bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Induced Interferon in Experimental Rhinovirus Infections in Volunteers
Authors: Douglas R. Gordon , Betts Robert F.
Published: January 2020

Nasal administration of an interferon inducer, CP-20,961 (
N, N
-dioctadecyl-
N′, N
′-bis(2-hydroxyethyl)propanediamine), was evaluated in a double-blind, placebo-controlled study of experimental rhinovirus infection in 29 volunteers. Detectable nasal interferon developed in 10 of 15 subjects treated with CP-20,961, and 2 of 14 in the group receiving placebo (
P
< 0.006). Titers of CP-20,961-induced interferon ranged from 10 to 250 international units, concentrations similar to those observed in rhinovirus infections. Ten in the CP-20,961 group and eight in the placebo group became ill (
P
> 0.05). However, mean total sign scores were significantly diminished among CP-20,961-treated subjects as compared with placebo-treated subjects (
P
< 0.025). No significant effect was noted on quantitative virus shedding patterns or neutralizing antibody responses. These findings suggest that such concentrations of induced interferon do not protect against rhinovirus infection, and that factors other than interferon may be important in recovery from rhinovirus infection.
Detection of Nonspecific Resistance to
Listeria monocytogenes
in Rabbits Infected with
Treponema pallidum
Authors: Schell Ronald F. , Musher Daniel M.
Published: January 2020

Several lines of evidence suggest that cell-mediated immunity (CMI) is suppressed in the early stages of infection caused by
Treponema pallidum
and becomes activated at the time that latency is induced. In the studies reported in this paper, rabbits were infected intravenously with
T. pallidum
and subsequently challenged with
Listeria monocytogenes.
Enhanced ability to suppress the growth of
Listeria
was detected in their livers between 3 and 5 weeks after infection with
T. pallidum
, corresponding to the onset and regression of the generalized syphilitic eruption. A second infection of
T. pallidum
4 weeks after the first, at a time when suppression was beginning to wane, prolonged the listericidal activity. These observations support the hypothesis that infection by
T. pallidum
stimulates CMI, which, in turn, may play a role in inducing latency.
Interaction Between
Escherichia coli
and
Shigella flexneri
in the Digestive Tract of “Gnotobiotic” Mice
Authors: Ducluzeau R. , Raibaud P.
Published: January 2020

When a strain of
Shigella flexneri
and then a strain of
Escherichia coli
were implanted at an interval of 1 day in the digestive tract of germfree mice, the
S. flexneri
was eliminated in 8 days. However, when
S. flexneri
was mono-associated with germfree mice in the absence of
E. coli
, a population of
S. flexneri
appeared which was resistant to the antagonistic effects of
E. coli
in vivo. The emergence of this population appeared to be a stepwise process, extending over a period of 3 months. The interaction between
S. flexneri
and
E. coli
in vivo and in vitro was significantly different in that the
Shigella
capable of coexisting with
E. coli
in the digestive tract was suppressed by that organism in vitro.
Leukocytosis-Promoting Factor of
Bordetella pertussis
III. Its Identity with Protective Antigen
Authors: Sato Yuji , Arai Hideo , Suzuki Kenji
Published: January 2020

Leukocytosis-promoting factor (LPF) was purified from the supernatant of a 5-day liquid culture of
Bordetella pertussis
strains Tohama and no. 134. The preparations appeared to be filamentous molecules (2 by 40 nm) and contained histamine-sensitizing and hemagglutinin activities in addition to leukocytosis-promoting activity. Active protection tests in mice demonstrated strong protective activities of 80 international protective units per mg of protein in LPF preparations of each strain toxoided by mild Formalin treatment. Passive protection tests in mice with anti-LPF sera indicated that anti-LPF is one of the protective antibodies.
Anti-Cardiolipin and Anti-Phosphatidylglycerol Antibodies Prepared Against Bacterial Phospholipids
Authors: DeSiervo August J.
Published: January 2020

Anti-phosphatidylglycerol and anti-cardiolipin antisera were prepared in rabbits by using phospholipids purified from
Micrococcus lysodeikticus
. Anti-phosphatidylglycerol antibodies were found in antisera when either phosphatidylglycerol or cardiolipin were used as immunogens, but adsorption studies indicated they were not similar. Antibodies which reacted with phosphatidylinositol and phosphatidic acid were also found in the anti-cardiolipin antiserum. Structures of the antigenic groups in phosphatidylglycerol and cardiolipin are suggested from cross-reaction and adsorption studies. Adsorption studies with pure phospholipid antigens indicated the importance of the spacial orientation of phospholipid haptens for immunological reactivity.
Prolonged Allograft Survival In Newcastle Disease Virus-Treated Mice
Authors: Woodruff Jack F. , Woodruff Judith J.
Published: January 2020

There was persistent lymphocytopenia and prolonged survival of C57Bl skin allografts when recipient BALB/c mice were injected daily with Newcastle disease virus.
Isolation of Substances Responsible for Lymphokine Activity from Sensitized Mouse Spleen Cells
Authors: Sandok P. L. , Hinsdill R. D. , Albrecht R. M.
Published: January 2020

Cultures of brucella-sensitized mouse spleen cells exposed to
Brucella abortus
antigens in vitro release macrophage migration inhibition factor (MIF) and macrophage spreading factor. Subjecting the supernatants from such cultures to preparative scale electrophoresis in acrylamide gel yields several fractions, one of which contains both MIF and macrophage spreading factor. This material has properties attributable to guinea pig MIF: it is nondialyzable, heat stable, nontoxic to macrophages from heterologous murine donors, and has a greater anodal electrophoretic mobility than guinea pig serum albumin. Another fraction from the gel column inhibits macrophage spreading; its electrophoretic mobility is similar to that of guinea pig gamma globulin. Neither brucella antigen nor skin reactive substances were detectable in any acrylamide gel column fraction when tested by the mouse footpad induration assay technique.
Bacterial Clearance and Endocarditis in American Opossums
Authors: Musher Daniel M. , Richie Yvonne
Published: January 2020

The American opossum is the only experimental animal that regularly develops bacterial endocarditis spontaneously. There was no relation between the ability of opossums to clear bacteria from the bloodstream and the subsequent development of endocarditis.
Specific and Nonspecific Cell-Mediated Resistance to Influenza Virus in Mice
Authors: Shayegani Mehdi , Lief Florence S. , Mudd Stuart
Published: January 2020

We found that influenza virus had the capacity to replicate in the peritoneal macrophages of normal mice, as revealed by the development of hemadsorption and the appearance intracellularly of S and V antigens. Cell-mediated resistance was studied in mice infected with influenza virus or a bacterial sytem of induction-elicitation. In the homologous system, mice were injected intraperitoneally or exposed by aerosol to a sublethal dose of an egg-adapted swine strain of influenza virus. In the heterologous system, they were infected repeatedly with
Staphylococcus aureus
and elicited by subcutaneous or aerosol administration of staphylococcal antigens. The peritoneal macrophages from mice specifically or nonspecifically immunized were significantly more resistant than those from normal mice. Also longer survival to in vivo challenge by the mouse-adapted virus, as compared with normal mice, was indicated in bacterially stimulated mice.
Cation-binding Capacity of Membranes Isolated from
Micrococcus lysodeikticus
Authors: Cutinelli C. , Galdiero F. , Tufano M. A.
Published: January 2020

A study was made of H
+
, Na
+
, K
+
, Ca
++
, and Mg
++
binding and ion-exchange properties of the plasma-mesosome membrane system isolated from
Micrococcus lysodeikticus
strain NCTC 2665. Titration curves were obtained on membranes prepared according to the method of M. R. J. Salton and further exposed to
p
H 4 for 4 hr (membranes-H). The dissociation coefficients and binding capacities were obtained by applying the mass law equation and the plot of G. Schatchard to the data. The membranes-H possess four kinds of dissociable groups with
p
K 4.96, 4.18, 3.60, and 3.09, respectively, and a total binding capacity of 0.65 meq/g (dry weight). Potentiometric titrations of cations in the presence and in the absence of membranes-H show that cations (Na
+
, K
+
, Ca
++
, and Mg
++
) are bound by the dissociated groups of the membrane. The fall in
p
H value for bivalent cations is greater than that for monovalent cations. Cations of the same valency produce equal diminutions on
p
H. Furthermore, ion-exchange tests carried out on membranes saturated with Mg
++
or Na
+
and suspended in a medium containing
45
Ca show that the cations are reversibly bound.
Mutants of
Escherichia coli
with an Altered Tyrosyl-Transfer Ribonucleic Acid Synthetase
Authors: Schlesinger Sondra , Nester Eugene W.
Published: January 2020

We have isolated several mutants defective in the gene for tyrosyl-transfer ribonucleic acid (tRNA) synthetase (
tyrS
). One of these mutants is described in detail. It was isolated as a tyrosine auxotroph with defects both in the tyrosyl-tRNA synthetase and in the tyrosine biosynthetic enzyme, prephenate dehydrogenase. It also had derepressed levels of the tyrosine-specific 3-deoxy-
d
-arabinoheptulosonic acid-7-phosphate (DAHP) synthetase. The latter finding suggested that a wild-type
tyrS
gene was required for repression of the tyrosine biosynthetic enzymes. The following results demonstrated that this hypothesis was not correct. (i) When the defective
tyrS
gene was transferred to another strain, the tyrosine-specific DAHP synthetase in that strain was not derepressed, and (ii) two other mutants with defective tyrosyl-tRNA synthetases had repressed levels of the tyrosine biosynthetic enzymes. The
tyrS
gene was located near minute 32 on the
Escherichia coli
chromosome by interrupted mating experiments.
Immunochemistry of a Formamide-extracted Antigen from
Clostridium perfringens
Cell Walls
Authors: Johnson Howard M. , Brenner Kristen , Hall Herbert E.
Published: January 2020

The type-specific antigen of a strain of
Clostridium perfringens
involved in food poisoning was isolated from the cell wall by the use of hot formamide. The antigen appears to consist of polysaccharide or mucopeptide. The formamide extract was shown to be heterogeneous by gel filtration on Sephadex G-200. The serologically active fraction contained about 25% of the amount of protein present in the original formamide extract. Hexosamine, acetyl groups, and carbohydrate also were detected. The formamide extract showed a high degree of serological activity. The serological activity was increased twofold on Sephadex gel filtration.
Purified Protoplasmic Peptides of Mycobacteria: Isolation of Species-Specific Peptides from Protoplasm of Mycobacteria
Authors: Beam R. E. , Stottmeier K. D. , Kubica G. P.
Published: January 2020

Infections with mycobacteria other than tubercle bacilli are responsible for a variable percentage of cross-reactions to tuberculin. Two major suggestions for circumventing this problem have been made: the first, development of a quantitative tuberculin test, is based on the fact that most cross-reactions are smaller than those caused by true tuberculous infections; the second, preparation of purified skin test antigens from other mycobacteria, is based on the hope that greater specificity will be displayed by homologous sensitin. Effort so far has been focused on the culture filtrates as the source of antigen. This article describes the preparation of low molecular weight purified protoplasmic peptides (PPP) of specificity and sensitivity superior to purified protein derivatives.
Purified Protoplasmic Peptides of Mycobacteria: In Vivo and In Vitro Comparison of the Species Specificity of Purified Protoplasmic Peptides and Purified Protein Derivatives of Mycobacterial Culture Filtrates
Authors: Stottmeier K. D. , Beam R. E. , Kubica G. P.
Published: January 2020

The specificity of purified protein derivatives (PPD) prepared from the culture filtrates of
Mycobacterium tuberculosis
(PPD),
M. kansasii
(PPD-Y),
M. intracellulare
(PPD-B), and
M. scrofulaceum
(PPD-G) were compared to comparable protoplasmic extracts (PPP) of the same organisms by gel diffusion and delayed hypersensitivity reactions in sensitized guinea pigs. PPD and, to a lesser degree, PPD-Y demonstrated specificities sufficient to enable identification of homologously sensitized guinea pigs in the above group of four mycobacteria. PPD-B and PPD-G did not always elicit the largest reaction in homologously sensitized animals. The PPP sensitins from
M. tuberculosis
and
M. kansasii
produced as good skin reactions at 24 and at 48 hr as did their PPD counterparts. The PPP from
M. scrofulaceum
and
M. intracellulare
were more specific and more reactive than corresponding PPD, regardless of the time of comparison. Although based on different immunological mechanisms, the specificity of these two groups of sensitins, as demonstrated by delayed hypersensitivity, correlated well with serological comparisons in the gel diffusion test. The low degree of specificity of PPD-B and PPD-G in contrast to that of corresponding PPP was reflected in the precipitin bands in agar gel.
Evolution of a Site of Specific Genetic Homology on the Chromosome of
Escherichia coli
Authors: Kahn Phyllis L.
Published: January 2020

Integration of the factors F
v
and F into the chromosome of a substrain of
Escherichia coli
K-12 has been studied. The F
v
factor is a fertility factor derived from Col V, lacking the ability to govern the production of colicin V. The derivatives of an Hfr
v
(Hfr isolated from a V colicinogenic parent) strain, PK2 (initially isolated from C600 V
+
), were shown to retain a unique bidirectional sex factor affinity locus between
recA
and
pheA
. This site shows no affinity for the
E. coli
K-12 F factor as shown by inability to isolate Hfr strains with origins in this region from a parental strain containing a cytoplasmic F factor. However this area exhibits two regions of homology to the V colicinogenic factor. One gives rise to Hfr
v
strains identical to the original Hfr
v
strain, PK2, with an origin and polarity of transfer designated
pheA
-CC injecting markers in the order
pheA-his-trp-pro
. The second gives rise to strains apparently originating at the same site but with reverse polarity designated
recA
-C, transferring markers in the order
recA-thyA-str-xyl
. For strains possessing the F
v
factor only the second homology is apparent. A model for the evolution of these strains is presented.
Synthesis of Bacterial Flagella: Chromosomal Synchrony and Flagella Synthesis
Authors: Van Alstyne D. , Grant G. F. , Simon M.
Published: January 2020

Synchronous cultures of
Bacillus subtilis
168 M were obtained from light-density spores germinated at 46 C and grown at 37 C. This procedure synchronizes both cell division and chromosome replication. The chromosome synchrony was demonstrated by using transformation to measure changes in marker frequency during the cell cycle. The synthesis of two enzymes and of bacterial flagellar protein was also followed. All of the proteins were found to be synthesized continuously with an abrupt doubling in the rate of synthesis at a specific time in the cell cycle. The time at which the doubling occurred for each enzyme corresponded to the time at which the structural gene for the enzyme was replicated. The doubling of the rate of flagella synthesis corresponded to the time of replication of the
hisA1
gene. We conclude that the genetic locus for the factors involved in the rate-limiting steps in flagella synthesis are located on the genetic map near the
hisA1
locus.
New Methionine Structural Gene in
Salmonella typhimurium
Authors: Childs J. D. , Smith D. A.
Published: January 2020

Eight
metH
mutants in
Salmonella typhimurium
with closely linked sites of mutation which could grow only on methionine were isolated from a
metE
mutant deficient in
N
5
-methyltetrahydropteroyltriglutamate-homocysteine transmethylase; their deficiency in cobalamin-dependent
N
5
-methyltetrahydrofolate-homocysteine transmethylase was supported by the results of enzyme studies of one of them. Cotransduction of
metH
and
metA
(homoserine
O
-transsuccinylase) mutants was obtained, thus revealing linkage between a second pair of the six known methionine structural genes. One
metH
mutant clearly differed from the rest in that it reverted at a higher frequency, was temperature sensitive, complemented all other
metH
mutants, and was located farthest from the
metA
gene.
Spontaneously Occurring Bacterial Transformations in Mice
Authors: Ottolenghi-Nightingale Elena
Published: January 2020

In 1963, it was reported that deoxyribonucleic acid (DNA)-mediated transformations could take place spontaneously between genetically distinguishable pneumococci growing in a living host, the mouse. It was found in the present study that such transformations could be increased in frequency if infected animals were treated with a drug which kills only one of the two infecting strains. The frequency of in vivo transformations was also increased if the infection was prolonged. Interspecific transformation between pneumococci and streptococci without the addition of purified DNA was demonstrated both in vitro and in vivo. These results make it seem more likely that DNA-mediated transformations occur in nature.
Violagabriellae Variant ofStaphylococcus epidermidison Normal Human Skin
Authors: Marples R. R.
Published: January 2020

Twenty-seven strains of a reddish violet pigment-producing variety ofStaphylococcus epidermidishave been recovered from normal human skin. They closely resemble the previously unique Castellani strain, namedMicrococcus violagabriellae, which was placed by K. J. Steel inS. epidermidis. These strains are classified asS. epidermidisby using the Baird-Parker schema; however, besides the pigment produced, they also differ fromS. epidermidisin proteolytic activity and effect on litmus milk. The variety seems to be part of the normal flora of the human axilla.
Leukocyte Bactericidal Activity in Chronic Granulomatous Disease: Correlation of Bacterial Hydrogen Peroxide Production and Susceptibility to Intracellular Killing
Authors: Mandell Gerald L. , Hook Edward W.
Published: January 2020

Susceptibility of bacteria to intracellular killing by polymorphonuclear leukocytes from a patient with chronic granulomatous disease could be correlated with bacterial hydrogen peroxide production.
Folate Reductase and Specific Dihydrofolate Reductase Activities of the Amethopterin-Sensitive
Streptococcus faecium
var.
durans
Authors: Albrecht Alberta M. , Hutchison Dorris J.
Published: January 2020

Preliminary evidence is presented that indicates that the dihydrofolate reductase activity of amethopterin-sensitive
Streptococcus faecium
var.
durans
ATCC 8043 is separable into two dihydrofolate reductases, one of which also reduces folate.
Active and Passive Immunization in the Adult Rabbit Ileal Loop Model as an Assay for Production of Antitoxin Immunity by Cholera Vaccines
Authors: Mosley Wiley H. , Ahmed Ansaruddin
Published: January 2020

Three field trial cholera vaccines did not induce antitoxic immunity. A choleragenic toxin induced high-serum neutralizing antibody, but protection to loop challenge with toxin was minimal.
Effect of Endotoxin on the Serum Ribonuclease Activity in Rats
Authors: Kutas Vera , Bertök L. , Szabö L. D.
Published: January 2020

The effects of endotoxin shock, endotoxin tolerance, and lead acetate plus a minute amount of endotoxin on the serum ribonuclease activity of rats was measured. Changes in serum ribonuclease activity after various entoxin treatments could be a primary effect or a secondary effect of the damaging effect of endotoxin.
Granuloma Formation Induced in Mice by Chemically Defined Mycobacterial Fractions
Authors: Bekierkunst A. , Levij I. S. , Yarkoni E. , Vilkas E. , Adam A. , Lederer E.
Published: January 2020

Amounts of trehalose-6,6-dimycolate as small as 1 to 5 μg can, after intravenous injection, induce in the lungs of mice formation of tubercles in which the cellular composition is indistinguishable from that in tubercles formed after an infection with living BCG bacilli. The strongest cellular response in mice was induced by cord factor from
Mycobacterium kansasii;
the weakest was induced by cord factor from the BCG strain of
M. bovis
. It was found that three intravenous injections of cord factor induced a more extensive cellular response than did one injection of the same total amount of cord factor. Mice treated intravenously with cord factor were protected against an intravenous challenge with the virulent H37Rv strain of
M. tuberculosis
. The cellular response in the lungs of mice to intraperitoneal injections of living BCG and cord factor was very weak compared with that after intravenous injections. Intraperitoneal vaccination of mice with cord factor did not protect the mice against a challenge with virulent tubercle bacilli. Mice vaccinated intraperitoneally with BCG were immunized although no granulomas, or very few, were present in the lungs at the time of the challenge. The significance of the cellular response induced by cord factor is discussed.
Dominance of Ultraviolet Radiation Resistance in Partial Diploids of
Escherichia coli
K-12
Authors: Uretz Robert B. , Markovitz Alvin
Published: January 2020

Although an F′13
cap
R
+
/
cap
R9 strain is nonmucoid and an F′13
cap
R9/
cap
R
+
strain is mucoid, both strains are ultraviolet (UV)-resistant. In contrast, haploid
cap
R9 strains are UV-sensitive. Therefore, UV resistance is dominant to UV sensitivity, regardless of whether the
cap
R
+
allele is on the chromosome or on the F′13 episome.
Regulation of Biotin Transport in
Saccharomyces cerevisiae
Authors: Rogers Thomas O. , Lichstein Herman C.
Published: January 2020

The metabolic control of biotin transport in
Saccharomyces cerevisiae
was investigated. Nonproliferating cells harvested from cultures grown in excess biotin (25 ng/ml) took up small amounts of biotin, whereas cells grown in biotin-sufficient medium (0.25 ng/ml) accumulated large amounts of the vitamin. Transport was inhibited maximally in cells grown in medium containing 9 ng (or more) of biotin per ml. When avidin was added to biotin-excess cultures, the cells developed the ability to take up large amounts of biotin. Boiled avidin was without effect, as was treatment of cells with avidin in buffer. Avidin did not relieve transport inhibition when added to biotin-excess cultures treated with cycloheximide, suggesting that protein synthesis was required for cells to develop the capacity to take up biotin after removal of extracellular vitamin by avidin. Cycloheximide did not inhibit the activity of the preformed transport system in biotin-sufficient cells. The presence of high intracellular free biotin pools did not inhibit the activity of the transport system. The characteristics of transport in biotin-excess cells (absence of temperature or
p
H dependence, no stimulation by glucose, absence of iodoacetate inhibition, independence of uptake on cell concentration, and nonsaturation kinetics) indicated that biotin entered these cells by diffusion. The results suggest that the synthesis of the biotin transport system in
S. cerevisiae
may be repressed during growth in medium containing high concentrations of biotin.
Genetic and Molecular Properties of an Infectious Antibiotic Resistance (R) Factor Isolated from
Klebsiella
Authors: Iyer Rajul V. , Iyer V. N.
Published: January 2020

A
Klebsiella
strain of human origin that was resistant to ampicillin, chloramphenicol, kanamycin, neomycin, streptomycin, and tetracycline was found to have all of these resistances associated with a R factor and a satellite molecular species of deoxyribonucleic acid (DNA) with an average buoyant density of 1.710 in cesium chloride gradients. There was no evidence of the existence of DNA with other buoyant densities. The strain bears two separable mutations for chloramphenicol resistance, both of which are associated with the R factor (KR9). Exposure of the
Klebsiella
strain to acridine derivatives or to ethidium bromide (which was more efficient) resulted in partial losses of resistance accompanied by the disappearance of the satellite DNA peak or shifts in its density. The R factor and its component genes were conjugally transmitted across generic boundaries and maintained in new hosts with different efficiencies. The basis of this difference lies not only in the efficiency of conjugal transfer but also in the stability of the components after transfer. All of the resistance genes and the resistance transfer factor were cotransducible by phage Plkc from
Escherichia coli
. Partially resistant strains could be reconstituted to full resistance or to a recombined pattern of partial resistance by conjugation with donors having complementary resistance patterns. This recombination serves as an efficient mechanism for rescuing superinfecting genes that are otherwise intracellularly excluded. KR9 is an
fi
+
type of R factor which in the natural state does not appear to be as repressed in conjugal transfer as other R factors.
Erythritol Metabolism in Wild-Type and Mutant Strains of
Schizophyllum commune
Authors: Braun M. L. , Niederpruem D. J.
Published: January 2020

Erythritol uptake and metabolism were compared in wild-type mycelium and a
dome
morphological mutant of the wood-rotting mushroom
Schizophyllum commune
. Wild-type mycelium utilized glucose, certain hexitols, and pentitols including ribitol, as well as
d
-erythrose, erythritol, and glycerol as sole carbon sources for growth. The
dome
mutant utilized all of these compounds except
d
-erythrose and erythritol. Erythritol- or glycerol-grown wild-type mycelium incorporated erythritol into various cellular constituents, whereas glucose-grown cells lagged considerably before initiation of erythritol uptake. This acquisition was inhibited by cycloheximide.
Dome
mycelium showed behavior similar to wild-type in uptake of erythritol after growth on glucose or glycerol, except that erythritol was not further catabolized. Enzymes of carbohydrate metabolism were compared in cell extracts of glucose-cultured wild-type mycelium and
dome
. Enzymes of hexose monophosphate catabolism, nicotinamide adenine dinucleotide (NAD)-dependent sugar alcohol dehydrogenases, and reduced nicotinamide adenine dinucleotide phosphate (NADPH)-coupled erythrose reductase were demonstrated in both. The occurrence of erythrose reductase was unaffected by the nature of the growth carbon source, showed optimal activity at
p
H 7, and generated NAD phosphate and erythritol as products of the reaction. Glycerol-,
d
-erythrose-, or erythritol-grown wild-type mycelium contained an NAD-dependent erythritol dehydrogenase absent in glucose cells. Erythritol dehydrogenase activity was optimal at
p
H 8.8 and produced erythrulose during NAD reduction. Glycerol-growth of
dome
mycelium induced the erythritol uptake system, but a functional erythritol dehydrogenase could not be demonstrated. Neither wild-type nor
dome
mycelium produced erythritol dehydrogenase during growth on ribitol. Erythritol metabolism in wild-type cells of
S. commune
, therefore, involves an NADPH-dependent reduction of
d
-erythrose to produce erythritol, followed by induction of an NAD-coupled erythritol dehydrogenase to form erythrulose. A deficiency in erythritol dehydrogenase rather than permeability barriers explains why
dome
cannot employ erythritol as sole carbon source for mycelial growth.
Adsorption of
3
H-Fatty Acid Esters of Streptococcal Groups A and E Cell Wall Polysaccharide Antigens by Red Blood Cells and Their Effect on Hemagglutination
Authors: Pavlovskis Olgerts , Slade Hutton D.
Published: January 2020

The streptococcal group A and E cell wall polysaccharide (PS) antigens were esterified under identical conditions with four fatty acid chlorides (lauroyl, myristoyl, palmitoyl, and stearoyl), varying from 12 to 18 carbon atoms. With group A PS, it was shown that the four resulting esters varied in their ability to sensitize red blood cells (RBC) to agglutination in the presence of specific antiserum. The most active was palmitoyl (16C) followed by myristoyl (14C). The least active was the lauroyl ester (12C). One-tenth as much palmitoyl ester was required as stearoyl group A PS ester. Such variation in the ability to sensitize RBC was not demonstrated with the group E esters, with the exception of the lauroyl ester which was the least active. Removal of
N
-acetylglucosamine from the esterified and the nonesterified group A PS by enzyme action resulted in a significant loss of serological activity of both antigens. No appreciable difference in the rate or total loss of activity was found in either case. It was demonstrated that both tritium-labeled stearic and palmitic acids and their respective PS esters were adsorbed in significant amounts to RBC. The results indicate that the esterified antigens were adsorbed to the RBC because of the presence of the fatty acid in the PS ester. Attempts to block the receptor sites on the red cell by presensitizing the cells with fatty acid were negative. Likewise, the adsorbed ester did not prevent the uptake of fatty acid at the levels tested. Tritium-labeled esterified group A PS and group E PS were used to show that the amount of antigen required to produce maximal agglutination was the same when cells from the same individual were used, whereas this was not the case when cells from different individuals were used. The amount of antigen required to produce maximal agglutination varied from one batch of sheep RBC to another. Once the optimal concentration of antigen was reached, any additional adsorption did not increase the titer of agglutination.
Properties of a Novel Pleiotropic Bacteriophage-Resistant Mutant of
Staphylococcus aureus
H
Authors: Chatterjee Anadi N. , Mirelman David , Singer Howard J. , Park James T.
Published: January 2020

A phage-resistant mutant of
Staphylococcus aureus
H (Sm
R
),
S. aureus
52A5, was previously shown to lack polymeric teichoic acid. This paper characterizes other phenotypic differences between the strains. In broth cultures the mutant cells grew more slowly, were larger, and formed much larger clumps than the parent strain. The clumps of cells appeared to be covalently linked and could only be separated by mild sonic energy—a process which yielded viable cells. Mutant and parent cells autolyzed at equal rates, whereas isolated cell walls of the mutant strain autolyzed faster than the wild type. Nevertheless, the specific activity of the autolytic enzyme in the wild type soluble fraction was much higher than in the mutant. In contrast to the parent, strain 52A5 failed to accumulate nucleotide-bound murein precursors when treated with penicillin. Mutant strains with these characteristics were repeatedly isolated both spontaneously and by chemical mutagenesis. Strain 52A5 was shown to be fully revertible. Thus, it appears to be a pleiotropic mutation, and the possible nature of the defect which causes these varied effects is discussed.
Bicomponent Nature of Lysin from
Streptococcus zymogenes
Authors: Granato Paul A. , Jackson Robert W.
Published: January 2020

Nonlytic mutants of
Streptococcus zymogenes
X-14 were isolated after exposure to nitrosoguanidine. Cross-streaking of certain of these mutants on brain Heart Infusion (BHI) blood agar plates resulted in formation of spur-shaped zones of hemolysis at the junction of the two streaks. Two types of mutants were recognized. Both of these excreted into the medium substances which are nonlytic but which together produce lytic activity. These substances behaved as an enzyme with an activator. Hence, one mutant type appeared to produce an activator and the other the catalytic molecule. Active complexes were temperature-sensitive and were inhibited by some teichoic acids as is the parental type of lysin.
Effect of Inhibitors on Phenoloxidase of
Mycobacterium leprae
Authors: Prabhakaran K. , Harris E. B. , Kirchheimer W. F.
Published: January 2020

Previous results had shown that the human leprosy bacilli possess a phenoloxidase, which, when compared with the enzyme from mammalian and plant sources, seemed unique in the range of substrates utilized and in the nature of the products formed. The effect of several inhibitors on the enzyme in
Mycobacterium leprae
was tested. Compounds which bind copper were found to be more effective than substrate analogues. Diethyldithiocarbamate penetrated the bacillus and completely suppressed its phenolase activity. Diasone (a derivative of diaminodiphenylsulfone used in the treatment of leprosy) proved to be a potent inhibitor of phenoloxidase of mammalian and plant origin. However, it was less efficient in the case of
M. leprae
. A biochemical peculiarity of
M. leprae
was observed in its ability to metabolize mimosine and penicillamine. These compounds produced total inhibition of tyrosinase in melanoma extract and of mushroom tyrosinase. Nontoxic inhibitors of phenoloxidase in the leprosy bacilli may be of value in developing a rational approach to chemotherapy of the disease.
Isocitrate Dehydrogenase and Glutamate Synthesis in
Acetobacter suboxydans
Authors: Greenfield Seymour , Claus G. W.
Published: January 2020

Acetobacter suboxydans
is an obligate aerobe for which an operative tricarboxylic acid cycle has not been demonstrated. Glutamate synthesis has been reported to occur by mechanisms other than those utilizing isocitrate dehydrogenase, a tricarboxylic acid cycle enzyme not previously detected in this organism. We have recovered α-ketoglutarate and glutamate from a system containing citrate, nicotinamide adenine dinucleotide (NAD), a divalent cation, pyridoxal phosphate, an amino donor, and dialyzed, cell-free extract. Aconitase activity was readily detected in these extracts, but isocitrate dehydrogenase activity, measured by NAD reduction, was masked by a cyanide-resistant, particulate, reduced NAD oxidase. Isocitrate dehydrogenase activity could be demonstrated after centrifuging the extracts at 150,000 ×
g
for 3 hr and treating the supernatant fluid with 2-heptyl-4-hydroxyquinoline
N
-oxide. It is concluded that
A. suboxydans
can utilize the conventional tricarboxylic acid cycle enzymes to convert citrate to α-ketoglutarate which can then undergo a transamination to glutamate.
Sulfur-Deficient Transfer Ribonucleic Acid in a Cysteine-Requiring, “Relaxed” Mutant of
Escherichia coli
Authors: Harris Charles L. , Titchener Edward B. , Cline Athol L.
Published: January 2020

A cysteine-requiring mutant of the parent strain
Escherichia coli
Hfr Cavalli (RC
rel
, Met
−
, λ) has been isolated. The mutant was selected by using replica plating after mutagenesis by
N
-methyl-
N
′-nitro-
N
-nitrosoguanidine. The mutation appears to be in the gene for sulfite reductase, since the mutant could utilize sulfide but not sulfite as a sulfur source. The mutant was found to be RC
rel
with respect to both methionine and cysteine. During cysteine starvation, transfer ribonucleic acid (tRNA) deficient in 4-thiouracil was produced, and in vivo studies indicate that this tRNA can accept sulfur groups to a greater extent than normal tRNA. Further, there were differences both in the rate and extent of amino acid acceptance between normal and sulfur-deficient tRNA. This suggests that thionucleotides are involved in at least one of the biological functions of the tRNA molecule.
Fine Structure ofVibrio choleraeDuring Toxin Production
Authors: Kennedy John R. , Richardson Stephen H.
Published: January 2020

The fine structural changes associated with cell growth and toxin production have been examined inVibrio choleraestrain 569B. No morphological alterations in the cell envelope are apparent during logarithmic growth with thin-section techniques. However, internal swelling, suggesting alteration of cell envelope permeability, is evident particularly during the late logarithmic and early stationary phases of growth. Certain extracellular material demonstrable with negative-stain techniques does appear during the period of toxin production. The possible origin of this material is discussed. The effects of high temperature (37 C) and aeration on cell structure are also examined.
Effect of Low
p
H on Thiomethyl-β-
d
-Galactoside Uptake by
Streptococcus lactis
Authors: Desai Pragna D. , Goldner M.
Published: January 2020

Maximal β-galactosidase activity in
Streptococcus lactis
was obtained at
p
H 7, but the maximal rate of thiomethyl-β-
d
-galactoside uptake was observed at
p
H 3.6 to 4. It is concluded that the decrease in β-galactosidase activity in intact cells at lowered
p
H is not due to diminished transport of β-galactoside.
Replacement Sporulation of
Bacillus subtilis
168 in a Chemically Defined Medium
Authors: Ramaley Robert F. , Burden Linda
Published: January 2020

A replacement sporulation technique (i.e., the sporulation of vegetative cells upon suspension in an appropriate medium) has been developed for
Bacillus subtilis
168 (a transformable Marburg strain of
B. subtilis
). The replacement sporulation medium used is composed of inorganic salts and 10 m
m
ammonium lactate or glutamate. The requirement for ammonium lactate or glutamate could also be satisfied by other compounds that are metabolized via the tricarboxylic acid cycle. Sporulation of the suspended vegetative cells was completed by 8 to 10 hr after suspension, and the resulting spores were indistinguishable from spores produced in a conventional growth and sporulation medium. Various physiological changes previously reported to be associated with sporulation (e.g., increase in the level of tricarboxylic acid cycle enzymes and changes in the rates of synthesis of deoxyribonucleic acid, ribonucleic acid, and protein) could also be demonstrated during replacement sporulation.
Fatty Acid Composition of Lipid Extracts of a Thermophilic
Bacillus
Species
Authors: Daron Harlow H.
Published: January 2020

Fatty acids having 16 or 17 carbon atoms accounted for over 80% of the fatty acids produced by a thermophilic
Bacillus
species. Under most conditions, branched-chain fatty acids were more abundant than normal fatty acids. The proportion of unsaturated fatty acids varied inversely with the growth temperature and was never greater than 14%. When acetate was used as a carbon source, the percentage of fatty acids having 15 or 17 carbon atoms was about twice that found when glucose was used as a carbon source. Increasing the growth temperature from 40 to 60 C resulted in a three-to fourfold increase in the ratio of the normal to branched-chain hexadecanoic acids. Two normal hexadecenoic acids were found and their relative abundance was influenced by the growth temperature.
Resistance of
Escherichia coli
to Penicillins VII. Purification and Characterization of a Penicillinase Mediated by the R Factor R1
Authors: Lindqvist R. Christer , Nordström Kurt
Published: January 2020

The penicillinase mediated by the R factor R1 in
Escherichia coli
has been purified and characterized. The purification procedure contained the following three steps: spheroplast formation, chromatography of the spheroplast supernatant fluid on DEAE cellulose, and preparative polyacrylamide-gel electrophoresis. The protein obtained gave only one band in analytical polyacrylamide-gel electrophoresis. To obtain milligram quantities of the enzyme, gel filtration on Sephadex G75 was run before the last step in the purification. By gel filtration on Sephadex G75, the molecular weight was estimated as 22,000. The
p
H optimum, tested in universal buffer, was 7.0. The turnover numbers for benzylpenicillin,
d
-ampicillin, and 6-aminopenicillanic acid were 4.2 × 10
4
, 6.3 × 10
4
, and 2.2 × 10
4
moles of substrate hydrolyzed per min by 1 mole of enzyme, whereas the Michaelis constants were 100, 160, and 440 μ
m
, respectively. Cephalosporins were much poorer substrates for the R1 penicillinase than were the penicillins. The turnover number for cephalosporin C, cephaloridine, and 7-amino-cephalosporanic acid were 2.4 × 10
3
, 5 × 10
2
, and less than 2 × 10
2
, respectively. These properties show that the R1 penicillinase is quite different from the chromosomally mediated penicillinase of
E. coli
(11). However, the R1 enzyme resembles another R-factor penicillinase previously purified by Richmond and Datta.
Electron Microscopic Observations on the Effects of Penicillin on the Morphology ofChlamydia psittaci
Authors: Matsumoto A. , Manire G. P.
Published: January 2020

L cells were infected at high multiplicity with meningopneumonitis organisms and incubated in medium containing 200 units per ml of penicillin. At intervals up to 48 hr after infection, cells were removed and thin sections were prepared for electron microscopic studies on the morphology of the developing organism. Penicillin had no effect on the initial reorganization of the infecting elementary body to form the developmental reticulate body (RB), and, up to 12 hr after infection, the treated and untreated cultures were identical. After that time, however, penicillin-treated organisms showed striking differences in that binary fission was prevented, large abnormal RB forms were seen in great numbers, masses of RB cytoplasmic membranes and envelopes were formed within and outside the RB itself, and large numbers of empty or partially filled small vesicles were pinched off the RB. After 36 hr immature nucleoids were formed within the RB. Throughout all of this period, both the outer cell envelope and the cytoplasmic membrane of these RB were recognized. When infected cells were transferred into penicillin-free medium, the abnormal RB showed recovery to form normal RB both by a budding-like process and by internal fragmentation or subdivision rather like endosporulation. We have concluded that penicillin inhibits binary fission and prevents the synthesis of certain components essential for the formation of the elementary body envelope.
2,4-Diaminovaleric Acid: an Intermediate in the Anaerobic Oxidation of Ornithine by
Clostridium sticklandii
Authors: Dyer John K. , Costilow Ralph N.
Published: January 2020

The oxidation of ornithine in the presence of proline by crude extracts of
Clostridium sticklandii
cells was stimulated by nicotinamide adenine dinucleotide, coenzyme A, α-ketoglutarate, dimethylbenzimidazolyl cobamide (DBC) coenzyme, MgCl
2
, and adenosine diphosphate. Deletion of various cofactors resulted in the accumulation of a new dibasic amino acid which was identified as 2,4-diaminovaleric acid. Both the oxidation of ornithine to alanine and acetate and the conversion of ornithine to 2,4-diaminovaleric acid were stimulated by addition of DBC coenzyme, and both were inhibited by intrinsic factor, an inhibitor of cobamide coenzyme-dependent reactions. This inhibition was reversed by addition of DBC coenzyme. However, the oxidation of 2,4-diaminovaleric acid was insensitive to added intrinsic factor. The data indicate that 2,4-diaminovaleric acid represents the first intermediate in the oxidation of ornithine by
C. sticklandii
.
Lipids of
Bacteroides melaninogenicus
Authors: Rizza Victor , Tucker Anne N. , White David C.
Published: January 2020

The lipids of
Bacteroides melaninogenicus
were readily extractable with chloroform-methanol. Three per cent of the fatty acids were not extractable. The neutral lipids contained 4% of the extractable fatty acids, the stench characteristic of these organisms, and 0.5 μmole of vitamin K
2
isoprenologues K
2
-35, K
2
-40, and K
2
-45 per g (dry weight). This is one-fifth to one-tenth of the vitamin K
2
level found in other bacteria. Ninety-six per cent of the extractable fatty acids were associated with the phospholipids (60 μmoles of lipid phosphate/g, dry weight), which consisted of the diacyl lipids phosphatidic acid, phosphatidyl serine, and phosphatidyl ethanolamine (with phosphatidyl glycerol and cardiolipin in one strain). The unusual phosphosphingolipids ceramide phosphorylethanolamine, ceramide phosphorylglycerol, and ceramide phosphorylglycerol phosphate accounted for 50 to 70% of the lipid phosphate. In protoheme-requiring strains, the protoheme concentration in the growth medium regulated the growth rate and the amount of enzymatically reducible cytochrome
c
. There were no gross changes in the lipid composition in cells containing different levels of enzymatically reducible cytochrome
c
.
Effect of Nitrate, Fumarate, and Oxygen on the Formation of the Membrane-Bound Electron Transport System of
Haemophilus parainfluenzae
Authors: Sinclair Peter R. , White David C.
Published: January 2020

The composition of the membrane-bound electron transport system of
Haemophilus parainfluenzae
underwent modification in response to the terminal electron acceptor in the growth medium.
H. parainfluenzae
was able to grow with O
2
, nitrate, fumarate, pyruvate, and substrate amounts of nicotinamide adenine dinucleotide (NAD) as electron acceptors. When O
2
served as the electron acceptor and its concentration was lowered below 20 μ
m
, the bacteria formed more cytochromes
b, c, a
1
,
a
2
, and
o
than were present in the cells grown at 150 to 200 μ
m
O
2
. Nitrate and nitrite reductase activities also appeared during growth at the low O
2
concentrations in the absence of added nitrate. Cytochrome levels in cells grown anaerobically with fumarate, pyruvate, or NAD as terminal acceptors were similar to those formed in cells grown at low O
2
concentrations. Cells grown with nitrate had higher levels of cytochromes
c, b
, and
o
, and of nitrate and nitrite reductases, than did cells grown with the other acceptors. The formation of cytochrome oxidase
a
2
was repressed by the presence of nitrate in the growth medium. The critical O
2
concentration (the O
2
concentration at which the rate of O
2
uptake becomes demonstrably dependent on the O
2
concentration) was about 100 μ
m
in cells grown with nitrate and about 15 μ
m
in cells grown with the other acceptors. A mutant of
H. parainfluenzae
was found to make about 10% as much cytochrome
c
as the wild type, and its formation of cytochrome
a
2
was not repressed by nitrate. The critical O
2
concentration of the mutant was high when it was grown with nitrate, suggesting that the high levels of cytochrome
c
and the absence of cytochrome
a
2
from the wild type are not responsible for the high critical O
2
concentration. The modifications of the respiratory system induced by changing the terminal electron acceptor were inhibited by the presence of chloramphenicol, which suggests that protein synthesis is involved.
Defined Medium for Growth of
Haemophilus influenzae
Authors: Herriott Roger M. , Meyer Eleanor Y. , Vogt Marcella , Modan Michaela
Published: January 2020

A chemically defined medium (MI
c
) is described in which cells of
Haemophilus influenzae
Rd grow rapidly (generation time, 35 ± 5 min) and reach a stationary level of 10
10
cells/ml. Our strain of cells grown in this medium developed high levels of competence when transferred to another medium designed for that purpose. Conditions governing the total development of competence in this organism have now been defined.