Sessile Legionella pneumophila is able to grow on surfaces and generate structured monospecies biofilms

• Published in: Biofouling (Chur, Switzerland) Switzerland), 2010-01, Vol.26 (7), p.809-819
• Main Authors: Pécastaings, S., Bergé, M., Dubourg, K. M., Roques, C.
• Format: Article
• Language: English
• Subjects: Animals; Bacterial Adhesion; Bacteriological Techniques; biofilm; Biofilms; Biofilms - growth & development; Broths; Clusters; Confocal; confocal microscopy; Culture Media; Genes; Legionella pneumophila; Legionella pneumophila - isolation & purification; Legionella pneumophila - physiology; Microorganisms; Microscopy, Confocal; Plankton - microbiology; Plankton - physiology; Reproducibility; sessile growth
• ISSN: 0892-7014; 1029-2454
• DOI: 10.1080/08927014.2010.520159

Currently, models for studying Legionella pneumophila biofilm formation rely on multi-species biofilms with low reproducibility or on growth in rich medium, where planktonic growth is unavoidable. The present study describes a new medium adapted to the growth of L. pneumophila monospecies biofilms in vitro. A microplate model was used to test several media. After incubation for 6 days in a specific biofilm broth not supporting planktonic growth, biofilms consisted of 5.36 ± 0.40 log (cfu cm −2 ) or 5.34 ± 0.33 log (gu cm −2 ). The adhered population remained stable for up to 3 weeks after initial inoculation. In situ confocal microscope observations revealed a typical biofilm structure, comprising cell clusters ranging up to ∼300 μm in height. This model is adapted to growing monospecies L. pneumophila biofilms that are structurally different from biofilms formed in a rich medium. High reproducibility and the absence of other microbial species make this model useful for studying genes involved in biofilm formation.