bluuebunny/crossref_metadata_2025 huggingface dataset:
Inhibitory Action of Fatty Acids on the Growth of
Neisseria gonorrhoeae
Authors: Miller Richard D. , Brown Kenneth E. , Morse Stephen A.
Published: January 2020

Fatty acids of various chain lengths (C
1
to C
24
) were examined for their effects on growth, oxygen consumption, and in vitro reduced nicotinamide adenine dinucleotide oxidase activity of
Neisseria gonorrhoeae
CS-7. The growth inhibition caused by saturated fatty acids increased with increasing chain length to a maximum with palmitic acid (C
16
). Stearic acid (C
18
) and longer saturated fatty acids showed little inhibition of growth. However, unsaturated fatty acids of chain length C
16
to C
20
were inhibitory. Similar inhibition was observed with
Bacillus subtilis
and a deep rough mutant of
Salmonella typhimurium.
Wildtype
S. typhimurium
and
Pseudomonas aeruginosa
were more resistant to medium-chain (C
7
to C
10
) fatty acids and completely resistant to long-chain (C
12
to C
18
) fatty acids. Thus, sensitivity of
N. gonorrhoeae
to long-chain fatty acids appears to be related to the permeability of the outer membrane. Growth inhibition by short-chain (C
1
to C
6
) fatty acids was pH dependent; inhibition of growth increased with decreasing pH. Saturated fatty acids inhibited oxygen consumption by log-phase cells of
N. gonorrhoeae.
This inhibition increased with increasing chain length to a maximum observed with myristic acid (C
14
). Whereas stearic acid (C
18
) had little effect upon oxygen consumption, unsaturated C
18
fatty acids were inhibitory. An in vitro inhibition of reduced nicotinamide adenine dinucleotide oxidase activity by saturated (C
1
to C
12
) and unsaturated (C
16
to C
20
) fatty acids was also observed. Although the inhibitory concentrations were generally higher than those required to inhibit growth or oxygen consumption, an inhibition of electron transport may be partially responsible for the observed growth inhibition.
Molecular basis for the different sucrose-dependent adherence properties of Streptococcus mutans and Streptococcus sanguis
Authors: Kuramitsu H , Ingersoll L
Published: January 2020

The enzymatic and adherence properties of Streptococcus mutans GS5 and S. sanguis ST3, both isolated from human carious lesions, have been compared. During growth in sucrose media, S. mutans GS5 adheres to smooth surfaces approximately three times more effectively than dose S. sanguis ST3. However, strain ST3 does not display sucrose-dependent adherence under nongrowth conditions, whereas strain GS5 displays significant adherence. Although both organisms synthesize both water-soluble and -insoluble glucans, the glucosyltransferases from S. mutans GS5 synthesize much more adherent glucan molecules than do the comparable enzymes from S. sanguis ST3. Both cell types bind exogenous glucosyltransferases synthesized by strain ST3 equally well, whereas cells of strain GS5 bind the comparable enzyme fraction that it synthesizes to a greater degree than do cell of S. sanguis ST3. However, in contrast to the results with cells of S. mutans GS5, the absorption of the glucosyltransferase activity synthesized by S. mutans GS5 to the surface of S. sanguis ST3 results in low levels of subsequent sucrose-dependent adherence. These results are discussed in terms of the molecular basis for the sucrose-dependent adherence of the oral streptococci to smooth surfaces.
Suppression of babesiosis in BCG-infected mice and its correlation with tumor inhibition
Authors: Clark I A , Wills E J , Richmond J E , Allison A C
Published: January 2020

Infection of mice with Bacillus Calmette-Guérin (BCG) provided good protection against Babesia species. The intensity and duration of this protection was similar to that established after natural recovery from babesiosis. It developed too soon after the first exposure to the parasite, and was too radioresistant, to be attributable to specific antibody production. In addition, the parasites degenerated within circulating erythrocytes. This phenomenon is inconsistent with phagocytosis or lysis of parasites or parasitized cells, or prevention of entry of parasites into erythrocytes, causing the observed protection. Hence the phenomenon is best explained by the release of a nonspecific mediator that can limit multiplication of parasites within erythrocytes. These results not only throw light on mechanisms of immunity against hemoprotozoa. There are many points of similarity between the nonspecific protection BCG and Corynebactium parvum provide against Babesia species and inhibition of tumor growth by these agents. Therefore, babesiosis in mice may be a convenient experimental model for assessing stimulation of the mononuclear phagocyte system, which appears to be the basis of nonspecific immunity against bacteria, parasites, and tumors.
Canine Migration Inhibitory Factor: Effect of
Corynebacterium parvum
Administration
Authors: Pineiro Maya S. , Bowles Charles A. , Cutchins Ernest C. , Bull Malcolm I.
Published: January 2020

Peripheral blood lymphocytes from dogs sensitized to streptolysin O (SLO) were assayed for migration inhibitory factor (MIF) production by the indirect MIF test, using guinea pig peritoneal exudate cells as the source of macrophages. A specific direct correlation was established between the degree of inhibition of migration and the concentration of SLO-stimulated supernatants from lymphocyte cultures (SLO-S) of untreated normal dogs. Undiluted SLO-S inhibited migration by 66.8%, whereas a dilution of 1:64 elicited a 3% inhibition. In parallel tests, purified protein derivative stimulation of lymphocytes from BCG-vaccinated dogs produced 92.6% inhibition. The effect of
Corynebacterium parvum
on SLO-specific MIF production was evaluated in three groups of dogs administered a single intramuscular injection of
C. parvum
at 5 or 50 mg/m
2
or 50 mg/m
2
in suspension with 10 mg of methylprednisolone. Inhibition of migration of macrophages exposed to a 1:4 dilution of SLO-S from dogs inoculated with
C. parvum
(5 mg/m
2
) was 33% greater (mean inhibition, 75%) than the same SLO-S dilution from uninoculated normal dogs (mean inhibition, 42%) (
P
< 0.0002). Similarly, lymphocytes from dogs administered 50 mg/m
2
caused an enhancement of migration inhibition, with a mean increase of 26% over controls (
P
< 0.002), whereas a dose of 50 mg/m
2
with methylprednisolone produced a 16% increase in migration inhibition (
P
< 0.05). The administration of
C. parvum
resulted in a three- to fourfold increase in the SLO-S dilution, which would reduce migration by 20% (MIF titer). This increase peaked between days 20 and 30 and lasted over 50 days post-
C. parvum
inoculation. These findings indicate that
C. parvum
specifically increases MIF production by canine lymphocytes in a linear correlation with SLO concentration and suggest its use as a stimulant of canine immunity.
Anticomplementary activity of Fusobacterium polymorphum in normal and C4-deficient sources of guinea pig complement
Authors: Hawley C E , Falkler W A
Published: January 2020

Fusobacterium polymorphum has been isolated from the gingival crevice in humans and has been implicated in the immunopathology of periodontal diseases. The presence of alternative complement pathway factors in gingival crevice material suggests the contribution of this process in the manifestation of the local host response. A complement consumption assay was used to show that the anticomplementary activity of a cell-wall preparation from F. polymorphum in guinea pig complement progressed optimally at 37 degrees C and suboptimally at 0 degrees C. Similar levels of complement consumption were recorded at both temperatures, but a higher concentration of cell walls was required to demonstrate maximum activity in the cold. Augmentation experiments with additional normal and heat-treated complement showed the presence of heat-labile factors that controlled and limited the consumption of complement to a constant proportion of the total amount present. These same experiments indicated that there were no reactive antibodies in the complement used in the assay. Similar tests with C4-deficient guinea pig sera confirmed that F. polymorphum cell walls were capable of generating alternative complement pathway activity in guinea pig sera.
Transplacental transmission of polyoma virus in mice
Authors: McCance D J , Mims C A
Published: January 2020

When pregnant mice were inoculated on day 1 of gestation with polyoma, some of them exhibited total resorption or reduced litter size, the extent depending on the dose of virus. Virus was detected in 4 out of 11 mouse embryo fibroblast (MEF) cultures made from infected mothers. After maternal infection on day 5 or 10 of gestation, virus titers of up to 10(7) 50% tissue culture infectious doses (TCID50)/g of fetus were found in all pools of fetuses tested 5 days later, with the titers falling by day 6. Hemagglutination-inhibiting antibodies against polyoma appeared in maternal serum by day 6 and rose to a maximum by day 14. Immunoglobulin G class antibodies were detected by day 7, with titers rising rapidly to a maximum at day 14. After maternal infection later in gestation (day 15), one out of three litters of newborn mice was found to have 10(5) TCID50 polyoma virus per g in pooled kidney samples.
Heterogeneity of the sensitivity of vesicular stomatitis virus to interferons
Authors: Ito Y , Montagnier L
Published: January 2020

Twelve cloned viruses were randomly isolated from original (uncloned) vesicular stomatitis virus (VSV), and their sensitivities to mouse and human interferons were examined. When the interferon sensitivities of these various VSVs were compared by the plaque reduction method in L cells, virus 3 was found to be sevenfold more sensitive than virus 11, and the interferon sensitivity of the original (uncloned) virus was intermediate. The present study shows that uncloned VSV Indiana strain is a mixture of viruses that have different sensitivities to interferon. The slope of the dose-response curve of original (uncloned) virus to mouse interferon was less steep than those of cloned viruses. Virus 11, which was the least sensitive to mouse interferon, was relatively sensitive to human interferon. There was no correlation between the sensitivities of virus clones to mouse interferon and their sensitivities to human interferon. When the interferon sensitivities were tested by various assay methods (plaque reduction, yield reduction, and cytopathic effect inhibition), the ranking of the interferon sensitivities of different viruses was not changed. These results indicate that the relative sensitivity of a virus to interferon is determined by the host cells in which the tests are performed, but not by assay method used.
Purification, resolution, and interaction of the glucosyltransferases of Streptococcus mutans 6715
Authors: Ciardi J E , Beaman A J , Wittenberger C L
Published: January 2020

The extracellular glucosyltransferase produced by Streptococcus mutans 6715 was purified from culture supernatant fluids to a specific activity of 9.6 IU/mg of protein, with an overall recovery of 87%. The purified enzyme preparation, designated unfractionated enzyme (UFE), synthesized only water-insoluble glucans from sucrose during the initial stages of the reaction, although some water-soluble polymers accumulated after extended periods of incubation. It was free from measurable fructosyltransferase activity. The UFE preparation was resolved into two different catalytically active components by ethanol fractionation. One fraction (designated insoluble product enzyme [IPE]) synthesized water-insoluble glucans, whereas the other (designated soluble product enzyme [SPE]) produced primarily water-soluble glucans. The difference between the insoluble glucans made by the UFE preparation and those made by the IPE fraction appeared to be due to interaction of the SPE and IPE components in the UFE preparation. Addition of commercial dextrans or enzymatically prepared glucans to the glucosyltransferase assay altered the amounts of soluble and insoluble glucans synthesized by the UFE preparation. The molecular weights of the major enzymatically active proteins producing insoluble and soluble glucans were estimated by gel filtration chromatography to be 150,000 and 175,000, respectively.
Tuberculin-specific transfer factor in dogs
Authors: Simon M R , Silva J , Freier D , Bruner J , Wiliams R
Published: January 2020

Five mongrel dogs were sensitized to tuberculoprotein with Freund adjuvant, as determined by responses to tuberculin skin tests and by in vitro lymphocyte cultures. These animals served as blood donors for production of transfer factor. Nine mongrel dogs received single doses of transfer factor that was tuberculin specific. Successful transfer of tuberculin sensitivity as measured by lymphocyte transformations was achieved in five of nine animals. Canine lymphocyte cultures frequently showed relatively low transformations to mitogens as compared with responses noted in other animals. Dissociation between skin test reactivity and in vitro lymphocyte transformation to tuberculoprotein was noted in two of nine animals. Increases in lymphocyte transformations to phytochemagglutinin were seen in three of nine recipient animals after transfer factor administration. Successful transfer from an animal sensitized by prior transfer factor administration was achieved in one instance. These data indicate that transfer factor-like substances are present in dogs. The reasons why successful transfer was achieved in only half of the recipient animals needs further explanation.
Polymorphonuclear Leukocyte Bactericidal Activity and Oxidative Metabolism During Glutathione Peroxidase Deficiency
Authors: Bass D. A. , DeChatelet L. R. , Burk R. F. , Shirley P. , Szejda P.
Published: January 2020

Glutathione peroxidase (GPx) deficiency has been proposed as a cause of some instances of chronic granulomatous disease (CGD). GPx activity varies greatly among species, and specific deficiency of this selenium-dependent enzyme can be produced by dietary selenium deficiency in rats. Bactericidal activity of polymorphonuclear (PMN) leukocytes from normal rats, humans, and guinea pigs (GPx high, intermediate, and nearly absent, respectively), selenium-deficient rats (GPx absent), and a patient with CGD were compared. There was no correlation between natural levels of GPx and bactericidal activity; only CGD was associated with inability to kill a
Proteus mirabilis
strain in vitro (killing known to be dependent on oxidative mechanisms). Postphagocytic metabolism was examined in normal and GPx-deficient rats. Both demonstrated normal iodination and superoxide production during phagocytosis and gave similar histochemical reduction of nitroblue tetrazolium dye under either resting or endotoxin-stimulation conditions. Postphagocytic hexose monophosphate shunt activity was somewhat lower in PMN from GPx-deficient animals as compared with normal but was substantially (10-fold) higher than that observed in resting cells. Thus, postphagocytic oxidative responses and subsequent bactericidal activity of PMN leukocytes were not compromised by complete absence of GPx, even in the species with the highest natural level of this enzyme. These results are not compatible with the hypothesis that CGD can be caused by a deficiency of GPx.
Cellular source of interferons in the circulation of mice with delayed hypersensitivity
Authors: Sonnenfeld G , Salvin S B , Youngner J S
Published: January 2020

The cellular origins of type I and type II interferons released into the circulation of mice with delayed hypersensitivity were investigated. We determined the effect of treatment with various immunosuppressive agents, including cyclophosphamide, cycloheximide, antithymocyte serum, and whole-body X-irradiation, on the release of interferons after intravenous injection of specific (old tuberculin) or nonspecific (lipopolysaccharide) stimuli. The results suggest that (i) a heterogeneous population of lymphocytes (T and B cells) produces type II interferon, (ii) type I interferon is produced by a different cell population, and (iii) type II interferon is produced de novo after challenge with old tuberculin of mice sensitized with Mycobacterium bovis BCG.
Glycolipoprotein from Pseudomonas aeruginosa as a protective antigen against P. aeruginosa infection in mice
Authors: Sensakovic J W , Bartell P F
Published: January 2020

After primary subcutaneous immunization of rabbits with glycolipoprotein from Pseudomonas aeruginosa BI, indirect hemagglutinating and bacterial agglutinating activities appeared in the antiserum 6 days after immunization and reached a peak between 15 and 20 days. Both these in vitro activities paralleled in vivo antipseudomonas-induced leukopenia and mouse passive-protection activities. Further experiments indicated that a functional association exists between the hemagglutinating and passive-protection activities, and that passive protection depends on activity levels in the plasma rather than in the peritoneum. After intraperitoneal injection in mice, in vitro and in vivo activities of antiglycolipoprotein serum declined in the peritoneal cavity as the plasma levels increased. After intravenous injection of the antiglycolipoprotein serum, initially high levels of in vitro and in vivo activity declined at approximately equal rates. Immunoglobulin G (IgG) and immunoglobulin M (IgM) fractions from 15-day antiglycolipoprotein serum were assayed for biological activity. Most of the hemagglutinating and bacterial agglutinating activity and all of the mouse passive-protection activity were found in the IgM fraction. Assay of antiglycolipoprotein serum after 2-mercaptoethanol inactivation of IgM showed that most of the in vitro and all of the passive-protection activities had been destroyed, again locating these activities principally in the IgM fraction of the original antiserum.
Mycoplasma-dependent activation of normal lymphocytes: mitogenic potential of mycoplasmas for mouse lymphocytes
Authors: Cole B C , Aldridge K E , Ward J R
Published: January 2020

Nonviable preparations of a wide variety of glucose-utilizing mycoplasma species, including Acholeplasma laidlawii and Spiroplasma citri, were found to be mitogenic for mouse lymphocytes. Particularly strong reactions were obtained with Mycoplasma synoviae, M. gallisepticum, M. pneumoniae, S. citri, and a strain of M. fermentans that was previously isolated from a leukemic patient. Nonviable preparations of arginine-utilizing mycoplasmas inhibited the uptake of [3H]thymidine by lymphocytes, but this effect could be reversed by heat treatment or arginine supplementation, and a stimulatory effect was then observed. Viable M. arthritidis was also found to have a mitogenic effect, as detected by an increased uptake of [3H]thymidine by normal lymphocytes and by autoradiographic techniques in which an increase in the numbers of transformed cells was seen. These observations provide the potential for enhanced immunological responsiveness or lymphokine-mediated inflammation in mycoplasma-infected hosts.
Mitogenic response of mouse spleen cells and gelation of limulus lysate by lipopolysaccharide of Yersinia pestis and evidence for neutralization of lipopolysaccharide by polymyxin B
Authors: Butler T , Möller G
Published: January 2020

Lipopolysaccharide (LPS) extracted with phenol and water from Yersinia pestis was compared with LPS of Escherichia coli for stimulation of deoxyribonucleic acid synthesis in mouse spleen cells (lymphocyte mitogenesis), gelation of limulus lysate, pyrogenicity in the rabbit, and susceptibility to inhibition of these activities by polymyxin B sulfate (PBS). LPS of Y. pestis stimulated deoxyribonucleic acid synthesis in mouse spleen cell cultures over the same quantitative range as LPS of E. coli. In the limulus tests and rabbit pyrogenicity studies, the LPS of Y. pestis was active but about 10 times less potent than E. coli LPS on a weight basis. PBS in concentrations from 1 to 10 microgram/ml diminished the rate of deoxyribonucleic acid synthesis in spleen cell cultures stimulated by LPS of both Y. pestis and E. coli. Addition of PBS to LPS of both Y. pestis and E. coli in a ratio of 100 parts of PBS to 1 part of LPS by weight increased by 10-fold the concentration of LPS required to produce gelation of limulus lysate and inhibited significantly pyrogenic responses in rabbits. These results demonstrating similarities of LPS of Y. pestis and E. coli may suggest that the pathogenesis of plague is similar to that of other gram-negative bacterial infections.
Toxicity of Low and Moderate Multiplicities of
Chlamydia psittaci
for Mouse Fibroblasts (L Cells)
Authors: Kellogg Kevin R. , Horoschak Karen D. , Moulder James W.
Published: January 2020

When mouse fibroblasts (L cells) were infected in suspension or in monolayer with 10 to 100 50% infectious doses (ID
50
) of
Chlamydia psittaci
(6BC) per host cell, they showed signs of damage 24 to 48 h later. Host-cell injuries were termed multiplication dependent when both the ingestion and subsequent reproduction of
C. psittaci
were required; when only ingestion but not replication was needed, the injuries were considered to be multiplication independent. The time that the injury was first apparent, as well as its final magnitude, was proportional to the multiplicity of infection. When L cells ingested infectious or ultraviolet-inactivated
C. psittaci
, damage was manifested by failure to exclude trypan blue, by leakage of lactic dehydrogenase, by inhibition of reproduction as measured by ability to form colonies, by inhibition of protein and deoxyribonucleic acid synthesis, and eventually by cell disintegration. Infectious, but not ultraviolet-killed, chlamydiae stimulated host-cell glycolysis. Heat-killed chlamydiae were without measurable toxicity. The time of appearance of host-cell injury was always earlier, and its terminal magnitude always greater, with infectious inocula than with ultraviolet-inactivated ones. The multiplication-independent toxicity of ultraviolet-killed
C. psittaci
disappeared with inocula of less than 10 ID
50
per L cell, but an inoculum of only a single ID
50
of infectious chlamydiae per host cell injured most of the cells it infected, as evidenced by increased trypan blue staining and decreased efficiency of colony formation. The toxicity of multiplicities of infection between 10 and 100 ID
50
of infectious
C. psittaci
per host cell was the sum of both multiplication-dependent and -independent components. The effects of chloramphenicol and isoleucine deficiency on the ability of
C. psittaci
to injure L cells suggested that some synthesis of protein by both parasite and host may be essential for expression of multiplication-independent chlamydial toxicity. The failure of infectious chlamydiae to stimulate host-cell glycolysis in the presence of cycloheximide suggested that this multiplication-dependent consequence of chlamydial infection was also dependent on protein synthesis by the host.
Chemotactic factor produced by Candida albicans
Authors: Cutler J E
Published: January 2020

Candida albicans was found to produce a substance that was chemotactically active for guinea pig polymorphonuclear neutrophils. The chemotactic factor was detected in culture filtrates of organisms grown under aeration and incubated at 37 degrees C for at least 12 h. Nutrients found to be essential for the production of chemotactic factor included glucose, yeast extract, and a mixture of amino acids. Several strains of C. albicans isolated from humans were tested, and varying degrees of chemotactic activity were found to be associated with the culture filtrates. Only one of the eight isolates did not produce a measurable amount of chemotactic activity. Culture filtrates remained chemotactically active after several cycles of freezing and thawing and after heating at 90 degrees C for 10 min. Substantial evidence is presented that the chemotactic activity is not dependent upon activation of complement.
Role of phagocytosis in mouse virulence of Salmonella typhimurium recombinants with O antigen 6,7 or 4,12
Authors: Valtonen M V
Published: January 2020

The quality of lipopolysaccharide has previously been shown to influence the mouse virulence of Salmonella so that strains with O antigen 4,12 were more virulent than their O-9,12 sister strains. Immunosuppression did not alter this O-antigen-dependent difference in virulence. I have now constructed smooth O-4,12 and O-6,7 sister hybrid strains of Salmonella typhimurium. No other phenotypic differences were found between these strains; they were all "common antigen" positive. In intraperitoneal infection, the O-4,12 strains were more mouse virulent than their O-6,7 sisters. The difference in virulence correlated with a difference in clearance rates; the O-6,7 hybrids were removed from the blood more rapidly than their O-4,12 sisters. No natural bactericidal antibodies were found in the sera of the mice.
Demonstration of cross-protection between Pasteurella multocida type A and Pasteurella haemolytica, serotype 1
Authors: Mukkur T K
Published: January 2020

Mice immunized with the potassium thiocyanate extract of Pasteurella haemolytica, serotype 1, were found to resist a challenge infection of P. multocida type A, thus demonstrating cross-protection. This finding was further supported by the finding that an antiserum directed against the potassium thiocyanate extract of P. haemolytica was bactericidal to P. multocida and vice versa.
Distribution of dextransucrase in Streptococcus mutans and observations on the effect of soluble dextran on dextransucrase activities
Authors: Montville T J , Cooney C L , Sinskey A J
Published: January 2020

Total and insoluble dextransucrase activities were measured in cell-associated and supernatant fractions of Streptococcus mutans GS-5 grown in several media. Although the amount of cell-associated and supernatant activity varied greatly as a function of medium, the total activity appeared constant. The distribution of dextransucrase could be altered without changing the total dextransucrase activity. This indicates that the distribution of the enzyme can be regulated independently of its synthesis. Strain GS-5 had significant cell-associated activity in media devoid of sucrose. In all cases, the ratio of insoluble to total dextransucrase activity was higher in the cell-associated fractions than in the cell-free supernatants. It is also demonstrated that exogenous soluble dextran caused a decrease in insoluble dextransucrase activity and an increase in soluble dextransucrase activity in both the cell-associated fraction and the culture supernatant. The stimulation of soluble dextran-synthesizing activity was not due to de novo synthesis. The inhibition of insoluble dextran-synthesizing activity is shown to be noncompetitive. These results support a physical rather than metabolic mechanism for the effect of soluble dextran on dextransucrase activities.
Induction and expression of immunity after BCG immunization
Authors: Lefford M J
Published: January 2020

The induction and expression of immunity to Mycobacterium tuberculosis after BCG immunization by intravenous, subcutaneous, and pulmonary routes has been investigated in mice. The speed with which protective immunity was engendered was a function of inoculum size; the immunization route was a less influential factor. Tuberculin hypersensitivity varied both with the inoculim size and immunization route, being least after pulmonary immunization. Once immunity was established, a steady state ensued in which the number of sensitized lymphocytes in the spleen was similar, regardless of the route or dose of vaccination. Actively immunized animals controlled intravenous and subcutaneous challenge infections, regardless of the method of vaccination. However, pulmonary challenge was resisted most efficiently by mice immunized by the pulmonary route. Adoptive immunity was well expressed in the spleen only, but the lungs were no more deficient in this regard than the footpad. It is suggested that enhanced immunity in the lungs depends on a population of resident sensitized lymphocytes.
Serum and tissue lysozyme in leprosy
Authors: Rea T H , Taylor C R
Published: January 2020

Mean serum lysozyme values were found to be elevated in untreated leprosy patients. Statistically significant elevations were present in each of the three major categories of leprosy, tuberculoid, borderline, and lepromatous. Values were particularly high in patients with severe reversal reactions or Lucio's phenomenon. Prolonged sulfone therapy was associated with a fall in serum lysozyme values. With an immunoperoxidase method to localize lysozyme in leprous tissues, two distinct staining patterns were found, granular and saccular. The grandular pattern of lysozymal staining was found in epithelioid cells and in giant cells, and the intensity of staining showed a positive correlation with serum lysozyme levels. Conversely, a saccular pattern of lysozymal staining was found in lepromatous histiocytes, buth the intensity of staining was unrelated to serum lysozyme levels; the saccular structures contained dense aggregates of Mycobacterium leprae. These two patterns of staining probably represent different functional responses of monocyte-derived granuloma cells, whereas the serum levels reflect, to a varying degree, both the absolute number of such cells and the rate of secretory activity of this cell population as a whole.
Role of bacterial products in periodontitis: immune response in gnotobiotic rats monoinfected with Eikenella corrodens
Authors: Johnson D A , Behling U H , Lai C H , Listgarten M , Socransky S , Nowotny A
Published: January 2020

The development of humoral and cell-mediated immune responses to Eikenella corrodens (a bacterium that causes periodontal lesions in gnotobiotic rats) was measured and compared with the rate of appearance of macroscopic lesions. A possible inverse relationship was found. A strong cell-mediated immune response, as measured by skin reactivity and lymphocyte mitogenesis, occurred between 4 and 6 weeks after infection and subsided soon thereafter to a low response level. Humoral antibodies to endotoxin from E. corrodens could not be detected at any time. The disease developed only after the cell-mediated immune response diminished, thus suggesting that lack of an efficient immune response may permit the development of the disease. This is seemingly in contradiction to the assumption that tissue destruction in such cases is caused by the immune response and its products. We are inclined to believe, based on our findings reported here, that the lack of immune responsiveness to the bacterium and/or its products is the major causative factor in the development of periodontitis. At the same time, we wish to emphasize that occurrence of both phenomena during the long development of periodontal disease is possible.
Studies on gonococcus infection. XII. Colony color and opacity varienats of gonococci
Authors: Swanson J
Published: January 2020

Colonies with markedly differing color and opacity characteristics were found for Neisseria gonorrhoeae propagated on translucent, solid medium. These optical properties of gonococcal colonies were independent of pilation and appeared to be related to the degree of aggregation among the gonococci comprising the colonies. Dark, opaque colonies contained highly aggregated gonococci which were more susceptible to killing and to solubilization of their 125-labeled surface components than were organisms comprising light, transparent colony forms.
Mitogenic activity of bacterial lipopolysaccharides in vivo: morphological and functinal characterization of responding cells
Authors: Peavy D L , Baughn R E , Musher D M
Published: January 2020

The in vivo effect of bacterial lipopolysaccharides (LPS) on mouse spleen cell subpopulations was investigated. Intravenous administration of LPS resulted in marked enlargement of the spleen, accompanied by increased cellular proliferation and enhanced nucleated cell recoveries. At least two morphologically distinct cell types appeared to be targets for LPS. Polymorphonuclear leukocytes accumulated rapidly with a relatively minor degree of cell division. In contrast, a substantial proportion of splenic lymphocytes transformed into large lymphocytes and blast cells which actively incorporated [3H]thymidine. Proliferating cells were identified as bone marrow-derived (B) lymphocytes by their ability to form C3-dependent rosettes and to synthesize immunoglobulin. These cellular responses were not antigenically induced, since LPS derived from mutants lacking the polysaccharide moiety gave similar results. Thus, splenic B lymphocytes appear to interact and respond to LPS in vivo in the same manner as observed in vitro. These data suggest that the capacity of LPS to directly activate B lymphocytes, initiate cellular proliferation, and induce immunoglobulin production by bone marrow-derived cells in vivo may contribute to its adjuvant activity.
Immunity to Mycobacterium leprae infections induced in mice by BCG vaccination at different times before or after challenge
Authors: Shepard C C , Walker L L , Van Landingham R M
Published: January 2020

Viable suspensions of BCG, an attenuated strain of Mycobacterium bovis, have been previously shown to immunize mice against infections with M. leprae. Usually, the mice have been vaccinated about 1 month before challenge. Experiments have now been carried out with single intradermal injections of BCG given before or after the M. leprae challenge. Approximately equal immunizing effect was seen in one experiment when the BCG was given at -168, -119, -70, and -28 days relative to challenge. Approximately equal protection was observed in another experiment when the vaccine was given at -28, +28, and +56 days. In the latter experiment, however, vaccine given at +91 days appeared to be somewhat less effective. Enlargement of the lymph nodes regional to the intradermal vaccine site persisted for at least the duration of the experiment, approximately 400 days. Thus, antigenic stimulation appears to have continued throughout the period of observation.
Effects of Fluoride on Carbohydrate Metabolism by Washed Cells of
Streptococcus mutans
Grown at Various pH Values in a Chemostat
Authors: Hamilton I. R. , Ellwood D. C.
Published: January 2020

Streptococcus mutans
Ingbritt was grown anaerobically in a chemostat, at a rate (mean generation time, 13 h) similar to that in dental plaque, in a complex medium with excess glucose and at pH values of 6.5, 6.0, and 5.5. The yield of cells was constant at pH 6.5 and 6.0 (2.00 mg/ml) but fell to 1.25 at pH 5.5;
Y
glucose
was relatively constant under all conditions. Lactic acid was the major end product. Amino acid analysis of the culture supernatants indicated that growth was probably limited by the availability of cysteine. Cells were harvested and monitored for their capacity to produce acid from endogenous polysaccharide and exogenous sugars in the presence and absence of NaF, as well as for their glucose phosphoenolpyruvate (PEP)-phosphotransferase activity. Surprisingly, cells grown at pH 5.5 possessed two to three times more glycolytic activity, as measured by the rate of acid production, than cells grown at pH 6.5 and 6.0 when incubated in a washed suspension at constant pH with a sugar source. Furthermore, the cells grown at pH 5.5 were about twice as resistant to the effect of NaF in reducing the rate of acid production in this system. Fluoride inhibition could be reversed by increasing the pH of the system. Cells grown at all three pH values showed significant acid production from endogenous reserves, despite the fact that the glucoamylase-specific glycogen content of the cells dropped from 33% of the total carbohydrate during pH 6.5 growth to only 3% after growth at pH 6.0 and 6.5. Incubation of washed cells for 18 h in phosphate buffer resulted in the loss of 62% of the total carbohydrate, indicating that nonglycogen cellular polysaccharide was metabolized. A comparison of the fluoride effect on endogenous and exogenous metabolism under pH fall conditions showed that, with pH 6.5- and 6.0-grown cells, the inhibitor was more effective in the presence of an exogenous carbon source than in its absence. This effect was not seen with pH 5.5-grown cells. The decreased sensitivity of the pH 5.5-grown cells to fluoride was probably associated with the decreased glucose PEP-phosphotransferase activity (11%) in these cells compared with the activity of those grown at pH 6.5. This evidence supports the hypothesis that
S. mutans
possesses at least two glucose transport systems, one of which is relatively fluoride insensitive.
Streptococcus mutans
Dextransucrase: Stimulation of Glucan Formation by Phosphoglycerides
Authors: Harlander Susan K. , Schachtele Charles F.
Published: January 2020

Lysophosphatidylcholine (LPC) and other phosphoglycerides stimulated water-insoluble and water-soluble glucan production by the
Streptococcus mutans
6715 dextransucrase (EC 2.4.1.5). LPC stimulated crude extracellular dextransucrase 1.7-fold, the water-insoluble glucan-producing α form of the enzyme 6.5-fold, the water-soluble glucan-producing β form of the enzyme 2.1-fold, and the cell-associated dextransucrase 2.0-fold. Kinetic studies demonstrated that LPC did not change the
K

m

for sucrose of α or β but increased the maximum velocity of the enzymes. The
K

m

for LPC of the α enzyme was 10
−5
M. LPC from various sources and synthetic preparations of lauroyl-LPC, myristoyl-LPC, and palmitoyl-LPC all stimulated glucan formation. Portions of phosphoglyceride molecules including fatty acids, phosphatidic acid, glycerophosphoric acid, glycerophos-phorylcholine, and choline, when tested individually or in combinations, did not enhance dextransucrase activity. The increased rates of glucan production caused by LPC and primer dextran were additive. Enzyme incubated with LPC before addition of sucrose was stimulated by dextran primer, and, conversely, enzyme treated with dextran was stimulated by addition of LPC with the sucrose substrate. Thus, dextransucrase can be activated by binding of intact phosphoglyceride molecules to a site on the enzyme that is distinct from either the glucosyl donor or glucosyl acceptor (primer) binding sites. Interactions between the
S. mutans
dextransucrase and amphipathic phosphoglycerides may explain properties of this enzyme which contribute to the cariogenicity of
S. mutans.
Virulence of Streptococcus mutans: comparison of the effects of a coupling sugar and sucrose on certain metabolic activities and cariogenicity
Authors: Ikeda T , Shiota T , McGhee J R , Otake S , Michalek S M , Ochiai K , Hirasawa M , Sugimoto K
Published: January 2020

A coupling sugar preparation (sucrose-free [CSSF]), which contains a mixture of sugars, oligosaccharides, and oligosaccharides terminated at the reducing end by sucrose, served as a substrate for growth and acid production by Streptococcus mutans 6715. However, CSSF was a poor substrate for cellular aggregation, glucosyltransferase activity, plaque formation, and adherence of cells to glass surfaces. In the presence of sucrose, CSSF inhibited glucosyltransfer activity and adherence of cells. The substitution of CSSF for sucrose in a rat diet significantly reduced caries score. Furthermore, rats fed diets containing sucrose and CSSF had significantly fewer carious lesions than did rats fed a sucrose diet.
Experimental murine candidiasis: pathological and immune responses to cutaneous inoculation with Candida albicans
Authors: Giger D K , Domer J E , McQuitty J T
Published: January 2020

Cutaneous infection of mice with Candida albicans elicited a predominantly acute inflammatory response, stimulated the production of precipitating antibodies, and conferred protection against subsequent intravenous challenge with the same organism. The acute inflammatory skin reaction seen after cutaneous infection suggested a predominantly humoral response to Candida. Animals infected cutaneously a second time with viable C. albicans developed larger skin lesions than animals infected only once, and the twice-infected animals were more resistant to an intravenous challenge as well. The cutaneous inoculation of mice with heat-killed C. albicans was less effective in stimulating antibody production, in eliciting the inflammatory response, and in inducing a protective response demonstrable by intravenous challenge with viable Candida. This model of experimental candidiasis represents a reproducible means of studying a protective immune response to the organism.
Humoral bactericidal systems: antibacterial potential of serum from young animals
Authors: Skarnes R C
Published: January 2020

The antibacterial potential of fresh serum obtained from young animals during a pre-antibody period of development was assessed against two smooth and two rough strains of gram-negative bacteria. The bactericidal capacity of serum from 3- to 4-week-old guinea pigs and 4- to 5-week-old rabbits was compared with that of serum from adults. Serum from young animals was deficient in natural antibodies, and in conventional dilution assays the bactericidal action was unimpressive, especially against the smooth strains. However, when decimal increments of bacteria were incubated in fresh undiluted serum, killing of both smooth and rough strains proved substantial. This finding may have particular meaning in the very young animal when natural antibodies are at ebb: cellular defense mechanisms may function less efficiently at this time and effect a greater reliance on humoral antibacterial systems.
Immunological response to infection with human reovirus-like agent: measurement of anti-human reovirus-like agent immunoglobulin G and M levels by the method of enzyme-linked immunosorbent assay
Authors: Yolken R H , Wyatt R G , Kim H W , Kapikian A Z , Chanock R M
Published: January 2020

The report describes the development of an enzyme-linked immunosorbent assay (ELISA) for the detection of antibodies against the human reovirus-like agent of infantile gastroenteritis (HRVLA). This ELISA system proved to be four times as sensitive as the standard anti-HRVLA fluorescent-antibody assay and ten times as sensitive as the standard anti-HRVLA complement fixation assay. In addition, the ELISA was capable of determining immunoglobulin G (IgG) and IgM subclasses of anti-HRVLA antibody using a single dilution os serum. With this assay, it was discovered that 11 of 21 infected children had anti-HRVLA IgM in their acute sera before the appearance of anti-HRVLA IgG. ELISA is a useful tool in the evaluation of immunological response to HRVLA infection.
Scanning and Transmission Electron Microscopic Study of
Escherichia coli
O15 (RDEC-1) Enteric Infection in Rabbits
Authors: Takeuchi Akio , Inman Lindsey R. , O'Hanley Peter D. , Cantey J. Robert , Lushbaugh William B.
Published: January 2020

RDEC-1 is a piliated strain of
Escherichia coli
that was isolated from and produces diarrhea in rabbits without invading the mucosa or synthesizing one of the classical enterotoxins. Previous histological and fluorescent-antibody studies of RDEC-1 diarrhea revealed an acute inflammatory response and large numbers of RDEC-1 associated with (adhering to) the mucosal surface of the ileum, cecum, and colon. The purpose of the present investigation was to further elucidate the histopathology by scanning (SEM) and transmission (TEM) electron microscopy. SEM revealed aggregates of bacteria on the surface of the gut; their distribution was patchy in the ileum and diffuse in the cecum and colon. Bacteria were in contact with each other and appeared to be closely associated with the epithelial surface. TEM showed that the brush border region of the epithelial cells was found to be in varying stages of degeneration, and the bacteria could not be seen adhering to the mucosal cells unless the brush border was absent. Bacteria were in close contact only with epithelial cells that had lost their brush border. The space between the bacteria and the epithelial cells was 11 nm, and it appeared to be filled, in most cases, with densely stained material. This
E. coli
rarely penetrated epithelial cells, but when it did; it was found in the supranuclear region and never reached the lamina propria. From previous and present studies, it seems probable that RDEC-1 produces diarrhea in rabbits by a mechanism that may be cytotoxic and differs from the classic mechanisms by which
E. coli
produces diarrhea.
Search for latent cytomegalovirus in renal allografts
Authors: Naraqi S , Jackson G G , Jonasson O , Rubenis M
Published: January 2020

Cytomegalovirus (CMV) infection is common after renal transplantation, and cytomegaloviruria occurs in about two-thirds of the recipients. These observations suggest that the allografts may be a site of latent infection with CMV and its reactivation may be the source of viruria. To investigate this possibility, 130 kidney specimens from 85 persons were cultured, and simultaneous explants were made of 63 of them from 50 people. No CMV was received from 33 normal kidney or cadaver donors or from 19 allograft recipients who had no evidence of posttransplantation infection with CMV. The experiment included 37 primary organ explants that yielded no evidence of latent virus. Among 33 allograft recipients with posttransplantation CMV infection, overt infectious virus was isolated from 6 of 57 allograft biopsies. All six positive specimens were from four patients, all of whom had viruria simultaneously. Organ explants from 20 of the recipients with demonstrated postoperative CMV infection, including 13 viruric patients, failed to unmask any latent CMV. Thus, allograft kidneys were infrequently infected with CMV (6%), even in patients with viruria (24%). The kidney parenchyma appears to be an uncommon site of latent CMV infection and may not be the usual source of virus in patients with viruria.
Adult mice as a model for early onset group B streptococcal disease
Authors: Wennerstrom D E , Schutt R W
Published: January 2020

The intravenous inoculation of adult mice with virulent group B streptococci serotype Ia resulted in fulminating sepsis with extensive colonization of the lungs and kidneys. The time course of the infection lasting 24 to 40 h, extensive pulmonary colonization, and resistance of the type Ia organism to phagocytosis in the absence of specific antibody suggest that mice are an appropriate model for the study of early onset streptococcal infection of human neonates.
Toxic activity of Bacillus sphaericus SSII-1 for mosquito larvae
Authors: Myers P , Yousten A A
Published: January 2020

Using larvae of the mosquito Culex pipiens var. quinquefasciatus as a bioassay system, we have verified an earlier proposal that pathogenicity of Bacillus sphaericus SSII-1 is a toxin-mediated rather than an infectious process. Chloroform or ultraviolet-light treatments that decreased the viable count of SSII-1 cells by 4 or 5 logs did not significantly alter the ability of the bacterial cells to kill larvae. Three lines of evidence indicated that toxic activity was not related to sporulation: (i) cells grown in either a complex or a defined medium were toxic at all ages; (ii) when supplemental Mn2+ was excluded from a complex medium, the culture yielded few spores but was of equal toxicity to a culture containing many spores; and (iii) several early blocked oligosporogenous mutants were isolated that had toxic activities comparable to that of the parent. The toxin was shown to be relatively unstable because activity was destroyed by heat and decreased by refrigeration, a freeze-thaw cycle, or two methods of cell breakage. Thin sections of SSII-1 cells did not reveal the presence of any inclusion body that might be related to toxicity.