Tropheyma whipplei, the causative agent of Whipple's disease, is associated with various clinical manifestations as well as an asymptomatic cariier status, and it exhibits genetic heterogeneity. However, relationship that may exist between environmental and clinical strains are unknown. Herein, we developed an efficient genotyping system based on four highly variale genomic sequences (HVGSs) selected on the basis of genome comparison. We analysed 39 samples from 39 patients with Whipple's disease and 10 samples from 10 asymptomatic carriers. Twenty-six classic gastrointestinal Whipple's disease associated with additional manifestations, six relapses of classic Whipple's disease (three gastrointestinal and three neurological relapses), and seven isolated infections due to T. shipplei without digestive involvement (five endocarditis, one spondylodiscitis and one neurological infection) were included in the study. We identified 24 HVGS genotypes among 39 T. whipplei DNA samples from the patients and 10 T. whipplei DNA samples from the asymtomatic carriers. No significant correlation between HVGS genotypes and clinical manifestations of Whipple's disease, or asymptomatic carriers, was found for the 49 samples tested. Our observations revealed a high genetic diversity of T. whipplei strains that is apparently independent of geographical distribution and unrelated to bacterial pathogenecity. Genotyping in Whipple's disease may, however, be useful in epidemiological studies.
Genotyping reveals a wide heterogenity of Tropheryma whipplei
BIAGI, FEDERICO;
2008-01-01
Abstract
Tropheyma whipplei, the causative agent of Whipple's disease, is associated with various clinical manifestations as well as an asymptomatic cariier status, and it exhibits genetic heterogeneity. However, relationship that may exist between environmental and clinical strains are unknown. Herein, we developed an efficient genotyping system based on four highly variale genomic sequences (HVGSs) selected on the basis of genome comparison. We analysed 39 samples from 39 patients with Whipple's disease and 10 samples from 10 asymptomatic carriers. Twenty-six classic gastrointestinal Whipple's disease associated with additional manifestations, six relapses of classic Whipple's disease (three gastrointestinal and three neurological relapses), and seven isolated infections due to T. shipplei without digestive involvement (five endocarditis, one spondylodiscitis and one neurological infection) were included in the study. We identified 24 HVGS genotypes among 39 T. whipplei DNA samples from the patients and 10 T. whipplei DNA samples from the asymtomatic carriers. No significant correlation between HVGS genotypes and clinical manifestations of Whipple's disease, or asymptomatic carriers, was found for the 49 samples tested. Our observations revealed a high genetic diversity of T. whipplei strains that is apparently independent of geographical distribution and unrelated to bacterial pathogenecity. Genotyping in Whipple's disease may, however, be useful in epidemiological studies.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.