We developed PCR-based assays to distinguish a human pathogenic strain of Anaplasma phagocytophilum, Ap-ha, from Ap-variant 1, a strain not associated with human infection. The assays were validated on A. phagocytophilum-infected black-legged ticks (Ixodes scapularis) collected in Canada. The relative prevalence of these 2 strains in I. scapularis ticks differed among geographic regions.

Real-time PCR analysis of a groESL heat shock operon segment showed the presence of two genetic lineages of Anaplasma phagocytophilum in Ixodes ricinus ticks as well as one variant in wild red and roe deer, the latter supposedly representing the natural reservoir of one variant of A. phagocytophilum.

Ixodes scapularis (deer ticks) from Maine were tested for multiple infections by polymerase chain reaction and immunofluorescence. In 1995, 29.5%, 9.5%, and 1.9% of deer ticks were infected with Borrelia burgdorferi, Anaplasma phagocytophilum, and Babesia microti, respectively. In 1996 and 1997, the number of A. phagocytophilum-infected ticks markedly declined. In 1995 through 1996, 4 (1.3%) of...

Anaplasma phagocytophilum is a veterinary and medical tick-borne pathogen of vertebrates which invades granulocytes. The potential reservoirs of Anaplasma include game animals and small mammals. The aim ofthis study was to gain insight into the variability ofnucleotide sequences of ribosomal and selected protein-coding genes (ankA, msp4 and the groESL heat-shock protein operon) present in isola...

We retrospectively confirmed 2 cases of human Anaplasma phagocytophilum infection. Patient blood samples contained unique p44/msp2 for the pathogen, and antibodies bound to A. phagocytophilum antigens propagated in THP-1 rather than HL60 cells. Unless both cell lines are used for serodiagnosis of rickettsiosis-like infections, cases of human granulocytic anaplasmosis could go undetected.

A total of 87 Thoroughbred horses and 10 ixodid ticks from a ranch in Hidaka district, Hokkaido were tested for tick-borne diseases. Using the indirect fluorescent antibody (IFA) method, 3.4, 92.0 and 97.7% of the horses showed antibody titers of ≥ 80 against Anaplasma phagocytophilum, Rickettsia helvetica, and Borrelia garinii, respectively. This is the first report of infection with the 3 pat...

Objectives The primary objective of this study was to determine the prevalence of Anaplasma phagocytophilum infection and exposure in adult feral cats in Massachusetts, an endemic area for A phagocytophilum and its tick vector Ixodes scapularis. The secondary objective was to determine if there were correlations between A phagocytophilum infection and the presence of anemia and thrombocytopenia...

BACKGROUND Borrelia burgdorferi sensu lato and Anaplasma phagocytophilum are able to infect horses. However, the extend to which Danish horses are infected and seroconvert due to these two bacteria is unknown. The aim of the present study was to evaluate the seroprevalence of B. burgdorferi sensu lato and A. phagocytophilum in Danish horses. METHODS A total of 390 blood samples collected from...

BACKGROUND The aim of the study was to determine the role of game animals as reservoirs of Anaplasma phagocytophilum, a bacteria species transmitted by Ixodes ricinus ticks, from north-western Poland (Zachodniopomorskie vovoidship). The area under question is endemic for A. phagocytophilum. MATERIAL AND METHODS Blood and spleen samples were taken from 72 roe deer between April and December 20...

Anaplasma phagocytophilum, the causative agent of human granulocytic anaplasmosis, is an obligate intracellular bacterium most commonly acquired from tick bites. High seroprevalence rates in endemic regions suggest that transfusion transmission of A phagocytophilum would be a common event; however, only 2 cases have previously been reported. The exact cause of this discrepancy is not known. Who...