bluuebunny/crossref_metadata_2025 huggingface dataset:
Heat-Labile Antigens ofSalmonella enteritidisII. Mouse-protection Studies
Authors: Collins F. M. , Milne Margaret
Published: January 2020

Collins, F. M. (University of Adelaide, Adelaide, South Australia),and Margaret Milne. Heat-labile antigens ofSalmonella enteritidis. II. Mouse-protection studies. J. Bacteriol.92:549–557. 1966.—A number of extracts prepared from a virulent and an avirulent strain ofSalmonella enteritidiswere used to immunize mice. Living and alcohol-killed whole-cell vaccines were also used to compare the relative protective value of the various preparations. All mice were challenged intravenously with 100 to 1,000ld50ofS. enteritidis. Daily counts of the liver, spleen, and blood populations of vaccinated and control mice revealed that the challenge organism was rapidly eliminated only in those mice which had been immunized with a living vaccine. Immunization with extracts resulted in rapid clearance ofS. enteritidisfrom the blood, but, after a delay of 24 to 48 hr, the bacterial populations increased until a maximal liver and spleen population of approximately 5 × 108was reached. Between 55 and 100% of the immunized animals died, compared with 95 to 100% of the controls. With all four extracts, it was only the first antigenic fraction eluted from diethylaminoethyl cellulose which had any detectable effect on host resistance. The ineffectiveness of vaccines prepared with the various extracts or with whole killed bacteria relative to the protection observed after immunization with living organisms is discussed.
Genetic Recombination Between α-Toxin Mutants of
Staphylococcus aureus
Authors: McClatchy J. K. , Rosenblum E. D.
Published: January 2020

McClatchy
, J. K. (The University of Texas Southwestern Medical School, Dallas),
and
E. D.
Rosenblum
. Genetic recombination between α-toxin mutants of
Staphylococcus aureus
. J. Bacteriol.
92:
580–583. 1966.—A demonstration of genetic recombination between
Staphylococcus aureus
nonhemolytic mutants was attempted by means of transduction. The results of two-point reciprocal transductions placed the mutants into two genetic groups. Recombination within each group was not detectable within the limits of the method, but hemolytic recombinants were obtained in transductional crosses when donor and recipient were from different groups. At least two genetic loci are therefore involved in α-toxin production. The 11 mutants of group II were fibrinolysin-negative. The recombinants were always found to be restored to fibrinolysin production as well as to α-toxin production. These data suggest the existence of a pleiotropic gene simultaneously affecting the synthesis of both α toxin and fibrinolysin. The nine mutants of group I were fibrinolysin-positive. Group I members are postulated to be α-toxin structural mutants. Three mutants were also negative for bound coagulase, but no linkage was observed between the locus controlling bound coagulase and the loci for either fibrinolysin or α-toxin production.
Glucose Effect and the Galactose Enzymes of
Escherichia coli
: Correlation Between Glucose Inhibition of Induction and Inducer Transport
Authors: Adhya Sankar , Echols Harrison
Published: January 2020

Adhya, Sankar
(University of Wisconsin, Madison),
and Harrison Echols
. Glucose effect and the galactose enzymes of
Escherichia coli
: correlation between glucose inhibition of induction and inducer transport. J. Bacteriol.
92:
601–608. 1966.—The inhibitory effect of glucose on the induction of the enzymes required for galactose utilization (“glucose effect”) was studied in
Escherichia coli
. Experiments on the uptake into the cell of labeled inducers (
d
-galactose-
C
14
and
d
-fucose-
H
3
) pointed to inhibition at the level of inducer transport as the possible primary mechanism of the glucose effect in the case of the
gal
enzymes. This interpretation was supported by the finding that a mutant constitutive for the
lac
enzymes was resistant to glucose inhibition of galactose induction of the
gal
enzymes; the mutant had acquired a glucose-resistant alternative transport mechanism for galactose via the constitutively synthesized galactoside permease. Further support for the transport inhibition model was provided by the finding that glucose did not substantially inhibit induction of the
gal
enzymes when glucose and galactose were produced intracellularly by β-galactosidase hydrolysis of lactose, even if excess glucose was added. The inducer uptake experiments also showed that
d
-galactose and
d
-fucose probably enter the cell via different transport systems, although uptake of both compounds was inhibited by glucose.
Mutants of
Escherichia coli
Variably Resistant to Bacteriophage T1
Authors: Carta Guy R. , Bryson Vernon
Published: January 2020

Carta, Guy
R. (Rutgers, The State University, New Brunswick, N.J.),
and Vernon Bryson
. Mutants of
Escherichia coli
variably resistant to bacteriophage T1. J. Bacteriol.
92:
1055–1061. 1966.—Mutants resistant to bacteriophage T1 were isolated from ultraviolet (UV)-irradiated cultures of
Escherichia coli
B/r, a UV-resistant variant. Bacterial populations derived from some of these mutants were partially but not completely resistant to the bacteriophage. Such mutants, designated variably resistant (B/r/1v), could not be obtained from
E. coli
B. Phage-free mutant populations taken from different stages in growth consisted of significantly different proportions of T1-resistant and T1-sensitive cells. The growth stage-dependent range of variation exceeded 1,000-fold. In broth cultures, the highest proportion of resistant cells consistently appeared at mid-log phase, and the highest proportion of sensitive cells at lag and stationary phases. Comparable evidence for environmentally dependent changes in host-cell phenotype was obtained by efficiency of plating and cloning efficiency analysis tests. Micromanipulation showed that, in clones growing in the presence of phage T1, sensitive bacteria appeared with high frequency and underwent lysis.
Ribonuclease Sensitivity ofEscherichia coliRibosomes
Authors: Santer Melvin , Smith Josephine R.
Published: January 2020

Santer, Melvin(Haverford College, Haverford, Pa.),and Josephine R. Smith. Ribonuclease sensitivity ofEscherichia coliribosomes. J. Bacteriol.92:1099–1110. 1966.—The ribonucleic acid (RNA) contained in 70Sribosomes and in 50Sand 30Ssubunits was hydrolyzed by pancreatic ribonuclease. A 7% amount of the RNA was removed from the 70Sparticle; at 10−4mmagnesium concentration, a maximum of 24 and 30% of the RNA in the 50Sand the 30Sfractions, respectively, was removed by ribonuclease. At the two lower magnesium ion concentrations, 50Sribosomes did not lose any protein, whereas 30Sribosomes lost protein as a result of ribonuclease treatment. A number of proteins were removed from the 30Sparticles by ribonuclease, and these proteins were antigenically related to proteins present in 50Sribosomes. The differential effect of ribonuclease on 50Sand 30Sribosomes suggested that they have structural dissimilarities.
Control of Dimorphism in
Mucor rouxii
Authors: Haidle C. W. , Storck R.
Published: January 2020

Haidle
, C. W. (The University of Texas, Austin),
and R. Storck
. Control of dimorphism in
Mucor rouxii
. J. Bacteriol.
92:
1236–1244. 1966.—Yeastlike cells of
Mucor rouxii
NRRL 1894 were converted to filaments in a medium containing glucose, mineral salts, casein hydrolysate, nicotinic acid, and thiamine when the gas phase was changed from CO
2
-N
2
or N
2
alone to air. Germ tubes began to appear 3 to 4 hr after exposure to air. Ribonucleic acid (RNA) precursors were incorporated into RNA in a discontinuous fashion during this conversion, but the incorporation was continuous during the anaerobic growth of yeastlike cells and during the aerobic germination of sporangiospores. The incorporation of labeled amino acids during the conversion was exponential. Labeling of ribosomal RNA occurred as shortly as 5 min after replacement of CO
2
-N
2
with air. However, P
32
-labeled RNA isolated 20 min after exposure to air had a guanine plus cytosine (GC) content of 41% (mole%) as compared with the 47% found for labeled and unlabeled RNA isolated at other stages of the life cycle of this organism or later during the conversion. In addition, the overall base composition of this 20-min pulse-labeled RNA resembled that of deoxyribonucleic acid (GC = 39%), suggesting that a significant proportion of this RNA is of the messenger type. Furthermore, the synthesis of cytochrome oxidase was induced upon exposure of yeastlike cells to air. Cyanide, acriflavine, and cycloheximide, which inhibited the action or synthesis of cytochrome oxidase, also inhibited the yeast to filament transition.
Agglutinating and Precipitating Capacity of Rabbit Anti-Salmonella typhosaγG and γM Antibodies During Prolonged Immunization
Authors: Pike Robert M. , Schulze Mary L. , Chandler Cleo H.
Published: January 2020

Pike, RobertM. (University of Texas Southwestern Medical School, Dallas),Mary L. Schulze, and Cleo H. Chandler. Agglutinating and precipitating capacity of rabbit anti-Salmonella typhosaγG and γM antibodies during prolonged immunization. J. Bacteriol.92:880–886. 1966.—Antibody produced in rabbits immunized with acetone-dried typhoid bacilli was followed over a period of 445 days by agglutination and by quantitative precipitation. Repeated injections of vaccine resulted in suppression of antibody titers. Both γG and γM antibodies were rapidly increased by booster injections after rest periods during which titers had decreased to low levels. The O agglutinin titers and the amount of antibody protein, as determined by precipitation with endotoxin, generally were parallel, except in serum specimens in which unusually large proportions of the agglutinating activity were found in the γG fraction. These exceptions were explained by the greater agglutinating capacity of the γM. Endotoxin precipitated about 10 times as much antibody from γG preparations as it did from γM fractions of equivalent agglutinating strength. A much higher proportion of the serological activity, therefore, was found in the γG fractions when antibody was measured by precipitation than when agglutination was used as the measure of activity.
Metabolism of Biotin and Analogues of Biotin by Microorganisms
Authors: Birnbaum Jerome , Lichstein Herman C.
Published: January 2020

Birnbaum, Jerome
(University of Cincinnati, Cinncinati, Ohio),
and Herman C. Lichstein
. Metabolism of biotin and analogues of biotin by microorganisms. II. Further studies on the conversion of
d
-biotin to biotin vitamers by
Lactobacillus plantarum
. J. Bacteriol.
92:
913–919. 1966.—
Lactobacillus plantarum
growing in excess biotin converts a portion to two vitamers (combinable and uncombinable with avidin) not utilizable for growth. These were detected by differential yeast-lactobacillus assay. In the present study, suspensions of 12- and 72-hr cells showed no converting activity. Vitamer formation by nonproliferating 24-hr cells required glucose and exhibited a lag; 17-hr cells showed neither a lag nor a glucose requirement. Iodoacetate and chloramphenicol inhibited vitamer formation by 24-hr cells, but had no effect on 17-hr cells. Addition of hydrolyzed casein or preincubation in biotin decreased the lag and enhanced vitamer formation in 24-hr cells, but had no effect in 17-hr cells. Apparently, 17-hr cells contain the converting enzymes which degenerate as growth proceeds; the lag exhibited by 24-hr cells represents the time necessary to reform the enzymes. Equal amounts of the two vitamers were formed in 17-hr cells; only the avidin-combinable form was produced initially by 24-hr cells, unless hydrolyzed casein was present. Electrophoresis revealed that the avidin-combinable vitamer has the same charge as biotin,whereas the uncombinable form possesses both positive and negative groups. Column chromatography was used to separate the avidin uncombinable material from biotin and the avidin-combinable form.
L. plantarum
was unable to accumulate the avidin-uncombinable vitamer under conditions permitting good biotin accumulation. It was concluded that
L. plantarum
sequentially converts biotin to avidin-combinable and -uncombinable vitamers, the latter being impermeable to the cells.
Leptospiral Selection, Growth, and Virulence in Synthetic Medium
Authors: Stalheim O. H. V.
Published: January 2020

Stalheim, O. H. V. (National Animal Disease Laboratory, Ames, Iowa). Leptospiral selection, growth, and virulence in synthetic medium. J. Bacteriol.92:946–951. 1966.—The need for protein in leptospiral cultural medium may be circumvented by the use of strains which tolerate the lytic activity of polyoxyethylene sorbitan monooleate (Tween 80), a relatively nonlytic source of essential fatty acids. In an otherwise adequate medium, the primary function of a serum protein (bovine albumin fraction V) in the cultivation ofLeptospira pomonawas detoxification of fatty acids. Treatment to destroy or block end groups (amino, sulfhydryl, or hydroxyl) did not impair this function, but, after treatment with trypsin, albumin was inactive. Synthetic and derived peptides or polyvinylpyrrolidone did not substitute for albumin.L. pomonagrew in medium with surface tension values of 44 to 58 dynes/cm2; after growth, the values were increased slightly (5 to 8). The growth responses did not correlate with the surface tension of the medium, but they were in proportion to the concentration of Tween 80. Of six strains ofL. pomona, five were transferred from medium containing rabbit serum and were subcultured in Tween synthetic medium (TSM) containing low, nonlytic concentrations (0.002%) of Tween 80. The poor antigenicity ofL. pomonain carbon-limited TSM was associated with a deficiency of those carbonaceous cellular components which were extractable with 50% ethyl alcohol. After as few as four subcultures in TSM,L. pomonatolerated higher concentrations of Tween 80 (0.06% was optimal; MTSM). If grown on a shaker, the rate and amount of growth and the antigenicity ofL. pomonain MTSM equaled that in medium supplemented with rabbit serum. After cultivation in MTSM, all of the five strains were avirulent when administered to hamsters, guinea pigs, and swine. They were still avirulent after three subcultures in complex media or after two serial passages in hamsters.
Periodate Inhibition of Transformation and Competence Development in
Haemophilus influenzae
Authors: Ranhand Jon M. , Lichstein Herman C.
Published: January 2020

Ranhand, Jon
M. (University of Cincinnati, Cincinnati, Ohio),
and Herman C. Lichstein
. Periodate inhibition of transformation and competence development in
Haemophilus influenzae
. J. Bacteriol.
92:
956–959. 1966.—Periodate treatment of competent cells reduced the frequency of transformation to streptomycin resistance about 90% while reducing cell viability about 30% or less. Moreover, when periodate was added to cells early in the competence-development phase, these, too, were unable to develop maximal competence. Periodate inhibition was dependent on time and concentration as well as on the composition of the suspending menstruum. Periodate had no effect on transforming deoxyribonucleic acid (DNA), nor did it prevent transformation when added to competent cells which had already reacted with DNA. Furthermore, the progeny from cells inactivated 90% could be made fully competent, showing that the inhibition was not genetic. It was concluded that the periodate-sensitive substrate may involve the DNA binding site(s).
Persistent, Noncytocidal Viral Infection: Nonsynchrony of Viral and Cellular Multiplication
Authors: Walker Duard L. , Chang Ping-Ping , Northrop Robert L. , Hinze Harry C.
Published: January 2020

Walker, Duard
L. (University of Wisconsin Medical School, Madison),
Ping-Ping Chang, Robert L. Northrop, and Harry C. Hinze
. Persistent, noncytocidal viral infection: nonsynchrony of viral and cellular multiplication. J. Bacteriol.
92:
983–989. 1966.—In cultures of human conjunctive cells persistently infected with mumps virus (C-M cultures), the degree to which viral multiplication is linked to cell multiplication was examined. First, cell multiplication was inhibited. This resulted in a 10-fold increase in virus-excreting cells in the culture and an 80-fold increase in virus in the medium as compared with vigorously growing control cultures. Second, by use of elevated incubation temperature, virus multiplication was inhibited without slowing multiplication of the cells, and uninfected cells that appeared in the culture were protected by virus antiserum. This resulted in accumulation of antigen-free cells and, in one experiment, in elimination of the virus. Evidence indicated that uninfected cells accumulated as a result of dilution of virus by repeated cell divisions, but not as a result of selection of uninfected cells. These data indicate that viral multiplication in the C-M system is not closely linked to cell multiplication and that each can proceed at a rate different from the other.
Mutants of Simian Virus 40 Differing in Plaque Size, Oncogenicity, and Heat Sensitivity
Authors: Takemoto K. K. , Kirschstein R. L. , Habel K.
Published: January 2020

Takemoto
, K. K. (National Institute of Allergy and Infectious Diseases, Bethesda, Md.), R. L.
Kirschstein, and K. Habel
. Mutants of simian virus 40 differing in plaque size, oncogenicity, and heat sensitivity. J. Bacteriol.
92:
990–994. 1966.—Three mutants of simian virus 40 were isolated on the basis of the type of plaques produced in primary cultures of African green monkey kidney cells and designated as L (large), S (small), and M (minute) strains. Significant differences in oncogenicity for hamsters were observed, with the 50% oncogenic dose being 10
4.5
for the L, 10
5.2
for the S, and 10
5.8
for the M strains. All three strains were capable of transforming human diploid cells (W138 strain). At temperatures up to 41 C, the S and M mutants were capable of multiplying to titers almost equivalent to those obtained at 37 C. In contrast, infectious virus was not produced when cells were infected with the L mutant and were incubated at temperatures above 39 C, although complement-fixing viral and tumor antigens were formed. The temperature-sensitive phase of replication of the L strain was shown to be a late stage in viral maturation or assembly.
Genetic Differentiation by Nucleic Acid Homology IV. Relationships Among Lancefield Groups and Serotypes of Streptococci
Authors: Weissman Sherman M. , Reich Paul R. , Somerson Norman L. , Cole Roger M.
Published: January 2020

Weissman, ShermanM. (National Cancer Institute, Bethesda, Md.),Paul R. Reich, Norman L. Somerson, and Roger M. Cole. Genetic differentiation by nucleic acid homology. IV. Relationships among Lancefield groups and serotypes of streptococci. J. Bacteriol.92:1372–1377. 1966.—A deoxyribonucleic acid-ribonucleic acid homology technique was used to measure the genetic relatedness among Lancefield groups and serotypes of streptococci. Organisms in different Lancefield groups were related, but were differentiated from each other. Serotypes within group A could be distinguished. Two isolates serologically classified in group A type 1 were indistinguishable.Streptococcus faecaliswas only remotely related to streptococci of Lancefield groups A and H, whereasDiplococcus pneumoniaewas more closely related to these organisms. The serological data were in good agreement with the results obtained with the homology method.
Characterization of a Low Molecular Weight Antigenic Protein from the Envelope of Influenza Virus
Authors: Eckert Edward A.
Published: January 2020

Eckert, Edward
A. (The University of Michigan, Ann Arbor). Characterization of a low molecular weight antigenic protein from the envelope of influenza virus. J. Bacteriol.
92:
1430–1434. 1966.—An antigenic protein from the lipid-extracted residue of influenza virus strain PR8 was solubilized with urea-dithiothreitol (DTT). The protein subunits had a sedimentation coefficient of 2
S
in urea-DTT and reassociated to a 4
S
state on dialysis. This form of the envelope protein did not agglutinate erythrocytes, but reacted with strain-specific antisera in the complement-fixation and blocking-antigen tests.
Genetic Analysis of theViA-hisChromosomal Region inSalmonella
Authors: Johnson E. M. , Krauskopf Barbara , Baron L. S.
Published: January 2020

Johnson, E. M. (Walter Reed Army Institute of Research, Washington, D.C.),Barbara Krauskopf, and L. S. Baron. Genetic analysis of theViA-hischromosomal region inSalmonella. J. Bacteriol.92:1457–1463. 1966.—The relative chromosomal location of theViAdeterminant, a gene required for Vi antigen expression inSalmonella typhosa(and present also inS. typhimurium), was examined inS. typhimurium×S. typhosamatings. The position of this gene was determined with respect to the histidine (his) and methionine (metG) biosynthesis markers, and to the genetic determinants of somatic antigens 5 (O-5) and 4 (O-4) ofS. typhimurium. The gene order established by analyses of the hybrid classes resulting from the genetic crosses wasViA–O-5–metG–O-4(his). This order suggests that neitherViAnorO-5is a member of the complex of functionally related structural genes which constitute theO-4locus. It allows for the possibility, however, of a functional relationship between the genes of theViAandO-5loci.
Reduction in Plaque Size and Reduction in Plaque Number as Differing Indices of Influenza Virus-Antibody Reactions
Authors: Jahiel R. I. , Kilbourne E. D.
Published: January 2020

Jahiel
, R. I. (Cornell University Medical College, New York, N.Y.),
and E. D. Kilbourne
. Reduction in plaque size and reduction in plaque number as differing indices of influenza virus-antibody reactions. J. Bacteriol.
92:
1521–1534. 1966.—The serological reactivity of an antigenically hybrid influenza virus recombinant (X-7) was studied in a heteroploid cell plaquing system in which antisera to the parental viruses NWS/(A
0
) and RI/5
+
(A
2
) were incorporated in agar overlay media. Two different effects on plaque formation were found. With NWS antiserum, there was close relationship between reduction in plaque size and in plaque number [plaque inhibition (PI) pattern]. With RI/5 antiserum, plaque size reduction (PSR) occurred over a wide zone of serum dilutions without concomitant change in plaque number (PSR pattern). Several different preinoculation neutralization tests showed a strong reactivity of X-7 with NWS antisera and little if any reactivity with RI/5 antisera. We interpret the differing effects of NWS and RI/5 antisera on X-7 as indicative of the possible occurrence of different mechanisms of neutralization or of the possible participation of different surface antigens. The kinetics of PSR are consistent with the hypothesis that it results from the reaction of RI/5 antiserum with the RI/5-like neuraminidase of X-7. Studies with the antiserum-in-overlay technique of PSR and PI patterns comprise a sensitive method for quantitative antigenic analysis of plaque-forming influenza viruses.
Differential Effects of Deoxyribonucleotides on Respiration of Virulent Pneumococci
Authors: Firshein William , Erickson Robert J. , Gargan Bernadette A.
Published: January 2020

Firshein, William
(Wesleyan University, Middletown, Conn.),
Robert J. Erickson, and Bernadette A. Gargan
. Differential effects of deoxyribonucleotides on respiration of virulent pneumococci. J. Bacteriol.
92:
1645–1654. 1966.—Four naturally occurring deoxyribonucleotides affect respiration in three virulent pneumococcal types (
Diplococcus pneumoniae
) differentially. Deoxyadenylic acid (dAMP) stimulates respiration in type I and slightly stimulates respiration in type III, but has no effect in type II. Deoxyguanylic acid (dGMP) stimulates respiration in type I, inhibits respiration in type II, and has no effect in type III. Thymidylic acid (dTMP) inhibits respiration of type I, but is stimulatory in types II and III. Deoxycytidylic acid (dCMP) inhibits respiration of all three pneumococcal types. Of a large number of related compounds, including many of the naturally occurring deoxynucleosides, nucleosides, nucleotides, purines, and pyrimidines, thymidine is slightly effective in types II and III, and deoxycytidine is slightly inhibitory in all three types. None of the remaining compounds affects respiration significantly. With a few exceptions, there is a correlation between the extent of uptake of each deoxynucleotide in the three types and their ability to stimulate (or inhibit) respiration. The greater the uptake, the greater the enhancement of respiration. The less uptake, the greater the inhibition of respiration. In cell-free extracts of type I, dAMP also stimulates the oxidative decarboxylation of pyruvic acid. During this reaction, dAMP is phosphorylated to deoxyadenosine diphosphate (dADP) and to deoxyadenosine triphosphate (dATP).
Ultraviolet Microscopy ofCandida albicans
Authors: Balish Edward , Svihla George
Published: January 2020

Balish, Edward(Argonne National Laboratory, Argonne, Ill.),and George Svihla. Ultraviolet microscopy ofCandida albicans. J. Bacteriol.92:1812–1820. 1966.—Yeast and mycelial strains ofCandida albicanswere grown in medium supplemented with sulfur amino acids in an effort to determine factors that control the morphology and pathogenicity of the organism. Ultraviolet microscopy revealed a greater concentration ofS-adenosylmethionine in the vacuoles of the mycelial phase than in those of yeast phases. Supplementation with amino acids greatly increased the concentration ofS-adenosylmethionine in the mycelial phase, and made these cells more sensitive to the lytic action of snail gut enzymes than two yeast phase strains. This indicates a difference in cell wall structure that may be related to the pathogenicity of the mycelial phase.
Conditional Mutations Involving Septum Formation inEscherichia coli
Authors: Walker James R. , Pardee Arthur B.
Published: January 2020

Thelon−mutation is responsible for a defect in cell division ofEscherichia colilightly irradiated with ultraviolet light (UV). Theselon−mutants can be isolated readily by a procedure described here. Physiological studies were performed with the objective of determining the role of thelongene. Unirradiatedlon−mutants grow normally, except that a correlation of this mutation with capsule formation has been noted previously. These two properties can be separated, however. After irradiation,lon−grows as long filaments because septum formation is prevented. The filaments eventually lyse. Mass increase and deoxyribonucleic acid and enzyme synthesis appear to proceed normally. Thus, the lesion produced by UV appears to be highly specific. In bacteria that carry both genes (merozygotes),lon+is dominant tolon−. Septum formation is restored to irradiatedlon−bacteria by introduction oflon+by conjugation. Also, normal growth can be restored by nutritional variations. It is concluded thatlon+is able to nullify the effects of the UV lesion under conditions wherelon−cannot. Possibly, capsule precursors that can accumulate in the latter are responsible for the difference because they interfere with repair of the UV lesion.
Heterogeneity of the Stability of Messenger Ribonucleic Acid in
Salmonella typhimurium
Authors: McClatchy J. K. , Rickenberg H. V.
Published: January 2020

Cells of
Salmonella typhimurium
strain SL 282, deflagellated by mechanical shear, regenerated their flagella in the absence of tryptophan, an amino acid required for growth but not found in flagellin. Ribonucleic acid (RNA) synthesis was severely inhibited by tryptophan starvation. These findings suggested that the messenger RNA (mRNA) for flagellin might be stable. Actinomycin D was used to inhibit RNA synthesis in ethylenediaminetetraacetate-treated bacteria. The introduction of an F
lac
episome into strain SL 282 permitted the simultaneous study of the synthesis of flagellin, β-galactosidase, and total protein. In the actinomycin-treated bacteria protein and β-galactosidase syntheses were inhibited by 90%, whereas flagellin synthesis was unaffected. We conclude that the mRNA for flagellin synthesis is stable and that species of mRNA vary with respect to metabolic stability in
S. typhimurium
.
Bacterial Metabolism of Mevalonic Acid
Authors: Siddiq Majid A. , Rodwell Victor W.
Published: January 2020

Soluble cell-free extracts of actinomycete S4 grown on media containing mevalonate catalyze acetoacetate formation from mevalonate, mevaldate, and β-hydroxy-β-methylglutaryl-coenzyme A (CoA). Conversion of mevalonate to acetoacetate involves formation of free β-hydroxy-β-methylglutaryl-CoA, but not free mevaldate. The reaction favors mevalonate oxidation, and nicotinamide adenine dinucleotide, rather than nicotinamide adenine dinucleotide phosphate, acts as oxidant.
Spectrophotometric and Kinetic Study of Nitrite and Formate Oxidation in
Nitrobacter winogradskyi
Authors: Van Gool A. , Laudelout H.
Published: January 2020

The reduction levels of cytochrome
c
and
a
1
in intact
Nitrobacter
cells and cell-free extracts, during and after nitrite or formate oxidation, were examined in combination with the amperometric measurement of oxygen uptake. Quite different reduction patterns were observed when comparing nitrite oxidation by intact cells and cell-free extracts. An inverse relationship was observed between the rate of electron flow and the steady-state reduction level of cytochrome
a
1
. Parallel observations on nitrite oxidation, by use of formate and reduced nicotinamide adenine dinucleotide as electron donors, showed the influence of the high oxidation-reduction potential of the nitrite-nitrate system on cytochrome reduction. A value for the apparent activation energy of the overall nitrite oxidation process, amounting to 15 kcal, was found in a study of the temperature dependence of cytochrome reduction.
Autoradiographic Evidence for the Impermeability of Mouse Peritoneal Macrophages to Tritiated Streptomycin
Authors: Bonventre Peter F. , Hayes Robert , Imhoff John
Published: January 2020

Cultured mouse peritoneal macrophages were found to be relatively impermeable to streptomycin. Based on radioactivity measurements and radioautographic evidence, macrophages were impermeable to tritiated dihydrostreptomycin for periods up to 20 hr of incubation. Little or no intracellular streptomycin could be detected even when incubation was carried out in the presence of therapeutic blood levels of carrier dihydrostreptomycin. When the cultured mouse macrophages were allowed to phagocytize staphylococci, yeast cells, or polystyrene latex particles in the presence of tritiated streptomycin, the impermeability of the cells to the antibiotic was not affected. These observations suggested that the process of phagocytosis does not facilitate the intracellular accumulation of streptomycin, as seems to be the case for the fixed phagocytic cells of the liver.
Lysostaphin in Experimental Renal Infections
Authors: Harrison Edward F. , Zygmunt Walter A.
Published: January 2020

By use of a renal staphylococcal infection model in mice, single intravenous doses of lysostaphin ranging from 1.56 to 50 mg/kg were effective in: (i) controlling the staphylococcal population of kidneys, (ii) reducing the mortality rate, and (iii) clearing high numbers of kidneys of infection. Semisynthetic penicillins and other antistaphylococcal antibiotics given in the same manner did not have significant activity. Only by the administration of a long-acting, depot form of penicillin (Bicillin) could results comparable to those seen with lysostaphin be obtained. The results of this study suggest that lysostaphin may be useful in staphylococcal septicemias in preventing the establishment of new foci of infection.
Mechanisms of Pathogenesis in
Listeria monocytogenes
Infection III. Carbohydrate Metabolism
Authors: Wilder Martin S. , Sword C. P.
Published: January 2020

Several enzymes and metabolites concerned with carbohydrate metabolism were examined in mice infected with
Listeria monocytogenes
. Liver glycogen and glucose decreased parallel to severity of infection. The concentration of glucose in the blood fell to abnormally low levels with a hypoglycemia being most evident at 72 hr. There was a significant decrease in the activity of hepatic uridine diphosphate glucose-glycogen transglucosylase. This decrease in enzymatic activity correlated with the rate of glycogen depletion. Phosphorylase activity declined in a similar fashion, contraindicating enhanced glycogenolysis as the mechanism responsible for glycogen depletion. Although glucose-6-phosphatase decreased throughout the infection period, it did not appear to be the major metabolic defect causing hypoglycemia in
Listeria
-infected mice. Further distortion of carbohydrate metabolism was indicated by findings of increased levels of pyruvate and lactate in the blood of infected animals.
Metabolism of Thiosulfate and Tetrathionate by Heterotrophic Bacteria from Soil
Authors: Trudinger P. A.
Published: January 2020

Two heterotrophic bacteria that oxidized thiosulfate to tetrathionate were isolated from soil. The enzyme system in one of the isolates (C-3) was constitutive, but in the other isolate (A-50) it was induced by thiosulfate or tetrathionate. The apparent

K
m

for oxygen for thiosulfate oxidation by A-50 was about 223 μ
m
, but, for lactate oxidation by A-50 or thiosulfate oxidation by C-3, the apparent

K
m

for oxygen was below 2 m
m
. The oxidation of thiosulfate by A-50 was first order with respect to oxygen from 230 μ
m
. The rate of oxidation was greatest at
p
H 6.3 to 6.8 and at about 10 m
m
thiosulfate, and it was strongly inhibited by several metal-binding reagents. Extracts of induced A-50 reduced ferricyanide, endogenous cytochrome
c
, and mammalian cytochrome
c
in the presence of thiosulfate. A-50, once induced to oxidize thiosulfate, also reduced tetrathionate to thiosulfate in the presence of an electron donor such as lactate. The optimal
p
H for this reaction was at 8.5 to 9.5, and the reaction was first order with respect to tetrathionate. There was no correlation between the formation of the thiosulfate-oxidizing enzyme of A-50 and the incorporation of thiosulfate-sulfur into cell sulfur. Thiosulfate did not affect the growth rate or yield of A-50.
Cross-reactive Antigen Shared by
Streptococcus agalactiae
and Certain Bovine Tissues
Authors: Dodd Kevin , Norcross Neil L.
Published: January 2020

Rabbits immunized with mucopeptide derived from cell wall debris of
Streptococcus agalactiae
by use of the formamide extraction technique developed specific antibodies for bovine heart, skeletal muscle, lymph nodes, and blood buffy coat extracts.
Properties ofMycoplasma hominis4330
Authors: Morton Harry E. , Roberts Ruth J.
Published: January 2020

Mycoplasmastrain 4330, one of the earliest strains of pleuropneumonia-like organisms to be isolated from man in the United States, has been found to resembleM. hoministype 1 by serological methods (the growth inhibition and latex agglutination tests). The results of earlier serological studies indicated a similarity between the Campo and 4330 strains which was not detected by use of the cultures currently available. Strain 4330 differs from strains ofMycoplasmarecently isolated from man by producing acid from a variety of carbohydrates. This acquisition of biochemical properties may be the result of hundreds of transfers on artificial media during a period of more than a quarter of a century. Identification of the strain was deemed advisable, since two different cultures and a mixed culture existed under the designation “4330.” The extraneous organisms were found to be closely related toM. laidlawiiby their biological and serological properties.
Growth of
Mycobacterium lepraemurium
in Cultures of Mouse Peritoneal Macrophages
Authors: Chang Y. T. , Andersen R. N. , Vaituzis Z.
Published: January 2020

Successful growth of
Mycobacterium lepraemurium
was observed in cultures of mouse peritoneal macrophages. The optimal host cell maintenance medium was composed of 40% horse serum, 50% of the chemically defined medium NCTC 109, and 10% of a 1:5 dilution of beef embryo extract, supplemented with both liver extract and ferric nitrate. Multiplication of the bacilli was observed in 1 week and maximal growth in 6 to 7 weeks. All macrophages were filled with tens to hundreds of the organisms in cultures showing maximal growth. Glycerol caused an increase in the normal length of
M. lepraemurium
, without a corresponding increase in the number of the bacilli. Elongation of
M. lepraemurium
was observed 3 or 4 days after infection. Rapid and uniform growth of
M. lepraemurium
was achieved in serially transferred cultures (subcultures). The cumulative increase of the number of intracellular bacilli was 1.4 × 10
20
-fold in 14 transfers over a period of 68 weeks in one series, and 10
17
-fold in 12 transfers over a period of 56 weeks in another series. The generation time of
M. lepraemurium
was 7 days, a growth rate which approximates the fastest growth of the organisms in vivo. Organisms harvested from cultures at various stages of growth produced murine leprosy in mice, but showed no growth in bacteriological media. The present model offers an opportunity for studies on the host-parasite relationship without the complication of extracellular growth of the parasites.
Large Bodies of
Mycoplasma
and L-Form Organisms
Authors: Kang K. S. , Casida L. E.
Published: January 2020

The large bodies of various
Mycoplasma
and L-form organisms were studied by ultraviolet fluorescence microscopy of preparations stained with various fluorochromes. Primuline and Thioflavine S specifically stained the outer portion or rim of the large bodies, and the fluorescence characteristics of the stained bodies differed from those for other microorganisms and for spheroplasts and protoplasts. Small granular structures similar in size and morphology to minimal reproductive units were observed within some of the large bodies by phase microscopy and by fluorescence microscopy with acridine orange or Coriphosphine O. Micromanipulation probing of the large bodies revealed their elastic nature; many of the large bodies could be subdivided into two or more smaller circular bodies, each retaining the fluorescence staining properties of the parent body. Under these conditions, however, a few of the large bodies were ruptured, leaving the stainable outer boundary area as a stable residual structure. The large bodies were somewhat resistant to various rigorous treatments normally employed to eliminate viability of
Mycoplasma
and L-form cultures. Structures similr to large bodies were observed in various natural tissues, and structures resembling large bodies in size, morphology, fluorescence staining characteristics, and reaction to micromanipulation probing were reconstructed from an acetone extract of egg yolk. Overall, the large bodies of
Mycoplasma
and L-form organisms appeared to be structures resulting from accumulations of metabolic by-products and medium components within or on which minimal reproductive units had become entrapped, although it could not be ruled out that they might be defined structures specifically formed during culture as protective lipoidal sacs for the minimal reproductive units.
Early Antibody Response in Mice to Either Infection or Immunization withSalmonella typhimurium
Authors: Kenny Kathryn , Herzberg Mendel
Published: January 2020

After immunization with either live or heat-killedSalmonella typhimurium, mice responded with an extremely rapid production of bactericidal antibody which was correlated with the appearance of immunity to a heavy challenge dose (100ld50) of the virulent bacteria. Inactivation of sera with mercaptoethanol along with Sephadex fractionation indicated that the observed bactericidal activity was associated with a macroglobulin which was completely mercaptoethanol-sensitive. The unexpected finding, that a heat-killed vaccine gave excellent protection from a challenge dose which killed all unimmunized control mice, seriously challenges the theory attributing immunity against typhoid infection entirely to a cellular host factor produced only in response to a live vaccine.
Inducible Lysis inClostridium tetani
Authors: Prescott Lawrence M. , Altenbern Robert A.
Published: January 2020

Lysis was induced in seven strains ofClostridium tetaniby exposure to mitomycin C. The search for a suitable indicator strain to detect bacteriophage in lysates has, so far, been unsuccessful. Inhibition studies on macromolecular synthesis during induction have shown that deoxyribonucleic acid, ribonucleic acid, and protein syntheses are all involved in the lysis induced by mitomycin C. In experiments comparing toxin and protein content in induced and uninduced cells ofC. tetani, the toxin-protein ratio proved to be the same in both systems up to the point of lysis. Several possible hypotheses deduced from these results are discussed.
Antigenic Relationship of
Brucella ovis
and
Brucella melitensis
Authors: Diaz Ramon , Jones Lois M. , Wilson J. B.
Published: January 2020

Immune sera were prepared in rabbits by the injection of living and acetone-killed cells of
Brucella ovis
and smooth and rough
B. melitensis
. The use of whole-cell antigens in agglutination and agglutinin-absorption tests revealed little relationship between
B. ovis
and smooth
B. melitensis
, although there was extensive cross-agglutination between
B. ovis
and rough
B. melitensis
. The use of water-soluble antigens prepared from ultrasonically treated cells of the three strains revealed extensive cross-reactions in indirect hemagglutination, agar gel precipitation, and immunoelectrophoresis tests, as well as in allergic skin tests in rabbits. The most definitive results were obtained with the immunoelectrophoresis technique.
B. ovis
antigen produced at least 11 lines with its homologous serum. All were removed by absorption of the serum with rough
B. melitensis
antigen. All but three were removed by absorption with smooth
B. melitensis
antigen. Smooth
B. melitensis
antigen produced 11 lines with its homologous serum, and all but 3 were removed by absorption with
B. ovis
antigen. Rough
B. melitensis
produced nine lines with its homologous serum, and eight were removed by
B. ovis
antigen. The extensive cross-reactions between soluble antigens of
B. ovis
and
B. melitensis
are added evidence that
B. ovis
belongs in the genus
Brucella
.
Growth Response of
Nitrosomonas europaea
to Amino Acids
Authors: Clark Connie , Schmidt E. L.
Published: January 2020

Growth responses of
Nitrosomonas europaea
to individual amino acids or vitamins was observed in log-phase cultures, as was the incorporation of carbon-14 labeled amino acids. Nitrite formation and protein synthesis were increased by
l
-glutamic acid,
l
-aspartic acid,
l
-serine, and
l
-glutamine.
l
-Lysine,
l
-histidine,
l
-threonine,
l
-valine,
l
-methionine, and
l
-arginine were inhibitory. The other amino acids had no effect on growth. All of the uniformly labeled amino acids added at low concentrations were taken up by growing cells and distributed into cell fractions. From 1 to 12% of the added radioactivity was present in cells analyzed in late log phase, depending on the amino acid; glycine and
l
-serine caused accumulation of the label to the greatest extent, whereas
l
-aspartic and
l
-glutamic acids were among those incorporated to the least extent. Aspartic acid increased both cell protein and nitrite values, but did not alter the ratio of protein to nitrite from that found in controls.
Induction of L Forms ofHaemophilus influenzaein Culture and Their Demonstration in Human Bronchial Secretions
Authors: Lapinski Elsie M. , Flakas E. Delle
Published: January 2020

Transitional forms and round bodies ofHaemophilus influenzaewere identified in sputa from patients with chronic bronchitis who were receiving penicillin therapy forH. influenzaeinfections. In vitro growth of L forms of this organism was induced by penicillin and glycine and was studied for comparison with development in vivo. Variant forms demonstrated in sputum were similar to variant forms observed in penicillin-induced L colonies. Recurrence of infection after cessation of therapy was related to reversion of persisting L forms to bacillary forms. That these forms were derived fromH. influenzaewas established by direct staining with fluoresceinlabeled specific antibody. This demonstration that transitional forms and round bodies ofH. influenzaeoccurred in vivo suggests that L forms of bacteria may be significant in chronic or recurrent infections.
Interference by Trypsin in the Interaction of Staphylococcal Enterotoxin B and Cell Cultures of Human Embryonic Intestine
Authors: Schaeffer Warren I. , Gabliks Janis , Calitis Ruta
Published: January 2020

The inhibitory effect of trypsin on the cytotoxicity of staphylococcal enterotoxin B acting with human embryonic intestine cell cultures was examined. Trypsin treatment of the cells rendered them resistant to enterotoxin for a period of 48 hr. The resistance increased proportionally with increased time of exposure of the cells to trypsin. Neither ethylenediaminetetraacetic acid nor scraping, which were used as alternate means of cell suspension, caused any resistance to the toxin. The effect is enzymatic and appears to be similar to the inhibitory action of trypsin and chymotrypsin on the attachment of polioviruses and coxsackieviruses to HeLa cells.
Influence of Urea on the Growth of T-Strain Mycoplasmas
Authors: Ford Denys K. , MacDonald Joyce
Published: January 2020

T-strain mycoplasmas require urea for propagation, but urea metabolism also occurs in nonpropagating viable cultures. Ammonia results from this metabolism and alkalinizes the medium. Ammonium ions and an alkaline
p
H both inhibit the multiplication of T strains and reduce the viability of T strains in broth. These toxic effects of urea metabolism currently limit the growth of T strains in broth. Stock T-strain cultures are optimally maintained in continuous culture if the routine medium at
p
H 6.0 is supplemented with 0.05% urea and 0.002% phenol red, but an incubation temperature of 30 C is preferable to 37 C for subculture at 24-hr intervals.
Occurrence of Urease in T Strains of
Mycoplasma
Authors: Shepard Maurice C. , Lunceford Carl D.
Published: January 2020

A previously unknown metabolite necessary for growth of T strains of
Mycoplasma
in artificial culture media has been identified as urea. The source of this metabolite was the mammalian plasma or serum enrichment of the culture medium. Normal horse serum was the most satisfactory native protein enrichment for cultivation of T strains of mycoplasma, and it is believed that its superior performance in agar and fluid culture media is associated with its relatively high urea content (approximately 40 mg/100 ml). T-strain urease activity was maximal at
p
H 6.0 ± 0.5. This is also the optimal
p
H for growth of T strains. Substrate concentrations greater than 1.0% urea were inhibitory to growth and urease activity of T-strain organisms, and optimal urea concentrations in fluid media appeared to lie within the range of 0.008 to 0.01
m
. This range of urea concentration permitted maximal growth of T-strain organisms without rapid loss of viability due to excessive ammonia accumulation and rise in
p
H to lethal levels. T strains of
Mycoplasma
were cultivated in a serum-free fluid medium containing urea as the only added metabolite and nitrogen source. T strains are the only known human mycoplasmas which exhibit urease activity, and this biochemical marker can be employed as an aid in the detection and identification of T strains of
Mycoplasma
(urease color test) and in distinguishing T strains from other members of the human
Mycoplasma
group.
d
-Arabinose Countertransport in Bakers' Yeast
Authors: Wilkins Peter O.
Published: January 2020

The initial rate of the glucose-induced countertransport of
d
-arabinose was measured at several concentrations of extracellular glucose. These data permit the calculation of the intracellular concentration of free glucose, and, if the rate of glucose metabolism is known, the maximal rate of glucose transport can be estimated. Since the maximal transport rate remained essentially constant when the extracellular glucose concentration was increased from 2 to 100 m
m
, the results are consistent with the hypothesis that, during glucose metabolism, glucose is transported across the yeast cell membrane by a symmetrical carrier system which functions independently of metabolism.