Effect of (2, 6-0-Dimethyl) Beta-Cyclodextrin (heptakis) on cell mass, pertussis toxin and filamentous hemagglutinin production in three bordetella pertussis vaccinal strains

Estudou-se a produçäo de toxina pertussis (PT) e hemaglutininas filamentosas (FHA) para vacinas do vírus Bortella pertussis em cultura supernadante e em supernadante de células lavadas com soluçöes iônicas. O vírus cresceu em meio Stainer-Scholte (SS) e na modificaçäo chamou-se CL-basal (CL-b) e desse meio com heptakis (2,6-0-Dimethyl Beta-Cyclodextrin (MeBCD). FHA e PT foram estimados pelo total de hemaglutinaçäo, hemaglutinaçäo diferencial (com colesterol) e imunoensaio dot-blot. O meio CL-b decresce a produçäo de massa celular e também decresceria a estabilidade e liberaçäo de hemaglutininas. A adiçäo of MeBCD para SS ou meio CL-b estimularia a produçäo, exportaçäo e estabilidade de PT e FHA. Esses efeitos säo maiores para meio CL-b e mais importante para FHA. Esses efeitos säo maiores par meio CL-b e mais importante para FHA que para PT. Obteve-se resultados similares com a adiçäo de 0,5 ou 1g/l de MeBCD para CL-b. Cultura supernadante contém FHA e PT mas supernadantes de células em soluçäo única contém basicamente FHA e seeria usada para prover esse campo

Virulence factors of Eschericha coli in urinary isolates

Escherichia coli strains isolated from 100 urine samples taken from patients with urinary tract infections (UTI) and from 20 normal fecal (NF) samples were examined for serum resistance, mannose-resistant hemagglutination of human erythrocytes (MRHA) and for production of aerobactin, hemolysis and colicin. Among the UTI E. coli strains, 79% produced aerobactin, 69% showed serum resistance, 44% produced MRHA, 32% were beta-hemolytic and 22% were colicinogenic. A greater proportion of UTI E. coli strains produced aerobactin, colicin V, beta-hemolysis and MRHA when compared to NF strains. Production of MR hemagglutins was significant correlated with that of aerobactin and hemolysin. These results suggest that the presence of aerobactin may be a significant etiological factor in UTI, and that the production of MR adhesins and of hemolysin also might contribute to the virulence of these strains

Characterization and distribution of the cell-bound haemagglutinins produced by Vibrio cholerae.

The two biotypes of Vibrio cholerae were found to produce two distinct cell-bound haemagglutinins (HAs). El Tor vibrios, most of their nonmotile mutants and nonpathogenic El Tor strains produced a mannose-sensitive cell-bound HA constitutively under all growth conditions examined. Some classical vibrios, their nonmotile mutants and antigenically rough mutants of classical strains produced a fucose-sensitive cell-bound HA continually. Other classical vibrios produced neither cell-bound HA nor a fucose-sensitive cell-bound HA transiently.