi; 8.5% of adults and 4.2% of nymphs were infected with A. phagocytophilum; and 1.9% of adults and 0.8% of nymphs were infected with B. miyamotoi. In most cases, treatment with the 4-Poster device was not associated with changes in the prevalence of infection with any of these three microorganisms among nymphal or adult ticks. However, the density of nymphs infected with B. burgdorferi, and consequently the entomologic risk for Lyme disease, was reduced overall by 68% in treated areas compared to control areas among the five study sites at the end of the study. The frequency of bacterial coinfections in ticks was generally equal to the product of the proportion of ticks infected with a single bacterium, indicating that enzootic maintenance of these pathogens is independent. We conclude that controlling ticks on deer by self-application of acaricide results in an overall decrease in the human risk for exposure to these three bacterial agents, which is due solely to a reduction in tick density.

Metazoarios parásitos de Tlacuatzin canescens y Marmosa mexicana (Mammalia: Didelphimorphia de México Metazoan parasites of Tlacuatzin canescens and Marmosa mexicana (Mammalia: Didelphimorphia from Mexico

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Carmen Guzmán-Cornejo

2012-06-01

Full Text Available Como parte de un estudio sobre los metazoarios parásitos de mamíferos de México se recolectaron 4 ejemplares de ratones tlacuache: 2 de Tlacuatzin canescens (Allen, 1893 procedentes de Oaxaca y 2 de Marmosa mexicana Merriam, 1897 de Veracruz. Se presentan 5 registros nuevos de hospedero y localidad para ácaros de las especies Ixodes luciae Sénevet, 1940, Ixodes sinaloa Kohls y Clifford, 1966, las pulgas Plusaetis mathesoni (Traub 1950 y Polygenis martinezbaezi Vargas 1951, así como para el cestodo Hymenolepis sp. y por primera vez en México se registra el nematodo Hoineffia simplicispicula Navone, Suriano y Pujol, 1991.As a part of an ongoing project to inventory the metazoan parasites of Mexican mammals, 4 specimens of 2 species of mouse opossums (2 Tlacuatzin canescens [Allen, 1893] and 2 Marmosa mexicana Merriam, 1897, were collected from Oaxaca and Veracuz states, Mexico, respectively. Five new locality and host records are presented for the acari Ixodes luciae Sénevet, 1940, Ixodes sinaloa Kohls and Clifford, 1966, of fleas Plusaetis mathesoni (Traub 1950, and Polygenis martinezbaezi Vargas 1951, as well as the cestode Hymenolepis sp., while the nematode Hoineffia simplicispicula Navone, Suriano and Pujol, 1991, is recorded for the first time in Mexico.

Soluble cysteine-rich tick saliva proteins Salp15 and Iric-1 from E. coli

OpenAIRE

Kolb, Philipp; Vorreiter, Jolanta; Habicht, J?ri; Bentrop, Detlef; Wallich, Reinhard; Nassal, Michael

2014-01-01

Ticks transmit numerous pathogens, including borreliae, which cause Lyme disease. Tick saliva contains a complex mix of anti-host defense factors, including the immunosuppressive cysteine-rich secretory glycoprotein Salp15 from Ixodes scapularis ticks and orthologs like Iric-1 from Ixodes ricinus. All tick-borne microbes benefit from the immunosuppression at the tick bite site; in addition, borreliae exploit the binding of Salp15 to their outer surface protein C (OspC) for enhanced transmissi...

Crimean–Congo Hemorrhagic Fever Virus and Borrelia burgdorferi sensu lato in Ticks from Kosovo and Albania

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Kurtesh Sherifi; Agim Rexhepi; Kristaq Berxholi; Blerta Mehmedi; Rreze M. Gecaj; Zamira Hoxha; Anja Joachim; Georg G. Duscher

2018-01-01

Tick-borne diseases pose a serious threat to human health in South-Eastern Europe, including Kosovo. While Crimean–Congo hemorrhagic fever (CCHF) is a well-known emerging infection in this area, there are no accurate data on Lyme borreliosis and tick-borne encephalitis (TBE). Therefore, we sampled and tested 795 ticks. Ixodes ricinus (n = 218), Dermacentor marginatus (n = 98), and Haemaphysalis spp. (n = 24) were collected from the environment by flagging (all from Kosovo), while Hyalomma mar...

The Tick Salivary Protein Salp15 Inhibits the Killing of Serum-Sensitive Borrelia burgdorferi Sensu Lato Isolates▿

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Schuijt, Tim J.; Hovius, Joppe W. R.; van Burgel, Nathalie D.; Ramamoorthi, Nandhini; Fikrig, Erol; van Dam, Alje P.

2008-01-01

Borrelia burgdorferi, the agent of Lyme disease, is transmitted by ticks. During transmission from the tick to the host, spirochetes are delivered with tick saliva, which contains the salivary protein Salp15. Salp15 has been shown to protect spirochetes against B. burgdorferi-specific antibodies. We now show that Salp15 from both Ixodes ricinus and Ixodes scapularis protects serum-sensitive isolates of Borrelia burgdorferi sensu lato against complement-mediated killing. I. ricinus Salp15 show...

Ability of two natural products, nootkatone and carvacrol, to suppress Ixodes scapularis and Amblyomma americanum (Acari: Ixodidae) in a Lyme disease endemic area of New Jersey.

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Dolan, Marc C; Jordan, Robert A; Schulze, Terry L; Schulze, Christopher J; Manning, Mark Cornell; Ruffolo, Daniel; Schmidt, Jason P; Piesman, Joseph; Karchesy, Joseph J

2009-12-01

We evaluated the ability of the natural, plant-derived acaricides nootkatone and carvacrol to suppress Ixodes scapularis Say and Amblyomma americanum (L.) (Acari: Ixodidae). Aqueous formulations of 1 and 5% nootkatone applied by backpack sprayer to the forest litter layer completely suppressed I. scapularis nymphs through 2 d. Thereafter, the level of reduction gradually declined to nootkatone was less effective, but at a 5% concentration, the level of control was similar or greater to that observed with I. scapularis through 21 d postapplication. Initial applications of 0.05% carvacrol were ineffective, but a 5% carvacrol formulation completely suppressed nymphs of both species through 2 d and resulted in significant reduction in I. scapularis and A. americanum nymphs through 28 and 14 d postapplication, respectively. Backpack sprayer applications of 5% nootkatone to the shrub and litter layers resulted in 100% control of I. scapularis adults through 6 d, but the level of reduction declined to 71.5% at 28 d postapplication. By contrast, high-pressure applications of 2% nootkatone to the litter layer resulted in 96.2-100% suppression of both I. scapularis and A. americanum nymphs through 42 d, whereas much lower control was obtained from the same formulation applied by backpack sprayer. Backpack sprayer application of a 3.1% nootkatone nanoemulsion resulted in 97.5-98.9 and 99.3-100% reduction in I. scapularis and A. americanum nymphs, respectively, at 1 d postapplication. Between 7 d and 35 d postapplication, the level of control varied between 57.1% and 92.5% for I. scapularis and between 78.5 and 97.1% for A. americanum nymphs. The ability of natural products to quickly suppress and maintain significant control of populations of these medically important ticks at relatively low concentrations may represent a future alternative to the use of conventional synthetic acaricides.

A Novel Scoring System Approach to Assess Patients with Lyme Disease (Nutech Functional Score)

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Geeta Shroff; Petra Hopf-Seidel

2018-01-01

Introduction: A bacterial infection by Borrelia burgdorferi referred to as Lyme disease (LD) or borreliosis is transmitted mostly by a bite of the tick Ixodes scapularis in the USA and Ixodes ricinus in Europe. Various tests are used for the diagnosis of LD, but their results are often unreliable. We compiled a list of clinically visible and patient-reported symptoms that are associated with LD. Based on this list, we developed a novel scoring system. Methodology: Nutech functional Score (NF...

Species distribution models and ecological suitability analysis for potential tick vectors of lyme disease in Mexico.

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Illoldi-Rangel, Patricia; Rivaldi, Chissa-Louise; Sissel, Blake; Trout Fryxell, Rebecca; Gordillo-Pérez, Guadalupe; Rodríguez-Moreno, Angel; Williamson, Phillip; Montiel-Parra, Griselda; Sánchez-Cordero, Víctor; Sarkar, Sahotra

2012-01-01

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.

Species Distribution Models and Ecological Suitability Analysis for Potential Tick Vectors of Lyme Disease in Mexico

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Patricia Illoldi-Rangel

2012-01-01

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.

Development and application of a universal Hemoplasma screening assay based on the SYBR green PCR principle.

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Willi, Barbara; Meli, Marina L; Lüthy, Ruedi; Honegger, Hanspeter; Wengi, Nicole; Hoelzle, Ludwig E; Reusch, Claudia E; Lutz, Hans; Hofmann-Lehmann, Regina

2009-12-01

Hemotropic mycoplasmas (hemoplasmas) are the causative agents of infectious anemia in several mammalian species. Their zoonotic potential has recently been substantiated by the identification of a feline hemoplasma isolate in an immunocompromised human patient. Although species-specific diagnostic molecular methods have been developed, their application as screening tools is limited due to the species diversity of hemoplasmas. The goals of this study were to develop a universal hemoplasma screening assay with broad specificity based on the SYBR green PCR principle, to compare the assay with hemoplasma-specific TaqMan PCR, and to analyze potential tick vectors and human blood samples to address the zoonotic potential. The newly developed PCR assay based on the 16S rRNA gene amplified feline, canine, bovine, porcine, camelid, and murine hemoplasmas, as well as Mycoplasma penetrans and Mycoplasma pneumoniae. The lower detection limit for feline and canine hemoplasmas was 1 to 10 copies/PCR. The assay exhibited 98.2% diagnostic sensitivity and 92.1% diagnostic specificity for feline hemoplasmas. All 1,950 Ixodes ticks were PCR negative, suggesting that Ixodes ticks are not relevant vectors for the above-mentioned hemoplasma species in Switzerland. None of the 414 blood samples derived from anemic or immunocompromised human patients revealed a clear positive result. The SYBR green PCR assay described here is a suitable tool to screen for known and so-far-undiscovered hemoplasma species. Positive results should be confirmed by specific TaqMan PCR or sequencing.

[Tick borne encephalitis and enviromental changes].

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Zajkowska, Joanna; Malzahn, Elzbieta; Kondrusik, Maciej; Grygorczuk, Sambor; Pancewicz, Sławomir S; Kuśmierczyk, Justyna; Czupryna, Piotr; Hermanowska-Szpakowicz, Teresa

2006-01-01

Currently observed markedly increased incidence of various tick borne diseases in many parts of Europe is due to documented climatic changes as well anthropogenic influence on habitat structure. One of the analyzed factors is tendency to increase of the spring temperatures, especially in the third decade of the April. Such conditions (spring temperatures above 7-10 degrees C) let the nymphs and larvae of Ixodes ricinus to feed simultaneously on rodents. This increases the risk of infection of Ixodes ricinus with TBE virus, so dangerous for humans.

Tick-Host Range Adaptation: Changes in Protein Profiles in Unfed Adult Ixodes scapularis and Amblyomma americanum Saliva Stimulated to Feed on Different Hosts

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Lucas Tirloni

2017-12-01

Full Text Available Understanding the molecular basis of how ticks adapt to feed on different animal hosts is central to understanding tick and tick-borne disease (TBD epidemiology. There is evidence that ticks differentially express specific sets of genes when stimulated to start feeding. This study was initiated to investigate if ticks such as Ixodes scapularis and Amblyomma americanum that are adapted to feed on multiple hosts utilized the same sets of proteins to prepare for feeding. We exposed I. scapularis and A. americanum to feeding stimuli of different hosts (rabbit, human, and dog by keeping unfed adult ticks enclosed in a perforated microfuge in close contact with host skin, but not allowing ticks to attach on host. Our data suggest that ticks of the same species differentially express tick saliva proteins (TSPs when stimulated to start feeding on different hosts. SDS-PAGE and silver staining analysis revealed unique electrophoretic profiles in saliva of I. scapularis and A. americanum that were stimulated to feed on different hosts: rabbit, human, and dog. LC-MS/MS sequencing and pairwise analysis demonstrated that I. scapularis and A. americanum ticks expressed unique protein profiles in their saliva when stimulated to start feeding on different hosts: rabbit, dog, or human. Specifically, our data revealed TSPs that were unique to each treatment and those that were shared between treatments. Overall, we identified a total of 276 and 340 non-redundant I. scapularis and A. americanum TSPs, which we have classified into 28 functional classes including: secreted conserved proteins (unknown functions, proteinase inhibitors, lipocalins, extracellular matrix/cell adhesion, heme/iron metabolism, signal transduction and immunity-related proteins being the most predominant in saliva of unfed ticks. With exception of research on vaccines against Rhipicephalus microplus, which its natural host, cattle, research on vaccine against other ticks relies feeding ticks

Effect of Climate and Land Use on the Spatio-Temporal Variability of Tick-Borne Bacteria in Europe

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Roberto Rosà

2018-04-01

Full Text Available The incidence of tick-borne diseases caused by Borrelia burgdorferi sensu lato, Anaplasma phagocytophilum and Rickettsia spp. has been rising in Europe in recent decades. Early pre-assessment of acarological hazard still represents a complex challenge. The aim of this study was to model Ixodes ricinus questing nymph density and its infection rate with B. burgdorferi s.l., A. phagocytophilum and Rickettsia spp. in five European countries (Italy, Germany, Czech Republic, Slovakia, Hungary in various land cover types differing in use and anthropisation (agricultural, urban and natural with climatic and environmental factors (Normalized Difference Vegetation Index (NDVI, Normalized Difference Water Index (NDWI, Land Surface Temperature (LST and precipitation. We show that the relative abundance of questing nymphs was significantly associated with climatic conditions, such as higher values of NDVI recorded in the sampling period, while no differences were observed among land use categories. However, the density of infected nymphs (DIN also depended on the pathogen considered and land use. These results contribute to a better understanding of the variation in acarological hazard for Ixodes ricinus transmitted pathogens in Central Europe and provide the basis for more focused ecological studies aimed at assessing the effect of land use in different sites on tick–host pathogens interaction.

Borrelia bissettiae sp. nov. and Borrelia californiensis sp. nov. prevail in diverse enzootic transmission cycles.

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Margos, Gabriele; Lane, Robert S; Fedorova, Natalia; Koloczek, Johannes; Piesman, Joseph; Hojgaard, Andrias; Sing, Andreas; Fingerle, Volker

2016-03-01

Two species of the genus Borrelia , Borrelia bissettiae sp. nov. and Borrelia californiensis sp. nov., were first described by Postic and co-workers on the basis of genetic analyses of several loci. Multilocus sequence analysis of eight housekeeping loci confirmed that these two Borrelia genomospecies are distinct members of the Borrelia burgdorferi sensu lato complex. B. bissettiae sp. nov. was initially described in transmission cycles involving Neotoma fuscipes wood rats and Ixodes pacificus ticks in California, and Neotoma mexicana and Ixodes spinipalpis in Colorado. The preferred host of B. californiensis sp. nov. appears to be the California kangaroo rat, Dipodomys californicus ; Ixodes jellisoni , I. spinipalipis and I. pacificus ticks are naturally infected with it. Thus, the ecological associations of the two genomospecies and their genetic distance from all other known Borrelia genomospecies species justify their description as separate genomospecies: B. bissettiae sp. nov. (type strain DN127 T  = DSM 17990 T  =  CIP 109136 T ) and B. californiensis (type strain CA446 T  = DSM 17989 T  = ATCC BAA-2689 T ).

A case of Guillain — Barre syndrome associated with ixodes tick borreliosis and listeriosis

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O.N. Domashenko

2017-03-01

, colorless, contains protein 0.71g/l, cytosis makes 1 cell per mcl (lymphocyte, red cell count was 1–3 per mcl, positive Pandy’s test, and glucose ratio of 3.9 mmol/l. IIFT (IgM, liquor as of 07.11.2016 indentified: negative Rubella virus; measles, mumps, Varicella zoster virus, adenovirus type 3; EBV, capsid antigen; Treponema pallidum; Toxoplasma gondii; HSV type I; negative HSV type II; Coxsackie virus type B1; Coxsackie virus type А7; Echo virus type 7; positive Borrelia afzelii; Borrelia burgdorferi sensu stricto; Borrelia garinii; Listeria monocytogenes 1/2а; Listeria monocytogenes 4b; СМV; negative Hemophilus influenza. PCR (liquor as of 07.11.2016 showed: no Toxoplasma gondii, Human herpes virus type 6, СМV. IgM antibodies profile to Borrelia antigens in the immunoblotting reaction (blood as of 09.11.2016 revealed specific antibodies of IgM class to Borrelia garinii (Flagellin, OspC; OspC to Borrelia afzelii — negative; OspC to Borrelia burgdorferi — negative. There was diagnosed Guillain — Barre acute inflammatory-allergic polyneuropathy (Landry type with pronounced quadriparesis, bulbar syndrome, oculomotor dysfunctions, associated with ixodes tick borreliosis and listeriosis, which were confirmed by IgM revealed to Borrelia garinii (IIFT in the liquor and Western blot reaction in the blood, IgM to Listeria monocytogenes 1/2а, 4b (IIFT in the liquor. The therapy included immunovenin, 5 sessions of plasmapheresis, cefepime, retarpen, cytoflavinum, cycloferonum, ceraxon, actovegin, neuromidin, proserinum, combilipen, diclophenacum, nucleo CMP, mexidol, fluconazole, probiotics, glucose solution, panangin, insulin, L-lysine aescinat, berlithion, suprastin, lasix, berlipril, bisoprololum, tube feeding, APV, microclysters. Since the 48th day of the disease the state of the patient started improving and the rapid recovery of neurological status was observed. Independent breathing restored. The laryngeal-pharyngeal reflexes, sensitive and motor activity

[Parasites of the Central American tapir Tapirus bairdii (Perissodactyla: Tapiridae) in Chiapas, Mexico].

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Cruz Aldán, Epigmenio; Lira Torres, Iván; Güiris Andrade, Dario Marcelino; Osorio Sarabia, David; Quintero M, Ma Teresa

2006-06-01

We analyzed 19 samples of Baird's tapir feces from La Sepultura Biosphere Reserve, collected between March and July 1999. We also took samples directly from a male tapir captured at the Montes Azules Biosphere Reserve. Both reserves are in Chiapas, Mexico. We used five techniques: flotation, MacMaster, micrometric, Ritchie's sedimentation and Ferreira's quantitative. In addition, we collected ectoparasites from animals captured in both reserves and from a captive couple from Tuxtla Gutierrez, Chiapas. These nematodes and protozoans were found: Agriostomun sp., Lacandoria sp., Neomurshidia sp., Trichostrongylus sp., Strongylus sp., Brachylumus sp, and an unidentified species of ancilostomaide. We also found Eimeria sp. and Balantidium coli, as well as the mites Dermacentor halli, Dermacentor latus, Amblyomma cajannense, Amblyomma coelebs, Amblyomma ovale, Anocentor nitens and Ixodes bicornis.

GENETIC POLYMORPHISM AND CYTOGENETIC CHANGES IN THE PERIPHERAL BLOOD T-LYMPHOCYTES OF PATIENTS WITH ARTHRITIS ASSOCIATED WITH IXODES TICK-BORNE BORRELIOSIS IN THE NORTHERN REGIONS OF SIBERIA

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N. N. Ilyinskikh

2017-01-01

Full Text Available The authors have previously conducted studies that demonstrate the increased level of cytogenetic disturbances in patients with Ixodes tick-borne borreliosis (ITB. The severity of arthritis associated with ITB (AITB is also ascertained to depend on whether the patient has certain HLA-DRB1 alleles.Objective: to assess the association between HLA-DRB1 gene polymorphism and cytogenetic changes in the peripheral blood T lymphocytes of patients with AITB.Subjects and methods. 146 patients with AITB, 100 clinically healthy convalescents with ITB (CITB, and a control group of 98 healthy blood donors (HBDs without a history of tick-borne infections were examined using cytogenetic (micronucleus analysis of cytokinesis-blocked peripheral blood T lymphocytes and molecular genetic (PCR analysis of HLA-DRB1 gene polymorphism methods.Results and discussion. The frequency of cytokinesis-blocked lymphocytes with micronuclei in the AITB group was significantly higher than that in the CITB and HBD groups (p<0.01 with the exception of the results obtained in the subgroup of patients with AITB who had the DRB1*10 allele (p>0.05. The highest levels of lymphocytes with micronuclei were observed in AITB patients with the DRB1*17(03, *01, and *04 alleles as compared to those in the CITB and HBD groups (p<0.001. The CITB group showed the most significant increase in the detection rate of lymphocytes with micronuclei in people with the DRB1*01, DRB1*04, or *17(03 alleles. At the same time, there were no significant differences in the number of lymphocytes with micronuclei in the HBD group, depending on the HLA-DRB1 gene alleles (p>0.05. Thus, the patients with AITB had the highest frequency of cytogenetic disorders with the exception of individuals with the DRB1*10 allele.

Prevalence of ticks and tick-borne pathogens: Babesia and Borrelia species in ticks infesting cats of Great Britain.

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Davies, Saran; Abdullah, Swaid; Helps, Chris; Tasker, Séverine; Newbury, Hannah; Wall, Richard

2017-09-15

In a study of tick and tick-borne pathogen prevalence, between May and October 2016, 278 veterinary practices in Great Britain examined 1855 cats. Six-hundred and one cats were found to have attached ticks. The most frequently recorded tick species was Ixodes ricinus (57.1%), followed by Ixodes hexagonus (41.4%) and Ixodes trianguliceps (1.5%). Male cats, 4-6 years of age living in rural areas were most likely to be carrying a tick; hair length and tick treatment history had no significant association with attachment. For cats that were parasitized by ticks in large urban areas, I. hexagonus was the most frequent species recorded. Molecular analysis was possible for 541 individual tick samples, others were too damaged for analysis; Babesia spp., and Borrelia burgdorferi sensu lato were identified in 1.1% (n=6) and 1.8% (n=10) of these, respectively. Babesia spp. included Babesia vulpes sp. nov./Babesia microti-like (n=4) in I. hexagonus and Babesia venatorum (n=2) in I. ricinus. Borrelia burgdorferi s.l. species included Borrelia garinii (n=6) and Borrelia afzelii (n=4). The majority of B. burgorferi s.l. cases were found in I. ricinus, with B. afzelii in one I. hexagonus nymph. No Borrelia or Babesia spp. were present in I. trianguliceps. To determine a true prevalence for ticks on cats, practices that only submitted questionnaires from cats with ticks and practices that submitted fewer than 5 returns per week were removed; amongst those considered to have adhered strictly to the collection protocol, feline tick prevalence amongst cats that had access to the outdoors was 6.6%. These results show that ticks can be found on cats throughout Great Britain, which harbour a range of species of Babesia and B. burgdorferi s.l. and that cats, particularly in green spaces within urban areas, may form an important host for I. hexagonus, a known vector of pathogens. Copyright © 2017 Elsevier B.V. All rights reserved.

[Genetic characterisation of Powassan virus (POWV) isolated from Haemophysalis longicornis ticks in Primorye and two strains of Tick-borne encephalitis virus (TBEV) (Flaviviridae, Flavivirus): Alma-Arasan virus (AAV) isolated from Ixodes persulcatus ticks in Kazakhstan and Malyshevo virus isolated from Aedes vexans nipponii mosquitoes in Khabarovsk kray].

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L'vov, D K; Al'khovskiĭ, S V; Shchelkanov, M Iu; Deriabin, P G; Gitel'man, A K; Botikov, A G; Aristova, V A

2014-01-01

The complete genomes of the three tick-borne flaviviruses (genus Flavivirus, fam. Bunyaviridae) were sequenced: Povassan virus (POWV, strain LEIV-3070Prm, isolated from Haemophysalis logicornis in Primorsky Krai, Russia in 1977), Alma-Arasan virus (AAV, strain LEIV-1380Kaz, isolated from Ixodes persulcatus ticks in Kazakhstan in 1977) and Malyshevo virus (isolated from a pool of Aedes vexans nipponii mosquitoes, in the Khabarovsk Krai, Russia in 1978). It is shown that AAV and Malyshevo virus are the strains of Tick-borne encephalitis virus (TBEV) and belong to Sibirian and Far-Eastern genotypes, respectively (GenBank ID: AAV KJ744033; strain Malyshevo KJ744034). Phylogenetically AAV is closest related (94,6% nt and 98,3% aa identity) to TBEV strains, isolated in Sibiria (Vasilchenko, Aino, Chita-653, Irkutsk-12). Malyshevo virus is closest related (96,4% nt and 98,3% nt identity) to strains of TBEV, isolated in Far Eastern part of Russia (1230, Spassk-72, Primorye-89). POWV LEIV-3070Prm has 99.7% identity with the prototype strain POWV LB, isolated in Canada and 99.5% of isolates with Far-Eastern strains of POWV (Spassk-9 and Nadezdinsk-1991).

Prevention of infectious tick-borne diseases in humans: Comparative studies of the repellency of different dodecanoic acid-formulations against Ixodes ricinus ticks (Acari: Ixodidae

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Dautel Hans

2008-04-01

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

Survey of ticks (Acari: Ixodidae) and tick-borne pathogens in North Dakota.

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Russart, Nathan M; Dougherty, Michael W; Vaughan, Jefferson A

2014-09-01

Ticks were sampled at nine locations throughout North Dakota during early summer of 2010, using flagging techniques and small mammals trapping. In total, 1,762 ticks were collected from eight of the nine locations. The dominant species were Dermacentor variabilis (Say) (82%), found throughout the state, and Ixodes scapularis Say (17%), found in northeastern counties. A few nymphal and adult I. scapularis tested positive for Borrelia burgdorferi (3%) and Anaplasma phagocytophilum (8%). This is the first report of I. scapularis and associated pathogens occurring in North Dakota and provides evidence for continued westward expansion of this important vector tick species in the United States.

Sample size estimation and sampling techniques for selecting a representative sample

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Aamir Omair

2014-01-01

Full Text Available Introduction: The purpose of this article is to provide a general understanding of the concepts of sampling as applied to health-related research. Sample Size Estimation: It is important to select a representative sample in quantitative research in order to be able to generalize the results to the target population. The sample should be of the required sample size and must be selected using an appropriate probability sampling technique. There are many hidden biases which can adversely affect the outcome of the study. Important factors to consider for estimating the sample size include the size of the study population, confidence level, expected proportion of the outcome variable (for categorical variables/standard deviation of the outcome variable (for numerical variables, and the required precision (margin of accuracy from the study. The more the precision required, the greater is the required sample size. Sampling Techniques: The probability sampling techniques applied for health related research include simple random sampling, systematic random sampling, stratified random sampling, cluster sampling, and multistage sampling. These are more recommended than the nonprobability sampling techniques, because the results of the study can be generalized to the target population.

Anaplasma phagocytophilum in Danish sheep: confirmation by DNA sequencing

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Thamsborg Stig M

2009-12-01

Full Text Available Abstract Background The presence of Anaplasma phagocytophilum, an Ixodes ricinus transmitted bacterium, was investigated in two flocks of Danish grazing lambs. Direct PCR detection was performed on DNA extracted from blood and serum with subsequent confirmation by DNA sequencing. Methods 31 samples obtained from clinically normal lambs in 2000 from Fussingø, Jutland and 12 samples from ten lambs and two ewes from a clinical outbreak at Feddet, Zealand in 2006 were included in the study. Some of the animals from Feddet had shown clinical signs of polyarthritis and general unthriftiness prior to sampling. DNA extraction was optimized from blood and serum and detection achieved by a 16S rRNA targeted PCR with verification of the product by DNA sequencing. Results Five DNA extracts were found positive by PCR, including two samples from 2000 and three from 2006. For both series of samples the product was verified as A. phagocytophilum by DNA sequencing. Conclusions A. phagocytophilum was detected by molecular methods for the first time in Danish grazing lambs during the two seasons investigated (2000 and 2006.

Microbial population analysis of the salivary glands of ticks; a possible strategy for the surveillance of bacterial pathogens.

Directory of Open Access Journals (Sweden)

Yongjin Qiu

Full Text Available Ticks are one of the most important blood-sucking vectors for infectious microorganisms in humans and animals. When feeding they inject saliva, containing microbes, into the host to facilitate the uptake of blood. An understanding of the microbial populations within their salivary glands would provide a valuable insight when evaluating the vectorial capacity of ticks. Three tick species (Ixodes ovatus, I. persulcatus and Haemaphysalis flava were collected in Shizuoka Prefecture of Japan between 2008 and 2011. Each tick was dissected and the salivary glands removed. Bacterial communities in each salivary gland were characterized by 16S amplicon pyrosequencing using a 454 GS-Junior Next Generation Sequencer. The Ribosomal Database Project (RDP Classifier was used to classify sequence reads at the genus level. The composition of the microbial populations of each tick species were assessed by principal component analysis (PCA using the Metagenomics RAST (MG-RAST metagenomic analysis tool. Rickettsia-specific PCR was used for the characterization of rickettsial species. Almost full length of 16S rDNA was amplified in order to characterize unclassified bacterial sequences obtained in I. persulcatus female samples. The numbers of bacterial genera identified for the tick species were 71 (I. ovatus, 127 (I. persulcatus and 59 (H. flava. Eighteen bacterial genera were commonly detected in all tick species. The predominant bacterial genus observed in all tick species was Coxiella. Spiroplasma was detected in Ixodes, and not in H. flava. PCA revealed that microbial populations in tick salivary glands were different between tick species, indicating that host specificities may play an important role in determining the microbial complement. Four female I. persulcatus samples contained a high abundance of several sequences belonging to Alphaproteobacteria symbionts. This study revealed the microbial populations within the salivary glands of three species of

Parásitos del tapir centroamericano Tapirus bairdii (Perissodactyla: Tapiridae en Chiapas, México

Directory of Open Access Journals (Sweden)

Epigmenio Cruz Aldán

2006-06-01

Full Text Available Se recolectaron 19 muestras de excretas del tapir centroamericano (Tapirus bairdii en la Reserva "La Sepultura" (marzo a julio de 1999, así como un muestreo directo a un tapir macho de la Reserva "Montes Azules" (Chiapas, México. Se analizaron con cinco técnicas (flotación, MacMaster, micrometría, sedimentación de Ritchie y cuantitativa de Ferreira. Además se recolectaron muestras en piel de animales capturados en en las dos reservas y en una pareja de zoológico proveniente de Tuxtla Gutiérrez, Chiapas. Se hallaron nematodos y protozoarios: Agriostomun sp., Lacandoria sp., Neomurshidia sp., Trichostrongylus sp., Strongylus sp., Brachylumus sp., y un ancilostomaideo aun por identificar. Además se informa la presencia de Eimeria sp., y Balantidium coli. Los ácaros hallados fueron; Dermacentor halli, Dermacentor latus, Amblyomma cajannense, Amblyomma coelebs, Amblyomma ovale, Anocentor nitens e Ixodes bicornis.Parasites of the Central American tapir Tapirus bairdii (Perissodactyla: Tapiridae in Chiapas, Mexico. We analyzed 19 samples of Baird´s tapir feces from La Sepultura Biosphere Reserve, collected between March and July 1999. We also took samples directly from a male tapir captured at the Montes Azules Biosphere Reserve. Both reserves are in Chiapas, Mexico. We used five techniques: flotation, MacMaster, micrometric, Ritchie’s sedimentation and Ferreira´s quantitative. In addition, we collected ectoparasites from animals captured in both reserves and from a captive couple from Tuxtla Gutierrez, Chiapas. These nematodes and protozoans were found: Agriostomun sp., Lacandoria sp., Neomurshidia sp., Trichostrongylus sp., Strongylus sp., Brachylumus sp, and an unidentified species of ancilostomaide. We also found Eimeria sp. and Balantidium coli, as well as the mites Dermacentor halli, Dermacentor latus, Amblyomma cajannense, Amblyomma coelebs, Amblyomma ovale, Anocentor nitens and Ixodes bicornis. Rev. Biol. Trop. 54(2: 445

Ehrlichiosis

Science.gov (United States)

... Ehrlichia bacteria can be carried by the: American dog tick Deer tick ( Ixodes scapularis ), which can also ... your vital signs, including: Blood pressure Heart rate Temperature Other tests include: Complete blood count ( CBC ) Granulocyte ...

Identification and characterization of histidine-rich peptides from hard ticks Ixodes ricinus and Ixodes scapularis.

OpenAIRE

DORŇÁKOVÁ, Veronika

2011-01-01

Antimicrobial (cationic) proteins play an important role in innate imunity. Such proteins can possess antibacterial, antiendotoxic or fungicidal abilities. The rising resistence of microbes to common antibiotics evokes acute need of studying more endogenous proteins to reveal new potential antibiotics. Ticks, the blood-feeding ectoparasites with effectual defense system, present an endless source of newly described and unknown antimicrobial peptides/proteins with significant theurapeutic pote...

Complex Population Structure of Lyme Borreliosis Group Spirochete Borrelia garinii in Subarctic Eurasia

Science.gov (United States)

Comstedt, Pär; Asokliene, Loreta; Eliasson, Ingvar; Olsen, Björn; Wallensten, Anders; Bunikis, Jonas; Bergström, Sven

2009-01-01

Borrelia garinii, a causative agent of Lyme borreliosis in Europe and Asia, is naturally maintained in marine and terrestrial enzootic cycles, which primarily involve birds, including seabirds and migratory passerines. These bird groups associate with, correspondingly, Ixodes uriae and Ixodes ricinus ticks, of which the latter species may bite and transmit the infection to humans. Studies of the overlap between these two natural cycles of B. garinii have been limited, in part due to the absence of representative collections of this spirochete's samples, as well as of the lack of reliable measure of the genetic heterogeneity of its strains. As a prerequisite for understanding the epidemiological correlates of the complex maintenance of B. garinii, the present study sought to assess the diversity and phylogenetic relationships of this species' strains from its natural hosts and patients with Lyme borreliosis from subarctic Eurasia. We used sequence typing of the partial rrs-rrl intergenic spacer (IGS) of archived and prospective samples of B. garinii from I. uriae ticks collected predominantly on Commander Islands in North Pacific, as well as on the islands in northern Sweden and arctic Norway. We also typed B. garinii samples from patients with Lyme borreliosis and I. ricinus ticks infesting migratory birds in southern Sweden, or found questing in selected sites on the islands in the Baltic Sea and Lithuania. Fifty-two (68%) of 77 B. garinii samples representing wide geographical range and associated with I. ricinus and infection of humans contributed 12 (60%) of total 20 identified IGS variants. In contrast, the remaining 25 (32%) samples recovered from I. uriae ticks from a few islands accounted for as many as 10 (50%) IGS types, suggesting greater local diversity of B. garinii maintained by seabirds and their ticks. Two IGS variants of the spirochete in common for both tick species were found in I. ricinus larvae from migratory birds, an indication that B

A molecular survey of Theileria and Babesia parasites in cattle, with a note on the distribution of ticks in Tunisia.

Science.gov (United States)

M'ghirbi, Y; Hurtado, A; Barandika, J F; Brandika, J; Khlif, K; Ketata, Z; Bouattour, A

2008-07-01

Between October and November 2006, a total of 278 bovine blood samples were examined, and 104 (37.4%) were positive for piroplasms by microscopy. A reverse line blot hybridisation with polymerase chain reaction detected Theileria annulata, T. buffeli, Babesia bovis and B. bigemina in cattle accounting for 48.6% of positive samples. The most frequently found species was T. buffeli, which was present in 39.2% of the samples. T. annulata was found in 48 samples (17.3%). Babesia infections were less frequently detected: B. bovis was found in 6.8% of the samples and B. bigemina in 4.3%. Mixed infections were detected in 45 samples, accounting for seven different combinations of species. Seven Ixodid tick species (Boophilus annulatus, Ixodes ricinus, Hyalomma marginatum, Hyalomma excavatum, Hyalomma detritum, Haemaphysalis punctata and Haemaphysalis sulcata) were collected from examined cattle in the 23 visited farms. I. ricinus was the dominant species (36%), mainly collected in the humid zone, while it seemed to be very rare in the semi-arid zone (where only 15 specimens were collected), whereas B. annulatus was the most commonly collected species in the sub-humid area (68.5% of ticks collected in this zone).

The Tick Salivary Protein Sialostatin L2 Inhibits Caspase-1-Mediated Inflammation during Anaplasma phagocytophilum Infection

Czech Academy of Sciences Publication Activity Database

Chen, G.; Wang, X.; Sakhon, O. S.; Sohail, M.; Brown, L.J.; Sircar, M.; Snyder, G.A.; Sundberg, E.J.; Ulland, T.K.; Olivier, A.K.; Andersen, J. F.; Zhou, Y.; Shi, G.-P.; Sutterwala, F.S.; Kotsyfakis, Michalis; Pedra, J. H. F.

2014-01-01

Roč. 82, č. 6 (2014), s. 2553-2564 ISSN 0019-9567 Institutional support: RVO:60077344 Keywords : granulocytic ehrlichiosis agent * Ixodes scapularis * tumor necrosis factor Subject RIV: EC - Immunology Impact factor: 3.731, year: 2014

Systematic sampling with errors in sample locations

DEFF Research Database (Denmark)

Ziegel, Johanna; Baddeley, Adrian; Dorph-Petersen, Karl-Anton

2010-01-01

analysis using point process methods. We then analyze three different models for the error process, calculate exact expressions for the variances, and derive asymptotic variances. Errors in the placement of sample points can lead to substantial inflation of the variance, dampening of zitterbewegung......Systematic sampling of points in continuous space is widely used in microscopy and spatial surveys. Classical theory provides asymptotic expressions for the variance of estimators based on systematic sampling as the grid spacing decreases. However, the classical theory assumes that the sample grid...... is exactly periodic; real physical sampling procedures may introduce errors in the placement of the sample points. This paper studies the effect of errors in sample positioning on the variance of estimators in the case of one-dimensional systematic sampling. First we sketch a general approach to variance...

[A comparison of convenience sampling and purposive sampling].

Science.gov (United States)

Suen, Lee-Jen Wu; Huang, Hui-Man; Lee, Hao-Hsien

2014-06-01

Convenience sampling and purposive sampling are two different sampling methods. This article first explains sampling terms such as target population, accessible population, simple random sampling, intended sample, actual sample, and statistical power analysis. These terms are then used to explain the difference between "convenience sampling" and purposive sampling." Convenience sampling is a non-probabilistic sampling technique applicable to qualitative or quantitative studies, although it is most frequently used in quantitative studies. In convenience samples, subjects more readily accessible to the researcher are more likely to be included. Thus, in quantitative studies, opportunity to participate is not equal for all qualified individuals in the target population and study results are not necessarily generalizable to this population. As in all quantitative studies, increasing the sample size increases the statistical power of the convenience sample. In contrast, purposive sampling is typically used in qualitative studies. Researchers who use this technique carefully select subjects based on study purpose with the expectation that each participant will provide unique and rich information of value to the study. As a result, members of the accessible population are not interchangeable and sample size is determined by data saturation not by statistical power analysis.

ANTIDotE: anti-tick vaccines to prevent tick-borne diseases in Europe

Czech Academy of Sciences Publication Activity Database

Sprong, H.; Trentelman, J.; Seemann, I.; Grubhoffer, Libor; Rego, Ryan O. M.; Hajdušek, Ondřej; Kopáček, Petr; Šíma, Radek; Nijhof, A.M.; Anguita, J.; Winter, P.; Rotter, B.; Havlíková, S.; Klempa, B.; Schetters, T.P.; Hovius, J.W.R.

2014-01-01

Roč. 7, FEB 2014 (2014), s. 77 ISSN 1756-3305 Institutional support: RVO:60077344 Keywords : Ixodes ricinus * vaccine * Lyme borreliosis * tick-borne encephalitis * babesiosis * public health Subject RIV: EC - Immunology Impact factor: 3.430, year: 2014

Ticks (Ixodidae) from passerine birds in the Carpathian region

Czech Academy of Sciences Publication Activity Database

Spitalska, E.; Literák, I.; Sparagano, O. A .E.; Golovchenko, Maryna; Kocianová, E.

2006-01-01

Roč. 118, 23/24 (2006), 759-764 ISSN 0043-5325 Institutional research plan: CEZ:AV0Z60220518 Keywords : Passerine birds * Ixodes ricinus * Borrelia * Rickettsia * Ehrlichia * Carpathians Subject RIV: EC - Immunology Impact factor: 0.804, year: 2006

Information sampling behavior with explicit sampling costs

Science.gov (United States)

Juni, Mordechai Z.; Gureckis, Todd M.; Maloney, Laurence T.

2015-01-01

The decision to gather information should take into account both the value of information and its accrual costs in time, energy and money. Here we explore how people balance the monetary costs and benefits of gathering additional information in a perceptual-motor estimation task. Participants were rewarded for touching a hidden circular target on a touch-screen display. The target’s center coincided with the mean of a circular Gaussian distribution from which participants could sample repeatedly. Each “cue” — sampled one at a time — was plotted as a dot on the display. Participants had to repeatedly decide, after sampling each cue, whether to stop sampling and attempt to touch the hidden target or continue sampling. Each additional cue increased the participants’ probability of successfully touching the hidden target but reduced their potential reward. Two experimental conditions differed in the initial reward associated with touching the hidden target and the fixed cost per cue. For each condition we computed the optimal number of cues that participants should sample, before taking action, to maximize expected gain. Contrary to recent claims that people gather less information than they objectively should before taking action, we found that participants over-sampled in one experimental condition, and did not significantly under- or over-sample in the other. Additionally, while the ideal observer model ignores the current sample dispersion, we found that participants used it to decide whether to stop sampling and take action or continue sampling, a possible consequence of imperfect learning of the underlying population dispersion across trials. PMID:27429991

Clinical outbreak of babesiosis caused by Babesia capreoli in captive reindeer (Rangifer tarandus tarandus) in the Netherlands.

Science.gov (United States)

Bos, Jan H; Klip, Fokko C; Sprong, Hein; Broens, Els M; Kik, Marja J L

2017-08-01

From a herd of captive reindeer (Rangifer tarandus tarandus) consisting of two males and seven females with five calves, three calves were diagnosed on post mortem examination with a Babesia capreoli infection. The diagnosis was indicated by PCR and when the other reindeer were examined two adult females and a one-year-old male were Babesia-positive. Molecular characterization of the 18S rDNA of the parasite showed complete identity with known B. capreoli sequences. Ixodes ricinus has been demonstrated to be a competent vector for B. capreoli from infected roe deer (Capreolus capreolus), the natural host of B. capreoli. The B. capreoli infection in these reindeer may have been transmitted by infected ticks (Ixodes ricinus) originating from roe deer living in the forest and meadows surrounding the enclosure. Copyright © 2017 Elsevier GmbH. All rights reserved.

Samples and Sampling Protocols for Scientific Investigations | Joel ...

African Journals Online (AJOL)

... from sampling, through sample preparation, calibration to final measurement and reporting. This paper, therefore offers useful information on practical guidance on sampling protocols in line with best practice and international standards. Keywords: Sampling, sampling protocols, chain of custody, analysis, documentation ...

North Spain (Burgos wild mammals ectoparasites

Directory of Open Access Journals (Sweden)

Domínguez G.

2004-09-01

Full Text Available Twenty-seven species of arthropods were collected from 105 wild mammals, six wolves Canis lupus (Linnaeus, 1758 included. A total of 87 animals (82,8 % harboured some ectoparasites. Ticks were found in 60 % of the samples, fleas in 51.4 %, chewing-lice in 3.8 %, and others (Mesostigmata and hippoboscids in 3.8 %. Moreover, 42.5 % were single infestation and 57.5 % mixed. Some of the species were new records for a host in spanish country such as Trichodectes canis (De Géer, 1778, Ixodes trianguliceps (Birula, 1895, Ceralophyllus (Monopsyllus S. sciurorum (Schrank, 1803 and Paraceras melis melis (Walker, 1856 on several mammals. Two species were new records for Spain: Chaetopsylla matina (Jordan, 1925 and Archaeopsylla erinacei erinacei (Bouché, 1835.

Flåtbårne infektioner i Danmark

DEFF Research Database (Denmark)

Jensen, Bo Bødker; Ocias, Lukas Frans; Andersen, Nanna Skaarup

2017-01-01

The castor bean tick, Ixodes ricinus, is common in woodlands in most of Denmark. Besides Borrelia burgdorferi, it can harbour a number of pathogenic microorganisms such as tick-borne encephalitis virus, Anaplasma phagocytophilum, Rickettsia helvetica, Francisella tularensis, Candidatus Neoehrlichia...

Abundance of questing ticks and molecular evidence for pathogens in ticks in three parks of Emilia-Romagna region of Northern Italy

Directory of Open Access Journals (Sweden)

Sara Aureli

2015-09-01

Full Text Available Introduction and objective. Infectious and parasitic diseases transmitted by ticks, such as Lyme diseases, granulocytic anaplasmosis and piroplasmosis, have been frequently reported in Europe, with increasing attention to them as an emerging zoonotic problem. The presented study was performed to assess the distribution and the density of questing ticks in three regional parks of Emilia-Romagna region of Northern Italy, and to seek molecular evidence of potential human pathogens in tick populations. Materials and Methods. In the period April-October 2010, 8,139 questing ticks were collected: 6,734 larvae, 1,344 nymphs and only a few adults – 28 females and 33 males. The abundance of[i] Ixodes ricinus[/i] questing ticks was compared among different sampling sites and related to microclimate parameters. 1,544 out of 8,139 ticks were examined for the presence of pathogens: PCR was used to detect piroplasms DNA and Real time Taqman PCR for [i]Anaplasma phagocytophilum[/i] and [i]Borrelia burgdorferi[/i] s.l. Results. The predominant species was [i]I. ricinus[/i] (overall abundance 1,075.9/100 m[sup]2[/sup] ; more rarely, [i]Dermacentor marginatus[/i] (n = 37 – 0.45%, [i]Scaphixodes frontalis[/i] (n = 13 – 0.16%, [i]Hyalomma[/i] spp. (n = 6 – 0.07% and [i]Ixodes acuminatus[/i] (n = 3 – 0.04% were also found. 28 out of 324 (8.6% samples of ticks were PCR-positive for piroplasm DNA. 11 amplicons of 18S rRNA gene were identical to each other and had 100% identity with[i] Babesia[/i] EU1 ([i]Babesia venatorum[/i] using BLAST analysis. Real time Taqman PCR gave positive results for [i]A. phagocytophilum[/i] in 23 out of 292 samples (7.9%, and for [i]B. burgdorferi[/i] s.l. in 78 out of 292 samples (26.7%. [i]I. ricinu[/i]s was the only species found positive for pathogens by molecular analysis; 16 tick samples were co-infected with at least 2 pathogens. Discussion. The peak of nymph presence was in May, and the higher prevalence of pathogens

Sampling and chemical analysis in environmental samples around Nuclear Power Plants and some environmental samples

Energy Technology Data Exchange (ETDEWEB)

Cho, Yong Woo; Han, Man Jung; Cho, Seong Won; Cho, Hong Jun; Oh, Hyeon Kyun; Lee, Jeong Min; Chang, Jae Sook [KORTIC, Taejon (Korea, Republic of)

2002-12-15

Twelve kinds of environmental samples such as soil, seawater, underground water, etc. around Nuclear Power Plants(NPPs) were collected. Tritium chemical analysis was tried for the samples of rain water, pine-needle, air, seawater, underground water, chinese cabbage, a grain of rice and milk sampled around NPPs, and surface seawater and rain water sampled over the country. Strontium in the soil that sere sampled at 60 point of district in Korea were analyzed. Tritium were sampled at 60 point of district in Korea were analyzed. Tritium were analyzed in 21 samples of surface seawater around the Korea peninsular that were supplied from KFRDI(National Fisheries Research and Development Institute). Sampling and chemical analysis environmental samples around Kori, Woolsung, Youngkwang, Wooljin Npps and Taeduk science town for tritium and strontium analysis was managed according to plans. Succeed to KINS after all samples were tried.

A tick mannose-binding lectin inhibitor interferes with the vertebrate complement cascade to enhance transmission of the lyme disease agent

NARCIS (Netherlands)

Schuijt, Tim J.; Coumou, Jeroen; Narasimhan, Sukanya; Dai, Jianfeng; Deponte, Kathleen; Wouters, Diana; Brouwer, Mieke; Oei, Anneke; Roelofs, Joris J. T. H.; van Dam, Alje P.; van der Poll, Tom; van't Veer, Cornelis; Hovius, Joppe W.; Fikrig, Erol

2011-01-01

The Lyme disease agent Borrelia burgdorferi is primarily transmitted to vertebrates by Ixodes ticks. The classical and alternative complement pathways are important in Borrelia eradication by the vertebrate host. We recently identified a tick salivary protein, designated P8, which reduced

Pierre Gy's sampling theory and sampling practice heterogeneity, sampling correctness, and statistical process control

CERN Document Server

Pitard, Francis F

1993-01-01

Pierre Gy's Sampling Theory and Sampling Practice, Second Edition is a concise, step-by-step guide for process variability management and methods. Updated and expanded, this new edition provides a comprehensive study of heterogeneity, covering the basic principles of sampling theory and its various applications. It presents many practical examples to allow readers to select appropriate sampling protocols and assess the validity of sampling protocols from others. The variability of dynamic process streams using variography is discussed to help bridge sampling theory with statistical process control. Many descriptions of good sampling devices, as well as descriptions of poor ones, are featured to educate readers on what to look for when purchasing sampling systems. The book uses its accessible, tutorial style to focus on professional selection and use of methods. The book will be a valuable guide for mineral processing engineers; metallurgists; geologists; miners; chemists; environmental scientists; and practit...

Systematic Sampling and Cluster Sampling of Packet Delays

OpenAIRE

Lindh, Thomas

2006-01-01

Based on experiences of a traffic flow performance meter this papersuggests and evaluates cluster sampling and systematic sampling as methods toestimate average packet delays. Systematic sampling facilitates for exampletime analysis, frequency analysis and jitter measurements. Cluster samplingwith repeated trains of periodically spaced sampling units separated by randomstarting periods, and systematic sampling are evaluated with respect to accuracyand precision. Packet delay traces have been ...

Sampling

CERN Document Server

Thompson, Steven K

2012-01-01

Praise for the Second Edition "This book has never had a competitor. It is the only book that takes a broad approach to sampling . . . any good personal statistics library should include a copy of this book." —Technometrics "Well-written . . . an excellent book on an important subject. Highly recommended." —Choice "An ideal reference for scientific researchers and other professionals who use sampling." —Zentralblatt Math Features new developments in the field combined with all aspects of obtaining, interpreting, and using sample data Sampling provides an up-to-date treat

[Using the polymerase chain reaction to Borrelia burgdorferi infection in localized scleroderma injure (morphea), in Venezuelan patients].

Science.gov (United States)

Espinoza-León, Fabiola; Arocha, Francisco; Hassanhi, Manzur; Arévalo, Julio

2010-09-01

Borrelia burgdorferi is the causative agent of Lyme Borreliosis, an infectious multisystemic disease transmitted to humans by the Ixodes ticks bite. A possible association of Borrelia burgdorferi with localized scleroderma has been postulated. However, published data do not provide unequivocal results. Previous serologic analysis of patients with localized scleroderma in South American countries (including Venezuela), have been reported as yielding some reactivity. The present study looked for evidence of Borrelia burgdorferi infection in venezuelan patients with localized scleroderma, using the polymerase chain reaction to analyze 21 skin samples of patients with this skin condition. The results were negative in all the samples studied. Our data do not support an association of Borrelia burgdorferi infection and the sclerotic lesions of localized scleroderma; but do not rule out the possibility of a relationship between localized scleroderma and an unknown geno-specie of Borrelia burgdorferi sensu lato complex, a different Borrelia specie or a different spirochetal organism, as the etiological agents of the skin lesions in this area.

Water born pollutants sampling using porous suction samples

International Nuclear Information System (INIS)

Baig, M.A.

1997-01-01

The common standard method of sampling water born pollutants in the vadoze zone is core sampling and it is followed by extraction of pore fluid. This method does not allow sampling at the same location next time and again later on. There is an alternative approach for sampling fluids (water born pollutants) from both saturated and unsaturated regions of vadose zone using porous suction samplers. There are three types of porous suction samplers, vacuum-operated, pressure-vacuum lysimeters, high pressure vacuum samples. The suction samples are operated in the range of 0-70 centi bars and usually consist of ceramic and polytetrafluorethylene (PTFE). The operation range of PTFE is higher than ceramic cups. These samplers are well suited for in situ and repeated sampling form the same location. This paper discusses the physical properties and operating condition of such samplers to the utilized under our environmental sampling. (author)

Choosing a suitable sample size in descriptive sampling

International Nuclear Information System (INIS)

Lee, Yong Kyun; Choi, Dong Hoon; Cha, Kyung Joon

2010-01-01

Descriptive sampling (DS) is an alternative to crude Monte Carlo sampling (CMCS) in finding solutions to structural reliability problems. It is known to be an effective sampling method in approximating the distribution of a random variable because it uses the deterministic selection of sample values and their random permutation,. However, because this method is difficult to apply to complex simulations, the sample size is occasionally determined without thorough consideration. Input sample variability may cause the sample size to change between runs, leading to poor simulation results. This paper proposes a numerical method for choosing a suitable sample size for use in DS. Using this method, one can estimate a more accurate probability of failure in a reliability problem while running a minimal number of simulations. The method is then applied to several examples and compared with CMCS and conventional DS to validate its usefulness and efficiency

Sampling and examination methods used for TMI-2 samples

International Nuclear Information System (INIS)

Marley, A.W.; Akers, D.W.; McIsaac, C.V.

1988-01-01

The purpose of this paper is to summarize the sampling and examination techniques that were used in the collection and analysis of TMI-2 samples. Samples ranging from auxiliary building air to core debris were collected and analyzed. Handling of the larger samples and many of the smaller samples had to be done remotely and many standard laboratory analytical techniques were modified to accommodate the extremely high radiation fields associated with these samples. The TMI-2 samples presented unique problems with sampling and the laboratory analysis of prior molten fuel debris. 14 refs., 8 figs

EST Table: DC572689 [KAIKOcDNA[Archive

Lifescience Database Archive (English)

Full Text Available DC572689 E_FL_wd--_27G20_R_0 10/09/28 53 %/126 aa ref|XP_002400269.1| DNA mismatch repair protein mlh1..., putative [Ixodes scapularis] gb|EEC09245.1| DNA mismatch repair protein mlh1, putative

EST Table: DC572641 [KAIKOcDNA[Archive

Lifescience Database Archive (English)

Full Text Available DC572641 E_FL_wd--_27E09_R_0 10/09/28 52 %/145 aa ref|XP_002400269.1| DNA mismatch repair protein mlh1..., putative [Ixodes scapularis] gb|EEC09245.1| DNA mismatch repair protein mlh1, putative

EST Table: DC563666 [KAIKOcDNA[Archive

Lifescience Database Archive (English)

Full Text Available DC563666 E_FL_wd--_01A16_R_0 10/09/28 53 %/141 aa ref|XP_002400269.1| DNA mismatch repair protein mlh1..., putative [Ixodes scapularis] gb|EEC09245.1| DNA mismatch repair protein mlh1, putative

EST Table: DC566703 [KAIKOcDNA[Archive

Lifescience Database Archive (English)

Full Text Available DC566703 E_FL_wd--_09O22_R_0 10/09/28 52 %/145 aa ref|XP_002400269.1| DNA mismatch repair protein mlh1..., putative [Ixodes scapularis] gb|EEC09245.1| DNA mismatch repair protein mlh1, putative

Forest fragmentation and Lyme disease

Science.gov (United States)

Lyme disease is the most commonly reported vectorborne disease in the United States. It is associated with human exposure to infected Ixodes ticks which exist even in degraded forest and herbaceous habitat. We provide an overview of the epidemiology, ecology and landscape charact...

Remodeling of tick cytoskeleton in response to infection with Anaplasma phagocytophilum

Czech Academy of Sciences Publication Activity Database

Cabezas Cruz, Alejandro; Alberdi, P.; Valdés, James J.; Villar, M.; de la Fuente, J.

2017-01-01

Roč. 22, Jun 1 (2017), s. 1830-1844 ISSN 1093-4715 EU Projects: European Commission(XE) 278976 - ANTIGONE Institutional support: RVO:60077344 Keywords : cytoskeleton * proteomics * transcriptomics * Ixodes scapularis * Anaplasma phagocytophilum Subject RIV: EB - Genetics ; Molecular Biology OBOR OECD: Biochemistry and molecular biology

Coinfection with Borrelia burgdorferi sensu stricto and Borrelia garinii alters the course of murine Lyme borreliosis

NARCIS (Netherlands)

Hovius, Joppe W. R.; Li, Xin; Ramamoorthi, Nandhini; van Dam, Alje P.; Barthold, Stephen W.; van der Poll, Tom; Speelman, Peter; Fikrig, Erol

2007-01-01

Ixodes ricinus ticks and mice can be infected with both Borrelia burgdorferi sensu stricto and Borrelia garinii. The effect of coinfection with these two Borrelia species on the development of murine Lyme borreliosis is unknown. Therefore, we investigated whether coinfection with the

Is sarcoidosis a rickettsiosis? An archival study

DEFF Research Database (Denmark)

Svendsen, Claus Bo; Milman, Nils; Andersen, Claus B

2011-01-01

Based on earlier research, Rickettsia helvetica could possibly be involved in the pathogenesis of sarcoidosis. Rickettsiae are transmitted to humans by a tick vector, Ixodes ricinus; this tick is highly prevalent in Northern Europe. We aimed to investigate the association between evidence...

Tick-borne encephalitis.

Science.gov (United States)

Dumpis, U; Crook, D; Oksi, J

1999-04-01

Tick-borne encephalitis (TBE) is a zoonotic arbovirus infection endemic to Russia and Eastern and Central Europe. Despite being a common and serious life-threatening disease for which a mass vaccination program was implemented in Austria, there is only limited reference to this disease in the English-language literature. TBE is transmitted to humans usually by the bite of a tick (either Ixodes persulcatus or Ixodes ricinus); occasionally, cases occur following consumption of infected unpasteurized milk. Transmission is seasonal and occurs in spring and summer, particularly in rural areas favored by the vector. TBE is a serious cause of acute central nervous system disease, which may result in death or long-term neurological sequelae. Effective vaccines are available in a few countries. The risk for travelers of acquiring TBE is increasing with the recent rise in tourism to areas of endemicity during spring and summer.

Natural Anaplasma phagocytophilum infection in ticks from a forest area of Selenge province, Mongolia

Directory of Open Access Journals (Sweden)

G Javkhlan

2014-03-01

Full Text Available Anaplasma phagocytophilum is a zoonotic agent of public health importance, infecting both humans and animals. An investigation of the presence of Anaplasma phagocytophilum as well as Anaplasma platys was conducted in a forest area of Selenge province, Mongolia, where ticks are widely distributed and tick-borne diseases are highly endemic. Ticks were collected and tested using polymerase chain reaction based on groEL methodology. Anaplasma phagocytophilum was detected in 14 (6% of Ixodes persulcatus ticks and four (1% Dermacentor nuttalli ticks; infection of Anaplasma platys was detected in 1% of Ixodes persulcatus ticks and 10% of Dermacentor nuttalli ticks. The phylogenetic tree showed that the Anaplasma phagocytophilum clustered with the Russian group, most likely due to similar geographical locations. This finding is significant for both veterinary and public health officials given that these agents can cause both animal and human illness.

Sampling and sample processing in pesticide residue analysis.

Science.gov (United States)

Lehotay, Steven J; Cook, Jo Marie

2015-05-13

Proper sampling and sample processing in pesticide residue analysis of food and soil have always been essential to obtain accurate results, but the subject is becoming a greater concern as approximately 100 mg test portions are being analyzed with automated high-throughput analytical methods by agrochemical industry and contract laboratories. As global food trade and the importance of monitoring increase, the food industry and regulatory laboratories are also considering miniaturized high-throughput methods. In conjunction with a summary of the symposium "Residues in Food and Feed - Going from Macro to Micro: The Future of Sample Processing in Residue Analytical Methods" held at the 13th IUPAC International Congress of Pesticide Chemistry, this is an opportune time to review sampling theory and sample processing for pesticide residue analysis. If collected samples and test portions do not adequately represent the actual lot from which they came and provide meaningful results, then all costs, time, and efforts involved in implementing programs using sophisticated analytical instruments and techniques are wasted and can actually yield misleading results. This paper is designed to briefly review the often-neglected but crucial topic of sample collection and processing and put the issue into perspective for the future of pesticide residue analysis. It also emphasizes that analysts should demonstrate the validity of their sample processing approaches for the analytes/matrices of interest and encourages further studies on sampling and sample mass reduction to produce a test portion.

Boat sampling

International Nuclear Information System (INIS)

Citanovic, M.; Bezlaj, H.

1994-01-01

This presentation describes essential boat sampling activities: on site boat sampling process optimization and qualification; boat sampling of base material (beltline region); boat sampling of weld material (weld No. 4); problems accompanied with weld crown varieties, RPV shell inner radius tolerance, local corrosion pitting and water clarity. The equipment used for boat sampling is described too. 7 pictures

A Bayesian Justification for Random Sampling in Sample Survey

Directory of Open Access Journals (Sweden)

Glen Meeden

2012-07-01

Full Text Available In the usual Bayesian approach to survey sampling the sampling design, plays a minimal role, at best. Although a close relationship between exchangeable prior distributions and simple random sampling has been noted; how to formally integrate simple random sampling into the Bayesian paradigm is not clear. Recently it has been argued that the sampling design can be thought of as part of a Bayesian's prior distribution. We will show here that under this scenario simple random sample can be given a Bayesian justification in survey sampling.

Graph sampling

OpenAIRE

Zhang, L.-C.; Patone, M.

2017-01-01

We synthesise the existing theory of graph sampling. We propose a formal definition of sampling in finite graphs, and provide a classification of potential graph parameters. We develop a general approach of Horvitz–Thompson estimation to T-stage snowball sampling, and present various reformulations of some common network sampling methods in the literature in terms of the outlined graph sampling theory.

Acceptance sampling using judgmental and randomly selected samples

Energy Technology Data Exchange (ETDEWEB)

Sego, Landon H.; Shulman, Stanley A.; Anderson, Kevin K.; Wilson, John E.; Pulsipher, Brent A.; Sieber, W. Karl

2010-09-01

We present a Bayesian model for acceptance sampling where the population consists of two groups, each with different levels of risk of containing unacceptable items. Expert opinion, or judgment, may be required to distinguish between the high and low-risk groups. Hence, high-risk items are likely to be identifed (and sampled) using expert judgment, while the remaining low-risk items are sampled randomly. We focus on the situation where all observed samples must be acceptable. Consequently, the objective of the statistical inference is to quantify the probability that a large percentage of the unsampled items in the population are also acceptable. We demonstrate that traditional (frequentist) acceptance sampling and simpler Bayesian formulations of the problem are essentially special cases of the proposed model. We explore the properties of the model in detail, and discuss the conditions necessary to ensure that required samples sizes are non-decreasing function of the population size. The method is applicable to a variety of acceptance sampling problems, and, in particular, to environmental sampling where the objective is to demonstrate the safety of reoccupying a remediated facility that has been contaminated with a lethal agent.

Spotted fever group rickettsiae detected in immature stages of ticks parasitizing on Iberian endemic lizard Lacerta schreiberi Bedriaga, 1878

Czech Academy of Sciences Publication Activity Database

Kubelová, M.; Papoušek, I.; Bělohlávek, T.; Goüy de Bellocq, Joëlle; Baird, Stuart J. E.; Široký, P.

2015-01-01

Roč. 6, č. 6 (2015), s. 711-714 ISSN 1877-959X Institutional support: RVO:68081766 Keywords : Spotted fever group rickettsiae * Rickettsia monacensis * Rickettsia helvetica * Ixodes ricinus * Lacerta schreiberi Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine Impact factor: 2.690, year: 2015

Effect of Climate and Land Use on the Spatio-Temporal Variability of Tick-Borne Bacteria in Europe

NARCIS (Netherlands)

Rosà, Roberto; Andreo, Veronica; Tagliapietra, Valentina; Baráková, Ivana; Arnoldi, Daniele; Hauffe, Heidi C.; Manica, Mattia; Rosso, Fausta; Blaňarová, Lucia; Bona, Martin; Derdáková, Marketa; Hamšíková, Zuzana; Kazimírová, Maria; Kraljik, Jasna; Kocianová, Elena; Mahríková, Lenka; Minichová, Lenka; Mošanský, Ladislav; Slovák, Mirko; Stanko, Michal; Špitalská, Eva; Ducheyne, Els; Neteler, Markus; Hubálek, Zdenek; Rudolf, Ivo; Venclikova, Kristyna; Silaghi, Cornelia; Overzier, Evelyn; Farkas, Robert; Földvári, Gábor; Hornok, Sándor; Takács, Nóra; Rizzoli, Annapaola

2018-01-01

The incidence of tick-borne diseases caused by Borrelia burgdorferi sensu lato, Anaplasma phagocytophilum and Rickettsia spp. has been rising in Europe in recent decades. Early pre-assessment of acarological hazard still represents a complex challenge. The aim of this study was to model Ixodes

A formulation to encapusulate nootkatone oil for tick control

Science.gov (United States)

Nootkatone is a component of grapefruit oil that is toxic to the disease vectoring tick, Ixodes scapularis Say, but unfortunately causes phytotoxicity to treated plants and has a short residual activity due to volatility. We prepared an encapsulated formulation of nootkatone using lignin to compare...

40 CFR 1065.245 - Sample flow meter for batch sampling.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 32 2010-07-01 2010-07-01 false Sample flow meter for batch sampling... Sample flow meter for batch sampling. (a) Application. Use a sample flow meter to determine sample flow... difference between a diluted exhaust sample flow meter and a dilution air meter to calculate raw exhaust flow...

Balanced sampling

NARCIS (Netherlands)

Brus, D.J.

2015-01-01

In balanced sampling a linear relation between the soil property of interest and one or more covariates with known means is exploited in selecting the sampling locations. Recent developments make this sampling design attractive for statistical soil surveys. This paper introduces balanced sampling

Ensemble Sampling

OpenAIRE

Lu, Xiuyuan; Van Roy, Benjamin

2017-01-01

Thompson sampling has emerged as an effective heuristic for a broad range of online decision problems. In its basic form, the algorithm requires computing and sampling from a posterior distribution over models, which is tractable only for simple special cases. This paper develops ensemble sampling, which aims to approximate Thompson sampling while maintaining tractability even in the face of complex models such as neural networks. Ensemble sampling dramatically expands on the range of applica...

Modern survey sampling

CERN Document Server

Chaudhuri, Arijit

2014-01-01

Exposure to SamplingAbstract Introduction Concepts of Population, Sample, and SamplingInitial RamificationsAbstract Introduction Sampling Design, Sampling SchemeRandom Numbers and Their Uses in Simple RandomSampling (SRS)Drawing Simple Random Samples with and withoutReplacementEstimation of Mean, Total, Ratio of Totals/Means:Variance and Variance EstimationDetermination of Sample SizesA.2 Appendix to Chapter 2 A.More on Equal Probability Sampling A.Horvitz-Thompson EstimatorA.SufficiencyA.LikelihoodA.Non-Existence Theorem More Intricacies Abstract Introduction Unequal Probability Sampling StrategiesPPS Sampling Exploring Improved WaysAbstract Introduction Stratified Sampling Cluster SamplingMulti-Stage SamplingMulti-Phase Sampling: Ratio and RegressionEstimationviiviii ContentsControlled SamplingModeling Introduction Super-Population ModelingPrediction Approach Model-Assisted Approach Bayesian Methods Spatial SmoothingSampling on Successive Occasions: Panel Rotation Non-Response and Not-at-Homes Weighting Adj...

Respondent-Driven Sampling – Testing Assumptions: Sampling with Replacement

Directory of Open Access Journals (Sweden)

Barash Vladimir D.

2016-03-01

Full Text Available Classical Respondent-Driven Sampling (RDS estimators are based on a Markov Process model in which sampling occurs with replacement. Given that respondents generally cannot be interviewed more than once, this assumption is counterfactual. We join recent work by Gile and Handcock in exploring the implications of the sampling-with-replacement assumption for bias of RDS estimators. We differ from previous studies in examining a wider range of sampling fractions and in using not only simulations but also formal proofs. One key finding is that RDS estimates are surprisingly stable even in the presence of substantial sampling fractions. Our analyses show that the sampling-with-replacement assumption is a minor contributor to bias for sampling fractions under 40%, and bias is negligible for the 20% or smaller sampling fractions typical of field applications of RDS.

Sample preparation

International Nuclear Information System (INIS)

Anon.

1992-01-01

Sample preparation prior to HPLC analysis is certainly one of the most important steps to consider in trace or ultratrace analysis. For many years scientists have tried to simplify the sample preparation process. It is rarely possible to inject a neat liquid sample or a sample where preparation may not be any more complex than dissolution of the sample in a given solvent. The last process alone can remove insoluble materials, which is especially helpful with the samples in complex matrices if other interactions do not affect extraction. Here, it is very likely a large number of components will not dissolve and are, therefore, eliminated by a simple filtration process. In most cases, the process of sample preparation is not as simple as dissolution of the component interest. At times, enrichment is necessary, that is, the component of interest is present in very large volume or mass of material. It needs to be concentrated in some manner so a small volume of the concentrated or enriched sample can be injected into HPLC. 88 refs

Population Bottlenecks during the Infectious Cycle of the Lyme Disease Spirochete Borrelia burgdorferi

Czech Academy of Sciences Publication Activity Database

Rego, Ryan O. M.; Bestor, A.; Štefka, Jan; Rosa, P. A.

2014-01-01

Roč. 9, č. 6 (2014), e101009 E-ISSN 1932-6203 Institutional support: RVO:60077344 Keywords : sensu stricto * mammalian host * peromyscus-leucopus * Ixodes ricinus * ticks * mice * transmission * dissemination * diversity * North America Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine Impact factor: 3.234, year: 2014

Molecular biology of tick Acetylcholinesterases – a minireview

Science.gov (United States)

Ticks are important hematophagous arthropod ectoparasites and like mosquitoes, are vectors for a wide variety of human and animal pathogens. Ticks have significant world-wide health and economic impacts. In the U.S., major impacts include the ability of the blacklegged tick, Ixodes scapularis, to tr...

Serological and molecular evidence for spotted fever group Rickettsia and Borrelia burgdorferi sensu lato co-infections in The Netherlands

NARCIS (Netherlands)

Koetsveld, Joris; Tijsse-Klasen, Ellen; Herremans, Tineke; Hovius, Joppe W. R.; Sprong, Hein

2016-01-01

Only a few reported cases indicate that Rickettsia helvetica and Rickettsia monacensis can cause disease in humans. Exposure to these two spotted fever group (SFG) rickettsiae occurs through bites of Ixodes ricinus, also the primary vector of Lyme borreliosis in Europe. To date, it is unclear how

New foci of Haemaphysalis punctata and Dermacentor reticulatus in the Netherlands

NARCIS (Netherlands)

Hofmeester, Tim R.; Lei, van der Pieter Bas; Docters Van Leeuwen, Arieke; Sprong, Hein; Wieren, van Sipke E.

2016-01-01

In 2014 Haemaphysalis punctata was found in several locations on the mainland of the Netherlands for the first time since 1897. In the same areas Dermacentor reticulatus and Ixodes ricinus were found. Haemaphysalis punctata and D. reticulatus were tested for presence of Babesia spp. and

Ixodidae ticks in the megapolis of Kyiv, Ukraine

Science.gov (United States)

The Ixodidae include the most common tick species encountered in Europe. The ticks transmit a variety of bacterial and protozoan agents of medical and veterinary significance. The aim of the current work was to investigate distribution of Ixodes ricinus and Dermacentor reticulatus ticks in Kyiv, the...

Klinik, diagnostik og behandling af Lyme-borreliose

DEFF Research Database (Denmark)

Ocias, Lukas Frans; Jensen, Bo Bødker; Knudtzen, Fredrikke Christie

2017-01-01

Lyme borreliosis is an infection caused by the Borrelia burgdorferi sensu lato complex and transmitted by Ixodes ricinus ticks in Denmark. It can manifest itself in several different forms of which erythema migrans is the most common and is diagnosed by clinical assessment of the characteristic...

First detection of tick-borne "Candidatus Neoehrlichia mikurensis" in Denmark 2011

DEFF Research Database (Denmark)

Fertner, Mette Ely; Mølbak, Lars; Pihl, Thomas Peter Boye

2012-01-01

This is the first reporting of the tick-borne zoonotic bacterium "Candidatus Neoehrlichia mikurensis" in Denmark. A total of 2,625 Ixodes ricinus ticks from 58 locations in Denmark were collected and analysed for "Ca. Neoehrlichia mikurensis". A nested PCR revealed the presence of the bacterium...

Ixodid ticks parasitizing wild carnivores in Romania

Czech Academy of Sciences Publication Activity Database

D'Amico, G.; Dumitrache, M.O.; Matei, I.A.; Ionică, A.M.; Gherman, C.M.; Sándor, A.D.; Modrý, David; Mihalca, A. D.

2017-01-01

Roč. 71, č. 2 (2017), s. 139-149 ISSN 0168-8162 Institutional support: RVO:60077344 Keywords : Dermacentor spp. * Haemaphysalis spp. * Ixodes spp. * Rhipicephalus spp. * wildlife * tick-host associations Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine OBOR OECD: Veterinary science Impact factor: 1.760, year: 2016

Sample summary report for ARG 1 pressure tube sample

International Nuclear Information System (INIS)

Belinco, C.

2006-01-01

The ARG 1 sample is made from an un-irradiated Zr-2.5% Nb pressure tube. The sample has 103.4 mm ID, 112 mm OD and approximately 500 mm length. A punch mark was made very close to one end of the sample. The punch mark indicates the 12 O'clock position and also identifies the face of the tube for making all the measurements. ARG 1 sample contains flaws on ID and OD surface. There was no intentional flaw within the wall of the pressure tube sample. Once the flaws are machined the pressure tube sample was covered from outside to hide the OD flaws. Approximately 50 mm length of pressure tube was left open at both the ends to facilitate the holding of sample in the fixtures for inspection. No flaw was machined in this zone of 50 mm on either end of the pressure tube sample. A total of 20 flaws were machined in ARG 1 sample. Out of these, 16 flaws were on the OD surface and the remaining 4 on the ID surface of the pressure tube. The flaws were characterized in to various groups like axial flaws, circumferential flaws, etc

A Novel Scoring System Approach to Assess Patients with Lyme Disease (Nutech Functional Score).

Science.gov (United States)

Shroff, Geeta; Hopf-Seidel, Petra

2018-01-01

A bacterial infection by Borrelia burgdorferi referred to as Lyme disease (LD) or borreliosis is transmitted mostly by a bite of the tick Ixodes scapularis in the USA and Ixodes ricinus in Europe. Various tests are used for the diagnosis of LD, but their results are often unreliable. We compiled a list of clinically visible and patient-reported symptoms that are associated with LD. Based on this list, we developed a novel scoring system. Nutech functional Score (NFS), which is a 43 point positional (every symptom is subgraded and each alternative gets some points according to its position) and directional (moves in direction bad to good) scoring system that assesses the patient's condition. The grades of the scoring system have been converted into numeric values for conducting probability based studies. Each symptom is graded from 1 to 5 that runs in direction BAD → GOOD. NFS is a unique tool that can be used universally to assess the condition of patients with LD.

The occurrence of parasitic arthropods in two groups of European bison in the Białowieza primeval forest.

Science.gov (United States)

Izdebska, J N

2001-01-01

Within 1992-2000, a total of 181 Białowieza Forest bison were examined from two winter herds. Twelf parasitic arthropod species were observed, a high infestation being typical of Demodex bisonianius, Chorioptes bovis, Ixodes ricinus, Dermacentor reticulatus, and Bisonicola sedecimdecembrii. The infestation in section 422 herd being higher for B. sedecimdecembrii, I. ricinus, D. reticulatus, Ch. bovis. D. bisonianus was slightly more prevalent in the section 391 herd, the intensity being, however, lower than that in the other herd. Among the remaining arthropods found in the Bialowieza Forest European bison, some Lipoptena cervi occurred in both herds, Demodex sp. and Sarcoptes scabiei were recorded only in the section 422 herd, Ixodes persulcatus was present only in the section 391 bison and those kept in the reservation, while D. bovis, Psoroptes ovis, and Melophagus ovinus were found in the reserve bison only. In the present study, the largest differences in the extent of infestation involved the hair-dwelling arthropods (B. sedecimdecembrii, I. rixinus).

Enhanced conformational sampling using enveloping distribution sampling.

Science.gov (United States)

Lin, Zhixiong; van Gunsteren, Wilfred F

2013-10-14

To lessen the problem of insufficient conformational sampling in biomolecular simulations is still a major challenge in computational biochemistry. In this article, an application of the method of enveloping distribution sampling (EDS) is proposed that addresses this challenge and its sampling efficiency is demonstrated in simulations of a hexa-β-peptide whose conformational equilibrium encompasses two different helical folds, i.e., a right-handed 2.7(10∕12)-helix and a left-handed 3(14)-helix, separated by a high energy barrier. Standard MD simulations of this peptide using the GROMOS 53A6 force field did not reach convergence of the free enthalpy difference between the two helices even after 500 ns of simulation time. The use of soft-core non-bonded interactions in the centre of the peptide did enhance the number of transitions between the helices, but at the same time led to neglect of relevant helical configurations. In the simulations of a two-state EDS reference Hamiltonian that envelops both the physical peptide and the soft-core peptide, sampling of the conformational space of the physical peptide ensures that physically relevant conformations can be visited, and sampling of the conformational space of the soft-core peptide helps to enhance the transitions between the two helices. The EDS simulations sampled many more transitions between the two helices and showed much faster convergence of the relative free enthalpy of the two helices compared with the standard MD simulations with only a slightly larger computational effort to determine optimized EDS parameters. Combined with various methods to smoothen the potential energy surface, the proposed EDS application will be a powerful technique to enhance the sampling efficiency in biomolecular simulations.

Standard methods for sampling and sample preparation for gamma spectroscopy

International Nuclear Information System (INIS)

Taskaeva, M.; Taskaev, E.; Nikolov, P.

1993-01-01

The strategy for sampling and sample preparation is outlined: necessary number of samples; analysis and treatment of the results received; quantity of the analysed material according to the radionuclide concentrations and analytical methods; the minimal quantity and kind of the data needed for making final conclusions and decisions on the base of the results received. This strategy was tested in gamma spectroscopic analysis of radionuclide contamination of the region of Eleshnitsa Uranium Mines. The water samples was taken and stored according to the ASTM D 3370-82. The general sampling procedures were in conformity with the recommendations of ISO 5667. The radionuclides was concentrated by coprecipitation with iron hydroxide and ion exchange. The sampling of soil samples complied with the rules of ASTM C 998, and their sample preparation - with ASTM C 999. After preparation the samples were sealed hermetically and measured. (author)

The Internet of Samples in the Earth Sciences (iSamples)

Science.gov (United States)

Carter, M. R.; Lehnert, K. A.

2015-12-01

Across most Earth Science disciplines, research depends on the availability of samples collected above, at, and beneath Earth's surface, on the moon and in space, or generated in experiments. Many domains in the Earth Sciences have recently expressed the need for better discovery, access, and sharing of scientific samples and collections (EarthCube End-User Domain workshops, 2012 and 2013, http://earthcube.org/info/about/end-user-workshops), as has the US government (OSTP Memo, March 2014). The Internet of Samples in the Earth Sciences (iSamples) is an initiative funded as a Research Coordination Network (RCN) within the EarthCube program to address this need. iSamples aims to advance the use of innovative cyberinfrastructure to connect physical samples and sample collections across the Earth Sciences with digital data infrastructures to revolutionize their utility for science. iSamples strives to build, grow, and foster a new community of practice, in which domain scientists, curators of sample repositories and collections, computer and information scientists, software developers and technology innovators engage in and collaborate on defining, articulating, and addressing the needs and challenges of physical samples as a critical component of digital data infrastructure. A primary goal of iSamples is to deliver a community-endorsed set of best practices and standards for the registration, description, identification, and citation of physical specimens and define an actionable plan for implementation. iSamples conducted a broad community survey about sample sharing and has created 5 different working groups to address the different challenges of developing the internet of samples - from metadata schemas and unique identifiers to an architecture of a shared cyberinfrastructure for collections, to digitization of existing collections, to education, and ultimately to establishing the physical infrastructure that will ensure preservation and access of the physical

Sample vial inserts: A better approach for sampling heterogeneous slurry samples in the SRS Defense Waste Processing Facility

International Nuclear Information System (INIS)

Coleman, C.J.; Goode, S.R.

1996-01-01

A convenient and effective new approach for analyzing DWPF samples involves the use of inserts with volumes of 1.5--3 ml placed in the neck of 14 ml sample vials. The inserts have rims that conform to the rim of the vials so that they sit straight and stable in the vial. The DWPF tank sampling system fills the pre-weighed insert rather than the entire vial, so the vial functions only as the insert holder. The shielded cell operator then removes the vial cap and decants the insert containing the sample into a plastic bottle, crucible, etc., for analysis. Inert materials such as Teflon, plastic, and zirconium are used for the insert so it is unnecessary to separate the insert from the sample for most analyses. The key technique advantage of using inserts to take DWPF samples versus filling sample vials is that it provides a convenient and almost foolproof way of obtaining and handling small volumes of slurry samples in a shielded cell without corrupting the sample. Since the insert allows the entire sample to be analyzed, this approach eliminates the errors inherent with subsampling heterogeneous slurries that comprise DWPF samples. Slurry samples can then be analyzed with confidence. Analysis times are dramatically reduced by eliminating the drying and vitrification steps normally used to produce a homogeneous solid sample. Direct dissolution and elemental analysis of slurry samples are achieved in 8 hours or less compared with 40 hours for analysis of vitrified slurry samples. Comparison of samples taken in inserts versus full vials indicate that the insert does not significantly affect sample composition

An invasive mammal (the gray squirrel, Sciurus carolinensis) commonly hosts diverse and atypical genotypes of the zoonotic pathogen Borrelia burgdorferi sensu lato

DEFF Research Database (Denmark)

Millins, Caroline; Magierecka, Agnieszka; Gilbert, Lucy

2015-01-01

and may support host specific strains. This study examined the role of grey squirrels (Sciurus carolinensis), (n=679), an invasive species in the United Kingdom (UK), as B. burgdorferi s.l. hosts. We found that grey squirrels were frequently infested with Ixodes ricinus, the main vector of B. burgdorferi...

Effectiviness and environmental hazards of acaricides applied to large mammals for tick control

NARCIS (Netherlands)

Wieren, van S.E.; Braks, Marieta A.H.; Lahr, J.

2016-01-01

Ticks are important vectors of a large number of pathogenic organisms. In the Netherlands, Ixodes ricinus is the most abundant tick species and the main vector for several Borrelia species that may cause Lyme borreliosis. Many chemicals have been developed for tick control. In this chapter, a few

Tick saliva increases production of three chemokines including monocyte chemoattractant protein-1, a histamine-releasing cytokine

Czech Academy of Sciences Publication Activity Database

Langhansová, Helena; Bopp, T.; Schmitt, E.; Kopecký, Jan

2015-01-01

Roč. 37, č. 2 (2015), s. 92-96 ISSN 0141-9838 R&D Projects: GA ČR GCP302/11/J029 Institutional support: RVO:60077344 Keywords : chemokine * histamine * Ixodes ricinus * mcp-1 * Th2 response * tick saliva Subject RIV: EC - Immunology Impact factor: 1.917, year: 2015

Emerging horizons for tick-borne pathogens: from the "one pathogen-one disease" vision to the pathobiome paradigm

Czech Academy of Sciences Publication Activity Database

Vayssier-Taussat, M.; Kazimírová, M.; Hubálek, Zdeněk; Hornok, S.; Farkas, R.; Cosson, J.-F.; Bonnet, S.; Vourch, G.; Gasqui, P.; Mihalca, A. D.; Plantard, O.; Silaghi, C.; Cutler, S.; Rizzoli, A.

2015-01-01

Roč. 10, č. 12 (2015), s. 2033-2043 ISSN 1746-0913 Institutional support: RVO:68081766 Keywords : co-infections * emerging diseases * Ixodes ricinus * new paradigm * next-generation sequencing * pathobiome * unknown pathogens * vector competence * zoonoses Subject RIV: FN - Epidemiology, Contagious Diseases ; Clinical Immunology Impact factor: 3.637, year: 2015

Novel Rickettsia in Ticks, Tasmania, Australia

OpenAIRE

Izzard, Leonard; Graves, Stephen; Cox, Erika; Fenwick, Stan; Unsworth, Nathan; Stenos, John

2009-01-01

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.

Tick salivary gland extract-activated transmission of Borrelia afzelii spirochaetes

Czech Academy of Sciences Publication Activity Database

Pechová, Jitka; Tresová, Gabriela; Kovář, Lubomír; Kopecký, Jan

2002-01-01

Roč. 49, č. 2 (2002), s. 153ů159 ISSN 0015-5683 R&D Projects: GA ČR GA524/02/0901 Institutional research plan: CEZ:AV0Z6022909 Keywords : Ixodes ricinus * salivary gland extract * Borrelia afzelii Subject RIV: EC - Immunology Impact factor: 0.515, year: 2002

Bacteria of the genus Rickettsia in ticks (Acari: Ixodidae) collected from birds in Costa Rica

Czech Academy of Sciences Publication Activity Database

Ogrzewalska, M.; Literák, I.; Čapek, Miroslav; Sychra, O.; Calderón, V. Á.; Rodríguez, B. C.; Prudencio, C.; Martins, T. F.; Labruna, M. B.

2015-01-01

Roč. 6, č. 4 (2015), s. 478-482 ISSN 1877-959X R&D Projects: GA AV ČR IAA601690901 Institutional support: RVO:68081766 Keywords : Rickettsia * Ticks * Birds * Ixodes * Amblyomma * Costa Rica Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine Impact factor: 2.690, year: 2015

Signal sampling circuit

NARCIS (Netherlands)

Louwsma, S.M.; Vertregt, Maarten

2011-01-01

A sampling circuit for sampling a signal is disclosed. The sampling circuit comprises a plurality of sampling channels adapted to sample the signal in time-multiplexed fashion, each sampling channel comprising a respective track-and-hold circuit connected to a respective analogue to digital

Signal sampling circuit

NARCIS (Netherlands)

Louwsma, S.M.; Vertregt, Maarten

2010-01-01

A sampling circuit for sampling a signal is disclosed. The sampling circuit comprises a plurality of sampling channels adapted to sample the signal in time-multiplexed fashion, each sampling channel comprising a respective track-and-hold circuit connected to a respective analogue to digital

Geographical and seasonal correlation of multiple sclerosis to sporadic schizophrenia

Directory of Open Access Journals (Sweden)

Fritzsche Markus

2002-12-01

Full Text Available Abstract Background Clusters by season and locality reveal a striking epidemiological overlap between sporadic schizophrenia and multiple sclerosis (MS. As the birth excesses of those individuals who later in life develop schizophrenia mirror the seasonal distribution of Ixodid ticks, a meta analysis has been performed between all neuropsychiatric birth excesses including MS and the epidemiology of spirochaetal infectious diseases. Results The prevalence of MS and schizophrenic birth excesses entirely spares the tropical belt where human treponematoses are endemic, whereas in more temperate climates infection rates of Borrelia garinii in ticks collected from seabirds match the global geographic distribution of MS. If the seasonal fluctuations of Lyme borreliosis in Europe are taken into account, the birth excesses of MS and those of schizophrenia are nine months apart, reflecting the activity of Ixodes ricinus at the time of embryonic implantation and birth. In America, this nine months' shift between MS and schizophrenic births is also reflected by the periodicity of Borrelia burgdorferi transmitting Ixodes pacificus ticks along the West Coast and the periodicity of Ixodes scapularis along the East Coast. With respect to Ixodid tick activity, amongst the neuropsychiatric birth excesses only amyotrophic lateral sclerosis (ALS shows a similar seasonal trend. Conclusion It cannot be excluded at present that maternal infection by Borrelia burgdorferi poses a risk to the unborn. The seasonal and geographical overlap between schizophrenia, MS and neuroborreliosis rather emphasises a causal relation that derives from exposure to a flagellar virulence factor at conception and delivery. It is hoped that the pathogenic correlation of spirochaetal virulence to temperature and heat shock proteins (HSP might encourage a new direction of research in molecular epidemiology.

Microfabricated Devices for Sample Extraction, Concentrations, and Related Sample Processing Technologies

Energy Technology Data Exchange (ETDEWEB)

Chen, Gang; Lin, Yuehe

2006-12-01

This is an invited book chapter. As with other analytical techniques, sample pretreatments, sample extraction, sample introduction, and related techniques are of extreme importance for micro-electro-mechanical systems (MEMS). Bio-MEMS devices and systems start with a sampling step. The biological sample then usually undergoes some kinds of sample preparation steps before the actual analysis. These steps may involve extracting the target sample from its matrix, removing interferences from the sample, derivatizing the sample to detectable species, or performing a sample preconcentration step. The integration of the components for sample pretreatment into microfluidic devices represents one of the remaining the bottle-neck towards achieving true miniaturized total analysis systems (?TAS). This chapter provides a thorough state-of-art of the developments in this field to date.

Environmental sampling

International Nuclear Information System (INIS)

Puckett, J.M.

1998-01-01

Environmental Sampling (ES) is a technology option that can have application in transparency in nuclear nonproliferation. The basic process is to take a sample from the environment, e.g., soil, water, vegetation, or dust and debris from a surface, and through very careful sample preparation and analysis, determine the types, elemental concentration, and isotopic composition of actinides in the sample. The sample is prepared and the analysis performed in a clean chemistry laboratory (CCL). This ES capability is part of the IAEA Strengthened Safeguards System. Such a Laboratory is planned to be built by JAERI at Tokai and will give Japan an intrinsic ES capability. This paper presents options for the use of ES as a transparency measure for nuclear nonproliferation

Soil Gas Sample Handling: Evaluation of Water Removal and Sample Ganging

Energy Technology Data Exchange (ETDEWEB)

Fritz, Brad G. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Abrecht, David G. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Hayes, James C. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Mendoza, Donaldo P. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2016-10-31

Soil gas sampling is currently conducted in support of Nuclear Test Ban treaty verification. Soil gas samples are collected and analyzed for isotopes of interest. Some issues that can impact sampling and analysis of these samples are excess moisture and sample processing time. Here we discuss three potential improvements to the current sampling protocol; a desiccant for water removal, use of molecular sieve to remove CO₂ from the sample during collection, and a ganging manifold to allow composite analysis of multiple samples.

Optimization of sampling parameters for standardized exhaled breath sampling.

Science.gov (United States)

Doran, Sophie; Romano, Andrea; Hanna, George B

2017-09-05

The lack of standardization of breath sampling is a major contributing factor to the poor repeatability of results and hence represents a barrier to the adoption of breath tests in clinical practice. On-line and bag breath sampling have advantages but do not suit multicentre clinical studies whereas storage and robust transport are essential for the conduct of wide-scale studies. Several devices have been developed to control sampling parameters and to concentrate volatile organic compounds (VOCs) onto thermal desorption (TD) tubes and subsequently transport those tubes for laboratory analysis. We conducted three experiments to investigate (i) the fraction of breath sampled (whole vs. lower expiratory exhaled breath); (ii) breath sample volume (125, 250, 500 and 1000ml) and (iii) breath sample flow rate (400, 200, 100 and 50 ml/min). The target VOCs were acetone and potential volatile biomarkers for oesophago-gastric cancer belonging to the aldehyde, fatty acids and phenol chemical classes. We also examined the collection execution time and the impact of environmental contamination. The experiments showed that the use of exhaled breath-sampling devices requires the selection of optimum sampling parameters. The increase in sample volume has improved the levels of VOCs detected. However, the influence of the fraction of exhaled breath and the flow rate depends on the target VOCs measured. The concentration of potential volatile biomarkers for oesophago-gastric cancer was not significantly different between the whole and lower airway exhaled breath. While the recovery of phenols and acetone from TD tubes was lower when breath sampling was performed at a higher flow rate, other VOCs were not affected. A dedicated 'clean air supply' overcomes the contamination from ambient air, but the breath collection device itself can be a source of contaminants. In clinical studies using VOCs to diagnose gastro-oesophageal cancer, the optimum parameters are 500mls sample volume

Establishment of a minor groove binder-probe based quantitative real time PCR to detect Borrelia burgdorferi sensu lato and differentiation of Borrelia spielmanii by ospA-specific conventional PCR

Directory of Open Access Journals (Sweden)

Strube Christina

2010-08-01

Full Text Available Abstract Background Borrelia burgdorferi sensu lato (sl, the causative agent of Lyme borreliosis, is transmitted by ticks of the genus Ixodes as vector. For identification of Borrelia infections in ticks a TaqMan™ minor groove binder (MGB probe-based quantitative real time PCR (qPCR was established targeting the 5S-23S intergenic spacer. Extension to a duplex qPCR included an Ixodes spp. positive control to verify successful DNA isolation. Besides qPCR, an ospA-specific conventional PCR for species-specific identification of B. spielmanii was established. Afterwards 1000 I. ricinus flagged in the city of Hanover, Germany, were investigated for B. burgdorferi sl infections followed by species identification. Furthermore, I. hexagonus ticks were investigated to proof applicability of the PCRs. Results Quantitative real time PCR (qPCR identifying B. burgdorferi sl in ticks was able to detect 1-10 copies per reaction. B. spielmanii ospA-specific conventional PCR was also highly specific and showed no cross reactions with the other tested Borrelia species. From 1000 hanoveranian ticks 24.3% were positive compared to only 7.4% positives by dark-field microscopy. Related to tick stage 1.7% larvae, 18.1% nymphs, and 34.6% adults were positive. The most frequent species was B. garinii, followed by B. afzelii, B. spielmanii, B. valaisiana and B. burgdorferi sensu stricto (ss. 70.6% of I. ricinus were mono-infected, whereas 28.0% and 1.4% were infected with two and three Borrelia species, respectively. From 232 I. hexagonus collected from hedgehogs in different sites of Germany, qPCR detected 5.7% to be infected with B. burgdorferi sl, which were identified as B. afzelii, B. garinii and B. spielmanii. Conclusions The evaluated qPCR to detect B. burgdorferi sl in Ixodes spp. is highly specific and sensitive. As a duplex qPCR including detection of Ixodes spp. DNA it is the first DNA based technique incorporating a control for successful DNA isolation from

Sample summary report for KOR1 pressure tube sample

International Nuclear Information System (INIS)

Lee, Hee Jong; Nam, Min Woo; Choi, Young Ha

2006-01-01

This summary report includes basically the following: - The FLAW CHARACTERIZATION TABLE of KOR1 sample and supporting documentation. - The CROSS REFERENCE TABLES for each investigator, which is the SAMPLE INSPECTION TABLE that cross reference to the FLAW CHARACTERIZATION TABLE. - Each Sample Inspection Report as Appendices

Language sampling

DEFF Research Database (Denmark)

Rijkhoff, Jan; Bakker, Dik

1998-01-01

This article has two aims: [1] to present a revised version of the sampling method that was originally proposed in 1993 by Rijkhoff, Bakker, Hengeveld and Kahrel, and [2] to discuss a number of other approaches to language sampling in the light of our own method. We will also demonstrate how our...... sampling method is used with different genetic classifications (Voegelin & Voegelin 1977, Ruhlen 1987, Grimes ed. 1997) and argue that —on the whole— our sampling technique compares favourably with other methods, especially in the case of exploratory research....

Divergence of Borrelia burgdorferi sensu lato spirochetes could be driven by the host: diversity of Borrelia strains isolated from ticks feeding on a single bird

Czech Academy of Sciences Publication Activity Database

Rudenko, Natalia; Golovchenko, Maryna; Belfiore, N. M.; Grubhoffer, Libor; Oliver, J. H., Jr.

2014-01-01

Roč. 7, JAN 2014 (2014), s. 4 ISSN 1756-3305 Institutional support: RVO:60077344 Keywords : Borrelia burgdorferi sensu lato * Ixodes minor * bird migration * bird reservoir host * multilocus sequence analysis * multilocus sequence typing * recombinant genotypes * Southeastern United States Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.430, year: 2014

Borrelia burgdorferi s.l. v klíšťatech na ostravských haldách

Czech Academy of Sciences Publication Activity Database

Jarošová, V.; Rudolf, Ivo; Halouzka, Jiří; Hubálek, Zdeněk

2009-01-01

Roč. 58, č. 2 (2009), s. 90-97 ISSN 1210-7913 R&D Projects: GA AV ČR KJB600930613 EU Projects: European Commission(XE) 10284 - EDEN Institutional research plan: CEZ:AV0Z60930519 Keywords : Ixodes ricinus * slag heaps * Lyme borreliosis * transmission risk Subject RIV: EE - Microbiology, Virology

Hard ticks and their bacterial endosymbionts (or would be pathogens)

Czech Academy of Sciences Publication Activity Database

Ahantarig, A.; Trinachartvanit, W.; Baimai, V.; Grubhoffer, Libor

2013-01-01

Roč. 58, č. 5 (2013), s. 419-428 ISSN 0015-5632 Institutional support: RVO:60077344 Keywords : Ixodes ricinus * Candidatus Midichloria mitochondrii * Francisella-like endosymbionts * vector Ambylomma americanum * fever group Rickettsiae * Dermacentor and ersoni * spotted fever * borne pathogens Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.145, year: 2013

Spatial and Temporal Distribution of Lyme Disease Infected Ticks in the Texas-Mexico Border Region

Science.gov (United States)

Lyme disease (LD) is the most prevalent arthropod-borne infection in the United States, with 33,097 cases of LD reported to the Centers for Disease Control and Prevention (CDC) in 2011. The disease is transmitted to a mammalian host by Ixodes ticks infected with Borrelia burgdorferi. Efforts to unde...

The ecology of Lyme borreliosis risk : interactions between lxodes ricinus, rodents and Borrelia burgdorferi sensu lato

NARCIS (Netherlands)

Duijvendijk, van Gilian

2016-01-01

The sheep tick (Ixodes ricinus) is widespread throughout Europe and can transmit Borrelia burgdorferi sensu lato (s.l.), which can cause Lyme borreliosis and B. miyamotoi, the agent of Borrelia miyamotoi disease in humans.

Neglected tick-borne pathogens in the Czech Republic, 2011–2014

Czech Academy of Sciences Publication Activity Database

Venclíková, Kristýna; Mendel, Jan; Betášová, Lenka; Blažejová, Hana; Jedličková, Petra; Straková, Petra; Hubálek, Zdeněk; Rudolf, Ivo

2016-01-01

Roč. 7, č. 1 (2016), s. 107-112 ISSN 1877-959X EU Projects: European Commission(XE) 261504 - EDENEXT Institutional support: RVO:68081766 Keywords : Ixodes ricinus * Rickettsia spp. * Candidatus N. mikurensis * Anaplasma phagocytophilum * Babesia spp. Subject RIV: FN - Epidemiology, Contagious Diseases ; Clinical Immunology Impact factor: 3.230, year: 2016

A Note on Information-Directed Sampling and Thompson Sampling

OpenAIRE

Zhou, Li

2015-01-01

This note introduce three Bayesian style Multi-armed bandit algorithms: Information-directed sampling, Thompson Sampling and Generalized Thompson Sampling. The goal is to give an intuitive explanation for these three algorithms and their regret bounds, and provide some derivations that are omitted in the original papers.

How Sample Size Affects a Sampling Distribution

Science.gov (United States)

Mulekar, Madhuri S.; Siegel, Murray H.

2009-01-01

If students are to understand inferential statistics successfully, they must have a profound understanding of the nature of the sampling distribution. Specifically, they must comprehend the determination of the expected value and standard error of a sampling distribution as well as the meaning of the central limit theorem. Many students in a high…

Comparisons of methods for generating conditional Poisson samples and Sampford samples

OpenAIRE

Grafström, Anton

2005-01-01

Methods for conditional Poisson sampling (CP-sampling) and Sampford sampling are compared and the focus is on the efficiency of the methods. The efficiency is investigated by simulation in different sampling situations. It was of interest to compare methods since new methods for both CP-sampling and Sampford sampling were introduced by Bondesson, Traat & Lundqvist in 2004. The new methods are acceptance rejection methods that use the efficient Pareto sampling method. They are found to be ...

Large Sample Neutron Activation Analysis of Heterogeneous Samples

International Nuclear Information System (INIS)

Stamatelatos, I.E.; Vasilopoulou, T.; Tzika, F.

2018-01-01

A Large Sample Neutron Activation Analysis (LSNAA) technique was developed for non-destructive analysis of heterogeneous bulk samples. The technique incorporated collimated scanning and combining experimental measurements and Monte Carlo simulations for the identification of inhomogeneities in large volume samples and the correction of their effect on the interpretation of gamma-spectrometry data. Corrections were applied for the effect of neutron self-shielding, gamma-ray attenuation, geometrical factor and heterogeneous activity distribution within the sample. A benchmark experiment was performed to investigate the effect of heterogeneity on the accuracy of LSNAA. Moreover, a ceramic vase was analyzed as a whole demonstrating the feasibility of the technique. The LSNAA results were compared against results obtained by INAA and a satisfactory agreement between the two methods was observed. This study showed that LSNAA is a technique capable to perform accurate non-destructive, multi-elemental compositional analysis of heterogeneous objects. It also revealed the great potential of the technique for the analysis of precious objects and artefacts that need to be preserved intact and cannot be damaged for sampling purposes. (author)

Sampling in practice

DEFF Research Database (Denmark)

Esbensen, Kim Harry; Petersen, Lars

2005-01-01

A basic knowledge of the Theory of Sampling (TOS) and a set of only eight sampling unit operations is all the practical sampler needs to ensure representativeness of samples extracted from all kinds of lots: production batches, - truckloads, - barrels, sub-division in the laboratory, sampling...... in nature and in the field (environmental sampling, forestry, geology, biology), from raw materials or manufactory processes etc. We here can only give a brief introduction to the Fundamental Sampling Principle (FSP) and these eight Sampling Unit Operations (SUO’s). Always respecting FSP and invoking only...... the necessary SUO’s (dependent on the practical situation) is the only prerequisite needed for eliminating all sampling bias and simultaneously minimizing sampling variance, and this is in addition a sure guarantee for making the final analytical results trustworthy. No reliable conclusions can be made unless...

Effective sample labeling

International Nuclear Information System (INIS)

Rieger, J.T.; Bryce, R.W.

1990-01-01

Ground-water samples collected for hazardous-waste and radiological monitoring have come under strict regulatory and quality assurance requirements as a result of laws such as the Resource Conservation and Recovery Act. To comply with these laws, the labeling system used to identify environmental samples had to be upgraded to ensure proper handling and to protect collection personnel from exposure to sample contaminants and sample preservatives. The sample label now used as the Pacific Northwest Laboratory is a complete sample document. In the event other paperwork on a labeled sample were lost, the necessary information could be found on the label

On the Sampling

OpenAIRE

Güleda Doğan

2017-01-01

This editorial is on statistical sampling, which is one of the most two important reasons for editorial rejection from our journal Turkish Librarianship. The stages of quantitative research, the stage in which we are sampling, the importance of sampling for a research, deciding on sample size and sampling methods are summarised briefly.

Sampling of ore

International Nuclear Information System (INIS)

Boehme, R.C.; Nicholas, B.L.

1987-01-01

This invention relates to a method of an apparatus for ore sampling. The method includes the steps of periodically removing a sample of the output material of a sorting machine, weighing each sample so that each is of the same weight, measuring a characteristic such as the radioactivity, magnetivity or the like of each sample, subjecting at least an equal portion of each sample to chemical analysis to determine the mineral content of the sample and comparing the characteristic measurement with desired mineral content of the chemically analysed portion of the sample to determine the characteristic/mineral ratio of the sample. The apparatus includes an ore sample collector, a deflector for deflecting a sample of ore particles from the output of an ore sorter into the collector and means for moving the deflector from a first position in which it is clear of the particle path from the sorter to a second position in which it is in the particle path at predetermined time intervals and for predetermined time periods to deflect the sample particles into the collector. The apparatus conveniently includes an ore crusher for comminuting the sample particle, a sample hopper means for weighing the hopper, a detector in the hopper for measuring a characteristic such as radioactivity, magnetivity or the like of particles in the hopper, a discharge outlet from the hopper and means for feeding the particles from the collector to the crusher and then to the hopper

Are most samples of animals systematically biased? Consistent individual trait differences bias samples despite random sampling.

Science.gov (United States)

Biro, Peter A

2013-02-01

Sampling animals from the wild for study is something nearly every biologist has done, but despite our best efforts to obtain random samples of animals, 'hidden' trait biases may still exist. For example, consistent behavioral traits can affect trappability/catchability, independent of obvious factors such as size and gender, and these traits are often correlated with other repeatable physiological and/or life history traits. If so, systematic sampling bias may exist for any of these traits. The extent to which this is a problem, of course, depends on the magnitude of bias, which is presently unknown because the underlying trait distributions in populations are usually unknown, or unknowable. Indeed, our present knowledge about sampling bias comes from samples (not complete population censuses), which can possess bias to begin with. I had the unique opportunity to create naturalized populations of fish by seeding each of four small fishless lakes with equal densities of slow-, intermediate-, and fast-growing fish. Using sampling methods that are not size-selective, I observed that fast-growing fish were up to two-times more likely to be sampled than slower-growing fish. This indicates substantial and systematic bias with respect to an important life history trait (growth rate). If correlations between behavioral, physiological and life-history traits are as widespread as the literature suggests, then many animal samples may be systematically biased with respect to these traits (e.g., when collecting animals for laboratory use), and affect our inferences about population structure and abundance. I conclude with a discussion on ways to minimize sampling bias for particular physiological/behavioral/life-history types within animal populations.

Laser sampling

International Nuclear Information System (INIS)

Gorbatenko, A A; Revina, E I

2015-01-01

The review is devoted to the major advances in laser sampling. The advantages and drawbacks of the technique are considered. Specific features of combinations of laser sampling with various instrumental analytical methods, primarily inductively coupled plasma mass spectrometry, are discussed. Examples of practical implementation of hybrid methods involving laser sampling as well as corresponding analytical characteristics are presented. The bibliography includes 78 references

Morphological anomalies in Ixodes ricinus and Ixodes inopinatus collected from tick-borne encephalitis natural foci in Central Europe

DEFF Research Database (Denmark)

Chitimia-Dobler, Lidia; Bestehorn, Malena; Bröker, Michael

2017-01-01

in Germany, Slovakia and Denmark. A total of 278 (1.9%) out of 14,602 nymph and adult ticks showed morphological anomalies. The anomalies were divided into general anomalies (body asymmetry) and local anomalies (anomalies of appendages, malformation of capitulum, exoskeleton anomalies and anal groove......, palps and exoskeleton. Anal groove deformation was observed in three females and three nymphs. In 2016, the frequency of anomalies in I. inopinatus was found five times higher (9.3%) than in I. ricinus (1.9%). This is the first report of anomaly (ectromely, leg atrophy, idiosoma deformation) in flagged...

Sample Transport for a European Sample Curation Facility

Science.gov (United States)

Berthoud, L.; Vrublevskis, J. B.; Bennett, A.; Pottage, T.; Bridges, J. C.; Holt, J. M. C.; Dirri, F.; Longobardo, A.; Palomba, E.; Russell, S.; Smith, C.

2018-04-01

This work has looked at the recovery of Mars Sample Return capsule once it arrives on Earth. It covers possible landing sites, planetary protection requirements, and transportation from the landing site to a European Sample Curation Facility.

Ticks (Acari: Ixodidae) infesting some small mammals from Northern Turkey with new tick-host associations and locality records.

Science.gov (United States)

Keskin, Adem; Selçuk, Ahmet Yesari; Kefelioğlu, Haluk

2017-12-01

Ticks are obligate ectoparasites of a vast range of terrestrial vertebrates which may play an important role in the transmission of many zoonotic pathogens to humans and animals. In the current study, we performed an investigation on ticks infesting some small mammals captured from Samsun and Tokat provinces, Northern Turkey. One hundred forty-five mammalian samples belonging to four species, namely Cricetulus migratorius (n = 1), Apodemus flavicollis (n = 17), Crocidura suaveolens (n = 102) and Sorex volnuchini (n = 25), were examined for the presence of tick infestations. A total of 273 (74 larvae, 194 nymphs, 5 females) hard ticks were collected from 88 mammalian samples. Ticks were identified as Ixodes laguri (1 nymph), I. redikorzevi (22 larvae, 186 nymphs, 5 females), I. ricinus (52 larvae, 4 nymphs) and Rhipicephalus turanicus (3 nymphs). Here, we also provided new tick mammalian host associations for Turkey. In addition, I. laguri and I. redikorzevi ticks were recorded for the first time in Samsun province of Turkey.

The first detection of Babesia species DNA from Japanese black bears (Ursus thibetanus japonicus) in Japan.

Science.gov (United States)

Ikawa, Kazuhito; Aoki, Mikiko; Ichikawa, Madoka; Itagaki, Tadashi

2011-06-01

In this study, we tried to detect protozoan blood parasites from the liver or blood of 156 Japanese black bears (Ursus thibetanus japonicus) in Iwate Prefecture of Japan by polymerase chain reaction. Two amplicons (approximately 540 bp and 480 bp) were detected by amplification for V4 hyper-variable regions of the 18S rRNA gene. Approximately 540-bp products were obtained in 119 samples (76.3%) and were considered to be DNA of Hepatozoon ursi. Approximately 480-bp products were obtained in 22 samples (14.1%) and were considered to be DNA of Babesia species. The nucleotide sequences (1635 bp) of the 18S rRNA gene of Babesia sp. were very similar (99.3%) to those (AY190123, AY190124) of Babesia sp. detected previously from Ixodes ovatus. Phylogenetic analysis showed that Babesia sp. detected in this study closely related to Babesia sp. derived from raccoons in Japan and the U.S.A. This is the first report of Babesia species detected from Japanese black bears. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Detection of Borrelia burgdorferi sensu stricto in Amblyomma americanum ticks in the southeastern United States: the case of selective compatibility

Czech Academy of Sciences Publication Activity Database

Rudenko, Natalia; Golovchenko, Maryna; Clark, K.; Oliver, J.; Grubhoffer, Libor

2016-01-01

Roč. 5, MAY 25 (2016), č. článku e48. ISSN 2222-1751 EU Projects: European Commission(XE) 278976 - ANTIGONE Institutional support: RVO:60077344 Keywords : lyme disease spirochete * Dermacentor variabilis * Ixodes scapularis * Ixodidae * Acari * strain Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine Impact factor: 5.605, year: 2016

Effect of tick saliva on immune interactions between Borrelia afzelii and murine dendritic cells

Czech Academy of Sciences Publication Activity Database

Slámová, M.; Skallová, A.; Páleníková, J.; Kopecký, Jan

2011-01-01

Roč. 33, č. 12 (2011), 654-660 ISSN 0141-9838 R&D Projects: GA AV ČR IAA600960811; GA MŠk(CZ) LC06009 Institutional research plan: CEZ:AV0Z60220518 Keywords : Borrelia * dendritic cell * immune modulation * Ixodes ricinus Subject RIV: EC - Immunology Impact factor: 2.601, year: 2011

Effect of tick saliva on mechanisms of innate immune response against Borrelia afzelii

Czech Academy of Sciences Publication Activity Database

Kýčková, Kateřina; Kopecký, Jan

2006-01-01

Roč. 43, č. 4 (2006), s. 1208-1214 ISSN 0022-2585 R&D Projects: GA ČR GA524/05/0811; GA MŠk(CZ) LC06009 Institutional research plan: CEZ:AV0Z60220518 Keywords : Ixodes ricinus * Borrelia afzelii * phagocytosis Subject RIV: EC - Immunology Impact factor: 1.950, year: 2006

Ticks infected via co-feeding transmission can transmit Lyme borreliosis to vertebrate hosts

Czech Academy of Sciences Publication Activity Database

Belli, A.; Sarr, A.; Rais, O.; Rego, Ryan O. M.; Voordouw, M.J.

2017-01-01

Roč. 7, JUL 10 (2017), č. článku 5006. ISSN 2045-2322 Institutional support: RVO:60077344 Keywords : Ixodes ricinus ticks * disease spirochete * borne pathogens * r-0 model * vector * mice * immunity * persistence Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine OBOR OECD: Veterinary science Impact factor: 4.259, year: 2016

Phytotherapeutic activity of Euphorbia cyparissias extracts on ...

African Journals Online (AJOL)

The in vivo study of the efficacy of E. cyparissias concentrations was performed on 35 naturally infested sheep and on 30 bovines parasitized with Ixodes ricinus, sprayed with tincture and glycerinate dilutions (bovines) on days 0 and 7. The results revealed detrimental effects on the survivability of female ticks, the most ...

Potential species distribution and richness of ixodidae ticks associated with wild vertebrates from Michoacán, Mexico

NARCIS (Netherlands)

Vargas-Sandoval, Margarita; Priego-Santander, Angel G.; Larrazabal de la Via, Alejandra Patricia; Sosa-Gutiérrez, Carolina G.; Lara-Chávez, Blanca; Avila-Val, Teresita

2014-01-01

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

A simple vibrating sample magnetometer for macroscopic samples

Science.gov (United States)

Lopez-Dominguez, V.; Quesada, A.; Guzmán-Mínguez, J. C.; Moreno, L.; Lere, M.; Spottorno, J.; Giacomone, F.; Fernández, J. F.; Hernando, A.; García, M. A.

2018-03-01

We here present a simple model of a vibrating sample magnetometer (VSM). The system allows recording magnetization curves at room temperature with a resolution of the order of 0.01 emu and is appropriated for macroscopic samples. The setup can be mounted with different configurations depending on the requirements of the sample to be measured (mass, saturation magnetization, saturation field, etc.). We also include here examples of curves obtained with our setup and comparison curves measured with a standard commercial VSM that confirms the reliability of our device.

The phenology of ticks and the effects of long-term prescribed burning on tick population dynamics in southwestern Georgia and northwestern Florida.

Science.gov (United States)

Gleim, Elizabeth R; Conner, L Mike; Berghaus, Roy D; Levin, Michael L; Zemtsova, Galina E; Yabsley, Michael J

2014-01-01

Some tick populations have increased dramatically in the past several decades leading to an increase in the incidence and emergence of tick-borne diseases. Management strategies that can effectively reduce tick populations while better understanding regional tick phenology is needed. One promising management strategy is prescribed burning. However, the efficacy of prescribed burning as a mechanism for tick control is unclear because past studies have provided conflicting data, likely due to a failure of some studies to simulate operational management scenarios and/or account for other predictors of tick abundance. Therefore, our study was conducted to increase knowledge of tick population dynamics relative to long-term prescribed fire management. Furthermore, we targeted a region, southwestern Georgia and northwestern Florida (USA), in which little is known regarding tick dynamics so that basic phenology could be determined. Twenty-one plots with varying burn regimes (burned surrounded by burned [BB], burned surrounded by unburned [BUB], unburned surrounded by burned [UBB], and unburned surrounded by unburned [UBUB]) were sampled monthly for two years while simultaneously collecting data on variables that can affect tick abundance (e.g., host abundance, vegetation structure, and micro- and macro-climatic conditions). In total, 47,185 ticks were collected, of which, 99% were Amblyomma americanum, 0.7% were Ixodes scapularis, and fewer numbers of Amblyomma maculatum, Ixodes brunneus, and Dermacentor variabilis. Monthly seasonality trends were similar between 2010 and 2011. Long-term prescribed burning consistently and significantly reduced tick counts (overall and specifically for A. americanum and I. scapularis) regardless of the burn regimes and variables evaluated. Tick species composition varied according to burn regime with A. americanum dominating at UBUB, A. maculatum at BB, I. scapularis at UBB, and a more even composition at BUB. These data indicate that

Optimal sampling designs for large-scale fishery sample surveys in Greece

Directory of Open Access Journals (Sweden)

G. BAZIGOS

2007-12-01

The paper deals with the optimization of the following three large scale sample surveys: biological sample survey of commercial landings (BSCL, experimental fishing sample survey (EFSS, and commercial landings and effort sample survey (CLES.

Fluidic sampling

International Nuclear Information System (INIS)

Houck, E.D.

1992-01-01

This paper covers the development of the fluidic sampler and its testing in a fluidic transfer system. The major findings of this paper are as follows. Fluidic jet samples can dependably produce unbiased samples of acceptable volume. The fluidic transfer system with a fluidic sampler in-line will transfer water to a net lift of 37.2--39.9 feet at an average ratio of 0.02--0.05 gpm (77--192 cc/min). The fluidic sample system circulation rate compares very favorably with the normal 0.016--0.026 gpm (60--100 cc/min) circulation rate that is commonly produced for this lift and solution with the jet-assisted airlift sample system that is normally used at ICPP. The volume of the sample taken with a fluidic sampler is dependant on the motive pressure to the fluidic sampler, the sample bottle size and on the fluidic sampler jet characteristics. The fluidic sampler should be supplied with fluid having the motive pressure of the 140--150 percent of the peak vacuum producing motive pressure for the jet in the sampler. Fluidic transfer systems should be operated by emptying a full pumping chamber to nearly empty or empty during the pumping cycle, this maximizes the solution transfer rate

Defining And Characterizing Sample Representativeness For DWPF Melter Feed Samples

Energy Technology Data Exchange (ETDEWEB)

Shine, E. P.; Poirier, M. R.

2013-10-29

Representative sampling is important throughout the Defense Waste Processing Facility (DWPF) process, and the demonstrated success of the DWPF process to achieve glass product quality over the past two decades is a direct result of the quality of information obtained from the process. The objective of this report was to present sampling methods that the Savannah River Site (SRS) used to qualify waste being dispositioned at the DWPF. The goal was to emphasize the methodology, not a list of outcomes from those studies. This methodology includes proven methods for taking representative samples, the use of controlled analytical methods, and data interpretation and reporting that considers the uncertainty of all error sources. Numerous sampling studies were conducted during the development of the DWPF process and still continue to be performed in order to evaluate options for process improvement. Study designs were based on use of statistical tools applicable to the determination of uncertainties associated with the data needs. Successful designs are apt to be repeated, so this report chose only to include prototypic case studies that typify the characteristics of frequently used designs. Case studies have been presented for studying in-tank homogeneity, evaluating the suitability of sampler systems, determining factors that affect mixing and sampling, comparing the final waste glass product chemical composition and durability to that of the glass pour stream sample and other samples from process vessels, and assessing the uniformity of the chemical composition in the waste glass product. Many of these studies efficiently addressed more than one of these areas of concern associated with demonstrating sample representativeness and provide examples of statistical tools in use for DWPF. The time when many of these designs were implemented was in an age when the sampling ideas of Pierre Gy were not as widespread as they are today. Nonetheless, the engineers and

Defining And Characterizing Sample Representativeness For DWPF Melter Feed Samples

International Nuclear Information System (INIS)

Shine, E. P.; Poirier, M. R.

2013-01-01

Representative sampling is important throughout the Defense Waste Processing Facility (DWPF) process, and the demonstrated success of the DWPF process to achieve glass product quality over the past two decades is a direct result of the quality of information obtained from the process. The objective of this report was to present sampling methods that the Savannah River Site (SRS) used to qualify waste being dispositioned at the DWPF. The goal was to emphasize the methodology, not a list of outcomes from those studies. This methodology includes proven methods for taking representative samples, the use of controlled analytical methods, and data interpretation and reporting that considers the uncertainty of all error sources. Numerous sampling studies were conducted during the development of the DWPF process and still continue to be performed in order to evaluate options for process improvement. Study designs were based on use of statistical tools applicable to the determination of uncertainties associated with the data needs. Successful designs are apt to be repeated, so this report chose only to include prototypic case studies that typify the characteristics of frequently used designs. Case studies have been presented for studying in-tank homogeneity, evaluating the suitability of sampler systems, determining factors that affect mixing and sampling, comparing the final waste glass product chemical composition and durability to that of the glass pour stream sample and other samples from process vessels, and assessing the uniformity of the chemical composition in the waste glass product. Many of these studies efficiently addressed more than one of these areas of concern associated with demonstrating sample representativeness and provide examples of statistical tools in use for DWPF. The time when many of these designs were implemented was in an age when the sampling ideas of Pierre Gy were not as widespread as they are today. Nonetheless, the engineers and

AND/OR Importance Sampling

OpenAIRE

Gogate, Vibhav; Dechter, Rina

2012-01-01

The paper introduces AND/OR importance sampling for probabilistic graphical models. In contrast to importance sampling, AND/OR importance sampling caches samples in the AND/OR space and then extracts a new sample mean from the stored samples. We prove that AND/OR importance sampling may have lower variance than importance sampling; thereby providing a theoretical justification for preferring it over importance sampling. Our empirical evaluation demonstrates that AND/OR importance sampling is ...

Occurrence of ticks on wild animals received and attended at the Parque Zoológico Municipal Quinzinho de Barros, Sorocaba, São Paulo, Brazil

Directory of Open Access Journals (Sweden)

Thiago Fernandes Martins

2015-12-01

Full Text Available Os carrapatos são ectoparasitas da classe Arachnida que parasitam vertebrados terrestres, anfíbios, repteis, aves e mamíferos. O presente trabalho relata a ocorrência de carrapatos ixodídeos em animais silvestres recebidos e atendidos pelo Hospital Veterinário do Parque Zoológico Municipal Quinzinho de Barros, localizado no município de Sorocaba, estado de São Paulo, Brasil. De setembro de 1999 a maio de 2015, foram coletados carrapatos em animais silvestres da região de Sorocaba e de outros 20 municípios do interior do estado de São Paulo. Ao todo, foram identificados 43 larvas, 637 ninfas e 1.178 adultos (631 machos e 547 fêmeas, totalizando 1.858 exemplares de 14 espécies distintas de ixodídeos. Durante exames clínicos de rotina, foram inspecionadas duas espécies de repteis, uma espécie de ave e 11 espécies distintas de mamíferos de um total de 103 animais silvestres amostrados. Nos repteis foram identificados Amblyomma rotundatum, nas aves Amblyomma sculptum e nos mamíferos Amblyomma aureolatum, Amblyomma brasiliense, Amblyomma calcaratum, Amblyomma dubitatum, Amblyomma longirostre, Amblyomma nodosum, Amblyomma ovale, A. sculptum, Amblyomma varium, Ixodes aragaoi, Haemaphysalis juxtakochi, Rhipicephalus microplus e Dermacentor nitens. Este estudo relata os primeiros registros de fêmeas de A. rotundatum parasitando Hydromedusa tectifera e Oxyrhopus guibei, assim como ninfas de A. dubitatum e H. juxtakochi em Chrysocyon brachyurus, ninfas de A. brasiliense em Myrmecophaga tridactyla e Tamandua tetradactyla, além de ninfas de A. sculptum em Alouatta guariba e Sphiggurus villosus no país, demonstrando que os zoológicos são uma fonte de informação valiosa para o conhecimento parasitológico da fauna silvestre brasileira.

Sequencing of complete mitochondrial genomes confirms synonymization of Hyalomma asiaticum asiaticum and kozlovi, and advances phylogenetic hypotheses for the Ixodidae.

Science.gov (United States)

Liu, Zhi-Qiang; Liu, Yan-Feng; Kuermanali, Nuer; Wang, Deng-Feng; Chen, Shi-Jun; Guo, Hui-Ling; Zhao, Li; Wang, Jun-Wei; Han, Tao; Wang, Yuan-Zhi; Wang, Jie; Shen, Chen-Feng; Zhang, Zhuang-Zhi; Chen, Chuang-Fu

2018-01-01

Phylogeny of hard ticks (Ixodidae) remains unresolved. Mitochondrial genomes (mitogenomes) are increasingly used to resolve phylogenetic controversies, but remain unavailable for the entire large Hyalomma genus. Hyalomma asiaticum is a parasitic tick distributed throughout the Asia. As a result of great morphological variability, two subspecies have been recognised historically; until a morphological data-based synonymization was proposed. However, this hypothesis was never tested using molecular data. Therefore, objectives of this study were to: 1. sequence the first Hyalomma mitogenome; 2. scrutinise the proposed synonymization using molecular data, i.e. complete mitogenomes of both subspecies: H. a. asiaticum and kozlovi; 3. conduct phylogenomic and comparative analyses of all available Ixodidae mitogenomes. Results corroborate the proposed synonymization: the two mitogenomes are almost identical (99.6%). Genomic features of both mitogenomes are standard for Metastriata; which includes the presence of two control regions and all three "Tick-Box" motifs. Gene order and strand distribution are perfectly conserved for the entire Metastriata group. Suspecting compositional biases, we conducted phylogenetic analyses (29 almost complete mitogenomes) using homogeneous and heterogeneous (CAT) models of substitution. The results were congruent, apart from the deep-level topology of prostriate ticks (Ixodes): the homogeneous model produced a monophyletic Ixodes, but the CAT model produced a paraphyletic Ixodes (and thereby Prostriata), divided into Australasian and non-Australasian clades. This topology implies that all metastriate ticks have evolved from the ancestor of the non-Australian branch of prostriate ticks. Metastriata was divided into three clades: 1. Amblyomminae and Rhipicephalinae (Rhipicephalus, Hyalomma, Dermacentor); 2. Haemaphysalinae and Bothriocrotoninae, plus Amblyomma sphenodonti; 3. Amblyomma elaphense, basal to all Metastriata. We conclude that

A review of the ticks (Acari, Ixodida of Brazil, their hosts and geographic distribution - 1. The State of Rio Grande do Sul, Southern Brazil

Directory of Open Access Journals (Sweden)

Evans DE

2000-01-01

Full Text Available A review of the ticks (Acari, Ixodida of the State of Rio Grande do Sul, southern Brazil, was completed as a step towards a definitive list (currently indicated as 12 of such species, their hosts and distribution. The ticks: Argas miniatus (poultry, Ixodes loricatus (opossums, Amblyomma aureolatum (dogs, A. calcaratum (anteaters, A. cooperi (capybaras, A. nodosum (anteaters, A. tigrinum (dogs (Neotropical and Rhipicephalus sanguineus (dogs (introduced, cosmopolitan, Afrotropical were confirmed as present, in addition to the predominant, Boophilus microplus (cattle (introduced, pan-tropical, Oriental. Of the further 18 species thus far reported in the literature as present in the state, but unavailable for examination: only Ornithodoros brasiliensis (humans and their habitations (Neotropical, Ixodes affinis (deer (Nearctic/Neotropical and I. auritulus (birds (Nearctic/Neotropical/Afrotropical/ Australasian are considered likely; 13 species would benefit from corroborative local data but the majority appear unlikely; reports of A. maculatum (Nearctic/Neotropical, but circum-Caribbean are considered erroneous; the validity of A. fuscum is in doubt. The very recent, first known report of the tropical Anocentor nitens (horses(Nearctic/Neotropical, but still apparent absence of the tropical A. cajennense (catholic (Nearctic/Neotropical and the sub-tropical/temperate Ixodes pararicinus (cattle (Neotropical in Rio Grande do Sul are important for considerations on their current biogeographical distribution and its dynamics in South America. The state has relatively long established, introduced ("exotic", Old World tick species (B. microplus, R. sanguineus that continue to represent significant pests and disease vectors to their traditional, introduced domestic animal hosts, cattle and urban dogs. There are also indigenous, New World ticks (A. miniatus, O. brasiliensis, A. aureolatum, A. nitens, as both long established and possibly newly locally

Genetic characterization of the human relapsing fever spirochete Borrelia miyamotoi in vectors and animal reservoirs of Lyme disease spirochetes in France.

Science.gov (United States)

Cosson, Jean-François; Michelet, Lorraine; Chotte, Julien; Le Naour, Evelyne; Cote, Martine; Devillers, Elodie; Poulle, Marie-Lazarine; Huet, Dominique; Galan, Maxime; Geller, Julia; Moutailler, Sara; Vayssier-Taussat, Muriel

2014-05-20

In France as elsewhere in Europe the most prevalent TBD in humans is Lyme borreliosis, caused by different bacterial species belonging to Borrelia burgdorferi sensu lato complex and transmitted by the most important tick species in France, Ixodes ricinus. However, the diagnosis of Lyme disease is not always confirmed and unexplained syndromes occurring after tick bites have become an important issue. Recently, B. miyamotoi belonging to the relapsing fever group and transmitted by the same Ixodes species has been involved in human disease in Russia, the USA and the Netherlands. In the present study, we investigate the presence of B. miyamotoi along with other Lyme Borreliosis spirochetes, in ticks and possible animal reservoirs collected in France. We analyzed 268 ticks (Ixodes ricinus) and 72 bank voles (Myodes glareolus) collected and trapped in France for the presence of DNA from B. miyamotoi as well as from Lyme spirochetes using q-PCR and specific primers and probes. We then compared the French genotypes with those found in other European countries. We found that 3% of ticks and 5.55% of bank voles were found infected by the same B. miyamotoi genotype, while co-infection with other Lyme spirochetes (B. garinii) was identified in 12% of B. miyamotoi infected ticks. Sequencing showed that ticks and rodents carried the same genotype as those recently characterized in a sick person in the Netherlands. The genotype of B. miyamotoi circulating in ticks and bank voles in France is identical to those already described in ticks from Western Europe and to the genotype isolated from a sick person in The Netherlands. This results suggests that even though no human cases have been reported in France, surveillance has to be improved. Moreover, we showed that ticks could simultaneously carry B. miyamotoi and Lyme disease spirochetes, increasing the problem of co-infection in humans.

Compressive sampling of polynomial chaos expansions: Convergence analysis and sampling strategies

International Nuclear Information System (INIS)

Hampton, Jerrad; Doostan, Alireza

2015-01-01

Sampling orthogonal polynomial bases via Monte Carlo is of interest for uncertainty quantification of models with random inputs, using Polynomial Chaos (PC) expansions. It is known that bounding a probabilistic parameter, referred to as coherence, yields a bound on the number of samples necessary to identify coefficients in a sparse PC expansion via solution to an ℓ 1 -minimization problem. Utilizing results for orthogonal polynomials, we bound the coherence parameter for polynomials of Hermite and Legendre type under their respective natural sampling distribution. In both polynomial bases we identify an importance sampling distribution which yields a bound with weaker dependence on the order of the approximation. For more general orthonormal bases, we propose the coherence-optimal sampling: a Markov Chain Monte Carlo sampling, which directly uses the basis functions under consideration to achieve a statistical optimality among all sampling schemes with identical support. We demonstrate these different sampling strategies numerically in both high-order and high-dimensional, manufactured PC expansions. In addition, the quality of each sampling method is compared in the identification of solutions to two differential equations, one with a high-dimensional random input and the other with a high-order PC expansion. In both cases, the coherence-optimal sampling scheme leads to similar or considerably improved accuracy

Compressive sampling of polynomial chaos expansions: Convergence analysis and sampling strategies

Science.gov (United States)

Hampton, Jerrad; Doostan, Alireza

2015-01-01

Sampling orthogonal polynomial bases via Monte Carlo is of interest for uncertainty quantification of models with random inputs, using Polynomial Chaos (PC) expansions. It is known that bounding a probabilistic parameter, referred to as coherence, yields a bound on the number of samples necessary to identify coefficients in a sparse PC expansion via solution to an ℓ1-minimization problem. Utilizing results for orthogonal polynomials, we bound the coherence parameter for polynomials of Hermite and Legendre type under their respective natural sampling distribution. In both polynomial bases we identify an importance sampling distribution which yields a bound with weaker dependence on the order of the approximation. For more general orthonormal bases, we propose the coherence-optimal sampling: a Markov Chain Monte Carlo sampling, which directly uses the basis functions under consideration to achieve a statistical optimality among all sampling schemes with identical support. We demonstrate these different sampling strategies numerically in both high-order and high-dimensional, manufactured PC expansions. In addition, the quality of each sampling method is compared in the identification of solutions to two differential equations, one with a high-dimensional random input and the other with a high-order PC expansion. In both cases, the coherence-optimal sampling scheme leads to similar or considerably improved accuracy.

Sampling soils for 137Cs using various field-sampling volumes

International Nuclear Information System (INIS)

Nyhan, J.W.; Schofield, T.G.; White, G.C.; Trujillo, G.

1981-10-01

The sediments from a liquid effluent receiving area at the Los Alamos National Laboratory and soils from intensive study area in the fallout pathway of Trinity were sampled for 137 Cs using 25-, 500-, 2500-, and 12 500-cm 3 field sampling volumes. A highly replicated sampling program was used to determine mean concentrations and inventories of 137 Cs at each site, as well as estimates of spatial, aliquoting, and counting variance components of the radionuclide data. The sampling methods were also analyzed as a function of soil size fractions collected in each field sampling volume and of the total cost of the program for a given variation in the radionuclide survey results. Coefficients of variation (CV) of 137 Cs inventory estimates ranged from 0.063 to 0.14 for Mortandad Canyon sediments, where CV values for Trinity soils were observed from 0.38 to 0.57. Spatial variance components of 137 Cs concentration data were usually found to be larger than either the aliquoting or counting variance estimates and were inversely related to field sampling volume at the Trinity intensive site. Subsequent optimization studies of the sampling schemes demonstrated that each aliquot should be counted once, and that only 2 to 4 aliquots out of an many as 30 collected need be assayed for 137 Cs. The optimization studies showed that as sample costs increased to 45 man-hours of labor per sample, the variance of the mean 137 Cs concentration decreased dramatically, but decreased very little with additional labor

Tick-borne encephalitis virus-specific RT-PCR - a rapid test for detection of the pathogen without viral RNA purification

Czech Academy of Sciences Publication Activity Database

Rudenko, Natalia; Golovchenko, Maryna; Cihlářová, Věra; Grubhoffer, Libor

2004-01-01

Roč. 48, č. 3 (2004), s. 167-171 ISSN 0001-723X R&D Projects: GA ČR GA524/03/1326 Institutional research plan: CEZ:AV0Z6022909 Keywords : Ixodes ricinus * tick-borne encephalitis virus * RT-PCR Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine Impact factor: 0.605, year: 2004

Analysis of Meteorological Effects on the Incidence of Tick-borne Encephalitis in the Czech Republic over a Thirty-year Period

Czech Academy of Sciences Publication Activity Database

Brabec, Marek; Daniel, M.; Malý, Marek; Danielová, V.; Kříž, B.; Kott, I.; Beneš, Č.

2017-01-01

Roč. 1, č. 1 (2017), č. článku March 13. ISSN 2514-4138 Grant - others:GA MZd(CZ) NT11425 Institutional support: RVO:67985807 Keywords : tick-borne encephalitis incidence * Ixodes ricinus * ambient temperature * poisson model * generalized additive model * seasonal trends Subject RIV: BB - Applied Statistics, Operational Research OBOR OECD: Statistics and probability

Choice of Sample Split in Out-of-Sample Forecast Evaluation

DEFF Research Database (Denmark)

Hansen, Peter Reinhard; Timmermann, Allan

, while conversely the power of forecast evaluation tests is strongest with long out-of-sample periods. To deal with size distortions, we propose a test statistic that is robust to the effect of considering multiple sample split points. Empirical applications to predictabil- ity of stock returns......Out-of-sample tests of forecast performance depend on how a given data set is split into estimation and evaluation periods, yet no guidance exists on how to choose the split point. Empirical forecast evaluation results can therefore be difficult to interpret, particularly when several values...... and inflation demonstrate that out-of-sample forecast evaluation results can critically depend on how the sample split is determined....

Sampling or gambling

Energy Technology Data Exchange (ETDEWEB)

Gy, P.M.

1981-12-01

Sampling can be compared to no other technique. A mechanical sampler must above all be selected according to its aptitude for supressing or reducing all components of the sampling error. Sampling is said to be correct when it gives all elements making up the batch of matter submitted to sampling an uniform probability of being selected. A sampler must be correctly designed, built, installed, operated and maintained. When the conditions of sampling correctness are not strictly respected, the sampling error can no longer be controlled and can, unknown to the user, be unacceptably large: the sample is no longer representative. The implementation of an incorrect sampler is a form of gambling and this paper intends to show that at this game the user is nearly always the loser in the long run. The users' and the manufacturers' interests may diverge and the standards which should safeguard the users' interests very often fail to do so by tolerating or even recommending incorrect techniques such as the implementation of too narrow cutters traveling too fast through the stream to be sampled.

Soil sampling

International Nuclear Information System (INIS)

Fortunati, G.U.; Banfi, C.; Pasturenzi, M.

1994-01-01

This study attempts to survey the problems associated with techniques and strategies of soil sampling. Keeping in mind the well defined objectives of a sampling campaign, the aim was to highlight the most important aspect of representativeness of samples as a function of the available resources. Particular emphasis was given to the techniques and particularly to a description of the many types of samplers which are in use. The procedures and techniques employed during the investigations following the Seveso accident are described. (orig.)

Current Status of Tick Fauna in North of Iran

Directory of Open Access Journals (Sweden)

P Shayan

2007-04-01

Full Text Available Background: The distribution and ecological preferences of ticks of domestic animals in North of Iran were studied four times a year from 2002 to 2005. Methods: A total of 1720 tick specimens were collected from cattle, sheep and goats from different localities of Caspian Sea areas consisting of Guilan, Mazandaran, Golestan and Ardebil provinces, Iran. Results: Fourteen tick species were identified as Hyalomma anatolicum anatolicum (5.23%, H.marginatum (20.34%, H.detritum (3.48%, Haemaphysalis punctata (12.79%, Haem. Parva (0.58%, Haem.concinna (0.58%, Haem.choldokovsky (6.97%, Ixodes ricinus (2.32%, Rhipicephalus sanguineus (19.76%, Rh.bursa (4.65%, Boophilus annulatus (9.88%, Dermacentor niveus (6.39%, D. marginatus (1.74% and Ornithodoros lahorensis (5.23%. Both Dermacentor and Ornithodoros were found only in Ardebil with cold climatic conditions and high altitude. The only ticks, which were found in forest area, were Boophilus annulatus and Ixodes ricinus. Conclusion: The veterinary and public health importance of the above species should be emphasized.

A Novel Scoring System Approach to Assess Patients with Lyme Disease (Nutech Functional Score

Directory of Open Access Journals (Sweden)

Geeta Shroff

2018-01-01

Full Text Available Introduction: A bacterial infection by Borrelia burgdorferi referred to as Lyme disease (LD or borreliosis is transmitted mostly by a bite of the tick Ixodes scapularis in the USA and Ixodes ricinus in Europe. Various tests are used for the diagnosis of LD, but their results are often unreliable. We compiled a list of clinically visible and patient-reported symptoms that are associated with LD. Based on this list, we developed a novel scoring system. Methodology: Nutech functional Score (NFS, which is a 43 point positional (every symptom is subgraded and each alternative gets some points according to its position and directional (moves in direction bad to good scoring system that assesses the patient's condition. Results: The grades of the scoring system have been converted into numeric values for conducting probability based studies. Each symptom is graded from 1 to 5 that runs in direction BAD → GOOD. Conclusion: NFS is a unique tool that can be used universally to assess the condition of patients with LD.

Sample representativeness verification of the FADN CZ farm business sample

Directory of Open Access Journals (Sweden)

Marie Prášilová

2011-01-01

Full Text Available Sample representativeness verification is one of the key stages of statistical work. After having joined the European Union the Czech Republic joined also the Farm Accountancy Data Network system of the Union. This is a sample of bodies and companies doing business in agriculture. Detailed production and economic data on the results of farming business are collected from that sample annually and results for the entire population of the country´s farms are then estimated and assessed. It is important hence, that the sample be representative. Representativeness is to be assessed as to the number of farms included in the survey and also as to the degree of accordance of the measures and indices as related to the population. The paper deals with the special statistical techniques and methods of the FADN CZ sample representativeness verification including the necessary sample size statement procedure. The Czech farm population data have been obtained from the Czech Statistical Office data bank.

Present status of NMCC and sample preparation method for bio-samples

International Nuclear Information System (INIS)

Futatsugawa, S.; Hatakeyama, S.; Saitou, S.; Sera, K.

1993-01-01

In NMCC(Nishina Memorial Cyclotron Center) we are doing researches on PET of nuclear medicine (Positron Emission Computed Tomography) and PIXE analysis (Particle Induced X-ray Emission) using a small cyclotron of compactly designed. The NMCC facilities have been opened to researchers of other institutions since April 1993. The present status of NMCC is described. Bio-samples (medical samples, plants, animals and environmental samples) have mainly been analyzed by PIXE in NMCC. Small amounts of bio-samples for PIXE are decomposed quickly and easily in a sealed PTFE (polytetrafluoroethylene) vessel with a microwave oven. This sample preparation method of bio-samples also is described. (author)

Experimental and Sampling Design for the INL-2 Sample Collection Operational Test

Energy Technology Data Exchange (ETDEWEB)

Piepel, Gregory F.; Amidan, Brett G.; Matzke, Brett D.

2009-02-16

This report describes the experimental and sampling design developed to assess sampling approaches and methods for detecting contamination in a building and clearing the building for use after decontamination. An Idaho National Laboratory (INL) building will be contaminated with BG (Bacillus globigii, renamed Bacillus atrophaeus), a simulant for Bacillus anthracis (BA). The contamination, sampling, decontamination, and re-sampling will occur per the experimental and sampling design. This INL-2 Sample Collection Operational Test is being planned by the Validated Sampling Plan Working Group (VSPWG). The primary objectives are: 1) Evaluate judgmental and probabilistic sampling for characterization as well as probabilistic and combined (judgment and probabilistic) sampling approaches for clearance, 2) Conduct these evaluations for gradient contamination (from low or moderate down to absent or undetectable) for different initial concentrations of the contaminant, 3) Explore judgment composite sampling approaches to reduce sample numbers, 4) Collect baseline data to serve as an indication of the actual levels of contamination in the tests. A combined judgmental and random (CJR) approach uses Bayesian methodology to combine judgmental and probabilistic samples to make clearance statements of the form "X% confidence that at least Y% of an area does not contain detectable contamination” (X%/Y% clearance statements). The INL-2 experimental design has five test events, which 1) vary the floor of the INL building on which the contaminant will be released, 2) provide for varying the amount of contaminant released to obtain desired concentration gradients, and 3) investigate overt as well as covert release of contaminants. Desirable contaminant gradients would have moderate to low concentrations of contaminant in rooms near the release point, with concentrations down to zero in other rooms. Such gradients would provide a range of contamination levels to challenge the sampling

Sample collection and sample analysis plan in support of the 105-C/190-C concrete and soil sampling activities

International Nuclear Information System (INIS)

Marske, S.G.

1996-07-01

This sampling and analysis plan describes the sample collection and sample analysis in support of the 105-C water tunnels and 190-C main pumphouse concrete and soil sampling activities. These analytical data will be used to identify the radiological contamination and presence of hazardous materials to support the decontamination and disposal activities

Sample size of the reference sample in a case-augmented study.

Science.gov (United States)

Ghosh, Palash; Dewanji, Anup

2017-05-01

The case-augmented study, in which a case sample is augmented with a reference (random) sample from the source population with only covariates information known, is becoming popular in different areas of applied science such as pharmacovigilance, ecology, and econometrics. In general, the case sample is available from some source (for example, hospital database, case registry, etc.); however, the reference sample is required to be drawn from the corresponding source population. The required minimum size of the reference sample is an important issue in this regard. In this work, we address the minimum sample size calculation and discuss related issues. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

Large sample neutron activation analysis of a reference inhomogeneous sample

International Nuclear Information System (INIS)

Vasilopoulou, T.; Athens National Technical University, Athens; Tzika, F.; Stamatelatos, I.E.; Koster-Ammerlaan, M.J.J.

2011-01-01

A benchmark experiment was performed for Neutron Activation Analysis (NAA) of a large inhomogeneous sample. The reference sample was developed in-house and consisted of SiO 2 matrix and an Al-Zn alloy 'inhomogeneity' body. Monte Carlo simulations were employed to derive appropriate correction factors for neutron self-shielding during irradiation as well as self-attenuation of gamma rays and sample geometry during counting. The large sample neutron activation analysis (LSNAA) results were compared against reference values and the trueness of the technique was evaluated. An agreement within ±10% was observed between LSNAA and reference elemental mass values, for all matrix and inhomogeneity elements except Samarium, provided that the inhomogeneity body was fully simulated. However, in cases that the inhomogeneity was treated as not known, the results showed a reasonable agreement for most matrix elements, while large discrepancies were observed for the inhomogeneity elements. This study provided a quantification of the uncertainties associated with inhomogeneity in large sample analysis and contributed to the identification of the needs for future development of LSNAA facilities for analysis of inhomogeneous samples. (author)

Influence of sampling depth and post-sampling analysis time on the ...

African Journals Online (AJOL)

Bacteriological analysis was carried out for samples taken at water depth and at 1, 6, 12 and 24 hours post-sampling. It was observed that the total and faecal coliform bacteria were significantly higher in the 3 m water depth samples than in the surface water samples (ANOVA, F = 59.41, 26.751, 9.82 (T.C); 46.41, 26.81, ...

Molecular cloning, sequencing and recombinant expression of a ...

African Journals Online (AJOL)

The 4D8 gene was recently discovered in Ixodes scapularis and identified as a tick protective antigen. Vaccination using recombinant 4D8 from I. scapularis showed a significant reduction against I. scapularis tick infestation in a sheep model. This protein is expressed in both salivary gland and gut tissues, and is thought to ...

Tick saliva affects both proliferation and distribution of Borrelia burgdorferi spirochetes in mouse organs and increases transmission of spirochetes to ticks

Czech Academy of Sciences Publication Activity Database

Horká, Helena; Černá-Kýčková, Kateřina; Skallová, Anna; Kopecký, Jan

2009-01-01

Roč. 299, č. 5 (2009), s. 373-380 ISSN 1438-4221 R&D Projects: GA AV ČR IAA600960811; GA MŠk(CZ) LC06009 Institutional research plan: CEZ:AV0Z60220518 Keywords : Borrelia burgdorferi * Ixodes ricinus * saliva-activated transmission * real-time PCR Subject RIV: EC - Immunology Impact factor: 2.802, year: 2009

Tick-borne zoonotic pathogens in ticks feeding on the common nightingale including a novel strain of Rickettsia sp

Czech Academy of Sciences Publication Activity Database

Dubská, L.; Literák, I.; Kverek, P.; Roubalová, Eva; Kocianova, E.; Taragelova, V.

2012-01-01

Roč. 3, č. 4 (2012), s. 265-268 ISSN 1877-959X Institutional support: RVO:60077344 Keywords : tick * Ixodes ricinus * Borrelia garinii * Anaplasma phagocytophilum * Rickettsia helvetica * Babesia sp. EU1 * Common nightingale Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine Impact factor: 2.353, year: 2012 http://www.sciencedirect.com/science/article/pii/S1877959X12000556

Molecular phylogeography of tick-borne encephalitis virus in central Europe

Czech Academy of Sciences Publication Activity Database

Weidmann, M.; Frey, S.; Freire, C.C.M.; Essbauer, S.; Růžek, Daniel; Klempa, B.; Zubrikova, D.; Vogerl, M.; Pfeffer, M.; Hufert, F.T.; Zanotto, P. M. de A.; Dobler, G.

2013-01-01

Roč. 94, SEP 2013 (2013), s. 2129-2139 ISSN 0022-1317 R&D Projects: GA ČR GAP502/11/2116 Grant - others:GA MŠk(CZ) ED0006/01/01 Institutional support: RVO:60077344 Keywords : Ixodes ricinus ticks * Dermacentor reticulatus * purifying selection Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.529, year: 2013

Glycobiochemistry of ticks, vectors of infectious diseases: carbohydrate-binding proteins and glycans

Czech Academy of Sciences Publication Activity Database

Grubhoffer, Libor; Hajdušek, Ondřej; Vancová, Marie; Štěrba, Ján; Rudenko, Natalia

2009-01-01

Roč. 276, S1 (2009), s. 141-141 ISSN 1742-464X. [34th FEBS Congress: Life's Molecular Interactions. 04.07.2009-09.07.2009, Prague] R&D Projects: GA MŠk(CZ) LC06009 Institutional research plan: CEZ:AV0Z60220518 Keywords : Carbohydrate-binding molecules * Ixodes ricinus * knock-down Subject RIV: EB - Genetics ; Molecular Biology

Phylogenetic and Virulence Analysis of Tick-Borne Encephalitis Virus Field Isolates From Switzerland

Czech Academy of Sciences Publication Activity Database

Gaumann, R.; Růžek, Daniel; Muhlemann, K.; Strasser, M.; Beuret, C. M.

2011-01-01

Roč. 83, č. 5 (2011), 853-863 ISSN 0146-6615 R&D Projects: GA ČR GPP302/10/P438; GA MŠk(CZ) LC06009 Institutional research plan: CEZ:AV0Z60220518 Keywords : molecular epidemiology * envelope protein * neuroinvasiveness/virulence * European subtype * Ixodes ricinus Subject RIV: EE - Microbiology, Virology Impact factor: 2.820, year: 2011

DNA Sampling Hook

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The DNA Sampling Hook is a significant improvement on a method of obtaining a tissue sample from a live fish in situ from an aquatic environment. A tissue sample...

Laboratory Sampling Guide

Science.gov (United States)

2012-05-11

environment, and by ingestion of foodstuffs that have incorporated C-14 by photosynthesis . Like tritium, C-14 is a very low energy beta emitter and is... bacterial growth and to minimize development of solids in the sample. • Properly identify each sample container with name, SSN, and collection start and...sampling in the same cardboard carton. The sample may be kept cool or frozen during collection to control odor and bacterial growth. • Once

Sampling Development

Science.gov (United States)

Adolph, Karen E.; Robinson, Scott R.

2011-01-01

Research in developmental psychology requires sampling at different time points. Accurate depictions of developmental change provide a foundation for further empirical studies and theories about developmental mechanisms. However, overreliance on widely spaced sampling intervals in cross-sectional and longitudinal designs threatens the validity of…

ExSample. A library for sampling Sudakov-type distributions

Energy Technology Data Exchange (ETDEWEB)

Plaetzer, Simon

2011-08-15

Sudakov-type distributions are at the heart of generating radiation in parton showers as well as contemporary NLO matching algorithms along the lines of the POWHEG algorithm. In this paper, the C++ library ExSample is introduced, which implements adaptive sampling of Sudakov-type distributions for splitting kernels which are in general only known numerically. Besides the evolution variable, the splitting kernels can depend on an arbitrary number of other degrees of freedom to be sampled, and any number of further parameters which are fixed on an event-by-event basis. (orig.)

ExSample. A library for sampling Sudakov-type distributions

International Nuclear Information System (INIS)

Plaetzer, Simon

2011-08-01

Sudakov-type distributions are at the heart of generating radiation in parton showers as well as contemporary NLO matching algorithms along the lines of the POWHEG algorithm. In this paper, the C++ library ExSample is introduced, which implements adaptive sampling of Sudakov-type distributions for splitting kernels which are in general only known numerically. Besides the evolution variable, the splitting kernels can depend on an arbitrary number of other degrees of freedom to be sampled, and any number of further parameters which are fixed on an event-by-event basis. (orig.)

Spherical sampling

CERN Document Server

Freeden, Willi; Schreiner, Michael

2018-01-01

This book presents, in a consistent and unified overview, results and developments in the field of today´s spherical sampling, particularly arising in mathematical geosciences. Although the book often refers to original contributions, the authors made them accessible to (graduate) students and scientists not only from mathematics but also from geosciences and geoengineering. Building a library of topics in spherical sampling theory it shows how advances in this theory lead to new discoveries in mathematical, geodetic, geophysical as well as other scientific branches like neuro-medicine. A must-to-read for everybody working in the area of spherical sampling.

An integrated and accessible sample data library for Mars sample return science

Science.gov (United States)

Tuite, M. L., Jr.; Williford, K. H.

2015-12-01

Over the course of the next decade or more, many thousands of geological samples will be collected and analyzed in a variety of ways by researchers at the Jet Propulsion Laboratory (California Institute of Technology) in order to facilitate discovery and contextualize observations made of Mars rocks both in situ and here on Earth if samples are eventually returned. Integration of data from multiple analyses of samples including petrography, thin section and SEM imaging, isotope and organic geochemistry, XRF, XRD, and Raman spectrometry is a challenge and a potential obstacle to discoveries that require supporting lines of evidence. We report the development of a web-accessible repository, the Sample Data Library (SDL) for the sample-based data that are generated by the laboratories and instruments that comprise JPL's Center for Analysis of Returned Samples (CARS) in order to facilitate collaborative interpretation of potential biosignatures in Mars-analog geological samples. The SDL is constructed using low-cost, open-standards-based Amazon Web Services (AWS), including web-accessible storage, relational data base services, and a virtual web server. The data structure is sample-centered with a shared registry for assigning unique identifiers to all samples including International Geo-Sample Numbers. Both raw and derived data produced by instruments and post-processing workflows are automatically uploaded to online storage and linked via the unique identifiers. Through the web interface, users are able to find all the analyses associated with a single sample or search across features shared by multiple samples, sample localities, and analysis types. Planned features include more sophisticated search and analytical interfaces as well as data discoverability through NSF's EarthCube program.

21 CFR 203.38 - Sample lot or control numbers; labeling of sample units.

Science.gov (United States)

2010-04-01

... numbers; labeling of sample units. (a) Lot or control number required on drug sample labeling and sample... identifying lot or control number that will permit the tracking of the distribution of each drug sample unit... 21 Food and Drugs 4 2010-04-01 2010-04-01 false Sample lot or control numbers; labeling of sample...

Remote sampling and analysis of highly radioactive samples in shielded boxes

International Nuclear Information System (INIS)

Kirpikov, D.A.; Miroshnichenko, I.V.; Pykhteev, O.Yu.

2010-01-01

The sampling procedure used for highly radioactive coolant water is associated with high risk of personnel irradiation and uncontrolled radioactive contamination. Remote sample manipulation with provision for proper radiation shielding is intended for safety enhancement of the sampling procedure. The sampling lines are located in an isolated compartment, a shielded box. Various equipment which enables remote or automatic sample manipulation is used for this purpose. The main issues of development of the shielded box equipment intended for a wider ranger of remote chemical analyses and manipulation techniques for highly radioactive water samples are considered in the paper. There were three principal directions of work: Transfer of chemical analysis performed in the laboratory inside the shielded box; Prevalence of computer-aided and remote techniques of highly radioactive sample manipulation inside the shielded box; and, Increase in control over sampling and determination of thermal-hydraulic parameters of the coolant water in the sampling lines. The developed equipment and solutions enable remote chemical analysis in the restricted volume of the shielded box by using ion-chromatographic, amperometrical, fluorimetric, flow injection, phototurbidimetric, conductometric and potentiometric methods. Extent of control performed in the shielded box is determined taking into account the requirements of the regulatory documents as well as feasibility and cost of the technical adaptation of various methods to the shielded box conditions. The work resulted in highly precise determination of more than 15 indexes of the coolant water quality performed in on-line mode in the shielded box. It averages to 80% of the total extent of control performed at the prototype reactor plants. The novel solutions for highly radioactive sample handling are implemented in the shielded box (for example, packaging, sample transportation to the laboratory, volume measurement). The shielded box is

Testing a groundwater sampling tool: Are the samples representative?

International Nuclear Information System (INIS)

Kaback, D.S.; Bergren, C.L.; Carlson, C.A.; Carlson, C.L.

1989-01-01

A ground water sampling tool, the HydroPunch trademark, was tested at the Department of Energy's Savannah River Site in South Carolina to determine if representative ground water samples could be obtained without installing monitoring wells. Chemical analyses of ground water samples collected with the HydroPunch trademark from various depths within a borehole were compared with chemical analyses of ground water from nearby monitoring wells. The site selected for the test was in the vicinity of a large coal storage pile and a coal pile runoff basin that was constructed to collect the runoff from the coal storage pile. Existing monitoring wells in the area indicate the presence of a ground water contaminant plume that: (1) contains elevated concentrations of trace metals; (2) has an extremely low pH; and (3) contains elevated concentrations of major cations and anions. Ground water samples collected with the HydroPunch trademark provide in excellent estimate of ground water quality at discrete depths. Groundwater chemical data collected from various depths using the HydroPunch trademark can be averaged to simulate what a screen zone in a monitoring well would sample. The averaged depth-discrete data compared favorably with the data obtained from the nearby monitoring wells

Sample size methodology

CERN Document Server

Desu, M M

2012-01-01

One of the most important problems in designing an experiment or a survey is sample size determination and this book presents the currently available methodology. It includes both random sampling from standard probability distributions and from finite populations. Also discussed is sample size determination for estimating parameters in a Bayesian setting by considering the posterior distribution of the parameter and specifying the necessary requirements. The determination of the sample size is considered for ranking and selection problems as well as for the design of clinical trials. Appropria

Novel Sample-handling Approach for XRD Analysis with Minimal Sample Preparation

Science.gov (United States)

Sarrazin, P.; Chipera, S.; Bish, D.; Blake, D.; Feldman, S.; Vaniman, D.; Bryson, C.

2004-01-01

Sample preparation and sample handling are among the most critical operations associated with X-ray diffraction (XRD) analysis. These operations require attention in a laboratory environment, but they become a major constraint in the deployment of XRD instruments for robotic planetary exploration. We are developing a novel sample handling system that dramatically relaxes the constraints on sample preparation by allowing characterization of coarse-grained material that would normally be impossible to analyze with conventional powder-XRD techniques.

Types of non-probabilistic sampling used in marketing research. „Snowball” sampling

OpenAIRE

Manuela Rozalia Gabor

2007-01-01

A significant way of investigating a firm’s market is the statistical sampling. The sampling typology provides a non / probabilistic models of gathering information and this paper describes thorough information related to network sampling, named “snowball” sampling. This type of sampling enables the survey of occurrence forms concerning the decision power within an organisation and of the interpersonal relation network governing a certain collectivity, a certain consumer panel. The snowball s...

Sampling procedure, receipt and conservation of water samples to determine environmental radioactivity

International Nuclear Information System (INIS)

Herranz, M.; Navarro, E.; Payeras, J.

2009-01-01

The present document informs about essential goals, processes and contents that the subgroups Sampling and Samples Preparation and Conservation believe they should be part of the procedure to obtain a correct sampling, receipt, conservation and preparation of samples of continental, marine and waste water before qualifying its radioactive content.

IAEA Sampling Plan

Energy Technology Data Exchange (ETDEWEB)

Geist, William H. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2017-09-15

The objectives for this presentation are to describe the method that the IAEA uses to determine a sampling plan for nuclear material measurements; describe the terms detection probability and significant quantity; list the three nuclear materials measurement types; describe the sampling method applied to an item facility; and describe multiple method sampling.

Sample Acquisition for Materials in Planetary Exploration (SAMPLE), Phase I

Data.gov (United States)

National Aeronautics and Space Administration — ORBITEC proposes to analyze, design, and develop a device for autonomous lunar surface/subsurface sampling and processing applications. The Sample Acquisition for...

Network and adaptive sampling

CERN Document Server

Chaudhuri, Arijit

2014-01-01

Combining the two statistical techniques of network sampling and adaptive sampling, this book illustrates the advantages of using them in tandem to effectively capture sparsely located elements in unknown pockets. It shows how network sampling is a reliable guide in capturing inaccessible entities through linked auxiliaries. The text also explores how adaptive sampling is strengthened in information content through subsidiary sampling with devices to mitigate unmanageable expanding sample sizes. Empirical data illustrates the applicability of both methods.

Sampling bee communities using pan traps: alternative methods increase sample size

Science.gov (United States)

Monitoring of the status of bee populations and inventories of bee faunas require systematic sampling. Efficiency and ease of implementation has encouraged the use of pan traps to sample bees. Efforts to find an optimal standardized sampling method for pan traps have focused on pan trap color. Th...

SAMPLING IN EXTERNAL AUDIT - THE MONETARY UNIT SAMPLING METHOD

Directory of Open Access Journals (Sweden)

E. Dascalu

2016-12-01

Full Text Available This article approaches the general issue of diminishing the evidence investigation space in audit activities, by means of sampling techniques, given that in the instance of a significant data volume an exhaustive examination of the assessed popula¬tion is not possible and/or effective. The general perspective of the presentation involves dealing with sampling risk, in essence, the risk that a selected sample may not be representative for the overall population, in correlation with the audit risk model and with the component parts of this model (inherent risk, control risk and non detection risk and highlights the inter-conditionings between these two models.

Statistical sampling strategies

International Nuclear Information System (INIS)

Andres, T.H.

1987-01-01

Systems assessment codes use mathematical models to simulate natural and engineered systems. Probabilistic systems assessment codes carry out multiple simulations to reveal the uncertainty in values of output variables due to uncertainty in the values of the model parameters. In this paper, methods are described for sampling sets of parameter values to be used in a probabilistic systems assessment code. Three Monte Carlo parameter selection methods are discussed: simple random sampling, Latin hypercube sampling, and sampling using two-level orthogonal arrays. Three post-selection transformations are also described: truncation, importance transformation, and discretization. Advantages and disadvantages of each method are summarized

Measurement of radioactivity in the environment - Soil - Part 2: Guidance for the selection of the sampling strategy, sampling and pre-treatment of samples

International Nuclear Information System (INIS)

2007-01-01

This part of ISO 18589 specifies the general requirements, based on ISO 11074 and ISO/IEC 17025, for all steps in the planning (desk study and area reconnaissance) of the sampling and the preparation of samples for testing. It includes the selection of the sampling strategy, the outline of the sampling plan, the presentation of general sampling methods and equipment, as well as the methodology of the pre-treatment of samples adapted to the measurements of the activity of radionuclides in soil. This part of ISO 18589 is addressed to the people responsible for determining the radioactivity present in soil for the purpose of radiation protection. It is applicable to soil from gardens, farmland, urban or industrial sites, as well as soil not affected by human activities. This part of ISO 18589 is applicable to all laboratories regardless of the number of personnel or the range of the testing performed. When a laboratory does not undertake one or more of the activities covered by this part of ISO 18589, such as planning, sampling or testing, the corresponding requirements do not apply. Information is provided on scope, normative references, terms and definitions and symbols, principle, sampling strategy, sampling plan, sampling process, pre-treatment of samples and recorded information. Five annexes inform about selection of the sampling strategy according to the objectives and the radiological characterization of the site and sampling areas, diagram of the evolution of the sample characteristics from the sampling site to the laboratory, example of sampling plan for a site divided in three sampling areas, example of a sampling record for a single/composite sample and example for a sample record for a soil profile with soil description. A bibliography is provided

Biological sample collector

Science.gov (United States)

Murphy, Gloria A [French Camp, CA

2010-09-07

A biological sample collector is adapted to a collect several biological samples in a plurality of filter wells. A biological sample collector may comprise a manifold plate for mounting a filter plate thereon, the filter plate having a plurality of filter wells therein; a hollow slider for engaging and positioning a tube that slides therethrough; and a slide case within which the hollow slider travels to allow the tube to be aligned with a selected filter well of the plurality of filter wells, wherein when the tube is aligned with the selected filter well, the tube is pushed through the hollow slider and into the selected filter well to sealingly engage the selected filter well and to allow the tube to deposit a biological sample onto a filter in the bottom of the selected filter well. The biological sample collector may be portable.

Quality Control Samples for the Radiological Determination of Tritium in Urine Samples

International Nuclear Information System (INIS)

Ost'pezuk, P.; Froning, M.; Laumen, S.; Richert, I.; Hill, P.

2004-01-01

The radioactive decay product of tritium is a low energy beta that cannot penetrate the outer dead layer of human skin. Therefore , the main hazard associated with tritium is internal exposure. In addition, due to the relatively long half life and short biological half life, tritium must be ingested in large amounts to pose a significant health risk. On the other hand, the internal exposure should be kept as low as practical. For incorporation monitoring of professional radiation workers the quality control is of utmost importance. In the Research Centre Juelich GmbH (FZJ) a considerable fraction of monitoring by excretion analysis relates to the isotope Tritium. Usually an aliquot of an urine sample is mixed with a liquid scintillator and measured in a liquid scintillation counter. Quality control samples in the form of three kind of internal reference samples (blank, reference samples with low activity and reference sample with elevated activity) were prepared from a mixed, Tritium (free) urine samples. 1 ml of these samples were pipetted into a liquid scintillation vial. In the part of theses vials a known amounts of Tritium were added. All these samples were stored at 20 degrees. Based on long term use of all these reference samples it was possible to construct appropriate control charts with the upper and lower alarm limits. Daily use of these reference samples decrease significantly the risk for false results in original urine with no significant increase of the determination time. (Author) 2 refs

A Method for Choosing the Best Samples for Mars Sample Return.

Science.gov (United States)

Gordon, Peter R; Sephton, Mark A

2018-05-01

Success of a future Mars Sample Return mission will depend on the correct choice of samples. Pyrolysis-FTIR can be employed as a triage instrument for Mars Sample Return. The technique can thermally dissociate minerals and organic matter for detection. Identification of certain mineral types can determine the habitability of the depositional environment, past or present, while detection of organic matter may suggest past or present habitation. In Mars' history, the Theiikian era represents an attractive target for life search missions and the acquisition of samples. The acidic and increasingly dry Theiikian may have been habitable and followed a lengthy neutral and wet period in Mars' history during which life could have originated and proliferated to achieve relatively abundant levels of biomass with a wide distribution. Moreover, the sulfate minerals produced in the Theiikian are also known to be good preservers of organic matter. We have used pyrolysis-FTIR and samples from a Mars analog ferrous acid stream with a thriving ecosystem to test the triage concept. Pyrolysis-FTIR identified those samples with the greatest probability of habitability and habitation. A three-tier scoring system was developed based on the detection of (i) organic signals, (ii) carbon dioxide and water, and (iii) sulfur dioxide. The presence of each component was given a score of A, B, or C depending on whether the substance had been detected, tentatively detected, or not detected, respectively. Single-step (for greatest possible sensitivity) or multistep (for more diagnostic data) pyrolysis-FTIR methods informed the assignments. The system allowed the highest-priority samples to be categorized as AAA (or A*AA if the organic signal was complex), while the lowest-priority samples could be categorized as CCC. Our methods provide a mechanism with which to rank samples and identify those that should take the highest priority for return to Earth during a Mars Sample Return mission. Key Words

Urine sample collection protocols for bioassay samples

Energy Technology Data Exchange (ETDEWEB)

MacLellan, J.A.; McFadden, K.M.

1992-11-01

In vitro radiobioassay analyses are used to measure the amount of radioactive material excreted by personnel exposed to the potential intake of radioactive material. The analytical results are then used with various metabolic models to estimate the amount of radioactive material in the subject`s body and the original intake of radioactive material. Proper application of these metabolic models requires knowledge of the excretion period. It is normal practice to design the bioassay program based on a 24-hour excretion sample. The Hanford bioassay program simulates a total 24-hour urine excretion sample with urine collection periods lasting from one-half hour before retiring to one-half hour after rising on two consecutive days. Urine passed during the specified periods is collected in three 1-L bottles. Because the daily excretion volume given in Publication 23 of the International Commission on Radiological Protection (ICRP 1975, p. 354) for Reference Man is 1.4 L, it was proposed to use only two 1-L bottles as a cost-saving measure. This raised the broader question of what should be the design capacity of a 24-hour urine sample kit.

Urine sample collection protocols for bioassay samples

Energy Technology Data Exchange (ETDEWEB)

MacLellan, J.A.; McFadden, K.M.

1992-11-01

In vitro radiobioassay analyses are used to measure the amount of radioactive material excreted by personnel exposed to the potential intake of radioactive material. The analytical results are then used with various metabolic models to estimate the amount of radioactive material in the subject's body and the original intake of radioactive material. Proper application of these metabolic models requires knowledge of the excretion period. It is normal practice to design the bioassay program based on a 24-hour excretion sample. The Hanford bioassay program simulates a total 24-hour urine excretion sample with urine collection periods lasting from one-half hour before retiring to one-half hour after rising on two consecutive days. Urine passed during the specified periods is collected in three 1-L bottles. Because the daily excretion volume given in Publication 23 of the International Commission on Radiological Protection (ICRP 1975, p. 354) for Reference Man is 1.4 L, it was proposed to use only two 1-L bottles as a cost-saving measure. This raised the broader question of what should be the design capacity of a 24-hour urine sample kit.

Improved sample size determination for attributes and variables sampling

International Nuclear Information System (INIS)

Stirpe, D.; Picard, R.R.

1985-01-01

Earlier INMM papers have addressed the attributes/variables problem and, under conservative/limiting approximations, have reported analytical solutions for the attributes and variables sample sizes. Through computer simulation of this problem, we have calculated attributes and variables sample sizes as a function of falsification, measurement uncertainties, and required detection probability without using approximations. Using realistic assumptions for uncertainty parameters of measurement, the simulation results support the conclusions: (1) previously used conservative approximations can be expensive because they lead to larger sample sizes than needed; and (2) the optimal verification strategy, as well as the falsification strategy, are highly dependent on the underlying uncertainty parameters of the measurement instruments. 1 ref., 3 figs

Lunar Sample Compendium

Science.gov (United States)

Meyer, Charles

2005-01-01

The purpose of the Lunar Sample Compendium will be to inform scientists, astronauts and the public about the various lunar samples that have been returned from the Moon. This Compendium will be organized rock by rock in the manor of a catalog, but will not be as comprehensive, nor as complete, as the various lunar sample catalogs that are available. Likewise, this Compendium will not duplicate the various excellent books and reviews on the subject of lunar samples (Cadogen 1981, Heiken et al. 1991, Papike et al. 1998, Warren 2003, Eugster 2003). However, it is thought that an online Compendium, such as this, will prove useful to scientists proposing to study individual lunar samples and should help provide backup information for lunar sample displays. This Compendium will allow easy access to the scientific literature by briefly summarizing the significant findings of each rock along with the documentation of where the detailed scientific data are to be found. In general, discussion and interpretation of the results is left to the formal reviews found in the scientific literature. An advantage of this Compendium will be that it can be updated, expanded and corrected as need be.

Sampling free energy surfaces as slices by combining umbrella sampling and metadynamics.

Science.gov (United States)

Awasthi, Shalini; Kapil, Venkat; Nair, Nisanth N

2016-06-15

Metadynamics (MTD) is a very powerful technique to sample high-dimensional free energy landscapes, and due to its self-guiding property, the method has been successful in studying complex reactions and conformational changes. MTD sampling is based on filling the free energy basins by biasing potentials and thus for cases with flat, broad, and unbound free energy wells, the computational time to sample them becomes very large. To alleviate this problem, we combine the standard Umbrella Sampling (US) technique with MTD to sample orthogonal collective variables (CVs) in a simultaneous way. Within this scheme, we construct the equilibrium distribution of CVs from biased distributions obtained from independent MTD simulations with umbrella potentials. Reweighting is carried out by a procedure that combines US reweighting and Tiwary-Parrinello MTD reweighting within the Weighted Histogram Analysis Method (WHAM). The approach is ideal for a controlled sampling of a CV in a MTD simulation, making it computationally efficient in sampling flat, broad, and unbound free energy surfaces. This technique also allows for a distributed sampling of a high-dimensional free energy surface, further increasing the computational efficiency in sampling. We demonstrate the application of this technique in sampling high-dimensional surface for various chemical reactions using ab initio and QM/MM hybrid molecular dynamics simulations. Further, to carry out MTD bias reweighting for computing forward reaction barriers in ab initio or QM/MM simulations, we propose a computationally affordable approach that does not require recrossing trajectories. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Seroprevalence of Borrelia burgdorferi antibodies in white-tailed deer from Texas

Directory of Open Access Journals (Sweden)

Shakirat A. Adetunji

2016-08-01

Full Text Available Lyme Disease is caused by the bacterial pathogen Borrelia burgdorferi, and is transmitted by the tick-vector Ixodes scapularis. It is the most prevalent arthropod-borne disease in the United States. To determine the seroprevalence of B. burgdorferi antibodies in white-tailed deer (Odocoileus virginianus from Texas, we analyzed serum samples (n = 1493 collected during the 2001–2015 hunting seasons, using indirect ELISA. Samples with higher sero-reactivity (0.803 and above than the negative control group (0.662 were further tested using a more specific standardized western immunoblot assay to rule out false positives. Using ELISA, 4.7% of the samples were sero-reactive against B. burgdorferi, and these originated in two eco-regions in Texas (Edwards Plateau and South Texas Plains. However, only 0.5% of the total samples were sero-reactive by standardized western immunoblot assay. Additionally, both ELISA and standardized western immunoblot assay results correlated with an increased incidence in human Lyme Disease cases reported in Texas. This is the first longitudinal study to demonstrate fluctuation in sero-reactivity of white-tailed deer to B. burgdorferi sensu stricto antigens in southern United States. Future ecological and geographical studies are needed to assess the environmental factors governing the prevalence of Lyme Disease in non-endemic areas of the southern United States.

Procedures for sampling and sample reduction within quality assurance systems for solid biofuels

Energy Technology Data Exchange (ETDEWEB)

NONE

2005-07-01

The objective of this experimental study on sampling was to determine the size and number of samples of biofuels required (taken at two sampling points in each case) and to compare two methods of sampling. The first objective of the sample-reduction exercise was to compare the reliability of various sampling methods, and the second objective was to measure the variations introduced as a result of reducing the sample size to form suitable test portions. The materials studied were sawdust, wood chips, wood pellets and bales of straw, and these were analysed for moisture, ash, particle size and chloride. The sampling procedures are described. The study was conducted in Scandinavia. The results of the study were presented in Leipzig in October 2004. The work was carried out as part of the UK's DTI Technology Programme: New and Renewable Energy.

Procedures for sampling and sample-reduction within quality assurance systems for solid biofuels

Energy Technology Data Exchange (ETDEWEB)

NONE

2005-04-15

The bias introduced when sampling solid biofuels from stockpiles or containers instead of from moving streams is assessed as well as the number and size of samples required to represent accurately the bulk sample, variations introduced when reducing bulk samples into samples for testing, and the usefulness of sample reduction methods. Details are given of the experimental work carried out in Sweden and Denmark using sawdust, wood chips, wood pellets, forestry residues and straw. The production of a model European Standard for quality assurance of solid biofuels is examined.

Superposition Enhanced Nested Sampling

Directory of Open Access Journals (Sweden)

Stefano Martiniani

2014-08-01

Full Text Available The theoretical analysis of many problems in physics, astronomy, and applied mathematics requires an efficient numerical exploration of multimodal parameter spaces that exhibit broken ergodicity. Monte Carlo methods are widely used to deal with these classes of problems, but such simulations suffer from a ubiquitous sampling problem: The probability of sampling a particular state is proportional to its entropic weight. Devising an algorithm capable of sampling efficiently the full phase space is a long-standing problem. Here, we report a new hybrid method for the exploration of multimodal parameter spaces exhibiting broken ergodicity. Superposition enhanced nested sampling combines the strengths of global optimization with the unbiased or athermal sampling of nested sampling, greatly enhancing its efficiency with no additional parameters. We report extensive tests of this new approach for atomic clusters that are known to have energy landscapes for which conventional sampling schemes suffer from broken ergodicity. We also introduce a novel parallelization algorithm for nested sampling.

Network Sampling with Memory: A proposal for more efficient sampling from social networks

Science.gov (United States)

Mouw, Ted; Verdery, Ashton M.

2013-01-01

Techniques for sampling from networks have grown into an important area of research across several fields. For sociologists, the possibility of sampling from a network is appealing for two reasons: (1) A network sample can yield substantively interesting data about network structures and social interactions, and (2) it is useful in situations where study populations are difficult or impossible to survey with traditional sampling approaches because of the lack of a sampling frame. Despite its appeal, methodological concerns about the precision and accuracy of network-based sampling methods remain. In particular, recent research has shown that sampling from a network using a random walk based approach such as Respondent Driven Sampling (RDS) can result in high design effects (DE)—the ratio of the sampling variance to the sampling variance of simple random sampling (SRS). A high design effect means that more cases must be collected to achieve the same level of precision as SRS. In this paper we propose an alternative strategy, Network Sampling with Memory (NSM), which collects network data from respondents in order to reduce design effects and, correspondingly, the number of interviews needed to achieve a given level of statistical power. NSM combines a “List” mode, where all individuals on the revealed network list are sampled with the same cumulative probability, with a “Search” mode, which gives priority to bridge nodes connecting the current sample to unexplored parts of the network. We test the relative efficiency of NSM compared to RDS and SRS on 162 school and university networks from Add Health and Facebook that range in size from 110 to 16,278 nodes. The results show that the average design effect for NSM on these 162 networks is 1.16, which is very close to the efficiency of a simple random sample (DE=1), and 98.5% lower than the average DE we observed for RDS. PMID:24159246

Image Sampling with Quasicrystals

Directory of Open Access Journals (Sweden)

Mark Grundland

2009-07-01

Full Text Available We investigate the use of quasicrystals in image sampling. Quasicrystals produce space-filling, non-periodic point sets that are uniformly discrete and relatively dense, thereby ensuring the sample sites are evenly spread out throughout the sampled image. Their self-similar structure can be attractive for creating sampling patterns endowed with a decorative symmetry. We present a brief general overview of the algebraic theory of cut-and-project quasicrystals based on the geometry of the golden ratio. To assess the practical utility of quasicrystal sampling, we evaluate the visual effects of a variety of non-adaptive image sampling strategies on photorealistic image reconstruction and non-photorealistic image rendering used in multiresolution image representations. For computer visualization of point sets used in image sampling, we introduce a mosaic rendering technique.

Sample preparation of environmental samples using benzene synthesis followed by high-performance LSC

International Nuclear Information System (INIS)

Filippis, S. De; Noakes, J.E.

1991-01-01

Liquid scintillation counting (LSC) techniques have been widely employed as the detection method for determining environmental levels of tritium and 14 C. Since anthropogenic and nonanthropogenic inputs to the environment are a concern, sampling the environment surrounding a nuclear power facility or fuel reprocessing operation requires the collection of many different sample types, including agriculture products, water, biota, aquatic life, soil, and vegetation. These sample types are not suitable for the direct detection of tritium of 14 C for liquid scintillation techniques. Each sample type must be initially prepared in order to obtain the carbon or hydrogen component of interest and present this in a chemical form that is compatible with common chemicals used in scintillation counting applications. Converting the sample of interest to chemically pure benzene as a sample preparation technique has been widely accepted for processing samples for radiocarbon age-dating applications. The synthesized benzene is composed of the carbon or hydrogen atoms from the original sample and is ideal as a solvent for LSC with excellent photo-optical properties. Benzene synthesis followed by low-background scintillation counting can be applied to the preparation and measurement of environmental samples yielding good detection sensitivities, high radionuclide counting efficiency, and shorter preparation time. The method of benzene synthesis provides a unique approach to the preparation of a wide variety of environmental sample types using similar chemistry for all samples

Quantitative portable gamma spectroscopy sample analysis for non-standard sample geometries

International Nuclear Information System (INIS)

Enghauser, M.W.; Ebara, S.B.

1997-01-01

Utilizing a portable spectroscopy system, a quantitative method for analysis of samples containing a mixture of fission and activation products in nonstandard geometries was developed. The method can be used with various sample and shielding configurations where analysis on a laboratory based gamma spectroscopy system is impractical. The portable gamma spectroscopy method involves calibration of the detector and modeling of the sample and shielding to identify and quantify the radionuclides present in the sample. The method utilizes the intrinsic efficiency of the detector and the unattenuated gamma fluence rate at the detector surface per unit activity from the sample to calculate the nuclide activity and Minimum Detectable Activity (MDA). For a complex geometry, a computer code written for shielding applications (MICROSHIELD) is utilized to determine the unattenuated gamma fluence rate per unit activity at the detector surface. Lastly, the method is only applicable to nuclides which emit gamma rays and cannot be used for pure beta emitters. In addition, if sample self absorption and shielding is significant, the attenuation will result in high MDA's for nuclides which solely emit low energy gamma rays. The following presents the analysis technique and presents verification results demonstrating the accuracy of the method

Gravimetric dust sampling for control purposes and occupational dust sampling.

CSIR Research Space (South Africa)

Unsted, AD

1997-02-01

Full Text Available Prior to the introduction of gravimetric dust sampling, konimeters had been used for dust sampling, which was largely for control purposes. Whether or not absolute results were achievable was not an issue since relative results were used to evaluate...

Sampling procedures and tables

International Nuclear Information System (INIS)

Franzkowski, R.

1980-01-01

Characteristics, defects, defectives - Sampling by attributes and by variables - Sample versus population - Frequency distributions for the number of defectives or the number of defects in the sample - Operating characteristic curve, producer's risk, consumer's risk - Acceptable quality level AQL - Average outgoing quality AOQ - Standard ISQ 2859 - Fundamentals of sampling by variables for fraction defective. (RW)

Integrated sampling and analysis plan for samples measuring >10 mrem/hour

International Nuclear Information System (INIS)

Haller, C.S.

1992-03-01

This integrated sampling and analysis plan was prepared to assist in planning and scheduling of Hanford Site sampling and analytical activities for all waste characterization samples that measure greater than 10 mrem/hour. This report also satisfies the requirements of the renegotiated Interim Milestone M-10-05 of the Hanford Federal Facility Agreement and Consent Order (the Tri-Party Agreement). For purposes of comparing the various analytical needs with the Hanford Site laboratory capabilities, the analytical requirements of the various programs were normalized by converting required laboratory effort for each type of sample to a common unit of work, the standard analytical equivalency unit (AEU). The AEU approximates the amount of laboratory resources required to perform an extensive suite of analyses on five core segments individually plus one additional suite of analyses on a composite sample derived from a mixture of the five core segments and prepare a validated RCRA-type data package

Evaluation of Respondent-Driven Sampling

Science.gov (United States)

McCreesh, Nicky; Frost, Simon; Seeley, Janet; Katongole, Joseph; Tarsh, Matilda Ndagire; Ndunguse, Richard; Jichi, Fatima; Lunel, Natasha L; Maher, Dermot; Johnston, Lisa G; Sonnenberg, Pam; Copas, Andrew J; Hayes, Richard J; White, Richard G

2012-01-01

Background Respondent-driven sampling is a novel variant of link-tracing sampling for estimating the characteristics of hard-to-reach groups, such as HIV prevalence in sex-workers. Despite its use by leading health organizations, the performance of this method in realistic situations is still largely unknown. We evaluated respondent-driven sampling by comparing estimates from a respondent-driven sampling survey with total-population data. Methods Total-population data on age, tribe, religion, socioeconomic status, sexual activity and HIV status were available on a population of 2402 male household-heads from an open cohort in rural Uganda. A respondent-driven sampling (RDS) survey was carried out in this population, employing current methods of sampling (RDS sample) and statistical inference (RDS estimates). Analyses were carried out for the full RDS sample and then repeated for the first 250 recruits (small sample). Results We recruited 927 household-heads. Full and small RDS samples were largely representative of the total population, but both samples under-represented men who were younger, of higher socioeconomic status, and with unknown sexual activity and HIV status. Respondent-driven-sampling statistical-inference methods failed to reduce these biases. Only 31%-37% (depending on method and sample size) of RDS estimates were closer to the true population proportions than the RDS sample proportions. Only 50%-74% of respondent-driven-sampling bootstrap 95% confidence intervals included the population proportion. Conclusions Respondent-driven sampling produced a generally representative sample of this well-connected non-hidden population. However, current respondent-driven-sampling inference methods failed to reduce bias when it occurred. Whether the data required to remove bias and measure precision can be collected in a respondent-driven sampling survey is unresolved. Respondent-driven sampling should be regarded as a (potentially superior) form of convenience-sampling

Evaluation of respondent-driven sampling.

Science.gov (United States)

McCreesh, Nicky; Frost, Simon D W; Seeley, Janet; Katongole, Joseph; Tarsh, Matilda N; Ndunguse, Richard; Jichi, Fatima; Lunel, Natasha L; Maher, Dermot; Johnston, Lisa G; Sonnenberg, Pam; Copas, Andrew J; Hayes, Richard J; White, Richard G

2012-01-01

Respondent-driven sampling is a novel variant of link-tracing sampling for estimating the characteristics of hard-to-reach groups, such as HIV prevalence in sex workers. Despite its use by leading health organizations, the performance of this method in realistic situations is still largely unknown. We evaluated respondent-driven sampling by comparing estimates from a respondent-driven sampling survey with total population data. Total population data on age, tribe, religion, socioeconomic status, sexual activity, and HIV status were available on a population of 2402 male household heads from an open cohort in rural Uganda. A respondent-driven sampling (RDS) survey was carried out in this population, using current methods of sampling (RDS sample) and statistical inference (RDS estimates). Analyses were carried out for the full RDS sample and then repeated for the first 250 recruits (small sample). We recruited 927 household heads. Full and small RDS samples were largely representative of the total population, but both samples underrepresented men who were younger, of higher socioeconomic status, and with unknown sexual activity and HIV status. Respondent-driven sampling statistical inference methods failed to reduce these biases. Only 31%-37% (depending on method and sample size) of RDS estimates were closer to the true population proportions than the RDS sample proportions. Only 50%-74% of respondent-driven sampling bootstrap 95% confidence intervals included the population proportion. Respondent-driven sampling produced a generally representative sample of this well-connected nonhidden population. However, current respondent-driven sampling inference methods failed to reduce bias when it occurred. Whether the data required to remove bias and measure precision can be collected in a respondent-driven sampling survey is unresolved. Respondent-driven sampling should be regarded as a (potentially superior) form of convenience sampling method, and caution is required

Sample Curation in Support of the OSIRIS-REx Asteroid Sample Return Mission

Science.gov (United States)

Righter, Kevin; Nakamura-Messenger, Keiko

2017-01-01

The OSIRIS-REx asteroid sample return mission launched to asteroid Bennu Sept. 8, 2016. The spacecraft will arrive at Bennu in late 2019, orbit and map the asteroid, and perform a touch and go (TAG) sampling maneuver in July 2020. After sample is stowed and confirmed the spacecraft will return to Earth, and the sample return capsule (SRC) will land in Utah in September 2023. Samples will be recovered from Utah [2] and then transported and stored in a new sample cleanroom at NASA Johnson Space Center in Houston [3]. The materials curated for the mission are described here. a) Materials Archive and Witness Plate Collection: The SRC and TAGSAM were built between March 2014 and Summer of 2015, and instruments (OTES,OVIRS, OLA, OCAMS, REXIS) were integrated from Summer 2015 until May 2016. A total of 395 items were received for the materials archive at NASA-JSC, with archiving finishing 30 days after launch (with the final archived items being related to launch operations)[4]. The materials fall into several general categories including metals (stainless steel, aluminum, titanium alloys, brass and BeCu alloy), epoxies, paints, polymers, lubricants, non-volatile-residue samples (NVR), sapphire, and various miscellaneous materials. All through the ATLO process (from March 2015 until late August 2016) contamination knowledge witness plates (Si wafer and Al foil) were deployed in the various cleanrooms in Denver and KSC to provide an additional record of particle counts and volatiles that is archived for current and future scientific studies. These plates were deployed in roughly monthly increments with each unit containing 4 Si wafers and 4 Al foils. We archived 128 individual witness plates (64 Si wafers and 64 Al foils); one of each witness plate (Si and Al) was analyzed immediately by the science team after archiving, while the remaining 3 of each are archived indefinitely. Information about each material archived is stored in an extensive database at NASA-JSC, and key

[EPIZOOTOLOGICAL AND EPIDEMIOLOGICAL CHARACTERISTICS OF TULAREMIA IN GEORGIA].

Science.gov (United States)

Elashvili, E; Velijanashvili, I

2017-02-01

The appropriate data as well as archival materials about the spread of Tularemia disease have been studied over of period from 1991-2014 in Georgia in order to evaluate the current situation in Kartli lowland foci as well as the main reasons of disease agent circulation and maintenance in the study area. 54 (24.6%) out of 220 suspicious cases were laboratory confirmed during the study period. Most of confirmed cases - 32 (59.26%) have been detected in Shida Kartli focus among the old population during the outbreaks in the winter period. Tularemia causative agent has been isolated from the environmental object on 87 occasions, 50 (57.5%) of them have been found in Shida Kartli and 8 (9.2%) - in Kvemo Kartli lowland. Existence of rodents and ixodes ticks in Kartli lowland greatly supports keeping up Tularemia foci in this area. The common vectors and kind of storage of disease are considered to be different species of ixodes ticks especially D. marginatus, Haem. Punctata, Haem. Sulcata. It should be noted that reduction of intensity of Tularemia agent partially should be linked to the reduction frequency of planned and intentional researches during the last period of time.

Vibronic Boson Sampling: Generalized Gaussian Boson Sampling for Molecular Vibronic Spectra at Finite Temperature.

Science.gov (United States)

Huh, Joonsuk; Yung, Man-Hong

2017-08-07

Molecular vibroic spectroscopy, where the transitions involve non-trivial Bosonic correlation due to the Duschinsky Rotation, is strongly believed to be in a similar complexity class as Boson Sampling. At finite temperature, the problem is represented as a Boson Sampling experiment with correlated Gaussian input states. This molecular problem with temperature effect is intimately related to the various versions of Boson Sampling sharing the similar computational complexity. Here we provide a full description to this relation in the context of Gaussian Boson Sampling. We find a hierarchical structure, which illustrates the relationship among various Boson Sampling schemes. Specifically, we show that every instance of Gaussian Boson Sampling with an initial correlation can be simulated by an instance of Gaussian Boson Sampling without initial correlation, with only a polynomial overhead. Since every Gaussian state is associated with a thermal state, our result implies that every sampling problem in molecular vibronic transitions, at any temperature, can be simulated by Gaussian Boson Sampling associated with a product of vacuum modes. We refer such a generalized Gaussian Boson Sampling motivated by the molecular sampling problem as Vibronic Boson Sampling.

Detection of tick-borne bacteria and babesia with zoonotic potential in Argas (Carios) vespertilionis (Latreille, 1802) ticks from British bats.

Science.gov (United States)

Lv, Jizhou; Fernández de Marco, Maria Del Mar; Goharriz, Hooman; Phipps, L Paul; McElhinney, Lorraine M; Hernández-Triana, Luis M; Wu, Shaoqiang; Lin, Xiangmei; Fooks, Anthony R; Johnson, Nicholas

2018-01-30

Ticks host a wide range of zoonotic pathogens and are a significant source of diseases that affect humans and livestock. However, little is known about the pathogens associated with bat ticks. We have collected ectoparasites from bat carcasses over a seven year period. Nucleic acids (DNA and RNA) were extracted from 296 ticks removed from bats and the species designation was confirmed in all ticks as Argas (Carios) vespertilionis. A subset of these samples (n = 120) were tested for the presence of zoonotic pathogens by molecular methods. Babesia species, Rickettsia spp., within the spotted fever group (SFG), and Ehrlichia spp. were detected in ticks removed from 26 bats submitted from 14 counties across England. The prevalence of Rickettsia spp. was found to be highest in Pipistrellus pipistrellus from southern England. This study suggests that the tick species that host B. venatorum may include the genus Argas in addition to the genus Ixodes. As A. vespertilionis has been reported to feed on humans, detection of B. venatorum and SFG Rickettsia spp. could present a risk of disease transmission in England. No evidence for the presence of flaviviruses or Issyk-Kul virus (nairovirus) was found in these tick samples.

Sampling on Quasicrystals

OpenAIRE

Grepstad, Sigrid

2011-01-01

We prove that quasicrystals are universal sets of stable sampling in any dimension. Necessary and sufficient density conditions for stable sampling and interpolation sets in one dimension are studied in detail.

The Lunar Sample Compendium

Science.gov (United States)

Meyer, Charles

2009-01-01

The Lunar Sample Compendium is a succinct summary of the data obtained from 40 years of study of Apollo and Luna samples of the Moon. Basic petrographic, chemical and age information is compiled, sample-by-sample, in the form of an advanced catalog in order to provide a basic description of each sample. The LSC can be found online using Google. The initial allocation of lunar samples was done sparingly, because it was realized that scientific techniques would improve over the years and new questions would be formulated. The LSC is important because it enables scientists to select samples within the context of the work that has already been done and facilitates better review of proposed allocations. It also provides back up material for public displays, captures information found only in abstracts, grey literature and curatorial databases and serves as a ready access to the now-vast scientific literature.

A simulative comparison of respondent driven sampling with incentivized snowball sampling--the "strudel effect".

Science.gov (United States)

Gyarmathy, V Anna; Johnston, Lisa G; Caplinskiene, Irma; Caplinskas, Saulius; Latkin, Carl A

2014-02-01

Respondent driven sampling (RDS) and incentivized snowball sampling (ISS) are two sampling methods that are commonly used to reach people who inject drugs (PWID). We generated a set of simulated RDS samples on an actual sociometric ISS sample of PWID in Vilnius, Lithuania ("original sample") to assess if the simulated RDS estimates were statistically significantly different from the original ISS sample prevalences for HIV (9.8%), Hepatitis A (43.6%), Hepatitis B (Anti-HBc 43.9% and HBsAg 3.4%), Hepatitis C (87.5%), syphilis (6.8%) and Chlamydia (8.8%) infections and for selected behavioral risk characteristics. The original sample consisted of a large component of 249 people (83% of the sample) and 13 smaller components with 1-12 individuals. Generally, as long as all seeds were recruited from the large component of the original sample, the simulation samples simply recreated the large component. There were no significant differences between the large component and the entire original sample for the characteristics of interest. Altogether 99.2% of 360 simulation sample point estimates were within the confidence interval of the original prevalence values for the characteristics of interest. When population characteristics are reflected in large network components that dominate the population, RDS and ISS may produce samples that have statistically non-different prevalence values, even though some isolated network components may be under-sampled and/or statistically significantly different from the main groups. This so-called "strudel effect" is discussed in the paper. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Chorionic villus sampling

Science.gov (United States)

... medlineplus.gov/ency/article/003406.htm Chorionic villus sampling To use the sharing features on this page, please enable JavaScript. Chorionic villus sampling (CVS) is a test some pregnant women have ...

The new Chalk River AMS ion source, sample changer and external sample magazine

International Nuclear Information System (INIS)

Koslowsky, V.T.; Bray, N.; Imahori, Y.; Andrews, H.R.; Davies, W.G.

1997-01-01

A new sample magazine, sample changer and ion source have been developed and are in routine use at Chalk River. The system features a readily accessible 40-sample magazine at ground potential that is external to the ion source and high-voltage cage. The samples are held in an inert atmosphere and can be individually examined or removed; they can be exchanged en masse as a complete magazine concurrent with an AMS measurement. On-line sample changing is done with a pneumatic rabbit transfer system employing two stages of differential pumping. At Chalk River this is routinely performed across a 200 kV potential. Sample positioning is precise, and hundreds of 36 Cl and 129 I samples have been measured over a period of several days without interruption or alteration of ion source operating conditions. (author)

Genetic Sample Inventory

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This database archives genetic tissue samples from marine mammals collected primarily from the U.S. east coast. The collection includes samples from field programs,...

Fluid sample collection and distribution system. [qualitative analysis of aqueous samples from several points

Science.gov (United States)

Brooks, R. L. (Inventor)

1979-01-01

A multipoint fluid sample collection and distribution system is provided wherein the sample inputs are made through one or more of a number of sampling valves to a progressive cavity pump which is not susceptible to damage by large unfiltered particles. The pump output is through a filter unit that can provide a filtered multipoint sample. An unfiltered multipoint sample is also provided. An effluent sample can be taken and applied to a second progressive cavity pump for pumping to a filter unit that can provide one or more filtered effluent samples. The second pump can also provide an unfiltered effluent sample. Means are provided to periodically back flush each filter unit without shutting off the whole system.

Contributions to sampling statistics

CERN Document Server

Conti, Pier; Ranalli, Maria

2014-01-01

This book contains a selection of the papers presented at the ITACOSM 2013 Conference, held in Milan in June 2013. ITACOSM is the bi-annual meeting of the Survey Sampling Group S2G of the Italian Statistical Society, intended as an international  forum of scientific discussion on the developments of theory and application of survey sampling methodologies and applications in human and natural sciences. The book gathers research papers carefully selected from both invited and contributed sessions of the conference. The whole book appears to be a relevant contribution to various key aspects of sampling methodology and techniques; it deals with some hot topics in sampling theory, such as calibration, quantile-regression and multiple frame surveys, and with innovative methodologies in important topics of both sampling theory and applications. Contributions cut across current sampling methodologies such as interval estimation for complex samples, randomized responses, bootstrap, weighting, modeling, imputati...

Catch me if you can: Comparing ballast water sampling skids to traditional net sampling

Science.gov (United States)

Bradie, Johanna; Gianoli, Claudio; Linley, Robert Dallas; Schillak, Lothar; Schneider, Gerd; Stehouwer, Peter; Bailey, Sarah

2018-03-01

With the recent ratification of the International Convention for the Control and Management of Ships' Ballast Water and Sediments, 2004, it will soon be necessary to assess ships for compliance with ballast water discharge standards. Sampling skids that allow the efficient collection of ballast water samples in a compact space have been developed for this purpose. We ran 22 trials on board the RV Meteor from June 4-15, 2015 to evaluate the performance of three ballast water sampling devices (traditional plankton net, Triton sampling skid, SGS sampling skid) for three organism size classes: ≥ 50 μm, ≥ 10 μm to Natural sea water was run through the ballast water system and untreated samples were collected using paired sampling devices. Collected samples were analyzed in parallel by multiple analysts using several different analytic methods to quantify organism concentrations. To determine whether there were differences in the number of viable organisms collected across sampling devices, results were standardized and statistically treated to filter out other sources of variability, resulting in an outcome variable representing the mean difference in measurements that can be attributed to sampling devices. These results were tested for significance using pairwise Tukey contrasts. Differences in organism concentrations were found in 50% of comparisons between sampling skids and the plankton net for ≥ 50 μm, and ≥ 10 μm to < 50 μm size classes, with net samples containing either higher or lower densities. There were no differences for < 10 μm organisms. Future work will be required to explicitly examine the potential effects of flow velocity, sampling duration, sampled volume, and organism concentrations on sampling device performance.

Iowa Geologic Sampling Points

Data.gov (United States)

Iowa State University GIS Support and Research Facility — Point locations of geologic samples/files in the IGS repository. Types of samples include well cuttings, outcrop samples, cores, drillers logs, measured sections,...

First confirmed report of outbreak of theileriosis/anaplasmosis in a cattle farm in Henan, China.

Science.gov (United States)

Cui, Yanyan; Wang, Xiaoxing; Zhang, Yan; Yan, Yaqun; Dong, Haiju; Jian, Fuchun; Shi, Ke; Zhang, Longxian; Wang, Rongjun; Ning, Changshen

2018-01-01

Tick-borne diseases (TBDs) impose a significant constraint to livestock production world widely. In this paper, we presented a case of TBD in a cattle farm in Henan, China. 35 blood samples (7 samples sent by veterinarian, 28 samples gathered by our colleagues) were collected from ill, surviving and asymptomatic cattle and microscopic observation and PCR assays were conducted to characterize the pathogens. Genus Ixodes feeding on these cattle were collected and identified. Theileria annulata-like and Anaplasma marginale-like pathogens were observed in the blood smears stained with Giemsa staining under microscope. Furthermore, 5 out of 7 cattle blood samples were found to be positive for T. annulata by PCR. In the 28 blood specimens, three were positive for T. annulata, while A. marginale DNA was detected in nine blood DNA samples. Besides, 56 ticks feeding on cattle were collected from this farm and were all identified as Rhipisephalus microplus, meanwhile, 10 of them were found to be positive for A. marginale. In addition, phylogenetic analysis of the msp4 gene sequences of A. marginale obtained in this study showed that the isolate from cattle (KX840009) fell in the same clade with that of R. microplus (KX904527), sharing 100% similarity. To the best of our knowledge, this is the first confirmed report of outbreak of theileriosis/anaplasmosis in cattle farms in Henan, China. Copyright © 2017. Published by Elsevier B.V.

Sampling device for withdrawing a representative sample from single and multi-phase flows

Science.gov (United States)

Apley, Walter J.; Cliff, William C.; Creer, James M.

1984-01-01

A fluid stream sampling device has been developed for the purpose of obtaining a representative sample from a single or multi-phase fluid flow. This objective is carried out by means of a probe which may be inserted into the fluid stream. Individual samples are withdrawn from the fluid flow by sampling ports with particular spacings, and the sampling parts are coupled to various analytical systems for characterization of the physical, thermal, and chemical properties of the fluid flow as a whole and also individually.

Coordination of Conditional Poisson Samples

Directory of Open Access Journals (Sweden)

Grafström Anton

2015-12-01

Full Text Available Sample coordination seeks to maximize or to minimize the overlap of two or more samples. The former is known as positive coordination, and the latter as negative coordination. Positive coordination is mainly used for estimation purposes and to reduce data collection costs. Negative coordination is mainly performed to diminish the response burden of the sampled units. Poisson sampling design with permanent random numbers provides an optimum coordination degree of two or more samples. The size of a Poisson sample is, however, random. Conditional Poisson (CP sampling is a modification of the classical Poisson sampling that produces a fixed-size πps sample. We introduce two methods to coordinate Conditional Poisson samples over time or simultaneously. The first one uses permanent random numbers and the list-sequential implementation of CP sampling. The second method uses a CP sample in the first selection and provides an approximate one in the second selection because the prescribed inclusion probabilities are not respected exactly. The methods are evaluated using the size of the expected sample overlap, and are compared with their competitors using Monte Carlo simulation. The new methods provide a good coordination degree of two samples, close to the performance of Poisson sampling with permanent random numbers.

Sampling methods

International Nuclear Information System (INIS)

Loughran, R.J.; Wallbrink, P.J.; Walling, D.E.; Appleby, P.G.

2002-01-01

Methods for the collection of soil samples to determine levels of 137 Cs and other fallout radionuclides, such as excess 210 Pb and 7 Be, will depend on the purposes (aims) of the project, site and soil characteristics, analytical capacity, the total number of samples that can be analysed and the sample mass required. The latter two will depend partly on detector type and capabilities. A variety of field methods have been developed for different field conditions and circumstances over the past twenty years, many of them inherited or adapted from soil science and sedimentology. The use of them inherited or adapted from soil science and sedimentology. The use of 137 Cs in erosion studies has been widely developed, while the application of fallout 210 Pb and 7 Be is still developing. Although it is possible to measure these nuclides simultaneously, it is common for experiments to designed around the use of 137 Cs along. Caesium studies typically involve comparison of the inventories found at eroded or sedimentation sites with that of a 'reference' site. An accurate characterization of the depth distribution of these fallout nuclides is often required in order to apply and/or calibrate the conversion models. However, depending on the tracer involved, the depth distribution, and thus the sampling resolution required to define it, differs. For example, a depth resolution of 1 cm is often adequate when using 137 Cs. However, fallout 210 Pb and 7 Be commonly has very strong surface maxima that decrease exponentially with depth, and fine depth increments are required at or close to the soil surface. Consequently, different depth incremental sampling methods are required when using different fallout radionuclides. Geomorphic investigations also frequently require determination of the depth-distribution of fallout nuclides on slopes and depositional sites as well as their total inventories

Applications of Liquid-Phase Microextraction in the Sample Preparation of Environmental Solid Samples

Directory of Open Access Journals (Sweden)

Helena Prosen

2014-05-01

Full Text Available Solvent extraction remains one of the fundamental sample preparation techniques in the analysis of environmental solid samples, but organic solvents are toxic and environmentally harmful, therefore one of the possible greening directions is its miniaturization. The present review covers the relevant research from the field of application of microextraction to the sample preparation of environmental solid samples (soil, sediments, sewage sludge, dust etc. published in the last decade. Several innovative liquid-phase microextraction (LPME techniques that have emerged recently have also been applied as an aid in sample preparation of these samples: single-drop microextraction (SDME, hollow fiber-liquid phase microextraction (HF-LPME, dispersive liquid-liquid microextraction (DLLME. Besides the common organic solvents, surfactants and ionic liquids are also used. However, these techniques have to be combined with another technique to release the analytes from the solid sample into an aqueous solution. In the present review, the published methods were categorized into three groups: LPME in combination with a conventional solvent extraction; LPME in combination with an environmentally friendly extraction; LPME without previous extraction. The applicability of these approaches to the sample preparation for the determination of pollutants in solid environmental samples is discussed, with emphasis on their strengths, weak points and environmental impact.

Applications of liquid-phase microextraction in the sample preparation of environmental solid samples.

Science.gov (United States)

Prosen, Helena

2014-05-23

Solvent extraction remains one of the fundamental sample preparation techniques in the analysis of environmental solid samples, but organic solvents are toxic and environmentally harmful, therefore one of the possible greening directions is its miniaturization. The present review covers the relevant research from the field of application of microextraction to the sample preparation of environmental solid samples (soil, sediments, sewage sludge, dust etc.) published in the last decade. Several innovative liquid-phase microextraction (LPME) techniques that have emerged recently have also been applied as an aid in sample preparation of these samples: single-drop microextraction (SDME), hollow fiber-liquid phase microextraction (HF-LPME), dispersive liquid-liquid microextraction (DLLME). Besides the common organic solvents, surfactants and ionic liquids are also used. However, these techniques have to be combined with another technique to release the analytes from the solid sample into an aqueous solution. In the present review, the published methods were categorized into three groups: LPME in combination with a conventional solvent extraction; LPME in combination with an environmentally friendly extraction; LPME without previous extraction. The applicability of these approaches to the sample preparation for the determination of pollutants in solid environmental samples is discussed, with emphasis on their strengths, weak points and environmental impact.

High speed network sampling

OpenAIRE

Rindalsholt, Ole Arild

2005-01-01

Master i nettverks- og systemadministrasjon Classical Sampling methods play an important role in the current practice of Internet measurement. With today’s high speed networks, routers cannot manage to generate complete Netflow data for every packet. They have to perform restricted sampling. This thesis summarizes some of the most important sampling schemes and their applications before diving into an analysis on the effect of sampling Netflow records.

Generalized sampling in Julia

DEFF Research Database (Denmark)

Jacobsen, Christian Robert Dahl; Nielsen, Morten; Rasmussen, Morten Grud

2017-01-01

Generalized sampling is a numerically stable framework for obtaining reconstructions of signals in different bases and frames from their samples. For example, one can use wavelet bases for reconstruction given frequency measurements. In this paper, we will introduce a carefully documented toolbox...... for performing generalized sampling in Julia. Julia is a new language for technical computing with focus on performance, which is ideally suited to handle the large size problems often encountered in generalized sampling. The toolbox provides specialized solutions for the setup of Fourier bases and wavelets....... The performance of the toolbox is compared to existing implementations of generalized sampling in MATLAB....

Molecular detection of Theileria annae and Hepatozoon canis in foxes (Vulpes vulpes) in Croatia.

Science.gov (United States)

Dezdek, Danko; Vojta, Lea; Curković, Snjezana; Lipej, Zoran; Mihaljević, Zeljko; Cvetnić, Zeljko; Beck, Relja

2010-09-20

An epizootiological field study on tick-borne protozoan infections in foxes (Vulpes vulpes) was carried out in different parts of Croatia. Spleen samples of 191 carcasses of red foxes killed in sanitary hunting, were examined for the presence of hematozoa by polymerase chain reaction (PCR) and subsequent sequencing. The investigation revealed four species of hematozoa in 57 foxes (30%), namely Theileria annae, Theileria sp. 3182/05 and Hepatozoon canis. T. annae was found in 10 foxes (5%), Theileria sp. 3182/05 in a single animal (1%), H. canis in 44 (23%) and Hepatozoon sp. was detected in two foxes (1%). T. annae and H. canis were distributed through all the studied regions, while Theileria sp. 3182/05 and Hepatozoon sp. were restricted to the Zagreb and Zagorje, and Istria regions, respectively. Detection of T. annae in all regions of Croatia indicates the presence of the natural cycle of the parasite and raises the possibility of other vectors other than the proposed Ixodes hexagonus.

How iSamples (Internet of Samples in the Earth Sciences) Improves Sample and Data Stewardship in the Next Generation of Geoscientists

Science.gov (United States)

Hallett, B. W.; Dere, A. L. D.; Lehnert, K.; Carter, M.

2016-12-01

Vast numbers of physical samples are routinely collected by geoscientists to probe key scientific questions related to global climate change, biogeochemical cycles, magmatic processes, mantle dynamics, etc. Despite their value as irreplaceable records of nature the majority of these samples remain undiscoverable by the broader scientific community because they lack a digital presence or are not well-documented enough to facilitate their discovery and reuse for future scientific and educational use. The NSF EarthCube iSamples Research Coordination Network seeks to develop a unified approach across all Earth Science disciplines for the registration, description, identification, and citation of physical specimens in order to take advantage of the new opportunities that cyberinfrastructure offers. Even as consensus around best practices begins to emerge, such as the use of the International Geo Sample Number (IGSN), more work is needed to communicate these practices to investigators to encourage widespread adoption. Recognizing the importance of students and early career scientists in particular to transforming data and sample management practices, the iSamples Education and Training Working Group is developing training modules for sample collection, documentation, and management workflows. These training materials are made available to educators/research supervisors online at http://earthcube.org/group/isamples and can be modularized for supervisors to create a customized research workflow. This study details the design and development of several sample management tutorials, created by early career scientists and documented in collaboration with undergraduate research students in field and lab settings. Modules under development focus on rock outcrops, rock cores, soil cores, and coral samples, with an emphasis on sample management throughout the collection, analysis and archiving process. We invite others to share their sample management/registration workflows and to

Low-sampling-rate ultra-wideband channel estimation using equivalent-time sampling

KAUST Repository

Ballal, Tarig

2014-09-01

In this paper, a low-sampling-rate scheme for ultra-wideband channel estimation is proposed. The scheme exploits multiple observations generated by transmitting multiple pulses. In the proposed scheme, P pulses are transmitted to produce channel impulse response estimates at a desired sampling rate, while the ADC samples at a rate that is P times slower. To avoid loss of fidelity, the number of sampling periods (based on the desired rate) in the inter-pulse interval is restricted to be co-prime with P. This condition is affected when clock drift is present and the transmitted pulse locations change. To handle this case, and to achieve an overall good channel estimation performance, without using prior information, we derive an improved estimator based on the bounded data uncertainty (BDU) model. It is shown that this estimator is related to the Bayesian linear minimum mean squared error (LMMSE) estimator. Channel estimation performance of the proposed sub-sampling scheme combined with the new estimator is assessed in simulation. The results show that high reduction in sampling rate can be achieved. The proposed estimator outperforms the least squares estimator in almost all cases, while in the high SNR regime it also outperforms the LMMSE estimator. In addition to channel estimation, a synchronization method is also proposed that utilizes the same pulse sequence used for channel estimation. © 2014 IEEE.

The Tick Salivary Protein Sialostatin L Inhibits the Th9-Derived Production of the Asthma-Promoting Cytokine IL-9 and Is Effective in the Prevention of Experimental Asthma

Czech Academy of Sciences Publication Activity Database

Horká, Helena; Staudt, V.; Klein, M.; Taube, Ch.; Reuter, S.; Dehzad, N.; Andersen, J. F.; Kopecký, Jan; Schild, H.; Kotsyfakis, Michalis; Hoffmann, M.; Gerlitzki, B.; Stassen, M.; Bopp, T.; Schmitt, E.

2012-01-01

Roč. 188, č. 6 (2012), s. 2669-2676 ISSN 0022-1767 R&D Projects: GA ČR GCP302/11/J029; GA MŠk(CZ) LC06009 Institutional support: RVO:60077344 Keywords : experimental asthma * airway hyperresponsiveness * eosinophilia * interleukin-9 * Th9 cells * Sialostatin L * therapeutic * Ixodes scapularis * cysteine protease inhibitor * tick saliva Subject RIV: EC - Immunology Impact factor: 5.520, year: 2012

New insights into the machinery of blood digestion by ticks

Czech Academy of Sciences Publication Activity Database

Sojka, Daniel; Franta, Zdeněk; Horn, Martin; Caffrey, C. R.; Mareš, Michael; Kopáček, Petr

2013-01-01

Roč. 29, č. 6 (2013), s. 276-285 ISSN 1471-4922 R&D Projects: GA ČR GA13-11043S; GA ČR(CZ) GAP207/10/2183; GA ČR GPP502/11/P682; GA AV ČR IAA600960910 Institutional support: RVO:60077344 ; RVO:61388963 Keywords : tick * Ixodes * hemoglobin * digestion * peptidase * cathepsin Subject RIV: EC - Immunology Impact factor: 6.217, year: 2013

Test sample handling apparatus

International Nuclear Information System (INIS)

1981-01-01

A test sample handling apparatus using automatic scintillation counting for gamma detection, for use in such fields as radioimmunoassay, is described. The apparatus automatically and continuously counts large numbers of samples rapidly and efficiently by the simultaneous counting of two samples. By means of sequential ordering of non-sequential counting data, it is possible to obtain precisely ordered data while utilizing sample carrier holders having a minimum length. (U.K.)

The Effect of Asymmetrical Sample Training on Retention Functions for Hedonic Samples in Rats

Science.gov (United States)

Simmons, Sabrina; Santi, Angelo

2012-01-01

Rats were trained in a symbolic delayed matching-to-sample task to discriminate sample stimuli that consisted of the presence of food or the absence of food. Asymmetrical sample training was provided in which one group was initially trained with only the food sample and the other group was initially trained with only the no-food sample. In…

Green approaches in sample preparation of bioanalytical samples prior to chromatographic analysis.

Science.gov (United States)

Filippou, Olga; Bitas, Dimitrios; Samanidou, Victoria

2017-02-01

Sample preparation is considered to be the most challenging step of the analytical procedure, since it has an effect on the whole analytical methodology, therefore it contributes significantly to the greenness or lack of it of the entire process. The elimination of the sample treatment steps, pursuing at the same time the reduction of the amount of the sample, strong reductions in consumption of hazardous reagents and energy also maximizing safety for operators and environment, the avoidance of the use of big amount of organic solvents, form the basis for greening sample preparation and analytical methods. In the last decade, the development and utilization of greener and sustainable microextraction techniques is an alternative to classical sample preparation procedures. In this review, the main green microextraction techniques (solid phase microextraction, stir bar sorptive extraction, hollow-fiber liquid phase microextraction, dispersive liquid - liquid microextraction, etc.) will be presented, with special attention to bioanalytical applications of these environment-friendly sample preparation techniques which comply with the green analytical chemistry principles. Copyright © 2016 Elsevier B.V. All rights reserved.

Toward cost-efficient sampling methods

Science.gov (United States)

Luo, Peng; Li, Yongli; Wu, Chong; Zhang, Guijie

2015-09-01

The sampling method has been paid much attention in the field of complex network in general and statistical physics in particular. This paper proposes two new sampling methods based on the idea that a small part of vertices with high node degree could possess the most structure information of a complex network. The two proposed sampling methods are efficient in sampling high degree nodes so that they would be useful even if the sampling rate is low, which means cost-efficient. The first new sampling method is developed on the basis of the widely used stratified random sampling (SRS) method and the second one improves the famous snowball sampling (SBS) method. In order to demonstrate the validity and accuracy of two new sampling methods, we compare them with the existing sampling methods in three commonly used simulation networks that are scale-free network, random network, small-world network, and also in two real networks. The experimental results illustrate that the two proposed sampling methods perform much better than the existing sampling methods in terms of achieving the true network structure characteristics reflected by clustering coefficient, Bonacich centrality and average path length, especially when the sampling rate is low.

Final Sampling and Analysis Plan for Background Sampling, Fort Sheridan, Illinois

National Research Council Canada - National Science Library

1995-01-01

.... This Background Sampling and Analysis Plan (BSAP) is designed to address this issue through the collection of additional background samples at Fort Sheridan to support the statistical analysis and the Baseline Risk Assessment (BRA...

Low-sampling-rate ultra-wideband digital receiver using equivalent-time sampling

KAUST Repository

Ballal, Tarig

2014-09-01

In this paper, we propose an all-digital scheme for ultra-wideband symbol detection. In the proposed scheme, the received symbols are sampled many times below the Nyquist rate. It is shown that when the number of symbol repetitions, P, is co-prime with the symbol duration given in Nyquist samples, the receiver can sample the received data P times below the Nyquist rate, without loss of fidelity. The proposed scheme is applied to perform channel estimation and binary pulse position modulation (BPPM) detection. Results are presented for two receivers operating at two different sampling rates that are 10 and 20 times below the Nyquist rate. The feasibility of the proposed scheme is demonstrated in different scenarios, with reasonable bit error rates obtained in most of the cases.

Low-sampling-rate ultra-wideband digital receiver using equivalent-time sampling

KAUST Repository

Ballal, Tarig; Al-Naffouri, Tareq Y.

2014-01-01

In this paper, we propose an all-digital scheme for ultra-wideband symbol detection. In the proposed scheme, the received symbols are sampled many times below the Nyquist rate. It is shown that when the number of symbol repetitions, P, is co-prime with the symbol duration given in Nyquist samples, the receiver can sample the received data P times below the Nyquist rate, without loss of fidelity. The proposed scheme is applied to perform channel estimation and binary pulse position modulation (BPPM) detection. Results are presented for two receivers operating at two different sampling rates that are 10 and 20 times below the Nyquist rate. The feasibility of the proposed scheme is demonstrated in different scenarios, with reasonable bit error rates obtained in most of the cases.

'Intelligent' approach to radioimmunoassay sample counting employing a microprocessor controlled sample counter

International Nuclear Information System (INIS)

Ekins, R.P.; Sufi, S.; Malan, P.G.

1977-01-01

The enormous impact on medical science in the last two decades of microanalytical techniques employing radioisotopic labels has, in turn, generated a large demand for automatic radioisotopic sample counters. Such instruments frequently comprise the most important item of capital equipment required in the use of radioimmunoassay and related techniques and often form a principle bottleneck in the flow of samples through a busy laboratory. It is therefore particularly imperitive that such instruments should be used 'intelligently' and in an optimal fashion to avoid both the very large capital expenditure involved in the unnecessary proliferation of instruments and the time delays arising from their sub-optimal use. The majority of the current generation of radioactive sample counters nevertheless rely on primitive control mechanisms based on a simplistic statistical theory of radioactive sample counting which preclude their efficient and rational use. The fundamental principle upon which this approach is based is that it is useless to continue counting a radioactive sample for a time longer than that required to yield a significant increase in precision of the measurement. Thus, since substantial experimental errors occur during sample preparation, these errors should be assessed and must be releted to the counting errors for that sample. It is the objective of this presentation to demonstrate that the combination of a realistic statistical assessment of radioactive sample measurement, together with the more sophisticated control mechanisms that modern microprocessor technology make possible, may often enable savings in counter usage of the order of 5-10 fold to be made. (orig.) [de

Visualizing the Sample Standard Deviation

Science.gov (United States)

Sarkar, Jyotirmoy; Rashid, Mamunur

2017-01-01

The standard deviation (SD) of a random sample is defined as the square-root of the sample variance, which is the "mean" squared deviation of the sample observations from the sample mean. Here, we interpret the sample SD as the square-root of twice the mean square of all pairwise half deviations between any two sample observations. This…

Radioactivity in environmental samples

International Nuclear Information System (INIS)

Fornaro, Laura

2001-01-01

The objective of this practical work is to familiarize the student with radioactivity measures in environmental samples. For that were chosen samples a salt of natural potassium, a salt of uranium or torio and a sample of drinkable water

Applications of Liquid-Phase Microextraction in the Sample Preparation of Environmental Solid Samples

OpenAIRE

Helena Prosen

2014-01-01

Solvent extraction remains one of the fundamental sample preparation techniques in the analysis of environmental solid samples, but organic solvents are toxic and environmentally harmful, therefore one of the possible greening directions is its miniaturization. The present review covers the relevant research from the field of application of microextraction to the sample preparation of environmental solid samples (soil, sediments, sewage sludge, dust etc.) published in the last decade. Several...

Perpendicular distance sampling: an alternative method for sampling downed coarse woody debris

Science.gov (United States)

Michael S. Williams; Jeffrey H. Gove

2003-01-01

Coarse woody debris (CWD) plays an important role in many forest ecosystem processes. In recent years, a number of new methods have been proposed to sample CWD. These methods select individual logs into the sample using some form of unequal probability sampling. One concern with most of these methods is the difficulty in estimating the volume of each log. A new method...

Jenis Sample: Keuntungan dan Kerugiannya

OpenAIRE

Suprapto, Agus

1994-01-01

Sample is a part of a population that are used in a study for purposes of making estimation about the nature of the total population that is obtained with sampling technic. Sampling technic is more adventagous than cencus because it can reduce cost, time, and it can gather deeper information and more accurate data. It is useful to distinguish two major types of sampling technics. First, Prob bility sampling i.e. simple random sampling. Second, Non Probability sampling i.e. systematic sam­plin...

A method of language sampling

DEFF Research Database (Denmark)

Rijkhoff, Jan; Bakker, Dik; Hengeveld, Kees

1993-01-01

In recent years more attention is paid to the quality of language samples in typological work. Without an adequate sampling strategy, samples may suffer from various kinds of bias. In this article we propose a sampling method in which the genetic criterion is taken as the most important: samples...... to determine how many languages from each phylum should be selected, given any required sample size....

Wet gas sampling

Energy Technology Data Exchange (ETDEWEB)

Welker, T.F.

1997-07-01

The quality of gas has changed drastically in the past few years. Most gas is wet with hydrocarbons, water, and heavier contaminants that tend to condense if not handled properly. If a gas stream is contaminated with condensables, the sampling of that stream must be done in a manner that will ensure all of the components in the stream are introduced into the sample container as the composite. The sampling and handling of wet gas is extremely difficult under ideal conditions. There are no ideal conditions in the real world. The problems related to offshore operations and other wet gas systems, as well as the transportation of the sample, are additional problems that must be overcome if the analysis is to mean anything to the producer and gatherer. The sampling of wet gas systems is decidedly more difficult than sampling conventional dry gas systems. Wet gas systems were generally going to result in the measurement of one heating value at the inlet of the pipe and a drastic reduction in the heating value of the gas at the outlet end of the system. This is caused by the fallout or accumulation of the heavier products that, at the inlet, may be in the vapor state in the pipeline; hence, the high gravity and high BTU. But, in fact, because of pressure and temperature variances, these liquids condense and form a liquid that is actually running down the pipe as a stream or is accumulated in drips to be blown from the system. (author)

An algorithm to improve sampling efficiency for uncertainty propagation using sampling based method

International Nuclear Information System (INIS)

Campolina, Daniel; Lima, Paulo Rubens I.; Pereira, Claubia; Veloso, Maria Auxiliadora F.

2015-01-01

Sample size and computational uncertainty were varied in order to investigate sample efficiency and convergence of the sampling based method for uncertainty propagation. Transport code MCNPX was used to simulate a LWR model and allow the mapping, from uncertain inputs of the benchmark experiment, to uncertain outputs. Random sampling efficiency was improved through the use of an algorithm for selecting distributions. Mean range, standard deviation range and skewness were verified in order to obtain a better representation of uncertainty figures. Standard deviation of 5 pcm in the propagated uncertainties for 10 n-samples replicates was adopted as convergence criterion to the method. Estimation of 75 pcm uncertainty on reactor k eff was accomplished by using sample of size 93 and computational uncertainty of 28 pcm to propagate 1σ uncertainty of burnable poison radius. For a fixed computational time, in order to reduce the variance of the uncertainty propagated, it was found, for the example under investigation, it is preferable double the sample size than double the amount of particles followed by Monte Carlo process in MCNPX code. (author)

Mars Sample Handling Functionality

Science.gov (United States)

Meyer, M. A.; Mattingly, R. L.

2018-04-01

The final leg of a Mars Sample Return campaign would be an entity that we have referred to as Mars Returned Sample Handling (MRSH.) This talk will address our current view of the functional requirements on MRSH, focused on the Sample Receiving Facility (SRF).

Big Data, Small Sample.

Science.gov (United States)

Gerlovina, Inna; van der Laan, Mark J; Hubbard, Alan

2017-05-20

Multiple comparisons and small sample size, common characteristics of many types of "Big Data" including those that are produced by genomic studies, present specific challenges that affect reliability of inference. Use of multiple testing procedures necessitates calculation of very small tail probabilities of a test statistic distribution. Results based on large deviation theory provide a formal condition that is necessary to guarantee error rate control given practical sample sizes, linking the number of tests and the sample size; this condition, however, is rarely satisfied. Using methods that are based on Edgeworth expansions (relying especially on the work of Peter Hall), we explore the impact of departures of sampling distributions from typical assumptions on actual error rates. Our investigation illustrates how far the actual error rates can be from the declared nominal levels, suggesting potentially wide-spread problems with error rate control, specifically excessive false positives. This is an important factor that contributes to "reproducibility crisis". We also review some other commonly used methods (such as permutation and methods based on finite sampling inequalities) in their application to multiple testing/small sample data. We point out that Edgeworth expansions, providing higher order approximations to the sampling distribution, offer a promising direction for data analysis that could improve reliability of studies relying on large numbers of comparisons with modest sample sizes.