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Genomes and Genes | Y RikihisaSummaryAffiliation: The Ohio State University Country: USA Publications
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New findings on members of the family Anaplasmataceae of veterinary importanceYasuko Rikihisa
Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, 1925 Coffey Road, Columbus, OH 43210, USA
Ann N Y Acad Sci 1078:438-45. 2006..It is through this work that surveillance, diagnosis, preventive measures, and treatment of ehrlichioses of both animals and humans can be improved...- Type IV secretion in the obligatory intracellular bacterium Anaplasma phagocytophilumYasuko Rikihisa
Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, OH 43210, USA
Cell Microbiol 12:1213-21. 2010..At the cellular level, the two effectors have distinct subcellular localization and signalling in host cells. Thus in this obligatory intracellular pathogen, the T4S system has evolved as a host-subversive survival factor... - Anaplasma phagocytophilum and Ehrlichia chaffeensis: subversive manipulators of host cellsYasuko Rikihisa
Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, 1925 Coffey Road, Columbus, Ohio 43210, USA
Nat Rev Microbiol 8:328-39. 2010..Here, I review the specialized properties and other adaptations of these intracellular bacteria... - Anaplasma phagocytophilum and Ehrlichia chaffeensis type IV secretion and Ank proteinsYasuko Rikihisa
Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, OH 43210, USA
Curr Opin Microbiol 13:59-66. 2010..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... - Molecular events involved in cellular invasion by Ehrlichia chaffeensis and Anaplasma phagocytophilumYasuko Rikihisa
Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, OH 43210, USA
Vet Parasitol 167:155-66. 2010..Such data can be applied towards treatment, diagnosis, and control of ehrlichiosis and anaplasmosis... - Type IV secretion system of Anaplasma phagocytophilum and Ehrlichia chaffeensisYasuko Rikihisa
Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, Ohio 43210, USA
Ann N Y Acad Sci 1166:106-11. 2009..Such data can be applied toward treatment, diagnosis, and control of ehrlichiosis and anaplasmosis... - Ehrlichia chaffeensis Induces Monocyte Inflammatory Responses through MyD88, ERK, and NF-?B but Not through TRIF, Interleukin-1 Receptor 1 (IL-1R1)/IL-18R1, or Toll-Like ReceptorsKoshiro Miura
Department of Veterinary Biosciences, The Ohio State University, 1925 Coffey Rd, Columbus, OH 43210
Infect Immun 79:4947-56. 2011..These results indicate that the E. chaffeensis Wakulla strain can induce inflammatory responses through MyD88-dependent NF-?B and ERK pathways, without the involvement of TRIF and TLRs... - Human infection with Ehrlichia canis accompanied by clinical signs in VenezuelaMiriam Perez
Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, 1925 Coffey Road, Columbus, OH 43210 1093, USA
Ann N Y Acad Sci 1078:110-7. 2006..canis Venezuelan human Ehrlichia (VHE) strain previously isolated from an asymptomatic human. This study is the first report of E. canis infection of human patients with clinical signs of HME... - Ehrlichia subversion of host innate responsesYasuko Rikihisa
Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, 1925 Coffey Road, Columbus, OH 43210, USA
Curr Opin Microbiol 9:95-101. 2006..They offer a fascinating example of how pathogens employ intricate strategies to usurp and subvert host cell function... - Mechanisms to create a safe haven by members of the family AnaplasmataceaeYasuko Rikihisa
Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, Ohio 43210 1093, USA
Ann N Y Acad Sci 990:548-55. 2003..This paper discusses our recent findings on these topics... - Molecular characterization of Aegyptianella pullorum (Rickettsiales, Anaplasmataceae)Yasuko Rikihisa
Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, Columbus, Ohio 43210, USA
J Clin Microbiol 41:5294-7. 2003..A specific PCR test was developed to analyze A. pullorum DNA. Phylogenic analysis revealed A. pullorum is most closely related to Anaplasma spp... - Analysis of p51, groESL, and the major antigen P51 in various species of Neorickettsia, an obligatory intracellular bacterium that infects trematodes and mammalsYasuko Rikihisa
Department of Veterinary Biosciences, The Ohio State University, 1925 Coffey Rd, Columbus, OH 43210, USA
J Clin Microbiol 42:3823-6. 2004..groESL sequencing results delineated the phylogenic relationships among Neorickettsia spp... - Neorickettsia risticii surface-exposed proteins: proteomics identification, recognition by naturally-infected horses, and strain variationsKathryn E Gibson
Department of Veterinary Biosciences, The Ohio State University College of Veterinary Medicine, 1925 Coffey Rd, Columbus, OH 43210, USA
Vet Res 42:71. 2011..This study showed N. risticii surface protein population dynamics, providing groundwork for designing immunodiagnostic targets for PHF... - Mechanisms of obligatory intracellular infection with Anaplasma phagocytophilumYasuko Rikihisa
Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, OH 43210, USA
Clin Microbiol Rev 24:469-89. 2011..An understanding of the molecular mechanisms underlying A. phagocytophilum infection will foster the development of creative ideas to prevent or treat this emerging tick-borne disease... - Transcriptional analysis of p30 major outer membrane multigene family of Ehrlichia canis in dogs, ticks, and cell culture at different temperaturesA Unver
Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, Ohio 43210-1093, USA
Infect Immun 69:6172-8. 2001..canis transmission as well as in designing a rational vaccine candidate immunogenic against canine ehrlichiosis... - Multiple p44 genes encoding major outer membrane proteins are expressed in the human granulocytic ehrlichiosis agentN Zhi
Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, Ohio 43210 1093, USA
J Biol Chem 274:17828-36. 1999..Characterization of p44-homologous genes expressed by the HGE agent in a tissue culture would assist in understanding a role of the p44 multigene family in pathogenesis and immune response in HGE... - Western blot analysis of sera reactive to human monocytic ehrlichiosis and human granulocytic ehrlichiosis agentsA Unver
Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus 43210-1093, USA
J Clin Microbiol 39:3982-6. 2001..Therefore, Western immunoblot analysis using rP44 and rP30 may be useful in discriminating dually HME and HGE IFA-reactive sera... - Cloning and characterization of multigenes encoding the immunodominant 30-kilodalton major outer membrane proteins of Ehrlichia canis and application of the recombinant protein for serodiagnosisN Ohashi
Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, Ohio 43210 1093, USA
J Clin Microbiol 36:2671-80. 1998..Cloning of multigenes encoding the 30-kDa major outer membrane proteins of E. canis will greatly facilitate understanding pathogenesis and immunologic study of canine ehrlichosis and provide a useful tool for phylogenetic analysis... - Analysis of transcriptionally active gene clusters of major outer membrane protein multigene family in Ehrlichia canis and E. chaffeensisN Ohashi
Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, Ohio 43210 1093, USA
Infect Immun 69:2083-91. 2001.... - Immunodominant major outer membrane proteins of Ehrlichia chaffeensis are encoded by a polymorphic multigene familyN Ohashi
Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus 43210 1093, USA
Infect Immun 66:132-9. 1998..chaffeensis. These findings suggest that the 30-kDa-range proteins of E. chaffeensis represent a family of antigenically related homologous proteins encoded by a single gene family... - Sensitive detection of Ehrlichia chaffeensis in cell culture, blood, and tick specimens by reverse transcription-PCRS Felek
Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, Ohio 43210-1093, USA
J Clin Microbiol 39:460-3. 2001..Positive results by RT-PCR also imply the presence of viable pathogens. This is the first demonstration of RNA of E. chaffeensis in infected blood and acquisition-fed male, nymphal, and larval A. americanum ticks... - Cloning and expression of the 44-kilodalton major outer membrane protein gene of the human granulocytic ehrlichiosis agent and application of the recombinant protein to serodiagnosisN Zhi
Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus 43210 1093, USA
J Clin Microbiol 36:1666-73. 1998..The use of the affinity-purified rP44 protein as antigen would provide a more specific, consistent, and simpler serodiagnosis for HGE than the use of whole infected cells or purified HGE agents... - Molecular and antigenic comparison of Ehrlichia canis isolates from dogs, ticks, and a human in VenezuelaA Unver
Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, Ohio 43210-1093, USA
J Clin Microbiol 39:2788-93. 2001..This is the first report of culture isolation and antigenic characterization of an ehrlichial agent from a dog in South America, as well as the first molecular characterization of E. canis directly from naturally infected ticks... - Neorickettsia risticii is vertically transmitted in the trematode Acanthatrium oregonense and horizontally transmitted to batsKathryn E Gibson
Department of Veterinary Biosciences, The Ohio State University, Columbus, OH 43210, USA
Environ Microbiol 7:203-12. 2005..fuscus and M. lucifugus bats, suggesting that N. risticii can also be transmitted horizontally from trematode to bat. These results indicate that A. oregonense is a natural reservoir and probably a vector of N. risticii... - Cloning of the heat shock protein 70 (HSP70) gene of Ehrlichia sennetsu and differential expression of HSP70 and HSP60 mRNA after temperature upshiftY Zhang
Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, Ohio 43210, USA
Infect Immun 66:3106-12. 1998..This study also provides a useful model system for examining mRNA expression in obligatory intracellular bacteria... - Identification of 19 polymorphic major outer membrane protein genes and their immunogenic peptides in Ehrlichia ewingii for use in a serodiagnostic assayChunbin Zhang
Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, 1925 Coffey Rd, Columbus, OH 43210 1093, USA
Clin Vaccine Immunol 15:402-11. 2008..The results support the utility of the tailored OMP-1 peptides as E. ewingii serologic test antigens... - Sequence and expression analysis of virB9 of the type IV secretion system of Ehrlichia canis strains in ticks, dogs, and cultured cellsSuleyman Felek
Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, 1925 Coffey Road, Columbus, OH 43210 1093, USA
Infect Immun 71:6063-7. 2003..virB9 was transcribed by E. canis in dogs, ticks, and cell culture. Infected dogs had antibodies to recombinant VirB9, indicating that VirB9 was produced by E. canis in dogs and was antigenic... - Western immunoblot analysis of Haemobartonella muris and comparison of 16S rRNA gene sequences of H. muris, H. felis, and Eperythrozoon suisY Rikihisa
Department of Veterinary Biosciences, College of Veterinary Medicine, Ohio State University, Columbus 43210, USA
J Clin Microbiol 35:823-9. 1997..79 to 83% similarity) than to Anaplasma marginale (72 to 75% similarity). Our results suggest that the Haemobartonella spp. and E. suis may be reclassified in the same genus in the family Mycoplasmataceae... - Ehrlichia sennetsu groE operon and antigenic properties of the GroEL homologY Zhang
Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus 43210, USA
FEMS Immunol Med Microbiol 18:39-46. 1997..coli. The recombinant 55-kDa protein would be a useful tool for studying the role of this antigen in the immune response to E. sennetsu infection... - Obligatory intracellular parasitism by Ehrlichia chaffeensis and Anaplasma phagocytophilum involves caveolae and glycosylphosphatidylinositol-anchored proteinsMingqun Lin
Department of Veterinary Biosciences, The Ohio State University, 1925 Coffey Road, Columbus, OH 43210, USA
Cell Microbiol 5:809-20. 2003.... - Cytokine gene expression by peripheral blood leukocytes in dogs experimentally infected with a new virulent strain of Ehrlichia canisAhmet Unver
Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, 1925 Coffey Road, Columbus, Ohio 43210, USA
Ann N Y Acad Sci 1078:482-6. 2006..This study showed that E. canis can induce chronic expression of a subset of proinflammatory cytokine genes: balance, timing, and duration of these cytokine generations may contribute to the progression of canine ehrlichiosis... - Transstadial and intrastadial experimental transmission of Ehrlichia canis by male Rhipicephalus sanguineusWilliam G Bremer
Department of Veterinary Preventive Medicine, The Ohio State University, 1920 Coffey Road, Columbus, OH 43210, USA
Vet Parasitol 131:95-105. 2005..canis in the absence of female ticks. This tick development stage could be important in transmission of E. canis, and perhaps related pathogens, between vertebrate hosts under natural and experimental conditions... - Effects of Anaplasma phagocytophila on NADPH oxidase components in human neutrophils and HL-60 cellsJason Mott
Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, Ohio 43210 1092, USA
Infect Immun 70:1359-66. 2002..phagocytophila to neutrophils is involved in the inhibition of O(2)(-) generation. Absence of colocalization of NADPH oxidase components with the inclusion further protects A. phagocytophila from oxidative damage... - Characterization of Ehrlichia risticii binding, internalization, and proliferation in host cells by flow cytometryJ B Messick
Department of Veterinary Pathobiology, College of Veterinary Medicine, Columbus, Ohio 43210 1092
Infect Immun 61:3803-10. 1993..Although E. risticii did not bind to the surface of equine PMN leukocytes at 4 degrees C, organisms were taken up by this cell at 37 degrees C. E. risticii, however, failed to survive in equine PMN leukocytes... - Virulence potential of Ehrlichia chaffeensis strains of distinct genome sequencesKoshiro Miura
Department of Veterinary Biosciences, The Ohio State University, 1925 Coffey Road, Columbus, OH 43210, USA
Infect Immun 75:3604-13. 2007..These results revealed distinct virulence phenotypes of E. chaffeensis strains with defined genome sequences... - Biochemical activities of three pairs of Ehrlichia chaffeensis two-component regulatory system proteins involved in inhibition of lysosomal fusionYumi Kumagai
Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, 1925 Coffey Road, Columbus, OH 43210-1093, USA
Infect Immun 74:5014-22. 2006..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... - Transcript heterogeneity of the p44 multigene family in a human granulocytic ehrlichiosis agent transmitted by ticksNing Zhi
Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, Ohio 43210 1093, USA
Infect Immun 70:1175-84. 2002..The present study provides new information for understanding the role of the p44 multigene family in transmission of the HGE agent between mammals and ticks... - Ehrlichia chaffeensis and Anaplasma phagocytophilum lack genes for lipid A biosynthesis and incorporate cholesterol for their survivalMingqun Lin
Department of Veterinary Biosciences, The Ohio State University, Columbus, Ohio 43210, USA
Infect Immun 71:5324-31. 2003..As the first report of gram-negative bacteria incorporating cholesterol for survival, these findings offer insight into the unique nature of their parasitism and imply that cholesterol is important in the control of human ehrlichioses... - Characterization and transcriptional analysis of gene clusters for a type IV secretion machinery in human granulocytic and monocytic ehrlichiosis agentsNorio Ohashi
Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, Ohio 43210 1093, USA
Infect Immun 70:2128-38. 2002..This unique regulation of gene expression for the type IV secretion system may be associated with intracellular survival and replication of Anaplasma and Ehrlichia spp. in granulocytes or monocytes... - Proteomic analysis of and immune responses to Ehrlichia chaffeensis lipoproteinsHaibin Huang
Department of Veterinary Biosciences, The Ohio State University, 1925 Coffey Rd, Columbus, OH 43210, USA
Infect Immun 76:3405-14. 2008..Multiple lipoproteins expressed by E. chaffeensis in vitro and in vivo may play key roles in pathogenesis and immune responses in HME... - Detection of Ehrlichia canis in canine carrier blood and in individual experimentally infected ticks with a p30-based PCR assayRoger W Stich
Department of Veterinary Preventive Medicine, The Ohio State University, Columbus, Ohio 43210 1092, USA
J Clin Microbiol 40:540-6. 2002.... - Analysis of sequences and loci of p44 homologs expressed by Anaplasma phagocytophila in acutely infected patientsQuan Lin
Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus 43210, USA
J Clin Microbiol 40:2981-8. 2002..Furthermore, several p44 genes are not hypermutatable in nature, based on the conservation of gene sequences and loci among isolates obtained 5 years apart... - Diagnosis of Ehrlichia ewingii infection by PCR in a puppy from OhioJennifer Gieg
Veterinary Clinical Sciences, College of Veterinary Medicine, The Ohio State University, Columbus, OH, USA
Vet Clin Pathol 38:406-10. 2009..ewingii in Ohio. More importantly, this case demonstrates the importance of PCR in making a definitive diagnosis of tick-borne disease and the potential pitfalls of relying on serologic testing alone in making a diagnosis... - Analysis of complete genome sequence of Neorickettsia risticii: causative agent of Potomac horse feverMingqun Lin
Department of Veterinary Biosciences, The Ohio State University, Columbus, OH 43210, USA
Nucleic Acids Res 37:6076-91. 2009..These data provide insights toward genomic potential of N. risticii and intracellular parasitism, and facilitate our understanding of PHF pathogenesis... - The omp-1 major outer membrane multigene family of Ehrlichia chaffeensis is differentially expressed in canine and tick hostsAhmet Unver
Department of Veterinary Biosciences, The Ohio State University, Columbus 43210-1093, USA
Infect Immun 70:4701-4. 2002..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... - Antibiotic clearance of Ehrlichia canis from dogs infected by intravenous inoculation of carrier bloodJohn J Schaefer
Department of Veterinary Preventive Medicine, Ohio State University, Columbus, Ohio, USA
Ann N Y Acad Sci 1149:263-9. 2008..Peripheral blood from all dogs became PCR negative after antibiotic treatment, suggesting that these infections were eliminated and that rifampin is an effective alternative chemotherapeutic agent for treatment of CME... - Intra-leukocyte expression of two-component systems in Ehrlichia chaffeensis and Anaplasma phagocytophilum and effects of the histidine kinase inhibitor closantelZhihui Cheng
Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, OH 43210, USA
Cell Microbiol 8:1241-52. 2006..These results suggest that these TCSs play an essential role in infection and survival of E. chaffeensis and A. phagocytophilum in human leukocytes... - Two monoclonal antibodies with defined epitopes of P44 major surface proteins neutralize Anaplasma phagocytophilum by distinct mechanismsXueqi Wang
Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, 1925 Coffey Rd, Columbus, OH 43210 1093, USA
Infect Immun 74:1873-82. 2006..The results indicate that antibodies directed to certain epitopes of P44 proteins have a critical role in inhibiting A. phagocytophilum infection of host cells... - Tick acquisition of Ehrlichia canis from dogs treated with doxycycline hyclateJohn J Schaefer
Department of Veterinary Preventive Medicine, The Ohio State University, Columbus, Ohio 43210, USA
Antimicrob Agents Chemother 51:3394-6. 2007..In this study, Ehrlichia canis was detected in dogs treated with doxycycline for 14 days and in ticks fed on these dogs, suggesting that treated dogs can remain reservoirs for E. canis... - Differential expression of VirB9 and VirB6 during the life cycle of Anaplasma phagocytophilum in human leucocytes is associated with differential binding and avoidance of lysosome pathwayHua Niu
Department of Veterinary Biosciences, The Ohio State University, Columbus, OH 43210, USA
Cell Microbiol 8:523-34. 2006..phagocytophilum intracellular life cycle and suggest that bacterial developmental stages influence the nature of binding to the hosts and early avoidance of late endosome-lysosome pathway... - Sequence analysis of p44 homologs expressed by Anaplasma phagocytophilum in infected ticks feeding on naive hosts and in mice infected by tick attachmentSuleyman Felek
Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, Ohio 43210-1093, USA
Infect Immun 72:659-66. 2004..phagocytophilum genome carries a set of p44 paralogs to be expressed. Thus, a large but restricted repertoire of p44 hypervariable sequences exists in A. phagocytophilum strains in the Northeastern United States... - Transcriptional analysis of p30 major outer membrane protein genes of Ehrlichia canis in naturally infected ticks and sequence analysis of p30-10 of E canis from diverse geographic regionsSuleyman Felek
Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, Ohio 43210 1093, USA
J Clin Microbiol 41:886-8. 2003..canis. The present study revealed transcription of p30-10 by E. canis in naturally infected ticks and sequence conservation of p30-10 genes for E. canis from diverse geographic regions... - Cyclic di-GMP signaling regulates invasion by Ehrlichia chaffeensis of human monocytesYumi Kumagai
Department of Veterinary Biosciences, The Ohio State University, Columbus, OH 43210, USA
J Bacteriol 192:4122-33. 2010..Furthermore, anti-HtrA inhibited CDGA-induced TRP120 degradation. Our results suggest that E. chaffeensis invasion is regulated by c-di-GMP signaling, which stabilizes some bacterial surface-exposed proteins against proteases... - Anaplasma phagocytophilum has a functional msp2 gene that is distinct from p44Quan Lin
Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, 1925 Coffey Road, Columbus, OH 43210 1093, USA
Infect Immun 72:3883-9. 2004..These findings may be important in understanding roles that Msp2 proteins play in granulocytic ehrlichia infection and evolution of the polymorphic major outer membrane protein gene families in Anaplasma species... - Ehrlichia ewingii infection delays spontaneous neutrophil apoptosis through stabilization of mitochondriaQingming Xiong
Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, USA
J Infect Dis 197:1110-8. 2008..These results suggest that E. ewingii delays spontaneous apoptosis of neutrophils via stabilization of host cell mitochondria... - The Anaplasma phagocytophilum PleC histidine kinase and PleD diguanylate cyclase two-component system and role of cyclic Di-GMP in host cell infectionTzung Huei Lai
Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, 1925 Coffey Road, Columbus, OH 43210 1093, USA
J Bacteriol 191:693-700. 2009..phagocytophilum infection in HL-60 cells. Our results suggest that the two-component PleC-PleD system is a diguanylate cyclase and that a c-di-GMP-receptor complex regulates A. phagocytophilum intracellular infection... - Proteomic identification of a novel Anaplasma phagocytophilum DNA binding protein that regulates a putative transcription factorXueqi Wang
Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, 1925 Coffey Road, Columbus, OH 43210 1093, USA
J Bacteriol 189:4880-6. 2007..Addition of regions I, II, and III did not enhance transactivation. These results show that ApxR is a novel transcriptional regulator that directly regulates tr1... - Experimental infection of dairy calves with Ehrlichia chaffeensisJose R C delos Santos
Department of Veterinary Preventive Medicine, Ohio State University, Columbus, OH, USA
J Med Microbiol 56:1660-8. 2007..These results suggest that a bovine disease model could facilitate the understanding of factors that affect the severity of HME... - Four VirB6 paralogs and VirB9 are expressed and interact in Ehrlichia chaffeensis-containing vacuolesWeichao Bao
Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, 1925 Coffey Road, Columbus, OH 43210 1093, USA
J Bacteriol 191:278-86. 2009..The results suggest that E. chaffeensis VirB9, the quadruple VirB6 proteins, and the VirB6-2 80-kDa fragment form a unique molecular subassembly to cooperate in type IV secretion... - Anaplasma phagocytophilum AnkA secreted by type IV secretion system is tyrosine phosphorylated by Abl-1 to facilitate infectionMingqun Lin
Department of Veterinary Biosciences, The Ohio State University, 1925 Coffey Road, Columbus, OH 43210, USA
Cell Microbiol 9:2644-57. 2007.... - Development of a p28-based PCR assay for Ehrlichia chaffeensisElizabeth R Wagner
Department of Veterinary Preventive Medicine, The Ohio State University, 1900 Coffey Road, Columbus, OH 43210-1092, USA
Mol Cell Probes 18:111-6. 2004..chaffeensis, E. canis and E. muris. These results indicate that this sensitive, specific and isolate-universal single-step PCR assay will be a useful tool in characterizing the transmission of this important zoonotic pathogen... - High-cholesterol diet facilitates Anaplasma phagocytophilum infection and up-regulates macrophage inflammatory protein-2 and CXCR2 expression in apolipoprotein E-deficient miceQingming Xiong
Department of Veterinary Biosciences, College of Veterinary Medicine, Ohio State University, Columbus, OH 43210, USA
J Infect Dis 195:1497-503. 2007..This bacterium requires cholesterol for host cell infection in vitro and incorporates exogenous cholesterol into its membrane... - Cholesterol-dependent anaplasma phagocytophilum exploits the low-density lipoprotein uptake pathwayQingming Xiong
Department of Veterinary Biosciences, The Ohio State University, Columbus, Ohio, United States of America
PLoS Pathog 5:e1000329. 2009..phagocytophilum. These data reveal that A. phagocytophilum exploits the host LDL uptake pathway and LDLR mRNA regulatory system to accumulate cholesterol in inclusions to facilitate its replication... - Polymorphism and transcription at the p44-1/p44-18 genomic locus in Anaplasma phagocytophilum strains from diverse geographic regionsQuan Lin
Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, Ohio 43210 1093, USA
Infect Immun 72:5574-81. 2004..These p44 loci provide insight into the molecular evolution and functional divergence of p44 paralogs and may serve as markers for typing strains from different geographic regions... - Rapid sequential changeover of expressed p44 genes during the acute phase of Anaplasma phagocytophilum infection in horsesXueqi Wang
Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, 1925 Coffey Road, Columbus, OH 43210-1093, USA
Infect Immun 72:6852-9. 2004..Results suggest that the rapid and synchronized switch of expression is an intrinsic property of p44s reinitiated after transmission to naive mammalian hosts and shaped upon exposure to immune plasma... - Activation of a p44 pseudogene in Anaplasma phagocytophila by bacterial RNA splicing: a novel mechanism for post-transcriptional regulation of a multigene family encoding immunodominant major outer membrane proteinsNing Zhi
Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, 1925 Coffey Road, 43210 1093, USA
Mol Microbiol 46:135-45. 2002..Collectively, the novel RNA splicing and the temperature-dependent transcription may account for the dominant p44-18 expression in mammals... - Anaplasma phagocytophilum Ats-1 is imported into host cell mitochondria and interferes with apoptosis inductionHua Niu
Department of Veterinary Biosciences, The Ohio State University, Columbus, Ohio, USA
PLoS Pathog 6:e1000774. 2010..Bax redistribution was inhibited in both etoposide-induced and Bax-induced apoptosis by Ats-1. Taken together, Ats-1 is the first example of a bacterial protein that traverses five membranes and prevents apoptosis at the mitochondria... - Analysis of involvement of the RecF pathway in p44 recombination in Anaplasma phagocytophilum and in Escherichia coli by using a plasmid carrying the p44 expression and p44 donor lociQuan Lin
Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, 1925 Coffey Road, Columbus, OH 43210, USA
Infect Immun 74:2052-62. 2006..coli strain with active RecF recombination pathway but not in strains with deficient RecF pathway. Our results support the view that the p44 gene conversion in A. phagocytophilum occurs through the RecF pathway... - Proposal to transfer 'Aegyptianella ranarum', an intracellular bacterium of frog red blood cells, to the family Flavobacteriaceae as 'Candidatus Hemobacterium ranarum' comb. novChunbin Zhang
Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, 1925 Coffey Road, Columbus, OH 43210, USA
Environ Microbiol 6:568-73. 2004..We propose to classify 'Aegyptianella ranarum' as 'Candidatus Hemobacterium ranarum' in the family Flavobacteriaceae. Our results provide a starting point for studies of related intraerythrocytic bacterial infections in frogs... - Cytokine gene expression by peripheral blood leukocytes in horses experimentally infected with Anaplasma phagocytophilaHyung-Yong Kim
Department of Veterinary Biosciences, The Ohio State University, Columbus, Ohio 43210-1093, USA
Clin Diagn Lab Immunol 9:1079-84. 2002..These results suggest that IL-1beta, TNF-alpha, and IL-8 generation during A. phagocytophila infection has a primary role in HGE pathogenesis and immunomodulation... - Roles of p38 mitogen-activated protein kinase, NF-kappaB, and protein kinase C in proinflammatory cytokine mRNA expression by human peripheral blood leukocytes, monocytes, and neutrophils in response to Anaplasma phagocytophilaHyung Yong Kim
Department of Veterinary Biosciences, The Ohio State University, Columbus 43210 1093, USA
Infect Immun 70:4132-41. 2002..These results suggest that A. phagocytophila transduces different signals between its host neutrophils and monocytes for proinflammatory cytokine generation... - Expression and porin activity of P28 and OMP-1F during intracellular Ehrlichia chaffeensis developmentYumi Kumagai
Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, 1925 Coffey Road, Columbus, OH 43210 1093, USA
J Bacteriol 190:3597-605. 2008..chaffeensis development at both temperatures... - Regulation of type IV secretion apparatus genes during Ehrlichia chaffeensis intracellular development by a previously unidentified proteinZhihui Cheng
Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, 1925 Coffey Road, Columbus, OH 43210 1093, USA
J Bacteriol 190:2096-105. 2008..The expression of ecxR was positively autoregulated by EcxR. These results suggest that the five virBD loci are coordinately regulated by EcxR to allow developmental stage-specific expression of the T4S system in E. chaffeensis... - Degradation of p22phox and inhibition of superoxide generation by Ehrlichia chaffeensis in human monocytesMingqun Lin
Department of Veterinary Biosciences, The Ohio State University, Columbus, OH 43210, USA
Cell Microbiol 9:861-74. 2007..These findings point to a unique survival mechanism of ROS-sensitive obligate intraleucocytic bacteria that involves the destabilization of p22(phox) following the binding of bacteria to host cell surface proteins... - Establishment of cloned Anaplasma phagocytophilum and analysis of p44 gene conversion within an infected horse and infected SCID miceQuan Lin
Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, 1925 Coffey Road, Columbus, OH 43210-1093, USA
Infect Immun 73:5106-14. 2005..The cloning method developed would facilitate precise analysis of the recombination process and the extent of diversity which the recombination creates in the antigenic repertoire... - Surface-exposed proteins of Ehrlichia chaffeensisYan Ge
Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, 1925 Coffey Road, Columbus, OH 43210, USA
Infect Immun 75:3833-41. 2007..The identification of E. chaffeensis surface-exposed proteins provides novel insights into the E. chaffeensis surface and lays the foundation for rational studies on pathogen-host interactions and vaccine development... - Identification of novel surface proteins of Anaplasma phagocytophilum by affinity purification and proteomicsYan Ge
Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, 1925 Coffey Rd, Columbus, OH 43210, USA
J Bacteriol 189:7819-28. 2007..phagocytophilum and the host. These proteins may serve as targets for development of chemotherapy, diagnostics, and vaccines... - Anaplasma phagocytophilum p44 mRNA expression is differentially regulated in mammalian and tick host cells: involvement of the DNA binding protein ApxRXueqi Wang
Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, 1925 Coffey Road, Columbus, OH 43210 1093, USA
J Bacteriol 189:8651-9. 2007..These results indicate that p44 genes and apxR are specifically up-regulated in the mammalian host environment and suggest that ApxR not only is positively autoregulated but also acts as a transcriptional regulator of p44E... - Cyclic dimeric GMP signaling regulates intracellular aggregation, sessility, and growth of Ehrlichia chaffeensisYumi Kumagai
Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, OH 43210 1093, USA
Infect Immun 79:3905-12. 2011..chaffeensis within the inclusion through stabilization of matrix proteins by preventing the serine protease activity, which is associated with bacterial intracellular proliferation and maturation... - Cloning of the major outer membrane protein expression locus in Anaplasma platys and seroreactivity of a species-specific antigenTzung Huei Lai
Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, OH 43210 1093, USA
J Bacteriol 193:2924-30. 2011..Together, determination of the genomic locus of A. platys outer membrane proteins not only contributes to the fundamental understanding of this enigmatic pathogen but also helps in developing A. platys-specific PCR and serodiagnosis... - Ultrastructure and phylogenetic analysis of 'Candidatus Neoehrlichia mikurensis' in the family Anaplasmataceae, isolated from wild rats and found in Ixodes ovatus ticksMakoto Kawahara
Nagoya City Public Health Research Institute, Hagiyama cho, Mizuho ku, Nagoya, 467 8615, Japan
Int J Syst Evol Microbiol 54:1837-43. 2004..It is proposed that this new cluster of bacteria should be designated 'Candidatus Neoehrlichia mikurensis'... - Molecular detection and characterization of Ehrlichia canis from dogs in TurkeyAhmet Unver
Department of Microbiology, Faculty of Veterinary Medicine, Kafkas University, Kars, Turkey
Berl Munch Tierarztl Wochenschr 118:300-4. 2005..The findings in this study would help for a better understanding of epidemiology of canine ehrlichiosis. This is the first report of molecular detection and characterization of an ehrlichial agent in Turkey... - Cytokine responses in dogs infected with Ehrlichia canis Oklahoma strainTomoko Tajima
Laboratory of Veterinary Microbiology, Graduate School of Life and Environmental Science, Osaka Prefecture University, Sakai, Osaka 599 8531, Japan
Ann N Y Acad Sci 1063:429-32. 2005..canis Oklahoma strain. We also examined production of interferon-gamma (IFN-gamma) by canine PBMCs infected with E. canis in vitro... - Comparative genomics of emerging human ehrlichiosis agentsJulie C Dunning Hotopp
The Institute for Genomic Research, Rockville, Maryland, USA
PLoS Genet 2:e21. 2006..These discoveries provide significant insights into the biology of these obligate intracellular pathogens... - 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 JapanMakoto Kawahara
Nagoya City Public Health Research Institute, Nagoya, Japan
Appl Environ Microbiol 72:1102-9. 2006..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... - Reinfection with Ehrlichia chaffeensis in a liver transplant recipientAllison M Liddell
Department of Medicine, Washington University School of Medicine, St. Louis, MO, 63110, USA
Clin Infect Dis 34:1644-7. 2002..We report a case of reinfection with E. chaffeensis after a 2-year interval in a 56-year-old liver transplant recipient with frequent tick attachments... - Evaluation of sensitivity and specificity of a Mycoplasma haemomuris-specific polymerase chain reaction testChunbin Zhang
Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus 43210, USA
Comp Med 52:313-5. 2002..haemomuris and did not amplify closely related species, such as M. haemofelis, M. haemosuis, M. orale, or Anaplasma marginale. CONCLUSION: This method is sensitive and specific for detection of M. haemomuris... - Subversion of cellular autophagy by Anaplasma phagocytophilumHua Niu
Department of Veterinary Biosciences, The Ohio State University, Columbus, OH 43210, USA
Cell Microbiol 10:593-605. 2008..phagocytophilum subverts this system to establish itself in an early autophagosome-like compartment segregated from lysosomes to facilitate its proliferation... - Molecular analysis of Neorickettsia risticii in adult aquatic insects in Pennsylvania, in horses infected by ingestion of insects, and isolated in cell cultureJason Mott
Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, Ohio 43210 1092, USA
J Clin Microbiol 40:690-3. 2002..16S rRNA and 51-kDa antigen gene sequences from blood, isolates, and caddis flies fed to the horses were identical, proving oral transmission of N. risticii from caddis flies to horses... - Porin activity of Anaplasma phagocytophilum outer membrane fraction and purified P44Haibin Huang
Department of Veterinary Biosciences, The Ohio State University, Columbus, OH 43210, USA
J Bacteriol 189:1998-2006. 2007.... - Anaplasma phagocytophilum delays spontaneous human neutrophil apoptosis by modulation of multiple apoptotic pathwaysYan Ge
Department of Veterinary Biosciences, The Ohio State University, Columbus, 43210, USA
Cell Microbiol 8:1406-16. 2006..These data point to a novel mechanism induced by A. phagocytophilum involving both extrinsic and intrinsic pathways to ensure to delay the apoptosis of host neutrophils... - Mechanisms of variable p44 expression by Anaplasma phagocytophilumQuan Lin
Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, 1925 Coffey Road, Columbus, OH 43210, USA
Infect Immun 71:5650-61. 2003..The data suggest that the P44 antigenic repertoire within the hypervariable region is restricted... - Ehrlichia chaffeensis downregulates surface Toll-like receptors 2/4, CD14 and transcription factors PU.1 and inhibits lipopolysaccharide activation of NF-kappa B, ERK 1/2 and p38 MAPK in host monocytesMingqun Lin
Department of Veterinary Biosciences, 1925 Coffey Road, The Ohio State University, Columbus, OH 43210, USA
Cell Microbiol 6:175-86. 2004..These data point to a novel mechanism by which E. chaffeensis can survive by inhibiting critical signalling in monocyte activation pathways linked to pattern recognition receptors...
Research Grants
- EHRLICHIACIDAL MECHANISM BY MACROPHAGE CA++ MOBILIZATIONYasuko Rikihisa; Fiscal Year: 1992....
- EHRLICHIACIDAL MECHANISM BY LEUKOCYTESYasuko Rikihisa; Fiscal Year: 2003..The knowledge will be exploited in identifying novel therapeutic and vaccine targets. ..
- GENE EXPRESSION BY HUMAN GRANULOCYTIC EHRLICHIOSIS AGYasuko Rikihisa; Fiscal Year: 2004..These efforts are expected to reveal an important role for the p44-multigene family in strategies of adaptive surface variation and avoidance of host immune responses. ..
- TYPE IV SECRETION & SIGNAL TRANSDUCTION IN EHRLICHIOSISYasuko Rikihisa; Fiscal Year: 2007..This project will potentially provide a technical breakthrough in this field of research. The results may point to a potential target for new treatment and prevention of HME and HGE. ..
- Comparison of Human Ehrlichiosis Agent GenomesYasuko Rikihisa; Fiscal Year: 2007..chaffeensis virulence determinants and their pathogenic mechanisms. The results may point to potential chemotherapy, chemopreventive and/or vaccine candidates for treatment and prevention of human ehrlichiosis. ..
- Ehrilchiacidal Mechanisms In LeukocytesYasuko Rikihisa; Fiscal Year: 2009..The results may point to a potential target for new treatment and prevention of HME and HGE. ..
- Comparison of Human Ehrlichiosis Agent GenomesYasuko Rikihisa; Fiscal Year: 2009..chaffeensis virulence determinants and their pathogenic mechanisms. The results may point to potential chemotherapy, chemopreventive and/or vaccine candidates for treatment and prevention of human ehrlichiosis. ..
- TYPE IV SECRETION & SIGNAL TRANSDUCTION IN EHRLICHIOSISYasuko Rikihisa; Fiscal Year: 2010....
- COMPARISON OF 3 HUMAN EHRLICHIOSIS GENOME SEQUENCESYasuko Rikihisa; Fiscal Year: 2002....
- ROLES OF EHRLICHIAL OUTER MEMBRANE PROTEIN IN PARASITISMYasuko Rikihisa; Fiscal Year: 2001..Aim 5 addresses hypothesis 3 by examining the effects of immunization with the ehrlichial OMP in a mouse model of human ehrlichiosis. ..
- Comparison of Human Ehrlichiosis Agent GenomesYasuko Rikihisa; Fiscal Year: 2010..chaffeensis virulence determinants and their pathogenic mechanisms. The results may point to potential chemotherapy, chemopreventive and/or vaccine candidates for treatment and prevention of human ehrlichiosis. ..