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BioMed Research International
Volume 2014 (2014), Article ID 678301, 7 pages
http://dx.doi.org/10.1155/2014/678301
Research Article

Emergent Bacteria in Cystic Fibrosis: In Vitro Biofilm Formation and Resilience under Variable Oxygen Conditions

1Institute for Biotechnology and Bioengineering (IBB), Centre for Biological Engineering, Universidade do Minho, Campus de Gualtar, 4710-057 Braga, Portugal
2LEPAE, Department of Chemical Engineering, Faculty of Engineering, University of Porto, 4200-465 Porto, Portugal

Received 22 February 2014; Accepted 15 April 2014; Published 29 April 2014

Academic Editor: Andrei Surguchov

Copyright © 2014 Susana P. Lopes et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Concurrent to conventional bacterial pathogens, unusual microbes are emerging from cystic fibrosis (CF) airways. Nonetheless, little is known about the contribution of these newly microbes to the resilience of CF-associated biofilms, particularly under variable-oxygen concentrations that are known to occur in vivo in the mucus of CF patients. Two CF-emergent bacterial species, Inquilinus limosus and Dolosigranulum pigrum, and the major pathogen Pseudomonas aeruginosa were studied in terms of biofilm development and antibiotic susceptibilities under in vitro atmospheres with different oxygen availabilities. All species were able to develop in vitro biofilms under different oxygen-available environments, with D. pigrum accumulating high amounts of biomass and respiratory activities. When established, biofilms were of difficult eradication, with antibiotics losing their effectiveness in comparison with the corresponding planktonic populations. Surprisingly, biofilms of each emergent organism displayed multidrug resistance under aerobic environments, enduring even in low-oxygen atmospheres. This study suggests a potential prospect on the impact of nonconventional organisms I. limosus and D. pigrum on CF lung infections, demonstrating capacity to adapt to biofilm mode of life under restricted-oxygen atmospheres resembling CF airways, which may ultimately endanger the efficacy of currently used antibiotic regimens.