Antibacterial Effects of Extracts of Pinus sylvestris and Picea abies against Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, and Streptococcus pneumoniae

Antibacterial effects of wood structural components and extractives from Pinus sylvestris and Picea abies on methicillin-resistant Staphylococcus aureus and Escherichia coli O157:H7

“…There are, however, contradictory findings, suggesting that wood or its components would be more effective against Gram-negative strains Klebsiella pneumoniae (Kavian-Jahromi et al 2015) and E. coli (Schönwälder et al 2002). When the wood extracts were studied in a broth against these same strains, the results were very similar to the present study, as would be expected (Vainio-Kaila et al 2015). However, the effect of pine sapwood on E. coli was stronger than that of pine heartwood in the broth with the extracts, whereas the results in this study were the opposite.…”

“…The antibacterial properties of the wood surface (Milling et al 2005a,b;Vainio-Kaila et al 2011 seem to be affected by several factors. Extractives, as has been shown earlier (Laireiter et al 2013;Vainio-Kaila et al 2015), are one of the main factors, but even lignin contributed to these properties. Lignin is more stable on the surface of wood; it does not dissolve as easily as extractives.…”

“…The extract surfaces were around 200 nm thick, whereas the MWL surfaces were only 10 nm thick. Most of the acetone extracts are not water-soluble, but they could affect bacteria in a water-based broth, which means that some active components of the extracts were dissolved in the broth (Vainio-Kaila et al 2015). However, the MWL covered the whole surface, and its thickness should not affect the results if the effect is purely contactbased and not due to any migration of compounds.…”

“…A limited amount of literature is available on the antibacterial effects of wood extracts. Scots pine heartwood (Laireiter et al 2013) and sapwood and spruce heartwood (Vainio-Kaila et al 2015) extracts inhibit the growth of several Gram-positive bacterial strains, while pine sapwood extract inhibits a Gram-negative strain. Extracts of Alaska cedar, western juniper, and several North American hardwoods have some antibacterial effects (Omar et al 2000;Johnston et al 2001).…”

The influence of wooden interior materials on indoor environment: a review

“…Gram-positive bacteria have more layers in their cell walls than Gram-negative bacteria, and it has been thought that this could provide more protection for Gram-positive bacteria against wood's antibacterial properties (Schönwalder et al 2002;Milling et al 2005a;Kavian-Jahromi et al 2015). However, some studies have found Gram-positive bacteria to be more sensitive (Laireiter et al 2013;Vainio-Kaila et al 2015, 2017a.…”