bluuebunny/crossref_metadata_2025 huggingface dataset:
Production of C2 toxin by Clostridium botulinum types C and D as determined by its vascular permeability activity
Authors: Ohishi I , Sakaguchi G
Published: January 2020

Vascular permeability (VP) activity was demonstrated by intradermal injection of culture supernatants of Clostridium botulinum types C and D and strains producing only C2 toxin. The activity was enhanced markedly by treatment with trypsin. It was abolished by antiserum against C2 toxin and by antisera specific for components I and II of C2 toxin, but not by anti-type C or -type D neurotoxin serum. Of 14 strains examined, 10 had VP activity. No VP activity was demonstrated in the culture supernatants of C. botulinum type A, B, E, or F. These results indicate that VP activity is a function of the C2 toxin elaborated by C. botulinum types C and D and that the toxin possesses VP as well as lethal activities. These findings raise the possibility that VP activity of C2 toxin exerts synergic effect(s) with neurotoxin in the pathogenesis of botulism caused by type C and D strains.
Fate of Listeria monocytogenes in murine peritoneal macrophage subpopulations
Authors: Harrington-Fowler L , Wilder M S
Published: January 2020

Peritoneal macrophages derived from CD-1 and C57BL/6 mice were separated into distinct groups based on their buoyant densities on discontinuous gradients of Percoll and assayed for antibacterial activity against Listeria monocytogenes. Subpopulations of peritoneal macrophages derived from Listeria-immune mice present a wide variation in their ability to control intracellular infection. Distinct subsets were found which exhibited bacteriostatic and listericidal activity. The fractionation procedure yielded a population of peroxidase-positive macrophages which were devoid of antilisterial action. Subpopulations of resident and elicited macrophages were also functionally heterogeneous in their ability to restrict intracellular growth of bacterial. In some experiments, subclasses were examined for secretion of plasminogen activator and phagocytosis of latex particles. These activities varied considerably with the status of activation of the macrophages, but failed to correlate with antimicrobial activity within given subpopulations.
Differentiation of mumps virus strains with monoclonal antibody to the HN glycoprotein
Authors: Server A C , Merz D C , Waxham M N , Wolinsky J S
Published: January 2020

A hybridoma cell line secreting antibody of the immunoglobulin G3 isotype with kappa light chains and with activity against the HN glycoprotein of the Kilham strain of mumps virus was established. The antibody exhibited structural homogeneity in sodium dodecyl sulfate-polyacrylamide gel electrophoresis and had a microheterogeneous isoelectric spectrum characteristic of an antibody of monoclonal origin. The specificity of the monoclonal antibody, shown by immunoprecipitation performed with radiolabeled virus and infected cell lysates, was for the larger mumps virus glycoprotein. In functional assays the antibody inhibited the hemagglutinating and neuraminidase activities and neutralized the infectivity of the homologous Kilham strain of virus and clearly differentiated this strain from two heterologous strains, Enders and O'Take. The antibody was markedly less effective with the O'Take strain than with either the Kilham or Enders strain in inhibiting both hemagglutination and neuraminidase activity against the macromolecular substrate fetuin. The inhibition of the neuraminidase activity of the Kilham strain was independent of substrate size, the antibody inhibiting the hydrolysis of both fetuin and the trisaccharide neuraminlactose. By contrast, the antibody did not inhibit the hydrolysis of neuraminlactose by the two heterologous mumps strains. These results provide the first demonstration of antigenic differences between mumps virus strains and highlight the utility of monoclonal antibody in analyzing the structural basis underlying functional activities of the HN glycoproteins.
Chemiluminescence of human neutrophils induced by soluble stimuli: effect of divalent cations
Authors: DeChatelet L R , Shirley P S
Published: January 2020

The effect of three soluble stimuli, phorbol myristate acetate, concanavalin A, and the calcium ionophore A23187, on the luminol-enhanced chemiluminescence of human neutrophils was investigated. All three stimuli elicited a strong burst of chemiluminescence which was dose dependent. The effect of phorbol myristate acetate was independent of the presence of divalent cations in the medium and, in fact, was greater in the presence of ethylene glycol-bis(beta-aminoethyl ether)-N,N-tetraacetic acid. The effect of concanavalin A was greatly stimulated by the presence of calcium in the medium, although some reaction was observed in the absence of this cation. In contrast, chemiluminescence induced by A23187 was absolutely dependent upon the presence of extracellular calcium. These results suggest that the mobilization of calcium into the cell is a sufficient, but not necessary, stimulus for initiation of the respiratory burst. Compounds such as phorbol myristate acetate, which act independently of extracellular divalent cations, may function by altering the intracellular ratio of bound/free calcium.
Adhesion of piliated Escherichia coli strains to phagocytes: differences between bacteria with mannose-sensitive pili and those with mannose-resistant pili
Authors: Blumenstock E , Jann K
Published: January 2020

Escherichia coli with mannose-resistant (MR) pili, in contrast to those with mannose-sensitive (MS) pili, did not adhere to rat peritoneal macrophages and human polymorphonuclear granulocytes, as measured by use of radioactive bacteria and by the chemiluminescence response induced by the cell contact. With some MS-piliated E. coli strains, unpiliated bacteria, obtained by growth at a pilus-restrictive temperature, did show MS adherence to phagocytes, presumably by virtue of bacterial cell wall adhesins which, like MS pili, recognize alpha-mannose-containing structures of the phagocyte membrane. Possible roles of MR pili, MS pili, and MS cell wall adhesins in the unspecific cellular host defense are discussed.
Fungistatic capacity of sera from guinea pigs injected with various iron solutions: differences between Trichophyton mentagrophytes and Rhizopus oryzae
Authors: Duncan R L , Artis W M
Published: January 2020

The fungistatic capacity and serum ion levels (SI) of guinea pigs given subcutaneous injections of various iron solutions were examined. The administration of 2.0 ml of 0.1 M ferric ammonium sulfate, ferric sulfate, or ferric chloride subcutaneously had no significant effect on the SI 3 h after administration, whereas ferric ammonium citrate, ferric citrate, or ferrous sulfate elevated the SI to 50 to 140 times that necessary to saturate the unbound transferrin in normal sera. The sera from 11 of 15 guinea pigs with an elevated SI remained fungistatic for Trichophyton mentagrophytes, whereas 3 of 15 guinea pigs with an elevated SI remained fungistatic for Rhizopus oryzae. The sera from normal guinea pigs were consistently fungistatic for Rhizopus oryzae. The sera from normal guinea pigs were consistently fungistatic for both T. mentagrophytes and R. oryzae. These data suggest that subcutaneous administration of certain iron compounds can significantly elevate the SI without completely abolishing the fungistatic capacity of the serum.
Natural Cytotoxicity to Murine Cytomegalovirus-Infected Cells Mediated by Mouse Lymphoid Cells: Role of Interferon in the Endogenous Natural Cytotoxicity Reaction
Authors: Lee Gerald D. , Keller Robert
Published: January 2020

Lymphoid cells from unstimulated normal C57BL/6J mice were shown to lyse murine cytomegalovirus (MCMV)-infected syngeneic mouse embryo fibroblasts but not uninfected mouse embryo fibroblasts. This cytotoxicity by mouse effector cells was not restricted to MCMV-infected syngeneic cells since MCMV-infected xenogeneic rat heart fibroblasts were also lysed. Characterization of the effector cells mediating this cytotoxicity against MCMV-infected cells indicated that the effector cells are similar to described natural killer (NK) cells mediating lysis of tumor cells and virus-infected cells. Because of the described augmentation of NK activity by interferon, we examined the role of interferon in the NK reaction. Although low levels of virus-induced interferon were detectable in supernatants of MCMV-infected mouse embryo fibroblasts, no interferon was detectable in supernatants of MCMV-infected rat heart fibroblasts, a target significantly more sensitive to NK cytolysis than infected mouse embryo fibroblasts. We were able to augment the NK reaction against MCMV-infected cells by in vitro treatments with interferon. However, the amounts of interferon required for augmentation were significantly greater than the amounts generated by infected target cells. In vitro interferon-stimulated NK cells retained selective cytotoxic activity since they continued to remain incapable of lysing uninfected target cells. MCMV-infected rat heart fibroblasts induced more interferon and were also more susceptible to NK activity than MCMV-infected mouse embryo fibroblasts. In spite of this difference in interferon-inducing capacity, there was no augmentation of cytotoxicity of MCMV-infected mouse embryo fibroblasts when mouse splenocytes were cocultivated with both target cells. Finally, when production of interferon in the NK reaction was inhibited by the addition of actinomycin D, no reduction of NK activity was seen. Our findings suggest that native mouse NK cells can discriminate between MCMV-infected cells and uninfected cells, this ability leading to the selective lysis of the virus-infected cells. Furthermore, although we could demonstrate augmentation of NK activity by interferon, interferon activation of NK cells may not be a necessary precondition for the development of endogenous NK activity.
Potentiating effect of bile on enterotoxin-induced diarrhea
Authors: Lange S , Lönnroth I
Published: January 2020

The influence of bile acids on adenosine 3',5'-phosphate-induced intestinal secretion was studied in mice. Bile flow was stopped by ligation of the common bile duct, and secretion was induced in ligated loops of the small intestine. The decrease of bile led to inhibition of hypersecretion after challenge with heat-labile enterotoxins from Vibrio cholerae and Escherichia coli, as well as with prostaglandin E1. In contrast, the fluid response induced by dibutyryl-adenosine 3',5'-phosphate was unaffected by intestinal bile. Injection of bile or bile acids into intestinal loops before cholera toxin challenge restored the toxin-induced secretion in the bile-depleted intestine. At the subcellular level the decrease of intestinal bile led to inhibition of cholera toxin-activated adenylate cyclase, whereas the bile concentration did not influence the binding of 125I-labeled toxin to the intestinal epithelial cells. The results suggest that intestinal bile interacts with adenylate cyclase in the induction of fluid secretion by enterotoxins and prostaglandin E1.
Modulatory effect of iron on the pathogenesis of Pseudomonas aeruginosa mouse corneal infections
Authors: Woods D E , Sokol P A , Iglewski B H
Published: January 2020

The iron concentration of the culture medium used to prepare the inocula influenced the pathogenesis of mouse corneal infections by Pseudomonas aeruginosa. When the parental strain PAO1 was cultured in high-iron medium (5 micrograms of Fe per ml), it was less virulent than when it was cultured in low-iron medium (0.05 microgram of Fe per ml). The iron concentration of the growth medium had no effect on the virulence of a P. aeruginosa mutant which was resistant to the iron regulation of toxin A yields (PAO-toxFeR-18). A severely defective iron transport mutant, PAO-toxFeR-10, was avirulent regardless of the iron concentration of the growth medium. These studies indicate that both iron acquisition and iron regulation of toxin production are important factors in the determination of P. aeruginosa virulence.
Alteration of granuloma angiotensin I-converting enzyme activity by regulatory T lymphocytes in murine schistosomiasis
Authors: Weinstock J V , Boros D L
Published: January 2020

Granulomatous inflammatory lesions in murine schistosomiasis mansoni undergo a spontaneous diminution at the chronic phase of the disease concurrent with an increase in angiotensin I-converting enzyme (ACE) activity. The objective of this investigation was to determine whether T cells influence ACE activity within the granulomas. Cyclophosphamide and cimetidine treatments of mice, which augment delayed-type hypersensitivity reactions, enhanced liver granuloma size and decreased granuloma ACE activity. The suppression of liver granuloma by the adoptive transfer of spleen cells from chronically infected, immunomodulated mice into recipients with acute infection increased ACE activity of granulomas and granuloma macrophages. The increased ACE activity was dependent upon the transfer of Thy 1.2+ splenic lymphocytes. The level of the ACE activity was proportionate to the number of administered spleen cells. Thus, the level of ACE activity within the egg-induced granuloma is dependent upon T lymphocytes present in the spleen and granulomas of infected animals.
Physiology of "mutans-like" Streptococcus ferus from wild rats
Authors: Freedman M L , Coykendall A L , O'Neill E M
Published: January 2020

Strains of Streptococcus ferus isolated from the oral cavities of wild rodents inhabiting sucrose-rich and sucrose-poor environments have many traits in common with the "mutans" streptococci. Thus, S. ferus HD3 and 8S1, like cariogenic S. sobrinus 6715-13, from adherent, alpha (1 leads to 3) glucopyranosyl-glucose linkage-rich, plaquelike deposits in vitro and in vivo through the action of constitutive glucosyltransferase(s) enzymes on sucrose, produce and degrade intracellular polysaccharide, produce short-chain fatty acids from the catabolism of mono- and disaccharides, carry the c antigen of S. mutans, and penetrate, persist, and proliferate in a sucrose-augmented fashion in the oral cavities of specific-pathogen-free rodent caries models. However, unlike infection with common S. mutans, infection with tested S. ferus strains does not cause caries. This avirulence appeared to result more from the reduced aciduricity of S. ferus than from differences in glucosyltransferase complements. Studies showed that despite generally similar growth rates and extracellular glucan syntheses, the acidogenic metabolism of S. ferus was more inhibited by declining environmental pH than was cariogenic S. sobrinus 6715-13 and that, in vitro, less hydroxyapatite was solubilized by S. ferus metabolic end products. The physiology of these S. ferus strains demonstrated that, in addition to plaque formation and acid production, acid tolerance was crucial to the carious process.
Relationship of HeLa cell infectivity to biochemical, serological, and virulence characteristics of Yersinia enterocolitica
Authors: Schiemann D A , Devenish J A
Published: January 2020

Examination of 69 strains of Yersinia enterocolitica which represented 20 serotypes and nontypable isolates for HeLa cell infectivity by a roller tube technique that provided a quantitative index of infection showed that infectivity (index, greater than 3.50) was confined to strains of serotypes O:8, O:3, O:5, 27, O:9, O:1, O:1,2,3, O:2,3, O:4,32, and O:21. All strains that were HeLa positive were sucrose positive and negative for salicin, esculin, rhamnose, raffinose, melibiose, alpha-methylglucoside, and citrate. All HeLa-negative strains were either sucrose and salicin positive or were sucrose negative. Twenty-one strains were examined for virulence by the ability to produce guinea pig conjunctivitis and diarrhea in mice. Positive strains were limited to those that were HeLa positive and were autoagglutination positive and calcium dependent at 35 degrees C. There was no association between virulence and the ability to produce enterotoxin measured by the infant mouse assay. Loss of autoagglutinability and calcium dependency was accompanied by loss of virulence, but HeLa cell infectivity was unchanged. The results suggest that at least two properties are necessary for virulence: the presence of the V and W antigens, mediated by the same plasmid as autoagglutination and calcium dependency, and an invasive factor demonstrated in vitro by HeLa cell infectivity. These virulence properties are found in only certain biotypes of Y. enterocolitica.
Genetics of murine resistance to Trypanosoma cruzi
Authors: Trischmann T M , Bloom B R
Published: January 2020

Resistance to the protozoan parasite Trypanosoma cruzi is governed by multiple genetic factors, including at least one coded for by a locus in or near the major histocompatibility complex of the mouse. The influence of the H-2 locus on resistance was evident when H-2 congenic mice on a strain background of intermediate resistance were challenged or when the survival of H-2 typed F2 mice was followed. The H-2k haplotype of the susceptible C3H/An strain was associated with higher mortality when compared with the H-2b haplotype of the resistant C57BL/10 strain. Genetic studies showed that resistance was a dominant trait and increased with genetic heterozygosity. F1 mice derived from crosses between resistant and susceptible strains, or even between two susceptible strains, were much more resistant than either parent. Crosses between two resistant strains, C57BL/6J and DBA/2J, led to resistant progeny in the F1 and F2 generations; but when recombinant inbred strains derived from these parental strains were challenged, susceptible strains were identified, indicating that different genes were responsible for resistance in the two strains.
Group B, type III streptococcal cell wall: composition and structural aspects revealed through endo-N-acetylmuramidase-catalyzed hydrolysis
Authors: De Cueninck B J , Shockman G D , Swenson R M
Published: January 2020

Cell walls from a group B, type III streptococcus strain were prepared, purified by extraction with sodium dodecyl sulfate, and solubilized by the M-1 fraction of mutanolysin, an endo-N-acetylmuramidase obtained from Streptomyces globisporus. The lysate was resolved into three fractions by ion-exchange chromatography: a fraction containing peptidoglycan (PG) fragments, free of neutral and acidic sugars and of phosphate; a complex of PG fragments and group B-specific polysaccharide; and a complex of PG fragments and group B-specific polysaccharide and type III-specific polysaccharide. The PG-polysaccharide complexes were large and heterogeneous in molecular size. When subjected to base-catalyzed beta-elimination, both complexes were disintegrated, and polysaccharides and low-molecular-weight PG fragments could then be separated by gel filtration. The low-molecular-weight PG fragment-containing fraction contained muramic acid, glucosamine, alanine, lysine, glutamic acid, and serine in molar ratios (to lysine) of 0.92:0.98:3.01:1.00:1.00:0.05. Wall-derived, purified group polysaccharide contained rhamnose, galactose, glucosamine, and phosphorus in molar ratios (to galactose) of 5.03:1.00:1.00:1.05. It also contained an unidentified sugar. Wall-derived, purified type III polysaccharide contained galactose, glucosamine, glucose, and N-acetylneuraminic acid in molar ratios (to glucose) of 1.94:0.85:1.00:1.39. On a dry-weight basis, the whole wall lysate contained 19.8 and 20.6% of group and type polysaccharide, respectively. Neither glycerol nor ribitol was found, and all of the cell wall phosphorus was accounted for as polysaccharide, indicating the absence of a wall teichoic acid.
Antiviral activity of bacteria-derived human alpha interferons against encephalomyocarditis virus infection of mice
Authors: Weck P K , Rinderknecht E , Estell D A , Stebbing N
Published: January 2020

Bacteria-derived human leukocyte interferon (IFN) subtypes, IFN-alpha A, -alpha B, and -alpha D, and two hybrid IFNs, IFN-alpha AD and -alpha DA, were examined for both in vitro and in vivo antiviral activity. Two of these materials in highly purified form (IFN-alpha D and -alpha D) protect mice against lethal doses of encephalomyocarditis virus infection. A single dose of 1 microgram of protein of IFN-alpha D 3 h before infection conferred protection in both BDF1 and CD-1 mice against encephalomyocarditis virus infection, and multiple treatments with IFN-alpha D or IFN-alpha AD extend the mean survival time of infected mice. On a weight basis, IFN-alpha AD was approximately 100-fold more effective than IFN-alpha D. There is a direct correlation between the antiviral activity of the various human IFN species in L-929 cells and in mice for both single and multiple treatments before infection, but none of the cloned human IFN subtypes were effective when administered 24 h after infection. Mixtures of the two parental materials, IFN-alpha A and -alpha D, were not as protective as the hybrid molecule IFN-alpha AD, suggesting that IFNs with unique and altered species specificity can be produced by recombinant DNA methods.
Effects of corticosteroids and cyclophosphamide on a mouse model of Chlamydia trachomatis pneumonitis
Authors: Stephens R S , Chen W J , Kuo C C
Published: January 2020

Suppression of the inflammatory reaction with daily doses of cortisone acetate or cyclophosphamide substantially prolonged the pulmonary infection in mice which had been intranasally inoculated with a trachoma biotype of Chlamydia trachomatis. Titration of organisms recovered from the lungs of treated mice revealed a drop in titer after day 2 (postinfection), followed by a prominent increase on day 6. In cyclophosphamide-treated mice the infection was resolved after day 12, whereas in cortisone acetate-treated mice a significant titer remained after day 17. In contrast, no organisms were recoverable after day 6 in control mice treated with saline or in mice treated with hydrocortisone succinate. Histologically, the ability of cortisone acetate and cyclophosphamide to inhibit the inflammatory reaction correlated with the respective course of chlamydial pneumonitis. This study demonstrated that mice were intrinsically capable of sustaining a lung infection induced by a human strain of S. trachomatis.
Effect of hydrocortisone on macrophage response to lymphokine
Authors: Masur H , Murray H W , Jones T C
Published: January 2020

To define the suppressive effects of corticosteroids on mononuclear phagocyte antiprotozoal activity, normal resident peritoneal macrophages were exposed to hydrocortisone (HC) before, during, and after in vitro activation with cell-free supernatants (lymphokines). The presence of pharmacological concentrations of HC before or during lymphokine activation prevented normal macrophages from acquiring the capacity to either respond oxidatively to Toxoplasma gondii ingestion or to inhibit intracellular toxoplasma replication. HC had no effect, however, on the cells fully stimulated by lymphokine or on macrophages previously activated in vivo. These findings indicate that although HC does not impair the ability of activated macrophages to control intracellular protozoan infection, it does compromise the antimicrobial activity of the cell-mediated immune system by rendering normal macrophages unresponsive to lymphokine.
Relationship between cell wall synthesis in Propionibacterium acnes and ability to stimulate the reticuloendothelial system
Authors: Pringle A T , Cummins C S
Published: January 2020

The addition of chloramphenicol or tetracycline to exponentially growing cells of Propionibacterium acnes, which are not normally able to induce splenomegaly until they reach stationary phase, resulted in a rapid development of ability to induce splenomegaly in mice. However, the activity resulting from chloramphenicol treatment was arrested by the addition of penicillin or vancomycin, which showed that the activity was dependent on cell wall synthesis.
Fundus lesions after carotid injection of Streptococcus mutans in monkeys
Authors: Meyers S M , Rodrigues M , Vasil M L
Published: January 2020

Carotid injection of Streptococcus mutans in pigtail monkeys caused fundus lesions clinically resembling those seen in humans with bacteremia. On histopathological examination microabscesses occurred in the retina, choroid, and optic nerve. Bacteria were observed in the histopathological sections of the microabscesses, and S. mutans was cultured from the retina and choroid.
High-molecular-weight hemolysin of Clostridium tetani
Authors: Mitsui K , Mitsui N , Kobashi K , Hase J
Published: January 2020

Clostridium tetani excretes hemolysins of two size classes, a high-molecular-weight hemolysin (HMH), which was eluted near void volume of a Sepharose 6B column, and conventional tetanolysin (molecular weight, approximately 50,000). The total hemolysin activity in the culture supernatant increased sharply with growth of bacteria and remained at a high level during autolysis. The content of HMH, however, decreased from 41% at 4 h of culture to 0.4% at the early stage of autolysis. The cell bodies also exhibited hemolytic activity, 70% of which could be solubilized and separated into HMH and the 50,000 Mr tetanolysin as extracellular hemolysins. The activity ratio of HMH to the total solubilized hemolysins was 0.45, on the average, at 6 h of culture but was 0.23 at the middle of logarithmic growth. Partially purified HMH from both sources appeared as broken pieces of cytoplasmic membranes under an electron microscope. The ratio of proteins to phospholipids in HMH was found to 3.26, a value similar to that in cell membrane. The total cell hemolytic activity decreased by 90 or 75% upon addition of chloramphenicol or anti-tetanolysin serum, respectively, into a 6-h-old culture of bacteria. It is suggested that HMH is a complex of tetanolysin with a membrane fragment and releases the conventional tetanolysin during bacterial culture.
Adherence of Shigella flexneri to guinea pig intestinal cells is mediated by a mucosal adhesion
Authors: Izhar M , Nuchamowitz Y , Mirelman D
Published: January 2020

Guinea pig colonic epithelial cells released by treating sections of the colon with solutions containing EDTA, dithiothreitol, and citrate avidly adhered Shigella flexneri bacteria. Separation of the intestinal cells from nonbound bacteria was achieved by differential sedimentation on a Percoll gradient. Adherence of S. flexneri to the colonic cells was Ca2+ (1 mM) and time dependent. The pH optimum was pH 6.2, and almost no attachment (less than 5%) was observed at low temperature (4 degrees C). The average number of bacteria which bound to colonic cells was 70 bacteria per cell, whereas attachment to cells isolated from the ileum region was 6 bacteria per cell. Colonic cells obtained from the intestine of rabbits or rats did not adhere Shigella. Adherence to guinea pig colonic cells was inhibited (50%) by several carbohydrates, such as 0.1% fucose or 0.5% glucose, as well as by a lipopolysaccharide preparation (10 micrograms /ml) isolated from S. flexneri. Fixation of the bacteria with glutaraldehyde or preincubation of the bacteria with lectins or proteolytic enzymes did not affect their adherence. Proteolytic digestions or fixation of the epithelial cells, as well as pretreatments with lipopolysaccharide or fucose solutions, abolished their ability to adhere bacteria. These results indicate that a carbohydrate-binding substance on the surface of guinea pig colonic epithelial cells is responsible for the attachment of the Shigella bacilli.
New fimbrial antigenic type (E8775) that may represent a colonization factor in enterotoxigenic Escherichia coli in humans
Authors: Thomas L V , Cravioto A , Scotland S M , Rowe B
Published: January 2020

An enterotoxigenic strain of Escherichia coli O25:H42 (strain E8775), isolated from a patient in Bangladesh with diarrhea, caused mannose-resistant hemagglutination (MRHA) of human and bovine erythrocytes. The strain did not show slide agglutination or immunodiffusion precipitin lines with antiserum specific for the colonization factor antigen CFA/I or CFA/II. A variant E. coli strain, E8775-B, did not cause MRHA or produce enterotoxin. Electron microscopy revealed the presence of fimbriae on the surface of strain E8775 but not strain E8775-B. When strain E8775 was grown at 22 degrees C, it became MRHA negative and fimbriae were absent. An antiserum prepared against strain E8775 was absorbed with strain E8775-B to make an antiserum specific for the fimbrial antigen. Using this absorbed antiserum, we found the fimbrial antigen in 48 of 742 enterotoxigenic E. coli strains. The 48 strains belonged to serogroups O25, O115, and O167. It is suggested by analogy to the properties of previously described colonization factors that these fimbriae may play a part in the colonization of the intestinal epithelium.
Uncoupled relationship between demyelination and primary infection of myelinating cells in Theiler's virus encephalomyelitis
Authors: Dal Canto M C
Published: January 2020

Theiler's virus infection in mice produces a chronic demyelinating disease which appears to be based on an immune pathogenesis rather than on direct viral destruction of myelin-supporting cells. The purpose of the present study is to ascertain whether viral antigen is present in the cytoplasm of such cells in areas of demyelination. Because of the difficulty of identifying oligodendrocytes in tissues rich in infiltrating mononuclear cells and fixed for immunohistochemistry, I turned to a recently described form of Theiler's virus encephalomyelitis which follows inoculation with the attenuated ww strain and is characterized by extensive spinal cord remyelination by invading Schwann cells and by recurrent demyelination of Schwann cell-remyelinated axons. The unlabeled antibody peroxidase-antiperoxidase technique was employed to study whether such spinal cord Schwann cells were primarily infected by virus at the time when recurrent demyelination was occurring. Whereas other types of cells, including neurons, astrocytes, and macrophages, contained abundant viral antigen, no positive immune reaction was observed in Schwann cells. These results correlate with our previous studies which had suggested that demyelination in this viral model is not dependent on primary viral attack on myelinating cells but is probably dependent on the host immune response.
Different effects of influenza virus, respiratory syncytial virus, and Sendai virus on human lymphocytes and macrophages
Authors: Roberts N J
Published: January 2020

Influenza virus, respiratory syncytial virus, and Sendai virus depress human cell-mediated immune responses, such as mitogen-induced lymphocyte transformation, but differ in their ability to induce other immune defense mechanisms, such as interferon production. Exposure to the different viruses resulted in depressed transformation responses to the mitogen phytohemagglutinin by affecting the function of lymphocytes, or macrophages, or both cell types.
Collagenolytic activity of Vibrio vulnificus: potential contribution to its invasiveness
Authors: Smith G C , Merkel J R
Published: January 2020

Vibrio vulnificus (lactose-positive vibrio) produced collagenase when grown in 2% synthetic sea salts supplemented with hydrolyzed casein. The addition of collagen or peptone to the medium increased the level of collagenase production. Collagenase activity was inhibited by EDTA but not by fetal calf serum.
Cell-mediated immunity in human cytomegalovirus infection
Authors: Fiorilli M , Sirianni M C , Iannetti P , Panà A , Divizia M , Aiuti F
Published: January 2020

The direct leukocyte migration inhibition test, in response to cytomegalovirus stimulation, was used to study cell-mediated immunity in a group of children with cytomegalovirus infection. The test was impaired in children with chronic disease associated with cytomegaloviruria. In those cases with no viruria at the moment of the test, leukocyte migration inhibition was normal. Our data suggest that the acquired chronic cytomegalovirus infection may be sustained by a state of specific cellular desensitization, as already demonstrated for congenital infection.
Cross-Immunogenicity of Pneumococcal Group 9 Capsular Polysaccharides in Adult Volunteers
Authors: Szu Shousun C. , Lee Chi-Jen , Parke J. C. , Schiffman Gerald , Henrichsen Jørgen , Austrian Robert , Rastogi Suresh C. , Robbins John B.
Published: January 2020

Group 9 organisms (types 9N, 9A, 9L, and 9V) account for about 3 to 4% of pneumococcal disease isolates throughout the world. Types 9N and 9V comprise about 90% of the group 9 disease isolates. Type 9N is more common than type 9V in adults, and type 9V predominates in infants and children. In the United States there have been eight reported cases due to group 9 pneumococci in individuals previously vaccinated; six were type 9V and two were type 9N. To ascertain the cross-immunogenicity of group 9 polysaccharides, volunteers were injected with vaccines of monovalent types 9N, 9A, 9V, or 9L, or bivalent (9N and 9A) or trivalent (9N, 9A, and 9V) polysaccharide vaccines. Monovalent types 9N, 9V, and 9L each stimulated a 5.8- to 7.5-fold geometric mean rise, and at least 80% of the volunteers responded with a twofold or greater homologous antibody rise. Type 9V induced a 5.8-fold geometric mean rise, but only 66% of the volunteers responded with a twofold or greater homologous antibody rise. Type 9N induced only a 2.1-fold geometric increase, and only 54% of the volunteers responded with a twofold or greater rise in anti 9V antibodies. Types 9L and 9A were the most cross-immunogenic. The trivalent preparation (9N, 9A, and 9V) gave the highest geometric mean titer and seroconversion rate to each of the group 9 polysaccharides. These results suggest that the polyvalent pneumococcal vaccine with its type 9N does not induce a satisfactory anti-type 9V response and should contain additional components in order to achieve greater protection against group 9 organisms.
Association between resistance to superinfection and patterns of surface protein labeling in mouse fibroblasts (L cells) persistently infected with Chlamydia psittaci
Authors: Moulder J W , Zeichner S L , Levy N J
Published: January 2020

When mouse fibroblasts (L cells) were persistently infected with Chlamydia psittaci strain 6BC, they became immune to superinfection because they no longer associated with exogenous C. psittaci in a way that led to ingestion and intracellular multiplication. At the same time, the persistently infected L cells also exhibited changes in surface structure as revealed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and autoradiographic visualization of the surface-exposed plasma membrane proteins that had been labeled with 125I by lactoperoxidase-catalyzed iodination. The most prominent changes were the appearance of a highly labeled band with an apparent molecular weight of 35,000 and the generalized reduction in intensity of labeling of proteins migrating in the apparent molecular weight range of 60,000 to 100,000. Neither resistance to superinfection nor alteration in cell surface structure depended on the presence of visible chlamydial inclusions. When L cells were cured of persistent infection, either spontaneously or by treatment with chlortetracycline or rifampin, immunity to superinfection disappeared, and the patterns of surface-labeled proteins of the cured cells once again resembled the patterns of wild L cells. It was suggested that resistance to superinfection is the result of reversible changes in the structure of the putative host cell receptor for chlamydiae that are produced in some unknown way by the persistent chlamydial infection.
Cell-mediated immunity in malnourished guinea pigs after Mycobacterium bovis BCG vaccination
Authors: McMurray D N , Yetley E A
Published: January 2020

Specific-pathogen-free guinea pigs were vaccinated with viable Mycobacterium bovis BCG and maintained on purified, isocaloric diets containing either 30% or 7.5% casein, or commercial chow. At intervals of 4, 5, 6, and 8 weeks postvaccination, groups of guinea pigs from each diet treatment were skin tested with purified protein derivative and killed. Protein-deficient animals exhibited progressive reductions in total serum proteins and albumin. Significantly greater numbers of viable M. bovis BCG were recovered from the vaccination site and inguinal lymph nodes of protein-deficient guinea pigs at all intervals. In contrast, the development of delayed hypersensitivity was markedly retarded in the 7.5% casein group and was also reduced somewhat in the 30% casein group as compared to chow control. Peripheral blood lymphocytes from protein-deficient animals did not respond normally in vitro to a polyclonal T cell mitogen, phytohemagglutinin. These results demonstrate that protein-calorie malnutrition in this model impairs the development of cell-mediated immunity as evidenced by skin test anergy, lymphocyte hyporesponsiveness, and failure to control levels of viable M. bovis BCG after vaccination.
Ability of Neisseria gonorrhoeae, Neisseria meningitidis, and commensal Neisseria species to obtain iron from lactoferrin
Authors: Mickelsen P A , Blackman E , Sparling P F
Published: January 2020

The ability of 107 Neisseria isolates to compete for iron with human lactoferrin (LF) was examined. Each of 15 meningococci, 53% of 59 selected gonococci, and 24% of 33 commensal Neisseria could use LF-bound iron for growth. Isolates which could not obtain iron from LF were growth inhibited when sufficient LF was added to defined agar medium to bind available free iron. No difference was observed in the ability of colony type 1 and colony type 4 gonococci of the same strain to compete with LF for iron. LF was growth inhibitory for 50% of 22 disseminated disease isolates (DGI strains) and 51% of 35 local urogenital disease isolates (UGI strains). Only 14% of gonococcal isolates requiring arginine, hypoxanthine, and uracil for growth were able to compete with LF for iron, whereas 87% of all other gonococcal isolates could do so (P less than 0.005). Ability to obtain iron from LF does not appear to be required for survival of Neisseria on mucosal surfaces, nor essential for invasion of the bloodstream by gonococci. However, ability to utilize LF as a source of iron may contribute to differences in pathogenicity among certain gonococcal isolates.
Neutrophil response and function during acute cytomegalovirus infection in guinea pigs
Authors: Yourtee E L , Bia F J , Griffith B P , Root R K
Published: January 2020

The mobilization and functional characteristics of polymorphonuclear leukocytes (PMNs) at the site of an inflammatory stimulus were studied during acute cytomegalovirus infection in guinea pigs. Weanling Hartley strain guinea pigs were inoculated subcutaneously with approximately 10(6) 50% tissue culture infective doses of virulent salivary gland-passaged guinea pig cytomegalovirus. The virus was uniformly present in bone marrow, buffy coat, and casein-elicited peritoneal exudate cells 5 to 7 days after the inoculation. The mean numbers of circulating PMNs in the animals were 2,862/microliters in uninfected controls and 880/microliters in infected animals. The total peritoneal PMNs recovered 14 h after casein injection were 491 X 10(6) and 237 X 10(6) in control and infected animals, respectively. The number of 50% tissue culture infective doses of guinea pig cytomegalovirus per 10(6) purified peritoneal PMNs was 10(2.17). Neutrophil O2 consumption was similar in infected and control animals in response to either stimulation by a neutrophil activator, phorbol myristate acetate, or phagocytosis of Staphylococcus aureus. However, the maximal rate of H2O2 release and the percent killing of S. aureus by peritoneal exudate cells from infected animals were significantly reduced compared with uninfected controls during acute infection. Granulocytopenia, a decreased mobilization of PMNs to the site of the inflammatory stimulus, a diminished cellular release of H2O2 in response to a bacterial stimulus, and a modest reduction in bacterial killing were demonstrated during experimental acute cytomegalovirus infection. Such reductions in granulocyte number and function at inflammatory sites during this type of infection could alter antimicrobial defenses.
Composition of peptidoglycans in Bacteroidaceae: determination and distribution of lanthionine
Authors: Vasstrand E N , Jensen H B , Miron T , Hofstad T
Published: January 2020

Peptidoglycans of organisms belonging to the strictly anaerobic family Bacteroidaceae were investigated for the presence of lanthionine. Different procedures for the quantitation of lanthionine were compared. Performic acid and peroxide oxidation procedures on 35S-labeled peptidoglycan from Fusobacterium nucleatum Fev1 resulted in low yields of cysteic acid (42 and 60%, respectively) and many other additional unidentified oxidation products. Lanthionine was, however, recovered in high yield (89% or more) from acid hydrolysates of unoxidized peptidoglycans. Lanthionine was found exclusively in some species of Fusobacterium, in particular F. nucleatum, F. necrophorum, F. russi, and F. gonidiaformans, for which lanthionine may be ascribed a function as a taxonomic marker. Peptidoglycans of these bacteria are thus proposed to belong to a new chemotype, assigned A1 delta. One strain of Fusobacterium, F. mortiferum VPI 0473 contained both lanthionine and diaminopimelic acid in about equal proportions. Species of F.plauti had a composition atypic of gram-negative cells. Chemotypic differences were also indicated among the species of Bacteroides investigated. Thus, some species contained lysine and not diaminopimelic acid as the major dibasic amino acid (e.g., F. asaccharolyticus). It is concluded that peptidoglycans of gram-negative organisms constitute a somewhat more heterogeneous group than hitherto assumed.
Adsorption of Lysozyme from Human Whole Saliva by
Streptococcus sanguis
903 and Other Oral Microorganisms
Authors: Laible Nancy J. , Germaine Greg R.
Published: January 2020

Several strains of
Streptococcus sanguis, Streptococcus mutans, Streptococcus mitis, Actinomyces viscosus
, and
Actinomyces naeslundii
plus fresh isolates of
Streptococcus salivarius
were surveyed for their abilities to deplete lysozyme from human-whole-saliva supernatant. Bacteria were incubated in saliva for 60 min at 37°C and then removed by centrifugation, and the recovered supernatant solutions were assayed for lysozyme activity by using whole cells of
Micrococcus lysodeikticus
as the substrate. Mean lysozyme depletions by bacterial strains varied over a wide (eightfold) range. The greatest mean depletion of lysozyme (60 to 70%) was observed with
S. sanguis
(biotype I), serotype
b
of
S. mutans
, and the fresh
S. salivarius
isolates. The lowest mean depletion was noted with
S. mitis
(15%) and biotype II
S. sanguis
(ca. 30%). The remaining species and strains exhibited an intermediate degree of depletion. In studies with
S. sanguis
903, lysozyme was depleted by normal or heated (90°C, 30 min) bacteria and could be recovered from the organism. Furthermore, under appropriate conditions, lysozyme depletion by cells at 0 and 37°C was very similar. On the basis of these observations, we concluded that depletion was due to the adsorption of lysozyme by the organism. With
S. sanguis
903, lysozyme adsorption depended on the concentration of bacteria, time of incubation, and the ionic strength of the medium. The extent of adsorption, however, was independent of pH's of 3.9 to 8.3. When a low concentration of
S. sanguis
903 was used, lysozyme adsorption reached saturation (4 μg of adsorbed lysozyme per 10
7
cells) at 20 μg of lysozyme added per ml. Salivary lysozyme adsorption by several other oral microorganisms (
A. viscosus
WVU 626 and WVU 627,
S. sanguis
73×11,
S. mutans
BHT, and
S. salivarius
NG) was similar to that of
S. sanguis
903 in sensitivity to ionic strength. Lysozyme adsorption by
S. sanguis
903 from either a buffer solution or a saliva supernatant was more sensitive to ionic strength at 0 than at 37°C. On the basis of results from experiments in saliva versus buffer, we concluded that saliva had no major effect on the extent of lysozyme adsorption by
S. sanguis
903 other than providing a source of ionic strength. A comparison of pH and ionic strength effects on lysozyme adsorption by
S. sanguis
903 with literature reports of lysozyme lysis of whole cells and hydrolysis of cell walls, peptidoglycan, and (GlcNAc)
4
suggested that adsorption by
S. sanguis
903 was more dependent on electrostatic interactions than was lysozyme catalysis. The possibility is discussed that anionic bacterial surface components mediate lysozyme adsorption and temper the potential effects of lysozyme on the microorganisms.
Detection of gamma interferon in the sera of patients with Behçet's disease
Authors: Ohno S , Kato F , Matsuda H , Fujii N , Minagawa T
Published: January 2020

The serum levels of interferon (IFN) in 58 patients with Behçet's disease were significantly higher than those in 79 normal controls (P less than 0.0001). The average IFN titer was 51.4 +/- 9.3 IU/ml in the patients and 5.9 +/- 1.1 IU/ml in the controls. The patients were then divided into two groups according to the stage of ocular disease. Forty-six patients in the ocular convalescent stage had higher IFN levels (61.3 +/- 11.2 IU/ml) than did 12 patients in the exacerbation stage (13.2 +/- 3.0 IU/ml). Moreover, the kinetics of the IFN level in the circulation of seven patients showed a significant decrease of IFN in the exacerbation stage. IFN activity in sera from patients was destroyed by acid treatment and heating at 56 degrees C for 30 min and was not neutralized with anti-human IFN-alpha and -beta sera. In addition, it was demonstrated that vesicular stomatitis virus inhibitors detected in sera from both the patients and the controls had no effect on our IFN assay. Therefore, antiviral activity detected in sera of patients seems to be due to gamma interferon (IFN-gamma). IFN-gamma may play a significant role in the pathophysiology of Behçet's disease.
Mechanisms of action of Mycobacterium bovis BCG-induced suppressor cells in mitogen-induced blastogenesis
Authors: Turcotte R , Lemieux S
Published: January 2020

Spleen cells from Mycobacterium bovis BCG-infected C57B1/6 mice when cultured in vitro for 72 h elicited soluble suppressor mediators capable of nonspecifically suppressing the mitogen-induced blastogenesis of normal splenocytes. Maximal production of suppressor mediators occurred during the first 24 h in culture, and their production ceased after 72 h. Attempts to isolate the mediators from fresh nonincubated splenocytes failed. After incubation, a strong residual suppressive activity was constantly detected in cell preparations used for production of suppressor factors. Supernatants prepared from cultures of spleen cells of mice infected 14 days earlier possessed higher suppressive activity than did those obtained 28 days after infection. In contrast, the residual cellular suppressive activity increased during the course of the infection. Although the activity of soluble factors was not inhibited, the residual activity of incubated cells was highly depressed by the presence of mouse erythrocytes in the cultures. Thus, the incubated cells appear to act through a direct cell-to-cell contact with the mitogen-responding cells. Finally, the results of depletion experiments suggest that the two populations of BCG-induced suppressor cells, namely, T lymphocytes and macrophage-like cells, are able to elicit suppressor mediators and to retain thereafter suppressive activity.