260 research outputs found

    Typing of Borrelia Relapsing Fever Group Strains

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    Partial sequencing of the 16S-23S rDNA intergenic spacer showed two to four genotypes each for Borrelia hermsii and B. turicatae, both relapsing fever agents transmitted by argasid ticks, and for B. miyamotoi and B. lonestari, transmitted by ixodid ticks. Field surveys of Ixodes ticks in Connecticut and Sweden showed limited local diversity for B. miyamotoi

    Borrelia burgdorferi infection in a natural population of Peromyscus leucopus mice: A longitudinal study in an area where lyme borreliosis is highly endemic

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    Blood samples from Peromyscus leucopus mice captured at an enzootic site in Connecticut were examined for antibodies to and DNA of Borrelia burgdorferi, to characterize the dynamics of infection in this reservoir population. From trappings conducted over the course of 2 transmission seasons, 598 (75%) of 801 serum samples from 514 mice were found to be positive by enzyme immunoassay. Seropositivity correlated with date of capture and mouse age, was similar among locations within the site, increased from 57% to 93% over the course of the transmission season, and was associated with antibodies to outer surface protein (Osp) C, but not to OspA. Longitudinal samples from 184 mice revealed an incidence of 0.2 cases/mouse/week. Nineteen (10%) of 187 samples were found by polymerase chain reaction to be positive for B. burgdorferi, and, of those, 14 (74%) were found to be seropositive. Nearly the entire population of P. leucopus mice became infected with B. burgdorferi by late August, coinciding with the peak activity period of host-seeking larvae uninfected with the spirochete Ixodes scapularis, thereby perpetuating the agent through succeeding generations of ticks.Centro de Estudios ParasitolĆ³gicos y de VectoresFacultad de Ciencias Naturales y Muse

    Borrelia burgdorferi infection in a natural population of Peromyscus leucopus mice: A longitudinal study in an area where lyme borreliosis is highly endemic

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    Blood samples from Peromyscus leucopus mice captured at an enzootic site in Connecticut were examined for antibodies to and DNA of Borrelia burgdorferi, to characterize the dynamics of infection in this reservoir population. From trappings conducted over the course of 2 transmission seasons, 598 (75%) of 801 serum samples from 514 mice were found to be positive by enzyme immunoassay. Seropositivity correlated with date of capture and mouse age, was similar among locations within the site, increased from 57% to 93% over the course of the transmission season, and was associated with antibodies to outer surface protein (Osp) C, but not to OspA. Longitudinal samples from 184 mice revealed an incidence of 0.2 cases/mouse/week. Nineteen (10%) of 187 samples were found by polymerase chain reaction to be positive for B. burgdorferi, and, of those, 14 (74%) were found to be seropositive. Nearly the entire population of P. leucopus mice became infected with B. burgdorferi by late August, coinciding with the peak activity period of host-seeking larvae uninfected with the spirochete Ixodes scapularis, thereby perpetuating the agent through succeeding generations of ticks.Centro de Estudios ParasitolĆ³gicos y de VectoresFacultad de Ciencias Naturales y Muse

    An ecological approach to preventing human infection: Vaccinating wild mouse reservoirs intervenes in the Lyme disease cycle

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    Many pathogens, such as the agents of West Nile encephalitis and plague, are maintained in nature by animal reservoirs and transmitted to humans by arthropod vectors. Efforts to reduce disease incidence usually rely on vector control or immunization of humans. Lyme disease, for which no human vaccine is currently available, is a commonly reported vector-borne disease in North America and Europe. In a recently developed, ecological approach to disease prevention, we intervened in the natural cycle of the Lyme disease agent (Borrelia burgdorferi) by immunizing wild white-footed mice (Peromyscus leucopus), a reservoir host species, with either a recombinant antigen of the pathogen, outer surface protein A, or a negative control antigen in a repeated field experiment with paired experimental and control grids stratified by site. Outer surface protein A vaccination significantly reduced the prevalence of B. burgdorferi in nymphal blacklegged ticks (Ixodes scapularis) collected at the sites the following year in both experiments. The magnitude of the vaccine's effect at a given site correlated with the tick infection prevalence found on the control grid, which in turn correlated with mouse density. These data, as well as differences in the population structures of B. burgdorferi in sympatric ticks and mice, indicated that nonmouse hosts contributed more to infecting ticks than previously expected. Thus, where nonmouse hosts play a large role in infection dynamics, vaccination should be directed at additional species.Facultad de Ciencias Naturales y MuseoCentro de Estudios ParasitolĆ³gicos y de Vectore

    Identification of Residual Blood Proteins in Ticks by Mass Spectrometry Proteomics

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    Mass spectrometryā€“based proteomics of individual ticks demonstrated persistence of mammalian host blood components, including Ī±- and Ī²-globin chains, histones, and mitochondrial enzymes, in Ixodes scapularis and Amblyomma americanum ticks for months after molting. Residual host proteins may identify sources of infection for ticks

    Identification of Residual Blood Proteins in Ticks by Mass Spectrometry Proteomics

    Get PDF
    Mass spectrometryā€“based proteomics of individual ticks demonstrated persistence of mammalian host blood components, including Ī±- and Ī²-globin chains, histones, and mitochondrial enzymes, in Ixodes scapularis and Amblyomma americanum ticks for months after molting. Residual host proteins may identify sources of infection for ticks
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