Linking chronic wasting disease to scrapie by comparison of Spiroplasma mirum ribosomal DNA sequences.
Transmissible spongiform encephalopathies (TSE) are fatal neurodegenerative diseases of man and animals and are transmitted by a filterable pathogen whose identity is currently unresolved. Our data indicates that Spiroplasma, a wall-less bacterium, is involved in the pathogenesis of TSE. We searched for Spiroplasma ribosomal gene sequences in 10 scrapie-infected sheep brains and 10 normal sheep brains, 7 cervid samples infected with chronic wasting disease (CWD), and 7 normal cervid brains. DNA was extracted from these tissue samples and amplified by polymerase chain reaction (PCR) using primers specific for Spiroplasma-specific 16S rDNA. Specificity of the amplicon was determined by Southern blotting and DNA sequence analyses. Spiroplasma 16S rDNA was found in 8 of 10 scrapie-infected sheep brains and 6 of 7 CWD-infected tissue samples. All normal animal brain samples were negative. Spiroplasma 16S rDNA was also found in two human Creutzfeldt-Jakob diseased (CJD) brains but not in two age-matched normal human brains. DNA sequence analyses of the amplified PCR products from human and animal TSE cases revealed greater than 99% nucleotide sequence homology with Spiroplasma mirum. The presence of Spiroplasma DNA in TSE-infected tissues supports our hypothesis that Spiroplasma may be involved in the pathogenesis of these diseases.
Bastian
Frank O
FO
Department of Pathology and Laboratory Medicine, Tulane University Health Sciences Center, New Orleans, LA 70112, USA. fbastian@tulane.edu
Dash
Srikanta
S
Garry
Robert F
RF
D000818:Animals; D001483:Base Sequence; D001921:Brain / Q000382:microbiology / Q000473:pathology; D007562:Creutzfeldt-Jakob Syndrome / Q000235:genetics / Q000382:microbiology / Q000473:pathology; D017931:DNA Primers / Q000737:chemistry; D015342:DNA Probes / Q000737:chemistry; D004275:DNA, Ribosomal / Q000032:analysis; D003670:Deer; D006801:Humans; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D012608:Scrapie / Q000235:genetics / Q000382:microbiology* / Q000473:pathology; D017422:Sequence Analysis, DNA; D012689:Sequence Homology, Nucleic Acid; D012756:Sheep; D013149:Spiroplasma / Q000235:genetics / Q000472:pathogenicity*; D034081:Wasting Disease, Chronic / Q000235:genetics / Q000382:microbiology* / Q000473:pathology
D017931:DNA Primers; D015342:DNA Probes; D004275:DNA, Ribosomal