Staphylococcus spp. eradication from surfaces by the engineered bacteriolytic enzymes

Summary

Staphylococcus spp. are Gram-positive bacteria that can be opportunistic pathogens capable of causing life-threatening infections. Staphylococcus aureus, the most harmful species among them produces heat-resistant endotoxins, which cause food intoxications. Staphylococci may form biofilms on food-processing surfaces and become more resistant to routinely used antimicrobials. The bacteriolytic enzymes Auresine and AuresinePlus, both derived from S. aureus LytM autolysin engineered catalytic domain, were tested for their specificity and activity against various staphylococcal species and other bacteria. Both enzymes exhibited lytic activity against all tested staphylococcal species except S. pasteuri. The specificity of staphylococcal strains to these enzymes depended on the composition of their peptidoglycan cross-bridges. The bacteriolytic effect of the enzymes depended on the growth phase, initial cell number of target bacteria and the enzyme concentration applied. Bacterial elimination and bactericidal effects of both Auresine and AuresinePlus against S. aureus biofilms were confirmed by live/dead staining, with AuresinePlus showing a more pronounced effect. Additionally, Auresine and AuresinePlus presented increased effectiveness in eliminating staphylococcal cells adhered to surfaces, when combined with a detergent or the enzymes - amylase and cellulase. Importantly, cells recovered from biofilms after enzyme treatment did not display decreased susceptibility to applied enzymes, indicating the sustained efficacy of Auresine and AuresinePlus. In conclusion, Auresine and AuresinePlus demonstrate promising bactericidal activity against various staphylococcal species, highlighting their potential as antibacterial agents.