Characterization and Transcriptional Analysis of Gene Clusters for a Type IV Secretion Machinery in Human Granulocytic and Monocytic Ehrlichiosis Agents

• DOI: 10.1128/iai.70.4.2128-2138.2002
• Publication Date: 2002-07-27T09:59:40Z
• Authors: Norio Ohashi; Ning Zhi; Quan Lin; Yasuko Rikihisa
• Keywords: Ehrlichia chaffeensis; Anaplasmataceae; Gene cluster

ABSTRACT Anaplasma ( Ehrlichia ) phagocytophila and chaffeensis , the etiologic agents of granulocytic monocytic ehrlichioses, respectively, are obligatory intracellular bacteria that cause febrile systemic illness in humans. We identified characterized clusters genes for a type IV secretion machinery these two bacteria, analyzed their gene expression cell culture mammalian hosts. Eight virB virD were found each bacterial genome, all transcribed culture. Although order orientation similar to those other eight clustered at separate loci genome. Five virB8 virB9 virB10 virB11 virD4 located downstream from ribA gene. These five both A. E. polycistronically controlled through least tandem promoters upstream human leukemia lines. The was transcriptionally active peripheral blood leukocytes ehrlichiosis patients experimentally infected animals. Three remaining virB3 virB4 virB6 arranged sodB cotranscribed with one or more leukocytes. This suggests transcription three spp. is regulated by factors influence expression. unique regulation system may be associated survival replication granulocytes monocytes.