Influence on uptake, distribution and elimination of Salmonella typhimurium in the blue mussel, Mytilus edulis, by the cell surface properties of the bacteria

• This study was carried out to investigate whether the cell surface charge of Salmonella typhimurium could influence the kinetics of uptake, distribution, and elimination in the blue mussel, Mytilus edulis. The bacteria (1 mu m) were labeled with Tc-99(m) in the presence of stannous fluoride. Two different concentrations of stannous fluoride were used to produce differences in the cell surface charges of the bacteria. A set of mussels in the investigation were also given Sn-113-labeled microspheres (15 mu m) together with bacteria to compare the impact between particle size and cell surface properties on the distribution kinetics. The distribution of radiolabeled particles in the mussel was followed and analyzed with a computer-aided gamma camera that can detect two isotopes simultaneously. Finally. the mussels were dissected and the radioactivity in the fractions was measured with a well-shielded NaI(Tl) detector. The reduced cell surface charge of S. typhimurium enhanced the preingestive selection on the gills or labial palps as well as the postingestive selection in the digestive glands in such a way that it became similar to the microspheres, despite the size differences. The uptake of the bacteria labeled in the presence of less stannous fluoride was significantly lower. However, the subsequent absorption of these bacteria in the digestive gland was greater, because the recovery of radioactivity outside the digestive tract was higher than for the more manipulated bacteria and the microspheres. Likewise, the elimination of the more manipulated bacteria was similar to that of the microspheres and significantly higher than that of the less affected bacteria. It is concluded that the cell surface properties of bacteria, possibly the charge, influence the uptake, distribution, and elimination in M. edulis and that this factor could have the same influence as size on the uptake capacity.

Nyckelord

Mytilus edulis

bivalves

molluscs

Salmonella typhimurium

gamma camera

Tc-99(m)-labeled bacteria

surface

uptake

preingestive selection

postingestive selection

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)