Original Research ARTICLE
Generalized growth of estuarine, household and clinical isolates of Pseudomonas aeruginosa
- 1Ecology and Evolutionary Biology, Yale University, United States
- 2University of Louisville, United States
- 3School of Forestry and Environmental Studies, Yale University, United States
- 4Microbiology Program, Yale School of Medicine, Yale University, United States
Pseudomonas aeruginosa is an opportunistic pathogen of particular concern to immune-compromised people, such as cystic fibrosis patients and burn victims. These bacteria grow in built environments including hospitals and households, and in natural environments such as rivers and estuaries. However, there is conflicting evidence whether recent environments like the human lung and open ocean affect P. aeruginosa growth performance in alternate environments. We hypothesized that bacteria recently isolated from dissimilar habitats should grow differently in media containing artificial versus natural resources. To test this idea, we examined growth of P. aeruginosa isolates from three environments (estuary, household, clinic) in three media types: minimal-glucose lab medium, and media prepared from sugar maple leaves or big bluestem grass. We used automated spectrophotometry to measure high-resolution growth curves for all isolate by media combinations, and studied two fitness parameters: growth rate and maximum population density. Results showed high variability in growth rate among isolates, both overall and in its dependence on assay media, but this variability was not associated with habitat of isolation. In contrast, total growth (change in absorbance over the experiment) differed overall among habitats of isolation, and there were media-specific differences in mean total growth among habitats of isolation, and in among-habitat variability in the media-specific response. This was driven primarily by greater total growth of estuary isolates when compared with those from other habitats of origin, and greater media-specific variability among household isolates than those from other habitats of origin. Taken together, these results suggest that for growth rate P. aeruginosa bacteria appear to be broad generalists without regard to current or recent habitat, whereas for total growth a signature of recent ecological history can be detected.
Keywords: Bacteria, evolutionary ecology, fitness, Genotype by environment interaction, Opportunistic pathogen
Received: 10 Jun 2017;
Accepted: 09 Feb 2018.
Edited by:John R. Battista, Louisiana State University, United States
Reviewed by:Rolf Kümmerli, University of Zurich, Switzerland
Bärbel U. Fösel, Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt, Germany
Copyright: © 2018 Diaz, Remold, Onyiri, Bozeman, Raymond and Turner. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: PhD. Paul E. Turner, Yale University, Ecology and Evolutionary Biology, New Haven, United States, firstname.lastname@example.org