INFLUENCE OF 3 DEFEATHERING SYSTEMS ON MICROTOPOGRAPHY OF TURKEY SKINAND ADHESION OF SALMONELLA-TYPHIMURIUM

The microtopography of turkey skin resulting from three different defe athering systems and consequent effect of skin microtopography on the adhesion of Salmonella typhimurium were examined. Turkeys from common flocks were scalded and picked using conventional, kosher, and steam-s pray systems. Breast skin was subsequently removed, irradiated to elim inate the resident microflora, then inoculated with S. typhimurium for 30 min. Scanning electron microscopy (SEM) and light microscopy revea led that three processes caused different skin microtopographies, whic h resulted in different amounts of bacterial adhesion. Conventional sk in had a comparatively smoother surface and less bacterial attachment. Kosher skin was very rough with a scaly keratinized epidermis and,sho wed little bacterial attachment. Steam-spray skin had a highly convolu ted surface (probably with underlying collagen fiber bundles) and show ed three times higher attachment of cells than conventional and kosher skins. Contrary to counts of attached cells obtained by scanning elec tron microscopy, plate counts of all inoculated skins were similar and increased linearly with increasing inoculum concentration. The highes t S(m) value (an indirect measurement of attachment strength) of koshe r skin reflected deep penetration/entrapment of cells within the skin rather than strong attachment of cells, whereas the high S(m) value of steam-spray skin would reflect the strong attachment of cells to the specific receptors in the skin. The lowest S(m) value and much bigger cell size of S. typhimurium on conventional skin reflected loose bacte rial attachment and different surface properties, respectively.