The ability of Escherichia coli which possess or lack mannose-sensitive adherence factors (adhesins) to associate with human peripheral leukocytes in vitro in the absence of serum was studied. E. coli 19+, which have mannose-sensitive adhesins, were derived from E. coli strain 19 by culturing in static Trypticase soy broth at 37 degrees C. E. coli 19-, which lack mannose-sensitive adhesins, wer...