EFFECTS OF DIFFERENT SURFACTANT PREPARATIONS ON BACTERIAL-GROWTH IN-VITRO

Several lines of evidence suggest that surfactant and surfactant prote ins may have direct effects on inhaled bacteria and are able to intera ct with lung defence mechanisms in many ways. We examined the effect o f three different surfactant preparations (Alveofact(R), Survanta(R) a nd Exosurf(R)) approved for treatment of the infant respiratory distre ss syndrome on different strains of Escherichia coli, Staphylococcus a ureus, Staphylococcus epidermidis and Streptococcus agalactiae which a re important neonatal pathogens and on Legionella pneumophila serogrou p 1 as a frequent cause of pneumonia in adults. Addition of Survanta t o saline seemed to delay the reduction of viable bacteria in sterile s aline and induced a considerably accelerated growth of all examined E. coli strains. As opposed to this, addition of surfactant did not infl uence the kinetics of bacterial growth in brain-heart infusion or buff ered yeast extract both with the exception of Exosurf which exerted an inhibitory effect on the multiplication of group B streptococci. Thou gh the exact mechanisms underlying these effects remain to be determin ed, the influence of surfactant therapy on the growth of bacteria with in the respiratory tract should be taken into account.