Synthesis and bioactivities of two multiple antigen peptides as potential vaccine against schistosoma

Based on the two antigenic peptides, 26-43 (P26) and 116-131 (P116), derived from 28 kDa glutathione S-transferase of Schistosoma mansoni (Sm28GST), two multiple antigenic peptides (MAPs), (P26)4-MAP and (P116)4-MAP with the same oligomeric lysine core, were synthesized by stepwise solid-phase peptide synthesis method. The antigenicities and protective effects of these two MAPs were examined on experimental animals. As shown in the dot-ELISA result, the synthetic MAPs could be recognized and bound by immunoglobins in both patient's and infected-rabbit's sera. After Kunming mice were immunized with (P26)4-MAP, the worm burden reduction rate and the liver egg reduction rate were 59.9% and 61.1%. In (P26)4-MAP or (P116)4-MAP immunized BALB/c mice, the worm burden reduction rates were 37.5% and 62.5%, respectively, and the liver egg reduction rates were 35.1% and 54.0%, respectively.

[Bacterio-parasitic interactions. Enterobacteria and schistosomes (Salmonella - schistosome association)]

The description of a case imported from Chad of an association of Salmonella typhi - Schistosoma haematobium and, in this connection, a new revised general account. The association Salmonella-Schistomas is wide-spread. It corresponds to a salmonello - schistosomo - micro - association by the fixation of precise bacteria in the case of a bacteriemia on the cutaneous surface of male schistosomes in clearly defined places. These Salmonella constitute a permanent antigenic solicitation and they are capable of mobilization and rejection (bacteriuria after passage through the blood-stream) whereas bacteriosis remains asymptomatic. In fact, on the practical level, a clear and absolute distinction must be made between:--the bacteriemia with the concomitant bacteriuria, which are largely physiological in nature, very frequent and originating from various germs, connected with the emunctory function of the kidneys and which can be observed in any subject.--the schistosomal bacteriuria which are specific entities and evidence of a veritable micro-association of a symbiotic nature between the Salmonella and the schistosome, a micro-association which the bacteriuria reveals unexpectedly whereas the clinical symptoms are absent, not clearly discernible or totally misleading.

[Studies in vivo and in vitro on relations between Schistosoma mansoni and some enterobacteria strains]

Studies performed in vivo and in vitro, using scanning electron microscopy, on relations between Schistosoma mansoni and some enterobacteria show a strong association for certain bacterial strains (Salmonella typhimurium). Salmonellae adhesion on tegumental surface of male and mature Schistosoma is only possible in vitro owing to bacterial synthesis of strong fibres penetrating inside the worm. These interactions are not found with Escherichia coli, Proteus mirabilis or with young schistosomula.