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Abdu F Azad - One of the best experts on this subject based on the ideXlab platform.
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immune responsive lysozymes from hemocytes of the american dog tick Dermacentor variabilis and an embryonic cell line of the rocky mountain wood tick d andersoni
Insect Biochemistry and Molecular Biology, 2004Co-Authors: Jason A Simser, Kevin R Macaluso, Albert Mulenga, Abdu F AzadAbstract:Abstract Immune-responsive lysozyme encoding cDNAs were identified from two medically important tick species by an expressed sequence tag approach of D. variabilis hemocytes (Dv Lys) and a D. andersoni embryonic derived cell line, DAE100. Comparative sequence analyses indicated the Dermacentor molecules to be products of orthologous genes and to be most similar to arthropod c-type lysozymes. Northern blotting analyses demonstrated that Dv Lys expression levels were most abundant in tick hemocytes and to a much lesser degree in the midgut while barely detectable in ovary, salivary gland, and Malpighian tubule tissues. Involvement of the Dermacentor c-type lysozymes in innate immunity was demonstrated by Escherichia coli challenges of D. variabilis ticks by injection resulting in a temporal profile of significantly elevated transcript abundances above those of naive controls that was similarly observed of the D. andersoni cells co-cultured with E. coli . In contrast to that reported of the digestive gut lysozyme of the soft tick Ornithodoros moubata , Dv Lys levels were not statistically differentially regulated by blood meal digestion. Additionally, given the differences in tissue distribution, sequence characteristics and phylogenetic placements between the Dermacentor and Ornithodoros lysozymes demonstrates that ticks possess differently adapted c-type lysozymes that are spatially and temporally differentially expressed.
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an immune responsive factor d like serine proteinase homologue identified from the american dog tick Dermacentor variabilis
Insect Molecular Biology, 2004Co-Authors: Jason A Simser, Kevin R Macaluso, Albert Mulenga, Abdu F AzadAbstract:A Dermacentor variabilis cDNA encoding a clip-domain serine proteinase homologue with glycine replacing the catalytic serine was identified from tick haemocytes. The D. variabilis product was most similar to Tachypleus tridentatus haemocyte antimicrobial factor D and shared significant homologies with a number of immune-responsive gene products of arthropods, including insect prophenoloxidase-activating cofactors. Northern blotting analyses confirmed that the tick serine proteinase homologue expression levels were highest in haemocytes, and to lesser degrees in ovaries and then salivary glands whereas steady-state levels of expression in whole ticks were found to be slightly higher in fed versus unfed adults or eggs. Challenge of fed adults by Escherichia coli injection demonstrated that transcript abundance was significantly increased above those of naive controls in a temporal fashion. Additionally, an apparent orthologue of the D. variabilis clip-domain molecule was cloned, and expression detected, from a Dermacentor andersoni cell line indicating cross species conservation.
Pierre-edouard Fournier - One of the best experts on this subject based on the ideXlab platform.
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sequence and annotation of rickettsia sibirica sibirica genome
Journal of Bacteriology, 2012Co-Authors: Erwin Sentausa, Catherine Robert, Khalid El Karkouri, Didier Raoult, Pierre-edouard FournierAbstract:Rickettsia sibirica sibirica is the causative agent of Siberian or North Asian tick typhus, a tick-borne rickettsiosis known to exist in Siberia and eastern China. Here we present the draft genome of Rickettsia sibirica sibirica strain BJ-90 isolated from Dermacentor sinicus ticks collected in Beijing, China.
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complete genome sequence of rickettsia slovaca the agent of tick borne lymphadenitis
Journal of Bacteriology, 2012Co-Authors: Pierre-edouard Fournier, Khalid El Karkouri, Catherine Robert, Claudine MedigueAbstract:The present study reports the complete and annotated genome sequence of the human pathogen Rickettsia slovaca strain 13-B, which was isolated from a Dermacentor tick in Slovakia in 1968. The 1.27-Mb genome provides further insights into the acquisition of virulence related to genome reduction in Rickettsia species.
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rickettsia raoultii sp nov a spotted fever group rickettsia associated with Dermacentor ticks in europe and russia
International Journal of Systematic and Evolutionary Microbiology, 2008Co-Authors: Oleg Mediannikov, Irina Tarasevich, Elena Rydkina, Philippe Brouqui, Veronique Roux, Kotaro Matsumoto, Irina Samoylenko, Michel Drancourt, Bernard Davoust, Pierre-edouard FournierAbstract:We describe the characterization of a novel Rickettsia species cultivated from Dermacentor ticks collected in Russia and France, for which we propose the name Rickettsia raoultii sp. nov. Using multigene sequencing, we demonstrated that five rickettsial isolates from Dermacentor silvarum, Dermacentor reticulatus, Dermacentor marginatus and Dermacentor nuttalli ticks were classified within this novel spotted fever rickettsia species. This rickettsia also exhibited a serotype distinct from previously described Rickettsia species. The type strain of Rickettsia raoultii sp. nov. is strain KhabarovskT (=CSUR R3T =ATCC VR-1596T).
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spotless rickettsiosis caused by rickettsia slovaca and associated with Dermacentor ticks
Clinical Infectious Diseases, 2002Co-Authors: Andras Lakos, J. Beytout, Philippe Brouqui, Florence Fenollar, Pierre-edouard FournierAbstract:The pathogenic role of Rickettsia slovaca was first demonstrated in 1997 in a patient who presented with a single inoculation lesion of the scalp and enlarged cervical lymph nodes after receiving a bite from a Dermacentor tick. Subsequently, we evaluated the occurrence of R. slovaca infections among patients living in France and Hungary who presented with these symptoms. R. slovaca infections were confirmed by polymerase chain reaction (PCR) in 17 of 67 enrolled patients. Infections were most likely to occur in patients aged <10 years and in patients who were bitten during the colder months of the year. The median duration of incubation for the disease was 7 days. Fever was present in only 2 patients, and only 1 patient developed a rash. Sequelae included persistent asthenia (3 cases) and localized alopecia (4 cases). Immunofluorescence and/or Western blot analysis detected antibodies in 50% of tested patients. Three Dermacentor ticks obtained from patients revealed R. slovaca by PCR.
Neil B Chilton - One of the best experts on this subject based on the ideXlab platform.
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range expansion of Dermacentor variabilis and Dermacentor andersoni acari ixodidae near their northern distributional limits
Journal of Medical Entomology, 2013Co-Authors: Shaun J Dergousoff, Philip S Curry, Robbin L Lindsay, Terry D Galloway, Neil B ChiltonAbstract:Distributional ranges of the ticks Dermacentor andersoni Stiles and Dermacentor variabilis (Say) in the Canadian Prairies were determined by passive surveillance and active collection. These findings were compared with historical records of both species, particularly in the province of Saskatchewan, where the northern distributional limits of both tick species occur. Before the 1960s, D. variabilis and D. andersoni were allopatric in Saskatchewan; however, since then, the distribution of D. variabilis has expanded westward and northward. Although the range of D. andersoni has remained relatively stable, range expansion of D. variabilis has resulted in a zone of sympatry at least 200 km wide. Twenty-nine species of mammals and three species of birds were identified as hosts for different life stages of these ticks.
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prevalence of rickettsia species in canadian populations of Dermacentor andersoni and d variabilis
Applied and Environmental Microbiology, 2009Co-Authors: Shaun J Dergousoff, Andrew J A Gajadhar, Neil B ChiltonAbstract:We determined the prevalence of rickettsiae in Dermacentor adults at 15 localities in Canada. Rickettsia rickettsii was not detected in any tick, whereas Rickettsia peacockii was present in 76% of Dermacentor andersoni adults and Rickettsia montanensis in 8% of Dermacentor variabilis adults. This host specificity was maintained in localities where both tick species occurred in sympatry.
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differentiation of three species of ixodid tick Dermacentor andersoni d variabilis and d albipictus by pcr based approaches using markers in ribosomal dna
Molecular and Cellular Probes, 2007Co-Authors: Shaun J Dergousoff, Neil B ChiltonAbstract:Three species of Dermacentor, Dermacentor albipictus, Dermacentor andersoni and Dermacentor variabilis, commonly occur in Canada. D. andersoni and D. variabilis are morphologically similar and are important vectors of human and animal pathogens. A practical polymerase chain reaction (PCR) assay, based on the amplification of part of the second internal transcribed spacer ribosomal DNA (pITS-2 rDNA), was developed to distinguish D. andersoni from D. variabilis. In addition, single-strand conformation polymorphism (SSCP) analysis of the pITS-2 rDNA provided a reliable method of distinguishing specimens of the three species of ixodid tick. PCR and pITS-2 SSCP were also used to determine whether there was hybridization between D. andersoni and D. variabilis at two localities in Saskatchewan where they occur in sympatry. These molecular tools will be useful for the unequivocal identification of D. andersoni and D. variabilis at all life cycle stages, which is essential for studies on their ecology and on the transmission of tick-borne diseases. Also, pITS-2 SSCP may be of potential use for discriminating among the other morphologically similar species within the genus Dermacentor.
Michael L. Levin - One of the best experts on this subject based on the ideXlab platform.
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first report of rickettsia identical to r slovaca in colony originated d variabilis in the united states detection laboratory animal model and vector competence of ticks
Vector-borne and Zoonotic Diseases, 2016Co-Authors: Galina E. Zemtsova, Lindsay F. Killmaster, Merrill Montgomery, Matt Burrows, Lauren Schumacher, Michael L. LevinAbstract:Abstract Ticks of the genus Dermacentor are known vectors of rickettsial pathogens in both the Old World and New World. In North America, Dermacentor variabilis and D. andersoni are vectors of Rickettsia rickettsii, while in Europe, D. marginatus and D. reticulatus transmit R. slovaca and R. raoultii, respectively. Neither the presence of R. slovaca in the Americas nor the ability of American tick species to maintain this pathogen have been reported. Here we describe detection of Rickettsia genetically identical to R. slovaca in D. variabilis, its molecular characterization, assessment of pathogenicity to guinea pigs, and vector competence of D. variabilis ticks. Ticks from a laboratory colony of D. variabilis, established from wild ticks and maintained on naive NZW rabbits, tested positive for spotted fever group (SFG) Rickettsia by PCR. Analysis of 17 kDa gltA, rpoB, ompA, ompB, and sca4 genes revealed 100% identity to R. slovaca sequences available in the GenBank. New Zealand white rabbits fed upon by ...
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Isolation of a Rickettsia slovaca-Like Agent from Dermacentor variabilis Ticks in Vero Cell Culture.
Vector borne and zoonotic diseases (Larchmont N.Y.), 2016Co-Authors: Lindsay F. Killmaster, Galina E. Zemtsova, Merrill Montgomery, Lauren B.m. Schumacher, Matt Burrows, Michael L. LevinAbstract:Rickettsia slovaca is transmitted by Dermacentor marginatus ticks, and is the causative agent of tick-borne lymphadenopathy and Dermacentor-borne necrosis erythema lymphadenopathy throughout Europe. It has not been found in New World ticks, nor have tick-borne lymphadenopathy or Dermacentor-borne necrosis erythema lymphadenopathy been reported in humans in the Americas. Here we describe the isolation of a R. slovaca-like agent from D. variabilis nymphs from a colony of ticks derived from field collected adults.
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life cycles of seven ixodid tick species acari ixodidae under standardized laboratory conditions
Journal of Medical Entomology, 2007Co-Authors: Danielle R Troughton, Michael L. LevinAbstract:Abstract Studies of transmission, maintenance, infectivity, virulence, and pathogenicity of tick-borne agents require the use of large numbers of live laboratory-raised ticks. Colonies of Ixodes scapularis Say, Ixodes pacificus Cooley & Kohls, Amblyomma americanum (L.), Dermacentor occidentalis Marx, Dermacentor variabilis (Say), Hemaphysalis leporispalustris (Packard), and Rhipicephalus sanguineus (Latrielle) have been maintained in our laboratory at the Centers for Disease Control and Prevention for five to 18 continuous generations. New Zealand White rabbits (Oryctolagus cuniculus) are used as hosts for all tick species and developmental stages. Between feedings, ticks are stored in environmental incubators at 22–24°C and 90% RH with a day/night photoperiod of 16:8 (L:D) h. The duration of feeding, molting, preoviposition, and periods of postmolting development were recorded. Here, we describe the life cycles of these common North American tick species under standardized laboratory conditions. At 22–24...
Philippe Brouqui - One of the best experts on this subject based on the ideXlab platform.
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rickettsia raoultii sp nov a spotted fever group rickettsia associated with Dermacentor ticks in europe and russia
International Journal of Systematic and Evolutionary Microbiology, 2008Co-Authors: Oleg Mediannikov, Irina Tarasevich, Elena Rydkina, Philippe Brouqui, Veronique Roux, Kotaro Matsumoto, Irina Samoylenko, Michel Drancourt, Bernard Davoust, Pierre-edouard FournierAbstract:We describe the characterization of a novel Rickettsia species cultivated from Dermacentor ticks collected in Russia and France, for which we propose the name Rickettsia raoultii sp. nov. Using multigene sequencing, we demonstrated that five rickettsial isolates from Dermacentor silvarum, Dermacentor reticulatus, Dermacentor marginatus and Dermacentor nuttalli ticks were classified within this novel spotted fever rickettsia species. This rickettsia also exhibited a serotype distinct from previously described Rickettsia species. The type strain of Rickettsia raoultii sp. nov. is strain KhabarovskT (=CSUR R3T =ATCC VR-1596T).
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Prevalence of Rickettsia spp. in Dermacentor marginatus ticks removed from game pigs (Sus scrofa) in southern France.
Annals of the New York Academy of Sciences, 2003Co-Authors: Y. O. Sanogo, Philippe Parola, Jean-louis Camicas, Philippe BrouquiAbstract:During the months of October and November 2000 a total of 70 Dermacentor marginatus ticks were removed from different game pigs Sus scrofa in southern France and investigated by PCR using primers derived from the citrate synthase (gltA) and the outer membrane protein (OmpB) genes of rickettsiae. Based on sequence analysis of 1,150 bp fragment of gltA, Rickettsia slovaca was identified in 11 ticks (15.7%). These results confirm that Rickettsia slovaca, an emerging pathogen is highly prevalent in Dermacentor marginatus ticks in France. Moreover, a new Rickettsia genotype was detected in one specimen (1.4%). The pathogenic role of this new rickettsia has yet to be demonstrated.
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spotless rickettsiosis caused by rickettsia slovaca and associated with Dermacentor ticks
Clinical Infectious Diseases, 2002Co-Authors: Andras Lakos, J. Beytout, Philippe Brouqui, Florence Fenollar, Pierre-edouard FournierAbstract:The pathogenic role of Rickettsia slovaca was first demonstrated in 1997 in a patient who presented with a single inoculation lesion of the scalp and enlarged cervical lymph nodes after receiving a bite from a Dermacentor tick. Subsequently, we evaluated the occurrence of R. slovaca infections among patients living in France and Hungary who presented with these symptoms. R. slovaca infections were confirmed by polymerase chain reaction (PCR) in 17 of 67 enrolled patients. Infections were most likely to occur in patients aged <10 years and in patients who were bitten during the colder months of the year. The median duration of incubation for the disease was 7 days. Fever was present in only 2 patients, and only 1 patient developed a rash. Sequelae included persistent asthenia (3 cases) and localized alopecia (4 cases). Immunofluorescence and/or Western blot analysis detected antibodies in 50% of tested patients. Three Dermacentor ticks obtained from patients revealed R. slovaca by PCR.
