bluuebunny/crossref_metadata_2025 huggingface dataset:
Fluorescent-Antibody and Histological Study of Vaccinated and Control Monkeys Challenged with
Shigella flexneri
Authors: Formal Samuel B. , Kent T. H. , Austin S. , LaBrec E. H.
Published: January 2020

Formal, Samuel B., (Walter Reed Army Institute of Research, Washington, D.C.), T. H. Kent, S. Austin, and E. H. LaBrec. Fluorescent-antibody and histological study of vaccinated and control monkeys challenged with
Shigella flexneri
. J. Bacteriol. 91:2368–2376. 1966.—Groups of monkeys were fed four doses of a living
Escherichia coli-Shigella flexneri
2a hybrid strain, and, together with control animals, were challenged with virulent
S. flexneri
2a. Two experiments were carried out; in the first, the animals were challenged 10 days after and in the second, 1 month after the last vaccine dose was administered. At 48 hr after challenge, tissues were removed from the vaccinated and control animals, and examined by use of histological and fluorescent-antibody techniques. The results of this study demonstrate that the animals receiving the vaccine were protected from the tissue damage ordinarily observed after experimental challenge with virulent dysentery bacilli. The virulent challenge strain appeared to be unable to penetrate into the intestinal mucosa of immunized animals.
Synthesis of Fatty Acids by Yeast Particles
Authors: Klein Harold P.
Published: January 2020

Klein, Harold
P. (Ames Research Center, Moffett Field, Calif.). Synthesis of fatty acids by yeast particles. J. Bacteriol.
92:
130–135. 1966.—When a mitochondria-free homogenate of
Saccharomyces cerevisiae
was centrifuged at 100,000 ×
g
for 60 min, the sedimented crude particles incorporated acetate into fatty acids, but not into nonsaponifiable lipids. Degradation of the fatty acids formed indicated this to be de novo synthesis rather than chain elongation. Subfractions of the crude particles were obtained. The “ribosomal” fraction was unable to synthesize fatty acids, but had properties indicating the presence of acetokinase, fatty acid desaturase, and, probably, acetyl-coenzyme A carboxylase. A “light” particle fraction with a high specific activity of fatty acid synthetase was also obtained. Fatty acid synthesis by the “soluble” supernatant fluid appeared to be the result of contamination by the “light” particles. The data suggested the presence of several particulate entities in mitochondria-free homogenates.
Chromosomal Mapping by Means of Mutational Induction in Synchronous Populations of
Streptococcus faecalis
Authors: Stonehill E. H. , Hutchison Dorris J.
Published: January 2020

Stonehill
, E. H. (Sloan-Kettering Institute for Cancer Research, New York, N.Y.
and Dorris J. Hutchison
. Chromosomal mapping by means of mutational induction in synchronous populations of
Streptococcus faecalis
. J. Bacteriol.
92:
136–143. 1966.—A new method for mapping genetic loci on the bacterial chromosome, based on the linear progression of the deoxyribonucleic acid-replicating enzyme (replicase) in synchronous cultures of
Streptococcus faecalis
, is described. Ultraviolet irradiation was used to induce mutations to drug and to bacteriophage resistance at various intervals during the progress of the replicase along the chromosome. The time of duplication of the gene in synchronous populations was determined from reductions in the rates of irradiation-induced mutation. After the replication of various genes, the rates fell to half their former values. The resulting data made possible the construction of a 1-hr time-map indicating the sequence of replication of five genes in
S. faecalis
.
Ultraviolet Mutagenesis in Bacteriophage T4 II. Photoreversal of Mutational Lesions
Authors: Drake John W.
Published: January 2020

Drake, John
W. (University of Illinois, Urbana). Ultraviolet mutagenesis in bacteriophage T4. II. Photoreversal of mutational lesions. J. Bacteriol.
92:
144–147. 1966.—T4
r
mutations were induced by ultraviolet irradiation of extracellular phage particles, using a phage mutant,
v
, which is particularly susceptible to photoreactivation. Most of the induced
r
mutations could be subsequently photoreversed intracellularly with white light. Ultraviolet irradiation induces both transitions and sign mutations, and both were susceptible to photoreversal. The results suggest that two very different types of mutational lesions may arise from a common type of photochemical lesion.
Characteristics of Group A Streptococcal Bacteriophages
Authors: Friend Patric L. , Slade Hutton D.
Published: January 2020

Friend, Patric
L. (Northwestern University Medical School, Chicago, Ill.),
and Hutton D. Slade
. Characteristics of group A streptococcal bacteriophages. J. Bacteriol.
92:
148–154. 1966.—A medium for the growth of group A streptococcal phages is described, consisting of Brain Heart Infusion broth supplemented with 0.2% yeast extract, 10
−4
m
CaCl
2
, and 10 μg/ml of
dl
-tryptophan. Cell and phage growth in this medium was excellent, and did not require the addition of serum or other proteins as indicated by other workers. Growth of one phage has also been achieved in a completely synthetic medium. The adsorption characteristics of two group A phages in protein broth and synthetic broth were studied, and the initial adsorption of phage was found to be more extensive in synthetic broth. However, the final amounts of adsorption in both were similar. The addition of purified group A carbohydrate antigen to the adsorption mixture in synthetic broth had no effect on the adsorption, and cells containing type-specific M protein adsorbed phage at the same rate as those lacking M protein. It was concluded that neither the group antigen nor the type antigen was the primary site of phage adsorption. One-step growth curves of the two phages showed a second step or burst occurring. Sonic oscillation of the bacterial cultures, which broke up the chains to single cells, abolished the second step of the growth curve. It appears that the second step is a function of the chain formation of streptococcal cells.
Selective Response of the Japanese Quail to Various Strains of Rous Sarcoma Virus
Authors: Shipman Charles , Levine Alvin S.
Published: January 2020

Shipman, Charles Jr.
(Indiana University School of Medicine, Indianapolis),
and Alvin S. Levine
. Selective response of the Japanese quail to various strains of Rous sarcoma virus. J. Bacteriol.
92:
161–163. 1966.—The Bryan “high-titer,” Carr-Zilber, Harris, Prague, Schmidt-Ruppin, and “29” strains of Rous sarcoma virus were used to initiate tumors in the Japanese quail (
Coturnix coturnix japonica
). Although all strains produced tumors upon primary inoculation, only the Bryan “high-titer” and Harris strains could be serially passaged with cell-free tumor extracts. Analysis by means of the end-point dilution technique and the interference test revealed that the tumor extract of the Bryan “high-titer” strain passaged 10 times in the quail contained a Rous-associated virus.
Comparative Biosynthesis of Ornithine and Lysine by
Mycoplasma
and L Forms
Authors: Smith Paul F.
Published: January 2020

Smith, Paul
F. (University of South Dakota, Vermillion). Comparative biosynthesis of ornithine and lysine by
Mycoplasma
and L forms. J. Bacteriol.
92:
164–169. 1966.—Seven species of
Mycoplasma
, two L forms not requiring salt and their parent bacteria, and two yeasts were examined for enzymes involved in the biosynthesis of ornithine and lysine. All organisms tested, except two species of
Mycoplasma
and the yeasts, decarboxylated
meso
-α, ε-diaminopimelic acid. None of the
Mycoplasma
species or L forms was capable either of reducing α-aminoadipic acid to its semialdehyde or of incorporating α-aminoadipic acid-
6-C
14
into lysine. All organisms, except the yeasts and
Mycoplasma
sp. caprine strain 14, acetylated glutamic acid, and all organisms possessed
N
α
-acetyl-
l
-ornithine:2-oxo-glutarate aminotransferase activity.
N
α
-acetylornithase activity was negligible in all organisms except
Proteus
and its L form. No transacetylation between acetylglutamic acid and ornithine, and vice versa, was demonstrable in any of the organisms.
Mycoplasma
species appear to possess the bacterial pathway to lysine. Ornithine does not appear to arise from glutamic acid.
Protection of Monkeys Against Experimental Shigellosis with a Living Attenuated Oral Polyvalent Dysentery Vaccine
Authors: Formal Samuel B. , Kent T. H. , May H. C. , Palmer A. , Falkow S. , LaBrec E. H.
Published: January 2020

Formal, Samuel
B. (Walter Reed Army Institute of Research, Washington, D.C.), T. H.
Kent, H. C. May, A. Palmer, and E. H. LaBrec
. Protection of monkeys against experimental challenge with a living attenuated oral polyvalent dysentery vaccine. J. Bacteriol.
91:
17–22. 1966.—Virulent strains of
Shigella flexneri
1b,
S. flexneri
3, and
S. sonnei
I were mated with an Hfr strain of
Escherichia coli
K-12, and hybrids were selected for the xylose marker. One hybrid strain of each of the serotypes was chosen for study of their biological characteristics. Their capacity to cause a fatal enteric infection in starved guinea pigs was reduced, they failed to cause dysentery when fed to monkeys, they caused keratoconjunctivitis in the guinea pig eye, and they penetrated HeLa cells. Two doses of a polyvalent oral vaccine composed of
S. flexneri
1b, 2a, and 3, and
S. sonnei
I hybrid strains were fed to groups of monkeys at an interval of 4 to 7 days, and they, together with controls, were challenged 10 days after the last dose with one or another of the virulent parent dysentery strains. A significant degree of protection was afforded in all vaccinated groups with the exception of one group challenged with
S. flexneri
6, a component not included in the vaccine. When animals were challenged with virulent
S. flexneri
2a 1 month after oral vaccination, they were also protected. The vaccine produced a rise in serum antibody, but we were not able to detect coproantibody in saline extracts of feces from animals which received the vaccine.
Nature of the Effector of Catabolite Repression of β-Galactosidase in
Escherichia coli
Authors: Loomis William F. , Magasanik Boris
Published: January 2020

Loomis, William
F.,
Jr.
(Massachusetts Institute of Technology, Cambridge, Mass.),
and Boris Magasanik
. Nature of the effector of catabolite repression of β-galactosidase in
Escherichia coli
. J. Bacteriol.
92:
170–177. 1966.—Many carbon sources were found to give rise to catabolite repression of β-galactosidase in a mutant strain of
Escherichia coli
lacking hexose phosphate isomerase activity. Compounds containing glucose or galactose cannot be formed from several of these carbon sources in this mutant strain, and, therefore, appear not to be required for catabolite repression of β-galactosidase. Glucose was observed to elicit catabolite repression of β-galactosidase in another mutant strain under conditions in which the formation of compounds of the citric acid cycle is inhibited. If catabolite repression of the
lac
operon is mediated by a single compound, it appears that the compound is related to the pentoses and trioses of intermediary metabolism. The repression of β-galactosidase by galactose in galactokinase negative strains was shown to be independent of the gene,
CR
, which determines catabolite sensitivity of the
lac
operon, and to be dependent on a functional
i
gene.
Studies with Hydroxyurea II. Prolonged Exposure of
Escherichia coli
to Hydroxyurea
Authors: Rosenkranz Herbert S. , Carr Howard S.
Published: January 2020

Rosenkranz, Herbert
S. (Columbia University, New York, N.Y.),
and Howard S. Carr
. Studies with hydroxyurea. II. Prolonged exposure of
Escherichia coli
to hydroxyurea. J. Bacteriol.
92:
178–185. 1966.—Concurrent with an inhibition of the synthesis of deoxyribonucleic acid, hydroxyurea devitalized
Escherichia coli
when exposure to the drug was prolonged to more than 3 hr. Active protein synthesis, but not ribonucleic acid (RNA) production, was a prerequisite for this lethal action. These findings are contrasted to thymineless death, which requires RNA synthesis.
Thymidylate Synthesis and Aminopterin Resistance in
Bacillus subtilis
Authors: Wilson Melba Carr , Farmer James L. , Rothman Frank
Published: January 2020

Wilson, Melba Carr
(Brown University, Providence, R.I.),
James L. Farmer, and Frank Rothman
. Thymidylate synthesis and aminopterin resistance in
Bacillus subtilis
. J. Bacteriol.
92:
186–196. 1966.—The thymine-requirement of
Bacillus subtilis
168
thy
results from mutation in two unlinked genes (i.e., genetic loci) designated
thyA
and
thyB
. The
thyB
gene is located between the
met
and
ile
markers. Both
thyA
+
thyB
and
thyA thyB
+
strains are phenotypically
thy
+
.
ThyA
+
thyB
strains resemble the wild type in their sensitivity to aminopterin, poor incorporation of exogenous thymine into deoxyribonucleic acid (DNA), and high level of thymidylate synthetase activity in crude extracts.
ThyA thyB
+
strains are resistant to aminopterin in the presence of thymine, incorporate exogenous thymine into DNA, and have no detectable thymidylate synthetase activity. Experiments designed to elucidate the role of the
thyB
gene indicate that it specifies an alternate pathway of thymidylate synthesis, similar to thymidylate synthetase but requiring a cofactor other than tetrahydrofolate. The mechanism of selection of thymine-requiring mutants by aminopterin is revealed by these results.
Electron Microscopy of the Infection and Subsequent Development of Soybean Nodule Cells
Authors: Goodchild D. J. , Bergersen F. J.
Published: January 2020

Goodchild
, D. J. (Commonwealth Scientific and Industrial Research Organization, Canberra, Australia),
and
F. J.
Bergersen
. Electron microscopy of the infection and subsequent development of soybean nodule cells. J. Bacteriol.
92:
204–213. 1966—Electron microscopy of thin sections of the developing central tissue cells of young soybean root nodules has shown that infection is initiated by a few infection threads which penetrate cells of the young central tissue. Extension growth of the threads may be a result of pressure developed from the growth of the bacteria within the threads. Release of bacteria from a thread is preceded by the development on an infection thread of a bulge with a cellulose-free membrane-bounded extension; bacteria move from this into the host cells by an endocytotic process and remain enclosed in an infection vacuole which is bounded by a membrane of host-cell origin. Multiplication of the intracellular bacteria takes place within these vacuoles. Until the host cell becomes filled with bacteria, the vacuoles separate into discrete units at each division. Later, division of the bacteria occurs within each vacuole, thus leading to the mature structure of the central tissue cells in which several bacteria are enclosed within each membrane-bounded unit.
Physical Properties of HumanMycoplasmaSpecies
Authors: Kim Kwang S. , Clyde Wallace A. , Denny Floyd W.
Published: January 2020

Kim, KwangS. (University of North Carolina, Chapel Hill),Wallace A. Clyde, Jr.,and Floyd W. Denny. Physical properties of human mycoplasma species. J. Bacteriol.92:214–219. 1966.—Studies were made of the comparative morphology and stability of fiveMycoplasmaspecies of human origin (M. hoministype 1,M. salivarium, M. fermentans, M. pneumoniae, M. pharyngis). Broth-cultivated organisms were examined by electron microscopy to determine their relative appearance after uniform processing, including fixation-drying with formaldehyde vapor.M. pneumoniaewas characterized by the occurrence of 250- to 300-mμ spheres in clusters, andM. pharyngisby the appearance of filaments 120 mμ by 1.5 to 8 μ; the remaining species revealed a variety of structures, including spheres, rings, and short filaments. To complement these findings, the effect of physical stresses on viability of the mycoplasmas was measured by exposing the organisms to heat (in saline), osmotic variations (in sucrose), and sonic oscillation and repetitive freeze-thawing (in culture medium).M. pneumoniaewas most resistant to heat, vibration, and freeze-thawing;M. pharyngiswas most sensitive to heart and vibration, but was least affected by osmotic changes. The remaining organisms assumed intermediate positions. The type-related variations in relative morphology and stability suggest differing physical attributes of the mycoplasmas studied, supporting taxonomic differentiation of the five species based on metabolic and immunological criteria.
Structural Details of Anthrax Spores During Stages of Transformation into Vegetative Cells
Authors: Moberly Betty J. , Shafa F. , Gerhardt Philipp
Published: January 2020

Moberly, Betty
J. (The University of Michigan, Ann Arbor), F.
Shafa, and Philipp Gerhardt
. Structural details of anthrax spores during stages of transformation into vegetative cells. J. Bacteriol.
92:
220–228. 1966.—Anthrax spores in stages of dormancy, activation, germination, and outgrowth into vegetative cells were examined in an electron microscope. The fine structure proved to be much like that observed in related species of
Bacillus
, except for a visible alteration after heat activation and clusters of vesicle-like bodies in the cytoplasm of vegetative cells.
Effect of Tryptophan on Growth and Morphology ofHansenula schneggiiCells
Authors: Sundhagul Malee , Hedrick L. R.
Published: January 2020

Sundhagul, Malee(Illinois Institute of Technology, Chicago),andL. R.Hedrick. Effect of tryptophan on growth and morphology ofHansenula schneggiicells. J. Bacteriol.92:241–249. 1966.—WhenHansenula schneggiicells were cultured aerobically in a tryptophan-glucose medium, 70 to 90% of the cells were elongated; no growth occurred under anaerobic conditions. The size of the elongated cells was 15 to 25 μ by 2 to 4 μ, as compared with 2.5 to 5 μ for ellipsoidal cells. Formation of elongated cells occurred essentially during the logarithmic growth period; the highest percentage of elongated cells was found soon after the end of this growth phase. In the later stationary phase, some of the cells formed spherical buds which became spherical cells. The rate of cell division during this period was greatly reduced, but the spherical cells formed decreased the percentage of elongated cells in the population. Cells cultured in a membrane-filter filtrate of a tryptophan-glucose medium (with limiting tryptophan), in which elongated cells had been grown, were ellipsoidal until nitrogenous nutrients were exhausted; thereafter the cells were elongated if tryptophan was added. Of compounds related to tryptophan, kynurenine was the only one which induced a high percentage of the cells to elongate. Some amino acids, such as cystine, histidine, phenylalanine, tyrosine, and threonine, induced elongation in about 15% of the cells. Growth of cells with other amino acids, or the addition of most of the other amino acids to tryptophan-glucose medium, resulted in a population of spherical cells. Several consecutive sequential transfers of cells into tryptophan medium induced elongation in 90% of the cells, but one transfer from a culture with elongated cells into a medium with ammonium sulfate, or a mixture of amino acids, gave a culture with ellipsoidal cells. Growth in media atpH 4 or 5 favored formation of elongated cells; as thepH was increased, the percentage of elongated cells decreased. Carbon sources other than glucose did not affect the percentage of elongated cells, except for the alcohols mannitol and erythitol, which gave comparable growth but reduced the percentage of elongated cells from 70 to 50%. Cell wall analyses of the two types of cells indicated that elongated cells have 2.5 times as much mannan as cell walls of ellipsoidal cells. This suggests that tryptophan, kynurenine, and, to a limited extent, some of the other amino acids cause a diversion of polysaccharide biosynthesis to mannan in the elongated cells rather than to glucan as in ellipsoidal cells.
Biological and Morphological Aspects of the Growth of Equine Abortion Virus
Authors: Darlington R. W. , James C.
Published: January 2020

Darlington, R. W. (St. Jude Children's Research Hospital, Memphis, Tenn.),and C. James. Biological and morphological aspects of the growth of equine abortion virus. J. Bacteriol.92:250–257. 1966.—The growth of equine abortion virus (EAV) was studied by bioassay and electron microscopy in L-cell monolayer and suspension cultures, and in HeLa and BHK 21/13 cell monolayers. Results of virus assay (plaque-forming units) indicated that production of cell-associated virus (CAV) began at 6 to 9 hr after infection in all of the cell strains used. Virus release occurred 1 to 2 hr later. By 15 to 20 hr after infection, the amount of released virus (RV) equaled or surpassed that of CAV in all cells other than the HeLa cells, where the amount of RV did not equal CAV until 48 hr after infection. Electron microscopy of infected cells revealed no differences in the morphology of virus development in any of the cells used. Developing virus particles were first detected in cell nuclei at 9 hr after infection. At 12 hr, virus particles could be seen budding from the inner nuclear envelope. Budding into cytoplasmic vacuoles was not seen. Budding virus, virus in cytoplasmic vacuoles, and extracellular virus were all approximately 145 mμ in diameter, and were indistinguishable morphologically. These results indicated that EAV is quite similar to herpes simplex virus with respect to growth and morphology, and that the inner nuclear membrane is the principal site of virus envelopment.
Replication of Mumps Virus in Human Leukocyte Cultures
Authors: Duc-Nguyen Huu , Henle Werner
Published: January 2020

Duc-Nguyen, Huu(The Children's Hospital of Philadelphia, Philadelphia, Pa.),and Werner Henle. Replication of mumps virus in human leukocyte cultures. J. Bacteriol.92:258–265. 1966.—Human peripheral leukocyte cultures maintained in the presence of phytohemagglutinin (PHA) were found to support to some extent the replication of mumps virus. When such cultures were exposed, within 24 hr after their initiation, to a high input multiplicity of virus, successful infection, as determined by immunofluorescence and plaque assays, did not become evident before the 3rd or 4th day. On exposure of cultures 4 to 5 days old, viral replication was detectable within 2 days. In both instances, peak immunofluorescence and virus titers were reached when the cultures were 7 to 9 days old and composed mainly of blast forms. With decreasing input multiplicities of infection, cells containing viral antigen and production of infectious viral progeny became detectable with increasing delay. No significant viral replication was noted in surviving cells maintained in the absence of PHA. These results indicate that mainly, if not solely, the PHA-stimulated cells of the lymphocytic series support viral multiplication. The extent of the infectious process was limited, however, because the life span of the cultures was not significantly shortened, the yields of infectious virus per immunofluorescent cell were at all times low, and most infected cells contained only a few well-delineated small masses of antigen, suggestive of an abortive infection. Only fresh cultures were capable of synthesizing interferon on stimulation by mumps, Newcastle disease, or Sendai viruses. When the cultures were set up in the presence of PHA, this capacity was lost within 24 hr. PHA per sefailed to induce detectable production of an interferon under the conditions used. The implications of these findings are discussed.
Alterations in Host Specificity of Bacterial Deoxyribonucleic Acid After an Increase in Growth Temperature of
Pseudomonas aeruginosa
Authors: Rolfe B. , Holloway B. W.
Published: January 2020

Rolfe
, B. (University of Melbourne, Victoria, Australia),
and B. W. Holloway
. Alterations in host specificity of bacterial deoxyribonucleic acid after an increase in growth temperature of
Pseudomonas aeruginosa
. J. Bacteriol.
92:
43–48. 1966.—Increased recombination frequency is found with some crosses of
Pseudomonas aeruginosa
if the FP
−
parent is grown at 43 C prior to mating. This occurs where there is a difference in host specificity between the FP
−
and FP
+
parents, as is found in strains 1 and 2. Differences in recovery of unlinked markers are found in such crosses, and the results can be explained in terms of an alteration of the restriction and modification mechanisms by growth at the higher temperature, similar to that previously shown to occur with host-modified bacteriophage. As with that system, persistence of the temperature effect occurs for a number of generations after the strains are returned for growth at 37 C.
Epidemiological and Immunological Studies ofCryptococcus neoformans
Authors: Walter Jinks E. , Atchison Robert W.
Published: January 2020

Walter, JinksE. (University of Pittsburgh, Pittsburgh, Pa.),and Robert W. Atchison. Epidemiological and immunological studies ofCryptococcus neoformans. J. Bacteriol.92:82–87. 1966.—The complement-fixation fluorescent-antibody test provided a means of differentiating between antibodies ofCryptococcus neoformansandCandida albicans. The test was applied to the sera of 134 pigeon fanciers for detection of antibodies toC. neoformansonly. About 22% were positive as compared with 3% of a control group composed of 36 non-pigeon breeders. Positive reactions were observed only withC. neoformanstypes A and B cells. It was concluded that the pigeon fanciers had presumably been infected previously withC. neoformanstype A or type B. Moreover, 48 of 49 isolates ofC. neoformanscultured from the pigeon habitats of 72 fanciers studied were serotype A. These findings would seem to substantiate the hypothesis that pigeon habitats serve as reservoirs for human infections, and also that subclinical cryptococcosis is more prevalent than is realized.
Effect of Mycoplasma on Interferon Production and Interferon Assay in Cell Cultures
Authors: Armstrong D. , Paucker K.
Published: January 2020

Armstrong
, D. (The Children's Hospital of Philadelphia, Philadelphia, Pa.),
and K. Paucker
. Effect of mycoplasma on interferon production and interferon assay in cell cultures. J. Bacteriol.
92:
97–101. 1966.—The influence of mycoplasma on the production and action of interferon was studied in cultures of both L and human embryonic kidney (HEK) cells.
Mycoplasma hominis
1, the Negroni agent, and the F12 mycoplasma were used for infection of L cells, and
M. hominis
1 and
M. pneumoniae
for inoculation of HEK cells. All strains were capable of multiplication in the culture systems employed. None produced detectable levels of interferon, and responsiveness of the cells to induction of interferon by virus remained unaltered. Infection with mycoplasma did not impair the sensitivity of the cells to the action of interferon, nor was the replication of vesicular stomatitis virus noticeably diminished.
Delayed Lactose Fermentation byEnterobacteriaceae
Authors: Goodman R. E. , Pickett M. J.
Published: January 2020

Goodman, R. E. (University of California, Los Angeles),andM. J.Pickett. Delayed lactose fermentation byEnterobacteriaceae. J. Bacteriol.92:318–327. 1966.—When 171Citrobacter freundiistrains and 14Paracolobactrum arizonaestrains examined, 51 of theC. freundii strainsand 13 of theP. arizonaestrains were found to be delayed or negative lactose fermenters. Of the slow fermenters, 65% yielded rapidly fermenting mutants in cultures undergoing delayed fermentation. Lactose fermentation could generally be hastened by increasing lactose concentrations. Many organisms which fermented lactose slowly grew readily on a medium containing lactose as the sole carbon source. Regardless of their ability to ferment lactose, all strains ofC. freundiiandP. arizonaeinvestigated could be shown to possess β-galactosidase. Delayed fermenters failed to take up lactose from the culture medium, whereas prompt fermenters did so readily. The β-galactosidases of 12 strains of enteric bacteria were studied in crude cell extracts with respect to specific activity, stability, and activity at varying substrate (o-nitrophenyl-β-d-galactopyranoside) concentrations, at varyingpH, and in the presence of sodium, potassium, and magnesium. The widely varying specific activities and the approximate similarity of the Michaelis constants (about 2 × 10−4m) suggested that the strains investigated produced differing amounts of β-galactosidase. Moreover, qualitative differences in the enzymes provided evidence that these strains synthesized different molecular forms of β-galactosidase. The results suggested that organisms which ferment lactose only after a prolonged delay do so because they possess multiple defects in their lactose-metabolizing machinery.
Occurrence and Distribution of Proteinase of
Streptococcus faecalis
var.
liquefaciens
Authors: Shugart Lee R. , Beck Raymond W.
Published: January 2020

Shugart, Lee
R. (University of Tennessee, Knoxville),
and Raymond W. Beck
. Occurrence and distribution of proteinase of
Streptococcus faecalis
var.
liquefaciens
. J. Bacteriol.
92:
338–341. 1966.—The proteolytic enzyme produced by
Streptococcus faecalis
var.
liquefaciens
(ATCC 13398) was shown to be an exoenzyme. The production of the proteinase was followed in growing cultures, and its distribution was compared with that of the intracellular enzymes reduced nicotinamide adenine dinucleotide (NADH
2
) peroxidase and lactate dehydrogenase. The proteinase appeared in the culture medium prior to the stationary phase of growth, whereas the other enzymes could be found only in whole cells. Fractionation of whole cells by sonic treatment and by treatment with lysozyme showed the proteinase to be associated primarily with the cell wall and cell membrane, and NADH
2
peroxidase to be associated only with the cytoplasmic fractions.
Immunological Tolerance to Microbial Antigens I. Absence of Specific Antibody-Containing Cells in Lymphoid Tissue of Mice Injected at Birth withShigellaSoluble Antigen
Authors: Friedman Herman
Published: January 2020

Friedman, Herman(Albert Einstein Medical Center, Philadelphia, Pa.). Immunological tolerance to microbial antigens. I. Absence of specific antibody-containing cells in lymphoid tissue of mice injected at birth withShigellasoluble antigen. J. Bacteriol.92:390–397. 1966.—Injection of a relatively large concentration ofShigellasoluble antigen (SSA) into newborn mice results in specific immunological tolerance (paralysis) characterized by inability of the animals to form normal levels of anti-Shigellaagglutinins upon subsequent challenge immunization withShigella. Spleen and lymph nodes fromShigella-tolerant mice, as well as from normal and control immunized mice, were examined by the indirect immunofluorescence technique for evidence of cells containing anti-Shigellaantibody. It was found that mice sacrificed at periodic intervals after neonatal administration of the tolerance-inducing inoculum of antigen and prior to and following challenge injection with a potential immunizing dose of SSA had only occasional specific fluorescing cells in spleens and lymph nodes. Tolerant mice also failed to develop significant levels of specific serum agglutinins after SSA challenge injection. In contrast, normal adult mice had a rapid appearance of numerous specific fluorescing cells in their spleens and lymph nodes, as well as a marked agglutinin response, after SSA immunization.Shigella-tolerant and normal control mice responded equally well with anti-Salmonellaagglutinin formation and specific antibody-containing lymphoid cells after immunization withSalmonellaantigen.
Detection of Biologically Active Adenovirions Unable to Plaque in Human Cells
Authors: Butel Janet S. , Melnick Joseph L. , Rapp Fred
Published: January 2020

Butel, Janet
S. (Baylor University College of Medicine, Houston, Tex.),
Joseph L. Melnick, and Fred Rapp
. Detection of biologically active adenovirions unable to plaque in human cells. J. Bacteriol.
92:
433–438. 1966.—Plaque formation in green monkey kidney (GMK) cells by a defective simian virus 40-adenovirus 7 “hybrid” population (PARA-adenovirus 7) was enhanced by the addition of excess adenovirions. Adenovirus types 2, 7, and 12 were capable of providing enhancement, although none of these viruses gives rise to plaques in simian cells in the absence of PARA (particle aiding replication of adenovirus). Near maximal enhancement of the PARA plaque titer on simian cells was obtained with input multiplicities ranging from 0.02 to 0.14 plaque-forming units (PFU) of helper adenovirus per GMK cell. The PFU of helper adenoviruses tested (types 2, 7, and 12) were measured in the most sensitive assay system, human kidney cells. This input corresponded to three to nine helper virus particles per GMK cell. The majority of particles capable of enhancing plaque formation by PARA banded at a density of 1.34 in CsCl. Adenoviruses inactivated by heat or ultraviolet light were not capable of enhancing plaque formation by PARA. Highest titers were obtained when PARA and helper adenovirus were inoculated simultaneously. Inoculation of the helper adenovirus 24 hr prior to the inoculation of PARA resulted in the formation of only 50% as many plaques, and no enhanced plaques developed when the adenovirus preceded PARA by 48 hr. Conversely, the addition of adenovirus 48 hr after the inoculation of PARA initiated 56% as many plaques as simultaneous inoculation; 4% of the enhanced plaques still formed when helper virus was added as late as 5 days after inoculation of PARA. These results suggest that adenovirus particles unable to plaque on human or monkey kidney cells are nevertheless capable of interacting with PARA in simian cells, thereby facilitating replication of both particles.
Fine Structure of
Thiobacillus thiooxidans
Authors: Mahoney Robert P. , Edwards Mercedes R.
Published: January 2020

Mahoney, Robert
P. (Skidmore College, Saratoga Springs, N.Y.),
and Mercedes R. Edwards
. Fine structure of
Thiobacillus thiooxidans
. J. Bacteriol.
92:
487–495. 1966.—Thin section analysis of the chemosynthetic autotroph
Thiobacillus thiooxidans
revealed structures comparable to gram-negative heterotrophic bacteria. Although this species is unique in that it oxidizes elemental sulfur for energy, uses carbon dioxide as its sole source of carbon, and can withstand a
p
H of less than 1, thin sections revealed a profile of the cell envelope (cell wall and plasmalemma) similar to other gram-negative species which have more common physiological traits. The cell wall is composed of five layers with an overall width of approximately 200 A, and the plasmalemma appears as a conventional “unit membrane” with a width of about 85 A. Volutin granules and less-dense bodies of similar shape and size were frequently observed in close association with the nucleoplasm. The nature and function of these bodies are unknown at this time.
Significance of Chromogenic Variants in Studies of Virulence Factors ofStaphylococcus aureus
Authors: Parisi Joseph T.
Published: January 2020

Parisi, JosephT. (Duquesne University, Pittsburgh, Pa.). Significance of chromogenic variants in studies of virulence factors ofStaphylococcus aureus. J. Bacteriol.92:589–591. 1966.—Large numbers of chromogenic variants were isolated from cultures of a parent strain ofStaphylococcus aureusgrowing in Brain Heart Infusion (Difco). The parent strain and four selected chromogenic variants were tested for either quantitative or qualitative differences in the production of extracellular substances associated with virulence. Quantitative differences were found in the ability of these strains to produce coagulase and hyaluronidase, whereas qualitative differences were found in the production of plate hemolysins, bound coagulase, opacity in an egg yolk medium, and a proteinase. In view of the rate and extent of the occurrence of these chromogenic variants, their presence in an inoculum could lead to inaccurate results in in vitro studies of staphylococcal virulence.
Unsaturated Fatty Acid Mutants of
Saccharomyces cerevisiae
Authors: Resnick Michael A. , Mortimer Robert K.
Published: January 2020

Resnick, Michael
A. (University of California, Berkeley),
and Robert K. Mortimer
. Unsaturated fatty acid mutants of
Saccharomyces cerevisiae
. J. Bacteriol.
92:
597–600. 1966.—The wild type of the yeast
Saccharomyces cerevisiae
does not require fatty acids or sterols for growth. Two types of lipid nutritional mutants have been induced in this organism. One of these classes of mutants requires an unsaturated fatty acid and is associated with a locus on chromosome VII. The other class of mutants needs either an unsaturated fatty acid or ergosterol for growth. Experiments involving identification and characterization of these mutants are presented.
Influence of Starvation for Methionine and Other Amino Acids on Subsequent Bacterial Deoxyribonucleic Acid Replication
Authors: Billen Daniel , Hewitt Roger
Published: January 2020

Billen, Daniel
(University of Texas M. D. Anderson Hospital and Tumor Institute, Houston, Tex.),
and Roger Hewitt
. Influence of starvation for methionine and other amino acids on subsequent bacterial deoxyribonucleic acid replication. J. Bacteriol.
92:
609–617. 1966.—A study has been made of the subsequent replicative fate of deoxyribonucleic acid (DNA) synthesized during amino acid starvation by several multiauxotrophic strains of
Escherichia coli
. Using radioisotopic and density labels and a procedure whereby total cellular DNA is analyzed, we have confirmed and extended a recent report that the DNA made during amino acid starvation behaves anomalously during subsequent DNA replication. When 5-bromouracil (BU) serves as the density lable, 40% or more of the DNA synthesized during starvation will subsequently fail to replicate during three cell generations. Selective amino acid effects were noted. In two methionine-requiring bacteria, methionine deprivation appeared to be of singular importance in influencing the subsequent replicative fate of the DNA made in its absence.

When a non-BU density label (N
15
, C
13
) was utilized, the effects of amino acid starvation were less obvious. Although the DNA synthesized during complete amino acid starvation in a methionine-requiring
E. coli
was subsequently more slowly replicated, most of the DNA was finally duplicated during three generations of growth. If methionine was present during starvation for other required amino acids, the subsequent replication rate of the DNA synthesized during this time was more nearly normal, and complete replication was observed. The results have been interpreted as indicating that DNA synthesized during amino acid starvation, and especially during methionine starvation, is somehow altered, and that BU substitution for thymine may interfere with the restoration of such DNA to its replicative state.
Effect of Amino Acids on the Nitrogenase System of
Klebsiella pneumoniae
Authors: Yoch D. C. , Pengra R. M.
Published: January 2020

Yoch
, D. C. (South Dakota State University, Brookings), and R. M.
Pengra
. Effect of amino acids on the nitrogenase system of
Klebsiella pneumoniae
. J. Bacteriol.
92:
618–622. 1966.—The effect of exogenous amino acids and the free amino acid pool on the synthesis of the nitrogenase system of
Klebsiella pneumoniae
M5al (formerly
Aerobacter aerogenes
M5al) was investigated. When an actively N
2
-fixing culture was used to inoculate a medium containing a limiting concentration of NH
4
+
, an induction lag period was observed. When either a single amino acid or a mixture of amino acids was substituted at the same nitrogen concentration, growth was uninterrupted by the induction period. It appears that a step or steps in the formation of the nitrogenase system are repressed by NH
4
+
and are not affected by amino acid N. The amino acids, far from repressing formation of nitrogenase as does NH
4
+
, actually stimulate its formation. It appears that both free and amino nitrogen are used simultaneously. The amino acids that served concomitantly with N
2
as a source of nitrogen were: aspartic acid, serine, threonine, leucine, and histidine. Of these amino acids, it was shown that aspartic acid is readily taken up by the cells. Of the amino acids not serving as an immediate nitrogen source, isoleucine is not taken up by the cells. The free amino acid pool of the cells was measured at the onset and termination of the induction period. Ninhydrin-positive material in the amino acid pool was depleted by 35% during the induction period.
Nitrite Reductase of
Escherichia coli
Specific for Reduced Nicotinamide Adenine Dinucleotide
Authors: Kemp John D. , Atkinson Daniel E.
Published: January 2020

Kemp, John
D. (University of California, Los Angeles),
and Daniel E. Atkinson
. Nitrite reductase of
Escherichia coli
specific for reduced nicotinamide adenine dinucleotide. J. Bacteriol.
92:
628–634. 1966.—A nitrite reductase specific for reduced nicotinamide adenine dinucleotide (NADH
2
) appears to be responsible for in vivo nitrite reduction by
Escherichia coli
strain Bn. In extracts, the reduction product is ammonium, and the ratio of NADH
2
oxidized to nitrite reduced or to ammonium produced is 3. The Michaelis constant for nitrite is 10 μ
m
. The enzyme is induced by nitrite, and the ability of intact cells to reduce nitrite parallels the level of NADH
2
-specific nitrite reductase activity demonstrable in cell-free preparations. Crude extracts of strain Bn will also reduce hydroxylamine, but not nitrate or sulfite, at the expense of NADH
2
. Kinetic observations indicate that hydroxylamine and nitrite may both be reduced at the same active site. The high apparent Michaelis constant for hydroxylamine (1.5 m
m
), however, seems to exclude hydroxylamine as an intermediate in nitrite reduction. In vitro activity is enhanced by preincubation with nitrite, and decreased by preincubation with NADH
2
.
Isolation and Identification of Obligate Thermophilic Sporeforming Bacilli from Ocean Basin Cores
Authors: Bartholomew J. W. , Paik George
Published: January 2020

Bartholomew
, J. W. (University of Southern California, Los Angeles),
and George Paik
. Isolation and identification of obligate thermophilic sporeforming bacilli from ocean basin cores. J. Bacteriol.
92:
635–638. 1966.—Obligate thermophilic sporeforming aerobic bacilli were isolated from 11 ocean basin cores taken from locations in a 150 mile long area off of the coast from Ensenada, Mexico, to Santa Catalina Island, and ranging as far out from shore as 160 miles. Isolated strains of bacilli were all identified as being identical, or closely related, to
Bacillus stearothermophilus
.
Soluble Antigens of Vaccinia-infected Mammalian Cells I. Separation of Virus-induced Soluble Antigens into Two Classes on the Basis of Physical Characteristics
Authors: Cohen Gary H. , Wilcox Wesley C.
Published: January 2020

Cohen, GaryH. (University of Pennsylvania, Philadelphia),and Wesley C. Wilcox. Soluble antigens of vaccinia-infected mammalian cells. I. Separation of virus-induced soluble antigens into two classes on the basis of physical characteristics. J. Bacteriol.92:676–686. 1966—Infection of mammalian cells with members of the poxvirus group elicits production of a number of virus-induced, soluble antigens. Immunoelectrophoresis and immunodiffusion techniques employing soluble antigen preparations obtained from vaccinia virus-infected KB cells revealed at least seven well-defined immunoprecipitin bands. On the basis of fractionation and subsequent characterization of the soluble antigen mixture by gel filtration, calcium phosphate chromatography, isoelectric precipitation, disc electrophoresis, and ultracentrifugation studies, two distinct classes of virus-induced antigens differing markedly in molecular weight were recognized. A high molecular weight class (200,000 and greater) contained at least three virus-induced antigens; a low molecular weight class (50,000 to 100,000 range) contained at least four immunoprecipitins. Further separation of the antigens within the two groups was accomplished. The two classes were distinguished also by their ability to stimulate synthesis of virus-neutralizing antibody. Antisera prepared against the high molecular weight class proved effective in neutralizing vaccinia virus. In contrast, the low molecular weight antigens showed little, if any, ability to induce formation of neutralizing antibody.
Pantothenate and Coenzyme A in Bacterial Growth
Authors: Toennies G. , Das D. N. , Feng F.
Published: January 2020

Toennies
, G. (Temple University School of Medicine, Philadelphia, Pa.), D. N.
Das, and F. Feng
. Pantothenate and coenzyme A in bacterial growth. J. Bacteriol.
92:
707–713. 1966.—The effect of environmental pantothenate levels on the growth of
Streptococcus faecalis
9790 was studied in terms of growth rate, depletion phenomena, cellular coenzyme A (CoA) content, and differential rates of wall and membrane synthesis. Low concentrations of pantothenate yielded normal exponential growth curves up to peak turbidities which are a function of pantothenate concentration. Attainment of these peaks was followed by lysis. Under such conditions, bacterial CoA increased initially in proportion with cell substance, but attained a peak level much earlier than cell substance, and then gradually decreased down to vanishing amounts. With higher pantothenate concentrations, cellular CoA levels increased to a maximum, and, under these conditions, the CoA content remained constant during exponential growth. Four-fifths of the pantothenate requirement of growing cells was eliminated by environmental oleate and palmitate. When CoA disappeared during growth on low pantothenate levels, cell wall synthesis seemed to continue at nearly normal rates, but membrane synthesis was severely curtailed. The data suggest that in fermentative organisms pantothenate action might be confined to wall and membrane synthesis, that these two processes differ in their quantitative dependence on pantothenate, and that pantothenate might occur in the form of acyl carrier protein as well as CoA.
Isolation of Amylolytic Strains of
Thermoactinomyces vulgaris
and Production of Thermophilic Actinomycete Amylases
Authors: Kuo M. J. , Hartman P. A.
Published: January 2020

Kuo
, M. J. (Iowa State University, Ames),
and P. A. Hartman
. Isolation of amylolytic strains of
Thermoactinomyces vulgaris
and production of thermophilic actinomycete amylases. J. Bacteriol.
92:
723–726. 1966.—Of 759 isolates obtained from dung, compost, and soil samples, a culture of
Thermoactinomyces vulgaris
(strain 5) was selected for further study on the basis of quantities of amylase produced in synthetic and nonsynthetic media, rapid growth and sporulation, culture stability upon prolonged storage at 5 C, and growth temperature range. Inoculum preparation, temperature optimum for amylase formation, and the effects of various kinds and levels of carbon and nitrogen sources on amylase production were studied with
T. vulgaris
strain 5. An optimal procedure for production of
T. vulgaris
amylases is proposed.
Comparison of Two Serologically Distinct Ribonucleic Acid Bacteriophages II. Properties of the Nucleic Acids and Coat Proteins
Authors: Overby L. R. , Barlow G. H. , Doi R. H. , Jacob Monique , Spiegelman S.
Published: January 2020

Overby
, L. R. (University of Illinois, Urbana), G. H.
Barlow, R. H. Doi, Monique Jacob, and S. Spiegelman
. Comparison of two serologically distinct ribonucleic acid bacteriophages. II. Properties of the nucleic acids and coat proteins. J. Bacteriol.
92:
739–745. 1966.—The ribonucleic acid (RNA) molecules and coat proteins of two RNA coliphages, MS-2 and Qβ, have been characterized. MS-2 RNA shows an
S
20,w
of 25.8 and a molecular weight by light scattering of 10
6
. The corresponding parameters for Qβ-RNA were 28.9 and 0.9 × 10
6
. A difference in base composition was reflected in the adenine-uracil ratio, which was 0.95 for MS-2 and 0.75 for Qβ. The two RNA preparations are readily separated by chromatography on columns of methylated albumin. Both gave identical bouyant densities in cesium sulfate of 1.64 g/ml. The coat protein subunits were of similar molecular weights: 15,500 (Qβ) and 14,000 (MS-2). They differed, however, in that the Qβ-protein lacked tryptophan and histidine, whereas the MS-2 protein lacked only histidine.