19 research outputs found

    Multistate Survey of American Dog Ticks \u3ci\u3e(Dermacentor variabilis)\u3c/i\u3e for \u3ci\u3eRickettsia\u3c/i\u3e Species

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    Dermacentor variabilis, a common human-biting tick found throughout the eastern half and along the west coast of the United States, is a vector of multiple bacterial pathogens. Historically, D. variabilis has been considered a primary vector of Rickettsia rickettsii, the causative agent of Rocky Mountain spotted fever. A total of 883 adult D. variabilis, collected between 2012 and 2017 from various locations in 12 states across the United States, were screened for rickettsial DNA. Tick extracts were evaluated using three real-time PCR assays; an R. rickettsii-specific assay, a Rickettsia bellii-specific assay, and a Rickettsia genus-specific assay. Sequencing of ompA gene amplicons generated using a seminested PCR assay was used to determine the rickettsial species present in positive samples not already identified by species-specific real-time assays. A total of 87 (9.9%) tick extracts contained R. bellii DNA and 203 (23%) contained DNA of other rickettsial species, including 47 (5.3%) with Rickettsia montanensis, 11 (1.2%) with Rickettsia amblyommatis, 2 (0.2%) with Rickettsia rhipicephali, and 3 (0.3%) with Rickettsia parkeri. Only 1 (0.1%) tick extract contained DNA of R. rickettsii. These data support multiple other contemporary studies that indicate infrequent detection of R. rickettsii in D. variabilis in North America

    On the Reproducibility of Science: Unique Identification of Research Resources in the Biomedical Literature

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    Scientific reproducibility has been at the forefront of many news stories and there exist numerous initiatives to help address this problem. We posit that a contributor is simply a lack of specificity that is required to enable adequate research reproducibility. In particular, the inability to uniquely identify research resources, such as antibodies and model organisms, makes it difficult or impossible to reproduce experiments even where the science is otherwise sound. In order to better understand the magnitude of this problem, we designed an experiment to ascertain the “identifiability” of research resources in the biomedical literature. We evaluated recent journal articles in the fields of Neuroscience, Developmental Biology, Immunology, Cell and Molecular Biology and General Biology, selected randomly based on a diversity of impact factors for the journals, publishers, and experimental method reporting guidelines. We attempted to uniquely identify model organisms (mouse, rat, zebrafish, worm, fly and yeast), antibodies, knockdown reagents (morpholinos or RNAi), constructs, and cell lines. Specific criteria were developed to determine if a resource was uniquely identifiable, and included examining relevant repositories (such as model organism databases, and the Antibody Registry), as well as vendor sites. The results of this experiment show that 54% of resources are not uniquely identifiable in publications, regardless of domain, journal impact factor, or reporting requirements. For example, in many cases the organism strain in which the experiment was performed or antibody that was used could not be identified. Our results show that identifiability is a serious problem for reproducibility. Based on these results, we provide recommendations to authors, reviewers, journal editors, vendors, and publishers. Scientific efficiency and reproducibility depend upon a research-wide improvement of this substantial problem in science today

    Rickettsia parkeri in Gulf Coast Ticks, Southeastern Virginia, USA

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    We report evidence that Amblyomma maculatum tick populations are well established in southeastern Virginia. We found that 43.1% of the adult Gulf Coast ticks collected in the summer of 2010 carried Rickettsia parkeri, suggesting that persons living in or visiting southeastern Virginia are at risk for infection with this pathogen
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