Remodeling of the Enterococcal Cell Envelope during Surface Penetration Promotes Intrinsic Resistance to Stress

Abstract

Enterococcus faecalis inhabits the GIT of multiple organisms, where its establishment could be mediated by the formation of biofilm-like aggregates. In susceptible individuals, this bacterium can overgrow and breach intestinal barriers, a process that may lead to lethal systemic infections.

Bacterial susceptibility and resistance to modelin-5

“…S1 and Table 2, ESI†) using mechanisms available to other Gram-positive bacteria, clearly suggesting that the peptide's activity against these bacteria may show a more limited spectrum. 55,71,142–148…”

“…10A) In support of this suggestion, Lys-PG has also been detected in the CM of other bacteria 55,[139][140][141] and appears to inhibit binding by AMPs in resistance mechanism with similarities to that mediated by the lipid in S. aureus. 55,71,[142][143][144][145][146][147][148] Interestingly, in what seems to be an evolutionary response, some creatures appear to produce anionic AMPs that bind Lys-PG to overcome S. aureus resistance mechanisms and promote their antibacterial action. 149 The weak affinity of M5-NH 2 for the CM of S. aureus appeared to limit rather than completely abolish the ability of the peptide to interact with these membranes.…”

“…S1 and Table 2, ESI †) using mechanisms available to other Gram-positive bacteria, clearly suggesting that the peptide's activity against these bacteria may show a more limited spectrum. 55,71,[142][143][144][145][146][147][148] Characterisation of the antibacterial activity of M5-NH 2 showed it to possess potent CL driven membranolytic action against P. aeruginosa but was rendered ineffective against S. aureus by Lys-PG driven inhibition of this action (Table 2). These observations clearly showed the effect of differences in the lipid compositions of bacterial membranes on the activity of AMPs and reinforce the importance of taking these differences into account when designing these peptides.…”

Uncovering Surface Penetration by Enterococci From Urinary Tract Infection Patients

“… 18 Despite its nonmotile nature, we have demonstrated that this bacterium can penetrate semisolid agar media and epithelial cell monolayers 18–20 . Exploiting this system, we observed that while some enterococcal cells remain on the agar surface, forming an external colony, others migrate within, resulting in a distinct “colony-print” formation within the semisolid medium 18,20 . Both external and penetrating enterococci exhibited unique genetic programs, conferring fitness advantages to the invading cells, including increased antibiotic resistance 20 .…”

“…Exploiting this system, we observed that while some enterococcal cells remain on the agar surface, forming an external colony, others migrate within, resulting in a distinct “colony-print” formation within the semisolid medium 18,20 . Both external and penetrating enterococci exhibited unique genetic programs, conferring fitness advantages to the invading cells, including increased antibiotic resistance 20 . Moreover, our research has unveiled that successful E faecalis agar penetration requires the formation of multicellular aggregates and the synthesis of extracellular polysaccharides, particularly highlighting the role of polyGlcNAc (an exopolysaccharide composed of N -acetylglucosamine) 18,19 .…”