Exemplar Abstract for Ehrlichia chaffeensis Anderson et al. 1992 emend. Hördt et al. 2020.

2003 ◽  
Author(s):  
Charles Thomas Parker ◽  
Dorothea Taylor ◽  
George M Garrity
Keyword(s):  
Ehrlichia Chaffeensis

scholarly journals Characterization of the Major Antigenic Protein 2 of Ehrlichia canis and Ehrlichia chaffeensis and Its Application for Serodiagnosis of Ehrlichiosis

2003 ◽  
Vol 10 (4) ◽  
pp. 520-524 ◽  
Author(s):  
Tamece T. Knowles ◽  
A. Rick Alleman ◽  
Heather L. Sorenson ◽  
David C. Marciano ◽  
Edward B. Breitschwerdt ◽  
...  
Keyword(s):  
Blot Analysis ◽  
Single Copy ◽  
Ehrlichia Canis ◽  
Specific Method ◽  
Ehrlichia Chaffeensis ◽  
Antigenic Protein ◽  
Canine Monocytic Ehrlichiosis ◽  
Copy Gene ◽  
Species Specific

ABSTRACT Canine monocytic ehrlichiosis, caused by Ehrlichia canis or Ehrlichia chaffeensis, can result in clinical disease in naturally infected animals. Coinfections with these agents may be common in certain areas of endemicity. Currently, a species-specific method for serological diagnosis of monocytic ehrlichiosis is not available. Previously, we developed two indirect enzyme-linked immunosorbent assays (ELISAs) using the major antigenic protein 2 (MAP2) of E. chaffeensis and E. canis. In this study, we further characterized the conservation of MAP2 among various geographic isolates of each organism and determined if the recombinant MAP2 (rMAP2) of E. chaffeensis would cross-react with E. canis-infected dog sera. Genomic Southern blot analysis using digoxigenin-labeled species-specific probes suggested that map2 is a single-copy gene in both Ehrlichia species. Sequences of the single map2 genes of seven geographically different isolates of E. chaffeensis and five isolates of E. canis are highly conserved among the various isolates of each respective ehrlichial species. ELISA and Western blot analysis confirmed that the E. chaffeensis rMAP2 failed to serologically differentiate between E. canis and E. chaffeensis infections.

scholarly journals Ehrlichia chaffeensis and Its Invasin EtpE Block Reactive Oxygen Species Generation by Macrophages in a DNase X-Dependent Manner

mBio ◽  
2017 ◽  
Vol 8 (6) ◽  
Author(s):  
Omid Teymournejad ◽  
Mingqun Lin ◽  
Yasuko Rikihisa
Keyword(s):  
Host Cell ◽  
Cell Receptor ◽  
Ros Generation ◽  
Ehrlichia Chaffeensis ◽  
Biological Processes ◽  
Wild Type ◽  
New Approach ◽  
Host Cell Receptor ◽  
Life Threatening ◽  
Human Monocytic Ehrlichiosis

ABSTRACT The obligatory intracellular pathogen Ehrlichia chaffeensis lacks most genes that confer resistance to oxidative stress but can block reactive oxygen species (ROS) generation by host monocytes-macrophages. Bacterial and host molecules responsible for this inhibition have not been identified. To infect host cells, Ehrlichia uses the C terminus of its surface invasin, entry-triggering protein of Ehrlichia (EtpE; EtpE-C), which directly binds the mammalian cell surface receptor glycosylphosphatidylinositol-anchored protein DNase X. We investigated whether EtpE-C binding to DNase X blocks ROS production by mouse bone marrow-derived macrophages (BMDMs). On the basis of a luminol-dependent chemiluminescence assay, E. chaffeensis inhibited phorbol myristate acetate (PMA)-induced ROS generation by BMDMs from wild-type, but not DNase X−/−, mice. EtpE-C is critical for inhibition, as recombinant EtpE-C (rEtpE-C)-coated latex beads, but not recombinant N-terminal EtpE-coated or uncoated beads, inhibited PMA-induced ROS generation by BMDMs from wild-type mice. DNase X is required for this inhibition, as none of these beads inhibited PMA-induced ROS generation by BMDMs from DNase X−/− mice. Previous studies showed that E. chaffeensis does not block ROS generation in neutrophils, a cell type that is a potent ROS generator but is not infected by E. chaffeensis. Human and mouse peripheral blood neutrophils did not express DNase X. Our findings point to a unique survival mechanism of ROS-sensitive obligate intramonocytic bacteria that involves invasin EtpE binding to DNase X on the host cell surface. This is the first report of bacterial invasin having such a subversive activity on ROS generation. IMPORTANCE Ehrlichia chaffeensis preferentially infects monocytes-macrophages and causes a life-threatening emerging tick-transmitted infectious disease called human monocytic ehrlichiosis. Ehrlichial infection, and hence the disease, depends on the ability of this bacterium to avoid or overcome powerful microbicidal mechanisms of host monocytes-macrophages, one of which is the generation of ROS. Our findings reveal that an ehrlichial surface invasin, EtpE, not only triggers bacterial entry but also blocks ROS generation by host macrophages through its host cell receptor, DNase X. As ROS sensitivity is an Achilles’ heel of this group of pathogens, understanding the mechanism by which E. chaffeensis rapidly blocks ROS generation suggests a new approach for developing effective anti-infective measures. The discovery of a ROS-blocking pathway is also important, as modulation of ROS generation is important in a variety of ailments and biological processes. IMPORTANCE Ehrlichia chaffeensis preferentially infects monocytes-macrophages and causes a life-threatening emerging tick-transmitted infectious disease called human monocytic ehrlichiosis. Ehrlichial infection, and hence the disease, depends on the ability of this bacterium to avoid or overcome powerful microbicidal mechanisms of host monocytes-macrophages, one of which is the generation of ROS. Our findings reveal that an ehrlichial surface invasin, EtpE, not only triggers bacterial entry but also blocks ROS generation by host macrophages through its host cell receptor, DNase X. As ROS sensitivity is an Achilles’ heel of this group of pathogens, understanding the mechanism by which E. chaffeensis rapidly blocks ROS generation suggests a new approach for developing effective anti-infective measures. The discovery of a ROS-blocking pathway is also important, as modulation of ROS generation is important in a variety of ailments and biological processes.

Ehrlichia chaffeensis in a Renal Transplant Recipient

1999 ◽  
Vol 19 (6) ◽  
pp. 674-676 ◽  
Author(s):  
Roxiana Sadikot ◽  
Mary Jo Shaver ◽  
W. Brian Reeves
Keyword(s):  
Renal Transplant ◽  
Transplant Recipient ◽  
Renal Transplant Recipient ◽  
Ehrlichia Chaffeensis

scholarly journals Ehrlichia chaffeensis TRP120 nucleomodulin binds DNA with disordered tandem repeat domain

PLoS ONE ◽  
2018 ◽  
Vol 13 (4) ◽  
pp. e0194891 ◽  
Author(s):  
Valerie J. Klema ◽  
Krishna Mohan Sepuru ◽  
Nadia Füllbrunn ◽  
Tierra R. Farris ◽  
Paige S. Dunphy ◽  
...  
Keyword(s):  
Tandem Repeat ◽  
Ehrlichia Chaffeensis ◽  
Repeat Domain

scholarly journals A case of human monocytic ehrlichiosis in Serbia

2014 ◽  
Vol 142 (1-2) ◽  
pp. 79-82 ◽  
Author(s):  
Bogdan Arsic ◽  
Ana Gligic ◽  
Elizabeta Ristanovic ◽  
Branislav Lako ◽  
Aleksandar Potkonjak ◽  
...  
Keyword(s):  
Indirect Immunofluorescence ◽  
Clinical Picture ◽  
Peripheral Blood ◽  
Immunofluorescence Assay ◽  
High Fever ◽  
Tick Bite ◽  
Indirect Immunofluorescence Assay ◽  
Ehrlichia Chaffeensis ◽  
Serum Samples ◽  
History Of

Introduction. Ehrlichiosis is a bacterial zoonosis transmitted by hematophagous arthropods - ticks. In humans, it occurs as monocytic, granulocytic, and ewingii ehrlichiosis. Pathological process is based on parasitic presence of Ehrlichia organisms within peripheral blood cells - monocytes and granulocytes. Case Outline. Fifty-two year old patient was admitted to hospital due to high fever of over 40?C that lasted two days, accompanied with chills, muscle aches, malaise, loss of appetite, headache, confusion, breathing difficulties, and mild dry cough. The history suggested tick bite that occurred seven days before the onset of disease. Doxycycline was introduced and administered for 14 days, causing the disease to subside. Indirect immunofluorescence assay was used to analyze three serum samples obtained from this patient for Ehrlichia chaffeensis antibodies, and peripheral blood smear was evaluated for the presence of Ehrlichia and Ehrlichia aggregation into morulae. Conclusion. Ehrlichiosis should be considered in each case where there is a history of tick bite together with the clinical picture (high fever, chills, muscle aches, headache, generalized weakness and malaise, and possible maculopapular rash). The presence of Ehrlichia chaffeensis antibodies was confirmed in a patient with the history of tick bite, appropriate clinical picture and indirect immunofluorescence assay. This confirmed the presence of human monocytotropic ehrlichiosis, a disease that is uncommonly identified in our country.

Experimental Transmission of Ehrlichia chaffeensis (Rickettsiales: Ehrlichieae) Among White-Tailed Deer by Amblyomma americanum (Acari: Ixodidae)

1995 ◽  
Vol 32 (3) ◽  
pp. 368-374 ◽  
Author(s):  
S. A. Ewing ◽  
J. E. Dawson ◽  
A. A. Kocan ◽  
R. W. Barker ◽  
C. K. Warner ◽  
...  
Keyword(s):  
Amblyomma Americanum ◽  
Ehrlichia Chaffeensis ◽  
Experimental Transmission
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