Biomedical subjects

C Barber

Publications and source records attributed to C Barber.

At least 73 records · Page 4Linked to original sources

PubMed1977

Salmonella gallinarum - Salmonella enteritidis relationship in rabbits.

The polysaccharide of S. gallinarum, sharing factors 9.12 with the Salmonellae of group D. cross-reacts with one of two serological determinants, present in the polysaccharide of S. enteritidis, and is different from the determinant responsible for the cross-reaction of S. enteritidis and S. typhy polysaccharides. The absorption of anti S. gallinarum sera with proteins from S. enteritidis removed all the antibodies induced for the homologous antigens; in contrast, the absorption of the anti S. enteritidis sera with proteins from S. gallinarum removed all the antigens common to S. gallinarum and S. enteritidis, leaving for reaction the antibodies induced to specific antigens of S. enteritidis.

Animals↗

PubMed1977

Neutralization of heterologous toxicities in mice immunized with proteins from S. typhimurium and from a human pathogen (S. emek).

Groups of mice immunized with proteins from S. typhimurium and from a non-pathogenic Salmonella for mice (S. emek) were infected with S. tymphimurium, S. emek, S. blockley and S. paratyphi A. The mice immunized with the S. typhimurium proteins were, as always protected against infection with the pathogen and resisted the toxicities, which killed the controls, of S. paratyphi A and S. emek but not of S. blockley. The mice immunized with S. emek proteins resisted the toxicity of S. paratyphi A and, to a lesser degree, that of the homologous S. emek. The animals did not resist the toxicity of a similar concentration of S. blockley and the immunized mice died, like the controls, within 20-40 hours. Mice in this group infected with S. typhimurium had a much longer delay before dying, than the controls. Antiprotein antibodies present in the sera of the immunized mice are, apparently, responsible for the neutralization of the toxicities of the heterologous strains and for the eventual protection against infection.

Animals↗

PubMed1977

Immunochemistry of Yersinia enterocolitica O3 grown at different temperatures.

Comparative agglutinations of homogeneous stable suspensions prepared with Yersinia enterocolitica growth at 37 degrees C and at 25 degrees C were performed with anti-sera prepared in rabbits with the bacteria grown at both these temperatures. Sera prepared with live Y. enterocolitica grown at 37 degrees C agglutinated both suspensions at a much lower titre than the sera prepared with formaldehyde-treated bacteria is grown at 25 degrees C. All the sera in which strongly precipitating antibodies were induced reacted, in agar-gel, against native and heated proteins. The small amounts of antipolysaccharides induced in all the sera reacted only in the ring test against the bacterial polysaccharides. The absorption of the sera prepared with live Y. enterocolitica grown at 37 degrees C, with antigens synthesized at 25 degrees C did not remove all the homologous antibodies; apparently, some determinants are specific for the bacteria grown at 37 degrees C. Morphological changes of the small rods to elongated bacilli and filamentous forms were observed in most cultures of the Y. enterocolitica grown at 37 degrees C; these changes coincided with a low yield of proteins and point to an inhibitory effect of the 37 degrees C temperature.

Agglutination Tests↗

PubMed1977

Behaviour of Salmonellae non-pathogenic for mice. I. Neutralization of their toxicities by induced antiprotein antibodies.

Groups of mice hyperimmunized with proteins from Salmonella strains which are not pathogens for mice (S. typhi o901, S. typhi Ty2, S. blockley, S. newport) resisted inoculation with concentrations of homologous and related heterologous liver bacteria, which killed all the controls in 20-48 hrs. The toxicity of the Salmonella tested was about 100-1000 times lower than that of the pathogenic S. typhimurium and concentrations of 10(8) or 10(9) bacteria (according to the strains used) were necessary to kill all the controls. In contrast to the period of incubation (2-12 days) required for S. typhimurium to kill all the controls and eventually some of the immunized mice, too, the killing with the human pathogenic Salmonella took place within 20-48 hrs. The toxicity of the big concentrations of bacteria needed to kill the controls was apparently neutralized by the antiprotein antibodies induced in the immunized mice. In no group of mice resisting inoculations with 1 x 10(8) or 1 x 10(9) of the homologous or heterologous tested Salmonellae protection could be obtained against infection with 1LD100 (1 x 10(6) of S. typhimurium. These results underline the specificity of host-parasite relations in infection and minimize the role attributed to the cellular mechanism, which is insufficient for protection against an infection if the pathogen tested is not specific for the host in experiment. In contrast to events in mice protected against the infection with S. typhimurium, and its related "in vivo", S. paratyphi B and S. paratyphi C, the antibodies initially present in the sera of the mice immunized with proteins from the human pathogens were no longer found 25 days after the infections. Reinfections of some of the groups of the surviving mice did not result in protections.

Animals↗

PubMed1976

Cross-protection induced in mice by immunizations with proteins of related bacteria species.

Groups of mice were immunized with detoxified protein from S. typhimurium, S. paratyphi B and S. paratyphi C. Consecutive infections with different concentrations of the homologous and heterologous strains showed that: 1. Immunizations with proteins from S. typhimurium induced protections in 65% of the mice infected with 50 LD100 of their natural pathogen, and in 80% of the mice infected with 50 LD100 of S. paratyphi B; the infection with S. paratyphi C of mice in this group afforded protection against 20 LD100 in 75% of the animals. 2. Immunization with proteins from S. paratyphi B induced protection in the mice against the infection with 20 LD100 of S. typhimurium (survival of 80% of the mice) and against 20 LD100 of the homologous S. paratyphi B (survival of 90% of the mice). 3. Immunization with proteins from S. paratyphi C protected the mice against the infection with 20 LD100 of S. typhimurium in a proportion of 80-85% of the animals; infection with the homologous S. paratyphi C did not result in protection against more than 20 LD100 of the bacteria (80-85% survivals). The survivors, in each group, when reinfected 30 days later with 50 LD100 of S. typhimurium resisted in a proportion of 100%, as a consequence of antibodies induced against more specific proteins released in the mice during the infections by the related pathogens.

Animals↗

PubMed1976

The unfortunate role of precedent in bacteriology. I. The main antigens of salmonellae: the proteins.

Proteins from S. paratyphi B were found to be better immunogens, in rabbits, than the bacteria from which they were extracted. Likewise, proteins from S. newport induced antibodies which reacted in agar gel, against proteins from many species of Salmonella. The immunogenicity of the bacterial proteins, as well as their many biological activities are ignored because the classic techniques used lose these main antigens of Enterobacteriaceae. The contrasting overemphasized role attributed to the lipopolysaccharides has created a precedent which is not to the advantage of bacteriology.

Animals↗

PubMed1976

The unfortunate role of precedent in bacteriology. II. Unrelated serological specificities of the polysaccharides from S. typhi and S. gallinarum sharing factors 9.12.

Tube and agar-gel precipitations of antigens isolated from S. typhi and S. gallinarum against homologous and heterologous rabbit antisera showed that the polysaccharides of these Salmonellae, sharing factors 9.12 do not cross-react. Thus, the serological analyses prove that sugars can not be related to factors in the Kauffmann-White scheme. The cross-reacting antigens from these Salmonellae of serogroup D are the free proteins and the proteinic moieties of their somatic antigens.

Antigens, Bacterial↗

PubMed1976

Sh. dysenteriae serotypes2,4,8-immunochemistry and phage receptor activity.

Among three analyzed serotypes of Shigella dysenteriae, namely, the serotypes 2,4 and 8, the serotype 2 proved to be a strong immunogen in rabbits, inducing anti-polysaccharide antibodies as well as antiprotein antibodies in all the animals. In contrast, the serotypes 4 and 8 were weak immunogens and among the rabbits some have synthesized only anti-proteins while others had antibodies against the somatic conjugate. Aside from the somatic antigens, large amounts of proteins were isolated from all the strains; however, the numerous determinants of these proteins were proven with the help of a serum to proteins from Sh. sonnei. The polysaccharides were specific for the serotype. The sensitivity of Sh. dysenteriae strains to phage P1 and the phage receptor actigity of different bacterial extracts were examined. By using the phage receptor neutralization test, it was possible to demonstrate that the receptor substance is a common component present in the lipopolysaccharide. The nature of neutralization has been discussed.

Animals↗

PubMed1976

The serological specificities of Salmonella typhi antigens.

Sera prepared with two different strains of Salmonella typhi were analysed against all the soluble antigens isolated from S. typhi 0901, S. typhi Ty2 and S. typhi Vi. Agar-gel diffusion against individual sera showed that, in all the sera, antibodies were induced against somatic antigens and free proteins. Absorptions of the sera with polysaccharides, split from the somatic antigens, removed the antibodies induced against the polysaccharide and its proteinic carrier in most of the somatic antigens of S. typhi 0901. The antibodies left in the absorbed sera reacted against the proteinic moieties of more complex somatic antigens of S. typhi and against free proteins from all the analysed strains. Only the absorption with proteins removed all the precipitating antibodies from the sera. Moreover, in incomplete absorptions with proteins, the first antibodies removed are the antipolysaccharides, since antibodies are never induced against the haptenic polysaccharide but against somatic conjugates; in these the proteinic moiety eventually varies with every batch of bacteria. The sera exhausted of precipitins still agglutinate the bacteria, thus confirming the assumption that agglutinins and precipitins may be different antibodies.

Animals↗

PubMed1975

Confirmation of the protective role of proteins from S. typhimurium in infection of mice with their natural pathogen.

The protective role of proteins from S. typhi-murium in infection of mice with their natural pathogens was confirmed. Hyperimmunization with either toxic or detoxified proteins, from the same batch, induced the synthesis of strongly precipitating antiprotein antibodies, and the mice were protected against infections with 15-75 LD100 of S. typhimurium. Reinfection of the same animals with 300-500 LD100 of S. typhi-murium induced, in the vaccinated mice, the synthesis of only anti-protein antibodies precipitating in agar-gel.

Animals↗

PubMed1975

Specific antibodies and heterologous antigensin monofactor sera.

A concentrated monofactor serum 9 (Wellcome lot K 8028) precipitated against proteins from 2 different strains of Salmonella enteritidis and from a strain of S. dublin, as well as against the proteinic moiety of the somatic antigen from S. typhi 0 901; no polysaccharide from the strains, sharing factor 9, precipitated against this serum. A concentrated monofactor serum 20 (Wellcome lot K 6733) precipitated against the proteins from S. emek (8, 20), but not against its polysaccharide. A monofactor serum 8 (Wellcome lot K 7801), different from a lot previously analysed (Wellcome lot K 6860), precipitated against the same proteins as the previous lot, but, in addition, precipitated strongly against the polysaccharide of S, newport (6.8) and weakly with the polysaccharide of S. emek too. According to these and previous results, it is not clear what sort of antibodies responsible for cross-agglutination are absorbed by the heterologous strains used in the operations. Since more often than not antipolysaccharide antibodies were not found in concentrated monofactor sera, it may be that just the antipolysaccharides. All the monofactor sera so far analysed (Wellcome) 1,2,4,5,8,9,20 are full of proteins left by the bacteria used for absorptions; due to these proteins, the presence of which may be meaningless for the agglutinations, strong precipitations in agar-gel were obtained between monofactor sera and different antibacterial and anti-protein sera containing antibodies induced against the corresponding free proteins.

Animals↗

PubMed1975

Antigenic, antibiotic and phage receptor activity of proteins from Sh. boydii 15.

The analyzed strain of Sh. boydii 15 induced antibodies against the somatic antigen conjugate, as in most Shigella. Except for the proteinic carrier of the somatic antigen, only a few of the homologous proteinic determinants induced corresponding antibodies; these were illustrated with the help of a serum to proteins from Sh. sonnei. The proteins of Sh. boydii 15 displayed a wide range of antibiotic activity against Shigella, E. coli and Salmonella. Another aspect concerning the biological activities of the proteins isolated from Sh. boydii 15 was its temperate phage receptor activity. This activity was found as well in the free proteins as in the proteinic moiety of the somatic antigen.

Animals↗

PubMed1975

Heterologous protections in experimental salmonellosis.

Immunizations of mice with proteins from S. paratyphi B protected the animals against infection with a concentration of S. paratyphi C which killed the controls and against an infection with 50 LD100 of the homologous S. paratyphi B. The sera of the infected mice showed common precipitation lines of proteins from the two species belonging to different serogroups. Consecutive inoculations with S. typhimurium of both groups of vaccinated mice protected the animals against the infection with their natural pathogen. Immunizations with proteins from S. cholerae-suis protected about 70% of the mice infected with S. paratyphi B and with S. paratyphi C; a higher protection was not, however, induced against infection with the homologous strain. Consecutive infections with S. typhi-murium of the mice resulted in total protection of the animals previously inoculated with S. paratyphi B and S. paratyphi C; the group of mice infected with S. cholerae-suis was less protected against the subsequent inoculation with S. typhi-murium (about 50%). In the infections of mice, S. paratyphi B and S. paratyphi C, seem related to S. typhi-murium by common proteins; the proportion of common protective determinants is not yet known.

Animals↗

PubMed1975

Unrelatedness between agglutinations of bacteria and the presence of anti-polysaccharides in sera of Salmonellae from groups B and D.

Rabbits hyperimmunized with two strains of S. paratyphi B provided sera with high agglutinating titers, although the sera were deprived of antipolysaccharide antibodies. However, the polysaccharides of both strains of S. paratyphi B precipitated against anti S. typhimurium sera in which antipolysaccharide antibodies were induced. Antisera obtained with three S. enteritidis strains showed a comparable unrelatedness between the agglutinating titers and the presence of antipolysaccharide antibodies in the corresponding sera. One of the strains, repeatedly used for immunization, never induced antipolysaccharide antibodies, while the agglutinating titers of the sera were high; the polysaccharide of this strain precipitated strongly against anti-Salmonella typhi O 901 sera and against the antisera of the other S. enteritidis strains in which antipolysaccharide antibodies were induced. According to these results, there is no apparent relationship between agglutinations of bacteria and the presence of antipolysaccharide antibodies in the corresponding sera. Heated proteins, isolated from all the strains after previous exhaustive extraction at 37 degrees C, showed strong serological precipitations.

Agglutination Tests↗

PubMed1974