Bdellovibrio bacteriovorus Inhibits Staphylococcus aureus Biofilm Formation and Invasion into Human Epithelial Cells

Abstract

Bdellovibrio bacteriovorus HD100 is a predatory bacterium that attacks many Gram-negative human pathogens. A serious drawback of this strain, however, is its ineffectiveness against Gram-positive strains, such as the human pathogen Staphylococcus aureus. Here we demonstrate that the extracellular proteases produced by a host-independent B. bacteriovorus (HIB) effectively degrade/inhibit the formation of S. aureus biofilms and reduce its virulence. A 10% addition of HIB supernatant caused a 75% or greater reduction in S. aureus biofilm formation as well as 75% dispersal of pre-formed biofilms. LC-MS-MS analyses identified various B. bacteriovorus proteases within the supernatant, including the serine proteases Bd2269 and Bd2321. Tests with AEBSF confirmed that serine proteases were active in the supernatant and that they impacted S. aureus biofilm formation. The supernatant also possessed a slight DNAse activity. Furthermore, treatment of planktonic S. aureus with the supernatant diminished its ability to invade MCF-10a epithelial cells by 5-fold but did not affect the MCF-10a viability. In conclusion, this study illustrates the hitherto unknown ability of B. bacteriovorus to disperse Gram-positive pathogenic biofilms and mitigate their virulence.

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“…Крім того, деякі представники цих родів про вокують пневмонії, пієлонефрити, ендокардити, кістозні фібрози, зубний наліт та найчастіше пов'язані з катетер-асоційованими інфекціями [5,8,13,18,21].…”

Role of Extracellular Proteases in Biofilm Disruption of Gram Positive Bacteria with Special Emphasis on Staphylococcus aureus Biofilms

“…To sustain this kind of lifestyle Bdellovibrio genus is known to produce a large number of proteolytic enzymes and nucleases. Monnappa et al report that addition of 10% of HIB supernatant resulted in 75% or more reduction in S. aureus biofilm formation as well as dispersal of pre-formed biofilms [40]. LC-MS-MS analyses revealed that host independent B. bacteriovorus supernatant contained various proteases, including two significant serine proteases that were named as Bd2269 and Bd2321 [40].…”

“…Monnappa et al report that addition of 10% of HIB supernatant resulted in 75% or more reduction in S. aureus biofilm formation as well as dispersal of pre-formed biofilms [40]. LC-MS-MS analyses revealed that host independent B. bacteriovorus supernatant contained various proteases, including two significant serine proteases that were named as Bd2269 and Bd2321 [40]. Authors carried out experiments with various protease inhibitors and significant inhibitory effect of AEBSF on the proteolytic activity of the HIB supernatant confirmed that serine proteases were present in the supernatant and that they were the ones responsible for S. aureus biofilm disruption [40].…”

“…Monnappa et al [40] describe the anti-biofilm/anti-virulence activity of extracellular proteases produced by a host-independent Bdellovibrio bacteriovorus (HIB) for the first time. Bdellovibrio sp.…”

Bacterial predator–prey dynamics in microscale patchy landscapes

“…Furthermore, given that B. bacteriovorus has shown potential to protect crops and reduce biofouling [26][27][28][29], it would be useful to know how its effectiveness in structured habitats relates to its effectiveness as measured in well-mixed (unstructured) culture flasks [30][31][32]. In this regard, B. bacteriovorus has also attracted significant interest because of its potential to eradicate bacterial biofilms which are spatially structured at the microscale [33,34].…”