bluuebunny/crossref_metadata_2025 huggingface dataset:
Response of mouse intestinal loop to botulinum C2 toxin: enterotoxic activity induced by cooperation of nonlinked protein components
Authors: Ohishi I
Published: January 2020

Botulinum C2 toxin, which is composed of two nonlinked protein components, components I and II, induced fluid accumulation in mouse intestinal loops. The secretory response to C2 toxin was initiated after a lag period of 1 to 2 h and increased gradually for at least 10 h. The activity of C2 toxin was enhanced by treatment with trypsin and abolished by neutralization with anti-component I or anti-component II sera. Neither component I nor component II alone induced the fluid accumulation in intestinal loops. The intestinal loop activity was demonstrated with the culture supernatants of strains of Clostridium botulinum types C and D that produced C2 toxin, but not with culture supernatants of strains that did not. None of the botulinum type A through F neurotoxins induced fluid accumulation in mouse intestinal loops. The results indicate that, in addition to lethal and vascular permeability activities, C2 toxin has an enterotoxic activity for which the cooperation of components I and II is necessary. The fluid accumulation in intestinal loops inoculated with C2 toxin was not diminished by removal of the toxin from the loops. Moreover, the secretory response was positive when intestinal lumina were exposed to component II followed by the removal of the component and inoculation with component I, but it was negative when the intestinal lumina were exposed to component I followed by the removal of the component and inoculation with component II. These results suggest that the secretory response of mouse intestinal loops to C2 toxin is induced by the binding of component II to the epithelial cell surfaces of the intestines and the consequent binding or penetration of component I into the cells.
Restricted replication of herpes simplex virus in spinal ganglia of resistant mice is accompanied by an early infiltration of immunoglobulin G-bearing cells
Authors: Cook M L , Stevens J G
Published: January 2020

In an attempt to define the nature of the difference in the susceptibility of C57BL/6 (resistant) and A/J (susceptible) mice to herpes simplex virus type 1, we initiated a study of virus progression through the nervous system. After inoculation of virus in a rear footpad, C57BL/6 mice were found to be more than 500-fold more resistant, but resistance did not extend to pseudorabies virus. In additional investigations, it was found that the virus was selectively restricted at the level of spinal ganglia in C57BL/6 mice. No intrinsic difference in the ability of this tissue from either mouse strain to replicate virus was found. However, by 4 days after infection, morphological investigations indicated that a mononuclear cell infiltrate was present surrounding infected neurons and satellite cells both earlier and in greater numbers in the ganglia of C57BL/6 mice. Immunohistochemical methods showed that most of these cells did not express Thy 1.2 antigen, but the vast majority bore immunoglobulin G. The mechanism by which these infiltrating cells could restrict virus spread is discussed.
Cytotoxicity and inhibition of normal collagen synthesis in mouse fibroblasts by lipoteichoic acid from Streptococcus pyogenes type 12
Authors: Leon O , Panos C
Published: January 2020

The toxicity of lipoteichoic acid (LTA) from Streptococcus pyogenes type 12 was investigated by using mouse fibroblasts in culture in the absence of serum. Morphologically, while low concentrations of LTA elicited a subtle effect characterized by progressive cellular degeneration with practically no release of protein, larger concentrations (greater than 50 micrograms/ml) of this amphiphile resulted in rapid death of cell monolayers. Metabolic studies utilized a concentration of LTA (17.5 micrograms/ml) which caused the smallest change in cell morphology in the least number of mouse fibroblast cells per monolayer. Under these conditions, cell monolayers showed an increase of 450% in their content of collagenous protein after exposure to LTA. However, the amount of such material secreted remained unchanged. Also, changes in the type of collagenous protein formed were observed after exposure to LTA. Collagenous protein accumulating intracellularly was found to be practically hydroxyproline-free. However, collagenous protein secreted by this cell line showed a significantly reduced content of hydroxyproline as compared with control cells unexposed to this coccal membrane component. Column chromatographic studies confirmed that the collagenous protein secreted by monolayers exposed to LTA was defective (under hydroxylated). It was concluded that LTA does not affect the amount of collagenous protein secreted. However, it does increase the amount of this protein formed and retained by this cell line as well as causing a reduction in the hydroxylation of proline in both intracellular and secreted collagenous material. A possible relationship between abnormal basement membrane morphology and disturbed collagen synthesis in post-streptococcal glomerulonephritis as related to LTA is discussed.
Production of staphylococcal enterotoxin F and pyrogenic exotoxin C by Staphylococcus aureus isolates from toxic shock syndrome-associated sources
Authors: Bonventre P F , Weckbach L , Staneck J , Schlievert P M , Thompson M
Published: January 2020

A total of 136 isolates of Staphylococcus aureus were tested for production of staphylococcal enterotoxin F (SEF) and pyrogenic exotoxin C (PEC), both of which have been identified as reliable indicators of toxic shock syndrome (TSS)-associated strains. SEF and PEC production by isolates from TSS-associated and other sources was tested independently in two laboratories, after which the two sets of data were compared. A 100% concordance between SEF and PEC production was obtained. The TSS toxin candidates were produced by 30 of 136 isolates, and in all instances SEF and PEC were made concurrently by the same strains; in no case was one toxin made and not the other. In the five groups of S. aureus tested, toxins were detected as follows: 23 of 25 (92%) acute TSS isolates, 2 of 48 (4.2%) genital non-TSS isolates, 2 of 16 (12.5%) recovered TSS isolates, 1 of 23 (4.3%) clinical nongenital isolates, and 2 of 24 (8.3%) enterotoxigenic food outbreak isolates. Comparison of purified SEF and purified PEC by immunological and biochemical criteria by immunodiffusion, isoelectric focusing, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and Western blot analysis show that the toxins are immunologically identical and strongly suggest that the two nominal TSS toxins are in fact a single protein.
Influence of lectins, hexoses, and neuraminidase on the association of purified elementary bodies of Chlamydia trachomatis UW-31 with HeLa cells
Authors: Bose S K , Smith G B , Paul R G
Published: January 2020

Using highly purified elementary bodies of Chlamydia trachomatis UW-31 (serotype K), we found that HeLa 229 monolayer cultures bound more 32P-labeled chlamydiae after pretreatment with the lectin wheat germ agglutinin. The lectin, on the other hand, inhibited competitively when chlamydial association was assayed in the presence of polycations. The two effects of wheat germ agglutinin were abolished when N-acetylneuraminic acid (NeuNAc)- or N-acetylglucosamine (GlcNAc)-preincubated wheat germ agglutinin was used. Brief exposure of HeLa cells to neuraminidase abolished the ability to bind the elementary bodies, whether or not polycations were present. Furthermore, at 5 degrees C but not at 37 degrees C, NeuNAc, GlcNAc and N-acetylgalactosamine inhibited chlamydial association only in the absence of the polycation DEAE-dextran. The results suggest that NeuNAc residues on the plasma membrane are the principal, but not the only, receptors for this strain of C. trachomatis.
Adherence and ingestion of Escherichia coli serotype 055 by trophozoites of Entamoeba histolytica
Authors: Bracha R , Mirelman D
Published: January 2020

Carbohydrate-binding activity present on the Entamoeba histolytica cell surfaces was found to mediate the adherence of two types of bacteria, Escherichia coli serotype 055 and Salmonella greenside 050. Adherence was inhibited by low-molecular-weight carbohydrates (10 mg/ml) such as galactose, lactose, and N-acetylgalactosamine, as well as by asialofetuin and the lipopolysaccharide extracted from E. coli 055. Mild periodate oxidation of the bacteria inhibited their adherence, whereas heat inactivation, glutaraldehyde fixation, or gamma-irradiation had no effect. On the other hand, pretreatment of trophozoites with glutaraldehyde, cytochalasin B, or cold (5 degrees C) abolished adherence. None of these treatments, however, affected the attachment of bacteria that contain on their cell surface type I pili with mannose-binding capacity. These findings lend further support to our earlier observations on how amoebae interact with bacteria.
Antibody responses induced by immunization of inbred mice susceptible and resistant to African trypanosomes
Authors: Mitchell L A , Pearson T W
Published: January 2020

We tested the ability of inbred mice that were either susceptible (strain A/J) or resistant (strain C57BL/6 and A/J X C57BL/6 hybrids) to African trypanosomes to produce specific antibodies to trypanosome antigens in the absence of living parasites. This experiment was carried out to eliminate the influence of trypanosome growth or metabolism on immune responsiveness. Mice were immunized with keyhole limpet hemocyanin or solubilized Trypanosoma brucei gambiense, and serum antibodies were measured in solid-phase radioimmunometric assays after primary and challenge injections. Both susceptible and resistant mice showed increases in keyhole limpet hemocyanin-specific or trypanosome-specific immunoglobulin M and immunoglobulin G after immunization. When immunized with trypanosome antigens, resistant mice made qualitatively and quantitatively superior specific immunoglobulin M responses, particularly to the trypanosome major variable surface glycoprotein. Susceptible A/J mice produced good specific antibody responses, although these were predominantly of the immunoglobulin G isotypes. These results show that A/J and C57BL/6 mice respond differentially in terms of immunoglobulin isotype and repertoire in response to injected antigens. The possibility that this differential antibody response influences susceptibility to African trypanosomes is discussed.
Interaction of human plasma fibronectin with cariogenic and non-cariogenic oral streptococci
Authors: Babu J P , Simpson W A , Courtney H S , Beachey E H
Published: January 2020

The interaction of purified human plasma fibronectin (Fn) with bacteria was studied with a variety of oral streptococci. Each of the strains of Streptococcus mutans, Streptococcus salivarius, Streptococcus sanguis, and Streptococcus mitis tested was aggregated by Fn to various degrees, depending on the concentration of Fn added to the test mixtures. Binding assays performed with radiolabeled Fn and various strains of streptococci demonstrated various capabilities to bind Fn, and the amount of Fn bound by each strain was paralleled by its Fn-induced aggregation, with S. mutans 6715 giving the highest values in both assays. Because of the avid binding of Fn by certain strains of potentially cariogenic streptococci, we investigated the possibility that Fn may be present in human saliva and may be adsorbed from saliva onto artificial tooth pellicles. Immunoreactive Fn was detected in paraffin-stimulated whole saliva by enzyme-linked immunosorbent assays of saliva adsorbed onto gelatin-coated cuvettes and by immunoelectroblots (Western blots) of salivary components separated on sodium dodecyl sulfate-polyacrylamide slab gels. Furthermore, immunoreactive Fn was found to be present in artificial tooth pellicles formed by incubating hydroxyapatite beads with whole human saliva. These results demonstrate that certain strains of oral streptococci bind to and are aggregated by Fn. The presence of Fn in artificial tooth pellicles suggests that this macromolecule may play a role in the attachment of potentially cariogenic and other oral streptococci to dental tissues.
Induction of active immunity with membrane fractions from Haemophilus influenzae type b
Authors: Burans J P , Lynn M , Solotorovsky M
Published: January 2020

Using Escherichia coli strain E-1 as a model, we developed procedures for the preparation of outer- and inner-membrane-enriched fractions as structural units. These procedures could be used to prepare relatively pure inner and outer membrane fractions as determined by succinate dehydrogenase activity, ketodeoxyoctonate levels, and polyacrylamide gradient gel electrophoresis. The use of these procedures to fractionate membrane components from Haemophilus influenzae type b strains H-2 and H-E led to good separation of outer- and inner-membrane-enriched fractions as determined by succinate dehydrogenase and ketodeoxyoctonate levels but incomplete separation as determined by polyacrylamide gradient gel electrophoresis. Although there were differences between the electrophoresis profiles of outer membrane fractions of strains H-2 and H-E, immunization with outer membrane of either strain led to the induction of a high degree of immunoprotection against challenge with the H-2 strain. Protection could also be elicited with inner membrane preparations, but such protection may be due to contamination with outer membrane. Extracted membrane protein induced levels of protection that were comparable to those induced by whole membrane fractions.
Ultrastructural localization of protein antigens I/II and III in Streptococcus mutans
Authors: Moro I , Russell M W
Published: January 2020

Peroxidase-conjugated antibodies to antigens I/II and III were used to stain cells of Streptococcus mutans serotypes a through g. Under the electron microscope, serotypes that possessed these antigens showed deposits of peroxidase reaction products in association with the cell surface.
Antigenic variants are not selected during persistent infection with Theiler's virus
Authors: Leibowitz J L , Rodriguez M
Published: January 2020

In this study, we demonstrated that non-neutralizable antigenic variants of Theiler's murine encephalomyelitis virus do not predominate during the course of chronic relapsing infection.
Acquired chemotactic inhibitors during infection with guinea pig cytomegalovirus
Authors: Tannous R , Myers M G
Published: January 2020

Factors involved in neutrophil and monocyte migrations were serially studied in strain 2 guinea pigs undergoing initial cytomegalovirus infection and sham-inoculated controls. All studies remained unchanged in uninfected animals. Monocyte migrations and neutrophil spontaneous migration remained unchanged in infected animals. However, transient abnormalities occurred early in infection, comprising a decrease in neutrophil-directed migration towards C5-derived chemotactic fractions (C5-fr) and a decrease in the chemotactic activity of zymosan-activated plasma. Consequently, the presence of neutrophil- and chemotaxin-directed inhibitors in plasma was investigated. Normal neutrophils, C5-fr, Escherichia coli-derived bacterial factor, and the synthetic peptide F-met-leu-phe were first incubated with control or infected plasmas and then assayed for directed migration and lysosomal enzyme release. Results indicated the de novo appearance of both neutrophil- and chemotaxin-directed inhibitory activities in plasma during early infection. The neutrophil-directed inhibition was heat stable (56 degrees C for 120 min) and nonspecific (responses to all chemotaxins were inhibited). The chemotaxin-directed inhibition was heat stable and C5-fr specific. The cytomegalovirus-induced inhibitors may be important in the enhanced susceptibility to concurrent opportunistic infections.
Enhancement of dengue virus type 2 replication in mouse macrophage cultures by bacterial cell walls, peptidoglycans, and a polymer of peptidoglycan subunits
Authors: Hotta H , Hotta S , Takada H , Kotani S , Tanaka S , Ohki M
Published: January 2020

The effects of bacterial cell walls, peptidoglycans, and a water-soluble polymer of peptidoglycan subunits on dengue virus type 2 replication in cultured mouse peritoneal macrophages were studied. Pretreatment of macrophage cultures with all of test cell walls isolated from seven bacterial species for 3 days significantly enhanced the virus production in the cultures. Peptidoglycans prepared from four of the above cell walls also exerted the virus production-enhancing effects in a similar manner as the walls. A water-soluble polymer of peptidoglycan subunits which was prepared by treatment of Staphylococcus epidermidis wall peptidoglycan with an interpeptide bridge-splitting enzyme (endopeptidase) also definitely enhanced the virus production in macrophage cultures, although its activity was weaker than that of the original wall and peptidoglycan. Macrophage cultures from athymic nude mice, when treated with cell walls and peptidoglycans of S. epidermidis and Lactobacillus plantarum for 3 days, also showed an increased ability to support dengue virus type 2 replication. The infectious center assay demonstrated that the virus replication enhancement by S. epidermidis cell wall and peptidoglycan was primarily due to an increase in the number of virus-infected cells. This finding did not seem to be in conflict with the observation that macrophages treated with the above cell wall or peptidoglycan phagocytized more latex particles than did untreated macrophages. The conclusions based on the above experiments are that the treatment of mouse peritoneal macrophage cultures with bacterial cell walls and their components increases the take of dengue virus type 2 by macrophages and thus raises the virus production in the macrophage cultures.
Influence of one virus infection on a second concurrent primary in vivo antiviral cytotoxic T-cell response
Authors: Brenan M , Zinkernagel R M
Published: January 2020

The influence of one virus on the in vivo cytotoxic T-cell response to a different concurrent viral infection was analyzed. Lymphocytic choriomeningitis and Newcastle disease viruses, known to induce high interferon titers, and the synthetic interferon inducer polyriboinosinic acid-polyribocytidylic acid inhibited the cytotoxic T-cell response against the second virus. In contrast, vaccinia and vesicular stomatitis viruses failed to induce inhibition. Inhibition directly correlated with the interferon titers; similarly, the interferon titers directly correlated with macrophage and natural killer cell activation. The involvement in vivo of interferon in macrophage and natural killer cell activation and the possible mechanisms of inhibition of the cytotoxic responses are shown by the inhibition of the effect by antibodies against interferon.
Detection of antigenically distinct rotaviruses from infants
Authors: Dimitrov D H , Estes M K , Rangelova S M , Shindarov L M , Melnick J L , Graham D Y
Published: January 2020

Antigenically distinct rotaviruses, i.e., viruses morphologically identical to conventional rotaviruses by electron microscopy, yet lacking the common group antigen(s) detected by an enzyme-linked immunosorbent assay, were found in 2 of 51 fecal samples from Bulgarian infants with rotavirus gastroenteritis. These antigenically distinct viruses contained 11 segments of double-stranded RNA, but they demonstrated a unique RNA migration profile after electrophoresis of the genome RNA in polyacrylamide gels. This report confirms the presence of a new group of rotaviruses in humans. The significance of these viruses is currently unknown, and specific diagnostic tests must be developed for epidemiological studies to determine their role as human and veterinary pathogens and to evaluate their impact on proposed vaccine development programs.
Expression of murine leukemia viruses in RFM mice with host versus graft disease after perinatal inoculation of (T6 X RFM)F1 lymphohemopoietic cells
Authors: Cross S S , Brede G , Tucker H S , Maloney M , Montour J L , Hard R C
Published: January 2020

Host versus graft disease is the fatal syndrome of altered immunity that follows the perinatal inoculation of related F1 hybrid spleen cells to susceptible strains of inbred mice. The allogenic reaction results in severe depletion of T-lymphocytes, but causes hyperplasia and hypersecretion of B-cells. Among the long-term survivors of acute host versus graft reactions, there is a high incidence of nonthymic lymphomas associated with ecotropic murine leukemia virus that may be of donor F1 origin. The present studies were done to determine whether ecotropic murine leukemia virus played any role in the pathogenesis of acute host versus graft disease in RFM mice perinatally inoculated with (T6 X RFM)F1 spleen cells. In RFM/(T6 X RFM)F1 chimeras, N-tropic murine leukemia virus can be detected as early as 3 days. The progression of the disease was accompanied by increasing viral expression. The inoculation of N-tropic virus of F1 donor origin into RFM neonates failed to induce disease, although the virus proliferated. Detection of progressively rising titers of antibody to murine leukemia virus linked the virus to the development of hyperimmunoglobulinemia by virtue of its ability to serve as a replicating source of antigens. These and other studies provided evidence that the seemingly paradoxical appearance of hyperimmunoglobulinemia in T-cell-deficient mice with the host versus graft syndrome is due, at least in part, to the stimulation of presensitized F1 donor B-cells, which are not destroyed in the allogenic reaction, as are the T-cells. Another unusual finding was the detection of polytropic murine leukemia virus in 25-day-old RFM/(T6 X RFM)F1 chimeras. It is suggested that the allogenic host versus graft reaction favored the formation of recombinants.
Circulating immune complexes in patients with acute measles and rubella virus infections
Authors: Ziola B , Lund G , Meurman O , Salmi A
Published: January 2020

A solid-phase C1q radioimmunoassay was used to test for immune complexes (ICs) in sera obtained longitudinally from patients recovering from acute, uncomplicated measles and rubella virus infections. ICs were detected in 12 (18.5%) of 65 sera from 14 measles patients who did not have prolonged IC formation. Of 12 IC-positive measles sera, 9 were collected 4 weeks or more after rash onset. Transient appearance of detectable circulating ICs occurred sooner in 22 rubella patients who did not have prolonged IC formation. Of 109 rubella sera, 14 (12.8%) were IC-positive, and, of these, 10 were collected within 3 weeks of rash onset. Prolonged IC formation was found for an additional four measles and two rubella virus patients. Fractionation of sera from these six patients revealed that levels of large-sized ICs were highest in the initial 10 days after rash onset. Levels of large-sized ICs then declined to those for medium- and small (approximately immunoglobulin G)-sized ICs. IC-associated virus-specific antigens were detected in some of the sera from the six patients having prolonged IC formation. These results suggest two things: first, measles and rubella virus patients differ in the timing of virus clearance or in the reestablishment of normal immunity after infection; second, virus clearance is prolonged in some measles and rubella virus patients who have seemingly normal recoveries from their infections.
Identification of surface antigens of schistosomula of Schistosoma mansoni recognized by antibodies from mice immunized by chronic infection and by exposure to highly irradiated cercariae
Authors: Simpson A J , James S L , Sher A
Published: January 2020

Surface components of mechanically transformed schistosomula of Schistosoma mansoni were labeled by lactoperoxidase-catalyzed iodination. After solubilization with Triton X-100, antigens were identified by immunoprecipitation. Serum from chronically infected Swiss mice reproducibly precipitated seven major polypeptides with approximate molecular weights (X 10(3] of 94, 68, 45, 40 to 32, 22, and 16. The antigens of molecular weights (X 10(3] of 94, 40 to 32, 22, and 16 were shown to be exposed on the parasite surface by interaction of the antibodies with intact labeled schistosomula. Sera from several strains of infected inbred mice precipitated the same polypeptides. The antibodies produced during chronic infection were found to be stimulated by adult worms since sera from 6-week-infected animals precipitated none of the surface antigens, and the pattern produced by precipitation with antibodies from a mouse infected with male worms only was indistinguishable from the pattern obtained with sera from mice with bisexual infections. Antibodies from mice immunized with highly irradiated cercariae reproducibly precipitated major polypeptides of approximately (X 10(3] 94, 68, 45, 32, 22, 19, and 15 daltons. The antigens of (X 10(3] 94, 43, 32, 22, and 15 daltons were shown to be exposed on the parasite surface by interaction of the antibodies with intact labeled schistosomula. The 15 X 10(3)-dalton surface protein was recognized by sera from vaccinated, but not chronically infected, mice, suggesting that it represents a stage-specific immunogen present on schistosomula but not on adult worms. Sera from two inbred strains of mice which develop different degrees of immunity recognized the same antigens.
Measurement of antibodies to influenza virus neuraminidase by an enzyme-linked immunosorbent assay
Authors: Callow K A
Published: January 2020

The contribution of influenza A neuraminidase antibodies to the reaction with whole virus in an enzyme-linked immunosorbent assay (ELISA) was assessed by specific absorption of rabbit hyperimmune sera. Although measurable and independent, the effect of neuraminidase antibodies was less than that of hemagglutinin antibodies. Recombinants with an irrelevant hemagglutinin were used successfully as antigens in an ELISA test for measuring neuraminidase antibodies in rabbit hyperimmune sera, but a low cross-reaction between N1 and N2 subtypes was observed. However, for the measurement of N2 antibody rises in human sera, ELISA was highly specific and compared favorably with two other methods, neuraminidase inhibition and single radial hemolysis.
Circulating immune complexes in experimental syphilis: identification of treponemal antigens and specific antibodies to treponemal antigens in isolated complexes
Authors: Baughn R E , Adams C B , Musher D M
Published: January 2020

As a prelude to characterization of the host and treponemal antigens present in purified immune complexes from the sera of rabbits with disseminated syphilis, autoradiographic and immunoenzymatic analyses of solubilized extracts of Treponema pallidum, Treponema phagedenis biotype Reiter, and Treponema refringens were performed on electroblots of polypeptides first separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Electroblots of purified immune complexes were developed with the same panel of antisera so that protein profiles could be compared. Eight treponemal antigens were consistently present in isolated complexes; four of these cross-reacted with antisera prepared against avirulent treponemes. The average molecular weights of these antigens were 87,000, 76,000, 66,000, and 45,000. Antibodies dissociated from isolated immune complexes, when used for the development of T. pallidum electroblots, reacted with four antigens of comparable molecular weight. Antibodies to those polypeptides were also present in the sera of animals immunized with immune complexes. The demonstration of treponemal antigens in purified immune complexes convincingly argues that their occurrence in experimental syphilis is not merely due to tissue destruction and responses to endogenous host antigens.
Molecular identification of surface protein antigens of Campylobacter jejuni
Authors: Logan S M , Trust T J
Published: January 2020

The technique of immunoblotting was used to identify the surface protein antigens of Campylobacter jejuni. Polyclonal antisera were raised in rabbits to formalinized cells of a typical human fecal isolate, C. jejuni VC74. Surface components were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Fractions analyzed included whole cell lysates, sarcosinate-extracted outer membranes, released outer membrane blebs (fragments), isolated flagella, 0.2 M glycine-hydrochloride (pH 2.2) extract, saline extract, and material released by osmotic shocking. The ability of the antisera to recognize corresponding antigens on other strains of thermophilic campylobacters and Campylobacter fetus was also determined. The results demonstrated that heat-labile antigenic specificity was conferred on C. jejuni VC74 by an outer membrane protein with an approximate molecular weight of 92,500. Both the major outer membrane protein and the flagella were immunogenic but did not confer either strain or species serospecificity on the strains tested. Another major antigen on thermophilic campylobacter cells was a surface protein with an approximate molecular weight of 31,000. This common antigen was preferentially removed by glycine extraction but was not detectable in outer membrane prepared by sarcosinate extraction.
Species specificity of Bordetella adherence to human and animal ciliated respiratory epithelial cells
Authors: Tuomanen E I , Nedelman J , Hendley J O , Hewlett E L
Published: January 2020

Bacteria of the genus Bordetella adhere preferentially to ciliated respiratory epithelial cells. We investigated the specificity of this unique tropism by assessing the concentration-dependent adherence of the three Bordetella species to ciliated cells from different hosts. Bordetella pertussis and Bordetella parapertussis adhere better to human ciliated cells than to those from rabbits, mice, or hamsters. In contrast, Bordetella bronchiseptica demonstrates preferential adherence to nonhuman mammalian ciliated cells of rabbits, mice, and hamsters. There was no attachment of any Bordetella organisms to chicken ciliated cells. These observations suggest that specificities of attachment may explain the marked predominance of B. pertussis as the cause of whooping cough in humans and of B. bronchiseptica as a respiratory pathogen of many nonhuman mammals.
Isolation and characterization of Escherichia coli pili from diverse clinical sources
Authors: Salit I E , Vavougios J , Hofmann T
Published: January 2020

Bacteria which attach to different mucous membranes should have differing specificities of adherence in vitro. Human Escherichia coli isolates from blood and urine (pathogens) and from stool and throat (commensals) were characterized as to the patterns of hemagglutination (HA), as well as the structure and function of their pili. Bacterial HA was done in microtiter plates and on slides after bacterial growth in broth or agar. Human erythrocytes were agglutinated by 95% of the pathogens and 65 to 70% of the commensals grown in broth or agar. Mannose-resistant HA was characteristically caused by pathogens, and commensals characteristically caused mannose-sensitive HA of guinea pig cells. Strains often had both mannose-resistant and mannose-sensitive reactions, or even a mannose-paradoxical reaction. Pathogens more often caused HA, but titers were lower than those for commensals. Slide HA was less sensitive than the microtiter method. All isolates were piliated. Commensals also had more pili than pathogens when grown in broth (117.8 versus 38.3 pili per bacterium), but pathogens had more pili after growth on agar (32.1 versus 8.1 pili per bacterium). Isolates causing high-titer HA had large numbers of pili (greater than 85 pili per bacterium), but some well-piliated strains were non-hemagglutinating. Pili were purified from seven E. coli strains from different sites of isolation and with different erythrocyte-binding specificity. Pili usually migrated as a single band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. However, more than one type of pilus could be copurified from some strains since there were two or more bands after separation in octyl-glucoside and two different amino terminal sequences. Protein sequencing was done on five different pili: four resembled type 1 pili and one was a P fimbria. The type 1-like pili (strains 2239 and 9353) had an initial variable sequence of 1 to 5 residues, followed by a common region of 21 residues. The P fimbria (strain 7714) had different erythrocyte-binding specificity but was still 27% homologous with 2239 and 9353. E. coli strains from different body sites have characteristic attachments to erythrocytes. Pili derived from these different sources may also have different binding specificity, but they are similar in primary structure.
Preparation of a semisynthetic vaccine to Streptococcus pneumoniae type 3
Authors: Snippe H , van Dam J E , van Houte A J , Willers J M , Kamerling J P , Vliegenthart J F
Published: January 2020

A semisynthetic vaccine to Streptococcus pneumoniae type 3 has been developed. The hexasaccharide [leads to 3)GlcpA beta(1 leads to 4)Glcp beta(1 leads to]3 was isolated from a partial acid hydrolysate of the capsular polysaccharide S3. It was coupled to stearylamine by reductamination with NaCNBH3 and then incorporated into liposomes. These haptenated liposomes were tested for immunogenicity in mice. They induced protection to a lethal dose (25 50% lethal doses) of S. pneumoniae type 3 and gave rise to immunoglobulin M antibodies. No cross-protection was observed against S. pneumoniae type 11.
Modulation of myelopoiesis in vivo by synthetic adjuvant-active muramyl peptides: induction of colony-stimulating activity and stimulation of stem cell proliferation
Authors: Galelli A , Chedid L
Published: January 2020

Modulation of myelopoiesis by three synthetic muramyl peptides was investigated in vivo. Two adjuvant-active compounds (N-acetylmuramyl dipeptide [MDP] and MDP-butyl-ester) elicited significant responses in DBA/2 mice characterized by a rise in the level of monocyte-macrophage colony-stimulating activity in serum, a proliferation of multipotential stem cells in the bone marrow, and an expansion of granulocyte-macrophage progenitors in the spleen. In contrast, the adjuvant-inactive stereoisomer MDP(D-D) induced only low levels of circulating colony-stimulating activity. Thus, MDP or MDP-butyl-ester injection could induce a greater number of macrophages and therefore enhance both specific and nonspecific immunity.
Inhibition of keratinocyte proliferation by extracts of Actinobacillus actinomycetemcomitans
Authors: Kamen P R
Published: January 2020

A heat-labile sonic extract of a nonleukotoxic strain of Actinobacillus actinomycetemcomitans caused a dose-dependent inhibition of proliferation of human keratinocytes. Exposure of cells to heat-labile sonic extract for periods as brief as 10 min produced significant suppression of [3H]thymidine uptake 72 h later. I propose that alteration of epithelial barriers may be one pathogenic mechanism of this organism.
Clearance and tissue distribution of intravenously injected Salmonella typhi polysaccharide in rabbits
Authors: Isibasi A , Jimenez E , Kumate J
Published: January 2020

The interaction of Freeman polysaccharide of Salmonella typhi with blood and tissues of rabbits was studied by radioimmunoassay. After intravenous injection of 1.0 mg of S. typhi Freeman polysaccharide, a rapid clearance phase (t1/2, 6.0 min) was followed by a slower clearance period (t1/2, 55.2 min). These results suggest first, that the distribution of whole lipopolysaccharide is a function of how the polysaccharides are handled by the host; further, that the O side chain determines how and where lipopolysaccharide is cleared from the circulatory system; and finally, that Freeman polysaccharide regulates the toxicity of lipopolysaccharide by influencing its clearance from blood.
Type 1 pili (F1) of porcine enterotoxigenic Escherichia coli: vaccine trial and tests for production in the small intestine during disease
Authors: To S C , Moon H W , Runnels P L
Published: January 2020

This study was performed to determine whether the F1 (type 1) pili of a porcine strain of enterotoxigenic Escherichia coli are protective antigens and whether they are produced in the pig small intestine during disease caused by an enterotoxigenic E. coli. Reciprocal cross-absorption experiments with antisera prepared against F1 pili purified from enterotoxigenic E. coli 431 (O101:K30,99:H-:F1) and P14 (O149:K91,88ac:8H+:F1) demonstrated that the F1 antigens of the two strains were closely related or identical. Pregnant swine vaccinated with a vaccine prepared from strain P14 (F1+) responded with a significant increase in antibody against F1 in their serum and colostrum. However, the vaccinated dams did not significantly protect their suckling pigs against fatal challenge with strain 431. There was no evidence of F1 pilus production in the strain 431-infected pigs, as determined by immunofluorescent staining of ileal sections, direct electron microscopic examination of bacteria from ilea, and titration of serum agglutinins in convalescent pigs. It was concluded that strain 431 did not produce F1 in the small intestine during disease and that F1 was not a protective antigen in this system.
Nucleotide sequence homology between the immunoglobulin A1 protease genes of Neisseria gonorrhoeae, Neisseria meningitidis, and Haemophilus influenzae
Authors: Koomey J M , Falkow S
Published: January 2020

Isolated DNA fragments encoding the immunoglobulin A1 (IgA1) protease of Neisseria gonorrhoeae were used as hybridization probes to search for homologous sequences in whole cell DNA from Neisseria meningitidis and Haemophilus influenzae. Significant homology was detected. That the detected homology represented IgA1 protease-specific sequences was confirmed by the cloning of these sequences in Escherichia coli HB101 and demonstrating the expression of IgA1 protease by these transformed cells. Molecular probing of commensal Neisseria and Haemophilus species, which do not elaborate IgA1 protease activity, revealed that they were devoid of sequence homology with the cloned IgA1 protease gene DNA.
Induction of human gamma interferon by structurally defined polypeptide fragments of group A streptococcal M protein
Authors: Weigent D A , Beachey E H , Huff T , Peterson J W , Stanton G J , Baron S
Published: January 2020

The presence of interferon (IFN) has been demonstrated previously (i) in fluids obtained from the middle ears of children with Streptococcus pneumoniae infections, (ii) from the serum of mice injected intraperitoneally with either S. pneumoniae or Streptococcus pyogenes, and (iii) from human lymphoid cell cultures treated with a variety of bacteria. In this study, we showed that highly purified peptic extracts of three different serotypes of group A streptococcal M protein (pep M5, pep M6, and pep M24) stimulated human peripheral leukocytes to produce IFN. IFN production was apparent by 10 h and peaked 24 h after exposure. Dose-response experiments indicated that IFN could be detected in cultures treated with concentrations of M protein as low as 6 micrograms/ml, whereas maximum IFN production occurred at a concentration of 200 micrograms/ml. The IFN had antigenic and physicochemical characteristics of IFN-gamma. Preliminary leukocyte fractionation studies revealed that the IFN-producing cell was a nonadherent lymphocyte with receptors for sheep erythrocytes (T cell). Rabbit antisera specific for these structurally defined polypeptide fragments of streptococcal M protein (pep M5, pep M6, and pep M24) blocked IFN induction by each of the polypeptides. The data suggest that the different serotypes of streptococcal M protein may induce IFN by a common structural determinant shared by each of the polypeptide fragments tested.
Isolation and characterization of the outer membrane and lipopolysaccharide from Eikenella corrodens
Authors: Progulske A , Holt S C
Published: January 2020

The chemical composition of the outer membrane fractions (OMFs) of Eikenella corrodens strains 23834 and 470 as well as the strain 23834 lipopolysaccharide (LPS) was determined. The OMFs were obtained by Triton X-100 treatment of the heavier membrane fraction from sucrose density centrifugation of the total membrane fraction. The resulting OMFs of strains 23834 and 470, free of cytoplasmic membrane components, were found to contain 69.6 and 75.0% (wt/wt) protein, 4.8 and 9.2% lipid, 4.6 and 4.7% carbohydrate, and 2.0 and 4.6% muramic acid, respectively. By sodium dodecyl sulfate-polyacrylamide gel electrophoresis both OMFs contained one major peptide determined to be 33,500 daltons for the strain 23834 OMF, and 37,500 daltons for the strain 470 OMF. Analysis of the OMF fatty acids revealed hexadecanoic, hexadecenoic, octadecenoic, and lesser amounts of octadecanoic acids. Transmission electron microscopic examination of the OMFs revealed typical large sheets of membrane. Structures (10 nm in diameter) resembling pores were also evident. The E. corrodens LPS was found to be composed of 34.5% (wt/wt) carbohydrate and 25.0% lipid A. Only minute amounts of 2-keto-3-deoxyoctonate and heptose could be detected. Fatty acid analysis revealed primarily octadecanoic and hexadecanoic acids, with lesser amounts of octadecenoic acid. No hydroxy fatty acids were detected. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis showed the E. corrodens LPS to resemble other smooth-type LPSs. Transmission electron microscopic examination revealed a vesicle-like morphology. The E. corrodens LPS appears not to be a "classical," i.e., enteric, type of LPS.
Mode of cytotoxic action of pseudomonal leukocidin on phosphatidylinositol metabolism and activation of lysosomal enzyme in rabbit leukocytes
Authors: Hirayama T , Kato I
Published: January 2020

The cytotoxic action of leukocidin from Pseudomonas aeruginosa was supported by the following observations. (i) The destruction of rabbit leukocytes by the toxin was reduced in the absence of Ca2+ and stimulated by the addition of calcium ionophore A23187 but inhibited by EDTA, EGTA, and TMB-8, an antagonist of intracellular Ca2+ transport. (ii) Uptake of 45Ca into leukocytes exposed to the toxin was enhanced about threefold the rate of uptake into untreated cells. The increased 45Ca uptake into the cells was slightly inhibited by trifluoperazine, an inhibitor of Ca2+-calmodulin activity, but not by ruthenium red. (iii) Pseudomonal leukocidin enhanced rapidly the labeling of phosphatidylinositol, polyphosphoinositides, phosphatidic acid, and lysophosphatidic acid from [32P]phosphate. The time course experiments of the labeling and breakdown of these phospholipids suggested that the initial action of this toxin was to stimulate phosphatidic acid production, presumably causing a rapid metabolic change of phosphatidylinositol correlating with the activities of phosphatidylinositol-specific phospholipase C and 1,2-diacylglycerol kinase. It was considered that a rapid formation of phosphatidic acid and degradation of polyphosphoinositides might be related to a Ca2+ movement from extra- and intracellular space. (iv) In leukocytes exposed to the toxin, acid phosphatase activity as a marker enzyme of lysosome was activated up to 75% of the lysosomal enzyme before cell destruction. The leakage of lysosomal enzyme from the cells occurred at the almost same time as leukocyte destruction. The mode of cytotoxic action of pseudomonal leukocidin is discussed.
Genetic analysis of phase change in Bordetella pertussis
Authors: Weiss A A , Falkow S
Published: January 2020

Avirulent-phase derivatives of Bordetella pertussis (those which have simultaneously lost the ability to synthesize several virulence-associated factors) and the genetic mechanism of the phase change were studied. Increased tolerance to erythromycin was shown to be an avirulent-phase marker. By the use of efficiency of plating on erythromycin, the proportion of avirulent-phase (Vir) variants in a virulent-phase (Vir+) population was determined to be between 10(-3) and 10(-6), depending on the strain. We showed that the phase shift is reversible and detected a complete Vir- to Vir+ to Vir- to cycle. In other experiments, hybridization studies with avirulent-phase mutants obtained by Tn5 mutagenesis suggested that a single region located at a unique site in the B. pertussis chromosome controls the phase change. One of the avirulent Tn5 mutants was used as a recipient in a conjugative cross with a virulent-phase donor. All recombinants which had reacquired the virulence-associated factors also lost Tn5, indicating the loss of Tn5 was required to restore the Vir+ phenotype. The Tn5 avirulent-phase mutants behave as if the insertion interrupted the function of a transacting gene product which is required for the expression of the other virulent-phase genes. A model of the molecular basis of the phase regulation is presented.
T-cell hybridoma-produced lymphokine that activates macrophages to suppress intracellular growth of Histoplasma capsulatum
Authors: Wu-Hsieh B , Zlotnik A , Howard D H
Published: January 2020

Supernatants from concanavalin A-stimulated T-cell hybridomas activated macrophages to suppress the intracellular growth of Histoplasma capsulatum and to kill tumor cells. The supernatants had high interferon activity and were pH 2 sensitive and heat resistant. Gamma interferon is suggested to be among the active substances in the supernatants. Neither alpha interferon nor beta interferon activated macrophages for the Histoplasma growth inhibitory activity.
Lyt phenotype and H-2 compatibility requirements of effector cells in the delayed-type hypersensitivity response to dengue virus infection
Authors: Pang T , Devi S , Yeen W P , McKenzie I F , Leong Y K
Published: January 2020

The nature of effector cells which mediate delayed-type hypersensitivity (DTH) to dengue type 2 virus and the influence of the H-2 complex on the cellular transfer of DTH was investigated. The DTH effector cells appeared to consist of two types of T cells, one Lyt-1.1+, the other Lyt-2.1+ or, alternatively, an interaction between these two T cell subsets may be required for maximal expression of DTH. Cellular transfer of DTH reactivity also required compatibility at the K and D or I region of the H-2 complex. Compatibility at the D region alone was not sufficient for transfer of DTH. The significance and implications of these findings are discussed.
Bacterial translocation from the gastrointestinal tracts of rats receiving thermal injury
Authors: Maejima K , Deitch E A , Berg R D
Published: January 2020

Rats receiving nonlethal thermal burns over 20 or 40% of their total body surface area were tested at various intervals for the translocation of indigenous bacteria from their gastrointestinal tracts to their mesenteric lymph nodes, peritoneal cavities, and bloodstreams. No indigenous bacteria were cultured from these organs of control rats or from rats receiving 20% burns. However, 44% of the rats receiving 40% burns exhibited viable Escherichia coli, Proteus mirabilis, Staphylococcus sp. and Clostridium sp. in their mesenteric lymph nodes 2 days after thermal injury. Bacterial translocation after burn stress also was tested in antibiotic-decontaminated rats monoassociated with E. coli. E. coli attained population levels in these animals of 10(8) to 10(9) per g cecum. E. coli translocated to 100% of the mesenteric lymph nodes of both the control and 40% burned rats. However, E. coli translocated at a greater incidence to the spleens, livers, and peritoneal cavities of the burned rats compared with translocation to these organs in control rats. The numbers of E. coli translocating to the mesenteric lymph nodes, spleens, and livers also were greater in the 40% burned rats than in control rats. By 14 days after thermal injury, the rats were able to clear E. coli from their spleens and livers, and the infection remained localized in the mesenteric lymph nodes. These results support the concept that the indigenous gastrointestinal flora or exogenous organisms colonizing the gastrointestinal tract are potential sources of septicemia after thermal injury.