Please use this identifier to cite or link to this item:
Title: Adaptation to an amoeba host leads to Pseudomonas aeruginosa isolates with attenuated virulence
Authors: Leong, Wai
Poh, Wee Han
Williams, Jonathan
Lutz, Carla
Hoque, M. Mozammel
Poh, Yan Hong
Yee, Benny Yeo Ken
Chua, Cliff
Givskov, Michael
Sanderson-Smith, Martina
Rice, Scott A.
McDougald, Diane
Keywords: Science::Biological sciences
Issue Date: 2022
Source: Leong, W., Poh, W. H., Williams, J., Lutz, C., Hoque, M. M., Poh, Y. H., Yee, B. Y. K., Chua, C., Givskov, M., Sanderson-Smith, M., Rice, S. A. & McDougald, D. (2022). Adaptation to an amoeba host leads to Pseudomonas aeruginosa isolates with attenuated virulence. Applied and Environmental Microbiology, 88(5), e02322-21-.
Journal: Applied and Environmental Microbiology 
Abstract: The opportunistic pathogen Pseudomonas aeruginosa is ubiquitous in the environment, and in humans, it is capable of causing acute or chronic infections. In the natural environment, predation by bacterivorous protozoa represents a primary threat to bacteria. Here, we determined the impact of long-term exposure of P. aeruginosa to predation pressure. P. aeruginosa persisted when coincubated with the bacterivorous Acanthamoeba castellanii for extended periods and produced genetic and phenotypic variants. Sequencing of late-stage amoeba-adapted P. aeruginosa isolates demonstrated single nucleotide polymorphisms within genes that encode known virulence factors, and this correlated with a reduction in expression of virulence traits. Virulence for the nematode Caenorhabditis elegans was attenuated in late-stage amoeba-adapted P. aeruginosa compared to early-stage amoeba-adapted and nonadapted counterparts. Further, late-stage amoeba-adapted P. aeruginosa showed increased competitive fitness and enhanced survival in amoebae as well as in macrophage and neutrophils. Interestingly, our findings indicate that the selection imposed by amoebae resulted in P. aeruginosa isolates with reduced virulence and enhanced fitness, similar to those recovered from chronic cystic fibrosis infections. Thus, predation by protozoa and long-term colonization of the human host may represent similar environments that select for similar losses of gene function. IMPORTANCE Pseudomonas aeruginosa is an opportunistic pathogen that causes both acute infections in plants and animals, including humans, and chronic infections in immunocompromised and cystic fibrosis patients. This bacterium is commonly found in soils and water, where bacteria are constantly under threat of being consumed by bacterial predators, e.g., protozoa. To escape being killed, bacteria have evolved a suite of mechanisms that protect them from being consumed or digested. Here, we examined the effect of long-term predation on the genotypes and phenotypes expressed by P. aeruginosa. We show that long-term coincubation with protozoa gave rise to mutations that resulted in P. aeruginosa becoming less pathogenic. This is particularly interesting as similar mutations arise in bacteria associated with chronic infections. Importantly, the genetic and phenotypic traits possessed by late-stage amoeba-adapted P. aeruginosa are similar to those observed in isolates obtained from chronic cystic fibrosis infections. This notable overlap in adaptation to different host types suggests similar selection pressures among host cell types as well as similar adaptation strategies.
ISSN: 0099-2240
DOI: 10.1128/aem.02322-21
Schools: School of Biological Sciences 
Research Centres: Singapore Centre for Environmental Life Sciences and Engineering (SCELSE) 
Rights: © 2022 Leong et al. This is an open-access article distributed under the terms of the Creative Commons Attribution 4.0 International license.
Fulltext Permission: open
Fulltext Availability: With Fulltext
Appears in Collections:SBS Journal Articles
SCELSE Journal Articles

Files in This Item:
File Description SizeFormat 
aem.02322-21.pdf1.94 MBAdobe PDFThumbnail

Citations 50

Updated on Dec 4, 2023

Web of ScienceTM
Citations 20

Updated on Oct 27, 2023

Page view(s)

Updated on Dec 11, 2023

Download(s) 50

Updated on Dec 11, 2023

Google ScholarTM




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