Impact of antibiotic treatment on Lactobacillus population dynamics and intestinal T cell regulatory function

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Presentation Time: 02:15 PM - 03:30 PM
Poster Board Number: B122
Abstract ID: 5489

Presenting Author:
Dormarie E. Rivera-Rodriguez , PhD Student at Emory Univ. Sch. of Med., Emory Natl. Primate Res. Ctr.

Abstract:

Antibiotics are our most important tool to treat bacterial infections. Many broad-spectrum antibiotics, like oral ciprofloxacin, are commonly prescribed for gastrointestinal infection treatment. However, antibiotic overuse promotes resistance in many bacteria, leading to a global crisis in infection treatment. During treatment, the microbiota is also affected. Previous studies showed that changes in the microbiota alter mucosal immunity. We aim to understand how oral ciprofloxacin impacts microbiota diversity and changes the intestinal regulatory immune system. We treated IL-10 reporter mice with ciprofloxacin for two weeks to examine if IL-10 production was affected. Our results show that IL-10 production from small intestinal T cells increases during treatment. Analyses of the microbiota composition by 16S rRNA sequencing showed an expansion of Lactobacilli in the ileum. We hypothesize that some Lactobacilli species have different resistance levels to ciprofloxacin. Our results show that L. reuteri and L. johnsonii are more resistant to ciprofloxacin in comparison to L. murinus. Interestingly, we observed that ciprofloxacin decreases L. murinus and expands L. johnsonii and L. reuteri. Future experiments will aim to determine if Lactobacilli expansion during ciprofloxacin increases IL-10 production in small intestinal T cells. Overall, this project will assess how ciprofloxacin affects Lactobacilli population dynamics and the host microbiome-immune system interactions.