Please use this identifier to cite or link to this item:
Title: Enterococcus faecalis antagonizes Pseudomonas aeruginosa growth in mixed-species interactions
Authors: Tan, Casandra Ai Zhu
Lam, Ling Ning
Biukovic, Goran
Soh, Eliza Ye-Chen
Toh, Xiao Wei
Lemos, José A.
Kline, Kimberly A.
Keywords: Science::Biological sciences
Issue Date: 2022
Source: Tan, C. A. Z., Lam, L. N., Biukovic, G., Soh, E. Y., Toh, X. W., Lemos, J. A. & Kline, K. A. (2022). Enterococcus faecalis antagonizes Pseudomonas aeruginosa growth in mixed-species interactions. Journal of Bacteriology, 204(7), e00615-21-.
Project: MOE2014-T2-1-129 
NIAID R21 AI37446 
Journal: Journal of Bacteriology 
Abstract: Enterococcus faecalis is often coisolated with Pseudomonas aeruginosa in polymicrobial biofilm-associated infections of wounds and the urinary tract. As a defense strategy, the host innately restricts iron availability at infection sites. Despite their coprevalence, the polymicrobial interactions of these two species in biofilms and under iron-restricted conditions remain unexplored. Here, we show that E. faecalis inhibits P. aeruginosa growth within biofilms when iron is restricted. E. faecalis lactate dehydrogenase (ldh1) gives rise to l-lactate production during fermentative growth. We find that an E. faecalis ldh1 mutant fails to inhibit P. aeruginosa growth. Additionally, we demonstrate that ldh1 expression is induced under iron-restricted conditions, resulting in increased lactic acid exported and, consequently, a reduction in local environmental pH. Together, our results suggest that E. faecalis synergistically inhibits P. aeruginosa growth by decreasing environmental pH and l-lactate-mediated iron chelation. Overall, this study emphasizes the importance of the microenvironment in polymicrobial interactions and how manipulating the microenvironment can impact the growth trajectory of bacterial communities. IMPORTANCE Many infections are polymicrobial and biofilm-associated in nature. Iron is essential for many metabolic processes and plays an important role in controlling infections, where the host restricts iron as a defense mechanism against invading pathogens. However, polymicrobial interactions between pathogens are underexplored under iron-restricted conditions. Here, we explore the polymicrobial interactions between commonly coisolated E. faecalis and P. aeruginosa within biofilms. We find that E. faecalis modulates the microenvironment by exporting lactic acid which further chelates already limited iron and also lowers the environmental pH to antagonize P. aeruginosa growth under iron-restricted conditions. Our findings provide insights into polymicrobial interactions between bacteria and how manipulating the microenvironment can be taken advantage of to better control infections.
ISSN: 0021-9193
DOI: 10.1128/jb.00615-21
Schools: School of Biological Sciences 
Research Centres: Singapore Centre for Environmental Life Sciences and Engineering 
Rights: © 2022 American Society for Microbiology. All rights reserved. This paper was published in Journal of Bacteriology and is made available with permission of American Society for Microbiology.
Fulltext Permission: open
Fulltext Availability: With Fulltext
Appears in Collections:SBS Journal Articles
SCELSE Journal Articles

Files in This Item:
File Description SizeFormat 
jb.00615-21.pdf2.17 MBAdobe PDFThumbnail

Citations 50

Updated on Sep 22, 2023

Web of ScienceTM
Citations 20

Updated on Sep 29, 2023

Page view(s)

Updated on Sep 30, 2023


Updated on Sep 30, 2023

Google ScholarTM




Items in DR-NTU are protected by copyright, with all rights reserved, unless otherwise indicated.