Poster No. 25
Title:
Utility of Pyrosequencing of the Bacterial 16S rRNA Genes and Computational Analysis in Studying
Alterations in the Gut Microbiota During Cryptosporidiosis
Authors:
Sean Nealy, Veeraraghavan Balaji, Sitara Rao Ajjampur, Rajiv Sarkar, Gagandeep Kang, Roberta O'Connor,
Honorine Ward, Anne Kane, Debra Poutsiaka
Presented by:
Sean Nealy
Departments:
Department of Medicine, Tufts University School of Medicine; Department of Gastrointestinal Sciences,
Christian Medical College, Vellore, India; Division of Geographic Medicine and Infectious Disease,
Tufts Medical Center
Abstract:
The microbiota of the gut play a role in many of the body’s functions and in numerous diseases. Fecal samples
from three pediatric patients enrolled a prospective cohort study of cryptosporidiosis in Vellore, South India
were used to show changes in the gastrointestinal (GI) microbiota before, during, and after infection. DNA was
isolated from stool samples, and the genes encoding bacterial 16S rRNA (16S rDNA) were amplified and
pyrosequenced. The resulting sequences were trimmed of poor quality sequences, aligned according to the RDP
Classifier and then clustered according to genetic relatedness. Subsequently indices describing the ecology of
the gut microbiota were analyzed. We found differences in richness over the course of cryptosporidiosis in two
of the three patients. In these patients, richness increased during cryptosporidiosis and fell after recovery.
Changes in diversity paralleled these results, with an increase during illness and a subsequent decrease
afterwards. There were also changes in the relative proportions of the major phyla represented in the gut
microbiota but these changes followed no pattern. A larger study will be necessary to provide conclusions about
gut microbiota alterations during cryptosporidiosis.
We conclude that pyrosequencing fecal bacterial 16S rDNA and computational analysis employing the RDP
Pipeline are useful tools in the study of the disruptions in the GI microbiota over the course of an illness.
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