bluuebunny/crossref_metadata_2025 huggingface dataset:
Genetic stability of Borrelia burgdorferi recovered from chronically infected immunocompetent mice
Authors: Persing D H , Mathiesen D , Podzorski D , Barthold S W
Published: January 2020

Persistent infection with Borrelia burgdorferi in the presence of a vigorous host immune response has been demonstrated in humans and in animal models of Lyme disease. Long-term persistence of B. burgdorferi was documented recently in our studies of BALB/c and C3H mice infected with cloned and uncloned strains of B. burgdorferi. From mice inoculated with the cloned strain, 11 isolates were recovered from the skin, bladder, and blood after 1 year of infection. Analysis of the genes encoding the major outer surface proteins (OspA and OspB) by restriction digestion and DNA sequencing showed no evidence of point mutations or other small genetic alterations after 1 year. Genomic macrorestriction analysis of whole B. burgdorferi showed no loss or gross alterations of the plasmids encoding OspA, OspB, or OspC. However, in two isolates, loss of a 38-kb plasmid encoding outer surface protein D was noted. Our studies suggest that loss or alteration of the genes encoding OspA and OspB is not a common occurrence during persistent spirochetal infection and that other possible mechanisms, including invasion of immunologically privileged sites, should be actively explored.
Ultrastructural study of Listeria monocytogenes entry into cultured human colonic epithelial cells
Authors: Karunasagar I , Senghaas B , Krohne G , Goebel W
Published: January 2020

Evidence that Listeria monocytogenes enters Caco-2 cells through the apical surface is presented. Attachment of bacteria to host cells seems to induce modifications of microvilli which are either in direct contact with the bacterial surface or in close vicinity, resulting in the formation of lamellipodia involved in the cellular uptake of the bacteria. Such modifications are not induced by L. monocytogenes SLCC 53, which carries a deletion in the prfA gene, although attachment of this mutant to Caco-2 cells occurs. Listeria innocua does not attach well to Caco-2 cells and also fails to cause structural alterations of the microvilli. Treatment of confluent monolayers of Caco-2 cells with ethylene glycol-bis(beta-aminoethyl ether)- N,N,N1,N1-tetraacetic acid (EGTA), which disrupts intercellular junctions, greatly reduced the uptake of Listeria cells. Attachment and invasion of L. monocytogenes was not accompanied by accumulation of filamentous actin around the entering bacterial cell.
Recombinant human bactericidal/permeability-increasing protein (rBPI23) is a universal lipopolysaccharide-binding ligand
Authors: Appelmelk B J , An Y Q , Thijs B G , MacLaren D M , de Graaff J
Published: January 2020

A recombinant 23-kDa protein (rBPI23) derived from human bactericidal/permeability-increasing protein (BPI) possesses potent endotoxin-neutralizing abilities in vitro and in vivo. Binding of rBPI23 to those endotoxins (lipopolysaccharides [LPSs]) encountered clinically would be a prerequisite for efficacy in decreasing mortality among patients suffering from gram-negative sepsis and shock, a disease state in which an etiological role for LPS has been implicated. rBPI23 binds well to lipid A (n = 7), to rough-mutant O-chain-deficient LPS (n = 18, Re to Ra chemotypes), to lipid A-core covalently linked to the O chain, to LPSs from clinically relevant serotypes (n = 100), and to bacterial cells (n = 88) of Escherichia coli, Pseudomonas aeruginosa, and Klebsiella pneumoniae, the species most often implicated in clinical gram-negative sepsis and shock. Significant binding of rBPI23 to these antigens took place at rBPI23 concentrations of 1 to 500 ng/ml (median, 16 to 32 ng/ml). Binding did not involve 3-deoxy-D-manno-octulosonate of the inner core. Determining the exact epitope recognized by rBPI23 would require further studies with synthetic lipid A substructures. The demonstrated ability of rBPI23 to universally bind LPS provides a sound basis for further testing of its endotoxin-neutralizing abilities, including clinical trials.
Outer surface lipoproteins of Borrelia burgdorferi stimulate nitric oxide production by the cytokine-inducible pathway
Authors: Ma Y , Seiler K P , Tai K F , Yang L , Woods M , Weis J J
Published: January 2020

The outer surface lipoproteins of Borrelia burgdorferi, OspA and OspB, stimulate the production of nitric oxide (NO) by murine bone marrow-derived macrophages from BALB/c, C3H/HeN, and C3H/HeJ mice. Gamma interferon (IFN-gamma) caused a three- to fivefold enhancement of this production of NO, and the L-arginine analog N-guanidino-monomethyl L-arginine inhibited it. Activation of transcription of the inducible NO synthase gene in stimulated macrophages was demonstrated by reverse transcriptase rapid PCR. Although IFN-gamma increased the amount of NO produced in macrophage cultures, it did not cause transcription of the inducible NO synthase gene greater than that seen with the Borrelia proteins. OspA and OspB also induced the production of high levels (40 to 150 ng/ml) of IFN-gamma in cultures of macrophages incubated with interleukin-2 (IL-2)-elicited cells from normal (T and NK cells) and scid (NK cells) mice but not in macrophages or IL-2-elicited cells cultured individually. This suggests that OspA stimulated macrophage production of cytokines, which, in turn, stimulated the production of IFN-gamma by NK and T cells. Reverse transcriptase rapid PCR demonstrated that OspA and sonicated B. burgdorferi stimulated production of several inflammatory cytokines in macrophage cultures, including IL-1, IL-6, IL-12, IFN-beta, and tumor necrosis factor alpha. As tumor necrosis factor alpha, IFN-beta, and IL-12 are potent activators of IFN-gamma production by T and NK cells, their presence in these cocultures could be responsible for the IFN-gamma production. Lymphocytes from infected C3H mice also produced IFN-gamma when stimulated with B. burgdorferi; thus, immune cells may also modulate NO responses. The generation of NO during infection with B. burgdorferi may be important, as NO has potent antimicrobial properties. NO can also be involved in pathological inflammatory processes in which its generation is detrimental to the host. Thus, the colocalization of B. burgdorferi lipoproteins, NO-producing cells, and regulatory cytokines may determine the outcome of infection.
Adhesion of Actinobacillus actinomycetemcomitans to a human oral cell line
Authors: Mintz K P , Fives-Taylor P M
Published: January 2020

Two quantitative, rapid assays were developed to study the adhesion of Actinobacillus actinomycetemcomitans, an oral bacterium associated with periodontal disease, to human epithelial cells. The human oral carcinoma cell line KB was grown in microtiter plates, and adherent bacteria were detected by an enzyme-linked immunosorbent assay with purified anti-A. actinomycetemcomitans serum and horseradish peroxidase-conjugated secondary antibody or [3H]thymidine-labeled bacteria. Adhesion was found to be time dependent and increased linearly with increasing numbers of bacteria added. Variation in the level of adhesion was noted among strains of A. actinomycetemcomitans. Adhesion was not significantly altered by changes in pH (from pH 5 to 9) but was sensitive to sodium chloride concentrations greater than 0.15 M. Pooled human saliva was inhibitory for adhesion when bacteria were pretreated with saliva before being added to the cells. Pretreatment of the KB cells with saliva did not inhibit adhesion. Protease treatment of A. actinomycetemcomitans reduced adhesion of the bacteria to KB cells. The data are consistent with the hypothesis that a protein(s) is required for bacterial adhesion and that host components may play a role in modulating adhesion to epithelial cells.
Platelet-activating factor augments meningeal inflammation elicited by Haemophilus influenzae lipooligosaccharide in an animal model of meningitis
Authors: Townsend G C , Scheld W M
Published: January 2020

Research into the pathophysiology of bacterial meningitis has suggested a role for various endogenous inflammatory mediators, such as platelet-activating factor (PAF). In the present study, rats were inoculated intracisternally with various doses of PAF, with Haemophilus influenzae lipooligosaccharide (LOS) in high doses (20 ng) alone, and with a low dose of LOS (200 pg) with or without low doses of PAF (25 ng to 2.5 micrograms). Values for cerebrospinal fluid leukocytosis and percent blood-brain barrier permeability to systemically administered 125I-labeled albumin observed after inoculation of low-dose LOS with PAF were greater (P < 0.05) than those observed after inoculation of low-dose LOS alone and not statistically different from those observed after inoculation of high-dose LOS. PAF alone elicited an inflammatory response only at high doses (25 micrograms). These results support the hypothesis that low cerebrospinal fluid PAF concentrations, such as those observed in children with bacterial meningitis, may augment the inflammatory response to the presence of bacteria in the subarachnoid space.
The immunoprotective Anaplasma marginale major surface protein 2 is encoded by a polymorphic multigene family
Authors: Palmer G H , Eid G , Barbet A F , McGuire T C , McElwain T F
Published: January 2020

An Anaplasma marginale Florida msp-2 gene was cloned and expressed in Escherichia coli. Pulsed-field gel electrophoresis and Southern blot analysis revealed the presence of multiple msp-2 gene copies that were widely distributed throughout the chromosomes of all three strains examined. Genomic polymorphism among copies was greatest in the 5' end of msp-2 but also occurred in 3' regions. The presence of gene-copy-specific epitopes was indicated by the reactivity of the cloned msp-2 copy with some, but not all, monoclonal antibodies that bound native MSP-2. Multiple antigenically distinct MSP-2 molecules were expressed within strains and were coexpressed by individual A. marginale organisms. These results suggest that expression of polymorphic msp-2 gene copies is responsible for the significant percentages of A. marginale organisms within strains that do not react with individual anti-MSP-2 monoclonal antibodies. Sequence analysis revealed highly significant MSP-2 homology with two rickettsial surface proteins, A. marginale MSP-4 and Cowdria ruminantium MAP-1. Immunization with MSP-4 has been shown to induce protective immunity in a manner similar to that of immunization with MSP-2. These findings support the hypothesis that A. marginale surface proteins are targets of protective immune responses but are antigenically polymorphic.
The gene encoding a new mitogenic factor in a Streptococcus pyogenes strain is distributed only in group A streptococci
Authors: Yutsudo T , Okumura K , Iwasaki M , Hara A , Kamitani S , Minamide W , Igarashi H , Hinuma Y
Published: January 2020

We recently cloned a gene encoding a new mitogenic factor (MF) from Streptococcus pyogenes NY-5. In the present study, we determined the distribution of this MF gene (mf) by PCR based upon its sequence. Of 371 streptococcal group A strains isolated from clinical specimens, 370 (99.7%) were positive for mf. The strain that was negative for the MF gene was also negative for the streptolysin O gene (slo). Some streptococcal strains belonging to groups C and G were negative for mf but positive for slo. Group B strains were negative for both. Furthermore, we examined the presence of mf in 54 strains belonging to 28 families and found mf only in group A streptococci. These results indicate that mf is distributed specifically in group A streptococci and the presence of mf in clinical samples strongly suggests infection with group A streptococci.
Fluid Secretory Response of Bovine Thiry Jejunal Fistula to Enterotoxin of
Clostridium perfringens
Authors: Niilo L.
Published: January 2020

The effect of enterotoxin of
Clostridium perfringens
type A was studied in Thiry fistula of the bovine jejunum. Accumulation of fluid as a pathological response was demonstrable within 30 min after introduction of enterotoxin into the fistula; the fluid volume increased rapidly within the first 2 hr and reached maximum in 7 hr. The enterotoxin was not destroyed by the jejunal fluid; 52% of it was absorbed in 2 to 3 hr, and all of the enterotoxin was taken up within 8 hr postinoculation. The accumulation of fluid by the fistula after 0.5 to 2 hr of exposure to enterotoxin ceased completely within 5 hr.
Effect of Anti-Cord Factor Antibody on Experimental Tuberculosis in Mice
Authors: Kato Masahiko
Published: January 2020

Either active immunization with trehalose-6, 6′-dimycolate (cord factor)-methylated bovine serum albumin complex or passive transfer of rabbit anti-cord factor serum induced in mice an enhanced resistance against infection with virulent human
Mycobacterium tuberculosis
. This suggests that the anti-cord factor antibody exerts an infection-protecting effect by neutralizing the toxic action of cord factor during the course of living virulent infection with tubercle bacilli. The protective effect of active immunization with cord factor-methylated bovine serum albumin complex and of anti-cord factor serum was found to be specific for the tuberculous infection among a number of experimental infections in mice with a variety of cytopathogenic microorganisms tested.
Passive Hemagglutination Test for Bovine Chlamydial Abortion
Authors: Belden E. L. , McKercher D. G.
Published: January 2020

Purified chlamydial elementary bodies were subjected to sonic lysis to produce soluble antigen for passive hemagglutination (PHA). PHA was more sensitive than complement fixation (CF) in detecting antibody in hyperimmunized rabbits, lambs, and calves. Both CF and PHA tests were used to monitor antibody responses in experimentally infected pregnant cows. All animals responded with rises in titers after experimental infection. Titers declined and then increased a second time near the time of abortion. PHA titers were considerably higher than CF titers.
Chlorite-Oxidized Amylose as an Adjuvant for Interferon Production
Authors: Levy Hilton B. , Duenwald Jeff , Buckler Charles E.
Published: January 2020

Chlorite-oxidized amylose (COAM), when given intraperitoneally to mice and to cats, increased the titer of serum interferon subsequently induced by polyinosinic·polycytidylic acid (In·Cn). Increases ranged from 6- to 100-fold. Maximal effect was observed when COAM was given 3 h prior to In·Cn. COAM given intravenously prior to Newcastle disease virus also significantly increased serum interferon titers.
Antibody Response to
Chlamydia
Agents: Lack of Immunoglobulin M Antibodies During the Secondary Immune Response
Authors: Isa Abdallah M.
Published: January 2020

Intramuscular inoculation of the monkey with a massive dose of
Chlamydia
agent particles resulted in the production of high levels of immunoglobulin M antibodies. These antibodies were broadly specific and reacted to high titers with heterologous antigens. Challenge inoculation of the same monkeys with heterologous
Chlamydia
agent particles resulted in the production of increased levels of immunoglobulin G but not immunoglobulin M antibodies. Some immunological implications of these results are discussed.
Quantitative Chemical Composition of Peptidoglycan of
Listeria monocytogenes
Authors: Srivastava K. K. , Siddique I. H.
Published: January 2020

The qualitative and quantitative chemical composition of the peptidoglycan layer of
Listeria monocytogenes
cell walls was determined. The peptidoglycan layer was isolated from intact cells after treatment with sodium lauryl sulfate and digestion with Pronase. The isolated peptidoglycan contained carbohydrates which included hexose, rhamnose, and amino sugars. The amino sugar was identified as glucosamine which was present in very high micromole concentration, as compared with the amino acids, muramic acid, or diaminopimelic acid. In addition, protein and phosphorus were also present. However, the presence of teichoic acid was not detected in the peptidoglycan. Protein moiety contained a total of 18 amino acids with lysine as the N-terminal amino acid.
Comparison of Strains of BCG I. Antigenic Analysis and Tuberculin Reactivity
Authors: Chaparas Sotiros D. , Hedrick Sally R.
Published: January 2020

At least 10 of 11 demonstrable antigens in unheated culture filtrates of 12 vaccine strains of BCG were shared as determined in a reference antigen-antibody immunoelectrophoresis system. Filtrates from each of the BCG strains gave equivalent skin test reactions in homologously and heterologously sensitized guinea pigs. By these immunological parameters, the 12 BCG strains were remarkably similar.
Low-Pathogenicity Variant of Lymphocytic Choriomeningitis Virus
Authors: Hotchin J. , Sikora E.
Published: January 2020

A noncytopathic virus has been isolated from a line of strain L mouse fibroblasts infected with lymphocytic choriomeningitis (LCM). This virus has low pathogenicity for mice and renders them immune to intracerebral challenge with virulent LCM virus.
Production of Staphylococcal Enterotoxins A, B, and C Under Conditions of Controlled pH and Aeration
Authors: Jarvis Audrey W. , Lawrence R. C. , Pritchard G. G.
Published: January 2020

The production of enterotoxins A, B, and C by nine strains of
Staphylococcus aureus
has been studied under controlled conditions in a fermenter. The strain to strain differences between staphylococci producing a specific enterotoxin were very marked. Increasing aeration in shake flasks improved both growth and production of all extracellular proteins measured other than that of enterotoxin C, the yield of which was decreased in one strain at high aeration. Silicone antifoam decreased the production of extracellular proteins, although enterotoxin A production from three strains was much less affected than that of enterotoxins B and C. In a detailed study of three strains, production of enterotoxins A and C was considerably greater in a defined amino acid medium than in a casein hydrolysate medium and was optimal for all three enterotoxins between pH 6.5 and 7.3. Changes in the pH or medium used in the fermenter that led to increased enterotoxin production could generally be correlated with a change in growth pattern, showing an extended transition period from exponential to stationary phase. Three out of five enterotoxin-A producing strains produced significantly more enterotoxin at a controlled pH of 6.5 in the fermenter than in shake-flask cultures. The yields with strain 100 were about five times greater than hitherto reported. Since many foods are buffered at pH 6 to 6.5, some strains may, therefore, produce sufficient enterotoxin A to cause food poisoning, although little or none may be produced when grown under normal testing procedures.
Immunofluorescent Study of the Replication of Infectious Pancreatic Necrosis Virus in Trout and Atlantic Salmon Cell Cultures
Authors: Piper Donald , Nicholson Bruce L. , Dunn James
Published: January 2020

Cell cultures of trout gonad tissue (RTG-2) and Atlantic salmon heart, kidney, liver, and spleen tissue were inoculated with 50 50% tissue culture infective doses (TCID
50
) of infectious pancreatic necrosis (IPN) virus per cell, and the titer of cell-associated and released virus was determined from 2 to 16 h postinoculation (PI). Cover slips were collected over the same period and stained for IPN viral antigen by the direct immunofluorescent (FA) technique. Viral replication was detected after a latent period of approximately 2 to 4 h and reached a peak titer of 10
8.2
to 10
8.4
TCID
50
per ml at 8 to 10 h PI. The release of virus was more rapid in Atlantic salmon cells than in RTG-2 cells. Viral antigen was first detected by FA from 3 to 4 h PI. Approximately 75 to 80% of the cells contained antigen in the cytoplasm 9 to 11 h PI. The direct FA technique was found to be a sensitive method for detecting IPN virus in infected cells. Three strains of IPN virus were tested for serological cross reactions by FA and virus neutralization tests.
Role of Zinc in the Production of
Clostridium perfringens
Alpha Toxin
Authors: Sato Hiroko , Murata Ryosuke
Published: January 2020

Clostridium perfringens
was found to produce alpha toxin in a synthetic medium containing zinc; in medium containing no zinc, a little toxin was detected in the early logarithmic phase of growth and it disappeared rapidly. No intracellular accumulation of alpha toxin protein occurred whether or not zinc was present in the medium. In zinc-deficient medium, the organisms produced and released into the surrounding medium the protein specifically precipitable with alpha antitoxin in an amount comparable to that of alpha toxin produced in the zinc-containing medium. The protein combined rapidly in some unknown way with zinc to form the active and stable alpha toxin.
In Vitro Transformation of Mouse Bone-Marrow-Derived (B) Lymphocytes Induced by the Lipid Component of Endotoxin
Authors: Rosenstreich David L. , Nowotny Alois , Chused Thomas , Mergenhagen Stephan E.
Published: January 2020

An analysis of which component of lipopolysaccharide, the lipid or the polysaccharide, is mitogenic for mouse B-lymphocytes has been performed. A purified glycolipid derived from a rough mutant of
Salmonella minnesota
(R595) that does not contain any o-polysaccharide at all is more mitogenic than an intact lipopolysaccharide derived from a smooth strain of
S. minnesota
. Results using fractions produced by several different chemical modifications of whole lipopolysaccharide confirm this result. Acid hydrolysis separates lipopolysaccharide into two components. The lipid fraction is mitogenic, whereas the polysaccharide fraction is not. Those procedures which degrade or modify only the lipid moiety while preserving the antigenic integrity of the polysaccharide also destroy mitogenicity. These include alkaline hydrolysis and deacylation by a more specific treatment with potassium methylate. The lipid preparations are fully active on highly purified B-lymphocyte populations (prepared by anti-theta antiserum and complement), whereas they have no effect on highly purified T-lymphocyte populations (prepared by anti-immunoglobulin and complement). These data demonstrate that the lipid moiety of endotoxin is the B-lymphocyte mitogen, whereas the polysaccharide has no demonstrable mitogenic activity.
Rubella Immunization of Volunteers Via the Respiratory Tract
Authors: Ganguly R. , Ogra P. L. , Regas S. , Waldman R. H.
Published: January 2020

The efficacy of various routes of administration of the live attenuated rubella virus vaccine was evaluated by using 46 seronegative volunteers who were divided into 4 vaccine groups: subcutaneous, nosedrops, spray into posterior oropharynx and nose using large particle aerosol, and inhalation of small particle aerosol through the mouth. Seroconversion was observed in all of the vaccinees regardless of route of immunization. Nasal secretion antibody 6 weeks after immunization was highest in the volunteers who received the vaccine by nose drops (all members of this group had demonstrable nasal secretion antibody after immunization). Only half of the volunteers in the subcutaneous group developed demonstrable nasal secretion antibody. This suggests that nasal secretion antibody was best stimulated when vaccine was given directly into the nose. Volunteers were challenged with the vaccine intranasally at 6 to 8 weeks. None of the volunteers exhibited clinical symptoms or fourfold or greater serum antibody rises after challenge, but fourfold or greater nasal secretion antibody rises were observed in three volunteers in the subcutaneous vaccine group and two in the aerosol group, suggesting that those volunteers had not been protected against challenge. Rubella virus was isolated 8 to 12 days after challenge in two persons in the subcutaneous group and three in the aerosol vaccine group, but none in the nose drops or spray groups. Thus, protection after nasal challenge appeared to be best in those groups which also had the best nasal secretion antibody response after immunization. However, protection did not seem to be correlated with either nasal secretion or serum antibody levels.
Virulence Differences in Mice of Type A and B
Histoplasma capsulatum
Yeasts Grown in Continuous Light and Total Darkness
Authors: Campbell Charlotte C. , Berliner Martha D.
Published: January 2020

Type B yeasts were more virulent for mice than type A under most experimental conditions. Mice infected with type B yeasts grown in the light lived significantly longer than those with type B yeasts grown in the dark. Virulence differences of type A yeasts grown in continuous fluorescent light versus total darkness were not statistically significant.
Quantitation of Immunoglobulin-Bearing Lymphocytes and Lymphocyte Response to Mitogens in Horses Persistently Infected by Equine Infectious Anemia Virus
Authors: Banks Keith L. , Henson J. B.
Published: January 2020

A defect in lymphocyte function could be responsible for persistent infection by the equine infectious anemia virus. The number of lymphocytes bearing surface immunoglobulin, as detected by immunofluorescence, and lymphocyte response to mitogens were the same in uninfected and equine infectious anemia-infected animals. A defect in T or B lymphocyte numbers or ability to respond to stimuli was not detected in this chronic virus disease.
Comparison of the Rhamnomannans from the Human Pathogen
Sporothrix schenckii
with Those from the
Ceratocystis
Species
Authors: Travassos L. R. , Gorin P. A. J. , Lloyd K. O.
Published: January 2020

Rhamnomannans from several isolates of
Sporothrix schenckii
and
Ceratocystis
species were compared. No major differences emerged in the analysis of the carbohydrate composition of polysaccharides from either species. Methylation analysis for the identification of the glycosidic linkages present in the polysaccharides showed that they all were very similar with minor differences being observed among strains and between polysaccharides obtained at 25 and 37 C. Partially methylated derivatives were identified by gas-liquid chromatography and mass spectrometry. Their proportions suggest that polysaccharides from
S. schenckii
and
C. stenoceras
have a general structure similar to that of
C. ulmi
: a (1 → 6)-linked α-
d
-mannopyranosyl main chain substituted in the 3-positions by α-
l
-rhamnopyranosyl and in many cases by α-
l
-rhamnopyranosyl (1→2)-
l
-rhamnopyranosyl side chains. Differences among polysaccharides resided in the proportions of the dirhamnosyl side chains and of 4-
O
-substituted and 2, 4-di-
O
-substituted mannose units. Increased proportions of dirhamnosyl side chains were observed in the polysaccharides from
S. schenckii
strains and from a pathogenic variant of
C. stenoceras
grown at 25 C. Proton magnetic resonance spectra (H-1 region) of the rhamnomannans showed that
S. schenckii
strains could be placed in two different groups similar but not identical to any
Ceratocystis
species. These spectra were very close to those of the polysaccharides from the
C. clavata
and
C. ambrosia
groups of
Ceratocystis
species.
Inhibition of Macrophage Migration by Nucleotide-Containing Streptococcal Preparations
Authors: Bültmann B. , Heymer B. , Schachenmayr W. , Haferkamp O. , Schmidt W. C.
Published: January 2020

Certain extracts of streptococcal cell walls are known to inhibit macrophage migration in vitro. In this study, we attempted to identify the streptococcal components responsible for this phenomenon. Trypsinized cell walls and cytoplasm from groups A and B streptococci were extracted with hot formamide followed by acetone precipitation. Subsequent gel filtration in aqueous solutions yielded a fraction devoid of C-carbohydrate and containing mostly oligonucleotides, apparently derived from streptococcal cytoplasm. This fraction significantly inhibited the migration of peritoneal exudate cells from rats sensitized to groups A and B streptococci. It was noteworthy that no inhibition of migration was observed with cells from nonsensitized animals or control rats injected with BCG or complete Freund adjuvant. Similarly, no inhibition was obtained with formamide extracts of calf thymus RNA. Although the inhibition does not show specificity for streptococcal groups, it seems to have immunological specificity since prior sensitization with streptococci is required for migration inhibition.
Synergistic Effect in Viral-Bacterial Infection: Combined Infection of the Murine Respiratory Tract with Sendai Virus and
Pasteurella pneumotropica
Authors: Jakab George J. , Dick Elliot C.
Published: January 2020

Synergism was demonstrated between Sendai virus and
Pasteurella pneumotropica
in the respiratory tract of mice showing no evidence of previous infection with either agent. Mice aerosol challenged with
P. pneumotropica
invariably eliminated the viable organism from their lungs within 72 h. In contrast, intrapulmonary killing was delayed in animals previously infected with Sendai virus. Maximum synergism was observed when virus infection preceded bacterial challenge by 6 days. At this time, a mortality rate of 37% was observed as compared with 0, 10, 20, and 10%, respectively, in those animals in which the virus infection preceded bacterial challenge by 1, 3, 9, and 12 days. Previous immunization with Sendai virus completely prevented virus infection and thus the synergistic effect. Synergism with endogenous flora was also noted. Six days after virus infection an endogenous
Pasteurella
sp. began to proliferate in the bronchopulmonary tissues. Up to 10
4
colony-forming units per lung were recovered but no animals died of the endogenous
Pasteurella
infection.
Purification and Characterization of Thermostable Direct Hemolysin of
Vibrio parahaemolyticus
Authors: Sakurai Jun , Matsuzaki Akiko , Miwatani Toshio
Published: January 2020

A thermostable direct hemolysin was purified from culture filtrates of
Vibrio parahaemolyticus.
The purified hemolysin gave one precipitation line with the antihemolysin antiserum on agar-gel diffusion test and a single band on polyacrylamide gel electrophoresis. The hemolysin was not inactivated by heating at 70 to 100 C for 10 min. The hemolytic activity was not enhanced by the addition of lecithin. It was demonstrated that the hemolysin was a protein with a molecular weight of approximately 118,000. Amino acid analysis revealed that 43% of total amino acids were acidic amino acids, whereas 11% were basic amino acids.
Filamentous Capsulated Streptococci from the Human Respiratory Tract II. Antigenic Structure of Provisional Capsular Types 89 and 83/89
Authors: Karakawa Walter W. , Kane Judith A. , Austrian Robert
Published: January 2020

Two immunologically distinct polysaccharides have been isolated from the filamentous alpha-hemolytic streptococcus of provisional capsular type 89, recovered from the human respiratory tract. Chemical analyses indicate that the capsular polysaccharide consists of glucose, galactose, and a small amount of rhamnose, whereas the cell wall-associated polymer contains galactosamine, glucosamine, glucose, and phosphorus. Immunological studies suggest that the capsular polysaccharide is type specific and that the cell wall-associated carbohydrate, which cross-reacts with the C
8
, or cell wall-like capsular polysaccharide of pneumococcus, may be group specific. A noncapsulated variant of the prototypic streptococcus of provisional type 89 was shown to possess the same cell wall-associated carbohydrate as the strain from which it was derived, but it proved to be poorly antigenic in rabbits. A filamentous capsulated streptococcus reacting with antisera to filamentous streptococci of both provisional capsular types 83 and 89 has been found to produce two capsular polysaccharides, each of which reacts with antibody to one of the aforementioned unitypic strains and represents an unusual binary capsulated streptococcus.
Inhibitory and Restorative Effects of Adenine Nucleotides on Rickettsial Adsorption and Hemolysis
Authors: Winkler Herbert H.
Published: January 2020

The adenine nucleotides, adenosine diphosphate, adenosine triphosphate, (ATP), and the methylene-bridge analogues are inhibitors of rickettsial adsorption to and the hemolysis of sheep erythrocytes. Other nucleotides, adenosine monophosphate, cyclic adenosine monophosphate, cytosine triphosphate, and guanosine triphosphate, are without effect. Adsorption and hemolysis require the generation of energy by the rickettsiae which is usually derived from glutamate. When the generation of energy from the metabolism of glutamate is inhibited by arsenite or cyanide, the addition of ATP can supply the energy to restore hemolysis. However, in the presence of the uncouplers, ATP can not restore hemolysis. Even when functioning in a restorative role, ATP still has its inhibitory properties. These results suggest that a high-energy intermediate (X ∼ I), rather than ATP itself, is the energy source. The interactions of inhibitory nucleotides suggest that these compounds share a common transport system.
Reactivity of Purified Proteins and Polysaccharides from
Mycobacterium tuberculosis
in Delayed Skin Test and Cultured Lymphocyte Mitogenesis Assays
Authors: Daniel Thomas M. , Hinz Carl F.
Published: January 2020

Hypersensitivity responses to two highly purified and well characterized mycobacterial proteins and a preparation of mycobacterial arabinogalactanarabinomannan were studied by using guinea pig skin tests and in vitro-cultured human lymphocyte mitogenesis stimulation assays. The purified proteins were found to elicit delayed-type hypersensitivity skin test reactions and to stimulate mitogenesis in cultured lymphocytes. The polysaccharide preparation was found to evoke delayed skin tests but not to stimulate cultured lymphocytes.
Impaired Cellular Immunity to Rubella Virus in Congenital Rubella
Authors: Fuccillo David A. , Steele Russell W. , Hensen Sally A. , Vincent Monroe M. , Hardy Janet B. , Bellanti Joseph A.
Published: January 2020

Specific cell-mediated immunity (CMI) responses to rubella virus were studied in 12 children with documented congenital rubella syndrome employing a
51
Cr lymphocytotoxicity microassay. Hemagglutination inhibition antibody was detected in 11 of the 12 children, with titers ranging from 1:4 to 1:128. CMI to rubella virus was demonstrated in only 3 of the 11 antibody-positive children. The 12th child was negative for both hemagglutination inhibition and CMI. Of the three children with a positive CMI response, two had histories of reinfection with rubella virus. These data suggest that congenital rubella infection produces an impaired CMI response which subsequently may be altered by reinfection with rubella virus. The lack of CMI in the presence of antibody and concurrent excretion of live virus in the child with documented congenital rubella infection suggest a factor to be explored in the pathogenesis of this disease.
Skin Testing of Guinea Pigs and Footpad Testing of Mice With a New Antigen for Detecting Delayed Hypersensitivity to
Cryptococcus neoformans
Authors: Murphy Juneann W. , Gregory Jay A. , Larsh Howard W.
Published: January 2020

This study was undertaken to evaluate the potential of a cryptococcal culture filtrate antigen, cryptococcin C184, for detecting delayed hypersensitivity in
Cryptococcus neoformans
-injected animals. The antigen was tested on guinea pigs which had received saline or
C. neoformans
and on animals sensitized to
Histoplasma capsulatum, Blastomyces dermatitidis, Candida albicans
, or
Sporothrix schenckii.
A delayed-type hypersensitivity response was elicited by cryptococcin C184 in
C. neoformans
-injected guinea pigs, whereas no indurations or erythemas were seen at 48 h after skin testing of saline controls or heterologously sensitized guinea pigs. Besides being specific for
Cryptococcus
, the antigen showed a high degree of sensitivity and was reproducible. Footpad tests were conducted with the antigen on mice which had previously received either 10
5
viable
C. neoformans
cells or saline. Delayed hypersensitivity was indicated in the
C. neoformans
-injected mice by the increase in thickness of antigen-injected footpads when compared with the saline-injected footpads. In control mice, antigen- and saline-injected footpads were comparable in thickness 24 h after injection. Mice sensitized to
B. dermatitidis
were footpad tested with C184, and no cross-reactivity was demonstrated.
Pseudomonas aeruginosa
Exotoxin in Mice: Localization and Effect on Protein Synthesis
Authors: Pavlovskis Olgerts R. , Shackelford Arligues H.
Published: January 2020

We studied the fate of
125
I-labeled
Pseudomonas aeruginosa
(PA 103) exotoxin injected intravenously into mice and the effect of the exotoxin on the protein synthesis of various organs. After 2 h, only 5% of the injected label remained in the blood, in comparison with 30% of the injected control, consisting of [
125
I]bovine serum albumin. The highest concentration of radioactivity was consistently observed in the kidneys of toxin-treated mice. Lesser amounts of the label were found in the liver and the spleen. The heart, pancreas, lung, and brain showed very little uptake. Approximately 30% of the label (non-trichloroacetic acid precipitable) was recovered from the urine within 2 h after the injection. The behavior of [
125
I]toxoid was similar to that of the [
125
I]toxin. In contrast, in [
125
I]bovine serum albumin-treated mice, the label was uniformly distributed among the organs examined, and the concentration was low. After intravenous administration of the exotoxin, a 50% inhibition of protein synthesis was observed in the liver within 4 h, and virtually complete inhibition was observed shortly before the time of death. Kidney and spleen displayed slight reduction of protein synthesis at 2 to 4 h and approximately 50% reduction during the terminal stage. It appeared that the highest concentration of the toxin occurred in the kidney, where it was degraded, but its greatest toxic effect took place in the liver.
Use of Inoculated Eggs as a Vehicle for the Oral Rabies Vaccination of Red Foxes (
Vulpes fulva
)
Authors: Debbie John G.
Published: January 2020

The ERA vaccine strain of rabies virus propagated on continuous porcine kidney tissue culture cells (PK15) was inoculated into the yolk sac of embryonated chicken eggs for the purpose of oral vaccine distribution. Two inoculated eggs were subsequently fed to each of 12 serologically rabies-negative foxes. Six (50%) of the foxes developed demonstrable rabies serum-neutralizing antibody within 4 weeks of vaccination and resisted challenge to street virus 14 weeks postvaccination. Testing of inoculated eggs for virus stability in the presence and absence of a casein hydrolysate-sucrose stabilizer at 6, 22, and 37 C for up to 15 days revealed no advantage to the stabilizer-vaccine mixture in eggs.
Susceptibility of Fertilized Mouse Eggs to Minute Virus of Mice
Authors: Mohanty S. B. , Bachmann P. A.
Published: January 2020

Fertilized two-celled mouse eggs deprived of their zona pellucida were susceptible to infection with minute virus of mice. The virus had no deleterious effect on development of embryos cultivated in vitro.
In Vitro Attachment of Streptococci to the Tooth Surface
Authors: Ørstavik Dag , Kraus Frederick W. , Henshaw L. Carolyn
Published: January 2020

The ability of
Streptococcus
strains to adhere to the tooth surface in vitro was investigated. Polished enamel slabs, with and without acquired pellicles, were incubated with buffer suspensions of oral streptococci, and attached bacteria were counted under a microscope using incident light. Low numbers of bacteria adhered to uncoated enamel; the presence of an acquired pellicle significantly enhanced the attachment of all strains tested. The adherence of
Streptococcus sanguis
was significantly greater than that of
Streptococcus salivarius
, and both of these strains adhered in greater numbers than did
Streptococcus mutans.
When bacteria were suspended in whole saliva, the adherence of
S. salivarius
and
S. mutans
was inhibited, whereas the adherence of
S. sanguis
was enhanced in some experiments and inhibited in others. The adherence of
S. sanguis
and
S. salivarius
was consistently inhibited by parotid fluid; this inhibitory effect persisted after thorough washing and resonication of the bacterial cells. Incubation in oral fluids was associated with the attachment of bacterial clumps to the pellicle, and parallel investigation revealed agglutination of
S. sanguis
and
S. salivarius
by whole saliva and, in particular, parotid fluid. The results are discussed in terms of surface microecology, and are related to the development of dental plaque.
Peptic Digestion of Streptococcal M Protein II. Extraction of M Antigen from Group A Streptococci With Pepsin
Authors: Beachey Edwin H. , Campbell Gary L. , Ofek Itzhak
Published: January 2020

M protein of group A streptococci was extracted by mild peptic digestion. Optimal amounts of type-specific M protein were released after 20 min of digestion with 0.02 mg of pepsin per ml at pH 5.8. Immunological analysis revealed that, unlike conventional HCl extracts, pepsin extracts lacked the surface C carbohydrate antigen and contained less non-type-specific, heat-stable cellular antigens; they also lacked detectable heat-labile T protein. Similar to HCl extracts, however, the pepsin-extracted M protein precipitated homologous-type M antisera and inhibited type-specific opsonization of homologous group A streptococci. Furthermore, the pepsin extract was capable of inducing type-specific opsonic M antibody in rabbits. This method may provide a useful initial step in the purification of M protein by reducing contaminating antigens.
Acetate Utilization and Macromolecular Synthesis During Sporulation of Yeast
Authors: Esposito Michael S. , Esposito Rochelle E. , Arnaud Maryvonne , Halvorson H. O.
Published: January 2020

Acetate utilization and macromolecule synthesis during sporulation (meiosis) of
Saccharomyces cerevisiae
were studied. When diploid cells are transferred from glucose nutrient medium to acetate sporulation medium at early stationary phase, respiration of the exogenously supplied acetate proceeds without any apparent lag. At the completion of ascospore development, 62% of the acetate carbon consumed has been respired, 22% remains in the soluble pool, and 16% is incorporated into lipids, protein, nucleic acids, and other cell components. Measurements of the rate of protein synthesis during sporulation reveal two periods of maximal synthetic activity: an early phase coincidental with increases in deoxyribonucleic acid, ribonucleic acid, and protein cellular content and a later phase during ascospore formation. Experiments in which protein synthesis was inhibited at intervals during sporulation indicate that protein synthesis is required both for the initiation and completion of ascus development.
Characterization of Pyridoxine Auxotrophs of
Escherichia coli:
Chromosomal Position of Linkage Group I
Authors: Dempsey Walter B.
Published: January 2020

The chromosomal location of Group I pyridoxine mutations in
Escherichia coli
is shown to be adjacent to
dsdA,aroC
, and
purF
(old
purC
) in
E. coli
B × K-12 hybrids. All mutants previously classified into Group I by nutrition tests and transduction frequency tests are shown to be linked to
dsdA
.
Endogenous Encystment of
Azotobacter vinelandii
Authors: Wyss Orville , Smith D. D. , Pope Leodocia M. , Olson K. E.
Published: January 2020

When young cells of
Azotobacter vinelandii
are impinged on membrane filters, washed free of carbon substrate, and placed on a mineral salts basal medium, the culture will proceed to encyst although at a slower rate than if
n
-butanol were supplied as a substrate. The endogenous cysts are depleted in polyβ-hydroxybutyrate and have a narrower intine but show an increased resistance to desiccation and are susceptible to lysis by chelating agents. Membrane-supported cells reveal details of the encystment process such as the formation of a zone within the capsule prior to exine formation and the early deposition of exine structures.
New Facultative
Thiobacillus
and a Reevaluation of the Heterotrophic Potential of
Thiobacillus novellus
Authors: Taylor Barrie F. , Hoare Derek S.
Published: January 2020

A new facultatively autotrophic
Thiobacillus
has been isolated in pure culture. The general physiological characteristics of the organism are described together with a redescription of
Thiobacillus novellus
. The new isolate differs from
T. novellus
in its ability to grow heterotrophically at faster rates and on a greater range of organic compounds. It can be transferred readily between autotrophic and heterotrophic conditions. It can grow anaerobically by nitrate respiration on a number of organic compounds, but not on thiosulfate. Some problems in the nomenclature and taxonomy of the thiobacilli are discussed with reference to the new isolate.
Volatile and Cellular Fatty Acids of
Haemophilus vaginalis
Authors: Moss C. Wayne , Dunkelberg W. E.
Published: January 2020

The major volatile acid produced by
Haemophilus vaginalis
was acetic acid. The absence of propionate, butyrate, and cellular branched-chain fatty acids indicates that
H. vaginalis
is not related to
Propionibacterium
or
Butyribacterium
.
Generic Identification of L-Forms by Polyacrylamide Gel Electrophoretic Comparison of Extracts from Parent Strains and Their Derived L-Forms
Authors: King James R. , Theodore Theodore S. , Cole Roger M.
Published: January 2020

A polyacrylamide gel electrophoretic method was used for identification of L-forms in the genera
Streptococcus, Staphylococcus
, and
Proteus
, by comparing phenol-acetic acid-water extracts of homologous parent L-form pairs to one another and to other pairs. The method requires only milligram quantities of material for analysis. The standard patterns for the strains used in this study are shown as pictures of the gels and as densitometric tracings of appropriate gels. They show that, despite occasional minor differences in some organisms, the gel electrophoretic patterns of homologous L-forms and bacterial pairs are sufficiently similar—as well as sufficiently dissimilar from patterns of other genera—to permit generic identification of an unknown L-form by reference to patterns derived from possible parental bacteria.
Method for Assessing the Frequency of Transfer of an R Factor on Solid Media and for Isolating Cells of the Donor Type from a Predominantly Repressed Culture
Authors: Lee Pat A. , Richmond M. H.
Published: January 2020

A method for assessing the incidence of R factor transfer on solid media is described. The method gives values similar to those obtained with conventional techniques but allows the derepressed cells from a predominantly repressed population to be isolated.
Role of Isoleucyl-Transfer Ribonucleic Acid Synthetase in Ribonucleic Acid Synthesis and Enzyme Repression in Yeast
Authors: McLaughlin Calvin S. , Magee P. T. , Hartwell Leland H.
Published: January 2020

Temperature-sensitive mutations in the isoleucyl-transfer ribonucleic acid (tRNA) synthetase of yeast, ilS
−
1-1 and ilS
−
1-2, were used to examine the role of aminoacyl-tRNA synthetase enzymes in the regulation of ribonucleic acid (RNA) synthesis and enzyme synthesis in a eucaryotic organism. At the permissive temperature, 70 to 100% of the intracellular isoleucyl-tRNA was charged in mutants carrying these mutations; at growth-limiting temperatures, less than 10% was charged with isoleucine. Other aminoacyl-tRNA molecules remained essentially fully charged under both conditions. Net protein and RNA syntheses were rapidly inhibited when the mutant was shifted from the permissive to the restrictive temperature. Most of the ribosomes remained in polyribosome structures at the restrictive temperature even though protein synthesis was strongly inhibited. Two of the enzymes of isoleucine biosynthesis, threonine deaminase and acetohydroxyacid synthetase, were derepressed about twofold during slow growth of the mutants at a growth-limiting temperature. This is about the same degree of derepression that is achieved by growth of an auxotroph on limiting isoleucine. We conclude that charged aminoacyl-tRNA is essential for RNA synthesis and for the multivalent repression of the isoleucine biosynthetic enzymes. Aminoacyl tRNA synthetase enzymes appear to play important regulatory roles in the cell physiology of eucaryotic organisms.