Phage release from biofilm and planktonicStaphylococcus aureuscells

Abstract

The ability of pathogenic staphylococci to form biofilms facilitates colonization and the development of chronic infections. Therapy is hampered by the high tolerance of biofilms towards antibiotic treatment and the immune system. We found evidence that lysogenic Staphylococcus aureus cells in a biofilm and in planktonic cultures spontaneously release phages into their surroundings. Phages were detected over a much longer period in biofilm cultures than in planktonic supernatants because the latter were degraded by secreted proteases. Phage release in planktonic and biofilm cultures was artificially increased by adding mitomycin C. Two morphologically distinct phages in the S. aureus strain used in this work were observed by electron microscopy. We postulate that phage-release is a frequent event in biofilms. The resulting lysis of cells in a biofilm might promote the persistence and survival of the remaining cells, as they gain a nutrient reservoir from their dead and lysed neighboring cells. This might therefore be an early differentiation and apoptotic mechanism.

Treponema denticola biofilm-induced expression of a bacteriophage, toxin–antitoxin systems and transposases

“…Other studies have recently demonstrated a high level of bacteriophage release in biofilms (Resch et al, 2005;Rice et al, 2009). The resulting lysis of cells may provide nutrients and allow the persistence of neighbouring cells.…”

Role of autolysin-mediated DNA release in biofilm formation of Staphylococcus epidermidis

“…Recently, another autolysin protein was identified in S. epidermidis, Aae, which has bacteriolytic activity and adhesive properties, although its role in DNA release remains to be investigated (Heilmann et al, 2003). More recently, Resch et al (2005) have reported the presence of phage activities in both planktonic and biofilm cells of Staphylococcus aureus, and phages were present over a much longer period in biofilm cultures than in planktonic supernatants. It is reasonable to believe that phage release resulting in cell lysis may occur during biofilm formation of S. epidermidis as well.…”

Polymicrobial Interactions: Impact on Pathogenesis and Human Disease

“…Phages are viruses with a specific tropism for bacterial cells which can infect and reduce bacterial populations by undergoing rounds of phage replication typically followed by bacterial lysis. While bactericidal activity was thought to primarily be a consequence of lytic events, it has been shown that phage particles encode depolymerases that demonstrate enzymatic activity against bacterial matrices, including exopolymeric compounds (95,173). For example, Glonti et al have shown that bacteriophage PT-6 produces an alginase capable of breaking down the thick polysaccharide alginate matrix elaborated by P. aeruginosa during lower airway infection of the CF lung (70).…”