bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of anaerobic bacteria on killing of Proteus mirabilis by human polymorphonuclear leukocytes
Authors: Namavar F , Verweij A M , Bal M , van Steenbergen T J , de Graaff J , MacLaren D M
Published: January 2020

Killing of Proteus mirabilis by human polymorphonuclear leukocytes was tested in the presence of different Bacteroides species. In vitro experiments showed that anaerobic bacteria interfered with the killing of aerobic bacteria. However, this inhibitory effect was not a property of all Bacteroides species. Bacteroides gingivalis W83 showed the greatest inhibitory effect of the five Bacteroides strains tested. Killing of P. mirabilis was inhibited by the culture supernatant of B. gingivalis but not by washed cells. Two factors were found in the supernatant of B. gingivalis to account for the inhibitory effect. One was heat stable with a molecular weight of less than 3,500 and inhibited the killing activity of leukocytes, and the other was heat labile and partly inactivated the complement system. The killing experiments paralleled chemiluminescence measurements.
Inhibition of neutrophil function by fluid phase C3b of complement
Authors: Ogle J D , Ogle C K , Alexander J W
Published: January 2020

A high-molecular-weight fragment of C3 was isolated from normal human serum by column chromatography, was generated by incubation of serum at 37 degrees C with inulin, and was produced from highly purified C3 by limited digestion with trypsin. This product was shown to inhibit the antibacterial function of neutrophils by using Escherichia coli O75 as the main test organism. The inhibitor reacted with anti-C3b and anti-C3c, but not with anti-C3B (anti-native C3) or anti-C3a. The manner of preparation of the inhibitor, the sodium dodecyl sulfate-polyacrylamide gel electrophoresis pattern, and the amino acid composition of the inhibitor indicated that it was fluid phase C3b. The inhibitor of neutrophil function (fluid phase C3b) was shown to bind to C3b receptors or acceptors on sheep erythrocytes in a model system.
Identification and distribution of immunocompetent cells in inflamed gingiva of human chronic periodontitis
Authors: Okada H , Kida T , Yamagami H
Published: January 2020

Advanced human periodontitis is considered to be a B-cell lesion, but the cellular infiltrate contains several cell types, the distribution of which has not been determined. This experiment was designed to characterize and identify the immunocompetent cells on histological sections and in eluates from diseased human gingiva. Immunoglobulin-bearing cells were detected on histological sections by direct immunofluorescence with F(ab')2 antisera monospecific for human immunoglobulin G (IgG), IgA, or IgM. Plasma cells predominated in the central portion of the lamina propria, with the proportions positive for IgG, IgA, and IgM accounting for 65.2 +/- 9.5, 11.2 +/- 1.1, and 1.3 +/- 1.1% of the total infiltrating cells, respectively. T lymphocytes, identified by indirect immunofluorescence with monoclonal antibody (Leu-1) against human T cells, accounted for 29.3 +/- 10.0% of the total infiltrated cells. Most of the T cells were located subjacent to the pocket epithelium, but there were a few in the central lamina propria. Similarly, Fc receptor-bearing cells detected by EA rosetting and macrophages and monocytes detected by nonspecific esterase staining with alpha-naphthylbutyrate esterase were also localized to the region immediately subjacent to the pocket epithelium. Infiltrated cells were harvested from minced gingival tissue after digestion with collagenase, hyaluronidase, and DNase. The eluates contained 35.3 +/- 6.0% T lymphocytes, 30.0 +/- 14.9% Fc receptor-bearing cells, and 12.9 +/- 4.4% monocytes and macrophages. Whereas T gamma cells comprised 13.3 +/- 1.4% of peripheral blood T cells, they accounted for only 6.0 +/- 2.0% of the eluate T cells. In contrast, T mu cells accounted for 44.7 +/- 4.9% of the T cells in the eluates and 51.6 +/- 4.4% in the peripheral blood. The decreased proportion of T gamma cells in the gingiva may indicate a form of abnormal immune regulation concerned with T suppression of B-cell proliferation.
Immunofluorescence studies of disseminated Hantaan virus infection of suckling mice
Authors: Kurata T , Tsai T F , Bauer S P , McCormick J B
Published: January 2020

Hantaan virus, the etiological agent of Korean hemorrhagic fever, was inoculated intracerebrally or intraperitoneally into suckling mice, and the course of the infection was followed by infectivity titration and immunofluorescence studies. Mice became ill and were moribund by 13 to 14 days postinfection. In mice inoculated either intracerebrally or intraperitoneally, virus antigen was present in brain, heart, lungs, liver, and kidney. Less consistently, specific fluorescence was observed in spleen, pituitary gland, thymus, lymph nodes, adrenal, pancreas, salivary glands, trigeminal ganglia, adipose tissue, intestine, and muscle. In all of these tissues, the primary target of infection was the capillary endothelium. In mice inoculated intracerebrally, virus antigen was present mainly in choroid plexus, hippocampal nuclei, and meninges, but in mice inoculated intraperitoneally, central nervous system infection was marked by antigen accumulation in cortical nuclei and thalamus.
Isolation and characterization of monoclonal antibodies to Shiga toxin
Authors: Griffin D E , Gentry M K , Brown J E
Published: January 2020

Hybridoma cell lines which produce monoclonal antibodies to Shiga toxin from Shigella dysenteriae 1 were prepared. The monoclonal antibodies were all of the immunoglobulin G1 isotype and differed in their ability to neutralize cytotoxicity and to bind to Shiga toxin in a solid-phase radioimmunoassay. When used for immunoblot analysis, these antibodies were able to identify specifically both nicked and unnicked Shiga toxin in crude lysates of S. dysenteriae.
Cutaneous unresponsiveness to Mycobacterium bovis BCG in intravenously infected mice
Authors: Turcotte R , Forget A
Published: January 2020

Mice injected with 1 mg (about 1 X 10(7) CFU) of Mycobacterium bovis BCG in the footpad showed high levels of delayed-type hypersensitivity (DTH) to BCG antigens and a continuous increase in circulating specific anti-immunoglobulin G (IgG) antibodies throughout a 6-week observation period. In contrast, mice injected intravenously with a 1-mg dose failed to mount a DTH and showed a depression in antibody production at week 5 postinfection. A dose-response study revealed that an optimum dose of BCG, when injected intravenously, can induce a small but significant DTH response. The delayed cutaneous unresponsiveness in intravenously infected mice lasted at least 6 weeks and was not antigenically specific, in that it depressed the DTH response to Corynebacterium parvum. No simple relationship existed between levels of DTH and the amount of circulating anti-IgG antibodies. Splenectomy and treatment with a high dose of cyclophosphamide before infection, although greatly reducing the humoral response, did not reverse the BCG-induced unresponsiveness nor enhance levels of DTH in mice infected in the footpad. It is concluded that the intravenous infection of mice with BCG exerts a nonspecific inhibitory effect on delayed-type immune reactions by the induction of some type of suppressor mechanisms that are resistant to cyclophosphamide.
Impaired autonomic responsiveness of the cardiovascular system of the rat induced by a heat-labile component of Bordetella pertussis vaccine
Authors: de Wildt D J , Kreeftenberg H G , Nijkamp F P
Published: January 2020

Bordetella pertussis vaccination induces severe impairment of the autonomic responsiveness of the cardiovascular system in rats. The vasodilation after beta 2-adrenoceptor stimulation with salbutamol as well as the negative chronotropic action induced by the muscarinic receptor stimulant arecoline were inhibited 4 days after vaccination. Moreover, basal blood pressure values appeared to be significantly lower in B. pertussis-vaccinated rats compared with control animals. These effects were dependent upon the bacterial strain used. Differences in pharmacological activity due to strain differences paralleled variations in the content of lymphocytosis-promoting factor of the vaccine. The inhibitory effects were absent after the administration of vaccine heated for 1 h at 80 degrees C, implicating an important role for a heat-labile component, e.g., lymphocytosis-promoting factor, and not for a heat-stable constituent, e.g., endotoxin (lipopolysaccharide). Previous studies indicate that some early biological effects elicited by B. pertussis vaccine can be attributed to lipopolysaccharide, whereas late induced effects are mainly brought about by lymphocytosis-promoting factor. For that reason a role for lipopolysaccharide might be excluded because 5 h after vaccination no disturbances of the autonomic nervous system were observed. We conclude that B. pertussis vaccination induces autonomic hyporesponsiveness due to a heat-labile component that is assumed to be lymphocytosis-promoting factor.
New Actinomyces and Streptococcus coaggregation groups among human oral isolates from the same site
Authors: Kolenbrander P E , Inouye Y , Holdeman L V
Published: January 2020

The coaggregation properties of recent human oral streptococcal and actinomyces isolates from the same site were determined and compared with the coaggregation properties of well-characterized stock strains of these two kinds of bacteria. Streptococcus sanguis, Actinomyces viscosus, Actinomyces naeslundii, and phenotypically similar strains of actinomyces were isolated from subgingival samples from periodontally healthy older individuals, from persons participating in an experimental gingivitis study, and from young persons with localized (juvenile) and generalized (severe) periodontitis. All 34 of the actinomyces isolates coaggregated with reagent strains of S. sanguis that represented the four streptococcal coaggregation groups. Most of these actinomyces exhibited coaggregations identical to those of actinomyces stock strains. However, five isolates of an Actinomyces WVa-963 serovar exhibited a coaggregation pattern different from any previously described, which was used to define coaggregation group F. All coaggregations with members of this group were lactose inhibitable. Only 57% (8 of 14) of the recent S. sanguis isolates coaggregated with actinomyces reagent strains. But when the nonreactive streptococcal isolates were tested for their ability to coaggregate with actinomyces from the same patient, a new, highly specific coaggregation pattern (group 6) for S. sanguis was discovered. Coaggregation of these streptococci was observed only with certain isolates of A. naeslundii (members of coaggregation group D) from the same site, and none of these coaggregations were inhibited by lactose. Subsequent testing revealed that streptococci of group 6 coaggregated with group D actinomyces from other sources but not with actinomyces of other coaggregation groups. Only two strains of S. sanguis failed to coaggregate with any strain of actinomyces tested. These results indicate that nearly all fresh isolates of these species obtained from both diseased and healthy sites exhibit specific, nonrandom patterns of coaggregation and suggest the widespread occurrence of in vivo cell-to-cell recognition between oral actinomyces and streptococci.
Isolation, chemical composition, and molecular size of extracellular type II and type Ia polysaccharides of group B streptococci
Authors: De Cueninck B J , Greber T F , Eisenstein T K , Swenson R M , Shockman G D
Published: January 2020

Polysaccharides carrying the type II- and type Ia-specific determinants of Lancefield group B streptococci were isolated and purified by anion-exchange chromatography and gel filtration from the supernatant culture medium after growth of strain 18RS21/67/1 (type II) and strain DS/1204/78 (type Ia), respectively. The average molecular weights of these polysaccharides were 97,000 (type II) and 94,000 (type Ia), as determined by reducing end group analyses. These molecular weights were in reasonably good agreement with molecular weights determined by gel filtration at high ionic strength on calibrated columns. The polysaccharides did not cross-react with antisera specific for the other type-specific determinants or with group B-specific antisera. Their content of galactose, glucose, glucosamine, and neuraminic acid (the last two calculated as N-acetyl derivatives) accounted for over 96% of their dry weight. The two polysaccharides differed from each other (and from type III polysaccharide) in their relative content of these monosaccharides. The molar ratios of galactose, glucose, and neuraminic acid to glucosamine were 3.3:2.3:1.35:1.0 for the type II polysaccharide and 2.0:0.8:1.4:1.0 for the type Ia polysaccharides. The results obtained indicate that these extracellular type II and Ia polysaccharides contain larger amounts of neuraminic acid than can be accounted for by previously proposed structures of their repeating units.
Comparison of effects of adjuvants on efficacy of virion envelope herpes simplex virus vaccine against labial infection of BALB/c mice
Authors: Thomson T A , Hilfenhaus J , Moser H , Morahan P S
Published: January 2020

A subunit virion envelope vaccine of herpes simplex virus type 1 was evaluated for its ability to protect labially infected mice from development of the primary herpetic lesion, encephalitic death, and latent virus infection in the trigeminal ganglion. Several adjuvants, including aluminum hydroxide and polyriboinosinic acid-polyribocytidylic acid complexed with poly-L-lysine and carboxymethyl cellulose were investigated for their ability to enhance protection of the subunit vaccine and were compared in effectiveness with complete Freund adjuvant. The subunit vaccine was demonstrated to be immunogenic, as shown by development of antibody detectable by an enzyme-linked immunosorbent assay. The humoral immune response was correlated with protection from herpetic encephalitis and, at a lower degree, with prevention of the appearance of primary herpetic lesions and acceleration of lesion resolution. The efficacy of the vaccine was most apparent in protecting mice from encephalitic death. To reduce or prevent the development of latent infection was most difficult, but was achieved with some vaccine regimens. Repeated administrations of vaccine with adjuvant were required for this protection. The most effective adjuvant was complete Freund adjuvant, but several synthetic adjuvants were effective, particularly aluminum hydroxide and the polyriboinosinic-polyribocytidylic acid-poly-L-lysine-carboxymethyl cellulose immunoadjuvant.
Complement activation by polysaccharide of lipopolysaccharide: an important virulence determinant of salmonellae
Authors: Liang-Takasaki C J , Saxén H , Mäkelä P H , Leive L
Published: January 2020

Salmonellae with differences only in the O-antigenic polysaccharide of their lipopolysaccharide were previously shown to differentially activate complement via the alternative pathway, causing them to be ingested at different rates by the mouse macrophage-like cell line J774. We now show that this mechanism could explain the different virulence of these strains in vivo. Mouse peritoneal macrophages (thioglycolate induced) ingest these salmonellae at rates that are inversely proportional to the known virulence of the organisms and virtually identical to the rates observed with J774. As with J774, complement is required for this differential uptake, since serum was required and heating (56 degrees C for 30 min) or zymosan treatment of the serum destroyed activity. The known receptor for nonreducing terminal mannose-, fucose-, N-acetylglucosamine, and glucose-containing glyco-proteins did not participate, since uptake was not inhibited by high concentrations of mannan. When clearance of bacteria from the bloodstream of mice was measured, the least virulent organism was cleared very much faster than the most virulent organism, in confirmation of earlier data. When complement in the mice was destroyed by pretreatment with cobra venom factor, the clearance of the least virulent strain was greatly reduced, whereas the very slow clearance of the most virulent strain was unaffected. These data strongly support the hypothesis that when bacteria have polysaccharide in lipopolysaccharide that activates complement efficiently, the bacteria will be phagocytosed, whereas if the polysaccharide activates complement poorly, the bacteria escape ingestion and may cause disease.
Immune (gamma) interferon production by a murine T cell lymphoma: requirements for macromolecular synthesis and lack of relationship with cell cycle
Authors: Sarzotti M , Landolfo S , Dianzani F
Published: January 2020

Macromolecular synthesis of immune interferon (IFN-gamma) by the L12-R4 T cell lymphoma, stimulated by phorbol myristic acetate, was studied by using reversible inhibitors of protein synthesis, puromycin and cycloheximide, and an irreversible inhibitor of RNA synthesis, actinomycin D. Reversible inhibition of protein synthesis during the first 3 h of stimulation had no effect on IFN-gamma production. The same treatment, performed 4 h after stimulation and maintained for an additional 5 h, decreased significantly the capability of L12-R4 cells to produce IFN-gamma. When the inhibitors of protein synthesis were left in the cultures, a complete block of IFN-gamma production was observed. Irreversible inhibitors of RNA synthesis at the beginning of stimulation did block IFN-gamma production by L12-R4 cells, but the same treatment was ineffective if performed 6 h after stimulation. These data suggest that continued protein synthesis is needed for IFN-gamma production, whereas the RNA seems to be completely synthesized within 4 to 6 h of stimulation. The relationship between IFN-gamma production and cell cycle phases was studied with the aid of a reversible drug, aphidicolin, that arrests cells at the G1/S border. Phorbol myristic acetate stimulation of L12-R4 cells after aphidicolin removal induced comparable levels of IFN-gamma at each different point of stimulation, indicating that IFN-gamma production by stimulated cells is not related to a particular phase but is continuously inducible during the cell cycle.
Association of an inflammatory I region-associated antigen-positive macrophage influx and genetic resistance of inbred mice to Rickettsia tsutsugamushi
Authors: Jerrells T R
Published: January 2020

Strains of C3H mice differing in susceptibility to intraperitoneal infection with the Gilliam strain of Rickettsia tsutsugamushi were used to investigate the role of the I region-associated (Ia) antigen-bearing macrophage in the genetic resistance of mice to this organism. Resistant mice (C3H/RV) were found to produce a quantitatively greater Ia antigen-positive macrophage response after infection compared to mice (C3H/HeDub) which underwent a lethal infection. The macrophage influx produced in response to infection of the C3H/HeDub mice was deficient in Ia antigen-bearing cells, as evaluated by antigen presentation function and by the use of macrophages as stimulator cells in a mixed lymphocyte response. The resistance to infection, as well as the Ia-positive macrophage response in C3H/RV mice, was sensitive to 450 to 600 rads of irradiation. C3H/HeDub mice produced exudates rich in Ia-positive macrophages if stimulated with concanavalin A or after challenge with R. tsutsugamushi (if previously immunized), ruling out an innate inability of this strain of mice to produce Ia-positive macrophages exudates. Challenge of either strain of mice immunized by a prior subcutaneous infection resulted in a rapid (3 to 5 days) peak of Ia-positive macrophages responding to the peritoneal cavity. It also was noted that subcutaneous infection alone resulted in an increase in the proportion and number of "resident" macrophages which were Ia positive. These data suggest that the macrophage influx in terms of Ia-bearing cells is at least associated with the genetic resistance of C3H/RV mice to infection with this rickettsiae and may play a role in resistance. Furthermore, it would appear that the Ia-positive macrophage is a factor in acquired immunological resistance to reinfection.
Human polymorphonuclear neutrophil functions are unaffected by human interferon-alpha 2
Authors: Farr B , Gwaltney J M , Hayden F G , Mandell G L
Published: January 2020

Leukocyte-derived interferons have been reported to enhance the functions of polymorphonuclear neutrophils. This study reveals no effect of the highly purified recombinant DNA-produced human interferon-alpha 2 on the oxidative, chemotactic, adherent, phagocytic, and bactericidal activities of human polymorphonuclear neutrophils in vitro.
Impaired response of neutrophils to a lymphokine by sera from patients with connective tissue disease
Authors: Kenney H M , Weisbart R H , Colburn K K , Abrass C K , Barnett E V , Golde D W
Published: January 2020

The studies reported here were designed to determine whether sera from various patients could prevent neutrophils from responding to the lymphokine, neutrophil migration inhibition factor from T lymphocytes (NIF-T). Neutrophils from healthy donors were treated with sera from 84 subjects and assayed for responses to NIF-T. Serum from 7 of 37 patients (19%) with rheumatoid arthritis, systemic lupus erythematosus, and various forms of vasculitis showed blocking activity. In contrast, none of 47 subjects, including healthy individuals and patients with spondylarthropathies, cancer, and active infections had a serum factor that prevented neutrophils from responding to NIF-T (P less than 0.01). Serum blocking activity occurred transiently in association with infection by Staphylococcus aureus in one patient with rheumatoid arthritis. Moreover, autologous neutrophils from this same patient showed impaired responses to NIF-T. Blocking activity could be eluted from protein A-Sepharose in three of three patients studied. In three of seven patients, blocking activity was detected in serum cryoprecipitates, with a recovery of 46 to 78% of the blocking activity and overall enrichment (purification) of 137- to 281-fold. Analysis of cryoprecipitates by sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed the predominance of immunoglobulins M and G. In one patient, the serum blocking activity was not cryoprecipitable, and cryoprecipitates from a patient with essential cryoglobulinemia failed to prevent neutrophils from responding to NIF-T. Blocking activity was relatively specific for NIF-T, as there was no effect on F-met-leu-phe-induced chemotaxis of neutrophils. Serum blocking activity in patients with connective tissue disease showed some correlation (r = 0.50; P less than 0.01) with immune complexes detected by polyethylene glycol precipitation but not Clq binding. These studies suggest that the response of neutrophils to NIF-T may be blocked by serum, possibly as a result of immune complexes or autoantibodies found primarily in patients with connective tissue disease.
Further purification and characterization of high-molecular-weight polysaccharide from Pseudomonas aeruginosa
Authors: Pier G B , Cohen M , Jennings H
Published: January 2020

Previously published reports on high-molecular-weight polysaccharides from immunotype 1 and 2 of Pseudomonas aeruginosa indicated the presence of high levels of mannose in these preparations. This mannose has been found to be due to the presence of a yeastlike mannan in high-molecular-weight polysaccharide preparations. The source of the mannan was found to be the tryptic soy broth used to grow the bacteria. Mannan could be removed from the polysaccharide preparations by chromatography over columns of concanavalin A-Sepharose. The resulting polysaccharides had the same serological reactivity against rabbit antisera and the same immunogenic properties in mice as did the mannan-containing polysaccharides. Comparison of mannan-depleted polysaccharide with preparations of high-molecular-weight polysaccharide obtained from either ultrafiltered tryptic soy broth or a chemically defined medium showed that these polysaccharides were immunologically and chemically similar. Human immune responses to mannan-depleted polysaccharide from the immunotype 1 strain of P. aeruginosa were comparable with those previously seen in humans receiving mannan-containing polysaccharides. Thus, we found that P. aeruginosa high-molecular-weight polysaccharides prepared in either tryptic soy broth and then subjected to concanavalin A-Sepharose chromatography, ultrafiltered tryptic soy broth, or a chemically defined medium were immunologically and chemically comparable.
Polyamine oxidase-mediated intraerythrocytic killing of Plasmodium falciparum: evidence against the role of reactive oxygen metabolites
Authors: Rzepczyk C M , Saul A J , Ferrante A
Published: January 2020

The polyamines spermine and spermidine, in the presence of polyamine oxidase, were shown to be cytotoxic in vitro to various isolates of Plasmodium falciparum. Neither polyamines nor polyamine oxidase alone was cytotoxic. This cytotoxicity was manifested by the degeneration of the parasites into crisis forms and by the inhibition of methionine incorporation by the parasites. Only 2 to 2.5 h of exposure to the reaction mixture (polyamine oxidase, 100 micrograms/ml; spermine, 1 mM) resulted in parasite death. It was shown that ammonia, hydrogen peroxide, and associated reactive oxygen intermediates produced during the oxidation of polyamines were not the cause of the parasite death observed in this system. This suggested that aldehydes or further breakdown products of these, e.g., acrolein (or both), need to be considered as the effector substances of the polyamine oxidase-mediated killing of P. falciparum.
Characterization of a pH-dependent chromophore from nutritionally variant streptococci
Authors: van de Rijn I , Bouvet A
Published: January 2020

Strains of nutritionally variant streptococci and Streptococcus mitis produce a chromophore when they are heated at acid pH. No other strains of streptococci elaborated this chromophore. Furthermore, the nutritionally variant streptococci produced approximately twice the amount of chromophore as the S. mitis strains. The chromophore was localized in the cell wall of these streptococcal strains and appeared to be resistant to trypsin treatment. Hydrolysis apparently is required because elevated temperatures at pH 2 are necessary for demonstration of the chromophore. The chromophore has a maximal absorbance at 504 nm with a pKa of 3.6. The chromophore absorbance spectrum showed an isosbestic point at 400 nm. This is the first example of a pH-dependent chromophore to be found in streptococci and serves as a positive characteristic for the description of nutritionally variant streptococci as well as S. mitis.
T-cell regulation of polyclonal B-cell activation induced by extracts of oral bacteria associated with periodontal diseases
Authors: Carpenter A B , Sully E C , Ranney R R , Bick P H
Published: January 2020

These studies were designed to examine the role of regulatory T cells in the polyclonal antibody response of human peripheral blood lymphocytes to extracts of bacterial isolates commonly associated with periodontal disease. Polyclonal antibody responses to the organisms tested were found to be T cell dependent, as are most of the B-cell activators in the human system. Functional T helper activity was resistant to 1,500 rads of irradiation. Optimal polyclonal antibody responses to the bacterial extracts occurred at a 3:1 T-cell-to-B-cell ratio, whereas pokeweed mitogen-induced responses peaked at a 1:1 ratio, suggesting a difference in T-cell regulatory influences in response to these activators. Purified populations of T helper and suppressor cells exerted potent regulatory control of the responses to the bacterial extracts. These findings support the conclusion that regulatory T lymphocytes exert a potent modulating influence over the polyclonal response to periodontally associated bacteria and may play an important role in regulating the lymphocyte response in the diseased site.
Lipopolysaccharide, capsule, and fimbriae as virulence factors among O1, O7, O16, O18, or O75 and K1, K5, or K100 Escherichia coli
Authors: Kusecek B , Wloch H , Mercer A , Vaisänen V , Pluschke G , Korhonen T , Achtman M
Published: January 2020

K1, K5, and K100 Escherichia coli isolates of the lipopolysaccharide antigen types O1, O7, O16, O18, or O75, which had formerly been assigned to clonal groupings were compared with K? E. coli isolates and with laboratory-derived mutants defective in capsule or lipopolysaccharide synthesis. The amount of K1 capsule, the length distribution of the lipopolysaccharide, and the expression of type I and P fimbriae were determined. The clonal groupings were uniform with regard to these properties within each group but different from each other. Many of the K? strains differed from the clonal representatives. The results are interpreted with regard to the different diseases caused by each of these bacterial groups.
Histopathological effect of botulinum C2 toxin on mouse intestines
Authors: Ohishi I , Odagiri Y
Published: January 2020

Botulinum C2 toxin has histopathological activity in the mouse intestine and induces fluid accumulation in intestinal loops. The toxin caused degenerative and necrotic changes in the intestinal mucosa: intracellular vacuolization of epithelial cells, desquamation and necrosis of the villous epithelium, intercellular edema, and infiltration of lymphocytes and histiocytes. The detectable changes in the morphology of the intestinal mucosa preceded the increase in fluid accumulation in intestinal loops. Intraluminal injection of botulinum C2 toxin also induced the leakage of plasma protein into the intestinal lumen as determined by the extravasation of Evans blue. In contrast to botulinum C2 toxin, cholera and Clostridium perfringens enterotoxin controls caused a very slight protein leakage, although these toxins induced marked fluid accumulation in intestinal loops. The results indicate that the mode of action of botulinum C2 toxin in eliciting the secretory response is distinguishable from those of cholera and C. perfringens enterotoxins and suggest that botulinum C2 toxin induces the secretory response by cytopathic effect(s) on the epithelial cells of the intestine.
Identification of specific outer membrane polypeptides associated with virulent Yersinia enterocolitica
Authors: Chang M T , Doyle M P
Published: January 2020

An antiserum (WA-SAA) that agglutinates specifically with mouse virulent but not avirulent strains of Yersinia enterocolitica was used to identify virulence-associated factors by Western blot techniques. Several outer membrane polypeptides were identified only in the virulent strains, which included serotypes O:8, O:3, O:9, O:4,32, O:5,27, and O:21. These included three, and possibly four, major outer membrane polypeptides. The prominent high-molecular-weight species was demonstrated by both sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blot, whereas the others were only revealed by the Western blot technique. Expression of these polypeptides correlated with antiserum agglutination reaction and the presence of a 42- and/or 82-megadalton plasmid. These polypeptides were highly temperature dependent and only slightly affected by the inclusion of 10 mM Ca2+ in the growth medium. These polypeptides were produced during both the logarithmic and stationary phases of growth at 37 degrees C. We suggest that the production of these specific polypeptides and calcium dependency may be coded for by the plasmid(s) but are regulated by independent mechanisms. These polypeptides appear to be novel markers specific for virulent strains of Y. enterocolitica and may be important to the pathogenicity of this organism.
Sealed adult mice: new model for enterotoxin evaluation
Authors: Richardson S H , Giles J C , Kruger K S
Published: January 2020

Outbred, inbred, and congenic strains of conventional mice which were ano-rectally occluded with cyanoacrylate ester glue and converted to sealed adult mice (SAM) were given, per os, crude cholera enterotoxin (CT) in 10% NaHCO3. At 6 h when the response was maximal, mice were killed, the small intestines were removed, and gut weight/body weight ratios were calculated. Experimental mice gave a linear response after receiving 1.5 to 60 micrograms of CT. Purified heat-stable enterotoxin from Escherichia coli and purified heat-labile enterotoxins from E. coli, Vibrio cholerae, and Clostridium difficile all elicited vigorous fluid outpouring as did culture filtrates from Vibrio fluvialis with cytotoxic activity. Active and passive immunization with crude CT completely or partially neutralized fluid secretion due to CT. Monospecific anti-CT incubated with CT before feeding also eliminated the response. Mice pretreated with penicillin, held in barrier cages, converted to SAM, and fed live vibrios, showed fluid responses similar to those seen with low doses of CT. Each of six different strains of inbred mice fed a half-maximal fluid accumulation response dose of CT gave fluid accumulation ratios which varied fourfold. There was no correlation of fluid accumulation with body weight, gut length, age, or sex. All poor responders were of H-2k haplotype and all good responders were H-2b. BALB congenic mice which differed only in H-2 haplotypes showed the same correlations, and body weights and gut lengths of all haplotypes were not significantly different.
Role of granulocytes and monocytes in experimental Escherichia coli endocarditis
Authors: Meddens M J , Thompson J , Bauer W C , van Furth R
Published: January 2020

The role of granulocytes and monocytes during the induction and course of Escherichia coli endocarditis was investigated in rabbits by selectively depleting monocytes from the circulation with the drug VP16-213 and granulocytes and monocytes with nitrogen mustard. For induction, the number of E. coli needed to infect the vegetations in 50% of the rabbits was significantly lower in rabbits with combined granulocytopenia and monocytopenia than in those with selective monocytopenia or in control rabbits, whereas the number of E. coli needed to infect 50% of the rabbits did not differ between the latter two. During the course of the endocarditis in endocardial vegetations, the numbers of CFU per gram of vegetation were significantly higher in the rabbits with combined granulocytopenia and monocytopenia than in the monocytopenic and control rabbits but did not differ between the latter two. The numbers of granulocytes in the circulation and the numbers of CFU per gram of vegetation showed a significant negative correlation that was not measurably influenced by the duration of the disease but was dependent on the number of E. coli injected for the induction of endocarditis. Granulocytes were found to be most effective at the lowest numbers of bacteria injected. In the circulation, too, the numbers of CFU per milliliter were significantly higher in rabbits with combined granulocytopenia and monocytopenia than in those with selective monocytopenia and control rabbits, and there was a significant negative correlation between the numbers of granulocytes and CFU per milliliter of blood. From these findings we conclude that granulocytes play a protective role during the induction and course of E. coli endocarditis in rabbits, whereas no role is demonstrable for monocytes.
Peptide utilization by oral streptococci
Authors: Andersson C , Sund M L , Linder L
Published: January 2020

Streptococcus mitis ATCC 903 and Streptococcus sanguis 804 could utilize large peptides present in proteose peptone as their sole source of nitrogen but grew poorly in amino acid medium. By contrast, Streptococcus mutans BHT and S. mutans IB grew in amino acid medium but could not utilize large peptides. Streptococcus sp. strain Bravato had requirements for both peptides and amino acids. Peptide size did not seem important for the utilization of peptides by S. mitis except that dipeptides were not utilized. Large peptides were essential for depressed hyaluronidase synthesis in nongrowing S. mitis. Intracellular aminopeptidase activities were high in S. mitis ATCC 903 and Streptococcus sp. strain Bravato, intermediate in S. sanguis 804, and low in S. mutans BHT and S. mutans IB.
Analysis of antigenicity of Clostridium botulinum type C1 and D toxins by polyclonal and monoclonal antibodies
Authors: Oguma K , Murayama S , Syuto B , Iida H , Kubo S
Published: January 2020

Clostridium botulinum type C1 toxin was purified from C-Stockholm (C-ST), and D toxin was purified from D-1873 and D-South African. Polyclonal antibodies against these toxins were prepared in rabbits. Twenty-eight monoclonal antibodies to these toxins were also prepared with BALB/c myeloma cells. The antibodies were analyzed by both enzyme-linked immunosorbent assay (ELISA) and a toxin neutralization test. ELISA was performed with the three purified toxins and heavy-chain (Hc) and light-chain (Lc) components derived from C-ST and D-1873 toxins. A neutralization test was carried out with 11 toxin preparations (7 from type C and 4 from type D cultures). ELISA results indicated that there exists at least one common antigenic determinant on each of the Hc and Lc components of the three purified toxins. The results of the neutralization test also indicated that type C1 and D toxin preparations contain several common antigenic sites in their molecules. Some are common to toxins from several specific cultures, whereas others are common to toxins from a large number of cultures. It was speculated that toxins from two type C strains are composed of Hc and Lc components which are somewhat similar to those of D-1873 and C-ST toxins, respectively.
B-cell function in vitro during rubella infection
Authors: Hyypiä T , Eskola J , Laine M , Meurman O
Published: January 2020

B-cell function in vitro was studied in patients with natural rubella virus infection. Lymphocyte responses to mitogens in a blast transformation test were decreased at the onset of the rash. Spontaneous immunoglobulin production by peripheral blood lymphocytes was increased during the acute phase of illness. In regulatory T-cell subpopulations, increased proportions of cells with suppressor/cytotoxic phenotypes and decreased proportions of cells with helper/inducer phenotypes were detected simultaneously with the increased spontaneous immunoglobulin production. All parameters studied were recovered during the convalescent phase.
Effect of the estrous cycle on uterine infection induced by Escherichia coli
Authors: Nishikawa Y , Baba T , Imori T
Published: January 2020

Escherichia coli was inoculated into the uterine lumen of rats and rabbits at different estrous stages; one uterine horn of each animal was ligated at the cervical end. In rats, a large number of E. coli were retained in the ligated horns regardless of the estrous stage. E. coli inoculated at diestrus or pseudopregnancy induced purulent endometritis, but when inoculated at proestrus-estrus the organism caused asymptomatic infection. In nonligated horns, few E. coli were recovered, and marked histopathological changes were not observed. Large numbers of E. coli were retained in the nonligated horn at proestrus as a result of physiological constriction of the cervix. E. coli inoculated at proestrus never caused purulent endometritis in either the ligated horn or the nonligated horn. In rabbits, E. coli infused into ligated horns brought about purulent inflammation irrespective of ovarian states. The number of recoverable E. coli was reduced rapidly at the follicular phase as compared with the luteal phase. These results suggest that the stage of the estrous cycle when animals are inoculated with E. coli influences the course of the uterine infection.
Alteration of murine immune response by Pseudomonas aeruginosa exotoxin A
Authors: Holt P S , Misfeldt M L
Published: January 2020

Pseudomonas exotoxin A has been implicated as a possible virulence factor in Pseudomonas infections. This toxin has a direct cytotoxic effect on a number of cell types, including macrophages and their precursors, and therefore may affect other cells of the immune system. NFR/N(H-2q) (+/nu or nu/nu) mice were immunized with either T-dependent or T-independent antigens along with various doses of exotoxin A. The immune response was then assayed by a modification of the Jerne plaque assay. Exotoxin A induced a dose-dependent suppression of the in vitro and in vivo immune responses to T-dependent and T-independent antigens in immunocompetent +/nu mice. However, in NFR/N nu/nu mice, suppression of the immune response to the T-independent antigen trinitrophenylated-Ficoll was not observed. Instead, a marked enhancement of the response was observed at doses of 100 and 10 ng of exotoxin A. Removal of T-cells with anti-Thy 1.2 antiserum plus complement before antigen and exotoxin A stimulation in +/nu mice results in abrogation of the suppression. These data suggest that Pseudomonas exotoxin A exerts an effect on both B- and T-lymphocyte populations to modulate the immune response and that this activity may be one facet of the pathogenic effects of this toxin.
Intestinal mucus trapping in the rapid expulsion of Trichinella spiralis by rats: induction and expression analyzed by quantitative worm recovery
Authors: Bell R G , Adams L S , Ogden R W
Published: January 2020

Rats were immunized with a Trichinella spiralis infection restricted by chemotherapy to the intestine (the T/M regime) or with a complete infection that resulted in the deposition of muscle larvae. After an oral challenge infection, rapid expulsion could be demonstrated in both groups within 20 min and with 100% recovery of the infectious dose from the stomachs and intestines of infected animals. Immune and nonimmune groups were distinguished by the large numbers of worms in the intestinal lumens of immune rats and large numbers of worms in the intestinal walls in nonimmune rats. Infectious larvae persisted in the stomach lumens for longer in the immune rats. There was no quantitative difference in worm distribution in the intestine during rapid expulsion in rats immunized with the T/M regime or those given a complete infection. However, in the complete infection group 69% of the luminal worms were trapped in mucus; this did not occur during rapid expulsion in rats immunized with the T/M regime. Mucus trapping was observed only when muscle larvae had matured to the infectious stage in muscle (28 days after the primary infection). Complete infection rats challenged at 14 or 21 days did not display significant mucus trapping of larvae in the intestinal lumen. We conclude that (i) mucus trapping is not essential for rapid expulsion and (ii) mucus trapping is produced by systemic exposure to target antigens of the infectious larvae.
Immunoglobulin G response to subgingival gram-negative bacteria in human subjects
Authors: Naito Y , Okuda K , Takazoe I
Published: January 2020

Serum and gingival crevicular fluid from normal healthy adults and patients with periodontitis were screened for immunoglobulin G antibodies to antigens from Bacteroides gingivalis 381, Bacteroides intermedius 24, Bacteroides loescheii ATCC 15930, Fusobacterium nucleatum ATCC 25586, Eikenella corrodens 1073, Actinobacillus actinomycetemcomitans ATCC 29522, and Capnocytophaga sp. strain M-12. Immunoglobulin G antibody titers to the antigens were measured by an enzyme-linked immunosorbent assay. The antibody levels to B. gingivalis in serum and gingival crevicular fluid were significantly higher in the samples from patients with periodontitis than in samples from healthy individuals. Although there were individual differences within patient groups, a positive correlation (P less than 0.01) was found between the serum immunoglobulin G levels to B. gingivalis and the development of periodontitis. The antibodies to F. nucleatum (P less than 0.05), E. corrodens (P less than 0.05), and A. actinomycetemcomitans were slightly higher in patients with periodontitis than in normal subjects. There were no remarkable differences between the two groups in titers to B. intermedius, B. loescheii, and Capnocytophaga sp.
Demonstration and solubilization of antigens expressed primarily on the surfaces of Candida albicans germ tubes
Authors: Smail E H , Jones J M
Published: January 2020

Antisera against mycelial-phase, but not yeast-phase, Candida albicans absorbed with yeast-phase organisms preferentially stained germ tube segments of several strains of mycelial-phase C. albicans by the indirect fluorescent-antibody staining technique. Germ tube segment antigens were not found in significant amounts on blastospore segments or on yeast-phase organisms. Absorption of the mycelial-phase reference sera with yeast-phase C. stellatoidea, but not with C. tropicalis, C. guillermondii, or Saccharomyces cerevisiae, resulted in preferential germ tube segment staining of C. albicans. A dithiothreitol extract of mycelial-phase C. albicans organisms blocked staining of the germ tube segment, but a dithiothreitol extract of yeast-phase organisms did not. When dithiothreitol extracts from both phases were reacted against yeast-absorbed reference sera in tandem crossed and crossed line immunoelectrophoresis, a cross-reacting arc and several arcs unique to the mycelial-phase extract were noted. Immunofluorescent staining tests were performed, using appropriately absorbed sera from patients with candidiasis to stain a laboratory strain of C. albicans. Human tissue slices infected with C. albicans were used as targets for appropriately absorbed rabbit antisera. These human data indicated that antigens preferentially expressed on the germ tube in vitro were also expressed on filamentous structures of the fungus in infected human tissues. In vitro and in vivo, the invasive mycelial phase of C. albicans expresses certain antigens that are highly concentrated on the germ tube.
Purification and characterization of Staphylococcus aureus type 8 capsular polysaccharide
Authors: Fournier J M , Vann W F , Karakawa W W
Published: January 2020

Clinical isolates of Staphylococcus aureus have been previously classified into eight types on the basis of their capsular polysaccharide. The high prevalence of the type 8 capsular polysaccharide among bacteremic isolates suggests the importance of this capsular antigen in staphylococcal disease. The capsular polysaccharide was purified from extracts of three clinical isolates of S. aureus type 8 of different geographic and temperal origin by ion-exchange chromatography and gel filtration. Gas chromatography, gas chromatography-mass spectrometry, and 13C-nuclear magnetic resonance showed that the type 8 capsular polysaccharide is composed of O-acetyl groups, N-acetylfucosamine, and an aminouronic acid similar to N-acetylgalactosaminouronic acid. The purified polysaccharide reacted only with type 8 antiserum in double diffusion experiments. Our analysis shows that the type 8 polysaccharide is both chemically and serologically distinct from teichoic acid and previously characterized polysaccharides of S. aureus.