96 research outputs found
Development of a Real-Time PCR for Identification of Brachyspira Species in Human Colonic Biopsies
Background: Brachyspira species are fastidious anaerobic microorganisms, that infect the colon of various animals. The
genus contains both important pathogens of livestock as well as commensals. Two species are known to infect humans: B.
aalborgi and B. pilosicoli. There is some evidence suggesting that the veterinary pathogenic B. pilosicoli is a potential
zoonotic agent, however, since diagnosis in humans is based on histopathology of colon biopsies, species identification is
not routinely performed in human materials.
Methods: The study population comprised 57 patients with microscopic evidence of Brachyspira infection and 26 patients
with no histopathological evidence of Brachyspira infection. Concomitant faecal samples were available from three infected
patients. Based on publically available 16S rDNA gene sequences of all Brachyspira species, species-specific primer sets were
designed. DNA was extracted and tested by real-time PCR and 16S rDNA was sequenced.
Results: Sensitivity and specificity for identification of Brachyspira species in colon biopsies was 100% and 87.7%
respectively. Sequencing revealed B. pilosicoli in 15.4% of patients, B. aalborgi in 76.9% and a third species, tentatively
named ‘‘Brachyspira hominis’’, in 26.2%. Ten patients (12.3%) had a double and two (3.1%) a triple infection. The presence of
Brachyspira pilosicoli was significantly associated with inflammatory changes in the colon-biopsy (p = 0.028).
Conclusions: This newly designed PCR allows for sub-differentiation of Brachyspira species in patient material and thus
allows large-scaled surveillance studies to elucidate the pathogenicity of human Brachyspira infections. One-third of
affected patients appeared to be infected with a novel species
- …