Active and secretory IgA-coated bacterial fractions elucidate dysbiosis in Clostridium difficile infection

Džunková, Mária, Moya, Andrés, Vázquez-Castellanos, Jorge F, Artacho, Alejandro, Chen, Xinhua, Kelly, Ciaran and D'Auria, Giuseppe (2016) Active and secretory IgA-coated bacterial fractions elucidate dysbiosis in Clostridium difficile infection. mSphere, 1 3: . doi:10.1128/mSphere.00101-16

Author Džunková, Mária
Moya, Andrés
Vázquez-Castellanos, Jorge F
Artacho, Alejandro
Chen, Xinhua
Kelly, Ciaran
D'Auria, Giuseppe
Title Active and secretory IgA-coated bacterial fractions elucidate dysbiosis in Clostridium difficile infection
Formatted title
Active and secretory IgA-coated bacterial fractions elucidate dysbiosis in Clostridium difficile infection
Journal name mSphere   Check publisher's open access policy
ISSN 2379-5042
Publication date 2016-05-01
Sub-type Article (original research)
DOI 10.1128/mSphere.00101-16
Open Access Status DOI
Volume 1
Issue 3
Total pages 11
Place of publication Washington, DC, United States
Publisher American Society for Microbiology
Language eng
Abstract The onset of Clostridium difficile infection (CDI) has been associated with treatment with wide-spectrum antibiotics. Antibiotic treatment alters the activity of gut commensals and may result in modified patterns of immune responses to pathogens. To study these mechanisms during CDI, we separated bacteria with high cellular RNA content (the active bacteria) and their inactive counterparts by fluorescence-activated cell sorting (FACS) of the fecal bacterial suspension. The gut dysbiosis due to the antibiotic treatment may result in modification of immune recognition of intestinal bacteria. The immune recognition patterns were assessed by FACS of bacterial fractions either coated or not with intestinal secretory immunoglobulin A (SIgA). We described the taxonomic distributions of these four bacterial fractions (active versus inactive and SIgA coated versus non-SIgA coated) by massive 16S rRNA gene amplicon sequencing and quantified the proportion of C. difficile toxin genes in the samples. The overall gut microbiome composition was more robustly influenced by antibiotics than by the C. difficile toxins. Bayesian networks revealed that the C. difficile cluster was preferentially SIgA coated during CDI. In contrast, in the CDI-negative group Fusobacterium was the characteristic genus of the SIgA-opsonized fraction. Lactobacillales and Clostridium cluster IV were mostly inactive in CDI-positive patients. In conclusion, although the proportion of C. difficile in the gut is very low, it is able to initiate infection during the gut dysbiosis caused by environmental stress (antibiotic treatment) as a consequence of decreased activity of the protective bacteria. IMPORTANCE C. difficile is a major enteric pathogen with worldwide distribution. Its expansion is associated with broad-spectrum antibiotics which disturb the normal gut microbiome. In this study, the DNA sequencing of highly active bacteria and bacteria opsonized by intestinal secretory immunoglobulin A (SIgA) separated from the whole bacterial community by FACS elucidated how the gut dysbiosis promotes C. difficile infection (CDI). Bacterial groups with inhibitory effects on C. difficile growth, such as Lactobacillales, were mostly inactive in the CDI patients. C. difficile was typical for the bacterial fraction opsonized by SIgA in patients with CDI, while Fusobacterium was characteristic for the SIgA-opsonized fraction of the controls. The study demonstrates that sequencing of specific bacterial fractions provides additional information about dysbiotic processes in the gut. The detected patterns have been confirmed with the whole patient cohort independently of the taxonomic differences detected in the nonfractionated microbiomes.
Keyword 16S rRNA gene sequencing
Bayesian networks
Clostridium difficile infection
Fluorescence-activated cell sorting
Human gut microbiome
Secretory immunoglobulin A
Q-Index Code C1
Q-Index Status Provisional Code
Institutional Status Non-UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: HERDC Pre-Audit
School of Chemistry and Molecular Biosciences
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Citation counts: TR Web of Science Citation Count  Cited 3 times in Thomson Reuters Web of Science Article | Citations
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Created: Wed, 15 Nov 2017, 13:52:43 EST