bluuebunny/crossref_metadata_2025 huggingface dataset:
Differences in resistance to Trypanosoma musculi infection among strains of inbred mice
Authors: Albright J W , Albright J F
Published: January 2020

Inbred strains of mice were inoculated with Trypanosoma musculi, and the course of the ensuing parasitemia was followed. The mouse strains fell into three groups: those displaying high and moderate (fivefold less) parasitemia and C57BL/6 (B/6) mice which had exceptionally low infections. To gain insight concerning the mechanisms responsible for interstrain variations in infections, several types of experiments were performed. Comparison of the ability of spleen cells from the various strains to provide the growth-promoting substances required by T. musculi for growth in culture revealed that B/6 cells were deficient; this suggested one mechanism for regulating parasite infections. Exposure of C3H (high parasitemia) and B/6 mice to graded levels of ionizing radiation revealed that B/6 mice have much greater innate resistance to infection than do C3H mice. The effects of treating mice with silica dust or mercaptoethanol indicated that relative resistance to infection is not primarily associated with macrophage activity or limited growth-promoting substances. We conclude that variations in immune responsiveness to parasite antigens (probably not associated with the H-2 complex), possibly in concert with variations in a non-immunological mechanism, account for interstrain variation in resistance to T. musculi infections.
Antigenic characterization of human and animal rotaviruses by immune adherence hemagglutination assay (IAHA): evidence for distinctness of IAHA and neutralization antigens
Authors: Kapikian A Z , Cline W L , Greenberg H B , Wyatt R G , Kalica A R , Banks C E , James H D , Flores J , Chanock R M
Published: January 2020

An immune adherence hemagglutination assay (IAHA) and a modified enzyme-linked immunosorbent assay for antigenic characterization of human rotaviruses were developed. The designations of type 1 and type 2 were identical to those established previously by specific complement fixation, enzyme-linked immunosorbent assay, and immune electron microscopy. By IAHA (and modified enzyme-linked immunosorbent assay) certain animal rotaviruses were found to be closely related to human rotavirus type 1. The pattern of IAHA reactivity and the cell culture neutralization serotype were found to be distinct properties. The separation of neutralization and IAHA reactivity was apparent when animal rotaviruses which were distinguishable from each other by neutralization assays were found to share IAHA specificity. Further evidence for the dissociation of the neutralization and IAHA specificities was found in studies of human and bovine rotaviruses which underwent genetic reassortment during coinfection. Thus, it appeared that the IAHA and neutralization antigens were coded for by different genes. In view of these findings, we suggest that the term serotype be reversed to identify the antigen that reacts with neutralizing antibodies as is customary for other viruses and that the term subgroup (instead of serotype) be used for the specificity detected by specific complement fixation, enzyme-linked immunosorbent assay, and now IAHA.
Vaginal isolates of Staphylococcus aureus associated with toxic shock syndrome
Authors: Barbour A G
Published: January 2020

Staphylococcus aureus has been isolated from vaginal fluids of women with toxic shock syndrome (TSS), a multisystem disease with onset usually during menses. A total of 15 vaginal isolates of S. aureus from TSS patients were compared with 18 vaginal isolates from women without TSS. Phenotypic traits which were significantly more frequent in the TSS group of strains than in the non-TSS group were arsenate resistance, proteolysis of hemoglobin, reduced hemolysis of sheep blood in agar medium, and lack of lethality of culture filtrates for chicken embryos and rabbits. In addition, isoelectric focusing of ethanol extracts of culture filtrates showed differences between the two groups in the occurrence of two proteins. All hemolytic and chicken embryo-lethal strains (3 TSS strains and 14 non-TSS strains) produced an extracellular protein with an isoelectric point of 8.6. In contrast, all TSS strains, but only one-half of non-TSS strains, released a protein with an isoelectric point of 7.0 and an apparent subunit molecular weight of 22,000.
ColV plasmid-specific aerobactin synthesis by invasive strains of Escherichia coli
Authors: Warner P J , Williams P H , Bindereif A , Neilands J B
Published: January 2020

Certain strains of Escherichia coli associated with bacteremia of humans and domestic animals harbor plasmids that promote efficient iron uptake. The mechanism, which is an important component of the virulence of invasive strains, is independent of the enterobactin system for iron uptake. Plasmid-specified siderophore was assayed by its ability to support the growth of a chelator-deficient mutant in conditions of iron deprivation. The chelator, which was chemically determined to be a hydroxamate compound, was identical on the basis of field desorption mass spectrometry with aerobactin, a siderophore synthesized by Aerobacter aerogenes. In conditions of iron stress, aerobactin is secreted into the culture medium of plasmid-bearing E. coli strains. Reconstruction experiments involving a chelator-deficient mutant growing with exogenous chelator suggested that association of a small fraction of the total siderophore synthesized with cellular material is due to transient binding of aerobactin to membrane receptors during active bacterial growth.
Immuno-electron microscopic study on the antigenicity of tubular structures associated with human rotavirus
Authors: Kimura T
Published: January 2020

Tubular structures associated with human rotavirus were antigenically related to the single-capsid layered particles having only an inner capsid of the virus because they were agglutinated by heterologous bovine rotavirus antiserum.
Relationship between plasmid content and auxotype in Neisseria gonorrhoeae isolates
Authors: Dillon J R , Pauzé M
Published: January 2020

One hundred and forty strains of Neisseria gonorrhoeae, representing 12 different auxotype groups, were examined for differences in plasmid content. Most auxotype groups harbored a phenotypically cryptic 2,6-megadalton plasmid; a few groups also carried a 24.5-megadalton plasmid which has been previously characterized as a transfer plasmid. However, isolates of the proline-, citrulline-, and uracil-requiring (PCU-) auxotype were consistently free of plasmids. The correlation between auxotype and plasmid content is especially significant since, in Canada, PCU- isolates have the second highest prevalence of all auxotypes.
Restoration by Normal Human Immunoglobulin G of Deficient Serum Opsonization for
Streptococcus pneumoniae
in Sickle Cell Disease
Authors: Bjornson Ann B. , Lobel Jeffrey S. , Magnafichi Patricia I. , Lampkin Beatrice C.
Published: January 2020

Supplementation of sera from four children with sickle cell disease with untreated or heated normal human serum or with normal human immunoglobulin G restored opsonic activity for serotype 10
Streptococcus pneumoniae,
whereas supplementation with normal human immunoglobulin M did not.
Tuberculin purified protein derivative-reactive T cells in cord blood lymphocytes
Authors: Shiratsuchi H , Tsuyuguchi I
Published: January 2020

Lymphocytes obtained from cord blood of newborn babies who were born of healthy mothers were studied in vitro for their responsiveness to purified protein derivative (PPD) of tuberculin. Cord blood lymphocytes proliferated in vitro by stimulation with PPD, despite wide variations in the results. Studies with fractionated lymphocytes revealed that PPD-responding cells belonged to E-rosetting, nylon wool-nonadherent T lymphocytes. Non-E-rosetting B lymphocytes alone did not proliferate at all after stimulation with PPD. In addition, bromodeoxyuridine and light treatment of in vitro PPD-stimulated lymphocytes eliminated the responsiveness to PPD. These results suggest that T lymphocytes do exist in cord blood and respond in vitro to stimulation with PPD. A possible role for PPD-reactive T lymphocytes in cell-mediated protective immunity in newborns is discussed.
Interaction of cytomegalovirus immune complexes with host cells
Authors: Rundell B B , Betts R F
Published: January 2020

After adsorption to host cells of a mixture of cytomegalovirus (CMV) and immunoglobulin G (IgG)-anti CMV, at least 99% of the surviving fraction consisted of infectious virus-antibody complexes which could be neutralized by anti-human IgG antibody. The virus-antibody complexes penetrated into cells and were uncoated more slowly than native virus. When the virus-antibody complexes were treated with anti-human IgG antibody before adsorption was allowed to take place, anti-human IgG antibody immune complexes were adsorbed to host cells less readily and uncoated less efficiently than were untreated complexes. Furthermore, after adsorption, anti-human IgG antibody-IgG-CMV complexes were further retarded in their penetration and uncoating. These observations suggest that neutralization of CMV by IgG-anti-CMV resulted from interference with the normal mechanisms of penetration and uncoating. Anti-human IgG antibody enhanced the degree of neutralization by augmenting the inhibitory effect of antibody on these stages of virus-host interaction and also reduced adsorption of the complex.
Oral ecology and virulence of Lactobacillus casei and Streptococcus mutans in gnotobiotic rats
Authors: Michalek S M , Hirasawa M , Kiyono H , Ochiai K , McGhee J R
Published: January 2020

Lactobacilli comprise a small percentage of the normal oral microbial flora of humans and are isolated commonly from saliva and frequently from an active caries lesion. We have compared the pathogenesis and colonization pattern of Lactobacillus casei with that of Streptococcus mutans strain 6715 in gnotobiotic rats. Of the two L. casei strains tested, L. casei strain ATCC 4646 caused slightly more caries than L. casei strain ATCC 11578. However, the level of caries induced by either L. casei strain was significantly lower (P less than 0.01) than that observed in similar-aged rats monoassociated with S. mutans strain 6715. When groups of rats were infected with mixtures of L. casei strain ATCC 4646 and S. mutans strain 6715, or with L. casei followed by S. mutans, higher numbers of L. casei than S. mutans were found associated with the tongue and in saliva; S. mutans always predominated in plaque. The level of caries observed in these groups of rats was similar to that seen with rats monoassociated with S. mutans except when L. casei comprised greater than 1% of the plaque microflora. In this latter situation, the level of caries was significantly lower (P less than or equal to 0.05) than that obtained in S. mutans-monoassociated rats. The results of this study suggest that L. casei colonizes sites in the oral cavity (including the tongue and saliva) other than the tooth surface in rats. The effect of L. casei in plaque toward reduction of S. mutans-induced dental caries in rats is discussed.
Participation of immunoglobulins and complement components in the intracellular killing of Staphylococcus aureus and Escherichia coli by human granulocytes
Authors: Leijh P C , van den Barselaar M T , Daha M R , van Furth R
Published: January 2020

Immunoglobulins and complement components are required for optimal ingestion and optimal killing of microorganisms by granulocytes. The degree of opsonization of microorganisms necessary for their ingestion was lower than that required for the killing of these bacteria during the ingestion phase. Killing during this phase was found to depend mainly on the presence of heat-labile opsonins, probably C3b, present on the microorganisms. Extracellular immunoglobulin G (IgG) and C3b were indispensable for optimal intracellular killing after ingestion was complete. This was established with an assay permitting assessment of the course of the number of viable intracellular bacteria independent of the ingestion of new live bacteria. Maximal intracellular killing by human granulocytes of ingested catalase-positive (Staphylococcus aureus and Escherichia coli) or catalase-negative (Streptococcus pyogenes and S. pneumoniae) microorganisms was found only when fresh serum was present extracellularly. Killing was suboptimal in the absence of serum. With heat-inactivated serum, the killing index lay between the indices obtained in the presence and absence of fresh serum. The stimulatory activity of heat-inactivated serum was most probably due to the interaction of IgG with the Fc receptor on the granulocyte membrane, since IgG subclasses IgG1 and IgG3 as well as pFc fragments of IgG stimulated the intracellular killing to the same degree as heat-inactivated serum did. In addition, (Fab1)2 fragments of IgG did not stimulate killing, and reduced killing was observed in the presence of heat-inactivated serum after reduction of the number of Fc receptors. The extra stimulation of the killing process in the presence of fresh serum compared with heat-inactivated serum was due to the interaction between membrane receptors and complement--most probably C3b generated by both the classical and the alternative pathways of complement activation. This conclusion is based on results obtained with sera in which one or both complement pathways were blocked, on the restoration of the killing-stimulatory activity of C3-deficient serum after addition of fresh C3, and on the reduced killing observed in the presence of fresh serum after reduction of the number of C3 receptors by the use of pronase or antigranulocyte serum.
Isolation and characterization of proteases from Bacteroides melaninogenicus
Authors: Fujimura S , Nakamura T
Published: January 2020

We isolated two types of intracellular proteases from a strain of Bacteroides melaninogenicus. These enzymes were extracted from cells by ultrasonic treatment and were partially purified. These two enzymes (proteases I and II) differed in molecular weight, heat stability, sensitivity to reducing agents, Km value, and optimum pH for activity.
Parasite-derived mitogenic activity for human T cells in Plasmodium falciparum continuous cultures
Authors: Ballet J J , Druilhe P , Querleux M A , Schmitt C , Agrapart M
Published: January 2020

Supernatants from Plasmodium falciparum continuous cultures exhibited mitogenic activity against human blood lymphocytes from unsensitized donors. This effect, which was not observed with supernatants from control cultures grown in the absence of the parasites, was dependent upon (i) the concentration of supernatant added to the lymphocyte cultures and (ii) the parasite concentration in the P. falciparum continuous cultures. T cells were the predominant target cells of this mitogenic activity. We observed similar response in lymphocytes from malaria-sensitized individuals to P. falciparum continuous culture material. We also detected a mitogenic activity in parasite-infected erythrocytes from P. falciparum continuous cultures. P. falciparum continuous cultures may provide practical quantities of parasite-derived substances which, presumably, are able to manipulate the immune effector mechanisms of an infected host.
Increased content of microbicidal cationic peptides in rabbit alveolar macrophages elicited by complete Freund adjuvant
Authors: Lehrer R I , Szklarek D , Selsted M E , Fleischmann J
Published: January 2020

We measured the microbicidal peptides MCP-1 and MCP-2 in rabbit alveolar macrophages (AM), comparing rabbits pretreated with complete Freund adjuvant with untreated control animals. Levels of MCP-1 increased from 4.7 +/- 0.6 microgram/10(7) resident AM to 13.2 +/- 0.1 microgram/10(7) complete Freund adjuvant-elicited AM. MCP-2 levels rose from 1.8 +/- 0.1 microgram/10(7) resident AM to 7.3 +/- 0.4 microgram/10(7) complete Freund adjuvant-elicited AM. The activities of five lysosomal hydrolases (beta-D-glucuronidase, beta-D-galactosidase, acid phosphatase, N-acetyl-beta-D-galactosaminidase, and N-acetyl-beta-D-glucosaminidase) were 44 to 96% higher in complete Freund adjuvant-elicited AM, and lysozyme activity was three- to fourfold higher. As MCP-1 and MCP-2 are major constituents of rabbit AM and exhibit potent antibacterial and antifungal properties, they may contribute to the expression of microbicidal activity in both resident and activated states.
Infectivity of respiratory syncytial virus by various routes of inoculation
Authors: Hall C B , Douglas R G , Schnabel K C , Geiman J M
Published: January 2020

To understand the transmission of respiratory syncytial virus, we examined the frequency of infection in volunteers after inoculation by different routes with varying doses of virus. Thirty-two adult volunteers received serial dilutions of a safety-tested live strain of respiratory syncytial virus instilled into nose, eye, or mouth. The highest inoculum, 5.2 log10 50% tissue culture infective dose (TCID50), was administered to four groups of four subjects each, by nose to one group, by eye to one group, and by mouth to two groups. Subsequently, 1:100 and 1:1,000 dilutions of this inoculum were administered by nose and eye. At the highest inoculum, infection occurred in three of four subjects inoculated by nose and in three of four subjects inoculated by eye. Infection occurred in one of eight subjects inoculated by mouth, but this subject most likely was infected by secondary spread. With an inoculum of 3.2 log10 TCID50, the proportion of subjects infected by either route diminished to 25%. When the inoculum was further reduced to 2.2 log10 TCID50, no infections occurred by either route. Infections after the highest inoculum were characterized by earlier and greater shedding. These findings suggest that respiratory syncytial virus may infect by eye or nose and that both of these routes appear equally sensitive. In comparison, the mouth appears to be an insensitive route of inoculation. This is of potential import in infection control procedures and in the development of vaccines or other prophylactic measures.
Polysaccharide of the slime glycolipoprotein of Pseudomonas aeruginosa
Authors: Koepp L H , Orr T , Bartell P F
Published: January 2020

The polysaccharide moiety was isolated by mild acid hydrolysis from the slime glycolipoprotein of Pseudomonas aeruginosa strain BI. After gel filtration, the polysaccharide obtained from the Carbohydrate peak fractions was found to be lipid- and protein-free. Analyses indicated that the polysaccharide contained the carbohydrate components of the parent glycolipoprotein. Molecular size of the polysaccharide was estimated by gel filtration as 70,000 to 100,000. The polysaccharide showed no indications of toxicity in mice at doses far in excess of the lethal dose for the parent glycolipoprotein, nor did the mice develop the leukopenia that characteristically follows intraperitoneal injection of glycolipoprotein. The polysaccharide acted as an inhibitor of indirect hemagglutination of glycolipoprotein-coated erythrocytes in the presence of anti-glycolipoprotein serum; however, it was not antigenic itself in rabbits. Coupled with methylated bovine serum albumin, the polysaccharide continued to lack the leukopenic and toxic properties of the parent glycolipoprotein, but the coupled polysaccharide was capable of stimulating indirect hemagglutinating antibody against both the polysaccharide and the glycolipoprotein coating erythrocytes. Moreover, the antibody to the coupled polysaccharide protected mice against challenge with lethal doses of viable P. aeruginosa with the same effectiveness as anti-glycolipoprotein serum.
Human fibronectin binding to staphylococcal surface protein and its relative inefficiency in promoting phagocytosis by human polymorphonuclear leukocytes, monocytes, and alveolar macrophages
Authors: Verbrugh H A , Peterson P K , Smith D E , Nguyen B Y , Hoidal J R , Wilkinson B J , Verhoef J , Furcht L T
Published: January 2020

The interaction between human fibronectin and 17 strains of staphylococci was studied in an attempt to elucidate the staphylococcal cell wall component(s) involved in fibronectin binding and to determine the influence of fibronectin upon phagocytosis by three types of phagocytic cells. Purified, radiolabeled fibronectin bound to a similar degree to six laboratory strains and three fresh clinical isolates of Staphylococcus aureus; similar binding of fibronectin was found with S. aureus strains deficient in cell wall teichoic acid or clumping factor and coagulase, as well as with three strains of S. epidermidis. There was minimal binding of fibronectin to encapsulated S. aureus and to Escherichia coli. Fibronectin bound to intact cells and to a crude cell wall preparation of S. aureus H, but not to purified cell walls or peptidoglycan. Trypsinization of staphylococci prevented subsequent fibronectin binding, but binding did not correlate well with the protein A content in S. aureus cell walls. At physiological concentrations, fibronectin binding to staphylococci did not promote phagocytosis of bacteria by human polymorphonuclear leukocytes, monocytes, or alveolar macrophages. Also, depletion of fibronectin from normal human serum did not result in a measurable loss of opsonic activity for staphylococci. It is concluded that fibronectin binding to staphylococci involves a surface protein shared among strains of S. aureus and S. epidermidis, and that in comparison to C3b and IgG, fibronectin plays a relatively minor role as an opsonin for staphylococci.
Biological activities of crystalline pertussigen from Bordetella pertussis
Authors: Munoz J J , Arai H , Bergman R K , Sadowski P L
Published: January 2020

We studied various biological activities of crystalline pertussigen and found that in mice as little as 0.5 ng of pertussigen induced hypersensitivity to histamine, 8 to 40 ng induced leukocytosis, 2 ng increased production of insulin, 0.1 ng increased production of immunoglobulin E and immunoglobulin G1 antibodies to hen egg albumin, 9.5 ng increased susceptibility to anaphylactic shock, and 0.5 ng increased the vascular permeability of striated muscle. We also found that in Lewis rats 20 ng of pertussigen promoted the induction of hyperacute experimental allergic encephalomyelitis. Pertussigen given intraperitoneally was toxic to mice at a dose of 546 ng. Treatment of pertussigen with glutaraldehyde eliminated this toxicity. Mice immunized with 1,700 ng of detoxified pertussigen were protected against intracerebral challenge with 3 x 10(4) viable Bordetella pertussis cells. When as little as 0.5 ng of pertussigen was given intravenously to mice, the increased susceptibility of the animals to histamine could still be detected 84 days later. The biological properties of crystalline pertussigen indicate its similarity to leukocytosis-promoting factor, Islet-activating protein, late-appearing toxic factor, and mouse-protective antigen of B. pertussis.
Intestinal colonization of neonatal animals by Campylobacter fetus subsp. jejuni
Authors: Field L H , Underwood J L , Pope L M , Berry L J
Published: January 2020

Neonatal mice (2.3 to 2.8 g) were inoculated intragastrically with different human isolates of Campylobacter fetus subsp. jejuni. At weekly intervals thereafter, mice were sacrificed and dilution plate counts were performed on segments of the gastrointestinal tract. Mice were uniformly colonized by some strains for 2 weeks, whereas other strains were being cleared at that time. One strain (BO216) persisted in some mice for 3 weeks. The greatest number of organisms (10(7)) was recovered from the cecum and large intestine. The small intestine had from 10(2) to 10(5) colony-forming units. Colonization of the stomach was not found consistently. One strain killed 13% of the infected mice. Deaths occurred between 1 and 5 days postinfection. Two other strains killed a smaller percentage of challenged animals, and two additional strains killed none. Retarded weight gain was noticed in some, but not all, of the infected mice. The intestines of neonatal rats and rabbits were colonized much the same as those of mice, whereas hamsters were resistant to colonization. Preweanling mice, up to about 6.5 to 7.0 g, could be colonized with C. fetus subsp. jejuni after intragastric challenge, but weanling mice of larger weight (9.8 g) and young adult mice (18.3 g) could not. Scanning electron photomicrographs of the lower ileum showed campylobacters in and below the dried mucous gel that lines the intestines. The use of this model for additional studies is discussed.
Elimination of Leishmania donovani amastigotes by activated macrophages
Authors: Haidaris C G , Bonventre P F
Published: January 2020

Tissue macrophages are the obligatory host cells for Leishmania donovani, the causative agent of visceral leishmaniasis. In this study we sought to determine whether activated macrophages, as defined by the functional criterion of tumor cell cytotoxicity, were also able to exert a microbicidal effect on ingested L. donovani amastigotes. We found that mouse peritoneal macrophages activated by a variety of means exerted a cytotoxic effect on tumor cell targets but were not able to kill L. donovani amastigotes unless the infected macrophages were exposed continually to an activating stimulus. Corynebacterium parvum, Mycobacterium tuberculosis H37Ra, and lymphokine-activated peritoneal macrophages from C57BL/6J mice were cytotoxic for EMT6 tumor cell targets. However, L. donovani Sudan strain 1S amastigotes were not killed by these macrophages unless the activated state was maintained by daily addition of lymphokine to the infected monolayers for several days postinfection. The killing of amastigotes was dependent on the time of exposure to lymphokine, as well as on the concentration of lymphokine added to the culture.
Factors affecting the rate as which a trachoma strain of Chlamydia trachomatis establishes persistent infections in mouse fibroblasts (McCoy cells)
Authors: Lee C K
Published: January 2020

Chlamydiae from mouse fibroblasts (McCoy cells) persistently infected with a trachoma strain (G17) of Chlamydia trachomatis repeatedly established new persistent infections in wild McCoy cells more rapidly than did wild chlamydiae. The density and nutritional state of the host cell populations may also influence the rate of establishment of persistent infections.
Immunoprotective activity of capsular polysaccharide in Klebsiella pneumoniae ribosomal preparations does not involve ribonucleic acid
Authors: Riottot M M , Fournier J M
Published: January 2020

Two peaks were obtained by cesium chloride density gradient ultracentrifugation of Klebsiella pneumoniae ribosomal preparations. Peak I contained capsular polysaccharide, lipopolysaccharide, protein, and less than 0.5% ribonucleic acid. Peak II consisted mainly of ribonucleic acid, with low amounts of protein and capsular polysaccharide. Expressed as capsular polysaccharide content, the 50% protective dose of peak I and of nonfractionated ribosomal preparations was nearly constant (2.6 and 1.2 ng, respectively). Since peak I contained less than 0.5% ribonucleic acid, these results provide evidence that ribosomal ribonucleic acid is not required for protection of mice by K. pneumoniae capsular polysaccharide which contaminates ribosomal preparations.
Group C Neisseria meningitidis variant polysaccharide vaccines in children
Authors: Steinhoff M C , Lewin E B , Gotschlich E C , Robbins J B
Published: January 2020

The currently United States-licensed group C Neisseria meningitidis vaccine, composed of the O-acetyl-positive capsular polysaccharide, is poorly immunogenic and does not afford protection from disease to infants and young children. Group C N. meningitidis O-acetyl-negative polysaccharide vaccine induces higher titers in adults than does the O-acetyl-positive vaccine. We compared the immunogenicity of these vaccines in 2-year-old children. Reactions were minimal and did not differ between the two vaccines. The postvaccination geometric mean titer was twofold greater in the O-acetyl-negative group (1.58 versus 0.73 micrograms of antibody per ml). The rates of decline in titer were similar in both groups. Further study regarding immunogenicity of and the anamnestic response to the O-acetyl-negative vaccine is warranted in the age group (less than 18 months) at highest risk for invasive meningococcal disease.
Specific lymphocyte blastogenic responses in children with cytomegalovirus and herpes simplex virus infections acquired early in infancy
Authors: Pass R F , Dworsky M E , Whitley R J , August A M , Stagno S , Alford C A
Published: January 2020

Cell-mediated immune responses in 27 infants and children with cytomegalovirus (CMV) infection acquired between birth and 1 year of age were compared with responses in 13 children who had neonatal herpes simplex virus (HSV) infection. Infection was asymptomatic in 25 of 27 CMV-infected children; the 13 patients with HSV infection were all ill as newborns. The median age when studied was 46 months for children infected with CMV and 24 months for those infected with HSV. We measured lymphocyte transformation responses (LTRs) to CMV antigens in the former group and to HSV type 1 (HSV-1) (and in six cases to HSV-2) in the latter group, with the results expressed as a stimulation index. Based on the results in seropositive and seronegative adult control subjects, stimulation indexes of greater than or equal to 3 were considered indicative of a positive LTR. Among the CMV-infected children, a positive LTR was observed in 0 to 13 assays performed before 1 year of age, 3 of 8 assays performed between 1 and 4 years of age, and 9 of 15 assays performed over 4 years of age. In contrast, a positive LTR to HSV-1 was seen in 15 to 18 assays performed in children under 1 year of age and in 14 of 16 assays performed in survivors of neonatal HSV infection older than 1 year. Six HSV-2-infected patients were tested simultaneously 13 times with HSV-1 and HSV-2 antigens. Those patients under 6 months of age responded similarly to each antigen, whereas those who were older had significantly higher LTRs to HSV-2. Children with CMV infection that was acquired early had persistently diminished specific LTRs. In contrast, after neonatal HSV infection, LTRs to HSV were present even in infancy and became more specific for the infecting type with increasing age.
Role of chemotaxis in the association of motile bacteria with intestinal mucosa: chemotactic responses of Vibrio cholerae and description of motile nonchemotactic mutants
Authors: Freter R , O'Brien P C
Published: January 2020

A motile, chemotactic, Ogawa strain of Vibrio cholerae was attracted by all 20 L-amino acids tested, in contrast to Escherichia coli AW 405, which did not react to several of these. The maximum number of vibrios entering a capillary was much lower when the capillary contained carbohydrates rather than amino acids, but the minimum effective concentrations of the carbohydrates and amino acids tested were of the same order of magnitude. L-Fucose, a sugar known to inhibit the adhesion of this vibrio strain to brush border membranes, had no attraction (taxin activity) for it. A pepsin digest of rabbit mucosal scrapings or tryptone attracted vibrios as strongly as the most active amino acids. Several nonchemotactic and one nonmotile mutant were selected from the parent vibrio. The nonchemotactic mutants were indistinguishable from the parent in their ability to attach in vitro to isolated intestinal brush border membranes, whereas the nonmotile mutant had lost this ability. Parent and nonchemotactic mutants had equal growth rates in stirred and still continuous flow cultures that were maintained in an anaerobic environment.
Activation of the alternative complement pathway by Trichomonas vaginalis
Authors: Gillin F D , Sher A
Published: January 2020

The mechanism underlying the lysis of Trichomonas vaginalis by normal human or guinea pig serum was investigated. The involvement of the complement system was demonstrated by the failure of human serum deficient in C3 or C8 to mediate parasite killing and by the ablation of lytic activity observed when fresh sera were heated at 56 degrees C or treated with ethylenediaminetetraacetate. Fixation of human C3 on the parasite surface was demonstrated by indirect immunofluorescence. The involvement of the alternative complement pathway was demonstrated (i) by the inability of properdin-depleted human serum to lyse T. vaginalis and (ii) by the normal killing observed with guinea pig serum lacking C4 and with normal human or guinea pig serum treated with ethylene glycol-bis(beta-aminoethyl ether)-N,N-tetraacetic acid and Mg2+ to selectively inhibit the classical pathway.
Attachment defect in mouse fibroblasts (L cells) persistently infected with Chlamydia psittaci
Authors: Moulder J W , Levy N J , Zeichner S L , Lee C K
Published: January 2020

Almost all the cells in populations of mouse fibroblasts (L cells) persistently infected with the 6BC strain of Chlamydia psittaci were immune to superinfection with high multiplicities of C. psittaci, whether or not the L cells contained visible chlamydial inclusions. As ascertained by experiments with 14C-labeled C. psittaci, immunity to superinfection resulted from the failure of added chlamydiae to attach to persistently infected host cells. However, when exogenous C. psittaci was introduced into persistently infected L cells by centrifuging the inoculum onto host cell monolayers or by pretreating the monolayers with diethylaminoethyl-dextran, these chlamydiae produced expected numbers of infectious progeny. Persistently infected L cells were associated in an unknown way with a C. psittaci population that entered the host cells only with the aid of centrifugation or pretreatment with diethylaminoethyl-dextran. Inclusion-free, persistently infected L cells appeared to present at least two separate hindrances to chlamydial activity: blockage of the attachment of exogenous elementary bodies to persistently infected host cells and prevention of the initiation of chlamydial multiplication by means of a normal developmental cycle in the absence of added C. psittaci.
In Vitro Production of an Extracellular Protease by
Legionella pneumophila
Authors: Thompson Michael R. , Miller Richard D. , Iglewski Barbara H.
Published: January 2020

Extracellular protease activity was measured in liquid cultures of representative strains from six serotypes of
Legionella pneumophila.
A variety of substrates were degraded, including denatured casein, skim milk, gelatin, and hide powder azure, but not elastin.
Stimulation of Clostridium perfringens enterotoxin formation by caffeine and theobromine
Authors: Labbe R G , Nolan L L
Published: January 2020

In the presence of 100 micrograms of caffeine per ml or 200 micrograms of theobromine per ml, sporulation of Clostridium perfringens NCTC 8679 rose from less than 1 to 80 or 85%. Enterotoxin concentration increased from undetectable levels to 450 micrograms/mg of cell extract protein. Heat-resistant spore levels increased from less than 1,000 to between 1 X 10(7) and 2 X 10(7)/ml. These effects were partially reversible by the addition of adenosine or thymidine. In the case of NCTC 8238, caffeine and theobromine caused a three- to fourfold increase in the percentages of cells possessing refractile spores and a similar increase in enterotoxin concentration. Heat-resistant spore levels, however, were unaffected. Inosine was ineffective in promoting sporulation in NCTC 8679.
Effect of immunization on the genesis of pneumococcal endocarditis in rabbits
Authors: Adler S W , Selinger D S , Reed W P
Published: January 2020

The effect of immunization with whole organisms on the development of Streptococcus pneumoniae endocarditis was examined by in vivo and in vitro methods. Immunization protected rabbits from pneumococcal endocarditis when the in vivo catheterization model was used. The inoculum size that caused endocarditis in 50% of the unimmunized rabbits was 1.1 X 10(5) colony-forming units, whereas 1.2 X 10(7) colony-forming units were required for infecting 50% of the immunized rabbits (P less than 0.001). Investigations were carried out to determine the mechanism which enabled immunization to prevent the development of pneumococcal endocarditis; they indicated that a reduction in bacterial adherence could not explain this phenomenon. In vitro studies showed that subagglutinating quantities of antibody increased the adherence (P less than 0.05) of pneumococci to rabbit aortic valve cusps. The adherence ratio of pneumococci to fibrin-platelet clots was at least doubled by the presence of subagglutinating dilutions of immune sera (P less than 0.001). Further studies showed that immunoglobulin G in the immune sera accounted for this increased in vitro adherence. However, further in vivo studies showed that immunized rabbits were able to clear live pneumococci from their bloodstreams within 4.5 h, whereas unimmunized rabbits failed to clear the organism within 24 h.
Interactions between Histoplasma capsulatum and macrophages from normal and treated mice: comparison of the mycelial and yeast phases in alveolar and peritoneal macrophages
Authors: Kimberlin C L , Hariri A R , Hempel H O , Goodman N L
Published: January 2020

Interactions between macrophages (alveolar and peritoneal) from normal, vaccinated (with heat-killed yeast cells), and Mycobacterium bovis BCG-treated mice and the mycelial and yeast phases of Histoplasma capsulatum were observed. Phagocytosis of microconidia, small hyphal fragments, and yeast cells occurred 4 to 6 h after the infection of macrophage cultures. Conversion to the yeast phase began at 6 to 7 h and was complete after a 72-h incubation at 37 degrees C. Macrophages surrounded and adhered to macroconidia and large hyphal elements. More macrophages (65 to 68%) from BCG-treated mice contained fungi at 24 h than did macrophages from normal or vaccinated mice. Although there was no increase in the number of fungi in macrophages from vaccinated mice, only the macrophages from BCG-treated mice contained fewer fungi after 48 h of infection with the mycelial phase of H. capsulatum. Fungal growth was not inhibited in any of the macrophage cultures when infected with the yeast phase. The macrophages infected with yeast cells were destroyed after 48 to 72 h in the culture. Only BCG-treated macrophages survived infection with the mycelial phase, whereas macrophages from normal and vaccinated mice were destroyed by the infection.
Cellular immune response during uncomplicated genital infection with Chlamydia trachomatis in humans
Authors: Brunham R C , Martin D H , Kuo C C , Wang S P , Stevens C E , Hubbard T , Holmes K K
Published: January 2020

A lymphocyte transformation (LT) assay for the study of the cellular immune response to Chlamydia trachomatis in humans is described. Subjects studied included 9 newborns whose mothers were C. trachomatis culture negative, 16 seronegative, sexually inexperienced adults, and 107 patients seen at a sexually transmitted disease clinic, including 31 men presenting with acute nongonococcal urethritis and 76 women with known or suspected uncomplicated gonorrhea or with uncomplicated C. trachomatis genital infection. LT stimulation indices (SI) were less than 3.5 in newborns and normal adults, as well as 11 of 12 seronegative, isolation-negative sexually transmitted disease clinic subjects. LTSI greater than 3.5 was found only with subjects who were sero- or culture positive for C. trachomatis. Among men with nongonococcal urethritis, the LTSI correlated better with culture than with antibody. Among women, the LTSI correlated better with antibody than with culture. LTSI decline significantly 3 to 4 weeks after curative therapy in men with nongonococcal urethritis, suggesting that LT response is short-lived and that the LTSI may be an indicator of acute C. trachomatis infection. The sensitivity, specificity, and predictive value of a positive LT assay and of serum and local antibody tests, in terms of C. trachomatis infection defined as positive isolation, were also compared. The predictive value of a positive LTSI for C. trachomatis infection was generally low in the sexually transmitted disease clinic patients: 62% in men with nongonococcal urethritis and 37% in women. However, this study did show the LT assay to be a useful specific test for monitoring the cellular immune response to C. trachomatis infection.
Evidence for two distinct populations of suppressor cells in the spleens of Mycobacterium bovis BCG-Sensitized mice
Authors: Turcotte R
Published: January 2020

Spleen cells from female C57BL/6 mice infected intravenously with 1 mg (about 10(7) viable units) of bacillus Calmette-Guérin (BCG) were shown to suppress the blastogenic responses induced by the T-cell mitogens phytohemagglutinin and concanavalin A and by the B-cell mitogen lipopolysaccharide in spleen cells from normal syngeneic mice. By using various separation procedures or cellular treatments, evidence was found for two distinct populations of splenic suppressor cells. One population belonged to the monocyte-macrophage lineage on the basis of their adherence to plastic surfaces, their removal after treatment with carbonyl iron, and their resistance to gamma irradiation. The other population of suppressor cells belonged to the T lymphocytes due to their sensitivity to an anti-Thy 1 antiserum and complement and to gamma irradiation. After separation on nylon wool columns, inhibitory activity was found in both the nonadherent and the adherent spleen cell populations. Both populations of suppressor cells were present in the spleens 14 days after BCG inoculation and persisted for at least 40 days after infection.
Immunization with major outer membrane protein (porin) preparations in experimental murine salmonellosis: effect of lipopolysaccharide
Authors: Kuusi N , Nurminen M , Saxén H , Mäkelä P H
Published: January 2020

A crude major outer membrane (porin) preparation, obtained from a rough strain of Salmonella typhimurium earlier shown to be protective both in active and passive immunization of mice against challenge with smooth S. typhimurium, was further purified. Removal of the main impurities, lipopolysaccharide (LPS) and lipoprotein, was accompanied by loss of protective capacity in passive immunization experiments. Reconstitution with rough LPS restored the protective capacity. Protection was, however, concluded not to be due to anti-LPS, because a large fraction of the anti-LPS antibodies could be removed from the protective rabbit antiserum with an LPS immunosorbent without loss of protection.
Isolation of special antibodies which react only with homologous enterotoxins from Vibrio cholerae and Enterotoxigenic Escherichia coli
Authors: Honda T , Takeda Y , Miwatani T
Published: January 2020

Cholera enterotoxin (CT) and heat-labile enterotoxin (LT) produced by enterotoxigenic Escherichia coli share a common antigenic determinant. In addition, CT and LT each have a unique antigenic determinant. Antisera were prepared by immunoaffinity chromatography against these unique antigenic determinants, that is, antiserum that reacted with CT but not with LT and antiserum that reacted with LT but not with CT. Antiserum against the common antigenic determinant to CT and LT was also prepared by immunoaffinity chromatography. The specificities of these antisera were demonstrated by Ouchterlony double-gel diffusion tests and by neutralization of the activities of CT and LT to cause morphological changes in Chinese hamster ovary cells.
In vitro formation of hybrid toxins between subunits of Escherichia coli heat-labile enterotoxin and those of cholera enterotoxin
Authors: Takeda Y , Honda T , Taga S , Miwatani T
Published: January 2020

Heat-labile enterotoxin (LT) was purified from cells of enterotoxigenic Escherichia coli isolated from a patient with traveller's diarrhea. Purified LT was separated into A and B subunits by treatment with 6 M urea solution in 0.1 M propionic acid (pH 4.0). Biologically active toxin was reconstituted from isolated A and B subunits of LT. Hybrid toxins with biological activity were obtained in vitro from the A subunit of cholera enterotoxin and B subunit of LT, and from the A subunit of LT and B subunit of cholera enterotoxin. The hybrid toxins show a similar toxicity to that of the parent toxins from which the A subunits were derived. The in vitro formations of the hybrid toxins were confirmed by polyacrylamide gel disk electrophoresis.
Molecular epidemiology of adenoviruses: alternating appearance of two different genome types of adenovirus 7 during epidemic outbreaks in Europe from 1958 to 1980
Authors: Wadell G , de Jong J C , Wolontis S
Published: January 2020

Four genome types of adenovirus serotype 7 (Ad7, Ad7a, Ad7b, and Ad7c) were identified by use of DNA restriction enzymes BamHI, EcoRI, and SmaI. We obtained information on the distribution of the four Ad7 genome types by typing 68 Ad7 isolates obtained in the Netherlands from 1958 to 1979 and 36 Ad7 isolates obtained in Sweden from 1964 to 1980. The Ad7 prototype was never detected, and only seven isolates were genome-typed Ad7a. Ad7b and Ad7c accounted for 94% of the genome-typed isolates obtained from patients. Ad7c was isolated in the Netherlands during 1958 to 1969, but only Ad7b has been detected there since 1970. In Sweden, Ad7c was recovered between 1964 to 1972, but only Ad7b has been isolated there since 1973. In conclusion, the newly recognized Ad7b and Ad7c genome types, which in the Netherlands and Sweden represent virtually all genome-typed isolates from patients, show a mutually exclusive appearance.
Effect of proteins on the immunogenicity of enterobacterial common antigen
Authors: Kuhn H M , Adamus G , Romanowska E , Mayer H
Published: January 2020

Enterobacterial common antigen isolated by two independent extraction procedures was found to precipitate with a number of basic or hydrophobic proteins. Complexes of enterobacterial common antigen with protamine sulfate, with methylated bovine serum albumin or with a fraction of outer membrane proteins of two different Shigella wild types proved to be highly immunogenic in rabbits upon intravenous immunization, in contrast to the enterobacterial common antigen preparations by themselves. This explains why crude isolates of enterobacterial common antigen usually are good immunogens in contrast to the isolated antigen, which was described to be either not or only very poorly immunogenic.
Attachment of killed Mycoplasma gallisepticum cells and membranes to erythrocytes
Authors: Banai M , Kahane I , Feldner J , Razin S
Published: January 2020

To correlate viability with attachment capacity, Mycoplasma gallisepticum cell harvested at different growth phases and treated by various agents were tested for their capacity to attach to human erythrocytes. The results show that viability per se is not essential for M. gallisepticum attachment to erythrocytes, as cells killed by ultraviolet irradiation anmd membranes isolated by lysing M. gallisepticum cells by various means retained attachment capacity. However, treatment of the mycoplasmas by protein-denaturing agents, such as heart, glutaraldehyde, or prolonged exposure to low pH, drastically affected or even abolished attachment, supporting the protein nature of the mycoplasma membrane components responsible for specific binding to the sialoglycoprotein receptors on the erythrocytes.