bluuebunny/crossref_metadata_2025 huggingface dataset:
Relationship between phagocytosis and immunoglobulin A release from human colostral macrophages
Authors: Weaver E A , Tsuda H , Goldblum R M , Goldman A S , Davis C P
Published: January 2020

Macrophages and neutrophils that contain mainly secretory immunoglobulin A (IgA) comprise the majority of cells in human colostrum. These cell populations were separated and analyzed for their ability to release total IgA and secretory IgA when stimulated to phagocytose. Colostral macrophages phagocytosed opsonized bacteria and nonopsonized latex particles; at the same time, IgA was released. Neutrophils poorly phagocytosed opsonized bacteria but actively phagocytosed latex particles. In contrast to the macrophages, the neutrophils did not release IgA, even after active phagocytosis of latex. Consequently, colostral macrophages are the main source of IgA released from colostral leukocytes when these cells are exposed to organisms or particles that are phagocytosed. A function for colostral neutrophils which sequester IgA is proposed.
Streptococcal neuraminidase and acute glomerulonephritis
Authors: Potter E V , Shaughnessy M A , Poon-King T , Earle D P
Published: January 2020

We examined the hypothesis that streptococcal neuraminidase may alter host serum immunoglobulin G so that autoantibodies are formed which lead to immune complexes and acute glomerulonephritis. We confirmed the observation that T-type 4 and T-type 12 streptococci (both associated with acute glomerulonephritis) are the most likely of many types studied to produce neuraminidase. However, we did not find this enzyme to be produced by any of 23 streptococcal strains isolated from patients with nephritis, whereas it was produced by two strains from patients with rheumatic fever and by one strain from a patient with scarlet fever. Also, we were unable to find direct or indirect evidence of increased neuraminidase activity in the sera of six patients with acute glomerulonephritis when they were compared with the sera of six patients with acute rheumatic fever and with those of six normal subjects.
Leishmaniasis in beige mice
Authors: Kirkpatrick C E , Farrell J P
Published: January 2020

The courses of two protozoal diseases, cutaneous and visceral leishmaniasis, were examined in three groups of C57BL/6J mice. One group of mice was homozygous recessive for the beige gene (bg/bg). Beige mice are the genetic homologue of the human Chédiak-Higashi syndrome and, among other defects, are profoundly deficient in natural killer cell activity. Wild-type (+/+) mice, which respond to experimental cutaneous or visceral leishmaniasis by eventually eliminating their parasites, and heterozygous beige (bg/+) mice served as controls; both are phenotypically normal in natural killer cell activity, which is particularly high in the spleen. In bg/bg mice, the course of Leishmania tropica, a causative agent of cutaneous leishmaniasis, was similar to that in control mice after both primary and challenge inoculations. All groups of mice expressed similar humoral and cellular immune responses to L. tropica antigen. However, bg/bg mice failed to eliminate amastigotes of Leishmania donovani, a causative agent of visceral leishmaniasis, from their spleens over an observation period of 56 days, in contrast to bg/+ and +/+ controls. Similar levels of anti-leishmanial antibody were produced by all groups of mice, and all mice responded comparably to footpad injections of L. donovani antigen. The results of this study suggest a possible role for natural killer cells in recovery from L. donovani but not from L. tropica infection.
Involvement of cytochrome b-245 in the respiratory burst of human neutrophils
Authors: Borregaard N , Simons E R , Clark R A
Published: January 2020

The cytochrome b 245 of human neutrophils was reduced when the neutrophils under anaerobic conditions were stimulated by serum-treated zymosan, immune complexes, or phorbol myristate acetate. Reintroduction of oxygen rapidly reoxidized the cytochrome; azide was without effect on any of these reactions. This indicates that cytochrome b 245 participates in the respiratory burst of neutrophils.
Restriction endonuclease analysis of DNA from genital isolates of herpes simplex virus type 2
Authors: Maitland N J , Smith I W , Peutherer J F , Robertson D H , Jones K W
Published: January 2020

High-resolution restriction endonuclease analysis of DNA from multiple herpes simplex virus type 2 isolates from 30 patients at a single clinical center has indicated that herpes simplex virus type 2 DNA sequences are highly conserved. However, the use of six endonucleases, EcoRI, BglII, HindIII, KpnI, BamHI, and SstI, established that each patient was infected by a unique virus. Comparison of virus isolates from the same patient show that the most sequence variation occurred in the terminal and subterminal BamHI fragments. The results suggest that each individual may induce specific variation in the herpes simplex virus type 2 genome and that the results of epidemiological studies based on restriction endonuclease analyses of herpes simplex virus type 2 DNA must be interpreted with care.
Antigenic determinant of the Lancefield group H antigen of Streptococcus sanguis
Authors: Rosan B , Argenbright L
Published: January 2020

Previous studies indicated that the teichoic acid isolated from strains of Streptococcus sanguis was group specific and defined the Lancefield group H streptococci. To determine the specific antigenic determinants, the antigen was extracted from a group H streptococcus (ATCC 903) by the phenol-water method and purified by column chromatography. The isolated antigen had a glycerol/phosphate/glucose molar ratio of 1:0.9:0.3; the lipid concentration was 7.6% of its dry weight. No nucleic acids were detected, and amino acids constituted approximately 2% of the dry weight. The minimum concentration of antigen required to sensitize erythrocytes for hemagglutination with a 1:1,000 dilution of either group H antiserum or antiteichoic acid serum was 0.02 microgram/ml. Hemagglutination inhibition studies suggested that the major antigenic determinant consisted of an alpha-glucose linked to the glycerol phosphate backbone.
Biological effects of the interaction of staphylococcal alpha-toxin with human serum
Authors: Gemmell C G , Peterson P K , Townsend K , Quie P G , Kim Y
Published: January 2020

The alpha-toxin (hemolysin) of Staphylococcus aureus is known to be an important determinant of pathogenicity although its precise role in the process of infection is not understood. In this study, the interaction of alpha-toxin with the human complement system was evaluated in terms of its effect on the opsonic activity of serum for S. aureus. Phagocytosis by human polymorphonuclear leukocytes was studied by measuring the uptake of preopsonized radiolabeled bacteria. It was found that alpha-toxin-treated serum had reduced opsonic activity and that this change was associated with complement consumption via the classical pathway. Levels of C3 to C9 were reduced in proportion to the amount of toxin added to the reaction mixture; levels of C2 were markedly reduced but those of factors B and D of the alternative pathway were unaltered in the presence of alpha-toxin. Heat-inactivated toxin, which had no hemolytic activity, also interacted with the complement system but with a significantly reduced effect. In addition, alpha-toxin behaved as a chemotaxinogen for polymorphonuclear leukocytes: human serum was activated by the toxin. These studies demonstrate that the interaction of staphylococcus alpha-toxin with human serum affects two important aspects of the host response to the staphylococcus.
Receptor-like glycocompounds in human milk that inhibit classical and El Tor Vibrio cholerae cell adherence (hemagglutination)
Authors: Holmgren J , Svennerholm A M , Lindblad M
Published: January 2020

The two biotypes of Vibrio cholerae were found to have cell-associated hemagglutinins which differ with regard to binding to different species of erythrocytes and inhibition by monosaccharides. A total of 12 classical V. cholerae strains (Inaba or Ogawa) strongly agglutinated human erythrocytes in a reaction specifically inhibited by L-fucose, whereas 12 El Tor strains preferably agglutinated chicken erythrocytes, a reaction reversed by D-mannose or by higher concentrations of D-fructose, D-glucose, alpha-methyl-D-mannoside, or sucrose. Milk from Swedish women inhibited both of these adherence reactions, and the predominating inhibitory activity for each reaction resisted boiling, was destroyed by periodate treatment, and bound a concanavalin A-Sepharose column, suggesting a carbohydrate structure. Further characterization indicated that the inhibitory activity for classical V. cholerae hemagglutination was distributed about equally on glycoprotein and free oligosaccharide, but was not present on glycolipid. The El Tor inhibiting activity, on the other hand, was almost exclusively of a high-molecular-weight glycoprotein nature. These results support our previous suggestion (Holmgren et al., Infect. Immun. 33:136-141, 1981) that human milk may contain receptor-like glycocompounds which can prevent bacterial adherence by competition with receptors on target cells.
Enhancement by Candida albicans of Staphylococcus aureus, Serratia marcescens, and Streptococcus faecalis in the establishment of infection in mice
Authors: Carlson E
Published: January 2020

Candida albicans has been shown to stimulate infection in mice by a number of bacteria. Mice inoculated intraperitoneally with as little as 500 colony-forming units of Staphylococcus aureus along with a nonlethal dose of 10(8) colony-forming units of C. albicans (one-third the dose causing 50% mortality in 7 days) developed widespread staphylococcal infection. S. aureus injected alone at that or considerably higher doses did not establish infection. Phage typing methods demonstrated that the staphylococcal infection was due to the bacterial organisms originally injected. A minimum dose of C. albicans between 1.1 X 10(5) and 1.1 X 10(7) colony-forming units was necessary for the amplification of virulence of S. aureus to take place. Serratia marcescens and Streptococcus faecalis inoculated intraperitoneally at small nonlethal doses could also be recovered from blood and tissues 5 days after animals were dually injected with C. albicans but not from animals which were inoculated with the same amounts of these bacteria alone.
Concentration-Dependent Multiple Binding Sites on Saliva-Treated Hydroxyapatite for
Streptococcus sanguis
Authors: Gibbons R. J. , Moreno E. C. , Etherden I.
Published: January 2020

The influence of bacterial cell concentration on estimates of the number of binding sites and the affinity for the adsorption of a strain of
Streptococcus sanguis
to saliva-treated hydroxyapatite was determined, and the possible presence of multiple binding sites for this organism was tested. The range of concentrations of available bacteria varied from 4.7 × 10
6
to 5,960 × 10
6
cells per ml. The numbers of adsorbed bacteria increased over the entire range tested, but a suggestion of a break in an otherwise smooth adsorption isotherm was evident. Values for the number of binding sites and the affinity varied considerably depending upon the range of available bacterial concentrations used to estimate them; high correlation coefficients were obtained in all cases. The use of low bacterial cell concentrations yielded lower values for the number of sites and much higher values for the affinity constant than did the use of high bacterial cell concentrations. When data covering the entire range of bacterial concentrations were employed, values for the number of sites and the affinity were similar to those obtained by using only high bacterial cell concentrations. The simplest explanation for these results is that there are multiple binding sites for
S. sanguis
on saliva-treated hydroxyapatite surfaces. When present in low concentration, the streptococci evidently attach to more specific high-affinity sites which become saturated when higher bacterial concentrations are employed. The possibility of multiple binding sites was substantiated by comparing estimates of the adsorption parameters from a computer-simulated isotherm with those derived from the experimentally generated isotherm. A mathematical model describing bacterial adsorption to binary binding sites was further evidence for the existence of at least two classes of binding sites for
S. sanguis.
Far fewer streptococci adsorbed to experimental pellicles prepared from saliva depleted of bacterial aggregating activity when low numbers of streptococci were used, but the magnitude of this difference was considerably less when high streptococcal concentrations were employed. This suggests an association between salivary components which possess bacterial-aggregating activity and bacterial adsorption to high-affinity specific binding sites on saliva-treated hydroxyapatite surfaces.
Lipoteichoic acid is the major cell wall component responsible for surface hydrophobicity of group A streptococci
Authors: Miörner H , Johansson G , Kronvall G
Published: January 2020

The contribution of lipoteichoic acid (LTA) to the hydrophobic surface properties of group A streptococci was investigated in aqueous dextran-polyethylene glycol two-phase systems. Enzymatic digestions were performed to characterize the hydrophobic surface structure. The results obtained indicated that LTA is a major factor responsible for the hydrophobic character of the cell surface of group A streptococci. This was further supported by the similarity of partition in polymer two-phase systems between whole group A streptococci and tritiated LTA extracted from a group A streptococcal strain. Surface LTA was also determined on intact organisms by a new method measuring the adsorption of antibodies to LTA to the bacterial surface. A correlation was found between the content of surface LTA and the hydrophobicity of the group A streptococci. We conclude that surface-associated LTA is the major factor determining surface hydrophobicity of group A streptococci.
Monoclonal Antibodies to
Trypanosoma cruzi
Inhibit Motility and Nucleic Acid Synthesis of Culture Forms
Authors: Alves Maria Julia Manso , Aikawa Masamichi , Nussenzweig Ruth S.
Published: January 2020

Monoclonal antibodies were raised against the surface of epimastigotes and metacylic trypomastigotes of
Trypanosoma cruzi
, as shown by electron microscopy, agglutination, and immunofluorescence. The antibodies were stage specific but not strain specific. A deleterious effect of the antibodies on
T. cruzi
culture forms was shown by the drastic reduction of parasite motility and incorporation of nucleic acid precursors. Some fraction of the parasite population, however, was viable and replicated and infected mouse macrophages in culture. The antibodies were found to also mediate complement-induced lysis of culture forms of
T. cruzi.
Localization of complement component 3 on Streptococcus pneumoniae: anti-capsular antibody causes complement deposition on the pneumococcal capsule
Authors: Brown E J , Joiner K A , Cole R M , Berger M
Published: January 2020

We have previously shown that complement component 3 (C3) deposited onto encapsulated Streptococcus pneumoniae by anti-capsular antibody (Ab) is a more efficient opsonin in vitro and in vivo than C3 deposited by anti-cell wall Ab (Brown et al., J. Clin. Invest. 69:85-98, 1982). In the present study, we explored the cellular location of C3b molecules that differ in opsonic efficiency by using avidin-ferritin to localize biotinylated Ab and C3 molecules on S. pneumoniae for electron microscopy. Anti-cell wall Ab and C3b molecules deposited by this Ab on unencapsulated S. pneumoniae were localized to S. pneumoniae cell walls. Anti-capsular Ab and C3b deposited by this Ab were seen in clusters on encapsulated S. pneumoniae at a distance from the cell wall. However, no avidin-ferritin staining of encapsulated S. pneumoniae was seen on incubation with biotinyl-anti-cell wall Ab, biotinylated C3 fixed by anti-cell wall Ab, or nonimmune serum containing biotinyl-C3. In each case, uptake of the biotinylated component was proven by radioactivity measurements, since biotinylated Ab and C3 were also radiolabeled with 125I. When avidin-ferritin did not bind to biotinylated components. Ouchterlony analysis indicated that C3 was bound to cell wall components on the encapsulated organisms. Thus, we conclude that, for encapsulated S. pneumoniae, opsonically efficient C3b molecules, deposited by anti-capsular Ab, are located on the S. pneumoniae capsule, whereas the opsonically inefficient C3b molecules deposited by anti-cell wall Ab or nonimmune serum are located on the cell wall. A major reason for the increased virulence of encapsulated compared to unencapsulated S. pneumoniae is that, in the absence of anti-capsular Ab, the S. pneumoniae capsule interferes with the recognition of cell wall-bound C3b molecules by phagocytic cell receptors.
Rous-associated virus type 7 induces a syndrome in chickens characterized by stunting and obesity
Authors: Carter J K , Ow C L , Smith R E
Published: January 2020

Infection of 10-day-old chicken embryos with an avian retrovirus. Rous-associated virus type 7, resulted in a disease characterized by stunting and hyperlipidemia. By 20 days after hatch, infected chickens were smaller than hatchmates and developed ataxia and obesity over the next 30 days. Histological examinations of livers from infected chickens revealed a diffuse panlobular fatty infiltrate involving an accumulation of fat in microdroplets. Electron microscopic examinations of livers from infected chickens revealed hepatocytes with swollen mitochondria that lacked cristae. The thyroid and pancreas were infiltrated with lymphoblastoid cells by 1 week after hatch. An examination of the blood revealed a mild anemia, a frank lipemia, and high levels of uric acid. This syndrome induced by Rous-associated virus type 7 in chickens may be useful for elucidating the nature of several diseases, including that found in the fatty liver and kidney syndrome of chickens and that observed in a strain of obese chickens.
Transformation of Human Erythrocyte Shape by Endotoxic Lipopolysaccharide
Authors: Warren John R. , Harris Alan S. , Wallas Charles H.
Published: January 2020

Human erythrocytes were observed to undergo a discocyte to echinocyte to spheroechinocyte shape transformation during brief incubation with endotoxic lipopolysaccharide. It was concluded that lipopolysaccharide-membrane interactions alter the curvature of erythrocyte membranes.
Influence of growth conditions on adherence of Streptococcus mutans ingbritt to saliva-coated hydroxyapatite
Authors: Campbell L K , Knox K W , Wicken A J
Published: January 2020

Streptococcus mutans Ingbritt grown under standardized conditions adhered less effectively to saliva-coated hydroxyapatite beads than did Streptococcus sanguis G9B, and there was competition for binding. The results with Ingbritt were influenced by the generation time, the pH of growth, and the carbohydrate source as shown by studies on organisms grown in continuous culture.
Elaboration of
Bacillus anthracis
Antigens in a New, Defined Culture Medium
Authors: Ristroph Joseph D. , Ivins Bruce E.
Published: January 2020

Improved culture conditions and a new, completely synthetic medium (R medium) were developed to facilitate the production of
Bacillus anthracis
holotoxin antigens. Levels of these antigens up to fivefold greater than the highest previously reported values were recovered with the described system. Cultures of Sterne, V770-NP1-R, and Vollum 1B strains of
B. anthracis
were monitored for growth, pH change, glucose utilization, supernatant protein concentration, lethal toxin activity, and protease activity.
p105, an Epstein-Barr virus-induced, phosphonoacetic acid-insensitive glycoprotein target of the anti-Epstein-Barr virus immune response
Authors: Casareale D , Jones W , Sairenji T , Humphreys R E
Published: January 2020

To describe structures and biological functions of targets for antibody-mediated immune responses to Epstein-Barr virus (EBV)-infected lymphoid cells, we have characterized a membrane-associated protein of 105,000 daltons, p105, which was prominently recognized in immunoprecipitates with some EBV antigen-reactive patients' sera. A rabbit antiserum to immunopurified p105 was developed. [35S]methionine-labeled p105 was specific to EBV-superinfected Raji cells, and its synthesis was not blocked with phosphonoacetic acid, indicating that it is an "early" viral antigen. Phosphonoacetic acid treatment of EBV-superinfected Raji cells was associated with the accumulation, mainly in the cytosol, of an 88,000-dalton protein, p88, which was also recognized with anti-p105 serum, but was not detected in superinfected cells which had not been treated with phosphonoacetic acid. Although anti-p105 serum immunoprecipitated a membrane fraction protein, it did not neutralize P3HR-1 virus and was not considered to be an exposed virion component. We conclude that p105 is an early, EBV-induced, membrane fraction antigen to which EBV-infected patients generate a substantial antibody response.
Salivary immunoglobulin A antibodies and recovery from challenge of Streptococcus mutans after oral administration of Streptococcus mutans vaccine in humans
Authors: Gahnberg L , Krasse B
Published: January 2020

Heat-killed Streptococcus mutans was administered orally in two periods of 1 week to six subjects in an attempt to affect the salivary immunoglobulin A (IgA) response to this bacterium. Enzyme-linked immunosorbent assays were used to detect specific IgA antibody activity, and an immunofluorescent assay was used for measurement of total IgA in parotid saliva. The salivary IgA response to S. mutans was compared with that against a noncross-reacting antigen preparation from Escherichia coli and with antibody responses in five sham-immunized subjects. No change in salivary IgA response to S. mutans was observed after oral administration of this organism. Significantly less streptomycin-resistant S. mutans could be recovered from the six test subjects than from the five controls after the first of two challenges with streptomycin-resistant microorganisms. At the day of the first challenge, a significantly higher IgA antibody response to all tested antigens was observed in the test group than in the control group. The data show that this difference was not related to the oral administration of S. mutans but rather was an occasional finding. The coincidence of a rapid elimination of the challenge strain and a high IgA antibody response to S. mutans supports the concept that salivary IgA antibodies could have a biological significance in the human defense against cariogenic microorganisms.
Production, purification, and properties of a bacteriocin from Staphylococcus aureus isolated from saliva
Authors: Nakamura T , Yamazaki N , Taniguchi H , Fujimura S
Published: January 2020

Staphylococci from samples of human saliva were isolated on staphylococcal-selective agar plates. These strains were tested for the inhibition of the growth of Staphylococcus aureus FDA209P. The frequency of inhibitory strains among all of the staphylococcal isolates was 5.2%. Strain IYS2, which formed the biggest inhibitory zone against the growth of the indicator strain, was used as the producer of bacteriocin. IYS2 was identified to be S. aureus, based on its biological properties. The bacteriocin was purified by sequential procedures, including ammonium sulfate precipitation, fractionation with ethanol, ion-exchange chromatography, and gel filtration. Its molecular weight was determined to be 5,000. The isoelectric point was 10.0. In amino acid composition, lysine, histidine, aspartic acid, valine, and phenylalanine were predominant. The bacteriocin was heat stable but inactivated by proteases or peptidase. The bacteriocin had a bactericidal effect on susceptible cells. An analysis of the inhibitory spectrum among typical oral indigenous bacteria showed that Streptococcus salivarius, Propionibacterium acnes, Corynebacterium parvulum, and Actinomyces israelii were susceptible to the bacteriocin. Streptococcus mutans, Streptococcus sanguis, Streptococcus mitis, Actinomyces viscosus, Actinomyces naeslundii, Fusobacterium nucleatum, Bacterionema matruchotii, and Bacteroides melaninogenicus were resistant. The majority of S. aureus tested were susceptible, and all Staphylococcus epidermidis strains tested were resistant.
Characteristics of Mononuclear Phagocytes Mediating Antilisterial Resistance in Splenectomized Mice
Authors: Pietrangeli Carolynn , Pang King C. , Skamene Emil , Kongshavn Patricia A. L.
Published: January 2020

The characteristics of mononuclear phagocytes mediating resistance to infection with
Listeria monocytogenes
during the early phase (up to 48 h) of the response were investigated in mice of the A strain that had undergone splenectomy. Although irradiation in the sham-operated host had no effect on its antilisterial response when administered immediately before infection, it markedly reduced the ability of the splenectomized host to resist listerial challenge. This effect of radiation was demonstrable in the high-dose range (600 r) and could not be reversed immediately by repopulation with 20 × 10
6
syngeneic nucleated bone marrow cells. Administration of silica 24 h before infection profoundly enhanced the growth of
L. monocytogenes
in the liver of splenectomized mice. Shielding of the liver, but not the bone marrow, protected the splenectomized host against the effects of radiation, indicating that the cell population responsible for mediating the enhanced antilisterial resistance resides in the liver. The enhanced antilisterial resistance of splenectomized mice was specifically because of the absence of the spleen and not merely because of the removal of a favorable replicating environment for listeria organisms.
Activation of peritoneal macrophages by concanavalin A or Mycobacterium bovis BCG for fungicidal activity against Blastomyces dermatitidis and effect of specific antibody and complement
Authors: Brummer E , Sugar A M , Stevens D A
Published: January 2020

With a new short-term assay, where the reduction of CFUs in the inoculum could be measured, we investigated the killing of the dimorphic fungal pathogen Blastomyces dermatitidis in its yeast phase by murine peritoneal macrophages. Peritoneal macrophages from concanavalin A- or Mycobacterium bovis BCG-treated mice, but not resident or thioglycolate-elicited macrophages, significantly reduced the CFUs of B. dermatitidis in the inoculum. The activation of peritoneal macrophages for fungicidal activity by concanavalin A treatment was shown to be dose dependent and transient, i.e., absent after 72 h. These results indicate that it is possible for murine peritoneal macrophages to kill B. dermatitidis in vitro. The addition of specific antibody or complement or both did not enhance the killing of B. dermatitidis by these nonspecifically activated macrophages.
Hemadsorption and virulence are separable properties of Mycoplasma pneumoniae
Authors: Leith D K , Hansen E J , Wilson R M , Krause D C , Baseman J B
Published: January 2020

A selective enrichment technique was used to isolate a hemadsorption-positive revertant of a hemadsorption-negative mutant strain of Mycoplasma pneumoniae. This hemadsorption-positive revertant was shown to have simultaneously regained both the ability to attach to neuraminidase-sensitive receptors on the tracheal ring respiratory epithelium in vitro and the ability to synthesize three virulent-strain-specific proteins which were not synthesized by the hemadsorption-negative mutant. Despite the persistence of the revertant in hamster lung tissue for 9 to 12 weeks postinfection, no cytopathology was observed. Intranasal inoculation of the revertant provided limited protection against a challenge dose of virulent M. pneumoniae.
Plasmid Coding for Drug Resistance and Production of Heat-Labile and Heat-Stable Toxins Harbored by an
Escherichia coli
Strain of Human Origin
Authors: Silva M. Lourdes M. , Scaletsky Isabel C. A. , Reis M. Henriqueta L. , Affonso M. Heloiza T. , Trabulsi Luiz R.
Published: January 2020

In a study of enterotoxigenic strains of
Escherichia coli
isolated from children with diarrhea in São Paulo, Brazil, a new enterotoxin and antibiotic resistance plasmid that carries heat-labile toxin, heat-stable toxin, and drug resistance genes was found. This is the first such plasmid to be found in a human strain of
E. coli.
The plasmid is nonconjugative, has a molecular weight of at least 54 × 10
6
, and is mobilized by the R plasmid present in the host strain.
Construction and expression of recombinant plasmids encoding type 1 fimbriae of a urinary Klebsiella pneumoniae isolate
Authors: Purcell B K , Clegg S
Published: January 2020

The type 1 fimbriae of Klebsiella pneumoniae have been implicated as important virulence factors in mediating Klebsiella urinary infections. The chromosomally encoded fimbrial genes were cloned by a cosmid cloning technique. Further subcloning was performed with the cloning vehicles pBR322 and pACYC184, and a recombinant plasmid containing the fimbrial genes was constructed. After transformation by this plasmid, both Escherichia coli and Salmonella typhimurium were shown to express fimbriae which reacted with Klebsiella fimbrial antiserum. The approximate location of the relevant genes on the chimeric plasmid was determined by insertion of the transposable element Tn5. Hemagglutination-negative phenotypes were used to estimate the minimum size of the DNA fragment necessary to encode fimbrial biosynthesis and expression. The size of the coding region of this fragment was found to be 5.5 kilobase pairs.
Amyloidosis and the serum amyloid A protein response to muramyl dipeptide analogs and different mycobacterial species
Authors: McAdam K P , Foss N T , Garcia C , DeLellis R , Chedid L , Rees R J , Wolff S M
Published: January 2020

Serum amyloid A protein (SAA) elevation accompanies induction of secondary amyloidosis in mice given Mycobacterium butyricum in Freund adjuvant. The synthesis of SAA by cultured hepatocytes is induced by a macrophage-derived mediator, which has been identified as interleukin 1. In these studies, SAA synthesis has been used as an index of macrophage activation to examine the in vivo response of mice to challenge with seven different mycobacteria and with synthetic analogs of the immunoadjuvant N-acetylmuramyl-L-alanyl-D-isoglutamine [MDP(L-D)]. SAA synthesis was stimulated by administration (by the intraperitoneal route) of the mycobacteria dissolved in saline, with Mycobacterium vaccae being the most active and Mycobacterium leprae being the least stimulatory. MDP(L-D), which is the minimal structure (molecular weight, 492) able to substitute for mycobacteria in Freund adjuvant, stimulated SAA synthesis, whereas the MDP(D-D) isomer was inactive. The butyl ester of MDP, which induces no detectable pyrogenicity but retains adjuvanticity, required a 100-fold greater dosage than MDP(L-D) in stimulating SAA synthesis. Amyloidosis was detected histologically only when active SAA inducers MDP(L-D), M. vaccae, and M. butyricum, were administered in incomplete Freund adjuvant, with amyloid-enhancing factor. These studies demonstrated that SAA elevation was a sensitive in vivo marker of the capacity of antigens to stimulate macrophages to produce interleukin 1. A point of considerable relevance to the human use of MDP was the observation that repeated injections of the adjuvant MDP in saline did not induce secondary amyloidosis.
Neurovirulence of murine coronavirus JHM temperature-sensitive mutants in rats
Authors: Wege H , Koga M , Watanabe R , Nagashima K , ter Meulen V
Published: January 2020

The murine coronavirus strain JHM is highly neurotropic in rats and has a marked tendency to cause demyelinating central nervous system diseases after intracerebral inoculation. The clinical diseases observed range from an acute encephalomyelitis occurring within 2 weeks postinfection to a subacute demyelinating encephalomyelitis developing several weeks or months postinfection. Uncloned wild-type virus induced both acute and subacute diseases, whereas cloned JHM virus grown in tissue culture caused only acute disease without the pronounced lesions of primary demyelination. In contrast, temperature-sensitive mutants selected from that clone were capable of inducing subacute demyelinating encephalomyelitis after prolonged incubation times. Viruses recovered from diseased animals were still temperature sensitive. Inoculation of temperature-sensitive mutants into suckling rats (age, 10 to 15 days) produced high rates of subacute demyelinating diseases running a more chronic course; these diseases often were not fatal. Those rats which did not show clinical signs frequently revealed inflammatory demyelinating lesions. These findings indicate that the rate and type of clinical disease are dependent on the neurovirulence of the virus mutant used for inoculation and the age of the animals at the time of infection.
Ability of Post-endotoxin serum from BCG-infected mice to induce nonspecific resistance and stimulation of granulopoiesis
Authors: Urbaschek R , Urbaschek B
Published: January 2020

Serum from BCG-infected mice obtained 2 h after injection with endotoxin induced elevated levels of colony-stimulating factor and an increase in splenic granulocyte-macrophage progenitor cells in C3H/HeJ mice. The capacity of such serum to stimulate granulopoiesis may be related to its ability to increase nonspecific resistance to lethal irradiation.
Effect of Friend Leukemia Virus and Rowson-Parr Virus on Immunological Maturation of Mice
Authors: Bendinelli M.
Published: January 2020

The effect of neonatal infection with Friend virus (FV) and Rowson-Parr virus (RPV) on the maturation of the capacity to respond to sheep red cells, as measured by the numbers of hemolytic plaque-forming cells in the spleen, was investigated in BALB/c mice. Both viruses affected immunological maturation but there were significant differences between their effects. The development with age of the ability to produce plaque-forming cells in response to antigen was virtually abolished by FV and only slightly impaired by RPV. Furthermore, FV also suppressed the development of background plaque-forming cells, whereas RPV did not.
Clinical Application of Immunofluorescence III. Identification of Lancefield Group B Streptococci
Authors: Smith Thomas B.
Published: January 2020

The identification of Lancefield group B streptococci with immunofluorescence was studied after significant differences between the precipitin and immunofluorescent results were noted. It was found that strains of group B streptococci, unlike groups A, C, and G streptococci, do not reliably react with a fluorescein isothiocyanate-labeled conjugate that contains antibodies mainly against C polysaccharide. It was assumed that the difficulty probably resulted from a blocking of the antigen-antibody reaction between the group antigen and its antibody by the S antigen located in the capsule. On the basis of this assumption, a conjugate was prepared that contained antibodies against the various S antigens of group B and it was found to be effective.
In Vitro Induction of Nonspecific Resistance in Macrophages by Specifically Sensitized Lymphocytes
Authors: Krahenbuhl James L. , Remington Jack S.
Published: January 2020

Experiments were carried out to determine whether macrophages can be activated in vitro to resist challenge with heterologous microorganisms. Sensitized spleen cells from guinea pigs chronically infected with
Toxoplasma gondii
were cultured with normal guinea pig peritoneal macrophages in the presence and absence of
Toxoplasma
antigen. Macrophage monolayers incubated with sensitized spleen cells and antigen were markedly resistant to challenge from
Listeria monocytogenes
. Resistance was manifested by prolonged survival of the monolayers and rapid intracellular killing of the bacteria. Macrophages incubated with sensitized spleen cells but in the absence of antigen, as well as macrophages cultured with normal spleen cells, in the presence or absence of antigen, were rapidly destroyed. Sensitized spleen cells responded to the presence of
Toxoplasma
antigen by increased uptake of tritium-labeled thymidine. Supernatant fluid medium obtained from cultures of macrophages, sensitized spleen cells, and antigen contained a macrophage migration inhibitory factor(s). In addition, these supernatant fluids were capable of inducing increased resistance to
Listeria
in normal macrophages.
Chronic Proliferative Arthritis of Mice Induced by
Mycoplasma arthritidis
I. Induction of Disease and Histopathological Characteristics
Authors: Cole B. C. , Ward J. R. , Jones R. S. , Cahill J. F.
Published: January 2020

Mice injected intravenously with
Mycoplasma arthritidis
developed a chronic arthritis which persisted through at least 269 days. Rats similarly treated developed an acute short-term infection. The mouse disease was characterized by periods of remission and exacerbation and was proliferative in nature, gradually spreading to adjacent joints.
M. arthritidis
strain 158 P10 was found to be less arthritogenic for mice than for rats, but further passage of this strain in mice substantially increased its virulence. Unlike rats, mice appeared to be susceptible to a “toxin” of
M. arthritidis
and they developed a necrotic spreading abscess after subcutaneous administration of the organisms. Histopathological studies revealed that mice varied greatly in the degree of joint inflammation, destruction, and repair. The disease was characterized by (i) an initial acute phase with infiltration of the articular and periarticular tissues with polymorphonuclear leukocytes and a mild hyperplasia of the synovial membrane; (ii) a mixed acute-chronic phase in which new areas of acute inflammation developed alongside areas of chronic lesions; (iii) a chronic phase followed which was characterized by massive synovial proliferation with mononuclear cell infiltration, irregularity in the articulating cartilage, pannus formation, and “punched out” defects in cortical bone near cartilagenous osseous junctures. The clinical course and histopathological characteristics of the chronic phase of mouse arthritis induced by
M. arthritidis
closely resembled those of rheumatoid arthritis of man.
Contribution of Humoral and Cellular Factors to the Resistance to Experimental Infection by
Pseudomonas aeruginosa
in Mice I. Interaction Between Immunoglobulins, Heat-Labile Serum Factors, and Phagocytic Cells in the Killing of Bacteria
Authors: Bjornson Ann B. , Michael J. Gabriel
Published: January 2020

Techniques have been described for the purification of mouse polymorphonuclear leukocytes (PMN) and macrophages and for determining their bactericidal activity against
Pseudomonas aeruginosa
in a rotating suspension. Requirements for human anti-
Pseudomonas
opsonins and heat-labile mouse serum factors have been determined. In the macrophage system, although heat-labile mouse serum factors had enhancing properties, both immunoglobulin G (IgG) and immunoglobulin M (IgM) opsonins alone sufficed to induce bactericidal activity. In contrast, both opsonins and heat-labile mouse serum factors were required for bactericidal activity by the mouse PMN. In the absence of heat-labile mouse serum factors, IgG and IgM opsonins contributed to the bactericidal activity of mouse macrophages to the same extent. However, in the presence of these factors, much less IgG than IgM antibody was required to achieve maximum bactericidal activity by these cells. Similarly, IgG opsonins were found to be more efficient than IgM opsonins in enhancing the killing of
P. aeruginosa
by mouse PMN.
Migration Inhibition of Mouse Macrophages by
Brucella
Antigens
Authors: Sandok Paul L. , Hinsdill Ronald D. , Albrecht Ralph M.
Published: January 2020

Mice are suitable donors of peritoneal macrophages for the capillary migration inhibition test, provided a period of preincubation with antigen is used
Correlation of Immunological Responsiveness with Lymphocyte Changes in Chickens Infected with Marek's Disease
Authors: Evans Donald L. , Patterson Loyd T.
Published: January 2020

Several immunological, hematological, and pathological responses associated with Marek's disease were determined. Four-week-old Marek's disease-infected and control chickens were injected with
Salmonella pullorum
antigen. About one-half of all infected chickens tested were unresponsive to antigenic challenge. Antibody titers in responsive infected chickens were significantly depressed at 1 and 2 weeks post-inoculation when compared to controls. Total white blood cell counts of control and control-antigen chickens were significantly lower than counts in infected chickens. Based on response to antigenic challenge, 24% of the responsive group had leukemia compared to 54% of the unresponsive chickens. The predominant cell populations in these two groups responsible for the mononuclear cell leukemia were large lymphocytes and blast cells. These cell increases were significantly greater in unresponsive chickens. Also, transient increases in the granulocytic elements were observed in some infected chickens. Large fluctuations in hematocrit values were observed in Marek's disease-infected chickens. As many as 30% of the infected chickens were anemic throughout the testing periods. Infected chickens which did not receive antigen had lower incidences of mortality and gross lesions than similarly treated chickens which did receive antigen. In addition, those chickens which were unresponsive to antigenic challenge had a higher mortality rate and increased percentages of gross lesions when compared with responsive chickens.
Cell-Free Passive Transfer of Delayed Hypersensitivity to Chemicals in Guinea Pigs
Authors: Burger Denis R. , Jeter Wayburn S.
Published: January 2020

Delayed-type cutaneous reactivity to 2,4-dinitrochlorobenzene and 2,4-dinitrofluorobenzene in guinea pigs was transferred passively by fluids in which leukocytes from sensitive animals were incubated. Cells from peritoneal exudates, lymph nodes, and alveolar washings were employed. The cell-free transfer material was dialyzable, of small molecular size, and stable to 56 C for 30 min and −65 C for at least 9 weeks. It gave a ratio at 280 to 260 nm of 0.71. The relationships between temperature,
p
H, and cellular release of the transfer material were studied.
Lymphocyte-Mediated Cellular Immunity in Histoplasmosis
Authors: Howard D. H. , Otto V. , Gupta R. K.
Published: January 2020

Mononuclear phagocytes freshly harvested from immunized animals restrict the intracellular growth of
Histoplasma capsulatum
, whereas the same cells maintained in culture for 48 hr do not. Experiments established that within the mixed cell population of the mouse peritoneal cavity the lymphocyte was the most likely mediator of the intracellular growth restriction observed. Partially purified lymphocytes, from the peritoneal cavity of mice immunized by sublethal infection, mediated the suppression of intracellular growth of the fungus in normal mouse macrophages in cell culture.
ADP-like platelet aggregation activity generated by viridans streptococci incubated with exogenous ATP
Authors: Herzberg M C , Brintzenhofe K L
Published: January 2020

To explore the possibility that Streptococcus sanguis aggregation of platelet-rich plasma (PRP) might be mediated by soluble agents, we tested cell-free S. sanguis supernatant for aggregation activity. The supernatant of untreated S. sanguis was without measurable PRP aggregation activity. In contrast, the cell-free supernatant of ATP-incubated S. sanguis produced an immediate wave of PRP aggregation. The supernatant with PRP aggregating activity contained insufficient protease to produce a response. The response increased with the time of incubation with ATP. Active supernatant was desalted and chromatographed on nucleotide-calibrated columns of Dowex 1-X8. An active ADP function was identified. The activity was insensitive to dicyclohexylcarbodiimide, but was sensitive to both Ca2+ and Ca2+-Mg2+ chelating agents, cold (4 degrees C), heat (80 degrees C), pH (optimum between pH 7 and 8), apyrase, and sodium molybdate. In addition, preincubation of PRP with adenosine inhibited activity. Strains of viridans streptococci were screened for activity. Aggregation-promoting strains showed two times more activity than did other strains. Although it was not vigorously excluded that the ADP was discharged from the microbes, the existence of an exogenous ATPase on S. sanguis was strongly suggested. The expression of the activity was associated with the lag time to onset of PRP aggregation with intact S. sanguis. This activity could, therefore, be a synergistic promoter of PRP aggregation and an additional virulence factor in endocarditis.
Preparation and physicochemical and immunological characterization of polysaccharide-outer membrane protein complexes of Neisseria meningitidis
Authors: Beuvery E C , Miedema F , van Delft R W , Haverkamp J , Leussink A B , te Pas B J , Teppema K S , Tiesjema R H
Published: January 2020

A crude complex containing group C polysaccharide, outer membrane proteins, and lipopolysaccharide (LPS) was isolated from the cell-free culture liquid of Neisseria meningitidis serogroup C, serotype 2a. Group C polysaccharide and LPS were removed from this complex, resulting in an outer membrane complex and a purified complex, respectively. Analysis by electron microscopy showed the outer membrane origin of the crude complex and the outer membrane complex, whereas such a structure was absent in the purified complex. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis patterns of the three complexes were identical. Pyrolysis-mass spectrometry data correlated well with those obtained by the biochemical assays and suggested a low LPS content in the purified complex and a low polysaccharide content in the outer membrane complex. The purified complex was shown to be nonpyrogenic and could be prepared with the same yield as that of purified polysaccharide. The immunogenic activities of the complexes were studied in mice. The antibodies were measured by the enzyme-linked immunosorbent assay; and the bactericidal antibody assay. All complexes induced immunoglobulin G antibodies to group C polysaccharide as well as to the serotype antigen, although the removal of polysaccharide and LPS resulted in a reduction of the immunogenic activities of outer membrane complex and purified complex, respectively. A second dose of all complexes produced a clear booster effect of both antibody responses. The antibodies were bactericidal.
Immunogenicity of meningococcal antigens as detected in patient sera
Authors: Poolman J T , Hopman C T , Zanen H C
Published: January 2020

The immunogenicity of meningococcal surface antigens was tested in acute- and convalescent-phase sera from patients with meningococcal diseases by enzyme-linked immunosorbent assay and gel immunoradioassay. In gel immunoradioassay, the antigens are separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis before testing their antibody-binding capacity. Both 125I-labeled protein A and 125I-labeled anti-human immunoglobulin G were used to detect antibody binding. It appeared that the variable, low-molecular-weight, heat-modifiable major outer membrane proteins (molecular weights, 25,000 to 32,000) induced strong, strain-specific immunoglobulin G antibody responses. In addition, pili induced strong, cross-reactive antibody responses that could be detected with 125I-labeled protein A, but not with 125I-labeled anti-immunoglobulin G. Antibody responses against capsular polysaccharides, lipopolysaccharides, and minor outer membrane proteins could also be detected by gel immunoradioassay. When tested by enzyme-linked immunosorbent assay against outer membrane complexes, patient sera demonstrated a large amount of cross-reactivity against heterologous meningococcal strains.