<i>Ehrlichia chaffeensis</i>in Child, Venezuela

Martínez, Marcelino Álvarez; Gutiérrez, Clara; Monger, Franklin; Ruiz, Johanny; Watts, Akemys; Mijares, Víctor M.; Rojas, María G.; Triana-Alonso, Francisco J.

doi:10.3201/eid1403.061304

Cited by 24 publications

(16 citation statements)

References 10 publications

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“…With the increase of income and living standards, and the pursuit of exotic and delicate foods, populations around the world have seen angiostrongyliasis become an important foodborne parasitic zoonosis (1)(2)(3)(4)(5)(6)(7)(8)(9).…”

Section: Enzootic Angiostrongyliasis In Shenzhen Chinamentioning

confidence: 99%

Molecular Detection ofEhrlichia chaffeensisinAmblyomma parvumTicks, Argentina

Tomassone¹,

Núñez²,

Gürtler³

et al. 2008

Emerg. Infect. Dis.

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Section: Enzootic Angiostrongyliasis In Shenzhen Chinamentioning

confidence: 99%

Molecular Detection ofEhrlichia chaffeensisinAmblyomma parvumTicks, Argentina

Tomassone¹,

Núñez²,

Gürtler³

et al. 2008

Emerg. Infect. Dis.

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“…E. chaffeensis, E. canis, and E. muris infect monocytes and macrophages, whereas E. ewingii infects granulocytes, and they cause subclinical or serious sometimes fatal infectious diseases (Buller et al, 1999;Paddock and Childs, 2003;Pritt et al, 2011). Human ehrlichiosis is characterized by fever, headache, myalgia, thrombocytopenia, leucopenia, and elevated liver enzyme levels (Perez et al, 1996(Perez et al, , 2006Buller et al, 1999;Paddock and Childs, 2003;Martinez et al, 2008;Pritt et al, 2011). Complications, such as pulmonary insufficiency, renal failure, encephalopathy, and disseminated intravascular coagulation can occur in fatal human cases of E. chaffeensis infection (Paddock et al, 1997).…”

Section: Introductionmentioning

confidence: 99%

Discovery of in vivo Virulence Genes of Obligatory Intracellular Bacteria by Random Mutagenesis

Bekebrede

Lin

Teymournejad

et al. 2020

Front. Cell. Infect. Microbiol.

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Ehrlichia spp. are emerging tick-borne obligatory intracellular bacteria that cause febrile and sometimes fatal diseases with abnormal blood cell counts and signs of hepatitis. Ehrlichia HF strain provides an excellent mouse disease model of fatal human ehrlichiosis. We recently obtained and established stable culture of Ehrlichia HF strain in DH82 canine macrophage cell line, and obtained its whole genome sequence and annotation. To identify genes required for in vivo virulence of Ehrlichia, we constructed random insertional HF strain mutants by using Himar1 transposon-based mutagenesis procedure. Of total 158 insertional mutants isolated via antibiotic selection in DH82 cells, 74 insertions were in the coding regions of 55 distinct protein-coding genes, including TRP120 and multicopy genes, such as p28/omp-1, virB2, and virB6. Among 84 insertions mapped within the non-coding regions, seven are located in the putative promoter region since they were within 50 bp upstream of the seven distinct genes. Using limited dilution methods, nine stable clonal mutants that had no apparent defect for multiplication in DH82 cells, were obtained. Mouse virulence of seven mutant clones was similar to that of wild-type HF strain, whereas two mutant clones showed significantly retarded growth in blood, livers, and spleens, and the mice inoculated with them lived longer than mice inoculated with wild-type. The two clones contained mutations in genes encoding a conserved hypothetical protein and a staphylococcal superantigen-like domain protein, respectively, and both genes are conserved among Ehrlichia spp., but lack homology to other bacterial genes. Inflammatory cytokine mRNA levels in the liver of mice infected with the two mutants were significantly diminished than those infected with HF strain wild-type, except IL-1β and IL-12 p40 in one clone. Thus, we identified two Ehrlichia virulence genes responsible for in vivo infection, but not for infection and growth in macrophages.Keywords: Ehrlichia HF strain, Himar1 transposon mutagenesis, mouse virulence, inflammatory cytokines, staphylococcal superantigen-like domain, obligatory intracellular bacteria IMPORTANCE Ehrlichiosis, a sometimes deadly febrile disease in man and animal, is caused by infection with Gram-negative obligatory intracellular bacteria, Ehrlichia. Ehrlichia species lack typical pathogen-associate molecular patterns (PAMPs), such as lipopolysaccharide, peptidoglycan, pili, and flagella, yet they induce acute and/or chronic inflammatory cytokines in infected animals.Bekebrede et al. In vivo Virulence Genes of EhrlichiaStudies to identify virulence factors and PAMPs of Ehrlichia species are hampered by the limitation to applicable genetic tools and small laboratory animal models. Mouse infection with Ehrlichia HF strain provides an excellent model for fatal human ehrlichiosis, as the HF strain is highly virulent in laboratory mice. However, due to inability to culture the HF stain, the use of this model has been limited. As we have succeeded in culturing and who...

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“…Serosurveys and molecular techniques have documented the presence of human ehrlichiosis in South America. [3][4][5][6][7] Evidence of human ehrlichiosis in Peru is lacking although E. canis infection was recently demonstrated in dogs. 8 Given the absence of data, we conducted a serosurvey in geographically distinct rural communities from Peru to establish the possible presence of this pathogen.…”

mentioning

confidence: 99%

“…9 Use of similar techniques in a more recent study suggested an E. chaffeensis infection in a Venezuelan child. 7 Serosurveys in Argentina, Brazil, Chile, Mexico, and Venezuela have detected human ehrlichiosis 3-6,10 but it is unclear what Ehrlichia species may be causing human infection. Recent findings using molecular diagnostic techniques indicate that E. chaffeensis may be present in the Brazilian marsh deer, which suggests that this mammal may act as a natural reservoir of the agents that cause HME.…”

mentioning

confidence: 99%

Serologic Evidence of Human Ehrlichiosis in Peru

Moro¹,

Shah

et al. 2009

Am J Trop Med Hyg

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A serosurvey for human ehrlichiosis caused by Ehrlichia chaffeensis and Anaplasma phagocytophilum was performed in different regions of Peru by using indirect immunofluorescence assays (IFAs). Regions included an urban community in a shantytown in Lima (Pampas) and three rural communities located on the northern coast of Peru (Cura Mori), in the southern Peruvian Andes (Cochapata), and in the Peruvian jungle region (Santo Tomas). An overall E. chaffeensis seroprevalence of 13% (21 of 160) was found by IFA. Seroprevalences in females and males was 15% (16 of 106) and 9% (5 of 53), respectively. Seroprevalences in Cura Mori, Cochapata, Pampas, and Santo Tomas were 25% (10 of 40), 23% (9 of 40), 3% (1 of 40), and 3% (1 of 40), respectively. Seroprevalences in Cura Mori and Cochapata were significantly higher than in Santo Tomas or Pampas (P < 0.01). No sera were reactive to A. phagocytophilum. These findings suggest that human infection with E. chaffeensis occurs in Peru. Further studies are needed to characterize Ehrlichia species in Peru, their vectors and their clinical significance.

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Ehrlichia chaffeensisin Child, Venezuela

Cited by 24 publications

References 10 publications

Molecular Detection ofEhrlichia chaffeensisinAmblyomma parvumTicks, Argentina

Molecular Detection ofEhrlichia chaffeensisinAmblyomma parvumTicks, Argentina

Discovery of in vivo Virulence Genes of Obligatory Intracellular Bacteria by Random Mutagenesis

Serologic Evidence of Human Ehrlichiosis in Peru

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