Ehrlichia chaffeensis (Human Monocytotropic Ehrlichiosis), Anaplasma phagocytophilum (Human Granulocytotropic Anaplasmosis), and Other Anaplasmataceae

2010 ◽  
pp. 2531-2538 ◽  
Author(s):  
J. STEPHEN DUMLER ◽  
DAVID H. WALKER
Keyword(s):  
Anaplasma Phagocytophilum ◽  
Ehrlichia Chaffeensis

scholarly journals Increasing Incidence of Ehrlichia chaffeensis and Anaplasma phagocytophilum in the United States, 2000–2007

2011 ◽  
Vol 85 (1) ◽  
pp. 124-131 ◽  
Author(s):  
F. Scott Dahlgren ◽  
Eric J. Mandel ◽  
John W. Krebs ◽  
Robert F. Massung ◽  
Jennifer H. McQuiston
Keyword(s):  
United States ◽  
Anaplasma Phagocytophilum ◽  
The United States ◽  
Ehrlichia Chaffeensis

scholarly journals Ehrlichia chaffeensis and Anaplasma phagocytophilum Lack Genes for Lipid A Biosynthesis and Incorporate Cholesterol for Their Survival

2003 ◽  
Vol 71 (9) ◽  
pp. 5324-5331 ◽  
Author(s):  
Mingqun Lin ◽  
Yasuko Rikihisa
Keyword(s):  
Anaplasma Phagocytophilum ◽  
Lipid A ◽  
Cholesterol Biosynthesis ◽  
Freeze Fracture ◽  
Ultrastructural Changes ◽  
Gram Negative Bacteria ◽  
Ehrlichia Chaffeensis ◽  
Gram Negative ◽  
Unique Nature ◽  
Obligate Intracellular Bacteria

ABSTRACT Ehrlichia chaffeensis and Anaplasma phagocytophilum are agents of human monocytic and granulocytic ehrlichioses, respectively. They are extremely sensitive to mechanical stress and are pleomorphic gram-negative bacteria. Membrane incorporation of cholesterol from the eukaryotic host is known to be essential for other fragile and pleomorphic bacteria and mycoplasmas that lack a cell wall. Thus, we tested whether cholesterol is required for E. chaffeensis and A. phagocytophilum. Using a freeze fracture technique and biochemical analysis, these bacteria were found to contain significant levels of membrane cholesterol. These bacteria lack genes for cholesterol biosynthesis or modification. However, host cell-free bacteria had the ability to take up directly exogenous cholesterol or NBD-cholesterol, a fluorescent cholesterol derivative. Treatment of the bacteria with cholesterol extraction reagent methyl-β-cyclodextrin caused their ultrastructural changes. Furthermore, pretreatment of the bacteria with methyl-β-cyclodextrin or NBD-cholesterol deprived these bacteria of the ability to infect leukocytes, thus killing these obligate intracellular bacteria. Analysis of E. chaffeensis and A. phagocytophilum genome sequences revealed that these bacteria lack all genes for the biosynthesis of lipid A and most genes for the biosynthesis of peptidoglycan, which confer structural strength to gram-negative bacteria. Taken together, these results suggest that human ehrlichiosis agents became cholesterol dependent due to the loss of these genes. 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.

scholarly journals Global Proteomic Analysis of Two Tick-Borne Emerging Zoonotic Agents: Anaplasma Phagocytophilum and Ehrlichia Chaffeensis

2011 ◽  
Vol 2 ◽  
Author(s):  
Mingqun Lin ◽  
Takane Kikuchi ◽  
Heather M. Brewer ◽  
Angela D. Norbeck ◽  
Yasuko Rikihisa
Keyword(s):  
Anaplasma Phagocytophilum ◽  
Proteomic Analysis ◽  
Ehrlichia Chaffeensis

scholarly journals Detection of Antibodies to Anaplasma phagocytophilum and Ehrlichia chaffeensis Antigens in Sera of Korean Patients by Western Immunoblotting and Indirect Immunofluorescence Assays

2003 ◽  
Vol 10 (6) ◽  
pp. 1059-1064 ◽  
Author(s):  
Jin-ho Park ◽  
Eun-jeong Heo ◽  
Kyoung-seong Choi ◽  
J. Stephen Dumler ◽  
Joon-seok Chae
Keyword(s):  
South Korea ◽  
Western Blot ◽  
Anaplasma Phagocytophilum ◽  
Fluorescent Antibody ◽  
Environmental Research ◽  
Ehrlichia Chaffeensis ◽  
Protein Antigens ◽  
Serum Samples ◽  
Western Blot Assay ◽  
Korean Patients

ABSTRACT Two hundred seventy one serum samples from South Korean patients were tested to detect antibodies against Anaplasma phagocytophilum (the human granulocytic ehrlichiosis agent) and Ehrlichia chaffeensis (the human monocytic ehrlichiosis agent) by indirect fluorescent-antibody assay (IFA) and the Western blot assay. These sera were collected from patients with symptoms of high fever. The rate of seropositivity for Orientia tsutsugamushi was 50.9% by IFA at the Public Health & Environmental Research Institute and National Institute of Health in South Korea. By IFA, 30 (11.1%) and 39 (14.4%) of the serum samples reacted with A. phagocytophilum and E. chaffeensis antigens, respectively. By the Western blot assays, 24 (8.9%) and 29 (10.7%) of the serum samples reacted with purified A. phagocytophilum and E. chaffeensis protein antigens, respectively. This report strengthens other evidence regarding the presence of A. phagocytophilum and E. chaffeensis infections in humans in South Korea.

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

2004 ◽  
Vol 48 (12) ◽  
pp. 4822-4828 ◽  
Author(s):  
S. Branger ◽  
J. M. Rolain ◽  
D. Raoult
Keyword(s):  
Real Time ◽  
Quantitative Pcr ◽  
Anaplasma Phagocytophilum ◽  
Point Mutations ◽  
Reference Method ◽  
Ehrlichia Canis ◽  
New Drugs ◽  
Ehrlichia Chaffeensis ◽  
Real Time Quantitative Pcr ◽  
Highly Active

ABSTRACT 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.

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