bluuebunny/crossref_metadata_2025 huggingface dataset:
Lytic sensitivity of Actinobacillus actinomycetemcomitans Y4 to lysozyme
Authors: Iacono V J , Boldt P R , MacKay B J , Cho M I , Pollock J J
Published: January 2020

The ability of both human and hen egg white lysozymes to lyse Actinobacillus actinomycetemcomitans Y4 was investigated. Lysis was followed optically at 540 nm by measuring the percent reduction in turbidity of freshly harvested log-phase cells suspended in Tris-maleate buffers within a wide range of pH (5.2 to 8.5) and molarity (0.01 to 0.2 M) and containing various amounts of enzyme and EDTA. In several instances, treated microorganisms were subsequently examined in thin sections by electron microscopy. Reductions in turbidity and clearing of suspensions occurred with small amounts of lysozyme (less than 1 microgram) under relatively alkaline conditions and at low ionic strength and in the presence of small amounts of EDTA (greater than 0.01 mM). Under the most alkaline conditions, EDTA alone effected turbidity reductions similar to those observed in the presence of lysozyme, which suggested that EDTA not only increased outer membrane permeability but also caused cell lysis. Ultrastructural analysis did not always correspond to turbidimetric observations. Cell lysis was virtually complete in suspensions containing both lysozyme and EDTA. However, in contrast to turbidimetric findings, a significant percentage of cells (greater than 25%) was lysed in the presence of lysozyme alone. Furthermore, significant damage occurred in the presence of EDTA alone. Spheroplast-like cell ghosts were present which surrounded condensed cytoplasm or relatively clear spaces. These findings further support the concept of the requirement for electron microscopy to assess lytic damage in addition to turbidimetric and biochemical methods. Our results are the first to demonstrate the remarkable sensitivity of A. actinomycetemcomitans Y4 to lysozyme and to show that EDTA not only affects outer membrane permeability but effects cell lysis, possibly through activation of autolytic enzymes at the cytoplasmic membrane. The exquisite sensitivity of A. actinomycetemcomitans Y4 to lysis could be an important mechanism by which lysozyme participates in the regulation of this suspected periodontal pathogen.
Molecular characterization of common treponemal antigens
Authors: Hanff P A , Miller J N , Lovett M A
Published: January 2020

A molecular characterization of cross-reactive antigens of Treponema pallidum Nichols and Treponema phagedenis biotype Reiter that are reactive with normal and syphilitic human sera is described. At least 8 common polypeptides, 14 T. pallidum-specific antigens, and 2 T. phagedenis biotype Reiter-specific antigens were identified.
Synovial fluid inhibits killing of Staphylococcus aureus by neutrophils
Authors: Simon G L , Miller H G , Borenstein D G
Published: January 2020

Serum in the extracellular environment promotes neutrophil bactericidal activity apart from its opsonizing properties. We examined the effect of non-inflammatory osteoarthritic synovial fluid on serum-mediated neutrophil killing of Staphylococcus aureus. This was done to evaluate the effect of synovial fluid on neutrophil bactericidal activity independent of opsonin concentration. With an initial inoculum of 5 X 10(6) CFU/ml, 1.47 +/- 0.14% bacteria survived after 120 min of incubation with 10% serum and neutrophils. In contrast, 4.07 +/- 0.33% bacteria survived after incubation in serum plus synovial fluid (P less than 0.001). This inhibitory effect was directly related to the concentration of synovial fluid in the incubation mixture. Increasing the concentration of synovial fluid resulted in an increased percent survival. Studies utilizing preopsonized bacteria and radiolabeled organisms demonstrated that synovial fluid did not interfere with opsonization or phagocytosis. Intracellular bactericidal activity was assayed separately from phagocytosis by utilizing a brief ingestion period followed by the removal of extracellular bacteria by either differential centrifugation or lysostaphin treatment. The reincubation of cells and associated bacteria with serum or serum plus synovial fluid revealed that synovial fluid significantly inhibited the promoting effect of serum on neutrophil bactericidal activity. After 60 min of incubation with 10% serum, 13.0 +/- 1.2% bacteria survived, whereas 21.5 +/- 2.3% survived after incubation in serum plus synovial fluid (P less than 0.005). Superoxide production was not affected by the presence of synovial fluid. These findings suggest that the inhibitory effect of synovial fluid is due to an interaction between synovial fluid and the serum factors that promote intracellular killing.
Immunogenicity of soluble and particulate antigens from Leishmania donovani: effect of glucan as an adjuvant
Authors: Cook J A , Holbrook T W
Published: January 2020

The protective efficacy of glucan as an adjuvant with killed promastigotes of Leishmania donovani was compared with that of soluble or particulate fractions of the parasite. When these vaccine preparations were injected either intravenously or subcutaneously in CF-1 mice, glucan potentiated resistance against L. donovani infections as reflected by significant reductions in hepatic amastigote counts relative to infected control mice. The leishmanial antigens alone afforded no protection. Serum direct agglutination titers to leishmanial antigens were highest in all groups given the vaccine intravenously, whereas the delayed-type hypersensitivity response to the antigen was positive only in groups immunized subcutaneously with glucan as an adjuvant. Some index of protection and immune response against visceral infection with the parasite was seen in groups vaccinated with glucan and soluble antigens. However, the protection afforded by glucan and particulate antigens of L. donovani more closely paralleled the resistance of mice treated with glucan and unfractionated killed promastigotes. Further antigenic analysis of particulate fractions of L. donovani may optimize effective immunization when used with appropriate adjuvants, e.g., glucan.
Dose response of A/Alaska/6/77 (H3N2) cold-adapted reassortant vaccine virus in adult volunteers: role of local antibody in resistance to infection with vaccine virus
Authors: Clements M L , O'Donnell S , Levine M M , Chanock R M , Murphy B R
Published: January 2020

An attenuated influenza A candidate vaccine virus, derived from the A/Ann Arbor/6/60 (H2N2) cold-adapted (ca) donor virus and the A/Alaska/6/77 (H3N2) wild-type virus, was evaluated in adult seronegative volunteers (serum hemagglutination-inhibiting antibody titer, less than or equal to 1:8) for level of attenuation, infectivity, antigenicity, and genetic stability. Four groups with similar preinoculation mean titers of serum and nasal wash antibodies were inoculated intranasally with 10(4.5), 10(5.5), 10(6.5), or 10(7.5) 50% tissue culture infectious doses (TCID50) of the ca reassortant virus, and eight other seronegative adult volunteers received the wild-type virus. Only 2 of 66 vaccinees developed fever or mild and brief systemic or upper respiratory tract illness or both. Both volunteers with vaccine-related reactions received the highest dose (10(7.5) TCID50) of ca virus, which indicates that the vaccine retains some mild reactogenicity at a high dosage. In contrast, four of eight volunteers infected with the wild-type virus became ill. Each of the 54 isolates tested retained the temperature-sensitive phenotype of the vaccine virus. Thus, the ca reassortant was genetically stable and attenuated at 10(4.5) to 10(7.5) TCID50 for seronegative adults. The 50% human infective dose of ca virus was approximately 10(5.3) TCID50. Ten and one hundred 50% human infectious doses infected 73 and 83% of vaccinees, respectively, and approximately 75% developed an immunological response at these doses. The failure of the vaccine virus to infect some volunteers was correlated with the presence of pre-inoculation nasal wash immunoglobulin A hemagglutinin antibody.
Lack of antibodies to human heart tissue in sera of rhesus monkeys immunized with Streptococcus mutans antigens and comparative study with rabbit antisera
Authors: Bergmeier L A , Lehner T
Published: January 2020

Immunization of rabbits and rhesus monkeys with Streptococcus mutans whole cells, cell walls, and defined streptococcal antigens (SAs) SA I/II, SA I, and SA II resulted in high antibody titers to SA I/II (10(-4) to 10(-6)) when tested by the solid-phase radioimmunoassay. Cross-reactive antibodies to heart homogenates (HH) were not elicited in rhesus monkeys. A few rabbits immunized with cell wall or SA II preparation in Freund complete adjuvant followed by the incomplete adjuvant yielded low antibody titers (up to 10(-2)) to the HH. The specificity of the putative heart cross-reactive antibodies was tested by immunoadsorption with related and unrelated antigens. Whereas antibody to SA I/II showed specific adsorption with SA I/II but not with HH, immunoglobulin G, or the unrelated antigens, antibody to HH seemed to have been adsorbed with all of the related and unrelated antigens. There was no evidence for the development of heart cross-reactive antibodies on immunization of rhesus monkeys or rabbits with SA I/II and aluminium hydroxide or Freund incomplete adjuvant, administered by the subcutaneous or intramuscular route in doses of up to 13 mg of the immunogen.
Immunoglobulin and complement in tissues of mice infected with Nocardia brasiliensis
Authors: Conde C , Mancilla R , Fresan M , Ortiz-Ortiz L
Published: January 2020

Two weeks after mice had been infected in the footpad with cells of Nocardia brasiliensis, immunoglobulin and C3 deposits were observed in tissue from the inoculation site. Both immunoglobulin and C3 were found in the actinomycotic granules that characterize the mycetoma and in the surrounding inflammatory zones, in which plasma cells were also present. Although anti-N. brasiliensis specificity was evidenced at 14 days postinfection in an eluate of infected tissue by an immunoenzymatic assay, no such antibody was found in the serum until 45 days postinfection. Immune complexes in the lesions, as indicated by the presence of C3, may also contribute to the pathology of the disease.
Effects of cell wall inhibitors on cell division in Streptococcus mutans
Authors: Kral T A , Daneo-Moore L
Published: January 2020

The addition of inhibitors of cell wall biosynthesis to exponential-phase cultures of Streptococcus mutans may do one of three things, depending on the concentrations used: (i) prevent cell division at a time coincident with the onset of chromosome replication, (ii) prevent cell division later in the cell cycle coincident with or near completion of septation, or (iii) lead to limited cell lysis. The relative tolerance of S. mutans to inhibitors of cell wall biosynthesis may be due to the fact that S. mutans cultures treated with low levels of cell wall antibiotics seem to be blocked at a stage before initiation of autolytic activity, whereas cultures treated with high levels of these antibiotics seem to be blocked after termination of the autolytic phase. Thus, the cells escape the lytic death that is seen in other streptococci exposed to inhibitors of cell wall biosynthesis.
Novel biological property of pertussis toxin: chemotactic activity on human monocytes
Authors: Ogawa T , Takada H , Kotani S , Sato H , Sato Y
Published: January 2020

Pertussis toxin isolated from Bordetella pertussis phase I strain Tohama enhanced the migration of human blood monocytes in an assay with a multiwell chemotaxis assembly. The monocyte migration enhancement by pertussis toxin was abolished by heating at 100 degrees C for 30 min, which caused a complete loss of the other biological activities of pertussis toxin. Checkerboard analysis demonstrated that the increased monocyte migration caused by pertussis toxin was directed toward a positive stimulus: chemotaxis.
Delayed expulsion of adult Trichinella spiralis by mast cell-deficient W/Wv mice
Authors: Ha T Y , Reed N D , Crowle P K
Published: January 2020

Mast cell-deficient W/Wv mice and their mast cell-sufficient littermates were given infections of Trichinella spiralis. W/Wv mice were slower than their littermates to expel adult T. spiralis. Repair of the mast cell deficiency of W/Wv mice by bone marrow grafting was accompanied by accelerated expulsion of T. spiralis.
Susceptibility of brain to aerobic, anaerobic, and fungal organisms
Authors: Costello G T , Heppe R , Winn H R , Scheld W M , Rodeheaver G T
Published: January 2020

The utility of an experimental animal model is dependent on its ability to simulate the actual clinical situation. With a stereotaxic injection procedure, the susceptibility of rat brain to the spectrum of organisms commonly associated with human brain abscess was determined. Two strains of Escherichia coli were more infective than Pseudomonas aeruginosa, Staphylococcus aureus, and Streptococcus pyogenes. Even between the E. coli strains it was possible to document significant differences in degree of infectivity. The E. coli strain with the K-1 capsular polysaccharide was significantly more infective than the E. coli strain without the capsular polysaccharide. The brain was also susceptible to Candida albicans, but at a level higher than any of the aerobic bacteria examined. Brain infection could not be created when microaerophilic or obligately anaerobic organisms alone were injected.
Oligonucleotide fingerprint analysis of enterovirus 70 isolates from the 1980 to 1981 pandemic of acute hemorrhagic conjunctivitis: evidence for a close genetic relationship among Asian and American strains
Authors: Kew O M , Nottay B K , Hatch M H , Hierholzer J C , Obijeski J F
Published: January 2020

Enterovirus 70 isolates obtained in Asia and the Americas between 1980 and 1981 from cases of acute hemorrhagic conjunctivitis were found to be very closely related by RNase T1 oligonucleotide fingerprinting. Two closely related isolates from the first acute hemorrhagic conjunctivitis epidemic (1969 to 1972) differed by many oligonucleotides from the 1980 to 1981 pandemic strains. The strong similarities of oligonucleotide patterns of isolates from the same epidemic but from distant regions of the world suggest that the genome of enterovirus 70 tends to be conserved during natural infection, a possible consequence of the transient nature of the disease.
Bacteriology of moderate (chronic) periodontitis in mature adult humans
Authors: Moore W E , Holdeman L V , Cato E P , Smibert R M , Burmeister J A , Ranney R R
Published: January 2020

A total of 171 taxa was represented among 1,900 bacterial isolates from 60 samples of sites affected with moderate periodontitis in 22 mature adult humans. The composition of the subgingival sulcus flora was statistically significantly different from that of the adjacent supragingival flora and the subgingival flora of 14 people with healthy gingiva, but was not significantly different from that of sulci affected with severe periodontitis in 21 young human adults. The sulcus floras of moderate periodontitis and severe periodontitis shared many of their predominant bacterial species, but there were differences in the relative proportions of some of these species. Similar relationships were found for seven taxa of treponemes that were cultured from the samples.
Isolation and preliminary characterization of circulating immune complexes from rabbits with experimental syphilis
Authors: Baughn R E , Musher D M
Published: January 2020

Immune complexes isolated from sera of rabbits with experimental, disseminated syphilis were found to have sedimentation coefficients greater than 19s. By radioimmunoblot assays, materials precipitated with 2.5% polyethylene glycol or chromatographed on DEAE-Affi-Gel Blue were found to contain albumin, C3, immunoglobulin M (IgM), IgG, and treponemal antigen(s), whereas control materials contained only albumin and IgG. When polyethylene glycol precipitation of immune complexes from syphilitic rabbits was followed by immobilization on protein A and acid elution, radioimmunoblots detected only IgG and treponemal antigen(s).
Binding of fibronectin to Staphylococcus strains
Authors: Switalski L M , Rydén C , Rubin K , Ljungh A , Höök M , Wadström T
Published: January 2020

Fibronectin, a major protein component of plasma and loose connective tissue has previously been shown to bind to several strains of Staphylococcus aureus. We examined a large number of strains of different species of Staphylococcus with respect to their ability to bind fibronectin. The relative numbers of strains defined as fibronectin-binders among the different species were as follows: S. aureus (22 of 23), S. haemolyticus (5 of 5), S. warneri (8 of 11), S. hyicus (5 of 6), S. hominis (13 of 17), S. saprophyticus (11 of 20), S. epidermidis (4 of 7), and S. simulans (8 of 10). Only three species showed a predominance of nonbinders over binders: S. capitis (4 of 14), S. xylosus (0 of 4), and S. cohnii (3 of 11). These data indicate that staphylococcal species isolated from soft tissue infections frequently have the ability to bind fibronectin and suggest that the ability to bind to this protein may contribute to the virulence of coagulase-positive and coagulase-negative staphylococci.
Monoclonal antibodies to subgroup 1 rotavirus
Authors: Singh N , Sereno M M , Flores J , Kapikian A Z
Published: January 2020

Subgroup 1-specific monoclones were analyzed and used successfully in an enzyme-linked immunosorbent assay to recognize certain subgroup 1 rotaviruses.
Aggregation of Streptococcus sanguis by a neuraminidase-sensitive component of serum and crevicular fluid
Authors: Morris E J , McBride B C
Published: January 2020

A number of strains of Streptococcus sanguis were found to aggregate in nonimmune serum and in crevicular fluid. All strains which aggregated in serum also aggregated in saliva, but some strains which aggregated in saliva did not aggregate in serum. Aggregation was destroyed by treatment of serum or crevicular fluid with neuraminidase and was inhibited by gangliosides. Treatment of serum with proteases reduced aggregating activity. Adsorption of serum to hydroxyapatite did not reduce the aggregating activity. The aggregating factor was partially purified by gel filtration and polyacrylamide gel electrophoresis and was found to be an acidic glycoprotein with a molecular weight of greater than 200,000, comprised of subunits with molecular weights of approximately 100,000. It did not appear to be an immunoglobulin and could not be identified with any other serum component tested. The possible role of the aggregating factor in providing nonimmune protection against colonization of S. sanguis in the gingival crevice and blood is discussed.
Enterobacterial common antigen-tetanus toxoid conjugate as immunogen
Authors: Lugowski C , Kułakowska M , Romanowska E
Published: January 2020

The methods of limited periodate oxidation and reductive amination were used to obtain covalently linked enterobacterial common antigen (ECA) with tetanus toxoid. This procedure is simple and gives a good yield of the conjugate with high ECA content (molecular ratio of ECA to tetanus toxoid, 6:1). The ECA-tetanus toxoid conjugate is immunogenic in rabbits, in contrast to free ECA or a mixture of ECA with proteins. This conjugate produces high levels of ECA-specific immunoglobulin G antibodies, which can be used as a standard serum.
Effect of human leukocyte interferon on invasiveness of Salmonella species in HEp-2 cell cultures
Authors: Bukholm G , Degré M
Published: January 2020

The effect of human leukocyte interferon on the invasiveness of Salmonella and Shigella species in HEp-2 cell cultures was examined. The intracellular and extracellular bacteria were identified by a combination of Nomarski differential interference contrast microscopy and UV incident light microscopy applied on the same microscope. Pretreatment of HEp-2 cells with human leukocyte interferon reduced the number of Salmonella typhimurium and Salmonella paratyphi-B bacteria per cell and the proportion of cells containing bacteria in a dose-dependent manner. Maximum inhibitory effect was observed with ca. 100 U of interferon per ml. The inhibitory effect was neutralized with anti-human interferon globulin. Murine fibroblast interferon did not influence the invasiveness of Salmonella species. Invasiveness of Shigella flexneri was not influenced by treatment of cells with human interferon.
Monoclonal antibodies against Neisseria meningitidis lipopolysaccharide
Authors: Sugasawara R J , Prato C , Sippel J E
Published: January 2020

A cell line producing monoclonal antibodies directed against a lipopolysaccharide component of Neisseria meningitidis group A has been established. These antibodies reacted with only one of three lipopolysaccharide serotyping strains of group A meningococci by coagglutination, enzyme-linked immunosorbent assay, and Western blotting techniques. A Western blot analysis showed that a NaOH digest of lipopolysaccharide was detectable by the serotype-specific antibody. The monoclonal antibodies cross-reacted with a group B meningococcal strain in an enzyme-linked immunosorbent assay. The immunoblotting analysis also showed that these antibodies reacted with the lipopolysaccharides of a group B meningococcus as well as Haemophilus influenzae type B, but not with the lipopolysaccharides of several strains of Salmonella typhi, Escherichia coli, Streptococcus pneumoniae, and Neisseria gonorrhoeae.
Organization of genes responsible for the production of mannose-resistant fimbriae of a uropathogenic Escherichia coli isolate
Authors: Clegg S , Pierce J K
Published: January 2020

A group of insertion mutants was used to define the genes of plasmid pDC5 required for the expression of mannose-resistant fimbriae. Minicell experiments identified four polypeptides (71,000, 45,000, 27,000, and 17,000 daltons) concerned with fimbrial production, the smallest of these being the fimbrial subunit. The approximate location of the structural genes encoding these polypeptides and one possible additional polypeptide not identified in minicell experiments has been established. Complementation experiments in vivo showed that these genes are arranged in more than one operon. The direction of transcription of the fimbrial genes was established by creating beta-galactosidase fusions by using the mini-Mu d1681 kanamycin resistance transposon.
Characterization of common virulence plasmids in Yersinia species and their role in the expression of outer membrane proteins
Authors: Portnoy D A , Wolf-Watz H , Bolin I , Beeder A B , Falkow S
Published: January 2020

The virulence plasmids pYV019, pYV8081, and pIB1 from Yersinia pestis, Yersinia enterocolitica, and Yersinia pseudotuberculosis, respectively, were characterized by restriction endonuclease analysis. The three plasmids exhibited a region of common DNA previously shown to encode determinants which confer Ca2+ dependence. The plasmids from Y. pestis and Y. pseudotuberculosis were similar throughout their genomes. In contrast, a region of the plasmid from Y. enterocolitica which contained an origin of replication differed from the other two plasmids as determined by DNA homology and replication properties. Plasmid-associated outer membrane proteins from all three species of Yersinia were characterized by polyacrylamide gel electrophoresis. There were no differences in the outer membrane protein profiles between plasmid-containing and homogenic strains lacking the plasmid after growth at 28 degrees C. After growth at 37 degrees C, both Y. enterocolitica and Y. pseudotuberculosis showed at least four major plasmid-associated outer membrane proteins. Y. pestis did not show any discernible changes after growth at 37 degrees C. It was shown by using E. coli minicell analysis that the plasmid DNA from all three species of Yersinia contained the coding capacity for production of the novel outer membrane proteins.
Characterization of Escherichia coli hemolysins conferring quantitative differences in virulence
Authors: Welch R A , Falkow S
Published: January 2020

Recombinant plasmids encoding hemolysins (hly) isolated from four different Escherichia coli strains were found to be very similar by restriction endonuclease fragment analysis within the hemolysin region. Each of the four recombinant plasmids were used to transform a nonhemolytic fecal strain of E. coli. The comparative virulence of the transformants was tested in a rat model of peritonitis. Despite the physical similarity among the hemolysin recombinant plasmids, each conferred different normally avirulent fecal E. coli strain. Reciprocal exchange of similar restriction endonuclease fragments enabled the construction of hybrid hemolysin determinants with two hemolysins of disparate extracellular hemolysin production and relative virulence levels. The hybrid plasmids were introduced into the standard avirulent fecal strain and tested in the rat peritonitis model. The region conferring quantitative differences in extracellular hemolysin production and virulence was found to be within a region of less than 1 kilobase where the hly c cistron is encoded as well as the probable transcription initiation ares for the entire hemolysin operon. A 750-base pair (bp) AvaI fragment from this region was isolated from a virulent hemolysin recombinant and inserted into a common AvaI site present in an avirulent hemolysin plasmid. This insertion resulted in an increase in the amount of extracellular hemolysin activity and the associated virulence when in the fecal E. coli background.
Priming of virus-immune memory T cells in newborn mice
Authors: Schwartz D H , Hurwitz J L , Greenspan N S , Doherty P C
Published: January 2020

Neonatal BALB/c mice can be primed at birth by intravenous inoculation of a small dose of A/Puerto Rico/8/34 (H1N1) (PR8) influenza virus. UV-inactivated PR8 virus, or PR8 virus complexed with monoclonal antibody to give a secondary cytotoxic T lymphocyte response when restimulated in vitro as adults. The frequency of responding T cells after secondary stimulation in vitro is approximately 40% of that found for adult mice primed intraperitoneally with a large dose of PR8 virus. The majority of the T cells generated from mice primed at birth or as adults are cross-reactive for H-2-compatible targets infected with the PR8 (H1N1) or A/Hong Kong/X31 (H3N2) viruses. Splenocytes from neonates receiving UV-inactivated vaccinia virus at birth give an augmented secondary cytotoxic T lymphocyte response when restimulated 8 days later in adoptive irradiated adult hosts. We found no indications of specific immunological unresponsiveness in mice exposed to either virus.
Isolation and characterization of Bordetella pertussis phenotype variants capable of growing on nutrient agar: comparison with phases III and IV
Authors: Peppler M S , Schrumpf M E
Published: January 2020

Unsupplemented nutrient agar (NA) was used to select spontaneous phenotype variants (PVs) of Bordetella pertussis Tohama I and 3779 which, by their growth on NA, could possibly be considered equivalent to phase IV in the system of Leslie and Gardner (P.H. Leslie and A.D. Gardner, J. Hyg. 31:423-434, 1931) or phase III in the system of Kasuga et al. (T. Kasuga, Y. Nakase, K. Ukishima, and K. Takatsu, Kitasato Arch. Exp. Med. 26:121-134, 1953). NA growers (Gna+) were selected from the flat, nonhemolytic, non-NA grower (Dom- Hly- Gna-) PV of both strains at a rate of between 10(-7) to 10(-8) per cell per generation. When cultured on Bordet-Gengou agar (BGA), more than one colony type was observed in strain 3779; these all retained the Gna+ characteristic during 10 to 30 passages on BGA. Analysis of 125I-surface-labeled whole cells by sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed no major changes between the Dom- Hly- Gna+ PV and their Dom- Hly- Gna- PV parents in polypeptide profile (by Coomassie stain), in surface exposure of proteins (by autoradiography), or in lipopolysaccharide profile (by silver stain). Increased resistance to oleic acid, tetracycline, erythromycin, rifampin, and penicillin G, however, was characteristic for the Dom- Hly- Gna+ PV. Five phase IV strains and a phase III B. pertussis strain had similar antibiotic and oleic acid sensitivity profiles as the Dom- Hly- Gna+ isolates and plated with similar efficiency on NA, despite heterogeneity in BGA colonial morphology and lipopolysaccharide profile.
Two physically and serologically distinct lipopolysaccharide profiles in strains of Bordetella pertussis and their phenotype variants
Authors: Peppler M S
Published: January 2020

The lipopolysaccharide (LPS) from nine strains representing 18 phenotype variants of Bordetella pertussis could be grouped into one of two distinct profiles by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and silver staining. One group, representing the wild-type LPS profile of B. pertussis, consisted of two silver-staining bands: a dominant brown-amber a band and a faster-migrating, minor, black-staining b band. The second group, representing a variant LPS profile, consisted of a single black-staining band of similar mobility to the b band in the wild-type profile. By electrophoretic transfer (Western) blot analysis, mouse antiserum raised against whole cells of Tohama I (prototype wild-type LPS strain) recognized only the a band from all strains/phenotypes possessing the wild-type LPS profile. In contrast, mouse antiserum raised against whole cells of 134 (prototype variant LPS strain) recognized all b bands, regardless of strain/phenotype, and could be shown to cross-react weakly with the a band from Tohama I. These results and results from cohemagglutination and immunodiffusion analyses support the classification of B. pertussis into one of two physiologically and serologically distinct LPS phenotypes: Lps AB for the wild-type profile and Lps B for the variant profile. The relationship of LPS type and phenotypic, or "phase," variation is discussed.
F41 antigen among porcine enterotoxigenic Escherichia coli strains lacking K88, K99, and 987P pili
Authors: To S C
Published: January 2020

Colonial morphological variations among enterotoxigenic Escherichia coli which lack K88, K99, and 987P (3P-) were shown to be correlated with expression of several surface antigens, i.e., type 1 pili, F41 pili, and somatic and capsular antigens. Such correlations were established by electron microscopy, serology, and hemagglutination of cells derived from these specific colonial types. Identification of F41 produced by the 3P- enterotoxigenic E. coli strains was made by immunodiffusion in agarose gel, immunofluorescence microscopy, subunit molecular weight determination in sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and hemagglutination of F41-piliated 3P- cells and purified F41 pili. Two of the 3P- enterotoxigenic E. coli strains were also shown to be virulent in conventional neonatal pigs and calves. Intense immunofluorescence staining by reference F41 serum of ileal villi of 3P- -infected animals indicated that F41 was expressed during the disease process.
Generation of chemotactic activity in serum by Haemophilus influenzae type b
Authors: Tosi M F , Kaplan S L , Mason E O , Buffone G J , Anderson D C
Published: January 2020

Studies were performed to characterize chemotactic activity generated by Haemophilus influenzae type b (HiTb) in serum or elaborated independent of serum. Neutrophil aggregometry, Sephadex G-75 gel chromatography, and anti-C5 neutralization studies were used to demonstrate that the complement fragment C5a represented the major chemotactic moiety derived from HiTb-serum interactions. HiTb elaborated minimal chemotactic activity independently. Maximal C5a generation by HiTb as measured by neutrophil response in chemotaxis, shape change, and aggregation assays required specific antibody to the capsular polysaccharide, polyribosyl ribitol phosphate (PRP). Significantly more C5a was generated in pooled normal human serum containing high titers of anti-PRP (determined by an enzyme-linked immunosorbent assay) than in hypogammaglobulinemic serum. Furthermore, C5a generated in hypogammaglobulinemic serum reconstituted with purified high-titer immunoglobulin G, hyperimmune rabbit serum or heat-inactivated normal human serum was comparable to that generated in normal human serum. Absorption of antibody with PRP versus whole HiTb showed a contribution by non-PRP-directed antibody. As shown with the use of C4-deficient guinea pig serum, C5a generation occurred via the alternative complement pathway in nonimmune serum, and activation of the alternative complement pathway was facilitated by specific anti-PRP. C5a generation in test sera was proportional to its opsonic activity for HiTb as assessed by a luminol-chemiluminescence assay. Overall low levels of C5a activity were observed in 13 pediatric patient serum samples obtained during the acute phase of HiTb meningitis, and no pulmonary symptoms or radiographic abnormalities consistent with a leukocyte aggregation syndrome were observed in these patients.
Effect of antiflagellar serum in the protection of mice against Clostridium chauvoei
Authors: Tamura Y , Tanaka S
Published: January 2020

Specific antiflagellar serum of Clostridium chauvoei showed a powerful protective effect which prevented bacterial growth in the liver, but not in infected muscle, against intramuscular challenge with calcium chloride-activated spores in normal mice. No protective effect was observed in mice with polymorphonuclear leucocytes depleted by cyclophosphamide treatment. The antiflagellar serum had approximately the same protective effect in mice with macrophages blocked selectively by carrageenan as it did in normal mice. We suggest that the antiflagellar serum exerted its effect by opsonic function and that opsonized C. chauvoei was eliminated mainly by polymorphonuclear leucocytes rather than by macrophages.
Isolation of protective antigens from Trypanosoma lewisi by using trypanostatic (ablastic) immunoglobulin G from the surface coat
Authors: Giannini S H , D'Alesandro P A
Published: January 2020

Antigens were purified from extracts of Trypanosoma lewisi on immunoadsorbent columns of trypanostatic immunoglobulin G eluted from parasite surface coats at 8 days postinfection. Eight absorbed proteins, with molecular weights between 15,000 and 70,000, were identified. These surface coat antigens (SCAgs) were then used to immunize rats. After immunization, sera were assayed in vitro for levels of circulating trypanostatic and trypanocidal antibodies. Approximately half of the immune sera had higher levels of trypanostatic antibody, compared with control sera; no trypanocidal antibodies (agglutinins) were detected in any of the sera. The rats were then challenged intraperitonally, and the parasitemias and division rates of the parasites were monitored. Parasitemias of all immunized rats were significantly (P less than 0.01) lower and of shorter duration than those of the controls. Division rates of trypanosomes were also significantly (P less than 0.01) lower in all immunized rats at all times before total cessation of division compared with control rats. A clear dose-response effect was observed, with greater amounts of SCAg eliciting higher levels of protection. Purified SCAgs were also more effective immunogens than were the crude trypanosome extracts from which they had been purified, and in which other proteins in addition to the SCAgs were present. These data provide conclusive evidence that the immunoglobulin G in the surface coats of T. lewisi, adsorbed during the course of infection, is specific antibody, in that it can be used to isolate parasite antigens that elicit a trypanostatic response in rats immunized with them.
Biological behavior of tumors and associated retroviremia in cats inoculated with Snyder-Theilen fibrosarcoma virus and the phenomenon of tumor recurrence after primary regression
Authors: Pedersen N C , Johnson L , Theilen G H
Published: January 2020

The fate of tumors and associated retroviremia was studied in 111 cats infected with the Snyder-Theilen strain of feline sarcoma virus (FeSV). Tumors appeared at the site of inoculation within 7 to 10 days. A retroviremia, due mainly to the associated feline leukemia virus helper virus (FeLV-helper), developed at the same time as tumors. Of the cats, 44 developed progressively growing tumors and therefore had to be killed, and 67 developed tumors that regressed. There was a strong correlation between the persistence of the accompanying retroviremia and the growth of the tumors. The 44 cats with progressively growing fibrosarcomas remained retroviremic until death. Conversely, 53 of the 67 cats with solitary, regressing tumors were only transiently retroviremic. Tumor regression in these cats paralleled the disappearance of retrovirus from the blood. The fate of tumors and retroviremia was not always the same, however. Twelve cats remained persistently retroviremic after all signs of gross tumors disappeared. Two other kittens became nonviremic within 20 days after inoculation, yet tumors continued to grow and even metastasize for another 3 to 5 weeks before regressing. Fibrosarcomas recurred 3 weeks to 8 months later in 8 of 12 persistently retroviremic cats with regressed tumors. Although the blood and bone marrow from these cats contained predominantly FeLV-helper, tumor cells yielded both FeSV and FeLV-helper. Of 53 animals, 3 developed recurrent fibrosarcomas 5 weeks to 8 months after all signs of tumors and retroviremia had disappeared. Cells cultured from these tumors appeared initially like normal fibroblasts and were virus nonproducers. After one to three passages in culture, however, cells became malignantly transformed and replicated both FeSV and FeLV-helper. Cultures of the bone marrow from these and other nonviremic cats with regressed tumors yielded only FeLV-helper.
Intra- and extracellular events in luminol-dependent chemiluminescence of polymorphonuclear leukocytes
Authors: Briheim G , Stendahl O , Dahlgren C
Published: January 2020

When polymorphonuclear leukocytes (PMNL) and soluble or particulate matter interact, the cells produce chemiluminescence. Luminol-dependent light emission from PMNL is linked to the myeloperoxidase (MPO)-H2O2 system. Light emission from a cell-free MPO-H2O2 system was found to be totally inhibited by human serum albumin (HSA), and since HSA is a large molecular protein that does not readily gain access to intracellular sites of PMNL, it could be used to determine the importance of extra- and intracellular events in PMNL chemiluminescence. In studies with cells from an MPO-deficient patient, we found that HSA inhibited more than 90% of extracellularly produced chemiluminescence. The chemotactic peptide formylmethionyl-leucyl-phenylalanine induced a two-peak chemiluminescence response in normal PMNL, and addition of HSA reduced the first peak, whereas the second peak was unaffected. This result indicated that the first peak was a result of extracellular reactions and the second peak was a result of intracellular reactions of the MPO-H2O2 system. Most of the phorbol myristate acetate-induced response in normal PMNL was due to intracellular events. Furthermore, chemiluminescence of intracellular origin seems to be limited not by generation of oxidative metabolites but by diffusion of luminol into the cells.
Mechanism of bacterial resistance to complement-mediated killing: inserted C5b-9 correlates with killing for Escherichia coli O111B4 varying in O-antigen capsule and O-polysaccharide coverage of lipid A core oligosaccharide
Authors: Joiner K A , Schmetz M A , Goldman R C , Leive L , Frank M M
Published: January 2020

The interaction of C3 and terminal complement components with three isogenic strains of Escherichia coli O111B4 varying in outer membrane and capsule composition was examined. Strains CL99 and 1-1, which possess O-antigen capsule and 74 to 77% coverage of lipid A core oligosaccharide, were sensitive to killing in pooled normal human serum (PNHS) or magnesium ethylene glycoltetraacetic acid PNHS in the presence but not the absence of antibody, although 1-1 contained 35% more lipopolysaccharide than CL99 and was slightly less sensitive to alternative pathway killing. In contrast, strain 1-2 lacks O-antigen capsule but contains 84% coverage and resists serum killing in the presence and absence of antibody in both PNHS and magnesium ethylene glycoltetraacetic acid PNHS. All three strains consumed C3 and C9 when incubated in PNHS, but consumption was most rapid with 1-2, which also bound the largest number of C3 molecules per CFU. Between 15 X 10(3) and 24 X 10(3) molecules of C9 per CFU bound to CL99 and 1-1 during incubation in 10% PNHS or 10% magnesium ethylene glycoltetraacetic acid PNHS, and binding was relatively stable. Binding and release of 3 X 10(3) to 8 X 10(3) molecules of C9 per CFU was observed for strain 1-2. The majority of C9 bound to CL99 and 1-1 in the presence of antibody distributed with the outer membrane after lysis of the organisms in a French press, whereas only 16.1 to 20.1% of C9 was deposited on these organisms in the absence of antibody, and 31.5 to 39.8% of C9 on strain 1-2 with or without antibody sedimented with the outer membrane. Between 4.6 X 10(3) and 5.5 X 10(3) molecules of C9 per CFU remained bound in a salt- and trypsin-resistant form to the outer membrane of organisms that were killed, whereas fewer than 1.4 X 10(3) molecules of C9 per CFU were bound to the outer membrane of organisms not killed by serum. These results indicate that C5b-9 that is bound to the outer membrane of E. coli O111B4 in a form resistant to salt or protease elution correlates with bacterial killing.
Adherence of Pseudomonas aeruginosa to human tracheobronchial mucin
Authors: Vishwanath S , Ramphal R
Published: January 2020

A microtiter plate assay was developed to study the adherence of Pseudomonas aeruginosa to purified human tracheobronchial mucin. The wells of the plates were treated with silicon to minimize nonspecific binding of bacteria and then coated with a solution of purified human tracheobronchial mucin. Bacteria were added to the wells, and the plates were incubated at 37 degrees C. The wells were washed 15 times in an automated microtiter plate washer, and the bacteria bound to wells were desorbed with Triton X-100 and plated for enumeration. Scanning electron microscopy verified bacterial adherence to the mucin-coated wells and desorption of bacteria by Triton X-100. Adherence of P. aeruginosa increased as the concentration of mucin used to coat the wells was increased, with saturation occurring at 0.5 microgram of mucin protein per ml. Other parameters that affected adherence included the time of incubation and concentration of bacteria. Similar studies with strains of Escherichia coli and Klebsiella pneumoniae indicated a relative lack of binding of these bacteria to mucin. In comparing different strains of P. aeruginosa, there were small differences in binding between strains. It is inferred that there may be specific sites on human tracheobronchial mucin which facilitate this preferential binding.
In vivo and in vitro administration of interleukin 2-containing preparation reverses T-cell unresponsiveness in Mycobacterium bovis BCG-infected mice
Authors: Colizzi V
Published: January 2020

Mice infected with high doses of Mycobacterium bovis BCG (3 X 10(7)) showed a marked impairment of delayed-type hypersensitivity to PPD in vivo, and their splenic T cells failed to proliferate when cultured in vitro with concanavalin A or PPD. However, this state of unresponsiveness could be reversed both in vitro and in vivo by the administration of an interleukin 2 (IL-2)-containing preparation. IL-2 produced spontaneously by the gibbon lymphosarcoma T-cell line MLA-144 and T-cell-conditioned medium from a mixed lymphocyte reaction were able to increase DNA synthesis of splenic T lymphocytes from BCG-immunosuppressed mice cultured with concanavalin A or PPD. Furthermore, BCG-infected mice treated in vivo with at least 100 U of IL-2 showed a positive skin reaction to PPD, and their spleen cells were fully responsive in vitro. The reversal of BCG-induced immunosuppression was not observed when infected mice were injected with IL-2 preparations previously incubated with blast cells, a procedure known to remove IL-2 activity. These results indicate that the basis of BCG-induced unresponsiveness is a deficiency in the production of IL-2 rather than a lack of reactive T cells.
Examination of Haemophilus pleuropneumoniae for immunoglobulin A protease activity
Authors: Mulks M H , Moxon E R , Bricker J , Wright A , Plaut A G
Published: January 2020

Haemophilus pleuropneumoniae, the etiological agent of porcine contagious pneumonia, was examined for the ability to produce an immunoglobulin A (IgA) protease specific for porcine IgA. No IgA protease activity against either porcine or human IgA was detected. Furthermore, no sequence homology was found between H. pleuropneumoniae chromosomal DNA and the gene which specifies IgA protease in Haemophilus influenzae.
Immunobiologically active lipid A analogs synthesized according to a revised structural model of natural lipid A
Authors: Kotani S , Takada H , Tsujimoto M , Ogawa T , Harada K , Mori Y , Kawasaki A , Tanaka A , Nagao S , Tanaka S
Published: January 2020

Synthetic lipid A analogs which have two amide-bound and two ester-bound (R)-3-hydroxytetradecanoyl groups at the C-2 and -2' and C-3 and -3' positions of beta(1-6)glucosamine disaccharide mono- or diphosphates showed high activities in most in vitro assays, and the lethality of a diphosphate derivative to galactosamine-treated mice was almost comparable to that of natural lipid A. The pyrogenicity and Shwartzman induction activity of the synthetic analogs, however, were much less than those of natural lipid A.
Elementary Body Envelopes from
Chlamydia psittaci
Can Induce Immediate Cytotoxicity in Resident Mouse Macrophages and L-Cells
Authors: Wyrick Priscilla B. , Davis Carolyn H.
Published: January 2020

Isolated, purified
Chlamydia psittaci
elementary body envelopes at a high multiplicity of infection (1,000:1) are capable of inducing immediate cytotoxicity in resident mouse macrophages and 929 L-cells.
Specificity of Mycobacterium tuberculosis antigen 5 determined with mouse monoclonal antibodies
Authors: Daniel T M , Gonchoroff N J , Katzmann J A , Olds G R
Published: January 2020

Four mouse monoclonal antibodies have been developed which react with Mycobacterium tuberculosis antigen 5. Each of these monoclonal antibodies has been used to prepare immunoabsorbents, and antigen has been isolated from unheated M. tuberculosis H37Ra culture filtrate by affinity chromatography with these absorbents. Antigen thus obtained was found to be similar in tuberculin reactivity and in enzyme-linked immunosorbent assays to antigen 5 isolated from polyclonal immunoabsorbents, and the protein yields from the monoclonal immunoabsorbents were similar to those from polyclonal absorbents. Antigen recovered from monoclonal absorbents cross-reacted with antigens of Mycobacterium kansasii in delayed skin tests. Immunoelectrophoresis demonstrated that the major component of the antigens eluted from the monoclonal immunoabsorbents was mycobacterial arabinomannan. Antigen 5 was not identified in the eluates by immunoelectrophoresis. These observations support the hypothesis that antigen 5 and M. tuberculosis arabinomannan contain a single major shared epitope.