# Adaptive alterations of lipids in mitis group streptococci

> **NIH NIH R01** · UNIVERSITY OF TEXAS DALLAS · 2020 · $487,947

## Abstract

Abstract
As major components of the cellular envelope, lipids play myriad roles in the survival of bacterial pathogens.
Pathogens can adjust the biochemical properties (such as electrostatic charge) of their membrane lipids to cope
with the changing and challenging conditions of their surroundings. We study lipids in the mitis group streptococci,
specifically, Streptococcus mitis, S. oralis, and S. pneumoniae, which share a very close phylogenetic
relationship. S. mitis and S. oralis are opportunistic pathogens that are among the leading causes of bacteremia
(bloodstream infection) and infective endocarditis (heart valve infection). S. pneumoniae is a major human
pathogen responsible for most cases of community-acquired pneumonia and meningitis in children and the
elderly, and is a major cause of childhood mortality worldwide. Despite the clinical significance of these
organisms and the critical functions of the lipids in host-microbe interactions, the membrane biology of mitis
group streptococci is understudied and poorly understood. Using liquid chromatography/mass spectrometry
(LC/MS)-based lipidomics, we analyzed lipids in the cell envelopes of mitis group streptococci and identified
several novel surface properties which we propose are important for coping with antibiotics, antimicrobial
peptides, and unfavorable conditions inside hosts. The overarching hypothesis of this project is that the ability of
mitis group streptococci to drastically alter the charged lipid compositions of their cellular envelope impacts their
interactions with hosts and their responses to antimicrobial stress. We propose to analyze the structure and
biosynthesis of anionic (Aim 1) and zwitterionic lipids (Aim 2) in mitis group streptococci, and their roles in host-
pathogen interactions (Aim 3). The knowledge gained will lead to a better understanding of the survival and
virulence of these pathogens in the host and may facilitate the development of novel therapeutics to combat
antibiotic resistance.

## Key facts

- **NIH application ID:** 10121367
- **Project number:** 1R01AI148366-01A1
- **Recipient organization:** UNIVERSITY OF TEXAS DALLAS
- **Principal Investigator:** Ziqiang Guan
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $487,947
- **Award type:** 1
- **Project period:** 2020-09-23 → 2025-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10121367

## Citation

> US National Institutes of Health, RePORTER application 10121367, Adaptive alterations of lipids in mitis group streptococci (1R01AI148366-01A1). Retrieved via AI Analytics 2026-05-25 from https://api.ai-analytics.org/grant/nih/10121367. Licensed CC0.

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