Recovery of blood-borne bacteria from human urine.

Recovery from the urine of organisms causing bacteraemia may depend on the bacterial species involved. The survival of the more common species of bacteria which cause bacteraemia was examined in human urine, serum and normal saline. All species survived well or grew in serum. Haemophilus influenzae, Streptococcus pneumoniae, Streptococcus sanguis and group A streptococci were killed in all urine samples. The number of colony-forming units of Staphylococcus aureus, Staphylococcus epidermidis, Staphylococcus saprophyticus and group B streptococci either remained the same or increased in the urine, while the numbers of Escherichia coli and Klebsiella pneumoniae increased rapidly. These data suggest that the observed differences in recovery from urine of these bacterial species that cause bacteraemia are related to the viability of the species in human urine.