Understanding the determinants of efficient tick-borne microbial transmission is needed to better predict the emergence of highly transmissible pathogen strains and disease outbreaks. Although the basic developmental cycle of Anaplasma and Ehrlichia spp. within the tick has been delineated, there are marked differences in the ability of specific strains to be efficiently tick transmitted. Using...

Anaplasma marginale is an ehrlichial pathogen of cattle that establishes lifelong persistent infection. Persistence is characterized by rickettsemic cycles in which new A. marginale variant types, defined by the sequence of the expressed msp2 transcripts, emerge. The polymorphic msp2 transcripts encode structurally distinct MSP2 proteins and result in an antigenically diverse and continually ch...

A total of 658 cattle in 6 provinces in the Philippines were screened for Anaplasma marginale infection by using a diagnostic heat-shock operon (groEL) gene-PCR assay. The screening-positive samples were further tested using the major surface antigen protein 1a (Msp1a) gene-PCR assay. Screening PCR results showed 130 cattle (19.8%) were positive for the A. marginale infection. Subsequent amplif...

A newly available competitive inhibition ELISA kit for the serological diagnosis of anaplasmosis was evaluated in Australia and Zimbabwe. In Australia the performance of the test was compared with the card agglutination test (CAT). The assay was evaluated using negative sera collected from Anaplasma-free herds, positive sera from experimentally infected cattle and sera from Anaplasma marginale-...

AIMS The occurrence of human granulocytic ehrlichiosis (HGE) in a patient with chronic myelogenous leukaemia (CML) provided an opportunity to study whether Anaplasma phagocytophilum, the aetiological agent of HGE, infects mature or immature cells, both in vivo and in vitro. METHODS Diagnosis of HGE was confirmed by culture, polymerase chain reaction (PCR), detection of intragranulocytic inclu...

Although scrub typhus and murine typhus are well-described tropical rickettsial illnesses, especially in Southeast Asia, only limited evidence is available for rickettsia-like pathogens contributing to the burden of undifferentiated febrile illness. Using commercially available kits, this study measured immunoglobulin G (IgG) antibody seroprevalence for Coxiella burnetii, Ehrlichia chaffeensis,...

Borrelia burgdorferi, the agent of Lyme disease, and Anaplasma phagocytophilum, the agent of human anaplasmosis, are both transmitted by Ixodes sp. ticks and may occasionally coinfect a host. The population distributions of tick-transmitted B. burgdorferi infection were assessed using quantitative PCR targeting the flaB gene of B. burgdorferi in the ear, heart base, quadriceps muscle, skin, and...

Tick-borne diseases (TBDs) caused by pathogens belonging to the genera Anaplasma, Ehrlichia, Babesia and Theileria in small ruminants are widespread tropical sub-tropical countries. The epidemiology of tick-borne (TBPs) is less understood compared those infecting cattle general. This study was carried out investigate characterize TBPs sheep goats using molecular tools. A total 107 blood samples...