Biomedical subjects
Publications and source records attributed to B B Diena.
Purified Vi antigen, acetic anthydride-treated Salmonella typhosa endotoxin, and potassium methylate-treated S. typhosa endotoxin employed as vaccines in Swiss white mice failed to protect these animals against challenge with a virulent S. typhimurium hybrid expressing S. typhosa antigens.
An intracerebral challenge of HPB black mice with Neisseria gonorrhoeae is described. In this mode, the mice died from 1 to 6 days after challenge, and T1 organisms were obtained up to the fifth day from brain, liver, kidney, and spleen. Experimental gonococcal vaccines gave good protection against the challenge.
Neisseria gonorrhoeae 188, type 1, was cultured with monolayers of Rhesus monkey kidney (RE2) cells. Attachment of gonococci to RE2 cells occurred from about 2 h after inoculation and appeared maximal by 6 h when stained with crystal violet solution and examined under a light microscope. Preferential attachment of gonococci to the perinuclear region of tissue cells could not be demonstrated. Enumeration of the colony-forming units revealed that gonococci became rapidly attached to RE2 cells, increased in number, and after 8 h gradually decreased. The number of cell-free gonococci (not bound to tissue cells) remained constant for the first few hours and then changed in parallel with the cell-bound bacterial number. Gonococci did not multiply in tissue-culture medium. When penicillin was added to the system at intervals, neither cell-free nor cell-bound gonococci were recovered. Electron microscopy of RE2 cells infected with N. gonorrhoeae revealed no intact intracellular organisms, only gonococci attached to tissue cells and imcompletely engulfed or partially digested gonococci. These observations indicate that gonococci only multiply extracellarly in the presence of RE2 cells. Furthermore, some gonococci were engulfed by RE2 cells, but appeared to be digested so rapidly that they could not multiply intracellularly.
Growth of Neisseria gonorrhoeae in the presence of Rhesus monkey kidney (RE2) cells containing Eagle's minimal essential medium (MEM) 'conditioned' by 18-20 h of contact with RE2 cells began 3-4 h after inoculation and by 16-20 h had reached a maximum. When 'conditioned' medium (CM) was removed from the tissue cells and replaced with fresh medium a 5-6 h lag period occurred before multiplication of gonococci began and by 16 h growth was also near a maximum. CM removed from tissue cells supported the growth of six strains of N. gonorrhoeae. Three strains failed to grow in CM but multiplied when tissue cells were present. None of the strains grew in the presence of tissue cells killed by heating or in tissue-culture medium alone. Of the six strains of N. gonorrhoeae which grew in CM, three kept as their major (90%) population T1 colonies, while the remaining strains produced T1 organisms and T1A, T3, and T4 colonial variants. These results indicate that tissue cells secrete growth factors which support the growth and maintenance of T1 colonial forms of certain strains of N. gonnorhoeae.
Intravenous inoculation of 11-day old chick embryos with Neisseria gonorrhoeae has confirmed the original observation of Bumgarner and Finkelstein that T1 and T2 gonocci are significantly more virulent than T3 and T4. Pili do not seem to be solely responsible for this virulence, since elimination of pili did not effect either the viability or the virulence of N. gonorrhoeae. In neutralization studies, there was only one log difference between the ability of normal and hyperimmune rabbit serum to protect the embryo against gonoccocal infection. However, when mouse sera were used in the same chick embryo system a clear difference was noted between the protective activity of normal serum and that antisera elicited in mice by purified gonococcal antigens. It is suggested therefore that mouse antisera be used in this chick embryo model for the assay for gonococcal antigens.
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Swiss white mice immunized with acetone-killed vaccines prepared from strains of Salmonella typhosa, S. typhimurium, and mouse-virulent S. typhimurium hybrids which had acquired, by conjugal genetic transfer, the S. typhosa antigens 9, Vi, and d were challenged with the S. typhimurium hybrids and with the S. typhimurium parent strain. The results of these experiments suggested that the Salmonella somatic antigens were important in conferring protection against death in this system. The S. typhosa Vi antigen did not appear to play any significant role in this protection. The S. typhimurium hybrids employed in these studies did not show any loss of mouse virulence as the consequence of acquisition of various combinations of the S. typhosa somatic, flagella, or Vi antigens, nor did S. typhosa hybrids which had acquired the somatic antigen of S. typhimurium show any increase in mouse virulence.
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Salmonella typhimurium hybrids expressing the S. typhosa antigens 9, d, and Vi were constructed by genetic crosses with an S. typhosa Hfr donor. The hybrids retained the same degree of mouse virulence as their S. typhimurium parent strain, the minimum lethal dose being less than 50 organisms when tested either in C(57) black mice or Swiss white mice. Vaccination of the Swiss white mice with S. typhosa Ty2 vaccines prepared by acetone treatment, alcohol treatment, or heat-killing conferred significant protection against challenge by the hybrid strains but not against their S. typhimurium parent. Both the acetone-treated and alcohol-treated typhoid vaccines were markedly more protective than the heat-killed, phenol-preserved vaccine.
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In this further study, an exhaustive investigation into the value of the bentonite flocculation test in detecting tuberculosis in cattle was made on a group of 358 cattle, with known intradermal (ID) tuberculin reactions and with or without tuberculosis lesions. Bentonite sensitized with human old tuberculin (OT) and a purified BCG carbohydrate fraction (BCG-F1) were used. In the group of 126 cows with tuberculosis lesions, 113 were positive to the tuberculin ID test and there were also 113 positive reactions to the flocculation test using OT sensitized bentonite. Only 62 were positive using the BCG-F1 sensitized bentonite. Out of the 232 animals with no visible lesions, 114 reacted positively to the tuberculin ID test, 148 had a titer to the flocculation test using OT sensitized bentonite and 70 were positive when using BCG-F1 sensitized bentonite.
An extraction of the cells of Neisseria meningitidis serogroup Y with an aqueous solution of calcium choride (0.9 m) has been shown to solubilize a number of antigens. By immunodiffusion, this mixture of antigens has been shown to react with its group-specific antiserum and also to cross-react with a number of other group-specific antisera. The cross-reacting antigen appears to be an antigen common to a number of other serogroups of meningococci, and there is some evidence that it is protein in nature. It has been demonstrated further that the calcium chloride extract contains a strong cross-protective antigen, as shown by its ability to provide good, active immunity in mice to both the homologous and heterologous serogroups of meningococci.
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