Project description:We report Anaplasma phagocytophilum infection of Ixodes persulcatus and I. ovatus ticks in Japan. Unique p44/msp2 paralogs (and/or 16S rRNA genes) were detected in tick tissues, salivary glands, and spleens of experimentally infected mice. These findings indicate the public health threat of anaplasmosis in Japan.
Project description:Ticks act as vectors of many pathogens of domestic animals and humans. Anaplasma phagocytophilum in Europe is transmitted by the ixodid tick vector Ixodes ricinus. A. phagocytophilum causes a disease with diverse clinical signs in various hosts. A great genetic diversity of the groESL operon of A. phagocytophilum has been found in ticks elsewhere. In Slovenia, the variety of the groESL operon was conducted only on deer samples. In this study, the prevalence of infected ticks was estimated and the diversity of A. phagocytophilum was evaluated. On 8 locations in Slovenia, 1924 and 5049 (6973) I. ricinus ticks were collected from vegetation in the years 2005 and 2006, respectively. All three feeding stages of the tick's life cycle were examined. The prevalence of ticks infected with A. phagocytophilum in the year 2005 and in the year 2006 was 0.31% and 0.63%, respectively, and it did not differ considerably between locations. The similarity among the sequences of groESL ranged from 95.6% to 99.8%. They clustered in two genetic lineages along with A. phagocytophilum from Slovenian deer. One sequence formed a separate cluster. According to our study, the prevalence of A. phagocytophilum in ticks is comparable to the findings in other studies in Europe, and it does not vary considerably between locations and tick stages. According to groESL operon analysis, two genetic lineages have been confirmed and one proposed. Further studies on other genes would be useful to obtain more information on genetic diversity of A. phagocytophilum in ticks in Slovenia.
Project description:BACKGROUND: Anaplasma phagocytophilum , the causative agent of granulocytic anaplasmosis, affects several species of wild and domesticated mammals, including horses. We used direct and indirect methods to compare and evaluate exposure to A. phagocytophilum in horses in northern Tunisia. METHODS: Serum from 60 horses was tested by IFA for antibodies to A. phagocytophilum , and whole blood was tested for A. phagocytophilum 16S rRNA gene using a nested-PCR. To examine the risk of A. phagocytophilum transmission, 154 ticks that had been collected from horses were examined for the presence of A. phagocytophilum by nested-PCR targeting 16S rRNA gene. RESULTS: This is the first time that A. phagocytophilum has been detected in horses in Tunisia, with an overall seroprevalence of 40/60 (67%). Six of the seroreactive samples (10%) had an IFA titer of 1:80, 14 (23%) of 1:160, 8 (13%) of 1:320 and 12 (20%) a titer 1???640. The seroprevalence revealed no significant regional and sex differences. In contrast, a significant difference was observed between breeds. Eight (13%) of the horses were positive for A. phagocytophilum in the PCR, with no significant breed and age differences. Hyalomma marginatum was a predominant tick species (130/154), and 3 were infected by A. phagocytophilum (a prevalence of 2.3%). The concordance rate of A. phagocytophilum detection between IFA and PCR had a k value of -0.07. CONCLUSIONS: The results presented in this study suggest that horses infested by ticks in Tunisia are exposed to A. phagocytophilum.
Project description:Fucosylated structures participate in a wide range of pathological processes in eukaryotes and prokaryotes. The impact of fucose on microbial pathogenesis, however, has been less appreciated in arthropods of medical relevance. Thus, we used the tick-borne bacterium Anaplasma phagocytophilum- the agent of human granulocytic anaplasmosis to understand these processes. Here we show that A. phagocytophilum uses alpha1,3-fucose to colonize ticks. We demonstrate that A. phagocytophilum modulates the expression of alpha1,3-fucosyltransferases and gene silencing significantly reduces colonization of tick cells. Acquisition but not transmission of A. phagocytophilum was affected when alpha1,3-fucosyltransferases were silenced during tick feeding. Our results uncover a novel mechanism of pathogen colonization in arthropods. Decoding mechanisms of pathogen invasion in ticks might expedite the development of new strategies to interfere with the life cycle of A. phagocytophilum.
Project description:A total of 2,121 small mammals in California were assessed for Anaplasma phagocytophilum from 2006 through 2008. Odds ratios were >1 for 4 sciurids species and dusky-footed woodrats. High seroprevalence was observed in northern sites. Ten tick species were identified. Heavily infested rodent species included meadow voles, woodrats, deer mice, and redwood chipmunks.
Project description:Anaplasma phagocytophilum is a zoonotic agent of public health importance, infecting both humans and animals. An investigation of the presence of Anaplasma phagocytophilum as well as Anaplasma platys was conducted in a forest area of Selenge province, Mongolia, where ticks are widely distributed and tick-borne diseases are highly endemic. Ticks were collected and tested using polymerase chain reaction based on groEL methodology. Anaplasma phagocytophilum was detected in 14 (6%) of Ixodes persulcatus ticks and four (1%) Dermacentor nuttalli ticks; infection of Anaplasma platys was detected in 1% of Ixodes persulcatus ticks and 10% of Dermacentor nuttalli ticks. The phylogenetic tree showed that the Anaplasma phagocytophilum clustered with the Russian group, most likely due to similar geographical locations. This finding is significant for both veterinary and public health officials given that these agents can cause both animal and human illness.
Project description: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.
Project description:Anaplasma phagocytophilum persists in nature by cycling between mammals and ticks. Human infection by the bite of an infected tick leads to a potentially fatal emerging disease called human granulocytic anaplasmosis. A. phagocytophilum is an obligatory intracellular bacterium that replicates inside mammalian granulocytes and the salivary gland and midgut cells of ticks. A. phagocytophilum evolved the remarkable ability to hijack the regulatory system of host cells. A. phagocytophilum alters vesicular traffic to create an intracellular membrane-bound compartment that allows replication in seclusion from lysosomes. The bacterium downregulates or actively inhibits a number of innate immune responses of mammalian host cells, and it upregulates cellular cholesterol uptake to acquire cholesterol for survival. It also upregulates several genes critical for the infection of ticks, and it prolongs tick survival at freezing temperatures. Several host factors that exacerbate infection have been identified, including interleukin-8 (IL-8) and cholesterol. Host factors that overcome infection include IL-12 and gamma interferon (IFN-?). Two bacterial type IV secretion effectors and several bacterial proteins that associate with inclusion membranes have been identified. An understanding of the molecular mechanisms underlying A. phagocytophilum infection will foster the development of creative ideas to prevent or treat this emerging tick-borne disease.
Project description:A nationwide epidemiologic investigation of domestic animal infections has been conducted in nine provinces and one city during 2007-2010. Serum samples from a total of 707 goats, 433 cattle, and 219 dogs were collected for detecting Anaplasma phagocytophilum IgG antibody by immunofluorescence assays and the average seroprevalences were 10.05% for dogs, 3.82% for goats, and 0.69% for cattle, respectively. A total of 472 goats, 201 cattle, 102 dog blood clots, and 1,580 ticks were collected for polymerase chain reaction (PCR) amplifying A. phagocytophilum 16S rRNA genes and the PCR-positive rates were 26.69% for goats, 23.38% for cattle, and 10.89% for dogs. Six species were identified and the average PCR-positive rates were 58.3% for Dermacentor silvarum, 43.9% for Haemaphysalis longicornis, 12.5% for Ixodes persulcatus, 7.5% (3 of 40) for Boophilus microplus, and 5.2% for Rhipicephalus sanguineus, respectively. The evidence in the study indicated the zoonotic Rickettsia is highly prevalent in China.