Inhibition of Collagenase Q1 of Bacillus cereus as a Novel Antivirulence Strategy for the Treatment of Skin‐Wound Infections

Abstract

Despite the progress in surgical techniques and antibiotic prophylaxis, opportunistic wound infections with Bacillus cereus remain a public health problem. Secreted toxins are one of the main factors contributing to B. cereus pathogenicity. A promising strategy to treat such infections is to target these toxins and not the bacteria. Although the exoenzymes produced by B. cereus are thoroughly investigated, little is known about the role of B. cereus collagenases in wound infections. In this report, the collagenolytic activity of secreted collagenases (Col) is characterized in the B. cereus culture supernatant (csn) and its isolated recombinantly produced ColQ1 is characterized. The data reveals that ColQ1 causes damage on dermal collagen (COL). This results in gaps in the tissue, which might facilitate the spread of bacteria. The importance of B. cereus collagenases is also demonstrated in disease promotion using two inhibitors. Compound 2 shows high efficacy in peptidolytic, gelatinolytic, and COL degradation assays. It also preserves the fibrillar COLs in skin tissue challenged with ColQ1, as well as the viability of skin cells treated with B. cereus csn. A Galleria mellonella model highlights the significance of collagenase inhibition in vivo.

The Structures and Binding Modes of Small-Molecule Inhibitors of Pseudomonas aeruginosa Elastase LasB

“…For instance, the beneficial effects of targeting virulence factors were observed in Neisseria species [ 17 ], such as the Type IV pili inhibition by trifluoperazine that reduces the host colonization and the formation of vascular lesions [ 18 ]. Given their key role in host colonization and their extracellular localization, the bacterial collagenases are considered to be crucial virulence factors [ 19 ] and therefore represent suitable drug targets for developing antivirulence compounds [ 20 , 21 , 22 , 23 ]. Inhibiting Staphylococcus aureus virulence factors also demonstrated attractive effects [ 24 ], such as the inhibition of the agr -mediated quorum sensing system by savirin, which promotes the host defense [ 25 ].…”

Discovery and Characterization of Synthesized and FDA-Approved Inhibitors of Clostridial and Bacillary Collagenases

“…We reported previously that treating the G. mellonella larvae with ColQ1 caused death of the larvae . We established B.…”

“…The experiments were done as described before. , Briefly, in a buffer containing 250 mM HEPES, 150 mM NaCl, 5 mM CaCl 2 , 5 μM ZnCl 2 , pH 7.5, 1 mg/mL acid-soluble type I collagen from bovine tail (Thermo Fischer Scientific) was incubated with 50 ng full-length ColQ1. Compounds were evaluated at various concentrations and incubated together with collagen and ColQ1 at 25 °C for 3 h. After stopping the reaction with 50 mM EDTA, the mixture was loaded on 12% SDS-PAGE gel and stained with colloidal coomassie G-250 dye .…”

“…Examples of known bacterial collagenase H and Q1 (ColH and ColQ1) inhibitors. (a) Structures of bacterial ColH inhibitors. − (b) Structures of the recently identified inhibitors of ColH and ColQ1. − Zinc-binding groups are highlighted by dashed rectangles. n.d.: not determined.…”

“…The first stable and selective inhibitor ( i.e. , compound 6 ) (Figure b) of ColH was recently reported. , Among various ZBGs, a phosphonate group has high stability and selectivity but moderate activities on ColH and ColQ1. , …”