TY - JOUR
T1 - Malthusian parameters as estimators of the fitness of microbes
T2 - A cautionary tale about the low side of high throughput
AU - Concepción-Acevedo, Jeniffer
AU - Weiss, Howard N.
AU - Chaudhry, Waqas Nasir
AU - Levin, Bruce R.
N1 - Funding Information:
We wish to thank Clara Park and Nina Walker for technical support. BRL would like to acknowledge useful conversations about growth dynamics and fitness estimation in bacteria with Sylvain Gandon. We thank the reviewers. Although inconvenient and time consuming, we believe their comments and suggestions improved the quality of this consideration of the limitations of microtiter plate readers for estimating exponential growth rates and relative fitness. This research was supported by a grant from the US National Institutes of General Medical Science, GM098175 (BRL) and from the Higher Education Commission Pakistan (WNC). The Bioscreen plate reader was purchased with funds from a grant from Procter and Gamble. The funders had no role in the study design, data collection and analysis, decision to publish, or preparation of the manuscripts.
Publisher Copyright:
© 2015, Public Library of Science. All rights reserved. This is an open access article, free of all copyright, and may be freely reproduced, distributed, transmitted, modified, built upon, or otherwise used by anyone for any lawful purpose. The work is made available under the Creative Commons CC0 public domain dedication.
PY - 2015/6/26
Y1 - 2015/6/26
N2 - The maximum exponential growth rate, the Malthusian parameter (MP), is commonly used as a measure of fitness in experimental studies of adaptive evolution and of the effects of antibiotic resistance and other genes on the fitness of planktonic microbes. Thanks to automated, multi-well optical density plate readers and computers, with little hands-on effort investigators can readily obtain hundreds of estimates of MPs in less than a day. Here we compare estimates of the relative fitness of antibiotic susceptible and resistant strains of E. coli, Pseudomonas aeruginosa and Staphylococcus aureus based on MP data obtained with automated multi-well plate readers with the results from pairwise competition experiments. This leads us to question the reliability of estimates of MP obtained with these high throughput devices and the utility of these estimates of the maximum growth rates to detect fitness differences.
AB - The maximum exponential growth rate, the Malthusian parameter (MP), is commonly used as a measure of fitness in experimental studies of adaptive evolution and of the effects of antibiotic resistance and other genes on the fitness of planktonic microbes. Thanks to automated, multi-well optical density plate readers and computers, with little hands-on effort investigators can readily obtain hundreds of estimates of MPs in less than a day. Here we compare estimates of the relative fitness of antibiotic susceptible and resistant strains of E. coli, Pseudomonas aeruginosa and Staphylococcus aureus based on MP data obtained with automated multi-well plate readers with the results from pairwise competition experiments. This leads us to question the reliability of estimates of MP obtained with these high throughput devices and the utility of these estimates of the maximum growth rates to detect fitness differences.
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U2 - 10.1371/journal.pone.0126915
DO - 10.1371/journal.pone.0126915
M3 - Article
C2 - 26114477
AN - SCOPUS:84938520532
SN - 1932-6203
VL - 10
JO - PloS one
JF - PloS one
IS - 6
M1 - e0126915
ER -