COCCOID LIKE FORMS (CLF) OF HELICOBACTER-PYLORI - ENZYME-ACTIVITY ANDANTIGENICITY

In this study we attempted to transform ''helical'' forms of Helicobac ter pylori to ''coccoid like forms'' (CLF) by induction with the follo wing substances in vitro: bismuth subcitrate, bismuth subsalicylate, a mpicillin, amoxicillin, erythromycin, ursodeoxycholic acid and glycoch enodeoxycholic acid. Some liquid cultures were incubated for 24 days t o induce CLF by aging. Changes in the protein pattern, urease enzyme a ctivity and in the serological response against specific antigens were investigated. In all strains a significant but strain-variable rate o f CLF was detected by induction of the tested substances. Beta-lactams and erythromycin generated a population of nearly 100% CLF, including many ''spheroblasts''. Relative induction rates by these substances w ere in the following order: beta-lactams and erythromycin > bismuth su bcitrate > bismuth subsalicylate > bile acids. Strain variable reactio n also was true for both inhibition of urease activity and influence o n immunological response. Urease activity was lost in CLF induced by a ging and was inhibited by bismuth salts. CLF induced by aging showed a loss of reactivity bands in the immunoblot. They always lost a 160 kD band and depending on the strain, 115 kD, 108 kD, 100 kD and 95 kD ba nds. Immunological response to the 120 kD band was reduced. Ultrastruc tural studies showed great degenerative changes of the cell wall in CL F induced by antibiotics but only few in CLF induced by bismuth salts and bile acids.