Deciphering the Antibacterial Role of Peptide From Bacillus subtilis subsp. spizizenii Ba49 Against Staphylococcus aureus

Abstract

An increase in antibiotic resistance has led to escalating the need for the development of alternate therapy. Antimicrobial peptides (AMPs) are at the forefront of replacing conventional antibiotics, showing slower development of drug resistance, antibiofilm activity, and the ability to modulate the host immune response. The ESKAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species) pathogens that jeopardize most conventional antibiotics are known to be involved in severe respiratory tract, bloodstream, urinary tract, soft tissue, and skin infections. Among them, S. aureus is an insidious microbe and developed resistance against conventional antibiotics. In the present study, an AMP (named as peptide-Ba49) isolated from Bacillus subtilis subsp. spizizenii strain from Allium cepa (the common onion) exhibited strong antibacterial efficacy against S. aureus ATCC 25923. The mode of action of this peptide-Ba49 on S. aureus was deciphered through various sensitive probes, i.e., DiSC3 (5) and H2DCFDA, suggesting the peptide-Ba49 to be acting upon through change in membrane potential and by triggering the production of reactive oxygen species (ROS). This induced disruption of the cell membrane was further supported by morphological studies using scanning electron microscopy (SEM). Investigations on a possible post-antibiotic effect (PAE) of peptide-Ba49 showed prolonged PAE against S. aureus. Furthermore, the peptide-Ba49 prevented the formation of S. aureus biofilm at low concentration and showed its potential to degrade the mature biofilm of S. aureus. The peptide-Ba49 also exhibited intracellular killing potential against S. aureus ATCC 25923 in the macrophage cells, and moreover, peptide-Ba49 was found to bolster the fibroblast cell migration in the scratch assay at low concentration, exhibiting a wound healing efficacy of this peptide. These studies demonstrated that peptide-Ba49 isolated from the strain B. subtilis subsp. spizizenii could be a therapeutic candidate to combat the pathogenic S. aureus infections.

A truncated peptide Spgillcin177–189 derived from mud crab Scylla paramamosain exerting multiple antibacterial activities

“…In this study, Spgillcin 177–189 showed potent antimicrobial effects against S. aureus without resistance, and Spgillcin 177–189 could effectively kill S. aureus in the culture supernatant of RAW 264.7 cells. This result was similar to the AMP Ba49, which exhibits a potential bactericidal activity against S. aureus in macrophage cells ( Taggar et al., 2021 ), and the AMP CATH-2, which kills S. aureus in macrophage cells ( Schneider et al., 2017 ). Therefore, Spgillcin 177–189 could be exploited as an effective anti-infective drug in the future.…”

Truncated Pleurocidin Derivative with High Pepsin Hydrolysis Resistance to Combat Multidrug-Resistant Pathogens

“…It is involved in maintaining the dynamic balance of bacterial proton dynamics and is essential for bacterial survival. We next evaluated the effect of GK-4 peptide on membrane potential using the fluorescent dye DiSC 3 (5) [ 35 ], as it accumulates in the cytoplasmic membrane in response to the Δψ component of bacteria. When Δψ is destroyed, the probe will be released into the extracellular environment, resulting in fluorescence enhancement.…”

Diversity and Mechanisms of Action of Plant, Animal, and Human Antimicrobial Peptides

“…In Taggar et al’s study, an AMP, named peptide-Ba49, was isolated from a Bacillus subtilis subsp. spizizenii strain cultivated from Allium cepa , also known as the common onion, which exhibited strong antibacterial activity against S. aureus ATCC 25923 [ 44 , 45 ]. The mode of action of this peptide on S. aureus was elucidated by the authors to occur through changes in the membrane potential and by triggering the production of reactive oxygen species (ROS) [ 44 , 45 ].…”