Inhibition of bacterial adherence to bladder cells has been assumed to account for the beneficial action ascribed to cranberry juice and cranberry juice cocktail in the prevention of urinary tract infections (A. E. Sobota, J. Urol. 131:1013-1016, 1984). We have examined the effect of the cocktail and juice on the adherence of Escherichia coli expressing surface lectins of defined sugar specificity to yeasts, tissue culture cells, erythrocytes, and mouse peritoneal macrophages. Cranberry juice cocktail inhibited the adherence of urinary isolates expressing type 1 fimbriae (mannose specific) and P fimbriae [specific for alpha-D-Gal(1----4)-beta-D-Gal] but had no effect on a diarrheal isolate expressing a CFA/I adhesin. The cocktail also inhibited yeast agglutination by purified type 1 fimbriae. The inhibitory activity for type 1 fimbriated E. coli was dialyzable and could be ascribed to the fructose present in the cocktail; this sugar was about 1/10 as active as methyl alpha-D-mannoside in inhibiting the adherence of type 1 fimbriated bacteria. The inhibitory activity for the P fimbriated bacteria was nondialyzable and was detected only after preincubation of the bacteria with the cocktail. Cranberry juice, orange juice, and pineapple juice also inhibited adherence of type 1 fimbriated E. coli, most likely because of their fructose content. However, the two latter juices did not inhibit the P fimbriated bacteria. We conclude that cranberry juice contains at least two inhibitors of lectin-mediated adherence of uropathogens to eucaryotic cells. Further studies are required to establish whether these inhibitors play a role in vivo.

This study was undertaken to examine whether Escherichia colt adherent to tissue cells gain advantages over nonadherent bacteria due to their proximity to the cells. We used tissue culture cells and isogenic derivatives of a proline auxotrophic strain of E. coli that were fimbriated (Fim') or nonfimbriated (Fim-), and were heat-labile enterotoxin producing (Tox+) or toxin nonproducing (Tox-). We found that the Fim' bacteria, which were capable of adhering to tissue culture cells, initiated growth much sooner than did nonadherent Fim-bacteria; the adherent bacteria used tissue cell-derived proline, which was available at high concentrations only in the zone of bacterial adherence. Likewise, cyclic AMP secreted by adherent (Fim') bacteria was maintained at high concentration on the tissue cell surfaces. As few as 2 X 105 adherent Fim' Tox+ bacteria exert toxic activity upon Y1 adrenal cells, whereas toxin secreted in the medium by 6 X 106 FimTox+ bacteria was undetectable. The results suggest that the growth advantage and enhanced toxicity of adherent E. coil is due to restricted diffusion of products secreted by the tissue culture and bacterial cells, respectively.

Antibiotic TA inhibited incorporation of diaminopimelic acid and uridine diphosphate-N-acetylglucosamine into Escherichia coli cell walls without altering the ratio of cross-linked to uncross-linked peptidoglycan. Formation of the lipid intermediate was not blocked by TA, suggesting that TA interferes with polymerization of the lipid-disaccharide-pentapeptide.

Toxicity to Y-1 adrenal mouse cells caused by heat-labile toxin secreted by an enterotoxigenic strain of Escherichia coli (H-10407-p) was 40-fold enhanced in mixtures containing organisms capable of adhering to the Y-1 cells compared with monolayers exposed to organisms whose adherence was inhibited by mannoside. Severalfold the concentrations of anti-heat-labile toxin antibodies required to neutralize the toxicity of nonadherent bacteria were unable to neutralize the toxicity caused by adherent bacteria. The cytolytic activity toward tissue culture cells and mouse peritoneal macrophages caused by streptolysin S carried by Streptococcus pyogenes was severalfold increased in mixtures containing organisms capable of adhering to the target cells compared with mixtures containing nonadherent bacteria. The ability of trypan blue and RNA core to inhibit the cell-bound streptolysin S was determined in tissue culture cells containing adherent streptococci and mixtures of streptococci randomly colliding with erythrocytes. Both inhibitors were markedly less effective in neutralizing cytolysis than in their ability to neutralize hemolysis. We conclude that compared with toxins produced by nonadherent bacteria, those produced by bacteria adherent to cells are targeted more efficiently and become relatively inaccessible to neutralization by toxin inhibitors.

The production of Myxococcus xanthus antibiotic TA was stimulated by addition of alanine, serine and glycine to Casitone medium. These three amino acids served as the major biosynthetic precursors of the antibiotic.Alanine and serine were incorporated via acetate. In Casitone medium supplemented with alanine and serine, 29 to 30 of the 34 carbon atoms of antibiotic TA were derived from these two amino acids. Both carbon atoms of glycine were incorporated into antibiotic TA by a mechanism not involving acetate as an intermediate. Antibiotic TA was split into two fragments by alkaline hydrolysis followed by periodate oxidation. Radioactive alanine was incorporated into both fragments, whereas glycine was incorporated only into the smaller, polar fragment.Myxococcus xanthus TA produces a broad spectrum antibiotic when grown under nutrionally limiting conditions.'-') This antibiotic, referred to as TA, causes lysis of growing bacteria by blocking cell wall synthesis at the stage of polymerization of the lipid-disaccharide-pentapeptide.3) Recently, the chemical properties of antibiotic TA (C34H57O9N) were reported.4) Since concentrations of peptone greater than 1 % inhibited antibiotic TA production in M. xanthus,' a study was made of the effect of individual amino acids on TA production. Alanine, serine and glycine were precursors of the antibiotic and stimulated its production. Materials and Methods Radioactive Bacteria and Growth ConditionsMyxococcus xanthus TA (ATCC 31046) is an antibiotic producing strain which grows in dispersed state in CT medium: 0.5% Casitone (Difco) and 0.2% MgSO4.7H2O. The strain was maintained by transferring fresh colonies from CT agar to CT liquid medium, incubating for 2 days at 30'C with aeration and then streaking on CT agar. Colonies appeared after 5 -7 days. Escherichia coli ESS capR is a chloramphenicol resistant strain of E. coli ESSS which was derived by transducing E. coli ESS with PI capR (Y. AHARONOVITCH, unpublished). E. coli ESS cap" was maintained on nutrient agar (Difco).Production and Assay of Antibiotic TA All antibiotic production experiments were performed in test tubes (inside diameter 12 mm). Starter cultures were obtained by inoculating 2 ml of CT medium with a fresh colony of M. xanthus TA and incubating with shaking for 2 days at 30°C. The starter culture (0.1 ml) was then inoculated into 4.4 ml of CT medium (with or without supplements) and incubated for 48 hours at 30°C with gyratory shaking. Culture turbidity was measured at 560 nm using a Gilford Model 240 Spectrophotometer. Antibiotic was extracted with an equal volume of CHC13 from the cell-free supernatant fluid following