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:THREE INDEPENDENT REPLICATES AND ARE THE CONTROL NON-INFECTED CELLS: GSM49939, GSM49940, GSM49941 THREE INFECTED INDEPEDENDENT REPLICATES: GSM49942, GSM49943, GSM49944 Keywords: ordered
Project description:BACKGROUND: Anaplasma phagocytophilum is the etiological agent of granulocytic anaplasmosis in humans and animals. Wild animals and ticks play key roles in the enzootic cycles of the pathogen. Potential ecotypes of A. phagocytophilum have been characterized genetically, but their host range, zoonotic potential and transmission dynamics has only incompletely been resolved. METHODS: The presence of A. phagocytophilum DNA was determined in more than 6000 ixodid ticks collected from the vegetation and wildlife, in 289 tissue samples from wild and domestic animals, and 69 keds collected from deer, originating from various geographic locations in The Netherlands and Belgium. From the qPCR-positive lysates, a fragment of the groEL-gene was amplified and sequenced. Additional groEL sequences from ticks and animals from Europe were obtained from GenBank, and sequences from human cases were obtained through literature searches. Statistical analyses were performed to identify A. phagocytophilum ecotypes, to assess their host range and their zoonotic potential. The population dynamics of A. phagocytophilum ecotypes was investigated using population genetic analyses. RESULTS: DNA of A. phagocytophilum was present in all stages of questing and feeding Ixodes ricinus, feeding I. hexagonus, I. frontalis, I. trianguliceps, and deer keds, but was absent in questing I. arboricola and Dermacentor reticulatus. DNA of A. phagocytophilum was present in feeding ticks and tissues from many vertebrates, including roe deer, mouflon, red foxes, wild boar, sheep and hedgehogs but was rarely found in rodents and birds and was absent in badgers and lizards. Four geographically dispersed A. phagocytophilum ecotypes were identified, that had significantly different host ranges. All sequences from human cases belonged to only one of these ecotypes. Based on population genetic parameters, the potentially zoonotic ecotype showed significant expansion. CONCLUSION: Four ecotypes of A. phagocytophilum with differential enzootic cycles were identified. So far, all human cases clustered in only one of these ecotypes. The zoonotic ecotype has the broadest range of wildlife hosts. The expansion of the zoonotic A. phagocytophilum ecotype indicates a recent increase of the acarological risk of exposure of humans and animals.
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:BackgroundHuman granulocytic anaplasmosis is a tick-borne zoonotic disease caused by Anaplasma phagocytophilum. Coinfections with A. phagocytophilum and other tick-borne pathogens are reported frequently, whereas the relationship between A. phagocytophilum and flea-borne Yersnia pestis is rarely concerned.ResultsA. phagocytophilum and Yersnia pestis were discovered within a Marmota himalayana found dead in the environment, as determined by 16S ribosomal rRNA sequencing. Comparative genomic analyses of marmot-derived A. phagocytophilum isolate demonstrated its similarities and a geographic isolation from other global strains. The 16S rRNA gene and GroEL amino acid sequence identity rates between marmot-derived A. phagocytophilum (JAHLEX000000000) and reference strain HZ (CP000235.1) are 99.73% (1490/1494) and 99.82% (549/550), respectively. 16S rRNA and groESL gene screenings show that A. phagocytophilum is widely distributed in marmots; the bacterium was more common in marmots found dead (24.59%, 15/61) than in captured marmots (19.21%, 29/151). We found a higher Y. pestis isolation rate in dead marmots harboring A. phagocytophilum than in those without it (2 = 4.047, p < 0.05). Marmot-derived A. phagocytophilum was able to live in L929 cells and BALB/c mice but did not propagate well.ConclusionsIn this study, A. phagocytophilum was identified for the first time in Marmota himalayana, a predominant Yersinia pestis host. Our results provide initial evidence for M. himalayana being a reservoir for A. phagocytophilum; moreover, we found with the presence of A. phagocytophilum, marmots may be more vulnerable to plague. Humans are at risk for co-infection with both pathogens by exposure to such marmots.
Project description:In the context of a serosurvey conducted on the Anaplasma marginale prevalence in Swiss cattle, we suspected that a serological cross-reactivity between A. marginale and A. phagocytophilum might exist. In the present study we demonstrate that cattle, sheep and horses experimentally infected with A. phagocytophilum not only develop antibodies to A. phagocytophilum (detected by immunofluorescent-antibody assay) but also to A. marginale (detected by a competitive enzyme-linked immunosorbent assay). Conversely, calves experimentally infected with A. marginale also developed antibodies to A. phagocytophilum using the same serological tests. The identity of 63% determined in silico within a 209-amino-acid sequence of major surface protein 5 of an isolate of A. marginale and one of A. phagocytophilum supported the observed immunological cross-reactivity. These observations have important consequences for the serotesting of both, A. marginale and A. phagocytophilum infection of several animal species. In view of these new findings, tests that have been considered specific for either infection must be interpreted carefully.
Project description:Gene expression profiling of human promyelocytic cells in response to infection with Anaplasma phagocytophilum. Total RNA derived from 3DPI Anaplasma phagocytophilum-infected HL-60 cells was labeled with A647 and total RNA derived from 3DPI Mock-infected HL-60 cells was labeled with A546. For each, 5 µg of total RNA was labeled using Genisphere Array900, Alexa Fluor dyes and SuperscriptII. Slide scanned with ScanArray Express and images processed with GenePix Pro version 4.0. Normalized log ratios VALUES determined using R-project statistical environment (http://www.r-project.org) and Bioconductor (http://www.bioconductor.org) through the GenePix AutoProcessor (GPAP, http://darwin.biochem.okstate.edu/gpap) website (P. Ayoubi, unpublished results). Keywords: time-course