bluuebunny/crossref_metadata_2025 huggingface dataset:
Antigen-reactivity pattern of T-cell hybridomas from Mycobacterium bovis BCG-infected mice
Authors: Müller I , Kaufmann S H
Published: January 2020

Lymph node cells from mice infected with live Mycobacterium bovis BCG were fused with BW5147 cells after short-term culturing in vitro. Both mycobacterium- and self-reactive T-cell hybridomas were identified. Some T-cell hybridoma clones displayed dual reactivity to self and to self plus mycobacterial antigen but did so to a different degree, indicating that infection with mycobacteria stimulates autoreactive immune responses.
Isolation and Characterization of a Leptospiral Type-Specific Antigen
Authors: Shinagawa M. , Yanagawa R.
Published: January 2020

The type-specific main (TM) antigen was extracted from the leptospiral cells of strain Kyoto of the Hebdomadis group by 90% phenol and was purified mainly by ethanol precipitation. The TM antigen was specific, forming one precipitin band by immunodiffusion and reacting by complement fixation test with anti-strain Kyoto serum; so far as has been tested, it does not appear to react with antisera of other serotypes. The sedimentation velocity of the TM antigen was 216
S
. Morphologically the TM antigen was filamentous in shape with a uniform width of 25 to 30 nm and various lengths from 50 nm to 1 μm. The infrared absorption pattern of the TM antigen generally resembled that of gram-negative bacterial endotoxin, and this fact suggests that the antigen is composed mainly of lipopolysaccharides. Galactose, rhamnose, xylose, arabinose, glucosamine, 13 kinds of acidic and neutral amino acids, lipids, and phosphorus were found in the TM antigen.
Mouse Splenic Peroxidase and Its Role in Bactericidal Activity
Authors: Strauss R. R. , Paul B. B. , Jacobs A. A. , Sbarra A. J.
Published: January 2020

Spleen cell suspensions from AKR and CD-1 mice contain peroxidase activity as determined by guaiacol oxidation. This activity is found predominately in the 20,000 ×
g
pellet fraction of spleen cell homogenates. In the presence of H
2
O
2
and chloride ion at acidic
p
H, splenic peroxidase mediates the oxidation of
d
- or
l
-alanine to CO
2
, NH
3
, and acetaldehyde. The same reaction mixture without added amino acid can kill both gram-positive and gram-negative bacteria. The conditions for both reactions are similar. Both have an absolute requirement for H
2
O
2
and chloride ion, neither is active at neutral or alkaline
p
H, and both are inhibited by the sulfonic amino acid taurine. In these aspects, splenic peroxidase is qualitatively similar in its activity to myeloperoxidase (MPO) from polymorphonuclear leukocytes. It is quantitatively different from MPO in that the latter is more potent on a per guaiacol unit basis with respect to both amino acid oxidation and bactericidal activity. Still another quantitative difference is that splenic peroxidase requires 0.1
m
NaCl for activity, whereas MPO functions with as little as 0.005
m
NaCl. Splenic peroxidase and MPO both appear to differ qualitatively from horseradish peroxidase in that the latter enzyme does not mediate amino acid oxidation.
Isolation and Characterization of
Mycoplasma conjunctivae
sp. n. from Sheep and Goats with Keratoconjunctivitis
Authors: Barile Michael F. , Del Giudice Richard A. , Tully Joseph G.
Published: January 2020

Fourteen conjunctival strains of mycoplasma were isolated from infected sheep and goats in two separate naturally occurring outbreaks of keratoconjunctivitis (pink-eye). The biological and serological properties and cell protein patterns of these strains are presented in this report. These strains were related to each other and were unrelated to 40 recognized
Mycoplasma
and
Acholeplasma
species and serotypes. We are proposing that this group of mycoplasmas be named
M. conjunctivae.
The role of
M. conjunctivae
in the etiology of keratoconjunctivitis in sheep and goats remains to be determined.
Experimental Tularemia in
Macaca mulatta:
Relationship of Aerosol Particle Size to the Infectivity of Airborne
Pasteurella tularensis
Authors: Day William C. , Berendt Richard F.
Published: January 2020

Ninety-six
Macaca mulatta
were exposed to aerosol particles containing
Pasteurella tularensis.
Four different aerosols were employed that contained particle size distributions with median diameters of 2.1, 7.5, 12.5, or 24.0 μm. Size distributions were calculated only for those particles observed by phase microscope to contain organisms. Animals exposed to particles whose median diameters were either 2.1 or 7.5 μm were all infected and showed extensive infection of the lower respiratory tract, evidenced by large patches of consolidation with many necrotic foci on the surface. Death occurred in these animals 4 to 8 days after exposure. Monkeys exposed to 12.5- or 24.0-μm median diameter particles presented involvement of the cervical and mandibular lymph nodes, evidenced by swelling and abscess formation. Thirty-eight of the 45 animals in this group were infected. Those animals succumbing to the disease died from 8 to 21 days after exposure. The respiratory LD
50
values increased from 14 to 4,447 cells as the median diameter was raised from 2.1 to 24.0 μm.
Antibody Formation to Trehalose-6, 6′-Dimycolate (Cord Factor) of
Mycobacterium tuberculosis
Authors: Kato Masahiko
Published: January 2020

A complex of trehalose-6, 6′-dimycolate (cord factor) and methylated bovine serum albumin was prepared, and its effect on the toxicity of cord factor in mice was studied. Either the active immunization with cord factor-methylated bovine serum albumin complex or the passive transfer of sera of rabbits vaccinated with the complex protected mice against the toxic action of cord factor. The antisera of mice and rabbits and gamma globulin fraction of rabbit antiserum demonstrated a precipitin reaction with an aqueous emulsion of cord factor. The reactivity of anticord factor was totally lost by treatment with 2-mercaptoethanol. The antigenic determinant group of cord factor was α-
d
-trehalose. Cord factor-anticord factor complex was devoid of activity to induce in vitro swelling and inhibition of respiratory and phosphorylative activity of mouse liver mitochondria. These results suggest that vaccination with cord factor-methylated bovine serum albumin complex induced the production of antibody to cord factor in mouse and rabbit serum which binds to cord factor and neutralizes its toxic activity either in vivo or in vitro.
Microbicidal Activity of Peroxidaseless Chicken Heterophile Leukocytes
Authors: Brune Kay , Leffell M. S. , Spitznagel J. K.
Published: January 2020

Polymorphonuclear leukocytes (PMN) of the domestic chicken lack myeloperoxidase and, therefore, may be useful for studies of myeloperoxidase-independent antimicrobial mechanisms. Before such studies were undertaken, it was important to investigate the antimicrobial capacity of these cells against species of opportunistic pathogens that cause infection in humans with defective PMN function. In vitro, chicken PMN, like normal human PMN, readily phagocytized and killed
Staphylococcus albus.
They also killed
Serratia marcescens, Escherichia coli
, and
Candida albicans.
Cytochemical methods confirmed the absence of myeloperoxidase from chicken PMN.
Enteric Immunization with Live Adenovirus Type 21 Vaccine II. Systemic and Local Immune Responses Following Immunization
Authors: Scott Robert McNair , Dudding Burton A. , Romano Salvatore V. , Russell Philip K.
Published: January 2020

Studies of the immunologic responses following administration of a live, enteric-coated adenovirus (ADV) type 21 vaccine showed that nine of ten vaccinees and none of five controls developed neutralizing antibody. Antibody activity of serum and secretory immunoglobulins was assayed by using a
14
C-labeled ADV-21 antigen in a radioimmunodiffusion system. Increases in immunoglobulin M, A and G (IgM, IgA, IgG) activity were detected in sera from vaccinees but not in those from controls. IgA copro antibody activity was also shown in vaccinees but not in controls. Nasal secretions showed no detectable IgA antibody responses by this method. These studies show marked differences in serum and local IgA antibody activity in induced enteric ADV infection compared to previously reported responses after natural infection. The protective role of secretory IgA in adenovirus infections is obscure. However, absence of nasal IgA responses may indicate that protection against disease with enteric ADV vaccines depends primarily upon humoral antibody.
Effect of Storage on the Ability of 2-Mercaptoethanol to Inactivate γM Antibody
Authors: Pike Robert M. , Chandler Cleo H.
Published: January 2020

A solution of 2-mercaptoethanol began to lose its reducing capacity after storage for a few days.
Iguana Virus, a Herpes-Like Virus Isolated from Cultured Cells of a Lizard,
Iguana iguana
Authors: Clark H. Fred , Karzon David T.
Published: January 2020

An agent cytopathic for
Terrapene
and
Iguana
cell cultures was isolated from spontaneously degenerating cell cultures prepared from a green iguana (
Iguana iguana
). The agent, designated iguana virus, caused a cytopathic effect (CPE) of a giant cell type, with eosinophilic inclusions commonly observed within giant cell nuclei. Incubation temperature had a marked effect on CPE and on virus release from infected cells. Within the range of 23 to 36 C, low temperatures favored CPE characterized by cytolysis and small giant cell formation, and significant virus release was observed. At warmer temperatures, a purely syncytial type of CPE and total absence of released virus were noted. A unique type of hexagonal eosinophilic cytoplasmic inclusion was observed within syncytia of infected
Terrapene
cell cultures incubated at 36 C. In vivo studies revealed no evidence of pathogenicity of iguana virus for suckling mice, embryonated hen's eggs, or several species of reptiles and amphibians. Inoculation of iguana virus into young iguanas consistently caused infection that was “unmasked” only when cell cultures were prepared directly from the infected animal. Filtration studies revealed a virion size of >100 nm and <220 nm. Iguana virus is ether-sensitive and, as presumptively indicated by studies of inhibition by bromodeoxyuridine, possesses a deoxyribonucleic type of nucleic acid. The virus characteristics described, as well as electron microscopy observations described in a separate report, indicate that iguana virus is a member of the herpesvirus group.
Mycoplasma pneumoniae
Vaccine: Antigenicity of Buffered Antigens in Volunteers
Authors: Brown Richard C. , Hendley J. Owen , Gwaltney Jack M.
Published: January 2020

The antigenicity of experimental
Mycoplasma pneumoniae
vaccines prepared from antigen grown in a medium buffered with
N
-2-hydroxyethylpiperazine-
N
′-2′-ethanesulfonic acid was tested in young, adult males. Formalin-inactivated antigens from a high-passage strain and a low-passage strain at various dilutions (12 to 123 μg of N/ml) were injected intramuscularly in 1-ml doses. Antibody responses were tested by the metabolic inhibition (MI) technique. Sixty-five to 86% of the volunteers in all vaccine groups responded with fourfold or greater MI antibody rises, but only nine (39%) of 23 antibody-free subjects converted compared to 53 (88%) of 60 of those with pre-existing antibody. A booster vaccination did not increase the number of converters or enhance the geometric mean titers. The antigen concentrations of vaccines with 24 or more μg of N/ml appeared to be above the threshold needed for maximal antibody responses in the dose range tested. MI antibody rises could not be detected in sputa and nasal washings obtained from a small group of vaccinees. The results of this study suggest that the new vaccines offer little or no improvement in antigenicity in man over earlier inactivated vaccines.
Natural and Immune Antibodies for
Vibrio fetus
in Serum and Secretions of Cattle
Authors: Duncan J. R. , Wilkie B. N. , Winter A. J.
Published: January 2020

Naturally occurring antibodies for
Vibrio fetus
with whole-cell and O antigen specificities were detected in sera of mature cattle by means of the agglutination and indirect immunofluorescence reactions. O antibodies occurred in each of 21 sera examined, and whole-cell antibodies, in lower concentrations, occurred in 15 of the 21 sera. Natural antibodies were detected in the immunoglobulin G, M, and A (IgG, IgM, IgA) classes. Parenteral immunization with whole cells in Freund's complete adjuvant caused an increase in antibodies, predominantly IgG, with both whole-cell and O specificities; genital infection produced minimal alterations in levels of serum antibody. O antibodies, predominantly of the IgA class, occurred in nasal secretions of most of these animals but only infrequently in saliva or tears. Nasal secretion titers of O antibodies fluctuated widely from week to week but appeared to be unaffected by parenteral immunization or experimental infection. It is hypothesized that the nasal passages serve as a site of antigenic stimulation and synthesis of naturally occurring
V. fetus
antibodies.
Zoonotic Infections in Military Scout and Tracker Dogs in Vietnam
Authors: Alexander A. D. , Binn L. N. , Elisberg B. , Husted P. , Huxsoll D. L. , Marshall J. D. , Needy C. F. , White A. D.
Published: January 2020

Significant levels of antibodies indicative of a variety of zoonotic infections were demonstrated in sera collected from 64 U.S. military scout and tracker dogs after service in the Republic of Vietnam (RVN). Scrub typhus antibodies were found in 45% of the specimens, melioidosis in 19%, group B arbovirus in 49%, and leptospirosis in 62%. Only 38% of the seropositive reactions for leptospirosis could be related to overseas infections. Tests were conducted on paired sera obtained from 32 of the dogs before service in RVN. Significant increases in titer were demonstrated with scrub typhus, melioidosis, leptospirosis, plague, group B arbovirus, and
Rickettsia canada
antigens. After 2 to 6 months of service in RVN, 8 of 19 dogs developed antibody titers to at least one of four zoonotic diseases. Only 3 of 45 dogs with 7 or more months of service failed to develop antibodies to one or more of the agents. The serological findings pose questions on the potential epidemiological importance and veterinary significance of scrub typhus, group B arbovirus, leptospirosis, and melioidosis infections in dogs.
Effects of Purified Staphylococcal Alpha Toxin on the Ultrastructure of Human and Rabbit Erythrocytes
Authors: Klainer Albert S. , Chang Te-Wen , Weinstein Louis
Published: January 2020

Previous studies have suggested that the primary site of action of purified staphylococcal alpha toxin is the cell membrane. Scanning and transmission electron microscopy studies were undertaken, therefore, to define toxin-induced alterations in the surface morphology of rabbit and human red blood cells. During the prelytic lag phase, scanning electron microscopy revealed multiple discrete blisters on the surface of rabbit red blood cells; during hemolysis, cellular collapse and ghosts were seen, but most striking was the separation of large fragments of cell membrane from red blood cell surfaces. In contrast, alterations in less sensitive human red blood cells were limited to occasional fingerlike protrusions during the period of accelerated lysis. Transmission electron microscopy substantiated these changes. These studies have provided further evidence that the cell membrane is the primary site of action of staphylococcal alpha toxin.
Specific and Nonspecific Staining in Detecting Staphylococcal Alpha Toxin on Erythrocytes by Immunofluorescence
Authors: Kaplan Milton T.
Published: January 2020

Specifically stained staphylococcal alpha toxin particles were detected on unstained and nonspecifically stained ghost membranes when rabbit erythrocytes were exposed to alpha toxin and stained with fluorescein isothiocyanate-labeled specific antitoxin. Fading of the nonspecific staining was observed and was attributed to the degradation of the membranes by alpha toxin.
Mechanisms of Pathogenesis in
Listeria monocytogenes
Infection VI. Oxidative Phosphorylation in Mouse Liver Mitochondria During Experimental Listeriosis
Authors: McCallum R. E. , Sword C. P.
Published: January 2020

Previous reports have demonstrated early changes in hepatic carbohydrate and energy metabolism in mice infected with
Listeria monocytogenes.
This study was undertaken to further elucidate mechanisms of damage involved in these changes. Female CD-1 mice were injected intraperitoneally with 10
6
L. monocytogenes
A4413. At 0, 10, and 20 hr after infection, groups of mice were sacrificed and the livers were removed and pooled. Oxidative phosphorylation was assayed immediately upon isolation of mitochondria from pooled liver homogenates. Appropriate metabolic inhibitors were employed to examine each of the three phosphorylation sites in mitochondrial electron transport. When pyruvate-malate (equimolar concentrations) and α-ketoglutarate were used as substrates, decreases in both phosphorylation and oxidation were noted as early as 10 hr after infection. With β-hydroxybutyrate and citrate as substrates, alterations were not noted until 20 hr after infection, whereas no changes were seen when glutamate, succinate, or ascorbate were employed. These results suggest possible derangement of the first site in oxidative phosphorylation as well as lowered activity of nicotinamide adenine dinucleotide-linked dehydrogenases during experimental listeriosis in mice.
Gamma interferon activates human macrophages to become tumoricidal and leishmanicidal but enhances replication of macrophage-associated mycobacteria
Authors: Douvas G S , Looker D L , Vatter A E , Crowle A J
Published: January 2020

Recombinant human gamma interferon (rIFN-gamma) was examined for its ability to activate human peripheral blood monocyte-derived macrophages to kill tumor cells and to affect the replication of two phylogenetically distinct intracellular pathogens, Mycobacterium tuberculosis and Leishmania donovani. Macrophages preincubated overnight with doses of rIFN-gamma from 5 to 500 U/ml killed [3H]thymidine-labeled mouse L929 tumor targets, as measured by the release of [3H]thymidine into the supernatant after 48 h. Counts of macrophages initially infected with leishmania promastigotes showed that rIFN-gamma-pretreated macrophages could both inhibit the replication of and kill the resulting intramacrophage amastigotes over a 7-day period. However, rIFN-gamma pretreatment of macrophages actually enhanced mycobacterial replication over a 5- to 7-day period, as assessed by (i) counting acid-fast bacilli or (ii) lysing macrophages to release bacteria and determining the numbers of viable units. Mycobacterial growth was not affected by rIFN-gamma in the absence of macrophages. rIFN-gamma pretreatment had opposite effects on the uptake of mycobacteria and leishmania. As many as 80% fewer activated macrophages ingested mycobacteria compared with controls, whereas 50% more activated macrophages were infected with leishmania. These results suggest that rIFN-gamma may interfere with the immune destruction of intracellular tubercle bacilli and that the mechanisms of immunity against mycobacteria and leishmania may differ.
Evaluation of Bordetella bronchiseptica vaccines in specific-pathogen-free piglets with bacterial cell surface antigens in enzyme-linked immunosorbent assay
Authors: Novotny P , Kobisch M , Cownley K , Chubb A P , Montaraz J A
Published: January 2020

The progenies of specific-pathogen-free sows which had been immunized with Bordetella bronchiseptica vaccines of various origin before parturition were challenged intranasally with B. bronchiseptica within 5 days of birth. Sera of piglets were taken weekly and investigated by enzyme-linked immunosorbent assay against a mixture of B. bronchiseptica cell surface antigens containing curled fibers and fimbriae, lipopolysaccharide, and a mixture of proteins mostly derived from the outer membrane. The serological response to this antigenic mixture was paradoxical; the highest titers were obtained with the least effective vaccines. Antibodies which did relate to protection were oriented against the outer-membrane-derived proteins, one of which, of 68,000 molecular weight, appeared to be particularly important for two reasons. First, its concentration within the antigenic mixture was dependent upon cultural conditions; of all the proteins present in virulent strains, it was the first to disappear upon modulation. Second, it was absent from a strain which was unable to induce atrophic rhinitis in specific-pathogen-free piglets. Although all vaccines tested had some beneficial effect on the various clinical manifestations of the disease, only two vaccines were effective (P less than 0.001) in the prevention of nasal pathological changes. These two vaccines also stimulated the highest titers against the 68,000-molecular-weight protein. A mouse protection test utilizing a lethal intraperitoneal challenge failed to monitor the efficacy of vaccines for protection against atrophic rhinitis.
Contribution of hydrophobicity to hemagglutination reactions of Pseudomonas aeruginosa
Authors: Garber N , Sharon N , Shohet D , Lam J S , Doyle R J
Published: January 2020

Several strains of Pseudomonas aeruginosa exhibited the ability to hemagglutinate erythrocytes. Hydrophobic bond-breaking agents, but not sugars and saccharides, were effective inhibitors of hemagglutination. The results suggest the involvement of hydrophobic bonds in hemagglutination reactions of P. aeruginosa.
Control of lipopolysaccharide-high-density lipoprotein interactions by an acute-phase reactant in human serum
Authors: Tobias P S , McAdam K P , Soldau K , Ulevitch R J
Published: January 2020

We have recently described several phenomena involving the interactions of lipopolysaccharides (LPS) from Salmonella minnesota Re595 (Re595-LPS) with rabbit serum, which are different in and unique to acute-phase serum as compared with normal serum (P.S. Tobias and R.J. Ulevitch, J. Immunol. 131:1913-1916, 1983). To determine whether these phenomena could also be observed in acute-phase human serum (APHS), we used APHS obtained from volunteers injected with etiocholanolone. As observed in acute-phase rabbit serum, we found that (i) in APHS, Re595-LPS forms a protein complex with a density of 1.3 g/cm3 which does not form in normal human serum (NHS), (ii) in APHS, the t1/2 for LPS-high-density lipoprotein (HDL) complexation is at least a factor of 10 slower than the t1/2 for LPS-HDL complexation in NHS, (iii) when Re595-LPS serum mixtures are dialyzed against a low salt buffer, Re595-LPS precipitates in less soluble form from APHS than from NHS, and (iv) the precipitate from Re595-LPS-APHS mixtures includes a protein with a molecular weight of approximately 60,000 which does not precipitate from Re595-LPS-NHS mixtures or from NHS or APHS alone. These indications of an altered status of LPS in NHS and APHS suggest that one or more acute-phase reactants interact with Re595-LPS to modify its rate of binding to HDL.
Attachment of staphylococci and streptococci on fibronectin, fibronectin fragments, and fibrinogen bound to a solid phase
Authors: Kuusela P , Vartio T , Vuento M , Myhre E B
Published: January 2020

The attachment of Staphylococcus aureus (Cowan I) and two strains of group A and G streptococci on glass cover slips coated with fibronectin, fibronectin fragments, or fibrinogen was studied. The attachment was quantitated by counting the attached bacteria on glass surfaces coated with a similar molarity of the proteins. Fibronectin was a more effective attachment factor than fibrinogen for staphylococci, while group G streptococci attached better on fibrinogen- than on fibronectin-coated cover slips. In this system, group A streptococci bound almost exclusively to substrate-bound fibrinogen. Attachment experiments involving the use of staphylococci pretreated with soluble fibronectin or fibrinogen revealed that bacterium-bound fibronectin and fibrinogen were able to enhance the adherence on cover slips coated with fibronectin. The 30-kilodalton NH2-terminal and the 120- to 140-kilodalton COOH-terminal fragments of fibronectin, both of which contain bacterial binding sites, mediated the staphylococcal attachment, suggesting that both parts of the molecule are involved in the attachment mediated by fibronectin.
Suppression of immune response to Listeria monocytogenes: mechanism(s) of immune complex suppression
Authors: Virgin H W , Wittenberg G F , Bancroft G J , Unanue E R
Published: January 2020

We have investigated possible mechanisms underlying immune complex suppression of resistance to Listeria monocytogenes. Inhibition of resistance was found when immune complexes were formed in vivo in immune mice or in nonimmune mice adoptively transferred with specific antibody. Suppression was also found when nonimmune mice were injected with immune complexes preformed in vitro. We investigated the role of complement by decomplementing mice with cobra venom factor purified by high-pressure liquid chromatography. Complete depletion of serum C3 did not eliminate immune complex suppression of resistance to L. monocytogenes, suggesting that complement activation is not required for immune complex suppression. Infection-induced changes in the surface phenotype and functional properties of macrophages from normal and immune complex-suppressed mice were also investigated. Macrophage expression of both H-2K and Ia molecules increased during the response of normal mice to L. monocytogenes. However, these changes were not found in immune complex-suppressed mice. In contrast, membrane interleukin 1 expression was increased in macrophages from suppressed mice compared with macrophages from normal mice. Macrophages from L. monocytogenes-infected normal and immune complex-suppressed mice expressed cytotoxicity against tumor cells in vitro. We conclude that immune complexes do not inhibit resistance to L. monocytogenes by activation of complement or decreasing macrophage cytotoxic activity. Rather, defects in Ia expression by macrophages from suppressed mice might be one component responsible for immune complex suppression of resistance to L. monocytogenes.
Bovine neutrophils ingest but do not kill Haemophilus somnus in vitro
Authors: Czuprynski C J , Hamilton H L
Published: January 2020

Phagocytosis of Haemophilus somnus by bovine blood neutrophils required opsonization of the bacteria with antibodies against H. somnus. Few bacteria were phagocytosed in the absence of serum; in addition, absorption of immune serum with Formalin-killed H. somnus significantly reduced ingestion of H. somnus. Heat inactivation of antiserum (56 degrees C for 30 min) to eliminate complement activity had little effect on its ability to opsonize H. somnus for uptake by bovine neutrophils. Antiserum from an H. somnus-immunized calf and autologous sera from adult cattle supported equivalent phagocytosis of H. somnus by bovine neutrophils, suggesting that normal, healthy cattle may contain sufficient antibodies in their sera to facilitate phagocytosis of H. somnus. Although bovine neutrophils readily ingested H. somnus, they were unable to kill the bacterium in vitro. These same neutrophils readily killed opsonized Escherichia coli and Staphylococcus epidermidis, suggesting that H. somnus is able to survive and perhaps multiply within bovine neutrophils. Because bovine neutrophils stimulated with opsonized H. somnus demonstrated a reduced oxidative burst (as measured by chemiluminescence) compared with neutrophils stimulated by opsonized E. coli, we suggest that reduced production of reactive oxygen intermediates during the phagocytosis of H. somnus may account, in part, for the enhanced survival of H. somnus in bovine neutrophils.
Activation of a heat-stable cytolytic protein associated with the surface membrane of Naegleria fowleri
Authors: Lowrey D M , McLaughlin J
Published: January 2020

Surface membrane-enriched fractions of Naegleria fowleri obtained after isopycnic centrifugation experiments contain a potent cytolytic activity as determined by hemolysis and 51Cr release assays. This surface membrane cytolysin was unaffected by a treatment at 75 degrees C for 30 min and accounted for 70 to 90% of cytolysis by whole-cell lysates of amoebae. This heat resistance as well as intimate membrane association distinguished the surface membrane cytolytic activity from a second heat-labile cytolytic activity which appears to be latent within lysosomes. The surface membrane cytolysin was found to be specifically activated by diluted samples of lysosomal fractions. The possible role of this surface membrane cytotoxin in the pathogenicity of N. fowleri is discussed.
Flagella and motility alterations in Pseudomonas aeruginosa strains from patients with cystic fibrosis: relationship to patient clinical condition
Authors: Luzar M A , Thomassen M J , Montie T C
Published: January 2020

Selected physiological parameters of 31 classic and rough Pseudomonas aeruginosa strains from respiratory tract cultures of patients with cystic fibrosis were examined. An association of a patient's clinical condition (good or poor) with strain physiology was made. Rough strains from patients in poor clinical condition demonstrated severe alterations in motility when compared with M-2, a highly motile and chemotactic burn strain. Of the 10 rough strains from patients in poor clinical condition, 70% lacked flagella, as determined by electron microscopy. The remaining few flagellated strains from this group exhibited weak motility both in soft agar and by the capillary assay. Their chemotactic response to three amino acids, when compared with that of strain M-2, was reduced approximately 30 to 90%. Classic strains from patients in poor clinical condition were less chemotactic than those from patients in good clinical condition. A majority of classic and rough strains from patients in good clinical condition were comparable to M-2 in both chemotaxis and motility. Changes in other physiological characteristics indicated by reduced growth rates, or auxotrophy, were seldom observed in the cystic fibrosis strains studied. The data suggest that host-selective pressures, associated primarily with patients with cystic fibrosis that are in poor clinical condition, result in the loss of factors related to invasiveness such as motility and chemotaxis. We propose that these results may reflect that there is a more general alteration in the cell envelope of cystic fibrosis strains.
Candida albicans and Candida stellatoidea, in contrast to other Candida species, bind iC3b and C3d but not C3b
Authors: Heidenreich F , Dierich M P
Published: January 2020

It was demonstrated that complement-coated sheep erythrocytes bind to Candida albicans cells grown in serum-free RPMI 1640 medium. Testing of purified complement components proved that iC3b and C3d were responsible for the reaction, whereas C3b and C3b-H reacted only slightly if at all. Binding occurred only to C. albicans and C. stellatoidea, not to other species pathogenic to humans. There was evidence of a lectinlike nature of the effect.
Lack of tuberculin activity of synthetic peptides
Authors: Toida I , Yamamoto S , Takuma S , Suzuki T , Hirata M
Published: January 2020

We synthesized an octapeptide, H-Asp-Gly-Gly-Ser-Glu-Ser-Glu-Gly-OH, and a hexadecapeptide, H-Asp-Gly-Gly-Ser-Glu-Ser-Glu-Gly-Lys-Asn-Gly-Ser-Gln-Met-Arg-Leu-OH, which corresponded to amino acids 61 to 68 and 61 to 76, respectively, of the amino acid sequence of a crystalline protein reported to be tuberculin active. Authenticity and purity of the synthesized peptides were confirmed by high-pressure liquid chromatography, amino acid analysis, mass spectrometry, and protein sequencer analysis. Tuberculin activity of the synthesized peptides was examined in guinea pigs sensitized with Mycobacterium tuberculosis or Mycobacterium bovis BCG and in tuberculin-positive healthy humans. Neither the octa- nor the hexadecapeptide was as active as tuberculin skin-test antigen.
Purification and characteristics of the streptococcal chemotactic factor inactivator
Authors: Wexler D E , Cleary P P
Published: January 2020

The biochemical and immunological characteristics of the chemotactic factor inactivator of group A streptococci (SCFI) were examined. SCFI was extracted from intact M+ bacteria by limited trypsin digestion and purified sequentially by ammonium sulfate fractionation, hydrophobic interaction chromatography, and anion-exchange chromatography. SCFI activity was associated with multiple species as indicated by gel permeation chromatography and DEAE high-pressure liquid chromatography analyses. Polyacrylamide gel electrophoresis of the column-purified protein also demonstrated a high degree of molecular heterogeneity, with most of the material in a 103,000 to 114,000 Mr cluster. SCFI activity was sensitive to destruction by several proteolytic enzymes, and polyclonal antiserum to SCFI was able to neutralize its antichemotactic activity. Two-dimensional immunoelectrophoresis of SCFI indicated that the various copurified species were immunologically cross-reactive and indicated a high degree of antigenic homogeneity within the preparation. Western blot analysis of crude detergent extracts of M+ bacteria identified a major antigenic species corresponding to 135,000 Mr and a less abundant species of 137,000 Mr. SCFI antiserum was not reactive with M protein, and therefore SCFI appeared to be a distinct molecule, despite its close association with the M+ phenotype.
Molecular identity and location of invariant antigens on Trypanosoma brucei rhodesiense defined with monoclonal antibodies reactive with sera from trypanosomiasis patients
Authors: Burgess D E , Jerrells T
Published: January 2020

Monoclonal antibodies (MAbs) which are reactive with several antigenically distinct variable antigen types were prepared by immunization with Trypanosoma brucei rhodesiense. Certain MAbs were shown to be specific for members of the genus Trypanosoma and not reactive with Leishmania spp. or Plasmodium falciparum by the indirect immunofluorescence assay. These genus-specific MAbs were used to identify the molecular location of these invariant antigen determinants in whole T. brucei rhodesiense antigen preparations. Two monoclonals reacted with a low-molecular-weight doublet of approximately 22,000 relative molecular weight on Western blots of whole trypanosome antigen preparations separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. These determinants did not appear to be on the variable surface glycoprotein molecule and were destroyed by trypsin digestion. Binding studies in which live, DEAE-purified, bloodstream trypanosomes were exposed to invariant antigen-specific MAbs suggested these determinants were accessible on living trypanosomes. Genus-specific MAbs also reacted with determinants present in sera from African trypanosomiasis patients in a dot immunobinding assay but not sera from patients with malaria or leishmaniasis. These results suggest that certain invariant molecules of African trypanosomes are immunogenic, possibly accessible on the trypanosome surface, and may be present as circulating invariant antigen in trypanosomiasis patients.
Monoclonal antibodies that recognize the P fimbriae F71, F72, F9, and F11 from uropathogenic Escherichia coli
Authors: de Ree J M , Schwillens P , van den Bosch J F
Published: January 2020

The Escherichia coli P fimbriae F71, F72, F9, and F11 from four cloned strains were purified, and polyclonal antisera were raised in rabbits. Cross-reactions of these antisera with eight different cloned and purified fimbriae were measured in an enzyme-linked immunosorbent assay. These antisera showed a reaction with the homologous fimbriae and also with most heterologous fimbriae. Monoclonal antibodies (MAbs) directed against the same four native fimbriae were produced by the fusion of spleen cells from immunized BALB/c mice with SP2/0 myeloma cells. The resulting four series of MAbs were also screened in an enzyme-linked immunosorbent assay with eight different cloned and purified fimbriae. Four different F71 hybridomas produced MAbs which recognized only epitopes on F71 fimbriae. Two F72 MAbs recognized epitopes on F72 and F9 fimbriae, whereas another F72 MAb recognized an epitope on only F72 fimbriae. Three MAbs raised against F9 reacted only with epitopes on F9 fimbriae. Six MAbs against F11 fimbriae could be divided into two groups: on the one hand two MAbs recognizing F11, pyelonephritis-associated pilus, Pap, and F72 fimbriae and on the other hand four MAbs recognizing F11 and "Clegg" fimbriae. None of the MAbs reacted with 1A or 1C fimbriae. In a hemagglutination inhibition assay it was shown that none of the MAbs produced inhibited the adhesive properties of homologous cloned strains.
Cloning of the cytotoxin-hemolysin gene of Vibrio vulnificus
Authors: Wright A C , Morris J G , Maneval D R , Richardson K , Kaper J B
Published: January 2020

Genes encoding the cytotoxin-hemolysin of Vibrio vulnificus were cloned in Escherichia coli by using the lytic cloning vector, lambda 1059. Subcloning in plasmid pBR325 resulted in the isolation of a 3.2-kilobase DNA fragment containing the cytotoxin gene. By using this fragment as a DNA probe, homologous gene sequences were detected in all 54 V. vulnificus strains studied; homologous sequences were present in none of 96 isolates from 29 other bacterial species.
Characterization of cerulenin-resistant mutants of Candida albicans
Authors: Hoberg K A , Cihlar R L , Calderone R A
Published: January 2020

Cerulenin, an inhibitor of fatty acid biosynthesis, has been used to study the role of the plasma membrane in germination of Candida albicans. To further elucidate this association, spontaneous, cerulenin-resistant mutants of C. albicans were isolated. Two of the mutants, 4918-2 and 4918-10, were compared biochemically with wild-type cells (4918). All strains grew equally well at 37 degrees C and synthesized fatty acids at comparable rates in the absence of the drug. In the presence of cerulenin, wild-type cells did not proceed through a logarithmic growth stage and exhibited a significantly impaired ability to incorporate [3H]acetate into newly synthesized lipid material. All strains were examined ultrastructurally. Alterations were observed in the membranous structures of cerulenin-treated wild-type cells. Such changes were not observed in cerulenin-treated mutant strains. Further examination of mutant strains revealed differences in cell wall protein and polysaccharide compositions when compared with those of wild-type cells. These apparent alterations in cell surface components may be correlated with the reduced abilities of mutant strains to adhere, in vitro, to mammalian cells.
Development and characterization of monoclonal antibodies to Pneumocystis carinii
Authors: Graves D C , McNabb S J , Ivey M H , Worley M A
Published: January 2020

Hybridoma-producing monoclonal antibodies against Pneumocystis carinii were produced by the fusion of nonsecreting mouse myeloma cells (P3X63-Ag8.653) with splenocytes from BALB/c mice that had been immunized with partially purified preparations of P. carinii. Of 227 hybridoma clones producing antibodies against P. carinii, as measured by an enzyme-linked immunosorbent assay, 12 monoclonal antibodies showing the highest reactivity in the enzyme-linked immunosorbent assay were further characterized. The majority (11 of 12) of the monoclonal antibodies did not cross-react with Candida albicans, Cryptococcus neoformans, Histoplasma capsulatum, or Mycobacterium avium as determined by absorption experiments. By using the indirect immunofluorescence assay, serological reactivity was shown for these antibodies with titers ranging from 1:40 to 1:10,240. By using a competitive binding assay, these 12 monoclonal antibodies could be divided into seven groups, each group reacting with a different antigenic determinant of P. carinii. Sodium dodecyl sulfate-polyacrylamide gradient gel electrophoresis of P. carinii, followed by Western immunoblot analysis, allowed the identification of one major antigen with an apparent molecular weight of 110,000 by all 12 monoclonal antibodies. Other minor bands with molecular weights of approximately 116,000, 90,000, 55,000, and 35,000 were recognized by several of the monoclonal antibodies.
Estradiol-binding proteins from mycelial and yeast-form cultures of Paracoccidioides brasiliensis
Authors: Stover E P , Schär G , Clemons K V , Stevens D A , Feldman D
Published: January 2020

Paracoccidioides brasiliensis, the etiologic agent of paracoccidioidomycosis, causes disease much more frequently in men than it does in women, suggesting that the hormonal milieu of the host might influence P. brasiliensis pathogenicity. We recently demonstrated that cytosol from yeast cultures of P. brasiliensis contains a high-affinity, low-capacity, tritiated 17 beta-estradiol [( 3H]estradiol)-binding protein. Estradiol and, to a lesser degree, diethylstilbestrol (DES), inhibited the transformation of P. brasiliensis cultures from the mycelial to the yeast form, an event critical to the establishment of infection. Our current studies demonstrated a somewhat higher affinity (apparent dissociation constant [Kd], approximately equal to 6 to 12 nM) of the estrogen-binding protein for [3H]estradiol than was previously described for yeast cytosol. The presence of both high- and low-affinity estrogen-binding sites in yeast-form P. brasiliensis cytosol was detected after warming the cytosol to 37 degrees C. The high-affinity protein was labile to further heating (56 degrees C), although the low-affinity protein was stable. Additional experiments demonstrated the presence of an estrogen-binding protein in cytosol prepared from mycelial-form P. brasiliensis. This estrogen-binding protein had a slightly lower affinity for [3H]estradiol (Kd approximately equal to 13 nM), and its cytosol contained somewhat fewer binding sites (approximately equal to 78 fmol/mg of protein) than did yeast-form P. brasiliensis cytosol. Of particular interest was the finding that DES, a weak competitor for [3H]estradiol binding in yeast cytosol, displaced [3H]estradiol from the mycelial-form binding moiety. DES had a 50- to 100-fold-lower affinity for the [3H]estradiol-binding protein than did estradiol, consistent with its lower bioactivity in the mycelial-to-yeast-form transformation studies. The current results lend further support to our hypothesis that endogenous estrogens in the host, acting through the cytosol binding protein in the fungus, inhibit mycelial-to-yeast-form transformation, thus explaining the resistance of women to paracoccidioidomycosis.
A defined fragment of bacterial protein I (OmpF) is a polyclonal B-cell activator
Authors: Vordermeier M , Stäb K , Bessler W G
Published: January 2020

Protein I from the outer membrane of Escherichia coli and other members of the family Enterobacteriaceae is a potent mitogen and polyclonal B-lymphocyte activator. To determine the part of the polypeptide responsible for biological activity, we cleaved the molecule into defined polypeptide fragments of approximate molecular weights 24,000, 15,000, 9,000, 7,000, and 3,000 by using the cyanogen bromide method. The fragments were purified by gel permeation chromatography and by preparative polyacrylamide gel electrophoresis. They were investigated for mitogenicity and for the induction of immunoglobulin synthesis in lymphocyte cultures from several inbred mouse strains. The fragment of molecular weight 24,000 turned out to be a potent polyclonal B-lymphocyte activator comparable to native protein I. The low-molecular-weight fragments exhibited only marginal effects. Neither purified T lymphocytes nor thymocytes were activated. Our results show that a defined fragment of protein I is responsible for its lymphocyte-stimulating activity.
Immunological study of lactate dehydrogenase from Streptococcus mutans and evidence of common antigenic domains with lactate dehydrogenases from lactic bacteria
Authors: Sommer P , Klein J P , Ogier J A , Frank R M
Published: January 2020

Rabbit polyclonal antibodies directed against purified Streptococcus mutans L-(+)-lactate dehydrogenase reacted with the purified enzyme, giving a marked deviation of its kinetic parameters. The enzyme affinity for pyruvate or NADH decreased in the presence of antibody, the affinity for fructose 1,6-diphosphate (FDP) appeared to be slightly affected, and the cooperativity of the ligand binding was lowered. A partial protective effect was observed when the enzyme was preincubated with FDP prior to the antibody adjunction. An enzyme-linked immunosorbent assay allowed detection of a 30% decrease in enzyme-antibody fixation when FDP was added. The protective effect observed with FDP could be correlated with a conformational change induced by the activator. A decrease of antibody binding in the presence of FDP was also obtained with S. sanguis, Actinomyces viscosus, and Lactobacillus casei lactate dehydrogenases, which reflects a similar mechanism of activation among lactic bacteria. NADH did not offer any protection against antibody inhibition or fixation, and the coenzyme affinity decrease could be attributed to an indirect mechanism. On the contrary, pyruvate and the immunoglobulins apparently could compete for specific binding sites. A decrease of antibody binding was also obtained with three heterologous lactic bacterial lactate dehydrogenases, indicating a conservation of antigenic determinants implicated in the substrate binding.
Ultrastructural and biochemical studies of two dynamically expressed cell surface determinants on Candida albicans
Authors: Brawner D L , Cutler J E
Published: January 2020

Variability in the expression of two different cell surface carbohydrate determinants was examined with two agglutinating immunoglobulin M monoclonal antibodies (H9 and C6) and immunoelectron microscopy during growth of three strains of Candida albicans. A single strain of Candida parapsilosis did not express either antigen at any time during growth. Antigens were detected on the surface of C. albicans by agglutination tests with either H9 or C6 over a 48-h growth period. The difference in specificities of the monoclonal antibodies was demonstrated by Ouchterlony double-diffusion tests with solubilized antigens and by variabilities in the reactivity of the agglutinins among yeast strains. The antigenic determinants were isolated by specific immunoprecipitation and protease digestion and characterized by methods including high-pressure liquid chromatography, gas-liquid chromatography, and mass spectroscopy with both chemical and electron ionization. These determinants both contain mannose and glucose. In the case of antigen H9, an additional carbohydrate was detected with gas chromatography and mass spectroscopy. The location of antigens on individual cells was determined by indirect labeling of the determinants, first reacting cells with H9 or C6 followed by goat anti-mouse antibody conjugated with 20-nm colloidal gold particles. Transmission electron microscopy was used to examine cells. The antigens that were reactive with the monoclonal antibodies were associated with a flocculent surface layer. Expression of this layer and expression of the antigens is a dynamic process which is growth phase and strain dependent. The antigens were not expressed on very young cells and disappeared from the cell surface of most C. albicans strains with age. The use of monoclonal antibody to cell surface determinants may allow characterization of cell surface antigens of C. albicans and be helpful in establishing receptors which mediate adherence.
Identification and preliminary characterization of external membrane-bound nuclease activities in Mycoplasma pulmonis
Authors: Minion F C , Goguen J D
Published: January 2020

Mycoplasma pulmonis has substantial DNase activity exposed on the cell surface. At least part of this activity is attributable to an endonuclease. The activity is destroyed at 56 degrees C and inhibited by either 5 mM EDTA or 10 mM zinc chloride. It can also be eliminated by treatment of intact organisms with trypsin and is regenerated by incubation of the treated organisms in a medium that supports protein synthesis. DNase exposed at the cell surface constitutes 20% of the total DNase activity present in M. pulmonis extracts.