Wooden boards affecting the survival of bacteria?

Abstract

The survival of bacteria on and in different wooden and plastic boards was examined by microbiological methods. Wood of different tree species and polyethylene were inoculated with Escherichia coli pIE639 and Enterococcus faecium as hygienically relevant test bacteria. The development of the bacterial titer was evaluated by culturing on agar contact plates and investigating wood shavings. Survival of the test bacteria depended on different factors such as tree species, the initial inoculum size and the characteristics of the inoculated strain. The bacterial titer decreased fastest on pine compared to other woods (spruce, beech, poplar) and plastic. After bacterial infestation only pine wood was germ-free at the surface and in the inner structure after a few hours. The survival of the bacteria on poplar and beech was comparable to their survival on plastic. The study indicated that an antibacterial effect of wood, especially for pine, is caused by the hygroscopic properties of wood and the wood extractives. The antibacterial effect of pine wood was not influenced by the storage time of the wood following harvest or the functional condition of the wood up to a germ load of 10 8 CFU/cm 2 E. coli pIE639. Beinflussen Holzbretter das Überleben von Bakterien? Das Ü berleben von Bakterien auf und in verschiedenen Brettchen aus Holz und Kunststoff wurde mit mikrobiologischen Methoden untersucht. Verschiedene Holzarten und Polyethylen wurden mit Escherichia coli pIE639 und Enterococcus faecium als hygienisch relevante Testbakterien beimpft. Die Entwicklung des Bakterientiters ist durch Abklatschproben und Untersuchung von Hobelspänen verfolgt worden. Das Ü berleben der Testbakterien war dabei von verschiedenen Faktoren abhängig, wie z.B. von der Holzart, der Animpfdichte und der Art des inokulierten Bakterienstamms. Der Bakterientiter nahm im Vergleich zu anderen Holzarten (Fichte, Buche, Pappel) und Kunststoff am schnellsten auf Kiefernholz ab. Nur Kiefernholz war innerhalb weniger Stunden an der Oberfläche und im Innern des Holzes keimfrei. Das Ü berleben der Bakterien auf Pappel-und Buchenholz war mit dem Ü berleben der Bakterien auf Kunststoff vergleichbar. Die Studie deutet auf eine antibakterielle Wirkung von Holz hin, besonders von Kiefernholz, aufgrund der hygroskopen Eigenschaften von Holz und der Wirkung von Holzinhaltsstoffen. Die antibakterielle Wirkung von Kiefernholz wurde durch die Dauer der Lagerung nach der Holzernte und den Gebrauchszustand der Brettchen bis zu einer Keimbelastung von 10 8 CFU/cm 2 E. coli pIE639 nicht beeinflusst.

Comparison of Sanitizing Methods for Reduction of Attached Microorganisms on Various Kitchen Cutting Boards

“…These reductions of pathogens on the surface of cutting boards might be due to antimicrobial substances within the cutting board materials. For example, pine has been shown to possess antibacterial properties [Schönwälder et al, 2002]. However, for the most part, this happens because evaporation of the suspending medium leads to desiccation of the immediate cellular environment reducing cell viability, particularly on nonporous surfaces [de Cesare et al, 2003;Kusumaningrum et al, 2003;Moore et al, 2003].…”

Pine heartwood and glass surfaces: easy method to test the fate of bacterial contamination

“…The most common methods used in similar studies are a contact plate method (Ak. et al 1994 a, b;Park and Cliver 1996;Gough and Dodd 1998;Schönwälder et al 2002;Koch et al 2002;Milling et al 2005b;Boursillon and Riethmüller 2007) where agar medium is pressed directly onto the test surface and a swab method (Gilbert and Watson 1971;Park and Cliver 1996;Miller et al 1996;Welker et al 1996;Koch et al 2002) where the test surface is swept with a swab or a sponge, and the bacterial count from the swab is then studied. Vortexing was chosen in the current study to avoid the possible effect of adherence.…”

“…Vortexing was chosen in the current study to avoid the possible effect of adherence. Destructive methods have been used by Park and Cliver (1996) and Ejwwp453_source Schönwälder et al (2002). This allows using solid wood samples and excludes the effect of adherence.…”

“…2002). The reasons behind antibacteriality are not well understood; it is supposed to be a combination of several factors such as wood surfaces drying and chemical composition (Schönwälder et al 2002). Some of the chemical components have been studied separately.…”

Inhibition of Listeria monocytogenes by resident biofilms present on wooden shelves used for cheese ripening

“…General recommendations concerning the safe use of wood in food processing have been proposed by several authors e.g. dry storage, careful handling, selection of wood species (Prechter, Betz, Cerny, Wegener, & Windeisen, 2002;Schönwälder, Kehr, Wulf, & Smalla, 2006). However, there is a clear need for systematic investigations on the interactions between L. monocytogenes cells and native wooden shelves during ripening in order to assess the hygienic status of this traditional material.…”