bluuebunny/crossref_metadata_2025 huggingface dataset:
Immunochemical characterization of high-molecular-weight polysaccharide from Fisher immunotype 3 Pseudomonas aeruginosa
Authors: Pier G B , Pollack M , Cohen M
Published: January 2020

A high-molecular-weight polysaccharide (PS) was isolated from the culture supernatant of a Fisher immunotype 3 (IT-3) strain of Pseudomonas aeruginosa. Consistent with previously reported findings for IT-1 and IT-2 PS, the preparation of IT-3 PS was found to be an immunogenic, nontoxic form of the O polysaccharide side chain on the lipopolysaccharide (LPS). The IT-3 PS was mainly carbohydrate in composition. It was serologically and chemically identical to LPS O side chain, but distinct from that structure in molecular size and immunogenicity. The IT-3 PS was nontoxic in mice and guinea pigs, nonpyrogenic in rabbits, and greater than 1,000-fold less reactive than IT-3 LPS in gelation of the Limulus amoebocyte lysate. Preliminary analyses by gas-liquid chromatography and 13C nuclear magnetic resonance have established the structural identity of IT-3 high-molecular-weight PS and the IT-3 O side chain. IT-3 PS was immunogenic in rabbits and mice. After active immunization, mice were protected against P. aeruginosa IT-3 intraperitoneal infection and burn wound sepsis. IT-3 PS also elicited protection against challenge with an IT-5 strain of P. aeruginosa, indicating that low-level contamination of the IT-3 PS with IT-3 LPS was not responsible for the immunogenic activity. These findings demonstrate the feasibility of preparing nontoxic immunogenic IT-3 PS capable of eliciting serotype-specific protective antibodies, employing methods similar to those previously described for the isolation of PS from other P. aeruginosa immunotypes.
Properties and requirements for production of a macrophage product which suppresses steroid production by adrenocortical cells
Authors: Mathison J C , La Forest A C , Ulevitch R J
Published: January 2020

Lipopolysaccharide-treated murine peritoneal exudate macrophages (PEM) release a factor or factors into the supernatant that suppress adrenocorticotropic hormone-induced steroidogenesis in explanted rabbit adrenocortical cells (J. C. Mathison et al., J. Immunol. 130:2757-2762, 1983). To determine the requirements for suppression, PEM supernatants (30 microliters) were added to explanted rabbit adrenocortical cells in a final volume of 120 microliters with 10 mU of adrenocorticotropic hormone per ml, and after 18 h at 37 degrees C, steroid concentrations were measured by a fluorometric assay. Supernatant from proteose peptone-elicited C3HeB/FeJ PEM (5 X 10(6) PEM per 3.5-cm well, 10 micrograms of Salmonella minnesota Re595 LPS per ml, 18 h) suppressed steroid production ca. 50%, and kinetic studies demonstrated that the appearance of suppressive activity in the supernatant was gradual over 4 to 18 h. Release of suppressive activity was not associated with decreased viability of the PEM (assessed by fluorescein diacetate staining and measurement of lactic dehydrogenase in the supernatant). Suppression was not observed when the PEM supernatant was diluted 10-fold before addition to the adrenocortical cells, whereas supernatant concentrated 20-fold (prepared with a 10,000-molecular-weight-cutoff filter) produced 75 to 80% suppression. The suppressive activity was stable at pH 4, pH 11, or 70 degrees C for 30 min but was inactivated at 100 degrees C (10 min). Suppressive activity was also induced in C3HeB/FeJ PEM by O111:B4 lipopolysaccharide or heat-killed Listeria monocytogenes. In contrast, PEM from C3H/HeJ mice did not produce detectable suppressive activity in response to Re595 lipopolysaccharide or heat-killed L. monocytogenes. Thus, these results provide additional support for the inducible, selective release of a macrophage product that could affect the host response to lipopolysaccharide by regulation of the adrenocortical response to adrenocorticotropic hormone.
Group A streptococcal peptidoglycan-polysaccharide inhibits phagocytic activity of human polymorphonuclear leukocytes
Authors: Leong P A , Cohen M S
Published: January 2020

Injection of sterile aqueous preparations of the peptidoglycan-polysaccharide of group A streptococci (PG-APS) produces chronic inflammation in several animal models. Chronic bacterial infection may be involved in some aspects of the pathogenesis of inflammation associated with the accumulation of PG-APS. Accordingly, the effect of PG-APS on human neutrophil (polymorphonuclear leukocyte [PMN]) bactericidal activity was studied with the supposition that this interaction may contribute to the inflammation observed. Concentrations of PG-APS greater than 10 micrograms/ml inhibited the ability of PMNs to kill Staphylococcus aureus. This inhibition was not due to a cytotoxic effect of PG-APS on PMNs, nor did PG-APS inhibit PMN metabolism required for the formation of microbicidal oxygen reduction products. PG-APS concentrations of 10 micrograms/ml or greater in the presence of 10% normal serum inhibited the attachment of bacteria to PMNs by 49% as compared with control cell populations. The concentrations of PG-APS required to inhibit uptake of Staphylococcus aureus were identical to those required for inhibition of PMN bactericidal activity. This inhibition did not occur in the presence of serum-free medium or medium with sera that had been heated to inactivate complement. These results show that PG-APS interacts with serum to inhibit PMN-mediated killing of S. aureus, most probably by interfering with bacterial uptake.
Fractionation of hemagglutinating and bacterial binding adhesins of Bacteroides gingivalis
Authors: Boyd J , McBride B C
Published: January 2020

An outer membrane complex containing hemagglutinating and bacterial aggregating activity has been isolated from Bacteroides gingivalis. Examination of the membrane material by biochemical analysis, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and immunological means revealed that the crude outer membrane preparation contained three major proteins and a lipopolysaccharide population that displayed size heterogeneity. At least two membrane proteins as well as the lipopolysaccharide were found to be antigenically active by immunoblot analysis. With gel chromatography and a lipopolysaccharide disaggregating buffer the membrane material was separated into two fractions. An accompanying separation of the two adherence activities was observed. The first membrane fraction, containing mostly protein and carbohydrate material, was found to contain the bacterial aggregating activity. This fraction also contained a high-molecular-weight lipopolysaccharide population. The second membrane fraction, consisting of low-molecular-weight lipopolysaccharide, protein, and loosely bound lipid was found to contain the hemagglutinating activity.
Identification of an iron-regulated 37,000-dalton protein in the cell envelope of Neisseria gonorrhoeae
Authors: Mietzner T A , Luginbuhl G H , Sandstrom E , Morse S A
Published: January 2020

We examined the outer membrane proteins which appear during the growth of Neisseria gonorrhoeae F62 in complex medium supplemented with 25 microM Desferal mesylate, a potent iron chelator. Outer membranes were prepared by Sarkosyl extraction and analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Several higher-molecular-weight (74,000 to greater than 94,000) proteins increased under iron-limiting conditions. In addition we observed the appearance of an iron-regulated protein with an apparent molecular weight of 37,000. This protein comigrated with the gonococcal protein I under normal Laemmli gel conditions. By increasing the ionic strength of the lower gel buffer, separation of protein I and the 37,000-dalton iron-regulated protein occurred. The 37,000-dalton protein stained poorly with Coomassie blue. However, when a silver stain was used, the protein appeared as a major component of the gonococcal outer membrane. Production of this 37,000-dalton protein was suppressed by the addition of iron to the medium. An iron-regulated protein with a similar molecular weight was observed in four clinical isolates and in an additional laboratory strain. Peptide mapping indicated that the 37,000-dalton protein was distinct from protein I and was identical between strains of the WI and WII serogroups.
Pulmonary clearance of encapsulated and unencapsulated Haemophilus influenzae strains
Authors: Toews G B , Viroslav S , Hart D A , Hansen E J
Published: January 2020

A mouse model system was employed to investigate the temporal pattern of pulmonary clearance of Haemophilus influenzae and to evaluate the effect of the type b polysaccharide capsule on this clearance pattern. The lungs of BALB/c mice were inoculated with boluses of several different H. influenzae strains via an endobronchial catheter. A fully encapsulated H. influenzae type b strain multiplied readily in the lungs for at least 6 h and then was eventually cleared from the lungs over the next 18 h. The pulmonary clearance pattern obtained with an unencapsulated variant of this H. influenzae type b strain was identical to that obtained with the fully encapsulated parent strain. Two nontypable H. influenzae strains isolated by transtracheal aspiration of patients with acute H. influenzae pneumonia also multiplied in the lung and resisted significant clearance for at least 6 h after inoculation. Bolus deposition of either H. influenzae type b or nontypable H. influenzae in the lungs resulted in an eventual influx of polymorphonuclear leukocytes into the alveoli. The observed delay in clearance of all these strains suggests that resident host defense mechanisms must be augmented for clearance to occur. Furthermore, these data indicate that one or more factors other than the Haemophilus capsule are important bacterial determinants of pulmonary clearance of H. influenzae.
Isolation and characterization of transposon-induced mutants of Pseudomonas aeruginosa deficient in production of exoenzyme S
Authors: Nicas T I , Iglewski B H
Published: January 2020

Exoenzyme S is an extracellular product of Pseudomonas aeruginosa. This enzyme catalyzes the transfer of ADP-ribose from NAD to a number of as yet unidentified eucaryotic proteins, but it is distinct from toxin A. To evaluate the role of exoenzyme S in the pathogenicity of P. aeruginosa, we isolated transposon-induced mutants of strain 388, a clinical isolate that produces exoenzyme S but no toxin A. The transposon Tn1 was introduced by using a temperature-sensitive derivative of plasmid RP1. A Tn1-induced mutant was found which had no detectable exoenzyme S activity or antigen in culture supernatants or in cell lysates. Except for its lack of exoenzyme S and resistance to carbenicillin, this mutant was indistinguishable from the parent strain. When tested in an experimental mouse burn infection model, this Tn1-induced mutant was reduced in virulence by at least 2,000-fold, suggesting a role for exoenzyme S in the virulence of this strain.
Protective levels of human immunoglobulin G antibody to group B streptococcus type Ib
Authors: Boyer K M , Kendall L S , Papierniak C K , Klegerman M E , Gotoff S P
Published: January 2020

We studied the concentration of circulating human immunoglobulin G (IgG) antibody to the native capsular polysaccharide of group B streptococcus (GBS) type Ib necessary to protect mice against lethal challenge by laboratory and clinical GBS Ib strains. Antibody was measured by an enzyme-linked immunosorbent assay in which native polysaccharide antigen coupled to human serum albumin was used. The assay was standardized by a quantitative precipitation test, using native antigen and specific human IgG antibody purified by affinity chromatography. IgG anti-GBS Ib antibody level-protection curves for 90% lethal dose challenge of mice were sigmoidal. The curves of whole serum and affinity-chromatographed IgG anti-GBS Ib were superimposable. The serum concentrations of human antibody required for complete protection of mice varied with the infecting strain and ranged from 0.038 to 0.175 microgram/ml. Protective levels of human IgG anti-GBS Ib were lower than those we found previously for homologous protection against GBS Ia challenge (range, 0.25 to 1.0 microgram/ml).
Bacteriophage Mu d1(Apr lac) generates vir-lac operon fusions in Shigella flexneri 2a
Authors: Maurelli A T , Curtiss R
Published: January 2020

Previous studies have demonstrated that expression of virulence in Shigella spp. is controlled by growth temperature. To study the regulation of virulence (vir) genes, we set out to develop a rapid, easily-assayed phenotype with which to measure expression of virulence. This report described a procedure for isolating vir-lac operon fusions in S. flexneri 2a by using the specialized transducing bacteriophage Mu d1(Apr lac) of Casadaban and Cohen (M. Casadaban and S. N. Cohen, Proc. Natl. Acad. Sci. U.S.A. 76:4530-4533, 1976). Mu d1(Apr lac) lysogens were isolated and screened for loss of virulence and for temperature-dependent expression of the lactose genes on Mu d1(Apr lac). A recombinant plasmid carrying the Mu immunity gene was also introduced into lysogens of interest to stabilize the Mu d1(Apr lac) insertion and prevent possible thermal induction at 37 degrees C. The mutant which we isolated failed to penetrate tissue culture cells in the assay for virulence and produced almost 15-fold more beta-galactosidase when grown at 37 degrees C than when grown at 30 degrees C. The site of insertion of Mu d1(Apr lac) in this strain was shown to be in the 140-megadalton plasmid pSf2a140, which is known to be associated with virulence. P1L4-mediated transduction of the insertion into a virulent recipient demonstrated genetic linkage of Mu d1(Apr lac) with loss of virulence and temperature-dependent expression of beta-galactosidase. All of these features fulfill the phenotype expected for a Mu d1(Apr lac)-induced vir-lac operon fusion. This mutant provides us with a means of measuring expression of a gene function required for virulence by assaying for beta-galactosidase. The insertion will also serve as a starting point for mapping of genes on pSf2a140 which are necessary for expression of virulence.
Purification of enterotoxins from Vibrio mimicus that appear to be identical to cholera toxin
Authors: Spira W M , Fedorka-Cray P J
Published: January 2020

Cholera toxin-like (CT-like) enterotoxins produced by two strains of Vibrio mimicus, 61892 and 63616, isolated from diarrhea patients in Bangladesh, were purified, and their physicochemical, biological, and immunological properties were compared with those of CT produced by classical Vibrio cholerae 569B. The CT-like toxins were produced by lincomycin-resistant mutants grown in the presence of lincomycin at 200 micrograms/ml for strain 63616 and 250 micrograms/ml for strain 61892 and were purified by coprecipitation with hexametaphosphate followed by chromatography on phosphocellulose. The pure CT-like toxins were indistinguishable from 569B CT in sodium dodecyl sulfate-polyacrylamide gel electrophoresis, rabbit intestinal loop and Y-1 adrenal cell assays, antiserum neutralization and binding inhibition assays, and Ouchterlony immunodiffusion, except that the CT-like toxins appeared to consist almost entirely of A subunit which was proteolytically unnicked. Trypsin nicking, however, resulted in fragments that appeared to be identical to those of 569B CT. These results indicate that at least one species of Vibrio other than V. cholerae can produce enterotoxins which are virtually identical to CT.
Production of luminol-reactive oxygen radicals during Plasmodium vinckei infection
Authors: Stocker R , Hunt N H , Clark I A , Weidemann M J
Published: January 2020

We tested the ability of whole blood and enriched fractions of peripheral blood polymorphonuclear leukocytes obtained from mice during the course of infection with Plasmodium vinckei to produce luminol-mediated chemiluminescence in response to phagocytic and nonphagocytic stimuli. The chemiluminescence response of whole blood to all stimuli increased dramatically and nonlinearly as the infection progressed, and there was a concomitant increase (80%) and decrease (70%) in the total numbers of leukocytes and erythrocytes, respectively. The proportion of polymorphonuclear leukocytes in the total leukocyte population increased threefold. On a per cell basis and at a constant hematocrit, the chemiluminescence response of peripheral leukocytes from infected animals to phorbol myristate acetate or opsonized zymosan was only slightly greater than that of cells from uninfected animals. Polymorphonuclear leukocytes isolated from the blood of infected animals also showed no large increase per cell in chemiluminescence responsiveness. Thus, although leukocyte numbers increase during a murine malarial infection, there appears to be no major change in the capacity of individual peripheral blood leukocytes to produce activated species of oxygen. However, the physiological reduction in the total concentration of hemoglobin at high parasitemia, due to hemolysis and hemoglobin digestion by the parasites, increases the possibility of oxygen radical-mediated damage to tissues and intraerythrocytic parasites as a result of decreased antioxidant protection.
A surface protein expressed during the transformation of zygotes of Plasmodium gallinaceum is a target of transmission-blocking antibodies
Authors: Grotendorst C A , Kumar N , Carter R , Kaushal D C
Published: January 2020

Antibodies against gametes of malarial parasites (Plasmodium spp.) have previously been shown to block infectivity of the parasites to mosquitoes by preventing fertilization of the parasites in the insect midgut. These antibodies did not have any effect on the development of fertilized parasites. We now report that a surface protein of Mr 26,000 synthesized by zygotes of P. gallinaceum is the target of antibodies which block infectivity of the fertilized parasites to mosquitoes. Identification of this target antigen offers a new stage of the parasite against which a malaria transmission-blocking vaccine could be developed.
Interleukin 1 production by peripheral blood mononuclear cells from leprosy patients
Authors: Watson S , Bullock W , Nelson K , Schauf V , Gelber R , Jacobson R
Published: January 2020

Quantitation of interleukin 1 production by adherent mononuclear cells from peripheral blood was performed in patients with tuberculoid and lepromatous forms of leprosy. Cells from patients with tuberculoid leprosy either secreted interleukin 1 spontaneously or produced amounts within the normal range in response to lipopolysaccharide stimulation. Conversely, stimulated cells from lepromatous patients failed to produce interleukin 1 in 5 of 13 (38.5%) cases.
Murine monoclonal antibodies reactive with human heart and group A streptococcal membrane antigens
Authors: Cunningham M W , Krisher K , Graves D C
Published: January 2020

Ten selected murine hybridoma cell lines that produce monoclonal antibodies against M type 5 Streptococcus pyogenes and human heart antigen were isolated. All of the monoclonal antibodies studied were determined to be the immunoglobulin M isotype. The antibodies were characterized on the basis of their reactions with Triton X-100-extracted whole human heart antigens, sodium dodecyl sulfate-extracted sarcolemmal antigens, and whole streptococci or their membranes. Enzyme-linked immunosorbent assays and Western immunoblotting techniques were used to compare the reactivity of the monoclonal antibodies. All 10 of the antibodies were first selected for their reactivity with Triton X-100-extracted heart antigens and whole group A, M type 5 streptococci. These antibodies were then divided into two categories: strong reactors or weak reactors with human sarcolemmal and streptococcal membranes. Among the strong reactors, two different types of monoclonal antibodies were observed on the basis of their immunobanding patterns with sarcolemmal and streptococcal membranes on Western blots. Monoclonal antibodies that were strong reactors with sarcolemmal and group A streptococcal membrane antigen were directed against a determinant on a family of proteins. The major reactants of sarcolemmal extracts were high-molecular-weight proteins near 200,000. Some monoclonal antibodies demonstrated more specificity for the heart than did others when reacted with separated Triton X-100-extracted tissue antigens from the heart, kidney, and skeletal muscle. One of the monoclonal antibodies that reacted with group A streptococci reacted with a Triton X-100-extracted heart antigen ca. 40,000 daltons in size. None of these monoclonal antibodies opsonized type 5 Streptococcus pyogenes, and in enzyme-linked immunosorbent assays most of the antibodies were found to react to a lesser degree with other groups of streptococci. Monoclonal antibody was used to probe normal and rheumatic sarcolemma for differences in reactivity. Although the rheumatic heart reacted more intensely, no major differences between the immunobanding patterns of normal and rheumatic hearts were observed.
Toxicity of staphylococcal toxic shock syndrome toxin 1 in rabbits
Authors: de Azavedo J C , Arbuthnott J P
Published: January 2020

Strains of Staphylococcus aureus associated with toxic shock syndrome produce toxic shock syndrome toxin 1 (TSST 1), which is lethal to conventional rabbits and acts synergistically with gram-negative lipopolysaccharide. The lethal effect of TSST 1 was examined in specific-pathogen-free rabbits on the basis that these rabbits, being less colonized by gram-negative bacteria, would be less susceptible than conventional animals. Although there was no significant difference in mortality between specific-pathogen-free and conventional rabbits in response to 100 micrograms of TSST 1, there was a difference in response between Dutch belted rabbits and New Zealand white rabbits. Both specific-pathogen-free and conventional New Zealand white rabbits were more susceptible to TSST 1 than the Dutch belted strain. Pretreatment of conventional New Zealand white rabbits with polymyxin B neutralized the lethal effect of TSST 1.
Chemical and biological characterization of a gonococcal growth inhibitor produced by Staphylococcus haemolyticus isolated from urogenital flora
Authors: Frenette M , Beaudet R , Bisaillon J G , Sylvestre M , Portelance V
Published: January 2020

The purified antigonococcal substance produced by Staphylococcus haemolyticus no. 7 has shown a broad antigonococcal spectrum and a narrow antibacterial spectrum. The inhibitor produced in vitro was also active in the guinea pig subcutaneous chamber. The inhibitor has shown hemolytic activity; the human, horse, and mouse erythrocytes were the most susceptible. Hemolytic and antigonococcal activities were inhibited in the presence of phosphatidylcholine. The amino acid composition of the antigonococcal substance was characterized by the absence of proline, tyrosine, histidine, cysteine, and tryptophan. The molecular weight was found to be 2,565, and the major isoelectric points were 4.8 and 4.9 in the presence of 8 M urea and 4.6 without urea. The inhibitor has some properties similar to those of the delta toxin of Staphylococcus aureus, although the two substances are different based mainly on their chemical characteristics. Also an antiserum directed against the gonococcal inhibitor did not give a precipitation line with the delta toxin, indicating that the two substances are antigenically unrelated.
Penicillin-induced lysis of Streptococcus mutans
Authors: Kral T A , Callaway M D
Published: January 2020

Treatment of Streptococcus mutans GS-5 cells with concentrations of penicillin G within a relatively narrow range resulted in substantial lysis. This penicillin-induced lysis was dependent upon cell density and pH of the lysis medium. Other oral streptococci (Streptococcus sobrinus, Streptococcus rattus, and Streptococcus cricetus) also demonstrated substantial levels of penicillin-induced lysis under appropriate conditions. Lesser degrees of lysis were seen in a related organism, Streptococcus ferus.
Processing of Bacillus subtilis peptidoglycan by a mouse macrophage cell line
Authors: Vermeulen M W , Gray G R
Published: January 2020

It has previously been established that muramyl dipeptide (N-acetylmuramyl-L-alanyl-D-isoglutamine) is an effective immunostimulant whose primary target cell type is the macrophage. Muramyl dipeptide is known to be structurally identical to a portion of the monomer unit of peptidoglycan, a nearly ubiquitous component of bacterial cell walls. To establish whether muramyl dipeptide or glycopeptides structurally related to it are formed as a result of macrophage processing of peptidoglycan, Bacillus subtilis cell walls radiolabeled in the muramic acid, glucosamine, and alanine residues of the constituent peptidoglycan were incubated in the presence of the cultured macrophage-like cell line RAW264, and the glycopeptides which released into the medium were fractionated and analyzed. Although muramyl dipeptide was not found in the culture medium, at least three glycopeptides structurally related to it were found, namely GlcNAc-MurNAc-Ala-isoGln-Dap-Ala, GlcNAc-MurNAc-Ala-isoGln-Dap, and GlcNAc-MurNAc-Ala-isoGln.
Inhibition of in vitro human lymphocyte response by the pneumococcal toxin pneumolysin
Authors: Ferrante A , Rowan-Kelly B , Paton J C
Published: January 2020

The effects of pneumolysin, a sulfhydryl-activated cytolytic toxin produced by Streptococcus pneumoniae, on the in vitro human lymphocyte response was examined. The toxin, at concentrations of one to five hemolytic units per ml, caused marked inhibition of the response of lymphocytes to concanavalin A, phytohemagglutinin, pokeweed mitogen, and protein A. The response was assessed by measuring both [3H]thymidine incorporation and the ability of lymphocytes to produce immunoglobulins and lymphokine activity. The effects of pneumolysin were irreversible, could be prevented by pretreatment of the toxin with cholesterol, and were not related to a direct cytotoxic effect on the lymphocytes. Pneumolysin appeared to act at the initiation phase of the immune response and had no effect on lymphocytes committed to DNA synthesis or to the synthesis and secretion of immunoglobulins. Furthermore, pneumolysin-mediated inhibition of the lymphocyte response was not due to the inhibition of binding of mitogens to leukocytes and is likely to be related to effects on membrane-mediated signals essential for lymphocyte triggering. This may be one means by which pneumolysin plays a role in the pathogenesis of pneumococcal infections.
H-2-linked genes which modify resistance of C57BL/10 mice to subcutaneous infection with Mycobacterium lepraemurium
Authors: Curtis J , Akuffo-Adu H , Turk J L
Published: January 2020

Strains of C57BL/10 mice with recombinants within the H-2 complex were used to map the genes which control the mononuclear cell response at the infection site and modify resistance to subcutaneous infection with Mycobacterium lepraemurium. Strains with b in the K-E beta regions of the H-2 complex mounted a more rapid cellular response in the infected footpad and were more resistant than mice with d or k in the K-E beta regions. Significant differences between strains with k in the K-E beta regions appeared to be controlled by a gene in the D region.
Effect of age on fever and acute-phase response of rats to endotoxin and Salmonella typhimurium
Authors: Tocco-Bradley R , Kluger M J , Kauffman C A
Published: January 2020

Age-related effects on endogenous pyrogen-mediated febrile and acute-phase responses to endotoxin and Salmonella typhimurium challenge were investigated in young adult and aged Fisher 344 rats. After injection of endotoxin, the febrile response over 6 h and the fall in plasma iron and zinc after 6 h were determined in 14 young adult and 14 aged rats in their thermoneutral zone (26 degrees C) and in 14 young adult and 14 aged rats maintained in a cold environment (15 degrees C). Although at 26 degrees C aged rats showed only a slightly diminished febrile response compared with that of young adult rats, at 15 degrees C they had a markedly diminished febrile response compared with that of young adult rats. At both 26 and 15 degrees C, the injection of endotoxin led to a fall in iron and zinc concentrations in the plasma of both young adult and aged rats. The intact trace metal response diminished but febrile response suggest that aged rats are able to produce endogenous pyrogen but have a reduced capacity to respond to this substance. In 22 aged and 22 young adult rats maintained at 26 degrees C and challenged with S. typhimurium, the febrile response was significantly less in the aged rats but the survival rate was virtually identical. When 10 young adult and 10 aged rats were placed at a temperature of 15 degrees C after injection with S. typhimurium, the febrile response in the aged rats was significantly lower than that in the young adult rats at only one time point, and the survival rate did not differ between the two age groups. Survival after challenge with S. typhimurium was not influenced adversely by the diminished febrile response.
Surface structures (peritrichous fibrils and tufts of fibrils) found on Streptococcus sanguis strains may be related to their ability to coaggregate with other oral genera
Authors: Handley P S , Carter P L , Wyatt J E , Hesketh L M
Published: January 2020

We screened 36 strains of Streptococcus sanguis biotype I and 8 strains of S. sanguis biotype II for the presence of surface structures and for their ability to coaggregate with Actinomyces viscosus, Actinomyces naeslundii, and Fusobacterium nucleatum. Negative staining under an electron microscope revealed detectable surface structures on all S. sanguis strains. The majority of strains (38 of 44) carried peritrichous fibrils, which have an irregular profile and no distinct width. They usually appeared as a fringe with a constant width around the cell. Strains selected for measurement had a fringe with an average length of 72.4 +/- 8.5 nm on biotype I strains and 51.6 +/- 3.3 nm on biotype II strains. Some fibrillar biotype I strains carried an additional, longer (158.7 +/- 33.1 nm) type of fibril projecting through the shorter fibrils. Fibrillar density was characteristic for each strain, ranging from very dense on all cells in a population to very sparse on a few cells in a population. A small group of six strains carried tufts of fibrils in a lateral or polar position on the cell. Either one or two lengths of fibril were present in the tuft depending on the strain. One strain carried both peritrichous fibrils and fimbriae. Fimbriae are flexible structures with a constant width (4.5 to 5.0 nm) all along their length but very variable lengths (less than or equal to 0.7 micron) on each cell. S. sanguis I and II both included strains with peritrichous fibrils and tufts of fibrils, but the mixed morphotype strain was confined to biotype II. Fibrils were present on cells at all stages throughout the growth cycle for the strains tested. Freshly isolated fibrillar strains coaggregated consistently well with A. viscosus and A. naeslundii, although some fibrillar reference strains lacked the ability. In addition, all tufted strains could not coaggregate, but the strains with the mixed morphotype coaggregated well. Coaggregation with F. nucleatum was very strong for the fibrillar strains, but less strong for the tufted strains. We discuss the possible correlation between S. sanguis surface structure and ability to coaggregate.
Anaerobic phagocytosis, killing, and degradation of Streptococcus pneumoniae by human peripheral blood leukocytes
Authors: Thore M , Löfgren S , Tärnvik A , Monsen T , Selstam E , Burman L G
Published: January 2020

Encapsulated Streptococcus pneumoniae of serotypes 2, 9N, 14, 21, and 23F and an unencapsulated variant of type 2 pneumococci were efficiently phagocytosed by both aerobically and anaerobically incubated human leukocytes. In the presence of O2, the pneumococci rapidly lost their viability, whereas during anaerobiosis, killing was considerably delayed. Type 14 pneumococci radiolabeled with [14C]choline or [14C]ethanolamine for cell wall teichoic acid, [14C]uracil for nucleic acids, or [14C]arachidonic acid for unsaturated cytoplasmic membrane lipids were used in studies of the fate of bacterial macromolecules after phagocytosis. The degradation of teichoic acid, RNA, and DNA during anaerobiosis approached that recorded in air at 60 min of incubation (45 to 70% and 55 to 75%, respectively). In contrast, the marked loss of [14C]arachidonic acid from pneumococcal membrane lipids observed in aerobic leukocytes did not occur during anaerobic incubation. Hence, lipid peroxidation could be involved in the rapid aerobic leukocyte killing of pneumococci, whereas a different leukocyte function of as yet unknown nature appears to be responsible for the killing seen in anaerobiosis. Autolysis-resistant type 14 pneumococci were obtained by substituting ethanolamine for choline in a defined culture medium. Differences between such bacteria and normal (autolytic) pneumococci in their killing and degradation by leukocytes were not detected in either the presence or the absence of O2. The aerobic and anaerobic handling of phagocytosed pneumococci by human blood leukocytes thus proceeded independently of the bacterial autolytic system.
Genetic resistance to murine cryptococcosis: the beige mutation (Chédiak-Higashi syndrome) in mice
Authors: Marquis G , Montplaisir S , Pelletier M , Mousseau S , Auger P
Published: January 2020

The influence of the bgJ and bg2J mutations on the susceptibility of mice to experimental cryptococcosis was studied in inbred mice of the C57BL/6J and C3H/HeJ strains. Although infected animals with the bg/bg genotype had a significantly shorter lifespan than bg/+ or +/+ animals, C3H/He beige-2J mice were less susceptible than C57BL/6 beige-J mice when compared with nonbeige mice of similar background. On days 18 and 19 after infection, quantitation of cryptococci in the brain, liver, and spleen revealed that the overall burden of organisms in infected C57BL/6 beige-J mice was in excess of one log unit above that found in the brain, liver, and spleen of infected C57BL/6 +/+ mice. At that time, C57BL/6 beige-J mice showed a 53% increase in mean brain weight, a 67.8% decrease in mean liver weight, and a 58.6% decrease in mean spleen weight, when compared with uninfected animals of the same age and genetical lineage. The corresponding figures for C57BL/6 +/+ mice were a 32% increase in mean brain weight, a 41.4% decrease in mean liver weight, and a 23.4% decrease in mean spleen weight. From these data, it is concluded that the beige mutation in mice is associated with increased susceptibility to cryptococcosis, the accrued susceptibility of the beige mutant is related to more rapid changes in the weight profile of the target organs as well as to a higher rate of growth or decreased clearance of Cryptococcus neoformans or both, and other autosomal genes are likely to be involved in the genetic control of susceptibility to murine cryptococcosis.
Interaction of bifidobacterial lipoteichoic acid with human intestinal epithelial cells
Authors: Op den Camp H J , Oosterhof A , Veerkamp J H
Published: January 2020

Binding of the lipoteichoic acids of Bifidobacterium bifidum to human colonic epithelial cells appeared to be specific, reversible, and cell concentration and time dependent. A single population of approximately 8.3 X 10(8) binding sites per cell was detected, with a dissociation constant of 125 microM. Ester-linked fatty acids are essential for binding.
Factors affecting binding of galacto ligands to Actinomyces viscosus lectin
Authors: Heeb M J , Marini A M , Gabriel O
Published: January 2020

The specificity requirements for the binding of Actinomyces viscosus T14V were examined by testing simple sugars, oligopeptides, and glycoproteins as inhibitors of the aggregation of glycoprotein-coated latex beads and washed A. viscosus cells. Lactose was the most inhibitory simple sugar; D-fucose and D-galactose were equally inhibitory, methyl-alpha-D-fucoside was slightly less inhibitory, and L-fucose and raffinose were not inhibitory. The concentration of galactose residues required for 50% inhibition of aggregation was 15 times higher in the form of lactose than in the form of asialoglycoprotein, suggesting an enhancement of lectin binding when galactose residues are clustered. However, when the inhibitory power of bi-, tri-, and tetraantennary asialooligopeptides of alpha 1-acid glycoprotein was compared with that of equivalent concentrations of galactose in the form of lactose, the biantennary form was slightly less effective than lactose, the triantennary form was approximately as effective as lactose, and the tetraantennary form was slightly more effective than lactose. Steric interference may prevent this type of clustering from enhancing lectin binding. The O-linked asialooligopeptides of asialofetuin were 10 times more inhibitory than an equivalent concentration of galactose in the form of N-linked asialooligopeptides. Thus, galactose beta-1----3 linked to N-acetylgalactosamine exhibits greater specificity for the A. viscosus lectin than does galactose beta-1----4 linked to N-acetylglucosamine. These results, taken together with previously reported data, are consistent with a lectin of low affinity, binding enhanced by multivalency, and specificity for beta-linked galactose.
Activation of the alternative complement pathway by pneumococcal lipoteichoic acid
Authors: Hummell D S , Swift A J , Tomasz A , Winkelstein J A
Published: January 2020

Cell wall teichoic acids of some gram-positive bacteria are potent activators of the alternative pathway of complement. It is unclear, however, whether the other form of teichoic acid, cell membrane lipoteichoic acid (LTA), can also activate the alternative pathway. In the present study, radiolabelled pneumococcal LTA was found to bind spontaneously to sheep erythrocytes in a temperature- and time-dependent fashion. In addition, the presence of pneumococcal LTA on the erythrocyte surface was verified by the fact that they could be agglutinated by a myeloma protein (TEPC-15) specific for choline, a constituent of pneumococcal LTA. Pneumococcal LTA when fixed to the surface of erythrocytes was able to activate the alternative pathway of complement in both guinea pig serum deficient in the fourth component of complement and human serum deficient in the second component of complement, resulting in lysis of the sensitized erythrocytes. The sensitizing principle of the LTA preparation was removed before erythrocyte sensitization by immunoabsorption, using the choline-specific TEPC-15 myeloma protein. These data demonstrate that purified pneumococcal LTA will bind to sheep erythrocytes and endow them with the ability to activate the alternative pathway.
Highly toxinogenic but avirulent Park-Williams 8 strain of Corynebacterium diphtheriae does not produce siderophore
Authors: Russell L M , Holmes R K
Published: January 2020

The highly toxinogenic Park-Williams 8 strain of Corynebacterium diphtheriae grows slowly in vitro and is avirulent. C. diphtheriae Park-Williams 8 is defective in iron uptake and does not produce the corynebacterial siderophore corynebactin. Addition of partially purified corynebactin stimulated iron uptake and growth of iron-deprived C. diphtheriae Park-Williams 8 cells.
Activation of mouse peritoneal adherent cells with N-acyl muramyl dipeptide derivatives
Authors: Nishimura K , Okumura H , Saiki I , Okuyama H , Azuma I
Published: January 2020

The effect of N-acyl derivatives of muramyl dipeptide (N-acetyl muramyl-L-alanyl-D-isoglutamine) on the activation of peritoneal adherent cells (PAC) in vivo and on the stimulation of nonspecific host resistance against Escherichia coli infection was examined in comparison with the effect of 6-O-stearoyl muramyl dipeptide. N-acyl muramyl dipeptide derivatives increased the release of hydrogen peroxide (H2O2) by PAC from mice treated 1 day before upon stimulation with phorbol myristate acetate, and their activities did not depend on the chain length or kinds of fatty acids introduced. The results obtained using N-stearoyl muramyl dipeptide analogs indicated that the acyl moiety combined to muramic acid played a more important role in the ability of PAC to release H2O2 than did the peptide moiety. PAC from mice treated with N-stearoyl muramyl dipeptide, N-(3-hydroxy-2-docosylhexacosanoyl) muramyl dipeptide, and 6-O-stearoyl muramyl dipeptide 1 day before, including 20 to 42% polymorphonuclear leukocytes, released large amount of H2O2, and most of the H2O2 released was due to the attribution of polymorphonuclear leukocytes. The cytostatic activity of PAC from mice treated with these three compounds reached a maximum on day 3 after injection, and the cytolytic activity of PAC was induced by N-stearoyl muramyl dipeptide on day 3 and by 6-O-stearoyl muramyl dipeptide on day 1 after injection. In contrast to the above results, N-acyl muramyl dipeptide derivatives did not stimulate nonspecific host resistance against E. coli infection in mice when compared to 6-O-stearoyl muramyl dipeptide.
Cloning of extracellular DNase and construction of a DNase-negative strain of Vibrio cholerae
Authors: Newland J W , Green B A , Foulds J , Holmes R K
Published: January 2020

The structural gene xds for extracellular DNase of Vibrio cholerae was cloned and inactivated by insertion of the transposon Tn5. The inactivated gene was introduced into the chromosome of V. cholerae by recombination to construct an extracellular DNase-negative strain. Tn5-mediated transposon-facilitated recombination was used to establish the position of xds between the pro-1 and ile-201 markers on the genetic map of V. cholerae. The extracellular DNase-negative strain described here should be useful for investigating the role of the xds-encoded DNase in the physiology of V. cholerae and its plasmids as well as for characterizing other DNases in this organism.
Naturally occurring antibodies in human sera that react with the iron-regulated outer membrane proteins of Escherichia coli
Authors: Griffiths E , Stevenson P , Thorpe R , Chart H
Published: January 2020

Sera from normal healthy human adults and infants, as well as sera from mice, rabbits, and guinea pigs, were examined by immunoblotting for naturally occurring antibodies reacting with outer membrane proteins of two Escherichia coli strains, O111 and O18. Some individuals had antibodies reacting very strongly with the iron-regulated outer membrane proteins, including the ferric-enterochelin receptor protein (Mr, 81,000), as well as with ompA. However, sera from infants contained predominantly antibodies to ompA; antibodies recognizing the iron-regulated outer membrane proteins were either absent or barely detectable. In human serum the antibodies were mainly of the immunoglobulin G class. No serotype-specific antibodies to the lipopolysaccharide of E. coli O111 or O18 were found in the sera tested.
Revised amino acid sequence for a heat-stable enterotoxin produced by an Escherichia coli strain (18D) that is pathogenic for humans
Authors: Thompson M R , Giannella R A
Published: January 2020

The amino acid sequence of heat-stable enterotoxin produced by enterotoxigenic Escherichia coli 18D has been revised. Amino acids originally assigned to positions 11 and 18, i.e., Tyr and Asn, respectively, were found to occupy positions 18 and 11, respectively. Thus all heat-stable enterotoxins composed of 18 amino acids sequenced to date from human, porcine, and bovine isolates of E. coli have identical primary structures, i.e., Asn-Thr-Phe-Tyr-Cys-Cys-Glu-Leu-Cys-Cys-Asn-Pro-Ala-Cys-Ala-Gly-Cys-Tyr. Furthermore, all 18- and 19-amino-acid heat-stable enterotoxins from E. coli share an almost identical core sequence, i.e., 14 of the 15 carboxy-terminal amino acid residues are identical.
Plaque formation by virulent Shigella flexneri
Authors: Oaks E V , Wingfield M E , Formal S B
Published: January 2020

An in vitro tissue culture plaque assay was developed to investigate the intracellular replication and intercellular spread of virulent shigellae. Shigella plaques were formed in HeLa cell monolayers in the presence of an agarose overlay containing tissue culture medium and gentamicin, which eliminated extracellular bacterial growth. Microscopically, the plaques were characterized by a central area of dead host cells surrounded by cells infected with shigellae. Cells further away from the plaque center were uninfected. Inclusion of chloramphenicol or nalidixic acid in the overlay completely abolished plaque formation. Plaque formation was completely inhibited when infected monolayers were shifted from 37 to 30 degrees C. Shifting infected monolayers from 30 degrees C, where plaques do not form, to 37 degrees C resulted in the formation of plaques. Cultures of Shigella boydii, Shigella sonnei (form I), and all six serotypes of Shigella flexneri produced plaques. Shigellae isolated from plaques were Sereny test positive, contained a 140-megadalton plasmid, and were gentamicin sensitive. Noninvasive shigellae did not form plaques.
Adhesion of a human fecal Escherichia coli strain to mouse colonic mucus
Authors: Cohen P S , Arruda J C , Williams T J , Laux D C
Published: January 2020

Escherichia coli F-18 isolated from the feces of a healthy human is an excellent colonizer of the CD-1 mouse colon. In the present investigation, adhesion of E. coli F-18 to CD-1 mouse colonic mucus and bovine serum albumin (BSA), immobilized on polystyrene, was studied. Adhesion of E. coli F-18 to mucus was two- to sixfold greater than to either BSA or polystyrene. E. coli F-18 lipopolysaccharide specifically blocked adhesion of E. coli F-18 to mucus and mimicked adhesion of E. coli F-18 to mucus, BSA, and polystyrene. Purified capsule also blocked adhesion of E. coli F-18 to mucus, but this inhibition was found to be entirely nonspecific. The specific E. coli F-18 receptor in mucus appeared to be a glycoprotein, containing sugars normally found in mucins and having a maximum molecular weight of between 1.25 X 10(5) and 2.5 X 10(5).
Disulfide-bonded outer membrane proteins in the genus Legionella
Authors: Butler C A , Street E D , Hatch T P , Hoffman P S
Published: January 2020

Legionella pneumophila and related species were examined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis for outer membrane proteins. Of the 10 species examined, 9 contained a 24-kilodalton (kDa) major outer membrane protein (MOMP) that was resolvable only when outer membrane material was heated in the presence of 2-mercaptoethanol. Labeling studies with [35S]cysteine indicated that the protein contained cysteine, and disulfide cross-linking of the unreduced complex was demonstrated by labeling with iodoacetamide. The unreduced outer membrane preparation contained peptidoglycan, and after treatment with lysozyme to remove peptidoglycan, a protein complex of 95 kDa was observed by sodium dodecyl sulfate polyacrylamide gel electrophoresis in the absence of 2-mercaptoethanol. Reduction of the 95-kDa complex yielded 24-kDa monomers, suggesting that the 95-kDa complex was composed of four subunits. The 24-kDa MOMP from L. pneumophila was purified, and antibody produced to this protein cross-reacted with all species of Legionella as determined from an immunoblot of a sodium dodecyl sulfate gel. Only serogroup 1 strains of L. bozemanii lacked the 24-kDa MOMP and showed no cross-reactivity. These results suggest that the 24-kDa MOMP common to most species of Legionella contains a genus-specific epitope.