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Full-Text Articles in Medicine and Health Sciences

Diagnosis Of Human Ehrlichiosis By Pcr Assay Of Acute-Phase Serum, James A. Comer, William L. Nicholson, John W. Sumner, James G. Olson, James E. Childs Jan 1999

Diagnosis Of Human Ehrlichiosis By Pcr Assay Of Acute-Phase Serum, James A. Comer, William L. Nicholson, John W. Sumner, James G. Olson, James E. Childs

Zoonotics and Wildlife Disease: Publications

A PCR assay of 43 acute-phase serum samples was evaluated as a method for early detection of human granulocytic ehrlichiosis (HGE) and determination of etiology when serologic testing is inconclusive. Sequenceconfirmed products of the HGE agent were amplified from three individuals residing or having exposure history in Minnesota or Wisconsin, and similarly confirmed products from Ehrlichia chaffeensis were amplified from three individuals from Florida or Maryland. Etiology, as determined by PCR and serology, was the same whenever there was a fourfold difference between the maximum titers of antibodies to both antigens, indicating that presumptive determination of etiology may be based …


Dusky-Footed Wood Rats (Neotoma Fuscipes) As Reservoirs Of Granulocytic Ehrlichiae (Rickettsiales: Ehrlichieae) In Northern California, William L. Nicholson, Martin B. Castro, Vicki L. Kramer, John W. Sumner, James E. Childs Jan 1999

Dusky-Footed Wood Rats (Neotoma Fuscipes) As Reservoirs Of Granulocytic Ehrlichiae (Rickettsiales: Ehrlichieae) In Northern California, William L. Nicholson, Martin B. Castro, Vicki L. Kramer, John W. Sumner, James E. Childs

Zoonotics and Wildlife Disease: Publications

Dusky-footed wood rats (Neotoma fuscipes) and Peromyscus sp. mice (P. maniculatus and P. truei) were collected from one site in Placer County, one site in Santa Cruz County, and two sites in Sonoma County in northern California. Serum or plasma samples from 260 rodents were tested for antibodies to the agent of human granulocytic ehrlichiosis. Of these, samples from 25 wood rats (34% of those tested) and 10 (8%) Peromyscus sp. mice were found to be seropositive, but only those from one site. PCR assays targeting the groESL heat shock operon were conducted on all seropositive …


Molecular Cloning And Characterization Of The Ehrlichia Chaffeensis Variable-Length Pcr Target: An Antigen-Expressing Gene That Exhibits Interstrain Variation, John W. Sumner, James E. Childs, Christopher D. Paddock Jan 1999

Molecular Cloning And Characterization Of The Ehrlichia Chaffeensis Variable-Length Pcr Target: An Antigen-Expressing Gene That Exhibits Interstrain Variation, John W. Sumner, James E. Childs, Christopher D. Paddock

Zoonotics and Wildlife Disease: Publications

A clone expressing an immunoreactive protein with an apparent molecular mass of 44 kDa was selected from an Ehrlichia chaffeensis Arkansas genomic library by probing with anti-E. chaffeensis hyperimmune mouse ascitic fluid. Nucleotide sequencing revealed an open reading frame (ORF) capable of encoding a 198-aminoacid polypeptide. The ORF contained four imperfect, direct, tandem 90-bp repeats. The nucleotide and deduced amino acid sequences did not show close homologies to entries in the molecular databases. PCR with primers whose sequences matched the sequences flanking the ORF was performed with DNA samples extracted from cell cultures infected with nine different isolates of E. …


Outcome Of Diagnostic Tests Using Samples From Patients With Culture-Proven Human Monocytic Ehrlichiosis: Implications For Surveillance, James E. Childs, John W. Sumner, William L. Nicholson, Robert F. Massung, Steven M. Standaert, Christopher D. Paddock Jan 1999

Outcome Of Diagnostic Tests Using Samples From Patients With Culture-Proven Human Monocytic Ehrlichiosis: Implications For Surveillance, James E. Childs, John W. Sumner, William L. Nicholson, Robert F. Massung, Steven M. Standaert, Christopher D. Paddock

Zoonotics and Wildlife Disease: Publications

We describe the concordance among results from various laboratory tests using samples derived from nine culture-proven cases of human monocytic ehrlichiosis (HME) caused by Ehrlichia chaffeensis. A class-specific indirect immunofluorescence assay for immunoglobulin M (IgM) and IgG, using E. chaffeensis antigen, identified 44 and 33% of the isolation-confirmed HME patients on the basis of samples obtained at initial clinical presentation, respectively; detection of morulae in blood smears was similarly insensitive (22% positive). PCR amplifications of ehrlichial DNA targeting the 16S rRNA gene, the variable-length PCR target gene, and the groESL operon were positive for whole blood specimens obtained …


Serologic Testing For Human Granulocytic Ehrlichiosis At A National Referral Center, James A. Comer, William L. Nicholson, James G. Olson, James E. Childs Jan 1999

Serologic Testing For Human Granulocytic Ehrlichiosis At A National Referral Center, James A. Comer, William L. Nicholson, James G. Olson, James E. Childs

Zoonotics and Wildlife Disease: Publications

An indirect immunofluorescence assay (IFA) was used to identify patients with antibodies reactive to the human granulocytic ehrlichiosis (HGE) agent. Serum samples collected from clinically ill individuals were submitted to the Centers for Disease Control and Prevention by physicians via state health departments from throughout the United States and tested against a panel of ehrlichial and rickettsial pathogens. Antibodies reactive to the HGE agent were detected in 142 (8.9%) of 1,602 individuals tested. There were 19 confirmed and 59 probable (n = 78) cases of HGE as defined by seroconversion or a fourfold or higher titer to the HGE agent …


Hidden Mortality Attributable To Rocky Mountain Spotted Fever: Immunohistochemical Detection Of Fatal, Serologically Unconfirmed Disease, James E. Childs, Patricia W. Greer, Tara L. Ferebee, Joseph Singleton Jr., Don B. Mckechnie, Tracee A. Treadwell, John W. Krebs, Matthew J. Clarke, Robert C. Holman, James G. Olson, Christopher D. Paddock, Sherif R. Zaki Jan 1999

Hidden Mortality Attributable To Rocky Mountain Spotted Fever: Immunohistochemical Detection Of Fatal, Serologically Unconfirmed Disease, James E. Childs, Patricia W. Greer, Tara L. Ferebee, Joseph Singleton Jr., Don B. Mckechnie, Tracee A. Treadwell, John W. Krebs, Matthew J. Clarke, Robert C. Holman, James G. Olson, Christopher D. Paddock, Sherif R. Zaki

Zoonotics and Wildlife Disease: Publications

Rocky Mountain spotted fever (RMSF) is the most severe tickborne infection in the United States and is a nationally notifiable disease. Since 1981, the annual case-fatality ratio for RMSF has been determined from laboratory-confirmed cases reported to the Centers for Disease Control and Prevention (CDC). Herein, a description is given of patients with fatal, serologically unconfirmed RMSF for whom a diagnosis of RMSF was established by immunohistochemical (IHC) staining of tissues obtained at autopsy. During 1996-1997, acute-phase serum and tissue samples from patients with fatal disease compatible with RMSF were tested at the CDC. As determined by indirect immunofluorescence assay, …


Search For The Ebola Virus Reservoir In Kikwit, Democratic Republic Of The Congo: Reflections On A Vertebrate Collection, Herwig Leirs, James N. Mills, John W. Krebs, James E. Childs, Dudu Akaibe, Neal Woollen, George Ludwig, Clarence J. Peters, Thomas G. Ksiazek Jan 1999

Search For The Ebola Virus Reservoir In Kikwit, Democratic Republic Of The Congo: Reflections On A Vertebrate Collection, Herwig Leirs, James N. Mills, John W. Krebs, James E. Childs, Dudu Akaibe, Neal Woollen, George Ludwig, Clarence J. Peters, Thomas G. Ksiazek

Zoonotics and Wildlife Disease: Publications

A 3-month ecologic investigation was done to identify the reservoir of Ebola virus following the 1995 outbreak in Kikwit, Democratic Republic of the Congo. Efforts focused on the fields where the putative primary case had worked but included other habitats near Kikwit. Samples were collected from 3066 vertebrates and tested for the presence of antibodies to Ebola (subtype Zaire) virus: All tests were negative, and attempts to isolate Ebola virus were unsuccessful. The investigation was hampered by a lack of information beyond the daily activities of the primary case, a lack of information on Ebola virus ecology, which precluded the …


Population Dynamics Of A Naturally Occurring Heterogeneous Mixture Of Borrelia Burgdorferi Clones, Erick K. Hofmeister, Gregory E. Glass, James E. Childs, David H. Persing Jan 1999

Population Dynamics Of A Naturally Occurring Heterogeneous Mixture Of Borrelia Burgdorferi Clones, Erick K. Hofmeister, Gregory E. Glass, James E. Childs, David H. Persing

Zoonotics and Wildlife Disease: Publications

Two unique isolates of Borrelia burgdorferi, differing in plasmid content and outer surface protein C expression, were cultured on sequential captures of a single free-living Peromyscus leucopus mouse and were examined for differences in transmissibility. Both isolates were transmissible from inoculated C.B-17 mice to larval Ixodes scapularis ticks and, subsequently, from infected nymphal ticks to C3H/HeJ mice. Plasmid and protein analyses suggested that the original isolates were a mixed population of B. burgdorferi, and cloning by limiting dilution resulted in the identification of two clonal groups. In addition to being heterogeneous in plasmid and genomic macrorestriction analyses, the …


Isolation Of A New Subspecies, Bartonella Vinsonii Subsp. Arupensis, From A Cattle Rancher: Identity With Isolates Found In Conjunction With Borrelia Burgdorferi And Babesia Microti Among Naturally Infected Mice, David F. Welch, Karen C. Carroll, Erick K. Hofmeister, David H. Persing, Denise A. Robison, Arnold G. Steigerwalt, Don J. Brenner Jan 1999

Isolation Of A New Subspecies, Bartonella Vinsonii Subsp. Arupensis, From A Cattle Rancher: Identity With Isolates Found In Conjunction With Borrelia Burgdorferi And Babesia Microti Among Naturally Infected Mice, David F. Welch, Karen C. Carroll, Erick K. Hofmeister, David H. Persing, Denise A. Robison, Arnold G. Steigerwalt, Don J. Brenner

Zoonotics and Wildlife Disease: Publications

Bacteremia with fever due to a novel subspecies of Bartonella vinsonii was found in a cattle rancher. The subspecies shared major characteristics of the genus Bartonella in terms of most biochemical features and cellular fatty acid profile, but it was distinguishable from other subspecies of B. vinsonii by good growth on heart infusion agar supplemented with X factor and by its pattern of enzymatic hydrolysis of peptide substrates. DNA relatedness studies verified that the isolate belonged to the genus Bartonella and that it was genotypically related to B. vinsonii. The highest level of relatedness was observed with recently characterized …


Oral Transmission And Early Lymphoid Tropism Of Chronic Wasting Disease PrpRes In Mule Deer Fawns (Odocoileus Hemionus), Christina J. Sigurdson, Elizabeth S. Williams, Michael W. Miller, Terry R. Spraker, Katherine I. O'Rourke, Edward A. Hoover Jan 1999

Oral Transmission And Early Lymphoid Tropism Of Chronic Wasting Disease PrpRes In Mule Deer Fawns (Odocoileus Hemionus), Christina J. Sigurdson, Elizabeth S. Williams, Michael W. Miller, Terry R. Spraker, Katherine I. O'Rourke, Edward A. Hoover

Zoonotics and Wildlife Disease: Publications

Mule deer fawns (Odocoileus hemionus) were inoculated orally with a brain homogenate prepared from mule deer with naturally occurring chronic wasting disease (CWD), a prion-induced transmissible spongiform encephalopathy. Fawns were necropsied and examined for PrPres, the abnormal prion protein isoform, at 10, 42, 53, 77, 78 and 80 days post-inoculation (p.i.) using an immunohistochemistry assay modified to enhance sensitivity. PrPres was detected in alimentarytract- associated lymphoid tissues (one or more of the following: retropharyngeal lymph node, tonsil, Peyer’s patch and ileocaecal lymph node) as early as 42 days p.i. and in all fawns examined thereafter …


Prp Genotypes Of Captive And Free-Ranging Rocky Mountain Elk (Cervus Elaphus Nelsoni) With Chronic Wasting Disease, Katherine I. O'Rourke, T. E. Besser, M. W. Miller, T. F. Cline, T. R. Spraker, A. L. Jenny, M. A. Wild, G. L. Zebarth Jan 1999

Prp Genotypes Of Captive And Free-Ranging Rocky Mountain Elk (Cervus Elaphus Nelsoni) With Chronic Wasting Disease, Katherine I. O'Rourke, T. E. Besser, M. W. Miller, T. F. Cline, T. R. Spraker, A. L. Jenny, M. A. Wild, G. L. Zebarth

Zoonotics and Wildlife Disease: Publications

The PrP gene encodes the putative causative agent of the transmissible spongiform encephalopathies (TSEs), a heterogeneous group of fatal, neurodegenerative disorders including human Creutzfeldt–Jakob disease, bovine spongiform encephalopathy, ovine scrapie and chronic wasting disease (CWD) of North American deer and elk. Polymorphisms in the PrP gene are associated with variations in relative susceptibility, pathological lesion patterns, incubation times and clinical course of TSEs of humans, mice and sheep. Sequence analysis of the PrP gene from Rocky Mountain elk showed only one amino acid change (Met to Leu at cervid codon 132). Homozygosity for Met at the corresponding polymorphic site (Met …


Conjunctivitis Caused By A Swine Chlamydia Trachomatis-Like Organism In Gnotobiotic Pigs, Douglas G. Rogers, Arthur A. Andersen Jan 1999

Conjunctivitis Caused By A Swine Chlamydia Trachomatis-Like Organism In Gnotobiotic Pigs, Douglas G. Rogers, Arthur A. Andersen

School of Veterinary and Biomedical Sciences: Faculty Publications

The objective of this study was to determine whether a chlamydial strain recovered from growing and finishing swine with conjunctivitis or keratoconjunctivitis could cause the same infections in gnotobiotic pigs. The strain shares biological characteristics with Chlamydia trachomatis. After propagation in Vero cells and preparation of the inoculum (107 inclusion-forming units/ml), chlamydial strain H7 was instilled into the ventral conjunctival sac (0.15 ml/sac) of 12 anesthetized 3-day-old gnotobiotic piglets. Four age-matched gnotobiotic piglets were anesthetized and sham infected with uninfected cell culture lysates. None of the principal piglets developed clinical symptoms of conjunctivitis or keratoconjunctivitis. Principal piglets necropsied 7 …


In Situ Hybridization For The Detection And Localization Of Swine Chlamydia Trachomatis, C. Chae, D.-S. Cheon, D. Kwon, O. Kim, B. Kim, J. Suh, D. G. Rogers, K. D. E. Everett, A. A. Anderson Jan 1999

In Situ Hybridization For The Detection And Localization Of Swine Chlamydia Trachomatis, C. Chae, D.-S. Cheon, D. Kwon, O. Kim, B. Kim, J. Suh, D. G. Rogers, K. D. E. Everett, A. A. Anderson

School of Veterinary and Biomedical Sciences: Faculty Publications

Gnotobiotic piglets were inoculated intralaryngeally with swine Chlamydia trachomatis strain R33 or orally with swine C. trachmatis strain R27. Archived formalin-fixed, paraffin-embedded tissues from piglets euthanatized 4–7 days postinoculation were examined by in situ hybridization for C. trachomatis nucleic acid using a nonradioactive digoxigenin-labeled DNA probes that targeted specific ribosomal RNA or omp1 mRNA molecules of the swine C. trachomatis strains. Positive hybridization signals were detected in bronchial epithelial cells, bronchiolar epithelial cells, pneumocytes, alveolar and interstitial macrophages, and jejunal and ileal enterocytes. Chlamydia-infected cells had a strong signal that was confined to the intracytoplasmic inclusions. Positive hybridization signals were …


Plasmd Bearing A Cdna Copy Of The Genome Of Bovine Viral Diarrhea Virus, Chimeric Derivatives Thereof, And Method Of Producing An Infectious Bovine Wral Darrheavirus Using Sad Plasmid, Ruben O. Donis, Ventzislav B. Vassilev Jan 1999

Plasmd Bearing A Cdna Copy Of The Genome Of Bovine Viral Diarrhea Virus, Chimeric Derivatives Thereof, And Method Of Producing An Infectious Bovine Wral Darrheavirus Using Sad Plasmid, Ruben O. Donis, Ventzislav B. Vassilev

School of Veterinary and Biomedical Sciences: Faculty Publications

A plasmid bearing a cDNA copy of the genome of bovine viral diarrhea virus (BVDV), chimeric derivatives of the plasmid and a method of producing an infectious bovine viral diarrhea virus using the plasmid are disclosed. The invention relates to a plasmid DNA molecule that replicates easily in E. coli and contains a sufficient portion of the genome of BVDV, cloned as cDNA, to be a suitable template to produce RNA in vitro which, upon transfection into bovine cells, gives rise to infectious BVDV. The BVDV created by the process of the invention can be engineered for use as a …