bluuebunny/crossref_metadata_2025 huggingface dataset:
Immunofluorescence of hepatitis A virus antigen in chimpanzees
Authors: Murphy B L , Maynard J E , Bradley D W , Ebert J W , Mathiesen L R , Purcell R H
Published: January 2020

Chimpanzee liver biopsies and necropsy tissues were examined by immunofluorescence for hepatitis A virus antigen. Results further indicate that the liver may be the sole site of replication for the virus.
Immunological Relationship of Different Preparations of Coliform Enterotoxins
Authors: Klipstein Frederick A. , Engert Richard F.
Published: January 2020

Antisera raised in rabbits to ultrafiltrate toxin preparations containing either the heat-labile (LT) toxin form obtained from whole cell lysates or broth filtrates or the heat-stable (ST) toxin form prepared from broth filtrates from nontoxigenic and toxigenic strains of
Escherichia coli
and
Klebsiella
were examined for their ability to neutralize the secretory effect on water transport of these toxins in the rat jejunum as determined by the in vivo marker perfusion technique. Antisera to the heat-labile toxin derived from whole cell lysate preparations from nontoxigenic strains had no neutralizing effect. Antisera to both types of LT preparation from both toxigenic strains neutralized, with several exceptions, all of the homologous and heterologous LT toxins as well as a heat-labile toxin preparation derived from sequential ultrafiltration of cell-free whole cell lysates which had a defined molecular weight of between 30,000 and 100,000. These antisera also neutralized homologous and heterologous ST preparations obtained from broth filtrates, but they had no neutraliziṅg effect on low-molecular-weight, ST toxin material obtained during the sequential ultrafiltration of cell lysates. Antisera to ST prepared from broth filtrates had no neutralizing capacity against either LT or ST toxin preparations. These observations (i) indicate that the immunological relationship of
E. coli
and
Klebsiella
LT and ST toxins extends to antisera raised against LT prepared by several different methods, (ii) raise the possibility that, based on the response to antisera to LT, there may be several immunologically heterogeneous forms of low-molecular-weight ST toxin, and (c) confirm the lack of immunogenicity of ST.
Pathogenesis of fever in delayed hypersensitivity: role of monocytes
Authors: Atkins E , Francis L , Bernheim H A
Published: January 2020

The present studies were designed to investigate the role of monocytes in the pathogenesis of fever in delayed hypersensitivity. Adherent rabbit blood monocytes (from both normal and sensitized donors) were separated on Ficoll-Hypaque gradients and incubated with antigen (Ag; ovalbumin) and sensitized draining-lymph-node lymphocytes (or their supernatants) from rabbits with delayed hypersensitivity, and release of endogenous pyrogen was assayed. Results indicated that monocytes are activated to produce endogenous pyrogen by Ag and suspensions of draining-lymph-node cells or by an agent (lymphokine) in the supernatants of sensitized lymphocytes preincubated with Ag. The release of lymphokine was Ag specific and was correlated with the skin test reactivity of the donor rabbits to the sensitizing Ag. No evidence was found that Ag-antibody complexes or (in the case of sensitized monocytes) cytophilic antibodies play a role in the activity of this lymphokine which appears to act selectively on monocytes rather than on granulocytes.
Interferon treatment of NZB mice: accelerated progression of autoimmune disease
Authors: Heremans H , Billiau A , Colombatti A , Hilgers J , de Somer P
Published: January 2020

The effect of long-term administration of interferon in New Zealand Black and New Zealand Black/New Zealand White F1 hybrid mice was studied. Treatment with moderate doses of interferon (10(4) units, five times weekly for 8 weeks) did not depress murine leukemia virus gp69/71 levels in serum and spleen, nor p30 levels in the spleen. Interferon given at 10(5.1) units (three times weekly for 37 weeks) caused an increased incidence of anti-erythrocyte antibodies in New Zealand Black mice. Finally, the hybrid mice given interferon at 10(6.0) units (three times weekly for 33 weeks) had increased renal immune complex deposits and increased incidences of proteinuria and anemia.
Immunological Method to Differentiate Between Antigens of Tubercle Bacilli, Other Mycobacterial Species, and Non-Acid-Fast Bacteria
Authors: Ferguson H. Rodney , McClatchy J. Kenneth , Sharpton Thomas R. , Minden Percy
Published: January 2020

Sera from rabbits immunized with sonicates of
Mycobacterium bovis
BCG were passed through an immunoadsorbent made of a soluble BCG extract to make partially purified antibodies to BCG. These antibodies were in turn used to prepare an immunoadsorbent through which the BCG extract was passed. The partially purified antigenic material was radiolabeled and subjected to electrophoresis in acrylamide gels. One of the radiolabeled fractions isolated (BCG-C) was found to bind to antibodies to BCG and H37Rv, but not to antibodies in sera from rabbits immunized with other mycobacterial species or
Nocardia asteroides
. The reaction between BCG-C and the partially purified antibodies to BCG was inhibited by small amounts of different BCG antigens. Cultures obtained from 25 patients with tuberculous diseases, other bacterial cultures, and various bacterial extracts were tested for their capacity to inhibit this reaction. Each of 13 mycobacteria identified as
M. tuberculosis
inhibited this reaction. Equivalent numbers of 12 strains of mycobacteria other than
M. tuberculosis
and high concentrations of other bacterial extracts did not inhibit, indicating that determinants of BCG present in
M. tuberculosis
were not detected in the other mycobacteria or in non-acid-fast bacteria. The use of sequential purification procedures could be of potential clinical value in quickly differentiating between
M. tuberculosis
and a variety of other mycobacteria.
Experimental infection with Treponema hyodysenteriae in guinea pigs
Authors: Joens L A , Songer J G , Harris D L , Glock R D
Published: January 2020

Outbred and inbred (Hartley strain) guinea pigs (GP) were inoculated intragastrically with pathogenic and nonpathogenic Treponema hyodysenteriae. GP 3 to 16 weeks old received T. hyodysenteriae after a fasting period of 36 to 72 h. Infected GP with pathogenic T. hyodysenteriae developed a diarrheal and/or depressive condition, with mucus but not blood in the feces. Of 88 GP, 40 had gross lesions resembling those of swine dysentery. Lesions were limited mainly to the large intestine. TP used as controls or inoculated with nonpathogenic T. hyodysenteriae did not develop these lesions in the large intestine. These studies suggest that the GP may be used as an animal model for swine dysentery.
Isolation and phenotypic characterization of virulence-deficient mutants of Vibrio cholerae
Authors: Baselski V S , Upchurch S , Parker C D
Published: January 2020

Mutants of Vibrio cholerae was isolated on the basis of reduced ability to induce diarrhea in orally challenged infant mice. Nitrosoguanidine-treated clones were screened for low fluid accumulation ratios in individual mice, and presumptive mutants were confirmed in additional mouse tests. Mutants were examined for alterations in phage type, motility, toxin production, proteolytic activity, neuraminidase production, amylase production, morphology, growth requirements, carbohydrate fermentations, in vitro growth patterns, and cell surface alterations. The types of mutants found included several with previously recognized virulence-associated markers (rough, nonmotile, toxin deficient, protease deficient); several types with pleiotropic alterations (cell morphology, decreased extracellular products); and several with no previously recognized virulence-deficient phenotype (purine requiring, cell surface altered, rapid death in vitro, no defect found). Dose-response kinetics showed that most mutants could provoke diarrhea if given in 100-fold greater numbers than the dose used for screening. Recovery of viable organisms from the gut late in infection showed reduction of survival and/or multiplication capacity for the mutants, with variation in the degree of reduction for the different classes.
In vitro evaluation of opsonic and cellular granulocyte function by luminol-dependent chemiluminescence: utility in patients with severe neutropenia and cellular deficiency states
Authors: Stevens P , Winston D J , Van Dyke K
Published: January 2020

Actively phagocytizing polymorphonuclear leukocytes (PMN) emit light or chemiluminescence (CL) which has been shown to be linked to the oxidative activity of the PMN. The measurement of CL has been demonstrated to be a useful tool for the in vitro assessment of intracellular and opsonophagocytic function of PMN. We have increased the sensitivity of the CL measurement by the addition of luminol to the in vitro reaction of PMN, bacteria, and serum. The presence of luminol, which can be oxidized to emit light, amplifies the detection of CL and PMN cellular activity. This amplification effectively reduces the number of PMN that are necessary for assessment of PMN function from 1 x 10(7) to as low as 2 x 10(4) PMN/assay and permits the evaluation of PMN function in severely neutropenic patients (100 PMN/mm3) in whom cellular PMN function has been heretofore extremely difficult to assess by other methodology. When this luminol-dependent CL method was used, three of eight neutropenic leukemic patients with gram-negative septicemia were found to have deficient opsonic activity and/or increased or depressed cellular oxidative activity. Because the initial slope of CL is dependent on the amount of serum and heat-labile factors, this method can also be used effectively as a simple technique for the analysis of specific rates of opsonophagocytosis of various microorganisms. Additionally, this method can detect the cellular PMN abnormalities of chronic granulomatous disease and myeloperoxidase deficiency. The luminol-dependent CL method is a simple, sensitive, reproducible technique that provides useful information about PMN metabolic activity, particularly in studies in which the number of PMN is limited.
Antibody-independent interaction of the first component of complement with Gram-negative bacteria
Authors: Loos M , Wellek B , Thesen R , Opferkuch W
Published: January 2020

The interaction of the first component of complement with two serum-sensitive strains of Escherichia coli and Klebsiella pneumoniae was studied. It could be demonstrated that highly purified C1, free of immunoglobulin G and immunoglobulin M, binds to E. coli or K. pneumoniae. C1 binding was also found with specifically absorbed human serum, after incubation of bacteria with normal serum in the presence of ethylenediaminetetraacetate or agammaglobulinemic serum; the number of C1 molecules taken up by the bacteria was not influenced, indicating that C1 binding was independent of naturally occurring antibodies. C1 bound to bacteria was still able to cleave C4, the natural substrate of C1. From these observations, it is concluded that C1 in an enzymatically active state can be bound directly to bacteria independently of antibody.
Cellular and Humoral Immune Responses to Herpes Simplex Virus During and After Primary Gingivostomatitis
Authors: Møller-Larsen Anné , Haahr Sven , Black Finn T.
Published: January 2020

A total of 17 children, aged 1 to 15 years, with gingivostomatitis were investigated to follow the development of immune parameters in those who suffered from herpes simplex virus stomatitis. Mouth swabs were obtained during the acute attack. Blood samples were collected on this occasion and again about 3 weeks later. Humoral immunity to herpes simplex virus was investigated by a complement fixation test and by an antibody-dependent cell-mediated cytotoxicity test. Cell-mediated immunity was investigated in a blast transformation assay with herpes simplex virus type 1 antigen and phytohemagglutinin. Interferon production in herpes-stimulated cultures was measured. Thirteen patients had a herpes simplex stomatitis. Twelve of these children were negative in the complement fixation test on the first serum specimen, but only five were negative in the antibody-dependent cell-mediated cytotoxicity test. These five were still febrile at the time of investigation. Blast transformation was negative at the first investigation in most children, whereas interferon was produced both in leukocyte cultures obtained during the infection and also in cultures made 3 to 4 weeks after the infection. An increase in immune parameters was seen in all patients with herpes stomatitis. From results in blast transformation and antibody-dependent cell-mediated cytotoxicity, it is seen that cell-mediated and humoral immunity can be found at the same time during recovery from this type of infection.
K99 surface antigen of Escherichia coli: antigenic characterization
Authors: Isaacson R E
Published: January 2020

K99 prepared by acid precipitation hemagglutinated guinea pig erythrocytes, whereas K99 prepared by chromatography on diethylaminoethyl-Sephadex did not. K99 purified by either procedure hemagglutinated horse erythrocytes. K99 prepared by acid precipitation contained a second antigen not presnet in the K99 prepared by chromatography on diethylaminoethyl-Sephadex. This antigen could be detected by immunoprecipitation with some, but not all, sera prepared against K99-positive Escherichia coli strains. It was assumed that this second antigen is not K99 and is responsible for the guinea pig erythrocyte hemagglutination reaction. Furthermore, the second antigen has an isoelectric point of 4.2, which has been reported by Morris and co-workers to be the isoelectric point of K99.
Lymphocyte transformation test in leprosy: decreased lymphocyte reactivity to Mycobacterium leprae in lepromatous leprosy, with no evidence for a generalized impairment
Authors: Faber W R , Leiker D L , Nengerman I M , Zeijlemaker W P , Schellekens P T
Published: January 2020

Untreated leprosy patients were examined with respect to lymphocyte transformation in vitro after stimulation with mycobacterial and other microbial antigens, allogeneic lymphocytes, or nonspecific mitogens. Methods were used to circumvent technical variability. The results were compared with those obtained in controls matched for age, sex, race, and environment. No evidence was found for a generalized impairment of lymphocyte transformation in vitro, whereas a specific defect towards Mycobacterium leprae was demonstrable in lepromatous leprosy patients. The response to M. leprae, investigated in untreated and treated leprosy patients, decreased along the leprosy spectrum. Moreover, the results of the one-way mixed lymphocyte cultures showed that lymphocytes from leprosy patients had a normal stimulator and responder capacity, when they were tested against a panel of allogeneic lymphocytes. The influence of serum factors was investigated in untreated leprosy patients in the mixed lymphocyte culture. On average, tuberculoid as well as lepromatous sera showed a low-level depressive effect, but some sera showed a stimulatory effect. Therefore, a depressive effect of serum factors cannot be considered to be a general feature of leprosy. The correlation between the Mitsuda type of lepromin skin test and the lymphocyte reactivity in vitro to M. leprae was studied, and a positive correlation was found.
Secretory immunoglobulin A and G antibodies prevent adhesion of Escherichia coli to human urinary tract epithelial cells
Authors: Svanborg-Edén C , Svennerholm A M
Published: January 2020

The adhesion of Escherichia coli to human urinary tract epithelial cells was inhibited by commercial gamma globulin, the total immunoglobulin fraction of human breast milk and urine, as well as the isolated immunoglobulin G and secretory immunoglobulin A fractions of urine from patients with acute pyelonephritis. Urinary anti-O6 antibodies reduced the adhesion of several O6 strains. Absorption of antibodies to the lipopolysaccharide of the adhering strain markedly decreased the antiadhesive capacity of all the immunoglobulin preparations, whereas elimination of antibodies to the capsular polysaccharide antigen consistently had a small but not significant effect. When urine was absorbed with whole, live bacteria of the patients' infecting strains, the antiadhesive effect completely disappeared. Absorption with bacteria lacking pili only partially reduced this effect.
Lung response to congenitally athymic (nude), heterozygous, and Swiss Webster mice to aerogenic and intranasal infection by Nocardia asteroides
Authors: Beaman B L , Goldstein E , Gershwin M E , Maslan S , Lippert W
Published: January 2020

Congenitally athymic (nude, Nu/Nu), heterozygous (Nu/+), and Swiss Webster mice were exposed to virulent Nocardia asteroides GUH-2 inhaled from aerosols or administered intranasally. Clearance of the bacteria from the lungs was determined at 6 h and 1, 2, 3 and 7 days after infection. N. asteroides aspirated into the lungs from intranasal administration were killed less rapidly and induced more severe pulmonary infections than did comparable numbers of organisms inhaled from aerosols. Bacterial clearance and histological data indicated that nude mice were significantly more susceptible to nocardial infection than were heterozygous littermates or Swiss Webster mice. From these data we conclude that: (i) pulmonary defenses cope less well with intranasally administered N. asteroides than with aerosolized organisms, (ii) alveolar macrophages alone appear not to be an efficient barrier to nocardial infections, and (iii) T cells are important to pulmonary clearance and prevention of dissemination of N. asteroides from the lung.
Viral etiology of age-dependent polioencephalomyelitis in C58 mice
Authors: Martinez D , Wolanski B , Tytell A A , Devlin R G
Published: January 2020

The etiology of immune polioencephalomyelitis (IPE) and the mechanisms of resistance to IPE induction were investigated in C58 mice. IPE was found to be induced by a lipid-solvent-sensitive, filterable replicating agent present in line Ib leukemic cell suspensions. IPE was serially transmitted in immunosuppressed mice with filtered extracts of spleens from diseased animals. The IPE-inducing activity of Ib cell extracts was abolished by chloroform or deoxycholate. Gel filtration of Ib cell extracts showed that the IPE agent has a molecular weight of at least 10(7). Electron microscopy of the active fractions from columns and of spinal cord extracts from mice with IPE revealed a virus-like particle, 40 nm in diameter, which is probably the IPE revealed a virus-like particle, 40 nm in diameter, which is probably the IPE agent. Administration of cyclophosphamide at various times after challenge increased the incidence of IPE in mice, suggesting that IPE is not autoimmune mediated. Immunosuppression resulted in maintenance of high levels of IPE agent in the central nervous system tissue, while immunization resulted in low levels. Moreover, immunized mice produced neutralizing antibodies. These data suggest that antibodies help restrict the amount of IPE agent in the nervous tissue, and that this restriction is required for resistance to IPE induction in C58 mice.
Cultivation of Ureaplasma urealyticum in continuous culture
Authors: Masover G K , Perez R , Matin A
Published: January 2020

Continuous culture of Ureaplasma urealyticum is reported with a steady-state cell biomass of greater than 10(6) cells per ml. Thus, large cell numbers can be easily obtained; in addition, the system provides a powerful means for exploring what nutrients(s) limits the growth yield of this organism. Urea is shown not to be the growth-limiting nutrient in conventional media, although when provided in excess it appears to be completely hydrolyzed.
Growth of Rickettsia typhi in irradiated L cells enhanced by lysosomal stabilization
Authors: Woodman D R , Schultz W W , Woodman K L , Weiss E
Published: January 2020

The growth of some obligate intracellular parasites is contingent upon avoidance of lysosomal activation during growth in their host cells. This is accomplished by the various parasites by different mechanisms and with different degrees of efficiency. The possibility was tested that the lysosomal stabilizer cortisone acetate might protect and thus enhance the growth of Rickettsia typhi in mouse L cells irradiated 6 days earlier. Beginning 2 days before infection of the L cells with a multiplicity of 10 rickettsiae, 20 microgram of cortisone per ml was added in medium 199 containing 5% fetal calf serum. This concentration of cortisone was below the cytotoxic level, as determined by viability staining, but was sufficient to significantly alter the ratios of cellular and released acid phosphatase and beta-glucuronidase in uninfected and infected cells, as shown by spectrophotometric analysis. Rickettsial replication, measured by hemolytic activity at 96 h and confirmed by microscopic observations at earlier stages of infection, was increased by the cortisone. Cortisone concentrations of 10 or 40 microgram/ml were less effective, and cortisone was ineffective when the rickettsial multiplicity per L cell was 2 or lower. These results indicate that amounts of cortisone that increase lysosomal stabilization in L cells favor rickettsial multiplication when the multiplicity of infection is relatively high.
Temperature-sensitive mutants of influenza A virus: evaluation of the A/Victoria/75-ts-1A2 temperature-sensitive recombinant virus in seronegative adult volunteers
Authors: Murphy B R , Chanock R M , Levine M M , van Blerk G A , Berquist E J , Douglas R G , Betts R F , Couch R B , Cate T R
Published: January 2020

An influenza A virus recombinant bearing the surface antigens of the A/Victoria/3/75 (H3N2) strain and the two ts genes of the A/Udorn/72-ts-1A2 virus was evaluated for attenuation, antigenicity, and protective effect in 42 doubly seronegative adult volunteers (i.e., individuals who lacked detectable serum antibodies for the hemagglutinin and neuraminidase antigens). This recombinant, which had a 37 degrees C shutoff temperature for plaque formation and ts mutations on the genes thought to code for the P1 and P3 polymerase proteins, infected 90% of the volunteers. Of the volunteers, 5% developed mild coryza or rhinitis but other signs or symptoms were not observed, indicating that the A/Victoria/75-ts-1A2 recombinant was more attenuated than the A/Victoria/75-ts-1[E] recombinant. Vaccinees shed virus for a shorter interval and at a lower titer than did the A/Victoria/75-ts-1[E] vaccinees. Each ts-1A2 isolate retained the ts phenotype indicating that the recombinant was stable genetically in doubly seronegative adults. Finally, the ts-1A2 recombinant induced significant resistance to subsequent challenge with A/Victoria/75 wild-type virus.
Cold-Adapted Variants of Influenza A Virus: Evaluation in Adult Seronegative Volunteers of A/Scotland/840/74 and A/Victoria/3/75 Cold-Adapted Recombinants Derived from the Cold-Adapted A/Ann Arbor/6/60 Strain
Authors: Murphy Brian R. , Holley H. Preston , Berquist Erick J. , Levine Myron M. , Spring Susan B. , Maassab Hunien F. , Kendal Alan P. , Chanock Robert M.
Published: January 2020

Influenza A/Scotland/74 (H3N2) and A/Victoria/75 (H3N2) cold-adapted (
ca
) recombinant viruses, prepared by mating the A/Ann Arbor/6/60 (H2N2)
ca
donor virus and influenza A wild-type virus, were evaluated in adult seronegative volunteers (serum hemagglutination-inhibiting antibody titer, ≤1:8) for level of attenuation, antigenicity, and genetic stability of the temperature-sensitive and
ca
phenotypes. At 10
7.0
to 10
7.5
50% tissue culture infective doses the A/Scotland/74 and A/Victoria/75
ca
recombinant viruses were clearly attenuated and antigenic. However, one of eight vaccinees infected with 10
7.5
50% tissue culture infective doses of the A/Scotland/74
ca
recombinant had a febrile reaction (39°C). At a 10-fold higher dose (10
8.5
50% tissue culture infective doses), 4 of 12 A/Scotland/74 vaccinees had a febrile and/or systemic reaction. Febrile reactions were not observed in volunteers who received the A/Victoria/75
ca
recombinant virus, whereas 3 of the 12 vaccinees had mild upper respiratory tract symptoms, in one instance associated with mild systemic manifestations. Significantly, the serum hemagglutination- and neuraminidase-inhibiting antibody responses were comparable to those induced by wild-type virus. Both
ca
recombinant viruses were shed in low titer for a short period of time. Each isolate retained the temperature-sensitive phenotype. However, there was evidence of genetic instability of the
ca
marker in that 7 of 24 isolates exhibited some loss of the
ca
property, and one isolate completely lost the capacity to produce plaques at 25°C. The retention of a low level of residual reactogenicity in the A/Scotland/74
ca
recombinant suggests that acquisition of the
ca
and temperature-sensitive phenotypes by a
ca
recombinant virus may not always bring about a satisfactory level of attenuation for individuals lacking hemagglutinin immunity.
Longitudinal study of experimentally induced periodontal disease in Macaca arctoides: relationship between microflora and alveolar bone loss
Authors: Slots J , Hausmann E
Published: January 2020

Macaca arctoides monkeys develop periodontal disease, and they harbor a periodontopathic indigenous flora largely similar to that of humans. This study showed that various Haemophilus isolates and H2O2-splitting asaccharolytic Bacteroides melaninogenicus strains constituted major segments of the monkey periodontal microflora. These organisms have not been previously identified among human isolates. Furthermore, the present data revealed that asaccharolytic B. melaninogenicus strains increased in proportion from a few percent to about 66% of the total isolates concomitant with the development of a significant loss of alveolar bone mass. Hence, this study strongly implicates B. melaninogenicus subsp. asaccharolyticus and closely related strains as important pathogens in actively destructive periodontal disease.
Chemotactic deactivation of human neutrophils: possible relationship to stimulation of oxidative metabolism
Authors: Nelson R D , McCormack R T , Fiegel V D , Herron M , Simmons R L , Quie P G
Published: January 2020

Neutrophils preexposed to high concentrations of activated complement or synthetic N-formyl methionyl peptides are inhibited in their subsequent spontaneous and chemotactic migratory responses. We have considered the possibility that a part of this nonspecific loss of migratory function may be attributable to the interaction of the leukocytes with reactive forms of oxygen deriving from the cytotaxin-induced burst of oxidative metabolic activity. For these studies we have assessed the effect of preexposure of neutrophils from patients with chronic granulomatous disease to cytotaxins on their subsequent migratory responses. We find that these responses are not altered by preexposure to either cytotaxin. Thus, there appears to be a functional relationship between deactivation and the ability of the normal neutrophil to undergo a cytotaxin-induced respiratory burst.
Thymic dependence of immunity to Eimeria falciformis var. pragensis in mice
Authors: Mesfin G M , Bellamy J E
Published: January 2020

Athymic (nude) mice, their normal littermates, and Swiss white mice were infected with 750 oocysts of Eimeria falciformis var. pragensis and reinfected twice with 20,000 oocysts, 20 and 40 days after the primary infection. The prepatent and patent periods of the primary infection were similar in each group of mice; however, the athymic mice discharged more oocysts. The normal littermates and Swiss white mice developed immunity to the parasite after the first or second infection, whereas the athymic mice never developed immunity. Infection with E. falciformis var. pragensis induced the production of antibodies in the normal littermates and Swiss white mice, whereas antibody production was impaired in athymic mice. Passive administration of immune serum did not protect athymic mice from reinfection by the parasite. Immunity to the parasite was thymus dependent, and "effector" T-lymphocytes seemed to be required for protection.
Pneumococcal adherence to human epithelial cells
Authors: Selinger D S , Reed W P
Published: January 2020

Evidence is presented that pneumococci adhere poorly to oropharyngeal cells in vitro and that the capsule may interfere with adherence. A brief survey indicated that pneumococci may also adhere poorly in vivo.
Properties of
Streptococcus mutans
Grown in a Synthetic Medium: Binding of Glucosyltransferase and In Vitro Adherence, and Binding of Dextran/Glucan and Glycoprotein and Agglutination
Authors: Wu-Yuan Christine D. , Tai Stella , Slade Hutton D.
Published: January 2020

The influence of culture media on various properties of
Streptococcus mutans
was investigated. Strains of
S. mutans
(serotypes
c, d, f,
and
g
) were grown in a complex medium (Todd-Hewitt broth [THB]) or a synthetic medium (SYN). The SYN cells, in contrast to THB cells, did not bind extracellular glucosyltransferase and did not produce in vitro adherence. Both types of cells possessed constitutive levels of glucosyltransferase. B13 cells grown in SYN plus invertase-treated glucose possessed the same level of constitutive enzyme as THB cells. In contrast to THB cells, the SYN cells of seven serotype strains did not agglutinate upon the addition of high-molecular-weight dextran/glucan. Significant quantities of lower-molecular-weight (2 × 10
4
or 7 × 10
4
) dextran and B13 glucan were bound by SYN cells. SYN cells agglutinated weakly in anti-glucan serum (titers, 0 to 16), whereas THB cells possessed titers of 32 to 256. Evidence for the existence of a second binding site in agglutination which does not possess a glucan-like polymer has been obtained. B13 cells grown in invertase-treated THB agglutinated to the same degree as normal THB cells. The nature of this site is unknown. SYN cells possess the type-specific polysaccharide antigen. B13 cells did not bind from THB a glycoprotein which reacts with antisera to the A, B, or T blood group antigens or which allows agglutination upon the addition of dextran. The results demonstrate that
S. mutans
grown in a chemically defined medium possesse markedly different biochemical and biological activities than cells grown in a complex organic medium.
Purification and physicochemical and biological characterization of a staphylococcal pyrogenic exotoxin
Authors: Schlievert P M , Schoettle D J , Watson D W
Published: January 2020

A staphylococcal pyrogenic exotoxin was purified and characterized biochemically and biologically. The organism producing the toxin was a group I Staphylococcus aureus strain which was isolated from a vaginal infection of a patient with mucocutaneous lymph node syndrome (Kawasaki's disease). The possible association of the toxin with the disease syndrome is discussed. The toxin was purified from cell-free culture supernatant fluids by means of differential precipitation with ethanol and resolubilization in pyrogen-free distilled water followed by preparative thin-layer isoelectric focusing. The pyrogenic exotoxin produced fevers in both rabbits and mice and enhanced host susceptibility to lethal shock and myocardial and liver damage by endotoxin. Also, the toxin was a potent nonspecific lymphocyte mitogen, stimulating rabbit spleen cells and human cord blood lymphocytes to proliferate. The toxin migrated as a homogeneous protein when tested with sodium dodecyl sulfate-polyacrylamide gel electrophoresis (molecular weight, 12,000) and reisoelectric focusing (pI 5.3). Hyperimmune antisera raised against the purified toxin reacted with ethanol-precipitated toxin, using immunodiffusion to form a single precipitin arc. The toxin was distinguished from other staphylococcal toxins by a variety of methods. The amino acid composition was determined.
Lipid A and Anti-Lipid A
Authors: Mattsby-Baltzer Inger , Kaijser Bertil
Published: January 2020

Lipid A in free form, in crude antigen preparations, and on Formalin-treated
Escherichia coli
and
Salmonella minnesota
R595 was employed in studies of its antigenic composition, immunogenicity, and availability on gram-negative bacteria. Analyses with immunodiffusion and crossed immunoelectrophoresis of isolated lipid A preparations revealed three components. Inhibition experiments with enzyme-linked immunosorbent assay showed that the lipid A structure was not exposed on the tested smooth or rough
E. coli
strains or on
S. minnesota
R595. In crude O antigen preparations from some of the strains, however, lipid A was available for reaction with antibodies. The inaccessibility of lipid A on the bacterial surface may explain the poor protective capacity of anti-lipid A antibodies against bacterial infections. An enzyme-linked immunosorbent assay was more sensitive for measuring anti-lipid A antibody activity than indirect hemolysis or indirect hemagglutination. With an enzyme-linked immunosorbent assay it was shown that in rabbits the immunogenicity of lipid A was approximately the same when coated on erythrocytes or, as is more commonly done, when lipid A-coated hydrolyzed bacteria were used. Some antisera from rabbits immunized with
E. coli
of different serotypes showed activity against lipid A, with a higher frequency for antisera from rabbits immunized with R mutants.
Effect of oral tetracycline, the microbial flora, and the athymic state on gastrointestinal colonization and infection of BALB/c mice with Candida albicans
Authors: Helstrom P B , Balish E
Published: January 2020

Scanning electron microscopy, light microscopy, and quantitative culture of microorganisms in intestinal contents were used to determine the effects of oral tetracycline, the bacterial flora of conventionally reared animals (conventional), and thymus-dependent immune competency on the capacity of Candida albicans to colonize and infect the gastrointestinal tract of four groups of mice: thymus-intact conventional mice, conventional athymic mice, flora-defined athymic mice, and thymus-intact bacteria-free mice. Thymus-intact conventional mice without antibiotic treatment began to shed C. albicans less than 48 h after oral yeast challenge and were devoid of detectable yeast by day 16. Tetracycline altered the bacterial flora qualitatively and quantitatively, allowing C. albicans to colonize in less than 48 h and to persist in the gut tract for 32 days. Only 2 of 72 of these conventional mice developed candidiasis (hyphal infection). Although tetracycline altered the bacterial flora of conventional athymic (nude) mice, it was not required to allow C. albicans to colonize their gut tract to levels significantly higher than those in thymus-intact conventional mice. All conventional nude mice were consistently colonized and 14 of 24 animals showed an increased yeast colonization of the keratinized stomach, but only 3 of 24 developed gastric candidiasis. Flora-defined athymic (nude) mice had significantly lower aerobic bacterial levels and significantly higher C. albicans levels in the gut contents than conventional athymic mice. The flora-defined nude mice, however, developed gastric candidiasis by day 5. Thymus-intact bacteria-free mice were uniformly colonized and infected with C. albicans less than 48 h after oral challenge regardless of tetracycline treatment. Populations of C. albicans in the gut of bacteria-free mice were significantly higher than in the gut tract of the thymus-intact conventional or athymic mice. Gastric mycelial infection was detected in 8 of 10 bacteria-free animals 2 days after oral challenge. By 32 days, 45 of 50 mice of both tetracycline-treated and control bacteria-free groups were infected with C. albicans. These data indicate that a competive bacteria flora is more effective than an intact immune system in preventing gastric candidiasis and that an immune deficiency may allow increased yeast colonization of the keratinized and glandular stomach epithelium. Tetracycline did not appear to enhance the invasiveness or pathogenicity of C. albicans in mice even though it facilitates yeast-phase gut colonization in conventionally reared mice.
Ultrastructural changes of cultured human amnion cells by Clostridiu difficile toxin
Authors: Chang T W , Lin P S , Gorbach S L , Bartlett J G
Published: January 2020

The ultrastructure of the surface of primary human amnion monolayer cells undergoing cytopathology induced by Clostridium difficile toxin was examined by scanning electron microscopy. Our observations indicated that the type and distribution of cell surface projections were altered dramatically by this toxin. The patterns of such surface changes were specific for the two different types of cells found in this cell culture. Cells with demarcated borders showed rearrangement of microvilli into globular chains or ridges which lined up with the branching membrane. Cells without demarcated borders exhibited studlike microvilli, all arranged into ridges or globular chains. These changes were noted after 1 h of toxin exposure and persisted without further progression, in spite of continued toxin exposure, up to 48 h. These data indicate that C. difficile produces a cytolytic toxin and that scanning electron microscopy may be useful in determining toxin-cell interactions.
Nature and mechanism of action of the CAMP protein of group B streptococci
Authors: Bernheimer A W , Linder R , Avigad L S
Published: January 2020

The extracellular product of group B streptococci responsible for the CAMP reaction was purified to near homogeneity. It is a relatively thermostable protein having a molecular weight of 23,500 and an isoelectric pH of 8.3. It was found that the CAMP reaction could be simulated by substituting [14C]glucose-containing liposomes prepared from sphingomyelin, cholesterol, and dicetyl phosphate for sheep erythrocytes. In the belief that the liposome system is a valid model, the mechanism of the CAMP reaction was further investigated by using liposomes in which N-acylsphingosine (ceramide) was substituted for sphingomyelin. In this system disruption of liposomes, as measured by release of trapped [14C]glucose, was effected by CAMP protein alone. As judged from thin-layer chromatography, CAMP protein caused no reduction in the amount of ceramide present in ceramide-containing liposomes, nor were split products demonstrable. However, binding of CAMP protein to ceramide-containing liposomes could be shown. It is inferred that in sheep erythrocytes CAMP protein reacts nonenzymatically with membrane ceramide formed by the prior action of staphylococcal sphingomyelinase and that binding of CAMP protein to ceramide disorganizes the lipid bilayer to an extent that results in cell lysis.
Immunological relationship between delta-hemolysins of Staphylococcus aureus and coagulase-negative strains of staphylococci
Authors: Turner W H , Pickard D J
Published: January 2020

Delta-hemolysin of coagulase-negative staphylococcal strains was immunologically identical to delta-hemolysin of Staphylococcus aureus (Newman) but distinct from delta-hemolysin from a canine strain of S. aureus.
In vivo and in vitro characterization of virulence-deficient mutants of Vibrio cholerae
Authors: Baselski V S , Medina R A , Parker C D
Published: January 2020

In vitro and in vivo interactions between Vibrio cholerae and the infant mouse intestinal environment were examined by using a number of virulence-deficient mutants of strain CA401 which are unable to induce a typical diarrheal response. In vitro interactions with upper bowel sections were evaluated by determining percent association of radiolabeled organisms with sections. In vivo behavior was evaluated in the upper bowel early in infection with radiolabeled inocula. Ths relative degree of mechanical clearance was indicated by the percent recovery of input label. The relative degree of multiplication and killing was determined by changes in the specific activities (counts per minute per colony-forming unit) of inocula compared with recovered viable organisms. The results indicated that, whereas some virulence-deficient mutant classes exhibit net multiplication in the upper bowel, other classes show net killing in and accelerated clearance from the upper bowel. The in vitro association patterns failed to correlate with in vivo upper bowel recovery.
Enterochelin (enterobactin): virulence factor for Salmonella typhimurium
Authors: Yancey R J , Breeding S A , Lankford C E
Published: January 2020

The ability of Salmonella typhimurium to synthesize enterochelin (enterobactin; ENT) affects its capacity to grow both in vivo and in vitro. An ENT mutant (96-1), blocked in the conversion of chorismate to 2,3-dihydroxybenzoate, was derived from SR-11, a strain of high mouse virulence. This mutant was unchanged in the other characteristics tested: colonial, biochemical, antigenic, and cellular. In contrast to SR-11, growth of this mutant in complement-inactivated human serum was strongly inhibited. However, addition of 5 muM ENT to the cultures relieved their inhibition. Viable counts of bacteria injected into the mouse peritoneal cavity showed that without ENT, growth of 96-1 was inhibited markedly; with ENT, the apparent growth rate of 96-1 exceeded that of SR-11. The 50% lethal dose (LD50) of 96-1 was 2 to 3 log units higher than that of SR-11. When ENT was injected, the ENT- mutant exhibited an ENT-dose-related decrease in its LD50. A single injection of 300 micrograms of ENT per mouse with the inoculum reduced the LD50 of 96-1 to that of the wild-type strain. These findings support the contention that ENT is a virulence factor for S. typhimurium.
Immune electron microscopy of cross-reactions between Mycoplasma pneumoniae and human erythrocytes
Authors: Deas J E , Janney F A , Lee L T , Howe C
Published: January 2020

Respiratory infection with Mycoplasma pneumoniae evokes immunoglobulin M autoantibody which agglutinates human erythrocytes at 4 degrees C (cold agglutinin) and is specific for I antigen. Cross-reactions between surface antigens of M. pneumoniae and human erythrocytes, previously examined by serological analysis, were examined by transmission and scanning electron microscopy. Ferritin-labeled human antimycoplasmal and rabbit antisera to erythrocyte membrane components reacted with antigens on the surface of both M. pneumoniae and erythrocytes. Adsorption of human erythrocytes to M. pneumoniae was blocked by the same antisera without ferritin label. It is proposed that the cross-reactive specificity lies in peripheral areas of the mycoplasmal cell, probably in a surface carbohydrate which has antigenic identity with erythrocyte glycoprotein.
Surface Mucopolysaccharides of
Treponema pallidum
Authors: Fitzgerald T. J. , Johnson R. C.
Published: January 2020

The viscous mucoid fluid that accumulates within syphilitic lesions may be due to breakdown of host tissue during infection, or may be synthesized by
Treponema pallidum.
Experiments were performed to investigate the acidic mucopolysaccharides that occur at the surface of
T. pallidum
(Nichols strain). These mucopolysaccharides were demonstrated by reaction with acidified bovine serum albumin and by agglutination with wheat germ agglutinin and soybean agglutinin. The polycations ruthenium red and toluidine blue influenced treponemal survival. Concentrations of both compounds at 200 μg/ml inhibited survival, whereas concentrations at 0.1μg/ml enhanced survival. The mucopolysaccharide concentration within the mucoid fluid that accumulates during intratesticular infection was determined by reaction with acidified bovine serum albumin; it ranged from 10,000 μg/ml to less than 8 μg/ml. The addition of this mucoid fluid to treponemal suspensions resulted in differing effects on
T. pallidum
survival. Some preparations were inhibitory, and others were stimulatory. Commercial preparations of hyaluronic acid and chondroitin sulfate at 400, 200, 100, and 50 μg/ml were detrimental to treponemal survival. The organisms exhibited pronounced clumping in the presence of the higher concentrations of hyaluronic acid. These clumps of treponemes were comprised of mucopolysaccharides as shown by acidified bovine serum albumin and toluidine blue reactions and by hyaluronidase degradation. Results are discussed in terms of the derivation and potential role of acidic mucopolysaccharides at the surface of
T. pallidum.
Relationship of
Treponema pallidum
to Acidic Mucopolysaccharides
Authors: Fitzgerald T. J. , Johnson R. C. , Ritzi D. M.
Published: January 2020

Attempts were made to relate
Treponema pallidum
to the acidic mucopolysaccharides that occur in vivo within host ground substance and in vitro on the surface of cultured testicular cells. Infected testicular tissue was fixed and processed for transmission electron microscopy in the presence of ruthenium red. The use of this inorganic dye demonstrated the large quantity of mucopolysaccharide within testicular tissue and the intimate association of treponemes with this material. Wheat germ agglutinin and soybean agglutinin agglutinated freshly harvested trypsinized testicular cells and trypsinized cultured cells derived from normal rabbit testes (NRT). When stained with toluidine blue, both cell preparations were metachromatic. Prior treatment of cultured NRT cells with hyaluronidase slightly decreased their sensitivity to agglutination by wheat germ agglutinin and soybean agglutinin. Lectin agglutination, metachromasia, and hyaluronidase susceptibility indicated that freshly harvested testicular cells and NRT cells have surface-associated acidic mucopolysaccharides that are probably hyaluronic acid and chondroitin sulfate. A rabbit erythrocyte “sandwich” technique was devised to show that hyaluronidase removed wheat germ agglutinin receptors from the cultured NRT cells. Prior incubation of NRT cells with hyaluronidase, followed by the addition of
T. pallidum
, resulted in a reduction in numbers of treponemes attached to the NRT cells. The attachment of
T. pallidum
appears to be mediated through the acidic mucopolysaccharides on the surface of NRT cells. The findings are discussed in terms of the importance of host ground substance mucopolysaccharide to the syphilitic infective process.
Effect of immune status on dengue 2 virus replication in cultured leukocytes from infants and children
Authors: Marchette N J , Halstead S B , O'Rourke T , Scott R M , Bancroft W H , Vanopruks V
Published: January 2020

Cord blood leukocytes from neonates with maternal dengue antibody supported dengue 2 virus replication in vitro; those from neonates without maternal antibody did not. Cord bloods of infants born to dengue-immune mothers contained a potent enhancing factor which gradually decayed with age and which was absent from neonates born to nonimmune mothers. Permissiveness of cultures of washed peripheral blood leukocytes from infants with maternal antibody declined steadily with increasing age in parallel with the decay of maternal antibody, and the leukocytes were no longer permissive after 10 to 12 months. The demonstration of a dengue maternal infection-enhancing factor in human cord blood from dengue-immune mothers supports the hypothesis that severe primary dengue hemorrhagic fever with shock seen in Bangkok infants is related to maternal immune status.