Busting biofilms: free-living amoebae disrupt preformed methicillin-resistant Staphylococcus aureus (MRSA) and Mycobacterium bovis biofilms

• Published in: Microbiology (Society for General Microbiology) Vol. 166; no. 8; pp. 695 - 706
• Main Authors: Martin, Kevin H, Borlee, Grace I, Wheat, William H, Jackson, Mary, Borlee, Bradley R
• Format: Journal Article
• Language: English
• Published: England Microbiology Society 01.08.2020
• Subjects: Amoebida - classification; Amoebida - metabolism; Amoebida - physiology; Antibiosis; Biofilms - drug effects; Biofilms - growth & development; Cell Survival - drug effects; Culture Media, Conditioned - metabolism; Culture Media, Conditioned - pharmacology; Methicillin-Resistant Staphylococcus aureus - drug effects; Methicillin-Resistant Staphylococcus aureus - physiology; Mycobacterium bovis - drug effects; Mycobacterium bovis - physiology; Species Specificity; Dictyostelium; Mycobacterium bovis; Acanthamoeba; MRSA; biofilm; Vermamoeba; amoebae; Staphylococcus aureus
• ISSN: 1350-0872; 1465-2080; 1465-2080
• DOI: 10.1099/mic.0.000933

Biofilm-associated infections are difficult to eradicate because of their ability to tolerate antibiotics and evade host immune responses. Amoebae and/or their secreted products may provide alternative strategies to inhibit and disperse biofilms on biotic and abiotic surfaces. We evaluated the potential of five predatory amoebae - , , , and - and their cell-free secretions to disrupt biofilms formed by methicillin-resistant (MRSA) and . The biofilm biomass produced by MRSA and was significantly reduced when co-incubated with , and , and their corresponding cell-free supernatants (CFS). spp. generally produced CFS that mediated biofilm dispersal rather than directly killing the bacteria; however, CFS demonstrated active killing of MRSA planktonic cells when the bacteria were present at low concentrations. The active component(s) of the CFS is resistant to freezing, but can be inactivated to differing degrees by mechanical disruption and exposure to heat. and its CFS also reduced preformed biofilms, whereas only decreased biofilm biomass when amoebae were added. These results highlight the potential of using select amoebae species or their CFS to disrupt preformed bacterial biofilms.