bluuebunny/crossref_metadata_2025 huggingface dataset:
Inhibition of onset of overt multiplication of Chlamydia psittaci in persistently infected mouse fibroblasts (L cells)
Authors: Moulder J W
Published: January 2020

When monolayers of mouse fibroblasts (L cells) persistently infected with Chlamydia psittaci (strain 6BC) were dispersed in medium 199 and plated out in new flasks, the monolayers that grew out consisted almost exclusively of inclusion-free host cells that retained full resistance to superinfection with C. psittaci (covert infection). After a delay that was inversely proportional to the initial density of the newly transferred L cell population, the percentage of host cells containing visible chlamydial inclusions increased rapidly (overt infection), and most of the L cells were destroyed by extensive chlamydial multiplication (wipeout), leaving only a few survivors to start new persistently infected monolayers. When persistently infected L cell populations grown in medium 199 were transferred to Eagle minimal essential medium, the onset of overt multiplication was strongly suppressed although covert multiplication of C. psittaci continued unabated, as shown by host cell retention of resistance to superinfection and the prompt resumption of overt multiplication after transfer back into medium 199. The difference(s) between the two media responsible for the different expression of the persistently infected state was not determined. A single dose of 100 U of penicillin G per ml of medium 199 given at the time persistently infected monolayers were divided almost completely suppressed the appearance of visible signs of chlamydial infection for several weeks, although resistance to superinfection was retained at all times. The same amount of penicillin given 7 days after replating did not prevent the occurrence of the first expected wipeout, but there was a long period of inclusion-free L cell growth between the first wipeout and the second. It was concluded that covert multiplication of C. psittaci in persistently infected L cells may continue indefinitely without the appearance of visible signs of infection. The transition between covert and overt chlamydial multiplication appears to be a penicillin-sensitive, multistep process that is regulated, at least in part, by the host cell density and the composition of the growth medium.
Effect of antibody on entry of Rickettsia tsutsugamushi into polymorphonuclear leukocyte cytoplasm
Authors: Rikihisa Y , Ito S
Published: January 2020

The effects of rickettsial antibodies on the entry of Rickettsia tsutsugamushi, Gilliam strain, into guinea pig polymorphonuclear leukocyte cytoplasm were studied by electron microscopy. Immunoglobulin G fractions were obtained from four rabbit antisera against: yolk sac-propagated rickettsiae; baby hamster kidney cell (BHK-21)-propagated rickettsiae; formaldehyde-fixed, BHK-21 cell-propagated rickettsiae; and glutaraldehyde-fixed, BHK-21 cell-propagated rickettsiae. A fuzzy coating was observed on the rickettsiae after reaction with each of the antibodies. All of the antibodies increased the uptake of rickettsiae by polymorphonuclear leukocytes. The opsonization effect was higher with an antibody against BHK-21 cell-propagated rickettsiae than with an antibody against yolk sac-propagated rickettsiae, and an antibody to live rickettsiae had a higher opsonization effect than did antibodies to chemically fixed rickettsiae. Rickettsiae were released from phagosomes into the cytoplasm with the four antibodies. The highest number of rickettsiae were released into the cytoplasm with antibody against live rickettsiae propagated in BHK-21 cells. The four antibodies inhibited the translocation of the cytoplasmic rickettsiae from the filamentous area to glycogen-rich zones. Almost 100% inhibition of translocation was observed with antibodies against live rickettsiae. These results indicate that rabbit antibodies against rickettsiae, when used alone, were unable to completely prevent rickettsial entry into polymorphonuclear leukocyte cytoplasm in vitro.
Stimulation of nonspecific resistance to infection induced by muramyl dipeptide analogs substituted in the gamma-carboxyl group and evaluation of N alpha-muramyl dipeptide-N epsilon-stearoyllysine
Authors: Matsumoto K , Otani T , Une T , Osada Y , Ogawa H , Azuma I
Published: January 2020

Stimulation of resistance to infection induced by the analogs of muramyl dipeptide (MDP) having substituted functions in the gamma-carboxyl group of D-isoglutamyl residue was examined in experimental Escherichia coli infections in mice. An MDP analog which is an efficient strengthener of resistance to infection, N alpha-MDP-N epsilon-stearoyllysine [MDP-Lys(L18)], was selected through the comparative assessment of a number of compounds in three categories: (i) gamma-alkylamides, (ii) gamma-esters, and (iii) N alpha-MDP-N epsilon-acyllysine derivatives. Furthermore, the antiinfectious activity of MDP-Lys(L18) was evaluated bacteriologically in comparison with that of MDP. The effect of MDP-Lys(L18) on the susceptibility of mice to infections with various species of microorganisms was studied. Protective activity was greatest against E. coli and staphylococcal infections, considerable against Pseudomonas and Candida infections, and least against Klebsiella infection. The effects of bacterial inoculum size and MDP treatment timing, dose, and route of administration on protective activity were studied. The efficacy of MDP-Lys(L18) in protection tests was demonstrated for all administration routes, even the oral. Its high potency was confirmed by the smaller influence of inoculum size and particularly small value of the minimum dosage required for inducing protective activity. A decrease in bacterial survival was observed in the blood and organs of mice treated with the analog and infected with E. coli. The following two useful effects were obtained: the synergistic effect of glycopeptide and chemotherapeutic agents and the stimulation of resistance to infection in animals immunocompromised by cyclophosphamide treatment.
Lack of correlative enhancement of passive transfer of delayed-type hypersensitivity and antilisterial resistance when using concanavalin A-stimulated primed spleen cells
Authors: Barry R A , Hinrichs D J
Published: January 2020

The adoptive transfer of resistance to Listeria monocytogenes can be significantly enhanced by in vitro incubation of primed murine spleen cells with concanavalin A (ConA) before transfer into syngeneic recipients. The level of transferred resistance, as measured by clearance of infectious organisms, can approach that observed in actively immunized mice. When delayed-type hypersensitivity (DTH) responses of passive transfer recipients were compared, there was no difference in the level of hypersensitivity exhibited by mice receiving either nonstimulated or ConA-stimulated, Listeria-immune spleen cells. In addition, the level of these adoptively transferred responses never approached the level of DTH observed in actively immunized mice. This inability of ConA-stimulated cells to enhance passive DTH in recipient mice was not dependent on the antigenic preparation of Listeria used to elicit the DTH response. Transfer of cultured, ConA-stimulated, Listeria-immune spleen cells did not lead either to specific or to nonspecific suppression of DTH responsiveness in actively immunized mice. These results indicate the possible existence of antigen-specific T-cells subpopulations which, after stimulation with ConA, exhibit differing efficiencies when responding in assays of cell-mediated immunity.
Effective antibacterial protection induced by a Listeria monocytogenes-specific T cell clone and its lymphokines
Authors: Kaufmann S H
Published: January 2020

The capacity of the murine Listeria monocytogenes-specific T cell clone 9-36-1 and of lymphokines derived therefrom to induce antibacterial protection in vivo was studied. Clone 9-36-1 was stimulated to proliferate and to produce lymphokines by in vitro culture with syngeneic accessory cells and heat-killed L. monocytogenes. Although 9-36-1 cells were highly active in vitro, intravenous transfer of the cells resulted in marginal protection against a systemic infection with L. monocytogenes. In contrast, 9-36-1 cells injected subcutaneously together with L. monocytogenes into the footpad induced marked protection in syngeneic, but not in allogeneic, mice. Multiplication of Salmonella typhimurium was not reduced by the T cell clone. Studies with 51Cr-labeled T cells indicated that the low activity of intravenously transferred cells was due to an altered migration pattern. Lymphokines produced by 9-36-1 cells in vitro induced protection against L. monocytogenes in syngeneic recipient mice. Lymphokine-induced protection was also demonstrable in allogeneic recipients and against S. typhimurium. These findings suggest that the L. monocytogenes-specific T cell clone 9-36-1, although unable to immigrate into sites of bacterial deposition, had retained its ability to mobilize antibacterial defense mechanisms once present at the site of reaction.
Adjuvant-induced arthritis in the temporomandibular joint of rats
Authors: Zamma T
Published: January 2020

When Lewis rats were immunized by intradermal injection into the parietal scalp rather than into the footpad with mycobacterial delipidated cells in squalene, arthritis could be produced in the temporomandibular joint (TMJ) with a maximum incidence of 60%, accompanied by systemic polyarthritis. Other methods of immunization including intradermal injection into the tail, posterior cervical region, or intra-inguinal lymph nodes did not induce arthritis in the TMJ. A combination of this inoculation and hemiocclusal loss markedly increased the incidence of arthritis in the TMJ. This arthritis in the TMJ was, however, milder than that in other joints and was apparent only histologically. The group given intradermal injection of adjuvants into the parietal scalp showed definite suppression of body weight gain. Since the method of intradermal injection into the parietal scalp can induce a high incidence of arthritis in the TMJ, our study presents a unique experimental model for study of arthritis in the TMJ.
Nuclear antigen detected in hepatoma cell lines containing integrated hepatitis B virus DNA
Authors: Wen Y M , Mitamura K , Merchant B , Tang Z Y , Purcell R H
Published: January 2020

We identified, by anticomplement immunofluorescence, a nuclear antigen (hepatitis B virus-associated nuclear antigen [HBNA]) in two human hepatoma cell lines containing integrated hepatitis B virus DNA but not in three hepatoma cell lines lacking it. The antigen resembled neoantigens associated with the oncogenesis of certain papovaviruses, adenoviruses, and herpesviruses. Antibody to the antigen (anti-HBNA) was found in 7.3% of hepatitis B surface antigen-positive sera from patients with hepatocellular carcinoma but not in surface antigen-negative sera. The staining of HBNA was characterized by two patterns, reticular nuclear fluorescence and nucleolar fluorescence. The expression of HBNA did not parallel the production of extracellular hepatitis B surface antigen. Treatment of cells with proteinase K, RNase, DNase, or cycloheximide significantly diminished the staining of HBNA.
Cross-reactions between Legionella pneumophila (serogroup 1) and twenty-eight other bacterial species, including other members of the family Legionellaceae
Authors: Collins M T , Espersen F , Høiby N , Cho S N , Friis-Møller A , Reif J S
Published: January 2020

Cross-reactions between Legionella pneumophila serogroup 1 and 28 other bacterial species were studied by various quantitative immunoelectrophoretic techniques. A sonicated L. pneumophila antigen and purified homologous rabbit antibody were used as a reference system. Few antigens (0 to 6) cross-reacted with non-Legionellaceae, but two were found in nearly all gram-negative bacteria tested (antigens no. 1 and 66). Antigen no. 66 of the L. pneumophila reference system was shown to be antigenically similar to the "common antigen" of Pseudomonas aeruginosa reported in many gram-negative bacteria. Greater than 85% of the antigens from L. pneumophila serogroup 1 cross-reacted with the other six serogroups of L. pneumophila. By contrast, Fluoribacter (Legionella) bozemanae, F. (L.) dumoffii, F. (L.) gormanii, and Tatlockia (Legionella) micdadei cross-reacted with only 45, 53, 39, and 43% of the reference system antigens, respectively. The antigenic relatedness of members of the Legionellaceae, expressed as a matching coefficient, is discussed in terms of its taxonomic significance. Serogroup-, genus-, and family-specific antigens are identified in the L. pneumophila reference system.
Immunoglobulin M-Immunoglobulin G mixed cryoglobulinemia in Schistosoma japonicum-infected rabbits
Authors: Robinson A , Lewert R M
Published: January 2020

Cryoprecipitation was observed in defibrinated serum from Schistosoma japonicum-infected rabbits. Ouchterlony immunodiffusion, sodium dodecyl sulfate-polyacrylamide gels, and anti-cryoprecipitate antiserum demonstrated the presence of immunoglobulin G (IgG), IgM, C3, fibrinogen, and an alpha-macroglobulin. Parasite antigen was not detected. IgG and IgM from pooled cryoprecipitates failed to react with each other in Ouchterlony immunodiffusion gels after separation by column chromatography. The data suggest that the IgG and IgM are not specifically complexed with each other but may simply be aggregates of altered proteins.
Inhibition by Rifampin of African Swine Fever Virus Replication in Tissue Culture
Authors: Dardiri A. H. , Bachrach H. L. , Heller E.
Published: January 2020

Vaccinia virus and African swine fever virus are deoxyribonucleic acid viruses of cytoplasmic origin. The fact that rifampin inhibits the replication of the former virus led to an investigation of its effect on African swine fever virus. The virus used was cytopathogenic to a PK-15 cell line, hemadsorbing in pig leukocyte cultures and lethal to pigs. Rifampin clearly inhibited the multiplication and cytopathogenicity of the virus in PK-15 cells. There was a 1- to 5-log reduction in virus titer depending upon the rifampin concentration, the multiplicity of infection, and the time after infection. Inhibition was greatest at a concentration of 200 μg of rifampin/ml. The drug was not viricidal per se, and the inhibition of virus replication was not due to the cell-granulating effect of rifampin since cultures which were transiently pretreated for long as 90 hr with 200 μg of drug/ml supported viral replication to the same degree as untreated cultures.
L-Forms of
Pseudomonas aeruginosa
Authors: Hubert Earl G. , Potter Clarence S. , Hensley Thomas J. , Cohen Morris , Kalmanson George M. , Guze Lucien B.
Published: January 2020

L-forms of a strain of
Pseudomonas aeruginosa
were produced by serial subculture of the bacterial form on agar medium containing sucrose as an osmotic stabilizer and carbenicillin. L-forms eventually became stable, i.e., would not revert in the absence of antibiotic, and were adapted to grow well in broth with the osmotic stabilizer. Gross morphology and light microscopic colony morphology were typical of an L-form. L-form cells were approximately spherical and bounded in part by a plasma membrane; they lacked the triple-layer cell wall structure and coarse, electron-dense nucleoidal granules of the parent bacterial form. The L-form, but not the bacterial form, contained cores, organelles previously reported only in group D streptococci. Antibiotic disc-sensitivity studies showed the stable L-form to be as sensitive as, or more sensitive than, the bacterial form to most antibiotics. Exceptions were polymyxin B, colimycin sulfate, and gentamicin, which were more active against the bacterial form. The remainder of the aminoglycosides and cell wall-active antibiotics showed no inhibition of either form. The L-form was more susceptible to cidal activity of normal human serum than the parent form. The L-form exhibited fewer biochemical activities than the parent bacteria or bacterial forms derived by reversion at a time when the L-form was still unstable. L-form colonies appeared colorless, and chemical analysis demonstrated that, if the L-form produces pigment at all, which was not demonstrated, it could not have been more than 3.6% of that produced by the bacterial form.
Cytochemical and Immunofluorescence Study of an Oncogenic Avian Adenovirus (CELO) in Mammalian Cell Cultures
Authors: Miller Louise T. , Yates Vance J.
Published: January 2020

Chicken embryo lethal orphan (CELO) virus replication studies in adult hamster kidney and green monkey kidney cell cultures by means of infectivity, cytochemistry, and fluorescent-antibody techniques indicated that replication in hamster kidney cells was limited to the production of neoantigen. Production of virus in green monkey kidney cells was limited but appeared to exceed the production of virus in hamster kidney cells. The data indicated that the replication cycle of CELO virus is abortive in hamster kidney and green monkey kidney cells.
Hemagglutinin from the L Phase of
Neisseria meningitidis
Group B, with Observations on a Serum Inhibitor
Authors: Crawford York E. , Nalewaik Robert P. , Lytle Ralph I. , O'Connell Joan L.
Published: January 2020

A hemagglutinin extracted from the L-phase of
Neisseria meningitidis
group B directly agglutinated rabbit and rooster erythrocytes but did not react with human, sheep, or guinea pig erythrocytes. Virtually all animal, chicken, and human sera tested showed inhibitory titers. In a significant number of Navy recruits, who became carriers of
N. meningitidis
, the titer of serum inhibitor began to decline 2 weeks before the bacterial infection was first detected. Titers of this serum inhibitor ranged from 256 to 4,096 in patients with meningitis. The hemagglutinin failed to boost the preexisting titers of serum inhibitor when injected into animals, although roosters showed a minimal but transitory response.
Specific Secondary Biological Properties of Purified Rabbit Immunoglobulin M and Immunoglobulin G Antibodies to
Brucella abortus
and
Bordetella pertussis
Authors: Schulkind Martin L. , Herzberg Mendel , Robbins John B.
Published: January 2020

Rabbit immunoglobulin (Ig)M and IgG antibodies to
Brucella abortus
and
Bordetella pertussis
were isolated as purified products and their specific secondary biological activities were compared. IgM antibodies were found to be more active than IgG proteins in inducing agglutination and sensitization of
B. abortus
for the complement-dependent bactericidal effect and in inhibiting
B. pertussis
-induced lymphocytosis in the mouse. IgM and IgG antibodies were found to be equally effective in inducing agglutination of
B. pertussis
suspended in a colloidal solution. These data parallel previous work to indicate that IgM antibodies to bacterial surface antigens are more efficient than IgG molecules in initiating biological processes concerned with the inactivation of these pathogens.
Immune Response to Sheep Red Blood Cells in Mice Pretreated with Mycobacterial Fractions
Authors: Bekierkunst A. , Yarkoni E. , Flechner I. , Morecki S. , Vilkas E. , Lederer E.
Published: January 2020

Ten micrograms of trehalose-6,6′ -dimycolate (cord factor) injected into the footpads of mice increased the antibody response to sheep red blood cells (SRBC) subsequently injected into the same sites. There is a relationship between the antibody response and the cellular reaction induced locally and in the draining lymph nodes by cord factor, as judged by a much weaker response when antigen is injected into the contralateral footpads. The time intervals between injection of cord factor and antigen were from 5 to 20 days. A similar increased antibody response to SRBC was evident after preliminary administration of Freund's complete adjuvant or living BCG bacilli into the footpads. There was no increased antibody response in mice pretreated with living BCG or Freund's adjuvant to SRBC injected into the contralateral footpads. Administration of wax D from human strains Peurois and Test was without any effect. Administration of SRBC emulsified in incomplete Freund's adjuvant containing 5 μg of cord factor induced a very strong antibody response in the mice as compared to that after injection of the same amount of antigen in incomplete Freund's adjuvant containing wax D or mycobacteria. The results are discussed.
Ability of
Veillonella
and
Neisseria
Species to Attach to Oral Surfaces and Their Proportions Present Indigenously
Authors: Liljemark W. F. , Gibbons R. J.
Published: January 2020

The present study describes the distribution of
Veillonella
and
Neisseria
species in the human oral cavity and indicates that their ability to attach to oral surfaces correlates with their proportions found in various sites of the mouth. The mean percentages of
Veillonella
and
Neisseria
of the total flora cultivable on anaerobic blood-agar plates was found to be: plaque, 0.75 and <0.13, respectively; lip, 0.38 and <0.05; cheek, 0.66 and <0.14; tongue dorsum, 9.4 and <0.12; saliva, 5.0 and <0.9. The ability of
Veillonella
and
Neisseria
species to attach to tooth surfaces was studied by cleaning the labial surfaces of incisors to render them relatively free of viable bacteria. Samples taken 1 hr later contained <0.27%
Veillonella
and <0.4%
Neisseria
, whereas saliva to which these teeth were exposed contained 20-fold higher proportions of
Veillonella.
These data indicate that
Veillonella
and
Neisseria
species possess a feeble ability to attach to cleaned teeth. The ability of these organisms to adhere to other oral surfaces was determined by introducing mixtures of streptomycin-resistant strains into the mouths of volunteers for 5 min. Labeled strains of
Streptococcus sanguis
and
S. salivarius
were included for comparative purposes. Analysis of samples obtained from oral surfaces after 45 min indicated that
Veillonella
and
Neisseria
adhere very poorly to preformed dental plaque as compared to
S. sanguis.
In contrast,
Veillonella
adhered to the tongue dorsum markedly better than
Neisseria, S. sanguis
, and
S. salivarius.
The greater ability of
Veillonella
to adhere to the tongue in relation to the other organisms studied correlates with the high proportions of
Veillonella
found on this site. The feeble ability of
Neisseria
to attach to surfaces in the oral cavity is reflected by their low proportions found on these surfaces.
Immunogenicity of R Factor-Carrying
Salmonella
Authors: Jarolmen H. , Hewel D. , Kain E.
Published: January 2020

An increased frequency of rough cultures with associated reductions in mouse virulence was detected after R-factor transmission into strains of
Salmonella choleraesuis
var.
kunzendorf
and
S. typhimurium
. All rough strains tested, with or without R factors, conferred protective immunity against challenge with homologous or heterologous species of
Salmonella
, some of which contained R factors. Although slight protection was afforded against challenge with
Staphylococcus aureus
, the immunity was specific to the extent that immunized mice were fully susceptible to infections with
Klebsiella pneumoniae
and
Pasteurella multocida.
Effect of Alkali-Treated Lipopolysaccharide on Erythrocyte Membrane Stability
Authors: Čižnár I. , Shands J. W.
Published: January 2020

The interaction of various lipopolysaccharides (LPS) with sheep erythrocytes was studied. When subjected to mild alkaline hydrolysis, the affinity of LPS for the red cell surface was greatly increased, as others have reported. In addition, excessive quantities of alkali-treated LPS (but not parent or heated products) were found to cause hemolysis of red cells. Experiments indicated that the hemolysis was caused by the LPS particles themselves and not by liberated free fatty acids.
Cell-Mediated Resistance Induced with Immunogenic Preparations of
Salmonella typhimurium
Authors: Venneman Martin R. , Berry L. Joe
Published: January 2020

Peritoneal cells obtained from mice immunized 15 or 30 days previously with (i) 0.1 LD
50
of attenuated
Salmonella typhimurium
(RIA), (ii) 20 μg (dry weight) of heat-killed
Salmonella
(SR-11), (iii) 20 μg (dry weight) of immunogenic ribosomal subfractions, or (iv) 20 μg of ribonucleic acid (RNA) subfractions were passively transferred to normal unimmunized mice. The ability of the recipient animals to inhibit or retard the multiplication of virulent challenge
S. typhimurium
5 days post-infection was determined by pathogen counts on the carcasses. Peritoneal cells from donors immunized with the RIA, ribosomal, or RNA preparations (i) conferred maximal resistance to challenge 10 to 15 days after cell transfer and demonstrable resistance throughout the 45-day assay period, (ii) conferred resistance to infection when 10
5
, 10
3
, or 10
2
peritoneal cells were injected subcutaneously but not with fewer than 10
5
cells administered intraperitoneally, and (iii) rendered recipients capable of acting as donors of peritoneal cells that conferred demonstrable resistance on normal recipients. Recipients of peritoneal cells obtained from donors immunized with heat-killed bacteria were unable to (i) significantly inhibit bacterial proliferation at 10 days post-transfer, (ii) resist infection by a challenge inoculum greater than 50 LD
50
, and (iii) secondarily confer resistance on normal animals through the passive transfer of cells or serum.
Infectivity and Virulence of Nonpesticinogenic
Pasteurella pestis
Authors: Surgalla M. J. , Beesley E. D.
Published: January 2020

Nonpesticinogenic
Pasteurella pestis
, which is also negative for coagulase and fibrinolytic activities and therefore referred to as (PI-C-F)
−
, was investigated to determine whether greatly reduced and erratic lethal responses observed in mice and guinea pigs might be due to inability of the inoculum to establish infection and multiply in survivors. Immunity of survivors was regarded as an indication of previous infection, and, in the case of guinea pigs infected intradermally, appearance of a local lesion and bubo were also noted. Evidence of infection was obtained in most mice and guinea pigs surviving injection of (PI-C-F)
−
strains G-32 and Dodson, suggesting that the virulence determinant (PI-C-F) is related to lethality rather than to infectivity.
Micro Complement Fixation Assay for Type-Specific Group A Streptococcal Antibody
Authors: Wittner M. K. , Fox Eugene N.
Published: January 2020

A micro complement fixation assay was devised to measure the type-specificity of anti-M antibody. Unabsorbed sera were from rabbits hyperimmunized with heat-killed streptococci and from humans with naturally occurring antibody or immunized with purified M protein vaccines. These sera fixed complement only in the presence of homologous M proteins (serotypes 1, 3, 6, 12, and 14). The complement fixation reaction paralleled the results obtained with the Lancefield bactericidal (opsonic) assay and did not exhibit the cross-reactions frequently seen with type-specific anti-M sera assayed by passive hemagglutination. All serological activity of the antisera resided in the fraction corresponding to 7
S
globulin eluted from a Sephadex G-200 gel filtration column. Because of the close correlation between micro complement fixation and the bactericidal assay for type-specific antibody, it is proposed that the micro complement fixation procedure, as we have described it, merits further evaluation as a substitute for the bactericidal test of immunity to group A streptococcal infection.
Production of Staphylococcal Alpha Toxin I. Relationship Between Cell Growth and Toxin Formation
Authors: Duncan James L. , Cho Gloria J.
Published: January 2020

Alpha toxin production and its relationship to cell growth were studied in the Wood 46 strain of
Staphylococcus aureus
. Toxin first appeared in the culture in the late logarithmic stage, but at least 80% was produced during the subsequent period of slower cell growth. The toxin concentration per unit of cell mass or viable count increased continually throughout the period of toxin production and and at its maximum represented 1.6 to 2.0% of the dry weight of the cells. The possibility that alpha toxin is released as a result of cell lysis was examined by using the appearance of cellular deoxyribonucleic acid in the medium as an indicator of lysis. The results showed that no appreciable amount of lysis occurred during toxin production; at a time when almost maximum amounts of toxin were present in the culture, less than% 4 of the cells had lysed. This finding, together with the observation that less than 0.25% of the total amount of toxin in the culture could be found intracellularly, indicates that alpha toxin is released from intact cells shortly after it is synthesized.
Anti-Immunoglobulin G Hemagglutination-Inhibition Test for Influenza
Authors: Hahon Nicholas , Booth James A. , Eckert Herbert L.
Published: January 2020

The sensitivity of the hemagglutination-inhibition test for influenza was significantly increased by the addition of species-specific anti-immunoglobulin G serum.
Effect of Actinomycin D on the Yield of Lymphocytic Choriomeningitis Virus in Baby Hamster Kidney Cells
Authors: Stanwick Trevor L. , Kirk B. E.
Published: January 2020

Depending on the concentration of actinomycin D, the yield of lymphocytic choriomeningitis virus in baby hamster kidney cells was either enhanced or inhibited.
Activation of Lysosomal Enzymes in Rabies-Infected Tissue Culture Cells Without Accompanying Cytopathic Effect
Authors: Diaz Ana M. , Diaz Francisco J. , Yager Pamela , Baer George M.
Published: January 2020

Lactic dehydrogenase and β-glucuronidase were assayed in tissue culture fluids and cellular lysates, respectively, from BHK-21/13S and Iota cell cultures infected with rabies virus. Activation of lysosomal enzymes was shown from the day 4 of infection on, without any indication of cytopathic effect.
Characterization of 3-
O
-Methylmannose from
Coccidioides immitis
Authors: Porter John F. , Scheer Eleanor R. , Wheat Robert W.
Published: January 2020

3-
O
-methylmannose isolated from
Coccidioides immitis
was characterized by gas chromatographic comparison of derivatives with those of synthetic 3-
O
-methylmannose. Gas chromatographic behavior of three derivatives of the natural and synthetic sugars was identical.
Effect of an Immunosuppressive Agent, Cyclophosphamide, on Chronic Lactic Dehydrogenase Virus Viremia of Mice
Authors: duBuy H. G. , Worthington M. , Johnson M. L.
Published: January 2020

The immunosuppressive drug cyclophosphamide was used to study the effect of immunosuppression on the degree of chronic lactic dehydrogenase virus (LDV) viremia in mice. Weekly injections of cyclophosphamide caused an increase of LDV viremia of ca. 2.5 log
10
50% infectious doses per ml as compared to the viremia in the nontreated mice. This increase occurred at about the same time that the formation of antibody with a neutralization index of 2 to 3 log
10
per ml could be demonstrated in the serum of control mice, whereas both neutralizing antibody and sensitized (antibody-bound but infectious) virus were absent in the immunosuppressed mice. In one experiment, antibody did not reappear 28 weeks after a 24-week course of cyclophosphamide treatment. In another experiment in which the drug was given for 12 weeks, antibody appeared again in the treated mice 14 weeks after cessation of drug administration and was accompanied by a decrease in viremia. The normal decrease of early viremia during the first 2 weeks of infection in immunosuppressed mice suggests that the immune response is not the cause of this initial decrease in LDV viremia but that interferon and perhaps other nonimmune factors may be involved here. The increased viremia in the immunosuppressed mice during the later stages of infection indicates that the immune response plays an important role in partial control of chronic viremia. The quantitative correlation between the decrease in neutralizing antibody and the increase in viremia in immunosuppressed mice suggests that antibody rather than cellular immunity may be the more important immune factor in the control of chronic viremia.
Bactericidal Activity of Granule Contents from Rat Polymorphonuclear Leukocytes
Authors: Hodinka Richard L. , Modrzakowski Malcolm C.
Published: January 2020

Granule contents from rat polymorphonuclear neutrophils were prepared by extraction with 0.2 M acetate (pH 4), dialyzed against phosphate-buffered saline (pH 7), and tested for bactericidal activity. Bactericidal assays consisted of mixing rat granule extract with 1 × 10
3
to 3 × 10
3
bacterial cells per ml at 37°C for 1 h in a medium suited for bacterial growth. The granule extract demonstrated a distinctive dose-dependent bactericidal activity against outer membrane lipopolysaccharide mutants of
Salmonella typhimurium
LT-2, independent of added hydrogen peroxide or other active oxygen derivatives. The rough bacterial mutants showed an ordered increase in sensitivity to the rat lysosomal extracts inversely related to the length of their lipopolysaccharide carbohydrate side chains. Fractionation of the rat polymorphonuclear neutrophil granule extract with Sephadex G-100 column chromatography revealed an elution profile containing three major areas (peaks) of protein. Polyacrylamide gel electrophoresis and examination of enzymatic activity showed that these peaks contained myeloperoxidase (peak A), neutral protease (peak B), and lysozyme (peak C) activities. Also observed in peak C were cationic protein species whose cathodal electrophoretic migration was faster than that for lysozyme. Only peak C exhibited a bactericidal activity against the rough mutants of
S. typhimurium
LT-2 similar to that obtained for the unfractionated granule extract, with susceptibility of the bacterial mutants increasing with a progressive loss of carbohydrate residues in the lipopolysaccharide of the cell wall. The bactericidal activity of the peak C protein fraction was dose dependent. Boiling the unfractionated granule extract or peak C for 30 min had little affect on their antimicrobial activity when reacted against a deep-rough lipopolysaccharide mutant. However, trypsin pretreatment of these fractions significantly reduced their antimicrobial activity for the same mutant chemotype.
Alteration of the immunoglobulin G subclass responses in mice to lipopolysaccharide: effects of nonbacterial proteins and bacterial membrane phospholipids or outer membrane proteins of Proteus mirabilis
Authors: Karch H , Gmeiner J , Nixdorff K
Published: January 2020

The immunoglobulin M (IgM) and the IgG1, IgG2ab, and IgG3 subclasses of plaque-forming cells (PFC) specific for lipopolysaccharide (LPS) were measured after immunization of mice with LPS alone and compared with the responses to LPS in combination with nonbacterial proteins and with bacterial membrane phospholipid vesicles or two major outer membrane proteins from Proteus mirabilis. The relative numbers of IgG PFC belonging to the IgG1, IgG2, or IgG3 subclasses induced by immunization with LPS alone depended upon the type of LPS administered. Phospholipids and the proteins effected characteristic alterations in not only the strength but also the subclass of the IgG responses to LPS. The results suggest that the hydrophobic-hydrophilic nature or state of aggregation of the preparations plays a role in the induction of IgG1 and IgG2 subclasses of PFC specific for LPS. Complex formation with LPS and adjuvant was apparently necessary to obtain these effects.
Vwa+ phenotype of Yersinia enterocolitica
Authors: Perry R D , Brubaker R R
Published: January 2020

Expression of the Vwa+ phenotype of Yersinia pestis in vitro is known to reflect maximum induction of virulence (or V and W antigens) at 37 degrees C with concomitant restriction of cell division. Both phenomena are potentiated by 20 mM Mg2+ and prevented by cultivation at 26 or 37 degrees C with 2.5 mM Ca2+. We have now compared this classic plasmid-mediated phenotype with those of Vwa+ Yersinia pseudotuberculosis and Yersinia enterocolitica which, unlike Y. pestis, produce ancillary outer membrane peptides unrelated to the V and W antigens. All of 10 wild-type strains of Y. enterocolitica (serotypes O:3, O:4,32, O:8, O:9, O:15, and O:21) exhibited a nutritional requirement for Ca2+ at 37 degrees C and produced significant V antigen. Like Y. pseudotuberculosis, autoagglutination of Vwa+ Y. enterocolitica was dependent upon prior growth at 37 degrees C but was not influenced by Ca2+. Autoagglutination of Y. pestis was never observed. Resistance of Y. enterocolitica to 10% human serum was typically dependent upon prior growth at 37 degrees C, either with or without added Ca2+, and carriage of a Vwa plasmid. In contrast, serum resistance of Y. pseudotuberculosis was temperature but not plasmid dependent and that of Y. pestis was constitutive.
Contribution of Adhesion to Bacterial Persistence in the Mouse Urinary Tract
Authors: Hagberg L. , Hull R. , Hull S. , Falkow S. , Freter R. , Edén C. Svanborg
Published: January 2020

The affinity of uropathogenic
Escherichia coli
to kidneys and bladders of experimentally infected mice was shown to be determined in part by the adhesive properties of the infecting bacteria. Mice were infected with various pairwise combinations of two homogeneic sets of bacteria: (i) mutants derived from a human pyelonephritis
E. coli
isolate which were selected to express either or both adhesins specific for globoseries glycolipid receptors or for “mannosides”; and (ii) transformants of a normal fecal isolate which harbored recombinant plasmids encoding the genes for one or the other adhesin or which harbored only the vector plasmid. The relative efficiency of survival of the strains to be compared was evaluated in each animal by plating on selective media of samples of homogenized kidneys and bladders taken 24 h after intravesical inoculation. The presence of adhesins specific for globoseries glycolipid receptors, which mediate the in vitro mannose-resistant attachment to human and mouse uroepithelial cells, enhanced bacterial recovery from both kidneys and bladders of infected animals. The addition to the infecting strain of adhesins binding mannoside residues further improved bacterial recovery from the bladder, but not from the kidney. The mutants and transformants with adhesins binding only mannosides were recovered in higher numbers from the bladder than those expressing adhesins specific for the globoseries glycolipids only. There was apparent selection in vivo decreasing expression of mannoside binding adhesins in the kidneys, but not in the bladders, of animals infected with the mutant expressing both types of adhesins. Regardless of adhesive properties, the mutants of the pyelonephritis isolate were recovered in significantly higher numbers than the fecal isolate with adhesins encoded on recombinant plasmids. We conclude that the adhesive properties in part determine the localization and retention of bacteria in the mouse urinary tract. However, the addition of adhesins to a commensal
E. coli
strain was not sufficient to confer colonization capacity comparable to that of a pyelonephritis strain.
Characterization of virulence plasmids and plasmid-associated outer membrane proteins in Shigella flexneri, Shigella sonnei, and Escherichia coli
Authors: Hale T L , Sansonetti P J , Schad P A , Austin S , Formal S B
Published: January 2020

The 140-megadalton plasmids of Shigella flexneri serotypes 1, 3, and 5, in addition to the 120-megadalton plasmid of Shigella sonnei, are associated with virulence. The present study showed that a 140-megadalton plasmid is also associated with virulence in Escherichia coli. When these plasmids were cleaved with EcoRI or BamHI restriction endonucleases, considerable homology was evident in plasmids from S. sonnei strains, whereas only a few common fragments were observed among the S. flexneri and enteroinvasive E. coli plasmids. Nitrocellulose filter hybridization demonstrated that, despite variations in restriction sites, all these plasmids shared a considerable complement of homologous sequences. Minicell-producing strains were obtained by N-methyl-N'-nitro-N-nitrosoguanidine mutagenesis. Transmission electron microscopy of infected HeLa cells showed that minicells from invasive strains retained the invasive phenotype. Sixteen polypeptides were labeled when S. flexneri 5 minicells were incubated with [35S]methionine. Fourteen of these plasmid-coded polypeptides were associated with the outer membrane in invasive strains of S. flexneri 5, and nine polypeptides of similar molecular weight were labeled in the outer membrane of invasive strains of S. flexneri 3, S. sonnei, and E. coli. Seven of the S. flexneri 5 polypeptides were not labeled in a noninvasive strain which had sustained a large deletion in the virulence-associated plasmid, and none were labeled in minicells which no longer harbored this plasmid.
Relative Contribution of ColV Plasmid and K1 Antigen to the Pathogenicity of
Escherichia coli
Authors: Agüero Maria E. , Cabello Felipe C.
Published: January 2020

To study the relevance of the ColV plasmid and the capsular K1 antigen in the pathogenicity of
Escherichia coli
, isogenic strains that differ only in these characteristics were constructed. Studies with these variants demonstrated that the presence of the ColV plasmid increased the serum resistance of
E. coli.
This increase did not depend on the expression of the K1 antigen. This work also demonstrated that the presence of the K1 antigen protects
E. coli
from the bactericidal activity of serum. Studies using mouse peritoneal macrophages in the presence of normal serum indicated that the presence of K1 antigen protects
E. coli
from phagocytosis. Similar experiments with the K1
+
strains performed in the presence of anti-K1 antibodies demonstrated that these antibodies opsonized these bacteria very efficiently in the absence of complement. The K1
−
E. coli
variants were efficiently phagocytized in the presence of normal human serum and absorbed human serum, indicating that they are able to be opsonized by complement deposited by activation of the alternative pathway of complement. Work using fluorescence microscopy confirmed that the K1
−
strains are able to fix complement in the absence of antibody. It was also found that the presence of the ColV plasmid may interfere with phagocytosis of the
E. coli
K1 strains and deposition of complement on these cells. To test the relevance of the results of the in vitro experiments for disease, the pathogenicity of the strains was tested in mice. The results showed that the K1 antigen is the main determinant of pathogenicity of these strains and that the presence of ColV can modify the pathogenic potential of the
E. coli
K1 strains through a mechanism that does not depend on the production of colicin V.
Monoclonal antibodies against three major glycoproteins of varicella-zoster virus
Authors: Grose C , Edwards D P , Friedrichs W E , Weigle K A , McGuire W L
Published: January 2020

Varicella-zoster virus (VZV) codes for three prominent glycoproteins--gp62, gp98, and gp118--in infected cell cultures. To characterize individually these known immunogens, we first inoculated BALB/c mice with crude VZV extracts, produced hybridoma cultures by Köhler-Milstein cell-fusion technology, and screened culture supernatants by indirect immunofluorescence for reactivity directed against unfixed VZV-infected cells (FAMA assay). Supernatants from five independently derived and subcloned hybridomas with a high VZV-FAMA titer but no reactivity against either uninfected or herpes simplex virus-infected cells were further analyzed by immunoprecipitation of [3H]fucose-labeled and detergent-solubilized VZV antigen preparations. Fractionation of the precipitates by sodium dodecyl sulfate-polyacrylamide gel electrophoresis demonstrated that four monoclonal antibodies reacted with both gp62 and gp98, and one precipitated only gp118. The profiles were unchanged whether performed under reducing or nonreducing conditions. When assayed for neutralizing activity, the secretory product of the single anti-gp118 hybridoma, but not the supernatants from the four anti-gp62/gp98 clones, inhibited VZV plaque formation by greater than 80%. Thus, at least one of the glycosylated antigens detected by the FAMA assay is a determinant which elicits neutralizing activity.
Application of monoclonal antibodies to detect intraocular mycoplasma antigens in Mycoplasma arthritidis-infected Sprague-Dawley rats
Authors: Thirkill C E , Song D Y , Gregerson D S
Published: January 2020

Sprague-Dawley rats infected with Mycoplasma arthritidis by tail vein inoculation develop extensive disseminated joint inflammation, frequently accompanied by conjunctivitis and anterior uveitis. The intraocular inflammation is apparently directed at mycoplasmas localized within the stroma of the ciliary body, which have been detected with monoclonal antibodies by indirect immunofluorescence. The monoclonal antibodies are directed against an antigenic determinant on the enzyme arginine deiminase isolated from M. arthritidis, but they do not react with the same enzyme derived from Mycoplasma hominis. The antigen bound by the monoclonal antibodies can also be detected by immunofluorescence in M. arthritidis-infected tissue cultures and is not lost after glutaraldehyde fixation or paraffin-embedding procedures. The value in the application of monoclonal antibodies reactive with arginine deiminase lies in the fact that although this enzyme may be found in mycoplasmas and several other species of bacteria it is not a normal constituent of mammalian tissues.
Interaction of
Leishmania donovani
Promastigotes with Human Phagocytes
Authors: Pearson Richard D. , Sullivan James A. , Roberts Denise , Romito Roseann , Mandell Gerald L.
Published: January 2020

Leishmania donovani
is an important intracellular protozoal pathogen of humans, which resides solely within mononuclear phagocytes. Phase-contrast microscopy and cinemicroscopy were used to examine the interaction of
L. donovani
promastigotes with human phagocytes to characterize and quantitate the sequence of events that results in leishmanial infection.
Human peritoneal macrophage phagocytic, killing, and chemiluminescent responses to opsonized Listeria monocytogenes
Authors: MacGowan A P , Peterson P K , Keane W , Quie P G
Published: January 2020

Opsonization with normal human serum, purified immunoglobulin G, or immunoglobulin G-deficient serum promoted phagocytosis of Listeria monocytogenes by human peritoneal macrophages. However, normal human serum was the most effective opsonin in elicting killing and chemiluminescent responses. Macrophages phagocytized and killed almost as much as polymorphonuclear leukocytes but produced considerably less chemiluminescence.
In vitro response of human T cells to Pseudomonas aeruginosa
Authors: Porwoll J M , Gebel H M , Rodey G E , Markham R B
Published: January 2020

Pseudomonas aeruginosa is a gram-negative bacillus that is a major cause of morbidity and mortality in immunosuppressed patients, burn patients, and patients with cystic fibrosis. Although immunity to these bacteria has been associated with serum antibody, more recent evidence suggests that T-cell-mediated immunity may also be important. To evaluate human T-cell responsiveness to these bacteria, the optimal conditions were determined for in vitro proliferation of human peripheral blood lymphocytes and T-lymphocytes to Fisher-Devlin immunotype 1 P. aeruginosa. The proliferative response of normal adult peripheral blood lymphocytes to heat-killed P. aeruginosa was studied in 34 subjects (range, 7,600 to 111,500 net cpm). Analysis of cell subpopulations indicated that T-lymphocytes are the major proliferating cells and that this response is enhanced by the presence of adherent cells. Data from fetal cord lymphocyte responses suggest that the proliferation seen in normal adult lymphocytes is induced by antigenic and not mitogenic stimulation.