A simple and rapid acid precipitation method has been applied successfully for separating free capsular polysaccharide of Haemophilus influenzae type b (polyribosyl ribitol phosphate, PRP) from PRP tetanus toxoid conjugate (PRP-T) in a final dosage amount of low-level materials. The unconjugated PRP was found to stay in the supernatant without precipitation, while conjugated PRP-T was fully pre...

conclusions we found ccd and rsm very effective in optimizing hib culture conditions, and hib biomass production was greatly influenced by ph and incubation temperature. therefore, optimization of the growth factors to maximize hib production can lead to 1) an increase in bacterial biomass and prp productions, 2) lower vaccine prices, 3) vaccination of more susceptible populations, and 4) lower...

Plackett-Burman experimental design was used to screen important medium components influencing the production of polyribosyl ribitol phosphate by Haemophilus influenzae type-B under submerged fermentation. Eleven media parameters such as Glutamic acid, Yeast extract, cystein, dextrose, NAD, heamin, NaCl, NH4Cl, Na2HPO4, KCl, and MgSO4.7H2O were screened in twelve experimental runs as per the de...

The capsular polysaccharide of Hemophilus influenzae type b, polyribosyl ribitol phosphate (PRP), is released from growing organisms during human infection and can be found in body fluids. It binds to untreated erythrocytes. Many patients with invasive infections with this organism develop significant hemolysis, but the mechanism has been unclear. We have found that PRP binds to human erythrocy...

Antibodies directed against the capsular polysaccharide (polyribosyl ribitol phosphate [PRP]) or the outer membrane proteins (OMP) of Haemophilus influenzae type b (Hib) promote bactericidal activity, complement 3 (C3) binding, and ingestion by phagocytic cells. To assess the relative contribution of anti-OMP to host defense against Hib, we compared the opsonic activities of anti-PRP and anti-O...

AIM To investigate the avidity of specific IgG polyribosyl ribitol phosphate (PRP) antibodies induced by three Haemophilus influenzae type b (Hib) conjugate vaccines: PRP-meningococcal outer membrane protein complex (PRP-OMP), PRP-non-toxic mutant diphtheria toxin, CRM197 (HbOC) and PRP-tetanus toxoid (PRP-T). METHODS One hundred and ten infants were immunised with one of the vaccines at two,...

We evaluated the functional activity of Haemophilus influenzae B (Hib) antibodies elicited in a group of infants immunized with the diphtheria-tetanus-pertussis vaccine combined with an Hib vaccine produced totally in Brazil after technological transfer of Hib vaccine production from Glaxo SmithKline, Belgium. Blood samples from immunized infants (N = 985) were collected for the determination o...

In the present study, seven isolates of Haemophilus influenzae type b were cultured in four different media to compare growth rate and capsule production. Four liquid media namely brain heart infusion broth (BHI), trypticase soy broth (TSB), Mueller Hinton Broth (MHB) and Gonococci broth (GC) with added supplements (1% hemoglobin, 1% Isovitalex) were used. The growth was measured by colony coun...

in the present study, seven isolates of haemophilus influenzae type b were cultured in four different media to compare growth rate and capsule production. four liquid media namely brain heart infusion broth (bhi), trypticase soy broth (tsb), mueller hinton broth (mhb) and gonococci broth (gc) with added supplements (1% hemoglobin, 1% isovitalex) were used. the growth was measured by colony coun...

Human antibodies specific, for polyribosyl-ribitol-phosphate (PRP), the capsular polysaccharide of Hemophilus influenzae b, were studied using idiotypic analysis. Antisera were prepared against purified F(ab')2 anti-PRP from two unrelated adults, H.H. and P.T. After repeated absorption with IgG myeloma proteins and with PRP-absorbed normal human Ig and donor Ig, anti-idiotypic (anti-Id) sera we...