Mannose-specific and hydrophobic interaction between Escherichia coli and polymorphonuclear leukocytes--influence of bacterial culture period.

The influence of culture period on mannose-specific and hydrophobic properties of the bacterial surface and on bacteria/polymorphonuclear leukocyte (PMNL) interaction was studied. Four E. coli strains, PN7 (01:K1), ABU2 (ON:K14), CU9 (06:K14) and CU13 (08:KN) and two Salmonella typhimurium strains 395 MR10 and 395 MS, well characterized according to physicochemical surface properties, presence of type 1 fimbriae and interaction with PMNL, were used in the study. The results show that with prolonged culture period, the liability to hydrophobic interaction increases, the agglutination-strength of mannose-specific maltobionamide liposomes increases, while the agglutination-titer with guinea-pig erythrocytes remains constant. Furthermore, the mannose-specific association with and metabolic activation of PMNL is augmented, while the ingestion is unchanged. In addition, our results demonstrate differences in sensitivity between the methods used to detect exposure of mannose-specific structures on the surface of bacteria, and that the culture condition is important for bacterial surface properties. It thus appears that the culture conditions have a great influence on the surface properties of E. coli bacteria and the interaction with phagocytic cells.