Reassessment of the Phylogenetic Position of the Bacterium Associated with Whipple's Disease and Determination of the 16S-23S Ribosomal Intergenic Spacer Sequence

Hygiene-Institut der Universität, Abteilung Hygiene und Medizinische Mikrobiologie, Heidelberg, Germany.
International journal of systematic bacteriology (Impact Factor: 2.27). 11/1996; 46(4):1078-82. DOI: 10.1099/00207713-46-4-1078
Source: PubMed

ABSTRACT Whipple's disease is a rare chronic illness associated with an unculturable bacterium that is constantly present in affected tissues. This bacterium was previously characterized at the molecular level by PCR and sequencing of the 16S rRNA gene. On the basis of 1,321 nucleotides of the sequence of its gene coding for 16S rRNA (16S rDNA), a phylogenetic relationship to the actinomycetes was established. In this study, we determined an almost complete 16S rDNA sequence (1,495 nucleotides), the 16S-23S ribosomal intergenic spacer sequence, and 200 nucleotides of the 23S rRNA gene. The 16S rDNA sequence was compared with the large number of actinomycete sequences that have been added to the database since the original study. Phylogenetic analysis revealed a branching position as the deepest branch of the cluster comprising the actinomycetes with group B peptidoglycan between this group and the family Cellulomonadaceae. This provides additional information on the phylogenetic position of this bacterium and some clues as to its characteristics. The spacer region between the 16S and 23S rRNA genes is 294 nucleotides long and does not contain tRNA genes. As has been shown in other instances, the increased variability of the ribosomal intergenic spacer compared with the 16S rRNA gene makes it a potential target for use in the differentiation of strains of the bacterium associated with Whipple's disease.

Download full-text


Available from: Fred A Rainey, Jun 26, 2015
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Heterogeneity in the 16S-23S rDNA spacer of uncultured 'Tropheryma whippelii' has previously been reported. In this study, the hypervariable insertion in the 23S rDNA domain III characteristic for actinobacteria was analysed. The finding of a unique sequence virtually identical among the subtypes supports the classification of 'T. whippelii' among the actinobacteria and the concept of three subtypes rather than three subspecies, and provides an alternative target for diagnostic assays.
    International Journal of Systematic and Evolutionary Microbiology 06/2000; 50 Pt 3(3):1007-11. DOI:10.1099/00207713-50-3-1007 · 2.80 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: A doença de Whipple é uma infecção bacteriana sistémica rara provocada pelo Tropheryma whipplei. As manifestações no sistema nervoso central caracterizam-se por demência lentamente progressiva, oftalmoplegia, cefaleias, mioclonias, disfunção hipotalâmica, e por um movimento patognomónico – miorritmia oculomastigatória--esquelética. O tratamento desta doença é efectuado com antibioterapia que ultrapasse a barreira hematoencefálica, durante pelo menos um ano. O rastreio da doença de Whipple em pacientes com quadros de clínica exclusivamente neurológica, por vezes atípicos ou sem diagnóstico definido, é muito importante dado que se trata de uma doença potencialmente tratável. Palavras chave: Doença de Whipple; Tropheryma whipplei; Infecção; Sistema Nervoso Central WHIPPLE DISEASE AND CENTRAL NERVOUS SYSTEM Whipple disease (WD) is a rare systemic infection caused by the bacteria Tropheryma whipplei. Slowly progressive dementia, supranuclear ophthalmoplegia, headache, myoclonus, hypothalamic dysfunction, oculomasticatory-skeletal myorythmia are characteristic manifestations when WD involves the central nervous system (CNS). Treatment of cerebral WD should be performed with antibiotics that reach the CNS for at the least one-year. We alert for the early diagnosis of WD in patients with exclusively neurological clinical pictures, sometimes with atypical or non-definitive diagnosis, because it is a potential treatable disease.
  • [Show abstract] [Hide abstract]
    ABSTRACT: Whipple's disease is a multisystem infection caused by the bacterium Tropheryma whipplei. The disease most commonly affects the intestine and causes a malabsorption syndrome, but almost any organ can be affected, so that it is part of the differential diagnosis of a wide range of clinical presentations. The Whipple's disease bacterium resisted attempts at cultivation for about four decades after the bacterial etiology was established; successful cultivation was reported in the year 2000. The genome sequences of two T. whipplei strains were published in 2003. The pathogenesis of Whipple's disease is not well understood; it is presumed that hosts have different susceptibilities due to immunological factors. The disease is commonly diagnosed by intestinal histopathology. Diagnostic PCR, cytology of body fluids, and electron microscopy are alternative diagnostic methods. Antibiotic therapy consistently leads to remission, but relapses, particularly those affecting the central nervous system, are a concern. New data from in vitro antibiotic susceptibility testing using cultivated T. whipplei have become available and complement existing recommendations that are based on empirical data.
    Clinical Microbiology Newsletter 12/2006; 28(23):177-184. DOI:10.1016/j.clinmicnews.2006.11.004