The origin of Staphylococcus saprophyticus from cattle and pigs

Staphylococcus saprophyticus is a common cause of urinary tract infections. We have earlier shown that the bacterium is a contaminant of food of animal origin. In order to trace the natural reservoir of the bacterium, samples were taken from farming environment and from slaughtered carcasses. S. saprophyticus was found in 7.1% of rectal swabs from cattle carcasses and in 7.3% of rectal swabs from slaughtered pigs. The seasonal variation of these isolates paralleled the seasonality of urinary tract infections due to the same bacterium. S. saprophyticus was also isolated in 1.1% of rectal swabs from living cows, in 1.6% from pasture grass and from 12.4% of various indoor fodder. The fodder presented a seasonal distribution with a peak incidence of S. saprophyticus some months earlier than in rectal swabs. The bacterium was especially frequent in samples of fodder taken from the managers. S. saprophyticus is most likely a bacterium with a zoonotic origin.