bluuebunny/crossref_metadata_2025 huggingface dataset:
Identification of Mycoplasma pneumoniae proteins associated with hemadsorption and virulence
Authors: Krause D C , Leith D K , Wilson R M , Baseman J B
Published: January 2020

Twenty-two mutants of Mycoplasma pneumoniae spontaneously deficient in hemadsorption were isolated. Examination of mutant protein profiles by one- and two-dimensional polyacrylamide gel electrophoresis permitted the grouping of these mutants into four classes. The largest class of mutants was deficient in four high-molecular-weight proteins (215,000, 210,000, 190,000, and 140,000). A second class of mutants lacked three proteins previously designated A, B, and C (72,000, 85,000, and 37,000, respectively). A single mutant, in addition to lacking proteins A, B, and C, was missing a fourth protein of 165,000 molecular weight. The remaining mutants exhibited protein profiles apparently identical to that of the wild-type strain. All mutant strains attached to the respiratory epithelium of hamster tracheal rings in vitro at reduced levels; however, mutants lacking proteins A, B, and C recognized only neuraminidase-insensitive receptors. None of the mutants tested produced detectable pneumonia in intranasally inoculated hamsters, although one mutant class demonstrated low-level survival in vivo.
Purification and certain properties of a bacteriocin from Streptococcus mutans
Authors: Ikeda T , Iwanami T , Hirasawa M , Watanabe C , McGhee J R , Shiota T
Published: January 2020

An inhibition factor from Streptococcus mutans strain C3603 (serotype c) was purified and isolated, and its properties indicated that it was a bacteriocin. Bacteriocin C3603 is a basic protein with a pI value of 10 and a molecular weight of 4,800. The activity of this bacteriocin was not affected by pH over a range of 1.0 to 12.0 or by storage at 100 degrees C for 10 min at pH 2.0 to 7.0 or storage at 121 degrees C for 15 min at pH 4.0. Pronase; papain, phospholipase C, trypsin, and alpha-amylase had no effect on the activity of the bacteriocin, whereas alpha-chymotrypsin and pancreatin were partially active against it. Bacteriocin activity was greater against certain S. mutans strains of serotypes b, c, e, and f than against certain S. mutans strains of serotypes a, d, and g. Bacteriocin C3603 was also effective against selected strains of S. sanguis, S. salivarius, S. bovis, S. faecium, S. lactis, Lactobacillus casei, L. plantarum, L. fermentum, Bifidobacterium bifidum, Bifidobacterium longum, Propionibacterium acnes, and Bacteroides melaninogenicus, but it was not effective against certain strains of Escherichia coli, Klebsiella pneumoniae, Corynebacterium parvum, and Candida albicans. The inhibition of S. mutans strains BHT and PS-14 by bacteriocin C3603 was found to be due to the bacteriocidal activity of the bacteriocin. When water or a diet containing bacteriocin C3603 was consumed by gnotobiotic and specific pathogen-free rats infected with S. mutans PS-14, the caries score was found to be significantly reduced.
Isoelectric points and surface hydrophobicity of Gram-positive cocci as determined by cross-partition and hydrophobic affinity partition in aqueous two-phase systems
Authors: Miörner H , Albertsson P A , Kronvall G
Published: January 2020

Thirty-nine streptococcal strains belonging to groups A, C, and G and 12 staphylococcal strains were investigated with respect to surface charge and hydrophobicity. Isoelectric points of the bacteria were determined by cross-partition experiments in dextran-polyethylene glycol two-phase systems containing charged polymers. The results obtained indicate that group A, C, and G streptococci have isoelectric points of pH 3.75 +/- 0.15 standard deviation. Staphylococci show an isoelectric point of around pH 2 and thereby differ markedly from the streptococci. Pretreatment of bacteria with human serum resulted in a significant change in the isoelectric points of streptococci. In a second series of experiments, an aqueous dextran-polyethylene glycol two-phase system containing polyethylene glycol palmitate or stearate was used to study the hydrophobic surface properties of the bacterial cells. The partition of the staphylococci was not influenced by the addition of up to 1% (wt/wt) polyethylene glycol palmitate or stearate, whereas the streptococci showed a large variation in affinity for polyethylene glycol-bound hydrophobic groups. The bacterial strains included in the study were also tested for uptake of human serum proteins. A positive correlation was found between the hydrophobic affinity of group A streptococci and the density of receptors for aggregated beta-2-microglobulin.
Purification and partial characterization of the major outer membrane protein of Neisseria gonorrhoeae
Authors: Blake M S , Gotschlich E C
Published: January 2020

A procedure is described to isolate the major outer membrane protein (protein I) from Neisseria gonorrhoeae in large quantities. The method involves precipitation of protein I by hexadecyltrimethylammonium bromide (CTB) at low ionic strength. CTB is lethal for the gonococci and solubilizes most other proteins. Protein I is brought into solution by raising the ionic strength, and the nucleic acids are subsequently removed by 20% ethanol precipitation. The CTB is removed by precipitating protein I with ethanol and replaced by N-tetradecyl-N,N-dimethyl-3-ammonia-1-propanesulfonate, a dipolar ionic detergent. Further purification is accomplished by ion-exchange and molecular sieve chromatography. Two species of protein I (34,000 daltons [34K] and 32K) were purified by these methods. The purified proteins reacted with antisera prepared against the homologous organisms. The 34K proteins I generated proteolytic fragments upon treatment with trypsin and chymotrypsin similar to those generated by 34K protein in intact gonococci. The amino acid compositions of the three proteins were much like those of other major proteins of gram-negative organisms.
Oral implantation of Bacteroides asaccharolyticus and Eikenella corrodens in conventional hamsters
Authors: Nagahata T , Kiyoshige T , Tomono S , Abe R , Sasaki S , Takazoe I
Published: January 2020

Oral implantation of Bacteroides asaccharolyticus 381-R' and Eikenella corrodens 1073S-R, which are highly resistant to streptomycin, was examined in conventional hamsters. The hamsters' first molars were ligatured with cotton threads preimmersed in bacterial suspensions. Bacterial inoculation was performed daily for 1 week, followed by a single weekly inoculation for 7 more weeks. Hamsters were fed Keyes' diet no. 2000 or ordinary powdered diet. Bacterial recovery, gingival histological changes, and immunological response were checked 2, 5, and 8 weeks after the daily serial inoculation. B. asaccharolyticus 381-R' was recovered from all hamsters during the experiment (6.7 X 10(6) to 6.3 X 10(8) colony-forming units). E. corrodens 10735-R was recovered from the hamsters fed Keyes' diet no. 2000 throughout the experimental period (2.4 X 10(5) to 1.2 X 10(6) colony-forming units), but not in the group fed the ordinary powdered diet. The histological changes in gingival tissues at the second week showed no differences among the control group, the B. asaccharolyticus-inoculated group, and the E. corrodens-inoculated group. However, by the eighth week, the inflammation persisted only in the bacteria-inoculated groups, especially in the B. asaccharolyticus-inoculated group. A relatively increased serum antibody titer was also observed in the B. asaccharolyticus-inoculated group, but not in the E. corrodens-inoculated group. These findings indicate that B. asaccharolyticus 381-R' and E. corrodens 1073S-R can be implanted in hamsters' oral cavity with the aid of cotton thread ligature. It was also suggested that B. asaccharolyticus may have some pathogenic role in the destruction of periodontal tissue in hamsters.
Antigenic changes during intracellular differentiation of Leishmania mexicana in cultured macrophages
Authors: Chang K P , Fong D
Published: January 2020

Antigenic changes during the intracellular transformation of Leishmania mexicana subsp. amazonensis from promastigotes to amastigotes in macrophages of J774G8 line were noted mostly among protein bands of 24 to 68 kilodaltons in apparent molecular weight. In this region, six were identified as common antigens of both stages, six to seven were identified as promastigote specific, and three to five were identified as amastigote specific. At the higher-molecular-weight region (greater than 68 kilodalton) were two bands, one being predominant in amastigotes and the other in promastigotes. There may be a transformation-specific band (apparent molecular weight = 20 kilodaltons). The transition of these stage-specific antigens varies considerably with different protein species and may play important roles in intracellular leishmanial differentiation.
In vitro cultivation of Treponema pallidum: independent confirmation
Authors: Norris S J
Published: January 2020

In vitro cultivation of the virulent Nichols strain of Treponema pallidum was achieved in a tissue culture system as described by A. H. Fieldsteel, D. L. Cox, and R. A. Moeckli (Infect. Immun. 32:908-915, 1981). In 7 of 8 experiments, 8.9- to 26.2-fold increases in the number of T. pallidum were observed over a 12- to 12-day period of incubation.
Murine cytomegalovirus-induced immunosuppression
Authors: Loh L , Hudson J B
Published: January 2020

The mechanism of murine cytomegalovirus-induced immunosuppression was investigated by examining the roles played by lymphocytes and adherent cells derived from spleens of infected SWR/J mice. As few as 100 infected cells per spleen were correlated with complete abrogation of mitogen responses at 4 and 5 days after infection. In a series of cell mixing experiments it was shown that the deficiency in infected spleens was due partly to the adherent cells, which apparently secreted an immunosuppressive factor, and partly to the infected lymphocytes, which upon exposure to this factor could no longer respond to concanavalin A presented to them by normal adherent cells.
High correlation of the presence of methyladenine in Neisseria gonorrhoeae DNA with the AHU auxotype
Authors: Kolodkin A B , Clark V L , Tenover F C , Young F E
Published: January 2020

Strains of Neisseria gonorrhoeae were tested for the presence of methyladenine in the DNA sequence GATC by using the site-specific restriction endonucleases MboI and DpnI. It was found that 43 of 83 strains tested contained methylated DNA. When methylation was compared with the auxotype of the organism, 35 of 35 strains with the AHU (arginine-, hypoxanthine-, and uracil-requiring) auxotype and 8 of 48 strains with other auxotypes contained methyladenine. When the incidence of methylation in strains isolated from patients suffering from disseminated gonococcal infection was compared with that in strains isolated from patients suffering from uncomplicated gonococcal infection, no correlation with methylation and disseminated gonococcal infection was observed.
Kinetics of immunoglobulin M and G responses of nude and normal mice to Trypanosoma musculi
Authors: Brooks B O , Wassom D L , Cypess R H
Published: January 2020

A sensitive and specific enzyme-linked immunosorbent assay was designed to measure the kinetics of Trypanosoma musculi-specific immunoglobulin M (IgM) and IgG responses in mice. Serum was obtained from congenitally athymic (nude) mice, their phenotypically normal, thymus-bearing littermates (NLM), and thymus cell-repaired nude mice (Nu-TC) at 6-day intervals throughout T. musculi parasitemia. NLM mice were shown to effect an antibody response to T. musculi that included an IgM to IgG shift and was correlated in time with reduction of parasite reproduction and stabilization of parasitemia. Nude mice were shown to effect a T. musculi-specific IgM response similar in onset and magnitude to that in NLM mice; this response was correlated in time with stabilization of parasitemia. Nu-TC mice were shown to effect IgM and IgG responses to T. musculi similar in time and magnitude to those in NLM mice. In marked contrast to NLM mice, Nu-TC mice did not exhibit suppression of T. musculi-specific IgM production after the IgM to IgG shift in response to this parasite.
Macrophage antiviral activity: extrinsic versus intrinsic activity
Authors: Stohlman S A , Woodward J G , Frelinger J A
Published: January 2020

Peritoneal exudate cells from strains of mice both resistant and susceptible to challenge with mouse hepatitis virus strain JHM were examined for extrinsic and intrinsic antiviral activity. Thioglycolate-elicited and resident peritoneal cells from uninfected mice were able to suppress viral growth in a permissive cell. The active cell in both populations is an adherent, radiation-resistant, Thy-1.2 antigen- and Ia antigen-negative cell. The suppression of virus replication was not related to nonspecific cellular cytotoxicity directed against the permissive host cell, and no interferon was detected. The expression of extrinsic antiviral activity was not related to the ability of the host to resist mouse hepatitis virus infection by virtue of either age or genetic background. The expression of intrinsic antiviral activity, on the other hand, correlated with the ability of the host to resist virus challenge, indicating a characteristic distinction between these two in vitro mechanisms of macrophage-mediated antiviral activity with regard to host resistance to viral infection. Further, the ability of a macrophage to support viral replication itself was independent of the ability of the macrophage to suppress virus growth in another cell.
Activity of rabbit monocytes, macrophages, and neutrophils in antibody-dependent cellular cytotoxicity of herpes simplex virus-infected corneal cells
Authors: Smith J W , Sheppard A M
Published: January 2020

Rabbit phagocytes were examined for their ability to kill target cells infected with herpes simplex virus by antibody-dependent cellular cytotoxicity. Two sources of rabbit corneal cells were used as targets: Staaten Seruminstitut Rabbit Cornea (a continuous cell line) and stromal keratocytes from the middle layer of corneas excised from New Zealand white rabbits. Peritoneal exudate and alveolar macrophages were found to be the most active effector cells, followed by blood neutrophils and monocytes. Peritoneal exudate and alveolar macrophages killed target cells with dilutions of antibody as high as 1:10,000. Monocyte antibody-dependent cellular cytotoxicity activity was absent in over one-third of the rabbits tested and was only weakly active in positive rabbits. In vitro aging of monocytes did not enhance activity. Antibody reactive with peritoneal exudate macrophages, alveolar macrophages, and blood neutrophil effector cells appeared 7 days after intracorneal injection of infectious herpes simplex virus. Results of these studies show that in vitro assays with a complete rabbit system (effectors cells, antibody, and target cells) can be developed to monitor herpetic disease and suggest an active role for rabbit phagocytes in cytotoxicity of herpes simplex virus-infected cells.
Detection, isolation, and analysis of a released Bordetella pertussis product toxic to cultured tracheal cells
Authors: Goldman W E , Klapper D G , Baseman J B
Published: January 2020

Cultured hamster trachea epithelial cells were selected as an in vitro model system to study Bordetella pertussis in the respiratory tract. DNA synthesis by serum-stimulated tracheal cells, in contrast to other cell types tested, was inhibited by the supernatant from log-phase B. pertussis broth cultures. A sensitive microassay with these tracheal cells permitted the development of a chromatographic purification scheme based on aggregation of the biological activity under salt-free conditions. The active fraction from this first stage of purification caused a dose-dependent inhibition of DNA synthesis without a similar effect on RNA or protein synthesis. Organ cultures of hamster tracheal rings, when exposed to this partially purified fraction, developed epithelial cytopathology comparable to that seen during B. pertussis infection. Ciliary activity showed and eventually ceased as ciliated cells were extruded from the ring, leaving an intact but mostly nonciliated epithelium. Further purification of this biological activity was achieved with preparative-scale high-voltage paper electrophoresis. Based on ninhydrin staining and the radioactive profile of material purified from radiolabeled B. pertussis cultures, four fractions were eluted from the paper by descending chromatography. Only component B caused a dose-dependent inhibition of cultured tracheal cell DNA synthesis and epithelial cytopathology in tracheal rings. Combination experiments also demonstrated enhanced inhibition by component B in the presence of component G (oxidized glutathione), a copurifying molecule from the growth medium. Amino acid analysis (five residues), glycine (two residues), cysteine (two residues), and diaminopimelic acid (one residue), as well as muramic acid and glucosamine.
Effects of the two toxins of Clostridium difficile in antibiotic-associated cecitis in hamsters
Authors: Libby J M , Jortner B S , Wilkins T D
Published: January 2020

Hamsters were vaccinated with toxoids containing toxin A, toxin B, both toxins, or a preparation containing neither toxin of Clostridium difficile, the causative agent of antibiotic-associated cecitis in hamsters and pseudomembranous colitis in humans. To determine whether these vaccines would reduce the severity of antibiotic-associated cecitis, the hamsters were injected subcutaneously with clindamycin. Nearly all of the hamsters protected against neither toxin or only one toxin died. These animals developed enlarged hemorrhagic ceca and diarrhea, although the ceca from the animals immunized against toxin B were less hemorrhagic. The hamsters immunized against both toxins survived clindamycin treatment and had ceca of normal size and appearance. Concentrations of both toxins were lower in the ceca of the latter animals than in the unprotected animals. To determine the effects of either toxin alone on the animals, nonimmunized hamsters were injected with either purified toxin A, which produced enlarged ceca with moderate hemorrhaging, or partially purified toxin B, which produced hemorrhagic ceca of normal size. All of the hamsters injected with either toxin at concentrations found in the ceca after clindamycin treatment died. These results suggest that toxin A causes the water influx, that both toxins cause hemorrhaging to different extents in the ceca of hamsters with antibiotic-associated cecitis and that either toxin alone can cause death. These studies may help explain the etiology of pseudomembranous colitis in humans.
Production of lipoteichoic acid by lactobacilli and streptococci grown in different environments
Authors: Wicken A J , Broady K W , Ayres A , Knox K W
Published: January 2020

Representative strains of Streptococcus sanguis serotype 2 and of four Lactobacillus species were examined for the production of cellular and extracellular lipoteichoic acid (LTA) when grown at pH 6.0 in batch culture to the stationary phase with either glucose or fructose. Extracellular LTA was a minor component in all cases except for L. fermentum and L. casei NIRD R094 grown in fructose. The total amount of LTA (cellular and extracellular) produced by fructose-grown cultures was also considerably greater for these two strains, for L. salivarius, and also two of the S. sanguis strains. Growth of L. fermentum and L. casei in continuous culture in a chemostat showed that generation time and pH of growth can influence the total amount of LTA and the proportion of extracellular material. The results for glucose-limited cultures were quite disparate, with L. fermentum forming considerably more extracellular LTA than L. casei. However, in fructose-limited cultures L. fermentum formed less total LTA and L. casei more so that the differences were only minor. A difference in the utilization of glucose and fructose by the heterofermentative L. fermentum and the homofermentative L. casei strains is also indicated by differences in the yield of organisms at different dilution rates in continuous culture.
Association of adhesive, invasive, and virulent phenotypes of Salmonella typhimurium with autonomous 60-megadalton plasmids
Authors: Jones G W , Rabert D K , Svinarich D M , Whitfield H J
Published: January 2020

The plasmid DNA content of six invasive and adhesive strains of Salmonella typhimurium was determined, and all six strains (CR8500 [S850], CR6600 [TML], W118, NY, PR, and S2204) were found to harbor at least one plasmid equivalent in size to the 60-megadalton plasmid ("cryptic" plasmid), pSLT, which is normally resident in S. typhimurium strain LT2. The role of such 60-megadalton plasmids in the adhesive and invasive properties of strain CR6600, a commonly encountered salmonella pathogen that produces type 1 fimbriae, and strain CR8500, a representative FIRN biotype which does not produce type 1 fimbriae, was studied further by obtaining derivatives of these strains that no longer harbored an autonomous 60-megadalton plasmid. Strains CR6260 and CR6190 and strains CR8100 and CR8353, which were "cured" derivatives of strains CR6600 and CR8500, respectively, were significantly less adhesive and invasive in the HeLa cell test. A 53.5-megadalton colicin plasmid harbored by strain CR6600 did not detectably influence these properties. Additionally, strain CR6260 was avirulent, and strain CR8100 was 1,000 to 10,000-fold less virulent for orally infected mice as compared with their respective parental strains. Significantly, the virulence of strain CR8100 correlated with tissue colonization by bacteria that exhibited autonomous copies of a 60-megadalton plasmid. We propose that this plasmid exists in both autonomous and integrated states and that the in vivo environment selects for bacteria with autonomous plasmid copies which can express the virulent phenotype, thus enabling such strains to survive the defense mechanisms of the host.
Increased severity of urinary tract infection and bacteremia in mice with urinary bladder injury induced by cyclophosphamide
Authors: Lyon D , Howard E B , Montgomerie J Z
Published: January 2020

The effect of cyclophosphamide on urinary tract infection was studied, using Pseudomonas aeruginosa in a murine model. Urinary tract infections were produced by injecting P. aeruginosa through a urethral catheter into the bladders of mice. The number of P. aeruginosa organisms in the bladder tissue and kidneys, histopathology, peripheral leukocyte count, and antibody response to P. aeruginosa was measured. The local effect of cyclophosphamide on the bladder was determined by measuring the bladder tissue water and examining the histopathology. Cyclophosphamide increased the susceptibility of mice to P. aeruginosa urinary tract infection, resulting in marked cystitis and an increase in renal infection, bacteremia, and mortality. These changes correlated with the toxic effect of cyclophosphamide on the wall of the bladder rather than with peripheral leukopenia or failure of antibody response.
Propagation and primary isolation of papovavirus JC in epithelial cells derived from human urine
Authors: Beckmann A M , Shah K V , Padgett B L
Published: January 2020

Human papovavirus JC, previously passaged in amnion cells or in primary human fetal glial cells, replicated efficiently in urine-derived epithelial cells. Primary isolation of the virus from brain extracts was possible in urine-derived cells, but these cells were not as sensitive as primary human fetal glial cells for this purpose. Primary isolations of human papovavirus JC from urine sediments of renal transplant patients were made in urine-derived cells.
Mapping of a gene in Vibrio cholerae that determines the antigenic structure of cholera toxin
Authors: Saunders D W , Schanbacher K J , Bramucci M G
Published: January 2020

In Ouchterlony-type immunodiffusion gels, the cholera toxin produced by the classical Vibrio cholerae strain 569B was indistinguishable from the cholera toxin of the Eltor strain RJ1. However, the cholera toxin produced by both of these strains was incompletely cross-reactive with the cholera toxin produced by the Eltor strain 3083-2. The allele of the gene responsible for the 569B and RJ1 type of toxin was designated vct-1, and the allele responsible for the 3083-2 type of toxin was designated vct-2. The vct-1 allele was transferred from RJ1 donors to 3083-2 recipients by conjugation. The vct locus was found to be between met and trp on the V. cholerae linkage map.
Loss of virulence associated with absence of flagellum in an isogenic mutant of Pseudomonas aeruginosa in the burned-mouse model
Authors: Montie T C , Doyle-Huntzinger D , Craven R C , Holder I A
Published: January 2020

To test the importance of flagella as a virulence factor, virulent strain Pseudomonas aeruginosa M-2 was mutagenized, and a Fla mutant was isolated. An M-2 Fla spontaneous motile revertant was isolated from M-2 Fla. The three strains were biochemically and morphologically identical. Assay of Fla in the burned-mouse model showed a severe loss of virulence. The Fla revertant was fully virulent. The importance of P. aeruginosa motility (flagella) for virulence in burns infections is indicated.
Regulatory effect of monocytes on T cell proliferative responses to oral microbial antigens
Authors: Stashenko P
Published: January 2020

Mononuclear cell preparations isolated by Ficoll-Hypaque centrifugation from human peripheral blood were found to vary considerably in the number of monocytes they contained (mean, 20.3%; range, 13 to 33%). The regulatory role of monocytes in T cell proliferative responses to sonic extracts of a panel of oral microorganisms was therefore investigated. T cells were fractionated by anti-immunoglobulin chromatography and depleted of monocytes by treatment with a monoclonal anti-human Ia-like (DR locus antigen) antibody and complement. Purified populations of monocytes were obtained by extensive adherence procedures. The resultant cell populations were greater than 95% pure, as judged by indirect immunofluorescence on a fluorescence-activated cell sorter. Monocyte-depleted T cells failed to respond by proliferation to the nonoral antigen tetanus toxoid, as well as to any oral microorganism, but retained responsiveness to phytohemagglutinin. Readdition of monocytes in final concentrations of from 5 to 15% resulted in the restoration of maximal T cell proliferation. Monocytes in greater numbers suppressed T cell responses to all sonic extracts tested.
Effect of exogenous nucleotides on Ca2+ dependence and V antigen synthesis in Yersinia pestis
Authors: Zahorchak R J , Brubaker R R
Published: January 2020

Cells of Yersinia pestis strain EV76 are known to cease growth after a shift from 26 to 37 degrees C in neutral Ca2+-deficient medium; this effect is potentiated by Mg2+. With 2.5 mM Mg2+ and no added Ca2+, restriction was relaxed at elevated pH at which maximum cell yields occurred in the presence of 20 mM exogenous ATP. This ATP-dependent growth was inhibited by Ca2+ or 20 mM Mg2+; the nucleotide was neither transported into the organism nor hydrolyzed extracellularly. With strain EV76, ATP could be replaced by GTP but not other nucleotides, nucleosides, free bases, or pyrophosphate. CTP and UTP also promoted growth of strain KIM, in which limited division also occurred with nucleoside di- and monophosphates. Intracellular V antigen was detected 1 h after temperature shift in Ca2+-deficient medium containing 20 mM Mg2+, a time corresponding to the earliest known events associated with restriction (shutoff of stable RNA synthesis and reduction of adenylate energy charge). Maximum yield of V was obtained 2 h later when cell division ceased; the titer of the antigen remained constant thereafter. The specific activity of V in cells grown with ATP was significantly reduced, especially at elevated pH. These results would be expected if exogenous nucleotides promote growth by sequestering sufficient Mg2+ to prevent restriction of cell division mediated by V antigen.
Purification and quantitative chemical analysis of cell wall peptidoglycans of Leptotrichia buccalis
Authors: Fukuhara H , Umemoto T , Sagawa H , Kato K , Kotani S
Published: January 2020

Peptidoglycans of Leptotrichia buccalis ATCC 14201 and ATCC 19616 were isolated by extraction with sodium dodecyl sulfate and subsequent digestion of the sodium dodecyl sulfate-insoluble residue with proteases and alpha-amylase. Cell wall fractions obtained by sodium dodecyl sulfate extraction and protease digestion were highly contaminated by a glucose polymer. The polyglucose was removed by alpha-amylase treatment, and the peptidoglycans were left behind. Analyses with amino acids and amino sugars of the cell wall fractions and peptidoglycan specimens revealed that D-glutamic acid, D-alanine, L-alanine, meso-2,6-diaminopimelic acid (A2pm), muramic acid, and glucosamine were the principal components. The dinitrophenylation method revealed that about half of the A2pm residue had a free amino group, and analysis by hydrazinolysis showed that a small part of alanine and A2pm was located at the C terminal. The above results indicate that one of the amino groups of the A2pm residue at one strand of the stem peptide subunit cross-linked to the carboxyl group of alanine of the neighboring strand. It was thus revealed that the peptidoglycans of L. buccalis belong to the A1 gamma type of the classification by Schleifer and Kandler (Bacteriol. Rev. 36:407-477).
Adherence of group A streptococci to fibronectin on oral epithelial cells
Authors: Simpson W A , Beachey E H
Published: January 2020

The possibility that fibronectin on the surface of oropharyngeal cells may serve as a receptor for the binding of group A streptococci (Streptococcus pyogenes) was investigated. Purified human plasma fibronectin inhibited the adherence of group A streptococci to oral epithelial cells in a dose-dependent manner. The relative amounts of fibronectin available on oral epithelial cells correlated closely with the ability of these cells to bind streptococci. Group A streptococci agglutinated latex beads containing covalently linked fibronectin on their surface, and this agglutination could be inhibited by lipoteichoic acid, the adhesion that mediates attachment of group A streptococci to epithelial cells. Gelatin and the alpha 1 chain of type I collagen partially inhibited both the adherence of streptococci to oral epithelial cells and the binding of radiolabeled fibronectin to streptococci; however, the purified fibronectin-binding peptide of collagen, alpha 1 (I)CB7, inhibited neither. The binding of radiolabeled fibronectin to streptococci was inhibited by lipoteichoic acid. These results suggest that fibronectin on oral epithelial cells serves as a lipoteichoic acid-sensitive receptor for group A streptococci.
Toxicity of staphylococcal alpha toxin for rabbit alveolar macrophages
Authors: McGee M P , Kreger A , Leake E S , Harshman S
Published: January 2020

Highly purified staphylococcal alpha toxin was toxic in vitro for rabbit alveolar macrophages. Cytotoxicity, manifested by loss of the ability to exclude trypan blue dye and by morphological evidence of cell necrosis and lysis, was observed after exposure for 4 h to 1 microgram of toxin preparation per ml and after exposure for 8 h to 0.1 microgram of toxin per ml. In addition, exposure to toxin under conditions which did not kill more than 10% of the cells (1 microgram/ml for 1.5 to 2 h) significantly reduced the phagocytic activity of the cells and their ability to respond to an activator of hexose monophosphate shunt activity.
Immunochemical Properties of the Major Outer Membrane Protein of
Vibrio cholerae
Authors: Kabir Shahjahan
Published: January 2020

Antisera to the major outer membrane protein of
Vibrio cholerae
(molecular weight, 48,000) raised in rabbits (i) agglutinated several strains of
V. cholerae
and (ii) immunoprecipitated outer membrane proteins prepared from both the biotypes and serotypes of
V. cholerae.
Antibodies of all isotypes to the major outer membrane protein were detected in immune human sera by enzyme-linked immunosorbent assay. These results suggest that the major outer membrane protein was the common outer membrane antigen of
V. cholerae
which was immunogenic in humans.
Specific immune response in the respiratory tract after administration of an oral polyvalent bacterial vaccine
Authors: Clancy R L , Cripps A W , Husband A J , Buckley D
Published: January 2020

An oral killed polyvalent bacterial vaccine was assessed in a double-blind trial involving healthy volunteers. Three courses of oral vaccine were given over a 2-month period; each course contained 10(10) Haemophilus influenzae and 7 X 10(9) Staphylococcus aureus organisms. Immunity was assessed by monitoring antibody in saliva and serum over a 3-month period. No evidence of a nonspecific effect on immune parameters (immunoglobulin levels and Escherichia coli antibody) was detected in saliva or serum. An increase in H. influenzae antibody in saliva was detected in 55% of subjects receiving the vaccine compared with 6.7% of the placebo group. Antibody was associated with immunoglobulin A (IgA), IgG, and IgM, but the greatest increases over preimmunization levels were detected in the IgA class. No increase in serum antibody levels was detected. Subjects with higher preimmunization levels of salivary antibody to H. influenzae were less likely to respond to the oral bacterial vaccine. No increase in S. aureus antibody was detected in saliva or serum.
Ingestion of yeast forms of Sporothrix schenckii by mouse peritoneal macrophages
Authors: Oda L M , Kubelka C F , Alviano C S , Travassos L R
Published: January 2020

The ingestion by thioglycolate-elicited mouse peritoneal macrophages of yeast forms of two strains of Sporothrix schenckii was studied. Yeast forms opsonized with concanavalin A (ConA) were extensively phagocytized, and the phagocytic indexes depended on the concentration of ConA and apparently on the number of lectin receptors at the yeast surface as well. Neuraminidase treatment of S. schenckii increased the ingestion of unopsonized yeasts 7.7-fold. The addition of monosaccharides and derivatives partially inhibited phagocytosis. Mannose, rhamnose, and galactose, which are major constituents of S. schenckii surface antigens, reduced the phagocytic indexes by 40 to 50%. Glucosamine, N-acetylglucosamine, and N-acetylneuraminic acid were equally effective as inhibitors of phagocytosis. A mixture of five neutral sugars and glucosamine inhibited phagocytosis by 73%. The inhibitory effect of simple sugars could be amplified by using neuraminidase-treated yeast cells. Pentoses and glucose were inactive or slightly inhibitory. A purified rhamnomannan inhibited phagocytosis of the homologous strain, whereas partially purified peptidopolysaccharides were toxic to peritoneal macrophages. A partially purified galactomannan from S. schenckii was inhibitory (62% inhibition), and a peptidopolysaccharide fraction in which the O-linked carbohydrate chains had been removed neither was toxic to macrophages nor inhibited phagocytosis. Pretreatment of macrophages with simple sugars under conditions inhibiting ingestion or binding of S. schenckii did not affect phagocytosis of latex particles or sensitized sheep erythrocytes. The presence of receptors at the peritoneal macrophages which bind S. schenckii cell surface components is suggested.
Bactericidal activity of alveolar and peritoneal macrophages exposed in vitro to three strains of Pasteurella multocida
Authors: Collins F M , Niederbuhl C J , Campbell S G
Published: January 2020

Normal ICR mice were infected intravenously, intraperitoneally, or aerogenically with Pasteurella multocida strains isolated from a turkey (S68), calf (V90), or rabbit (J20) lung. Both the turkey and calf isolates were highly virulent for mice and multiplied logarithmically in the lungs, liver, and spleen, resulting in death of the animals in 18 to 36 h. The rabbit strain was avirulent for mice, but repeated passage in mice did result in some increased virulence. All three strains of P. multocida were inactivated rapidly by normal mouse peritoneal macrophages, provided that the organisms were opsonized with specific hyperimmune serum before being exposed to the macrophage monolayers. P. multocida was slowly inactivated by normal mouse alveolar macrophages when the organisms were preopsonized. However, the surviving organisms later multiplied extensively in vitro. Macrophages harvested from hyperimmunized mice were no better at inactivating opsonized P. multocida cells than were normal mouse cells. The relative importance of the different phagocytic cell populations in the uptake and killing of opsonized P. multocida cells is discussed in relation to immunity to this important animal pathogen.
Failure to detect cell-mediated cytotoxicity against Chlamydia trachomatis-infected cells
Authors: Pavia C S , Schachter J
Published: January 2020

Mice were infected with Chlamydia trachomatis (L2/434) and at various intervals after infection their lymphoid cells were tested directly for cytotoxic activity against Chlamydia-infected L929 cells. In a modified cell-mediated lympholysis assay, splenic, lymph node, and peritoneal exudate cells did not significantly cause the destruction of the infected targets, although infection did result in the formation of antichlamydial antibodies. Whereas chlamydial antigens are capable of activating cell-mediated immunity in other experimental models, our results show that either this chlamydial infection does not induce the generation of cytotoxic effector cells or chlamydial antigens are absent from the surface of infected cells.
Uridinediphosphogalactose-4-Epimerase Deficiency in
Salmonella typhimurium
and Its Correction by Plasmid-Borne Galactose Genes of
Escherichia coli
K-12: Effects on Mouse Virulence, Phagocytosis, and Serum Sensitivity
Authors: Krishnapillai V.
Published: January 2020

The synthesis of smooth lipopolysaccharide (LPS) in relation to mouse virulence and resistance to serum bactericidal activity in vitro and to rapid intravenous clearance in vivo was studied in
Salmonella typhimurium
by using a virulent [median lethal dose (LD
50
) = 10
2
], smooth, and genetically marked strain, a uridinediphosphogalactose epimerase-deficient mutant of it which was, therefore, rough, and a derivative of the mutant made smooth again by acquisition of the galactose-positive genes of
Escherichia coli
. The mutant was of reduced virulence (LD
50
= 10
6
) but the smooth derivative regained the virulence character typical of the parent. The non-smooth phenotype also made the mutant, but not the smooth relatives (parent and derivative), susceptible to serum bactericidal activity and also to rapid intravenous clearance by phagocytosis by the liver. The mutant was similarly treated by germ-free mice (expected to be relatively free of opsonizing antibodies). The clearance of the mutant could be impaired by prior intravenous inoculation of homologous bacteria or their LPS but was reversible by preopsonization of the second inoculum with nonimmune mouse serum, suggesting that the initial inoculum preempted the opsonizing antibodies. Independent evidence of clearance specificity was also provided in mixed inoculum experiments on impaired mice by the rapid clearance of an antigenically unrelated heptose-deficient mutant while maintaining the decelerated clearance of the epimerase mutant. The latter, however, was converted to accelerated clearance by the intravenous inoculation during the impaired state of anti-epimerase mutant immune mouse serum.
Immunobiological Activity of Cell Wall Antigens of
Staphylococcus aureus
Authors: Kowalski J. J. , Berman David T.
Published: January 2020

Guinea pigs sensitized with washed, Formalin-killed cells of
Staphylococcus aureus
, strains 263 or Copenhagen, were skin-tested with various antigens from these strains including washed viable and heat-killed whole cells, cell walls, the peptidoglycan complexes of the walls, teichoic acid, teichoic acid-peptidoglycan fragments, and peptidoglycan fragments. In nonsensitized control animals, all antigens but teichoic acid elicited acute inflammatory reactions which decreased in size after 10 hr. In animals sensitized with the Copenhagen strain, the reactions to all antigens but teichoic acid and peptidoglycan fragments from either strain remained erythematous and indurated for at least 30 hr and were interpreted as hypersensitivity of the delayed type. Responses in animals sensitized with strain 263 generally resembled those in controls, although in some experiments there was evidence of hypersensitivity.
Lytic and Turbid Plaque-Type Mutants of Lymphocytic Choriomeningitis Virus as a Cause of Neurological Disease or Persistent Infection
Authors: Hotchin John , Kinch William , Benson Lois
Published: January 2020

Mouse-passaged lymphocytic choriomeningitis (LCM) virus was found to contain a mixture of two different plaque-type mutants when plated on BHK-21/13S cells in agarose suspension. One mutant gave rise to clear plaques, with death of the cells, whereas the other produced turbid plaques which were sometimes very difficult to see. The clear-plaque variant caused a pronounced cytopathic effect on BHK-21 cells, but the turbid variant caused none; it also interfered with the cytopathic effect due to the clear variant. Brain-passed LCM virus was found to consist mainly of the clear-plaque-type, whereas liver-passed virus was mainly turbid-plaque-type. The clear type induced convulsions and early death after intracerebral inoculation of adult mice; the turbid variant caused no convulsions and late deaths. In newborn mice, the clear-plaque-type was uniformly fatal, whereas the turbid variant caused no deaths but instead induced persistent tolerant infection.
Serum-Mediated Resistance Induced with Immunogenic Preparations of
Salmonella typhimurium
Authors: Venneman Martin R. , Berry L. Joe
Published: January 2020

Serum obtained from animals immunized with attenuated
Salmonella typhimurium
strain RIA, heat-killed bacterial suspensions, or immunogenic ribosomal preparations was capable of passively conferring protection on normal recipient mice to challenge infection with virulent
S. typhimurium
strain SR-11. Protection was measured by the ability of a recipient animal to reduce the total number of challenge organisms significantly below that found in challenged control mice. Intraperitoneal administration of 0.1 ml of pooled sera was more effective than 0.05 ml in transferring resistance. The transfer of equivalent amounts of immune serum subcutaneously did not result in demonstrable resistance. In all cases in which serum transfer was effective, resistance was maximal at 5 days, greatly diminished by 10 days, and gone by 15 days post-transfer. Pooled serum obtained from normal donor mice or 0.2 ml of serum from mice hyperimmunized with immunogenic ribonucleic acid preparations did not possess the capacity to confer demonstrable resistance on normal recipients.
Purification of Pneumolysin
Authors: Shumway Clare N. , Klebanoff Seymour J.
Published: January 2020

A procedure for the purification of pneumolysin has been developed. Its use results in a 96-fold increase in specific activity from the original crude pneumococcal extract to the final purified product. The purified material is heat-labile and is inactivated by trypsin and cholesterol; inactivation by
p
-hydroxymercuribenzoate can be reversed by mercaptoethanol. Intravenous administration of the material to rabbits results in crenation, increased osmotic fragility, and intravascular lysis of the erythrocytes of the animal.
Antigen-Antibody Crossed Electrophoresis (Laurell) Applied to the Study of the Antigenic Structure of
Candida albicans
Authors: Axelsen Nils H.
Published: January 2020

By means of the antigen-antibody crossed electrophoresis procedure of Laurell, 68 antigens were demonstrated in
Candida albicans
. This is about four times the number of antigens described earlier by means of classical immunoelectrophoresis. The procedures for obtaining this result are described, including the preparation of antigen, the immunization of rabbits, and the method of N. M. G. Harboe for the production of purified and concentrated rabbit antibodies suitable for quantitative immunoelectrophoresis. The immunoplates were stained by means of the sensitive Coomassie brilliant blue R. The various quantitative immunoelectrophoretic methods offer considerable possibilities for qualitative and quantitative characterization of antigens, even in complex mixtures, and are therefore well suited for the investigation of microbial antigens.
In Vitro Attachment of Radioactive Endotoxins to Lysosomes
Authors: Bona C. , Chedid L. , Lamensans A.
Published: January 2020

The experiments reported here demonstrate that under certain conditions endotoxin can interact with lysosomes in vitro. After incubation of large granular fraction with
51
Cr-labeled antigen under the conditions required for acid hydrolytic activity, radioactivity was associated with the pellet after centrifugation. This effect can be inhibited by preincubation of the large granular fraction with unlabeled homologous or heterologous endotoxins. High resolution autoradiography showed that
14
C-labeled endotoxin was predominantly attached to the lysosomes contained in the large granular fraction. The mechanism of this interaction and its relationship to the toxic effect of endotoxins on lysosomes are discussed.
Enhanced Toxicity for Mice of Combinations of Antibiotics with
Escherichia coli
Cells or
Salmonella typhosa
Endotoxin
Authors: Rose W. C. , Bradley S. G.
Published: January 2020

Enhanced lethality for BALB/c mice has been observed after the administration of
Salmonella typhosa
endotoxin with either actinomycin D, cycloheximide, or nogalamycin. The dose of actinomycin D required to kill half of the mice (LD
50
) was 0.8 mg/kg in normal animals, 0.35 mg/kg in mice administered 0.08 mg of endotoxin per kg, and 0.28 mg/kg in mice administered 0.2 mg of endotoxin per kg. The LD
50
of endotoxin in normal mice was 12 mg/kg and in mice given 0.4 mg of actinomycin D per kg was 0.067 mg/kg. The LD
50
of actinomycin D in mice administered 1.8 × 10
8
live
Escherichia coli
cells per kg or 1.8 × 10
9
heat-killed
E. coli
cells per kg was reduced to 0.4 mg/kg. The LD
50
of cycloheximide was 181 mg/kg in normal animals and 28 mg/kg in mice administered 4 mg of endotoxin per kg. The LD
50
of endotoxin in mice given 120 mg of cycloheximide per kg was 0.02 mg/kg. Enhanced lethality due to various combinations of cycloheximide and endotoxin was abolished by pretreatment of mice with endotoxin. The LD
50
of nogalamycin was 21 mg/kg in normal mice and 13 mg/kg in mice receiving 1 mg of endotoxin per kg.
Proportions of
Streptococcus sanguis
, an Organism Associated with Subacute Bacterial Endocarditis, in Human Feces and Dental Plaque
Authors: van Houte J. , Jordan H. V. , Bellack S.
Published: January 2020

The relative absence of
Streptococcus sanguis
in human feces, in contrast to its high concentration on teeth, supports the concept of the mouth as the likely bacterial source in cases of subacute bacterial endocarditis involving this organism.
Serum Factors and the Reticuloendothelial Uptake of
Staphylococcus aureus
II. Role of a Zymosan-Adsorbable Serum Opsonin
Authors: Felts Stephen K. , Treanor L. Lockie , Goodman Jay S. , Koenig M. Glenn
Published: January 2020

A heat-stable factor in the serum of normal rabbits adsorbed by zymosan at 16 C in the presence of ethylenediaminetetraacetic acid has been found to enhance the uptake of an encapsulated strain of
Staphylococcus aureus
(Smith diffuse) by the isolated perfused rabbit liver. This opsonin does not appear to be a rate-limiting component of the hemolytic complement system, properdin, immunoglobulins G or M. It does, however, require the presence of a heat-labile cofactor(s) for expression of its activity.