Linking chronic wasting disease to scrapie by comparison of Spiroplasma mirum ribosomal DNA sequences

Bastian, Frank O.; Dash, Srikanta; Garry, Robert F.

doi:10.1016/j.yexmp.2004.02.002

Cited by 40 publications

(39 citation statements)

References 28 publications

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“…This finding is at odds with that of Bastian and colleagues (3,4), who have reported finding spiroplasma 16S rRNA gene sequences in most samples from CJD-infected humans, scrapie-infected sheep, and chronic wasting disease-infected cervids but not in control samples from the same species. Our DNA extraction method, the PCR protocol using Pharmacia Ready-to-Go beads, and the spiroplasma and mollicute primers were chosen to be essentially the same as those used by Bastian et al It is highly unlikely that the TSE strains of these different hosts would differ from hamster scrapie in the nature of the infectious agent or in the involvement of a bacterial factor.…”

Section: Discussionmentioning

confidence: 57%

“…(iv) Laboratory controls can be perfectly matched by birth cohort and growth conditions to the infected animals. In contrast, the control tissues used by Bastian et al (3,4) were from different populations and were collected under different conditions from those for the infected samples. This may have introduced systematic errors that account for the lack of amplifications in the controls and near-perfect correlations with the infected samples.…”

Section: Discussionmentioning

confidence: 99%

“…The spiroplasma sequences reported by Bastian et al were detected in humans, sheep and deer (3,4), species for which the concentration of infectivity in brain and other tissues is uncertain but is suspected to be lower and more variable than that obtained in well-characterized experimental rodent models. The 263K strain of hamster-adapted scrapie used in this study reliably produces the highest titers in brain known for any TSE disease.…”

mentioning

confidence: 93%

“…More recently, Bastian et al (3,4) have reported the presence of spiroplasma-specific 16S rRNA genes in brain tissue taken at autopsy/necropsy from TSE-infected humans and animals. PCR amplification of 16S rRNA genes, or "ribotyping," is a powerful method for detecting and identifying microbial agents in environmental and clinical specimens.…”

mentioning

confidence: 99%

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Absence of Spiroplasma or Other Bacterial 16S rRNA Genes in Brain Tissue of Hamsters with Scrapie

et al. 2006

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Spiroplasma spp. have been proposed to be the etiological agents of the transmissible spongiform encephalopathies (TSEs). In a blind study, a panel of 20 DNA samples was prepared from the brains of uninfected hamsters or hamsters infected with the 263K strain of scrapie. The brains of the infected hamsters contained >10 10 infectious doses/g. The coded panel was searched for bacterial 16S rRNA gene sequences, using primers selective for spiroplasma sequences, primers selective for mollicutes in general, and universal bacterial primers. After 35 PCR cycles, no samples were positive for spiroplasma or any other bacterial DNA, while control Spiroplasma mirum genomic DNA, spiked at 1% of the concentration required to account for the scrapie infectivity present, was readily detected. After 70 PCR cycles, nearly all samples yielded amplified products which were homologous to various bacterial 16S rRNA gene sequences, including those of frequent environmental contaminants. These sequences were seen in uninfected as well as infected samples. Because the concentration of scrapie infectivity was at a known high level, it is very unlikely that a bacterial infection at the same concentration could have escaped detection. We conclude that the infectious agent responsible for TSE disease cannot be a spiroplasma or any other eubacterial species.The identity of the causal agents of the transmissible spongiform encephalopathies (TSEs)-neurodegenerative diseases which include scrapie in sheep, Creutzfeldt-Jakob disease (CJD) in humans, bovine spongiform encephalopathy in cattle, and chronic wasting disease in deer and elk-has been a major source of controversy since these diseases were shown to be transmissible (41,43,17,38). Early experiments showing that TSE infectivity passed through bacterial filters (54) and was resistant to disinfection by common bacteriocides (27,10,41,42,9) seemingly eliminated bacteria as the agent. However, the discovery in the 1970s of spiroplasmas, very small, thermostable, wall-less, helical-fibrillar bacteria that pass through 0.2-m bacterial filters and show remarkable resistance to many common biocides including heat (47), provided a possible bacterial candidate for the infectious agent of TSEs. There have also been reports of spiral structures resembling spiroplasmas in brain tissue from CJD patients (2, 23, 39, 33), although other investigators have suggested these structures might be artifactual (24, 28). Moreover, no spiroplasmas could be cultured from CJD brain tissue (32). Intracranial inoculation of Spiroplasma mirum into new-born hamsters (31), suckling rats (5), or suckling mice (16) produces central nervous system disease, though not a progressive spongiform encephalopathy (16).More recently, Bastian et al. (3,4) have reported the presence of spiroplasma-specific 16S rRNA genes in brain tissue taken at autopsy/necropsy from TSE-infected humans and animals. PCR amplification of 16S rRNA genes, or "ribotyping," is a powerful method for detecting and identifying microbial agents in environm...

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Section: Discussionmentioning

confidence: 57%

Section: Discussionmentioning

confidence: 99%

mentioning

confidence: 93%

mentioning

confidence: 99%

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Absence of Spiroplasma or Other Bacterial 16S rRNA Genes in Brain Tissue of Hamsters with Scrapie

et al. 2006

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“…6 CWD information is controversial in its own right due to underlying scientific uncertainty about the disease. While scientific consensus points to prions (misshapen protein molecules) as the source of CWD, some scientists disagree about the hypothesized infectious agent and transmission methods (Bastian, Dash & Garry, 2004). While this skepticism is often dismissed as bfringe scienceQ, most scientists acknowledge significant gaps in knowledge.…”

Section: Chronic Wasting Disease Backgroundmentioning

confidence: 99%

Examining the role of Web site information in facilitating different citizen–government relationships: A case study of state Chronic Wasting Disease Web sites

Eschenfelder

Miller

2007

Government Information Quarterly

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This paper develops a framework to assess the text-based public information provided on program level government agency Web sites. The framework informs the larger e-government question of how, or whether, state administrative agencies are using Web sites in a transformative capacity-to change relationships between citizens and government. It focuses on assessing the degree to which text information provided on government Web sites could facilitate various relationships between government agencies and citizens. The framework incorporates four views of government information obligations stemming from different assumptions about citizen-government relationships in a democracy: the private citizen view, the attentive citizen view, the deliberative citizen view, and the citizen-publisher view. Each view suggests inclusion of different types of information on government agency web sites. The framework is employed to assess state Web sites containing information about chronic wasting disease, a disease effecting deer and elk in numerous U.S. states and Canada. D

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Spiroplasma

Williamson¹,

Gasparich²,

Regassa³

et al. 2015

Bergey's Manual of Systematics of Archaea and Bacteria

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Spi.ro.plas'ma. Gr. n. speira (L. transliteration spira ) a coil, spiral; Gr. neut. n. plasma something formed or molded, a form; N.L. neut. n. Spiroplasma spiral form. Tenericutes / Mollicutes / Entomoplasmatales / Spiroplasmataceae / Spiroplasma Cells are pleomorphic, varying in size and shape from helical and branched nonhelical filaments to spherical or ovoid. The helical forms, usually 100–200 nm in diameter and 3–5 µm in length, generally occur during the exponential phase of growth and in some species persist during stationary phase. The cells of some species are short (1–2 µm). In certain cases, helical cells may be very tightly coiled, or the coils may show continuous variation in amplitude. Spherical cells ~300 nm in diameter and nonhelical filaments are frequently seen in the stationary phase, where they may not be viable, and in all growth phases in suboptimal growth media, where they may or may not be viable. In some species during certain phases, spherical forms may be the replicating form. Helical filaments are motile, with flexional and twitching movements, and often show an apparent rotatory motility. Fibrils are associated with the membrane, but flagellae, periplasmic fibrils, or other organelles of locomotion are absent . Fimbriae and pili observed on the cell surface of insect‐ and plant‐pathogenic spiroplasmas are believed to be involved in host‐cell attachment and conjugation (Ammar et al., 2004; Özbek et al., 2003), but not in locomotion. Cells divide by binary fission, with doubling times of 0.7–37 h. Facultatively anaerobic. The temperature growth range varies among species, from 5 to 41°C. Colonies on solid media are frequently diffuse , with irregular shapes and borders, a condition that reflects the motility of the cells during active growth (Figure 111). Colony type is strongly dependent on the agar concentration. Colony sizes vary from 0.1 to 4.0 mm in diameter. Colonies formed by nonmotile variants or mutants, or by cultures growing on inadequate media are typically umbonate with diameters of 200 µm or less. Some species, such as Spiroplasma platyhelix , have barely visible helicity along most of their length and display little rotatory or flexing motility. Colonies of motile, fast‐growing spiroplasmas are diffuse, often with satellite colonies developing from foci adjacent to the initial site of colony development. Light turbidity may be produced in liquid cultures. Chemo‐organotrophic. Acid is produced from glucose. Hydrolysis of arginine is variable. Urea, arbutin, and esculin are not hydrolyzed. Sterol requirements are variable. An optimum osmolality, usually in the range of 300–800 mOsm, has been demonstrated for some spiroplasmas. Media containing mycoplasma broth base, serum, and other supplements are required for primary growth, but after adaptation, growth often occurs in less complex media. Defined or semi‐defined media are available for some species. Resistant to 10,000 U/ml penicillin. Insensitive to rifampicin, sensitive to erythromycin and tetracycline. Isolated from the surfaces of flowers and other plant parts, from the guts and hemolymph of various insects and crustaceans, and from tick triturates. Also isolated from vascular plant fluids ( phloem sap ) and insects that feed on the fluids . Specific host associations are common. The type species, Spiroplasma citri , is pathogenic for citrus (e.g., orange and grapefruit), producing “stubborn” disease. Experimental or natural infections also occur in horseradish, periwinkle, radish, broad bean, carrot, and other plant species. Spiroplasma kunkelii is a maize pathogen. Some species are pathogenic for insects. Certain species are pathogenic, under experimental conditions, for a variety of suckling rodents (rats, mice, hamsters and rabbits) and/or chicken embryos. Genome sizes vary from 780 to 2220 kbp (PFGE). DNA G + C content ( mol %): 24–31 ( T m , Bd). Type species : Spiroplasma citri Saglio, L'Hospital, Laflèche, Dupont, Bové, Tully and Freundt 1973, 202 AL .

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Linking chronic wasting disease to scrapie by comparison of Spiroplasma mirum ribosomal DNA sequences

Cited by 40 publications

References 28 publications

Absence of Spiroplasma or Other Bacterial 16S rRNA Genes in Brain Tissue of Hamsters with Scrapie

Absence of Spiroplasma or Other Bacterial 16S rRNA Genes in Brain Tissue of Hamsters with Scrapie

Examining the role of Web site information in facilitating different citizen–government relationships: A case study of state Chronic Wasting Disease Web sites

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