bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthetic Salmonella-type lipid A antigen with high serological specificity
Authors: Kasai N , Arata S , Mashimo J , Okuda K , Aihara Y , Kotani S , Takada H , Shiba T , Kusumoto S , Imoto M
Published: January 2020

A synthetic compound (compound 516), beta(1-6)-linked D-glucosamine disaccharide 1,4'-bisphosphate, which is acylated by (R)-3-hexadecanoyloxytetradecanoyl, (R)-3-hydroxytetradecanoyl, (R)-3-dodecanoyloxytetradecanoyl, and (R)-3-tetradecanoyloxytetradecanoyl groups at positions 2,3,2', and 3', respectively, exhibited in vitro antigenic reactivity of high specificity comparable to that of free lipid A from Salmonella minnesota R595. This was confirmed by an enzyme-linked immunosorbent assay and an enzyme-linked immunosorbent assay inhibition test with monoclonal and conventional antibodies. The results of comparative analysis performed with several synthetic lipid A analogs as well as three monosaccharide derivatives suggested that the complete structure involving both phosphate groups at the C-1 and C-4' positions and the 3-acyloxyacyl groups at the C-2, C-2', and C-3' positions of the glucosamine disaccharide are required for the expression of the serological specificity of Salmonella-type lipid A. This was deduced from the observations that compound 506, a synthetic Escherichia coli-type lipid A which has the same structure as that of compound 516, except that 3-hydroxytetradecanoyl group is substituted for an acyloxyacyl residue at the C-2 position, exhibited significantly reduced antigenic reactivity as compared with compound 516 and that the replacement by the hydrogen atom of the phosphoryl group at the C-1 position or by 3-hydroxytetradecanoyl or tetradecanoyl groups of acyl residues at the 2, 3, 2', and 3' positions of compound 516 results in a marked reduction of reactivity with monoclonal antibodies 5G and 36G. Similar results were obtained by assays with conventional rabbit antibodies, but the structural difference between compounds 516 and 506 could not be distinguished by these polyclonal antibodies. The results of cross-reactions among synthetic analogs with monoclonal antibodies 161M and 1-9M, which have been confirmed to exhibit different serological specificities from the 5G or 36G antibody, also suggested that the nature and linkage of fatty acyl residues as well as the backbone structure of lipid A play an important role in determining serological specificity of the lipid A molecule.
Antimicrobial factors in whole saliva of human infants
Authors: Tenovuo J , Lehtonen O P , Aaltonen A S , Vilja P , Tuohimaa P
Published: January 2020

Antimicrobial factors were analyzed in samples of whole saliva from 31 children, aged 0.8 to 3.8 years. When compared with the adult reference group, the children displayed similar levels of lysozyme, salivary peroxidase, and hypothiocyanite (OSCN-), whereas the amounts of immunoglobulins (isotypes A, G, and M), lactoferrin, myeloperoxidase, thiocyanate (SCN-), amylase, and protein were significantly lower than the adult values. The child's behavior during the collection period noticeably influenced the composition of the saliva. Children who were restless and crying during the collection had significantly more immunoglobulins, lysozyme, lactoferrin, salivary peroxidase, myeloperoxidase, and protein in their saliva samples, obviously due to the contamination of saliva mixed with nasal or lacrimal secretions. Therefore, the normal values for saliva could be determined for the noncrying children only. These salivary defense systems did not show any relation to the length of breast-feeding or to the previous history of antibiotic treatment. Thus, with the exception of lactoferrin and myeloperoxidase, the nonimmunoglobulin antimicrobial saliva systems studied here seem to be already at the adult level during early childhood, when the protective antibody systems are still immature.
Outer membrane proteins from Legionella pneumophila serogroups and other Legionella species
Authors: Hindahl M S , Iglewski B H
Published: January 2020

Outer membranes were isolated from eight serogroups of L. pneumophila and five other Legionella species. The protein composition of the membranes was characterized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. A single, disulfide stabilized protein with a molecular size of 29,000 to 30,000 daltons was found to be the major outer membrane protein (MOMP) of all the serogroups. The equivalent of the L. pneumophila MOMP was not observed in any of the other Legionella species examined. Silver staining of sodium dodecyl sulfate-polyacrylamide gel electrophoresis gels revealed distinctive patterns for each serogroup and other Legionella species that were not observed by staining with Coomassie blue and may result from the presence of lipopolysaccharide in the membrane preparations. The MOMP from serogroup 1 was isolated by exposing crude peptidoglycan to detergent in the presence of heat and reducing agent and was found to be tightly associated with lipopolysaccharide. Antibodies to this complex were used to probe the outer membranes of the remaining, L. pneumophila serogroups and other Legionella species by Western blotting. Serogroup 1 anti-MOMP antibodies were found to react with the MOMP from the remaining seven serogroups examined, whereas antibodies directed against the lipopolysaccharide of serogroup 1 only reacted with lipopolysaccharide from two of the remaining seven serogroups.
Serogroup specificity of Legionella pneumophila is related to lipopolysaccharide characteristics
Authors: Ciesielski C A , Blaser M J , Wang W L
Published: January 2020

We studied the lipopolysaccharide (LPS) of Legionella pneumophila and six other Legionella species to determine whether strain differences were apparent. The LPS was purified by a cold ethanol extraction procedure, and total carbohydrates represented 10 to 20% of LPS weight. 2-keto-3-deoxyoctonate represented 1 to 13% of the total carbohydrate present in the LPS. By sodium dodecyl sulfate-polyacrylamide gel electrophoresis, all strains except L. dumoffi showed smooth-type LPS with multiple high-molecular-weight complexes. Proteinase K-treated, whole-cell lysates showed profiles similar to those of purified LPS. Each serogroup of L. pneumophila and each Legionella species had a distinct sodium dodecyl sulfate-polyacrylamide gel electrophoresis profile. L. pneumophila lipid A is antigenically related to the lipid A of Enterobacteriaceae. In immunoblot assays with the LPS of L. pneumophila serogroups 1 to 6 as antigens, serogroup-specific immune monkey sera recognized homologous purified LPS, but not the LPS of the five heterologous serogroups. These studies indicate that LPS composition may be a determinant of serogroup specificity as defined by the immunofluorescence-based serogrouping schema for L. pneumophila and other Legionella species.
Morphological and biochemical comparison of virulent and avirulent isolates of Haemophilus pleuropneumoniae serotype 5
Authors: Jensen A E , Bertram T A
Published: January 2020

Capsular structure and biochemical composition varied between two isolates (virulent and avirulent) of Haemophilus pleuropneumoniae serotype 5. The presence of capsule was determined by transmission electron microscopy with glutaraldehyde-osmium, ruthenium red, alcian blue, and phosphotungstic acid staining procedures. The virulent isolate of H. pleuropneumoniae had a distinct, adherent capsule. The avirulent isolate had a fragile, easily removed capsule. Capsular material (CM) and a lipopolysaccharide (LPS) were isolated from each bacterial isolate and were compared biochemically and biologically. CM from both isolates contained carbohydrates, no detectable protein, and no detectable to trace amounts of lipid A. Each LPS contained heptose, hexose, galactose, glucosamine, 2-keto-3-deoxyoctonate, and lipid A. Biological responses to CM and LPS from both isolates were demonstrated in the proclotting enzyme of Limulus polyphemus amebocyte lysate activation and in serological cross-reactions by immunofluorescence and immunodiffusion precipitation. The virulent isolate contained approximately 10 mg of LPS per g more on an original dry weight basis than the avirulent isolate. LPS from the virulent isolate contained approximately 13 times more galactose than LPS from the avirulent isolate. The differences of capsular structure and biochemical composition may contribute to the role of CM in porcine H. pleuropneumoniae infections.
Localized gut-associated lymphoid tissue hemorrhage induced by intravenous peptidoglycan-polysaccharide polymers
Authors: Sartor R B , Anderle S K , Cromartie W J , Schwab J H
Published: January 2020

A hemorrhage into gut-associated lymphoid tissue developed as early as 3 min after the intravenous injection of group A streptococcal peptidoglycan-polysaccharide polymers into rats. Extravasated erythrocytes were specifically located in the lamina propria and organized lymphoid follicles of the intestines and mesenteric lymph nodes and did not occur in the lungs, kidneys, liver, spleen, adrenal glands, or submandibular and popliteal lymph nodes, as determined by gross and histologic observations and measurement of radiolabeled erythrocytes. Petechial hemorrhage was preferentially located within the intestine to the distal ileum, Peyer's patches, and lymphoid aggregates of the colon. The hemorrhage was transient and occurred in a dose-dependent fashion. It was maximal 5 min after injection and resolved completely by 3 days. A unique feature of this altered vascular permeability was the absence of polymorphonuclear leukocytic infiltration, edema, vasculitis, and tissue necrosis.
Human antibody response to a group B serotype 2a meningococcal vaccine determined by immunoblotting
Authors: Wedege E , Frøholm L O
Published: January 2020

The antibody response of 30 volunteers vaccinated with a complex of group B polysaccharide and outer membrane vesicles (OMV) from serotype 2a Neisseria meningitidis and of 3 individuals who received a placebo vaccine was determined by immunoblotting. OMV were separated by sodium dodecyl sulfate-gel electrophoresis and electrotransferred to nitrocellulose filters. Binding of immunoglobulin G (IgG), IgA, and IgM antibodies in the human sera to OMV components was detected with class-specific peroxidase-conjugated antibodies. The immunoblotting results were also related to the bactericidal activity of the sera and the meningococcal carrier status of the volunteers. Before vaccination weakly reactive bands in the molecular weight range of 140,000 to 10,000 were observed on the blots. Sera from carriers showed more marked bands. Individual patterns of increased reactivity were seen 6 weeks after vaccination. The main immunoreactive components of OMV corresponded to a molecular weight of 43,000 (class 1 protein), 30,000 (class 5 proteins), and 22,000. IgG antibodies in postvaccination sera of high bactericidal titers showed distinct binding to the 43,000-molecular-weight antigen. Meningococcal carriers had antibodies against an antigen of 22,000 molecular weight; in polyacrylamide gels this component did not stain with Coomassie brilliant blue or silver. The marked binding of IgG antibodies to the class 5 proteins decreased considerably between weeks 6 and 25 after vaccination. Periodate oxidation of OMV abolished the binding of IgG antibodies to the class 5 proteins, whereas the antigenicity of the 43,000-molecular-weight (class 1 protein) and 22,000-molecular-weight antigens was unaffected.
Experimental meningococcal infection in mice: a model for mucosal invasion
Authors: Salit I E , Tomalty L
Published: January 2020

A more complete understanding of meningococcal disease has been hampered by the lack of an appropriate animal model. Previous models have utilized injections of meningococci, which precludes the study of nasopharyngeal colonization and invasion. We have developed a model for meningococcal disease in which litters of 5-day-old mice are challenged intranasally with 10(7) viable meningococci. Bacteremia is monitored by jugular venous blood cultures, and cerebrospinal fluid is sampled by cisternal punctures. Human disease-associated and carrier strains were compared; nasopharyngeal colonization was similar for these bacteria, but the case-associated strains were much more frequently invasive and caused bacteremia. Twenty-one percent of bacteremic animals had meningitis. There was an age-related susceptibility to infection which correlated inversely with the levels of serum complement. Preinjection of iron dextran increased the number of animals which were bacteremic, the concentration of bacteria in blood, and nasopharyngeal colonization. Noncapsular variants of virulent meningococci did not colonize nasopharyngeal tissue in vivo, and they were not invasive. This neonatal mouse model mimics meningococcal disease as seen in humans and may be useful in studying the initial events in the pathogenesis of meningococcal disease.
Protection of guinea pigs against cutaneous leishmaniasis by combined infection and chemotherapy
Authors: El-On J , Witztum A , Schnur L F
Published: January 2020

A paromomycin and methylbenzethonium chloride ointment cured Leishmania enriettii infections in guinea pigs. Amastigotes were totally eliminated from the treated lesion after 10 days of treatment. A delayed effect also occurred on untreated lesions in the same animals. Lesions treated at various times after infection permitted protective immunity to develop, and 90% of treated animals were refractory to reinfection.
Effect of iron compounds on antibacterial function of human polymorphs and plasma
Authors: Ward C G , Hammond J S , Bullen J J
Published: January 2020

Human plasma was bactericidal for small numbers of Klebsiella pneumoniae, but larger numbers grew slowly over a period of 24 h. Human polymorphs in a clot of autologous plasma had a bacteriostatic effect on relatively large numbers of bacteria for up to 24 h and were much more effective than plasma alone. The bactericidal effect of plasma could be abolished by saturating the plasma albumin and hemopexin with hematin, the haptoglobin with hemoglobin, and the transferrin with Fe3+. Stimulation of bacterial growth in the presence of polymorphs depended on the degree of saturation of the plasma proteins which bind the Fe3+ or heme compounds. Hematin bound to albumin appeared to be readily available to K. pneumoniae. Free hemoglobin stimulated bacterial growth but the organism could not utilize the haptoglobin-hemoglobin complex. In the presence of polymorphs the addition of Fe3+ to give 60% saturation of the transferrin with iron led to rapid growth after a long delay (19 h). Progressive increases in saturation above 60% gave correspondingly quicker growth, suggesting that the higher the saturation of transferrin, the easier it is for the bacteria to acquire iron. The antibacterial effect of the plasma appears to be critically dependent on the availability of iron for the bacteria, and this in turn affects the ability of the polymorphs to control bacterial growth.
Differences in susceptibility of inbred mice to Bacillus anthracis
Authors: Welkos S L , Keener T J , Gibbs P H
Published: January 2020

Animal species differ in their resistance both to infection by Bacillus anthracis and to anthrax toxin. A mouse model was developed to study the basis of the host differences and the pathogenesis of infection. When mice were infected with the virulent B. anthracis strain Vollum 1B, low 50% lethal dose (LD50) values (5 to 30 spores) were found for all 10 strains of inbred mice tested. However, analysis of time-to-death data revealed significant differences among the strains, which could be divided into three groups: most susceptible (A/J and DBA/2J); least susceptible (CBA/J, BALB/cJ, and C57BR/cdJ); and intermediate (the remaining five strains). In contrast, the mice were distinctly susceptible or resistant to lethal infection by the toxigenic, nonencapsulated Sterne vaccine strain. The LD50 for the susceptible A/J and DBA/2J mice was approximately 10(3) spores of the Sterne strain, whereas the remaining eight relatively resistant strains were killed only by 10(6) or more spores. F1 hybrid and backcross studies suggested that resistance to the Sterne strain is determined by a single dominant gene or gene complex. Mice lethally infected with B. anthracis showed an acute course of infection, characterized by extensive gelatinous edema and large concentrations of bacilli in the blood and organs (e.g., 10(9) CFU/g of spleen). The susceptibility of A/J and CBA/J mice to intravenously injected anthrax toxin components appeared to differ from their susceptibility to infection. The toxin LD50 values for both strains were similar. However, CBA/J mice died sooner than did A/J mice, with mean time to death of 0.9 and 3.7 days, respectively, in mice given 4 LD50 of toxin. The mouse model appears to be useful in studies on host resistance to anthrax and on the pathogenesis of the infection.
Suppression of pathogenesis in cutaneous leishmaniasis by UV irradiation
Authors: Giannini M S
Published: January 2020

The effects of suberythematous levels of UV-B radiation on the development of of cutaneous leishmaniasis were studied in B10.129(10M) mice. Doses of 15 mJ cm-2 UV-B applied locally to the injection site suppressed the development of skin lesions after the inoculation of Leishmania major promastigotes. The primary targets of UV-B radiation appeared to be host cells and not leishmanial parasites, because UV-B irradiation of parasites cultured in vitro did not affect their viability, but did kill host cells. Furthermore, the same numbers of parasites were recovered from skin at the injection site in both irradiated and control mice. UV-B irradiation abrogated the induction of contact hypersensitivity to dinitrofluorobenzene and also abrogated the induction of delayed-type hypersensitivity responses to leishmanial antigens. These results suggest that local perturbations in the functions of the skin-associated lymphoid tissue during the initial phases of leishmanial infection can profoundly influence immunological response and the subsequent development of clinical disease.
Characterization of antibody to the ferripyochelin-binding protein of Pseudomonas aeruginosa
Authors: Sokol P A , Woods D E
Published: January 2020

An outer membrane protein of Pseudomonas aeruginosa was previously shown to bind 59Fe-labeled pyochelin. Antibodies to the purified ferripyochelin-binding protein (FBP) were characterized by using a variety of assays. Anti-FBP cross-reacted with several P. aeruginosa isolates in an enzyme-linked immunosorbent assay. Anti-FBP significantly enhanced phagocytosis of P. aeruginosa by human polymorphonuclear leukocytes. In a serum bactericidal assay we observed no difference in viability between cells incubated with antiserum to FBP and cells incubated with preimmune serum. Anti-FBP immunoglobulin G inhibited both binding and uptake of 59Fe-labeled pyochelin by whole cells. Passive protection by anti-FBP was examined in experimental P. aeruginosa burn infections in mice. The protection provided by this antibody was strain dependent but lipopolysaccharide serotype independent.
Effect of cyclosporin A on immunity to Listeria monocytogenes
Authors: Hügin A W , Cerny A , Wrann M , Hengartner H , Zinkernagel R M
Published: January 2020

The effect of the immunosuppressive drug cyclosporin A (CS-A) on immunity to the facultative intracellular bacterium Listeria monocytogenes was investigated in unprimed and primed mice. Different treatment protocols were followed to evaluate the time dependence of CS-A-mediated immune suppression and the effect of CS-A on immunological memory to L. monocytogenes. The effect of CS-A was observed only during and after activation of T cell-mediated immunity, whereas early resistance exerted by macrophages assessed 6 and 70 min after challenge remained unaffected. CS-A suppressed efficient elimination of L. monocytogenes even when given after day 3 of a primary infection. This contrasts with findings in other models, including viral infections, where CS-A must be administered very early in an immune response to suppress it. CS-A suppressed antibacterial resistance in mice primed at various times before challenge; suppression of protection was time dependent and was virtually complete in livers, whereas CS-A-resistant memory persisted in spleens for up to 10 months.
Clearance of endotoxin from blood of rabbits injected with staphylococcal toxic shock syndrome toxin-1
Authors: Fujiwaka H , Igarashi H , Usami H , Tanaka S , Tamura H
Published: January 2020

This study was undertaken to examine some of the properties of staphylococcal toxic shock syndrome toxin 1 (TSST-1) with regard to the clearance of endotoxin from blood. The concentration of endotoxin in blood was measured by using a chromogenic limulus test and modified perchloric acid method. When TSST-1, which produces fever in rabbits, was injected (100 ng/ml or 100 micrograms/ml per kg) intravenously (i.v.) into the animals, no measurable level of endotoxin was detected in the blood. In control animals, which were given 5 micrograms of endotoxin per ml per kg i.v., endotoxin could be detected in the blood at rapidly declining levels. These results suggested that TSST-1 might not lead bacterial endotoxin from other body sites into the blood. When the animals were given TSST-1 (1 to 100 ng/ml per kg) i.v. and then endotoxin (5 micrograms/ml per kg) i.v. 4 h later, endotoxin was detected in the blood at a high level, depending on the dose of TSST-1 injected. These results showed that TSST-1 inhibited the clearance of endotoxin in the blood; this clearance is thought to be mainly done by the reticuloendothelial system. In the animals given TSST-1 (100 ng/ml per kg) and endotoxin (5 micrograms/ml per kg) simultaneously, the endotoxin level in the blood was found to be higher than that in control animals given endotoxin only but lower than that in the animals given TSST-1 and then endotoxin at the same doses.
Isolation and identification of an exoantigen specific for Coccidioides immitis
Authors: Cox R A , Britt L A
Published: January 2020

Results of previous studies have established that mycelial-phase cells of Coccidioides immitis produce a heat-stable (HS) exoantigen that is specific for this fungus. In the present study, the HS exoantigen was isolated from a heterogeneous culture filtrate of C. immitis mycelia by using a combination of physicochemical procedures. Affinity chromatography of the culture filtrate on concanavalin A yielded two fractions: an effluent fraction that did not bind to the lectin and an eluate fraction that eluted in alpha-2-methylmannoside. Antigenic analyses by two-dimensional immunoelectrophoresis established that of the seven antigens detected in the unfractionated culture filtrate preparation, only two were present in the column effluent, and of these, only one was stable to heating at 56 degrees C for 30 min. Reactivity in the immunodiffusion assay for the HS exoantigen was demonstrable with the column effluent fraction and not the column eluate. The detection of only one precipitinogen in two-dimensional immunoelectrophoresis of the heat-treated concanavalin A effluent fraction, coupled with the reactivity of this fraction in the immunodiffusion assay for the HS antigen, provides strong, if not definitive, evidence that this antigen is the HS exoantigen. Purification of the HS antigen and the production of monospecific antiserum will provide the necessary reagents for the development of a sensitive and specific immunoassay for detecting the HS antigen in C. immitis cultures.
Purification and partial characterization of a non-O1 Vibrio cholerae hemolysin that cross-reacts with thermostable direct hemolysin of Vibrio parahaemolyticus
Authors: Yoh M , Honda T , Miwatani T
Published: January 2020

A newly identified hemolysin (NAG-rTDH), which is related to the thermostable direct hemolysin (Vp-TDH) of Vibrio parahaemolyticus produced by non-O1 Vibrio cholerae, was studied. NAG-rTDH was purified by successive column chromatographies on DEAE-cellulose and an immunoaffinity column coupled with anti-Vp-TDH immunoglobulin. The molecular weight of NAG-rTDH was estimated as 18,500, similar to that of Vp-TDH, as judged by sodium dodecyl sulfate slab gel electrophoresis, but its charge or molecular shape was different, judging from its electrophoretic mobility. The lytic activities of NAG-rTDH on erythrocytes of most animals were essentially similar to those of Vp-TDH, but that on sheep erythrocytes was different. The hemolytic activity of NAG-rTDH was stable on heating at 100 degrees C for 10 min, as was that of Vp-TDH. Immunological cross-reactivity between NAG-rTDH and Vp-TDH was demonstrated by both the Ouchterlony test and the neutralization test. Thus, we conclude that non-O1 V. cholerae produce a new type of hemolysin that is similar but not identical to the thermostable direct hemolysin of V. parahaemolyticus.
Properties of dermonecrotic toxin prepared from sonic extracts Bordetella bronchiseptica
Authors: Kume K , Nakai T , Samejima Y , Sugimoto C
Published: January 2020

A toxin with dermonecrotic activity (DNT) was purified from sonic extracts of Bordetella bronchiseptica L3 of pig origin at phase I by chromatographic and electrophoretic methods. The purification procedure was one developed for obtaining the Pasteurella multocida DNT from sonic extracts with some modifications. Dermonecrotizing activity of B. bronchiseptica-purified DNT was increased by 600-fold compared with that of the crude extract, and the average yield was about 3%. The toxin was homogeneous, as determined by Ouchterlony double immunodiffusion, crossed immunoelectrophoresis, and disk isoelectric focusing in polyacrylamide gels. The toxin gave a single band on polyacrylamide disk gel electrophoresis (PAGE) and sodium dodecyl sulfate-SDS PAGE. The molecular weight of the toxin was ca. 190,000 +/- 5,000, as determined by SDS-PAGE. The isoelectric point of the toxin was ca. 6.5 to 6.6. The minimal necrotizing dose of the toxin for guinea pigs was about 2 ng of protein per 0.1 ml, the 50% lethal dose per mouse was about 0.3 micrograms, and the minimal cytotoxic dose for embryonic bovine lung cells was about 2 ng/ml. The toxin was heat labile and sensitive to inactivation by trypsin, Formalin, and glutaraldehyde. The mildly trypsinized B. bronchiseptica DNT preparation dissociated into two polypeptide chains, with molecular weights of ca. 75,000 +/- 4,000 (fragment 1) and ca. 118,000 +/- 5,000 (fragment 2), after treatment with dithiothreitol-SDS or urea. Upon removal of dithiothreitol and urea from the dissociated DNT preparation, the fragments reassociated, and the DNT that was formed was indistinguishable from the native toxin.
Influence of body temperature on bacterial growth rates in experimental pneumococcal meningitis in rabbits
Authors: Small P M , Täuber M G , Hackbarth C J , Sande M A
Published: January 2020

We examined the role of fever as a host defense in experimental pneumococcal meningitis in rabbits. Twelve hours after intracisternal inoculation of an encapsulated type 3 Streptococcus pneumoniae strain, body temperature was manipulated by using two different anesthetic drugs: pentobarbital, which did not affect temperature, and urethane, which mitigated the febrile response to infection. Growth rates of pneumococci in cerebrospinal fluid were dramatically influenced by modification of the febrile response. Rabbits whose fever was not suppressed had mean bacterial doubling times of 2.76 +/- 1.43 h. Animals with a blunted febrile response had a significantly faster mean bacterial growth rate (doubling time = 1.10 +/- 0.27 h; P less than 0.02). When the antipyretic effect of urethane was counteracted by raising the ambient temperature, animals also showed a marked reduction in pneumococcal growth rates. In vitro, the pneumococci grew well at 37 degrees C in Trypticase soy broth (doubling time = 0.61 +/- 0.05 h) and in pooled rabbit cerebrospinal fluid (doubling time = 0.85 +/- 0.07 h). However, at 41 degrees C neither medium supported growth. Thus, body temperature appears to be a critical determinant of pneumococcal growth rates in experimental meningitis, and fever could be a host defense in this disease.
Antibody response to Giardia muris trophozoites in mouse intestine
Authors: Heyworth M F
Published: January 2020

The protozoan parasite Giardia muris colonizes the mouse small intestinal lumen. This parasite is cleared immunologically from the intestine of normal mice. In contrast, T-lymphocyte-deficient (nude) mice have an impaired immunological response to G. muris and become chronically infected. In the present study, trophozoites were harvested from the intestinal lumen of immunocompetent BALB/c mice and nude mice and examined for surface-bound mouse immunoglobulins by immunofluorescence microscopy. Immunoglobulin A (IgA) and IgG, but not IgM, were detected on trophozoites obtained from BALB/c mice, from day 10 of the infection onwards. Trophozoites from nude mice showed very little evidence of surface-bound mouse immunoglobulin at any time during the 5-week period immediately following infection of these animals with G. muris cysts. Intestinal G. muris infection was cleared by the BALB/c mice but not by the nude animals. The data suggest that parasite-specific IgA and IgG bind to G. muris trophozoites in the intestinal lumen of immunocompetent BALB/c mice. Intestinal antibodies that bind to trophozoite surfaces are likely to play an important part in the clearance of G. muris infection by immunocompetent mice. The inability of nude mice to clear this infection at a normal rate is likely to be due to impairment of Giardia-specific intestinal antibody production.
Complexing of bacterial lipopolysaccharide with lung surfactant
Authors: Brogden K A , Cutlip R C , Lehmkuhl H D
Published: January 2020

Lipopolysaccharides (LPS) from Escherichia coli, Salmonella typhi, Klebsiella pneumoniae, Serratia marcescens, or Pseudomonas aeruginosa were mixed with pulmonary surfactant to investigate their in vitro interaction. After 6 h of incubation at 37 degrees C, LPS-surfactant mixtures were examined by sucrose density gradient centrifugation. The E. coli LPS-surfactant mixture was examined by immunoelectron microscopy with protein A-colloidal gold. The binding that occurred between LPS and the surfactant vesicles resulted in a complex with a density higher than the density of the surfactant alone. The protein A-colloidal gold identified LPS in the LPS-surfactant complexes. The toxicity of E. coli LPS was enhanced by complexing with the surfactant when compared with the intraperitoneal injection into CF1 mice, even at a 64:1 ratio of surfactant to LPS. The complexing of LPS and surfactant in the lung may alter the physiologic properties of surfactant that contribute to the physiopathological changes observed with some types of pneumonia.
Binding of Staphylococcus aureus by human serum spreading factor in an in vitro assay
Authors: Fuquay J I , Loo D T , Barnes D W
Published: January 2020

Human serum spreading factor, an animal cell adhesion-promoting glycoprotein, bound Staphylococcus aureus in an assay in which association of bacteria to protein-precoated microtiter wells was quantitated. Interaction of human serum spreading factor with S. aureus suggests that this protein may play a role in host defenses and in the invasiveness and pathogenicity of microbial infections.
Functionally distinct monoclonal antibodies reactive with enzymatically active and binding domains of Pseudomonas aeruginosa toxin A
Authors: Chia J K , Pollack M , Avigan D , Steinbach S
Published: January 2020

Monoclonal antibodies (MAbs) are described which react with two discrete structural domains of Pseudomonas aeruginosa toxin A and which have two distinct functional profiles. The MAbs designated T3-1C7 and T4-1F2 reacted with a 46,000-dalton peptide similar to the putative B or binding fragment of toxin A. These antibodies neutralized the cytotoxic and lethal properties of toxin but had no effect on its ADP-ribosyl transferase activity. T4-1F2 interfered with the binding of toxin A to membrane receptors on mouse fibroblasts (L cells), although the epitope for the antibody appears to be distinct from the actual receptor binding site. The MAb designated T2-1H2 reacted with intact toxin A and with a cloned, enzymatically active carboxy-terminal polypeptide similar to the toxin A fragment. This MAb neutralized the ADP-ribosyl transferase activity of activated holotoxin and of the cloned peptide, but inhibited neither binding of toxin to membrane receptors nor its cytotoxic and lethal actions. The complementary specificity and function of these MAbs confirm the functional specialization of discrete structural domains within the toxin A molecule. Our findings suggest the greater antitoxic potential of antibodies that block binding, compared with those which inhibit the enzymatic activity of toxin A.
Solubilization and characterization of surface antigenic components of Erysipelothrix rhusiopathiae T28
Authors: Lachmann P G , Deicher H
Published: January 2020

The antigenicity of Erysipelothrix rhusiopathiae T28 (serotype 2) was investigated. Antigens were solubilized from the cell surface with detergents. By means of sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting it was shown that the molecular weight of the main antigenic component--a nonprotein--was 14,000 to 22,000. This major antigen was shown to be a polydisperse anionic polysaccharide located on the surface of E. rhusiopathiae. Affinity chromatography also revealed a number of immunologically active proteins with molecular weights of 78,000, 72,000, 68,000, and 48,000.
Antischistosomal effect of cyclosporin A: cure and prevention of mouse and rat schistosomiasis mansoni
Authors: Bout D , Deslèe D , Capron A
Published: January 2020

C57BL/6 mice infected with Schistosoma mansoni at day 0 and injected with cyclosporin A (CyA) either daily or from day -1 to day 3 were protected against schistosomiasis mansoni as indicated by a decrease in the number of worms recovered from the liver 45 days after infection. CyA treatment also protected rats and strains of mice with known immunity defects (nu/nu, P/N, CBA/N). Protection was evident against both primary and secondary infection in mice infected at day 0, reinfected at day 42, and treated daily with CyA either during the course of the experiment or only from day -1 to day 3, as indicated by the worm burden at day 67. In such an experiment of infection and reinfection, the immature worms were shown to be the target of CyA. Administration of the drug 27, 45, 62, or 100 days before infection confirmed the long-term protective effect of CyA. This drug did not evoke the killing of adult worms in vivo. These data confirm and define the curative and preventive effect of CyA against schistosomiasis mansoni.
Siderophore-mediated iron acquisition from transferrin by Pseudomonas aeruginosa
Authors: Sriyosachati S , Cox C D
Published: January 2020

Pseudomonas aeruginosa placed across a dialysis membrane from [55Fe]transferrin caused the mobilization of the iron from the transferrin side to the bacterial or dialysate side of the membrane. Although the bacteria were capable of obtaining iron from transferrin for growth, the siderophores of P. aeruginosa failed to convert iron bound to transferrin into dialyzable, low-molecular-weight chelates. The crucial factor produced by the bacteria which was not present when the siderophores were added alone was the acid produced from the glucose minimal medium. The siderophores mobilized considerable iron from transferrin when used in the dialysis assay at pH values between 5.0 and 6.0, values which were commonly found during incubation of bacteria in the assays. When the siderophores were tested individually, pyoverdin was more effective than pyochelin in mobilizing iron across dialysis membranes at pH values of 5.0 and 6.0, but neither had appreciable activity at pH 7.4. The amounts of iron mobilized from conalbumin were comparable to the amounts from transferrin, but there was negligible release from lactoferrin at the three pH values. When the two siderophores were combined, the level of iron mobilization was identical to that demonstrated by pyoverdin alone. When the dialysis membrane was removed and the bacteria were mixed with the siderophores and transferrin, pyoverdin was again more active than pyochelin in mediating iron transport. Although no pyochelin-mediated iron mobilization could be detected at pH 7.4, there was transport. Therefore, the bacteria appeared to be aiding the siderophores in iron mobilization from transferrin.
Shigella flexneri O-antigen epitopes: chemical and immunochemical analyses reveal that epitopes of type III and group 6 antigens are identical
Authors: Carlin N I , Wehler T , Lindberg A A
Published: January 2020

In the present investigation we studied the nature of a Shigella flexneri O antigen, the type III antigen. No structural entity has yet been attributed to this antigen. Phenol-water-extracted lipopolysaccharides (LPSs) from all S. flexneri serotypes possessing either group 6 antigen or both type III antigen and group 6 antigen were subjected to de-O-acetylation by weak alkali treatment. Two-dimensional nuclear magnetic resonance spectra of serotype 3a native LPS and de-O-acetylated LPS were completely resolved, confirming the established structure (L. Kenne, B. Lindberg, K. Petersson, E. Katzenellenbogen, and E. Romanowska, Eur. J. Biochem. 91:279-284, 1978) and proving that no other structural alteration was introduced by the treatment. Both native and de-O-acetylated LPSs of serotypes 1b, 3a, 3b, and 4b were tested in an enzyme-linked immunosorbent assay against four absorbed rabbit anti-S. flexneri antisera and three monoclonal antibodies with specificity for different parts of the S. flexneri type III antigen and group 6 antigen. Upon de-O-acetylation, all binding capacity for the tested antibodies was lost. The chemical and immunological results indicate that the type III and group 6 antigens of S. flexneri are one and the same, a result of the presence of the O-acetyl group in rhamnose III of the repeating unit of the S. flexneri O-antigen chain.
Factors responsible for increased susceptibility of mice to intestinal colonization after treatment with streptomycin
Authors: Que J U , Casey S W , Hentges D J
Published: January 2020

Streptomycin sulfate (5 mg/ml) was added to the drinking water of Swiss white mice. After treatment for 1 week, the mice were challenged orogastrically with 10(8) Pseudomonas aeruginosa cells. The organism failed to multiply in the intestinal tract of either treated or untreated animals, but could be recovered from contents and tissues after 48 h. In a previous study, Salmonella typhimurium was shown to multiply in the intestines of streptomycin-treated but not untreated mice when 10(3) organisms were used as inoculum. Streptomycin administration had little effect on Eh, protein or carbohydrate concentrations of cecal contents, or intestinal motility. However, it caused a statistically significant increase in water content and pH of contents and a decrease in the concentrations of acetic, propionic, butyric, and valeric acids. S. typhimurium multiplied in pooled cecal contents obtained from both streptomycin-treated and untreated animals, but its multiplication rate and total populations were significantly greater in contents from treated animals. P. aeruginosa did not multiply in contents from either treated or untreated mice. Similar results were obtained when the organisms were inoculated into nutrient broth adjusted to simulate the pH levels and volatile fatty acid (VFA) concentrations in cecal contents of treated and untreated mice. The addition of brain heart infusion broth to cecal contents from untreated animals, in concentrations that support multiplication of S. typhimurium and P. aeruginosa, did not reverse inhibition. The addition of VFA to cecal contents from treated animals to equal the concentration in cecal contents from untreated animals caused inhibition of a magnitude observed in cecal contents from untreated animals. The results indicate that VFA operating at the pH level of cecal contents of conventional mice inhibit the multiplication of both S. typhimurium and P. aeruginosa and restrict colonization of the intestine by these organisms. The decrease in VFA concentrations that occurs as a result of streptomycin administration adequately explains the increased susceptibility of treated mice to colonization with S. typhimurium. It does not explain the increased susceptibility of treated mice to P. aeruginosa colonization, however.
Expression of Mycoplasma pneumoniae antigens in Escherichia coli
Authors: Trevino L B , Haldenwang W G , Baseman J B
Published: January 2020

A genomic library of Mycoplasma pneumoniae was generated by using bacteriophage lambda EMBL3 as the vector. Screening of the library for the expression of M. pneumoniae protein antigens with adsorbed anti-M. pneumoniae serum revealed strong reactivity from a third of those clones which contained mycoplasma DNA inserts. Three of the most highly reactive clones were analyzed in detail and found to synthesize discrete mycoplasma proteins. Two carried overlapping fragments of mycoplasma DNA which encoded a protein that was readily detected in Escherichia coli after infection with recombinant bacteriophage. The third clone contained a novel mycoplasma DNA fragment which directed the synthesis of two additional mycoplasma proteins. Further screening of the library with antiserum raised against the major M. pneumoniae adhesin protein P1 (165 kilodaltons [kDa]) yielded one clone which produced an immunologically reactive protein of 140 kDa. Adsorption of anti-P1 serum by this clone selected a population of antibodies that were reactive with M. pneumoniae adhesin P1 (165 kDa). These results demonstrate that immunologically active M. pneumoniae proteins are synthesized in E. coli.
A common neisserial antigen evidenced by immunization of mice with live Neisseria meningitidis
Authors: Martin P M , Lavitola A , Aoun L , Ancelle R , Cremieux A C , Riou J Y
Published: January 2020

Mice immunized with live meningococci developed antibodies directed against various antigens of Neisseria gonorrhoeae and Neisseria meningitidis, as demonstrated by immunoblotting. An antigen of 70 kilodaltons appeared to be common and stable in all gonococcal strains tested and highly immunogenic in mice infected with N. meningitidis.
Gamma-interferon-induced inhibition of the growth of Rickettsia prowazekii in fibroblasts cannot be explained by the degradation of tryptophan or other amino acids
Authors: Turco J , Winkler H H
Published: January 2020

We examined the role of amino acid deprivation in gamma-interferon-induced (IFN-gamma) suppression of the growth of Rickettsia prowazekii in mouse L929 cells and human fibroblasts by measuring the amino acid pools in untreated and IFN-gamma-treated cells. In recombinant IFN-gamma-treated cultures of human fibroblasts, tryptophan was undetectable in both the intracellular pool and the extracellular medium. In contrast, tryptophan was not depleted from the intracellular pool or the extracellular medium of L929 cells treated with recombinant IFN-gamma or crude mouse lymphokines. None of the other amino acids measured was severely depleted in IFN-gamma-treated L929 cells and human fibroblasts. Extracts prepared from IFN-gamma-treated human fibroblasts exhibited indoleamine 2,3-dioxygenase activity, converting tryptophan into products that cochromatographed with N-formylkynurenine and kynurenine; however, extracts prepared from untreated human fibroblasts, untreated L929 cells, recombinant IFN-gamma-treated L929 cells, and mouse lymphokine-treated L929 cells did not degrade tryptophan. Human HeLa cells resembled the human fibroblasts in that they degraded tryptophan after IFN-gamma treatment. Similarly, mouse 3T3-A31 cells and mouse embryo fibroblasts resembled mouse L929 cells in that they did not degrade tryptophan. Supplementation of the extracellular medium with additional tryptophan reconstituted the tryptophan pool in mock-infected and R. prowazekii-infected, X-irradiated, IFN-gamma-treated human fibroblasts to values greater than those observed in untreated control cultures. However, reconstitution of the tryptophan pool did not relieve IFN-gamma-induced inhibition of rickettsial growth. Addition of kynurenine or N-formylkynurenine to rickettsia-infected human fibroblasts at concentrations four times the usual tryptophan concentration did not inhibit growth of R. prowazekii. We conclude that neither tryptophan depletion nor depletion of the other amino acids studied explains the inhibitory effect of IFN-gamma on rickettsial growth in mouse L929 cells. In IFN-gamma-treated human fibroblasts, either tryptophan depletion is not involved in the inhibition of rickettsial growth or tryptophan depletion and some other mechanism(s) together contribute to the inhibition of rickettsial growth.
Augmentation of host defense by a unicellular green alga, Chlorella vulgaris, to Escherichia coli infection
Authors: Tanaka K , Koga T , Konishi F , Nakamura M , Mitsuyama M , Himeno K , Nomoto K
Published: January 2020

Protection against Escherichia coli inoculated intraperitoneally into mice was enhanced by intraperitoneal, intravenous, or subcutaneous administration of a water-soluble, high-molecular-weight fraction extracted from a dialyzed hot-water extract from a strain of Chlorella vulgaris (CVE-A). The enhancing effect was detected with doses over 2.0 mg/kg and when doses were administered 1, 4, or 7 days before the infection. The elimination of bacteria from the spleen of CVE-A-treated mice was increased, and this enhanced elimination may have been related to the acceleration of superoxide generation and chemokinesis in polymorphonuclear leucocytes by CVE-A treatment. A cyclophosphamide-induced decrease in protection against E. coli could be prevented by subcutaneous administration of CVE-A.
Biological effects of anti-lipid and anti-protein monoclonal antibodies on Mycoplasma pneumoniae
Authors: Morrison-Plummer J , Leith D K , Baseman J B
Published: January 2020

Monoclonal antibodies directed against Mycoplasma pneumoniae surface components were examined for their ability to block mycoplasma attachment to chicken erythrocytes. Purified preparations of antibodies which recognize the major mycoplasma ligand mediating cytadherence (protein P1, 165 kilodaltons) inhibited attachment by more than 85% of the control values. Monoclonal antibodies reactive with two other surface proteins of 110 and 32 kilodaltons also blocked attachment. Surprisingly, monoclonal antibodies specific for M. pneumoniae lipids (J. Morrison-Plummer, D. H. Jones, and J. B. Baseman, J. Immunol. Methods 64:165-178, 1983) enhanced mycoplasma-erythrocyte binding. All antibodies examined had no effect on thymidine incorporation by M. pneumoniae.