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Sample records for ehrlichia chaffeensis tandem

  1. Tyrosine-phosphorylated Ehrlichia chaffeensis and Ehrlichia canis tandem repeat orthologs contain a major continuous cross-reactive antibody epitope in lysine-rich repeats.

    PubMed

    McBride, Jere W; Zhang, Xiaofeng; Wakeel, Abdul; Kuriakose, Jeeba A

    2011-08-01

    A small subset of major immunoreactive proteins have been identified in Ehrlichia chaffeensis and Ehrlichia canis, including three molecularly and immunologically characterized pairs of immunoreactive tandem repeat protein (TRP) orthologs with major continuous species-specific epitopes within acidic tandem repeats (TR) that stimulate strong antibody responses during infection. In this study, we identified a fourth major immunoreactive TR-containing ortholog pair and defined a major cross-reactive epitope in homologous nonidentical 24-amino-acid lysine-rich TRs. Antibodies from patients and dogs with ehrlichiosis reacted strongly with recombinant TR regions, and epitopes were mapped to the N-terminal TR region (18 amino acids) in E. chaffeensis and the complete TR (24 amino acids) in E. canis. Two less-dominant epitopes were mapped to adjacent glutamate/aspartate-rich and aspartate/tyrosine-rich regions in the acidic C terminus of E. canis TRP95 but not in E. chaffeensis TRP75. Major immunoreactive proteins in E. chaffeensis (75-kDa) and E. canis (95-kD) whole-cell lysates and supernatants were identified with TR-specific antibodies. Consistent with other ehrlichial TRPs, the TRPs identified in ehrlichial whole-cell lysates and the recombinant proteins migrated abnormally slow electrophoretically a characteristic that was demonstrated with the positively charged TR and negatively charged C-terminal domains. E. chaffeensis TRP75 and E. canis TRP95 were immunoprecipitated with anti-pTyr antibody, demonstrating that they are tyrosine phosphorylated during infection of the host cell.

  2. Proteomic Analysis of and Immune Responses to Ehrlichia chaffeensis Lipoproteins

    SciTech Connect

    Huang, Hai; Lin, Mingqun ..; Wang, Xueqi; Kikuchi, Takane; Mottaz, Heather M.; Norbeck, Angela D.; Rikihisa, Yasuko

    2008-08-01

    Ehrlichia chaffeensis is an obligatory intracellular Gram-negative bacterium and is the etiologic agent of human monocytic ehrlichiosis (HME). Although E. chaffeensis induces generation of several cytokines and chemokines by leukocytes, E. chaffeensis lacks LPS and peptidoglycan. Bioinfomatic analysis of the E. chaffeensis genome, however, predicted genes encoding fifteen lipoproteins and three posttranslational lipoprotein processing enzymes. The present study showed that using multidimensional liquid chromatography followed by tandem mass spectrometry, all predicted lipoproteins as well as lipoprotein-processing enzymes were expressed by E. chaffeensis cultured in human promyelocytic leukemia cell line, HL-60. Consistent with this observation, a signal peptidase II inhibitor, globomycin was found to inhibit E. chaffeensis infection and lipoprotein processing in HL-60 cell culture. To study in vivo E.chaffeensis lipoprotein expression and host immune responses to E. chaffeensis lipoproteins, thirteen E. chaffeensis lipoprotein genes were cloned into a mammalian expression vector.

  3. Ehrlichia chaffeensis Infection of Sika Deer, Japan

    PubMed Central

    Kawahara, Makoto; Tajima, Tomoko; Torii, Harumi; Yabutani, Mitsutaka; Ishii, Joji; Harasawa, Makiko; Isogai, Emiko

    2009-01-01

    To determine whether Ehrlichia chaffeensis exists in Japan, we used PCR to examine blood from sika deer in Nara, Japan. Of 117 deer, 36 (31%) were infected with E. chaffeensis. The E. chaffeensis 16S rRNA base and GroEL amino acid sequences from Japan were most closely related to those of E. chaffeensis Arkansas. PMID:19961683

  4. An Ehrlichia chaffeensis tandem repeat protein interacts with multiple host targets involved in cell signaling, transcriptional regulation, and vesicle trafficking.

    PubMed

    Wakeel, Abdul; Kuriakose, Jeeba A; McBride, Jere W

    2009-05-01

    Ehrlichia chaffeensis is an obligately intracellular bacterium that exhibits tropism for mononuclear phagocytes forming cytoplasmic membrane-bound microcolonies called morulae. To survive and replicate within phagocytes, E. chaffeensis exploits the host cell by modulating a number of host cell processes, but the ehrlichial effector proteins involved are unknown. In this study, we determined that p47, a secreted, differentially expressed, tandem repeat (TR) protein, interacts with multiple host proteins associated with cell signaling, transcriptional regulation, and vesicle trafficking. Yeast two-hybrid analysis revealed that p47 interacts with polycomb group ring finger 5 (PCGF5) protein, Src protein tyrosine kinase FYN (FYN), protein tyrosine phosphatase non-receptor type 2 (PTPN2), and adenylate cyclase-associated protein 1 (CAP1). p47 interaction with these proteins was further confirmed by coimmunoprecipitation assays and colocalization in HeLa cells transfected with p47-green fluorescent fusion protein (AcGFP1-p47). Moreover, confocal microscopy demonstrated p47-expressing dense-cored (DC) ehrlichiae colocalized with PCGF5, FYN, PTPN2, and CAP1. An amino-terminally truncated form of p47 containing TRs interacted only with PCGF5 and not with FYN, PTPN2, and CAP1, indicating differences in p47 domains that are involved in these interactions. These results demonstrate that p47 is involved in a complex network of interactions involving numerous host cell proteins. Furthermore, this study provides a new insight into the molecular and functional distinction of DC ehrlichiae, as well as the effector proteins involved in facilitating ehrlichial survival in mononuclear phagocytes.

  5. Hacker within! Ehrlichia chaffeensis Effector Driven Phagocyte Reprogramming Strategy

    PubMed Central

    Lina, Taslima T.; Farris, Tierra; Luo, Tian; Mitra, Shubhajit; Zhu, Bing; McBride, Jere W.

    2016-01-01

    Ehrlichia chaffeensis is a small, gram negative, obligately intracellular bacterium that preferentially infects mononuclear phagocytes. It is the etiologic agent of human monocytotropic ehrlichiosis (HME), an emerging life-threatening tick-borne zoonosis. Mechanisms by which E. chaffeensis establishes intracellular infection, and avoids host defenses are not well understood, but involve functionally relevant host-pathogen interactions associated with tandem and ankyrin repeat effector proteins. In this review, we discuss the recent advances in our understanding of the molecular and cellular mechanisms that underlie Ehrlichia host cellular reprogramming strategies that enable intracellular survival. PMID:27303657

  6. Ehrlichia chaffeensis Tandem Repeat Proteins and Ank200 are Type 1 Secretion System Substrates Related to the Repeats-in-Toxin Exoprotein Family

    PubMed Central

    Wakeel, Abdul; den Dulk-Ras, Amke; Hooykaas, Paul J. J.; McBride, Jere W.

    2011-01-01

    Ehrlichia chaffeensis has type 1 and 4 secretion systems (T1SS and T4SS), but the substrates have not been identified. Potential substrates include secreted tandem repeat protein (TRP) 47, TRP120, and TRP32, and the ankyrin repeat protein, Ank200, that are involved in molecular host–pathogen interactions including DNA binding and a network of protein–protein interactions with host targets associated with signaling, transcriptional regulation, vesicle trafficking, and apoptosis. In this study we report that E. chaffeensis TRP47, TRP32, TRP120, and Ank200 were not secreted in the Agrobacterium tumefaciens Cre recombinase reporter assay routinely used to identify T4SS substrates. In contrast, all TRPs and the Ank200 proteins were secreted by the Escherichia coli complemented with the hemolysin secretion system (T1SS), and secretion was reduced in a T1SS mutant (ΔTolC), demonstrating that these proteins are T1SS substrates. Moreover, T1SS secretion signals were identified in the C-terminal domains of the TRPs and Ank200, and a detailed bioinformatic analysis of E. chaffeensis TRPs and Ank200 revealed features consistent with those described in the repeats-in-toxins (RTX) family of exoproteins, including glycine- and aspartate-rich tandem repeats, homology with ATP-transporters, a non-cleavable C-terminal T1SS signal, acidic pIs, and functions consistent with other T1SS substrates. Using a heterologous E. coli T1SS, this investigation has identified the first Ehrlichia T1SS substrates supporting the conclusion that the T1SS and corresponding substrates are involved in molecular host–pathogen interactions that contribute to Ehrlichia pathobiology. Further investigation of the relationship between Ehrlichia TRPs, Ank200, and the RTX exoprotein family may lead to a greater understanding of the importance of T1SS substrates and specific functions of T1SS in the pathobiology of obligately intracellular bacteria. PMID:22919588

  7. Ehrlichia chaffeensis: a Prototypical Emerging Pathogen

    PubMed Central

    Paddock, Christopher D.; Childs, James E.

    2003-01-01

    Ehrlichia chaffeensis is an obligately intracellular, tick-transmitted bacterium that is maintained in nature in a cycle involving at least one and perhaps several vertebrate reservoir hosts. The moderate to severe disease caused by E. chaffeensis in humans, first identified in 1986 and reported for more than 1,000 patients through 2000, represents a prototypical “emerging infection.” Knowledge of the biology and natural history of E. chaffeensis, and of the epidemiology, clinical features, and laboratory diagnosis of the zoonotic disease it causes (commonly referred to as human monocytic ehrlichiosis [HME]) has expanded considerably in the period since its discovery. In this review, we summarize briefly the current understanding of the microbiology, pathogenesis, and clinical manifestations associated with this pathogen but focus primarily on discussing various ecological factors responsible for the recent recognition of this important and potentially life-threatening tick-borne disease. Perhaps the most pivotal element in the emergence of HME has been the staggering increases in white-tailed deer populations in the eastern United States during the 20th century. This animal serves as a keystone host for all life stages of the principal tick vector (Amblyomma americanum) and is perhaps the most important vertebrate reservoir host for E. chaffeensis. The contributions of other components, including expansion of susceptible human populations, growth and broadening geographical distributions of other potential reservoir species and A. americanum, and improvements in confirmatory diagnostic methods, are also explored. PMID:12525424

  8. Ehrlichia chaffeensis presenting with bilateral anterior thigh pain (Louria's sign).

    PubMed

    Cunha, Burke A; Petelin, Andrew; Hage, Jean E

    2012-09-01

    Bilateral anterior thigh pain may indicate bacteremia (Louria's Sign). We present a case of Ehrlichiosis due to Ehrlichia chaffeensis whose predominant presenting symptom was localized bilateral anterior thigh pain. Copyright © 2012 Elsevier Ltd. All rights reserved.

  9. Sequential Evaluation of Dogs Naturally Infected with Ehrlichia canis, Ehrlichia chaffeensis, Ehrlichia equi, Ehrlichia ewingii, or Bartonella vinsonii

    PubMed Central

    Breitschwerdt, Edward B.; Hegarty, Barbara C.; Hancock, Susan I.

    1998-01-01

    Historically, disease manifestations in dogs seroreactive to Ehrlichia canis antigens by indirect immunofluorescent antibody testing have been attributed to infection with either E. canis or Ehrlichia ewingii. A 1996 study by Dawson and colleagues provided PCR evidence that healthy dogs from southeastern Virginia could be naturally infected with Ehrlichia chaffeensis. This observation stimulated us to determine which Ehrlichia spp. infected sick dogs that were referred to our hospital from the same region. Based upon PCR amplification with species-specific primers, sick dogs seroreactive to E. canis antigens were determined to be infected with four Ehrlichia species: E. canis, E. chaffeensis, E. equi, and E. ewingii. Coinfection with three Ehrlichia species (E. canis, E. ewingii, and E. equi) was documented for one dog. An additional canine pathogen presumed to be tick transmitted, Bartonella vinsonii subsp. berkhoffii, was identified in 7 of 12 dogs. Importantly, our results indicate that in naturally infected dogs, E. chaffeensis can cause severe disease manifestations that are clinically and serologically indistinguishable from disease manifestations of E. canis or E. ewingii. In addition, our findings support the efficacy of doxycycline for treatment of E. canis, E. equi, and E. ewingii infections but indicate that, based upon the persistence of E. chaffeensis DNA for 1 year following treatment, E. chaffeensis infection in dogs may be more refractory to doxycycline treatment. Undetected coinfection with Bartonella may also complicate the evaluation of treatment efficacy while resulting in disease manifestations that mimic ehrlichiosis. PMID:9705408

  10. Ehrlichia chaffeensis Exploits Host SUMOylation Pathways To Mediate Effector-Host Interactions and Promote Intracellular Survival

    PubMed Central

    Dunphy, Paige Selvy; Luo, Tian

    2014-01-01

    Ehrlichia chaffeensis is an obligately intracellular Gram-negative bacterium that selectively infects mononuclear phagocytes. We recently reported that E. chaffeensis utilizes a type 1 secretion (T1S) system to export tandem repeat protein (TRP) effectors and demonstrated that these effectors interact with a functionally diverse array of host proteins. By way of these interactions, TRP effectors modulate host cell functions; however, the molecular basis of these interactions and their roles in ehrlichial pathobiology are not well defined. In this study, we describe the first bacterial protein posttranslational modification (PTM) by the small ubiquitin-like modifier (SUMO). The E. chaffeensis T1S effector TRP120 is conjugated to SUMO at a carboxy-terminal canonical consensus SUMO conjugation motif in vitro and in human cells. In human cells, TRP120 was selectively conjugated with SUMO2/3 isoforms. Disruption of TRP120 SUMOylation perturbed interactions with known host proteins, through predicted SUMO interaction motif-dependent and -independent mechanisms. E. chaffeensis infection did not result in dramatic changes in the global host SUMOylated protein profile, but a robust colocalization of predominately SUMO1 with ehrlichial inclusions was observed. Inhibiting the SUMO pathway with a small-molecule inhibitor had a significant impact on E. chaffeensis replication and recruitment of the TRP120-interacting protein polycomb group ring finger protein 5 (PCGF5) to the inclusion, indicating that the SUMO pathway is critical for intracellular survival. This study reveals the novel exploitation of the SUMO pathway by Ehrlichia, which facilitates effector-eukaryote interactions necessary to usurp the host and create a permissive intracellular niche. PMID:25047847

  11. Molecular and Clinical Evidence of Ehrlichia chaffeensis Infection in Cameroonian Patients with Undifferentiated Febrile Illness

    PubMed Central

    Ndip, Lucy M.; Labruna, Marcelo; Ndip, Roland N.; Walker, David H.; McBride, Jere W.

    2010-01-01

    Human monocytotropic ehrlichiosis (HME) is an emerging tick-transmitted zoonosis in the United States caused by Ehrlichia chaffeensis. Ehrlichia canis, E, chaffeensis and E. ewingii have recently been detected in dogs and Rhipicephalus sanguineus ticks from Cameroon; thus the potential exists for human infections. The objective of this study was to determine if Ehrlichia species were associated with acute fevers of unknown etiology in patients from the coastal region of Cameroon. E. chaffeensis was detected in peripheral blood from 12 (10%) of 118 patients using real-time polymerase chain reaction (PCR) amplification of the genus-specific disulfide bond (dsb) formation protein gene. Furthermore, DNA sequencing of PCR amplicons revealed that the dsb gene sequence was identical to E. chaffeensis (Arkansas strain). Patients with detectable E. chaffeensis DNA had clinical manifestations that included fever, headache, myalgia, arthralgia, pulmonary involvement, and diffuse rash. PMID:20030996

  12. Note on Ehrlichia chaffeensis, Ehrlichia ewingii, and "Borrelia lonestari" infection in lone star ticks (Acari: Ixodidae), Nebraska, USA.

    PubMed

    Maegli, Amanda; Loy, J Dustin; Cortinas, Roberto

    2016-02-01

    The lone star tick, Amblyomma americanum (L.) (Acari: Ixodidae), is established in southeastern Nebraska yet the prevalence of tick-associated microorganisms is not known. An initial PCR-based analysis for Ehrlichia chaffeensis, Ehrlichia ewingii, and Borrelia infection in host-seeking adult ticks collected in southeast Nebraska was conducted. A total of 251 adult ticks collected in six sites in southeast Nebraska were tested. E. chaffeensis, E. ewingii, and Borrelia spp. were present, and the prevalence of each was approximately 1.6%. This study demonstrates that Ehrlichia spp. are present in Nebraska lone star tick populations.

  13. Molecular Variation in the Variable-Length PCR Target and 120-Kilodalton Antigen Genes of Ehrlichia chaffeensis from White-Tailed Deer (Odocoileus virginianus)

    PubMed Central

    Yabsley, Michael J.; Little, Susan E.; Sims, Ethan J.; Dugan, Vivien G.; Stallknecht, David E.; Davidson, William R.

    2003-01-01

    Genes encoding two surface-expressed antigens of Ehrlichia chaffeensis, the variable-length PCR target (VLPT) and the 120-kDa antigen, which contain variable numbers of tandem repeats, were characterized for E. chaffeensis from white-tailed deer (Odocoileus virginianus). Both genes from infected deer contained numbers of repeats similar to those reported in genes from humans and ticks, although a new variant of the 120-kDa antigen gene containing five repeat units and coinfection with multiple VLPT and 120-kDa antigen gene genetic types were detected. Sequence analysis of both genes revealed more nucleotide variation than previously reported for E. chaffeensis from infected humans or ticks. This is the most extensive study of E. chaffeensis VLPT and 120-kDa antigen gene genetic variation to date and is the first to examine genetic variation in E. chaffeensis from a nonhuman vertebrate host. PMID:14605163

  14. The omp-1 Major Outer Membrane Multigene Family of Ehrlichia chaffeensis Is Differentially Expressed in Canine and Tick Hosts

    PubMed Central

    Unver, Ahmet; Rikihisa, Yasuko; Stich, Roger W.; Ohashi, Norio; Felek, Suleyman

    2002-01-01

    Sixteen of 22 omp-1 paralogs encoding 28-kDa-range immunodominant outer membrane proteins of Ehrlichia chaffeensis were transcribed in blood monocytes of dogs throughout a 56-day infection period. Only one paralog was transcribed by E. chaffeensis in three developmental stages of Amblyomma americanum ticks before or after E. chaffeensis transmission to naïve dogs. PMID:12117987

  15. Analysis of Transcriptionally Active Gene Clusters of Major Outer Membrane Protein Multigene Family in Ehrlichia canis and E. chaffeensis

    PubMed Central

    Ohashi, Norio; Rikihisa, Yasuko; Unver, Ahmet

    2001-01-01

    Ehrlichia canis and E. chaffeensis are tick-borne obligatory intramonocytic ehrlichiae that cause febrile systemic illness in humans and dogs, respectively. The current study analyzed the pleomorphic multigene family encoding approximately 30-kDa major outer membrane proteins (OMPs) of E. canis and E. chaffeensis. Upstream from secA and downstream of hypothetical transcriptional regulator, 22 paralogs of the omp gene family were found to be tandemly arranged except for one or two genes with opposite orientations in a 28- and a 27-kb locus in the E. canis and E. chaffeensis genomes, respectively. Each locus consisted of three highly repetitive regions with four nonrepetitive intervening regions. E. canis, in addition, had a 6.9-kb locus which contained a repeat of three tandem paralogs in the 28-kb locus. These total 47 paralogous and orthologous genes encoded OMPs of approximately 30 to 35 kDa consisting of several hypervariable regions alternating with conserved regions. In the 5′-end half of the 27-kb locus or the 28-kb locus of each Ehrlichia species, 14 paralogs were linked by short intergenic spaces ranging from −8 bp (overlapped) to 27 bp, and 8 remaining paralogs in the 3′-end half were connected by longer intergenic spaces ranging from 213 to 632 bp. All 22 paralogs, five unknown genes, and secA in the omp cluster in E. canis were transcriptionally active in the monocyte culture, and the paralogs with short intergenic spaces were cotranscribed with their adjacent genes, including the respective intergenic spaces at both the 5′ and the 3′ sides. Although omp genes are diverse, our results suggest that the gene organization of the clusters and the gene locus are conserved between two species of Ehrlichia to maintain a unique transcriptional mechanism for adaptation to environmental changes common to them. PMID:11254561

  16. Ehrlichia chaffeensis: a prevalent, life-threatening, emerging pathogen.

    PubMed Central

    Walker, David H.; Ismail, Nahed; Olano, Juan P.; McBride, Jere W.; Yu, Xue-Jie; Feng, Hui-Min

    2004-01-01

    Ehrlichia chaffeensis are small, obligately intracellular, endosomal bacteria with tropism for macrophages. Persistent infection in reservoir white-tailed deer is transmitted by lone star ticks. Flu-like illness can progress to severe multisystem disease with toxic shock-like syndrome, meningitis, or ARDS. The case-fatality rate is 2.7%. Leukopenia and thrombocytopenia are diagnostically useful. Granulomas are associated with control of the infection. Ehrlichial proteins and glycoproteins have been sequenced and expressed for diagnostic serology and vaccine development. Mouse models (mild disease and persistent infection with E. muris and fatal monocytotropic ehrlichiosis with a Japanese tick isolate) revealed that CD4 and CD8 T type 1 lymphocyte responses, IFN-gamma, TNF-alpha, and antibodies play roles in protective immunity, while a weak CD4 T-helper response, overproduction of TNF-alpha, and very high IL-10 are associated with toxic shock-like mortality. Protection against fatal ehrlichiosis was achieved by prior infection with low virulence E. muris. Acute clinical diagnosis is difficult except by PCR. Response to doxycycline is dramatic. PMID:17060980

  17. Mutations in Ehrlichia chaffeensis Causing Polar Effects in Gene Expression and Differential Host Specificities.

    PubMed

    Cheng, Chuanmin; Nair, Arathy D S; Jaworski, Deborah C; Ganta, Roman R

    2015-01-01

    Ehrlichia chaffeensis, a tick-borne rickettsial, is responsible for human monocytic ehrlichiosis. In this study, we assessed E. chaffeensis insertion mutations impacting the transcription of genes near the insertion sites. We presented evidence that the mutations within the E. chaffeensis genome at four genomic locations cause polar effects in altering gene expressions. We also reported mutations causing attenuated growth in deer (the pathogen's reservoir host) and in dog (an incidental host), but not in its tick vector, Amblyomma americanum. This is the first study documenting insertion mutations in E. chaffeensis that cause polar effects in altering gene expression from the genes located upstream and downstream to insertion sites and the differential requirements of functionally active genes of the pathogen for its persistence in vertebrate and tick hosts. This study is important in furthering our knowledge on E. chaffeensis pathogenesis.

  18. Molecular Cloning and Characterization of the Ehrlichia chaffeensis Variable-Length PCR Target: an Antigen-Expressing Gene That Exhibits Interstrain Variation

    PubMed Central

    Sumner, John W.; Childs, James E.; Paddock, Christopher D.

    1999-01-01

    A clone expressing an immunoreactive protein with an apparent molecular mass of 44 kDa was selected from an Ehrlichia chaffeensis Arkansas genomic library by probing with anti-E. chaffeensis hyperimmune mouse ascitic fluid. Nucleotide sequencing revealed an open reading frame (ORF) capable of encoding a 198-amino-acid polypeptide. The ORF contained four imperfect, direct, tandem 90-bp repeats. The nucleotide and deduced amino acid sequences did not show close homologies to entries in the molecular databases. PCR with primers whose sequences matched the sequences flanking the ORF was performed with DNA samples extracted from cell cultures infected with nine different isolates of E. chaffeensis, blood samples from seven patients with monocytic ehrlichiosis, and Amblyomma americanum ticks collected in four different states. The resulting amplicons varied in length, containing three to six repeat units. This gene, designated the variable-length PCR target, is useful for PCR detection of E. chaffeensis and differentiation of isolates. PMID:10203503

  19. Molecular cloning and characterization of the Ehrlichia chaffeensis variable-length PCR target: an antigen-expressing gene that exhibits interstrain variation.

    PubMed

    Sumner, J W; Childs, J E; Paddock, C D

    1999-05-01

    A clone expressing an immunoreactive protein with an apparent molecular mass of 44 kDa was selected from an Ehrlichia chaffeensis Arkansas genomic library by probing with anti-E. chaffeensis hyperimmune mouse ascitic fluid. Nucleotide sequencing revealed an open reading frame (ORF) capable of encoding a 198-amino-acid polypeptide. The ORF contained four imperfect, direct, tandem 90-bp repeats. The nucleotide and deduced amino acid sequences did not show close homologies to entries in the molecular databases. PCR with primers whose sequences matched the sequences flanking the ORF was performed with DNA samples extracted from cell cultures infected with nine different isolates of E. chaffeensis, blood samples from seven patients with monocytic ehrlichiosis, and Amblyomma americanum ticks collected in four different states. The resulting amplicons varied in length, containing three to six repeat units. This gene, designated the variable-length PCR target, is useful for PCR detection of E. chaffeensis and differentiation of isolates.

  20. Ehrlichia chaffeensis TRP120 Activates Canonical Notch Signaling To Downregulate TLR2/4 Expression and Promote Intracellular Survival

    PubMed Central

    Lina, Taslima T.; Dunphy, Paige S.; Luo, Tian

    2016-01-01

    ABSTRACT Ehrlichia chaffeensis preferentially targets mononuclear phagocytes and survives through a strategy of subverting innate immune defenses, but the mechanisms are unknown. We have shown E. chaffeensis type 1 secreted tandem repeat protein (TRP) effectors are involved in diverse molecular pathogen-host interactions, such as the TRP120 interaction with the Notch receptor-cleaving metalloprotease ADAM17. In the present study, we demonstrate E. chaffeensis, via the TRP120 effector, activates the canonical Notch signaling pathway to promote intracellular survival. We found that nuclear translocation of the transcriptionally active Notch intracellular domain (NICD) occurs in response to E. chaffeensis or recombinant TRP120, resulting in upregulation of Notch signaling pathway components and target genes notch1, adam17, hes, and hey. Significant differences in canonical Notch signaling gene expression levels (>40%) were observed during early and late stages of infection, indicating activation of the Notch pathway. We linked Notch pathway activation specifically to the TRP120 effector, which directly interacts with the Notch metalloprotease ADAM17. Using pharmacological inhibitors and small interfering RNAs (siRNAs) against γ-secretase enzyme, Notch transcription factor complex, Notch1, and ADAM17, we demonstrated that Notch signaling is required for ehrlichial survival. We studied the downstream effects and found that E. chaffeensis TRP120-mediated activation of the Notch pathway causes inhibition of the extracellular signal-regulated kinase 1/2 (ERK1/2) and p38 mitogen-activated protein kinase (MAPK) pathways required for PU.1 and subsequent Toll-like receptor 2/4 (TLR2/4) expression. This investigation reveals a novel mechanism whereby E. chaffeensis exploits the Notch pathway to evade the host innate immune response for intracellular survival. PMID:27381289

  1. Naturally Occurring Ehrlichia chaffeensis Infection in Two Prosimian Primate Species: Ring-tailed Lemurs (Lemur catta) and Ruffed Lemurs (Varecia variegata)

    PubMed Central

    Van Steenhouse, Jan L.; Bradley, Julie M.; Hancock, Susan I.; Hegarty, Barbara C.; Breitschwerdt, Edward B.

    2002-01-01

    A naturally occurring infection of Ehrlichia chaffeensis in lemurs is described. DNA of Ehrlichia chaffeensis was identified by polymerase chain reaction in peripheral blood from six of eight clinically ill lemurs. Organisms were cultured from the blood of one lemur exhibiting clinical and hematologic abnormalities similar to those of humans infected with E. chaffeensis. PMID:12498671

  2. Natural history of Ehrlichia chaffeensis (Rickettsiales: Ehrlichieae) in the piedmont physiographic province of Georgia.

    PubMed

    Lockhart, J M; Davidson, W R; Stallknecht, D E; Dawson, J E; Little, S E

    1997-10-01

    The roles of wild mammals and ticks in the epidemiology of Ehrlichia chaffeensis at a suspected endemic site were investigated using serologic testing, culture, and polymerase chain reaction (PCR) supported by restriction endonuclease analysis and DNA sequencing. Antibodies reactive to E. chaffeensis (> or = 1:64) were detected in 92% of white-tailed deer (Odocoileus virginianus), 21% of raccoons (Procyon lotor), and 8% of opossums (Didelphis virginianus), but not in 8 other species of mammals. Of 7 species of ticks found by host and environmental sampling, Amblyomma americanum was the dominant species, accounting for greater than 99% of all ticks collected. Deer, raccoons, and opossums were the only species parasitized by all life stages of A. americanum, and A. americanum was the only tick parasitizing deer. A nested PCR protocol incorporating E. chaffeensis-specific primers detected E. chaffeensis DNA in blood, lymph nodes, or spleen from 54% of deer examined. The nested PCR detected E. chaffeensis DNA in 6 of 50 (12%) individual adult A. americanum collected from the environment, in 14 of 79 (18%) pools representing 402 adult A. americanum collected from the environment, and in 7 of 25 (28%) pools of mixed stages of A. americanum collected from deer. Although no Ehrlichia spp. were isolated in culture, sequencing of representative amplicons from deer and ticks confirmed PCR products as E. chaffeensis. These data provide strong evidence that white-tailed deer and lone star ticks are the primary reservoir and vector of E. chaffeensis, respectively. The same PCR protocol, incorporating primers specific for an Ehrlichia-like organism of white-tailed deer, detected this organism in blood, lymph nodes, or spleen from 96% of these deer. The Ehrlichia-like organism of deer was detected by PCR from 0 of 50 individual ticks, 7 of 79 (9%) pools, and 1 of 25 (4%) pools of A. americanum collected from deer. Sequencing of representative amplicons from deer and ticks

  3. Ehrlichia chaffeensis (Rickettsiales: Ehrlichieae) infection in Amblyomma americanum (Acari: Ixodidae) at Aberdeen Proving Ground, Maryland.

    PubMed

    Stromdahl, E Y; Randolph, M P; O'Brien, J J; Gutierrez, A G

    2000-05-01

    Human monocytic ehrlichiosis (HME) is a sometimes fatal, emerging tick-borne disease caused by the bacterium Ehrlichia chaffeensis. It is frequently misdiagnosed because its symptoms mimic those of the flu. Current evidence indicates that Amblyomma americanum (L.), the lone star tick, is the major vector of HME. To determine if E. chaffeensis is present in ticks at Aberdeen Proving Ground, MD, questing A. americanum ticks were collected from 33 sites. Nucleic acid was extracted from 34 adult and 81 nymphal pools. Sequences diagnostic for E. chaffeensis from three different loci (16S rRNA, 120-kDa protein, and a variable-length polymerase chain reaction [PCR] target, or VLPT) were targeted for amplification by the PCR. Fifty-two percent of the collection sites yielded pools infected with E. chaffeensis, confirming the presence and widespread distribution of E. chaffeensis at Aberdeen Proving Ground. Analysis with the both the 120-kDa protein primers and the VLPT primers showed that genetic variance exists. A novel combination of variance for the two loci was detected in two tick pools. The pathogenic implications of genetic variation in E. chaffeensis are as yet unknown.

  4. Evaluation of Antibiotic Susceptibilities of Ehrlichia canis, Ehrlichia chaffeensis, and Anaplasma phagocytophilum by Real-Time PCR

    PubMed Central

    Branger, S.; Rolain, J. M.; Raoult, D.

    2004-01-01

    We determined MICs of antibiotics against Anaplasma phagocytophilum, Ehrlichia chaffeensis, and Ehrlichia canis by real-time quantitative PCR. The doubling times of the organisms were established: 19 h for E. chaffeensis, 26 h for A. phagocytophilum, and 28 h for E. canis. In comparison to the reference method for determining sensitivities, which uses Diff-Quick staining, our PCR assay was very sensitive and specific. We confirmed that doxycycline and rifampin are highly active against these bacteria and found variable susceptibilities to fluoroquinolones; A. phagocytophilum was susceptible, but E. canis and E. chaffeensis were only partly susceptible. β-Lactam compounds, cotrimoxazole, macrolide compounds, and telithromycin showed no activity against any of the three organisms. Thiamphenicol was found to be more active than chloramphenicol. For the first time, we showed that these three species have numerous point mutations in their 23S RNA genes, with those at positions 754, 2057, 2058, 2059, and 2611 (Escherichia coli numbering) known to confer resistance to macrolide compounds in other bacteria. The role of each of these mutations in resistance to these drugs should be investigated in the future. Our study confirms previous reports that quantitative PCR is a reliable method for determining antibiotic susceptibility; therefore, it might be useful for screening new drugs. PMID:15561862

  5. Persistent Ehrlichia chaffeensis infection occurs in the absence of functional major histocompatibility complex class II genes

    NASA Technical Reports Server (NTRS)

    Ganta, Roman Reddy; Wilkerson, Melinda J.; Cheng, Chuanmin; Rokey, Aaron M.; Chapes, Stephen K.

    2002-01-01

    Human monocytic ehrlichiosis is an emerging tick-borne disease caused by the rickettsia Ehrlichia chaffeensis. We investigated the impact of two genes that control macrophage and T-cell function on murine resistance to E. chaffeensis. Congenic pairs of wild-type and toll-like receptor 4 (tlr4)- or major histocompatibility complex class II (MHC-II)-deficient mice were used for these studies. Wild-type mice cleared the infection within 2 weeks, and the response included macrophage activation and the synthesis of E. chaffeensis-specific Th1-type immunoglobulin G response. The absence of a functional tlr4 gene depressed nitric oxide and interleukin 6 secretion by macrophages and resulted in short-term persistent infections for > or =30 days. In the absence of MHC-II alleles, E. chaffeensis infections persisted throughout the entire 3-month evaluation period. Together, these data suggest that macrophage activation and cell-mediated immunity, orchestrated by CD4(+) T cells, are critical for conferring resistance to E. chaffeensis.

  6. Persistent Ehrlichia chaffeensis infection occurs in the absence of functional major histocompatibility complex class II genes

    NASA Technical Reports Server (NTRS)

    Ganta, Roman Reddy; Wilkerson, Melinda J.; Cheng, Chuanmin; Rokey, Aaron M.; Chapes, Stephen K.

    2002-01-01

    Human monocytic ehrlichiosis is an emerging tick-borne disease caused by the rickettsia Ehrlichia chaffeensis. We investigated the impact of two genes that control macrophage and T-cell function on murine resistance to E. chaffeensis. Congenic pairs of wild-type and toll-like receptor 4 (tlr4)- or major histocompatibility complex class II (MHC-II)-deficient mice were used for these studies. Wild-type mice cleared the infection within 2 weeks, and the response included macrophage activation and the synthesis of E. chaffeensis-specific Th1-type immunoglobulin G response. The absence of a functional tlr4 gene depressed nitric oxide and interleukin 6 secretion by macrophages and resulted in short-term persistent infections for > or =30 days. In the absence of MHC-II alleles, E. chaffeensis infections persisted throughout the entire 3-month evaluation period. Together, these data suggest that macrophage activation and cell-mediated immunity, orchestrated by CD4(+) T cells, are critical for conferring resistance to E. chaffeensis.

  7. Global proteomic analysis of two tick-borne emerging zoonotic agents: Anaplasma phagocytophilum and Ehrlichia chaffeensis

    SciTech Connect

    Lin, Mingqun ..; Kikuchi, Takane; Brewer, Heather M.; Norbeck, Angela D.; Rikihisa, Yasuko

    2011-02-17

    Anaplasma phagocytophilum and Ehrlichia chaffeensis are obligatory intracellular {alpha}-proteobacteria that infect human leukocytes and cause potentially fatal emerging zoonoses. In the present study, we determined global protein expression profiles of these bacteria cultured in the human promyelocytic leukemia cell line, HL-60. Mass spectrometric (MS) analyses identified a total of 1,212 A. phagocytophilum and 1,021 E. chaffeensis proteins, representing 89.3 and 92.3% of the predicted bacterial proteomes, respectively. Nearly all bacterial proteins ({approx}99%) with known functions were expressed, whereas only approximately 80% of hypothetical proteins were detected in infected human cells. Quantitative MS/MS analyses indicated that highly expressed proteins in both bacteria included chaperones, enzymes involved in biosynthesis and metabolism, and outer membrane proteins, such as A. phagocytophilum P44 and E. chaffeensis P28/OMP-1. Among 113 A. phagocytophilum p44 paralogous genes, 110 of them were expressed and 88 of them were encoded by pseudogenes. In addition, bacterial infection of HL-60 cells up-regulated the expression of human proteins involved mostly in cytoskeleton components, vesicular trafficking, cell signaling, and energy metabolism, but down regulated some pattern recognition receptors involved in innate immunity. Our proteomics data represent a comprehensive analysis of A. phagocytophilum and E. chaffeensis proteomes, and provide a quantitative view of human host protein expression profiles regulated by bacterial infection. The availability of these proteomic data will provide new insights into biology and pathogenesis of these obligatory intracellular pathogens.

  8. Susceptibility of white-tailed deer (Odocoileus virginianus) to infection with Ehrlichia chaffeensis, the etiologic agent of human ehrlichiosis.

    PubMed Central

    Dawson, J E; Stallknecht, D E; Howerth, E W; Warner, C; Biggie, K; Davidson, W R; Lockhart, J M; Nettles, V F; Olson, J G; Childs, J E

    1994-01-01

    Although more than 320 cases of human ehrlichiosis have been diagnosed in 27 states since 1986, the reservoir host or hosts remain unknown. Since antibodies reactive to Ehrlichia chaffeensis, the etiologic agent of human ehrlichiosis, have been found in white-tailed deer (Odocoileus virginianus), we experimentally evaluated the susceptibilities of four white-tailed deer to infection with E. chaffeensis and Ehrlichia canis, a closely related species. A fifth deer served as a negative control. Isolation and nested PCR amplification results from peripheral blood indicated that E. chaffeensis circulated for at least 2 weeks. The deer developed antibodies to E. chaffeensis by day 10 after inoculation, but there was no indication of clinical disease. Immunohistochemical staining identified E. chaffeensis within macrophage-type cells in lymph nodes. The deer inoculated with E. canis did not become infected and did not seroconvert. These results indicate that white-tailed deer can support an E. chaffeensis infection with resulting rickettsemia of at least 2 weeks. The resistance to infection and the absence of seroconversion upon exposure to E. canis indicate that antibody responses previously detected among wild deer are not E. canis cross-reactions. The role of deer as competent reservoirs in the life cycle of E. chaffeensis remains to be explored with suspected tick vectors. Images PMID:7852563

  9. Ehrlichia chaffeensis TRP120 Interacts with a Diverse Array of Eukaryotic Proteins Involved in Transcription, Signaling, and Cytoskeleton Organization ▿ †

    PubMed Central

    Luo, Tian; Kuriakose, Jeeba A.; Zhu, Bing; Wakeel, Abdul; McBride, Jere W.

    2011-01-01

    Ehrlichia chaffeensis is an obligately intracellular bacterium that exhibits tropism for mononuclear phagocytes and survives by evading host cell defense mechanisms. Recently, molecular interactions between E. chaffeensis 47-kDa tandem repeat (TR) protein (TRP47) and the eukaryotic host cell have been described. In this investigation, yeast (Saccharomyces cerevisiae) two-hybrid analysis demonstrated that E. chaffeensis-secreted tandem repeat protein 120 (TRP120) interacts with a diverse group of host cell proteins associated with major biological processes, including transcription and regulation, cell signaling, protein trafficking, and actin cytoskeleton organization. Twelve target proteins with the highest frequency of interaction with TRP120 were confirmed by cotransformation in yeast. Host targets, including human immunoglobulin lambda locus (IGL), cytochrome c oxidase subunit II (COX2), Golgi-associated gamma adaptin ear-containing ARF binding protein 1 (GGA1), polycomb group ring finger 5 (PCGF5), actin gamma 1 (ACTG1), and unc-13 homolog D (UNC13D; Caenorhabditis elegans), colocalized strongly with TRP120 in HeLa cells and with E. chaffeensis dense-cored morulae and areas adjacent to morulae in the host cytoplasm. The TR domain of TRP120 interacted only with PCGF5, indicating that distinct TRP120 domains contribute to specific host target interactions and that multiple domains are required to reconstitute TRP120 interactions with other host targets. Three previously defined molecular interactions between TRP47 and host proteins, PCGF5, IGLL1, and CAP1, were also associated with TRP120, demonstrating that molecular cross talk occurs between Ehrlichia TRPs and host targets. These findings further support the role of TRPs as effectors that reprogram the host cell. PMID:21859857

  10. Anaplasma phagocytophilum and Ehrlichia chaffeensis type IV secretion and Ank proteins

    PubMed Central

    RIKIHISA, YASUKO; LIN, MINGQUN

    2011-01-01

    Summary of recent advances The obligatory intracellular bacterial pathogens Anaplasma and Ehrlichia infect leukocytes by hijacking host-cell components and processes. The type IV secretion system is up-regulated during infection. Among type IV secretion candidate substrates, an ankyrin repeat protein of Anaplasma phagocytophilum, AnkA, is delivered into the host cytoplasm via a complex that includes VirD4. AnkA is highly tyrosine-phosphorylated and binds to the Abl interactor 1, SHP-1, and nuclear DNA fragments. Ehrlichia chaffeensis AnkA was recently reported to be translocated into host cell nucleus. The recent discovery of several ankyrin repeat proteins secreted via the type IV secretion system of different intracellular bacteria suggests that a common strategy evolved to subvert host-cell functions. PMID:20053580

  11. Molecular Events Involved in Cellular Invasion by Ehrlichia chaffeensis and Anaplasma phagocytophilum

    PubMed Central

    Rikihisa, Yasuko

    2009-01-01

    Ehrlichia chaffeensis and Anaplasma phagocytophilum are obligatory intracellular bacteria that preferentially replicate inside leukocytes by utilizing biological compounds and processes of these primary host defensive cells. These bacteria incorporate cholesterol from the host for their survival. Upon interaction with host monocytes and granulocytes, respectively, these bacteria usurp the lipid raft domain containing GPI-anchored protein to induce a series of signaling events that result in internalization of the bacteria. Monocytes and neutrophils usually kill invading microorganisms by fusion of the phagosomes containing the bacteria with granules containing both antimicrobial peptides and lysosomal hydrolytic enzymes and/or through sequestering vital nutrients. However, E. chaffeensis and A. phagocytophilum alter vesicular traffic to create a unique intracellular membrane-bound compartment that allows their replication in seclusion from lysosomal killing. These bacteria are quite sensitive to reactive oxygen species (ROS), so in order to survive in host cells that are primary mediators of ROS-induced killing, they inhibit activation of NADPH oxidase and assembly of this enzyme in their inclusion compartments. Moreover, host phagocyte activation and differentiation, apoptosis, and IFN-γ signaling pathways are inhibited by these bacteria. Through reductive evolution, lipopolysaccharide and peptidoglycan that activate the innate immune response, have been eliminated from these gram-negative bacteria at the genomic level. Upon interaction with new host cells, bacterial genes encoding the type IV secretion apparatus and the two-component regulatory system are upregulated to sense and adapt to the host environment. Thus dynamic signal transduction events concurrently proceed both in the host cells and in the invading E. chaffeensis and A. phagocytophilum bacteria for successful establishment of intracellular infection. Several bacterial surface exposed proteins and

  12. Isolation of Ehrlichia chaffeensis from wild white-tailed deer (Odocoileus virginianus) confirms their role as natural reservoir hosts.

    PubMed Central

    Lockhart, J M; Davidson, W R; Stallknecht, D E; Dawson, J E; Howerth, E W

    1997-01-01

    Field and experimental studies have implicated white-tailed deer (Odocoileus virginianus) as probable reservoir hosts for Ehrlichia chaffeensis, the causative agent of human monocytic ehrlichiosis, but natural infection in deer has not been confirmed through isolation of E. chaffeensis. Thirty-five white-tailed deer collected from three Amblyomma americanum-infested populations in Georgia were examined for evidence of E. chaffeensis infection by serologic, molecular, cell culture, and xenodiagnostic methods. Twenty-seven deer (77%) had E. chaffeensis-reactive indirect fluorescent-antibody assay titers of > or = 1:64; and the blood, spleens, or lymph nodes of seven (20%) deer were positive in a nested PCR assay with E. chaffeensis-specific primers. E. chaffeensis was isolated in DH82 cell cultures from the blood of five (14%) deer, including two deer that were PCR negative. Combination of culture and PCR results indicated that six (17%) deer were probably rickettsemic and that nine (26%) were probably infected. Restriction digestion of PCR products amplified from deer tissues and cell culture isolates resulted in a banding pattern consistent with the E. chaffeensis 16S rRNA gene sequence. The sequences of all PCR products from deer tissues or cell culture isolates were identical to the sequence of the Arkansas type strain of E. chaffeensis. Xenodiagnosis with C3H mice inoculated intraperitoneally with deer blood, spleen, or lymph node suspensions was unsuccessful. When viewed in the context of previous studies, these findings provide strong evidence that E. chaffeensis is maintained in nature primarily by a tick vector-vertebrate reservoir system consisting of lone star ticks and white-tailed deer. PMID:9196173

  13. Isolation of Ehrlichia chaffeensis from wild white-tailed deer (Odocoileus virginianus) confirms their role as natural reservoir hosts.

    PubMed

    Lockhart, J M; Davidson, W R; Stallknecht, D E; Dawson, J E; Howerth, E W

    1997-07-01

    Field and experimental studies have implicated white-tailed deer (Odocoileus virginianus) as probable reservoir hosts for Ehrlichia chaffeensis, the causative agent of human monocytic ehrlichiosis, but natural infection in deer has not been confirmed through isolation of E. chaffeensis. Thirty-five white-tailed deer collected from three Amblyomma americanum-infested populations in Georgia were examined for evidence of E. chaffeensis infection by serologic, molecular, cell culture, and xenodiagnostic methods. Twenty-seven deer (77%) had E. chaffeensis-reactive indirect fluorescent-antibody assay titers of > or = 1:64; and the blood, spleens, or lymph nodes of seven (20%) deer were positive in a nested PCR assay with E. chaffeensis-specific primers. E. chaffeensis was isolated in DH82 cell cultures from the blood of five (14%) deer, including two deer that were PCR negative. Combination of culture and PCR results indicated that six (17%) deer were probably rickettsemic and that nine (26%) were probably infected. Restriction digestion of PCR products amplified from deer tissues and cell culture isolates resulted in a banding pattern consistent with the E. chaffeensis 16S rRNA gene sequence. The sequences of all PCR products from deer tissues or cell culture isolates were identical to the sequence of the Arkansas type strain of E. chaffeensis. Xenodiagnosis with C3H mice inoculated intraperitoneally with deer blood, spleen, or lymph node suspensions was unsuccessful. When viewed in the context of previous studies, these findings provide strong evidence that E. chaffeensis is maintained in nature primarily by a tick vector-vertebrate reservoir system consisting of lone star ticks and white-tailed deer.

  14. Insights into the CtrA Regulon in Development of Stress Resistance in Obligatory Intracellular Pathogen Ehrlichia chaffeensis

    PubMed Central

    Cheng, Zhihui; Miura, Koshiro; Popov, Vsevolod L.; Kumagai, Yumi; Rikihisa, Yasuko

    2011-01-01

    Summary Ehrlichia chaffeensis is an obligate intracellular bacterium that causes human monocytic ehrlichiosis. Ehrlichiae have a biphasic developmental cycle consisting of dense-cored cells (DCs) and reticulate cells (RCs). Isolated DCs are more stress resistant and infectious than RCs. Here, we report that a response regulator, CtrA was upregulated in human monocytes at the late growth stage when DCs develop. E. chaffeensis CtrA bound to the promoters of late-stage transcribed genes: ctrA, ompA (peptidoglycan-associated lipoprotein), bolA (stress-induced morphogen), and surE (stationary phase survival protein), which contain CtrA-binding motifs, and transactivated ompA, surE, and bolA promoter-lacZ fusions in Escherichia coli. OmpA was predominantly expressed in DCs. E. chaffeensis binding to and subsequent infection of monocytes were inhibited by anti-OmpA IgG. E. chaffeensis BolA bound to the promoters of genes encoding outer surface proteins TRP120 and ECH_1038, which were expressed in DCs, and transactivated trp120 and ECH_1038 promoter-lacZ fusions. E. chaffeensis bolA complemented a stress-sensitive E. coli bolA mutant. E. coli expressing E. chaffeensis surE exhibited increased resistance to osmotic stress. Our results suggest that E. chaffeensis CtrA plays a role in coordinating development of the stress resistance for passage from the present to the next host cells through its regulon. PMID:22014113

  15. Ehrlichia chaffeensis TRP120 binds a G+C-rich motif in host cell DNA and exhibits eukaryotic transcriptional activator function.

    PubMed

    Zhu, Bing; Kuriakose, Jeeba A; Luo, Tian; Ballesteros, Efren; Gupta, Sharu; Fofanov, Yuriy; McBride, Jere W

    2011-11-01

    Ehrlichia chaffeensis is an obligately intracellular bacterium that modulates host cell gene transcription in the mononuclear phagocyte, but the host gene targets and mechanisms involved in transcriptional modulation are not well-defined. In this study, we identified a novel tandem repeat DNA-binding domain in the E. chaffeensis 120-kDa tandem repeat protein (TRP120) that directly binds host cell DNA. TRP120 was observed by immunofluorescent microscopy in the nucleus of E. chaffeensis-infected host cells and was detected in nuclear extracts by Western immunoblotting with TRP120-specific antibody. The TRP120 binding sites and associated host cell target genes were identified using high-throughput deep sequencing (Illumina) of immunoprecipitated DNA (chromatin immunoprecipitation and high-throughput DNA sequencing). Multiple em motif elicitation (MEME) analysis of the most highly enriched TRP120-bound sequences revealed a G+C-rich DNA motif, and recombinant TRP120 specifically bound synthetic oligonucleotides containing the motif. TRP120 target gene binding sites were mapped most frequently to intersecting regions (intron/exon; 49%) but were also identified in upstream regulatory regions (25%) and downstream locations (26%). Genes targeted by TRP120 were most frequently associated with transcriptional regulation, signal transduction, and apoptosis. TRP120 targeted inflammatory chemokine genes, CCL2, CCL20, and CXCL11, which were strongly upregulated during E. chaffeensis infection and were also upregulated by direct transfection with recombinant TRP120. This study reveals that TRP120 is a novel DNA-binding protein that is involved in a host gene transcriptional regulation strategy.

  16. In vitro antibiotic susceptibility of the newly recognized agent of ehrlichiosis in humans, Ehrlichia chaffeensis.

    PubMed Central

    Brouqui, P; Raoult, D

    1992-01-01

    Ehrlichiosis in humans, a rickettsial disease recently discovered in the United States, is generally treated successfully with tetracyclines; however treatment with these agents is usually avoided with children and pregnant women. The in vitro susceptibility of Ehrlichia chaffeensis, the agent of human ehrlichiosis in the United States, was assessed by a quantitative evaluation of infected DH82 cells cultivated in 96-well microtiter plates in the presence of different concentrations of selected antibiotics. Extracellular MICs and MBCs were evaluated after 72 h of exposure to the antibiotics. Doxycycline and rifampin were found to exert rapidly bactericidal effects, with MBCs in the extracellular culture medium of less than 0.5 and 0.125 microgram/ml, respectively. E. chaffeensis was resistant to chloramphenicol, ciprofloxacin, erythromycin, co-trimoxazole, penicillin, and gentamicin, which had MICs greater than 16, 4, 8, 4, 40, and 32 micrograms/ml, respectively. These observations are consistent with the finding that human ehrlichiosis appears to respond to tetracycline therapy, which has been the therapy of first choice. Further clinical investigations are necessary to evaluate the role of rifampin in the treatment of human ehrlichiosis, especially in children. PMID:1482148

  17. Detection of Ehrlichia chaffeensis in adult and nymphal stage lone star ticks (Amblyomma americanum) from Long Island, New York

    USGS Publications Warehouse

    Mixson, T.R.; Ginsberg, H.S.; Campbell, S.R.; Sumner, J.W.; Paddock, C.D.

    2004-01-01

    The lone star tick, Amblyomma americanum (L.), has increased in abundance in several regions of the northeastern United States, including areas of Long Island, NY. Adult and nymphal stage A. americanum collected from several sites on Long Island were evaluated for infection with Ehrlichia chaffeensis, the causative agent of human monocytic ehrlichiosis (HME), by using a nested polymerase chain reaction assay. Fifty-nine (12.5%) of ,17.3 adults and eight of 11.3 pools of five nymphs each (estimated minimum prevalence of infection 1.4%) contained DNA of E. chaffeensis. These data, coupled with the documented expansion of lone star tick populations in the northeastern United States, confirm that E. chaffeensis is endemic to many areas of Long Island and that HME should be considered among the differential diagnoses of the many distinct tick-borne diseases that occur in this region.

  18. Differential clearance and immune responses to tick cell-derived versus macrophage culture-derived Ehrlichia chaffeensis in mice.

    PubMed

    Ganta, Roman R; Cheng, Chuanmin; Miller, Elizabeth C; McGuire, Bridget L; Peddireddi, Lalitha; Sirigireddy, Kamesh R; Chapes, Stephen K

    2007-01-01

    Human monocytic ehrlichiosis is caused by a tick-transmitted rickettsia, Ehrlichia chaffeensis. We recently reported that E. chaffeensis grown in tick cells expresses different proteins than bacteria grown in macrophages. Therefore, we tested the hypothesis that immune responses against E. chaffeensis would be different if the mice are challenged with bacteria grown in macrophages or tick cells. We assessed the E. chaffeensis clearance from the peritoneum, spleen, and liver by C57BL/6J mice using a TaqMan-based real-time reverse transcription-PCR assay. Macrophage-grown E. chaffeensis was cleared in 2 weeks from the peritoneum, whereas the pathogen from tick cells persisted for nine additional days and included three relapses of increasing bacterial load separated by three-day intervals. Tick cell-grown bacteria also persisted in the livers and spleens with higher bacterial loads compared to macrophage-grown bacteria and fluctuated over a period of 35 days. Three-day periodic cycles were detected in T-cell CD62L/CD44 ratios in the spleen and bone marrow in response to infections with both tick cell- and macrophage-grown bacteria and were accompanied by similar periodic cycles of spleen cell cytokine secretions and nitric oxide and interleukin-6 by peritoneal macrophages. The E. chaffeensis-specific immunoglobulin G response was considerably higher and steadily increased in mice infected with the tick cell-derived E. chaffeensis compared to DH82-grown bacteria. In addition, antigens detected by the immunoglobulins were significantly different between mice infected with the E. chaffeensis originating from tick cells or macrophages. The differences in the immune response to tick cell-grown bacteria compared to macrophage-grown bacteria reflected a delay in the shift of gene expression from the tick cell-specific Omp 14 gene to the macrophage-specific Omp 19 gene. These data suggest that the host response to E. chaffeensis depends on the source of the bacteria and that

  19. Biochemical Activities of Three Pairs of Ehrlichia chaffeensis Two-Component Regulatory System Proteins Involved in Inhibition of Lysosomal Fusion†

    PubMed Central

    Kumagai, Yumi; Cheng, Zhihui; Lin, Mingqun; Rikihisa, Yasuko

    2006-01-01

    Ehrlichia chaffeensis, the etiologic agent of human monocytic ehrlichiosis, replicates in early endosomes by avoiding lysosomal fusion in monocytes and macrophages. In E. chaffeensis we predicted three pairs of putative two-component regulatory systems (TCSs) designated PleC-PleD, NtrY-NtrX, and CckA-CtrA based on amino acid sequence homology. In the present study to determine biochemical pairs and specificities of the TCSs, the recombinant proteins of the three putative histidine kinase (HK) kinase domains (rPleCHKD, rNtrYHKD, and MBP-rCckAHKD) and the full-length forms of three putative response regulators (RRs) (rPleD, rNtrX, and rCtrA) as well as the respective mutant recombinant proteins (rPleCHKDH244A, rNtrYHKDH498A, MBP-rCckAHKDH449A, rPleDD53A, rNtrXD59A, and rCtrAD53A) were expressed and purified as soluble proteins. The in vitro HK activity, the specific His residue-dependent autophosphorylation of the kinase domain, was demonstrated in the three HKs. The specific Asp residue-dependent in vitro phosphotransfer from the kinase domain to the putative cognate RR was demonstrated in each of the three RRs. Western blot analysis of E. chaffeensis membrane and soluble fractions using antibodies specific for each recombinant protein detected PleC and CckA in the membrane fraction, whereas it detected NtrY, NtrX, and PleD in the soluble fraction. CtrA was found in the two fractions at similar levels. E. chaffeensis was sensitive to closantel, an HK inhibitor. Closantel treatment induced lysosomal fusion of the E. chaffeensis inclusion in a human monocytic leukemia cell line, THP-1 cells, implying that functional TCSs are essential in preventing lysosomal fusion of the E. chaffeensis inclusion compartment. PMID:16926392

  20. Comparative Genomics of the Zoonotic Pathogen Ehrlichia chaffeensis Reveals Candidate Type IV Effectors and Putative Host Cell Targets

    PubMed Central

    Noroy, Christophe; Meyer, Damien F.

    2017-01-01

    During infection, some intracellular pathogenic bacteria use a dedicated multiprotein complex known as the type IV secretion system to deliver type IV effector (T4E) proteins inside the host cell. These T4Es allow the bacteria to evade host defenses and to subvert host cell processes to their own advantage. Ehrlichia chaffeensis is a tick-transmitted obligate intracellular pathogenic bacterium, which causes human monocytic ehrlichiosis. Using comparative whole genome analysis, we identified the relationship between eight available E. chaffeensis genomes isolated from humans and show that these genomes are highly conserved. We identified the candidate core type IV effectome of E. chaffeensis and some conserved intracellular adaptive strategies. We assigned the West Paces strain to genetic group II and predicted the repertoires of T4Es encoded by E. chaffeensis genomes, as well as some putative host cell targets. We demonstrated that predicted T4Es are preferentially distributed in gene sparse regions of the genome. In addition to the identification of the two known type IV effectors of Anaplasmataceae, we identified two novel candidates T4Es, ECHLIB_RS02720 and ECHLIB_RS04640, which are not present in all E. chaffeensis strains and could explain some variations in inter-strain virulence. We also identified another novel candidate T4E, ECHLIB_RS02720, a hypothetical protein exhibiting EPIYA, and NLS domains as well as a classical type IV secretion signal, suggesting an important role inside the host cell. Overall, our results agree with current knowledge of Ehrlichia molecular pathogenesis, and reveal novel candidate T4Es that require experimental validation. This work demonstrates that comparative effectomics enables identification of important host pathways targeted by the bacterial pathogen. Our study, which focuses on the type IV effector repertoires among several strains of E. chaffeensis species, is an original approach and provides rational putative targets

  1. Antibody-Mediated Elimination of the Obligate Intracellular Bacterial Pathogen Ehrlichia chaffeensis during Active Infection

    PubMed Central

    Winslow, Gary M.; Yager, Eric; Shilo, Konstantin; Volk, Erin; Reilly, Andrew; Chu, Frederick K.

    2000-01-01

    It is generally accepted that cellular, but not humoral immunity, plays an important role in host defense against intracellular bacteria. However, studies of some of these pathogens have provided evidence that antibodies can provide immunity if present during the initiation of infection. Here, we examined immunity against infection by Ehrlichia chaffeensis, an obligate intracellular bacterium that causes human monocytic ehrlichiosis. Studies with mice have demonstrated that immunocompetent strains are resistant to persistent infection but that SCID mice become persistently and fatally infected. Transfer of immune serum or antibodies obtained from immunocompetent C57BL/6 mice to C57BL/6 scid mice provided significant although transient protection from infection. Bacterial clearance was observed when administration occurred at the time of inoculation or well after infection was established. The effect was dose dependent, occurred within 2 days, and persisted for as long as 2 weeks. Weekly serum administration prolonged the survival of susceptible mice. Although cellular immunity is required for complete bacterial clearance, the data show that antibodies can play a significant role in the elimination of this obligate intracellular bacterium during active infection and thus challenge the paradigm that humoral responses are unimportant for immunity to such organisms. PMID:10722619

  2. Distribution of Ehrlichia chaffeensis (Rickettsiales: Rickettsiaeceae) in Amblyomma americanum in southern Indiana and prevalence of E. chaffeensis--reactive antibodies in white-tailed deer in Indiana and Ohio in 1998.

    PubMed

    Irving, R P; Pinger, R R; Vann, C N; Olesen, J B; Steiner, F E

    2000-07-01

    To continue monitoring the prevalence and distribution of Ehrlichia chaffeensis (Rickettsiales: Rickettsiaeceae) in southern Indiana, a total of 498 Amblyomma americanum (L.) ticks (262 adults and 292 nymphs) was collected from five southern Indiana counties during May and June 1998. Ticks were pooled and examined for the presence of E. chaffeensis using nested polymerase chain reaction and primers specific for the 16S rRNA gene of E. chaffeensis. The average minimum infection rate for adult ticks collected in 1998 was 3.8% (ranging from 0 to 7.7% in various counties) as compared with previous average minimum infection rates of 1.6% in 1995 and 4.9% in 1997. None of the pools of A. americanum nymphs tested positive. In addition, blood samples were collected from 325 white-tailed deer taken in Indiana and 327 taken in Ohio in November 1998. Serum samples were tested for the presence of E. chaffeensis-like organisms reactive to antibodies using an indirect immunofluorescence assay (IFA). Antibodies were found in deer from six Indiana counties where infection rates ranged from 42.6 to 66.7% and in four Ohio countries where infection rates ranged from 4.4 to 25%. The results of this study reconfirm that E. chaffeensis is well established in southern Indiana and also provide the first evidence of E. chaffeensis-like organisms infecting white-tailed deer in Ohio, suggesting the need to survey Ohio ticks for the presence of Ehrlichia.

  3. Intra-leukocyte expression of two-component systems in Ehrlichia chaffeensis and Anaplasma phagocytophilum and effects of the histidine kinase inhibitor closantel.

    PubMed

    Cheng, Zhihui; Kumagai, Yumi; Lin, Mingqun; Zhang, Chunbin; Rikihisa, Yasuko

    2006-08-01

    The two-component system (TCS) composed of a pair of a sensor histidine kinase and a response regulator, allows bacteria to sense signals and respond to changes in their environment through specific gene activation or repression. The present study examined TCS in the obligatory intracellular bacteria Ehrlichia chaffeensis and Anaplasma phagocytophilum, that cause human monocytic ehrlichiosis (HME) and human granulocytic anaplasmosis (HGA) respectively. The genomes of E. chaffeensis and A. phagocytophilum were each predicted to encode three pairs of TCSs. All six genes encoding three histidine kinases and three response regulators were expressed in both E. chaffeensis and A. phagocytophilum cultured in human leukocytes. Pretreatment of host cell-free E. chaffeensis or A. phagocytophilum with closantel, an inhibitor of histidine kinases, completely blocked the infection of host cells. Treatment of infected cells 1 day post infection with closantel cleared infection in dose-dependent manner. All six genes in E. chaffeensis were cloned, recombinant proteins were expressed, and polyclonal antibodies were produced. Double immunofluorescence labelling and Western blot analysis revealed that all six proteins were expressed in cell culture. Autokinase activities of the three recombinant histidine kinases from E. chaffeensis were inhibited by closantel in vitro. A number of E. chaffeensis genes, including the six TCS genes, were downregulated within 5-60 min post closantel treatment. These results suggest that these TCSs play an essential role in infection and survival of E. chaffeensis and A. phagocytophilum in human leukocytes.

  4. Increasing Incidence of Ehrlichiosis in the United States: A Summary of National Surveillance of Ehrlichia chaffeensis and Ehrlichia ewingii Infections in the United States, 2008–2012

    PubMed Central

    Heitman, Kristen Nichols; Dahlgren, F. Scott; Drexler, Naomi A.; Massung, Robert F.; Behravesh, Casey Barton

    2016-01-01

    Human ehrlichiosis is a potentially fatal disease caused by Ehrlichia chaffeensis and Ehrlichia ewingii. Cases of ehrlichiosis are reported to Centers for Disease Control and Prevention through two national surveillance systems: Nationally Notifiable Diseases Surveillance System (NNDSS) and Case Report Forms. During 2008–2012, 4,613 cases of E. chaffeensis infections were reported through NNDSS. The incidence rate (IR) was 3.2 cases per million person-years (PYs). The hospitalization rate (HR) was 57% and the case fatality rate (CFR) was 1%. Children aged < 5 years had the highest CFR of 4%. During 2008–2012, 55 cases of E. ewingii infection were reported through NNDSS. The national IR was 0.04 cases per million PY. The HR was 77%; no deaths were reported. Immunosuppressive conditions were reported by 26% of cases. The overall rate for ehrlichiosis has increased 4-fold since 2000. Although previous literature suggests E. ewingii primarily affects those who are immunocompromised, this report shows most cases occurred among immunocompetent patients. This is the first report to show children aged < 5 years with ehrlichiosis have an increased CFR, relative to older patients. Ongoing surveillance and reporting of tick-borne diseases are critical to inform public health practice and guide disease treatment and prevention efforts. PMID:26621561

  5. Ehrlichia Moonlighting Effectors and Interkingdom Interactions with the Mononuclear Phagocyte

    PubMed Central

    Dunphy, Paige Selvy; Luo, Tian; McBride, Jere W.

    2013-01-01

    Ehrlichia chaffeensis is an obligately intracellular gram negative bacterium with a small genome that thrives in mammalian mononuclear phagoctyes by exploiting eukaryotic processes. Herein, we discuss the latest findings on moonlighting tandem repeat protein effectors and their secretion mechanisms, and novel molecular interkingdom interactions that provide insight into the intracellular pathobiology of ehrlichiae. PMID:24141087

  6. Targeted and random mutagenesis of Ehrlichia chaffeensis for the identification of genes required for in vivo infection.

    PubMed

    Cheng, Chuanmin; Nair, Arathy D S; Indukuri, Vijaya V; Gong, Shanzhong; Felsheim, Roderick F; Jaworski, Deborah; Munderloh, Ulrike G; Ganta, Roman R

    2013-02-01

    Ehrlichia chaffeensis is a tick transmitted pathogen responsible for the disease human monocytic ehrlichiosis. Research to elucidate gene function in rickettsial pathogens is limited by the lack of genetic manipulation methods. Mutational analysis was performed, targeting to specific and random insertion sites within the bacterium's genome. Targeted mutagenesis at six genomic locations by homologous recombination and mobile group II intron-based methods led to the consistent identification of mutants in two genes and in one intergenic site; the mutants persisted in culture for 8 days. Three independent experiments using Himar1 transposon mutagenesis of E. chaffeensis resulted in the identification of multiple mutants; these mutants grew continuously in macrophage and tick cell lines. Nine mutations were confirmed by sequence analysis. Six insertions were located within non-coding regions and three were present in the coding regions of three transcriptionally active genes. The intragenic mutations prevented transcription of all three genes. Transposon mutants containing a pool of five different insertions were assessed for their ability to infect deer and subsequent acquisition by Amblyomma americanum ticks, the natural reservoir and vector, respectively. Three of the five mutants with insertions into non-coding regions grew well in deer. Transposition into a differentially expressed hypothetical gene, Ech_0379, and at 18 nucleotides downstream to Ech_0230 gene coding sequence resulted in the inhibition of growth in deer, which is further evidenced by their failed acquisition by ticks. Similarly, a mutation into the coding region of ECH_0660 gene inhibited the in vivo growth in deer. This is the first study evaluating targeted and random mutagenesis in E. chaffeensis, and the first to report the generation of stable mutants in this obligate intracellular bacterium. We further demonstrate that in vitro mutagenesis coupled with in vivo infection assessment is a

  7. Ehrlichia chaffeensis Uses Its Surface Protein EtpE to Bind GPI-Anchored Protein DNase X and Trigger Entry into Mammalian Cells

    PubMed Central

    Mohan Kumar, Dipu; Yamaguchi, Mamoru; Miura, Koshiro; Lin, Mingqun; Los, Marek; Coy, Johannes F.; Rikihisa, Yasuko

    2013-01-01

    Ehrlichia chaffeensis, an obligatory intracellular rickettsial pathogen, enters and replicates in monocytes/macrophages and several non-phagocytic cells. E. chaffeensis entry into mammalian cells is essential not only for causing the emerging zoonosis, human monocytic ehrlichiosis, but also for its survival. It remains unclear if E. chaffeensis has evolved a specific surface protein that functions as an ‘invasin’ to mediate its entry. We report a novel entry triggering protein of Ehrlichia, EtpE that functions as an invasin. EtpE is an outer membrane protein and an antibody against EtpE (the C-terminal fragment, EtpE-C) greatly inhibited E. chaffeensis binding, entry and infection of both phagocytes and non-phagocytes. EtpE-C-immunization of mice significantly inhibited E. chaffeensis infection. EtpE-C-coated latex beads, used to investigate whether EtpE-C can mediate cell invasion, entered both phagocytes and non-phagocytes and the entry was blocked by compounds that block E. chaffeensis entry. None of these compounds blocked uptake of non-coated beads by phagocytes. Yeast two-hybrid screening revealed that DNase X, a glycosylphosphatidyl inositol-anchored mammalian cell-surface protein binds EtpE-C. This was confirmed by far-Western blotting, affinity pull-down, co-immunoprecipitation, immunofluorescence labeling, and live-cell image analysis. EtpE-C-coated beads entered bone marrow-derived macrophages (BMDMs) from wild-type mice, whereas they neither bound nor entered BMDMs from DNase X-/- mice. Antibody against DNase X or DNase X knock-down by small interfering RNA impaired E. chaffeensis binding, entry, and infection. E. chaffeensis entry and infection rates of BMDMs from DNase X-/- mice and bacterial load in the peripheral blood in experimentally infected DNase X-/- mice, were significantly lower than those from wild-type mice. Thus this obligatory intracellular pathogen evolved a unique protein EtpE that binds DNase X to enter and infect eukaryotic cells

  8. Comparative Experimental Infection Study in Dogs with Ehrlichia canis, E. chaffeensis, Anaplasma platys and A. phagocytophilum.

    PubMed

    Nair, Arathy D S; Cheng, Chuanmin; Ganta, Chanran K; Sanderson, Michael W; Alleman, Arthur R; Munderloh, Ulrike G; Ganta, Roman R

    2016-01-01

    Dogs acquire infections with the Anaplasmataceae family pathogens, E. canis, E. chaffeensis, E. ewingii, A. platys and A. phagocytophilum mostly during summer months when ticks are actively feeding on animals. These pathogens are also identified as causing diseases in people. Despite the long history of tick-borne diseases in dogs, much remains to be defined pertaining to the clinical and pathological outcomes of infections with these pathogens. In the current study, we performed experimental infections in dogs with E. canis, E. chaffeensis, A. platys and A. phagocytophilum. Animals were monitored for 42 days to evaluate infection-specific clinical, hematological and pathological differences. All four pathogens caused systemic persistent infections detectible throughout the 6 weeks of infection assessment. Fever was frequently detected in animals infected with E. canis, E. chaffeensis, and A. platys, but not in dogs infected with A. phagocytophilum. Hematological differences were evident in all four infected groups, although significant overlap existed between the groups. A marked reduction in packed cell volume that correlated with reduced erythrocytes and hemoglobin was observed only in E. canis infected animals. A decline in platelet numbers was common with E. canis, A. platys and A. phagocytophilum infections. Histopathological lesions in lung, liver and spleen were observed in all four groups of infected dogs; infection with E. canis had the highest pathological scores, followed by E. chaffeensis, then A. platys and A. phagocytophilum. All four pathogens induced IgG responses starting on day 7 post infection, which was predominantly comprised of IgG2 subclass antibodies. This is the first detailed investigation comparing the infection progression and host responses in dogs after inoculation with four pathogens belonging to the Anaplasmataceae family. The study revealed a significant overlap in clinical, hematological and pathological changes resulting from the

  9. Comparative Experimental Infection Study in Dogs with Ehrlichia canis, E. chaffeensis, Anaplasma platys and A. phagocytophilum

    PubMed Central

    Nair, Arathy D. S.; Cheng, Chuanmin; Ganta, Chanran K.; Sanderson, Michael W; Alleman, Arthur R.; Munderloh, Ulrike G.; Ganta, Roman R.

    2016-01-01

    Dogs acquire infections with the Anaplasmataceae family pathogens, E. canis, E. chaffeensis, E. ewingii, A. platys and A. phagocytophilum mostly during summer months when ticks are actively feeding on animals. These pathogens are also identified as causing diseases in people. Despite the long history of tick-borne diseases in dogs, much remains to be defined pertaining to the clinical and pathological outcomes of infections with these pathogens. In the current study, we performed experimental infections in dogs with E. canis, E. chaffeensis, A. platys and A. phagocytophilum. Animals were monitored for 42 days to evaluate infection-specific clinical, hematological and pathological differences. All four pathogens caused systemic persistent infections detectible throughout the 6 weeks of infection assessment. Fever was frequently detected in animals infected with E. canis, E. chaffeensis, and A. platys, but not in dogs infected with A. phagocytophilum. Hematological differences were evident in all four infected groups, although significant overlap existed between the groups. A marked reduction in packed cell volume that correlated with reduced erythrocytes and hemoglobin was observed only in E. canis infected animals. A decline in platelet numbers was common with E. canis, A. platys and A. phagocytophilum infections. Histopathological lesions in lung, liver and spleen were observed in all four groups of infected dogs; infection with E. canis had the highest pathological scores, followed by E. chaffeensis, then A. platys and A. phagocytophilum. All four pathogens induced IgG responses starting on day 7 post infection, which was predominantly comprised of IgG2 subclass antibodies. This is the first detailed investigation comparing the infection progression and host responses in dogs after inoculation with four pathogens belonging to the Anaplasmataceae family. The study revealed a significant overlap in clinical, hematological and pathological changes resulting from the

  10. Initial development and preliminary evaluation of a multiplex bead assay to detect antibodies to Ehrlichia canis, Anaplasma platys, and Ehrlichia chaffeensis outer membrane peptides in naturally infected dogs from Grenada, West Indies.

    PubMed

    Wilkerson, Melinda J; Black, Kelley E; Lanza-Perea, Marta; Sharma, Bhumika; Gibson, Kathryn; Stone, Diana M; George, Anushka; Nair, Arathy D S; Ganta, Roman R

    2017-01-01

    Tick-borne bacteria, Ehrlichia canis, Anaplasma platys, and Ehrlichia chaffeensis are significant pathogens of dogs worldwide, and coinfections of E. canis and A. platys are common in dogs on the Caribbean islands. We developed and evaluated the performance of a multiplex bead-based assay to detect antibodies to E. canis, A. platys, and E. chaffeensis peptides in dogs from Grenada, West Indies, where E. canis and A. platys infections are endemic. Peptides from outer membrane proteins of P30 of E. canis, OMP-1X of A. platys, and P28-19/P28-14 of E. chaffeensis were coupled to magnetic beads. The multiplex peptide assay detected antibodies in dogs experimentally infected with E. canis and E. chaffeensis, but not in an A. platys experimentally infected dog. In contrast, the multiplex assay and an in-house enzyme-linked immunosorbent assay (ELISA) detected A. platys antibodies in naturally infected Grenadian dogs. Following testing of 104 Grenadian canine samples, multiplex assay results had good agreement with commercially available ELISA and immunofluorescent assay for E. canis antibody-positive dogs ( K values of 0.73 and 0.84), whereas A. platys multiplex results had poor agreement with these commercial assays ( K values of -0.02 and 0.01). Prevalence of seropositive E. canis and A. platys Grenadian dogs detected by the multiplex and commercial antibody assays were similar to previous reports. Although the multiplex peptide assay performed well in detecting the seropositive status of dogs to E. canis and had good agreement with commercial assays, better antigen targets are necessary for the antibody detection of A. platys.

  11. Ehrlichia chaffeensis infection in the reservoir host (white-tailed deer) and in an incidental host (dog) is impacted by its prior growth in macrophage and tick cell environments.

    PubMed

    Nair, Arathy D S; Cheng, Chuanmin; Jaworski, Deborah C; Willard, Lloyd H; Sanderson, Michael W; Ganta, Roman R

    2014-01-01

    Ehrlichia chaffeensis, transmitted from Amblyomma americanum ticks, causes human monocytic ehrlichiosis. It also infects white-tailed deer, dogs and several other vertebrates. Deer are its reservoir hosts, while humans and dogs are incidental hosts. E. chaffeensis protein expression is influenced by its growth in macrophages and tick cells. We report here infection progression in deer or dogs infected intravenously with macrophage- or tick cell-grown E. chaffeensis or by tick transmission in deer. Deer and dogs developed mild fever and persistent rickettsemia; the infection was detected more frequently in the blood of infected animals with macrophage inoculum compared to tick cell inoculum or tick transmission. Tick cell inoculum and tick transmission caused a drop in tick infection acquisition rates compared to infection rates in ticks fed on deer receiving macrophage inoculum. Independent of deer or dogs, IgG antibody response was higher in animals receiving macrophage inoculum against macrophage-derived Ehrlichia antigens, while it was significantly lower in the same animals against tick cell-derived Ehrlichia antigens. Deer infected with tick cell inoculum and tick transmission caused a higher antibody response to tick cell cultured bacterial antigens compared to the antibody response for macrophage cultured antigens for the same animals. The data demonstrate that the host cell-specific E. chaffeensis protein expression influences rickettsemia in a host and its acquisition by ticks. The data also reveal that tick cell-derived inoculum is similar to tick transmission with reduced rickettsemia, IgG response and tick acquisition of E. chaffeensis.

  12. Use of Peptide-Based Enzyme-Linked Immunosorbent Assay followed by Immunofluorescence Assay To Document Ehrlichia chaffeensis as a Cause of Febrile Illness in Nicaragua

    PubMed Central

    Chikeka, Ijeuru; Matute, Armando J.; Woods, Christopher W.; Mayorga, Orlando

    2016-01-01

    Ehrlichia chaffeensis, the etiologic agent of human monocytic ehrlichiosis (HME), has been extensively studied as a cause of acute febrile illness and an emerging tick-borne zoonosis in the United States. Limited data suggest its presence in other regions, including Central and South America but not Nicaragua to date. Diagnosis of E. chaffeensis infection by indirect immunofluorescence assay (IFA) is the reference standard due to its presumed high sensitivity and specificity, but IFA is impractical, variably reproducible, and cumbersome for large epidemiologic studies and for clinical diagnosis in resource-poor regions. We evaluated a high-throughput, objective peptide-based enzyme-linked immunosorbent assay (ELISA) for use alone or in combination with IFA. We found that it performed best as a screening test (sensitivity, 100%; specificity, 84%) to reduce the proportion of serum samples that were required by the more cumbersome and subjective IFA testing to <20%. Using a two-step diagnostic approach (IFA is performed if the ELISA is positive), we identified E. chaffeensis or a serologically and antigenically similar organism as a heretofore unrecognized cause of acute febrile illness in humans in Nicaragua and demonstrated the utility of the peptide ELISA as a screening tool for large-scale clinical studies. PMID:27053675

  13. Antibodies to Rickettsia rickettsii, Rickettsia typhi, Coxiella burnetii, Bartonella henselae, Bartonella quintana, and Ehrlichia chaffeensis among healthy population in Minas Gerais, Brazil.

    PubMed

    da Costa, Paulo Sérgio Gonçalves; Brigatte, Marcos Emilio; Greco, Dirceu Bartolomeu

    2005-12-01

    Rickettsial diseases except those belonging to spotted fever group rickettsioses are poorly studied in South America particularly in Brazil where few epidemiological reports have been published. We describe a serosurvey for Rickettsia rickettsii, R. typhi, Coxiella burnetii, Bartonella henselae, B. quintana, and Ehrlichia chaffeensis in 437 healthy people from a Brazilian rural community. The serum samples were tested by indirected micro-immunoflourescence technique and a cutoff titer of 1:64 was used. The seroprevalence rates for R. rickettsii, R. typhi, C. burnetii, B. henselae, B. quintana, and E. chaffeensis were respectively 1.6% (7 samples); 1.1% (5 samples); 3.9% (17 samples); 13.7% (60 samples); 12.8% (56 samples), and 10.5% (46 samples). Frequent multiple/cross-reactivity was observed in this study. Age over 40 years old, urban profession, and rural residence were significantly associated with some but not all infections rate. Low seropositivity rates for R. rickettsii, R. typhi, and C. burnetii contrasted with higher rates of seropositivity for B. quintana, B. henselae, and E. chaffeensis. These results show that all tested rickettsial species or antigenically closely related possible exist in this particular region.

  14. Predominance of Ehrlichia chaffeensis in Rhipicephalus sanguineus ticks from a kennel-confined dogs in Limbe, Cameroon

    PubMed Central

    Ndip, Lucy M.; Ndip, Roland N.; Esemu, Seraphine N.; Walker, David H.; McBride, Jere W.

    2009-01-01

    Rhipicephalus sanguineus ticks (n=63) collected from five dogs (two adults and three puppies) housed in a kennel were screened for ehrlichial agents (E. canis, E. chaffeensis and E. ewingii) using a species-specific multicolor real-time TaqMan PCR amplification of the (disulphide bond formation protein (dsb) gene. E. chaffeensis DNA was detected in 33 (56 %) ticks, E. canis DNA was detected in four (6 %) ticks, and one tick was coinfected. The E. chaffeensis and E. canis nucleotide sequences of the amplified dsb gene (374-bp) obtained from the Cameroonian R. sanguineus ticks were identical to the North American genotypes. PMID:19693681

  15. Ehrlichia chaffeensis Infection in the Reservoir Host (White-Tailed Deer) and in an Incidental Host (Dog) Is Impacted by Its Prior Growth in Macrophage and Tick Cell Environments

    PubMed Central

    Nair, Arathy D. S.; Cheng, Chuanmin; Jaworski, Deborah C.; Willard, Lloyd H.; Sanderson, Michael W.; Ganta, Roman R.

    2014-01-01

    Ehrlichia chaffeensis, transmitted from Amblyomma americanum ticks, causes human monocytic ehrlichiosis. It also infects white-tailed deer, dogs and several other vertebrates. Deer are its reservoir hosts, while humans and dogs are incidental hosts. E. chaffeensis protein expression is influenced by its growth in macrophages and tick cells. We report here infection progression in deer or dogs infected intravenously with macrophage- or tick cell-grown E. chaffeensis or by tick transmission in deer. Deer and dogs developed mild fever and persistent rickettsemia; the infection was detected more frequently in the blood of infected animals with macrophage inoculum compared to tick cell inoculum or tick transmission. Tick cell inoculum and tick transmission caused a drop in tick infection acquisition rates compared to infection rates in ticks fed on deer receiving macrophage inoculum. Independent of deer or dogs, IgG antibody response was higher in animals receiving macrophage inoculum against macrophage-derived Ehrlichia antigens, while it was significantly lower in the same animals against tick cell-derived Ehrlichia antigens. Deer infected with tick cell inoculum and tick transmission caused a higher antibody response to tick cell cultured bacterial antigens compared to the antibody response for macrophage cultured antigens for the same animals. The data demonstrate that the host cell-specific E. chaffeensis protein expression influences rickettsemia in a host and its acquisition by ticks. The data also reveal that tick cell-derived inoculum is similar to tick transmission with reduced rickettsemia, IgG response and tick acquisition of E. chaffeensis. PMID:25303515

  16. A serological survey of tick-borne pathogens in dogs in North America and the Caribbean as assessed by Anaplasma phagocytophilum, A. platys, Ehrlichia canis, E. chaffeensis, E. ewingii, and Borrelia burgdorferi species-specific peptides

    PubMed Central

    Qurollo, Barbara A.; Chandrashekar, Ramaswamy; Hegarty, Barbara C.; Beall, Melissa J.; Stillman, Brett A.; Liu, Jiayou; Thatcher, Brendon; Pultorak, Elizabeth; Cerrito, Brian; Walsh, Mary; Breitschwerdt, Edward B.

    2014-01-01

    Introduction Tick-borne pathogens cause a spectrum of disease manifestations in both dogs and humans. Recognizing regional and temporal shifts in exposure are important as tick distributions change. To better delineate regional exposure to canine tick-borne pathogens, an expanded set of species-specific peptides were used to detect Anaplasma phagocytophilum (Aph), Anaplasma platys (Apl), Ehrlichia canis (Ec), Ehrlichia chaffeensis (Ech), Ehrlichia ewingii (Eew), and Borrelia burgdorferi (Bb) antibodies in canine serum. Methods Archived canine serum samples (n=6,582) collected during 2008–2010 and in 2012 from the US, Canada, and the Caribbean were retrospectively screened for antibodies against Ehrlichia and Anaplasma species-specific peptides. Overall, regional and temporal seroprevalence rates were determined. Results Overall Bb and Eew were the most seroprevalent pathogens. During 2008–2010, seroprevalence rates increased overall for Aph and Ech, and regionally, Bb and Aph seroprevalence rates increased in the South. Canada had unexpectedly high seroprevalence rates for Ec and Apl. The most common co-exposures were Eew+Ech, followed by Aph+Bb and Eew+Bb. Conclusions This study demonstrated significant shifts in canine vector-borne disease seroprevalence rates. The use of specific peptides facilitated improved geographic delineation of tick-borne pathogen distributions among dogs, which may enhance epidemiological surveillance of vector-borne pathogens shared by dogs and humans. PMID:25405006

  17. Migratory and carnivorous birds in Brazil: reservoirs for Anaplasma and Ehrlichia species?

    PubMed

    Machado, Rosangela Zacarias; André, Marcos Rogério; Werther, Karin; de Sousa, Eliane; Gavioli, Fernando Antônio; Alves Junior, José Roberto Ferreira

    2012-08-01

    In order to investigate new hosts for Anaplasmataceae agents in Brazil, we collected blood samples from 21 wild birds. Using molecular techniques, we detected the presence of Anaplasma phagocytophilum, Ehrlichia chaffeensis, and an Ehrlichia species closely related to Ehrlichia canis in carnivorous avian blood samples. In addition, an Ehrlichia species closely related to an Ehrlichia species found in wild felines in Brazil was also detected in a goose blood sample. Wild birds may play a role as carriers of Anaplasmataceae agents in Brazil.

  18. Natural coinfection of a white-tailed deer (Odocoileus virginianus) population with three Ehrlichia spp.

    PubMed

    Little, S E; Stallknecht, D E; Lockhart, J M; Dawson, J E; Davidson, W R

    1998-10-01

    The ticks Amblyomma americanum and Ixodes scapularis, strongly implicated vectors of Ehrlichia chaffeensis and the human granulocytic ehrlichiosis (HGE) agent, respectively, commonly are found on white-tailed deer (Odocoileus virginianus). As deer can be infected with E. chaffeensis, the HGE agent, and another Ehrlichia-like organism, a deer population parasitized by both tick species in coastal Georgia was tested for evidence of Ehrlichia spp. infection using serologic, molecular, and culture techniques. Antibodies to both E. chaffeensis (geometric mean titer = 111) and Ehrlichia equi, surrogate antigen for the HGE agent, (geometric mean titer = 1,024) were detected by indirect fluorescent antibody testing. Nested polymerase chain reaction employing species-specific primers demonstrated sequence-confirmed 16S rDNA fragments of 3 distinct Ehrlichia spp. in this population: E. chaffeensis (1/5), the HGE agent (3/5), and an Ehrlichia-like organism previously described from white-tailed deer (5/5). Ehrlichia chaffeensis was isolated in culture from the inguinal lymph node of a single deer. An Ehrlichia-type morula was identified in a neutrophil of 1 deer on examination of blood smears. This work provides the first evidence of the HGE agent in a nonhuman host in the southeastern United States and documents infection with both E. chaffeensis and the HGE agent in a single deer population, thereby supporting the importance of white-tailed deer in the natural history of the human ehrlichioses agents.

  19. Predominance of Ehrlichia ewingii in Missouri Dogs

    PubMed Central

    Liddell, Allison M.; Stockham, Steven L.; Scott, Michael A.; Sumner, John W.; Paddock, Christopher D.; Gaudreault-Keener, Monique; Arens, Max Q.; Storch, Gregory A.

    2003-01-01

    To investigate the species distribution of Ehrlichia present in Missouri dogs, we tested 78 dogs suspected of having acute ehrlichiosis and 10 healthy dogs. Blood from each dog was screened with a broad-range 16S rRNA gene PCR assay that detects known pathogenic species of Ehrlichia and Anaplasma. The species was determined by using species-specific PCR assays and nucleotide sequencing. Ehrlichia antibody testing was performed by using an indirect immunofluorescence assay with Ehrlichia chaffeensis as the antigenic substrate. The broad-range assay detected Ehrlichia or Anaplasma DNA in 20 (26%) of the symptomatic dogs and 2 (20%) of the asymptomatic dogs. E. ewingii accounted for 20 (91%), and E. chaffeensis accounted for 1 (5%) of the positives. Anaplasma phagocytophilum DNA was detected in one dog, and the sequences of regions of the 16S rRNA gene and the groESL operon amplified from the blood of this dog matched the published sequences of this organism. Antibodies reactive with E. chaffeensis were detected in 14 (67%) of the 21 PCR-positive dogs and in 12 (19%) of the 64 PCR-negative dogs. Combining the results of PCR and serology indicated that 33 (39%) of 85 evaluable dogs had evidence of past or current Ehrlichia infection. We conclude that E. ewingii is the predominant etiologic agent of canine ehrlichiosis in the areas of Missouri included in this survey. E. canis, a widely recognized agent of canine ehrlichiosis, was not detected in any animal. The finding of E. ewingii in asymptomatic dogs suggests that dogs could be a reservoir for this Ehrlichia species. PMID:14532192

  20. The genome of the heartwater agent Ehrlichia ruminantium contains multiple tandem repeats of actively variable copy number.

    PubMed

    Collins, Nicola E; Liebenberg, Junita; de Villiers, Etienne P; Brayton, Kelly A; Louw, Elmarié; Pretorius, Alri; Faber, F Erika; van Heerden, Henriette; Josemans, Antoinette; van Kleef, Mirinda; Steyn, Helena C; van Strijp, M Fransie; Zweygarth, Erich; Jongejan, Frans; Maillard, Jean Charles; Berthier, David; Botha, Marli; Joubert, Fourie; Corton, Craig H; Thomson, Nicholas R; Allsopp, Maria T; Allsopp, Basil A

    2005-01-18

    Heartwater, a tick-borne disease of domestic and wild ruminants, is caused by the intracellular rickettsia Ehrlichia ruminantium (previously known as Cowdria ruminantium). It is a major constraint to livestock production throughout subSaharan Africa, and it threatens to invade the Americas, yet there is no immediate prospect of an effective vaccine. A shotgun genome sequencing project was undertaken in the expectation that access to the complete protein coding repertoire of the organism will facilitate the search for vaccine candidate genes. We report here the complete 1,516,355-bp sequence of the type strain, the stock derived from the South African Welgevonden isolate. Only 62% of the genome is predicted to be coding sequence, encoding 888 proteins and 41 stable RNA species. The most striking feature is the large number of tandemly repeated and duplicated sequences, some of continuously variable copy number, which contributes to the low proportion of coding sequence. These repeats have mediated numerous translocation and inversion events that have resulted in the duplication and truncation of some genes and have also given rise to new genes. There are 32 predicted pseudogenes, most of which are truncated fragments of genes associated with repeats. Rather then being the result of the reductive evolution seen in other intracellular bacteria, these pseudogenes appear to be the product of ongoing sequence duplication events.

  1. Evaluation of Gulf Coast Ticks (Acari: Ixodidae) for Ehrlichia and Anaplasma Species.

    PubMed

    Allerdice, Michelle E J; Hecht, Joy A; Karpathy, Sandor E; Paddock, Christopher D

    2017-03-01

    Amblyomma maculatum Koch (the Gulf Coast tick) is an aggressive, human-biting ixodid tick distributed throughout much of the southeastern United States and is the primary vector for Rickettsia parkeri, an emerging human pathogen. Amblyomma maculatum has diverse host preferences that include white-tailed deer, a known reservoir for Ehrlichia and Anaplasma species, including the human pathogens E. ewingii and E. chaffeensis. To examine more closely the potential role of A. maculatum in the maintenance of various pathogenic Ehrlichia and Anaplasma species, we screened DNA samples from 493 questing adult A. maculatum collected from six U.S. states using broad-range Anaplasmataceae and Ehrlichia genus-specific PCR assays. Of the samples tested, four (0.8%) were positive for DNA of Ehrlichia ewingii, one (0.2%) was positive for Anaplasma platys, and one (0.2%) was positive for a previously unreported Ehrlichia species closely related to Ehrlichia muris and an uncultivated Ehrlichia species from Haemaphysalis longicornis ticks in Japan. No ticks contained DNA of Ehrlichia chaffeensis, Ehrlichia canis, the Panola Mountain Ehrlichia, or Anaplasma phagocytophilum. This is the first identification of E. ewingii, A. platys, and the novel Ehrlichia in questing Gulf Coast ticks; nonetheless the low prevalence of these agents suggests that A. maculatum is not likely an important vector of these zoonotic pathogens.

  2. Development of antibodies to and PCR detection of Ehrlichia spp. in dogs following natural tick exposure.

    PubMed

    Starkey, Lindsay A; Barrett, Anne W; Chandrashekar, Ramaswamy; Stillman, Brett A; Tyrrell, Phyllis; Thatcher, Brendon; Beall, Melissa J; Gruntmeir, Jeff M; Meinkoth, James H; Little, Susan E

    2014-10-10

    Dogs exposed to ticks in the southern US may become infected with multiple species of Ehrlichia. To better define infection risk, blood samples collected from 10 dogs infested with ticks via a natural infestation model were evaluated by blood smear examination, PCR, patient-side ELISAs (SNAP® 4Dx® and SNAP® 4Dx® Plus), IFA, and peptide based ELISA for evidence of infection with Ehrlichia canis, E. chaffeensis, and/or E. ewingii. Although morulae were rarely identified in blood smears, every dog (10/10) became infected with Ehrlichia spp. as evidenced by nested PCR detection of E. chaffeensis (7/10) and E. ewingii DNA (10/10); real-time PCR detection of E. chaffeensis (0/10) and E. ewingii (9/10); seroconversion on two different patient-side ELISAs (4/10 or 10/10); seroconversion on IFA to E. canis (10/10, maximum inverse titer=128-4096, GMTMAX=548.7) and E. chaffeensis (10/10, maximum inverse titer=1024-32,768, GMTMAX=4096); and seroconversion on peptide specific ELISA to E. chaffeensis VLPT (7/10) and E. ewingii p28 (9/10). Rickettsemia with E. chaffeensis and E. ewingii, as determined by nested PCR, persisted in dogs for an average of 3.2 or 30.5 days, respectively. Ehrlichia canis was not detected in any dog by any method, and no dogs developed signs of clinical disease. Our data suggest that in areas where ticks are common, dogs are at high risk of infection with Ehrlichia spp., particularly E. ewingii and E. chaffeensis, and can serve as a sentinel for monitoring for the presence of these zoonotic pathogens.

  3. Defining the Immune Response to Ehrlichia species Using Murine Models

    PubMed Central

    Chapes, Stephen K.; Ganta, Roman R.

    2008-01-01

    Pathogenic bacteria belonging to the family Anaplasmataceae include species of the genera Ehrlichia and Anaplasma. Ehrlichia chaffeensis, first known as the causative agent of human monocytic ehrlichiosis, also infects several vertebrate hosts including white-tailed deer, dogs, coyotes and goats. E. chaffeensis is transmitted from the bite of an infected hard tick, such as Amblyomma americanum. E. chaffeensis and other tick-transmitted pathogens have adapted to both the tick and vertebrate host cell environments. Although E. chaffeensis persists in both vertebrate and tick hosts for long periods of time, little is known about that process. Immunological studies will be valuable in assessing how the pathogen persists in nature in both vertebrate and invertebrate hosts. Understanding the host immune response to the pathogen originating from dual host backgrounds is also important to develop effective methods of diagnosis, control and treatment. In this paper, we provide our perspective of the current understanding of the immune response against E. chaffeensis in relation to other related Anaplasmataceae pathogens. PMID:19028013

  4. Ehrlichia ewingii Infection in White-Tailed Deer (Odocoileus virginianus)

    PubMed Central

    Varela, Andrea S.; Tate, Cynthia M.; Dugan, Vivien G.; Stallknecht, David E.; Little, Susan E.; Davidson, William R.

    2002-01-01

    Two closely related zoonotic ehrlichiae, Ehrlichia chaffeensis and E. ewingii, are transmitted by Amblyomma americanum, the lone star tick. Because white-tailed deer (Odocoileus virginianus) are critical hosts for all mobile stages of A. americanum and are important vertebrate reservoirs of E. chaffeensis, we investigated whether deer may be infected with E. ewingii, a cause of granulocytotropic ehrlichiosis in humans and dogs. To test for E. ewingii infection, we used polymerase chain reaction and inoculation of fawns with whole blood from wild deer. Of 110 deer tested from 20 locations in 8 U.S. states, 6 (5.5%) were positive for E. ewingii. In addition, natural E. ewingii infection was confirmed through infection of captive fawns. These findings expand the geographic distribution of E. ewingii, along with risk for human infection, to include areas of Kentucky, Georgia, and South Carolina. These data suggest that white-tailed deer may be an important reservoir for E. ewingii. PMID:12095432

  5. Ehrlichia sp. infection in carthorses of low-income owners, Southern Brazil.

    PubMed

    Vieira, Thállitha S; Vieira, Rafael F; Krawczak, Felipe S; Soares, Herbert S; Guimarães, Ana M; Barros-Filho, Ivan R; Marcondes, Mary; Labruna, Marcelo B; Biondo, Alexander W; Vidotto, Odilon

    2016-10-01

    Although well established in dogs, Ehrlichia sp. infection has been scarcely reported in horses. The aim was to perform a comprehensive serological and molecular survey for the detection of Ehrlichia spp. in carthorses from Southern Brazil. Blood samples from 190 carthorses from Paraná State were sampled. Horses were also tested for Borrelia burgdorferi and Anaplasma phagocytophilum. Anti-Ehrlichia sp. antibodies were detected by a commercial rapid ELISA, and immunofluorescence antibody assays (IFA) with E. chaffeensis and E. canis as crude antigens. The molecular and phylogenetic analysis of Ehrlichia sp. was based on 16S rRNA and dsb genes. A total of 52 (27.4%), 4 (2.1%), and 3 (1.6%) horses were positive for Ehrlichia spp., Anaplasma spp. and Borrelia burgdorferi, respectively, by the commercial rapid ELISA. Thirty-eight (20.0%) and 37 (19.5%) horses showed anti-E. chaffeensis and anti-E. canis antibodies by IFA, respectively. One blood sample that also showed anti-E. chaffeensis antibodies was PCR positive for the 16S rRNA and dsb genes of Ehrlichia spp., showing an identity of>98.0% to the uncultured Ehrlichia sp. previously detected in Brazilian jaguars (Panthera onca). Anti-Ehrlichia sp. antibodies and Ehrlichia DNA were detected in carthorses from Southern Brazil, which may post public health concerns due to intimate contact with low-income owners. This is the first report of a natural infection of this bacteria in horses from South America. Clinical signs and the tick vector remain unknown.

  6. Ehrlichiae and ehrlichial diseases in china.

    PubMed

    Wen, Bohai; Cao, Wuchun; Pan, Hua

    2003-06-01

    The various ticks collected from different areas of China were examined for the existence of ehrlichial agents by polymerase chain reaction (PCR) with genus- or species-specific primers designed on the basis of ehrlichial 16S rRNA genes and sequence analyses. In southern China, E. chaffeensis was detected in Amblyomma testudinarium ticks from infested cattle, Haemaphysalis yeni ticks from hare, and Ixodes ovatus ticks from Muntiacus reevesi. E. canis was identified in Rhipicephalus sanguineus ticks from dogs and Boophilus microplus ticks from goats. A new species of the genus Ehrlichia, closely related to E. chaffeensis, and Anaplasma marginale were found in B. microplus ticks from cattle in Tibet. In northern China, E. chaffeensis was detected in Dermacentor silvarum and I. persulcatus ticks; the granulocytic ehrlichial agents were detected in I. persulcatus ticks from an area where Lyme disease is endemic. Canine ehrlichiosis was found in southern China and E. canis and E. platys were identified in dogs; human ehrlichioses were demonstrated by amplifying the 16S rRNA genes of E. chaffeensis and granulocytic ehrlichial agents from patients' blood specimens. In comparison of 16S rRNA gene sequences, the sequences of E. chaffeensis, E. canis, and E. platys in China were found to be different from that in other countries at certain nucleotide positions. These results reveal that a variety of tick-borne ehrlichial agents and diseases exist in China, and the ehrlichial agents and their tick-vectors are same as or different from that in other countries at species or strain levels.

  7. Identification of Ehrlichia spp in canines in Thailand.

    PubMed

    Jirapattharasate, Charoonluk; Chatsiriwech, Jarin; Suksai, Parut; Changbunjong, Tanasak; Rawangchue, Thanakorn; Moonarmart, Walasinee; Sungpradit, Sivapong

    2012-07-01

    Canine ehrlichiosis is an endemic parasitic disease widely found in Thailand. The causative microorganism is tick-borne Ehrlichia spp, an obligate intracellular rickettsia residing in leukocytes. Ehrlichia spp in morulae-positive canine blood samples were identified using polymerase chain reaction amplification and direct sequencing of Ehrlichia spp. 16S rDNA 396 bp fragment and 36 of 59 were positive for E. canis. E. chaffeensis and E. ewingii were not detected. Sequencing alignment and phylogenetic analysis showed that 16S rDNA sequences of E. canis strains are 99.1-100% identical among E. canis strains from different countries worldwide. Further studies are required in order to determine new target sequence for genotyping of E. canis strains in the dog population in Thailand.

  8. Ehrlichial infection in Cameroonian canines by Ehrlichia canis and Ehrlichia ewingii.

    PubMed

    Ndip, L M; Ndip, R N; Esemu, S N; Dickmu, V L; Fokam, E B; Walker, D H; McBride, J W

    2005-11-30

    Ehrlichia chaffeensis and Ehrlichia ewingii are agents of emerging human ehrlichioses in North America and are transmitted primarily by Amblyomma americanum ticks, while Ehrlichia canis is the globally distributed cause of canine monocytic ehrlichiosis (CME) and is transmitted by the brown dog tick, Rhipicephalus sanguineus. Although E. canis and Ehrlichia ruminantium are endemic in Africa, the presence of ehrlichial agents in dogs and ticks in Cameroon has not been investigated. The objective of this study was to determine the prevalence of ehrlichial infections in Cameronian dogs using a combination of serologic and molecular methods. Peripheral blood was collected, clinical signs and the presence or absence of ticks on dogs (n=104) presenting for various reasons at local veterinary clinics around the Mount Cameroon region were noted. IFA identified 33 dogs (32%) with antibodies reactive with E. canis, and reactivity of these sera with all major E. canis antigens (200, 140, 95, 75, 47, 36, 28, and 19-kDa) was confirmed by immunoblotting. Multicolor real-time PCR detected ehrlichial DNA (E. canis (15) and E. ewingii (2)) in 17 dogs (16.3%), all of which had attached ticks at time of presentation. The dsb amplicons (378 bp) from E. canis and E. ewingii were identical to gene sequences from North American isolates. This study identifies canine ehrlichiosis as a prevalent unrecognized cause of disease in Cameroonian canines.

  9. Development and use of specific polymerase reaction for the detection of an organism resembling Ehrlichia sp. in white-tailed deer.

    PubMed

    Little, S E; Dawson, J E; Lockhart, J M; Stallknecht, D E; Warner, C K; Davidson, W R

    1997-04-01

    The role of white-tailed deer (Odocoileus virginianus) in the epidemiology of Ehrlichia chaffeensis and the agent of human granulocytic ehrlichiosis (HGE) is not fully understood, and diagnostic procedures may be complicated by the recent detection of 16S rDNA sequence from an Ehrlichia sp.-like organism in wild deer. A specific forward primer (DGA) and an Ehrlichia spp. reverse primer (GA1UR) were constructed to amplify this new, distinct Ehrlichia sp.-like 16S rDNA. The DGA primer, a forward primer specific for E. chaffeensis (DCH), and a forward primer specific for the E. phagocytophila genogroup (GE9f) were each used with GA1UR in nested polymerase chain reactions to amplify 16S rDNA sequences from control samples containing the deer Ehrlichia sp.-like organism, E. chaffeensis, or the HGE agent. Primer pairs DGA/GA1UR and DCH/GA1UR specifically amplified 16S rDNA sequences from the corresponding target organism, whereas GE9f/GA1UR amplified 16S rDNA sequence from both the HGE agent and the deer Ehrlichia sp.-like organism. With a nested PCR using DGA/GA1UR and DCH/GA1IUR on DNA extracted from white blood cells from 62 deer from 10 populations in four U.S. states, we observed a high prevalence (65%) of 16S rDNA sequences of the deer Ehrlichia sp.-like organism, and a low prevalence (5%) of the E. chaffeensis sequence. In this field survey, E. chaffeensis-reactive antibodies detected by indirect fluorescence assays were associated (P < 0.001) with PCR evidence of the deer Ehrlichia sp.-like organism, but not E. chaffeensis. Infestations of Amblyomma americanum also were associated (P < 0.001) with PCR evidence of the deer Ehrlichia sp.-like organism. The potential for serologic cross-reactions and non-specific PCR products arising from the deer Ehrlichia sp.-like organism should be considered when evaluating the role of deer and their ticks in the epidemiology of ehrlichial pathogens of humans.

  10. DNA gyrase-mediated natural resistance to fluoroquinolones in Ehrlichia spp.

    PubMed

    Maurin, M; Abergel, C; Raoult, D

    2001-07-01

    Fluoroquinolone susceptibility heterogeneity between various Ehrlichia species has been previously demonstrated. In gram-negative bacteria, resistance to fluoroquinolones most often corresponds to specific amino acid variations in a portion of the protein sequence of the A subunit of DNA gyrase (GyrA), referred to as the quinolone resistance-determining region (QRDR). We suspected a similar mechanism to be responsible for natural resistance in some Ehrlichia species. To verify this hypothesis, we sequenced the entire gyrA gene of the quinolone-susceptible species Ehrlichia sennetsu and designed specific primers to amplify and sequence the QRDR of four other Ehrlichia species as well as the closely related species Cowdria ruminantium. We identified in the fluoroquinolone-resistant species Ehrlichia chaffeensis and Ehrlichia canis a specific GyrA QRDR amino acid sequence, also present in C. ruminantium (whose susceptibility to fluoroquinolones remains unknown). These three species belong to a single phylogenetic cluster referred to as the E. canis genogroup. A different GyrA QRDR pattern, shared by the Ehrlichia species representatives of the E. sennetsu and Ehrlichia phagocytophila genogroups, was identified. Three of the four species tested are known to be susceptible to fluoroquinolones. A serine residue in position 83 (Escherichia coli numbering) in the susceptible species is replaced by an alanine residue in fluoroquinolone-resistant species. These results are consistent with the current knowledge on fluoroquinolone resistance in other gram-negative bacteria. They are indicative of a natural gyrase-mediated resistance to fluoroquinolones in the E. canis genogroup.

  11. First isolation and molecular characterization of Ehrlichia canis in Costa Rica, Central America.

    PubMed

    Romero, L E; Meneses, A I; Salazar, L; Jiménez, M; Romero, J J; Aguiar, D M; Labruna, M B; Dolz, G

    2011-08-01

    The present study investigated Ehrlichia species in blood samples from dogs suspected of clinical ehrlichiosis, using molecular and isolation techniques in cell culture. From a total of 310 canine blood samples analyzed by 16S rRNA nested PCR, 148 (47.7%) were positive for Ehrlichia canis. DNA from Ehrlichia chaffeensis or Ehrlichia ewingii was not detected in any sample using species-specific primers in separated reactions. Leukocytes from five PCR-positive dogs were inoculated into DH82 cells; successful isolation of E. canis was obtained in four samples. Partial sequence of the dsb gene of eight canine blood samples (including the five samples for in vitro isolation) was obtained by PCR and their analyses through BLAST showed 100% of identity with the corresponding sequence of E. canis in GenBank. This study represents the first molecular diagnosis, isolation, and molecular characterization of E. canis in dogs from Costa Rica.

  12. Detection of genotype-specific Ehrlichia canis exposure in Brazilian dogs by TRP36 peptide ELISA.

    PubMed

    Aguiar, Daniel M; Zhang, Xiaofeng; Braga, Isis A; Taques, Isis I G G; McBride, Jere W

    2016-02-01

    We recently characterized a novel genotype of Ehrlichia canis based on the tandem repeat (TR) sequence of the TRP36 gene in Brazil. The TR amino acid sequence of the Brazilian (Br) genotype (ASVVPEAE) was divergent from the previously described US genotype (TEDSVSAPA) of E. canis. In this study, we developed an ELISA based on TRP36 TR synthetic peptides from both Br and US E. canis TRP36 genotypes to serologically detect and distinguish infections caused by these genotypes. Sera from 30 Brazilian dogs naturally infected with E. canis, sera from dogs experimentally infected E. canis (Jake and Cuiabá #1 strains) and E. chaffeensis (Arkansas strain) and 12 seronegative E. canis dogs were evaluated. Fifteen naturally infected Brazilian dogs had antibodies that reacted with the US TRP36 (n=9) or Br TRP36 (n=6) only, and 13 dogs had antibodies that reacted with both TPR36 peptides suggesting that these dogs were exposed to both genotypes. Most dogs (n=28) had antibodies that reacted with the highly conserved E. canis TRP19 peptide; however, two dogs had antibodies to E. canis TRP19, but did not have TRP36 antibodies, raising the possibility that another novel TRP36 genotype is circulating in Brazil. Our results demonstrate that synthetic peptides based on the TR region of E. canis TRP36 can be used to serologically distinguish infections or identify coinfections by different genotypes, and to determine the seroprevalence of various E. canis genotypes in Brazil.

  13. Detection of A. phagocytophilum and E. chaffeensis in patient and mouse blood and ticks by a duplex real-time PCR assay.

    PubMed

    Dong, Tuo; Qu, Zhangyi; Zhang, Lijuan

    2013-01-01

    Human granulocytic anaplasmosis (HGA) and human monocytic ehrlichiosis (HME) are emerging, tick-borne, zoonotic infectious diseases caused by Anaplasma phagocytophilum and Ehrlichia chaffeensis, respectively. Early diagnosis is essential for rapid clinical treatment to avoid misdiagnosis and severe patient outcomes. Simple, sensitive and reliable diagnostic methods are urgently needed. In this study, we developed a duplex real-time PCR assay targeting the A. phagocytophilum ankA gene and the E. chaffeensis TRP120 gene, respectively. The lowest limit of detection of the duplex real-time PCR assay was 100 copies of the targeted A. phagocytophilum ankA gene and the E. chaffeensis TRP120 gene per reaction, and the specificity was 100%. Detection in blood DNA samples from the acute stage of illness for 22 HGA cases and 8 HME cases indicated that the duplex real-time PCR assay was more sensitive than the nested PCR assay. The infection of Citellusundulatus Pallas with A. phagocytophilum and E. chaffeensis was first confirmed in Xinjiang Province and the positive rate was 3.1% for A. phagocytophilum, 6.3% for E. chaffeensis and 3.1% for co-infection with both pathogens. The rates of A. phagocytophilum and E. chaffeensis infection of D. silvarum ticks collected from Shanxi Province were 8.2% and 14.8%, respectively, and the co-infection rate was 3.3%. The rates of A. phagocytophilum and E. chaffeensis infection in H. longicornis ticks collected from Shandong Province were 1.6% and 6.3%, respectively, and the co-infection rate was 1.6%.

  14. Prevalence of Babesia spp., Ehrlichia spp., and Tick Infestations in Oklahoma Black Bears (Ursus americanus).

    PubMed

    Skinner, Delaina; Mitcham, Jessica R; Starkey, Lindsay A; Noden, Bruce H; Fairbanks, W Sue; Little, Susan E

    2017-06-28

    American black bears (Ursus americanus) are commonly infested with ticks throughout their range, but there are few surveys for tick-borne disease agents in bears. To characterize tick infestations and determine the prevalence of current infection with Babesia spp. and past or current infection with Ehrlichia spp. in newly re-established populations of black bears in east central and southeastern Oklahoma, we identified adult (n=1,048) and immature (n=107) ticks recovered from bears (n=62). We evaluated serum and whole blood samples from a subset (n=49) for antibodies reactive to, and characteristic DNA fragments of Ehrlichia spp. as well as characteristic DNA fragments of Babesia spp. Amblyomma americanum, the most common tick identified, was found on a majority (56/62; 90%) of bears and accounted for 697/1,048 (66.5%) of all ticks recovered. Other ticks included Dermacentor variabilis (338/1,048; 32.3%) from 36 bears, Amblyomma maculatum (9/1,048; 0.9%) from three bears, and Ixodes scapularis (4/1,048; 0.4%) from three bears. Antibodies reactive to Ehrlichia spp. were detected in every bear tested (49/49; 100%); maximum inverse titers to Ehrlichia chaffeensis ranged from 64-4,096 (geometric mean titer 1,525). However, PCR failed to identify active infection with E. chaffeensis, Ehrlichia ewingii, or an Ehrlichia ruminantium-like agent. Infection with Babesia spp. was detected by PCR in 3/49 (6%) bears. Together these data confirm that tick infestations and infection with tick-borne disease agents are common in bears in the southern US. The significance of these infestations and infections to the health of bears, if any, and the identity of the Ehrlichia spp. responsible for the antibody reactivity seen, warrant further evaluation.

  15. Two novel Ehrlichia strains detected in Amblyomma tigrinum ticks associated to dogs in peri-urban areas of Argentina.

    PubMed

    Cicuttin, Gabriel L; De Salvo, M Nazarena; Nava, Santiago

    2017-08-01

    The aim of this work was to describe two novel strains of Ehrlichia associated to Amblyomma tigrinum from Argentina. Molecular detection of agents belonging to the family Anaplasmataceae was performed targeting three different loci: 16S rRNA gene, dsb gene and a fragment of groESL heat shock operon. The results have shown that two different strains of Ehrlichia sp. associated to A. tigrinum are circulating in peri-urban areas of Argentina. The Ehrlichia strain detected in ticks from San Luis Province, named as Ehrlichia sp. strain San Luis, is closely related to the Ehrlichia chaffeensis. The novel Ehrlichia strain detected in Córdoba Province, named as Ehrlichia sp. strain Córdoba, is phylogenetically related to three Ehrlichia strains from Brazil, two of them isolated from wild carnivorous and the third one isolated from horse. Even though Ehrlichia sp. strain Córdoba was clustered with the three Ehrlichia strains from Brazil, the genetic similarity was too low to consider them as the same taxonomic entity. Blood samples of dogs were positive to Anaplasma platys. The association of these two novel strains with A. tigrinum has epidemiological relevance because adult stages of this tick species are common parasite of dogs in rural and peri-urban areas and they are aggressive to humans. The presence of these two novel Ehrlichia strains implies a potential epidemiological risk in Argentina because the species of the genus Ehrlichia are known to be pathogenic to both domestic mammals and humans. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Ehrlichia Meningitis Mimicking Aneurysmal Subarachnoid Hemorrhage

    PubMed Central

    Dredla, Brynn

    2015-01-01

    Thunderclap headache is a sudden and severe headache that can occur after an aneurysmal subarachnoid hemorrhage (SAH). Subarachnoid hemorrhage is a medical emergency that requires prompt attention and hospitalization. Patients with thunderclap headache often undergo a noncontrast head computed tomography (CT) scan to ascertain SAH bleeding and, if the scan is negative, then undergo a lumbar puncture to look for cerebrospinal fluid (CSF) red blood cells (RBCs), which would be consistent with an aneurysmal leak. If the initial CT is negative and CSF is positive for RBCs, patients are usually admitted to the hospital for evaluation of intracranial aneurysm. We encountered a patient with thunderclap headache whose initial head CT was negative for SAH and whose CSF tested positive for RBCs. The patient was referred to our center for evaluation and management of aneurysmal SAH. However, on careful review of the patient’s medical history, serum laboratory values, and spinal fluid values, the patient was diagnosed with Ehrlichia chaffeensis meningitis. While Ehrlichia meningitis is rare, it is important to recognize the clinical clues that could help avoid formal cerebral angiography, a costly and potentially unnecessary procedure. We present how this case represented a cognitive framing bias and anchoring heuristic as well as steps that medical providers can use to prevent such cognitive errors in diagnosis. PMID:27053985

  17. Genetic profiling for Anaplasma and Ehrlichia species in ticks collected in the Eastern Cape Province of South Africa.

    PubMed

    Iweriebor, Benson C; Mmbaga, Elia J; Adegborioye, Abiodun; Igwaran, Aboi; Obi, Larry C; Okoh, Anthony I

    2017-02-27

    Anaplasma and Ehrlichia are emerging tick-borne pathogens that cause anaplasmosis and ehrlichiosis in humans and other animals worldwide. Infections caused by these pathogens are deadly if left untreated. There has been relatively no systematic survey of these pathogens among ticks in South Africa, thus necessitating this study. The presence of Anaplasma and Ehrlichia species were demonstrated by PCR in ticks collected from domestic ruminants at some selected communities in the Eastern Cape of South Africa. The ticks were identified by morphological characteristics and thereafter processed to extract bacterial DNA, which was analyzed for the presence of genetic materials of Anaplasma and Ehrlichia. Three genera of ticks comprising five species were identified. The screening yielded 16 positive genetic materials that were phylogenetically related to Ehrlichia sequences obtained from GenBank, while no positive result was obtained for Anaplasma. The obtained Ehrlichia sequences were closely related to E. chaffeensis, E. canis, E. muris and the incompletely described Ehrlichia sp. UFMG-EV and Ehrlichia sp. UFMT. The findings showed that ticks in the studied areas were infected with Ehrlichia spp. and that the possibility of transmission to humans who might be tick infested is high.

  18. Prevalence of antibodies to spotted fever group Rickettsia spp. and Ehrlichia spp. in coyotes (Canis latrans) in Oklahoma and Texas, USA.

    PubMed

    Starkey, Lindsay A; West, Misti D; Barrett, Anne W; Saucier, Jill M; O'Connor, Tom P; Paras, Kelsey L; Reiskind, Michael H; Reichard, Mason V; Little, Susan E

    2013-07-01

    Coyotes (Canis latrans) are commonly infested with ticks, including Amblyomma americanum, the predominant vector of Ehrlichia chaffeensis and Ehrlichia ewingii; Dermacentor variabilis, an important vector of Rickettsia rickettsii; and Amblyomma maculatum, a major vector of Rickettsia parkeri, a spotted fever group (SFG) Rickettsia. To determine the degree to which coyotes are infected with or exposed to tick-borne bacterial disease agents, serum samples collected from coyotes in Oklahoma and Texas were tested for antibodies reactive to R. rickettsii, Ehrlichia canis, E. chaffeensis, E. ewingii, Borrelia burgdorferi, and Anaplasma phagocytophilum by indirect fluorescent antibody (IFA) testing or enzyme-linked immunosorbent assay (ELISA). Of the coyotes tested, 60% (46/77) and 64% (47/74) had antibodies reactive to R. rickettsii and E. chaffeensis, respectively, on IFA. Additionally, 5% (4/77) had antibodies reactive to E. canis, but not B. burgdorferi or A. phagocytophilum, on SNAP(®) 4Dx(®) ELISA; subsequent serologic analysis by plate ELISA using species-specific peptides revealed antibodies to E. ewingii, E. canis, and E. chaffeensis in 46% (23/50), 18% (9/50), and 4% (2/50) of serum samples, respectively. Taken together, these data indicate that coyotes in this region are commonly exposed to SFG Rickettsia and E. ewingii and that further consideration of coyotes as a component of the maintenance cycle for these pathogens may be warranted.

  19. DNA Gyrase-Mediated Natural Resistance to Fluoroquinolones in Ehrlichia spp.

    PubMed Central

    Maurin, M.; Abergel, C.; Raoult, D.

    2001-01-01

    Fluoroquinolone susceptibility heterogeneity between various Ehrlichia species has been previously demonstrated. In gram-negative bacteria, resistance to fluoroquinolones most often corresponds to specific amino acid variations in a portion of the protein sequence of the A subunit of DNA gyrase (GyrA), referred to as the quinolone resistance-determining region (QRDR). We suspected a similar mechanism to be responsible for natural resistance in some Ehrlichia species. To verify this hypothesis, we sequenced the entire gyrA gene of the quinolone-susceptible species Ehrlichia sennetsu and designed specific primers to amplify and sequence the QRDR of four other Ehrlichia species as well as the closely related species Cowdria ruminantium. We identified in the fluoroquinolone-resistant species Ehrlichia chaffeensis and Ehrlichia canis a specific GyrA QRDR amino acid sequence, also present in C. ruminantium (whose susceptibility to fluoroquinolones remains unknown). These three species belong to a single phylogenetic cluster referred to as the E. canis genogroup. A different GyrA QRDR pattern, shared by the Ehrlichia species representatives of the E. sennetsu and Ehrlichia phagocytophila genogroups, was identified. Three of the four species tested are known to be susceptible to fluoroquinolones. A serine residue in position 83 (Escherichia coli numbering) in the susceptible species is replaced by an alanine residue in fluoroquinolone-resistant species. These results are consistent with the current knowledge on fluoroquinolone resistance in other gram-negative bacteria. They are indicative of a natural gyrase-mediated resistance to fluoroquinolones in the E. canis genogroup. PMID:11408229

  20. Survey of Ticks Collected from Tennessee Cattle and Their Pastures for Anaplasma and Ehrlichia Species.

    PubMed

    Pompo, K; Mays, S; Wesselman, C; Paulsen, D J; Fryxell, R T Trout

    2016-02-01

    Anaplasma marginale is the causative agent for bovine anaplasmosis (BA) and Ehrlichia ruminantium is the causative agent for heartwater, 2 devastating diseases of cattle. BA is common in the United States and frequently reported in western Tennessee cattle; however, cases of heartwater are not yet established in the continental United States. Because both pathogens are transmitted via the bites of infected ticks, the objective of this study was to survey cattle and pastures for ticks and for each pathogen. University of Tennessee AgResearch has 7 research and education centers (REC) located throughout the state at which they manage cattle. Ticks were collected from selected cattle (every fourth to sixth animal) and pastures (via dragging) associated with the herd from each REC during the summer of 2013. A total of 512 ticks were collected from cattle (n = 386) and pastures (n = 126) and were PCR-screened for Anaplasma and Ehrlichia using genus-specific primers. Collections consisted of 398 (77.7%) Amblyomma americanum, 84 (16.4%) Amblyomma maculatum, and 30 (5.9%) Dermacentor variabilis. Ticks were not recovered from pastures or cattle east of the Tennessee Plateau. The North American vectors for An. marginale and E. ruminantium were identified (D. variabilis and A. maculatum, respectively), but neither pathogen was recovered. A large proportion of ticks were collected from cattle and, of these, a majority were attached to their host (compared to questing on their host or engorged on the host). Four A. americanum were positive for Ehrlichia spp. (Ehrlichia ewingii, Ehrlichia chaffeensis, and Panola Mountain Ehrlichia), all in western Tennessee. With the identification of a few Ehrlichia infections in cattle-associated ticks and current A. marginale rates in Tennessee beef cattle nearing 11%, additional research is needed to establish baseline tick, Anaplasma, and Ehrlichia data for future management studies.

  1. Development of multiple-locus variable-number tandem-repeat analysis for rapid genotyping of Ehrlichia ruminantium and its application to infected Amblyomma variegatum collected in heartwater endemic areas in Uganda.

    PubMed

    Nakao, Ryo; Morrison, Liam J; Zhou, Lijia; Magona, Joseph W; Jongejan, Frans; Sugimoto, Chihiro

    2012-01-01

    The rickettsial bacterium Ehrlichia ruminantium is the causative agent of heartwater, a serious tick-borne disease in ruminants. The genetic diversity of organisms in the field will have implications for cross-protective capacities of any vaccine developed, and for an effective vaccine design strategy proper genotyping and understanding of existing genetic diversity in the field is necessary. We searched for variable-number tandem-repeat (VNTR) loci for use in a multi-locus VNTR analysis (MLVA). Sequencing analysis of 30 potential VNTRs using a panel of 17 reference strains from geographically diverse origins identified 12 VNTRs with allelic profiles differing between strains. Application of MLVA to 38 E. ruminantium-infected Amblyomma variegatum collected from indigenous cattle in 6 different districts of Uganda identified 21 MLVA types. The discriminatory power of MLVA was greater than that of map1 PCR-restriction fragment length polymorphism analysis, with which only 6 genotypes were obtained. The high discriminatory power as well as cost- effective performance of MLVA provide the potential for this technique to be applied in the future with respect to optimizing vaccine trials by identifying local strain diversity, and also raise the possibility of exploring the association between E. ruminantium genotypes and phenotypes such as pathological outcome in the ruminant host.

  2. Prevalence of Ehrlichia, Borrelia, and Rickettsial agents in Amblyomma americanum (Acari : Ixodidae) collected from nine states

    USGS Publications Warehouse

    Mixson, T.R.; Campbell, S.R.; Gill, J.S.; Ginsberg, H.S.; Reichard, M.V.; Schultz, T.L.; Dasch, G.A.

    2006-01-01

    Ambyomma antericanum (L.) (Acari: Ixodidae) is an aggressive tick that feeds on humans during all postembryonic life stages. In many regions of the United States, it is the tick most commonly found attached to humans. Public health interest has grown recently, due to the recognition of new human pathogens transmitted by A. antericanum and the expanding distribution of the tick. A. americanum is a vector of several bacteria pathogenic to humans. Ehrlichia chaffeensis and Ehrlichia ewingii cause moderate-to-severe febrile illness. 'Rickettsia amblyommii,' a member of the spotted fever group Rickettsia, also has recently been implicated as a possible human pathogen based on serologic evidence from persons recovering from illness after a tick bite. We have determined the prevalence of infection of Ehrlichia chaffeensis, E. ewingii, 'Borrelia lonestari,' and R. amblyommii within A. americanum ticks from 29 sites in nine states. Overall infection prevalences were 4.7% for E. chaffeensis (range, 0-27%), 3.5% for E. ewingii (range, 0-18.6%), 2.5% for B. lonestari (range, 0-12.2%), and 41.2% for R. amblyommii (range, 0-84.0%). In addition, 87 ticks (4.3%) were infected with two or more bacteria. This report documents new distribution records for E. ewingii, B. lonestari, and R. amblyommii and underscores the nonhomogeneous distribution of pathogen foci of infection. Additional surveillance throughout the range of A. antericanum is warranted to increase physician and public awareness of the risk of disease to humans from exposure to the agents transmitted by this tick.

  3. Molecular identification of Ehrlichia species and host bloodmeal source in Amblyomma americanum L. from two locations in Tennessee, United States.

    PubMed

    Harmon, Jessica R; Scott, M Cathy; Baker, Ellen M; Jones, Carl J; Hickling, Graham J

    2015-04-01

    The current status of tick-borne diseases in the southeastern United States is challenging to define due to emerging pathogens, uncertain tick/host relationships, and changing disease case definitions. A golf-oriented retirement community on the Cumberland Plateau in Tennessee experienced an ehrlichiosis outbreak in 1993, prompting efforts to reduce the local tick population using '4-Poster' acaricide devices targeting white-tailed deer (Odocoileus virginianus). In 2009, the prevalence of Ehrlichia spp. in questing ticks was surveyed in the area and compared to a Tennessee state park where acaricide had not been applied. The range of wildlife hosts that immature Amblyomma americanum fed upon and the role that these hosts may play in pathogen dynamics were investigated using a reverse line blot (RLB) bloodmeal analysis technique. Amblyomma americanum was by far the most common tick species in both study areas (>99% of ticks collected). Of 303 adult and nymphal A. americanum tested at the retirement community, six were positive for Ehrlichia chaffeensis (2.0%), 16 were positive for E. ewingii (5.3%), and six were positive for Panola Mountain Ehrlichia (2.0%). This is the first confirmation of Panola Mountain Ehrlichia in A. americanum from the state of Tennessee. The 9.3% prevalence of Ehrlichia spp. in ticks from the retirement community was similar to that detected at the state park site (5.5%), suggesting that the 4-Poster treatment had not been sufficient to reduce Ehrlichia spp. cycling in the tick population. At both study sites, A. americanum fed on a wide range of mammal and bird species, with a minority of detectable bloodmeals coming from deer. Of the Ehrlichia-infected nymphs with positive bloodmeal identification, none fed on deer, indicating that multiple vertebrate species are contributing to sylvatic maintenance of Ehrlichia spp. at these sites. This highlights the difficulty of attempting to reduce the risk of tick-borne disease through host

  4. Serological survey of Ehrlichia species in dogs, horses and humans: zoonotic scenery in a rural settlement from southern Brazil.

    PubMed

    Vieira, Rafael Felipe da Costa; Vieira, Thállitha Samih Wischral Jayme; Nascimento, Denise do Amaral Gomes; Martins, Thiago F; Krawczak, Felipe S; Labruna, Marcelo B; Chandrashekar, Ramaswamy; Marcondes, Mary; Biondo, Alexander Welker; Vidotto, Odilon

    2013-01-01

    The aims of this study were to determine the seroprevalence of Ehrlichia spp. and risk factors for exposure in a restricted population of dogs, horses, and humans highly exposed to tick bites in a Brazilian rural settlement using a commercial ELISA rapid test and two indirect immunofluorescent assays (IFA) with E. canis and E. chaffeensis crude antigens. Serum samples from 132 dogs, 16 horses and 100 humans were used. Fifty-six out of 132 (42.4%) dogs were seropositive for E. canis. Dogs > one year were more likely to be seropositive for E. canis than dogs ≤ one year (p = 0.0051). Ten/16 (62.5%) and 8/16 (50%) horses were seropositive by the commercial ELISA and IFA, respectively. Five out of 100 (5%) humans were seropositive for E. canis and E. chaffeensis. Rhipicephalus sanguineus (n = 291, 97.98%) on dogs and Amblyomma cajennense (n = 25, 96.15%) on horses were the most common ticks found. In conclusion, anti-Ehrlichia spp. antibodies were found in horses; however, the lack of a molecular characterization precludes any conclusion regarding the agent involved. Additionally, the higher seroprevalence of E. canis in dogs and the evidence of anti-Ehrlichia spp. antibodies in humans suggest that human cases of ehrlichiosis in Brazil might be caused by E. canis, or other closely related species.

  5. SEROLOGICAL SURVEY OF Ehrlichia SPECIES IN DOGS, HORSES AND HUMANS: ZOONOTIC SCENERY IN A RURAL SETTLEMENT FROM SOUTHERN BRAZIL

    PubMed Central

    Vieira, Rafael Felipe da Costa; Vieira, Thállitha Samih Wischral Jayme; Nascimento, Denise do Amaral Gomes; Martins, Thiago F.; Krawczak, Felipe S.; Labruna, Marcelo B.; Chandrashekar, Ramaswamy; Marcondes, Mary; Biondo, Alexander Welker; Vidotto, Odilon

    2013-01-01

    SUMMARY The aims of this study were to determine the seroprevalence of Ehrlichia spp. and risk factors for exposure in a restricted population of dogs, horses, and humans highly exposed to tick bites in a Brazilian rural settlement using a commercial ELISA rapid test and two indirect immunofluorescent assays (IFA) with E. canis and E. chaffeensis crude antigens. Serum samples from 132 dogs, 16 horses and 100 humans were used. Fifty-six out of 132 (42.4%) dogs were seropositive for E. canis. Dogs > one year were more likely to be seropositive for E. canis than dogs ≤ one year (p = 0.0051). Ten/16 (62.5%) and 8/16 (50%) horses were seropositive by the commercial ELISA and IFA, respectively. Five out of 100 (5%) humans were seropositive for E. canis and E. chaffeensis. Rhipicephalus sanguineus (n = 291, 97.98%) on dogs and Amblyomma cajennense (n = 25, 96.15%) on horses were the most common ticks found. In conclusion, anti-Ehrlichia spp. antibodies were found in horses; however, the lack of a molecular characterization precludes any conclusion regarding the agent involved. Additionally, the higher seroprevalence of E. canis in dogs and the evidence of anti-Ehrlichia spp. antibodies in humans suggest that human cases of ehrlichiosis in Brazil might be caused by E. canis, or other closely related species. PMID:24037288

  6. Prevalence of antibodies against Ehrlichia spp. and Orientia tsutsugamushi in small mammals around harbors in Taiwan.

    PubMed

    Tsai, Kun-Hsien; Chang, Shu-Feng; Yen, Tsai-Ying; Shih, Wei-Liang; Chen, Wan-Jen; Wang, Hsi-Chieh; Yu, Xue-Jie; Wen, Tzai-Hung; Wu, Wen-Jer; Shu, Pei-Yun

    2016-01-27

    Tick-borne ehrlichiosis and mite-borne scrub typhus represent important emerging zoonotic rickettsial diseases. Although scrub typhus has been recognized by the Taiwanese public health system, information on ehrlichial infections is scarce in Taiwan. In this study, the risk of spread of ectoparasites on rodents through aerial and marine transportation was assessed in international and domestic harbors. Here, we report the first systematic surveillance of seroprevalence against Ehrlichia spp. in small mammals on the main island of Taiwan. In total, 1648 small mammals were trapped from 8 international ports, 18 domestic fishing harbors, and 7 local public health centers around Taiwan from November 2004 to December 2008. Sera were analyzed using indirect immunofluorescence assays to detect IgG antibodies against Ehrlichia chaffeensis and Orientia tsutsugamushi. A serum titer of ≧1:80 was considered positive. Antibodies against Ehrlichia spp. and O. tsutsugamushi were detected in 3.28% and 4.92% of small mammals active around harbors, respectively. The seropositive rate against Ehrlichia was higher in northern Taiwan from 2005 to 2008. However, O. tsutsugamushi infections increased in southern Taiwan during this period. The serological evidence of ehrlichial and O. tsutsugamushi infections in all international ports were included in the study. No significant differences were found among the seropositive rates of Ehrlichia spp. and O. tsutsugamushi in small mammals trapped between international and local harbors. The overall prevalence of Ehrlichia spp. and O. tsutsugamushi infections in small mammals active around harbors was 3.28% and 4.92%, respectively. The results provided serological evidence supporting the potential risks of transporting pathogens through air and maritime traffic. This study highlights serious issues of the emergence and spread of rickettsial diseases in Taiwan. The incidence of human ehrlichiosis requires further investigation.

  7. Cloning and Characterization of Multigenes Encoding the Immunodominant 30-Kilodalton Major Outer Membrane Proteins of Ehrlichia canis and Application of the Recombinant Protein for Serodiagnosis

    PubMed Central

    Ohashi, Norio; Unver, Ahmet; Zhi, Ning; Rikihisa, Yasuko

    1998-01-01

    A 30-kDa major outer membrane protein of Ehrlichia canis, the agent of canine ehrlichiosis, is the major antigen recognized by both naturally and experimentally infected dog sera. The protein cross-reacts with a serum against a recombinant 28-kDa protein (rP28), one of the outer membrane proteins of a gene (omp-1) family of Ehrlichia chaffeensis. Two DNA fragments of E. canis were amplified by PCR with two primer pairs based on the sequences of E. chaffeensis omp-1 genes, cloned, and sequenced. Each fragment contained a partial 30-kDa protein gene of E. canis. Genomic Southern blot analysis with the partial gene probes revealed the presence of multiple copies of these genes in the E. canis genome. Three copies of the entire gene (p30, p30-1, and p30a) were cloned and sequenced from the E. canis genomic DNA. The open reading frames of the two copies (p30 and p30-1) were tandemly arranged with an intergenic space. The three copies were similar but not identical and contained a semivariable region and three hypervariable regions in the protein molecules. The following genes homologous to three E. canis 30-kDa protein genes and the E. chaffeensis omp-1 family were identified in the closely related rickettsiae: wsp from Wolbachia sp., p44 from the agent of human granulocytic ehrlichiosis, msp-2 and msp-4 from Anaplasma marginale, and map-1 from Cowdria ruminantium. Phylogenetic analysis among the three E. canis 30-kDa proteins and the major surface proteins of the rickettsiae revealed that these proteins are divided into four clusters and the two E. canis 30-kDa proteins are closely related but that the third 30-kDa protein is not. The p30 gene was expressed as a fusion protein, and the antibody to the recombinant protein (rP30) was raised in a mouse. The antibody reacted with rP30 and a 30-kDa protein of purified E. canis. Twenty-nine indirect fluorescent antibody (IFA)-positive dog plasma specimens strongly recognized the rP30 of E. canis. To evaluate whether the rP30

  8. Ehrlichia secretes Etf-1 to induce autophagy and capture nutrients for its growth through RAB5 and class III phosphatidylinositol 3-kinase

    PubMed Central

    Lin, Mingqun; Liu, Hongyan; Xiong, Qingming; Niu, Hua; Cheng, Zhihui; Yamamoto, Akitsugu; Rikihisa, Yasuko

    2016-01-01

    Ehrlichia chaffeensis is an obligatory intracellular bacterium that causes a potentially fatal emerging zoonosis, human monocytic ehrlichiosis. E. chaffeensis has a limited capacity for biosynthesis and metabolism and thus depends mostly on host-synthesized nutrients for growth. Although the host cell cytoplasm is rich with these nutrients, as E. chaffeensis is confined within the early endosome-like membrane-bound compartment, only host nutrients that enter the compartment can be used by this bacterium. How this occurs is unknown. We found that ehrlichial replication depended on autophagy induction involving class III phosphatidylinositol 3-kinase (PtdIns3K) activity, BECN1 (Beclin 1), and ATG5 (autophagy-related 5). Ehrlichia acquired host cell preincorporated amino acids in a class III PtdIns3K-dependent manner and ehrlichial growth was enhanced by treatment with rapamycin, an autophagy inducer. Moreover, ATG5 and RAB5A/B/C were routed to ehrlichial inclusions. RAB5A/B/C siRNA knockdown, or overexpression of a RAB5-specific GTPase-activating protein or dominant-negative RAB5A inhibited ehrlichial infection, indicating the critical role of GTP-bound RAB5 during infection. Both native and ectopically expressed ehrlichial type IV secretion effector protein, Etf-1, bound RAB5 and the autophagy-initiating class III PtdIns3K complex, PIK3C3/VPS34, and BECN1, and homed to ehrlichial inclusions. Ectopically expressed Etf-1 activated class III PtdIns3K as in E. chaffeensis infection and induced autophagosome formation, cleared an aggregation-prone mutant huntingtin protein in a class III PtdIns3K-dependent manner, and enhanced ehrlichial proliferation. These data support the notion that E. chaffeensis secretes Etf-1 to induce autophagy to repurpose the host cytoplasm and capture nutrients for its growth through RAB5 and class III PtdIns3K, while avoiding autolysosomal killing. PMID:27541856

  9. Ehrlichia secretes Etf-1 to induce autophagy and capture nutrients for its growth through RAB5 and class III phosphatidylinositol 3-kinase.

    PubMed

    Lin, Mingqun; Liu, Hongyan; Xiong, Qingming; Niu, Hua; Cheng, Zhihui; Yamamoto, Akitsugu; Rikihisa, Yasuko

    2016-11-01

    Ehrlichia chaffeensis is an obligatory intracellular bacterium that causes a potentially fatal emerging zoonosis, human monocytic ehrlichiosis. E. chaffeensis has a limited capacity for biosynthesis and metabolism and thus depends mostly on host-synthesized nutrients for growth. Although the host cell cytoplasm is rich with these nutrients, as E. chaffeensis is confined within the early endosome-like membrane-bound compartment, only host nutrients that enter the compartment can be used by this bacterium. How this occurs is unknown. We found that ehrlichial replication depended on autophagy induction involving class III phosphatidylinositol 3-kinase (PtdIns3K) activity, BECN1 (Beclin 1), and ATG5 (autophagy-related 5). Ehrlichia acquired host cell preincorporated amino acids in a class III PtdIns3K-dependent manner and ehrlichial growth was enhanced by treatment with rapamycin, an autophagy inducer. Moreover, ATG5 and RAB5A/B/C were routed to ehrlichial inclusions. RAB5A/B/C siRNA knockdown, or overexpression of a RAB5-specific GTPase-activating protein or dominant-negative RAB5A inhibited ehrlichial infection, indicating the critical role of GTP-bound RAB5 during infection. Both native and ectopically expressed ehrlichial type IV secretion effector protein, Etf-1, bound RAB5 and the autophagy-initiating class III PtdIns3K complex, PIK3C3/VPS34, and BECN1, and homed to ehrlichial inclusions. Ectopically expressed Etf-1 activated class III PtdIns3K as in E. chaffeensis infection and induced autophagosome formation, cleared an aggregation-prone mutant huntingtin protein in a class III PtdIns3K-dependent manner, and enhanced ehrlichial proliferation. These data support the notion that E. chaffeensis secretes Etf-1 to induce autophagy to repurpose the host cytoplasm and capture nutrients for its growth through RAB5 and class III PtdIns3K, while avoiding autolysosomal killing.

  10. Energy Metabolism of Monocytic Ehrlichia

    DTIC Science & Technology

    1989-03-01

    Security Classification) Energy metabolism of monocytic Ehrlichia 12. PERSONAL AU1TOR(S) Weiss E, Williams JC, Dasch GA, Kang Y 13a. TYPE OF REPORT 13b...monocytic Ehrlichia (intracellular bacteria/animal pathogens/human pathogens) EMILIO WEISS*t, JIM C. WILLIAMSO§, GREGORY A. DASCH*, AND YUAN-HSU KANG...by Carl R. Woese, December 1, 1988 ABSTRACT We investigated if the monocytic Ehrlichia some ATP from the metabolism of glutamine. as is the case are

  11. Investigating the Adult Ixodid Tick Populations and Their Associated Anaplasma, Ehrlichia, and Rickettsia Bacteria at a Rocky Mountain Spotted Fever Hotspot in Western Tennessee.

    PubMed

    Trout Fryxell, Rebecca T; Hendricks, Brain M; Pompo, Kimberly; Mays, Sarah E; Paulsen, Dave J; Operario, Darwin J; Houston, Allan E

    2017-08-01

    Ehrlichiosis and rickettsiosis are two common bacterial tick-borne diseases in the southeastern United States. Ehrlichiosis is caused by ehrlichiae transmitted by Amblyomma americanum and rickettsiosis is caused by rickettsiae transmitted by Amblyomma maculatum and Dermacentor variabilis. These ticks are common and have overlapping distributions in the region. The objective of this study was to identify Anaplasma, Ehrlichia, and Rickettsia species associated with questing ticks in a Rocky Mountain spotted fever (RMSF) hotspot, and identify habitats, time periods, and collection methods for collecting questing-infected ticks. Using vegetation drags and CO2-baited traps, ticks were collected six times (May-September 2012) from 100 sites (upland deciduous, bottomland deciduous, grassland, and coniferous habitats) in western Tennessee. Adult collections were screened for Anaplasma and Ehrlichia (simultaneous polymerase chain reaction [PCR]) and Rickettsia using genus-specific PCRs, and resulting positive amplicons were sequenced. Anaplasma and Ehrlichia were only identified within A. americanum (Ehrlichia ewingii, Ehrlichia chaffeensis, Panola Mountain Ehrlichia, and Anaplasma odocoilei sp. nov.); more Ehrlichia-infected A. americanum were collected at the end of June regardless of habitat and collection method. Rickettsia was identified in three tick species; "Candidatus Rickettsia amblyommii" from A. americanum, R. parkeri and R. andeanae from A. maculatum, and R. montanensis ( = montana) from D. variabilis. Overall, significantly more Rickettsia-infected ticks were identified as A. americanum and A. maculatum compared to D. variabilis; more infected-ticks were collected from sites May-July and with dragging. In this study, we report in the Tennessee RMSF hotspot the following: (1) Anaplasma and Ehrlichia are only found in A. americanum, (2) each tick species has its own Rickettsia species, (3) a majority of questing-infected ticks are collected May-July, (4) A

  12. Survey of ticks collected in Mississippi for Rickettsia, Ehrlichia, and Borrelia species.

    PubMed

    Goddard, Jerome; Sumner, John W; Nicholson, William L; Paddock, Christopher D; Shen, John; Piesman, Joseph

    2003-12-01

    From November 1999 through October 2000, we tested ticks collected from vegetation as well as from deer, dogs, and humans for spotted fever group (SFG) rickettsiae, Ehrlichia chaffeensis, and Borrelia spp. spirochetes. A total of 149 adult ticks representing four species was collected from 11 collection sites from southwestern to northern Mississippi. Amblyomma americanum was most commonly collected (n=68), followed by Ixodes scapularis (n=53). The bird tick, Ixodes brunneus (usually rare), was the third most commonly collected tick (n=17). Eleven Dermacentor variabilis were also collected. Ticks were cut longitudinally to make smears on three microscope slides. The remaining body parts were frozen at -65 degrees C for additional testing. Tick smears were stained by direct immunofluorescence assays (DFA) for Rickettsia spp. and Borrelia spp., while indirect immunofluorescence assays (IFA) were used for Ehrlichia spp. The corresponding tick for each positive smear was evaluated using PCR analysis. None of the 149 ticks tested was DFA positive for Borrelia spp. However, smears of 30 (20%) and 32 (22%) ticks reacted with anti-E. chaffeensis sera and anti-R. rickettsii conjugate (known to react with several members of the spotted fever group), respectively. None of the ticks staining with the IFA for Ehrlichia was positive for E. chaffeensis using PCR. However, 23 (72%) of 32 FA-positive ticks for SFG rickettsiae yielded amplicons of the appropriate size when tested using a PCR assay for SFG rickettsiae, corresponding to an overall infection rate with SFG rickettsiae among the collected ticks of 15%. Smears of 12 (71%) of 17 I. brunneus revealed abundant bacilliform bacteria. PCR amplification of DNA from a single I. brunneus containing these bacteria was performed using universal primers for the 16S rRNA gene as well as Borrelia-specific primers. The predominant sequence obtained using the universal primers did not match any sequence in GenBank, but it showed 91

  13. Molecular survey of Anaplasma and Ehrlichia infections of feral raccoons (Procyon lotor) in Hokkaido, Japan.

    PubMed

    Sashika, Mariko; Abe, Go; Matsumoto, Kotaro; Inokuma, Hisashi

    2011-04-01

    Infection by Anaplasma and Ehrlichia in feral raccoons (Procyon lotor) in Hokkaido, Japan, was examined by molecular methods. A polymerase chain reaction (PCR) screen for Anaplasmataceae, based on 16S rRNA, showed that 38 (5.4%) of 699 raccoons examined were positive. These 38 positive samples were examined for Anaplasma phagocytophilum, Anaplasma bovis, Ehrlichia chaffeensis, and Ehrlichia canis infection by species-specific nested PCR. Nested PCR results indicated that 36 of the 38 samples were positive for A. bovis. All 38 samples were PCR negative for A. phagocytophilum, E. chaffeensis, and E. canis. This is the first report of the detection of A. bovis in the peripheral blood of raccoons. A total of 124 raccoons were infested with ticks, including Ixodes ovatus, Ixodes persulcatus, and Haemaphysalis spp. The rate of A. bovis infection in raccoons infested with Haemaphysalis spp. (46.7%, 7/15) was significantly higher than that in raccoons without Haemaphysalis spp. infestation (3.7%, 4/109, p < 0.001). No significant differences were observed in A. bovis infection rates between raccoons infested with I. ovatus or I. persulcatus and those not so infested. A total of four ticks (two males and two nymphs) and one larval pools from four raccoons showed positive for A. bovis-specific nested PCR. This results support the correlation between the A. bovis infection of raccoons and Haemaphysalis infestation. In conclusion, raccoons could be possible reservoir animals for A. bovis, and A. bovis infection in raccoons may be related to infestation with Haemaphysalis spp.

  14. Detection of Ehrlichia spp., Anaplasma spp., Rickettsia spp., and other eubacteria in ticks from the Thai-Myanmar border and Vietnam.

    PubMed

    Parola, Philippe; Cornet, Jean-Paul; Sanogo, Yibayiri Osée; Miller, R Scott; Thien, Huynh Van; Gonzalez, Jean-Paul; Raoult, Didier; Telford III, Sam R; Wongsrichanalai, Chansuda

    2003-04-01

    A total of 650 ticks, including 13 species from five genera, were collected from animals, from people, or by flagging of the vegetation at sites on the Thai-Myanmar border and in Vietnam. They were tested by PCR to detect DNA of bacteria of the order RICKETTSIALES: Three Anaplasma spp. were detected in ticks collected in Thailand, including (i) Anaplasma sp. strain AnDa465, which was considered a genotype of Anaplasma platys (formerly Ehrlichia platys) and which was obtained from Dermacentor auratus ticks collected from dogs; (ii) Anaplasma sp. strain AnAj360, which was obtained from Amblyomma javanense ticks collected on a pangolin; and (iii) Anaplasma sp. strain AnHl446, which was closely related to Anaplasma bovis and which was detected in Haemaphysalis lagrangei ticks collected from a bear. Three Ehrlichia spp. were identified, including (i) Ehrlichia sp. strain EBm52, which was obtained from Boophilus microplus ticks collected from cattle from Thailand; (ii) Ehrlichia sp. strain EHh324, which was closely related to Ehrlichia chaffeensis and which was detected in Haemaphysalis hystricis ticks collected from wild pigs in Vietnam; and (iii) Ehrlichia sp. strain EHh317, which was closely related to Ehrlichia sp. strain EBm52 and which was also detected in H. hystricis ticks collected from wild pigs in Vietnam. Two Rickettsia spp. were detected in Thailand, including (i) Rickettsia sp. strain RDla420, which was detected in Dermacentor auratus ticks collected from a bear, and (ii) Rickettsia sp. strain RDla440, which was identified from two pools of Dermacentor larvae collected from a wild pig nest. Finally, two bacteria named Eubacterium sp. strain Hw124 and Eubacterium sp. strain Hw191 were identified in Haemaphysalis wellingtoni ticks collected from chicken in Thailand; these strains could belong to a new group of bacteria.

  15. [Ehrlichia infection in a child: clinical findings and review of the literature].

    PubMed

    Halac, Eduardo

    2016-06-01

    A 12 year old child was brought in by his parents due to persistent fever of 3 weeks duration, sore throat, malaise, chills, small joint arthralgia, myalgias, and a pink macular rash. The first clinical impression of the physicians was infectious mononucleosis but serologic testing ruled out the diagnosis. He was then treated with oral ampicillin without a favorable response. He was referred to us for a second evaluation. A detailed clinical history revealed that he had a few days of vacation in a rural area in the northern region of the province of Cordoba, in close contact with horses, dogs and cats. His parents found 2 ticks on his abdomen, and removed them with tweezers. Serology and blood count carried out in a specialized laboratory showed positive titers (> 160) for Ehrlichia chaffeensis. Further confirmation was obtained using genus-specific polymerase chain reaction. After a 3-week course of doxycicline the patient recovered and serological titers decreased.

  16. Expanded Geographic Distribution and Clinical Characteristics of Ehrlichia ewingii Infections, United States.

    PubMed

    Harris, Rebecca M; Couturier, Brianne A; Sample, Stephan C; Coulter, Katrina S; Casey, Kathleen K; Schlaberg, Robert

    2016-05-01

    Ehrlichiosis is a bacterial zoonosis, spread through the bites of infected ticks, that is most commonly caused in the United States by infection with the bacterium Ehrlichia chaffeensis. We retrospectively reviewed samples from an 18-month study of ehrlichiosis in the United States and found that E. ewingii was present in 10 (9.2%) of 109 case-patients with ehrlichiosis, a higher rate of infection with this species than had previously been reported. Two patients resided in New Jersey and Indiana, where cases have not been reported. All patients with available case histories recovered. Our study suggests a higher prevalence and wider geographic distribution of E. ewingii in the United States than previous reports have indicated.

  17. Expanded Geographic Distribution and Clinical Characteristics of Ehrlichia ewingii Infections, United States

    PubMed Central

    Harris, Rebecca M.; Couturier, Brianne A.; Sample, Stephan C.; Coulter, Katrina S.; Casey, Kathleen K.

    2016-01-01

    Ehrlichiosis is a bacterial zoonosis, spread through the bites of infected ticks, that is most commonly caused in the United States by infection with the bacterium Ehrlichia chaffeensis. We retrospectively reviewed samples from an 18-month study of ehrlichiosis in the United States and found that E. ewingii was present in 10 (9.2%) of 109 case-patients with ehrlichiosis, a higher rate of infection with this species than had previously been reported. Two patients resided in New Jersey and Indiana, where cases have not been reported. All patients with available case histories recovered. Our study suggests a higher prevalence and wider geographic distribution of E. ewingii in the United States than previous reports have indicated. PMID:27089171

  18. Ehrlichia Meningitis Mimicking Aneurysmal Subarachnoid Hemorrhage: A Case Study for Medical Decision-Making Heuristics.

    PubMed

    Dredla, Brynn; Freeman, William D

    2016-04-01

    Thunderclap headache is a sudden and severe headache that can occur after an aneurysmal subarachnoid hemorrhage (SAH). Subarachnoid hemorrhage is a medical emergency that requires prompt attention and hospitalization. Patients with thunderclap headache often undergo a noncontrast head computed tomography (CT) scan to ascertain SAH bleeding and, if the scan is negative, then undergo a lumbar puncture to look for cerebrospinal fluid (CSF) red blood cells (RBCs), which would be consistent with an aneurysmal leak. If the initial CT is negative and CSF is positive for RBCs, patients are usually admitted to the hospital for evaluation of intracranial aneurysm. We encountered a patient with thunderclap headache whose initial head CT was negative for SAH and whose CSF tested positive for RBCs. The patient was referred to our center for evaluation and management of aneurysmal SAH. However, on careful review of the patient's medical history, serum laboratory values, and spinal fluid values, the patient was diagnosed with Ehrlichia chaffeensis meningitis. While Ehrlichia meningitis is rare, it is important to recognize the clinical clues that could help avoid formal cerebral angiography, a costly and potentially unnecessary procedure. We present how this case represented a cognitive framing bias and anchoring heuristic as well as steps that medical providers can use to prevent such cognitive errors in diagnosis.

  19. Genetic diversity of Ehrlichia canis in Brazil.

    PubMed

    Aguiar, D M; Zhang, X; Melo, A L T; Pacheco, T A; Meneses, A M C; Zanutto, M S; Horta, M C; Santarém, V A; Camargo, L M A; McBride, J W; Labruna, M B

    2013-06-28

    Canine monocytic ehrlichiosis is a highly prevalent disease in Brazil, where the genetic diversity of Ehrlichia canis remains undefined. In this study, we used the TRP36 gene to examine the genetic diversity of E. canis strains from naturally infected dogs residing in five distinct geographic regions in Brazil. E. canis DNA was detected in 82/126 (65%) dogs by dsb-specific PCR and E. canis was isolated in cell culture from 13 dogs. Sequences obtained from dsb genes amplified from the isolates were identical to the US E. canis strain. An extended molecular characterization based on the TRP36 gene identified two major genogroups based on differences among eight isolates. Isolates with tandem repeat amino acid sequence (TEDSVSAPA) identical to the previously reported TRP36 sequence were found in the midwest, northeast and southeast regions of Brazil, and classified into the US genogroup. A novel Brazilian genotype with a different tandem repeat sequence (ASVVPEAE) was also identified in midwest, northern and southern regions. Similarity in the N-terminal sequence of a US genogroup member with the Brazilian genogroup suggested that genomic recombination between the two genogroups may have occurred. Other subtypes within the Brazilian genogroup were also identified using C-terminal amino acid divergence. We identified two distinct major Brazilian genogroups and several subtypes based on analysis of TRP36, and such information will be useful for further genotyping and possible associations with disease severity, understanding of the genetic and antigenic variability of E. canis, and for developing strain-specific vaccines and diagnostic methods based on TRP36.

  20. Ehrlichia and spotted fever group Rickettsiae surveillance in Amblyomma americanum in Virginia through use of a novel six-plex real-time PCR assay.

    PubMed

    Gaines, David N; Operario, Darwin J; Stroup, Suzanne; Stromdahl, Ellen; Wright, Chelsea; Gaff, Holly; Broyhill, James; Smith, Joshua; Norris, Douglas E; Henning, Tyler; Lucas, Agape; Houpt, Eric

    2014-05-01

    The population of the lone star tick Amblyomma americanum has expanded in North America over the last several decades. It is known to be an aggressive and nondiscriminatory biter and is by far the most common human-biting tick encountered in Virginia. Few studies of human pathogen prevalence in ticks have been conducted in our state since the mid-twentieth century. We developed a six-plex real-time PCR assay to detect three Ehrlichia species (E. chaffeensis, E. ewingii, and Panola Mountain Ehrlichia) and three spotted fever group Rickettsiae (SFGR; R. amblyommii, R. parkeri, and R. rickettsii) and used it to test A. americanum from around the state. Our studies revealed a presence of all three Ehrlichia species (0-24.5%) and a high prevalence (50-80%) of R. amblyommii, a presumptively nonpathogenic SFGR, in all regions surveyed. R. parkeri, previously only detected in Virginia's Amblyomma maculatum ticks, was found in A. americanum in several surveyed areas within two regions having established A. maculatum populations. R. rickettsii was not found in any sample tested. Our study provides the first state-wide screening of A. americanum ticks in recent history and indicates that human exposure to R. amblyommii and to Ehrlichiae may be common. The high prevalence of R. amblyommii, serological cross-reactivity of all SFGR members, and the apparent rarity of R. rickettsii in human biting ticks across the eastern United States suggest that clinical cases of tick-borne disease, including ehrlichiosis, may be commonly misdiagnosed as Rocky Mountain spotted fever, and that suspicion of other SFGR as well as Ehrlichia should be increased. These data may be of relevance to other regions where A. americanum is prevalent.

  1. Ehrlichia and Spotted Fever Group Rickettsiae Surveillance in Amblyomma americanum in Virginia Through Use of a Novel Six-Plex Real-Time PCR Assay

    PubMed Central

    Operario, Darwin J.; Stroup, Suzanne; Stromdahl, Ellen; Wright, Chelsea; Gaff, Holly; Broyhill, James; Smith, Joshua; Norris, Douglas E.; Henning, Tyler; Lucas, Agape; Houpt, Eric

    2014-01-01

    Abstract The population of the lone star tick Amblyomma americanum has expanded in North America over the last several decades. It is known to be an aggressive and nondiscriminatory biter and is by far the most common human-biting tick encountered in Virginia. Few studies of human pathogen prevalence in ticks have been conducted in our state since the mid-twentieth century. We developed a six-plex real-time PCR assay to detect three Ehrlichia species (E. chaffeensis, E. ewingii, and Panola Mountain Ehrlichia) and three spotted fever group Rickettsiae (SFGR; R. amblyommii, R. parkeri, and R. rickettsii) and used it to test A. americanum from around the state. Our studies revealed a presence of all three Ehrlichia species (0–24.5%) and a high prevalence (50–80%) of R. amblyommii, a presumptively nonpathogenic SFGR, in all regions surveyed. R. parkeri, previously only detected in Virginia's Amblyomma maculatum ticks, was found in A. americanum in several surveyed areas within two regions having established A. maculatum populations. R. rickettsii was not found in any sample tested. Our study provides the first state-wide screening of A. americanum ticks in recent history and indicates that human exposure to R. amblyommii and to Ehrlichiae may be common. The high prevalence of R. amblyommii, serological cross-reactivity of all SFGR members, and the apparent rarity of R. rickettsii in human biting ticks across the eastern United States suggest that clinical cases of tick-borne disease, including ehrlichiosis, may be commonly misdiagnosed as Rocky Mountain spotted fever, and that suspicion of other SFGR as well as Ehrlichia should be increased. These data may be of relevance to other regions where A. americanum is prevalent. PMID:24746145

  2. Divergence of the TRP36 protein (gp36) in Ehrlichia canis strains found in Brazil.

    PubMed

    Aguiar, Daniel M; Melo, Andreia L T

    2015-03-01

    The molecular characterization of 16S rRNA gene and immunoreactive proteins of Ehrlichia canis usually provide little information about the overall diversity of this organism. On the other hand, distinct sequences of the Tandem Repeat Protein 36 (TRP36/gp36) gene of E. canis have been reported, indicating substantial degree of diversity. The present letter aims to update and discuss the molecular divergence of the TRP36 protein between strains of E. canis isolated in different countries including Brazil.

  3. Molecular-genetic and ultrastructural characteristics of 'Candidatus Ehrlichia khabarensis', a new member of the Ehrlichia genus.

    PubMed

    Rar, V A; Pukhovskaya, N M; Ryabchikova, E I; Vysochina, N P; Bakhmetyeva, S V; Zdanovskaia, N I; Ivanov, L I; Tikunova, N V

    2015-07-01

    Recently, a new Ehrlichia genetic variant, Ehrlichia sp. Khabarovsk, was identified in tissue samples of small mammals captured in the Russian Far East. To further characterize Ehrlichia sp. Khabarovsk, tissue homogenate from a naturally infected gray red-backed vole (Myodes rufocanus) was passaged three times in newborn laboratory mice. Using nested PCR Ehrlichia sp. Khabarovsk DNA was detected in tissue samples from infected mice at 1-4 weeks post inoculation. Electron microscopic examination revealed morulae containing gram-negative bacterial cells in monocytes of mouse spleen and liver. The size and ultrastructure of these cells corresponded to those described previously and allowed us to identify the bacteria as Ehrlichia sp. The comparison of ehrlichial 16S rRNA, groEL and gltA genes and putative GroEL and GltA amino acid sequences has demonstrated that Ehrlichia sp. Khabarovsk, like Ehrlichia ruminantium, is more distant from all other Ehrlichia species than these species are between themselves. Phylogenetic analysis has shown that Ehrlichia sp. Khabarovsk belongs to the clade formed by Ehrlichia spp. but clusters separately from other Ehrlichia species and genetic variants. These data indicate that Ehrlichia sp. Khabarovsk can be considered as a new candidate species. We propose to designate it as 'Candidatus Ehrlichia khabarensis' according to the territory where this species was found. Copyright © 2015 Elsevier GmbH. All rights reserved.

  4. Hemocytic rickettsia-like organisms in ticks: serologic reactivity with antisera to Ehrlichiae and detection of DNA of agent of human granulocytic ehrlichiosis by PCR.

    PubMed Central

    Magnarelli, L A; Stafford, K C; Mather, T N; Yeh, M T; Horn, K D; Dumler, J S

    1995-01-01

    Ixodid ticks were collected from Connecticut, Massachusetts, Missouri, Pennsylvania, Rhode Island, and British Columbia (Canada) during 1991 to 1994 to determine the prevalence of infection with hemocytic (blood cell), rickettsia-like organisms. Hemolymph obtained from these ticks was analyzed by direct and indirect fluorescent antibody (FA) staining methods with dog, horse, or human sera containing antibodies to Ehrlichia canis, Ehrlichia equi, or Rickettsia rickettsii. Of the 693 nymphal and adult Amblyomma americanum, Dermacentor variabilis, Ixodes scapularis, and Ixodes pacificus ticks tested with dog anti-E. canis antiserum, 209 (32.5%) contained hemocytic bacteria. The prevalence of infected ticks varied greatly with species and locale. In parallel tests of duplicate hemolymph preparations from adult I. scapularis ticks, the hemocytic organisms reacted positively with E. canis and/or E. equi antisera, including sera from persons who had granulocytic ehrlichiosis. In separate PCR analyses, DNA of the agent of human granulocytic ehrlichiosis was detected in 59 (50.0%) of 118 adult and in 1 of 2 nymphal I. scapularis ticks tested from Connecticut. There was no evidence of Ehrlichia chaffeensis DNA in these ticks. In indirect FA tests of hemolymph for spotted fever group rickettsiae, the overall prevalence of infection was less than 4%. Specificity tests of antigens and antisera used in these studies revealed no cross-reactivity between E. canis and E. equi or between any of the ehrlichial reagents and those of R. rickettsii. The geographic distribution of hemocytic microorganisms with shared antigens to Ehrlichia species or spotted fever group rickettsiae is widespread. PMID:8567911

  5. Heartwater--Ehrlichia ruminantium infection.

    PubMed

    Allsopp, B A

    2015-08-01

    Summary Heartwater is a notifiable disease that is listed by the World Organisation for Animal Health. It is caused by Ehrlichia ruminantium, an obligately intracellular Gram-negative bacterium in the order Rickettsiales and the family Anaplasmataceae. The disease is borne byticks in the genus Amblyomma and causes heartwater, or cowdriosis, in wild and domestic ruminants, primarily in Africa, but also in parts of the Caribbean. The disease was recognised in South Africa in the 19th Century and determined to be tick borne in 1900, while the organism was identified in 1925 and first cultured in vitro in 1985. This latter achievement boosted research into the disease at a time when biology was moving into the molecular genetic age. Over the last 20 years, there have been significant improvements in our understanding of E. ruminantium, yielding major advances in diagnosis, epidemiology, genetic characterisation, phylogeny, immunology, and vaccine development. The organism is genetically highly variable; this has important implications for future control measures, and is making it difficult to develop an effective vaccine for protection against tick challenge. Research is continuing into three different types of vaccine, inactivated, attenuated, and recombinant, and the current state of development of each is discussed.

  6. PCR Amplification and Phylogenetic Analysis of groESL Operon Sequences from Ehrlichia ewingii and Ehrlichia muris

    PubMed Central

    Sumner, John W.; Storch, Gregory A.; Buller, Richard S.; Liddell, Allison M.; Stockham, Steven L.; Rikihisa, Yasuko; Messenger, Sharon; Paddock, Christopher D.

    2000-01-01

    Broad-range PCR primers were used to amplify part of the groESL operon of the canine pathogen Ehrlichia ewingii, recently recognized as a human pathogen, and the murine pathogen Ehrlichia muris. Phylogenetic analysis supported the relationships among Ehrlichia species previously determined by comparison of 16S rRNA gene sequences. These sequences provide additional PCR targets for species for which few gene sequences have been determined. PMID:10878077

  7. The spreading process of Ehrlichia canis in macrophages is dependent on actin cytoskeleton, calcium and iron influx and lysosomal evasion.

    PubMed

    Alves, R N; Levenhagen, M A; Levenhagen, M M M D; Rieck, S E; Labruna, M B; Beletti, M E

    2014-01-31

    Ehrlichia canis is an obligate intracellular microorganism and the etiologic agent of canine monocytic ehrlichiosis. The invasion process has already been described for some bacteria in this genus, such as E. muris and E. chaffeensis, and consists of four stages: adhesion, internalisation, intracellular proliferation and intercellular spreading. However, little is known about the spreading process of E. canis. The aim of this study was to analyse the role of the actin cytoskeleton, calcium, iron and lysosomes from the host cell in the spreading of E. canis in dog macrophages in vitro. Different inhibitory drugs were used: cytochalasin D (actin polymerisation inhibitor), verapamil (calcium channel blocker) and deferoxamine (iron chelator). Our results showed a decrease in the number of bacteria in infected cells treated with all drugs when compared to controls. Lysosomes in infected cells were cytochemically labelled with acid phosphatase to allow the visualisation of phagosome-lysosome fusion and were further analysed by transmission electron microscopy. Phagosome-lysosome fusion was rarely observed in vacuoles containing viable E. canis. These data suggest that the spreading process of E. canis in vitro is dependent on cellular components analysed and lysosomal evasion.

  8. Two USA Ehrlichia spp. cause febrile illness in goats.

    PubMed

    Loftis, Amanda D; Levin, Michael L; Spurlock, J Paul

    2008-08-25

    Ehrlichia spp. are not currently recognized as a cause of illness in goats in the USA, but three Ehrlichia are enzootic in lone star ticks (Amblyomma americanum) in the eastern USA, and related bacteria in other countries cause illness in goats. We exposed naïve goats to Ehrlichia-infected Amblyomma and demonstrated that infection and clinical illness can be caused by two USA species, E. ewingii and the recently discovered Panola Mountain Ehrlichia sp. Clinical features in all five goats are described; ehrlichioses were associated with pyrexia, serous nasal discharge, inappetance, lethargy, decreased alkaline phosphatase, and, in most cases, neutropenia. Goats remained chronically infected for several months following exposure to ehrlichiae and transmitted the pathogens to uninfected ticks. In the eastern USA, undifferentiated febrile illness in goats might be caused by previously unrecognized ehrlichial infections, and pastures housing-infected goats could become infested with a large number of infected ticks.

  9. Ehrlichia minasensis sp. nov., a new species within the genus Ehrlichia isolated from the tick Rhipicephalus microplus.

    PubMed

    Cabezas-Cruz, Alejandro; Zweygarth, Erich; Vancová, Marie; Broniszewska, Marzena; Grubhoffer, Libor; Passos, Lygia Maria Friche; Ribeiro, Múcio Flávio Barbosa; Alberdi, Pilar; de la Fuente, José

    2016-01-12

    Recently, we obtained a rickettsial isolate (Ehrlichia sp. UFMG-EV) from the hemolymph of Rhipicephalus microplus engorged tick females. On the basis of maximum likelihood phylogenetic analysis using 16S rRNA, groEL, dsb, gltA and trp36 nucleotide sequences we showed that Ehrlichia sp. UFMG-EV belongs to the α-Proteobacteria, family Anaplasmataceae, genus Ehrlichia. Ehrlichia sp. UFMG-EV is a sister taxa of E. canis with 16S rRNA, groEL, dsb, gltA and trp36 nucleotide sequence similarity of 98.3%, 97.2%, 94.7%, 94.3% and 49.1%, respectively. Ehrlichia sp. UFMG-EV has been maintained in the laboratory by continuous passage in the IDE8 tick cell line where the ultrastructure was characterized using electron microscopy and it resembles that of E. canis, E. muris and E. chaffensis, but not E. ruminantium and E. ewingii. We propose the name Ehrlichia minasensis sp. nov. for this bacterium to acknowledge the place from where it was isolate for first time, Minas Gerais, Brazil. The type strain of Ehrlichia minasensis sp. nov. is strain Ehrlichia sp. UFMG-EV (= DSM 100393, = TCB-TBB-0018).

  10. A novel Ehrlichia genotype strain distinguished by the TRP36 gene naturally infects cattle in Brazil and causes clinical manifestations associated with ehrlichiosis.

    PubMed

    Aguiar, Daniel M; Ziliani, Thayza F; Zhang, Xiaofeng; Melo, Andreia L T; Braga, Isis A; Witter, Rute; Freitas, Leodil C; Rondelli, André L H; Luis, Michele A; Sorte, Eveline C B; Jaune, Felipe W; Santarém, Vamilton A; Horta, Mauricio C; Pescador, Carolina A; Colodel, Edson M; Soares, Herbert S; Pacheco, Richard C; Onuma, Selma S M; Labruna, Marcelo B; McBride, Jere W

    2014-09-01

    A novel Ehrlichia genotype most closely related to E. canis was reported in North American cattle in 2010, and a similar agent was subsequently identified in the hemolymph of Brazilian Rhipicephalus (Boophilus) microplus ticks and isolated in 2012. The purpose of this study was to determine whether this or other novel ehrlichial agents naturally infect Brazilian cattle. Using PCR targeting the genus-conserved dsb gene, DNA from this novel ehrlichial agent in Brazilian cattle was detected. Attempts to isolate the organism in vitro were performed using DH82 cells, but morulae and ehrlichial DNA could only be detected for approximately one month. In order to further molecularly characterize the organism, PCR was performed using primers specific for multiple E. canis genes (dsb, rrs, and trp36). Sequence obtained from the conserved rrs and dsb genes demonstrated that the organism was 99-100% identical to the novel Ehrlichia genotypes previously reported in North American cattle (rrs gene) and Brazilian ticks (rrs and dsb genes). However, analysis of the trp36 gene revealed substantial strain diversity between these Ehrlichia genotypes strains, including divergent tandem repeat sequences. In order to obtain preliminary information on the potential pathogenicity of this ehrlichial agent and clinical course of infection, a calf was experimentally infected. The calf showed clinical signs of ehrlichiosis, including fever, depression, lethargy, thrombocytopenia, and morulae were observed in peripheral blood monocytes. This study reports a previously unrecognized disease-causing Ehrlichia sp. in Brazilian cattle that is consistent with the genotype previously described in North America cattle and ticks from Brazil. Hence, it is likely that this is the organism previously identified as Ehrlichia bovis in Brazil in 1982. Furthermore, we have concluded that strains of these Ehrlichia genotypes can be molecularly distinguished by the trp36 gene, which has been widely utilized to

  11. Enzyme-Linked Immunosorbent Assay with Conserved Immunoreactive Glycoproteins gp36 and gp19 Has Enhanced Sensitivity and Provides Species-Specific Immunodiagnosis of Ehrlichia canis Infection▿

    PubMed Central

    Cárdenas, Ana Maria; Doyle, C. Kuyler; Zhang, Xiaofeng; Nethery, Kimberly; Corstvet, Richard E.; Walker, David H.; McBride, Jere W.

    2007-01-01

    Ehrlichia canis is the primary etiologic agent of canine monocytic ehrlichiosis, a globally distributed and potentially fatal disease of dogs. We previously reported on the identification of two conserved major immunoreactive antigens, gp36 and gp19, which are the first proteins to elicit an E. canis-specific antibody response, and gp200 and p28, which elicit strong antibody responses later in the acute phase of the infection. In this report, the sensitivities and specificities of five recombinant E. canis proteins for the immunodiagnosis of E. canis infection by an enzyme-linked immunosorbent assay (ELISA) were evaluated. Recombinant polypeptides gp36, gp19, and gp200 (N and C termini) exhibited 100% sensitivity and specificity for immunodiagnosis by the recombinant glycoprotein ELISA compared with the results obtained by an indirect fluorescent-antibody assay (IFA) for the detection of antibodies in dogs that were naturally infected with E. canis. Moreover, the enhanced sensitivities of gp36 and gp19 for immunodiagnosis by the recombinant glycoprotein ELISA compared to those obtained by IFA were demonstrated with dogs experimentally infected with E. canis, in which antibodies were detected as much as 2 weeks earlier, on day 14 postinoculation. gp36 and gp19 were not cross-reactive with antibodies in sera from E. chaffeensis-infected dogs and thus provided species-specific serologic discrimination between E. canis and E. chaffeensis infections. This is the first demonstration of the improved detection capability of the recombinant protein technology compared to the capability of the “gold standard” IFA and may eliminate the remaining obstacles associated with the immunodiagnosis of E. canis infections, including species-specific identification and the lack of sensitivity associated with low antibody titers early in the acute phase of the infection. PMID:17151186

  12. TpE: PANOLA MOUNTAIN EHRLICHIA: A NOVEL TICK-TRANSMITTED PATHOGEN IN THE USA CLOSELY RELATED TO EHRLICHIA RUMINANTIUM, CAUSAL AGENT OF HEARTWATER DISEASE IN RUMINANTS

    USDA-ARS?s Scientific Manuscript database

    Ehrlichia ruminantium, the economically most important pathogen in the genus Ehrlichia, is enzootic in sub-Saharan Africa and occurs on islands in the Caribbean. The pathogen causes heartwater disease in ruminants and might also cause illness in humans. We recently found a novel Ehrlichia, genetical...

  13. Novel genotype of Ehrlichia canis detected in samples of human blood bank donors in Costa Rica.

    PubMed

    Bouza-Mora, Laura; Dolz, Gaby; Solórzano-Morales, Antony; Romero-Zuñiga, Juan José; Salazar-Sánchez, Lizbeth; Labruna, Marcelo B; Aguiar, Daniel M

    2017-01-01

    This study focuses on the detection and identification of DNA and antibodies to Ehrlichia spp. in samples of blood bank donors in Costa Rica using molecular and serological techniques. Presence of Ehrlichia canis was determined in 10 (3.6%) out of 280 blood samples using polymerase chain reaction (PCR) targeting the ehrlichial dsb conserved gene. Analysis of the ehrlichial trp36 polymorphic gene in these 10 samples revealed substantial polymorphism among the E. canis genotypes, including divergent tandem repeat sequences. Nucleotide sequences of dsb and trp36 amplicons revealed a novel genotype of E. canis in blood bank donors from Costa Rica. Indirect immunofluorescence assay (IFA) detected antibodies in 35 (35%) of 100 serum samples evaluated. Thirty samples showed low endpoint titers (64-256) to E. canis, whereas five sera yielded high endpoint titers (1024-8192); these five samples were also E. canis-PCR positive. These findings represent the first report of the presence of E. canis in humans in Central America. Copyright © 2016 Elsevier GmbH. All rights reserved.

  14. Retrospective clinical and molecular analysis of conditioned laboratory dogs (Canis familiaris) with serologic reactions to Ehrlichia canis, Borrelia burgdorferi, and Rickettsia rickettsii.

    PubMed

    Scorpio, Diana G; Wachtman, Lynn M; Tunin, Richard S; Barat, Nicole C; Garyu, Justin W; Dumler, J Stephen

    2008-09-01

    Dogs are susceptible to different tickborne infections, including members of the Anaplasmataceae (Ehrlichia canis, E. ewingii, E. chaffeensis, Anaplasma phagocytophilum, A. platys), Borrelia burgdorferi, and Rickettsia rickettsii. These diseases can manifest with clinical signs including fever, anorexia, malaise, lameness, rash, and bleeding episodes; however, these signs are nonpathognomonic, and infections can occur in the absence of clinical signs. Hematologic abnormalities can include leukopenia, thrombocytopenia, hyperproteinemia and hypergammaglobulinemia. In biomedical research, diseases such as canine monocytic ehrlichiosis, Lyme disease, and Rocky Mountain spotted fever may cause morbidity among exposed dogs and confound research results. Random-source dogs are susceptible to these diseases because of their increased risk of arthropod exposure. Nonpurpose bred, randomly selected conditioned dogs (n = 21) were examined; blood samples were taken for hematology, biochemistry analysis, tickborne pathogen serology, and PCR. Of these, 2 dogs (10% of the population) presented with illness characterized by fever, malaise, lameness, or hemostatic abnormalities, and 15 (71%) had antibodies to one or more tickborne pathogens. No specific hematologic or biochemical differences were apparent between seronegative dogs and seropositive dogs reactive to all 3 pathogens. E. canis and B. burgdorferi PCR of tissues and blood were negative for all dogs. PCR amplification of several Ehrlichia and Anaplasma genes yielded no positive samples. From this cohort of dogs, serologic and molecular results indicate prior exposure without active infection or clinical disease. Exposure to and potential for infection with these bacteria and other pathogens may contribute to blood and tissue alterations that could confound experiments and lead to misinterpretation of data in canine models.

  15. Phylogenetic relationships among Ehrlichia ruminantium isolates.

    PubMed

    Allsopp, M T E P; Van Heerden, H; Steyn, H C; Allsopp, B A

    2003-06-01

    Ehrlichia ruminantium, the causative agent of heartwater, is a tick-borne pathogen infecting ruminants throughout sub-Saharan Africa and on some Caribbean islands. The most reliable test for E. ruminantium is PCR-based, but this gives positive results in some areas free of clinical heartwater and of the known Amblyomma spp. tick vectors. To investigate the molecular basis for this finding we have sequenced and carried out phylogenetic analysis of a range of genes from a number of E. ruminantium isolates. The genes include ribonuclease III and cytochrome c oxidase assembly protein genes (the pCS20 region), groESL, citrate synthase (gltA), and 16S ribosomal RNA. Relationships among major antigenic protein (map1) genes have been exhaustively investigated in a previous study that showed that the genes are variable in length, have non-synonymous mutations, and show no geographical specificity among isolates. The 16S sequences are highly conserved, except in the V1 loop region. The pCS20, groESL, and gltA genes show only single nucleotide polymorphisms (SNPs) dispersed throughout the sequenced regions. Phylogenetic analysis using pCS20 data differentiates the western African isolates into a single clade, which also includes a southern African isolate. All other southern African isolates and a Caribbean isolate fall into a further clade, which is subdivided into two groups. Sequence variation within this clade is greater than that within the western African clade, suggesting that E. ruminantium originated in southern Africa.

  16. [Factors associated with Ehrlichia canis infection in dogs infested with ticks from Huanuco, Peru].

    PubMed

    Huerto-Medina, Edward; Dámaso-Mata, Bernardo

    2015-10-01

    The aim of the study was to determine the frequency and associated factors of Ehrlichia canis infection in dogs. Blood samples from 150 dogs infested with ticks in 10 veterinary clinics in the city of Huanuco in Peru were collected. The dogs were randomly selected without regard to breed, age or sex. Ehrlichia canis antibodies were detected by chromatographic immunoassay.51.3% of dogs were infected with Ehrlichia canis. In the multivariate analysis, factors associated with the presence of Ehrlichia canis were: poor health of the dog (p = 0.049), a higher average of tick infestation (p = 0.018), and adult dogs (p = 0.038). The frequency of Ehrlichia canis in dogs of this city is high. Control of the brown dog tick (Rhipicephalus sanguineus) vector of Ehrlichia canis is recommended.

  17. First detection and molecular characterization of Ehrlichia canis from dogs in Nigeria.

    PubMed

    Kamani, Joshua; Lee, Chung-Chan; Haruna, Ayuba M; Chung, Ping-Jun; Weka, Paul R; Chung, Yang-Tsung

    2013-02-01

    The present study aimed to detect the presence of Ehrlichia canis in naturally infected dogs in Nigeria, using a combination of PCR and sequence analysis of the 16S rRNA gene and two genes encoding the tandem repeat-containing proteins (TRPs), TRP19 and TRP36. Out of a total of 100 blood samples collected from domestic dogs presented to veterinary hospitals in Jos, the capital city of Plateau State of Nigeria, 11 were positive in nested PCR for E. canis. Sequencing results for these amplicons showed that all of the 16S rDNA sequences (1623 bp) or the TRP19 coding sequences (414 bp) were identical to each other and had very high similarities (99.3-100%) with those from other E. canis strains accessible in GenBank. The TRP36 gene sequences derived from the 11 Nigerian isolates were identical to each other except for the number of the 27-bp repeat unit in a tandem repeat region, which was found to be 8, 12 or 18. Without considering the number of tandem repeats, these sequences had 100% identity to that of the reported Cameroon 71 isolate, but distinctly differed from those obtained from other geographically distant E. canis strains previously published. A phylogenetic tree of E. canis based on the TRP36 amino acid sequences showed that the Nigerian isolates and the Cameroon 71 isolate fell into a separate clade, indicating that they may share a common ancestor. Overall, this study not only provides the first molecular evidence of E. canis infections in dogs from Nigeria but also highlights the value of the TRP36 gene as a tool to classify E. canis isolates and to elucidate their phylogeographic relationships.

  18. The genome of obligately intracellular Ehrlichia canis revealsthemes of complex membrane structure and immune evasion strategies

    SciTech Connect

    Mavromatis, K.; Kuyler Doyle, C.; Lykidis, A.; Ivanova, N.; Francino, P.; Chain, P.; Shin, M.; Malfatti, S.; Larimer, F.; Copeland,A.; Detter, J.C.; Land, M.; Richardson, P.M.; Yu, X.J.; Walker, D.H.; McBride, J.W.; Kyrpides, N.C.

    2005-09-01

    Ehrlichia canis, a small obligately intracellular, tick-transmitted, gram-negative, a-proteobacterium is the primary etiologic agent of globally distributed canine monocytic ehrlichiosis. Complete genome sequencing revealed that the E. canis genome consists of a single circular chromosome of 1,315,030 bp predicted to encode 925 proteins, 40 stable RNA species, and 17 putative pseudogenes, and a substantial proportion of non-coding sequence (27 percent). Interesting genome features include a large set of proteins with transmembrane helices and/or signal sequences, and a unique serine-threonine bias associated with the potential for O-glycosylation that was prominent in proteins associated with pathogen-host interactions. Furthermore, two paralogous protein families associated with immune evasion were identified, one of which contains poly G:C tracts, suggesting that they may play a role in phase variation and facilitation of persistent infections. Proteins associated with pathogen-host interactions were identified including a small group of proteins (12) with tandem repeats and another with eukaryotic-like ankyrin domains (7).

  19. Development of a Quantitative PCR Assay for Differentiating the Agent of Heartwater Disease, Ehrlichia ruminantium, from the Panola Mountain Ehrlichia.

    PubMed

    Sayler, K A; Loftis, A D; Mahan, S M; Barbet, A F

    2016-12-01

    Panola Mountain Ehrlichia (PME) is an emerging Ehrlichia sp. reported in ten US states. Based on the sequence homology of all known genes, PME is closely related to Ehrlichia ruminantium (ER), the causative agent of heartwater. Heartwater is an economically important tick-borne disease of cattle, sheep and goats responsible for stock losses in sub-Saharan Africa. Unfortunately, ER was imported to the Caribbean islands in the 19th century, and the presence of this foreign animal disease in the Caribbean poses a threat to the US mainland. If introduced, a heartwater outbreak would cause massive losses of naïve livestock. The serologic assay of choice to diagnose heartwater is cross-reactive with Ehrlichia spp., including PME, as we demonstrate here, which would confound disease surveillance in the event of a heartwater outbreak. The purpose of this study was to develop a diagnostic assay capable of rapidly distinguishing between these pathogens. Using synthetic MAP-1B peptides for ER and PME, we tested the cross-reactivity of this assay using sera from infected livestock. The MAP-1B ELISA cannot distinguish between animals infected with PME and ER. Therefore, a dual-plex Taqman(™) qPCR assay targeting the groEL gene of PME and ER was developed and validated. Primers were designed that are conserved among all known strains of ER, allowing for the amplification of strains from the Caribbean and Africa. The assay is highly sensitive (10 copies of DNA) and specific. This assay distinguishes between infection with PME and ER and will be a valuable tool in the event of heartwater outbreak on the US mainland, or for epidemiological studies involving either disease-causing organism.

  20. Diagnosis of canine monocytotropic ehrlichiosis (Ehrlichia canis): an overview.

    PubMed

    Harrus, Shimon; Waner, Trevor

    2011-03-01

    Canine monocytotropic ehrlichiosis (CME), caused by the rickettsia Ehrlichia canis, an important canine disease with a worldwide distribution. Diagnosis of the disease can be challenging due to its different phases and multiple clinical manifestations. CME should be suspected when a compatible history (living in or traveling to an endemic region, previous tick exposure), typical clinical signs and characteristic hematological and biochemical abnormalities are present. Traditional diagnostic techniques including hematology, cytology, serology and isolation are valuable diagnostic tools for CME, however a definitive diagnosis of E. canis infection requires molecular techniques. This article reviews the current literature covering the diagnosis of infection caused by E. canis.

  1. Ehrlichia canis in Rhipicephalus sanguineus ticks in the Ivory Coast.

    PubMed

    Socolovschi, Cristina; Gomez, José; Marié, Jean-Lou; Davoust, Bernard; Guigal, Pierre-Michel; Raoult, Didier; Parola, Philippe

    2012-12-01

    Canine monocytic ehrlichiosis caused by Ehrlichia canis is distributed globally, but its prevalence in Africa is poorly known. In the study reported herein, 27% of Rhipicephalus sanguineus ticks collected from watchdogs in Abidjan, Ivory Coast, were positive for E. canis using quantitative real-time PCR. A new molecular strategy is proposed that can be used not only for epidemiological study, but also for the diagnosis of canine monocytic ehrlichiosis. Our findings show for the first time the presence of E. canis using molecular tools in the Ivory Coast, providing direct evidence for the presence of this pathogen.

  2. Anaplasma, Ehrlichia, and "Candidatus Neoehrlichia" bacteria: pathogenicity, biodiversity, and molecular genetic characteristics, a review.

    PubMed

    Rar, Vera; Golovljova, Irina

    2011-12-01

    The family Anaplasmataceae includes gram-negative obligate intracellular alphaproteobacteria, which amplify within membrane-bound vacuoles. The genera Anaplasma and Ehrlichia as well as the recently specified cluster "Candidatus Neoehrlichia" comprise all bacteria of the family that are transmitted by ixodid ticks to mammalian hosts and cause infections in humans and numerous domestic and wild animal species. Totally, six Anaplasma, five Ehrlichia, and two "Candidatus Neoehrlichia" species as well as a variety of Ehrlichia bacteria with undefined taxonomic position belong to tick-borne bacteria. This review briefs the ecology, pathogenic properties, and molecular genetic diversity of Anaplasmataceae validated species, "Candidatus" species, and undefined novel Ehrlichia genetic variants. Copyright © 2011 Elsevier B.V. All rights reserved.

  3. Improved molecular detection of Ehrlichia and Anaplasma species applied to Amblyomma ticks collected from cattle and sheep in Ethiopia.

    PubMed

    Teshale, S; Geysen, D; Ameni, G; Asfaw, Y; Berkvens, D

    2015-02-01

    Detection of Ehrlichia and Anaplasma species in animals and tick vectors is crucial for an understanding of the epidemiology of diseases caused by these pathogens. In this study, a pair of primers designated EBR2 and EBR3 was designed from the Anaplasma 16S rDNA sequence and was used along with a previously described primer EHR 16SD for the simultaneous detection of Ehrlichia and Anaplasma species by nested PCR. The primers were used to amplify 925bp of DNA from known species of Ehrlichia and Anaplasma. Restriction with MboII and MspI enzymes allowed Ehrlichia and Anaplasma speciation. Restriction with MboII differentiated between An. marginale, Anaplasma (formerly Ehrlichia) sp. Omatjenne, and An. centrale with An. marginale and Anaplasma (formerly Ehrlichia) sp. Omatjenne yielding 2 distinct fragments each while An. centrale produced 3 distinct bands. Ehrlichia ruminantium and An. phagocytophylum remained undigested. Subsequent restriction with MspI differentiated E. ruminantium from An. phagocytophylum with 2 and 4 fragments, respectively. When used on tick samples from the field, 63 ticks (16.4%) out of 384 collected from cattle and sheep were positive for one or more species of Ehrlichia and Anaplasma. The positivity ranged from 6.3% at Andasa to 36.7% at Habernosa. Higher overall infection rates were found in Amblyomma lepidum than in Amblyomma variegatum ticks (p=0.009). Amblyomma lepidum from Habernosa were more often infected with all detected species of Anaplasma and Ehrlichia than Am. variegatum. At Bako, however, Anaplasma (formerly Ehrlichia) sp. Omatjenne was detected only in Am. variegatum. A significantly higher proportion of ticks collected from cattle (20.6%) was found positive than in those collected from sheep (3.3%) (p=0.003). Simultaneous detection of Ehrlichia and Anaplasma species and correct identification of mixed infections was possible. Since the ticks were collected from animals, the occurrence of the major species of Ehrlichia and

  4. Hematological values associated to the serological and molecular diagnostic in cats suspected of Ehrlichia canis infection.

    PubMed

    Braga, Isis Assis; dos Santos, Luana Gabriela Ferreira; Melo, Andréia Lima Tomé; Jaune, Felipe Wolf; Ziliani, Thaysa Felfili; Girardi, Angela Ferronatto; de Aguiar, Daniel Moura

    2013-01-01

    The literature contains several studies on feline ehrlichiosis. However, information about the characteristics of Ehrlichia infection in cats is still scanty. This study evaluated the association between Ehrlichia spp. infection and the hematologic data of 93 cats treated at the Federal University of Mato Grosso Veterinary Hospital in Cuiabá, state of Mato Grosso, Brazil. The presence of or exposure to Ehrlichia spp. infection was evaluated by Polymerase Chain Reaction (PCR) targeting the dsb and 16S rRNA gene of Ehrlichia, and by detection of anti-Ehrlichia canis IgG antibodies in Indirect Fluorescence Assay (IFA), respectively. Eight (8.6%) cats tested positive by PCR and the partial DNA sequence obtained from PCR products was a 100% match to E. canis. Forty-two (45.1%) cats showed antibody reactivity against Ehrlichia spp. Hematological alterations such as low erythrocyte count, thrombocytopenia, lymphopenia and monocytosis were observed in PCR positive cats. Among them, low erythrocyte counts were associated with IgG antibody titers of 40 to 640 and five cats also tested positive by PCR. Furthermore, PCR-positive cats showed a tendency to be lymphopenic. No correlation was found between age and sex, and no ticks were observed in any of the examined cats.

  5. Molecular Detection of Anaplasma spp. and Ehrlichia spp. in Ruminants from Twelve Provinces of China

    PubMed Central

    Qiu, Haixiang; Kelly, Patrick John; Zhang, Jilei; Luo, Qinghua; Yang, Yi; Mao, Yongjiang; Yang, Zhangping; Li, Jing; Wu, Hongzhuan

    2016-01-01

    Anaplasma spp. and Ehrlichia spp. are tick-transmitted bacteria that are of significant economic importance as they can infect large and small ruminants and also people. There is little information on anaplasmosis and ehrlichiosis in ruminants in China. 16S rRNA FRET-qPCRs were used to screen convenience whole blood samples from 2,240 domestic ruminants in 12 provinces of China for Anaplasma spp. and Ehrlichia spp. Positive samples were further analyzed with a standard PCR for the gltA. Anaplasma spp. DNA was detected in the sheep (11.7%; 13/111), goats (81.8%; 219/270), cattle (13.2%; 241/1,830), and water buffaloes (6.9%; 2/29). Ehrlichia spp. DNA was detected in sheep (1.8%; 2/111), goats (1.1%; 3/270), and cattle (3.6%; 65/1830) but not in water buffaloes (0/29). Sequencing of gltA PCR products showed that A. marginale, A. ovis, Ehrlichia canis, and Ehrlichia sp. (JX629807) were present in ruminants from China, while the 16S rRNA FRET-qPCR sequence data indicated that there might also be A. platys, A. phagocytophilum, Anaplasma sp. BL126-13 (KJ410243), and Anaplasma sp. JC3-6 (KM227012). Our study shows that domestic ruminants from China are not uncommonly infected with a variety of Anaplasma spp. and Ehrlichia spp. PMID:28096822

  6. Simultaneous detection of Anaplasma and Ehrlichia species in ruminants and detection of Ehrlichia ruminantium in Amblyomma variegatum ticks by reverse line blot hybridization.

    PubMed

    Bekker, Cornelis P J; de Vos, Sander; Taoufik, Amar; Sparagano, Olivier A E; Jongejan, Frans

    2002-10-22

    The detection of Anaplasma and Ehrlichia species is usually based on species-specific PCR assays, since no assay is yet available which can detect and identify these species simultaneously. To this end, we developed a reverse line blot (RLB) assay for simultaneous detection and identification of Anaplasma and Ehrlichia species in domestic ruminants and ticks. In a PCR the hypervariable V1 region of the 16S ribosomal RNA (rRNA) gene was amplified with a set of primers unique for members of the genera Anaplasma and Ehrlichia [Int. J. Syst. Evol. Microbiol. 51 (2001) 2145]. Amplified PCR products from blood of domestic ruminants or Amblyomma variegatum tick samples were hybridized onto a membrane to which eight species-specific oligonucleotide probes and one Ehrlichia and Anaplasma catch-all oligonucleotide probe were covalently linked. No DNA was amplified from uninfected blood, nor from other hemoparasites such as Theileria annulata, or Babesia bigemina. The species-specific probes did not cross-react with DNA amplified from other species. E. ruminantium, A. ovis and another Ehrlichia were identified by RLB in blood samples collected from small ruminants in Mozambique. Finally, A. variegatum ticks were tested after feeding on E. ruminantium infected sheep. E. ruminantium could be detected in adult ticks even if feeding of nymphs was carried out 3.5 years post-infection. In conclusion, the developed species-specific oligonucleotide probes used in an RLB assay can simultaneously detect and identify several Ehrlichia and Anaplasma species. However, as no quantitative data for the detection limit are available yet, only positive results are interpretable at this stage.

  7. Molecular detection of Ehrlichia canis in dogs in Malaysia.

    PubMed

    Nazari, Mojgan; Lim, Sue Yee; Watanabe, Mahira; Sharma, Reuben S K; Cheng, Nadzariah A B Y; Watanabe, Malaika

    2013-01-01

    An epidemiological study of Ehrlichia canis infection in dogs in Peninsular Malaysia was carried out using molecular detection techniques. A total of 500 canine blood samples were collected from veterinary clinics and dog shelters. Molecular screening by polymerase chain reaction (PCR) was performed using genus-specific primers followed by PCR using E. canis species-specific primers. Ten out of 500 dogs were positive for E. canis. A phylogenetic analysis of the E. canis Malaysia strain showed that it was grouped tightly with other E. canis strains from different geographic regions. The present study revealed for the first time, the presence of genetically confirmed E. canis with a prevalence rate of 2.0% in naturally infected dogs in Malaysia.

  8. In vitro susceptibility of Ehrlichia sennetsu to antibiotics.

    PubMed Central

    Brouqui, P; Raoult, D

    1990-01-01

    Antibiotic efficacies were evaluated by Diff-Quik (Dade, Düdingen, Federal Republic of Germany) staining of Ehrlichia sennetsu in P388D1 murine macrophages grown in 96-well microtiter plates. Sennetsu disease is generally cured with tetracyclines. In vivo, E. sennetsu is susceptible to doxycycline and is resistant to erythromycin, penicillin, and chloramphenicol. Our study confirmed, in vitro, the efficacy of doxycycline, which had an MIC of 0.125 micrograms/ml. E. sennetsu was found to be resistant to erythromycin, chloramphenicol, penicillin, gentamicin, and co-trimoxazole, while it was very susceptible to ciprofloxacin (MIC, 0.125 micrograms/ml) and rifampin (MIC, 0.5 micrograms/ml). PMID:2221869

  9. In vitro susceptibility of Ehrlichia sennetsu to antibiotics.

    PubMed

    Brouqui, P; Raoult, D

    1990-08-01

    Antibiotic efficacies were evaluated by Diff-Quik (Dade, Düdingen, Federal Republic of Germany) staining of Ehrlichia sennetsu in P388D1 murine macrophages grown in 96-well microtiter plates. Sennetsu disease is generally cured with tetracyclines. In vivo, E. sennetsu is susceptible to doxycycline and is resistant to erythromycin, penicillin, and chloramphenicol. Our study confirmed, in vitro, the efficacy of doxycycline, which had an MIC of 0.125 micrograms/ml. E. sennetsu was found to be resistant to erythromycin, chloramphenicol, penicillin, gentamicin, and co-trimoxazole, while it was very susceptible to ciprofloxacin (MIC, 0.125 micrograms/ml) and rifampin (MIC, 0.5 micrograms/ml).

  10. The Genome of the Obligately Intracellular Bacterium Ehrlichia canis Reveals Themes of Complex Membrane Structure and Immune Evasion Strategies

    SciTech Connect

    Mavromatis, K; Doyle, C Kuyler; Lykidis, A; Ivanova, N; Francino, M P; Chain, Patrick S; Shin, M; Malfatti, Stephanie; Larimer, Frank W; Copeland, A; Detter, J C; Land, Miriam L; Richardson, P M; Yu, X J; Walker, D H; McBride, J W; Kyripides, N C

    2006-01-01

    Ehrlichia canis, a small obligately intracellular, tick-transmitted, gram-negative, {alpha}-proteobacterium, is the primary etiologic agent of globally distributed canine monocytic ehrlichiosis. Complete genome sequencing revealed that the E. canis genome consists of a single circular chromosome of 1,315,030 bp predicted to encode 925 proteins, 40 stable RNA species, 17 putative pseudogenes, and a substantial proportion of noncoding sequence (27%). Interesting genome features include a large set of proteins with transmembrane helices and/or signal sequences and a unique serine-threonine bias associated with the potential for O glycosylation that was prominent in proteins associated with pathogen-host interactions. Furthermore, two paralogous protein families associated with immune evasion were identified, one of which contains poly(G-C) tracts, suggesting that they may play a role in phase variation and facilitation of persistent infections. Genes associated with pathogen-host interactions were identified, including a small group encoding proteins (n = 12) with tandem repeats and another group encoding proteins with eukaryote-like ankyrin domains (n = 7).

  11. Associated Factors to Seroprevalence of Ehrlichia spp. in Dogs of Quintana Roo, Mexico

    PubMed Central

    Martínez-Vega, Pedro Pablo; Rodríguez-Vivas, Roger Iván; Pérez-Osorio, Carlos; Villegas-Perez, Sandra Luz; Sauri-Arceo, Carlos Humberto

    2016-01-01

    The objective of this study was to determine the seroprevalence to Ehrlichia spp. in dogs from Xcalak, Quintana Roo, Mexico, and the associated factors. Serum samples were obtained from 118 dogs and used in an indirect immunofluorescent assay test for the detection of antibodies against Ehrlichia spp. A questionnaire was used to obtain information about possible variables associated with seroprevalence. These variables were analyzed through Chi2 test and logistic regression. Dog seroprevalence of antibodies against Ehrlichia spp. was 64% (75/118). Fifty-two percent (61/118) of dogs had tick infestation which was identified as Rhipicephalus sanguineus sensu lato. Anemia was observed in 36% of dogs. Leucopenia (2.5%), thrombocytopenia (70%), and hemorrhage (14%) were also observed. Thirty-one percent (23/75) of dogs with anemia, 4% (3/75) of dogs with leucopenia, 80% (60/75) of dogs with thrombocytopenia, 17% (13/75) of dogs with hemorrhages, and 59% (44/75) of dogs with ticks were positive for Ehrlichia spp. antibodies. The factors associated with seroprevalence were age (1–3 and >3 years old, OR = 7.77 and OR = 15.39, resp.), tick infestation (OR = 3.13), and thrombocytopenia (OR = 3.36). In conclusion, seroprevalence of Ehrlichia spp. was high in the community of Xcalak and its associated factors were age, tick infestation, and thrombocytopenia. PMID:28096818

  12. Anaplasma, Ehrlichia and rickettsial pathogens in ixodid ticks infesting cattle and sheep in western Oromia, Ethiopia.

    PubMed

    Teshale, Sori; Kumsa, Bersissa; Menandro, Maria Luisa; Cassini, Rudi; Martini, Marco

    2016-10-01

    Although ticks are widely distributed in all agro-ecological zones of Ethiopia, information on tick-borne pathogens is scarce. This study was conducted to determine the presence of Anaplasma spp., Ehrlichia spp., and Rickettsia spp. in Rhipicephalus evertsi and Rhipicephalus (Boophilus) decoloratus collected from cattle and sheep at Bako, western Oromia, Ethiopia, using polymerase chain reaction and sequencing. Anaplasma ovis and Anaplasma spp., Ehrlichia ruminantium and Ehrlichia spp. were detected in Rh. decoloratus, whereas only A. ovis was detected in Rh. evertsi. Both tick species were found to harbor DNA belonging to Rickettsia spp., and Rickettsia africae. Our findings highlight the risk of infection of animals and humans with these zoonotic tick-borne bacteria in Ethiopia.

  13. Tandem betatron

    DOEpatents

    Keinigs, Rhonald K.

    1992-01-01

    Two betatrons are provided in tandem for alternately accelerating an electron beam to avoid the single flux swing limitation of conventional betatrons and to accelerate the electron beam to high energies. The electron beam is accelerated in a first betatron during a period of increasing magnetic flux. The eletron beam is extracted from the first betatron as a peak magnetic flux is reached and then injected into a second betatron at a time of minimum magnetic flux in the second betatron. The cycle may be repeated until the desired electron beam energy is obtained. In one embodiment, the second betatron is axially offset from the first betatron to provide for electron beam injection directly at the axial location of the beam orbit in the second betatron.

  14. Serodetection of Ehrlichia canis amongst dogs in central Namibia.

    PubMed

    Manyarara, Rutendo; Tubbesing, Ulf; Soni, Minty; Noden, Bruce H

    2015-06-01

    Ehrlichia canis is a major pathogen in dogs throughout Africa, yet it has not been reported in Namibia. The aim of this study was to determine the seroprevalence of canine ehrlichiosis in central Namibia using the ImmunoComb assay (Biogal, Galed Laboratories). The study included 76 dogs that presented to the Rhino Park Veterinary Clinic in the north-western suburb of Khomasdal, Windhoek, Namibia, as well as 30 stray dogs from the Windhoek branch of the Society for the Prevention of Cruelty to Animals. Of the 106 dogs tested, 53.8% were seropositive at titres > 1:80. Dogs that presented with symptoms of E. canis infection had a significantly higher seroprevalence (86.6%) compared with apparently healthy dogs (41.6%) (P = 0.00). Location of habitation was significant (P < 0.017), with a high percentage of dogs exposed to E. canis living in the northern or north-western part of Windhoek. As the first study to serologically establish E. canis as a major pathogen in dogs in central Namibia, it is notable that the highest proportion of seropositive dogs came from low-income areas. Further investigation is necessary to describe the ecology of this important tick-borne pathogen of companion animals in Namibia.

  15. In vitro susceptibilities of Ehrlichia risticii to eight antibiotics.

    PubMed Central

    Rikihisa, Y; Jiang, B M

    1988-01-01

    Inhibition of the proliferation of Ehrlichia risticii cultured in murine macrophage P388D1 cells by eight antibiotics was evaluated by indirect fluorescent-antibody staining with an antiserum specific to E. risticii. There was a negative correlation between the percentage of infected cells and the log10 of the concentrations of all antibiotics examined. The ranks of the antibiotics in the order of 50% inhibitory concentrations (on a microgram-per-milliliter basis) after 48 h of exposure were as follows: demeclocycline, doxycycline, and oxytetracycline less than minocycline less than rifampin less than tetracycline less than erythromycin and nalidixic acid. When the antibiotics were removed after 48 h of incubation, continuous inhibition of proliferation was evident at 72 h. At 96 h regrowth of the organisms occurred in most of the cultures. The rate of regrowth was the highest with nalidixic acid, followed by erythromycin, at all concentrations of the antibiotic tested. Regrowth was observed with less than 0.1 microgram of minocycline per ml and less than 0.01 microgram of oxytetracycline, tetracycline, and doxycycline per ml. With more than 0.01 microgram of demeclocycline per ml, however, the inhibition persisted for up to 72 h after removal of the antibiotic. These results indicate that demeclocycline was slightly more effective than doxycycline, oxytetracycline, and minocycline in eliminating E. risticii in macrophages in vitro, whereas tetracycline and rifampin were less effective. Nalidixic acid and erythromycin were ineffective. PMID:3142345

  16. Molecular characterization of Ehrlichia canis infecting dogs, Buenos Aires.

    PubMed

    Cicuttin, Gabriel L; De Salvo, María N; Gury Dohmen, Federico E

    2016-07-01

    Canine monocytic ehrlichiosis (CME) is a worldwide potentially fatal tick-borne rickettsial disease of dogs caused by Ehrlichia canis and transmitted by Rhipicephalus sanguineus sensu lato. CME diagnosis includes indirect (serology) and direct (e.g. blood smears and PCR) methods. PCR is more sensitive and specific than direct microscopic examination and positive PCR results confirm infection, whereas positive serologic test results only confirm exposure. The aim of the present study was to perform a molecular characterization of E. canis from canine samples of the Metropolitan Area of Buenos Aires. We studied 223 blood samples of dogs submitted to our institute for CME diagnoses. The samples were initially screened for Anaplasmataceae family by PCR, resulting in 30 positive dogs (13.4%). Subsequently, positive DNAs were analyzed by nested PCR 16S rRNA specific for E. canis or Anaplasma platys, resulting in 15 (6.7%) and 16 (7.2%) positive dogs, respectively. For molecular characterization, samples positive for E. canis were subjected to amplification of a fragment of the dsb and p28 genes. The nucleotide sequences obtained for the dsb fragment resulted in 100% identity with others E. canis found in dogs from different regions of worldwide. The nucleotide sequences obtained for p28 gene resulted in 100% of identity with each other and closely with E. canis str. Jaboticabal (Brazil). Identity with others sequences of E. canis ranged from 76.9 to 79.7%. The occurrence of canine cases molecularly confirmed in Metropolitan Area of Buenos Aires highlights the need for more studies in order to understand epidemiological factors associated with CME, especially the disease transmission dynamic in South America given the existence of two lineages of R. sanguineus sensu lato with different vectorial capacity for transmission of E. canis.

  17. Detection of Dirofilaria immitis and Ehrlichia species in coyotes (Canis latrans), from rural Oklahoma and Texas.

    PubMed

    Paras, Kelsey L; Little, Susan E; Reichard, Mason V; Reiskind, Michael H

    2012-07-01

    There is a lack of knowledge regarding the prevalence of Dirofilaria immitis and Ehrlichia spp. in coyotes in Oklahoma and Texas. Documenting the prevalence of these vector-borne disease agents in coyotes from Oklahoma and Texas underscores the importance of wild canids as reservoir hosts that infect companion animals and humans. To learn more about the sylvatic cycle of D. immitis and Ehrlichia spp. in coyotes from Oklahoma and Texas, we tested for infection with and exposure to, respectively, these disease agents. Coyote carcasses were collected opportunistically from animal control experts and hunters in seven counties in Oklahoma and Texas from January to March, 2010. Serum samples from 77 coyotes were tested with a commercial ELISA test. Five (6.5%) coyotes had D. immitis antigens, and four (5.2%) had antibodies to Ehrlichia spp. The overall prevalence of D. immitis was low relative to studies from the eastern United States. Little is known about the prevalence of Ehrlichia spp. throughout the United States, but coyotes from rural Oklahoma in the current study had a higher exposure rate than those reported from California, and a lower rate than data from an earlier study from Oklahoma.

  18. Detection of Ehrlichia canis in domestic cats in the central-western region of Brazil.

    PubMed

    Braga, Ísis Assis; dos Santos, Luana Gabriela Ferreira; de Souza Ramos, Dirceu Guilherme; Melo, Andréia Lima Tomé; da Cruz Mestre, Gustavo Leandro; de Aguiar, Daniel Moura

    2014-01-01

    Ehrlichiosis is a worldwide distributed disease caused by different bacteria of the Ehrlichia genus that are transmitted by arthropod vectors. Its occurrence in dogs is considered endemic in several regions of Brazil. Regarding cats, however, few studies have been done and, consequently, there is not enough data available. In order to detect Ehrlichia spp. in cats from the central-western region of Brazil, blood and serum samples were collected from a regional population of 212 individuals originated from the cities of Cuiabá and Várzea Grande. These animals were tested by the Immunofluorescence Assay (IFA) and the Polymerase Chain Reaction (PCR) designed to amplify a 409 bp fragment of the dsb gene. The results obtained show that 88 (41.5%) cats were seropositive by IFA and 20 (9.4%) cats were positive by PCR. The partial DNA sequence obtained from PCR products yielded twenty samples that were found to match perfectly the Ehrlichia canis sequences deposited on GenBank. The natural transmission of Ehrlichia in cats has not been fully established. Furthermore, tick infestation was not observed in the evaluated cats and was not observed any association between age, gender and positivity of cats in both tests. The present study reports the first serological and molecular detection of E. canis in domestic cats located in the endemic area previously mentioned.

  19. Frequency and Distribution of Rickettsiae, Borreliae, and Ehrlichiae Detected in Human-Parasitizing Ticks, Texas, USA

    PubMed Central

    Mitchell, Elizabeth A.; Williamson, Phillip C.; Billingsley, Peggy M.; Seals, Janel P.; Ferguson, Erin E.

    2016-01-01

    To describe the presence and distribution of tickborne bacteria and their vectors in Texas, USA, we screened ticks collected from humans during 2008–2014 for Rickettsia, Borrelia, and Ehrlichia spp. Thirteen tick species were identified, and 23% of ticks carried bacterial DNA from at least 1 of the 3 genera tested. PMID:26811941

  20. Detection of Ehrlichia canis in domestic cats in the central-western region of Brazil

    PubMed Central

    Braga, Ísis Assis; dos Santos, Luana Gabriela Ferreira; de Souza Ramos, Dirceu Guilherme; Melo, Andréia Lima Tomé; da Cruz Mestre, Gustavo Leandro; de Aguiar, Daniel Moura

    2014-01-01

    Ehrlichiosis is a worldwide distributed disease caused by different bacteria of the Ehrlichia genus that are transmitted by arthropod vectors. Its occurrence in dogs is considered endemic in several regions of Brazil. Regarding cats, however, few studies have been done and, consequently, there is not enough data available. In order to detect Ehrlichia spp. in cats from the central-western region of Brazil, blood and serum samples were collected from a regional population of 212 individuals originated from the cities of Cuiabá and Várzea Grande. These animals were tested by the Immunofluorescence Assay (IFA) and the Polymerase Chain Reaction (PCR) designed to amplify a 409 bp fragment of the dsb gene. The results obtained show that 88 (41.5%) cats were seropositive by IFA and 20 (9.4%) cats were positive by PCR. The partial DNA sequence obtained from PCR products yielded twenty samples that were found to match perfectly the Ehrlichia canis sequences deposited on GenBank. The natural transmission of Ehrlichia in cats has not been fully established. Furthermore, tick infestation was not observed in the evaluated cats and was not observed any association between age, gender and positivity of cats in both tests. The present study reports the first serological and molecular detection of E. canis in domestic cats located in the endemic area previously mentioned. PMID:25242952

  1. Molecular and Cellular Pathobiology of Ehrlichia Infection: Targets for New Therapeutics and Immunomodulation Strategies

    PubMed Central

    McBride, Jere W.; Walker, David H.

    2013-01-01

    Ehrlichia are small gram-negative obligately intracellular bacteria in the order Rickettsiales that are transmitted by ticks and associated with emerging life-threatening human zoonoses. Vaccines are not available for human ehrlichiosis, and therapeutic options are limited to a single antibiotic class. Ehrlichia are able to subvert both innate and adaptive host defenses, and advances in understanding molecular Ehrlichia-eukaryotic host cell interactions and the cellular and immunologic basis of disease are important for developing effective next generation therapies. New technologies for exploring host-pathogen interactions have yielded recent advances in understanding the molecular interactions between these intracellular pathogens and host cell components and identified new targets for therapeutic and vaccine development including those that target pathogen virulence mechanisms or disrupt the processes associated with ehrlichial effector proteins. Animal models have also provided insight into immunopathologic mechanisms that contribute significantly to understanding severe disease manifestations that will lead to the development of immunomodulatory approaches for treating patients nearing or experiencing severe disease states. In this review, we discuss the recent advances in our understanding of molecular and cellular pathobiology and the immunobiology of Ehrlichia infection. We identify new molecular host-pathogen interactions that can be targets of new therapeutics and prospects for treating immunologic dysregulation that occurs during acute infection leading to life-threatening complications. PMID:21276277

  2. The Microbiome of Ehrlichia-Infected and Uninfected Lone Star Ticks (Amblyomma americanum)

    PubMed Central

    Trout Fryxell, R. T.; DeBruyn, J. M.

    2016-01-01

    The Lone Star tick, Amblyomma americanum, transmits several bacterial pathogens including species of Anaplasma and Ehrlichia. Amblyomma americanum also hosts a number of non-pathogenic bacterial endosymbionts. Recent studies of other arthropod and insect vectors have documented that commensal microflora can influence transmission of vector-borne pathogens; however, little is known about tick microbiomes and their possible influence on tick-borne diseases. Our objective was to compare bacterial communities associated with A. americanum, comparing Anaplasma/Ehrlichia -infected and uninfected ticks. Field-collected questing specimens (n = 50) were used in the analyses, of which 17 were identified as Anaplasma/Ehrlichia infected based on PCR amplification and sequencing of groEL genes. Bacterial communities from each specimen were characterized using Illumina sequencing of 16S rRNA gene amplicon libraries. There was a broad range in diversity between samples, with inverse Simpson’s Diversity indices ranging from 1.28–89.5. There were no statistical differences in the overall microbial community structure between PCR diagnosed Anaplasma/Ehrlichia-positive and negative ticks, but there were differences based on collection method (P < 0.05), collection site (P < 0.05), and sex (P < 0.1) suggesting that environmental factors may structure A. americanum microbiomes. Interestingly, there was not always agreement between Illumina sequencing and PCR diagnostics: Ehrlichia was identified in 16S rRNA gene libraries from three PCR-negative specimens; conversely, Ehrlichia was not found in libraries of six PCR-positive ticks. Illumina sequencing also helped identify co-infections, for example, one specimen had both Ehrlichia and Anaplasma. Other taxa of interest in these specimens included Coxiella, Borrelia, and Rickettsia. Identification of bacterial community differences between specimens of a single tick species from a single geographical site indicates that intra

  3. Prevalence of granulocytic Ehrlichia infection among white-tailed deer in Wisconsin.

    PubMed Central

    Belongia, E A; Reed, K D; Mitchell, P D; Kolbert, C P; Persing, D H; Gill, J S; Kazmierczak, J J

    1997-01-01

    Human granulocytic ehrlichiosis (HGE) is caused by an agent that is nearly indistinguishable from the veterinary pathogens Ehrlichia equi and Ehrlichia phagocytophila. The deer tick, Ixodes scapularis, is a vector of the HGE agent, and the white-tailed deer is the primary host for adult Ixodes ticks. We assessed the distribution of granulocytic Ehrlichia infection among deer living within (Wisconsin) and outside (western and southern Iowa) the geographic range of L. scapularis. Whole-blood samples were tested for HGE 16S ribosomal DNA (rDNA) by PCR, and E. equi antibody was detected by indirect immunofluorescence assay (IFA). Antibody titers of > or = 1:64 were defined as positive, and all positive samples were retested with a second lot of substrate antigen. E. equi antibody was present in 14 (8%) of 187 Wisconsin deer and 0 of 60 Iowa specimens (rate ratio undefined; P = 0.025). An additional 30 serum samples from Wisconsin deer were excluded because IFA results were discrepant between substrate lots. The reciprocal antibody titers ranged from 64 to 512 (geometric mean, 141) for positive samples. PCR results were positive for 27 (15%) of 181 Wisconsin deer. The prevalence of infection in northwestern Wisconsin deer was not significantly different from that in central Wisconsin deer, as determined by IFA and PCR. In two samples that were sequenced, the 16S rDNA was nearly identical to that of the granulocytic Ehrlichia species but distinct from that of Anaplasma marginale. The DNA sequences of the samples differed from the published sequences for E. equi, E. phagocytophila, and the HGE agent by 1 or 2 nucleotides (> or = 99.1% homology) at phylogenetically informative sites. Granulocytic Ehrlichia organisms in deer are widely distributed within the geographic range of L. scapularis in Wisconsin. Deer may serve as useful sentinels for areas where HGE transmission to humans may occur. PMID:9163463

  4. Novel Anaplasma and Ehrlichia organisms infecting the wildlife of two regions of the Brazilian Amazon.

    PubMed

    Soares, Herbert S; Marcili, Arlei; Barbieri, Amália R M; Minervino, Antonio H H; Malheiros, Antonio F; Gennari, Solange M; Labruna, Marcelo B

    2017-10-01

    During 2009-2012, wild animals were sampled in the Amazon biome of Brazil. Animal tissues and blood were tested by polymerase chain reaction (PCR) assays targeting DNA of the bacterial family Anaplasmataceae (genera Anaplasma, Ehrlichia, Wolbachia) and the genus Borrelia. Overall, 181 wild animals comprising 36 different species (2 reptiles, 5 birds, and 29 mammals) were sampled. All birds and reptiles were negative by all PCR assays, as well as all mammals for the Borrelia PCR assay. Anaplasmataceae agents were searched by PCR assays targeting two different genes, the ribosomal 16S rRNA gene and the protein-coding dsb gene. Three dsb closely related haplotypes were generated from 3 white-lipped peccaries (Tayassu pecari). In a phylogenetic analysis inferred from dsb partial sequences, these haplotypes grouped with previously reported Ehrlichia haplotypes from jaguar (Panthera onca) and horse from Brazil, suggesting that they could all represent a single species, yet to be properly characterized. A unique dsb haplotype was generated from a sloth (Bradypus tridactylus), and could also represent a different Ehrlichia species. All these dsb haplotypes formed a clade sister to the Ehrlichia ruminantium clade. Three distinct 16S rRNA gene haplotypes were generated from a wild guinea pig (Cavia sp.), a woolly mouse opossum (Micoureus demerarae), and two from robust capuchin monkeys (Sapajus sp.). In a phylogenetic analysis inferred from 16S rRNA gene partial sequence, these haplotypes grouped within the Wolbachia clade, and are likely to represent Wolbachia organisms that were infecting invertebrate metazoarians (e.g., filarids) associated with the sampled mammals. Two deer (Mazama americana) samples yielded two distinct 16S rRNA gene sequences, one identical to several sequences of Anaplasma bovis, and an unique sequence that grouped in a clade with different Anaplasma species. Our results indicate that a variety of genetically distinct Anaplasmataceae organisms

  5. Minimum infection rate of Ehrlichia minasensis in Rhipicephalus microplus and Amblyomma sculptum ticks in Brazil.

    PubMed

    Carvalho, Izabelle T S; Melo, Andréia L T; Freitas, Leodil C; Verçoza, Rodolfo V; Alves, Alvair S; Costa, Jackeliny S; Chitarra, Cristiane S; Nakazato, Luciano; Dutra, Valéria; Pacheco, Richard C; Aguiar, Daniel M

    2016-07-01

    A new genotype phylogenetically close to Ehrlichia canis named as Ehrlichia minasensis was identified infecting cattle and deer in Canada, as well as Rhipicephalus microplus ticks and cattle in Brazil. Although it was detected in R. microplus, little is known about the epidemiology of this ehrlichiosis, especially in other tick species. This study evaluated the minimum infection rate of E. minasensis in Amblyomma sculptum and R. microplus ticks from locations where naturally infected cattle were previously detected. Overall, 45 engorged R. microplus ticks after molting [43 pools of adults (13.4%), and 2 pools of nymphs (4%)], and 42 engorged females post-oviposition (30.6%) (p=0.008) were positive by PCR for Ehrlichia sp. using the dsb, 16S rRNA and TRP36 genes, making a total of 87 R. microplus samples positive for Ehrlichia spp. (17.1%, IC 95% 14.01-20.75%). The partial sequences generated in the present study were 99-100% similar to the dsb DNA sequence of E. minasensis genotypes UFMG-EV and UFMT-BV, respectively, 100% similar to the 16S rRNA sequence of the E. minasensis genotype BOV2010 from Canada, and 99% similar to the TRP36 sequence of the Ehrlichia sp. UFMT-BV. The results of this study confirm the occurrence of transstadial transmission of this agent in R. microplus ticks and highlight the importance of R. microplus in the epidemiology and transmission of ehrlichiosis in cattle. No A. sculptum ticks were positive by PCR for E. minasensis.

  6. Pathogenic, immunologic, and molecular differences between two Ehrlichia risticii strains.

    PubMed

    Vemulapalli, R; Biswas, B; Dutta, S K

    1995-11-01

    Ehrlichia risticii is the causative agent of Potomac horse fever (PHF), an acute infectious disease of horses. In the last few years, there have been several reports of PHF cases occurring even in vaccinated horses. We isolated a new strain of E. risticii (90-12 strain) from a vaccinated horse suffering from clinical PHF. The major pathogenic, immunologic, and molecular differences between the 90-12 strain and the 25-D stain, which was originally isolated during the outbreaks in 1984, were studied. The 90-12 strain was more pathogenic for mice and horses compared with the 25-D strain. In enzyme-linked immunosorbent assay and immunofluorescence assay with mouse and horse antisera of both the strains, two- to fourfold differences were observed between (immunoblot) with mouse and horse antisera and also with the recombinant clone-specific antibodies. Though several antigens were similar in both the strains, there were significant differences between them in the 110-, 85-, 70-, 51-, and 33-kDa antigens. The 85-kDa antigen was present only in the 90-12 strain but cross-reacted with a 50-kDa antigen of the 25-D strain. The 51-kDa antigens of both strains had different migration patterns, Southern blot hybridization of the genome from both the strains with DNA probes made from the 51-, 55-, and clones for both the strains, whereas the probe of the 85-kDa clone showed a completely different pattern. The 16S rRNA gene sequences from the two strains were identical. Neither strain replicated in gamma interferon-treated mouse peritoneal macrophages. In in vitro neutralization assay, sera from the 25-D strain-infected horse neutralized the homologous strain but did not neutralize the 90-12 strain, whereas sera from the 90-12 strain-infected horse neutralized both the strains. In mouse protection experiments, there was complete homologous protection. But in cross-protection, mice immunized with the 25-D strain were only partially protected against challenge with the 90-12 strain

  7. Ehrlichia canis infection in a dog with no history of travel outside the United Kingdom.

    PubMed

    Wilson, H E; Mugford, A R; Humm, K R; Kellett-Gregory, L M

    2013-08-01

    A two-year-old female neutered Tibetan terrier was referred following a one-month history of lethargy, inappetence and pancytopenia, which had been poorly responsive to immunosuppressive and fluoroquinolone treatment. The dog was diagnosed with pure red cell aplasia and was found to be positive for Ehrlichia canis by both antibody titre measurement and polymerase chain reaction. The dog lived in London and had not travelled outside the UK. The dog was treated with doxycycline, prednisolone and ciclosporin, but died as a result of gastrointestinal tract haemorrhage. To the authors' knowledge, this represents the first reported case of Ehrlichia canis in a dog in the UK with no previous travel history. © 2013 British Small Animal Veterinary Association.

  8. First detection of Ehrlichia canis in Rhipicephalus bursa ticks in Sardinia, Italy.

    PubMed

    Masala, Giovanna; Chisu, Valentina; Foxi, Cipriano; Socolovschi, Christina; Raoult, Didier; Parola, Philippe

    2012-12-01

    Canine monocytic ehrlichiosis is a common and widespread disease. This disease is present in Sardinia year-round because the temperate weather on the island permits the survival of many types of tick vectors. A total of 35 ticks was collected from goats in south-eastern Sardinia, Italy, and tested for Ehrlichia DNA using polymerase chain reaction and DNA sequencing. This study provides the first evidence of the presence of Ehrlichia canis in Rhipicephalus bursa ticks. The data presented here increase our knowledge of tick-borne diseases in Sardinia and provide a useful contribution toward understanding their epidemiology. The role of R. bursa in the life cycle and transmission of E. canis needs however further investigation.

  9. Molecular survey of Rickettsia, Ehrlichia, and Anaplasma infection of domestic cats in Japan.

    PubMed

    Sasaki, Hiromi; Ichikawa, Yasuaki; Sakata, Yoshimi; Endo, Yasuyuki; Nishigaki, Kazuo; Matsumoto, Kotaro; Inokuma, Hisashi

    2012-12-01

    The prevalence of Rickettsia, Ehrlichia, and Anaplasma in 1764 DNA samples extracted from feline peripheral blood from all 47 prefectures in Japan was evaluated by screening real-time PCR, genus-specific PCR, and DNA nucleotide sequencing. The survey revealed that all cats were negative for Rickettsia infection. Two cats were positive for Ehrlichia or Anaplasma based on the screening PCR assay. Nucleotide sequence analysis of the partial 16S rRNA including the divergent region near the 3'-end revealed that the 2 positives were most similar to Anaplasma bovis with percent identities of 99.8% and 99.2%. This was the first detection of A. bovis DNA fragments in cats. Although these 2 cats showed stomatitis, both were also infected with feline immunodeficiency virus. The relationship between A. bovis carriage and clinical disease is not yet understood.

  10. Human Infection with Ehrlichia muris–like Pathogen, United States, 2007–20131

    PubMed Central

    Johnson, Diep K. Hoang; Schiffman, Elizabeth K.; Davis, Jeffrey P.; Neitzel, David F.; Sloan, Lynne M.; Nicholson, William L.; Fritsche, Thomas R.; Steward, Christopher R.; Ray, Julie A.; Miller, Tracy K.; Feist, Michelle A.; Uphoff, Timothy S.; Franson, Joni J.; Livermore, Amy L.; Deedon, Alecia K.; Theel, Elitza S.

    2015-01-01

    An Ehrlichia muris–like (EML) pathogen was detected among 4 patients in Minnesota and Wisconsin during 2009. We characterized additional cases clinically and epidemiologically. During 2004–2013, blood samples from 75,077 patients from all 50 United States were tested by PCR from the groEL gene for Ehrlichia spp. and Anaplasma phagocytophilum. During 2007–2013, samples from 69 (0.1%) patients were positive for the EML pathogen; patients were from 5 states: Indiana (1), Michigan (1), Minnesota (33), North Dakota (3), and Wisconsin (31). Most (64%) patients were male; median age was 63 (range 15–94) years; and all 69 patients reported likely tick exposure in Minnesota or Wisconsin. Fever, malaise, thrombocytopenia, and lymphopenia were the most common symptoms. Sixteen (23%) patients were hospitalized (median 4 days); all recovered, and 96% received doxycycline. Infection with the EML pathogen should be considered for persons reporting tick exposure in Minnesota or Wisconsin. PMID:26402378

  11. Early diagnosis of Ehrlichia ewingii infection in a lung transplant recipient by peripheral blood smear.

    PubMed

    Regunath, Hariharan; Rojas-Moreno, Christian; Olano, Juan P; Hammer, Richard D; Salzer, William

    2017-04-01

    Ehrlichiosis in lung transplant (LT) recipients is associated with severe outcomes. Ehrlichia ewingii is a less frequent cause of symptomatic ehrlichiosis, characterized by cytoplasmic inclusions (morulae) within circulating neutrophils. We report a case of E. ewingii infection in an LT recipient diagnosed promptly by blood smear exam and confirmed with molecular studies. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  12. Molecular diagnosis and species identification of Ehrlichia and Anaplasma infections in dogs from Panama, Central America.

    PubMed

    Santamaria, Annamaria; Calzada, Jose E; Saldaña, Azael; Yabsley, Michael J; Gottdenker, Nicole L

    2014-05-01

    The prevalence and distribution of Anaplasma and Ehrlichia were estimated in 201 symptomatic dogs from Panama by nested PCR and DNA sequencing of the 16S rRNA gene. In total, 163 dogs (70.6%; 163/201) were infected with either Anaplasma or Ehrlichia. On the basis of PCR results, the majority of cases were infected with E. canis (64.2%; 129/201) followed by 21.4% (43/201) with A. platys, whereas 7.5% (15/201) had Anaplasma/Ehrlichia co-infections. Further analyses of 16S rDNA partial sequences show sequence homology with E. canis and A. platys from other countries. Hematology findings from 79 E. canis PCR-positive dogs included anemia (74.7%), thrombocytopenia (81.9%), macroplatelets (29.1%), and leukopenia (6.3%). Among 16 A. platys PCR-positive dogs with available hematology, 62.5% were anemic, 75% had thrombocytopenia, and 100% had macroplatelets. On the basis of E.canis serology (enzyme-linked immunosorbent assay [ELISA]) (n=92 dogs), 30 dogs that were seropositive for E. canis were also PCR-positive, whereas among seronegatives (n=62), 10 were PCR-positive for E. canis. This study provides the first characterization of canine anaplasmosis and ehrlichiosis infections in Panama and is important to veterinary public health and comparative studies of these pathogens in the Americas.

  13. Molecular Survey of Anaplasma and Ehrlichia of Red Deer and Sika Deer in Gansu, China in 2013.

    PubMed

    Li, Y; Chen, Z; Liu, Z; Liu, J; Yang, J; Li, Q; Li, Y; Luo, J; Yin, H

    2016-12-01

    Anaplasma and Ehrlichia are important emerging tick-borne pathogens in both humans and animals. Here, we conducted a molecular surveillance study in Gansu, China to assess the prevalence of Anaplasma and Ehrlichia spp. in red deer and sika deer based on polymerase chain reaction (PCR) analysis and sequencing of 16S rRNA or msp genes. PCR revealed that the prevalence of Anaplasma ovis, Anaplasma bovis and Anaplasma platys of the Qilian Mountain samples was 32%, 9% and 9%, respectively; the prevalence of Anaplasma ovis, Anaplasma bovis, Anaplasma platys was 20%, 15% and 15% among the Long Mountain samples, respectively. Of the Long Mountain samples, two (5%) of the 40 samples were positive for Ehrlichia canis, but all 44 of the Qilian Mountain samples were negative for E. canis, and no other Anaplasma or Ehrlichia spp. were found in the samples. The phylogenetic tree showed that the newly isolated Anaplasma and Ehrlichia spp. could be classified as belonging to four clades, including an A. bovis cluster, A. ovis cluster, A. platys cluster and E. canis cluster. In addition, Bartonella schoenbuchensis was firstly identified in blood samples from red deer in Gansu, China. Our results provide important data to increase the understanding of the epidemiology of anaplasmosis and ehrlichiosis of red deer and sika deer and will assist with the implementation of measures to control anaplasmosis and ehrlichiosis transmission to red deer, sika deer and other animals in Gansu, China.

  14. Direct detection of Ehrlichia canis by PCR in the conjunctiva of a dog with bilateral anterior uveitis.

    PubMed

    Walser-Reinhard, L; Schaarschmidt-Kiener, D; Forster, J L; Matheis, F; Spiess, B

    2012-04-01

    The following report describes the direct detection of Ehrlichia canis by real-time PCR in the conjunctiva of a 1-year-old female Maltese dog. After being imported from Brazil, the dog was presented because of anorexia, dehydration, fever, and palpable mandibular lymph nodes. A few days later, the dog developed bilateral blepharospasm, photophobia and anterior uveitis. Monocytic ehrlichia was diagnosed by a positive PCR result and the detection of IgM and IgG antibodies. Because of the massive uveitis a conjunctival sample was taken with a cytobrush, which also tested positive for Ehrlichia canis DNA by real-time PCR. Only one week after starting treatment with systemic doxycycline and local anti-inflammatory and cyclopalgic therapy the dog recovered from systemic and eye diseases. After therapy the follow-up examination revealed a full remission of clinical and hematological parameters and negative PCR result.

  15. Detection of Ehrlichia risticii, the Agent of Potomac Horse Fever, in Freshwater Stream Snails (Pleuroceridae: Juga spp.) from Northern California

    PubMed Central

    Barlough, Jeffrey E.; Reubel, Gerhard H.; Madigan, John E.; Vredevoe, Larisa K.; Miller, Paul E.; Rikihisa, Yasuko

    1998-01-01

    Ehrlichia DNA was identified by nested PCR in operculate snails (Pleuroceridae: Juga spp.) collected from stream water in a northern California pasture in which Potomac horse fever (PHF) is enzootic. Sequencing of PCR-amplified DNA from a suite of genes (the 16S rRNA, groESL heat shock operon, 51-kDa major antigen genes) indicated that the source organism closely resembled Ehrlichia risticii, the causative agent of PHF. The minimum percentage of Juga spp. harboring the organism in the population studied was 3.5% (2 of 57 snails). No ehrlichia DNA was found in tissues of 123 lymnaeid, physid, and planorbid snails collected at the same site. These data suggest that pleurocerid stream snails may play a role in the life cycle of E. risticii in northern California. PMID:9687446

  16. A survey of antibodies against Rickettsia rickettsii and Ehrlichia chafeensis in domestic animals from a rural area of Colombia.

    PubMed

    Hidalgo, Marylin; Vesga, Juan Fernando; Lizarazo, Diana; Valbuena, Gustavo

    2009-06-01

    In a rural area of Colombia endemic for Rocky Mountain spotted fever, we performed indirect immunofluorescent antibody assays for Rickettsia spp. and Ehrlichia spp. using sera from randomly sampled dogs and horses to test the use of domestic animals as possible sentinels. Antibodies against Ehrlichia spp. were detected in 8 dogs (31.8%). Antibody titers against Rickettsia rickettsii antigen were positive in 4 dogs (18.2%) and 26 horses (16.3%). These values, albeit not directly comparable, are lower than those previously reported for humans in this region. A systemic approach to understanding dynamics of transmission is needed before implementing the use of domestic animals for disease surveillance activities.

  17. Molecular identification and characterization of Anaplasma platys and Ehrlichia canis in dogs in Mexico.

    PubMed

    Almazán, Consuelo; González-Álvarez, Vicente H; Fernández de Mera, Isabel G; Cabezas-Cruz, Alejandro; Rodríguez-Martínez, Rafael; de la Fuente, José

    2016-03-01

    The tick-borne pathogens Ehrlichia canis and Anaplasma platys are the causative agents of canine monocytic ehrlichiosis (CME) and canine cyclic thrombocytopenia (CCT). Although molecular evidence of E. canis has been shown, phylogenetic analysis of this pathogen has not been performed and A. platys has not been identified in Mexico, where the tick vector Rhipicephalus sanguineus sensu lato (s.l.) is common. The aim of this research was to screen, identify and characterize E. canis and A. platys by PCR and phylogenetic analysis in dogs from La Comarca Lagunera, a region formed by three municipalities, Torreon, Gomez-Palacio and Lerdo, in the Northern states of Coahuila and Durango, Mexico. Blood samples and five engorged R. sanguineus s.l. ticks per animal were collected from 43 females and 57 male dogs presented to veterinary clinics or lived in the dog shelter from La Comarca Lagunera. All the sampled dogs were apparently healthy and PCR for Anaplasma 16S rRNA, Ehrlichia 16S rRNA, and E. canis trp36 were performed. PCR products were sequenced and used for phylogenetic analysis. PCR products were successfully amplified in 31% of the samples using primers for Anaplasma 16S rRNA, while 10% and 4% amplified products using primers for Ehrlichia 16S rRNA and E. canis trp36 respectively. Subsequent sequencing and phylogenetic analyses of these products showed that three samples corresponded to A. platys and four to E. canis. Based on the analysis of trp36 we confirmed that the E. canis strains isolated from Mexico belong to a conservative clade of E. canis and are closely related to strains from USA. In conclusion, this is the first molecular identification of A. platys and the first molecular characterization and phylogenetic study of both A. platys and E. canis in dogs in Mexico.

  18. Novel Ehrlichia and Hepatozoon agents infecting the crab-eating fox (Cerdocyon thous) in southeastern Brazil.

    PubMed

    Almeida, Aliny P; Souza, Tayse D; Marcili, Arlei; Labruna, Marcelo B

    2013-05-01

    This study evaluated infection by vector-borne agents in 58 crab-eating fox (Cerdocyon thous L.) that were road-killed in an Atlantic rainforest reserve in the state of Espírito Santo, southeastern Brazil. Spleen, lung, or blood samples collected from the foxes were tested in the laboratory by a battery of polymerase chain reaction (PCR) assays targeting bacteria of the genera Rickettsia, Borrelia, Coxiella, Anaplasma, and Ehrlichia; and protozoa of the genera Babesia, Hepatozoon, and Leishmania. Of the targeted organisms, evidence of infection in the foxes was detected for Ehrlichia and Hepatozoon organisms only. Overall, six (10.3%) foxes were infected by an ehrlichial agent closely related to an ehrlichial agent recently detected in free-ranging Jaguars [(Panthera onca (L.)] in central-western Brazil, and to Ehrlichia ruminantium. For Hepatozoon, 28 (48.3%) foxes were infected by an agent closely related to Hepatozoon sp. Curupira 2 and H. americanum; and one (1.7%) fox was infected by an organism closely related to reptile-associated Hepatozoon agents. Finally, 11 (19.0%) foxes were found infested by Amblyomma cajennense (F.) nymphs, which were all PCR negative for the range of vector-borne agents cited above. Because the haplotypes found in free-ranging foxes are genetically closely related to pathogens of great veterinary importance, namely E. ruminantium and H. americanum, it is highly desirable to know if these novel organisms have any important role as agents of diseases in domestic animals and wildlife in Brazil.

  19. Novel Genetic Variants of Anaplasma phagocytophilum, Anaplasma bovis, Anaplasma centrale, and a Novel Ehrlichia sp. in Wild Deer and Ticks on Two Major Islands in Japan

    PubMed Central

    Kawahara, Makoto; Rikihisa, Yasuko; Lin, Quan; Isogai, Emiko; Tahara, Kenji; Itagaki, Asao; Hiramitsu, Yoshimichi; Tajima, Tomoko

    2006-01-01

    Wild deer are one of the important natural reservoir hosts of several species of Ehrlichia and Anaplasma that cause human ehrlichiosis or anaplasmosis in the United States and Europe. The primary aim of the present study was to determine whether and what species of Ehrlichia and Anaplasma naturally infect deer in Japan. Blood samples obtained from wild deer on two major Japanese islands, Hokkaido and Honshu, were tested for the presence of Ehrlichia and Anaplasma by PCR assays and sequencing of the 16S rRNA genes, major outer membrane protein p44 genes, and groESL. DNA representing four species and two genera of Ehrlichia and Anaplasma was identified in 33 of 126 wild deer (26%). DNA sequence analysis revealed novel strains of Anaplasma phagocytophilum, a novel Ehrlichia sp., Anaplasma centrale, and Anaplasma bovis in the blood samples from deer. None of these have been found previously in deer. The new Ehrlichia sp., A. bovis, and A. centrale were also detected in Hemaphysalis longicornis ticks from Honshu Island. These results suggest that enzootic cycles of Ehrlichia and Anaplasma species distinct from those found in the United States or Europe have been established in wild deer and ticks in Japan. PMID:16461655

  20. Serological evidence of exposure to Ehrlichia canis and Anaplasma phagocytophilum in Central Italian healthy domestic cats.

    PubMed

    Ebani, Valentina V; Bertelloni, Fabrizio

    2014-10-01

    The aim of the present survey was to estimate the seroprevalences of Ehrlichia canis and Anaplasma phagocytophilum in the Central Italian feline population. Serum samples of 560 healthy domestic cats were examined by indirect immunofluorescence assay (IFAT), considering an antibody titre of 1:40 as cut-off. Seroprevalences of 6.4% and 4.5% were found for E. canis and A. phagocytophilum, respectively. Adult, mixed breed cats showed seroprevalences higher than younger and purebred subjects, whereas no differences were observed in relation to gender and living conditions.

  1. [Molecular identification of Ehrlichia canis in a dog from Arica, Chile].

    PubMed

    López, Javier; Abarca, Katia; Mundaca, M Isabel; Caballero, Carla; Valiente-Echeverría, Fernando

    2012-10-01

    We report a molecular confirmed case of canine ehrlichiosis caused by Ehrlichia canis. A 10-year old female crossbred Siberian from the city of Arica, which was infested by ticks, presented hemorrhagic manifestations (hematomas and snout bleeding) and prostration. Blood cell count revealed thrombocytopenia (30,000 platelets/ mm³). Immunochromatographic rapid testing for E. canis IgG was positive. Amplification and sequencing of a fragment of the 16S rRNA gen from a blood sample showed 100% homology with E. canis from Perú. This is the first report of E. canis in Chile, an agent with known zoonotic potential.

  2. Molecular survey of Anaplasma phagocytophilum and Ehrlichia canis in red foxes (Vulpes vulpes) from central Italy.

    PubMed

    Ebani, Valentina Virginia; Verin, Ranieri; Fratini, Filippo; Poli, Alessandro; Cerri, Domenico

    2011-07-01

    During the 2007-2008 hunting season, 150 spleen samples were collected from free-ranging red foxes (Vulpes vulpes) in central Italy. The specimens were tested by two nested PCR assays to detect DNA of Anaplasma phagocytophilum, etiologic agent of granulocytic ehrlichiosis of animals and humans, and DNA of Ehrlichia canis, which causes the monocytic ehrlichiosis in canids. None of the foxes were PCR-positive for E. canis; 25 (16.6%) were positive for A. phagocytophilum. No specific gross alterations were detected at necropsy, and no histopathologic lesions found on PCR-positive spleen samples.

  3. Tandem mobile robot system

    DOEpatents

    Buttz, James H.; Shirey, David L.; Hayward, David R.

    2003-01-01

    A robotic vehicle system for terrain navigation mobility provides a way to climb stairs, cross crevices, and navigate across difficult terrain by coupling two or more mobile robots with a coupling device and controlling the robots cooperatively in tandem.

  4. [Morphologic identification of Ehrlichia sp. in the platelets of patients infected with the human immunodeficiency virus in Venezuela].

    PubMed

    de Tamí, Irene del Carmen; Tamí-Maury, Irene María

    2004-11-01

    To determine the frequency of infection by bacteria of the genus Ehrlichia in a population of patients infected with the human immunodeficiency virus (HIV). As is widely recognized, HIV infection is usually followed by the acquired immunodeficiency syndrome (AIDS) after a variable period during which the individual can develop different types of opportunistic infections whose severity depends on his/her immune status. Human ehrlichiosis is a newly-recognized tick-borne infectious disease caused by Ehrlichia spp., which are obligate intracellular, Gram-negative bacteria showing tropism for blood cells (leukocytes and platelets). In Venezuela, the disease was first recognized in humans in 1994, when intra-cytoplasmic microcolonies (morula) were found in human platelets. We collected peripheral blood samples from 87 HIV-positive persons that were received at the Immunology Laboratory of the Oncology and Hematology Institute in Caracas, Venezuela, one of the country's referral centers for cases of HIV infection. Slides prepared from buffy coat that had been stained with Wright's solution and sealed with resin for preservation were examined retrospectively under the light microscope. Ehrlichia spp. were found in the platelets of 12 of the 87 (13.8%) patients whose slides were examined. The presence of Ehrlichia sp. in the platelets of HIV-positive patients suggests that ehrlichiosis should be among the differential diagnoses of opportunistic infection in this group of patients.

  5. First description of natural Ehrlichia canis and Anaplasma platys infections in dogs from Argentina.

    PubMed

    Eiras, Diego Fernando; Craviotto, María Belén; Vezzani, Darío; Eyal, Osnat; Baneth, Gad

    2013-03-01

    Bacteria belonging to the Anaplasmataceae family are vector transmitted agents that affect a variety of vertebrate hosts including the tick-borne pathogens Ehrlichia canis and Anaplasma platys, which cause canine monocytic ehrlichiosis and cyclic thrombocytopenia, respectively. These two infections, typically reported from tropical and sub-tropical regions, have not been previously reported in dogs from Argentina. A total of 86 blood samples from dogs with suspected rickettsial disease and 28 non-suspected dogs were studied. Analysis included evaluation of hematological findings, PCR for Ehrlichia and Anaplasma species and sequencing of the positive PCR products. E. canis was detected in the blood of six dogs and A. platys in eighteen. All the dogs categorized as non-suspected were negative by PCR. Co-infection with Hepatozoon canis and Babesia vogeli was documented. This first report of E. canis and A. platys infections in dogs from Argentina indicates that these tick-borne infections have a considerably broader range than previously recognized in South America.

  6. Molecular detection of Ehrlichia canis and Anaplasma platys in dogs in Southern Brazil.

    PubMed

    Lasta, Camila Serina; dos Santos, Andrea Pires; Messick, Joanne Belle; Oliveira, Simone Tostes; Biondo, Alexander Welker; Vieira, Rafael Felipe da Costa; Dalmolin, Magnus Larruscaim; González, Félix Hilario Diaz

    2013-01-01

    The aims of this study were to determine the occurrence of Anaplasma platys and Ehrlichia canis infection in dogs in Porto Alegre, Southern Brazil; and to investigate their association with hematological abnormalities. Serum samples from 196 dogs were first tested using dot-ELISA for antibodies against Anaplasma spp. and Ehrlichia canis. Peripheral blood samples from 199 dogs were subjected to 16S rRNA nested PCR (nPCR) for A. platys and E. canis, followed by DNA sequencing to ensure pathogen identity. A total of 19/196 samples (9.69%) were positive for Anaplasma spp. using ELISA and 28/199 (14.07%) samples were positive for A. platys by nested PCR. All the dog samples were negative for E. canis, both in anti-E. canis antibody tests and in nested PCR. There were no significant differences in hematological parameters between A. platys-PCR positive and negative dogs and Anaplasma spp. serologically positive dogs, except for basophil counts, which were higher in nPCR-positive dogs. This is the first report showing A. platys presence in dogs in Southern Brazil. In conclusion, hematological parameters may not be sufficient to diagnose A. platys infection in dogs in Southern Brazil, probably due either to low pathogenicity or to chronic infection. On the other hand, E. canis may either have very low occurrence or be absent in dogs in Porto Alegre.

  7. Assessment of a quantitative 5' nuclease real-time polymerase chain reaction using groEL gene for Ehrlichia and Anaplasma species in rodents in Brazil.

    PubMed

    Benevenute, Jyan Lucas; Dumler, John Stephen; Ogrzewalska, Maria; Roque, André Luiz Rodrigues; Mello, Victoria Valente Califre; de Sousa, Keyla Carstens Marques; Gonçalves, Luiz Ricardo; D'Andrea, Paulo Sérgio; de Sampaio Lemos, Elba Regina; Machado, Rosangela Zacarias; André, Marcos Rogério

    2017-06-01

    New genotypes of Anaplasmataceae agents have been detected in wild carnivores, birds and deer in Brazil. The present work aimed to investigate the presence of Ehrlichia and Anaplasma species in rodents sampled in Brazil. Additionally, a newly designed quantitative 5' nuclease real-time multiplex PCR for Ehrlichia and Anaplasma spp. detection based on groEL gene amplification was designed, showing high specificity and sensitivity (10 groEL fragment copy/μL). Between 2000 and 2011, different rodent species [n=60] were trapped in 5 Brazilian biomes. Among 458 rodent spleen samples, 0.4% (2/458) and 2.4% (11/458) were positive for Ehrlichia and Anaplasma spp., respectively. Of 458 samples, 2.0% (9/458) and 1.1% (5/458) were positive for Anaplasma sp. and Ehrlichia sp., respectively, using conventional 16S rRNA PCR assays. Maximum Likelihood phylogenetic analyse based on a small region of 16S rRNA genes positioned the Anaplasma genotypes in rodents near Anaplasma phagocytophilum or Anaplasma marginale and Anaplasma odocoilei isolates. Ehrlichia genotypes were closely related to E. canis. There was a low occurrence of Anaplasma and Ehrlichia in wild and synanthropic rodents in Brazil, suggesting the circulation of new genotypes of these agents in rodents in the studied areas. Copyright © 2017 Elsevier GmbH. All rights reserved.

  8. Babesia canis vogeli, Ehrlichia canis, and Anaplasma platys infection in a dog.

    PubMed

    Al Izzi, Salah; Martin, Donald S; Chan, Roxanne Y Y; Leutenegger, Christian M

    2013-12-01

    A 12-month-old male neutered mixed breed dog was presented with a history of diarrhea, lethargy, emaciation, polydypsia, and sniffling. Physical examination findings included pale mucous membranes, increased heart and respiratory rates, and normal rectal temperature (38°C). Hematologic abnormalities included anemia and thrombocytopenia. Biochemical abnormalities included hypoalbuminemia, hyperbilirubinemia, and elevated ALP and ALT activities. A SNAP 4Dx test result was positive for Ehrlichia canis. Babesia canis vogeli organisms were found in the peripheral blood films, while morulae of E canis were not seen. Real-time polymerase chain reaction testing confirmed the presence of both B c vogeli and E canis organisms, and also was positive for Anaplasma platys infection. The dog recovered following treatment with doxycycline and imidocarb dipropionate, with normal hematology and biochemical profiles.

  9. First molecular detection of Ehrlichia canis and Anaplasma platys in ticks from dogs in Cebu, Philippines.

    PubMed

    Ybañez, Adrian P; Perez, Zandro O; Gabotero, Shirleny R; Yandug, Ryan T; Kotaro, Matsumoto; Inokuma, Hisashi

    2012-12-01

    Ehrlichia canis infection of dogs in the Philippines has been detected by serological and peripheral blood smear examination methods, but not by molecular means. Anaplasma platys infection in dogs has not yet been officially reported, although it is suspected to occur in the country. Thus, sensitive and specific molecular techniques were used in this study to demonstrate the presence of both E. canis and A. platys in the Philippines. A total of 164 Rhipicephalus sanguineus ticks was collected from 36 dogs. Seven tick samples were found positive with E. canis and one sample with A. platys. To further characterize these pathogens, molecular analyses based on citrate synthase and heat-shock operon genes were also performed. Philippine strains were found to be not divergent from strains from other countries. The present results are the first molecular detection and analyses of E. canis and A. platys in ticks from dogs in the Philippines.

  10. Serum DHEA-S increases in dogs naturally infected with Ehrlichia canis.

    PubMed

    Rondelli, M C H; Munhoz, T D; Catandi, P B; Freschi, C R; Palacios Junior, R J G; Machado, R Z; Tinucci-Costa, M

    2015-06-01

    Adrenocortical disturbances are expected in canine ehrlichiosis due to the immunological challenges caused by infection and consequent inflammation. Thus, this study aimed to evaluate the occurrence of adrenocortical hormonal alterations in dogs naturally infected with Ehrlichia canis (n = 21) as positively confirmed by the presence of anti-E. canis antibodies (Dot-ELISA) and nested PCR (nPCR). Serum dehydroepiandrosterone sulfate (DHEA-S) concentrations were assessed via ELISA before and one hour after ACTH stimulation. Another 10 healthy dogs were subjected to the same stimulation protocol and used as controls. The results revealed that baseline and post-ACTH DHEA-S concentrations were significantly greater in sick dogs, regardless of gender, and this finding illustrates the stress induced by naturally acquired ehrlichiosis in dogs.

  11. Rickettsia, Ehrlichia, Anaplasma, and Bartonella in ticks and fleas from dogs and cats in Bangkok.

    PubMed

    Foongladda, Suporn; Inthawong, Dutsadee; Kositanont, Uraiwan; Gaywee, Jariyanart

    2011-10-01

    Flea and tick specimens (5-10 fleas or ticks) on dogs and cats from various sites in Bangkok were tested by polymerase chain reaction and DNA sequencing to detect DNA of bacteria Rickettsia (gltA and 17 kDa genes), Anaplasmataceae (16S rRNA gene), and Bartonella (pap31 and its genes). We confirmed that Rickettsia sp. related to Rickettsia felis was detected in 66 of 98 (67.4%) flea specimens from dogs, whereas 8 Bartonella henselae and 2 Bartonella clarridgeiae were detected in 10 of 54 (18.5%) flea specimens from cats. Further, this work provides the first evidence of 10 Ehrlichia canis (3.3%), 7 Anaplasma platys (2.3%), and 2 Wolbachia spp. (0.66%) in 304 Rhipicephalus sanguineus tick specimens in Thailand.

  12. Detection of human pathogenic Ehrlichia muris-like agent in Peromyscus leucopus.

    PubMed

    Castillo, Caroline G; Eremeeva, Marina E; Paskewitz, Susan M; Sloan, Lynne M; Lee, Xia; Irwin, William E; Tonsberg, Stefan; Pritt, Bobbi S

    2015-03-01

    An Ehrlichia muris-like (EML) bacterium was recently detected in humans and Ixodes scapularis ticks in Minnesota and Wisconsin. The reservoir for this agent is unknown. To investigate the occurrence of the EML agent, groEL PCR testing and sequencing was performed on blood from small mammals and white-tailed deer that were collected in areas where human and tick infections were previously demonstrated. DNA of the EML agent was detected in two Peromyscus leucopus of 146 small mammals (1.4%); while 181 O. virginianus tested negative. This report provides the first evidence that DNA from the EML agent is found in P. leucopus, the same animal that is a reservoir for Anaplasma phagocytophilum in this region. The role of white-tailed deer remains inconclusive. Further sampling is warranted to understand the spatial and temporal distribution, transmission and maintenance of this pathogen. Copyright © 2014 Elsevier GmbH. All rights reserved.

  13. First evidence of feline herpesvirus, calicivirus, parvovirus, and Ehrlichia exposure in Brazilian free-ranging felids.

    PubMed

    Filoni, Claudia; Catão-Dias, José Luiz; Bay, Gert; Durigon, Edison Luiz; Jorge, Rodrigo Silva Pinto; Lutz, Hans; Hofmann-Lehmann, Regina

    2006-04-01

    Serum samples from 18 pumas (Puma concolor), one ocelot (Leopardus pardalis), and two little spotted cats (Leopardus tigrinus) collected from free-ranging animals in Brazil between 1998 and 2004 were tested by indirect immunofluorescence (IFA) for antibodies to feline herpesvirus 1 (FHV 1), calicivirus (FCV), coronavirus (FCoV), parvo-virus (FPV), Ehrlichia canis, Anaplasma pha-gocytophilum, and Bartonella henselae. Serum samples also were tested, by Western blot and ELISA, for feline leukemia virus (FeLV) specific antibodies and antigen, respectively, by Western blot for antibodies to feline immunodeficiency virus (FIV), and by indirect ELISA for antibodies to puma lentivirus (PLV). Antibodies to FHV 1, FCV, FCoV, FPV, FeLV, FIV, PLV or related viruses, and to B. henselae were detected. Furthermore, high-titered antibodies to E. canis or a closely related agent were detected in a puma for the first time.

  14. Results from an indirect fluorescent antibody test using three different strains of Ehrlichia canis.

    PubMed

    Aguirre, Enara; Ayllón, Tania; Sainz, Angel; Amusategui, Inmaculada; Villaescusa, Alejandra; Rodríguez-Franco, Fernando; Tesouro, Miguel A

    2009-11-01

    An indirect fluorescent antibody (IFA) test is usually performed to detect antibodies in dogs naturally infected by Ehrlichia canis. In this work, results obtained using three different E. canis strains as antigen (a commercial antigen, the E. canis Oklahoma strain and the E. canis Madrid strain) were compared. One hundred and forty-nine serum samples obtained from dogs living in the centre of Spain were analysed. When qualitative results were evaluated, identical results were detected in 87.2% of samples for the three antigens tested. When comparing antibody titre results, differences between the Madrid strain and the commercial antigen, and between the Madrid and Oklahoma strains were statistically significant (P<0.0001). No differences were found when comparing the Oklahoma strain with the commercial antigen (P=0.562). Subtle intra-laboratory variations shown in this study suggest a higher sensitivity of the IFA test when an autochthonous strain is used as antigen.

  15. Co-Feeding Transmission of the Ehrlichia muris–Like Agent to Mice (Mus musculus)

    PubMed Central

    Karpathy, Sandor E.; Allerdice, Michelle E.J.; Sheth, Mili; Dasch, Gregory A.; Levin, Michael L.

    2016-01-01

    The Ehrlichia muris–like agent (EMLA) is a newly recognized human pathogen found in Wisconsin and Minnesota. Ecological investigations have implicated both the blacklegged tick, Ixodes scapularis, and the white-footed mouse, Peromyscus leucopus, as playing roles in the maintenance of EMLA in nature. The work presented here shows that I. scapularis is an efficient vector of EMLA in a laboratory mouse model, but that Dermacentor variabilis, another frequent human biting tick found in EMLA endemic areas, is not. Additionally, I. scapularis larvae are able to acquire EMLA through co-feeding with infected nymphs. As EMLA only persists in mouse blood for a relatively short period of time, co-feeding transmission may play an important role in the maintenance of EMLA in ticks, and subsequently may play a role in limiting the geographic distribution of this pathogen in areas where co-feeding of larvae and nymphs is less common. PMID:26824725

  16. Tandem Air Propellers

    NASA Technical Reports Server (NTRS)

    Lesley, E.P.

    1937-01-01

    Tests of 2-blade, adjustable-pitch, counterrotating tandem model propellers, adjusted to absorb equal power at maximum efficiency, were made at Stanford University. The characteristics, for 15 degrees, 25 degrees, 35 degrees, and 45 degrees pitch settings at 0.75 R of the forward propeller and for 8 1/2%, 15% and 30% diameter spacings, were compared with those of 2-blade and 4-blade propellers of the same blade form. The tests showed that the efficiency of the tandem propellers was from 0.5% to 4% greater than that of a 4-blade propeller and, at the high pitch settings, not appreciable inferior to that of a 2-blade propeller. It was found that the rear tandem propeller should be set at a pitch angle slightly less than that of the forward propeller to realize the condition of equal power at maximum efficiency. Under this condition the total power absorbed by the tandem propellers was from 3% to 9% more than that absorbed by the 4-blade propeller and about twice that absorbed by a 2-blade propeller.

  17. Use of an automated system for detection of canine serum antibodies against Ehrlichia canis glycoprotein 36.

    PubMed

    Moroff, Scott; Sokolchik, Irene; Woodring, Todd; Woodruff, Colby; Atkinson, Brett; Lappin, Michael R

    2014-07-01

    Ehrlichia canis is the most common cause of monocytotropic ehrlichiosis in dogs around the world. The purpose of the present study was to validate a new automated fluorescence system (Accuplex4™ BioCD system; Antech Diagnostics, Lake Success, New York) to detect antibodies against the E. canis immunodominant glycoprotein 36 (gp36). Sera and blood samples (ethylenediamine tetra-acetic acid) were collected from mixed sex beagles ( n = 8) on days 0, 3, 7, 10, 14, 17, 21, 28, 42, 49, 56, 63, 70, 77, 84, and 98 after intravenous inoculation with culture-derived E. canis. Sera were assayed using the Accuplex4 BioCD system (Accuplex4), an E. canis indirect fluorescent antibody test (IFAT), and a commercially available kit. A complete blood cell count and a proprietary E. canis polymerase chain reaction (PCR) were performed on each blood sample. On the day thrombocytopenia was first detected for each dog, E. canis DNA was amplified from blood of all dogs. At those times, E. canis antibodies were detected in 7 of 8 dogs by the Accuplex4, 1 of 8 dogs by the commercial kit, and 4 of 8 dogs by IFAT. Ehrlichia canis DNA was amplified from blood before seroconversion in any antibody assay for 6 dogs. Antibodies against gp36 were detected by Accuplex4 within 3 days of PCR-positive test results and were detected up to 25 days sooner than the commercial kit. After starting doxycycline treatment, E. canis DNA was no longer amplified by PCR assay, but serum antibodies remained detectable by all assays.

  18. Bacterial Profiling Reveals Novel "Ca. Neoehrlichia", Ehrlichia, and Anaplasma Species in Australian Human-Biting Ticks.

    PubMed

    Gofton, Alexander W; Doggett, Stephen; Ratchford, Andrew; Oskam, Charlotte L; Paparini, Andrea; Ryan, Una; Irwin, Peter

    2015-01-01

    In Australia, a conclusive aetiology of Lyme disease-like illness in human patients remains elusive, despite growing numbers of people presenting with symptoms attributed to tick bites. In the present study, we surveyed the microbial communities harboured by human-biting ticks from across Australia to identify bacteria that may contribute to this syndrome. Universal PCR primers were used to amplify the V1-2 hyper-variable region of bacterial 16S rRNA genes in DNA samples from individual Ixodes holocyclus (n = 279), Amblyomma triguttatum (n = 167), Haemaphysalis bancrofti (n = 7), and H. longicornis (n = 7) ticks. The 16S amplicons were sequenced on the Illumina MiSeq platform and analysed in USEARCH, QIIME, and BLAST to assign genus and species-level taxonomies. Nested PCR and Sanger sequencing were used to confirm the NGS data and further analyse novel findings. All 460 ticks were negative for Borrelia spp. by both NGS and nested PCR analysis. Two novel "Candidatus Neoehrlichia" spp. were identified in 12.9% of I. holocyclus ticks. A novel Anaplasma sp. was identified in 1.8% of A. triguttatum ticks, and a novel Ehrlichia sp. was identified in both A. triguttatum (1.2%) ticks and a single I. holocyclus (0.6%) tick. Further phylogenetic analysis of novel "Ca. Neoehrlichia", Anaplasma and Ehrlichia based on 1,265 bp 16S rRNA gene sequences suggests that these are new species. Determining whether these newly discovered organisms cause disease in humans and animals, like closely related bacteria do abroad, is of public health importance and requires further investigation.

  19. Ehrlichia canis in dogs in a semiarid region of Northeastern Brazil: serology, molecular detection and associated factors.

    PubMed

    Tanikawa, A; Labruna, M B; Costa, A; Aguiar, D M; Justiniano, S V; Mendes, R S; Melo, A L T; Alves, C J; Azevedo, S S

    2013-06-01

    This study investigated infection by Ehrlichia spp. agents by PCR, immunofluorescence assay test (IFAT), and by Giemsa-stained blood smears in 108 dogs from a semiarid region of the state of Paraíba, Northeastern Brazil. Seventy-five (69.4%) of the 108 dogs were found to be seropositive to Ehrlichia canis, while only four dogs (3.7%) were positive in real-time PCR for E. canis. In six dogs (5.6%) E. canis-like morulae were observed in monocytes. Animals that stayed in environment whose floor was dried dirt, and dogs whose owners reported low frequency of cleaning the dog environment had higher (P<0.05) PCR positivity for E. canis. Increasing seropositivity was found in older dogs (P=0.012). This study provides the first molecular detection of E. canis in the semiarid region of Northeastern Brazil.

  20. Detection of Ehrlichia phagocytophila DNA in Ixodes ricinus Ticks from Areas in Switzerland Where Tick-Borne Fever Is Endemic

    PubMed Central

    Pusterla, Nicola; Huder, Jon B.; Lutz, Hans; Braun, Ueli

    1998-01-01

    A total of 1,523 adult Ixodes ricinus ticks were collected from regions where bovine ehrlichiosis is endemic and were examined for Ehrlichia phagocytophila via PCR. Of the ticks from cattle with ehrlichiosis, the ticks from healthy cattle, and the free-living ticks, 26.5% (18 of 68), 4.4% (35 of 802), and 0.8% (5 of 653), respectively, were positive. PMID:9705425

  1. Association of Ehrlichia canis, Hemotropic Mycoplasma spp. and Anaplasma platys and severe anemia in dogs in Thailand.

    PubMed

    Kaewmongkol, Gunn; Lukkana, Nicha; Yangtara, Sarawut; Kaewmongkol, Sarawan; Thengchaisri, Naris; Sirinarumitr, Theerapol; Jittapalapong, Sathaporn; Fenwick, Stanley G

    2017-03-01

    Canine tick-borne bacteria; Ehrlichia canis, hemotropic Mycoplasma spp. and Anaplasma spp., are organisms transmitted by Rhipicephalus sanguineus ticks. However, only a few clinical studies evaluating dogs infected with these organisms and anemia condition have been published. In this study, the potential tick-borne bacteria linked to anemia were investigated in eighty-one blood samples selected from anemic dogs using a broad range nested-PCR of the 16S rRNA gene. Positive results were shown in 12/81 blood specimens (14.81%). Nucleotide sequences from the PCR products were analyzed using BLAST and resulted in identification of Ehrlichia canis (8), Candidatus Mycoplasma haematoparvum (1) and Anaplasma platys (3). Two other PCR assays were used to detect and identify the positive results of these pathogens including a specific PCR for Ehrlichia canis (gp36) and a specific nested-PCR for hemoplasma species (16S rRNA) and the phylogenetic analyses of E. canis and canine hemoplasmas were performed using these two loci. These specific PCRs revealed co-infection of E. canis and Mycoplasma haemocanis in two cases. These two male dogs had presented with jaundice, severe hemolytic anemia, severe thrombocytopenia, leukocytosis, mild azotemia and hepatitis. Ehrlichia canis was detected in a significantly greater number of severe anemia cases (PCV<15%) than moderate or mild anemia cases (PCV 16-29%) (P<0.05) and these severe anemia cases were 7-fold more at risk of having E. canis infections (odds ratio: 7.11, p=0.020). However, no statistical differences were detected between E. canis detection and degrees of thrombocytopenia or leukopenia. From the results of this study, we conclude that the severity of anemia is associated with E. canis infections rather than the severity of thrombocytopenia.

  2. Bacteria of the genera Ehrlichia and Rickettsia in ticks of the family Ixodidae with medical importance in Argentina.

    PubMed

    Sebastian, Patrick S; Tarragona, Evelina L; Bottero, María N Saracho; Mangold, Atilio J; Mackenstedt, Ute; Nava, Santiago

    2017-01-01

    The aim of this study was to get an overview about the occurrence of bacteria from the genus Ehrlichia and Rickettsia in ixodid ticks with medical importance in Argentina. Therefore, in 2013 and 2014, free-living ticks were collected in different provinces of northern Argentina. These ticks were determined as Amblyomma sculptum, Amblyomma neumanni, Amblyomma parvum, Amblyomma triste, Amblyomma ovale, Amblyomma tonelliae and Haemaphysalis juxtakochi. All samples were tested to determine the infection with Ehrlichia spp. and Rickettsia spp. by PCR assays. Rickettsial DNA was detected in all tested tick species, with the exception of A. tonelliae. 'Candidatus Rickettsia amblyommii', 'Candidatus Rickettsia andeanae', and Rickettsia parkeri were found in A. neumanni, A. parvum, and A. triste, respectively. Another rickettsial species, Rickettsia bellii, was found in A. sculptum, A. ovale and H. juxtakochi. None of the tested ticks showed infection with Ehrlichia. The results of the study demonstrate that Rickettsia species belonging to the spotted fever group are associated with various species of Amblyomma throughout a wide area of northern Argentina, where cases of Amblyomma ticks biting humans are common.

  3. Molecular and serological detection of Ehrlichia canis in naturally exposed dogs in Iran: an analysis on associated risk factors.

    PubMed

    Maazi, Nadi; Malmasi, Abdolali; Shayan, Parviz; Nassiri, Seyed Mahdi; Salehi, Taghi Zahraei; Fard, Mojdeh Sharifian

    2014-03-01

    The general aim of this study, which was conducted for the first time in Iran, was to evaluate the seroprevalence and geographical distribution of Ehrlichia canis in a dog population in Iran, followed by molecular confirmation using PCR and sequencing. Blood samples were collected from 240 dogs in different areas of Alborz and Tehran Provinces and initially analyzed using the immunofluorescent antibody (IFA) test to detect anti-Ehrlichia canis IgG antibodies. Subsequently, nested PCR was performed based on a fragment of the 16S rRNA gene of E. canis on serologically positive samples. The results showed that 40/240 dogs (16.6%) presented anti-Ehrlichia canis IgG antibodies and that nine of the blood samples from the 40 seropositive dogs (22.5%) contained E. canis DNA, which was confirmed by sequencing. The seroprevalence of E. canis tended to be higher in purebred, one to three-year-old male dogs living in the Plain zone, in rural areas; however, this difference was not statistically significant.

  4. Lack of lysosomal fusion with phagosomes containing Ehrlichia risticii in P388D1 cells: abrogation of inhibition with oxytetracycline.

    PubMed Central

    Wells, M Y; Rikihisa, Y

    1988-01-01

    Fusion of lysosomes with phagosomes containing Ehrlichia risticii, an obligate intracellular parasite, was evaluated in P388D1 murine macrophagelike cells. Lysosomes in cells ranging in infectivity from 30 to 70% were labeled cytochemically with acid phosphatase or via endocytosis of thorium dioxide or cationized ferritin to document phagosome-lysosome (P-L) fusion in untreated cells and cells treated with oxytetracycline. Regardless of the marker used, P-L fusion was generally not observed in E. risticii-containing vacuoles in untreated cells, while significantly greater P-L fusion with ehrlichia-containing vacuoles was observed after oxytetracycline treatment. When latex beads were introduced into uninfected cell cultures, P-L fusion was observed with vacuoles containing latex. Fusion of lysosomes with latex-containing vacuoles in cells was significantly greater than fusion of lysosomes with ehrlichia-containing vacuoles in the same infected cells. These findings indicate that E. risticii is able to inhibit P-L fusion, whereas oxytetracycline deprives organisms of this ability. Images PMID:3182078

  5. Molecular detection of novel Anaplasmataceae closely related to Anaplasma platys and Ehrlichia canis in the dromedary camel (Camelus dromedarius).

    PubMed

    Bastos, Armanda D S; Mohammed, Osama B; Bennett, Nigel C; Petevinos, Charalambos; Alagaili, Abdulaziz N

    2015-09-30

    Serological surveys have confirmed Anaplasma marginale and Anaplasma phagocytophilum infections in dromedary camels, but molecular surveys and genetic characterisation of camel-associated Anaplasma species are lacking. In this study, we detected tick-borne Anaplasmataceae in 30 of 100 (30%) healthy dromedary camels screened using a combined 16S rRNA-groEL PCR-sequencing approach. Nucleotide sequencing confirmed Anaplasmataceae genome presence in 28 of the 33 16S rRNA PCR-positive samples, with two additional positive samples, for which 16S rRNA sequence data were ambiguous, being identified by groEL gene characterisation. Phylogenetic analyses of a 1289 nt segment of the 16S rRNA gene confirmed the presence of a unique Ehrlichia lineage and a discrete Anaplasma lineage, comprising three variants, occurring at an overall prevalence of 4% and 26%, respectively. Genetic characterisation of an aligned 559 nt groEL gene region revealed the camel-associated Anaplasma and Ehrlichia lineages to be novel and most closely related to Anaplasma platys and Ehrlichia canis. Based on the confirmed monophyly, minimum pairwise genetic distances between each novel lineage and its closest sister taxon, and the inability to isolate the bacteria, we propose that Candidatus status be assigned to each. This first genetic characterisation of Anaplasmataceae from naturally infected, asymptomatic dromedary camels in Saudi Arabia confirms the presence of two novel lineages that are phylogenetically linked to two pathogenic canid species of increasing zoonotic concern.

  6. Rangelia vitalii, Babesia spp. and Ehrlichia spp. in dogs in Passo Fundo, state of Rio Grande do Sul, Brazil.

    PubMed

    Gottlieb, Juliana; André, Marcos Rogério; Soares, João Fábio; Gonçalves, Luiz Ricardo; Tonial de Oliveira, Mateus; Costa, Marcio Machado; Labruna, Marcelo Bahia; Bortolini, Carlos Eduardo; Machado, Rosangela Zacarias; Vieira, Maria Isabel Botelho

    2016-06-14

    Pathogens transmitted by ticks are an emerging problem worldwide, this study aimed to diagnose the causal agents of infection in dogs presenting suspected hemoparasitoses. Fifty-eight dogs with clinical signs such as depression, hemorrhagic diathesis and fever were evaluated regarding clinical presentation, hemogram, blood smears and serological tests, using the indirect immunofluorescence method for the agents Babesia vogeli and Ehrlichia canis and conventional PCR for Babesia spp. (gene 18S rRNA), Rangelia vitalii (gene 18S rRNA) and Ehrlichia spp. (gene dsb). Five (8.6%) of the 58 dogs were serologically positive for Babesia spp. and three (5.1%) for E. canis. Four dogs (6.8%) were positive for R. vitalii through the molecular diagnosis. The PCR products were sequenced and the DNA from R. vitalii was found to be 99% genetically identical to samples of R. vitalii that had been isolated in Brazil. No presence of Babesia spp. or E. canis was observed through PCR on the dogs evaluated here. The results indicate the presence of R. vitalii and exposure to Babesia spp. and Ehrlichia spp. among the dogs analyzed.

  7. Fatal Monocytic Ehrlichiosis in Woman, Mexico, 2013

    PubMed Central

    Sosa-Gutierrez, Carolina G.; Solorzano-Santos, Fortino; Walker, David H.; Torres, Javier; Serrano, Carlos A.

    2016-01-01

    Human monocytic ehrlichiosis is a febrile illness caused by Ehrlichia chaffeensis, an intracellular bacterium transmitted by ticks. In Mexico, a case of E. chaffeensis infection in an immunocompetent 31-year-old woman without recognized tick bite was fatal. This diagnosis should be considered for patients with fever, leukopenia, thrombocytopenia, and elevated liver enzyme levels. PMID:27088220

  8. Fatal Monocytic Ehrlichiosis in Woman, Mexico, 2013.

    PubMed

    Sosa-Gutierrez, Carolina G; Solorzano-Santos, Fortino; Walker, David H; Torres, Javier; Serrano, Carlos A; Gordillo-Perez, Guadalupe

    2016-05-01

    Human monocytic ehrlichiosis is a febrile illness caused by Ehrlichia chaffeensis, an intracellular bacterium transmitted by ticks. In Mexico, a case of E. chaffeensis infection in an immunocompetent 31-year-old woman without recognized tick bite was fatal. This diagnosis should be considered for patients with fever, leukopenia, thrombocytopenia, and elevated liver enzyme levels.

  9. Tandem resonator reflectance modulator

    DOEpatents

    Fritz, I.J.; Wendt, J.R.

    1994-09-06

    A wide band optical modulator is grown on a substrate as tandem Fabry-Perot resonators including three mirrors spaced by two cavities. The absorption of one cavity is changed relative to the absorption of the other cavity by an applied electric field, to cause a change in total reflected light, as light reflecting from the outer mirrors is in phase and light reflecting from the inner mirror is out of phase with light from the outer mirrors. 8 figs.

  10. Tandem resonator reflectance modulator

    DOEpatents

    Fritz, Ian J.; Wendt, Joel R.

    1994-01-01

    A wide band optical modulator is grown on a substrate as tandem Fabry-Perot resonators including three mirrors spaced by two cavities. The absorption of one cavity is changed relative to the absorption of the other cavity by an applied electric field, to cause a change in total reflected light, as light reflecting from the outer mirrors is in phase and light reflecting from the inner mirror is out of phase with light from the outer mirrors.

  11. Bifacial tandem solar cells

    DOEpatents

    Wojtczuk, Steven J.; Chiu, Philip T.; Zhang, Xuebing; Gagnon, Edward; Timmons, Michael

    2016-06-14

    A method of fabricating on a semiconductor substrate bifacial tandem solar cells with semiconductor subcells having a lower bandgap than the substrate bandgap on one side of the substrate and with subcells having a higher bandgap than the substrate on the other including, first, growing a lower bandgap subcell on one substrate side that uses only the same periodic table group V material in the dislocation-reducing grading layers and bottom subcells as is present in the substrate and after the initial growth is complete and then flipping the substrate and growing the higher bandgap subcells on the opposite substrate side which can be of different group V material.

  12. Monolithic tandem solar cell

    DOEpatents

    Wanlass, Mark W.

    1991-01-01

    A single-crystal, monolithic, tandem, photovoltaic solar cell is described which includes (a) an InP substrate having upper and lower surfaces, (b) a first photoactive subcell on the upper surface of the InP substrate, and (c) a second photoactive subcell on the first subcell. The first photoactive subcell is GaInAsP of defined composition. The second subcell is InP. The two subcells are lattice matched. The solar cell can be provided as a two-terminal device or a three-terminal device.

  13. Negative tandem mirror

    SciTech Connect

    Poulsen, P.; Allen, S.L.; Casper, T.A.; Grubb, D.P.; Jong, R.A.; Nexsen, W.E.; Porter, G.D.; Simonen, T.C.

    1981-11-30

    A tandem mirror configuration can be created by combining hot electron end cell plasmas with neutral beam pumping. A region of large negative potential formed in each end cell confines electrons in the central cell. The requirement of charge neutrality causes the central cell potential to become negative with respect to ground in order to confine ions as well as electrons. We discuss the method of producing and calculating the desired axial potential profile, and show the calculated axial potential profile and plasma parameters for a negative configuration of TMX-Upgrade.

  14. Field evidence that roe deer (Capreolus capreolus) are a natural host for Ehrlichia phagocytophila.

    PubMed Central

    Alberdi, M. P.; Walker, A. R.; Urquhart, K. A.

    2000-01-01

    Samples of blood, spleen and legs from 112 culled roe deer (Capreolus capreolus) were collected from nine sites widespread in the United Kingdom. The prevalence of infection with Ehrlichia phagocytophila was determined by serology and polymerase chain reaction. Means of 58% of 102 plasma or serum samples were seroreactive by IFA, 38% of 84 blood samples and 29% of 82 spleen samples were positive by PCR. Ticks on legs of 71 roe deer were Ixodes ricinus larvae, nymphs and adults and 83% of legs were infested. Numbers of ticks corresponded positively to the percentage of samples positive for E. phagocytophila by serology and PCR for different sampling sites. Ixodes ricinus nymphs collected from the vegetation at one site with infected deer were analysed for infection with E. phagocytophila by examination of Feulgen stained salivary glands. Of 135 nymphs 5% were infected. These results confirm that roe deer are commonly parasitized by both E. phagocytophila and its vector tick in such a way that it is likely to be an important natural mammalian reservoir of E. phagocytophila. PMID:10813158

  15. Iron metabolism and oxidative profile of dogs naturally infected by Ehrlichia canis: Acute and subclinical disease.

    PubMed

    Bottari, Nathieli B; Crivellenti, Leandro Z; Borin-Crivellenti, Sofia; Oliveira, Jéssica R; Coelho, Stefanie B; Contin, Catarina M; Tatsch, Etiane; Moresco, Rafael N; Santana, Aureo E; Tonin, Alexandre A; Tinucci-Costa, Mirela; Da Silva, Aleksandro S

    2016-03-01

    The aim of this study was to evaluate the oxidant profile and iron metabolism in serum of dogs infected by Ehrlichia canis. Banked sera samples of dogs were divided into two groups: negative control (n = 17) and infected by E. canis on acute (n = 24), and subclinical (n = 18) phases of the disease. The eritrogram, leucogram, and platelet counts were evaluate as well as iron, ferritin, and transferrin levels, latent iron binding capacity (LIBC), and transferrin saturation index (TSI) concentration. In addition, the advanced oxidation protein products (AOPP) and ferric reducing ability of plasma (FRAP) in sera were also analyzed. Blood samples were examined for the presence of E. canis by PCR techniques. History and clinical signals were recorded for each dog. During the acute phase of the disease, infected animals showed thrombocytopenia and anemia when compared to healthy animals (P < 0.05) as a consequence of lower iron levels. Ferritin and transferrin levels were higher in both phases (acute and subclinical) of the disease. The AOPP and FRAP levels increased in infected animals on the acute phase; however, the opposite occurred in the subclinical phase. We concluded that dogs naturally infected by E. canis showed changes in the iron metabolism and developed an oxidant status in consequence of disease pathophysiology.

  16. The occurrence of Dirofilaria immitis, Borrelia burgdorferi, Ehrlichia canis and Anaplasma phagocytophium in dogs in China.

    PubMed

    Xia, Z; Yu, D; Mao, J; Zhang, Z; Yu, J

    2012-06-01

    A survey of the occurrence of Dirofilaria immitis, Borrelia burgdorferi, Ehrlichia canis and Anaplasma phagocytophium in dogs was undertaken in the People's Republic of China between October 2008 and October 2009. A total of 600 blood samples were taken from dogs in four cities in China: 300 in Beijing, 150 in Shenzhen, 30 in Shanghai and 120 in Zhengzhou. All samples were tested for the heartworm antigen and antibodies of canine B. burgdorferi, E. canis and A. phagocytophium by using the canine SNAP® 4Dx® test kit. The occurrence of D. immitis, B. burgdorferi, E. canis and A. phagocytophium was 1.17% (7/600), 0.17% (1/600), 2.17% (13/600) and 0.5% (3/600), respectively. In Shenzhen city 2% (3/150), 8.67% (13/150) and 2% (3/150) of samples were positive for D. immitis, E. canis and A. phagocytophium, respectively. The occurrence of heartworm antigen was 0.33% (1/300) in Beijing, 2.00% (3/150) in Shenzhen, 3.33% (1/30) in Shanghai and 1.67% (2/120) in Zhengzhou. We found E. canis and A. phagocytophium only at one site, Shenzhen, while the only occurrence of B. burgdorferi was at Beijing. In conclusion, the dog population in China is at potential risk for D. immitis, B. burgdorferi, E. canis and A. phagocytophium infection, the risk being especially high in southern China.

  17. Molecular and serological detection of Ehrlichia canis and Babesia vogeli in dogs in Colombia.

    PubMed

    Vargas-Hernández, G; André, M R; Faria, J L M; Munhoz, T D; Hernandez-Rodriguez, M; Machado, R Z; Tinucci-Costa, M

    2012-05-25

    Ehrlichiosis and babesiosis are tick-borne diseases, caused mainly by Ehrlichia canis and Babesia canis, respectively, with a worldwide occurrence in dogs, whose main vector is the brown-dog tick, Rhipicephalus sanguineus. The present work aimed to detect the presence of E. canis and Babesia sp. in 91 dog blood samples in Colombia, by molecular and serological techniques. We also performed sequence alignment to indicate the identity of the parasite species infecting these animals. The present work shows the first molecular detection of E. canis and B. vogeli in dogs from Colombia. Immunoglobulin-G (IgG) antibodies to E. canis and Babesia vogeli were found in 75 (82.4%) and 47 (51.6%) sampled dogs, respectively. Thirty-seven (40.6%) and 5 (5.5%) dogs were positive in PCR for E. canis and Babesia sp., respectively. After sequencing, amplicons showed 99% of identity with isolates of E. canis and B. vogeli. The phylogenetic trees based on 16S rRNA-Anaplasmataceae sequences and 18S rRNA-piroplasmid sequences supported the identity of the found E. canis and B. vogeli DNAs, respectively. The present work shows the first molecular detection of E. canis and B. vogeli in dogs in Colombia.

  18. First record of autochthonous canine ehrlichiosis caused by Ehrlichia canis in Romania.

    PubMed

    Morar, Doru; Dărăbuş, Gheorghe; Imre, Mirela; Ilie, Marius Stelian; Imre, Kálmán

    2015-06-01

    This case study describes the first genetically confirmed and clinically manifested autochthonous Ehrlichia canis infection in a 9-year-old female mixed-breed dog from Romania. Health screening of the dog included clinical examination, evaluation of stained peripheral blood smear and hematologic variables, as well as serologic testing and molecular analysis. Clinical signs included fever, apathy, dehydration, pale mucous membranes, and weakness. The microscopic examination of the blood smear and immunologic assays for Borrelia burgdorferi, Anaplasma phagocytophilum, and E canis antibodies, and for Dirofilaria immitis antigen yielded negative results. Hematologic abnormalities included moderate nonregenerative anemia, leucopenia with neutropenia, and moderate thrombocytopenia. The biochemical abnormalities identified were hypoalbuminemia, and mildly increased serum enzyme activities of AST and ALT. In addition, increased urea and creatinine levels associated with low urine specific gravity and proteinuria were also present. Nested PCR amplification of the partial E canis 16S rRNA gene demonstrated the presence of this rickettsial pathogen in the dog's blood, which subsequently was confirmed through sequencing based on the 100% homology with GenBank deposited E canis isolates. After specific treatment with doxycycline (10 mg/kg, orally, SID) for one month, the proteinuria, and hematologic and serum biochemical abnormalities with the exception of mild azotemia resolved. This report supports the geographical expansion of canine ehrlichiosis caused by E canis in nonendemic regions of Europe.

  19. Occurrence of Ehrlichia canis and Anaplasma platys in household dogs from northern Parana.

    PubMed

    da Silva, Gislaine Cristina Ferreira; Benitez, Aline do Nascimento; Girotto, Aline; Taroda, Alessandra; Vidotto, Marilda Carlos; Garcia, João Luis; de Freitas, Julio Cesar; Arlington, Selwyn Headley; Vidotto, Odilon

    2012-01-01

    Canine monocytic ehrlichiosis caused primarily by Ehrlichia canis and canine thrombocytic anaplasmosis induced by Anaplasma platys are important emerging zoonotic tick-borne diseases of dogs. There is evidence that these pathogens can also affect humans. This study evaluated the presence of E. canis and A. platys in blood samples collected from 256 domiciled dogs in the municipality of Jataizinho, located in north region of the State of Parana, Brazil, by PCR assay. The occurrence of E. canis and A. platys was 16.4% (42/256) and 19.4% (49/256), respectively; while 5.47% (14/256) of the dogs evaluated were co-infected by these two organisms. The presence of E. canis and A. platys was not significantly associated with the variables evaluated (sex, age, outdoor access, and presence of ticks during blood collection). Infection of dogs by E. canis was associated with anemia and thrombocytopenia, while infection induced by A. platys was related only to thrombocytopenia. Canine monocytic ehrlichiosis and canine thrombocytic anaplasmosis should be included in the differential diagnoses when these hematological alterations are observed during routine laboratory evaluation of dogs.

  20. Molecular Diagnosis of Ehrlichia canis in Dogs and Ticks Rhipicephalus sanguineus (Acari: Ixodidae) in Yucatan, Mexico.

    PubMed

    Pat-Nah, Henry; Rodriguez-Vivas, Roger Ivan; Bolio-Gonzalez, Manuel Emilio; Villegas-Perez, Sandra Luz; Reyes-Novelo, Enrique

    2015-01-01

    Ehrlichia canis is the etiological agent behind canine monocytic ehrlichiosis, and the tick Rhipicephalus sanguineus (Latreille) is its main vector. Blood smear and nested polymerase chain reaction (PCR) techniques were used to identify E. canis infection in dogs and R. sanguineus, and explore factors possibly associated with infection in dogs in Yucatan, Mexico. Blood samples were taken and ticks R. sanguineus collected from 50 dogs (10 house dogs and 40 in an animal control center). Data were collected on dog age, sex, body condition, and signs associated with platelet deficiencies (epistaxis). Blood smears were analyzed to identify E. canis morulae and generate platelet counts. Nested PCR analysis was done on blood samples and 200 ticks. A χ(2) test was done to identify factors associated with the E. canis infection in the tested dogs. The overall prevalence for infection, as determined by PCR, was 36% (18 out of 50). All positive dogs were from samples collected from the animal shelter, representing prevalence, for this sampling site, of 45% (18 out of 40). Morulae in monocytes were identified in only 4% of samples. Dog origin (i.e. animal control center) was the only variable associated with E. canis infection (P < 0.01). Male ticks had a higher (P < 0.05) infection rate than female ticks (24.5 vs 13.5%). It is concluded that E. canis infection is present in both dogs and the brown dog ticks R. sanguineus in Yucatan, Mexico.

  1. Genetic diversity of Ehrlichia canis strains from naturally infected dogs in Rio de Janeiro, Brazil.

    PubMed

    Ferreira, Renata Fernandes; Cerqueira, Aloysio de Mello Figueiredo; Castro, Tatiana Xavier de; Ferreira, Eliane de Oliveira; Neves, Felipe Piedade Gonçalves; Barbosa, André Victor; Macieira, Daniel de Barros; Almosny, Nádia Regina Pereira

    2014-01-01

    The aim of this study was to characterize Ehrlichia canis strains from naturally infected dogs in Rio de Janeiro, Brazil. In addition, all the clinical and hematological findings observed in these dogs were reported. PCR targeting the 16S rRNA gene was used for diagnostic purposes, and the TRP19 and TRP36 genes were sequenced to evaluate the genetic diversity. Fifteen samples were positive for E. canis. The polymerase chain reaction for the TRP19 gene resulted in 11 amplicons (11/15), which were cloned into the pGEM-T easy vector for sequencing. The complete sequence of TRP19 gene was compared to those in the GenBank, revealing high identicalness. Phylogenetic analysis on the TRP36 gene sequences demonstrated two distinct strains from two dogs, named 56C and 70C. The 56C strain was grouped with the strain Cuiaba 16, which is a hybrid strain formed by Brazilian and US genogroups; and the 70C strain was grouped with other strains of the US genogroup, thus suggesting that there are at least two genogroups of E. canis in Rio de Janeiro (US and Brazilian). Those animals, in which the 70C and 56C strains were isolated, showed distinct clinical and hematological manifestations of the disease. The appearance of different genotypes may express new phenotypes, thus resulting in different forms of presentation of the disease and making its diagnosis more complex.

  2. Detection of Ehrlichia canis and Anaplasma platys DNA using multiplex PCR.

    PubMed

    Rufino, Claudia Pinheiro; Moraes, Pablo Henrique Gonçalves; Reis, Thais; Campos, Ruan; Aguiar, Délia Cristina Figueira; McCulloch, John Anthony; Meneses, Andre Marcelo Conceição; Gonçalves, Evonnildo Costa

    2013-12-01

    We hereby propose a novel sensitive, specific, and cost-efficient method to detect Ehrlichia canis and Anaplasma platys DNA from canine whole blood samples by multiplex PCR. Blood samples from hemoparasited dogs attending the Veterinary Hospital at the Universidade Federal Rural da Amazônia-UFRA, Belém, Brazil, were collected in tubes containing EDTA. Amplification of E. canis and A. platys 16S rDNA by nested (n) PCR was successfully achieved by using primers specific to the Anaplasmataceae in the first round of PCR, followed by a second round of PCR using E. canis-specific primers in conjunction with A. platys-specific primers. The amplicons obtained were cloned and sequenced, yielding sequences of 478 and 473 bp (including primers) pertaining to regions of the 16S rDNA of E. canis and A. platys, respectively. The protocol we here propose may help to measure the prevalence of canine monocytic ehrlichiosis (CME) and canine cyclic thrompocytopenia, not only in northern Brazil, where there is no data available, but also elsewhere.

  3. Molecular detection of Anaplasma platys and Ehrlichia canis in dogs from Kabylie, Algeria.

    PubMed

    Dahmani, Mustapha; Loudahi, Abdelghani; Mediannikov, Oleg; Fenollar, Florence; Raoult, Didier; Davoust, Bernard

    2015-03-01

    Ehrlichia canis and Anaplasma platys are bacteria belonging to the Anaplasmataceae family that cause acute, self-limiting and sometimes fatal vector-borne infections in dogs. These bacteria have been reported worldwide and are transmitted mainly by Rhipicephalus sanguineus. Aside from a report on E. canis once in 1935, no other Anaplasmataceae bacteria have been reported in Algeria to date. The aim of this study was to identify the microbial species implicated in ehrlichiosis and anaplasmosis by a molecular epidemiological survey in dogs. The study was carried out in Kabylie, in northeast Algeria. Sampling was performed in 11 municipalities in the province of Tizi Ouzou and 2 municipalities in the province of Béjaïa. Peripheral blood samples from 110 dogs were screened by qPCR, which is capable of identifying most Anaplasmataceae bacteria. Out of 110, a total of 13 samples screened positive (7/110 E. canis and 6/110 A. platys), and two genetic variants of A. platys and one of E. canis were identified. This is the first study to report the presence of A. platys in dogs from Algeria using a molecular investigative method. This survey was conducted in early spring. As tick activity can affect the prevalence of these pathogens in dogs, further investigations are needed to establish the year-round prevalence of these infections.

  4. Serum canine pancreatic lipase immunoreactivity in experimentally induced and naturally occurring canine monocytic ehrlichiosis (Ehrlichia canis).

    PubMed

    Mylonakis, Mathios E; Xenoulis, Panagiotis G; Theodorou, Konstantina; Siarkou, Victoria I; Steiner, Jörg M; Harrus, Shimon; Leontides, Leonidas; Rallis, Timoleon; Suchodolski, Jan S; Koutinas, Christos K; Koutinas, Alexander F

    2014-03-14

    Ehrlichia canis infection causes multisystemic disease in dogs (canine monocytic ehrlichiosis, CME) which is associated with variable morbidity and mortality. Atypical clinical manifestations, including gastrointestinal signs, may occasionally occur in CME and approximately 10-15% of dogs are presented with historical or clinical evidence of vomiting, diarrhea, and/or abdominal discomfort. The objective of this study was to investigate if there are any alterations in serum canine pancreatic lipase immunoreactivity (cPLI) in dogs with experimentally induced or naturally occurring monocytic ehrlichiosis. Serum samples from 10 Beagle dogs experimentally infected with E. canis and two healthy uninfected Beagles were serially examined; samples from 20 naturally infected dogs (10 with non-myelosuppressive [NME] and 10 with myelosuppressive [ME] ehrlichiosis) were also examined at a given point in time (cross-sectional sampling). None of the experimentally infected Beagles showed gastrointestinal signs or increased cPLI concentrations prior to or following the artificial infection. Three naturally infected dogs with NME and one with ME demonstrated serum cPLI concentrations in the diagnostic range for pancreatitis (>400 μg/L) without showing gastrointestinal signs. The results of the present study indicated that 4/20 (20%) of dogs naturally infected with E. canis demonstrated increased serum cPLI concentrations consistent with mild and clinically inapparent pancreatitis.

  5. Synovial fluid cytology in experimental acute canine monocytic ehrlichiosis (Ehrlichia canis).

    PubMed

    Theodorou, Konstantina; Leontides, Leonidas; Siarkou, Victoria I; Petanides, Theodoros; Tsafas, Konstantinos; Harrus, Shimon; Mylonakis, Mathios E

    2015-05-15

    Evidence-based information of a cause-and-effect relationship between Ehrlichia canis infection and polyarthritis in naturally- or experimentally-infected dogs is currently lacking. The aim of this prospective study was to investigate whether synovial fluid cytological evidence of arthritis could be documented in dogs with acute monocytic ehrlichiosis. Direct synovial fluid cytology smears from eight Beagle dogs experimentally infected with E. canis were examined prior to, and on 21, 35 and 63 days post-inoculation. The cytological variables assessed included cellularity, percentages of mononuclear cells and neutrophils, macrophage reactivity and evidence of E. canis morulae. The median cellularity and percentages of mononuclear cells and neutrophils prior to inoculation did not differ when compared to post-inoculation cytological evaluation. Increased cellularity, E. canis morulae or cytological evidence of arthritis or macrophage reactivity were not observed throughout the course of the study. In the present study, no cytological evidence of arthritis was found in dogs with experimental acute canine monocytic ehrlichiosis, suggesting that E. canis infection should be considered a rather uncommon cause of arthritis in dogs.

  6. Sequence and phylogenetic analysis of the gp200 protein of Ehrlichia canis from dogs in Taiwan.

    PubMed

    Huang, Chia-Chia; Hsieh, Yu-Chen; Tsang, Chau-Loong; Chung, Yang-Tsung

    2010-12-01

    Ehrlichia (E.) canis is a Gram-negative obligate intracellular bacterium responsible for canine monocytic ehrlichiosis. Currently, the genetic diversity of E. canis strains worldwide is poorly defined. In the present study, sequence analysis of the nearly full-length 16S rDNA (1,620 bp) and the complete coding region (4,269 bp) of the gp200 gene, which encodes the largest major immunoreactive protein in E. canis, from 17 Taiwanese samples was conducted. The resultant 16S rDNA sequences were found to be identical to each other and have very high homology (99.4~100%) with previously reported E. canis sequences. Additionally, phylogenetic analysis of gp200 demonstrated that the E. canis Taiwanese genotype was genetically distinct from other reported isolates obtained from the United States, Brazil, and Israel, and that it formed a separate clade. Remarkable variations unique to the Taiwanese genotype were found throughout the deduced amino acid sequence of gp200, including 15 substitutions occurring in two of five known species-specific epitopes. The gp200 amino acid sequences of the Taiwanese genotype bore 94.4~94.6 identities with those of the isolates from the United States and Brazil, and 93.7% homology with that of the Israeli isolate. Taken together, these results suggest that the Taiwanese genotype represents a novel strain of E. canis that has not yet been characterized.

  7. Molecular survey of Ehrlichia canis and Coxiella burnetii infections in wild mammals of southern Italy.

    PubMed

    Santoro, Mario; Veneziano, Vincenzo; D'Alessio, Nicola; Di Prisco, Francesca; Lucibelli, Maria Gabriella; Borriello, Giorgia; Cerrone, Anna; Dantas-Torres, Filipe; Latrofa, Maria Stefania; Otranto, Domenico; Galiero, Giorgio

    2016-11-01

    Ehrlichiosis and Q fever caused by the intracellular bacteria Ehrlichia canis and Coxiella burnetii, respectively, are tick-borne diseases with zoonotic potential and widespread geographical distribution. This study investigated the prevalence of both infections in wild mammals in southern Italy. Tissue samples obtained from the red fox (Vulpes vulpes), European badger (Meles meles), gray wolf (Canis lupus), beech marten (Martes foina), and crested porcupine (Hystrix cristata) were processed for molecular detection of both pathogens. E. canis was detected in 55 out of 105 (52 %) red foxes and three out of six gray wolves. Four sequence types were identified, three of which were found in the spleen and liver samples of red foxes and wolves, and one in the kidney of a red fox. None of the examined mammals was positive to C. burnetii type. This represents the first report of E. canis in free-ranging wolves worldwide, as well as the first evidence of this pathogen in red foxes in the peninsular Italy. Our results suggest that E. canis infection is common in free-ranging canids in southern Italy and that a sylvatic life cycle of this pathogen may occur.

  8. Experimental evaluation of Peromyscus leucopus as a reservoir host of the Ehrlichia muris-like agent.

    PubMed

    Lynn, Geoffrey E; Oliver, Jonathan D; Cornax, Ingrid; O'Sullivan, M Gerard; Munderloh, Ulrike G

    2017-01-28

    The Ehrlichia muris-like agent (EMLA) is a newly recognized human pathogen in the North Central United States. Although blacklegged ticks (Ixodes scapularis) have been identified as capable vectors, wild reservoirs have not yet been established for EMLA. As key hosts for I. scapularis, white-footed mice (Peromyscus leucopus) are important reservoirs for various tick-borne pathogens, and potentially, for EMLA. The objective of this study was to evaluate reservoir competence in P. leucopus using a natural vector. Mice acquired EMLA infection from feeding ticks and were able to transmit infection to naïve ticks. Transmission between simultaneously feeding tick life stages was also demonstrated. Infections in mice were acute and severe, with systemic dissemination. Limited host survival and clearance of infection among survivors resulted in a narrow interval where EMLA could be acquired by feeding ticks. Peromyscus leucopus is a competent reservoir of EMLA and likely to play a role in its enzootic transmission cycle. The duration and severity of EMLA infection in these hosts suggests that tick phenology is a critical factor determining the geographic distribution of EMLA in North America.

  9. Colorimetric detection of Ehrlichia canis via nucleic acid hybridization in gold nano-colloids.

    PubMed

    Muangchuen, Ajima; Chaumpluk, Piyasak; Suriyasomboon, Annop; Ekgasit, Sanong

    2014-08-08

    Canine monocytic ehrlichiosis (CME) is a major thick-bone disease of dog caused by Ehrlichia canis. Detection of this causal agent outside the laboratory using conventional methods is not effective enough. Thus an assay for E. canis detection based on the p30 outer membrane protein gene was developed. It was based on the p30 gene amplification using loop-mediated isothermal DNA amplification (LAMP). The primer set specific to six areas within the target gene were designed and tested for their sensitivity and specificity. Detection of DNA signals was based on modulation of gold nanoparticles' surface properties and performing DNA/DNA hybridization using an oligonucleotide probe. Presence of target DNA affected the gold colloid nanoparticles in terms of particle aggregation with a plasmonic color change of the gold colloids from ruby red to purple, visible by the naked eye. All the assay steps were completed within 90 min including DNA extraction without relying on standard laboratory facilities. This method was very specific to target bacteria. Its sensitivity with probe hybridization was sufficient to detect 50 copies of target DNA. This method should provide an alternative choice for point of care control and management of the disease.

  10. Molecular detection and phylogenetic analysis of Ehrlichia canis in a Philippine dog.

    PubMed

    Maekawa, Naoya; Konnai, Satoru; Balbin, Michelle M; Mingala, Claro N; Gicana, Karlo R B; Bernando, Francis A E M; Murata, Shiro; Ohashi, Kazuhiko

    2017-09-20

    Canine monocytic ehrlichiosis (CME), caused by a rickettsial bacterium, Ehrlichia canis, is distributed worldwide, particularly in tropical and subtropical regions. Transmission of E. canis is primarily mediated by the vector tick, Rhipicephalus sanguineus sensu lato and the bacteria then infect and replicate in monocytes and macrophages. Many cases are seen in veterinary hospitals and treated routinely; however, the genetic variation of E. canis strains found in the Philippines has been poorly investigated to date. In this study, the 16S rRNA gene and the gp200 gene of E. canis were detected by polymerase chain reaction from an infected dog in the Philippines, and the deduced amino acid sequence of the gp200 gene was subjected to a phylogenetic analysis. The Philippine genotype formed a cluster with the Taiwan genotype, and was somewhat divergent from the USA and Brazil strains. This suggested that E. canis underwent evolution in East and Southeast Asia, confirming the utility of the gp200 gene for the assessment of genetic relationships among strains. Copyright © 2017 Elsevier GmbH. All rights reserved.

  11. Colorimetric Detection of Ehrlichia Canis via Nucleic Acid Hybridization in Gold Nano-Colloids

    PubMed Central

    Muangchuen, Ajima; Chaumpluk, Piyasak; Suriyasomboon, Annop; Ekgasit, Sanong

    2014-01-01

    Canine monocytic ehrlichiosis (CME) is a major thick-bone disease of dog caused by Ehrlichia canis. Detection of this causal agent outside the laboratory using conventional methods is not effective enough. Thus an assay for E. canis detection based on the p30 outer membrane protein gene was developed. It was based on the p30 gene amplification using loop-mediated isothermal DNA amplification (LAMP). The primer set specific to six areas within the target gene were designed and tested for their sensitivity and specificity. Detection of DNA signals was based on modulation of gold nanoparticles' surface properties and performing DNA/DNA hybridization using an oligonucleotide probe. Presence of target DNA affected the gold colloid nanoparticles in terms of particle aggregation with a plasmonic color change of the gold colloids from ruby red to purple, visible by the naked eye. All the assay steps were completed within 90 min including DNA extraction without relying on standard laboratory facilities. This method was very specific to target bacteria. Its sensitivity with probe hybridization was sufficient to detect 50 copies of target DNA. This method should provide an alternative choice for point of care control and management of the disease. PMID:25111239

  12. Ehrlichia ruminantium grows in cell lines from four ixodid tick genera.

    PubMed

    Bell-Sakyi, L

    2004-05-01

    Continuous cell lines from the ticks Amblyomma variegatum, Boophilus decoloratus, Boophilus microplus, Hyalomma anatolicum anatolicum, Ixodes scapularis, Ixodes ricinus and Rhipicephalus appendiculatus were tested for ability to support growth of the rickettsial pathogen Ehrlichia (previously Cowdria) ruminantium. Five E.ruminantium isolates, from West Africa, South Africa and the French West Indies, were used. Twelve tick cell lines were inoculated with E.ruminantium derived either from cultures of a bovine endothelial cell strain designated BPC or from other tick cell lines. Successful infection resulted in either continuous growth (in which the pathogen/cell line system could be perpetuated through regular subculture on fresh, uninfected cells for many months or years) or finite growth (in which the pathogen disappeared after one or a few subcultures). Infection with E.ruminantium from BPC was established in I.scapularis, I.ricinus and A.variegatum cell lines; E.ruminantium was transferred from these infected cell lines to B.decoloratus, B.microplus and R. appendiculatus cell lines. H.a.anatolicum cells could not be infected with E.ruminantium by any procedure. All five E.ruminantium isolates grew continuously in at least one tick cell line at temperatures between 28 degrees C and 37 degrees C; three of the isolates were successfully re-established in BPC following prolonged maintenance in tick cells. This study demonstrates that E.ruminantium is not intrinsically restricted to growth in cells from ticks of the natural vector genus Amblyomma.

  13. Tandems as injectors for synchrotrons

    SciTech Connect

    Ruggiero, A.G.

    1992-08-01

    This is a review on the use of Tandem electrostatic accelerators for injection and filling of synchrotrons to accelerate intense beams of heavy-ions to relativistic energies. The paper emphasizes the need of operating the Tandems in pulsed mode for this application. It has been experimentally demonstrated that at the present this type of accelerators still provides the most reliable and best performance.

  14. Canine infection with Dirofilaria immitis, Borrelia burgdorferi, Anaplasma spp., and Ehrlichia spp. in the United States, 2010–2012

    PubMed Central

    2014-01-01

    Background The geographic distribution of canine infection with vector-borne disease agents in the United States appears to be expanding. Methods To provide an updated assessment of geographic trends in canine infection with Dirofilaria immitis, Borrelia burgdorferi, Ehrlichia spp., and Anaplasma spp., we evaluated results from an average of 3,588,477 dogs tested annually by veterinarians throughout the United States from 2010 – 2012. Results As in an earlier summary report, the percent positive test results varied by agent and region, with antigen of D. immitis and antibody to Ehrlichia spp. most commonly identified in the Southeast (2.9% and 3.2%, respectively) and antibody to both B. burgdorferi and Anaplasma spp. most commonly identified in the Northeast (13.3% and 7.1%, respectively) and upper Midwest (4.4% and 3.9%, respectively). Percent positive test results for D. immitis antigen were lower in every region considered, including in the Southeast, than previously reported. Percent positive test results for antibodies to B. burgdorferi and Ehrlichia spp. were higher nationally than previously reported, and, for antibodies to Anaplasma spp., were higher in the Northeast but lower in the Midwest and West, than in the initial report. Annual reports of human cases of Lyme disease, ehrlichiosis, and anaplasmosis were associated with percent positive canine test results by state for each respective tick-borne disease agent (R2 = 0.701, 0.457, and 0.314, respectively). Within endemic areas, percent positive test results for all three tick-borne agents demonstrated evidence of geographic expansion. Conclusions Continued national monitoring of canine test results for vector-borne zoonotic agents is an important tool for accurately mapping the geographic distribution of these agents, and greatly aids our understanding of the veterinary and public health threats they pose. PMID:24886589

  15. Panola Mountain Ehrlichia in Amblyomma maculatum From the United States and Amblyomma variegatum (Acari: Ixodidae) From the Caribbean and Africa.

    PubMed

    Loftis, Amanda D; Kelly, Patrick J; Paddock, Christopher D; Blount, Keith; Johnson, Jason W; Gleim, Elizabeth R; Yabsley, Michael J; Levin, Michael L; Beati, Lorenza

    2016-05-01

    Panola Mountain Ehrlichia (PME) has been suggested as an emerging pathogen of humans and dogs. Domestic goats and white-tailed deer (Odocoileus virginianus) are also susceptible and likely serve as reservoirs. Experimentally, both the lone star tick (Amblyomma americanum (L.)) and the Gulf Coast tick (Amblyomma maculatum Koch) can transmit PME among deer and goats. In the current study, we detected PME in adult wild-caught A. maculatum from the United States and Amblyomma variegatum (F.) from the Caribbean and Africa. This significantly expands the range, potential tick vectors, and risk for exposure to PME.

  16. Use of Chimeric DNA-RNA Primers in Quantitative PCR for Detection of Ehrlichia canis and Babesia canis▿ †

    PubMed Central

    Peleg, Ofer; Baneth, Gad; Eyal, Osnat; Inbar, Jacob; Harrus, Shimon

    2009-01-01

    To overcome the problem of nonspecific by-products in quantitative PCR (qPCR) assays, we constructed DNA-RNA chimeric primers and evaluated their use in the detection and quantification of the Ehrlichia canis 16S rRNA, Babesia canis Hsp70, and canine β-actin genes. Several RNA bases were incorporated into specific positions in the DNA primers, while no RNA stretches were allowed. qPCR reactions were carried out without preamplification steps. This resulted in decreased formation of undesirable by-products and a 10-fold increase in assay sensitivity. PMID:19633128

  17. Modern tandem control systems

    NASA Astrophysics Data System (ADS)

    Lutz, J. R.; Marsaudon, J. C.

    1993-04-01

    Nowadays, tandem electrostatic accelerators can benefit greatly from the growing possibilities provided by modern control facilities. Controlling an electrostatic accelerator first requires the solution of technological problems raised by the necessity of fitting inside the tank equipment which is highly stressed by the physical environment. Then, these controls can take advantage of new techniques which appear on the market. Present computer technology provides cheap powerful workstations for efficient operator interfacing, and new modular and distributed control concepts have been developed for general use in experimental physics, in data acquisition and in control systems. The general trend towards standardization is now accepted for both hardware and software and this brings benefits to the designer and the user.

  18. Evaluation of an attenuated strain of Ehrlichia canis as a vaccine for canine monocytic ehrlichiosis.

    PubMed

    Rudoler, Nir; Baneth, Gad; Eyal, Osnat; van Straten, Michael; Harrus, Shimon

    2012-12-17

    Canine monocytic ehrlichiosis is an important tick-borne disease worldwide. No commercial vaccine for the disease is currently available and tick control is the main preventive measure against the disease. The aim of this study was to evaluate the potential of a multi-passaged attenuated strain of Ehrlichia canis to serve as a vaccine for canine monocytic ehrlichiosis, and to assess the use of azithromycin in the treatment of acute ehrlichiosis. Twelve beagle dogs were divided into 3 groups of 4 dogs. Groups 1 and 2 were inoculated (vaccinated) with an attenuated strain of E. canis (#611A) twice or once, respectively. The third group consisted of naïve dogs which served as controls. All 3 groups were challenged with a wild virulent strain of E. canis by administering infected dog-blood intravenously. Transient thrombocytopenia was the only hematological abnormality observed following inoculation of dogs with the attenuated strain. Challenge with the virulent strain resulted in severe disease in all 4 control dogs while only 3 of 8 vaccinated dogs presented mild transient fever. Furthermore, the mean blood rickettsial load was significantly higher in the control group (27-92-folds higher during days 14-19 post challenge with the wild the strain) as compared to the vaccinated dogs. The use of azithromycin was assessed as a therapeutic agent for the acute disease. Four days treatment resulted in further deterioration of the clinical condition of the dogs. Molecular comparison of 4 genes known to express immunoreactive proteins and virulence factors (p30, gp19, VirB4 and VirB9) between the attenuated strain and the challenge wild strain revealed no genetic differences between the strains. The results of this study indicate that the attenuated E. canis strain may serve as an effective and secure future vaccine for canine ehrlichiosis.

  19. Inhibitory effect of interferon gamma on frequency of Ehrlichia canis-infected cells in vitro.

    PubMed

    Tajima, Tomoko; Wada, Makoto

    2013-12-15

    Ehrlichia canis is an obligate intracellular bacterium that infects the macrophage-monocyte cells of dogs, causing canine monocytic ehrlichiosis. Interferon-γ (IFN-γ), along with other cytokines, mediates the immune response to such intracellular bacterial invasions. To determine the role of IFN-γ in the immunity of dogs to E. canis infection, peripheral blood mononuclear cells (PBMC) and white blood cells (WBC) were collected from E. canis-infected dogs and added to a culture of E. canis in DH82 cells. The number of E. canis inclusion-positive cells was significantly reduced in cultures containing PBMC and WBC from E. canis-infected dogs compared to uninfected dogs. However, this resistance was inhibited by the addition of an anti-dog IFN-γ antibody. Resistance was also observed when PBMC were added to the Cell Culture Inserts, which prohibited contact of PBMC to DH82 cells, while allowed the diffusion of soluble cell products. The results of this study indicate that resistance was not dependent on cell to cell contact, but was associated with soluble cell products, such as IFN-γ. The addition of recombinant canine IFN-γ to the E. canis culture also reduced the number of infected cells. A commercial recombinant canine IFN-γ, which is sold in Japan, was also effective at reducing E. canis-infected cell number. These results indicate that IFN-γ has an inhibitory effect on the frequency of E. canis-infected cells in vitro and that contact between effector and target cells is not necessary for the resistance.

  20. Recombination Is a Major Driving Force of Genetic Diversity in the Anaplasmataceae Ehrlichia ruminantium

    PubMed Central

    Cangi, Nídia; Gordon, Jonathan L.; Bournez, Laure; Pinarello, Valérie; Aprelon, Rosalie; Huber, Karine; Lefrançois, Thierry; Neves, Luís; Meyer, Damien F.; Vachiéry, Nathalie

    2016-01-01

    The disease, Heartwater, caused by the Anaplasmataceae E. ruminantium, represents a major problem for tropical livestock and wild ruminants. Up to now, no effective vaccine has been available due to a limited cross protection of vaccinal strains on field strains and a high genetic diversity of Ehrlichia ruminantium within geographical locations. To address this issue, we inferred the genetic diversity and population structure of 194 E. ruminantium isolates circulating worldwide using Multilocus Sequence Typing based on lipA, lipB, secY, sodB, and sucA genes. Phylogenetic trees and networks were generated using BEAST and SplitsTree, respectively, and recombination between the different genetic groups was tested using the PHI test for recombination. Our study reveals the repeated occurrence of recombination between E. ruminantium strains, suggesting that it may occur frequently in the genome and has likely played an important role in the maintenance of genetic diversity and the evolution of E. ruminantium. Despite the unclear phylogeny and phylogeography, E. ruminantium isolates are clustered into two main groups: Group 1 (West Africa) and a Group 2 (worldwide) which is represented by West, East, and Southern Africa, Indian Ocean, and Caribbean strains. Some sequence types are common between West Africa and Caribbean and between Southern Africa and Indian Ocean strains. These common sequence types highlight two main introduction events due to the movement of cattle: from West Africa to Caribbean and from Southern Africa to the Indian Ocean islands. Due to the long branch lengths between Group 1 and Group 2, and the propensity for recombination between these groups, it seems that the West African clusters of Subgroup 2 arrived there more recently than the original divergence of the two groups, possibly with the original waves of domesticated ruminants that spread across the African continent several thousand years ago. PMID:27747194

  1. Population-based evaluation of the Ehrlichia ruminantium MAP 1B indirect ELISA.

    PubMed

    Peter, T F; O'Callaghan, C J; Medley, G F; Perry, B D; Semu, S M; Maha, S M

    2001-01-01

    The indirect MAP 1B ELISA based on the recombinant MAP 1B fragment of the immunodominant MAP I protein of Ehrlichia ruminantium is considered to be the most sensitive and specific assay for the serodiagnosis of heartwater. In this study, we evaluated its reliability in detecting exposure to E. ruminantium in field populations of domestic ruminants in Zimbabwe. Cattle and goat herds in endemically stable areas with high infection pressure and an expected close to 100% prevalence of E. ruminantium exposure were sampled. Bovine sera (858) and caprine sera (706) collected at seven locations representative of the two main production systems (communal lands and large scale commercial farms) in the two main agroecological zones of Zimbabwe (highveld and lowveld) were analysed. The prevalence of MAP 1B-specific antibodies in goats was similar and high, ranging from 67 to 100%, at all except one site (43%). Age-specific differences in goats (1, 2, 3, 4, 5 years) were not observed. In contrast, MAP 1B seroprevalence in cattle was significantly lower (P < 0.001), ranging from 46 to 61% in the lowveld communal area and from 24 to 33% in the remaining areas (P < 0.001). Age-specific differences in seroprevalence (1, 2, 3, 4, 5-7 + years) were similarly not evident in cattle (P < 0.15). Hence, the indirect MAP 1B ELISA may be an unreliable indicator of past exposure to heartwater in field-infected cattle in Zimbabwe. Although the reasons for this low response in field cattle are not fully understood, this study illustrates the need for field validation of the performance of new diagnostic tests prior to their use for epidemiological purposes.

  2. C-reactive protein and alpha 1-acid glycoprotein levels in dogs infected with Ehrlichia canis.

    PubMed Central

    Rikihisa, Y; Yamamoto, S; Kwak, I; Iqbal, Z; Kociba, G; Mott, J; Chichanasiriwithaya, W

    1994-01-01

    To elucidate whether acute-phase protein responses occur in dogs infected with Ehrlichia canis, C-reactive protein (CRP) and alpha 1-acid glycoprotein (AAG) levels were serially measured in the plasma of five dogs experimentally inoculated with E. canis and 10 sham-inoculated or noninoculated control dogs. The CRP concentration was measured by a canine-specific capture enzyme-linked immunosorbent assay, and the AAG concentration was measured by a canine-specific radial immunodiffusion method. In all E. canis-inoculated dogs, a 3.3- to 6.5-fold increase in the plasma CRP concentration and a 1.9- to 8.6-fold increase in the plasma AAG concentration over the preinoculation level occurred at days 4 to 6 postexposure. Despite the persistence of E. canis and high antibody titers, both CRP and AAG concentrations gradually declined to preexposure levels by day 34 postexposure. E. canis-infected dogs had mild and transient clinical signs which resolved without treatment by day 14 postexposure. The CRP and AAG concentrations in control inoculated or nontreated dogs remained within the normal range throughout the experimental period. Of 12 dogs naturally infected with E. canis, 75% had greater than 50 micrograms of CRP per ml and 83% had greater than 500 micrograms of AAG per ml. All of these 12 dogs had chronic and severe clinical signs of canine ehrlichiosis. Thus, elevations in the levels of acute-phase proteins occur in both acute and chronic canine ehrlichiosis. Determination of CRP and AAG concentrations may help in assessing the severity of inflammatory damage in dogs with E. canis infections. PMID:8027343

  3. Seroprevalence of Ehrlichia ruminantium antibodies and its associated risk factors in indigenous goats of South Africa.

    PubMed

    Mdladla, Khanyisile; Dzomba, Edgar F; Muchadeyi, Farai C

    2016-03-01

    The present study investigated the seroprevalence of antibodies to Ehrlichia ruminantium and the associated risk factors in goats from five different farming provinces of South Africa. Sera collected from 686 goats of the commercial meat type (n=179), mohair type (n=9), non-descript indigenous goats from Eastern Cape (n=56), KwaZulu-Natal (n=209), Limpopo (n=111), North West (n=61) and Northern Cape (n=11) provinces and a feral Tankwa goat (n=50) were tested for the presence of immunoglobulin G (IgG) antibodies to antigens of E. ruminantium using the indirect fluorescent-antibody test (IFAT). Fifty two percent of these goats had ticks. The overall seroprevalence of antibodies to E. ruminantium was 64.87% (445/686) with the highest seroprevalence reported for Limpopo (95.50%) and lowest for Northern Cape (20.29%). Highest seroprevalence for antibodies to E. ruminantium was observed in goats from endemic regions (76.09%), and from smallholder production systems (89.54%). High seroprevalence was also observed in non-descript indigenous goats (85.04%), adult goat (69.62%), in does (67.46%) and goats infested with ticks (85.79%). The logistic model showed a gradient of increasing risk for commercial meat type Savanna (OR=3.681; CI=1.335-10.149) and non-descript indigenous (OR=3.466; CI=1.57-7.645) compared to Boer goats and for goats from the smallholder production system (OR=2.582; CI=1.182-5.639) and those with ticks (OR=3.587; CI=2.105-6.112). Results from this study showed that E. ruminantium infections were prevalent but were widely and unevenly distributed throughout South Africa. Findings from the study facilitate identification and mapping of risk areas for heartwater and its endeminicity in South Africa and should be taken into consideration for future disease control strategies and local goat improvement programs.

  4. Intraoperative bleeding in dogs from Grenada seroreactive to Anaplasma platys and Ehrlichia canis.

    PubMed

    Lanza-Perea, M; Zieger, U; Qurollo, B A; Hegarty, B C; Pultorak, E L; Kumthekar, S; Bruhl-Day, R; Breitschwerdt, E B

    2014-01-01

    Frequent exposure of Grenadian dogs to Rhipicephalus sanguineus results in Anaplasma platys, and Ehrlichia canis seroreactivity. During elective surgeries, substantial intraoperative hemorrhage occurs in some seroreactive dogs. To assess hemostatic parameters and bleeding tendencies as well as prevalence of PCR positivity in apparently healthy A. platys and E. canis seroreactive and seronegative free-roaming dogs from Grenada. Forty-seven elective surgery dogs allocated to 4 groups: Seronegative control (n = 12), A. platys (n = 10), E. canis (n = 14) and A. platys, and E. canis (n = 11) seroreactive. Preoperatively, hemostasis was assessed by platelet count, prothrombin time, activated partial thromboplastin time, and buccal mucosal bleeding time. Intra- and postoperative bleeding scores were subjectively assigned. Blood, spleen, bone marrow, and lymph node aspirates were tested by PCR. Bleeding scores in dogs coseroreactive for A. platys and E. canis were higher (P = .015) than those of seronegative dogs. A. platys DNA was amplified from 7/21 (33%) A. platys seroreactive dogs and from 1 E. canis seroreactive dog; E. canis DNA was amplified from 21/25 (84%) E. canis seroreactive dogs. E. canis DNA was amplified most often from blood, whereas A. platys DNA was amplified most often from bone marrow. Apparently healthy, free-roaming dogs coseropositive for A. platys and E. canis may have increased intraoperative bleeding tendencies despite normal hemostatic parameters. Future investigations should explore the potential for vascular injury as a cause for bleeding in these dogs. Improved tick control is needed for dogs in Grenada. Copyright © 2014 by the American College of Veterinary Internal Medicine.

  5. Prevalence of Ehrlichia ruminantium in adult Amblyomma variegatum collected from cattle in Cameroon.

    PubMed

    Esemu, Seraphine N; Besong, Willington O; Ndip, Roland N; Ndip, Lucy M

    2013-03-01

    Ehrlichia ruminantium, the etiologic agent of the economically important disease heartwater, is an obligate intracellular bacterium transmitted by ticks of the genus Amblyomma, particularly A. hebraeum and A. variegatum. Although serologic and microscopic evidence of the presence of heartwater have been reported in ruminants in Cameroon, knowledge of E. ruminantium infection in the tick vector, A. variegatum, is lacking. In order to determine the infectivity of A. variegatum ticks by E. ruminantium, we analysed 500 un-engorged A. variegatum ticks collected by hand-picking from predilection sites from 182 cattle [115 ticks from 82 cattle at Société de Développement et d'Exploitation des Productions Animales (SODEPA) Dumbo ranch (SDR) and 385 ticks from 100 cattle at the Upper Farms ranch (UFR)] by amplification of the open reading frame (ORF) 2 of the pCS20 region of E. ruminantium. PCR amplification of the 279 bp fragment of the pCS20 region detected E. ruminantium DNA in 142 (28.4 %) of the 500 ticks with a higher infection rate (47/115; 40.9 %) observed in ticks from SDR and 24.7 % (95/385) of ticks collected from cattle at UFR. Twenty five randomly selected PCR products were sequenced and results indicated that some of the isolates shared homology with one another and to sequences of E. ruminantium in the GenBank. This report represents the first molecular evidence of E. ruminantium infection in A. variegatum ticks in Cameroon and suggests possible exposure of cattle to this pathogen in our environment.

  6. Mining the genetic diversity of Ehrlichia ruminantium using map genes family.

    PubMed

    Raliniaina, Modestine; Meyer, Damien F; Pinarello, Valérie; Sheikboudou, Christian; Emboulé, Loic; Kandassamy, Yane; Adakal, Hassane; Stachurski, Frédéric; Martinez, Dominique; Lefrançois, Thierry; Vachiéry, Nathalie

    2010-02-10

    Understanding bacterial genetic diversity is crucial to comprehend pathogenesis. Ehrlichia ruminantium (E. ruminantium), a tick-transmitted intracellular bacterial pathogen, causes heartwater disease in ruminants. This model rickettsia, whose genome has been recently sequenced, is restricted to neutrophils and reticulo-endothelial cells of its mammalian host and to the midgut and salivary glands of its vector tick. E. ruminantium harbors a multigene family encoding for 16 outer membrane proteins including MAP1, a major antigenic protein. All the 16 map paralogs are expressed in bovine endothelial cells and some are specifically translated in the tick or in the mammalian host. In this study, we carried out phylogenetic analyses of E. ruminantium using sequences of 6 MAP proteins, MAP1, MAP1-2, MAP1-6, MAP1-5, MAP1+1 and MAP1-14, localized either in the center or at the borders of the map genes cluster. We show that (i) map1 gene is a good tool to characterize the genetic diversity among Africa, Caribbean islands and Madagascar strains including new emerging isolates of E. ruminantium; (ii) the different map paralogs define different genotypes showing divergent evolution; (iii) there is no correlation between all MAP genotypes and the geographic origins of the strains; (iv) The genetic diversity revealed by MAP proteins is conserved whatever is the scale of strains sampling (village, region, continent) and thus was not related to the different timing of strains introduction, i.e. continuous introduction of strains versus punctual introduction (Africa versus Caribbean islands). These results provide therefore a significant advance towards the management of E. ruminantium diversity. The differential evolution of these paralogs suggests specific roles of these proteins in host-vector-pathogen interactions that could be crucial for developing broad-spectrum vaccines.

  7. Nested PCR for detection and genotyping of Ehrlichia ruminantium: use in genetic diversity analysis.

    PubMed

    Martinez, Dominique; Vachiéry, Nathalie; Stachurski, Frederic; Kandassamy, Yane; Raliniaina, Modestine; Aprelon, Rosalie; Gueye, Arona

    2004-10-01

    Ehrlichia ruminantium, the agent of cowdriosis transmitted by Amblyomma ticks, presents an extensive genetic and antigenic diversity of key importance for vaccine formulation. Two means of nested polymerase chain reaction (PCR) targeting were developed to conduct molecular epidemiology studies in the Caribbean and Africa. The first used a conserved DNA fragment for detection of the pathogen in animals and vectors, and the second relied on the polymorphic map1 gene for genotyping. As compared to a PCR, the nested PCR showed a 2-Log10 improvement of sensitivity and allowed amplification from ticks, blood, brain, and lungs from infected animals, providing a more accurate picture of the tick infection rate. In Guadeloupe, this rate reached 36% (N = 212) instead of 1.7% (N = 224), as previously estimated. Genetic typing was done by restriction fragment length polymorphism or sequencing of map1 amplification products. Molecular epidemiology studies conducted in field sites selected for vaccination trials with inactivated vaccine, revealed the circulation of genetically divergent strains in limited geographical areas. It is known, then, that genetic clustering based on map1 has no predictive value regarding the protective value of a given strain against a new strain. However, tracing the strains by this technique revealed the extent of E. ruminantium diversity that one can expect in a given region, and the method allows differentiation between an inadequate immune response and the challenge by a breakthrough strain on animals dying despite vaccination. Up to now, genetic typing does not avoid cross-protection studies, which were conducted in parallel, although on a more limited scale. The importance of pathogen diversity studies for optimization of vaccine design is discussed as well as the research for new polymorphic genes. These genes may allow better predictions on cross-protection, given the recent completion of the sequence of the full genome of two E. ruminantium

  8. Draft Genome Sequences of Three Strains of Ehrlichia ruminantium, a Tick-Borne Pathogen of Ruminants, Isolated from Zimbabwe, The Gambia, and Ghana

    PubMed Central

    Nakao, Ryo; Jongejan, Frans

    2016-01-01

    The rickettsial bacterium Ehrlichia ruminantium is the causative pathogen of heartwater in ruminants. Here, we report the draft genome sequences of three strains of E. ruminantium, namely, the Crystal Springs strain from Zimbabwe, the Kerr Seringe strain from The Gambia, and the Sankat 430 strain from Ghana. PMID:27313287

  9. Covalently linked tandem lesions in DNA.

    PubMed

    Patrzyc, Helen B; Dawidzik, Jean B; Budzinski, Edwin E; Freund, Harold G; Wilton, John H; Box, Harold C

    2012-12-01

    Reactive oxygen species (ROS) generate a type of DNA damage called tandem lesions, two adjacent nucleotides both modified. A subcategory of tandem lesions consists of adjacent nucleotides linked by a covalent bond. Covalently linked tandem lesions generate highly characteristic liquid chromotography-tandem mass spectrometry (LC-MS/MS) elution profiles. We have used this property to comprehensively survey X-irradiated DNA for covalently linked tandem lesions. A total of 15 tandem lesions were detected in DNA irradiated in deoxygenated aqueous solution, five tandem lesions were detected in DNA that was irradiated in oxygenated solution.

  10. Covalently Linked Tandem Lesions in DNA

    PubMed Central

    Patrzyc, Helen B.; Dawidzik, Jean B.; Budzinski, Edwin E.; Freund, Harold G.; Wilton, John H.; Box, Harold C.

    2013-01-01

    Reactive oxygen species (ROS) generate a type of DNA damage called tandem lesions, two adjacent nucleotides both modified. A subcategory of tandem lesions consists of adjacent nucleotides linked by a covalent bond. Covalently linked tandem lesions generate highly characteristic liquid chromotography-tandem mass spectrometry (LC-MS/MS) elution profiles. We have used this property to comprehensively survey X-irradiated DNA for covalently linked tandem lesions. A total of 15 tandem lesions were detected in DNA irradiated in deoxygenated aqueous solution, five tandem lesions were detected in DNA that was irradiated in oxygenated solution. PMID:23106212

  11. Sequence alignment with tandem duplication

    SciTech Connect

    Benson, G.

    1997-12-01

    Algorithm development for comparing and aligning biological sequences has, until recently, been based on the SI model of mutational events which assumes that modification of sequences proceeds through any of the operations of substitution, insertion or deletion (the latter two collectively termed indels). While this model has worked farily well, it has long been apparent that other mutational events occur. In this paper, we introduce a new model, the DSI model which includes another common mutational event, tandem duplication. Tandem duplication produces tandem repeats which are common in DNA, making up perhaps 10% of the human genome. They are responsible for some human diseases and may serve a multitude of functions in DNA regulation and evolution. Using the DSI model, we develop new exact and heuristic algorithms for comparing and aligning DNA sequences when they contain tandem repeats. 30 refs., 3 figs.

  12. The first clinical and laboratory evidence of co-infection by Anaplasma phagocytophilum and Ehrlichia canis in a Brazilian dog.

    PubMed

    Silveira, Júlia A G; Valente, Pâmela C L G; Paes, Paulo R O; Vasconcelos, Artur V; Silvestre, Bruna T; Ribeiro, Múcio F B

    2015-04-01

    Information on Anaplasma phagocytophilum in Brazil is very restricted. The aim of this study was to report clinical, parasitological, hematological and molecular evidence of a natural A. phagocytophilum infection of an urban Brazilian dog. The dog was an eight-month-old male French bulldog. Veterinary clinical examinations were performed three times: in April, June and December 2013. Biochemical and hematological analyses were performed during all examinations, and blood samples were collected for parasitological surveys in June and December. Morulae were present within neutrophils in blood smears from June. Both samples were PCR positive for A. phagocytophilum and Ehrlichia spp. Phylogenetic analysis revealed that the phylogenetic topology placed samples from this study in close proximity to other A. phagocytophilum isolates. Ehrlichia isolates from this dog were 100% identical to E. canis isolates, thus E. canis and A. phagocytophilum co-infection was diagnosed in this dog. Lethargy and skin lesions were the clinical signs observed in this dog. Abnormal hematological parameters, among those, severe thrombocytopenia, were observed in all three occasions. This finding highlights the growing importance of A. phagocytophilum in South America.

  13. Host surveys, ixodid tick biology and transmission scenarios as related to the tick-borne pathogen, Ehrlichia canis

    PubMed Central

    Stich, R. W.; Schaefer, John J.; Bremer, William G.; Needham, Glen R.; Jittapalapong, Sathaporn

    2008-01-01

    The ehrlichioses have been subject to increasing interest from veterinary and public health perspectives, but experimental studies of these diseases and their etiologic agents can be challenging. Ehrlichia canis, the primary etiologic agent of canine monocytic ehrlichiosis, is relatively well characterized and offers unique advantages and opportunities to study interactions between a monocytotropic pathogen and both its vertebrate and invertebrate hosts. Historically, advances in tick-borne disease control strategies have typically followed explication of tick-pathogen-vertebrate interactions, thus it is reasonable to expect novel, more sustainable approaches to control of these diseases as the transmission of their associated infections are investigated at the molecular through ecological levels. Better understanding of the interactions between E. canis and its canine and tick hosts would also elucidate similar interactions for other Ehrlichia species as well as the potential roles of canine sentinels, reservoirs and models of tick-borne zoonoses. This article summarizes natural exposure studies and experimental investigations of E. canis in the context of what is understood about biological vectors of tick-borne Anaplasmataceae. PMID:18963493

  14. A survey for spotted fever group rickettsiae and ehrlichiae in Amblyomma variegatum from St. Kitts and Nevis.

    PubMed

    Kelly, Patrick J; Fournier, Pierre-Edouard; Parola, Philippe; Raoult, Didier

    2003-07-01

    Eighty-nine Amblyomma variegatum ticks were collected from the islands of St. Kitts and Nevis in the Caribbean and preserved in 70% ethanol or local rum. After being washed in sterile water, their DNA was extracted and analyzed by a polymerase chain reaction (PCR) for DNA of spotted fever group rickettsiae and ehrlichiae. None of the tested ticks was positive in a PCR assay using the primers 16S EHRD and 16S EHRR for the 16S rRNA gene of Ehrlichia spp.. Forty-one percent of the A. variegatum (36 of 89 of which 34 [47%] of 72 were adult males, 2 (13%) of 16 were adult females, and 0 (0%) of 1 were nymphs) were positive in a PCR assay using the primer pair 190-70 and 190-701 for the outer membrane protein A (ompA) gene of spotted fever group rickettsiae. All PCR amplification products obtained had 100% sequence homology with Rickettsia africae, the agent of African tick-bite fever.

  15. Surveillance of Egyptian fleas for agents of public health significance: Anaplasma, Bartonella, Coxiella, Ehrlichia, Rickettsia, and Yersinia pestis.

    PubMed

    Loftis, Amanda D; Reeves, Will K; Szumlas, Daniel E; Abbassy, Magda M; Helmy, Ibrahim M; Moriarity, John R; Dasch, Gregory A

    2006-07-01

    Serologic surveys in Egypt have documented human and animal exposure to vector-borne bacterial pathogens, but the presence and distribution of these agents in arthropods has not been determined. Between July 2002 and July 2003, fleas were collected from 221 mammals trapped in 17 cities throughout Egypt. A total of 987 fleas were collected, representing four species (Ctenocephalides felis, Echidnophaga gallinacea, Leptopsylla segnis, and Xenopsylla cheopis); 899 of these fleas were X. cheopis from rats (Rattus spp.). Fleas were tested for DNA from Anaplasma spp., Bartonella spp., Coxiella burnetii, Ehrlichia spp., Rickettsia spp., and Yersinia pestis. Rickettsia typhi, the agent of murine typhus, was detected in X. cheopis and L. segnis from rats from nine cities. A spotted-fever group Rickettsia sp. similar to "RF2125" was detected in E. gallinacea, and two unidentified spotted fever group Rickettsia were detected in two X. cheopis. Novel Bartonella genotypes were detected in X. cheopis and L. segnis from three cities. Coxiella burnetii was detected in two fleas. Anaplasma, Ehrlichia, and Y. pestis were not detected.

  16. Prevalence and diversity of Babesia, Hepatozoon, Ehrlichia, and Bartonella in wild and domestic carnivores from Zambia, Africa.

    PubMed

    Williams, Brianna M; Berentsen, Are; Shock, Barbara C; Teixiera, Maria; Dunbar, Michael R; Becker, Matthew S; Yabsley, Michael J

    2014-03-01

    A molecular survey was conducted for several hemoparasites of domestic dogs and three species of wild carnivores from two sites in Zambia. Three Babesia spp. were detected including Babesia felis and Babesia leo in lions (Panthera leo) and a Babesia sp. (similar to Babesia lengau) in spotted hyenas (Crocuta crocuta) and a single lion. All wild dogs (Lycaon pictus) and domestic dogs were negative for Babesia. High prevalences for Hepatozoon were noted in all three wild carnivores (38-61%) and in domestic dogs (13%). Significantly higher prevalences were noted in hyenas and wild dogs compared with domestic dogs and lions. All carnivores were PCR negative for Ehrlichia canis, Ehrlichia ewingii, and Bartonella spp. Overall, high prevalences and diversity of Babesia and Hepatozoon were noted in wild carnivores from Zambia. This study is the first molecular characterization of Babesia from any hyena species and is the first report of a Babesia sp. closely related to B. lengau, a parasite previously only reported from cheetahs (Acinonyx jubatus), in lions and hyenas. Although usually benign in wild carnivores, these hemoparasites can be pathogenic under certain circumstances. Importantly, data on vectors for these parasites are lacking, so studies are needed to identify vectors as well as determine transmission routes, infection dynamics, and host specificity of these hemoparasites in wildlife in Africa and also the risk of transmission between domestic animals and wildlife.

  17. Tandem Terminal Ion Source

    SciTech Connect

    2000-10-23

    OAK-B135 Tandem Terminal Ion Source. The terminal ion source (TIS) was used in several experiments during this reporting period, all for the {sup 7}Be({gamma}){sup 8}B experiment. Most of the runs used {sup 1}H{sup +} at terminal voltages from 0.3 MV to 1.5 MV. One of the runs used {sup 2}H{sup +} at terminal voltage of 1.4 MV. The other run used {sup 4}He{sup +} at a terminal voltage of 1.37 MV. The list of experiments run with the TIS to date is given in table 1 below. The tank was opened four times for unscheduled source repairs. On one occasion the tank was opened to replace the einzel lens power supply which had failed. The 10 kV unit was replaced with a 15 kV unit. The second time the tank was opened to repair the extractor supply which was damaged by a tank spark. On the next occasion the tank was opened to replace a source canal which had sputtered away. Finally, the tank was opened to replace the discharge bottle which had been coated with aluminum sputtered from the exit canal.

  18. Medical Surveillance Monthly Report (MSMR). Volume 6, Number 10, December 2000

    DTIC Science & Technology

    2000-12-01

    first recognized in 1935 as a disease of dogs (canine ehrlichiosis) caused by Ehrlichia canis . The first human ehrlichial infection to be recognized...blood of a US Army reservist at Fort Chaffee, Arkansas.2,3 This new species of ehrlichiae , E. chaffeensis, was found to resemble E. canis both...Hawley RC, Ristic M, Cox D, McDade JE. Human infection with Ehrlichia canis , a leukocytic rickettsia. N Engl J Med, 1987;316:853-6. 2. Dawson JE

  19. Tandem Cylinder Noise Predictions

    NASA Technical Reports Server (NTRS)

    Lockhard, David P.; Khorrami, Mehdi R.; CHoudhari, Meelan M.; Hutcheson, Florence V.; Brooks, Thomas F.; Stead, Daniel J.

    2007-01-01

    In an effort to better understand landing-gear noise sources, we have been examining a simplified configuration that still maintains some of the salient features of landing-gear flow fields. In particular, tandem cylinders have been studied because they model a variety of component level interactions. The present effort is directed at the case of two identical cylinders spatially separated in the streamwise direction by 3.7 diameters. Experimental measurements from the Basic Aerodynamic Research Tunnel (BART) and Quiet Flow Facility (QFF) at NASA Langley Research Center (LaRC) have provided steady surface pressures, detailed off-surface measurements of the flow field using Particle Image Velocimetry (PIV), hot-wire measurements in the wake of the rear cylinder, unsteady surface pressure data, and the radiated noise. The experiments were conducted at a Reynolds number of 166 105 based on the cylinder diameter. A trip was used on the upstream cylinder to insure a fully turbulent shedding process and simulate the effects of a high Reynolds number flow. The parallel computational effort uses the three-dimensional Navier-Stokes solver CFL3D with a hybrid, zonal turbulence model that turns off the turbulence production term everywhere except in a narrow ring surrounding solid surfaces. The current calculations further explore the influence of the grid resolution and spanwise extent on the flow and associated radiated noise. Extensive comparisons with the experimental data are used to assess the ability of the computations to simulate the details of the flow. The results show that the pressure fluctuations on the upstream cylinder, caused by vortex shedding, are smaller than those generated on the downstream cylinder by wake interaction. Consequently, the downstream cylinder dominates the noise radiation, producing an overall directivity pattern that is similar to that of an isolated cylinder. Only calculations based on the full length of the model span were able to

  20. Transmission of Ehrlichia canis by Rhipicephalus sanguineus ticks feeding on dogs and on artificial membranes.

    PubMed

    Fourie, Josephus J; Stanneck, Dorothee; Luus, Herman G; Beugnet, Frederic; Wijnveld, Michiel; Jongejan, Frans

    2013-11-08

    A South African strain of Ehrlichia canis was isolated and used to infect a laboratory-bred Beagle dog. Rhipicephalus sanguineus nymphs, which fed on this dog, moulted to adult ticks which carried infection rates of E. canis between 12% and 19% and were used in a series of in vivo and in vitro experiments. Five groups of 6 dogs were challenged with the infected R. sanguineus ticks, which were removed 24h, 12h, 6h or 3h after the ticks had been released onto the dogs. The animals were monitored for fever and thrombocytopenia and were considered infected if they became serologically positive for E. canis antibodies as well as PCR positive for E. canis DNA. Seven dogs became infected with E. canis in the following groups: Group 1 (24h tick challenge) 1 out of 6; Group 2 (12h) 1 of 6; Group 3 (6h) 2 of 6; Group 4 (6h) 2 of 6 and Group 5 (3h) 1 out of 6. Six of those 7 infected dogs developed fever and a significant thrombocytopenia. One dog did not show any symptoms, but seroconverted and was found PCR positive on several occasions. Five additional dogs were PCR positive on one test sample only but were not considered infected because they did not develop any specific E. canis antibodies. In vitro, R. sanguineus ticks attached and fed on bovine blood through silicone membranes with attachment rates up to 72.5% after 24h increasing to 84.2% at 72 h. The ticks transmitted E. canis as soon as 8h post application as demonstrated by E. canis DNA found in the nutritive blood medium. In conclusion, transmission of E. canis by R. sanguineus ticks starts within a few hours after attachment, which is earlier than previously thought. These findings underpin the need for acaricides to provide either a repellent, an anti-attachment and/or a rapid killing effect against ticks in order to decrease the risk of transmission of E. canis. Copyright © 2013 Elsevier B.V. All rights reserved.

  1. Serology, molecular detection and risk factors of Ehrlichia canis infection in dogs in Costa Rica.

    PubMed

    Barrantes-González, Alexander V; Jiménez-Rocha, Ana E; Romero-Zuñiga, Juan José; Dolz, Gaby

    2016-10-01

    A cross-sectional study combining different serological and molecular techniques for the detection of Ehrlichia species in dogs and their ticks was carried out with data from all regions of Costa Rica. A seroprevalence of 32.1% (131/408), and infection with E. canis of 3.2% (13/407) was found, whereas 6.9% (9/130) of ticks attached to the dogs were PCR positive to E. canis. Higher prevalences were found outside the Greater Metropolitan Area (GMA). Risk factors associated with E. canis seropositivity were age, between 2 and 7 years (RR: 1.6, 95% CI: 1.2-2.2) and 8-15 years (RR: 1.8, 95% CI: 1.2-3.0), number of dogs/total of households [Dogs per Household Ratio (DHR) ≥3.1 (RR: 2.0; 95% CI: 1.4-3.0)], number of dogs infested with at least one tick/total of dogs sampled [Tick Infestation Prevalence (TIP)≥31% (RR: 2.1; 95% CI:1.3-3.3)] and living outside the GMA (RR: 1.7; 95% CI: 1.2-2.4) and being a mixed-breed dog (RR: 1.5; 95% CI: 1.1-2.1). Risk factors for E. canis PCR positive dogs were a depressive attitude (OR: 11.2; 95% CI: 1.1-115.9), fever (OR:4.8; 95% CI:1.2-19.3), DHR≥3.1 (OR: 5.7; 95% CI:1.7-19.2)], number of ticks/total of dogs sampled [Tick Distribution Ratio (TDR) ≥2.1 (OR: 6.5; 95% CI: 1.3-31.8)], and TIP≥40% (OR: 5.7; 95% CI: 1.7-19.2). This paper describes E. canis seroprevalence, PCR prevalence and tick analysis in dogs from Costa Rica, with associated clinical signs and owner perceptions. In summary, most of the E. canis infections in dogs in our country seemed to pass unnoticed by owners. Since most of the seropositive dogs (97.7%, 131/134) were negative for E. canis DNA in their blood, it is important to determine in future studies if these dogs recovered from the E. canis infection without any medication, or are persistently infected, and will develop chronic disease. Copyright © 2016 Elsevier GmbH. All rights reserved.

  2. Tandem clerking: maximising workplace learning.

    PubMed

    Ahearn, David; Eccles, Jennifer; Jorna, Thomas; Kotecha, Ashish; Baker, Paul; Singh, Salil

    2013-12-01

    Medical assessment units (MAUs) are a valuable source of educational opportunities, but these are often not realised because of service pressures. We trialled a method of collaborative working, where junior and senior trainees work in 'tandem' to see new admissions. The roles are alternated throughout the shift with the aim of encouraging shared decisions, learning and feedback. A 4-month trial of tandem clerking was implemented. An anonymous questionnaire of junior doctors collected quantitative and qualitative data to assess educational aspects of tandem clerking in the MAU of a busy district general hospital. Junior doctors (n = 14) report seeing a larger number and wider variety of patients using tandem clerking, with more useful feedback and a greater chance of meeting learning objectives and completing assessments. Some respondents expressed concern over a lack of autonomy. Respondents stated they were less likely to spend time completing mundane and non-educational tasks. Eight respondents preferred the new system, four favoured the traditional system and two had no preference. Tandem clerking is an innovative method to increase the educational aspects of the assessment unit, both in terms of feedback opportunities and exposure to a wider variety of patients. The technique is partly dependent on the enthusiasm and interest of both parties. © 2013 John Wiley & Sons Ltd.

  3. Detection of Rickettsia and Ehrlichia spp. in Ticks Associated with Exotic Reptiles and Amphibians Imported into Japan.

    PubMed

    Andoh, Masako; Sakata, Akiko; Takano, Ai; Kawabata, Hiroki; Fujita, Hiromi; Une, Yumi; Goka, Koichi; Kishimoto, Toshio; Ando, Shuji

    2015-01-01

    One of the major routes of transmission of rickettsial and ehrlichial diseases is via ticks that infest numerous host species, including humans. Besides mammals, reptiles and amphibians also carry ticks that may harbor Rickettsia and Ehrlichia strains that are pathogenic to humans. Furthermore, reptiles and amphibians are exempt from quarantine in Japan, thus facilitating the entry of parasites and pathogens to the country through import. Accordingly, in the current study, we examined the presence of Rickettsia and Ehrlichia spp. genes in ticks associated with reptiles and amphibians originating from outside Japan. Ninety-three ticks representing nine tick species (genera Amblyomma and Hyalomma) were isolated from at least 28 animals spanning 10 species and originating from 12 countries (Ghana, Jordan, Madagascar, Panama, Russia, Sri Lanka, Sudan, Suriname, Tanzania, Togo, Uzbekistan, and Zambia). None of the nine tick species are indigenous in Japan. The genes encoding the common rickettsial 17-kDa antigen, citrate synthase (gltA), and outer membrane protein A (ompA) were positively detected in 45.2% (42/93), 40.9% (38/93), and 23.7% (22/93) of the ticks, respectively, by polymerase chain reaction (PCR). The genes encoding ehrlichial heat shock protein (groEL) and major outer membrane protein (omp-1) were PCR-positive in 7.5% (7/93) and 2.2% (2/93) of the ticks, respectively. The p44 gene, which encodes the Anaplasma outer membrane protein, was not detected. Phylogenetic analysis showed that several of the rickettsial and ehrlichial sequences isolated in this study were highly similar to human pathogen genes, including agents not previously detected in Japan. These data demonstrate the global transportation of pathogenic Rickettsia and Ehrlichia through reptile- and amphibian-associated ticks. These imported animals have potential to transfer pathogens into human life. These results highlight the need to control the international transportation of known and

  4. Detection of Rickettsia and Ehrlichia spp. in Ticks Associated with Exotic Reptiles and Amphibians Imported into Japan

    PubMed Central

    Andoh, Masako; Sakata, Akiko; Takano, Ai; Kawabata, Hiroki; Fujita, Hiromi; Une, Yumi; Goka, Koichi; Kishimoto, Toshio; Ando, Shuji

    2015-01-01

    One of the major routes of transmission of rickettsial and ehrlichial diseases is via ticks that infest numerous host species, including humans. Besides mammals, reptiles and amphibians also carry ticks that may harbor Rickettsia and Ehrlichia strains that are pathogenic to humans. Furthermore, reptiles and amphibians are exempt from quarantine in Japan, thus facilitating the entry of parasites and pathogens to the country through import. Accordingly, in the current study, we examined the presence of Rickettsia and Ehrlichia spp. genes in ticks associated with reptiles and amphibians originating from outside Japan. Ninety-three ticks representing nine tick species (genera Amblyomma and Hyalomma) were isolated from at least 28 animals spanning 10 species and originating from 12 countries (Ghana, Jordan, Madagascar, Panama, Russia, Sri Lanka, Sudan, Suriname, Tanzania, Togo, Uzbekistan, and Zambia). None of the nine tick species are indigenous in Japan. The genes encoding the common rickettsial 17-kDa antigen, citrate synthase (gltA), and outer membrane protein A (ompA) were positively detected in 45.2% (42/93), 40.9% (38/93), and 23.7% (22/93) of the ticks, respectively, by polymerase chain reaction (PCR). The genes encoding ehrlichial heat shock protein (groEL) and major outer membrane protein (omp-1) were PCR-positive in 7.5% (7/93) and 2.2% (2/93) of the ticks, respectively. The p44 gene, which encodes the Anaplasma outer membrane protein, was not detected. Phylogenetic analysis showed that several of the rickettsial and ehrlichial sequences isolated in this study were highly similar to human pathogen genes, including agents not previously detected in Japan. These data demonstrate the global transportation of pathogenic Rickettsia and Ehrlichia through reptile- and amphibian-associated ticks. These imported animals have potential to transfer pathogens into human life. These results highlight the need to control the international transportation of known and

  5. Canine vector-borne co-infections: Ehrlichia canis and Hepatozoon canis in the same host monocytes.

    PubMed

    Baneth, Gad; Harrus, Shimon; Gal, Arnon; Aroch, Itamar

    2015-02-28

    The protozoon Hepatozoon canis and the rickettsia Ehrlichia canis are tick-borne pathogens, transmitted by Rhipicephalus sanguineus, which cause canine hepatozoonosis and canine monocytic ehrlichiosis, respectively. Co-infection of the same host monocytes with H. canis and E. canis confirmed by molecular characterization of the infecting agents and quantitative assessment of co-infected cells is described for the first time in three naturally-infected dogs. Blood smear evaluation indicated that at least 50% of the leukocytes infected with H. canis gamonts contained E. canis morulae. Co-infection of the same host cell demonstrated in this report suggests that infection with one pathogen may permit or enhance invasion or prolonged cellular survival of the other.

  6. Molecular assessment of the transplacental transmission of Toxoplasma gondii, Neospora caninum, Brucella canis and Ehrlichia canis in dogs.

    PubMed

    Taques, Isis Indaiara Gonçalves Granjeiro; Barbosa, Tatiane Rodrigues; Martini, Andresa de Cássia; Pitchenin, Letícia Camara; Braga, Ísis Assis; de Melo, Andréia Lima Tomé; Nakazato, Luciano; Dutra, Valéria; de Aguiar, Daniel Moura

    2016-12-01

    Given the fact that numerous microbial species can be detected in pregnant female dogs, the objective of this study was to assess the transplacental transmission of Brucella canis, Ehrlichia canis, Neospora caninum and Toxoplasma gondii in stillborn puppies. This study involved 41 stillborn puppies, 78.6% of which were positive for T. gondii, 52.4% for N. caninum and 59.5% for B. canis. E. canis was not detected in any of the analyzed puppies. Pregnancy is an important physiological condition for the transmission of infectious agents to puppies and transplacental transmission may be epidemiologically relevant in the spread of these opportunistic agents. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Bacterial Profiling Reveals Novel “Ca. Neoehrlichia”, Ehrlichia, and Anaplasma Species in Australian Human-Biting Ticks

    PubMed Central

    Gofton, Alexander W.; Doggett, Stephen; Ratchford, Andrew; Oskam, Charlotte L.; Paparini, Andrea; Ryan, Una; Irwin, Peter

    2015-01-01

    In Australia, a conclusive aetiology of Lyme disease-like illness in human patients remains elusive, despite growing numbers of people presenting with symptoms attributed to tick bites. In the present study, we surveyed the microbial communities harboured by human-biting ticks from across Australia to identify bacteria that may contribute to this syndrome. Universal PCR primers were used to amplify the V1-2 hyper-variable region of bacterial 16S rRNA genes in DNA samples from individual Ixodes holocyclus (n = 279), Amblyomma triguttatum (n = 167), Haemaphysalis bancrofti (n = 7), and H. longicornis (n = 7) ticks. The 16S amplicons were sequenced on the Illumina MiSeq platform and analysed in USEARCH, QIIME, and BLAST to assign genus and species-level taxonomies. Nested PCR and Sanger sequencing were used to confirm the NGS data and further analyse novel findings. All 460 ticks were negative for Borrelia spp. by both NGS and nested PCR analysis. Two novel “Candidatus Neoehrlichia” spp. were identified in 12.9% of I. holocyclus ticks. A novel Anaplasma sp. was identified in 1.8% of A. triguttatum ticks, and a novel Ehrlichia sp. was identified in both A. triguttatum (1.2%) ticks and a single I. holocyclus (0.6%) tick. Further phylogenetic analysis of novel “Ca. Neoehrlichia”, Anaplasma and Ehrlichia based on 1,265 bp 16S rRNA gene sequences suggests that these are new species. Determining whether these newly discovered organisms cause disease in humans and animals, like closely related bacteria do abroad, is of public health importance and requires further investigation. PMID:26709826

  8. Asymmetric tandem organic solar cells

    NASA Astrophysics Data System (ADS)

    Howells, Thomas J.

    Organic photovoltaics (OPVs) is an area that has attracted much attention recently as a potential low cost, sustainable source of energy with a good potential for full-scale commercialisation. Understanding the factors that determine the efficiency of such cells is therefore a high priority, as well as developing ways to boost efficiency to commercially-useful levels. In addition to an intensive search for new materials, significant effort has been spent on ways to squeeze more performance out of existing materials, such as multijunction cells. This thesis investigates double junction tandem cells in the context of small molecule organic materials. . Two different organic electron donor materials, boron subphthalocyanine chloride (SubPc) and aluminium phthalocyanine chloride (ClAlPc) were used as donors in heterojunctions with C60 to create tandem cells for this thesis. These materials have been previously used for solar cells and the absorption spectra of the donor materials complement each other, making them good candidates for tandem cell architectures. The design of the recombination layer between the cells is considered first, with silver nanoparticles demonstrated to work well as recombination centres for charges from the front and back sub-cells, necessary to avoid a charge build-up at the interface. The growth conditions for the nanoparticles are optimised, with the tandem cells outperforming the single heterojunction architecture. Optical modelling is considered as a method to improve the understanding of thin film solar cells, where interference effects from the reflective aluminium electrode are important in determining the magnitude of absorption a cell can achieve. The use of such modelling is first demonstrated in hybrid solar cells based on a SubPc donor with a titanium oxide (TiOx) acceptor; this system is ideal for observing the effects of interference as only the SubPc layer has significant absorption. The modelling is then applied to tandem cells

  9. Development of a mitochondrial 12S rDNA analysis for distinguishing Sciuridae species with potential to transmit Ehrlichia and Borrelia species to feeding Amblyomma americanum (Acari: Ixodidae).

    PubMed

    Goessling, Lisa S; Allan, Brian F; Mandelbaum, Rachel S; Thach, Robert E

    2012-05-01

    Unique oligonucleotide probes were synthesized to distinguish among closely related vertebrate mitochondrial rDNA sequences present in residual bloodmeals in emergent Amblyomma americanum (L.) (Acari: Ixodidae) nymph life-stage ticks. Use of these probes enabled the identification of the Eastern gray squirrel as an important bloodmeal source in nymphs harboring Ehrlichia and Borrelia species. These results were confirmed by identifying these same bacterial genera in Eastern gray squirrel tissues.

  10. MR-Tandem: parallel X!Tandem using Hadoop MapReduce on Amazon Web Services

    PubMed Central

    Pratt, Brian; Howbert, J. Jeffry; Tasman, Natalie I.; Nilsson, Erik J.

    2012-01-01

    Summary: MR-Tandem adapts the popular X!Tandem peptide search engine to work with Hadoop MapReduce for reliable parallel execution of large searches. MR-Tandem runs on any Hadoop cluster but offers special support for Amazon Web Services for creating inexpensive on-demand Hadoop clusters, enabling search volumes that might not otherwise be feasible with the compute resources a researcher has at hand. MR-Tandem is designed to drop in wherever X!Tandem is already in use and requires no modification to existing X!Tandem parameter files, and only minimal modification to X!Tandem-based workflows. Availability and implementation: MR-Tandem is implemented as a lightly modified X!Tandem C++ executable and a Python script that drives Hadoop clusters including Amazon Web Services (AWS) Elastic Map Reduce (EMR), using the modified X!Tandem program as a Hadoop Streaming mapper and reducer. The modified X!Tandem C++ source code is Artistic licensed, supports pluggable scoring, and is available as part of the Sashimi project at http://sashimi.svn.sourceforge.net/viewvc/sashimi/trunk/trans_proteomic_pipeline/extern/xtandem/. The MR-Tandem Python script is Apache licensed and available as part of the Insilicos Cloud Army project at http://ica.svn.sourceforge.net/viewvc/ica/trunk/mr-tandem/. Full documentation and a windows installer that configures MR-Tandem, Python and all necessary packages are available at this same URL. Contact: brian.pratt@insilicos.com PMID:22072385

  11. MR-Tandem: parallel X!Tandem using Hadoop MapReduce on Amazon Web Services.

    PubMed

    Pratt, Brian; Howbert, J Jeffry; Tasman, Natalie I; Nilsson, Erik J

    2012-01-01

    MR-Tandem adapts the popular X!Tandem peptide search engine to work with Hadoop MapReduce for reliable parallel execution of large searches. MR-Tandem runs on any Hadoop cluster but offers special support for Amazon Web Services for creating inexpensive on-demand Hadoop clusters, enabling search volumes that might not otherwise be feasible with the compute resources a researcher has at hand. MR-Tandem is designed to drop in wherever X!Tandem is already in use and requires no modification to existing X!Tandem parameter files, and only minimal modification to X!Tandem-based workflows. MR-Tandem is implemented as a lightly modified X!Tandem C++ executable and a Python script that drives Hadoop clusters including Amazon Web Services (AWS) Elastic Map Reduce (EMR), using the modified X!Tandem program as a Hadoop Streaming mapper and reducer. The modified X!Tandem C++ source code is Artistic licensed, supports pluggable scoring, and is available as part of the Sashimi project at http://sashimi.svn.sourceforge.net/viewvc/sashimi/trunk/trans_proteomic_pipeline/extern/xtandem/. The MR-Tandem Python script is Apache licensed and available as part of the Insilicos Cloud Army project at http://ica.svn.sourceforge.net/viewvc/ica/trunk/mr-tandem/. Full documentation and a windows installer that configures MR-Tandem, Python and all necessary packages are available at this same URL. brian.pratt@insilicos.com

  12. Nanocrystal assembly for tandem catalysis

    DOEpatents

    Yang, Peidong; Somorjai, Gabor; Yamada, Yusuke; Tsung, Chia-Kuang; Huang, Wenyu

    2014-10-14

    The present invention provides a nanocrystal tandem catalyst comprising at least two metal-metal oxide interfaces for the catalysis of sequential reactions. One embodiment utilizes a nanocrystal bilayer structure formed by assembling sub-10 nm platinum and cerium oxide nanocube monolayers on a silica substrate. The two distinct metal-metal oxide interfaces, CeO.sub.2--Pt and Pt--SiO.sub.2, can be used to catalyze two distinct sequential reactions. The CeO.sub.2--Pt interface catalyzed methanol decomposition to produce CO and H.sub.2, which were then subsequently used for ethylene hydroformylation catalyzed by the nearby Pt--SiO.sub.2 interface. Consequently, propanal was selectively produced on this nanocrystal bilayer tandem catalyst.

  13. Plasmonic polymer tandem solar cell.

    PubMed

    Yang, Jun; You, Jingbi; Chen, Chun-Chao; Hsu, Wan-Ching; Tan, Hai-ren; Zhang, Xing Wang; Hong, Ziruo; Yang, Yang

    2011-08-23

    We demonstrated plasmonic effects in an inverted tandem polymer solar cell configuration by blending Au nanoparticles (NPs) into the interconnecting layer (ICL) that connects two subcells. Experimental results showed this plasmonic enhanced ICL improves both the top and bottom subcells' efficiency simultaneously by enhancing optical absorption. The presence of Au NPs did not cause electrical characteristics to degrade within the tandem cell. As a result, a 20% improvement of power conversion efficiency has been attained by the light concentration of Au NPs via plasmonic near-field enhancement. The simulated near-field distribution and experimental Raman scattering investigation support our results of plasmonic induced enhancement in solar cell performance. Our finding shows a great potential of incorporating the plasmonic effect with conventional device structure in achieving highly efficient polymer solar cells. © 2011 American Chemical Society

  14. Tandem motors reduce well costs

    SciTech Connect

    Hooper, M.; Daigle, C.; Crowe, R.

    1995-10-01

    The new generation of tandem mud motors that recently appeared on the drilling scene is significantly affecting drilling efficiency worldwide. These motors provide drillers with increased horsepower at the bit, higher torque, and faster rates of penetration (ROP). With advanced engineering and more durable materials, motor life is being extended, thereby increasing the time between bit trips and reducing drilling costs. This article reviews the performance, design, and operation of these motors.

  15. Portable Tandem Mass Spectrometer Analyzer

    DTIC Science & Technology

    1991-07-01

    The planned instrument was to be small enough to be portable in small vehicles and was to be able to use either an atmospheric pressure ion source or a...conventional electron impact/chemical ionization ion source. In order to accomplish these developments an atmospheric pressure ionization source was...developed for a compact, commercially available tandem quadrupole mass spectrometer. This ion source could be readily exchanged with the conventional

  16. "Nanocrystal bilayer for tandem catalysis"

    SciTech Connect

    Yamada, Yusuke; Tsung, Chia Kuang; Huang, Wenyu; Huo, Ziyang; E.Habas, Susan E; Soejima, Tetsuro; Aliaga, Cesar E; Samorjai, Gabor A; Yang, Peidong

    2011-01-24

    Supported catalysts are widely used in industry and can be optimized by tuning the composition and interface of the metal nanoparticles and oxide supports. Rational design of metal-metal oxide interfaces in nanostructured catalysts is critical to achieve better reaction activities and selectivities. We introduce here a new class of nanocrystal tandem catalysts that have multiple metal-metal oxide interfaces for the catalysis of sequential reactions. We utilized a nanocrystal bilayer structure formed by assembling platinum and cerium oxide nanocube monolayers of less than 10 nm on a silica substrate. The two distinct metal-metal oxide interfaces, CeO2-Pt and Pt-SiO2, can be used to catalyse two distinct sequential reactions. The CeO2-Pt interface catalysed methanol decomposition to produce CO and H2, which were subsequently used for ethylene hydroformylation catalysed by the nearby Pt-SiO2 interface. Consequently, propanal was produced selectively from methanol and ethylene on the nanocrystal bilayer tandem catalyst. This new concept of nanocrystal tandem catalysis represents a powerful approach towards designing high-performance, multifunctional nanostructured catalysts

  17. Achieving 15% Tandem Polymer Solar Cells

    DTIC Science & Technology

    2015-06-23

    AFRL-OSR-VA-TR-2015-0145 Achieving 1% Tandem Polymer Solar Cells Yang Yang UNIVERSITY OF CALIFORNIA LOS ANGELES Final Report 06/23/2015 DISTRIBUTION...15% tandem polymer solar cells 5a. CONTRACT NUMBER 5b. GRANT NUMBER FA9550-12-1-0074 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER...1) develop novel low bandgap conjugated polymers for high efficiency tandem solar cell – single junction cell with 9% PCE achieved (2) develop

  18. Short Tandem Repeat DNA Internet Database

    National Institute of Standards and Technology Data Gateway

    SRD 130 Short Tandem Repeat DNA Internet Database (Web, free access)   Short Tandem Repeat DNA Internet Database is intended to benefit research and application of short tandem repeat DNA markers for human identity testing. Facts and sequence information on each STR system, population data, commonly used multiplex STR systems, PCR primers and conditions, and a review of various technologies for analysis of STR alleles have been included.

  19. Recent Activities at Tokai Tandem Accelerator

    SciTech Connect

    Ishii, Tetsuro

    2010-05-12

    Recent activities at the JAEA-Tokai tandem accelerator facility are presented. The terminal voltage of the tandem accelerator reached 19.1 MV by replacing acceleration tubes. The multi-charged positive-ion injector was installed in the terminal of the tandem accelerator, supplying high-current noble-gas ions. A superconducting cavity for low-velocity ions was developed. Radioactive nuclear beams of {sup 8,9}Li and fission products, produced by the tandem accelerator and separated by the ISOL, were supplied with experiment. Recent results of nuclear physics experiments are reported.

  20. Detecting long tandem duplications in genomic sequences

    PubMed Central

    2012-01-01

    Background Detecting duplication segments within completely sequenced genomes provides valuable information to address genome evolution and in particular the important question of the emergence of novel functions. The usual approach to gene duplication detection, based on all-pairs protein gene comparisons, provides only a restricted view of duplication. Results In this paper, we introduce ReD Tandem, a software using a flow based chaining algorithm targeted at detecting tandem duplication arrays of moderate to longer length regions, with possibly locally weak similarities, directly at the DNA level. On the A. thaliana genome, using a reference set of tandem duplicated genes built using TAIR,a we show that ReD Tandem is able to predict a large fraction of recently duplicated genes (dS < 1) and that it is also able to predict tandem duplications involving non coding elements such as pseudo-genes or RNA genes. Conclusions ReD Tandem allows to identify large tandem duplications without any annotation, leading to agnostic identification of tandem duplications. This approach nicely complements the usual protein gene based which ignores duplications involving non coding regions. It is however inherently restricted to relatively recent duplications. By recovering otherwise ignored events, ReD Tandem gives a more comprehensive view of existing evolutionary processes and may also allow to improve existing annotations. PMID:22568762

  1. The characterization of tandem and corrugated wings

    NASA Astrophysics Data System (ADS)

    Lian, Yongsheng; Broering, Timothy; Hord, Kyle; Prater, Russell

    2014-02-01

    Dragonfly wings have two distinct features: a tandem configuration and wing corrugation. Both features have been extensively studied with the aim to understand the superior flight performance of dragonflies. In this paper we review recent development of tandem and corrugated wing aerodynamics. With regards to the tandem configuration, this review will focus on wing/wing and wing/vortex interactions at different flapping modes and wing spacing. In addition, the aerodynamics of tandem wings under gusty conditions will be reviewed and compared with isolated wings to demonstrate the gust resistance characteristics of flapping wings. Regarding corrugated wings, we review their structural and aerodynamic characteristics.

  2. Molecular detection of Ehrlichia canis, Hepatozoon canis and Babesia canis vogeli in stray dogs in Mahasarakham province, Thailand.

    PubMed

    Piratae, Supawadee; Pimpjong, Kiattisak; Vaisusuk, Kotchaphon; Chatan, Wasupon

    2015-01-01

    Canine tick borne diseases showing distribution worldwide have caused morbidity and mortality in dogs. This study observed the mainly tick borne pathogens described for dogs in Thailand, Ehrlichia canis, Hepatozoon canis and Babesia canis vogeli. From May to July 2014, blood samples were collected from 79 stray dogs from 7 districts of Mahasarakham province to molecular surveyed for 16s rRNA gene of E. canis and 18s rRNA gene of H. canis and B. canis vogeli. Twenty eight (35.44%) of stray dogs showed the infection with tick borne pathogens. The prevalence of E. canis infection was the highest with 21.5% (17/79). DNA of H. canis and B. canis vogeli were detected at the prevalence of 10.1% (8/79) and 6.3% (5/79), respectively. Co-infection between E. canis and B. canis vogeli were identified in 2 (2.5%) dogs. The results indicated that a wide range of tick borne pathogens are circulation in the canine population in Mahasarakham province. This study is the first report on prevalence of E. canis, H. canis and B. canis vogeli in stray dogs in Mahasarakham, a province in northern part of Thailand. This data providing is important to understand the prevalence of E. canis, H. canis and B. canis vogeli infection in stray dogs in this region, which will assist in the management of these blood parasite.

  3. The efficacy of Advantix® to prevent transmission of Ehrlichia canis to dogs by Rhipicephalus sanguineus ticks.

    PubMed

    Fourie, Josephus Johannes; Luus, Herman Gerhardus; Stanneck, Dorothee; Jongejan, Frans

    2013-01-01

    The capacity of a topical combination of imidacloprid and permethrin (Advantix(®)) to prevent transmission of Ehrlichia canis was studied in two groups of six dogs. One group served as controls, whereas the other group was treated. All dogs were exposed to E. canis-infected Rhipicephalus sanguineus ticks on Days 7, 14, 21 and Day 28 post acaricidal treatment. The adult R. sanguineus ticks were released into the individual kennels of the dogs to simulate natural tick exposure. In situ tick counts were conducted on Day 9, 16 and 23 and any remaining ticks were counted and removed on Day 30. The efficacy of the acaricidal treatment against R. sanguineus ranged between 96.1% and 98.9% at 48 h post-application and lasted up to 4 weeks. Four out of six control dogs became infected with E. canis, as demonstrated by the presence of specific E. canis antibodies and the detection by PCR of E. canis DNA in blood samples. These dogs became thrombocytopenic and displayed fever and were consecutively rescue-treated by doxycycline. None of the six treated dogs became infected with E. canis, as confirmed by the lack of specific antibodies and absence of E. canis DNA in blood samples. Advantix(®) prevented transmission of E. canis and provided protection against monocytic ehrlichiosis for 4 weeks post acaricidal treatment.

  4. Increase nitric oxide and oxidative stress in dogs experimentally infected by Ehrlichia canis: effect on the pathogenesis of the disease.

    PubMed

    Da Silva, Aleksandro S; Munhoz, Thiago D; Faria, Joice L M; Vargas-Hérnandez, Giovanni; Machado, Rosangela Z; Almeida, Taís C; Moresco, Rafael N; Stefani, Lenita M; Tinucci-Costa, Mirela

    2013-06-28

    The aim of this study was to evaluate nitric oxide levels, lipid peroxidation, protein oxidation and glutathione reductase activity in serum of dogs experimentally infected by Ehrlichia canis. Banked serum samples of dogs divided into two groups were used: negative control (n=5) and infected by E. canis (n=5). The concentration of nitrite/nitrate (NOx), lipid peroxidation (TBARS), advanced oxidation protein products (AOPP), and glutathione reductase (GR) activity in sera were evaluated. Samples were collected on days 0, 3, 6, 18 and 30 post-infection (PI). NOx and TBARS levels were significantly (P<0.05) higher in the infected group at 18 and 30 days PI, as well as AOPP levels at 30 days PI when compared to samples from control group. The GR activity was significant (P<0.05) increased in serum of dogs infected by E. canis on days 18 and 30 PI. Based on the increased levels of NOx, TBARS, AOPP and GR activity we concluded that dogs experimentally infected by E. canis develop a state of redox imbalance and that these changes might be involved in the pathophysiology of the disease.

  5. Isolation, in vitro propagation, genetic analysis, and immunogenic characterization of an Ehrlichia canis strain from southeastern Brazil.

    PubMed

    Alves, Rosiane Nascimento; Rieck, Susana Elisa; Ueira-Vieira, Carlos; Labruna, Marcelo Bahia; Beletti, Marcelo EmÍlio

    2014-01-01

    Amplification of the 16S rRNA gene from a blood sample obtained from a dog in southeastern Brazil was used to confirm a naturally acquired Ehrlichia (E.) canis infection. Following isolation and culturing of the new bacterial strain called Uberlandia, partial sequences of the dsb and p28 genes were obtained. The dsb partial sequence of the novel strain was 100% similar to dsb gene sequences of E. canis obtained from different geographic areas around the world. Conversely, the p28 partial sequence for the E. canis Uberlândia strain differed at several nucleotides from other sequences available in GenBank. To confirm the antigenic profile of the Uberlândia strain, an indirect immunofluorescence assay against E. canis antigens was performed using dog sera collected from two different areas in Brazil (Uberlândia and São Paulo). The results suggest that both antigens were able to identify animals seropositive for E. canis in Brazil since these Brazilian strains appear to be highly conserved.

  6. Multiplex real-time qPCR for the detection of Ehrlichia canis and Babesia canis vogeli.

    PubMed

    Peleg, Ofer; Baneth, Gad; Eyal, Osnat; Inbar, Jacob; Harrus, Shimon

    2010-10-29

    Ehrlichia canis and Babesia canis vogeli are two tick-borne canine pathogens with a worldwide importance. Both pathogens are transmitted by Rhipicephalus sanguineus, the brown dog tick, which has an increasing global distribution. A multiplex quantitative real-time PCR (qPCR) assay for the simultaneous detection of the tick-borne pathogens E. canis and B. canis vogeli was developed using dual-labeled probes. The target genes were the 16S rRNA of E. canis and the heat shock protein 70 (hsp70) of B. canis vogeli. The canine beta actin (ACTB) gene was used as an internal control gene. The assay was conducted without using any pre-amplification steps such as nested reactions. The sensitivity of each reaction in the multiplex qPCR assay was tested in the presence of high template concentrations of the other amplified genes in the same tube and in the presence of canine DNA. The detection threshold of the multiplex assay was 1-10 copies/μl in all channels and the amplifications of the B. canis hsp70 and ACTB were not affected by the other simultaneous reactions, while minor interference was observed in the amplification of the E. canis 16S rRNA gene. This assay would be useful for diagnostic laboratories and may save time, labor and costs.

  7. Pathology of dogs in Campo Grande, MS, Brazil naturally co-infected with Leishmania infantum and Ehrlichia canis.

    PubMed

    Andrade, Gisele Braziliano; Barreto, Wanessa Teixeira Gomes; Santos, Luciana Ladislau dos; Ribeiro, Laura Raquel Rios; Macedo, Gabriel Carvalho de; Sousa, Keyla Carstens Marques de; André, Marcos Rogério; Machado, Rosangela Zacarias; Herrera, Heitor Miraglia

    2014-01-01

    Different parasites that commonly occur concomitantly can influence one another, sometimes with unpredictable effects. We evaluated pathological aspects of dogs naturally co-infected with Leishmania infantum and Ehrlichia canis. The health status of the dogs was investigated based on histopathological, hematological and biochemical analyses of 21 animals infected solely with L. infantum and 22 dogs co- infected with L. infantum and E. canis. The skin of both groups showed chronic, predominantly lymphohistioplasmacytic inflammatory reaction. The plasmacytosis in the lymphoid tissues was likely related with the hypergammaglobulinemia detected in all the dogs. The disorganization of extracellular matrix found in the reticular dermis of the inguinal region and ear, characterized by the substitution of thick collagen fibers for thin fibers, was attributed to the degree of inflammatory reaction, irrespective of the presence of parasites. In addition, the histopathological analysis revealed that twice as many dogs in the co-infected group presented Leishmania amastigotes in the ear skin than those infected solely with Leishmania, increasing the possibility of becoming infected through sand fly vectors. Our findings highlight the fact that the health of dogs infected concomitantly with L. infantum and E. canis is severely compromised due to their high levels of total plasma protein, globulins, alkaline phosphatase and creatine kinase, and severe anemia.

  8. Molecular detection of Ehrlichia canis, Anaplasma bovis, Anaplasma platys, Candidatus Midichloria mitochondrii and Babesia canis vogeli in ticks from Israel.

    PubMed

    Harrus, S; Perlman-Avrahami, A; Mumcuoglu, K Y; Morick, D; Eyal, O; Baneth, G

    2011-03-01

    : Ticks are vectors of important pathogens of human and animals. Therefore, their microbial carriage capacity is constantly being investigated. The aim of this study was to characterize the diversity of domestic animal pathogens in ticks collected from vegetation and the ground, from different parts of Israel. Non-engorged questing adult ticks were collected from 13 localities. A total of 1196 ticks in 131 pools-83 pools of Rhipicephalus turanicus and 48 of Rhipicephalus sanguineus (with two to ten ticks per pool)-were included in this study. In addition, 13 single free-roaming Hyalomma spp. ticks were collected. Screening by molecular techniques revealed the presence of Ehrlichia canis, Anaplasma platys, Anaplasma bovis and Babesia canis vogeli DNA in R. turanicus ticks. E. canis, A. bovis, B. canis vogeli and Candidatus Midichloria mitochondrii DNA sequences were detected in R. sanguineus ticks. Candidatus Midichloria mitochondrii DNA was also detected in Hyalomma spp. ticks. Neither Hepatozoon spp. nor Bartonella spp. DNA was detected in any of the ticks examined. This study describes the first detection of E. canis in the tick R. turanicus, which may serve as a vector of this canine pathogen; E. canis was the most common pathogen detected in the collected questing ticks. It also describes the first detection of A. bovis and Candidatus Midichloria mitochondrii in Israel. To the best of the author's knowledge, this is the first report describing the detection of DNA of the latter two pathogens in R. sanguineus, and of A. bovis in R. turanicus.

  9. Immunoserologic evidence of coinfection with Borrelia burgdorferi, Babesia microti, and human granulocytic Ehrlichia species in residents of Wisconsin and Minnesota.

    PubMed Central

    Mitchell, P D; Reed, K D; Hofkes, J M

    1996-01-01

    In Wisconsin and Minnesota, Ixodes scapularis (Ixodes dammini) ticks are the vector of three microorganisms that may cause significant disease in humans and lower mammals. These diseases include Lyme borreliosis, which is caused by Borrelia burgdorferi, babesiosis, which is caused by Babesia microti, and human granulocytic ehrlichiosis (HGE), which is caused by an apparently new species in the genus Ehrlichia. Immunoserologic testing was performed on sera from patients with a diagnosis of one of these diseases to determine if there was evidence of coinfection with one or more of the other agents. Of 96 patients with Lyme borreliosis, 9 (9.4%) demonstrated immunoserologic evidence of coinfection: 5 (5.2%) with the agent of HGE, 2 (2.1%) with B. microti, and 2 (2.1%) with both microorganisms. Of 19 patients diagnosed with HGE, 3 (15.8%) showed immunoserologic evidence of coinfection: 1 (5.3%) with B. burgdorferi, 1 (5.3%) with B. microti, and 1 (5.3%) with both microorganisms. One patient diagnosed with babesiosis was also seropositive for ehrlichiosis. These results provide evidence for coinfection, perhaps explaining the variable manifestations and clinical responses noted in some patients with tick-transmitted diseases. In certain clinical settings, laboratory testing for coinfection is indicated to ensure that appropriate antimicrobial treatment is given. PMID:8904446

  10. Seroprevalence and Risk Factors of Ehrlichia canis Infection among Companion Dogs of Mashhad, North East of Iran, 2009–2010

    PubMed Central

    Ansari-Mood, Maneli; Khoshnegah, Javad; Mohri, Mehrdad; Rajaei, Seyed Mehdi

    2015-01-01

    Background: The aims of this study were to determine the seroprevalence of canine ehrlichiosis and risk factors of this disease in companion dogs’ population of Mashhad, North East of Iran. Canine Monocytic Ehrlichiosis (CME) is a zoonotic disease transmitted by ticks, Rhipicephalus sanguineus, and caused by an obligate intracellular bacterium, Ehrlichia canis. Methods: During September 2009 until November 2010, 250 companion dogs from Mashhad, North-East of Iran, were examined for serum antibody detection against E. canis by means of immunofluorescence assay test (IFAT) and factors associated with a positive antibody response. Results: There was a very low prevalence of anti-E. canis antibodies (0.8%, 2/250) among studied dogs. The antibody titers for two seropositive dogs were 1:80 and 1:160, respectively. One (0.4%) of seropositive dogs was infested with, R. sanguineus. In blood smears from one of infested dogs (0.4%), typical morulae of E. canis was observed in lymphocytes. The results confirm that the lowest occurrence of reactive dogs indoors probably related to low tick infestion. Conclusion: This is the first report that describes serological evidences of canine monocytic ehrlichiosis in North-East of Iran. Results suggested that E. canis infection in owned pet dogs from North of Khorasan was not endemic from 2009 to 2010. Additional molecular studies are necessary to confirm E. canis infection and to identify the local strains of the organism. PMID:26623430

  11. Seroprevalence and Risk Factors of Ehrlichia canis Infection among Companion Dogs of Mashhad, North East of Iran, 2009-2010.

    PubMed

    Ansari-Mood, Maneli; Khoshnegah, Javad; Mohri, Mehrdad; Rajaei, Seyed Mehdi

    2015-12-01

    The aims of this study were to determine the seroprevalence of canine ehrlichiosis and risk factors of this disease in companion dogs' population of Mashhad, North East of Iran. Canine Monocytic Ehrlichiosis (CME) is a zoonotic disease transmitted by ticks, Rhipicephalus sanguineus, and caused by an obligate intracellular bacterium, Ehrlichia canis. During September 2009 until November 2010, 250 companion dogs from Mashhad, North-East of Iran, were examined for serum antibody detection against E. canis by means of immunofluorescence assay test (IFAT) and factors associated with a positive antibody response. There was a very low prevalence of anti-E. canis antibodies (0.8%, 2/250) among studied dogs. The antibody titers for two seropositive dogs were 1:80 and 1:160, respectively. One (0.4%) of seropositive dogs was infested with, R. sanguineus. In blood smears from one of infested dogs (0.4%), typical morulae of E. canis was observed in lymphocytes. The results confirm that the lowest occurrence of reactive dogs indoors probably related to low tick infestion. This is the first report that describes serological evidences of canine monocytic ehrlichiosis in North-East of Iran. Results suggested that E. canis infection in owned pet dogs from North of Khorasan was not endemic from 2009 to 2010. Additional molecular studies are necessary to confirm E. canis infection and to identify the local strains of the organism.

  12. Differential transcription of the major antigenic protein 1 multigene family of Ehrlichia ruminantium in Amblyomma variegatum ticks.

    PubMed

    Postigo, M; Taoufik, A; Bell-Sakyi, L; de Vries, E; Morrison, W I; Jongejan, F

    2007-06-21

    The rickettsial pathogen Ehrlichia ruminantium causes heartwater in ruminants and is transmitted by ticks of the genus Amblyomma. The map1 gene, encoding the major surface protein MAP1, is a member of a multigene family containing 16 paralogs. In order to investigate differential transcription of genes of the map1 multigene family in vivo in unfed and feeding ticks, RNA was extracted from midguts and salivary glands of E. ruminantium-infected adult female Amblyomma variegatum ticks and analysed by RT-PCR using MAP1 paralog-specific primers. In unfed ticks, only transcripts from the map1-1 gene were observed in midguts and no transcripts were detected in salivary glands. In feeding ticks, map1-1 transcripts were more abundant in midguts whereas high levels of map1 transcripts were observed in salivary glands. Our results show that differential transcription of genes of the E. ruminantium map1 cluster occurs in vivo in different tissues of infected ticks before and during transmission feeding, indicating that this multigene family may be involved in functions of biological relevance in different stages of the life cycle of E. ruminantium.

  13. Molecular detection of Dirofilaria immitis, Hepatozoon canis, Babesia spp., Anaplasma platys and Ehrlichia canis in dogs on Costa Rica.

    PubMed

    Wei, Lanjing; Kelly, Patrick; Ackerson, Kate; El-Mahallawy, Heba S; Kaltenboeck, Bernhard; Wang, Chengming

    2014-03-01

    Although vector-borne diseases are important causes of morbidity and mortality in dogs in tropical areas, there is little information on these conditions in Costa Rica. In PCRs of blood from dogs in Costa Rica, we did not detect DNAs of Rickettsia (R.) felis and Coxiella (C.) burnetii but we did find evidence of infection with Dirofilaria (D.) immitis (9/40, 22.5%), Hepatozoon (H.) canis (15/40, 37.5%), Babesia spp. (10/40, 25%; 2 with B. gibsoni and 8 with B. vogeli), Anaplasma (A.) platys (3/40, 7.5%) and Ehrlichia (E.) canis (20/40, 50%). Nine dogs (22.5%) were free of any vector-borne pathogens while 14 (35%) were infected with a single pathogen, 11 (27.5%) with two, 4 (10%) with three, 1 (2.5%) with four, and 1 (2.5%) with five pathogens. Dogs in Costa Rica are commonly infected with vector-borne agents.

  14. Serological reactivity to Ehrlichia canis, Anaplasma phagocytophilum, Neorickettsia risticii, Borrelia burgdorferi and Rickettsia conorii in dogs from northwestern Spain.

    PubMed

    Amusategui, Inmaculada; Tesouro, Miguel A; Kakoma, Ibulaimu; Sainz, Angel

    2008-12-01

    The aim of the present work was to investigate the seroprevalence against Ehrlichia canis (Ec), Anaplasma phagocytophilum (Ap), Neorickettsia risticii (Nr), Rickettsia conorii (Rc), and Borrelia burgdorferi (Bb) in two different clusters of canine samples from Northwestern Spain. Cluster 1 included 479 dogs presented at veterinary clinics located in Ourense and Pontevedra. Cluster II included 170 dogs from the public kennel of Ourense. All 649 canine serum samples were analyzed by immunofluorescent antibody test. Prevalences against the above-mentioned agents in cluster I were: Rc (24.6%), Bb (6.26%), Ec (3.13%), Ap (5.01%), and Nr (1.04%), whereas for cluster II were: Rc (50%), Bb (8.8%), Ec (54.7%), Ap (45.3%), and Nr (4.7%). Rc was significantly associated with age and history of exposure to ticks, and Bb showed a statistical relationship with age and clinical status. Ec and Ap were related to the occupation of the dogs, with stray dogs being the most frequently seropositive. Furthermore, seroreactivity against Ec and Ap was significantly higher in Ourense than in Pontevedra. The univariate analysis demonstrated a significant concomitant seroreactivity between Ec and Ap and between Rc and Ec and Ap antigens. The seroreactivity to Nr must be interpreted very cautiously as this infectious agent has been seldom reported outside North America.

  15. [Ehrlichia canis in dogs attended in a veterinary hospital from Botucatu, São Paulo State, Brazil].

    PubMed

    Ueno, Tatiana E H; Aguiar, Daniel M; Pacheco, Richard C; Richtzenhain, Leonardo J; Ribeiro, Márcio G; Paes, Antônio C; Megid, Jane; Labruna, Marcelo B

    2009-01-01

    This study investigated the etiology of canine ehrlichiosis and possible clinical and epidemiological data associated with the infection in 70 dogs suspect of ehrlichiosis attended at the Veterinary Hospital of the São Paulo State University in Botucatu city during 2001 and 2002. Dogs were evaluated by clinical-epidemiological and hematological data and molecular analysis by partial amplification and DNA sequencing of the ehrlichial dsb gene. E. canis DNA was amplified and sequenced in 28 (40.0%) dogs. Dogs younger than 12 months old showed significantly higher infection rates (65.0%; P < 0.05). Diarrhea, apathy, and anorexia were the major clinical signs observed in 55.2% (P = 0.05), 47.0% (P > 0.05), and 42.4% (P > 0.05) of the PCR-positive dogs, respectively. Twenty-five anemic (<5.5 x 10(6) RBC x microL (-1)), and 8 leukopenic (<5.5 x 103 WBC x microL (-1)) dogs were PCR-positive (P > 0.05). All 28 PCR-positive dogs showed thrombocytopenia (< 175 x 103 platelets x microL (-1)) and revealed statistical significance (P < 0.05). E. canis was the only Ehrlichia species found in dogs in the studied region, with higher infection rates in younger dogs, and statistically associated with thrombocytopenia.

  16. 47 CFR 69.111 - Tandem-switched transport and tandem charge.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... circuits used in the tandem to end office links (or a surrogate based on the proportion of copper and fiber... the relative number of DS1 and DS3 circuits used in the tandem to end office links (or a surrogate... circuits used in the tandem to end office links (or a surrogate based on the proportion of copper and...

  17. 47 CFR 69.111 - Tandem-switched transport and tandem charge.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... circuits used in the tandem to end office links (or a surrogate based on the proportion of copper and fiber... the relative number of DS1 and DS3 circuits used in the tandem to end office links (or a surrogate... circuits used in the tandem to end office links (or a surrogate based on the proportion of copper and...

  18. Tandem mirror technology demonstration facility

    SciTech Connect

    Not Available

    1983-10-01

    This report describes a facility for generating engineering data on the nuclear technologies needed to build an engineering test reactor (ETR). The facility, based on a tandem mirror operating in the Kelley mode, could be used to produce a high neutron flux (1.4 MW/M/sup 2/) on an 8-m/sup 2/ test area for testing fusion blankets. Runs of more than 100 h, with an average availability of 30%, would produce a fluence of 5 mW/yr/m/sup 2/ and give the necessary experience for successful operation of an ETR.

  19. Prevalence and Distribution of Human and Tick Infections with the Ehrlichia muris-Like Agent and Anaplasma phagocytophilum in Wisconsin, 2009-2015.

    PubMed

    Murphy, Darby S; Lee, Xia; Larson, Scott R; Johnson, Diep K Hoang; Loo, Theoren; Paskewitz, Susan M

    2017-04-01

    Ehrlichiosis and anaplasmosis are important emerging tickborne zoonoses that affect both humans and animals. Knowledge of the geographic distribution and prevalence of Ehrlichia spp. and Anaplasma phagocytophilum in Wisconsin is important information as a baseline for future comparisons. Reported human cases between 2009 and 2015 were identified using the Wisconsin Electronic Disease Surveillance System (WEDSS) and mapped by county of residence. Vector surveillance was established using ticks collected from animals by partners, including veterinary medical clinics, domestic animal shelters, and wildlife rehabilitation centers from 40 Wisconsin counties. A total of 1835 Ixodes scapularis tick specimens (larvae, nymphs, and adults) were collected from 18 different domestic and wildlife species from July 2011 to November 2015. An additional 1136 nymphs were collected by drag sampling at 23 locations in 19 counties in 2015. A real-time PCR assay that detects and distinguishes several Ehrlichia species, including a pathogenic Ehrlichia muris-like agent (EMLA), and A. phagocytophilum was performed on adult and nymphal ticks. A total of 757 I. scapularis ticks (predominately adults) were tested from animal collections, with 67 (8.9%) individuals positive for A. phagocytophilum and 22 (2.9%) positive for EMLA DNA. Of the 1150 questing nymphs, 62 (5.4%) were positive for A. phagocytophilum and 10 (0.9%) were positive for EMLA DNA. Specimens of I. scapularis that were positive for A. phagocytophilum were found in 27 of the 33 counties surveyed. Specimens that were positive for EMLA were less common and were found in nine counties. This study provides the first statewide survey of I. scapularis ticks for these pathogens and indicates that the risk of human exposure is widely distributed.

  20. Argonne Tandem-Linac Accelerator System

    SciTech Connect

    Bollinger, L.M.

    1983-01-01

    Design considerations and operational experience for the existing heavy-ion accelerator consisting of a tandem injecting into a superconducting linac are summarized, with emphasis on the general features of the system. This introduction provides the basis for a discussion of the objectives and design of ATLAS, a larger tandem-linac system being formed by expanding the existing superconducting linac.

  1. 33 CFR 401.41 - Tandem lockage.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Tandem lockage. 401.41 Section 401.41 Navigation and Navigable Waters SAINT LAWRENCE SEAWAY DEVELOPMENT CORPORATION, DEPARTMENT OF TRANSPORTATION SEAWAY REGULATIONS AND RULES Regulations Seaway Navigation § 401.41 Tandem lockage. Where two or...

  2. First report of Anaplasma platys infection in red foxes (Vulpes vulpes) and molecular detection of Ehrlichia canis and Leishmania infantum in foxes from Portugal.

    PubMed

    Cardoso, Luís; Gilad, Matan; Cortes, Helder C E; Nachum-Biala, Yaarit; Lopes, Ana Patrícia; Vila-Viçosa, Maria João; Simões, Margarida; Rodrigues, Paula A; Baneth, Gad

    2015-03-23

    The bacteria Anaplasma platys and Ehrlichia canis and the protozoan Leishmania infantum are vector-borne agents that cause canine vector-borne diseases, some of which are zoonotic. The present survey investigated the prevalence of Anaplasma, Ehrlichia and Leishmania in red foxes (Vulpes vulpes) from Portugal by molecular analysis, in order to evaluate the epidemiological role of these canids as reservoirs of infection. Blood and/or bone marrow samples were collected from 78 red foxes obtained in eight districts of northern, central and southern Portugal. Real-time polymerase chain reactions (PCR) amplified a 123 bp fragment of the 16S rRNA gene of Anaplasma spp. and Ehrlichia spp. and a 265 bp fragment of the L. infantum internal transcribed spacer one (ITS1) region of the rRNA operon evaluated by PCR-high resolution melt analysis (PCR-HRM), with sequencing of the DNA products. A phylogenetic analysis was carried out to compare these to other sequences from Anaplasma spp. and Ehrlichia spp. deposited in GenBank. A. platys was detected in 10 (14.5%) and E. canis in two (2.9%) out of 69 foxes; and L. infantum was detected in one (1.3%) of the 78 foxes. The prevalence of A. platys was significantly different from the prevalence of E. canis (p=0.016) and from that of L. infantum (p=0.002). No co-infections were found in any one of the 78 foxes. No statistically significant differences were found between the type of sample (blood and bone marrow), geographic regions (north/centre and south), age (<2 years and ≥2 years) and gender for any one of the agents. This is the first known report of A. platys in red foxes worldwide, as well as the first molecular evidence of E. canis in foxes from Portugal. The moderate prevalence of A. platys suggests that red foxes may play a role in the epidemiology of infection with this bacterium and serve as a reservoir for domestic dogs.

  3. Prevalence of Dirofilaria immitis, Ehrlichia canis, and Borrelia burgdorferi in pet dogs, racing greyhounds, and shelter dogs in Florida.

    PubMed

    Tzipory, Nirit; Crawford, P Cynda; Levy, Julie K

    2010-07-15

    Arthropod vectors of canine infectious diseases are present throughout Florida. Since crowded housing has the potential to bring vectors and infected dogs into close proximity, it is possible that prevalence of infection is higher in intensely housed dogs. In this study, the seroprevalence of Dirofilaria immitis, Ehrlichia canis, and Borrelia burgdorferi in dogs residing in two types of intensive housing, greyhound kennels and animal shelters, was compared to dogs residing in low-intensity housing, private homes. Serum was collected from a cross-section of 1500 adult dogs from Florida, including 500 pet dogs referred to the Veterinary Medical Center of the College of Veterinary Medicine at the University of Florida, 500 racing greyhounds, and 500 dogs residing in animal shelters. Serum was tested for D. immitis antigen, E. canis antibodies, and B. burgdorferi antibodies by ELISA. Seroprevalence of D. immitis was significantly higher (14.6%) in shelter dogs and in pet dogs (1.4%) than in racing greyhounds (0.2%) (P<0.04). There were no significant differences in the seroprevalence of E. canis (0.4-1.6%) or B. burgdorferi (0-0.8%) among the groups. There was no association of sex or age with D. immitis infection, but pit bull type dogs were more than twice as likely to be infected than other breeds (P=0.003). Evidence for vector-borne infections, particularly D. immitis, was found in dogs throughout the state. The prevalence was greatest for D. immitis infection in shelter dogs, likely due to lack of preventive medications prior to impoundment. Although heartworm infection is considered to be a treatable condition, insufficient resources in shelters may lead to euthanasia of infected dogs that would otherwise be considered adoptable. Copyright (c) 2010 Elsevier B.V. All rights reserved.

  4. Ferritin 1 silencing effect in Rhipicephalus sanguineus sensu lato (Acari: Ixodidae) during experimental infection with Ehrlichia canis.

    PubMed

    Ferrolho, Joana; Antunes, Sandra; Sanches, Gustavo S; Couto, Joana; Évora, Patrícia M; Rosa, Catarina; André, Marcos R; Machado, Rosângela Z; Bechara, Gervásio H; Domingos, Ana

    2017-01-01

    Rhipicephalus sanguineus sensu lato (s.l.) is a very common ectoparasite of domestic dogs able to transmit several pathogens of human and veterinary importance. Tick infestations and tick-borne diseases (TBDs) remain a serious and persistent problem, due to the lack of efficient control measures. It is therefore vital that novel approaches to control are pursued. Whilst vaccination is recognised as a potential control method to reduce tick infestation, no anti-R. sanguineus vaccine is available. Ticks depend on their blood meals to obtain nutrients and to achieve sexual maturity, which exposes them to vast amounts of iron. Although an essential molecule for several biological processes, its excess can lead to oxidative stress. Iron homeostasis is achieved with the help of iron-binding proteins called ferritins, among others, present in several tick tissues and developmental stages. These evolutionarily conserved proteins regulate iron homeostasis by storing and releasing iron in a controlled manner. In this study the R. sanguineus ferritin 1 gene was silenced through RNA interference (RNAi) in adult females exposed to an experimental infection with Ehrlichia canis. The purpose of this study was to assess the role of this protein in tick feeding, ovary development, oogenesis, and pathogen acquisition. Our data has shown that silencing ferritin 1 alters tick competence to normally engorge and causes morphologic and histochemical changes in the ovaries (OV) and oocytes. Furthermore, our data revealed that no E. canis DNA was found in either experimental group. Determining the function of molecules that act in key biological processes, such as blood digestion or reproduction, and that could be considered potential tick antigens will contribute towards the improvement of current control measures against these ectoparasites and the pathogens they vector.

  5. [Occurrence of Ehrlichia canis in dogs living in Germany and comparison of direct and indirect diagnostic methods].

    PubMed

    Csokai, Jacqueline; Klas, Eva Maria; Heusinger, Anton; Müller, Elisabeth

    2017-09-13

    To study the occurrence of Ehrlichia (E.) canis in dogs living in Germany and evaluate the possibilities and limits of direct and indirect diagnostic methods. The first part of the study was a retrospective analysis of routine samples, which had been examined for E. canis antibodies using an indirect immunofluorescence antibody test (IFAT). The examination was part of a laboratory profile for the detection of travel-related diseases (travel disease profile) or was performed on an individual basis. In the second part, samples which were examined within a travel disease profile, including E. canis antibodies, were further evaluated for E. canis DNA by a polymerase chain reaction (PCR). Medical histories were obtained of E. canis-positive dogs (animals which were positive in IFAT and/or PCR) and for a part of the negative animals. For 2015, 11.8% of 12220 samples had antibodies for E. canis. Dogs, which were examined with a travel disease profile, displayed antibodies in 5.6% cases of 1172 animals (investigation period February to March 2016). Of the E. canis-positive dogs (n = 67), 91% were positive with only the IFAT, 7.5% with the IFAT and PCR and 1.5% were only positive by PCR. Anamnesis showed that particularly imported dogs without symptoms were controlled for travel diseases during their first year in Germany. Although endemic E. canis infections play a minor role in Germany, infections with this pathogen are still of importance in this country, particularly because of the import of dogs. Therefore, a medical history helps in early ehrlichiosis diagnosis and to start an adequate treatment. Pathogen detection in imported E. canis-seropositive dogs, which often did not display clinical symptoms in this study, was frequently negative in blood samples by PCR. The diagnostic method should be chosen depending on the disease phase and the underlying question (symptoms or preventive screening).

  6. A Molecular survey of Anaplasma spp., Rickettsia spp., Ehrlichia canis and Babesia microti in foxes and fleas from Sicily.

    PubMed

    Torina, A; Blanda, V; Antoci, F; Scimeca, S; D'Agostino, R; Scariano, E; Piazza, A; Galluzzo, P; Giudice, E; Caracappa, S

    2013-11-01

    Fleas (Insecta: Siphonaptera) are obligate bloodsucking insects, which parasitize birds and mammals, and are distributed throughout the world. Several species have been implicated in pathogen transmission. This study aimed to monitor red foxes and the fleas isolated from them in the Palermo and Ragusa provinces of Sicily, Italy, as these organisms are potential reservoirs and vectors of pathogens. Thirteen foxes (Vulpes vulpes) and 110 fleas were analysed by polymerase chain reaction (PCR) to detect DNA of the pathogens Ehrlichia canis, Babesia microti, Rickettsia spp., Anaplasma phagocytophilum, Anaplasma platys, Anaplasma marginale and Anaplasma ovis. In the foxes, A. ovis was detected in only one animal, whereas the prevalence of the E. canis pathogen was 31%. B. microti and Rickettsia spp. were not detected. Of all of the collected fleas, 75 belonged to the species Xenopsylla cheopis, 32 belonged to Ctenocephalides canis, two belonged to Ctenocephalides felis and one belonged to Cediopsylla inaequalis. In the fleas, the following pathogens were found: A. ovis (prevalence 25%), A. marginale (1%), A. phagocytophilum (1%), Rickettsia felis (2%) and E. canis (3%). X. cheopis was the flea species most frequently infected with Anaplasma, in particular A. ovis (33%), A. marginale (1%) and A. phagocytophilum (1%). Both C. felis exemplars were positive for R. felis. E. canis was found in the lone C. inaequalis and also in 3% of the X. cheopis specimens. No fleas were positive for B. microti or A. platys. As foxes often live in proximity to domestic areas, they may constitute potential reservoirs for human and animal parasites. Further studies should be performed on fleas to determine their vectorial capacity. © 2013 Blackwell Verlag GmbH.

  7. Transcription analysis of the major antigenic protein 1 multigene family of three in vitro-cultured Ehrlichia ruminantium isolates.

    PubMed

    Bekker, Cornelis P J; Postigo, Milagros; Taoufik, Amar; Bell-Sakyi, Lesley; Ferraz, Conchita; Martinez, Dominique; Jongejan, Frans

    2005-07-01

    Ehrlichia ruminantium, an obligate intracellular bacterium transmitted by ticks of the genus Amblyomma, causes heartwater disease in ruminants. The gene coding for the major antigenic protein MAP1 is part of a multigene family consisting of a cluster containing 16 paralogs. In the search for differentially regulated genes between E. ruminantium grown in endothelial and tick cell lines that could be used in vaccine development and to determine if differences in the map1 gene cluster exist between different isolates of E. ruminantium, we analyzed the map1 gene cluster of the Senegal and Gardel isolates of E. ruminantium. Both isolates contained the same number of genes, and the same organization as found in the genome sequence of the Welgevonden isolate (H. Van Heerden, N. E. Collins, K. A. Brayton, C. Rademeyer, and B. A. Allsopp, Gene 330:159-168, 2004). However, comparison of two subpopulations of the Gardel isolate maintained in different laboratories demonstrated that recombination between map1-3 and map1-2 had occurred in one subpopulation with deletion of one entire gene. Reverse transcription-PCR on E. ruminantium derived mRNA from infected cells using gene-specific primers revealed that all 16 map1 paralogs were transcribed in endothelial cells. In one vector (Amblyomma variegatum) and several nonvector tick cell lines infected with E. ruminantium, transcripts were found for between 4 and 11 paralogs. In all these cases the transcript for the map1-1 gene was detected and was predominant. Our results indicate that the map1 gene cluster is relatively conserved but can be subject to recombination, and differences in the transcription of map1 multigenes in host and vector cell environments exist.

  8. Imidacloprid 10 % / flumethrin 4.5 % collars (Seresto®, Bayer) successfully prevent long-term transmission of Ehrlichia canis by infected Rhipicephalus sanguineus ticks to dogs.

    PubMed

    Stanneck, Dorothee; Fourie, Josephus J

    2013-08-01

    The objective of this study was to determine the empirical efficacy of imidacloprid 10 %/flumethrin 4.5 % (Seresto®) collars in preventing long-term transmission of Ehrlichia canis by infected Rhipicephalus sanguineus ticks to dogs. The study was a parallel group design, single centre, randomised, non-blinded, controlled, long-term efficacy study. The treatment group of 8 dogs was fitted with Seresto® collars, the untreated control group of 8 dogs received no collars. Ehrlichia canis-infected ticks were released into the dogs sleeping quarters at 14-day intervals up to Day +378. Control group dogs infected with E. canis were continuously replaced to keep the control sample size constant, and a total of 39 control dogs were required. The final clinical examination and blood sampling occurred on Day +420. The primary assessment criterion was the number of dogs infected with E. canis, as confirmed by IFA and PCR, and the secondary criterion was the acaricidal efficacy based on tick counts. All scheduled blood samples taken were subject to analyses for both PCR and IFA, but only positive cases are discussed. Up to Day +378, none of the collar-treated dogs were infected with E. canis, whereas 34 of the 35 untreated dogs enrolled before Day +371 were infected. The acaricidal efficacy of the collar ranged from 90 % to 100 % for the duration of the assessment period.

  9. Infection with Ehrlichia canis and Anaplasma platys (Rickettsiales: Anaplasmataceae) in two lineages of Rhipicephalus sanguineus sensu lato (Acari: Ixodidae) from Argentina.

    PubMed

    Cicuttin, Gabriel L; Tarragona, Evelina L; De Salvo, M Nazarena; Mangold, Atilio J; Nava, Santiago

    2015-09-01

    Natural infection with Ehrlichia canis and Anaplasma platys in ticks belonging to the tropical and temperate lineages of Rhipicephalus sanguineus sensu lato from Argentina was evaluated. Samples were tested for Ehrlichia canis infection by PCR assays using 16S rRNA, dsb and p28 gene, while detection of A. platys was performed with 16S rRNA and groESL gene. The assignment of the ticks to each lineage was corroborated with 16S rDNA sequences. All ticks infected with E. canis and A. platys belonged to the tropical lineage. These results constitute the first record of E. canis infection in R. sanguineus s.l ticks from Argentina. No ticks from the temperate lineage were found to be infected with E. canis, coinciding with previous studies performed in Argentina and Uruguay where E. canis infection was not detected in R. sanguineus s.l from the temperate lineage. Because the presence of the tropical lineage of R. sanguineus s.l has been documented in tropical areas of northern Argentina between 22° and 24° of south latitude, the findings of this work indicate that transmission of E. canis and A. platys to dogs by R. sanguineus s.l probably occurs along this region.

  10. Effects of doxycycline on haematology, blood chemistry and peripheral blood lymphocyte subsets of healthy dogs and dogs naturally infected with Ehrlichia canis.

    PubMed

    Villaescusa, A; García-Sancho, M; Rodríguez-Franco, F; Tesouro, M Á; Sainz, Á

    2015-06-01

    Canine monocytic ehrlichiosis (CME), caused by Ehrlichia canis, is a vector-borne disease with a worldwide distribution. It has been proposed that the pathogenesis, clinical severity and outcome of disease caused by Ehrlichia spp. can be attributed to the immune response rather than to any direct rickettsial effect. Moreover, doxycycline, the antimicrobial of choice for the treatment of CME, has immunomodulatory and anti-inflammatory properties associated with blood leukocyte proliferation function, cytokine synthesis, and matrix metalloproteinase activity. In order to assess the potential effects of doxycycline, dependent and independent of its antimicrobial activity, the present study compared changes in haematology, blood chemistry and circulating lymphocyte subpopulations in 12 healthy dogs and 20 dogs with CME after doxycycline therapy. Some changes were recorded only in the CME affected dogs, probably due to the antimicrobial effect of doxycycline. However, increases in mean corpuscular haemoglobin, mean corpuscular haemoglobin concentration, platelet count and α2-globulins, and decreased plasma creatinine were observed in both healthy and CME affected dogs. The absolute count of B lymphocytes (CD21(+)) increased initially, but then decreased until the end of the study period in both groups. A potential effect of doxycycline unrelated to its antimicrobial activity against E. canis is suggested, taking into account the results observed both in healthy dogs and in dogs with CME.

  11. Seroprevalence and risk factors to Ehrlichia spp. and Rickettsia spp. in dogs from the Pantanal Region of Mato Grosso State, Brazil.

    PubMed

    Melo, Andréia L T; Martins, Thiago F; Horta, Maurício C; Moraes-Filho, Jonas; Pacheco, Richard C; Labruna, Marcelo B; Aguiar, Daniel M

    2011-12-01

    Sera of 320 dogs from urban and rural areas of a Pantanal region of Brazil were evaluated for rickettsial (Rickettsia rickettsii, R. parkeri, R. amblyommii, R. rhipicephali, R. felis, and R. bellii) and ehrlichial (Ehrlichia canis) infection by the immunofluorescence assay (IFA). Risk factors for ehrlichiosis or rickettsiosis were also evaluated. Positive reaction against Ehrlichia spp. was detected in 227 (70.9%) dogs, 119 (74.3%) from an urban area and 108 (67.5%) from rural areas (P>0.05). For Rickettsia spp., 152 (47.5%) dogs were positive, 31 (19.3%) from urban and 121 (75.6%) from rural areas (P<0.05). Highest anti-Rickettsia spp. endpoint titers were observed for R. amblyommii, suggesting homologous reactions to this agent or a very closely related organism. While most of the urban dogs were found parasitized by the tick Rhipicephalus sanguineus, infestations on rural dogs were predominated by Amblyomma cajenennse. Rickettsial infection was significantly higher (P<0.05) in rural dogs, in dogs with hunting practice, or in A. cajennense-infested dogs.

  12. A real-time PCR assay for detection of the Ehrlichia muris-like agent, a newly recognized pathogen of humans in the upper Midwestern United States

    PubMed Central

    Allerdice, Michelle E.J.; Pritt, Bobbi S.; Sloan, Lynne M.; Paddock, Christopher D.; Karpathy, Sandor E.

    2015-01-01

    The Ehrlichia muris-like agent (EMLA) is an emerging, tick-transmitted human pathogen that occurs in the upper Midwestern United States. Here, we describe the development and validation of a p13-based quantitative real-time PCR TaqMan assay to detect EMLA in blood or tissues of ticks, humans, and rodents. The primer and probe specificities of the assay were ascertained using a large panel of various Ehrlichia species and other members of Rickettsiales. In addition to control DNA, both non-infected and EMLA-infected human blood, Mus musculus blood, and Mus musculus tissue extracts were evaluated, as were non-infected and EMLA-infected I. scapularis and uninfected D. variabilis DNA lysates. The specificity of the probe was determined via real-time PCR. An EMLA p13 control plasmid was constructed, and serial dilutions were used to determine the analytical sensitivity, which was found to be 1 copy per 4 μl of template DNA. The sensitivity and specificity of this assay provides a powerful tool for ecological studies involving arthropod vectors and their mammalian hosts. PMID:26507653

  13. Tandem Mirror Reactor Systems Code (Version I)

    SciTech Connect

    Reid, R.L.; Finn, P.A.; Gohar, M.Y.; Barrett, R.J.; Gorker, G.E.; Spampinaton, P.T.; Bulmer, R.H.; Dorn, D.W.; Perkins, L.J.; Ghose, S.

    1985-09-01

    A computer code was developed to model a Tandem Mirror Reactor. Ths is the first Tandem Mirror Reactor model to couple, in detail, the highly linked physics, magnetics, and neutronic analysis into a single code. This report describes the code architecture, provides a summary description of the modules comprising the code, and includes an example execution of the Tandem Mirror Reactor Systems Code. Results from this code for two sensitivity studies are also included. These studies are: (1) to determine the impact of center cell plasma radius, length, and ion temperature on reactor cost and performance at constant fusion power; and (2) to determine the impact of reactor power level on cost.

  14. TRDB—The Tandem Repeats Database

    PubMed Central

    Gelfand, Yevgeniy; Rodriguez, Alfredo; Benson, Gary

    2007-01-01

    Tandem repeats in DNA have been under intensive study for many years, first, as a consequence of their usefulness as genomic markers and DNA fingerprints and more recently as their role in human disease and regulatory processes has become apparent. The Tandem Repeats Database (TRDB) is a public repository of information on tandem repeats in genomic DNA. It contains a variety of tools for repeat analysis, including the Tandem Repeats Finder program, query and filtering capabilities, repeat clustering, polymorphism prediction, PCR primer selection, data visualization and data download in a variety of formats. In addition, TRDB serves as a centralized research workbench. It provides user storage space and permits collaborators to privately share their data and analysis. TRDB is available at . PMID:17175540

  15. 33 CFR 401.41 - Tandem lockage.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... TRANSPORTATION SEAWAY REGULATIONS AND RULES Regulations Seaway Navigation § 401.41 Tandem lockage. Where two or... stop a sufficient distance from the preceding vessel to avoid a collision; and (b) Be moved...

  16. Oak Ridge 25-MV tandem accelerator

    SciTech Connect

    Jones, C.M.

    1981-01-01

    A brief description is presented of the scope and status of the heavy ion accelerator facility, and status of the project is discussed. Initial operation of the 25 MV tandem accelerator from National Electrostatics Corporation is covered. (GHT)

  17. Tandem Spinal Stenosis: A Systematic Review.

    PubMed

    Overley, Samuel C; Kim, Jun S; Gogel, Brooke A; Merrill, Robert K; Hecht, Andrew C

    2017-09-05

    Tandem spinal stenosis refers to spinal canal diameter narrowing in at least 2 distinct regions of the spine, most commonly the lumbar and cervical regions. This entity can be an asymptomatic radiographic finding, or it can present with severe myelopathy and lower-extremity symptoms. Tandem spinal stenosis may impact surgeon decision-making when planning either cervical or lumbar spine surgery, and there is currently no consensus in the literature regarding the treatment algorithm for operative intervention. A MEDLINE literature search was performed using PubMed, the Cochrane Database of Systematic Reviews, and Embase from January 1980 to February 2015 using Medical Subject Heading queries for the terms "tandem spinal stenosis," "cervical stenosis AND lumbar stenosis," and "concomitant spinal stenosis." We included studies involving adult patients, tandem spinal stenosis of the cervical and lumbar regions, and a minimum of 5 patients. Articles that did not discuss spinal disorders or only explored disorders at a single spinal region were excluded. The initial database review resulted in 234 articles. After abstracts were reviewed, only 17 articles that met inclusion criteria were identified: 2 cadaveric studies, 5 clinical studies of patients with radiographic tandem spinal stenosis, and 10 clinical studies of patients with symptomatic tandem spinal stenosis. Tandem spinal stenosis is a common condition present in up to 60% of patients with spinal stenosis. This disorder, however, is often overlooked, which can lead to serious complications. Identification of tandem spinal stenosis is paramount as a first step in management and, although there is still no preferred intervention, both staged and simultaneous procedures have been shown to be effective. Surgeons may utilize a single, staged, or combined approach to decompression, always addressing cervical myelopathy as a priority.

  18. In vitro culture and structural differences in the major immunoreactive protein gp36 of geographically distant Ehrlichia canis isolates.

    PubMed

    Zweygarth, Erich; Cabezas-Cruz, Alejandro; Josemans, Antoinette I; Oosthuizen, Marinda C; Matjila, Paul T; Lis, Katarzyna; Broniszewska, Marzena; Schöl, Heidrun; Ferrolho, Joana; Grubhoffer, Libor; Passos, Lygia M F

    2014-06-01

    Ehrlichia canis, the etiologic agent of canine ehrlichiosis, is an obligate intracytoplasmic Gram-negative tick-borne bacterium belonging to the Anaplasmataceae family. E. canis is distributed worldwide and can cause serious and fatal infections in dogs. Among strains of E. canis, the 16S rRNA gene DNA sequences are highly conserved. Using this gene to genetically differentiate isolates is therefore difficult. As an alternative, the gene gp36, which encodes for a major immunoreactive protein in E. canis, has been successfully used to characterize the genetic diversity of this pathogen. The present study describes the isolation and continuous propagation of a Spanish and 2 South African isolates of E. canis in IDE8 tick cells. Subsequently, canine DH82 cell cultures were infected using initial bodies obtained from infected IDE8 cultures. It was possible to mimic the life cycle of E. canis in vitro by transferring infection from tick cells to canine cells and back again. To characterize these E. canis strains at the molecular level, the 16S rRNA and gp36 genes were amplified by PCR, sequenced, and aligned with corresponding sequences available in GenBank. All 16S rRNA sequences amplified in this study were identical to previously reported E. canis strains. Maximum likelihood analysis based on the gp36 amino acid sequences showed that the South African and Spanish strains fall into 2 well-defined phylogenetic clusters amongst other E. canis strains. The members of these 2 phylogenetic clusters shared 2 unique molecular properties in the gp36 amino acid sequences: (i) deletion of glycine 117 and (ii) the presence of an additional putative N-linked glycosylation site. We further show correlation between the putative secondary structure and the theoretical isoelectric point (pI) of the gp36 amino acid sequences. A putative role of gp36 as an adhesin in E. canis is discussed. Overall, we report the successful in vitro culture of 3 new E. canis strains which present

  19. Molecular detection of Anaplasma platys, Anaplasma phagocytophilum and Wolbachia sp. but not Ehrlichia canis in Croatian dogs.

    PubMed

    Huber, Doroteja; Reil, Irena; Duvnjak, Sanja; Jurković, Daria; Lukačević, Damir; Pilat, Miroslav; Beck, Ana; Mihaljević, Željko; Vojta, Lea; Polkinghorne, Adam; Beck, Relja

    2017-09-14

    The bacteria Anaplasma platys, Anaplasma phagocytophilum and Ehrlichia canis are tick-borne agents that cause canine vector-borne disease. The prevalence of these pathogens in South Eastern Europe is unknown with the exception of an isolated case of A. platys detected in a dog imported into Germany from Croatia. To gain a better insight into their presence and prevalence, PCR-based screening for these bacterial pathogens was performed on domesticated dogs from different regions of Croatia. Blood samples from 1080 apparently healthy dogs from coastal and continental parts of Croatia as well as tissue samples collected from 63 deceased dogs with a history of anaemia and thrombocytopenia were collected for molecular screening by an Anaplasmataceae-specific 16S rRNA conventional PCR. Positive samples were confirmed using a second Anaplasmataceae-specific PCR assay with the PCR product sequenced for the purpose of bacterial species identification. All sequenced isolates were georeferenced and a kernel intensity estimator was used to identify clusters of greater case intensity. 42/1080 (3.8%; CI 2.7-5.0) of the healthy dogs were PCR positive for bacteria in the Anaplasmataceae. Sequencing of the 16S rRNA gene amplified from these positive samples revealed the presence of A. platys in 2.5% (CI 1.6-3.4%, 27 dogs), A. phagocytophilum in 0.3% (CI 0-0.6%, 3 dogs) and a Wolbachia endosymbiont in 1.1% (CI 0.4-1.6%, 12 dogs) of dogs screened in this study. Necropsied dogs were free from infection. Notably, no evidence of E. canis infection was found in any animal. This survey represents a rare molecular study of Anaplasmataceae in dogs in South Eastern Europe, confirming the presence of A. platys and A. phagocytophilum but not E. canis. The absence of E. canis was surprising given it has been described in all other Mediterranean countries surveyed and raises questions over the regional vector capacity of the Rhipicephalus sanguineus tick.

  20. Retrospective analyses of dogs found serologically positive for Ehrlichia canis in Cebu, Philippines from 2003 to 2014.

    PubMed

    Ybañez, Adrian P; Ybañez, Rochelle Haidee D; Villavelez, Rex R; Malingin, Honey Pearl F; Barrameda, Dana Natasha M; Naquila, Sharmaine V; Olimpos, Shiella Mae B

    2016-01-01

    The study aimed to document the clinical and hematological observations of dogs found serologically positive for Ehrlichia canis and to identify parameters or factors that are associated with the disease with focus on the anemic and thrombocytopenic state of the infected dogs. From 7 participating veterinary establishments, a total of 913 cases from 2003 to 2014 were initially assessed using inclusion criteria, including E. canis diagnosis by the attending veterinarian and the presence of ticks or history of infestation, thrombocytopenia, and/or anemia. From these, 438 cases that were found serologically positive for E. canis using commercial test kits were selected. Profile, clinical observations and hematological test results were obtained from the selected cases. Computations for statistical associations between the anemic and thrombocytopenic state of the infected dogs and their profile, observed clinical signs and other hematological values were performed. Most of the dogs were purebred (60.0%) and female (51.1%) and were within the age range of 1-5 years (38.4%). The mean packed cell volume (PCV), red blood cell (RBC) count, and platelet count were lower than the normal values while the absolute count of basophils were higher than normal values. Creatinine and blood urea nitrogen (BUN) appear to be elevated. The most common clinical signs observed were inappetence (41.3%), lethargy/depression (35.6%), vomiting (32.4%), fever (18.5%), paleness (8.2%), and epistaxis (6.6%). Analyses showed that there were no significant differences on the hematological values and clinical signs between thrombocytopenic and non-thrombocytopenic seropositive dogs. Moreover, very weak correlations between platelet count and RBC count, absolute lymphocyte count, and neutrophil count were found. On the other hand, only paleness (p=0.008) and epistaxis (p=0.004) were found to be significantly different between anemic and non-anemic patients. This coincided with the linear regression

  1. Retrospective analyses of dogs found serologically positive for Ehrlichia canis in Cebu, Philippines from 2003 to 2014

    PubMed Central

    Ybañez, Adrian P.; Ybañez, Rochelle Haidee D.; Villavelez, Rex R.; Malingin, Honey Pearl F.; Barrameda, Dana Natasha M.; Naquila, Sharmaine V.; Olimpos, Shiella Mae B.

    2016-01-01

    Aim: The study aimed to document the clinical and hematological observations of dogs found serologically positive for Ehrlichia canis and to identify parameters or factors that are associated with the disease with focus on the anemic and thrombocytopenic state of the infected dogs. Materials and Methods: From 7 participating veterinary establishments, a total of 913 cases from 2003 to 2014 were initially assessed using inclusion criteria, including E. canis diagnosis by the attending veterinarian and the presence of ticks or history of infestation, thrombocytopenia, and/or anemia. From these, 438 cases that were found serologically positive for E. canis using commercial test kits were selected. Profile, clinical observations and hematological test results were obtained from the selected cases. Computations for statistical associations between the anemic and thrombocytopenic state of the infected dogs and their profile, observed clinical signs and other hematological values were performed. Results: Most of the dogs were purebred (60.0%) and female (51.1%) and were within the age range of 1-5 years (38.4%). The mean packed cell volume (PCV), red blood cell (RBC) count, and platelet count were lower than the normal values while the absolute count of basophils were higher than normal values. Creatinine and blood urea nitrogen (BUN) appear to be elevated. The most common clinical signs observed were inappetence (41.3%), lethargy/depression (35.6%), vomiting (32.4%), fever (18.5%), paleness (8.2%), and epistaxis (6.6%). Analyses showed that there were no significant differences on the hematological values and clinical signs between thrombocytopenic and non-thrombocytopenic seropositive dogs. Moreover, very weak correlations between platelet count and RBC count, absolute lymphocyte count, and neutrophil count were found. On the other hand, only paleness (p=0.008) and epistaxis (p=0.004) were found to be significantly different between anemic and non-anemic patients. This

  2. Ectoparasite Infestations and Canine Infection by Rickettsiae and Ehrlichiae in a Semi-Arid Region of Northeastern Brazil

    PubMed Central

    Araes-Santos, Ana Isabel; Moraes-Filho, Jonas; Peixoto, Renata M.; Spolidorio, Mariana G.; Azevedo, Sérgio S.; Costa, Mateus M.; Labruna, Marcelo B.

    2015-01-01

    Abstract This study investigated the prevalence of Rickettsia spp. and Ehrlichia canis infection in dogs and their ectoparasites from rural and urban areas of two municipalities, Petrolina and Juazeiro, within a semiarid region (Caatinga biome) of northeastern Brazil, by immunofluorescence assay (IFA) and polymerase chain reaction (PCR). Overall, 12.1% (61/504) and 23.0% (116/504) of canine plasma samples had antibodies reactive to Rickettsia spp. and E. canis. E. canis DNA was detected by PCR in 8.3% (42/504) of canine blood samples, whereas no blood sample was positive for Rickettsia spp. The infection by E. canis was determined by PCR in 4.9% (14/285) Rhipicephalus sanguineus sensu lato (s.l.) ticks and by Rickettsia felis in 1.1% (3/285) and 40.6% (74/182) ticks and fleas, respectively. Multivariate regression analyses revealed that canine seropositivity to Rickettsia spp. was associated statistically with the variables “to reside in Petrolina” and “presence of ectoparasites.” Our results indicate that canine infection by E. canis might be endemic in the Caatinga biome as it is in other Brazilian biomes. Although no previous serosurvey for Rickettsia spp. has been conducted on dogs from the Caatinga biome, our values are much lower than the ones reported for rural dogs from other Brazilian biomes. These differences are likely related to the semiarid climate of the aatinga biome, which minimizes the exposure of rural dogs to Amblyomma spp. ticks, the most common vectors of Rickettsia spp. in Brazil. Considering that dogs are excellent sentinels for human exposure to Rickettsia spp., we can infer that the risks of human acquiring tick-borne rickettsiosis in the Caatinga region of the present study are low. The rickettsial infection rates in fleas and ticks were not related to canine seropositivity; i.e., areas with higher Rickettsia infection rates in fleas had the lowest canine seroreactivity to Rickettsia spp. PMID:26565771

  3. Tandem Organic Light-Emitting Diodes.

    PubMed

    Fung, Man-Keung; Li, Yan-Qing; Liao, Liang-Sheng

    2016-12-01

    A tandem organic light-emitting diode (OLED) is an organic optoelectronic device that has two or more electroluminescence (EL) units connected electrically in series with unique intermediate connectors within the device. Researchers have studied this new OLED architecture with growing interest and have found that the current efficiency of a tandem OLED containing N EL units (N > 1) should be N times that of a conventional OLED containing only a single EL unit. Therefore, this new architecture is potentially useful for constructing high-efficiency, high-luminance, and long-lifetime OLED displays and organic solid-state lighting sources. In a tandem OLED, the intermediate connector plays a crucial role in determining the effectiveness of the stacked EL units. The interfaces in the connector control the inner charge generation and charge injection into the adjacent EL units. Meanwhile, the transparency and the thickness of the connector affect the light output of the device. Therefore, the intermediate connector should be made to meet both the electrical and optical requirements for achieving optimal performance. Here, recent advances in the research of the tandem OLEDs is discussed, with the main focus on material selection and interface studies in the intermediate connectors, as well as the optical design of the tandem OLEDs. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Growth of Ehrlichia canis, the causative agent of canine monocytic ehrlichiosis, in vector and non-vector ixodid tick cell lines.

    PubMed

    Ferrolho, Joana; Simpson, Jennifer; Hawes, Philippa; Zweygarth, Erich; Bell-Sakyi, Lesley

    2016-06-01

    Canine monocytic ehrlichiosis is caused by Ehrlichia canis, a small gram-negative coccoid bacterium that infects circulating monocytes. The disease is transmitted by the brown dog tick Rhipicephalus sanguineus s.l. and is acknowledged as an important infectious disease of dogs and other members of the family Canidae worldwide. E. canis is routinely cultured in vitro in the canine monocyte-macrophage cell line DH82 and in non-vector Ixodes scapularis tick cell lines, but not in cells derived from its natural vector. Here we report infection and limited propagation of E. canis in the tick cell line RSE8 derived from the vector R. sanguineus s.l., and successful propagation through six passages in a cell line derived from the experimental vector Dermacentor variabilis. In addition, using bacteria semi-purified from I. scapularis cells we attempted to infect a panel of cell lines derived from non-vector species of the tick genera Amblyomma, Dermacentor, Hyalomma, Ixodes and Rhipicephalus with E. canis and, for comparison, the closely-related Ehrlichia ruminantium, causative agent of heartwater in ruminants. Amblyomma and non-vector Dermacentor spp. cell lines appeared refractory to infection with E. canis but supported growth of E. ruminantium, while some, but not all, cell lines derived from Hyalomma, Ixodes and Rhipicephalus spp. ticks supported growth of both pathogens. We also illustrated and compared the ultrastructural morphology of E. canis in DH82, RSE8 and I. scapularis IDE8 cells. This study confirms that E. canis, like E. ruminantium, is able to grow not only in cell lines derived from natural and experimental tick vectors but also in a wide range of other cell lines derived from tick species not known to transmit this pathogen.

  5. Halide Perovskites for Tandem Solar Cells.

    PubMed

    Lee, Jin-Wook; Hsieh, Yao-Tsung; De Marco, Nicholas; Bae, Sang-Hoon; Han, Qifeng; Yang, Yang

    2017-05-04

    Perovskite solar cells have become one of the strongest candidates for next-generation solar energy technologies. A myriad of beneficial optoelectronic properties of the perovskite materials have enabled superb power conversion efficiencies (PCE) exceeding 22% for a single-junction device. The high PCE achievable via low processing costs and relatively high variability in optical properties have opened new possibilities for perovskites in tandem solar cells. In this Perspective, we will discuss current research trends in fabricating tandem perovskite-based solar cells in combination with a variety of mature photovoltaic devices such as organic, silicon, and Cu(In,Ga)(S,Se)2 (CIGS) solar cells. Characteristic features and present limitations of each tandem cell will be discussed and elaborated upon. Finally, key issues for further improvement and the future outlook will be discussed.

  6. Transmission of bacterial agents from lone star ticks to white-tailed deer.

    PubMed

    Varela-Stokes, Andrea S

    2007-05-01

    Amblyomma americanum (L.), the lone star tick, is an aggressive ixodid tick that has been implicated as a vector for several bacteria. Among these bacteria are the disease agents Ehrlichia chaffeensis and Ehrlichia ewingii, and the putative disease agent "Borrelia lonestari." The hypothesis in this study was that wild lone star ticks from northeastern Georgia are capable of transmitting all three agents to white-tailed deer, Odocoileus virginianus, a known reservoir host for E. chaffeensis. In this study, transmission of all three agents from wild caught lone star ticks to captive reared white-tailed deer was demonstrated by polymerase chain reaction (PCR), culture, or serology. Two of three deer showed evidence of E. chaffeensis and E. ewingii infection by polymerase chain reaction assay; all three deer showed evidence of B. lonestari by PCR assay. E. chaffeensis was isolated in culture from both PCR-positive deer on multiple days. All three deer seroconverted to E. chaffeensis, whereas one deer seroconverted to B. lonestari. This study supports the role of lone star ticks and white-tailed deer as a vector and reservoir host for E. chaffeensis and E. ewingii and suggests for the first time, transmission of B. lonestari from lone star ticks to white-tailed deer.

  7. SDetection of vector-borne agents in lone star ticks, Amblyomma americanum (Acari: Ixodidae), from Mississippi.

    PubMed

    Castellaw, A H; Showers, J; Goddard, J; Chenney, E F; Varela-Stokes, A S

    2010-05-01

    In this study, we evaluated Amblyomma americanum (lone star tick) in Mississippi for the presence of Ehrlichia chaffeensis, causative agent of human monocytic ehrlichiosis; Ehrlichia ewingii, causative agent of human and canine granulocytic ehrlichiosis; Borrelia lonestari, putative agent of southern tick-associated rash illness; Francisella tularensis, the agent of tularemia; and Rickettsia spp., particularly R. amblyommii, a suspected pathogen. We collected adult A. americanum from four regions of Mississippi: Northeast, Northwest, Southeast, and East. Of the ticks collected, 192 were dissected and DNA was extracted for nested polymerase chain reaction (PCR) assays to detect the above bacteria. In all, 3% of tick extracts had evidence of Borrelia sp., 4% for E. chaffeensis, 6% for E. ewingii, and 44% for a Rickettsia species. As determined by sequencing, most Rickettsia spp. were R. amblyommii. In addition, extracts from 42 pools (total of 950) of larval A. americanum collected in Southwest Mississippi were tested for the presence of E. chaffeensis and Rickettsia species. Of these extracts from pools, nine of 37 (24%) were PCR positive for a Rickettsia sp., most often, R. amblyommii; none had evidence of E. chaffeensis, supporting the ability of lone star ticks to transovarially transmit R. amblyommii, but not E. chaffeensis. This study demonstrates E. chaffeensis, E. ewingii, "B. lonestari", and R. amblyommii in A. americanum by PCR for the first time in Mississippi. Understanding the prevalence and epidemiology of these agents in Mississippi should increase awareness of tick-borne disease in the medical community.

  8. Field Evaluation of a Fluorogenic Probe-Based PCR Assay for Identification of a Visceral Leishmaniasis Gene Target

    DTIC Science & Technology

    2004-06-01

    options pour la recherche et la technologie)., The original document contains color images . 14. ABSTRACT 15. SUBJECT TERMS 16. SECURITY...virus serotype 1 CS1 - CS4 - Dengue virus serotype 2 CS1 -CS6 - Hanta virus - Leptospira borgpeternenii - Leptospira interrogans - Leptospira ...biflexia - Leptospira icterohaemmorrhagiae - Leptospira patoc-1 - Rickettsia rickettsia - Ehrlichia chaffeensis pD2 - Field Evaluation of a

  9. High performance polymer tandem solar cell

    PubMed Central

    da Silva, Wilson Jose; Schneider, Fabio Kurt; Mohd Yusoff, Abd. Rashid bin; Jang, Jin

    2015-01-01

    A power conversion efficiency of 9.02% is obtained for a fully solution-processed polymer tandem solar cell, based on the diketopyrrolopyrrole unit polymer as a low bandgap photoactive material in the rear subcell, in conjunction with a new robust interconnecting layer. This interconnecting layer is optically transparent, electrically conductive, and physically strong, thus, the charges can be collected and recombined in the interconnecting layer under illumination, while the charge is generated and extracted under dark conditions. This indicates that careful interface engineering of the charge-carrier transport layer is a useful approach to further improve the performance of polymer tandem solar cells. PMID:26669577

  10. Tandem mirror thermal barrier experimental program plan

    SciTech Connect

    Coensgen, F.H.; Drake, R.P.; Simonen, T.C.

    1980-01-02

    This report describes an experimental plan for the development of the Tandem Mirror Thermal Barrier. Included is: (1) a description of thermal barrier related physics experiments; (2) thermal barrier related experiments in the existing TMX and Phaedrus experiments; (3) a thermal barrier TMX upgrade; and (4) initiation of investigations of axisymmetric magnetic geometry. Experimental studies of the first two items are presently underway. Results are expected from the TMX upgrade by the close of 1981 and from axisymmetric tandem mirror experiments at the end of 1983. Plans for Phaedrus upgrades are developing for the same period.

  11. Tandem-mirror program: status and projection

    SciTech Connect

    Van Atta, C.M.

    1981-03-12

    Construction of MFTF-B is scheduled for completion in 1985. Results of experiments in TMX-U and MFTF-B will permit the design of the D-T burning tandem-mirror next-step facility (TMNS) in which physics issues will not be at issue. TMNS will be a facility for engineering research and development. The end cells of TMNS are expected to be appropriate for a tandem-mirror demonstration fusion reactor (TMR), construction of which should begin about 1986 for operation in the 1990's.

  12. A survey for infection with Dirofilaria immitis, Ehrlichia canis, Borrelia burgdorferi, and Babesia canis in feral and client-owned dogs in the Turks and Caicos Islands, British West Indies

    PubMed Central

    Hoff, Brent; McEwen, Beverly; Peregrine, Andrew S.

    2008-01-01

    The frequency of infection with Dirofilaria immitis and Babesia canis and seropositivity to Ehrlichia canis and Borrelia burgdorferi in feral and client-owned dogs was determined. Feral dogs were 14.8 and 11.2 times more likely to be seropositive to D. immitis and E. canis, respectively, than were client-owned dogs. None of the dogs tested positive for B. burgdorferi or B. canis. PMID:18624070

  13. A survey for infection with Dirofilaria immitis, Ehrlichia canis, Borrelia burgdorferi, and Babesia canis in feral and client-owned dogs in the Turks and Caicos Islands, British West Indies.

    PubMed

    Hoff, Brent; McEwen, Beverly; Peregrine, Andrew S

    2008-06-01

    The frequency of infection with Dirofilaria immitis and Babesia canis and seropositivity to Ehrlichia canis and Borrelia burgdorferi in feral and client-owned dogs was determined. Feral dogs were 14.8 and 11.2 times more likely to be seropositive to D. immitis and E. canis, respectively, than were client-owned dogs. None of the dogs tested positive for B. burgdorferi or B. canis.

  14. High voltage series connected tandem junction solar battery

    DOEpatents

    Hanak, Joseph J.

    1982-01-01

    A high voltage series connected tandem junction solar battery which comprises a plurality of strips of tandem junction solar cells of hydrogenated amorphous silicon having one optical path and electrically interconnected by a tunnel junction. The layers of hydrogenated amorphous silicon, arranged in a tandem configuration, can have the same bandgap or differing bandgaps. The tandem junction strip solar cells are series connected to produce a solar battery of any desired voltage.

  15. 14 CFR 23.302 - Canard or tandem wing configurations.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Canard or tandem wing configurations. 23... General § 23.302 Canard or tandem wing configurations. The forward structure of a canard or tandem wing configuration must: (a) Meet all requirements of subpart C and subpart D of this part applicable to a wing;...

  16. 14 CFR 23.302 - Canard or tandem wing configurations.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Canard or tandem wing configurations. 23... General § 23.302 Canard or tandem wing configurations. The forward structure of a canard or tandem wing configuration must: (a) Meet all requirements of subpart C and subpart D of this part applicable to a wing;...

  17. 14 CFR 23.302 - Canard or tandem wing configurations.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Canard or tandem wing configurations. 23... General § 23.302 Canard or tandem wing configurations. The forward structure of a canard or tandem wing configuration must: (a) Meet all requirements of subpart C and subpart D of this part applicable to a wing;...

  18. 14 CFR 23.302 - Canard or tandem wing configurations.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Canard or tandem wing configurations. 23... General § 23.302 Canard or tandem wing configurations. The forward structure of a canard or tandem wing configuration must: (a) Meet all requirements of subpart C and subpart D of this part applicable to a wing;...

  19. 14 CFR 23.302 - Canard or tandem wing configurations.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Canard or tandem wing configurations. 23... General § 23.302 Canard or tandem wing configurations. The forward structure of a canard or tandem wing configuration must: (a) Meet all requirements of subpart C and subpart D of this part applicable to a wing;...

  20. 14 CFR 105.45 - Use of tandem parachute systems.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 2 2012-01-01 2012-01-01 false Use of tandem parachute systems. 105.45... (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES PARACHUTE OPERATIONS Parachute Equipment and Packing § 105.45 Use of tandem parachute systems. (a) No person may conduct a parachute operation using a tandem...

  1. 14 CFR 105.45 - Use of tandem parachute systems.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 2 2011-01-01 2011-01-01 false Use of tandem parachute systems. 105.45... (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES PARACHUTE OPERATIONS Parachute Equipment and Packing § 105.45 Use of tandem parachute systems. (a) No person may conduct a parachute operation using a tandem...

  2. 14 CFR 105.45 - Use of tandem parachute systems.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 2 2013-01-01 2013-01-01 false Use of tandem parachute systems. 105.45... (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES PARACHUTE OPERATIONS Parachute Equipment and Packing § 105.45 Use of tandem parachute systems. (a) No person may conduct a parachute operation using a tandem...

  3. 14 CFR 105.45 - Use of tandem parachute systems.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 2 2014-01-01 2014-01-01 false Use of tandem parachute systems. 105.45... (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES PARACHUTE OPERATIONS Parachute Equipment and Packing § 105.45 Use of tandem parachute systems. (a) No person may conduct a parachute operation using a tandem...

  4. 47 CFR 69.129 - Signalling for tandem switching.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 3 2013-10-01 2013-10-01 false Signalling for tandem switching. 69.129 Section... (CONTINUED) ACCESS CHARGES Computation of Charges § 69.129 Signalling for tandem switching. A charge that is... provision of signalling for tandem switching. ...

  5. 47 CFR 69.129 - Signalling for tandem switching.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 3 2010-10-01 2010-10-01 false Signalling for tandem switching. 69.129 Section... (CONTINUED) ACCESS CHARGES Computation of Charges § 69.129 Signalling for tandem switching. A charge that is... provision of signalling for tandem switching. ...

  6. 47 CFR 69.129 - Signalling for tandem switching.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 3 2012-10-01 2012-10-01 false Signalling for tandem switching. 69.129 Section... (CONTINUED) ACCESS CHARGES Computation of Charges § 69.129 Signalling for tandem switching. A charge that is... provision of signalling for tandem switching. ...

  7. 47 CFR 69.129 - Signalling for tandem switching.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 3 2011-10-01 2011-10-01 false Signalling for tandem switching. 69.129 Section... (CONTINUED) ACCESS CHARGES Computation of Charges § 69.129 Signalling for tandem switching. A charge that is... provision of signalling for tandem switching. ...

  8. Organic Tandem Solar Cells: Design and Formation

    NASA Astrophysics Data System (ADS)

    Chen, Chun-Chao

    In the past decade, research on organic solar cells has gone through an important development stage leading to major enhancements in power conversion efficiency, from 4% to 9% in single-junction devices. During this period, there are many novel processing techniques and device designs that have been proposed and adapted in organic solar-cell devices. One well-known device architecture that helps maximize the solar cell efficiency is the multi-junction tandem solar-cell design. Given this design, multiple photoactive absorbers as subcells are stacked in a monolithic fashion and assembled via series connection into one complete device, known as the tandem solar cell. Since multiple absorbers with different optical energy bandgaps are being applied in one tandem solar-cell device, the corresponding solar cell efficiency is maximized through expanded absorption spectrum and reduced carrier thermalization loss. In Chapter 3, the architecture of solution-processible, visibly transparent solar cells is introduced. Unlike conventional organic solar-cell devices with opaque electrodes (such as silver, aluminum, gold and etc.), the semi-transparent solar cells rely on highly transparent electrodes and visibly transparent photoactive absorbers. Given these two criteria, we first demonstrated the visibly transparent single-junction solar cells via the polymer absorber with near-infrared absorption and the top electrode based on solution-processible silver nanowire conductor. The highest visible transparency (400 ˜ 700 nm) of 65% was achieved for the complete device structure. More importantly, power conversion efficiency of 4% was also demonstrated. In Chapter 4, we stacked two semi-transparent photoactive absorbers in the tandem architecture in order to realize the semi-transparent tandem solar cells. A noticeable performance improvement from 4% to 7% was observed. More importantly, we modified the interconnecting layers with the incorporation of a thin conjugated

  9. Note on Hovering Turns with Tandem Helicopters

    NASA Technical Reports Server (NTRS)

    Reeder, John P; Tapscott, Robert J

    1955-01-01

    The source of an appreciable pitching-moment difference between left and right hovering turns for a tandem helicopter is described. The difference in pitching moment results from the difference in rotational speed of the counter rotating rotors with respect to the air while the helicopter is turning.

  10. Tandem mirror next step conceptual design

    SciTech Connect

    Doggett, J.N.; Damm, C.C.; Bulmer, R.H.

    1980-10-14

    A study was made to define the features of the experimental mirror fusion device - The Tandem Mirror Next Step, or TMNS - that will bridge the gap between present mirror confinement experiments and a power-producing reactor. We outline the project goals, describe some initial device parameters, and relate the technological requirements to ongoing development programs.

  11. Advances in Tandem Mirror fusion power reactors

    SciTech Connect

    Perkins, L.J.; Logan, B.G.

    1986-05-20

    The Tandem Mirror exhibits several distinctive features which make the reactor embodiment of the principle very attractive: Simple low-technology linear central cell; steady-state operation; high-..beta.. operation; no driven current or disruptions; divertorless operation; direction conversion of end-loss power; low-surface heat loads; and advanced fusion fuel capability. In this paper, we examine these features in connection with two tandem mirror reactor designs, MARS and MINIMARS, and several advanced reactor concepts including the wall-stabilized reactor and the field-reversed mirror. With a novel compact end plug scheme employing octopole stabilization, MINIMARS is expressly designed for short construction times, factory-built modules, and a small (600 MWe) but economic reactor size. We have also configured the design for low radioactive afterheat and inherent/passive safety under LOCA/LOFA conditions, thereby obviating the need for expensive engineered safety systems. In contrast to the complex and expensive double-quadrupole end-cell of the MARS reactor, the compact octopole end-cell of MINIMARS enables ignition to be achieved with much shorter central cell lengths and considerably improves the economy of scale for small (approx.250 to 600 MWe) tandem mirror reactors. Finally, we examine the prospects for realizing the ultimate potential of the tandem mirror with regard to both innovative configurations and novel neutron energy conversion schemes, and stress that advanced fuel applications could exploit its unique reactor features.

  12. Electrospray tandem mass spectrometric investigations of morphinans.

    PubMed

    Raith, Klaus; Neubert, Reinhard; Poeaknapo, Chotima; Boettcher, Christian; Zenk, Meinhart H; Schmidt, Jürgen

    2003-11-01

    In this study positive ESI tandem mass spectra of the [M + H]+ ions of morphinan alkaloids obtained using an ion trap MS were compared with those from a triple quadrupole MS. This allows to assess the differences of the tandem-in-time versus the tandem-in-space principle, often hampering the development of ESI MS/MS libraries. Fragmentation pathways and possible fragment ion structures were discussed. In order to obtain elemental composition, accurate mass measurements were performed. According to the MS/MS fragmentation pathway, the investigated compounds can be grouped into 4 subsets: (1) morphine and codeine, (2) morphinone, codeinone, and neopinone, (3) thebaine and oripavine, (4) salutaridine and salutaridinol. Salutaridinol-7-O-acetate shows a different fragmentation behavior because of the favored loss of acetic acid. Although most fragment ions occur in both ion trap and triple quad tandem mass spectra, some are exclusively seen in either type. For triple quad, quadrupole time-of-flight and FT-ICR MS/MS, the base peak of morphine results from an ion at m/z 165 that contains neither nitrogen nor oxygen. This ion is not found in ion trap MS/MS, but in subsequential MS3 and MS4.

  13. Technology for large tandem mirror experiments

    SciTech Connect

    Thomassen, K.I.

    1980-09-04

    Construction of a large tandem mirror (MFTF-B) will soon begin at Lawrence Livermore National Laboratory (LLNL). Designed to reach break-even plasma conditions, the facility will significantly advance the physics and technology of magnetic-mirror-based fusion reactors. This paper describes the objectives and the design of the facility.

  14. Modelling of tandem cell temperature coefficients

    SciTech Connect

    Friedman, D.J.

    1996-05-01

    This paper discusses the temperature dependence of the basic solar-cell operating parameters for a GaInP/GaAs series-connected two-terminal tandem cell. The effects of series resistance and of different incident solar spectra are also discussed.

  15. Vortex interaction between two tandem flexible propulsors

    NASA Astrophysics Data System (ADS)

    Park, Sung Goon; Sung, Hyung Jin; Flow Control Laboratory Team

    2015-11-01

    Schooling behaviors of flying and swimming animals are widespread phenomena in nature. Inspired by schooling behaviors of swimming jellyfish, self-propelling flexible bodies with a paddling-based locomotion were modeled in a tandem configuration. The interactions between surrounding fluids and propulsors were considered by using the immersed boundary method. The hydrodynamic patterns generated by the interactions between tandem flexible propulsors were analyzed in the presen study. As a result of the flow-mediated interactions between them, stable configurations were formed spontaneously in which the gap distance between propulsors increased and decreased during the contraction and relaxation phases of the upstream propulsor. The stable configuration was not affected by the initial gap distance but influenced by the phase difference in the flapping frequency between them. Both tandem propulsors benefited from the tandem configuration in terms of the locomotion as compared with an isolated propulsor. This study was supported by the Creative Research Initiatives (No. 2015-001828) program of the National Research Foundation of Korea (MSIP).

  16. 25 MV tandem accelerator at Oak Ridge

    SciTech Connect

    Jones, C.M.

    1980-01-01

    A new heavy-ion accelerator facility is under construction at the Oak Ridge National Laboratory. A brief description of the scope and status of this project is presented with emphasis on the first operational experience with the 25 MV tandem accelerator.

  17. Inverted Three-Junction Tandem Thermophotovoltaic Modules

    NASA Technical Reports Server (NTRS)

    Wojtczuk, Steven

    2012-01-01

    An InGaAs-based three-junction (3J) tandem thermophotovoltaic (TPV) cell has been investigated to utilize more of the blackbody spectrum (from a 1,100 C general purpose heat source GPHS) efficiently. The tandem consists of three vertically stacked subcells, a 0.74-eV InGaAs cell, a 0.6- eV InGaAs cell, and a 0.55-eV InGaAs cell, as well as two interconnecting tunnel junctions. A greater than 20% TPV system efficiency was achieved by another group with a 1,040 C blackbody using a single-bandgap 0.6- eV InGaAs cell MIM (monolithic interconnected module) (30 lateral junctions) that delivered about 12 V/30 or 0.4 V/junction. It is expected that a three-bandgap tandem MIM will eventually have about 3 this voltage (1.15 V) and about half the current. A 4 A/cm2 would be generated by a single-bandgap 0.6-V InGaAs MIM, as opposed to the 2 A/cm2 available from the same spectrum when split among the three series-connected junctions in the tandem stack. This would then be about a 50% increase (3xVoc, 0.5xIsc) in output power if the proposed tandem replaced the single- bandgap MIM. The advantage of the innovation, if successful, would be a 50% increase in power conversion efficiency from radioisotope heat sources using existing thermophotovoltaics. Up to 50% more power would be generated for radioisotope GPHS deep space missions. This type of InGaAs multijunction stack could be used with terrestrial concentrator solar cells to increase efficiency from 41 to 45% or more.

  18. Quality evaluation of tandem mass spectral libraries.

    PubMed

    Oberacher, Herbert; Weinmann, Wolfgang; Dresen, Sebastian

    2011-06-01

    Tandem mass spectral libraries are gaining more and more importance for the identification of unknowns in different fields of research, including metabolomics, forensics, toxicology, and environmental analysis. Particularly, the recent invention of reliable, robust, and transferable libraries has increased the general acceptance of these tools. Herein, we report on results obtained from thorough evaluation of the match reliabilities of two tandem mass spectral libraries: the MSforID library established by the Oberacher group in Innsbruck and the Weinmann library established by the Weinmann group in Freiburg. Three different experiments were performed: (1) Spectra of the libraries were searched against their corresponding library after excluding either this single compound-specific spectrum or all compound-specific spectra prior to searching; (2) the libraries were searched against each other using either library as reference set or sample set; (3) spectra acquired on different mass spectrometric instruments were matched to both libraries. Almost 13,000 tandem mass spectra were included in this study. The MSforID search algorithm was used for spectral matching. Statistical evaluation of the library search results revealed that principally both libraries enable the sensitive and specific identification of compounds. Due to higher mass accuracy of the QqTOF compared with the QTrap instrument, matches to the MSforID library were more reliable when comparing spectra with both libraries. Furthermore, only the MSforID library was shown to be efficiently transferable to different kinds of tandem mass spectrometers, including "tandem-in-time" instruments; this is due to the coverage of a large range of different collision energy settings-including the very low range-which is an outstanding characteristics of the MSforID library.

  19. In situ detection of tandem DNA repeat length

    SciTech Connect

    Yaar, R.; Szafranski, P.; Cantor, C.R.; Smith, C.L.

    1996-11-01

    A simple method for scoring short tandem DNA repeats is presented. An oligonucleotide target, containing tandem repeats embedded in a unique sequence, was hybridized to a set of complementary probes, containing tandem repeats of known lengths. Single-stranded loop structures formed on duplexes containing a mismatched (different) number of tandem repeats. No loop structure formed on duplexes containing a matched (identical) number of tandem repeats. The matched and mismatched loop structures were enzymatically distinguished and differentially labeled by treatment with S1 nuclease and the Klenow fragment of DNA polymerase. 7 refs., 4 figs.

  20. Tandem microwave waste remediation and decontamination system

    DOEpatents

    Wicks, George G.; Clark, David E.; Schulz, Rebecca L.

    1999-01-01

    The invention discloses a tandem microwave system consisting of a primary chamber in which microwave energy is used for the controlled combustion of materials. A second chamber is used to further treat the off-gases from the primary chamber by passage through a susceptor matrix subjected to additional microwave energy. The direct microwave radiation and elevated temperatures provide for significant reductions in the qualitative and quantitative emissions of the treated off gases. The tandem microwave system can be utilized for disinfecting wastes, sterilizing materials, and/or modifying the form of wastes to solidify organic or inorganic materials. The simple design allows on-site treatment of waste by small volume waste generators.

  1. Progress in the tandem mirror program

    NASA Astrophysics Data System (ADS)

    Fowler, T. K.; Borchers, R. R.

    1981-09-01

    Experimental results in TMX have confirmed the basic principles of the tandem mirror concept. A center cell particle confinement parameter eta tau approximately one hundred billion cu cm obtained at ion temperatures around 100 eV, which is a hundred fold improvement over single mirrors at the same temperatures. For TMX these results were obtained at peak beta values in the center cell in the range 10 to 40%, not yet limited by MHD activity, and ion cyclotron resonant heating in the Phaedrus tandem mirror experiment has produced beta values approximately 25%, which is several times the ideal MHD limit for that device. In addition, it was demonstrated that the end fan chambers of TMX simultaneously isolate the hot electrons from the end walls, provide adequate pumping and conveniently dispose of the exhaust plasma energy either by thermal deposition on the end wall or by direct conversion to electricity (at 48% efficiency in agreement with calculations).

  2. Mechanically stacked concentrator tandem solar cells

    NASA Technical Reports Server (NTRS)

    Andreev, V. M.; Rumyantsev, V. D.; Karlina, L. B.; Kazantsev, A. B.; Khvostikov, V. P.; Shvarts, M. Z.; Sorokina, S. V.

    1995-01-01

    Four-terminal mechanically stacked solar cells were developed for advanced space arrays with line-focus reflective concentrators. The top cells are based on AlGaAs/GaAs multilayer heterostructures prepared by low temperature liquid phase epitaxy. The bottom cells are based on heteroepitaxial InP/InGaAs liquid phase epitaxy or on homo-junction GaSb, Zn-diffused structures. The sum of the highest reached efficiencies of the top and bottom cells is 29.4 percent. The best four-terminal tandems have an efficiency of 27 to 28 percent. Solar cells were irradiated with 1 MeV electrons and their performances were determined as a function of fluence up to 10(exp 16) cm(exp-2). It was shown that the radiation resistance of developed tandem cells is similar to the most radiative stable AlGaAs/GaAs cells with a thin p-GaAs photoactive layer.

  3. Current results of the tandem mirror experiment

    SciTech Connect

    Drake, R.P.

    1980-04-09

    The basic operating characteristics of the Tandem Mirror Experiment, (TMX) at the Lawrence Livermore Laboratory in the USA have been established. Tandem-mirror plasmas have been produced using neutral-beam-fueled end plugs and a gas-fueled center cell. An axial potential well between the end plugs has been measured. There is direct evidence that this potential well enhances the axial confinement of the center-cell ions. The observed densities and loss currents are consistent with preliminary studies of the particle sources and losses near the magnetic axis. The observed confinement is consistent with theory when plasma fluctuations are low. When the requirement of drift-cyclotron loss-cone mode stability is violated, the plasma fluctuations degrade the center-cell confinement.

  4. The LLNL multi-user tandem laboratory

    NASA Astrophysics Data System (ADS)

    Davis, J. C.

    1989-04-01

    An FN tandem laboratory, cofunded by several Lawrence Livermore National Laboratory Divisions, Sandia Livermore, and the University of California Regents, is now operational at Livermore. The accelerator, formerly the University of Washington injector, has been upgraded with SF 6, Dowlish tubes, and a NEC pelletron charging system. A conventional duoplasmatron, a tritium source, and two Cs sputtering sources will be fielded on the accelerator. Pulsed beams will be available from two source positions. The laboratory has been designed to accommodate up to 19 experimental positions with excellent optics and working vacuum. The facility is unshielded with both accelerator and radiological systems under the control of a distributed microprocessor system. Research activities at the tandem include nuclear physics and astrophysics, materials science and characterization programs, and accelerator mass spectrometry for archaeology, biomedical, environmental and geoscience investigators.

  5. Locomotion by Tandem and Parallel Wings

    NASA Astrophysics Data System (ADS)

    Tanida, Yoshimichi

    A two-dimensional analysis was carried out on the locomotion by tandem and parallel wings in relation to the free flight of dragonflies and beetles, remarking the mutual interference between fore and hind wings. The results obtained are summarized as follows: In the case of tandem wings, (1)High thrust and propulsive efficiency can be achieved when the forewing oscillates with a definite phase lag behind the hindwing, as in the case of real dragonflies, (2)Somewhat smaller amplitude of hindwing leads to optimum condition for work sharing of two wings, (3)The hard forewing does not serve for the thrust and propulsive efficiency, whereas the hard hindwing does for the augmentation of them; In the case of parallel wings, (4)The hard wing placed near the soft wing acts nearly as an infinite plate, as for the ground effect, increasing both thrust and propulsive efficiency.

  6. Steroid Hormone Analysis by Tandem Mass Spectrometry

    PubMed Central

    Soldin, Steven J.; Soldin, Offie P.

    2013-01-01

    BACKGROUND New high-performance liquid chromatography/ tandem mass spectrometry (LC-MS/MS) methods are among the most successful approaches to improve specificity problems inherent in many immunoassays. CONTENT We emphasize problems with immunoassays for the measurement of steroids and review the emerging role of LC-MS/MS in the measurement of clinically relevant steroids. The latest generation of tandem mass spectrometers has superior limits of quantification, permitting omission of previously employed derivatization steps. The measurement of steroid profiles in the diagnosis and treatment of congenital adrenal hyperplasia, adrenal insufficiency, chronic pelvic pain and prostatitis, oncology (breast cancer), and athletes has important new applications. CONCLUSIONS LC-MS/MS now affords the specificity, imprecision, and limits of quantification necessary for the reliable measurement of steroids in human fluids, enhancing diagnostic capabilities, particularly when steroid profiles are available. PMID:19325015

  7. DDES and IDDES of tandem cylinders.

    SciTech Connect

    Balakrishnan, R.; Garbaruk, A.; Shur, M.; Strelets, M.; Spalart, P.; New Technologies and Services - Russia; St.-Peterburg State Polytechnic Univ.; Boeing Commercial Airplanes

    2010-09-09

    The paper presents an overview of the authors contribution to the BANC-I Workshop on the flow past tandem cylinders (Category 2). It includes an outline of the simulation approaches, numerics, and grid used, the major results of the simulations, their comparison with available experimental data, and some preliminary conclusions. The effect of varying the spanwise period in the simulations is strong for some quantities, and not others.

  8. Cold Climate Heat Pumps Using Tandem Compressors

    SciTech Connect

    Shen, Bo; Abdelaziz, Omar; Rice, C Keith; Baxter, Van D

    2016-01-01

    In cold climate zones, e.g. ASHRAE climate regions IV and V, conventional electric air-source heat pumps (ASHP) do not work well, due to high compressor discharge temperatures, large pressure ratios and inadequate heating capacities at low ambient temperatures. Consequently, significant use of auxiliary strip heating is required to meet the building heating load. We introduce innovative ASHP technologies as part of continuing efforts to eliminate auxiliary strip heat use and maximize heating COP with acceptable cost-effectiveness and reliability. These innovative ASHP were developed using tandem compressors, which are capable of augmenting heating capacity at low temperatures and maintain superior part-load operation efficiency at moderate temperatures. Two options of tandem compressors were studied; the first employs two identical, single-speed compressors, and the second employs two identical, vapor-injection compressors. The investigations were based on system modeling and laboratory evaluation. Both designs have successfully met the performance criteria. Laboratory evaluation showed that the tandem, single-speed compressor ASHP system is able to achieve heating COP = 4.2 at 47 F (8.3 C), COP = 2.9 at 17 F (-8.3 C), and 76% rated capacity and COP = 1.9 at -13 F (-25 C). This yields a HSPF = 11.0 (per AHRI 210/240). The tandem, vapor-injection ASHP is able to reach heating COP = 4.4 at 47 F, COP = 3.1 at 17 F, and 88% rated capacity and COP = 2.0 at -13 F. This yields a HSPF = 12.0. The system modeling and further laboratory evaluation are presented in the paper.

  9. Current and lattice matched tandem solar cell

    DOEpatents

    Olson, Jerry M.

    1987-01-01

    A multijunction (cascade) tandem photovoltaic solar cell device is fabricated of a Ga.sub.x In.sub.1-x P (0.505.ltoreq.X.ltoreq.0.515) top cell semiconductor lattice matched to a GaAs bottom cell semiconductor at a low-resistance heterojunction, preferably a p+/n+ heterojunction between the cells. The top and bottom cells are both lattice matched and current matched for high efficiency solar radiation conversion to electrical energy.

  10. Oak Ridge 25-MV tandem accelerator

    SciTech Connect

    Ziegler, N.F.; Richardson, E.G.; Mann, J.E.; Juras, R.C.; Jones, C.M.; Biggerstaff, J.A.; Benjamin, J.A.

    1981-01-01

    A new heavy-ion accelerator facility is nearing completion at the Oak Ridge National Laboratory. This paper presents a brief description of the scope and status of this project and a discussion of some aspects of the first operational experience with the 25 MV tandem accelerator which is being provided by the National Electrostatics Corporation (NEC) as a major component of the first phase of the facility.

  11. Flow field interactions between two tandem cyclists

    NASA Astrophysics Data System (ADS)

    Barry, Nathan; Burton, David; Sheridan, John; Thompson, Mark; Brown, Nicholas A. T.

    2016-12-01

    Aerodynamic drag is the primary resistive force acting on cyclists at racing speeds. Many events involve cyclists travelling in very close proximity. Previous studies have shown that interactions result in significant drag reductions for inline cyclists. However, the interaction between cyclist leg position (pedalling) and the vortical flow structures that contribute significantly to the drag on an isolated cyclist has not previously been quantified or described for tandem cyclists of varying separation. To this end, scale model cyclists were constructed for testing in a water channel for inline tandem configurations. Particle image velocimetry was used to capture time-averaged velocity fields around two tandem cyclists. Perhaps surprisingly, the wake of a trailing cyclist maintains strong similarity to the characteristic wake of a single cyclist despite a significant disturbance to the upstream flow. Together with streamwise velocity measurements through the wake and upstream of the trailing cyclist, this work supports previous findings, which showed that the trailing cyclist drag reduction is primarily due to upstream sheltering effects reducing the stagnation pressure on forward-facing surfaces.

  12. TandEM: Titan and Enceladus mission

    NASA Astrophysics Data System (ADS)

    Coustenis, A.; Atreya, S. K.; Balint, T.; Brown, R. H.; Dougherty, M. K.; Ferri, F.; Fulchignoni, M.; Gautier, D.; Gowen, R. A.; Griffith, C. A.; Gurvits, L. I.; Jaumann, R.; Langevin, Y.; Leese, M. R.; Lunine, J. I.; McKay, C. P.; Moussas, X.; Müller-Wodarg, I.; Neubauer, F.; Owen, T. C.; Raulin, F.; Sittler, E. C.; Sohl, F.; Sotin, C.; Tobie, G.; Tokano, T.; Turtle, E. P.; Wahlund, J.-E.; Waite, J. H.; Baines, K. H.; Blamont, J.; Coates, A. J.; Dandouras, I.; Krimigis, T.; Lellouch, E.; Lorenz, R. D.; Morse, A.; Porco, C. C.; Hirtzig, M.; Saur, J.; Spilker, T.; Zarnecki, J. C.; Choi, E.; Achilleos, N.; Amils, R.; Annan, P.; Atkinson, D. H.; Bénilan, Y.; Bertucci, C.; Bézard, B.; Bjoraker, G. L.; Blanc, M.; Boireau, L.; Bouman, J.; Cabane, M.; Capria, M. T.; Chassefière, E.; Coll, P.; Combes, M.; Cooper, J. F.; Coradini, A.; Crary, F.; Cravens, T.; Daglis, I. A.; de Angelis, E.; de Bergh, C.; de Pater, I.; Dunford, C.; Durry, G.; Dutuit, O.; Fairbrother, D.; Flasar, F. M.; Fortes, A. D.; Frampton, R.; Fujimoto, M.; Galand, M.; Grasset, O.; Grott, M.; Haltigin, T.; Herique, A.; Hersant, F.; Hussmann, H.; Ip, W.; Johnson, R.; Kallio, E.; Kempf, S.; Knapmeyer, M.; Kofman, W.; Koop, R.; Kostiuk, T.; Krupp, N.; Küppers, M.; Lammer, H.; Lara, L.-M.; Lavvas, P.; Le Mouélic, S.; Lebonnois, S.; Ledvina, S.; Li, J.; Livengood, T. A.; Lopes, R. M.; Lopez-Moreno, J.-J.; Luz, D.; Mahaffy, P. R.; Mall, U.; Martinez-Frias, J.; Marty, B.; McCord, T.; Menor Salvan, C.; Milillo, A.; Mitchell, D. G.; Modolo, R.; Mousis, O.; Nakamura, M.; Neish, C. D.; Nixon, C. A.; Nna Mvondo, D.; Orton, G.; Paetzold, M.; Pitman, J.; Pogrebenko, S.; Pollard, W.; Prieto-Ballesteros, O.; Rannou, P.; Reh, K.; Richter, L.; Robb, F. T.; Rodrigo, R.; Rodriguez, S.; Romani, P.; Ruiz Bermejo, M.; Sarris, E. T.; Schenk, P.; Schmitt, B.; Schmitz, N.; Schulze-Makuch, D.; Schwingenschuh, K.; Selig, A.; Sicardy, B.; Soderblom, L.; Spilker, L. J.; Stam, D.; Steele, A.; Stephan, K.; Strobel, D. F.; Szego, K.; Szopa, C.; Thissen, R.; Tomasko, M. G.; Toublanc, D.; Vali, H.; Vardavas, I.; Vuitton, V.; West, R. A.; Yelle, R.; Young, E. F.

    2009-03-01

    TandEM was proposed as an L-class (large) mission in response to ESA’s Cosmic Vision 2015-2025 Call, and accepted for further studies, with the goal of exploring Titan and Enceladus. The mission concept is to perform in situ investigations of two worlds tied together by location and properties, whose remarkable natures have been partly revealed by the ongoing Cassini-Huygens mission. These bodies still hold mysteries requiring a complete exploration using a variety of vehicles and instruments. TandEM is an ambitious mission because its targets are two of the most exciting and challenging bodies in the Solar System. It is designed to build on but exceed the scientific and technological accomplishments of the Cassini-Huygens mission, exploring Titan and Enceladus in ways that are not currently possible (full close-up and in situ coverage over long periods of time). In the current mission architecture, TandEM proposes to deliver two medium-sized spacecraft to the Saturnian system. One spacecraft would be an orbiter with a large host of instruments which would perform several Enceladus flybys and deliver penetrators to its surface before going into a dedicated orbit around Titan alone, while the other spacecraft would carry the Titan in situ investigation components, i.e. a hot-air balloon (Montgolfière) and possibly several landing probes to be delivered through the atmosphere.

  13. TandEM: Titan and Enceladus mission

    USGS Publications Warehouse

    Coustenis, A.; Atreya, S.K.; Balint, T.; Brown, R.H.; Dougherty, M.K.; Ferri, F.; Fulchignoni, M.; Gautier, D.; Gowen, R.A.; Griffith, C.A.; Gurvits, L.I.; Jaumann, R.; Langevin, Y.; Leese, M.R.; Lunine, J.I.; McKay, C.P.; Moussas, X.; Muller-Wodarg, I.; Neubauer, F.; Owen, T.C.; Raulin, F.; Sittler, E.C.; Sohl, F.; Sotin, Christophe; Tobie, G.; Tokano, T.; Turtle, E.P.; Wahlund, J.-E.; Waite, J.H.; Baines, K.H.; Blamont, J.; Coates, A.J.; Dandouras, I.; Krimigis, T.; Lellouch, E.; Lorenz, R.D.; Morse, A.; Porco, C.C.; Hirtzig, M.; Saur, J.; Spilker, T.; Zarnecki, J.C.; Choi, E.; Achilleos, N.; Amils, R.; Annan, P.; Atkinson, D.H.; Benilan, Y.; Bertucci, C.; Bezard, B.; Bjoraker, G.L.; Blanc, M.; Boireau, L.; Bouman, J.; Cabane, M.; Capria, M.T.; Chassefiere, E.; Coll, P.; Combes, M.; Cooper, J.F.; Coradini, A.; Crary, F.; Cravens, T.; Daglis, I.A.; de Angelis, E.; De Bergh, C.; de Pater, I.; Dunford, C.; Durry, G.; Dutuit, O.; Fairbrother, D.; Flasar, F.M.; Fortes, A.D.; Frampton, R.; Fujimoto, M.; Galand, M.; Grasset, O.; Grott, M.; Haltigin, T.; Herique, A.; Hersant, F.; Hussmann, H.; Ip, W.; Johnson, R.; Kallio, E.; Kempf, S.; Knapmeyer, M.; Kofman, W.; Koop, R.; Kostiuk, T.; Krupp, N.; Kuppers, M.; Lammer, H.; Lara, L.-M.; Lavvas, P.; Le, Mouelic S.; Lebonnois, S.; Ledvina, S.; Li, Ji; Livengood, T.A.; Lopes, R.M.; Lopez-Moreno, J. -J.; Luz, D.; Mahaffy, P.R.; Mall, U.; Martinez-Frias, J.; Marty, B.; McCord, T.; Salvan, C.M.; Milillo, A.; Mitchell, D.G.; Modolo, R.; Mousis, O.; Nakamura, M.; Neish, Catherine D.; Nixon, C.A.; Mvondo, D.N.; Orton, G.; Paetzold, M.; Pitman, J.; Pogrebenko, S.; Pollard, W.; Prieto-Ballesteros, O.; Rannou, P.; Reh, K.; Richter, L.; Robb, F.T.; Rodrigo, R.; Rodriguez, S.; Romani, P.; Bermejo, M.R.; Sarris, E.T.; Schenk, P.; Schmitt, B.; Schmitz, N.; Schulze-Makuch, D.; Schwingenschuh, K.; Selig, A.; Sicardy, B.; Soderblom, L.; Spilker, L.J.; Stam, D.; Steele, A.; Stephan, K.; Strobel, D.F.; Szego, K.; Szopa,

    2009-01-01

    TandEM was proposed as an L-class (large) mission in response to ESA's Cosmic Vision 2015-2025 Call, and accepted for further studies, with the goal of exploring Titan and Enceladus. The mission concept is to perform in situ investigations of two worlds tied together by location and properties, whose remarkable natures have been partly revealed by the ongoing Cassini-Huygens mission. These bodies still hold mysteries requiring a complete exploration using a variety of vehicles and instruments. TandEM is an ambitious mission because its targets are two of the most exciting and challenging bodies in the Solar System. It is designed to build on but exceed the scientific and technological accomplishments of the Cassini-Huygens mission, exploring Titan and Enceladus in ways that are not currently possible (full close-up and in situ coverage over long periods of time). In the current mission architecture, TandEM proposes to deliver two medium-sized spacecraft to the Saturnian system. One spacecraft would be an orbiter with a large host of instruments which would perform several Enceladus flybys and deliver penetrators to its surface before going into a dedicated orbit around Titan alone, while the other spacecraft would carry the Titan in situ investigation components, i.e. a hot-air balloon (Montgolfi??re) and possibly several landing probes to be delivered through the atmosphere. ?? Springer Science + Business Media B.V. 2008.

  14. Evaluation of a commercial in-clinic point-of-care polymerase chain reaction test for Ehrlichia canis DNA in artificially infected dogs.

    PubMed

    Waner, Trevor; Nachum-Biala, Yaarit; Harrus, Shimon

    2014-12-01

    A novel in-clinic point-of-care (ICPOC) polymerase chain reaction (PCR) test was evaluated for its ability to detect Ehrlichia canis DNA in artificially infected dogs compared to a real-time PCR assay. Six Beagle dogs negative for E. canis antibodies and PCR negative were artificially infected with an Israeli E. canis strain (611). All dogs developed IgG antibodies 8 days post infection (PI), and clinical and hematological abnormalities on day 10 PI. Only the real-time PCR detected E. canis DNA in the blood of five dogs at days 3 and 5 PI. At day 12 PI during the acute phase of the disease, 1 day after the initiation of doxycycline treatment, the ICPOC PCR assay detected E. canis DNA in all infected dogs, which were also positive by the real-time PCR. Two days later the ICPOC PCR assay was able to detect only 3/6 infected dogs, which were all positive by the real-time PCR. At days 17 and 19 PI, the ICPOC PCR assay did not detect E. canis DNA in the dogs while the real-time PCR detected all dogs as positive on day 17 PI and two dogs on day 19 PI. In conclusion, the sensitivity of the ICPOC PCR assay was 75% for the acute phase of the disease and 30% for the whole study, suggesting that this ICPOC assay has a potential utility for the diagnosis of acute canine monocytic ehrlichiosis.

  15. Critical analysis of vector-borne infections in dogs: Babesia vogeli, Babesia gibsoni, Ehrlichia canis and Hepatozoon canis in Punjab, India.

    PubMed

    Singla, Lachhman Das; Sumbria, Deepak; Mandhotra, Ajay; Bal, M S; Kaur, Paramjit

    2016-12-01

    There are few published studies on various vector borne diseases of dogs in India and most depict clinical infection in dogs, diagnosed by observation of the haemopathogens in stained blood smears. This study provides the first report regarding molecular confirmation and ancestral relationship analysis of blood smears positive cases of assorted haemopathogens in Punjab province of India. On blood smear examination, haemopathogens were observed in 124 out of 778 (15.95%, 95% CI: 13.53- 18.68) blood smears. Further polymerase chain reactions (PCR) was used on bloods smear positive cases to validate the results. Out of 778 blood samples, Babesia gibsoni was most common parasite infecting dogs (15.04%, 95% CI: 12.7-17.72), followed by Ehrlichia canis (0.39%, 95% CI: 0.0-1.13), infection of Babesia vogeli and Hepatozoon canis was same (0.26%, 95% CI: 0.0-0.9). Among various risk factors studied (age, sex, season), prevalence of infection was non-significantly higher in 1-2 year of age group (19.88%, 95% CI: 14.45-26.71), regarding sex same prevalence was recorded (15.94%), and chances of infection was highest in pre-monsoon i.e. summer (18.26%, 95% CI: 14.49-22.76). Phylogenetic analysis revealed ancestral background of Ludhiana isolates of B. vogeli, B. gibsoni, H. canis, and E. canis with the isolates of Philippines, Mongolia and Tunisia.

  16. Prevalence of antibodies against Rickettsia conorii, Babesia canis, Ehrlichia canis, and Anaplasma phagocytophilum antigens in dogs from the Stretto di Messina area (Italy).

    PubMed

    Pennisi, Maria-Grazia; Caprì, Alessandra; Solano-Gallego, Laia; Lombardo, Gabriella; Torina, Alessandra; Masucci, Marisa

    2012-12-01

    The aims of this study were to determine the seroprevalence for Rickettsia conorii, Ehrlichia canis, Anaplasma phagocytophilum, and Babesia canis in outdoor-kennelled dogs (n=249) from the Stretto di Messina (Italy) and to compare seroprevalence in 2 public shelters and 4 privately-owned kennels where different tick-preventive measures were implemented in order to focus on the specific sanitary risk posed by public shelters in southern Italy for tick-borne pathogens. R. conorii (72%) and B. canis (70%) were the most prevalent infections when compared to E. canis (46%) and A. phagocytophilum (38%). Seroprevalence for R. conorii, E. canis, and A. phagocytophilum was significantly higher in public shelters than in private kennels. However, B. canis seropositivity was similar in both types of kennels. In addition, in private kennels where a regular ectocide treatment was carried out by means of spot-on devices, dogs did not present E. canis and A. phagocytophilum antibodies. One hundred fifty-one dogs out of 249 (61%) were seropositive to more than one pathogen with R. conorii and B. canis the most common ones. Coinfections were more frequently found in public-shelter dogs. This study demonstrated high seroprevalences against R. conorii, B. canis, E. canis, and A. phagocytophilum in kennelled dogs from both coastal sites of the Stretto di Messina and the importance of regular tick-bite prevention by means of individual spot-on devices.

  17. High throughput pyrosequencing technology for molecular differential detection of Babesia vogeli, Hepatozoon canis, Ehrlichia canis and Anaplasma platys in canine blood samples.

    PubMed

    Kaewkong, Worasak; Intapan, Pewpan M; Sanpool, Oranuch; Janwan, Penchom; Thanchomnang, Tongjit; Kongklieng, Amornmas; Tantrawatpan, Chairat; Boonmars, Thidarut; Lulitanond, Viraphong; Taweethavonsawat, Piyanan; Chungpivat, Sudchit; Maleewong, Wanchai

    2014-06-01

    Canine babesiosis, hepatozoonosis, ehrlichiosis, and anaplasmosis are tick-borne diseases caused by different hemopathogens. These diseases are causes of morbidity and mortality in dogs. The classic method for parasite detection and differentiation is based on microscopic observation of blood smears. The limitations of the microscopic method are that its performance requires a specially qualified person with professional competence, and it is ineffective in differentiating closely related species. This study applied PCR amplification with high throughput pyrosequencing for molecular differential detection of the following 4 hemoparasites common to tropical areas in dog blood samples: Babesia vogeli, Hepatozoon canis, Ehrlichia canis, and Anaplasma platys. PCR was initially used to amplify specific target regions of the ribosomal RNA genes of each parasite using 2 primer pairs that included 18S rRNA for protozoa (B. vogeli and H. canis) and 16S rRNA for rickettsia (E. canis and A. platys). Babesia vogeli and H. canis were discriminated using 9 nucleotide positions out of 30 base pairs, whereas E. canis and A. platys were differentiated using 15 nucleotide positions out of 34 base pairs that were determined from regions adjacent to 3' ends of the sequencing primers. This method provides a challenging alternative for a rapid diagnosis and surveillance of these tick-borne diseases in canines.

  18. Mimicry epitope from Ehrlichia canis for interphotoreceptor retinoid-binding protein 201-216 prevents autoimmune uveoretinitis by acting as altered peptide ligand.

    PubMed

    Gangaplara, Arunakumar; Massilamany, Chandirasegaran; Steffen, David; Reddy, Jay

    2013-10-15

    We report here identification of novel mimicry epitopes for interphotoreceptor retinoid-binding protein (IRBP) 201-216, a candidate ocular antigen that causes experimental autoimmune uveoretinitis (EAU) in A/J mice. One mimicry epitope from Ehrlichia canis (EHC), designated EHC 44-59, induced cross-reactive T cells for IRBP 201-216 capable of producing T helper (Th)1 and Th17 cytokines, but failed to induce EAU in A/J mice. In addition, animals first primed with suboptimal doses of IRBP 201-216 and subsequently immunized with EHC 44-59 did not develop EAU; rather, the mimicry epitope prevented the disease induced by IRBP 201-216. However, alteration in the composition of EHC 44-59 by substituting alanine with valine at position 49, similar to the composition of IRBP 201-216, enabled the mimicry epitope to acquire uveitogenicity. The data provide new insights as to how microbes containing mimicry sequences for retinal antigens can prevent ocular inflammation by acting as naturally occurring altered peptide ligands.

  19. Development of a sensitive and specific indirect enzyme-linked immunosorbent assay based on a baculovirus recombinant antigen for detection of specific antibodies against Ehrlichia canis.

    PubMed

    López, Lissett; Venteo, Angel; Aguirre, Enara; García, Marga; Rodríguez, Majosé; Amusátegui, Inmaculada; Tesouro, Miguel A; Vela, Carmen; Sainz, Angel; Rueda, Paloma

    2007-11-01

    An indirect enzyme-linked immunosorbent assay (ELISA) based on baculovirus recombinant P30 protein of Ehrlichia canis and the 1BH4 anticanine IgG monoclonal antibody was developed and evaluated by examining a panel of 98 positive and 157 negative sera using the indirect fluorescent antibody (IFA) test as the reference technique. The P30-based ELISA appeared to be sensitive and specific (77.55% and 95.54%, respectively) when qualitative results (positive/negative) were compared with those of the IFA test; the coefficient of correlation (R) between the 2 tests was 0.833. Furthermore, it was possible to establish a mathematical formula for use in comparing the results of both techniques. These results indicate that recombinant P30 antigen-based ELISA is a suitable alternative of the IFA test for simple, consistent, and rapid serodiagnosis of canine ehrlichiosis. Moreover, the use of this recombinant protein as antigen offers a great advantage for antigen preparation in comparison with other techniques in which the whole E. canis organism is used as antigen.

  20. Dynamics of IgG1 and IgG2 subclass response in dogs naturally and experimentally infected with Ehrlichia canis.

    PubMed

    Harrus, S; Waner, T; Strauss-Ayali, D; Bark, H; Jongejan, F; Hecht, G; Baneth, G

    2001-07-31

    Immunoglobulin (Ig) G subclasses were measured in dogs naturally and experimentally infected with Ehrlichia canis using enzyme-linked immunosorbant assay (ELISA). In this study, a higher IgG2 subclass response was noticed to natural and experimental E. canis infection in dogs. Anti-E. canis-IgG2 optic density (OD) values were found to be significantly higher than anti-E. canis-IgG1 during the different phases of the disease, and no differences in the IgG subclass responses to E. canis infection were found between symptomatic and asymptomatic dogs. Doxycycline treatment, which eliminated the rickettsia in three of four persistently infected dogs, had no noticeable influence on the E. canis-IgG subclass OD values during the treatment period. In order to facilitate the study, an ELISA for the detection of anti-E. canis IgG was developed and was shown to be sensitive and specific for E. canis-IgG, and in a significant correlation with the indirect immunofluorescence antibody test.

  1. Detection of Ehrlichia canis in canine blood samples by real-time fluorescence resonance energy transfer (FRET) PCR and melting curve analysis.

    PubMed

    Kongklieng, Amornmas; Thanchomnang, Tongjit; Intapan, Pewpan M; Boonmars, Thidarut; Janwan, Penchom; Sanpool, Oranuch; Lulitanond, Viraphong; Taweethavonsawat, Piyanan; Chungpivat, Sudchit; Morakote, Nimit; Maleewong, Wanchai

    2014-09-01

    Ehrlichia canis is a small pleomorphic gram-negative, coccoid, obligatory intracellular bacterium and the cause of canine monocytic ehrlichiosis. A real-time fluorescence resonance energy transfer polymerase chain reaction (real-time FRET PCR) coupled with melting curve analysis was established for detection of E. canis infection in canine blood samples. The VirB9 gene was amplified using one pair of primers and the melting curve analysis was generated by heating the hybridizing probes and amplified products. Eight E. canis-infected dog blood samples were initially identified using the Giemsa staining/microscopic method followed by conventional PCR (cPCR)/Sanger sequencing for confirmation. The sensitivity and specificity of the real-time FRET PCR detection were 87.5% and 100%, respectively and the limit of detection was 6.6 x 10(3) copies of positive E. canis control plasmids. The real-time FRET PCR with melting curve analysis reported here is better than microscopic visualization or cPCR because the method is not affected by the false bias inherent in the microscopic method. Furthermore, many samples can be processed rapidly at the same time. This convenient tool is beneficial as an alternative assay for the epidemiologic study of canine ehrlichiosis as well as for eradication of these organisms in prevention and control programs in endemic areas.

  2. The prevalence of Anaplasma platys and a potential novel Anaplasma species exceed that of Ehrlichia canis in asymptomatic dogs and Rhipicephalus sanguineus in Taiwan.

    PubMed

    Yuasa, Yumi; Tsai, Yi-Lun; Chang, Chao-Chin; Hsu, Tien-Huan; Chou, Chi-Chung

    2017-09-12

    Canine anaplasmosis is regarded as an infection by Anaplasma platys rather than zoonotic Anaplasma phagocytophilum in subtropical areas based on the assumption that the common dog tick species is Rhipicephalus sanguineus, which transmits E. canis and presumably A. platys. We investigated asymptomatic dogs and dog ticks from 16 communities in Nantou County, Taiwan to identify common dog tick species and to determine the prevalence of Anaplasma and Ehrlichia spp. Of total 175 canine blood samples and 315 ticks, including 306 R. sanguineus and 9 Haemaphysalis hystricis, 15 dogs and 3 R. sanguineus ticks were positive for E. canis, while 47 dogs and 71 R. sanguineus ticks were positive for A. platys, via nested PCR for 16S rDNA and DNA sequencing of selected positive amplicons. However, among the dogs and ticks that were positive to A. platys 16S rDNA, only 20 dogs and 11 ticks were positive to nested PCR for A. platys groEL gene. These results revealed the importance of searching for novel Anaplasma spp. closely related to A. platys in dogs and ticks. Seropositivity to a commercial immunochromatographic test SNAP 4Dx Anaplasma sp. was not significantly associated with PCR positivity for A. platys but with infestation by ticks carrying A. platys (P<0.05). Accordingly, R. sanguineus may be involved in transmission of A. platys but may not act as a reservoir of E. canis and PCR results for 16S rDNA could be a problematic diagnostic index for A. platys infection.

  3. Production and Characterization of Ehrlichia risticii, the Agent of Potomac Horse Fever, from Snails (Pleuroceridae: Juga spp.) in Aquarium Culture and Genetic Comparison to Equine Strains

    PubMed Central

    Reubel, Gerhard H.; Barlough, Jeffrey E.; Madigan, John E.

    1998-01-01

    We report on the production and characterization of Ehrlichia risticii, the agent of Potomac horse fever (PHF), from snails (Pleuroceridae: Juga spp.) maintained in aquarium culture and compare it genetically to equine strains. Snails were collected from stream waters on a pasture in Siskiyou County, Calif., where PHF is enzootic and were maintained for several weeks in freshwater aquaria in the laboratory. Upon exposure to temperatures above 22°C the snails released trematode cercariae tentatively identified as virgulate cercariae. Fragments of three different genes (genes for 16S rRNA, the groESL heat shock operon, and the 51-kDa major antigen) were amplified from cercaria lysates by PCR and sequenced. Genetic information was also obtained from E. risticii strains from horses with PHF. The PCR positivity of snail secretions was associated with the presence of trematode cercariae. Sequence analysis of the three genes indicated that the source organism closely resembled E. risticii, and the sequences of all three genes were virtually identical to those of the genes of an equine E. risticii strain from a property near the snail collection site. Phylogenetic analyses of the three genes indicated the presence of geographical E. risticii strain clusters. PMID:9620368

  4. Genetic diversity of Ehrlichia ruminantium in Amblyomma variegatum ticks and small ruminants in The Gambia determined by restriction fragment profile analysis.

    PubMed

    Faburay, Bonto; Jongejan, Frans; Taoufik, Amar; Ceesay, Ansumana; Geysen, Dirk

    2008-01-01

    Understanding genetic diversity of Ehrlichia ruminantium in host and vector populations is an important prerequisite to controlling heartwater by vaccination in traditional livestock systems in sub-Saharan Africa. We carried out a study in two phases: (i) evaluating the usefulness of the PCR-RFLP assay based on the map1 coding sequence of E. ruminantium as a discriminatory tool to characterise genetic diversity, (ii) applying the technique to field samples from Amblyomma variegatum ticks and small ruminants to characterise genotypic diversity of the organism in three main agroecological zones of The Gambia, Sudano-Guinean (SG), Western Sudano-Sahelian (WSS) and Eastern Sudano-Sahelian (ESS). Restriction fragment length polymorphisms were observed among different strains of E. ruminantium supporting the usefulness of the PCR-RFLP technique for studying genetic diversity of the organism. Restriction enzyme map1 profile analysis indicated the presence in The Gambia of multiple genotypes (at least 11) of E. ruminantium with sites in the WSS and SG zones showing comparatively high number of diverse genotypes. Profiles similar to the Kerr Seringe genotype (DQ333230) showed the highest distribution frequency, being present at sites in all three agroecological zones, thereby making the strain a suitable candidate for further characterisation in cross-protection studies. An additional three genotypes showed relatively high distribution frequency and were present in all three zones making them equally important for isolation and subsequent characterisation. The study demonstrated the occurrence of mixed infections with E. ruminantium genotypes in ruminants and ticks.

  5. Organic Light-Emitting Devices with Tandem Structure.

    PubMed

    Chiba, Takayuki; Pu, Yong-Jin; Kido, Junji

    2016-06-01

    Tandem organic light-emitting devices (OLEDs) have attracted considerable attention for solid-state lighting and flat panel displays because their tandem architecture enables high efficiency and long operational lifetime simultaneously. In the tandem OLED structure, plural light-emitting units (LEUs) are stacked in series through a charge generation layer (CGL) and an electron injection layer (EIL). In this chapter, we focus on the key features of tandem OLEDs for high efficiency and long operational lifetimes. We also demonstrate the effect of the CGL comprising a Lewis acid, an n-type semiconductor metal oxide, and an organic electron-accepting material. We discuss the two types of EILs in tandem OLEDs: alkali metals containing n-type compounds and ultra-thin metals. Finally, we focus on the recent progress of the state-of-the-art solution-processed tandem OLEDs.

  6. Status of the JAERI tandem accelerator and its booster

    SciTech Connect

    Takeuchi, Suehiro; Abe, Shinichi; Hanashima, Susumu; Horie, Katsuzo; Ishizaki, Nobuhiro; Kanda, Susumu; Matsuda, Makoto; Ohuchi, Isao; Tayama, Hidekazu; Tsukihashi, Yoshihiro; Yoshida, Tadashi

    1999-04-26

    The JAERI tandem accelerator has been operating effectively since 1982 and heavy ions from the tandem has been boosted in energy by the superconducting independently phased booster linac for the experiments at higher bombarding energies since 1994. Present operating status of the tandem accelerator and its booster, status of their use for experiments and an on-going improvement project with an ECR ion source are described.

  7. Flexible and fragmentable tandem photosensitive nanocrystal skins

    NASA Astrophysics Data System (ADS)

    Akhavan, S.; Uran, C.; Bozok, B.; Gungor, K.; Kelestemur, Y.; Lesnyak, V.; Gaponik, N.; Eychmüller, A.; Demir, H. V.

    2016-02-01

    We proposed and demonstrated the first account of large-area, semi-transparent, tandem photosensitive nanocrystal skins (PNSs) constructed on flexible substrates operating on the principle of photogenerated potential buildup, which avoid the need for applying an external bias and circumvent the current-matching limitation between junctions. We successfully fabricated and operated the tandem PNSs composed of single monolayers of colloidal water-soluble CdTe and CdHgTe nanocrystals (NCs) in adjacent junctions on a Kapton polymer tape. Owing to the usage of a single NC layer in each junction, noise generation was significantly reduced while keeping the resulting PNS films considerably transparent. In each junction, photogenerated excitons are dissociated at the interface of the semi-transparent Al electrode and the NC layer, with holes migrating to the contact electrode and electrons trapped in the NCs. As a result, the tandem PNSs lead to an open-circuit photovoltage buildup equal to the sum of those of the two single junctions, exhibiting a total voltage buildup of 128.4 mV at an excitation intensity of 75.8 μW cm-2 at 350 nm. Furthermore, we showed that these flexible PNSs could be bent over 3.5 mm radius of curvature and cut out in arbitrary shapes without damaging the operation of individual parts and without introducing any significant loss in the total sensitivity. These findings indicate that the NC skins are promising as building blocks to make low-cost, flexible, large-area UV/visible sensing platforms with highly efficient full-spectrum conversion.We proposed and demonstrated the first account of large-area, semi-transparent, tandem photosensitive nanocrystal skins (PNSs) constructed on flexible substrates operating on the principle of photogenerated potential buildup, which avoid the need for applying an external bias and circumvent the current-matching limitation between junctions. We successfully fabricated and operated the tandem PNSs composed of

  8. Flexible and fragmentable tandem photosensitive nanocrystal skins.

    PubMed

    Akhavan, S; Uran, C; Bozok, B; Gungor, K; Kelestemur, Y; Lesnyak, V; Gaponik, N; Eychmüller, A; Demir, H V

    2016-02-28

    We proposed and demonstrated the first account of large-area, semi-transparent, tandem photosensitive nanocrystal skins (PNSs) constructed on flexible substrates operating on the principle of photogenerated potential buildup, which avoid the need for applying an external bias and circumvent the current-matching limitation between junctions. We successfully fabricated and operated the tandem PNSs composed of single monolayers of colloidal water-soluble CdTe and CdHgTe nanocrystals (NCs) in adjacent junctions on a Kapton polymer tape. Owing to the usage of a single NC layer in each junction, noise generation was significantly reduced while keeping the resulting PNS films considerably transparent. In each junction, photogenerated excitons are dissociated at the interface of the semi-transparent Al electrode and the NC layer, with holes migrating to the contact electrode and electrons trapped in the NCs. As a result, the tandem PNSs lead to an open-circuit photovoltage buildup equal to the sum of those of the two single junctions, exhibiting a total voltage buildup of 128.4 mV at an excitation intensity of 75.8 μW cm(-2) at 350 nm. Furthermore, we showed that these flexible PNSs could be bent over 3.5 mm radius of curvature and cut out in arbitrary shapes without damaging the operation of individual parts and without introducing any significant loss in the total sensitivity. These findings indicate that the NC skins are promising as building blocks to make low-cost, flexible, large-area UV/visible sensing platforms with highly efficient full-spectrum conversion.

  9. Tandem robot control system and method for controlling mobile robots in tandem

    DOEpatents

    Hayward, David R.; Buttz, James H.; Shirey, David L.

    2002-01-01

    A control system for controlling mobile robots provides a way to control mobile robots, connected in tandem with coupling devices, to navigate across difficult terrain or in closed spaces. The mobile robots can be controlled cooperatively as a coupled system in linked mode or controlled individually as separate robots.

  10. 47 CFR 69.111 - Tandem-switched transport and tandem charge.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... where the incumbent local exchange carrier has implemented density pricing zones as described in section... circuits used in the tandem to end office links (or a surrogate based on the proportion of copper and fiber... exchange carrier. (ii) In study areas where the incumbent local exchange carrier has implemented density...

  11. 47 CFR 69.111 - Tandem-switched transport and tandem charge.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... areas where the incumbent local exchange carrier has implemented density pricing zones as described in... circuits used in the tandem to end office links (or a surrogate based on the proportion of copper and fiber... exchange carrier. (ii) In study areas where the incumbent local exchange carrier has implemented density...

  12. Flute waves in a tandem mirror

    SciTech Connect

    Mikhailovskaya, L.V.

    1984-03-01

    Stability conditions are derived for flute waves in a short tandem mirror stabilized by end cells with a min B. The frequency spectrum of the flute waves is analyzed. Those conditions under which the resonant excitation of waves by ions and electrons must be taken into account are found. When end cells without a min B are added to a central mirror system, the system becomes destabilized as the result of resonant excitation of waves at a frequency near the precession frequency of ions having a finite energy distribution.

  13. The Naples University 3 MV tandem accelerator

    SciTech Connect

    Campajola, L.; Brondi, A.

    2013-07-18

    The 3 MV tandem accelerator of the Naples University is used for research activities and applications in many fields. At the beginning of operation (1977) the main utilization was in the field of nuclear physics. Later, the realization of new beam lines allowed the development of applied activities as radiocarbon dating, ion beam analysis, biophysics, ion implantation etc. At present, the availability of different ion sources and many improvements on the accelerator allow to run experiments in a wide range of subjects. An overview of the characteristics and major activities of the laboratory is presented.

  14. Method of fabricating bifacial tandem solar cells

    SciTech Connect

    Wojtczuk, Steven J; Chiu, Philip T; Zhang, Xuebing; Gagnon, Edward; Timmons, Michael

    2014-10-07

    A method of fabricating on a semiconductor substrate bifacial tandem solar cells with semiconductor subcells having a lower bandgap than the substrate bandgap on one side of the substrate and with subcells having a higher bandgap than the substrate on the other including, first, growing a lower bandgap subcell on one substrate side that uses only the same periodic table group V material in the dislocation-reducing grading layers and bottom subcells as is present in the substrate and after the initial growth is complete and then flipping the substrate and growing the higher bandgap subcells on the opposite substrate side which can be of different group V material.

  15. A Hybrid Approach To Tandem Cylinder Noise

    NASA Technical Reports Server (NTRS)

    Lockard, David P.

    2004-01-01

    Aeolian tone generation from tandem cylinders is predicted using a hybrid approach. A standard computational fluid dynamics (CFD) code is used to compute the unsteady flow around the cylinders, and the acoustics are calculated using the acoustic analogy. The CFD code is nominally second order in space and time and includes several turbulence models, but the SST k - omega model is used for most of the calculations. Significant variation is observed between laminar and turbulent cases, and with changes in the turbulence model. A two-dimensional implementation of the Ffowcs Williams-Hawkings (FW-H) equation is used to predict the far-field noise.

  16. Terminal ion source for an FN tandem

    SciTech Connect

    Harper, G.C.

    1995-09-01

    An RF discharge source assembly has been developed for use in the terminal of the FN tandem van de Graaff accelerator at the Nuclear Physics Laboratory of the University of Washington. The primary motivation for developing the source was to provide a high intensity beam of {sup 3}He{sup +} to produce {sup 8}B from the reaction {sub 6}Li({sup 3}He,n){sup 8}B. The design of the optics and the performance of the source are described here.

  17. Some new ideas for Tandem Mirror blankets

    SciTech Connect

    Neef, W.S. Jr.

    1981-10-12

    The Tandem Mirror Reactor, with its cylindrical central cell, has led to numerous blanket designs taking advantage of the simple geometry. Also many new applications for fusion neutrons are now being considered. To the pure fusion electricity producers and hybrids producing fissile fuel, we are adding studies of synthetic fuel producers and fission-suppressed hybrids. The three blanket concepts presented are new ideas and should be considered illustrative of the breadth of Livermore's application studies. They are not meant to imply fully analyzed designs.

  18. Update and Commentary on Four Emerging Tick-Borne Infections: Ehrlichia muris-like Agent, Borrelia miyamotoi, Deer Tick Virus, Heartland Virus, and Whether Ticks Play a Role in Transmission of Bartonella henselae.

    PubMed

    Wormser, Gary P; Pritt, Bobbi

    2015-06-01

    Emerging tick-borne infections continue to be observed in the United States and elsewhere. Current information on the epidemiology, clinical and laboratory features, and treatment of infections due to Ehrlichia muris-like agent, deer tick virus, Borrelia miyamotoi sensu lato, and Heartland virus was provided and critically reviewed. More research is needed to define the incidence and to understand the clinical and the laboratory features of these infections. There is also a growing need for the development of sensitive and specific serologic and molecular assays for these infections that are easily accessible to clinicians. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. Progress in the tandem mirror program

    SciTech Connect

    Fowler, T.K.; Borchers, R.R.

    1981-09-13

    Experimental results in TMX have confirmed the basic principles of the tandem-mirror concept. A center-cell particle confinement parameter eta tau approx. 10/sup 11/ cm/sup -3/ s has been obtained at ion temperatures around 100 eV, which is a hundred-fold improvement over single mirrors at the same temperatures. For TMX these results have been obtained at peak beta values in the center cell in the range 10 to 40%, not yet limited by MHD activity; and ion-cyclotron resonant heating (ICRH) in the Phaedrus tandem-mirror experiment has produced beta values approx. 25%, which is several times the ideal MHD limit for that device. In addition, it has been demonstrated that the end fan chambers of TMX simultaneously isolate the hot electrons from the end walls, provide adequate pumping and conveniently dispose of the exhaust plasma energy either by thermal deposition on the end wall or by direct conversion to electricity (at 48% efficiency in agreement with calculations). Also, evidence was obtained for inherent divertor action in TMX, presumably in part responsible for the observed low impurity level (<0.5% low-Z ions in the center cell).

  20. Exhaustive whole-genome tandem repeats search.

    PubMed

    Krishnan, Arun; Tang, Francis

    2004-11-01

    Approximate tandem repeats (ATR) occur frequently in the genomes of organisms, and are a source of polymorphisms observed in individuals, and thus are of interest to those studying genetic disorders. Though extensive work has been done in order to identify ATRs, there are inherent limitations with the current approaches in terms of the number of pattern sizes that can be searched or the size of the input length. This paper describes (1) a new algorithm which exhaustively finds all variable-length ATRs in a genomic sequence and (2) a precise description of, and an algorithm to significantly reduce, redundancy in the output. Our ATR definition is parameterized by a mismatch ratio p which allows for more mismatches in longer tandem repeats (and fewer in shorter). Furthermore, our algorithm is embarrassingly parallel and thus can attain near-linear speed-up on Beowulf clusters. We present results of our algorithm applied to sequences of widely differing lengths (from genes to chromosomes). Source and binaries are available on request.

  1. Form-Focused Interaction in Online Tandem Learning

    ERIC Educational Resources Information Center

    O'Rourke, Breffni

    2005-01-01

    Tandem language learning--a configuration involving pairs of learners with complementary target/native languages--is an underexploited but potentially very powerful use of computer-mediated communication (CMC) in second-language pedagogy. Tandem offers the benefits of authentic, culturally grounded interaction, while also promoting a pedagogical…

  2. Monitoring Bilingualism: Pedagogical Implications of the Bilingual Tandem Analyser

    ERIC Educational Resources Information Center

    Schwienhorst, Klaus; Borgia, Alexandre

    2006-01-01

    Tandem learning is the collaborative learning partnership of two language learners with complementary language combinations, for example an Irish student learning German and a German student learning English. One of the major principles in tandem learning, apart from reciprocity and learner autonomy, is balanced bilingualism. While learners may…

  3. Monitoring Bilingualism: Pedagogical Implications of the Bilingual Tandem Analyser

    ERIC Educational Resources Information Center

    Schwienhorst, Klaus; Borgia, Alexandre

    2006-01-01

    Tandem learning is the collaborative learning partnership of two language learners with complementary language combinations, for example an Irish student learning German and a German student learning English. One of the major principles in tandem learning, apart from reciprocity and learner autonomy, is balanced bilingualism. While learners may…

  4. Summary of the tandem energy focusing explosive warhead technologies

    SciTech Connect

    Zhou, T.S.

    1996-09-26

    In this paper, on the basis of a great amount of the analysis of the tandem energy focusing explosive warhead in our country and other countries, we summarize the design demand of the tandem warhead, the delayed ignition controlling technique between the explosives, the isolating explosion protection technique and the detonator technique.

  5. A tandem-based compact dual-energy gamma generator

    SciTech Connect

    Persaud, A.; Kwan, J.W.; Leitner, M.; Leung, K.N.; Ludewigt, B.; Tanaka, N.; Waldron, W.; Wilde, S.; Antolak, A.J.; Morse, D.H.; Raber, T.

    2009-11-11

    A dual-energy tandem-type gamma generator has been developed at E.O. Lawrence Berkeley National Laboratory and Sandia National Laboratories. The tandem accelerator geometry allows higher energy nuclear reactions to be reached, thereby allowing more flexible generation of MeV-energy gammas for active interrogation applications.

  6. Negotiating Multiple Identities through eTandem Learning Experiences

    ERIC Educational Resources Information Center

    Yang, Se Jeong; Yi, Youngjoo

    2017-01-01

    Much of eTandem research has investigated either linguistic or cross-cultural aspects of second language (L2) learning, but relatively little is known about issues of identity construction in an eTandem context. Situating the study within theories and research of language learner identity, we examined ways in which two adult L2 learners (a Korean…

  7. Tandem-type pulse tube refrigerator without reservoir

    NASA Astrophysics Data System (ADS)

    Ki, Taekyung; Jeong, Sangkwon; Ko, Junseok; Park, Jiho

    2015-12-01

    In this paper, a tandem-type pulse tube refrigerator without a reservoir is discussed and investigated. For its practical application a tandem-type compressor is designed to generate two pulsating pressure waves with opposite phases, simultaneously. A tandem-type pulse tube refrigerator consists of a tandem-type compressor and two identical pulse tube refrigerators. The two identical pulse tube refrigerators share the same heat exchangers and one can be connected with the other by an inertance tube without a reservoir. In this proposed configuration, the mechanical vibration and temperature oscillations in the cold-end heat exchanger can be internally suppressed due to its intrinsic opposite-characteristic operation. To examine the quantitative evaluation of the tandem feature which does not require a reservoir in the pulse tube, an evolutionary approach has been attempted. A general structure of a pulse tube refrigerator is modified into tandem Stirling-type and GM-type machines and the transformed configuration has been simulated for tandem operation. The simulation results clearly demonstrate that a properly designed tandem-type pulse tube refrigerator without a reservoir can function favorably.

  8. Current Surveys of the Seroprevalence of Borrelia burgdorferi, Ehrlichia canis, Anaplasma phagocytophilum, Leishmania infantum, Babesia canis, Angiostrongylus vasorum and Dirofilaria immitis in Dogs in Bulgaria.

    PubMed

    Pantchev, Nikola; Schnyder, Manuela; Vrhovec, Majda Globokar; Schaper, Roland; Tsachev, Ilia

    2015-08-01

    Canine vector-borne diseases (CVBDs) have increasingly become a focus of interest in recent years. Some of the CVBDs are zoonotic and may therefore also represent a risk for the human population. Different factors are in discussion to explain the expansion of vectors and pathogens into formerly unaffected areas. Knowledge of the prevalence and distribution of CVBDs in Bulgaria is scant overall and most data rely on single case descriptions. The aim of the present study was to determine the seroprevalence of important CVBDs in 167 dogs from central-southern Bulgaria (Stara Zagora), with special emphasis on hitherto uninvestigated babesiosis and angiostrongylosis, on poorly investigated Lyme borreliosis and canine granulocytic anaplasmosis, and on the potentially zoonotic dirofilariosis and leishmaniosis. Relatively high prevalence rates were documented for anti-Babesia canis antibodies, Dirofilaria immitis antigen (16.2 %; 27/167 each), anti-Ehrlichia canis (21 %; 35/167) and anti-Anaplasma phagocytophilum antibodies (30.5 - 46.1 %; 51 - 77/167), while Borrelia burgdorferi seroprevalence was low (2.4 %; 4/167). All samples were negative for Leishmania infantum antibodies and Angiostrongylus vasorum antigen and antibodies. In total, 64.7 % (108/167) of the samples indicated infection or exposure to at least one agent and a high proportion of dual infections (39.8 %; 43/108) was demonstrated. Multiple infections with up to four different organisms were also detected. Our data underline the importance of CVBDs and especially of co-infections which could influence the clinical outcome in dogs.

  9. In silico characterization of three two-component systems of Ehrlichia canis and evaluation of a natural plant-derived inhibitor.

    PubMed

    Santos, E V; Silva, G; Cardozo, G P; Bitencourt, T A; França, S C; Fachin, A L; Marins, M

    2012-10-04

    Two-component signal transduction systems (TCS) are important elements in the interaction of endobacteria with host cells. They are basically composed of two proteins, an environmental signal sensor and a response regulator, which activate genes involved in a wide range of bacterial responses to their environment. We analyzed three sets of genes corresponding to TCS of Ehrlichia canis, a common tick-borne canine pathogen and the etiologic agent of canine monocytic ehrlichiosis, in order to identify the characteristic domains of the sensor and response regulator components. Analysis of sequence alignments of the corresponding proteins indicated a high degree of similarity to other members of the Anaplasmataceae TCS proteins, demonstrating that they could be useful as universal targets for development of new drugs against these bacteria. We also evaluated by quantitative PCR inhibition of E. canis by (2H)-1,4-benzoxazin-3(4H)-one (BOA), the core compound of the plant phenolic compound DIMBOA, which shows inhibitory action against TCS of the phytopathogen Agrobacterium tumefasciens. This bacterium exerts its pathogenicity by transferring oncogenic DNA (T-DNA) into plant cells; this transfer is mediated through a type-IV secretion system, which is regulated by the VirA/VirG TCS. The process of infection and pathogenesis of E. canis is associated with the secretion of effector proteins into the host cell cytoplasm through a T4SS system, which blocks the cell defense response. We suggest that BOA, and possibly other plant phenolic compounds that are TCS inhibitors, can be exploited in the search for new antiehrlichial drugs to be used alone or as complements in the treatment of canine monocytic ehrlichiosis.

  10. Prevention of transmission of Ehrlichia canis by Rhipicephalus sanguineus ticks to dogs treated with a combination of fipronil, amitraz and (S)-methoprene (CERTIFECT®).

    PubMed

    Fourie, Josephus J; Ollagnier, Catherine; Beugnet, Frederic; Luus, Herman G; Jongejan, Frans

    2013-03-31

    The ability of CERTIFECT(®) (a combination of fipronil, amitraz and (S)-methoprene) to prevent transmission of Ehrlichia canis was studied in two groups of eight dogs. One group was treated with CERTIFECT while the other group remained untreated. All dogs were exposed to E. canis-infected Rhipicephalus sanguineus ticks on Days 7, 14, 21 and again on day 28 post-treatment by releasing ticks into the kennels of the dogs to simulate the natural way of infestation. Animals were examined in situ for ticks on Days 9, 16 and 23 and any ticks present were counted and removed on Day 30. The efficacy of CERTIFECT against R. sanguineus was 100%, since no ticks were found on the treated dogs at any time. Clinical examinations (including monitoring body temperature and blood collections for PCR analysis and serology) were performed at intervals throughout the study until Day 56. Five out of 8 untreated control dogs (62.5%) became infected with E. canis, as demonstrated by detection of specific E. canis antibodies and the presence of E. canis DNA in blood samples by PCR. These dogs displayed fever and thrombocytopenia and were rescue-treated with doxycline. None of the 8 dogs treated with CERTIFECT became infected with E. canis, in comparison to the 5/8 control dogs, as confirmed by the lack of specific antibodies and absence of any ehrlichial DNA in blood samples by PCR. CERTIFECT prevented transmission of E. canis and effectively provided protection against monocytic ehrlichiose for at least 4 weeks post treatment.

  11. Comparative Evaluation of the Vector Competence of Four South American Populations of the Rhipicephalus sanguineus Group for the Bacterium Ehrlichia canis, the Agent of Canine Monocytic Ehrlichiosis.

    PubMed

    Moraes-Filho, Jonas; Krawczak, Felipe S; Costa, Francisco B; Soares, João Fábio; Labruna, Marcelo B

    2015-01-01

    This study compared the vector competence of four populations of Rhipicephalus sanguineus group ticks for the bacterium Ehrlichia canis, the agent of canine monocytic ehrlichiosis (CME). Ticks (larvae and nymphs) from the four populations-one from São Paulo state, southeastern Brazil (BSP), one from Rio Grande do Sul state, southern Brazil (BRS), one from Argentina (ARG), and one from Uruguay (URU)-were exposed to E. canis infection by feeding on dogs that were experimentally infected with E. canis. Engorged ticks (larvae and nymphs) were allowed to molt to nymphs and adults, respectively, which were tested by molecular analysis (E. canis-specific PCR assay) and used to infest naïve dogs. Through infestation of adult ticks on naïve dogs, after nymphal acquisition feeding on E. canis-infected dogs, only the BSP population was shown to be competent vectors of E. canis, i.e., only the dogs infested with BSP adult ticks developed clinical illness, seroconverted to E. canis, and yielded E. canis DNA by PCR. This result, demonstrated by two independent replications, is congruent with epidemiological data, since BSP ticks were derived from São Paulo state, Brazil, where CME is highly endemic. On the other hand, BRS, ARG, and URU ticks were derived from a geographical region (South America southern cone) where CME has never been properly documented. Molecular analysis of unfed adults at 30 days post molting support these transmission results, since none of the BRS, ARG, and URU ticks were PCR positive, whereas 1% of the BSP nymphs and 31.8% of the BSP adults contained E. canis DNA. We conclude that the absence or scarcity of cases of CME due to E. canis in the South America southern cone is a result of vector incompetence of the R. sanguineus group ticks that prevail on dogs in this part of South America.

  12. Serological detection of Anaplasma phagocytophilum, Borrelia burgdorferi sensu lato and Ehrlichia canis antibodies and Dirofilaria immitis antigen in a countrywide survey in dogs in Poland.

    PubMed

    Krämer, Friederike; Schaper, Roland; Schunack, Bettina; Połozowski, Andrzej; Piekarska, Jolanta; Szwedko, Aleksandra; Jodies, Robert; Kowalska, Dagmara; Schüpbach, Dörte; Pantchev, Nikola

    2014-09-01

    Canine vector-borne diseases (CVBDs) have increasingly become a focus of attention in the past few years. Nevertheless, in many parts of Europe information on their occurrence is still scarce. In a large study in Poland 3,094 serum samples taken from dogs throughout all 16 Polish provinces were tested using a commercial kit for the detection of circulating antibodies against Anaplasma phagocytophilum, Borrelia burgdorferi sensu lato and Ehrlichia canis and of Dirofilaria immitis antigen. A total of 12.31% (381/3,094; 95% confidence interval [CI]: 11.18-13.52%) and 3.75% (116/3,094; 95% CI: 3.11-4.48%) of the dogs were positive for A. phagocytophilum and B. burgdorferi s.l. antibodies, respectively. Furthermore, 0.26% (8/3,094; 95% CI: 0.11-0.51%) were positive for E. canis antibodies and 0.16% (5/3,094; 95% CI: 0.05-0.38%) for D. immitis antigen. The highest percentages of A. phagocytophilum-positive dogs were noted in Lesser Poland, Silesia and Łódź Provinces. For B. burgdorferi s.l., the highest prevalence was recorded in Łódź Province. Co-infections with A. phagocytophilum and B. burgdorferi s.l. were recorded in 1.71% of all examined dogs (53/3,094; 95% CI: 1.29-2.23%). One dog even had a triple infection, testing positive for E. canis too. Both A. phagocytophilum and B. burgdorferi s.l. have previously been reported in Poland and were confirmed in the present study by positive samples from all 16 provinces. Concerning E. canis and D. immitis travel history or importation cannot be excluded as factors which may have determined the occurrence of these pathogens in the relevant animals. Practitioners in Poland should be aware of the above mentioned CVBDs and of prophylactic measures to protect dogs and their owners.

  13. Development and evaluation of a loop-mediated isothermal amplification assay for detection of Ehrlichia canis DNA in naturally infected dogs using the p30 gene.

    PubMed

    Pinhanelli, V C; Costa, P N M; Silva, G; Aguiar, D M; Silva, C M L; Fachin, A L; Marins, M

    2015-12-22

    Canine monocytic ehrlichiosis (CME) is a common tick-borne disease caused by the rickettsial bacterium Ehrlichia canis (Rickettsiales: Anaplasmataceae). In view of the different stages and variable clinical signs of CME, which can overlap with those of other infections, a conclusive diagnosis can more readily be obtained by combining clinical and hematological evaluations with molecular diagnostic methods. In this study, a loop-mediated isothermal amplification (LAMP) assay targeting the p30 gene of E. canis was developed. The assay was developed using DNA extracted from E. canis-infected cultures of the macrophage cell line DH82 and samples from dogs testing positive for E. canis DNA by PCR. The LAMP assay was compared to a p30-based PCR assay, using DNA extracted from EDTA-anticoagulated blood samples of 137 dogs from an endemic region in Brazil. The LAMP assay was sensitive enough to detect a single copy of the target gene, and identified 74 (54.0%) E. canis DNA-positive samples, while the p30 PCR assay detected 50 positive samples (36.5%) among the field samples. Agreement between the two assays was observed in 42 positive and 55 negative samples. However, 32 positive samples that were not detected by the PCR assay were identified by the LAMP assay, while eight samples identified as E. canis-positive by PCR showed negative results in LAMP. The developed E. canis LAMP assay showed the potential to maximize the use of nucleic acid tests in a veterinary clinical laboratory, and to improve the diagnosis of CME.

  14. Seroprevalence and geographic distribution of Dirofilaria immitis and tick-borne infections (Anaplasma phagocytophilum, Borrelia burgdorferi sensu lato, and Ehrlichia canis) in dogs from Romania.

    PubMed

    Mircean, Viorica; Dumitrache, Mirabela Oana; Györke, Adriana; Pantchev, Nikola; Jodies, Robert; Mihalca, Andrei Daniel; Cozma, Vasile

    2012-07-01

    Tick-borne diseases are of great concern worldwide. Despite this, in Romania there is only limited information regarding the prevalence of vector-borne pathogens in dogs. In all, 1146 serum samples were tested by SNAP(®) 4Dx(®) (IDEXX Laboratories, Inc., Westbrook, ME) for Anaplasma phagocytophilum, Borrelia burgdorferi, and Ehrlichia canis antibodies, and for Dirofilaria immitis antigen. The correlation between positive cases and their geographic distribution, as well as potential risk factors (age, sex, breed, type of dog, habitat, and prophylactic treatments) were evaluated. Overall, 129 dogs (11.3%) were serologically-positive to one or more of the tested pathogens. The seroprevalence for the four infectious agents were: A. phagocytophilum 5.5% (63/1146), D. immitis 3.3% (38/1146), E. canis 2.1% (24/1146), and B. burgdorferi 0.5% (6/1146). Co-infection with E. canis and A. phagocytophilum was registered in 2 dogs (0.2%). The geographical distribution of the seropositive cases suggests clustered foci in southern regions and in the western part of the country for D. immitis, and in the southeastern region (Constanţa County) for E. canis. A. phagocytophilum and B. burgdorferi showed a homogenous distribution, with a tendency for Lyme-positive samples to concentrate in central Romania. For D. immitis, A. phagocytophilum, and E. canis, administering prophylactic treatments was a risk factor associated with infection. Another associated risk factor was the type of dog (stray dogs were at risk being positive for D. immitis, shelter dogs for E. canis, and hunting dogs for B. burgdorferi). The prevalence of D. immitis was significantly higher in males and in dogs older than 2 years. This survey represents the first data detailing A. phagocytophilum and E. canis seroprevalence in Romanian dogs, and the most comprehensive epidemiological study on vector-borne infections in dogs from this country.

  15. Serological survey of Borrelia burgdorferi sensu lato, Anaplasma phagocytophilum, and Ehrlichia canis infections in rural and urban dogs in Central Italy.

    PubMed

    Ebani, Valentina Virginia; Bertelloni, Fabrizio; Torracca, Beatrice; Cerri, Domenico

    2014-01-01

    Borrelia burgdorferi sensu lato (s.l.) and Anaplasma phagocytophilum are well known zoonotic pathogens, whereas Ehrlichia canis is usually considered to be of veterinary concern, although on the basis of recent reports it also seems to be able to infect humans. The aim of the study was to determine the seroprevalence of B. burgdorferi s.l., A. phagocytophilum and E. canis in an Italian canine population, and to verify if there are differences between dogs living in urban areas and those from a rural environment. Blood sera of 1,965 dogs, 1,235 from cities and 730 from rural areas, were tested by indirect immunofluorescent assay (IFAT). The overall seroprevalence was highest for E. canis (7.07%), followed by A. phagocytophilum (4.68%), and B. burgdorferi s.l. (1.47%). Rural dogs showed the highest seroprevalence to B. burgdorferi s.l. and A. phagocytophilum. No significant differences were observed between rural and urban E. canis-positive dogs. A low percentage (1.32%) of dogs with dual seropositivity was detected, and no triple positive reactions were observed. No significant differences were detected in the seroprevalence of the three agents in relationship to the age and gender of the dogs. Seroprevalence in the five years considered were not statistically different, except for the lowest rate for E. canis observed in 2012. The results confirm the presence of B. burgdorferi s.l., A. phagocytophilum and E. canis in Italian dogs in both urban and rural areas. Monitoring pet dogs, which share the same environment with their owners, is useful for identifying the presence of tick-borne disease agents of both veterinary and public health significance.

  16. Comparative Evaluation of the Vector Competence of Four South American Populations of the Rhipicephalus sanguineus Group for the Bacterium Ehrlichia canis, the Agent of Canine Monocytic Ehrlichiosis

    PubMed Central

    Moraes-Filho, Jonas; Krawczak, Felipe S.; Costa, Francisco B.; Soares, João Fábio; Labruna, Marcelo B.

    2015-01-01

    This study compared the vector competence of four populations of Rhipicephalus sanguineus group ticks for the bacterium Ehrlichia canis, the agent of canine monocytic ehrlichiosis (CME). Ticks (larvae and nymphs) from the four populations—one from São Paulo state, southeastern Brazil (BSP), one from Rio Grande do Sul state, southern Brazil (BRS), one from Argentina (ARG), and one from Uruguay (URU)–were exposed to E. canis infection by feeding on dogs that were experimentally infected with E. canis. Engorged ticks (larvae and nymphs) were allowed to molt to nymphs and adults, respectively, which were tested by molecular analysis (E. canis-specific PCR assay) and used to infest naïve dogs. Through infestation of adult ticks on naïve dogs, after nymphal acquisition feeding on E. canis-infected dogs, only the BSP population was shown to be competent vectors of E. canis, i.e., only the dogs infested with BSP adult ticks developed clinical illness, seroconverted to E. canis, and yielded E. canis DNA by PCR. This result, demonstrated by two independent replications, is congruent with epidemiological data, since BSP ticks were derived from São Paulo state, Brazil, where CME is highly endemic. On the other hand, BRS, ARG, and URU ticks were derived from a geographical region (South America southern cone) where CME has never been properly documented. Molecular analysis of unfed adults at 30 days post molting support these transmission results, since none of the BRS, ARG, and URU ticks were PCR positive, whereas 1% of the BSP nymphs and 31.8% of the BSP adults contained E. canis DNA. We conclude that the absence or scarcity of cases of CME due to E. canis in the South America southern cone is a result of vector incompetence of the R. sanguineus group ticks that prevail on dogs in this part of South America. PMID:26414283

  17. Comparative Proteomic Profiling of Ehrlichia ruminantium Pathogenic Strain and Its High-Passaged Attenuated Strain Reveals Virulence and Attenuation-Associated Proteins

    PubMed Central

    Marcelino, Isabel; Ventosa, Miguel; Pires, Elisabete; Müller, Markus; Lisacek, Frédérique; Lefrançois, Thierry; Vachiery, Nathalie; Coelho, Ana Varela

    2015-01-01

    The obligate intracellular bacterium Ehrlichia ruminantium (ER) causes heartwater, a fatal tick-borne disease in livestock. In the field, ER strains present different levels of virulence, limiting vaccine efficacy, for which the molecular basis remains unknown. Moreover, there are no genetic tools currently available for ER manipulation, thus limiting the knowledge of the genes/proteins that are essential for ER pathogenesis and biology. As such, to identify proteins and/or mechanisms involved in ER virulence, we performed the first exhaustive comparative proteomic analysis between a virulent strain (ERGvir) and its high-passaged attenuated strain (ERGatt). Despite their different behaviors in vivo and in vitro, our results from 1DE-nanoLC-MS/MS showed that ERGvir and ERGatt share 80% of their proteins; this core proteome includes chaperones, proteins involved in metabolism, protein-DNA-RNA biosynthesis and processing, and bacterial effectors. Conventional 2DE revealed that 85% of the identified proteins are proteoforms, suggesting that post-translational modifications (namely glycosylation) are important in ER biology. Strain-specific proteins were also identified: while ERGatt has an increased number and overexpression of proteins involved in cell division, metabolism, transport and protein processing, ERGvir shows an overexpression of proteins and proteoforms (DIGE experiments) involved in pathogenesis such as Lpd, AnkA, VirB9 and B10, providing molecular evidence for its increased virulence in vivo and in vitro. Overall, our work reveals that ERGvir and ERGatt proteomes are streamlined to fulfill their biological function (maximum virulence for ERGvir and replicative capacity for ERGatt), and we provide both pioneering data and novel insights into the pathogenesis of this obligate intracellular bacterium. PMID:26691135

  18. Seroprevalence and risk factors associated with Ehrlichia canis, Anaplasma spp., Borrelia burgdorferi sensu lato, and D. immitis in hunting dogs from southern Italy.

    PubMed

    Piantedosi, Diego; Neola, Benedetto; D'Alessio, Nicola; Di Prisco, Francesca; Santoro, Mario; Pacifico, Laura; Sgroi, Giovanni; Auletta, Luigi; Buch, Jesse; Chandrashekar, Ramaswamy; Breitschwerdt, Edward B; Veneziano, Vincenzo

    2017-08-04

    Canine vector-borne diseases (CVBDs) are caused by a range of pathogens transmitted to dogs by arthropods. The present study investigates Ehrlichia canis, Anaplasma spp., Borrelia burgdorferi sensu lato, and Dirofilaria immitis seroprevalences in hunting dogs from southern Italy. Dogs (no. 1335) were tested using a commercial in-clinic enzyme-linked immunosorbent assay kit. Odds ratios (ORs) were calculated by logistic regression analysis to identify risk factors. Overall, 138/1335 dogs (10.3%) were seroreactive to at least one CVBD pathogen. E. canis, Anaplasma spp., B. burgdorferi s.l., and D. immitis seroprevalences were 7.6, 4.4, 0.3, and 0.2%, respectively. E. canis and Anaplasma spp. co-exposures were found in 30 dogs (2.2%), compared with Anaplasma spp. and B. burgdorferi s.l. co-exposures in 2 dogs (0.1%). Adult age was a risk factor for E. canis (OR 2.35) seroreactivity whereas hunting fur-bearing animals for E. canis (OR 4.75) and Anaplasma spp. (OR 1.87), respectively. The historical presence of tick infestation was identified as a risk factor for positivity to E. canis (OR 2.08) and Anaplasma spp. (OR 2.15). Finally, larger dog pack size was significantly associated with E. canis (OR 1.85) and Anaplasma spp. (OR 2.42) exposures. The results of the present survey indicated that hunting dog populations are at relative risk of CVBDs in southern Italy. Further studies are needed to evaluate the role of hunting dogs in the epidemiology of vector-borne organisms due to sharing common environments with wild, sympatric animal populations.

  19. Analysis of 16S rRNA and 51-kilodalton antigen gene and transmission in mice of Ehrlichia risticii in virgulate trematodes from Elimia livescens snails in Ohio.

    PubMed

    Kanter, M; Mott, J; Ohashi, N; Fried, B; Reed, S; Lin, Y C; Rikihisa, Y

    2000-09-01

    Operculate snails (the family Pleuroceridae: Elimia livescens) were collected between June and October 1998 from a river in central Ohio where repeated cases of Potomac horse fever (PHF) have occurred. Of collected snails, consistently 50 to 80% carried a combination of cercariae and sporocysts of digenetic virgulate trematodes. The trematodes obtained from each snail were pooled and tested for Ehrlichia risticii, the agent of PHF, by nested PCR using primers specific to the 16S rRNA gene. Out of a total of 209 trematode pools, 50 pools were found to be positive by PCR. The DNA sequence of the 16S rRNA gene identified in one trematode pool was identical to that of the type strain of E. risticii, and the sequence of the gene identified in another pool differed from that of the type strain by 1 nucleotide. Comparison of the deduced amino acid sequence of the partial 51-kDa antigen gene from various sources revealed that Maryland, Ohio (except Ohio 081), and Kentucky strains are in a cluster distinct from the sequences obtained from sources in California and Oregon. Ohio 081 was shown previously by antigenic composition analysis to be distinct from other groups. However, all sequences examined were not segregated according to their sources: horse blood or infected trematodes. E. risticii was found to be transmittable from trematodes to mice and was subsequently passaged from infected mice to additional mice, as determined by PCR analysis. Our findings suggest the evolution of E. risticii in the natural reservoir in separate geographic regions and persistent infection of trematode populations with E. risticii during summer and early fall. The study also suggests that the mouse can be used to isolate E. risticii from the infected trematode.

  20. Prevalence of Ehrlichia canis, Anaplasma platys, Babesia canis vogeli, Hepatozoon canis, Bartonella vinsonii berkhoffii, and Rickettsia spp. in dogs from Grenada.

    PubMed

    Yabsley, Michael J; McKibben, John; Macpherson, Calum N; Cattan, Peggy F; Cherry, Natalie A; Hegarty, Barbara C; Breitschwerdt, Edward B; O'Connor, Tom; Chandrashekar, Ramaswamy; Paterson, Tara; Perea, Marta Lanza; Ball, Geoffrey; Friesen, Stanley; Goedde, Jill; Henderson, Brooke; Sylvester, Wayne

    2008-02-14

    To identify the tick-borne pathogens in dogs from Grenada, we conducted a serologic survey for Ehrlichia canis in 2004 (104 dogs) and a comprehensive serologic and molecular survey for a variety of tick-borne pathogens in 2006 (73 dogs). In 2004 and 2006, 44 and 32 dogs (42.3% and 43.8%) were seropositive for E. canis, respectively. In 2006, several tick-borne pathogens were identified by serology and PCR. DNA of E. canis, Anaplasma platys, Babesia canis vogeli, Hepatozoon canis, and Bartonella sp. were identified in 18 (24.7%), 14 (19.2%), 5 (7%), 5 (7%), and 1 (1.4%) dogs, respectively. Six (8.2%) dogs were seropositive for Bartonella vinsonii subsp. berkhoffii. All dogs were seronegative and PCR-negative for Rickettsia spp. Coinfection with two or three pathogens was observed in eight dogs. Partial 16S rRNA E. canis and A. platys sequences were identical to sequences in GenBank. Partial 18S rRNA gene sequences from the Grenadian H. canis were identical to each other and had one possible mismatch (ambiguous base) from H. canis detected from Spain and Brazil. Grenadian B. c. vogeli sequences were identical to B. c. vogeli from Brazil and Japan. All of the detected pathogens are transmitted, or suspected to be transmitted, by Rhipicephalus sanguineus. Results of this study indicate that dogs from Grenada are infected with multiple tick-borne pathogens; therefore, tick-borne diseases should be included as differentials for dogs exhibiting thrombocytopenia, leukopenia, fever, or lethargy. One pathogen, E. canis, is also of potential public health significance.

  1. Molecular detection of Anaplasma platys, Ehrlichia canis, Hepatozoon canis and Rickettsia monacensis in dogs from Maio Island of Cape Verde archipelago.

    PubMed

    Lauzi, Stefania; Maia, João P; Epis, Sara; Marcos, Ricardo; Pereira, Cristina; Luzzago, Camilla; Santos, Marta; Puente-Payo, Pablo; Giordano, Alessia; Pajoro, Massimo; Sironi, Giuseppe; Faustino, Augusto

    2016-07-01

    Tick-borne diseases are emerging worldwide and have an important zoonotic relevance. Dogs play an important role in the epidemiology of several zoonotic tick-borne pathogens acting as sentinels and/or reservoirs. This study focused on the molecular identification of tick-borne pathogens in blood samples of 153 autochthonous asymptomatic dogs in Maio Island, Cape Verde archipelago. Eighty-four (54.9%) dogs were positive for one or more pathogens. Fifty-five (35.9%) dogs were infected with Hepatozoon canis, 53 (34.6%) with Anaplasma platys, five (3.3%) with Ehrlichia canis and Rickettsia monacensis, an emerging human pathogen, was also identified in a single dog (0.7%). The former three pathogens cause important canine tick-borne diseases that are transmitted or potentially transmitted by Rhipicephalus sanguineus s.l., the only hard tick identified in Cape Verde. Furthermore, Wolbachia spp. was amplified from the blood of one dog. None of the dogs were positive for Anaplasma phagocytophilum, Borrelia burgdorferi sensu lato, Midichloria mitochondrii, Bartonella spp., Babesia spp. or Theileria spp. Fifty-four (35.3%) animals showed single infections and 30 (19.6%) co-infections, with A. platys and H. canis co-infection being the most frequent (28 dogs, 18.3%). The frequency of E. canis infection was statistically different among age groups (P=0.017), being higher among dogs older than 4 years compared to younger dogs. Infection by A. platys was also statistically different among age groups (P=0.031), being higher in dogs younger than 2 years compared to older dogs. The statistical analyses showed no significant association of PCR positivity with gender or location. The frequency of tick-borne pathogens detected in dogs in Maio Island, including R. monacensis, highlights the need to improve diagnosis and control in order to prevent the risk of transmission of these pathogens among dogs and humans living in or travelling to this touristic island.

  2. Chained and tandem fixed-interval schedules of punishment1

    PubMed Central

    Silverman, Philip J.

    1971-01-01

    Pigeons' key pecks were both punished with electric shock on four-component chained and tandem fixed-interval schedules and reinforced on a variable-interval schedule of food presentation. Pecking was suppressed less in the early components of the chained schedule than in the early components of the tandem schedule. Related multiple and mixed schedules of punishment were also presented; these schedules were identical to the chained and tandem schedules, respectively, except that components changed independently of responding. Similar effects were obtained, in that responding was suppressed in all components of the mixed schedule and only in the fourth component of the multiple schedule of punishment. The performances maintained on the chained and tandem schedules of punishment were generally symmetrical to those found in analogous chained and tandem schedules of food reinforcement. PMID:16811527

  3. The physiological effects of cycling on tandem and single bicycles

    PubMed Central

    Seifert, J; Bacharach, D; Burke, E; Langenfeld, M; Snyder, A

    2003-01-01

    Objective: The purpose of this field study was to compare the physiological responses from cycling on a tandem road bicycle to those from cycling on a single road bicycle. Methods: Nine pairs of experienced, recreational tandem cyclists rode a tandem or their single bicycle for 5 min at each velocity of 19.3, 22.5, 25.8, and 29.0 kph on a flat, paved surface. Heart rate (HR), rating of perceived exertion (RPE), and lactic acid (LA) data were collected after each interval. Results: Riding a tandem resulted in lower HR, RPE, and LA mean values across the four velocities compared to the single bicycle. Mean (SD) HR, RPE, and LA for tandem and single bicycles were 126 (20.7) v 142 (20.1) bpm, 10.1 (1.7) v 11.3 (2.6), and 1.46 (1.0) mM/L v 2.36 (1.7) mM/L, respectively. No position differences were observed between the captain and stoker (front and rear positions) when both were on the tandem. Stokers had significantly lower HR, LA, and RPE values when they rode a tandem compared to a single bicycle. No statistical differences were observed between bicycles for the captains. When on the single bicycle, captains exhibited significantly lower HR, RPE, and LA values than stokers. Conclusion: Cycling on a tandem resulted in lower physiological stress than when cycling at the same velocity on a single bicycle. Cyclists were able to ride from 4.8–8.0 kph faster on a tandem than on a single bicycle at similar physiological stress. Apparently, stokers can add to power output on a tandem without adding significantly to wind resistance. PMID:12547743

  4. Electronic Tandem Language Learning (eTandem): A Third Approach to Second Language Learning for the 21st Century

    ERIC Educational Resources Information Center

    Cziko, Gary A.

    2004-01-01

    Tandem language learning occurs when two learners of different native languages work together to help each other learn the other language. First used in face-to-face contexts, Tandem is now increasingly being used by language-learning partners located in different countries who are linked via various forms of electronic communication, a context…

  5. Axisymmetric Tandem Mirrors: Stabilization and Confinement Studies

    SciTech Connect

    Post, R F; Fowler, T K; Bulmer, R; Byers, J; Hua, D; Tung, L

    2004-07-15

    The 'Kinetic Stabilizer' has been proposed as a means of MHD stabilizing an axisymmetric tandem mirror system. The K-S concept is based on theoretical studies by Ryutov, confirmed experimentally in the Gas Dynamic Trap experiment in Novosibirsk. In the K-S beams of ions are directed into the end of an 'expander' region outside the outer mirror of a tandem mirror. These ions, slowed, stagnated, and reflected as they move up the magnetic gradient, produce a low-density stabilizing plasma. At the Lawrence Livermore National Laboratory we have been conducting theoretical and computational studies of the K-S Tandem Mirror. These studies have employed a low-beta code written especially to analyze the beam injection/stabilization process, and a new code SYMTRAN (by Hua and Fowler) that solves the coupled radial and axial particle and energy transport in a K-S TM. Also, a 'legacy' MHD stability code, FLORA, has been upgraded and employed to benchmark the injection/stabilization code and to extend its results to high beta values. The FLORA code studies so far have confirmed the effectiveness of the K-S in stabilizing high-beta (40%) plasmas with stabilizer plasmas the peak pressures of which are several orders of magnitude smaller than those of the confined plasma. Also the SYMTRAN code has shown D-T plasma ignition from alpha particle energy deposition in T-M regimes with strong end plugging. Our studies have confirmed the viability of the K-S-T-M concept with respect to MHD stability and radial and axial confinement. We are continuing these studies in order to optimize the parameters and to examine means for the stabilization of possible residual instability modes, such as drift modes and 'trapped-particle' modes. These modes may in principle be controlled by tailoring the stabilizer plasma distribution and/or the radial potential distribution. In the paper the results to date of our studies are summarized and projected to scope out possible fusion-power versions of the K

  6. Investigation of tick-borne bacteria (Rickettsia spp., Anaplasma spp., Ehrlichia spp. and Borrelia spp.) in ticks collected from Andean tapirs, cattle and vegetation from a protected area in Ecuador.

    PubMed

    Pesquera, Cristina; Portillo, Aránzazu; Palomar, Ana M; Oteo, José A

    2015-01-24

    Ixodid ticks play an important role in the transmission and ecology of infectious diseases. Information about the circulation of tick-borne bacteria in ticks is lacking in Ecuador. Our aims were to investigate the tick species that parasitize Andean tapirs and cattle, and those present in the vegetation from the buffer zone of the Antisana Ecological Reserve and Cayambe-Coca National Park (Ecuador), and to investigate the presence of tick-borne bacteria. Tick species were identified based on morphologic and genetic criteria. Detection of tick-borne bacteria belonging to Rickettsia, Anaplasma, Ehrlichia and Borrelia genera was performed by PCRs. Our ticks included 91 Amblyomma multipunctum, 4 Amblyomma spp., 60 Rhipicephalus microplus, 5 Ixodes spp. and 1 Ixodes boliviensis. A potential Candidatus Rickettsia species closest to Rickettsia monacensis and Rickettsia tamurae (designated Rickettsia sp. 12G1) was detected in 3 R. microplus (3/57, 5.3%). In addition, Anaplasma spp., assigned at least to Anaplasma phagocytophilum (or closely related genotypes) and Anaplasma marginale, were found in 2 A. multipunctum (2/87, 2.3%) and 13 R. microplus (13/57, 22.8%). This is the first description of Rickettsia sp. in ticks from Ecuador, and the analyses of sequences suggest the presence of a potential novel Rickettsia species. Ecuadorian ticks from Andear tapirs, cattle and vegetation belonging to Amblyomma and Rhipicephalus genera were infected with Anaplasmataceae. Ehrlichia spp. and Borrelia burgdorferi sensu lato were not found in any ticks.

  7. Negative deuterium ions for tandem mirror next step and tandem mirror reactors

    SciTech Connect

    Hamilton, G.W.

    1980-09-25

    Recent designs for mirror fusion reactors with good power balance include ambipolar potential plugs to reduce end losses and thermal barriers to maintain a difference in electron temperature between the large-volume central cell plasma and the confining end plugs. These designs led to several new requirements for D/sup 0/ neutral beams derived from negative ions at energies of 150 to 200 keV and possibly higher. Such beams are required for injection of fat ions into the plugs and the barrier and for charge-exchange pumping of thermal ions diffusing into the barrier. Negative ions are preferred for these purposes because of their relatively high efficiency of neutralization and their high purity of single-energy D/sup -/. Examples of injector designs for Tandem Mirror Next Step (TMNS) and Tandem Mirror Reactors (TMR) are presented.

  8. Prevalence of Tick-Borne Pathogens in Host-Seeking Amblyomma americanum (Acari: Ixodidae) and Odocoileus virginianus (Artiodactyla: Cervidae) in Florida.

    PubMed

    Sayler, Katherine A; Loftis, Amanda D; Beatty, Sarah K; Boyce, Carisa L; Garrison, Elina; Clemons, Bambi; Cunningham, Mark; Alleman, Arthur R; Barbet, Anthony F

    2016-07-01

    Amblyomma americanum (L.), the lone star tick, is an aggressive tick that is expanding its geographic range within the United States. This tick is the vector for the human and veterinary pathogens Ehrlichia chaffeensis and Ehrlichia ewingii and is associated with other microbes of unspecified pathogenicity including Rickettsia amblyommii, Panola Mountain Ehrlichia, and Borrelia lonestari In Florida, there has been sparse contemporary data on the prevalence of these organisms in host-seeking lone star ticks. To determine the prevalence of this tick and associated microbes in North Central Florida state parks, ∼1,500 lone star tick specimens were collected between 2010 and 2012 analyzed by polymerase chain reaction (PCR) sequencing. Additionally, 393 white-tailed deer, Odocoileus virginianus (Zimmerman), samples were analyzed for pathogen prevalence using molecular methods and serology. In lone star ticks, 14.6, 15.6, and 57.1% were positive for E. chaffeensis, E. ewingii, and Rickettsia spp. DNA, respectively. Panola Mountain Ehrlichia or B. lonestari DNA were each detected in nearly 2% of tick specimens. In white-tailed deer, 7.3% were PCR positive for E. chaffeensis, 6.0% for E. ewingii, and 3.2% for rickettsial species. Approximately 45% of white-tailed deer specimens had antibodies to Ehrlichia spp., and <1% had antibodies to Borrelia burgdorferi In summary, E. chaffeensis, E. ewingii, and spotted fever group rickettsia are highly prevalent in host-seeking lone star ticks and in white-tailed deer in Florida. The molecular and serological evidence of these microbes underscore their zoonotic potential in this region. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  9. TMX-U (Tandem Mirror Experiment-Upgrade) tandem-mirror thermal-barrier experiments

    SciTech Connect

    Simonen, T.C.; Allen, S.L.; Baldwin, D.E.; Barter, J.D.; Berzins, L.V.; Carter, M.R.; Casper, T.A.; Clauser, J.F.; Coensgen, F.H.; Correll, D.L.

    1986-10-29

    Thermal-barrier experiments have been carried out in the Tandem Mirror Experiment-Upgrade (TMX-U). Measurements of nonambipolar and ambipolar radial transport show that these transport processes, as well as end losses, can be controlled at modest densities and durations. Central-cell heating methods using ion-cyclotron heating (ICH) and neutral-beam injection have been demonstrated. Potential mesurements with recently developed methods indicate that deep thermal barriers can be established.

  10. Electrospray and tandem mass spectrometry in biochemistry.

    PubMed Central

    Griffiths, W J; Jonsson, A P; Liu, S; Rai, D K; Wang, Y

    2001-01-01

    Over the last 20 years, biological MS has changed out of all recognition. This is primarily due to the development in the 1980s of 'soft ionization' methods that permit the ionization and vaporization of large, polar, and thermally labile biomolecules. These developments in ionization mode have driven the design and manufacture of smaller and cheaper mass analysers, making the mass spectrometer a routine instrument in the biochemistry laboratory today. In the present review the revolutionary 'soft ionization' methods will be discussed with particular reference to electrospray. The mass analysis of ions will be described, and the concept of tandem MS introduced. Where appropriate, examples of the application of MS in biochemistry will be provided. Although the present review will concentrate on the MS of peptides/proteins and lipids, all classes of biomolecules can be analysed, and much excellent work has been done in the fields of carbohydrate and nucleic acid biochemistry. PMID:11311115

  11. Electrospray and tandem mass spectrometry in biochemistry.

    PubMed

    Griffiths, W J; Jonsson, A P; Liu, S; Rai, D K; Wang, Y

    2001-05-01

    Over the last 20 years, biological MS has changed out of all recognition. This is primarily due to the development in the 1980s of 'soft ionization' methods that permit the ionization and vaporization of large, polar, and thermally labile biomolecules. These developments in ionization mode have driven the design and manufacture of smaller and cheaper mass analysers, making the mass spectrometer a routine instrument in the biochemistry laboratory today. In the present review the revolutionary 'soft ionization' methods will be discussed with particular reference to electrospray. The mass analysis of ions will be described, and the concept of tandem MS introduced. Where appropriate, examples of the application of MS in biochemistry will be provided. Although the present review will concentrate on the MS of peptides/proteins and lipids, all classes of biomolecules can be analysed, and much excellent work has been done in the fields of carbohydrate and nucleic acid biochemistry.

  12. Parametric systems analysis for tandem mirror hybrids

    SciTech Connect

    Lee, J.D.; Chapin, D.L.; Chi, J.W.H.

    1980-09-01

    Fusion fission systems, consisting of fissile producing fusion hybrids combining a tandem mirror fusion driver with various blanket types and net fissile consuming LWR's, have been modeled and analyzed parametrically. Analysis to date indicates that hybrids can be competitive with mined uranium when U/sub 3/O/sub 8/ cost is about 100 $/lb., adding less than 25% to present day cost of power from LWR's. Of the three blanket types considered, uranium fast fission (UFF), thorium fast fission (ThFF), and thorium fission supressed (ThFS), the ThFS blanket has a modest economic advantage under most conditions but has higher support ratios and potential safety advantages under all conditions.

  13. Protein Sequencing with Tandem Mass Spectrometry

    NASA Astrophysics Data System (ADS)

    Ziady, Assem G.; Kinter, Michael

    The recent introduction of electrospray ionization techniques that are suitable for peptides and whole proteins has allowed for the design of mass spectrometric protocols that provide accurate sequence information for proteins. The advantages gained by these approaches over traditional Edman Degradation sequencing include faster analysis and femtomole, sometimes attomole, sensitivity. The ability to efficiently identify proteins has allowed investigators to conduct studies on their differential expression or modification in response to various treatments or disease states. In this chapter, we discuss the use of electrospray tandem mass spectrometry, a technique whereby protein-derived peptides are subjected to fragmentation in the gas phase, revealing sequence information for the protein. This powerful technique has been instrumental for the study of proteins and markers associated with various disorders, including heart disease, cancer, and cystic fibrosis. We use the study of protein expression in cystic fibrosis as an example.

  14. A tandem-based compact dual-energy gamma generator.

    PubMed

    Persaud, A; Kwan, J W; Leitner, M; Leung, K-N; Ludewigt, B; Tanaka, N; Waldron, W; Wilde, S; Antolak, A J; Morse, D H; Raber, T

    2010-02-01

    A dual-energy tandem-type gamma generator has been developed at E. O. Lawrence Berkeley National Laboratory and Sandia National Laboratories. The tandem accelerator geometry allows higher energy nuclear reactions to be reached, thereby allowing more flexible generation of MeV-energy gammas for active interrogation applications. Both positively charged ions and atoms of hydrogen are created from negative ions via a gas stripper. In this paper, we show first results of the working tandem-based gamma generator and that a gas stripper can be utilized in a compact source design. Preliminary results of monoenergetic gamma production are shown.

  15. Classroom Tandem--Outlining a Model for Language Learning and Instruction

    ERIC Educational Resources Information Center

    Karjalainen, Katri; Pörn, Michaela; Rusk, Fredrik; Björkskog, Linda

    2013-01-01

    The aim of this paper is to outline classroom tandem by comparing it with informal tandem learning contexts and other language instruction methods. Classroom tandem is used for second language instruction in mixed language groups in the subjects of Finnish and Swedish as L2. Tandem learning entails that two persons with different mother tongues…

  16. 47 CFR 36.124 - Tandem switching equipment-Category 2.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 2 2011-10-01 2011-10-01 false Tandem switching equipment-Category 2. 36.124... Central Office Equipment § 36.124 Tandem switching equipment—Category 2. (a) Tandem switching equipment is contained in Accounts 2210, 2211, and 2212. It includes all switching equipment in a tandem central office...

  17. Serological detection of antibodies to Anaplasma spp., Borrelia burgdorferi sensu lato and Ehrlichia canis and of Dirofilaria immitis antigen in dogs from Costa Rica.

    PubMed

    Montenegro, Víctor M; Bonilla, Marta C; Kaminsky, Darwin; Romero-Zúñiga, Juan José; Siebert, Susanne; Krämer, Friederike

    2017-03-15

    In a study in Costa Rica 314 serum samples from dogs throughout all seven provinces were tested using a commercial kit for the detection of circulating antibodies against Anaplasma spp., Borrelia burgdorferi sensu lato and Ehrlichia canis, and of circulating antigen of Dirofilaria immitis. A total of 6.4% (20/314) and 38.2% (120/314) were positive for Anaplasma spp. (An) and E. canis (Ec) antibodies. Overall, 8.0% (25/314) were positive for D. immitis (Di) antigen. One single dog reacted positive with B. burgdorferi s.l. (Bb) antigen (0.3%, 1/314). E. canis positive dogs were detected in all provinces (highest percentages in Guanacaste, Puntarenas [both significantly different compared to the overall] and Limón). Guanacaste and Puntarenas also showed the highest prevalences of Anaplasma spp. (both significantly different compared to the overall). The highest prevalence of D. immitis was detected in Puntarenas (significantly different compared to the overall). Double pathogen exposure (Ec plus An; Ec plus Di; Ec plus Bb) were recorded in 8.9% (28/314). Two dogs showed a triple pathogen exposure (0.6%, 2/314; An, Ec and Di). There was a significant difference between male (11.5%, 18/156) and female (4.4%, 7/158) animals for D. immitis positive results. There was also a significant difference between breed and no breed dogs regarding the characteristics of a general positive test, as well as seropositivity to the single pathogens of Anaplasma spp., E. canis and D. immitis. Finally there was a significant difference in the presence of clinical signs again regarding the characteristics of a general positive test, as well as seropositivity to Anaplasma spp., E. canis and D. immitis. Practitioners in Costa Rica should be aware of the canine vector-borne diseases mentioned as dogs are at risk of becoming infected. Concerning the positive B. burgdorferi s.l. dog, an autochthonous occurrence cannot be confirmed due to a history of adoption and an unusual tattoo number

  18. Light management of tandem solar cells on nanostructured substrates

    NASA Astrophysics Data System (ADS)

    Chin, Alan H.; Keshavarz, Majid; Wang, Guo; Yu, Rosaline; Niu, Xinwei; Yang, Liyou

    2017-04-01

    We report the use of nanostructured substrates as a simple approach to improve the performance of tandem micromorph silicon solar cells. In the proposed approach, nanostructured substrates are produced using a low-cost, self-assembled growth process. The use of a nanostructured substrate coated with a thick transparent conductive oxide electrode layer enables the conformal deposition of the tandem solar cell absorber layers while allowing the solar cell to exhibit a modified surface morphology caused by the underlying nanostructured morphology. Using this nanostructured substrate approach, we demonstrated a 78% relative enhancement in the conversion efficiency of a tandem micromorph silicon cell on a nanostructured substrate compared to a standard tandem micromorph cell deposited onto a flat substrate.

  19. SYMTRAN - A Time-dependent Symmetric Tandem Mirror Transport Code

    SciTech Connect

    Hua, D; Fowler, T

    2004-06-15

    A time-dependent version of the steady-state radial transport model in symmetric tandem mirrors in Ref. [1] has been coded up and first tests performed. Our code, named SYMTRAN, is an adaptation of the earlier SPHERE code for spheromaks, now modified for tandem mirror physics. Motivated by Post's new concept of kinetic stabilization of symmetric mirrors, it is an extension of the earlier TAMRAC rate-equation code omitting radial transport [2], which successfully accounted for experimental results in TMX. The SYMTRAN code differs from the earlier tandem mirror radial transport code TMT in that our code is focused on axisymmetric tandem mirrors and classical diffusion, whereas TMT emphasized non-ambipolar transport in TMX and MFTF-B due to yin-yang plugs and non-symmetric transitions between the plugs and axisymmetric center cell. Both codes exhibit interesting but different non-linear behavior.

  20. Detailed balance limit of the efficiency of tandem solar cells

    NASA Astrophysics Data System (ADS)

    de Vos, A.

    1980-05-01

    The fundamental (detailed balance) limit of the performance of a tandem structure is presented. The model takes into account the fact that a particular cell is not only illuminated by part of the solar irradiance but also by the electroluminescence of other cells of the set. Whereas under 1 sun irradiance a single solar cell only converts 30% of the solar energy, a tandem structure of two cells can convert 42%, a tandem structure of three cells can convert 49%, etc. Under the highest possible light concentration, these efficiencies are 40% (one cell), 55% (two cells), 63% (three cells), etc. The model also allows one to predict the ideal efficiency of a stack with an infinite number of solar cells. Such a tandem system can convert 68% of the unconcentrated sunlight, and 86% of the concentrated sunlight.

  1. Solar-to-Chemical Energy Conversion with Photoelectrochemical Tandem Cells.

    PubMed

    Sivula, Kevin

    2013-01-01

    Efficiently and inexpensively converting solar energy into chemical fuels is an important goal towards a sustainable energy economy. An integrated tandem cell approach could reasonably convert over 20% of the sun's energy directly into chemical fuels like H2 via water splitting. Many different systems have been investigated using various combinations of photovoltaic cells and photoelectrodes, but in order to be economically competitive with the production of H2 from fossil fuels, a practical water splitting tandem cell must optimize cost, longevity and performance. In this short review, the practical aspects of solar fuel production are considered from the perspective of a semiconductor-based tandem cell and the latest advances with a very promising technology - metal oxide photoelectrochemical tandem cells - are presented.

  2. D STAND DELIVERY END OF #44 TANDEM BREAKDOWN MILL WITH ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    D STAND DELIVERY END OF #44 TANDEM BREAKDOWN MILL WITH UPCOILER. BACKUP ROLLS, 40 TONS. WORK ROLLS, 20 TONS., C. 1900. OPERATING SPEED, 600'/MINUTE. AUTOMATIC GAUGE CONTROL. - American Brass Foundry, 70 Sayre Street, Buffalo, Erie County, NY

  3. Design of tandem mirror reactors with thermal barriers

    SciTech Connect

    Carlson, G.A.

    1980-01-01

    End-plug technologies for tandem mirror reactors include high-field superconducting magnets, neutral beam injectors, and gyrotrons for electron cyclotron resonant heating (ECRH). In addition to their normal use for sustenance of the end-plug plasmas, neutral beam injectors are used for ''pumping'' trapped ions from the thermal barrier regions by charge exchange. An extra function of the axially directed pump beams is the removal of thermalized alpha particles from the reactor. The principles of tandem mirror operation with thermal barriers will be demonstrated in the upgrade of the Tandem Mirror Experiment (TMX-U) in 1981 and the tandem configuration of the Mirror fusion Test Facility (MFTF-B) in 1984.

  4. Plasma-wall interactions in tandem mirror machines

    SciTech Connect

    Allen, S.L.

    1984-11-01

    A description is presented of the plasma-surface interactions in thermal-barrier tandem-mirror machines. The thermal-barrier mode of axial confinement is an integral part of a tandem mirror, and it dictates the required plasma conditions, particularly at the surface of the plasma. For this reason, a qualitative discussion of the thermal barrier is presented first in Section 2. A brief description of the experimental configuration used in tandem mirrors to create the thermal barrier is then examined in detail in Section 3; the TMX-U and MFTF-B machines are used as specific examples. In Section 4, the relevant plasma-surface interaction issues are addressed, and experimental results from currently operating tandom mirror machines are included. Section 5 is both a summary and a discussion of future work concerned with plasma-surface interactions in tandem mirrors.

  5. Monolithic Perovskite Silicon Tandem Solar Cells with Advanced Optics

    SciTech Connect

    Goldschmidt, Jan C.; Bett, Alexander J.; Bivour, Martin; Blasi, Benedikt; Eisenlohr, Johannes; Kohlstadt, Markus; Lee, Seunghun; Mastroianni, Simone; Mundt, Laura; Mundus, Markus; Ndione, Paul; Reichel, Christian; Schubert, Martin; Schulze, Patricia S.; Tucher, Nico; Veit, Clemens; Veurman, Welmoed; Wienands, Karl; Winkler, Kristina; Wurfel, Uli; Glunz, Stefan W.; Hermle, Martin

    2016-11-14

    For high efficiency monolithic perovskite silicon tandem solar cells, we develop low-temperature processes for the perovskite top cell, rear-side light trapping, optimized perovskite growth, transparent contacts and adapted characterization methods.

  6. Tandem wheel drop-legs for standard truck trailer

    NASA Technical Reports Server (NTRS)

    Cantwell, W.; Selstad, R.

    1970-01-01

    Tandem wheel drop-leg device provides a semitrailer with fore and aft mobility that allows it to be moved without a prime mover. The modified drop-legs have trunnion dual wheels and an adjustable brace.

  7. 5. GENERAL VIEW OF UNITEDTOD TWIN TANDEM STEAM ENGINE. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. GENERAL VIEW OF UNITED-TOD TWIN TANDEM STEAM ENGINE. - Republic Iron & Steel Company, Youngstown Works, Blooming Mill & Blooming Mill Engines, North of Poland Avenue, Youngstown, Mahoning County, OH

  8. Engineering problems of tandem-mirror reactors

    SciTech Connect

    Moir, R.W.; Barr, W.L.; Boghosian, B.M.

    1981-10-22

    We have completed a comparative evaluation of several end plug configurations for tandem mirror fusion reactors with thermal barriers. The axi-cell configuration has been selected for further study and will be the basis for a detailed conceptual design study to be carried out over the next two years. The axi-cell end plug has a simple mirror cell produced by two circular coils followed by a transition coil and a yin-yang pair, which provides for MHD stability. This paper discusses some of the many engineering problems facing the designer. We estimated the direct cost to be 2$/W/sub e/. Assuming total (direct and indirect) costs to be twice this number, we need to reduce total costs by factors between 1.7 and 2.3 to compete with future LWRs levelized cost of electricity. These reductions may be possible by designing magnets producing over 20T made possible by use of combinations of superconducting and normal conducting coils as well as improvements in performance and cost of neutral beam and microwave power systems. Scientific and technological understanding and innovation are needed in the area of thermal barrier pumping - a process by which unwanted particles are removed (pumped) from certain regions of velocity and real space in the end plug. Removal of exhaust fuel ions, fusion ash and impurities by action of a halo plasma and plasma dump in the mirror end region is another challenging engineering problem discussed in this paper.

  9. Light Signaling Mechanism of Two Tandem Bacteriophytochromes

    PubMed Central

    Yang, Xiaojing; Stojković, Emina A.; Ozarowski, Wesley B.; Kuk, Jane; Davydova, Erna; Moffat, Keith

    2015-01-01

    RpBphP2 and RpBphP3, two tandem bacteriophytochromes from the photosynthetic bacterium R. palustris, share high sequence identity but exhibit distinct photoconversion behavior. Unlike the canonical RpBphP2, RpBphP3 photoconverts to an unusual nearred-absorbing (Pnr) state; both are required for synthesis of light harvesting complexes under low-light conditions. Here we report the crystal structures of the photosensory core modules of RpBphP2 and RpBphP3. Despite different quaternary structures, RpBphP2 and RpBphP3 adopt nearly identical tertiary structures. The RpBphP3 structure reveals “tongue-and-groove” interactions at the interface between the GAF and PHY domains. A single mutation in the PRxSF motif at the GAF-PHY interface abolishes light-induced formation of the Pnr state in RpBphP3, possibly due to altered structural rigidity of the chromophore-binding pocket. Structural comparisons suggest that long-range signaling involves structural rearrangement of the helical spine at the dimer interface. These structures together with mutational studies provide insights into photoconversion and long-range signaling mechanism in phytochromes. PMID:26095026

  10. Software dependability in the Tandem GUARDIAN system

    NASA Technical Reports Server (NTRS)

    Lee, Inhwan; Iyer, Ravishankar K.

    1995-01-01

    Based on extensive field failure data for Tandem's GUARDIAN operating system this paper discusses evaluation of the dependability of operational software. Software faults considered are major defects that result in processor failures and invoke backup processes to take over. The paper categorizes the underlying causes of software failures and evaluates the effectiveness of the process pair technique in tolerating software faults. A model to describe the impact of software faults on the reliability of an overall system is proposed. The model is used to evaluate the significance of key factors that determine software dependability and to identify areas for improvement. An analysis of the data shows that about 77% of processor failures that are initially considered due to software are confirmed as software problems. The analysis shows that the use of process pairs to provide checkpointing and restart (originally intended for tolerating hardware faults) allows the system to tolerate about 75% of reported software faults that result in processor failures. The loose coupling between processors, which results in the backup execution (the processor state and the sequence of events) being different from the original execution, is a major reason for the measured software fault tolerance. Over two-thirds (72%) of measured software failures are recurrences of previously reported faults. Modeling, based on the data, shows that, in addition to reducing the number of software faults, software dependability can be enhanced by reducing the recurrence rate.

  11. Tandem-mirror technology demonstration facility

    SciTech Connect

    Fowler, T.K.; Logan, B.G.

    1981-09-18

    Preliminary calculations at LLNL indicate that a Technology Demonstration Facility (TDF) consisting of a tandem mirror machine about the size of TMX could begin providing fusion nuclear engineering data as early as 1988. With high density operation based on physics already demonstrated in TMX, this machine would produce 12 MW of DT neutrons in steady-state from a plasma column 0.08 m in radius and 8 m in length. Allowing space for neutral beam injectors at each end of the column, this would permit testing of blanket modules and components at 1 MW/m/sup 2/ neutron wall load over a cylindrical surface 8 m/sup 2/ in area at a radius of 0.25 m; or one could irradiate thousands of small samples at 2 MW/m/sup 2/ at r = 0.125 m (4 m/sup 2/ area). With improved end-plug physics to be tested in TMX-Upgrade in 1982-83, the wall load at 0.25 m could be increased to 2 MW/m/sup 2/ (4 MW/m/sup 2/ at r = 0.125 m). Construction of the TDF could begin in FY84 and be completed in 4 to 5 years, at a cost roughly estimated as $700M in '81 dollars including engineering and 30% contingency.

  12. Transcription of tandemly repetitive DNA: functional roles.

    PubMed

    Biscotti, Maria Assunta; Canapa, Adriana; Forconi, Mariko; Olmo, Ettore; Barucca, Marco

    2015-09-01

    A considerable fraction of the eukaryotic genome is made up of satellite DNA constituted of tandemly repeated sequences. These elements are mainly located at centromeres, pericentromeres, and telomeres and are major components of constitutive heterochromatin. Although originally satellite DNA was thought silent and inert, an increasing number of studies are providing evidence on its transcriptional activity supporting, on the contrary, an unexpected dynamicity. This review summarizes the multiple structural roles of satellite noncoding RNAs at chromosome level. Indeed, satellite noncoding RNAs play a role in the establishment of a heterochromatic state at centromere and telomere. These highly condensed structures are indispensable to preserve chromosome integrity and genome stability, preventing recombination events, and ensuring the correct chromosome pairing and segregation. Moreover, these RNA molecules seem to be involved also in maintaining centromere identity and in elongation, capping, and replication of telomere. Finally, the abnormal variation of centromeric and pericentromeric DNA transcription across major eukaryotic lineages in stress condition and disease has evidenced the critical role that these transcripts may play and the potentially dire consequences for the organism.

  13. X!!Tandem, an Improved Method for Running X!Tandem in Parallel on Collections of Commodity Computers

    PubMed Central

    Bjornson, Robert D.; Carriero, Nicholas J.; Colangelo, Christopher; Shifman, Mark; Cheung, Kei-Hoi; Miller, Perry L.; Williams, Kenneth

    2013-01-01

    The widespread use of mass spectrometry for protein identification has created a demand for computationally efficient methods of matching mass spectrometry data to protein databases. A search using X!Tandem, a popular and representative program, can require hours or days to complete, particularly when missed cleavages and post-translational modifications are considered. Existing techniques for accelerating X!Tandem by employing parallelism are unsatisfactory for a variety of reasons. The paper describes a parallelization of X!Tandem, called X!!Tandem, that shows excellent speedups on commodity hardware and produces the same results as the original program. Furthermore, the parallelization technique used is unusual and potentially useful for parallelizing other complex programs. PMID:17902638

  14. Amblyomma americanum: a potential vector of human ehrlichiosis.

    PubMed

    Anderson, B E; Sims, K G; Olson, J G; Childs, J E; Piesman, J F; Happ, C M; Maupin, G O; Johnson, B J

    1993-08-01

    Polymerase chain reaction primers specific for Ehrlichia chaffeensis were used to amplify DNA from extracts of pooled ticks. Amplification was performed on extracts from 140 pools (1,579 total ticks) consisting of three tick genera collected from five states. The characteristic 389-basepair product was observed after amplification of extracts from seven different pools of adult Amblyomma americanum (117 pools, 1,462 ticks), but not from pools of nymphs. No specific product was observed after amplification of 20 pools (105 ticks) of Dermacentor variabilis and three pools of Ixodes scapularis (12 ticks). Ehrlichia chaffeensis was present in A. americanum at a minimum frequency of > or = 0.48%, suggesting that A. americanum may be a vector of human ehrlichiosis.

  15. Tandem mirror reactors with thermal barriers

    SciTech Connect

    Logan, B.G.; Arfin, B.; Barr, W.L.

    1980-05-23

    Preliminary calculations of Q and magnet designs are presented for three different versions of tandem mirror reactors (TMR) using thermal barriers to enhance plug potentials by auxiliary electron heating. These three versions, called A-cell-barrier TMR, axisymmetric-barrier TMR, and inside-barrier TMR, exhibit reduced plug density (n/sub p/ << 10/sup 19/ m/sup -3/) and less required magnetic mirror field (B/sub mirror approx. = 9 T) compared to TMR designs without thermal barriers. A-cell barrier TMR Q's range from 5 to 25 depending on the central-cell length (L/sub c/ = 100 to 200 m) and peak center-cell beta ..beta../sub c/ (0.3 to 0.7) allowed by MHD stability. Axisymmetric-barrier TMR Q's range from 14 at L/sub c/ = 100 m to 30 at L/sub c/ = 200 m, if peak ..beta../sub c/ = 1. From a global equilibrium model for the inside-barrier TMR, Q values greater than 15 are achieved for ..nu.. = 0.5 in the modified Boltzmann relation for the plug potential. Even higher Q's are obtained using ECRF heating in the barrier to create a hot, mirror-trapped electron population. TMR's burning D-D as a fuel have been analyzed with a modified version of the global equilibrium model and under the assumption of an axisymmetric plug and barrier stabilized by surface magnetic fields. High-barrier mirror ratio is now feasible (R/sub b/ = 30-50), and short barrier length permits Q/sub DD/ values greater than 5.

  16. Parallel Tandems of Dye Sensitized Solar Cells with CNT Collector

    NASA Astrophysics Data System (ADS)

    Velten, Josef; Yuan, Chao-Chen; Zakhidov, Anvar

    2009-03-01

    In this presentation, we demonstrate the fabrication of monolithic parallel tandem dye sensitized solar cells using a semitransparent layer of carbon nanotubes. Each DSC sub-cell has titania photoelectrode with two different dyes: N 719 and N 749, which absorb light in different parts of solar spectrum. This layer of carbon nanotubes laminated on highly porous polymeric Millipore filter acts as both the collector of charge carrier and as the catalyst of the I/I3^- redox reaction that completes the function of the cell, overall allowing easier fabrication for tandem solar cell devices, with a potential for creating flexible devices in the future. The parallel tandem shows the total photocurrent which is nearly the sum of two Isc currents of constituent cells, and total Voc, which is average of two Voc, while conventional in-series DSC tandems show the lowest Voc and slightly increased Isc[1]. Thus the higher efficiency can be achieved in parallel DSC tandems, and we discuss the physical reasons for this effect. [1] Yanagida, et.al. J. of Photochemistry and Photobiology A: Chemistry Volume 164, Issues 1-3, 1 June 2004, Pages 33-39

  17. Cooperative cell motility during tandem locomotion of amoeboid cells

    PubMed Central

    Bastounis, Effie; Álvarez-González, Begoña; del Álamo, Juan C.; Lasheras, Juan C.; Firtel, Richard A.

    2016-01-01

    Streams of migratory cells are initiated by the formation of tandem pairs of cells connected head to tail to which other cells subsequently adhere. The mechanisms regulating the transition from single to streaming cell migration remain elusive, although several molecules have been suggested to be involved. In this work, we investigate the mechanics of the locomotion of Dictyostelium tandem pairs by analyzing the spatiotemporal evolution of their traction adhesions (TAs). We find that in migrating wild-type tandem pairs, each cell exerts traction forces on stationary sites (∼80% of the time), and the trailing cell reuses the location of the TAs of the leading cell. Both leading and trailing cells form contractile dipoles and synchronize the formation of new frontal TAs with ∼54-s time delay. Cells not expressing the lectin discoidin I or moving on discoidin I–coated substrata form fewer tandems, but the trailing cell still reuses the locations of the TAs of the leading cell, suggesting that discoidin I is not responsible for a possible chemically driven synchronization process. The migration dynamics of the tandems indicate that their TAs’ reuse results from the mechanical synchronization of the leading and trailing cells’ protrusions and retractions (motility cycles) aided by the cell–cell adhesions. PMID:26912787

  18. High-Efficiency Polycrystalline Thin Film Tandem Solar Cells.

    PubMed

    Kranz, Lukas; Abate, Antonio; Feurer, Thomas; Fu, Fan; Avancini, Enrico; Löckinger, Johannes; Reinhard, Patrick; Zakeeruddin, Shaik M; Grätzel, Michael; Buecheler, Stephan; Tiwari, Ayodhya N

    2015-07-16

    A promising way to enhance the efficiency of CIGS solar cells is by combining them with perovskite solar cells in tandem devices. However, so far, such tandem devices had limited efficiency due to challenges in developing NIR-transparent perovskite top cells, which allow photons with energy below the perovskite band gap to be transmitted to the bottom cell. Here, a process for the fabrication of NIR-transparent perovskite solar cells is presented, which enables power conversion efficiencies up to 12.1% combined with an average sub-band gap transmission of 71% for photons with wavelength between 800 and 1000 nm. The combination of a NIR-transparent perovskite top cell with a CIGS bottom cell enabled a tandem device with 19.5% efficiency, which is the highest reported efficiency for a polycrystalline thin film tandem solar cell. Future developments of perovskite/CIGS tandem devices are discussed and prospects for devices with efficiency toward and above 27% are given.

  19. The design and numerical analysis of tandem thermophotovoltaic cells

    NASA Astrophysics Data System (ADS)

    Yang, Hao-Yu; Liu, Ren-Jun; Wang, Lian-Kai; Lü, You; Li, Tian-Tian; Li, Guo-Xing; Zhang, Yuan-Tao; Zhang, Bao-Lin

    2013-10-01

    In this paper, numerical analysis of GaSb =(Eg = 0.72 eV)/Ga0.84In0.16As0.14Sb0.86 (Eg = 0.53 eV) tandem thermophotovoltaic (TPV) cells is carried out by using Silvaco/Atlas software. In the tandem cells, a GaSb p-n homojunction is used for the top cell and a GaInAsSb p-n homojunction for the bottom cell. A heavily doped GaSb tunnel junction connects the two sub-cells together. The simulations are carried out at a radiator temperature of 2000 K and a cell temperature of 300 K. The radiation photons are injected from the top of the tandem cells. Key properties of the single- and dual-junction TPV cells, including I-V characteristic, maximum output power (Pmax), open-circuit voltage (Voc), short-circuit current (Isc), etc. are presented. The effects of the sub-cell thickness and carrier concentration on the key properties of tandem cells are investigated. A comparison of the dual-TPV cells with GaSb and GaInAsSb single junction cells shows that the Pmax of tandem cells is almost twice as great as that of the single-junction cells.

  20. Test of the Tandem transmission at low terminal voltages

    SciTech Connect

    Rehm, K.E.; Blumenthal, D.; Gehring, J.

    1995-08-01

    For a planned experiment with {sup 18}F beams at energies below 1 MeV/u the transmission of the Tandem-Linac system was investigated. The energies required in the experiment are typically around 600 keV/u, which for the most abundant charge states for F(4{sup +}) corresponds to terminal voltages between 2-3 MV. We studied the transmission from the source to the tandem accelerator and to the spectrograph in area II with {sup 18}O and {sup 19}F beams using two different approaches. In the first method only the tandem accelerator was used producing a 14-MeV DC {sup 18}O beam. In the second method a pulsed beam was accelerated to 33 MeV with the tandem accelerator followed by deceleration to 14 MeV with the first 9 resonators of ATLAS. The total transmission from ion source to target was in both cases about 10%. Because of the smaller complexity we used the first method for the {sup 18}F experiment. In future runs we are planning to use the electrostatic lens in the terminal of the tandem to improve the overall transmission.

  1. Design of a new tandem wings hybrid airship

    NASA Astrophysics Data System (ADS)

    Li, Feng; Ye, ZhengYin; Gao, Chao

    2012-10-01

    It is scientifically important science value and engineering promising to develop the buoyancy-lift integrated hybrid airship for high attitude platform. Through the numerical method, a new tandem wings hybrid airship with both higher utility value and economy efficiency was obtained and its total performance and technical parameters were analyzed in detail. In order to further improve the lift-drag characteristics, we implemented the optimization design for aerodynamic configuration of tandem wings hybrid airship via the response surface method. The results indicate that the tandem wings hybrid airship has considerable volume efficiency and higher aerodynamic characteristics. After optimization, the lift-drag ratio of this hybrid airship was increased by 6.08%. In a given gross lift condition, tandem wings hybrid airship may provide more payload and specific productivity. Furthermore, the size of tandem airship is smaller so the demand for skin flexible materials can be reduced. Results of this study could serve as a new approach to designing buoyancy-lifting integrated hybrid airship.

  2. The Tandem-ALPI-PIAVE accelerator complex of LNL

    SciTech Connect

    Ur, C. A.

    2013-07-18

    Heavy ion beams are delivered at the Laboratori Nazionali di Legnaro by the accelerator complex Tandem-ALPI-PIAVE. The Tandem XTU is a Van de Graaff accelerator normally operated at terminal voltages of up to about 15 MV. The Tandem accelerator can be operated in stand-alone mode or as an injector for the linac booster ALPI. The linear accelerator ALPI is built of superconducting resonant cavities and consists of a low-beta branch, particularly important for the acceleration of the heavier mass ions, a medium-beta branch, and a high-beta branch. ALPI can be operated also with the PIAVE injector that consists of a superconducting linac and an ECR source. The PIAVE source was mainly used for the acceleration of intense noble gas beams but most recently also a first metallic beam was delivered to the users. The accelerator complex delivers beams of ions from protons to gold in three experimental areas on 11 different beam lines. A rich scientific activity is ongoing at the Tandem-ALPI-PIAVE accelerator complex, beam time being shared between nuclear physics research and applied and interdisciplinary physics research. An overview of the present status and perspectives of the Tandem-ALPI-PIAVE complex and its physics program is given in the present paper.

  3. TassDB: a database of alternative tandem splice sites.

    PubMed

    Hiller, Michael; Nikolajewa, Swetlana; Huse, Klaus; Szafranski, Karol; Rosenstiel, Philip; Schuster, Stefan; Backofen, Rolf; Platzer, Matthias

    2007-01-01

    Subtle alternative splice events at tandem splice sites are frequent in eukaryotes and substantially increase the complexity of transcriptomes and proteomes. We have developed a relational database, TassDB (TAndem Splice Site DataBase), which stores extensive data about alternative splice events at GYNGYN donors and NAGNAG acceptors. These splice events are of subtle nature since they mostly result in the insertion/deletion of a single amino acid or the substitution of one amino acid by two others. Currently, TassDB contains 114 554 tandem splice sites of eight species, 5209 of which have EST/mRNA evidence for alternative splicing. In addition, human SNPs that affect NAGNAG acceptors are annotated. The database provides a user-friendly interface to search for specific genes or for genes containing tandem splice sites with specific features as well as the possibility to download large datasets. This database should facilitate further experimental studies and large-scale bioinformatics analyses of tandem splice sites. The database is available at http://helios.informatik.uni-freiburg.de/TassDB/.

  4. Selection against tandem splice sites affecting structured protein regions.

    PubMed

    Hiller, Michael; Szafranski, Karol; Huse, Klaus; Backofen, Rolf; Platzer, Matthias

    2008-03-21

    Alternative selection of splice sites in tandem donors and acceptors is a major mode of alternative splicing. Here, we analyzed whether in-frame tandem sites leading to subtle mRNA insertions/deletions of 3, 6, or 9 nucleotides are under natural selection. We found multiple lines of evidence that the human protein coding sequences are under selection against such in-frame tandem splice events, indicating that these events are often deleterious. The strength of selection is not homogeneous within the coding sequence as protein regions that fold into a fixed 3D structure (intrinsically ordered) are under stronger selection, especially against sites with a strong minor splice site. Investigating structures of functional protein domains, we found that tandem acceptors are preferentially located at the domain surface and outside structural elements such as helices and sheets. Using three-species comparisons, we estimate that more than half of all mutations that create NAGNAG acceptors in the coding region have been eliminated by selection. We estimate that ~2,400 introns are under selection against possessing a tandem site.

  5. Advanced System for Worldwide Surveillance of Rickettsial Disease Antibodies. Phase 1

    DTIC Science & Technology

    1996-10-01

    includes several arthropod-borne, obligately intracell- ular bacteria (including the genera Rickettsia , Orientia, Coxiella, and Ehrlichia) which are...Edlinger, A. D. Waddell, and M. R. Jones. 1976. Infec- tion cycle of Rickettsia rickettsii in chicken embryo and L-929 cells in culture. Infect. Immun. 14...NUMBER SPECIFICITY E. CHAFFEENSIS HGE RR- 1 Rickettsia rickettsii 0 0 RC- 1 Rickettsia conorii 0 4 RT-1 Rickettsia typhi 0 0 OTs- 1 Orientia tsutsugamushi

  6. Disease agents in Amblyomma americanum from northeastern Georgia.

    PubMed

    Varela, A S; Moore, V A; Little, S E

    2004-07-01

    Amblyomma americanum (lone star tick) is known or suspected to vector several organisms that are implicated as human pathogens, including Ehrlichia chaffeensis, E. ewingii, and Borrelia lonestari. These three agents have also been detected in white-tailed deer (Odocoileus virginianus). Because northeastern Georgia has a high abundance of both lone star ticks and white-tailed deer, and one of these organisms, E. chaffeensis, is already known to be endemic in the area, we assayed individual adult A. americanum, collected during the spring of 2001, 2002, and 2003, for these three organisms. A total of 400 ticks were dissected and tissues assayed by polymerase chain reaction (PCR) using Ehrlichia species-specific and Borrelia genus-wide primers. Of ticks tested, 2.0% (8/398) had evidence of E. chaffeensis, 4.8% (19/398) had evidence of E. ewingii, and 1.0% (4/398) had evidence of B. lonestari. Borrelia sp. spirochetes were also visualized by an indirect fluorescent antibody test, using an anti-flagellin monoclonal antibody (H9724), in a total of 10.7% (32/300) of ticks tested in 2003. These results reconfirm the presence of E. chaffeensis and establish evidence of E. ewingii and B. lonestari in questing adult A. americanum ticks from northeastern Georgia. Detection of at least two of the three organisms in ticks collected each year suggests that people in northeastern Georgia are at risk of infection with these organisms.

  7. The query execution engine in Tandem`s new ServerWare SQL product

    SciTech Connect

    Celis, P.; Zeller, H.

    1996-12-31

    Tandem has re-written its SQL compiler and its query execution engine into a new product that will be available on multiple operating systems. The new product uses a novel query execution engine and we will highlight the unique aspects of the new engine. ServerWare SQL uses a data flow and scheduler driven task model to execute queries. Tasks communicate either via in-memory queues or via interprocess communication. Partitioned, pipelined, or independent operations are executed in parallel. By adding new task types the model can be easily extended. Parallelism in a distributed memory environment is implemented as a special {open_quotes}Exchange{close_quotes} task type, as in the Volcano research prototype. Scheduling and load balancing are performed by separate scheduler tasks.

  8. Counter-Rotating Tandem Motor Drilling System

    SciTech Connect

    Kent Perry

    2009-04-30

    Gas Technology Institute (GTI), in partnership with Dennis Tool Company (DTC), has worked to develop an advanced drill bit system to be used with microhole drilling assemblies. One of the main objectives of this project was to utilize new and existing coiled tubing and slimhole drilling technologies to develop Microhole Technology (MHT) so as to make significant reductions in the cost of E&P down to 5000 feet in wellbores as small as 3.5 inches in diameter. This new technology was developed to work toward the DOE's goal of enabling domestic shallow oil and gas wells to be drilled inexpensively compared to wells drilled utilizing conventional drilling practices. Overall drilling costs can be lowered by drilling a well as quickly as possible. For this reason, a high drilling rate of penetration is always desired. In general, high drilling rates of penetration (ROP) can be achieved by increasing the weight on bit and increasing the rotary speed of the bit. As the weight on bit is increased, the cutting inserts penetrate deeper into the rock, resulting in a deeper depth of cut. As the depth of cut increases, the amount of torque required to turn the bit also increases. The Counter-Rotating Tandem Motor Drilling System (CRTMDS) was planned to achieve high rate of penetration (ROP) resulting in the reduction of the drilling cost. The system includes two counter-rotating cutter systems to reduce or eliminate the reactive torque the drillpipe or coiled tubing must resist. This would allow the application of maximum weight-on-bit and rotational velocities that a coiled tubing drilling unit is capable of delivering. Several variations of the CRTDMS were designed, manufactured and tested. The original tests failed leading to design modifications. Two versions of the modified system were tested and showed that the concept is both positive and practical; however, the tests showed that for the system to be robust and durable, borehole diameter should be substantially larger than

  9. Identifying tandem Ankyrin repeats in protein structures.

    PubMed

    Chakrabarty, Broto; Parekh, Nita

    2014-12-30

    Tandem repetition of structural motifs in proteins is frequently observed across all forms of life. Topology of repeating unit and its frequency of occurrence are associated to a wide range of structural and functional roles in diverse proteins, and defects in repeat proteins have been associated with a number of diseases. It is thus desirable to accurately identify specific repeat type and its copy number. Weak evolutionary constraints on repeat units and insertions/deletions between them make their identification difficult at the sequence level and structure based approaches are desired. The proposed graph spectral approach is based on protein structure represented as a graph for detecting one of the most frequently observed structural repeats, Ankyrin repeat. It has been shown in a large number of studies that 3-dimensional topology of a protein structure is well captured by a graph, making it possible to analyze a complex protein structure as a mathematical entity. In this study we show that eigen spectra profile of a protein structure graph exhibits a unique repetitive profile for contiguous repeating units enabling the detection of the repeat region and the repeat type. The proposed approach uses a non-redundant set of 58 Ankyrin proteins to define rules for the detection of Ankyrin repeat motifs. It is evaluated on a set of 370 proteins comprising 125 known Ankyrin proteins and remaining non-solenoid proteins and the prediction compared with UniProt annotation, sequence-based approach, RADAR, and structure-based approach, ConSole. To show the efficacy of the approach, we analyzed the complete PDB structural database and identified 641 previously unrecognized Ankyrin repeat proteins. We observe a unique eigen spectra profile for different repeat types and show that the method can be easily extended to detect other repeat types. It is implemented as a web server, AnkPred. It is freely available at 'bioinf.iiit.ac.in/AnkPred'. AnkPred provides an elegant and

  10. Dosimetric Comparison of Tandem and Ovoids vs. Tandem and Ring for Intracavitary Gynecologic Applications

    SciTech Connect

    Levin, Daphne Menhel, Janna; Rabin, Tanya; Pfeffer, M. Raphael; Symon, Zvi

    2008-01-01

    We evaluated dosimetric differences in tandem and ovoid (TO) and tandem and ring (TR) gynecologic brachytherapy applicators. Seventeen patients with cervical cancer (Stages II-IV) receiving 3 high-dose-rate (HDR) brachytherapy applications (both TO and TR) were studied. Patients underwent computed tomography (CT) scans with contrast in bladder, and were prescribed 8 Gy to ICRU points A, with additional optimization goals of maintaining the pear-shaped dose distribution and minimizing bladder and rectum doses. Bladder and rectum point doses, mean, and maximum doses were calculated. Total treatment time and volumes treated to 95%, 85%, 50%, and 20% or the prescription dose were compared. There were no significant differences between TO and TR applicators in doses to prescription points or critical organs. However, there were significant differences (p < 0.001) between the applicators in treated volumes and total treatment time. The TO treated larger volumes over a longer time. Within each patient, when the applicators were compared, treated volumes were also found to be significantly different (p < 0.01, {chi}{sup 2}). Our results demonstrate that the 2 applicators, while delivering the prescribed dose to points A and keeping critical organ doses below tolerance, treat significantly different volumes. It is unclear if this difference is clinically meaningful. TO applicators may be treating surrounding healthy tissue unnecessarily, or TR applicators may be underdosing tumor tissue. Further investigation with appropriate imaging modalities is required for accurate delineation of target volumes. Clearly, the TO and TR are not identical, and should not be used interchangeably without further study.

  11. A new optically pumped tandem magnetometer: principles and experiences

    NASA Astrophysics Data System (ADS)

    Pulz, E.; Jäckel, K.-H.; Linthe, H.-J.

    1999-11-01

    In this paper we describe a new design for an optically pumped tandem magnetometer situated at the GeoForschungsZentrum Potsdam. A tandem magnetometer combines the fast response of a self-oscillating vapour magnetometer with the accuracy of a narrow line Mz-type magnetometer. A newly patented method of coupling the two sensors avoids any stray magnetic fields and so allows a compact design of the instrument itself, as well as facilitating its operation in close proximity to other magnetometers. A prototype Cs-K tandem magnetometer for use in magnetic observatories is described. We then show typical results of a long-term comparison with both a second type of optically pumped magnetometer and an Overhauser proton magnetometer. Finally, a resuméis given of four years of continuous operation of this new type of magnetometer with respect to the data quality produced and its operational reliability.

  12. High efficiency all-polymer tandem solar cells

    PubMed Central

    Yuan, Jianyu; Gu, Jinan; Shi, Guozheng; Sun, Jianxia; Wang, Hai-Qiao; Ma, Wanli

    2016-01-01

    In this work, we have reported for the first time an efficient all-polymer tandem cell using identical sub-cells based on P2F-DO:N2200. A high power conversion efficiency (PCE) of 6.70% was achieved, which is among the highest efficiencies for all polymer solar cells and 43% larger than the PCE of single junction cell. The largely improved device performance can be mainly attributed to the enhanced absorption of tandem cell. Meanwhile, the carrier collection in device remains efficient by optimizing the recombination layer and sub-cell film thickness. Thus tandem structure can become an easy approach to effectively boost the performance of current all polymer solar cells. PMID:27226354

  13. A tandem mirror plasma source for hybrid plume plasma studies

    NASA Technical Reports Server (NTRS)

    Yang, T. F.; Chang, F. R.; Miller, R. H.; Wenzel, K. W.; Krueger, W. A.

    1985-01-01

    A tandem mirror device to be considered as a hot plasma source for the hybrid plume rocket concept is discussed. The hot plamsa from this device is injected into an exhaust duct, which will interact with an annular hypersonic layer of neutral gas. The device can be used to study the dynamics of the hybrid plume, and to verify the numerical predictions obtained with computer codes. The basic system design is also geared towards low weight and compactness, and high power density at the exhaust. The basic structure of the device consists of four major subsystems: (1) an electric power supply; (2) a low temperature, high density plasma gun, such as a stream gun, an MPD source or gas cell; (3) a power booster in the form of a tandem mirror machine; and (4) an exhaust nozzle arrangement. The configuration of the tandem mirror section is shown.

  14. Tandem repeat distribution of gene transcripts in three plant families

    PubMed Central

    2009-01-01

    Tandem repeats (microsatellites or SSRs) are molecular markers with great potential for plant genetic studies. Modern strategies include the transfer of these markers among widely studied and orphan species. In silico analyses allow for studying distribution patterns of microsatellites and predicting which motifs would be more amenable to interspecies transfer. Transcribed sequences (Unigene) from ten species of three plant families were surveyed for the occurrence of micro and minisatellites. Transcripts from different species displayed different rates of tandem repeat occurrence, ranging from 1.47% to 11.28%. Both similar and different patterns were found within and among plant families. The results also indicate a lack of association between genome size and tandem repeat fractions in expressed regions. The conservation of motifs among species and its implication on genome evolution and dynamics are discussed. PMID:21637460

  15. Structural analysis of a multifunctional, tandemly repeated inositol polyphosphatase.

    PubMed

    Gruninger, Robert J; Selinger, L Brent; Mosimann, Steven C

    2009-09-11

    Mitsuokella multacida expresses a unique inositol polyphosphatase (PhyAmm) that is composed of tandem repeats (TRs). Each repeat possesses a protein tyrosine phosphatase (PTP) active-site signature sequence and fold. Using a combination of structural, mutational, and kinetic studies, we show that the N-terminal (D1) and C-terminal (D2) active sites of the TR have diverged and possess significantly different specificities for inositol polyphosphate. Structural analysis and molecular docking calculations identify steric and electrostatic differences within the substrate binding pocket of each TR that may be involved in the altered substrate specificity. The implications of our results for the biological function of related PTP-like phytases are discussed. Finally, the structures and activities of PhyAmm and tandemly repeated receptor PTPs are compared and discussed. To our knowledge, this is the first example of an inositol phosphatase with tandem PTP domains possessing substrate specificity for different inositol phosphates.

  16. A periodic table of symmetric tandem mismatches in RNA.

    PubMed

    Wu, M; McDowell, J A; Turner, D H

    1995-03-14

    The stabilities and structures of a series of RNA octamers containing symmetric tandem mismatches were studied by UV melting and imino proton NMR. The free energy increments for tandem mismatch formation are found to depend upon both mismatch sequence and adjacent base pairs. The observed sequence dependence of tandem mismatch stability is UGGU > GUUG > GAAG > or = AGGA > UUUU > CAAC > or = CUUC approximately UCCU approximately CCCC approximately ACCA approximately AAAA, and the closing base pair dependence is 5'G3'C > 5'C3'G > 5'U3'A approximately 5'A3'U. These results differ from expectations based on models used in RNA folding algorithms and from the sequence dependence observed for folding of RNA hairpins. Imino proton NMR results indicate the sequence dependence is partially due to hydrogen bonding within mismatches.

  17. A tandem mirror hybrid plume plasma propulsion facility

    NASA Technical Reports Server (NTRS)

    Yang, T. F.; Krueger, W. A.; Peng, S.; Urbahn, J.; Chang-Diaz, F. R.

    1988-01-01

    This paper discusses a novel concept in electrodeless plasma propulsion, in which the materials problems are ameliorated by an electrodeless magnetic confinement scheme borrowed from the tandem mirror approach to controlled thermonuclear fusion. The concept also features a two-stage magnetic nozzle with an annular hypersonic coaxial gas injector near the throat. The nozzle produces hybrid plume by the coaxial injection of hypersonic neutral gas, and the gas layer thus formed protects the material walls from the hot plasma and, through increased collisions, helps detach it from the diverging magnetic field. The tandem mirror plasma propulsion facility is capable of delivering a variable I(sp). The results of numerical simulation of this concept are presented together with those from an experimental tandem-mirror plasma propulsion device.

  18. Overall Photoelectrochemical Water Splitting using Tandem Cell under Simulated Sunlight.

    PubMed

    Kim, Jin Hyun; Kaneko, Hiroyuki; Minegishi, Tsutomu; Kubota, Jun; Domen, Kazunari; Lee, Jae Sung

    2016-01-08

    A stand-alone photoelectrochemical (PEC) water-splitting system driven only by sunlight was demonstrated with a tandem-scheme of Pt/CdS/CuGa3 Se5 /(Ag,Cu)GaSe2 photocathode and NiOOH/FeOOH/Mo:BiVO4 photoanode in a neutral phosphate buffer solution as an electrolyte. The as-prepared semi-transparent Mo:BiVO4 layer allows sunlight to pass through the top photoanode and reach the bottom photocathode. Consequently, the tandem cell showed stoichiometric hydrogen and oxygen evolution with a solar-to-hydrogen (STH) conversion efficiency of 0.67 % over 2 h without degradation. The stability and STH efficiency are the highest among similar configuration of PEC tandem cells. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Tandem photovoltaic solar cells and increased solar energy conversion efficiency

    NASA Technical Reports Server (NTRS)

    Loferski, J. J.

    1976-01-01

    Tandem photovoltaic cells, as proposed by Jackson (1955) to increase the efficiency of solar energy conversion, involve the construction of a system of stacked p/n homojunction photovoltaic cells composed of different semiconductors. It had been pointed out by critics, however, that the total power which could be extracted from the cells in the stack placed side by side was substantially greater than the power obtained from the stacked cells. A reexamination of the tandem cell concept in view of the development of the past few years is conducted. It is concluded that the use of tandem cell systems in flat plate collectors, as originally envisioned by Jackson, may yet become feasible as a result of the development of economically acceptable solar cells for large scale terrestrial power generation.

  20. Tandem photovoltaic solar cells and increased solar energy conversion efficiency

    NASA Technical Reports Server (NTRS)

    Loferski, J. J.

    1976-01-01

    Tandem photovoltaic cells, as proposed by Jackson (1955) to increase the efficiency of solar energy conversion, involve the construction of a system of stacked p/n homojunction photovoltaic cells composed of different semiconductors. It had been pointed out by critics, however, that the total power which could be extracted from the cells in the stack placed side by side was substantially greater than the power obtained from the stacked cells. A reexamination of the tandem cell concept in view of the development of the past few years is conducted. It is concluded that the use of tandem cell systems in flat plate collectors, as originally envisioned by Jackson, may yet become feasible as a result of the development of economically acceptable solar cells for large scale terrestrial power generation.

  1. mreps: efficient and flexible detection of tandem repeats in DNA

    PubMed Central

    Kolpakov, Roman; Bana, Ghizlane; Kucherov, Gregory

    2003-01-01

    The presence of repeated sequences is a fundamental feature of genomes. Tandemly repeated DNA appears in both eukaryotic and prokaryotic genomes, it is associated with various regulatory mechanisms and plays an important role in genomic fingerprinting. In this paper, we describe mreps, a powerful software tool for a fast identification of tandemly repeated structures in DNA sequences. mreps is able to identify all types of tandem repeats within a single run on a whole genomic sequence. It has a resolution parameter that allows the program to identify ‘fuzzy’ repeats. We introduce main algorithmic solutions behind mreps, describe its usage, give some execution time benchmarks and present several case studies to illustrate its capabilities. The mreps web interface is accessible through http://www.loria.fr/mreps/. PMID:12824391

  2. A tandem mirror plasma source for hybrid plume plasma studies

    NASA Technical Reports Server (NTRS)

    Yang, T. F.; Chang, F. R.; Miller, R. H.; Wenzel, K. W.; Krueger, W. A.

    1985-01-01

    A tandem mirror device to be considered as a hot plasma source for the hybrid plume rocket concept is discussed. The hot plamsa from this device is injected into an exhaust duct, which will interact with an annular hypersonic layer of neutral gas. The device can be used to study the dynamics of the hybrid plume, and to verify the numerical predictions obtained with computer codes. The basic system design is also geared towards low weight and compactness, and high power density at the exhaust. The basic structure of the device consists of four major subsystems: (1) an electric power supply; (2) a low temperature, high density plasma gun, such as a stream gun, an MPD source or gas cell; (3) a power booster in the form of a tandem mirror machine; and (4) an exhaust nozzle arrangement. The configuration of the tandem mirror section is shown.

  3. Highly Loaded Fan by Using Tandem Cascade Rotor Blade

    NASA Astrophysics Data System (ADS)

    Hasegawa, Hiroaki; Suga, Shinya; Matsuoka, Akinori

    For axial flow compressors and fans in the aircraft engines higher pressure ratio is required in order to attain the high thrust engines. In this study, the fan with the tandem cascades was introduced to increase the fan pressure ratio. The use of tandem cascades in the fan allows savings in length and weight and therefore a compact fan could be built. The design of fan with tandem cascades and the fan testing were carried out to develop the high pressure ratio fan for the Air Turbo Ramjet (ATR) propulsion system. The ATR is a combined cycle engine which performs like a turbojet engine at subsonic speeds and a ramjet at supersonic speeds. In particular, high fan pressure ratio contributes to increase the engine thrust during subsonic flight at which the engine does not make use of ram effect. The results of the fan testing indicate that the pressure ratio of 2.2 is achieved in single stage fan.

  4. Summary of the MARS tandem-mirror reactor design

    SciTech Connect

    Logan, B.G.

    1983-09-01

    A recently completed two-year study of a commercial tandem-mirror reactor design (Mirror Advanced Reactor Study (MARS)) is briefly reviewed. The end plugs are designed for trapped-particle stability, MHD ballooning, balanced geodesic curvature, and small radial electric fields in the central cell. New technologies such as lithium-lead blankets, 24 T hybrid coils, gridless direct converters and plasma halo vacuum pumps are highlighted. General characteristics of the MARS tandem mirror and STARFIRE tokamak reactor design are compared. A design of an upgrade of MFTF-B incorporating many of the MARS features is discussed.

  5. Tandem riboswitch architectures exhibit complex gene control functions.

    PubMed

    Sudarsan, Narasimhan; Hammond, Ming C; Block, Kirsten F; Welz, Rüdiger; Barrick, Jeffrey E; Roth, Adam; Breaker, Ronald R

    2006-10-13

    Riboswitches are structured RNAs typically located in the 5' untranslated regions of bacterial mRNAs that bind metabolites and control gene expression. Most riboswitches sense one metabolite and function as simple genetic switches. However, we found that the 5' region of the Bacillus clausii metE messenger RNA includes two riboswitches that respond to S-adenosylmethionine and coenzyme B12. This tandem arrangement yields a composite gene control system that functions as a two-input Boolean NOR logic gate. These findings and the discovery of additional tandem riboswitch architectures reveal how simple RNA elements can be assembled to make sophisticated genetic decisions without involving protein factors.

  6. Performance of a tandem-rotor/tandem-stator conical-flow compressor designed for a pressure ratio of 3

    NASA Technical Reports Server (NTRS)

    Wood, J. R.; Owen, A. K.; Schumann, L. F.

    1982-01-01

    A conical-flow compressor stage with a large radius change through the rotor was tested at three values of rotor tip clearance. The stage had a tandem rotor and a tandem stator. Peak efficiency at design speed was 0.774 at a pressure ratio of 2.613. The rotor was tested without the stator, and detailed survey data were obtained for each rotor blade row. Overall peak rotor efficiency was 0.871 at a pressure ratio of 2.952.

  7. Development of high band gap materials for tandem solar cells and simulation studies on mechanical tandem solar cells

    NASA Astrophysics Data System (ADS)

    Vijayakumar, Vishnuvardhanan

    Development of low cost, high efficiency tandem solar cells is essential for large scale adoption of solar energy especially in densely populated regions of the world. In this thesis four-terminal mechanical (stack like) tandem solar cells were evaluated using detailed simulation models and design criteria for selecting candidate materials were established. Since silicon solar cells are low cost and have a multi-giga watt global manufacturing and supply chain capacity already in place then only tandem stacks incorporating silicon as one of the layers in the device was investigated. Two candidate materials which have high band gaps that could be used as top cells in the mechanical tandem device were explored as part of the thesis. Dye-sensitized solar cells (DSSC) sensitized with N719 dye (one of the candidates for the top cell) were fabricated with the goal of enabling a flexible processing path to lower cost. Stainless steel (SS) mesh substrates were used to fabricate anodes for flexible DSSC in order to evaluate them as replacements for more expensive Transparent Conducting Oxides (TCO's). Loss mechanisms in DSSC's due to SS mesh oxidation were quantified and protective coatings to prevent oxidation of SS mesh were developed. The second material which was evaluated for use as the top cell was copper zinc tin sulfide (CZTS). CZTS was deposited through a solution deposition route. Detailed investigations were done on the deposited films to understand the chemistry, crystal structure and its opto-electronic properties. Deposited CZTS films were found to be highly crystalline in <112> direction. The films had a direct band gap of 1.5 eV with absorption coefficient greater than 104 cm -1 in agreement with published values. In the second part of the thesis detailed electrical and optical simulation models of the mechanical tandem solar cells were developed based on the most up-to-date materials physical constants available for each layer. The modeling was used to

  8. 14 CFR 105.45 - Use of tandem parachute systems.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...) Has completed a minimum of 500 freefall parachute jumps using a ram-air parachute, and (iii) Holds a... parachute jump with a tandem parachute system unless— (1) The main parachute has been packed by a certificated parachute rigger, the parachutist in command making the next jump with that parachute, or a...

  9. Robust Decentralized Detection and Social Learning in Tandem Networks

    NASA Astrophysics Data System (ADS)

    Ho, Jack; Tay, Wee Peng; Quek, Tony Q. S.; Chong, Edwin K. P.

    2015-10-01

    We study a tandem of agents who make decisions about an underlying binary hypothesis, where the distribution of the agent observations under each hypothesis comes from an uncertainty class. We investigate both decentralized detection rules, where agents collaborate to minimize the error probability of the final agent, and social learning rules, where each agent minimizes its own local minimax error probability. We then extend our results to the infinite tandem network, and derive necessary and sufficient conditions on the uncertainty classes for the minimax error probability to converge to zero when agents know their positions in the tandem. On the other hand, when agents do not know their positions in the network, we study the cases where agents collaborate to minimize the asymptotic minimax error probability, and where agents seek to minimize their worst-case minimax error probability (over all possible positions in the tandem). We show that asymptotic learning of the true hypothesis is no longer possible in these cases, and derive characterizations for the minimax error performance.

  10. Tandem warhead considerations for electronic safety and arming devices

    SciTech Connect

    Dell, D.; Medina, A.

    1990-01-01

    There are four issues that an ESA designer must address when designing a tandem system: (1) warhead detonation shock, (2) warhead detonation ion cloud, (3) warhead detonation electromagnetic pulse, and (4) slapper/sparkgap electromagnetic pulse. Each of these hazards can upset the ESA time delay circuitry which would then either dud the munition or prematurely detonate the main charge. 14 figs.

  11. The Dynamics of Social Interaction in Telecollaborative Tandem Exchanges

    ERIC Educational Resources Information Center

    Janssen Sanchez, Brianna

    2015-01-01

    Using both quantitative and qualitative methods of inquiry, this dissertation study undertakes an exploration of the dynamics of the social interaction in discourse co-constructed by pairs of college students in telecollaborative tandem exchanges. Two groups of participants, Mexican learners of English as a foreign language and American learners…

  12. High efficiency GaAs/Ge monolithic tandem solar cells

    NASA Technical Reports Server (NTRS)

    Tobin, S. P.; Vernon, S. M.; Bajgar, C.; Haven, V. E.; Geoffroy, L. M.; Sanfacon, M. M.; Lillington, D. R.; Hart, R. E., Jr.

    1988-01-01

    Two-terminal monolithic tandem cells consisting of a GaAs solar cell grown epitaxially on a Ge solar cell substrate are very attractive for space applications. Tandem cells of GaAs grown by metal-organic chemical vapor deposition on thin Ge were investigated to address both higher efficiency and reduced weight. Two materials growth issues associated with this heteroepitaxial system, autodoping of the GaAs layers by Ge and diffusion of Ga and As into the Ge substrate, were addressed. The latter appears to result in information of an unintentional p-n junction in the Ge. Early simulator measurements gave efficiencies as high as 21.7 percent for 4 cm2 GaAs/Ge cells, but recent high-altitude testing has given efficiencies of 18 percent. Sources of errors in simulator measurements of two-terminal tandem cells are discussed. A limiting efficiency of about 36 percent for the tandem cell at AMO was calculated. Ways to improve the performance of present cells, primarily by increasing the Isc and Voc of the Ge cell, are proposed.

  13. Bio-olefins from unsaturated fatty acids via tandem catalysis

    USDA-ARS?s Scientific Manuscript database

    A new catalytic route to bio-olefins from unsaturated fatty acids will be described. At the heart of the process, the catalyst apparently functions in a tandem mode by both dynamically isomerizing the positions of double bonds in an aliphatic chain and, subsequently, decarboxylating specific isomers...

  14. Dynamics of tandem bubble interaction in a microfluidic channel

    PubMed Central

    Yuan, Fang; Sankin, Georgy; Zhong, Pei

    2011-01-01

    The dynamics of tandem bubble interaction in a microfluidic channel (800 × 21 μm, W × H) have been investigated using high-speed photography, with resultant fluid motion characterized by particle imaging velocimetry. A single or tandem bubble is produced reliably via laser absorption by micron-sized gold dots (6 μm in diameter with 40 μm in separation distance) coated on a glass surface of the microfluidic channel. Using two pulsed Nd:YAG lasers at λ = 1064 nm and ∼10 μJ/pulse, the dynamics of tandem bubble interaction (individual maximum bubble diameter of 50 μm with a corresponding collapse time of 5.7 μs) are examined at different phase delays. In close proximity (i.e., interbubble distance = 40 μm or γ = 0.8), the tandem bubbles interact strongly with each other, leading to asymmetric deformation of the bubble walls and jet formation, as well as the production of two pairs of vortices in the surrounding fluid rotating in opposite directions. The direction and speed of the jet (up to 95 m/s), as well as the orientation and strength of the vortices can be varied by adjusting the phase delay. PMID:22088007

  15. Dynamics of tandem bubble interaction in a microfluidic channel.

    PubMed

    Yuan, Fang; Sankin, Georgy; Zhong, Pei

    2011-11-01

    The dynamics of tandem bubble interaction in a microfluidic channel (800  ×  21 μm, W × H) have been investigated using high-speed photography, with resultant fluid motion characterized by particle imaging velocimetry. A single or tandem bubble is produced reliably via laser absorption by micron-sized gold dots (6 μm in diameter with 40 μm in separation distance) coated on a glass surface of the microfluidic channel. Using two pulsed Nd:YAG lasers at λ = 1064 nm and ∼10 μJ/pulse, the dynamics of tandem bubble interaction (individual maximum bubble diameter of 50 μm with a corresponding collapse time of 5.7 μs) are examined at different phase delays. In close proximity (i.e., interbubble distance = 40 μm or γ = 0.8), the tandem bubbles interact strongly with each other, leading to asymmetric deformation of the bubble walls and jet formation, as well as the production of two pairs of vortices in the surrounding fluid rotating in opposite directions. The direction and speed of the jet (up to 95 m/s), as well as the orientation and strength of the vortices can be varied by adjusting the phase delay.

  16. High efficiency GaAs/Ge monolithic tandem solar cells

    NASA Technical Reports Server (NTRS)

    Tobin, S. P.; Vernon, S. M.; Bajgar, C.; Haven, V. E.; Geoffroy, L. M.; Sanfacon, M. M.; Lillington, D. R.; Hart, R. E., Jr.

    1988-01-01

    Two-terminal monolithic tandem cells consisting of a GaAs solar cell grown epitaxially on a Ge solar cell substrate are very attractive for space applications. Tandem cells of GaAs grown by metal-organic chemical vapor deposition on thin Ge were investigated to address both higher efficiency and reduced weight. Two materials growth issues associated with this heteroepitaxial system, autodoping of the GaAs layers by Ge and diffusion of Ga and As into the Ge substrate, were addressed. The latter appears to result in information of an unintentional p-n junction in the Ge. Early simulator measurements gave efficiencies as high as 21.7 percent for 4 cm2 GaAs/Ge cells, but recent high-altitude testing has given efficiencies of 18 percent. Sources of errors in simulator measurements of two-terminal tandem cells are discussed. A limiting efficiency of about 36 percent for the tandem cell at AMO was calculated. Ways to improve the performance of present cells, primarily by increasing the Isc and Voc of the Ge cell, are proposed.

  17. Optochemokine Tandem for Light-Control of Intracellular Ca2+

    PubMed Central

    Weissbecker, Juliane; Sauer, Frank; Wood, Phillip G.; Bamberg, Ernst

    2016-01-01

    An optochemokine tandem was developed to control the release of calcium from endosomes into the cytosol by light and to analyze the internalization kinetics of G-protein coupled receptors (GPCRs) by electrophysiology. A previously constructed rhodopsin tandem was re-engineered to combine the light-gated Ca2+-permeable cation channel Channelrhodopsin-2(L132C), CatCh, with the chemokine receptor CXCR4 in a functional tandem protein tCXCR4/CatCh. The GPCR was used as a shuttle protein to displace CatCh from the plasma membrane into intracellular areas. As shown by patch-clamp measurements and confocal laser scanning microscopy, heterologously expressed tCXCR4/CatCh was internalized via the endocytic SDF1/CXCR4 signaling pathway. The kinetics of internalization could be followed electrophysiologically via the amplitude of the CatCh signal. The light-induced release of Ca2+ by tandem endosomes into the cytosol via CatCh was visualized using the Ca2+-sensitive dyes rhod2 and rhod2-AM showing an increase of intracellular Ca2+ in response to light. PMID:27768773

  18. Design considerations for the Tandem Junction Solar Cell

    NASA Technical Reports Server (NTRS)

    Matzen, W. T.; Carbajal, B. G.; Hardy, R. W.

    1979-01-01

    Structure and operation of the tandem junction cell (TJC) are described. The impact of using only back contacts is discussed. A model is presented which explains operation of the TJC in terms of transistor action. The model is applied to predict TJC performance as a function of physical parameters.

  19. Interpretation of tandem mass spectra of posttranslationally modified peptides.

    PubMed

    Bunkenborg, Jakob; Matthiesen, Rune

    2013-01-01

    Tandem mass spectrometry provides a sensitive means of analyzing the amino acid sequence of peptides and modified peptides by providing accurate mass measurements of precursor and fragment ions. Modern mass spectrometry instrumentation is capable of rapidly generating many thousands of tandem mass spectra and protein database search engines have been developed to match the experimental data to peptide candidates. In most studies there is a schism between discarding perfectly valid data and including nonsensical peptide identifications-this is currently a major bottleneck in data-analysis and it calls for an understanding of tandem mass spectrometry data. Manual evaluation of the data and perhaps experimental cross-checking of the MS data can save many months of experimental work trying to do biological follow-ups based on erroneous identifications. Especially for posttranslationally modified peptides there is a need for manual validation of the data because search algorithms seldom have been optimized for the identification of modified peptides and because there are many pitfalls for the unwary. This chapter describes some of the issues that should be considered when interpreting and validating tandem mass spectra and gives some useful tables to aid this process.

  20. High power tandem-pumped thulium-doped fiber laser.

    PubMed

    Wang, Yao; Yang, Jianlong; Huang, Chongyuan; Luo, Yongfeng; Wang, Shiwei; Tang, Yulong; Xu, Jianqiu

    2015-02-09

    We propose a cascaded tandem pumping technique and show its high power and high efficient operation in the 2-μm wavelength region, opening up a new way to scale the output power of the 2-μm fiber laser to new levels (e.g. 10 kW). Using a 1942 nm Tm(3+) fiber laser as the pump source with the co- (counter-) propagating configuration, the 2020 nm Tm(3+) fiber laser generates 34.68 W (35.15W) of output power with 84.4% (86.3%) optical-to-optical efficiency and 91.7% (92.4%) slope efficiency, with respect to launched pump power. It provides the highest slope efficiency reported for 2-μm Tm(3+)-doped fiber lasers, and the highest output power for all-fiber tandem-pumped 2-μm fiber oscillators. This system fulfills the complete structure of the proposed cascaded tandem pumping technique in the 2-μm wavelength region (~1900 nm → ~1940 nm → ~2020 nm). Numerical analysis is also carried out to show the power scaling capability and efficiency of the cascaded tandem pumping technique.

  1. ORIC stripping foil positioner for tandem beam injection

    SciTech Connect

    Ludemann, C.A.; Lord, R.S.; Hudson, E.D.; Irwin, F.; Beckers, R.M.; Haynes, D.L.; Casstevens, B.J.; Mosko, S.W.

    1981-01-01

    The Oak Ridge Isochronous Cyclotron (ORIC) is used as an energy booster for heavy ions from a 25 MV tandem accelerator. This operation requires precise placement of a stripping foil in the cyclotron for capture of the injected ions into an acceleration orbit. The mechanical design and control of the foil positioning device are described.

  2. Production of Arq+ ions with a tandem linear Paul trap

    NASA Astrophysics Data System (ADS)

    Higaki, H.; Nagayasu, K.; Iwai, T.; Ito, K.; Okamoto, H.

    2015-06-01

    A tandem linear Paul trap was used to create highly charged Argon ions by electron impact ionizations. By improving the operation scheme, the production of Ar4+ ions was confirmed. Possible improvements for the future experiments with laser cooled Ca+ ions are suggested.

  3. Tandem Fan Applications in Advanced STOVL Fighter Configurations

    NASA Technical Reports Server (NTRS)

    Zola, Charlse L.; Wilson, Samuel B., III; Eskey, Megan A.

    1984-01-01

    The series/parallel tandem fan engine is evaluated for application in advanced STOVL supersonic fighter aircraft. Options in engine cycle parameters and design of the front fan flow diverter are examined for their effects on engine weight, dimensions, and other factors in integration of the engine with the aircraft. Operation of the engine in high-bypass flow mode during cruise and loiter flight is considered as a means of minimizizng fuel consumption. Engine thrust augmentation by burning in the front fan exhaust is discussed. Achievement of very sort takeoff with vectored thrust in briefly reviewed for tandem fan engine configurations with vectorable front fan nozzles. Examples are given of two aircraft configuration planforms, a delta-canard, and a forward-swept wing, to illustrate the major features. design considerations, and potential performance of the tandem fan installation in each. Full realization of the advantages of tandem fan propulsion are found to depend on careful selection of the aircraft configuration, since integration requirements can strongly influence the engine performance.

  4. The "Bologna-München" Tandem--Experiencing Interculturality

    ERIC Educational Resources Information Center

    De Martino, Sandro

    2016-01-01

    This case study describes the "Bologna-München" Tandem, a cross-border collaboration which began in 2011. The aim of the collaboration is to give students studying Italian at the Ludwig- Maximilians-University in Munich and students studying German at the University of Bologna the opportunity to experience interculturality through…

  5. Propulsion Research on the Variable Tandem Mirror Plasma Rocket.

    DTIC Science & Technology

    1994-02-07

    T.F. Yang. and F.R. Chang-Diaz. An icrh beach effect in a tandem mirror device. To be submitted to Physics of Fluid. 9; Scott Peng, , J. Freidberg ...mirror plasma propulsion device. Technical Report To be Published, MIT Plasma Fusion Center, 1990. 14j J. F. Freidberg . Ideal magnetohydrodynamic theory

  6. PCR-free digital minisatellite tandem repeat genotyping.

    PubMed

    Chen, Yuchao; Seo, Tae Seok

    2011-06-01

    We demonstrated a proof-of-concept for novel minisatellite tandem repeat typing, called PCR-free digital VNTR (variable number tandem repeat) typing, which is composed of three steps: a ligation reaction instead of PCR thermal cycling, magnetic bead-based solid-phase capture for purification, and an elongated sample stacking microcapillary electrophoresis (μCE) for sensitive digital coding of repeat number. We designed a 16-bp fluorescently labeled ligation probe which is complementary to a repeat unit of a biotinylated synthetic template mimicking the human D1S80 VNTR locus and is randomly hybridized with the minisatellite tandem repeats. A quick isothermal ligation reaction was followed to link the adjacent ligation probes on the DNA templates, and then the ligated products were purified by streptavidin-coated magnetic beads. After a denaturing step, a large amount of ligated products whose size difference was equivalent to the repeat unit were released and recovered. Through the elongated sample stacking μCE separation on a microdevice, the fluorescence signal of the ligated products was generated in the electropherogram and the peak number was directly counted which was exactly matched with the repeat number of VNTR locus. We could successfully identify the minisatellite tandem repeat number with only 5 fmol of DNA template in 30 min.

  7. The Dynamics of Social Interaction in Telecollaborative Tandem Exchanges

    ERIC Educational Resources Information Center

    Janssen Sanchez, Brianna

    2015-01-01

    Using both quantitative and qualitative methods of inquiry, this dissertation study undertakes an exploration of the dynamics of the social interaction in discourse co-constructed by pairs of college students in telecollaborative tandem exchanges. Two groups of participants, Mexican learners of English as a foreign language and American learners…

  8. II-IV-V Based Thin Film Tandem Photovoltaic Cell

    SciTech Connect

    Newman, Nathan; van Schilfgaarde, Mark

    2012-10-04

    [Through a combination of theory and experiment that, absent unknown mitigating factors, a tandem cell whose (wide-gap. 1.8 eV) top layer is made of ZnSnP2 and whose (narrow gap, 1.1 eV) bottom layer consisting of ZnGeAs2 are near-ideal materials for a tandem cell. Not only are there gaps optimally adjusted to the solar spectrum, but the two compounds are lattice-matched, and their energy band structure and optical absorption are also near-ideal (they closely resemble that of GaAs). Our first major challenge is to establish that high-quality II-IV-V thin films can be synthesized. We have begun growing and characterizing films of ZnGeAs2 and ZnSnP2, initially grown on Ge substrates (the lattice constant of Ge matches these compounds) by pulsed laser ablation and sputtering. In tandem are theoretical calculations to guide the experiments. The goal is to develop methods that can be used to produce a pair of lattice-matched thin films that will be useful in tandem cells.

  9. Development of an advanced spacecraft tandem mass spectrometer

    NASA Technical Reports Server (NTRS)

    Drew, Russell C.

    1992-01-01

    The purpose of this research was to apply current advanced technology in electronics and materials to the development of a miniaturized Tandem Mass Spectrometer that would have the potential for future development into a package suitable for spacecraft use. The mass spectrometer to be used as a basis for the tandem instrument would be a magnetic sector instrument, of Nier-Johnson configuration, as used on the Viking Mars Lander mission. This instrument configuration would then be matched with a suitable second stage MS to provide the benefits of tandem MS operation for rapid identification of unknown organic compounds. This tandem instrument is configured with a newly designed GC system to aid in separation of complex mixtures prior to MS analysis. A number of important results were achieved in the course of this project. Among them were the development of a miniaturized GC subsystem, with a unique desorber-injector, fully temperature feedback controlled oven with powered cooling for rapid reset to ambient conditions, a unique combination inlet system to the MS that provides for both membrane sampling and direct capillary column sample transfer, a compact and ruggedized alignment configuration for the MS, an improved ion source design for increased sensitivity, and a simple, rugged tandem MS configuration that is particularly adaptable to spacecraft use because of its low power and low vacuum pumping requirements. The potential applications of this research include use in manned spacecraft like the space station as a real-time detection and warning device for the presence of potentially harmful trace contaminants of the spacecraft atmosphere, use as an analytical device for evaluating samples collected on the Moon or a planetary surface, or even use in connection with monitoring potentially hazardous conditions that may exist in terrestrial locations such as launch pads, environmental test chambers or other sensitive areas. Commercial development of the technology

  10. Monolithic Parallel Tandem Organic Photovoltaic Cell with Transparent Carbon Nanotube Interlayer

    NASA Technical Reports Server (NTRS)

    Tanaka, S.; Mielczarek, K.; Ovalle-Robles, R.; Wang, B.; Hsu, D.; Zakhidov, A. A.

    2009-01-01

    We demonstrate an organic photovoltaic cell with a monolithic tandem structure in parallel connection. Transparent multiwalled carbon nanotube sheets are used as an interlayer anode electrode for this parallel tandem. The characteristics of front and back cells are measured independently. The short circuit current density of the parallel tandem cell is larger than the currents of each individual cell. The wavelength dependence of photocurrent for the parallel tandem cell shows the superposition spectrum of the two spectral sensitivities of the front and back cells. The monolithic three-electrode photovoltaic cell indeed operates as a parallel tandem with improved efficiency.

  11. Monolithic Parallel Tandem Organic Photovoltaic Cell with Transparent Carbon Nanotube Interlayer

    NASA Technical Reports Server (NTRS)

    Tanaka, S.; Mielczarek, K.; Ovalle-Robles, R.; Wang, B.; Hsu, D.; Zakhidov, A. A.

    2009-01-01

    We demonstrate an organic photovoltaic cell with a monolithic tandem structure in parallel connection. Transparent multiwalled carbon nanotube sheets are used as an interlayer anode electrode for this parallel tandem. The characteristics of front and back cells are measured independently. The short circuit current density of the parallel tandem cell is larger than the currents of each individual cell. The wavelength dependence of photocurrent for the parallel tandem cell shows the superposition spectrum of the two spectral sensitivities of the front and back cells. The monolithic three-electrode photovoltaic cell indeed operates as a parallel tandem with improved efficiency.

  12. A novel combination of fipronil and permethrin (Frontline Tri-Act®/Frontect®) reduces risk of transmission of Babesia canis by Dermacentor reticulatus and of Ehrlichia canis by Rhipicephalus sanguineus ticks to dogs.

    PubMed

    Jongejan, Frans; de Vos, Christa; Fourie, Josephus J; Beugnet, Frederic

    2015-11-19

    The ability of Frontline Tri-Act®/Frontect®, a topical ectoparasiticide containing fipronil and permethrin for dogs, to prevent the transmission of Babesia canis as well as Ehrlichia canis was evaluated by infesting dogs with infected vector ticks. For the Babesia canis study, 16 dogs were randomly allocated to two groups. Eight dogs were treated on day 0 with a topical spot-on formulation containing 6.76 % w/v fipronil plus 50.48 % w/v permethrin and eight dogs served as the untreated control group. Dermacentor reticulatus ticks, with a B. canis infection rate ranging between 2 and 10 %, were placed onto dogs on days 7, 14, 21 and 28. In situ tick counts were performed on Days 9, 16 and 23. Ticks were counted and removed on Day 30. Infection of the dogs with B. canis was monitored by rectal temperature readings, clinical examinations and blood smears as well as PCR and IFA (indirect fluorescent antibody assay). For the Ehrlichia canis study, another 16 dogs were allocated to two groups. Eight dogs were treated with the fipronil and permethrin combination on days 0 and 28 and eight dogs served as untreated controls. Rhipicephalus sanguineus ticks, carrying an infection rate of 13 % for E. canis, were released in the sleeping kennels of the dogs on days 7, 14, 21, 28, 35, 42, 49 and 56. Ticks were counted in situ on the dogs on a weekly basis. All ticks were removed and counted on the final assessment day 58. Infection of the dogs with E. canis was monitored by rectal temperature, clinical examinations, and testing of blood samples by PCR, IFA and platelet counts. B. canis was transmitted by D. reticulatus ticks to all eight untreated control dogs and to one treated dog, which was confirmed by blood smears, PCR and IFA. E.canis was transmitted by R. sanguineus ticks to all eight untreated control dogs. Two of the dogs in the treated group were found positive based on PCR and/or IFA. Frontline Tri-Act®/Frontect® significantly lowered the risk for dogs to

  13. Large tandem repeats make up the chromosome bar code: a hypothesis.

    PubMed

    Podgornaya, Olga; Gavrilova, Ekaterina; Stephanova, Vera; Demin, Sergey; Komissarov, Aleksey

    2013-01-01

    Much of tandem repeats' functional nature in any genome remains enigmatic because there are only few tools available for dissecting and elucidating the functions of repeated DNA. The large tandem repeat arrays (satellite DNA) found in two mouse whole-genome shotgun assemblies were classified into 4 superfamilies, 8 families, and 62 subfamilies. With the simplified variant of chromosome positioning of different tandem repeats, we noticed the nonuniform distribution instead of the positions reported for mouse major and minor satellites. It is visible that each chromosome possesses a kind of unique code made up of different large tandem repeats. The reference genomes allow marking only internal tandem repeats, and even with such a limited data, the colored "bar code" made up of tandem repeats is visible. We suppose that tandem repeats bare the mechanism for chromosomes to recognize the regions to be associated. The associations, initially established via RNA, become fixed by histone modifications (the histone or chromatin code) and specific proteins. In such a way, associations, being at the beginning flexible and regulated, that is, adjustable, appear as irreversible and inheritable in cell generations. Tandem repeat multiformity tunes the developed nuclei 3D pattern by sequential steps of associations. Tandem repeats-based chromosome bar code could be the carrier of the genome structural information; that is, the order of precise tandem repeat association is the DNA morphogenetic program. Tandem repeats are the cores of the distinct 3D structures postulated in "gene gating" hypothesis. Copyright © 2013 Elsevier Inc. All rights reserved.

  14. Fully integrated, fully automated generation of short tandem repeat profiles

    PubMed Central

    2013-01-01

    Background The generation of short tandem repeat profiles, also referred to as ‘DNA typing,’ is not currently performed outside the laboratory because the process requires highly skilled technical operators and a controlled laboratory environment and infrastructure with several specialized instruments. The goal of this work was to develop a fully integrated system for the automated generation of short tandem repeat profiles from buccal swab samples, to improve forensic laboratory process flow as well as to enable short tandem repeat profile generation to be performed in police stations and in field-forward military, intelligence, and homeland security settings. Results An integrated system was developed consisting of an injection-molded microfluidic BioChipSet cassette, a ruggedized instrument, and expert system software. For each of five buccal swabs, the system purifies DNA using guanidinium-based lysis and silica binding, amplifies 15 short tandem repeat loci and the amelogenin locus, electrophoretically separates the resulting amplicons, and generates a profile. No operator processing of the samples is required, and the time from swab insertion to profile generation is 84 minutes. All required reagents are contained within the BioChipSet cassette; these consist of a lyophilized polymerase chain reaction mix and liquids for purification and electrophoretic separation. Profiles obtained from fully automated runs demonstrate that the integrated system generates concordant short tandem repeat profiles. The system exhibits single-base resolution from 100 to greater than 500 bases, with inter-run precision with a standard deviation of ±0.05 - 0.10 bases for most alleles. The reagents are stable for at least 6 months at 22°C, and the instrument has been designed and tested to Military Standard 810F for shock and vibration ruggedization. A nontechnical user can operate the system within or outside the laboratory. Conclusions The integrated system represents the

  15. Summary of results from the Tandem Mirror Experiment (TMX)

    SciTech Connect

    Simonen, T.C.

    1981-02-26

    This report summarizes results from the successful experimental operation of the Tandem Mirror Experiment (TMX) over the period October 1978 through September 1980. The experimental program, summarized by the DOE milestones given in Table 1-1, had three basic phases: (1) an 8-month checkout period, October 1978 through May 1979; (2) a 6-month initial period of operation, June through November 1979, during which the basic principles of the tandem configuration were demonstrated (i.e., plasma confinement was improved over that of a single-cell mirror); and (3) a 10-month period, December 1979 through September 1980, during which the initial TMX results were corroborated by additional diagnostic measurements and many detailed physics investigations were carried out. This report summarizes the early results, presents results of recent data analysis, and outlines areas of ongoing research and data analysis which will be reported in future journal publications.

  16. Verification of automated peptide identifications from proteomic tandem mass spectra

    PubMed Central

    Tabb, David L; Friedman, David B; Ham, Amy-Joan L

    2010-01-01

    Shotgun proteomics yields tandem mass spectra of peptides that can be identified by database search algorithms. When only a few observed peptides suggest the presence of a protein, establishing the accuracy of the peptide identifications is necessary for accepting or rejecting the protein identification. In this protocol, we describe the properties of peptide identifications that can differentiate legitimately identified peptides from spurious ones. The chemistry of fragmentation, as embodied in the ‘mobile proton’ and ‘pathways in competition’ models, informs the process of confirming or rejecting each spectral match. Examples of ion-trap and tandem time-of-flight (TOF/TOF) mass spectra illustrate these principles of fragmentation. PMID:17406459

  17. Challenges and developments in tandem mass spectrometry based clinical metabolomics.

    PubMed

    Ceglarek, Uta; Leichtle, Alexander; Brügel, Mathias; Kortz, Linda; Brauer, Romy; Bresler, Kristin; Thiery, Joachim; Fiedler, Georg Martin

    2009-03-25

    'Clinical metabolomics' aims at evaluating and predicting health and disease risk in an individual by investigating metabolic signatures in body fluids or tissues, which are influenced by genetics, epigenetics, environmental exposures, diet, and behaviour. Powerful analytical techniques like liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) offers a rapid, effective and economical way to analyze metabolic alterations of pre-defined target metabolites in biological samples. Novel hyphenated technical approaches like the combination of tandem mass spectrometry combined with linear ion trap (QTrap mass spectrometry) combines both identification and quantification of known and unknown metabolic targets. We describe new concepts and developments of mass spectrometry based multi-target metabolome profiling in the field of clinical diagnostics and research. Particularly, the experiences from newborn screening provided important insights about the diagnostic potential of metabolite profiling arrays and directs to the clinical aim of predictive, preventive and personalized medicine by metabolomics.

  18. Marine Hydrokinetic Turbines operating in a streamwise tandem arrangement

    NASA Astrophysics Data System (ADS)

    Beninati, M. L.; Markovic, U. V.; Krane, M. H.

    2015-12-01

    A laboratory-scale study of the impact of separation distance on the performance of marine hydrokinetic turbines in a streamwise tandem arrangement is described. The study aims to give guidance concerning minimum, or optimal, turbine spacing in arrays. Testing was conducted in the hydraulic flume facility (9.8 m long, 1.2 m wide and 0.4 m deep) at Bucknell University. The devices were two-bladed model marine turbines with a rotor diameter of 0.1 m. For each separation distance, rotational speed of each device and velocity profiles of flow incident on the downstream turbine were measured. Results suggest limits for the minimum spacing between two turbines arranged in a tandem array.

  19. Versatile communication strategies among tandem WW domain repeats.

    PubMed

    Dodson, Emma Joy; Fishbain-Yoskovitz, Vered; Rotem-Bamberger, Shahar; Schueler-Furman, Ora

    2015-03-01

    Interactions mediated by short linear motifs in proteins play major roles in regulation of cellular homeostasis since their transient nature allows for easy modulation. We are still far from a full understanding and appreciation of the complex regulation patterns that can be, and are, achieved by this type of interaction. The fact that many linear-motif-binding domains occur in tandem repeats in proteins indicates that their mutual communication is used extensively to obtain complex integration of information toward regulatory decisions. This review is an attempt to overview, and classify, different ways by which two and more tandem repeats cooperate in binding to their targets, in the well-characterized family of WW domains and their corresponding polyproline ligands.

  20. Protein identification using nano liquid chromatography-tandem mass spectrometry.

    PubMed

    Negroni, Luc

    2007-01-01

    Tandem mass spectrometry is an efficient technique for the identification of peptides on the basis of their fragmentation pattern (MS/MS scan). It can generate individual spectra for each peptide, thereby creating a powerful tool for protein identification on the basis of peptide characterization. This important advance in automatic data acquisition has allowed an efficient association between liquid chromatography and tandem mass spectrometry, and the use of nanocolumns and nanoelectrospray ionization has dramatically increased the efficiency of this method. Now large sets of peptides can be identified at a femtomole level. At the end of the process, batch processing of the MS/MS spectra produces peptide lists that identify purified proteins or protein mixtures with high confidence.