bluuebunny/crossref_metadata_2025 huggingface dataset:
Tissue Receptor for Cholera Exotoxin: Postulated Structure from Studies with G
M1
Ganglioside and Related Glycolipids
Authors: Holmgren J. , Lönnroth I. , Svennerholm L.
Published: January 2020

By a double-diffusion precipitation-in-gel technique, isolated cholera toxin as well as its natural toxoid were shown to be fixed and precipitated by the ganglioside G
M1
but not by any of the related glycolipids G
M3
, G
M2
, G
M1
-GlcNAc, G
D1a
, G
D1b
, G
T1
, globoside, G
A1
, and tetrahexoside-GlcNAc. Twenty-five nanograms of G
M1
was enough to give a precipitation line with 1.2 μg of toxin, whereas about 50 ng was required with this amount of toxoid. G
M1
also inactivated the toxin in the ileal loop as well as in the intradermal models in rabbits. A 1: 1 molar ratio of ganglioside to toxin was found limiting, e.g., 100 pg of G
M1
could inactivate 5 ng (about 50 blueing doses) of isolated toxin. G
M1
inactivated crude toxin (culture fil rate) with the same efficiency as isolated toxin, and the inactivating capacity of G
M1
was unaffected by mixing with other gangliosides, indicating the specificity in the reaction between G
M1
and toxin. The other glycolipids tested did not inactivate toxin except G
D1a
and G
A1
which did so with approximately 1,000 times less efficiency than G
M1
. This identified the portion Gal → GalNAc [Formula: see text] as the critical region in G
M1
for toxin fixation, and it is postulated that this may be the tissue receptor structure for the cholera toxin.
In Vitro Migration of Human Alveolar Macrophages: Effects of Cigarette Smoking
Authors: Warr Glenn A. , Martin R. Russell
Published: January 2020

The responsiveness of alveolar macrophages lavaged from healthy volunteers to migration inhibitory factor (MIF) was tested by using the capillary-tube assay method. In every instance, macrophages from nonsmokers responded to MIF as demonstrated by a depression in migration of at least 30%, whereas MIF did not inhibit migration of macrophages from smokers. Cells from smokers migrated at a rate three times faster than cells from nonsmokers. Migration of macrophages from nonsmokers with delayed hypersensitivity skin reactions to
Candida albicans
antigen was inhibited when antigen was present in the tissue culture medium. Antigen did not inhibit macrophages from subjects who lacked delayed hypersensitivity to the antigen, or from subjects who were cigarette smokers. Since alveolar macrophages can respond to MIF in vitro, they may play a role in cell-mediated immune reactions in the lung. Cigarette smoking may interfere with this participation.
Distribution by Serological Type of Group B Streptococci Isolated from a Variety of Clinical Material over a Five-Year Period (with Special Reference to Neonatal Sepsis and Meningitis)
Authors: Wilkinson Hazel W. , Facklam R. R. , Wortham E. C.
Published: January 2020

A total of 898 group B streptococci isolated from a wide variety of human clinical sources from July 1967 through June 1972 were typed by the Lancefield precipitin test. Only 11% of the strains were nontypable. Twenty-six percent of the group B strains were from respiratory sources, 22% were from cerebrospinal fluid (CSF) and blood, 13% were from the female genital tract, 12% were urine specimens, and the remaining 27% were from other varied sources. The clinical conditions reported for patients from whom these organisms were isolated included neonatal meningitis and sepsis, pharyngitis, urinary tract and female genital tract infections, and various skin and wound infections. Seventy percent of the CSF and blood cultures from patients with meningitis or sepsis, or both, were type III, whereas the overall percentage of this type was 32%. All but three CSF isolates were from patients under 2 years of age; the distribution of CSF isolates appeared to be the same for both sexes. In contrast, group B streptococci were isolated more frequently from the blood of males than from the blood of females. There were twice as many blood cultures from patients under 2 years of age than from those that were older.
Some Observations on the Serology of
Pneumocystis carinii
Infections in the United States
Authors: Norman Lois , Kagan I. G.
Published: January 2020

An indirect immunofluorescent (IF) test with antigen of partially cleaned
Pneumocystis carinii
cysts was evaluated for sensitivity and specificity. The test was reactive at the 1:8 and above level for 44% of the persons who had suspected and confirmed infections, for 7.3% of the healthy contacts, and for 1.4% of the general population. Results of tests with sera from people with measurable antibodies to other diseases and those on immunosuppressant therapy suggest that only titers of 1:20 and above are specific. At this level, tests with sera of 32% of the cases, 4% of the contacts, 0% of the healthy controls, and from 0% to 37% (average 5%) of individuals on long-term immunosuppressive therapy or with antibodies to other diseases were positive. The high percentage of positive reactions in cytomegalovirus and in fungal infections could represent double infections. The complement fixation test was less sensitive than the IF test. Antibodies measured by the IF test were immunoglobulin G. No differences in antigenicity were demonstrated by the IF test among the cysts from eight human infections or from induced rat infections.
Source of Neuraminidase in Human Whole Saliva
Authors: Fukui Yoshio , Fukui Kazuhiro , Moriyama Takafumi
Published: January 2020

Whole saliva specimens from eight healthy human adults were examined for neuraminidase. The presence of two types of neuraminidase in four samples out of eight was demonstrated by means of polyacrylamide gel electrophoresis and sucrose density gradient centrifugation. One type is soluble and the other an insoluble, perhaps particle-bound, enzyme. The pH optima were 5.8 for the former and 5.0 to 5.3 for the latter. However, the soluble enzyme could not be detected in the other four saliva specimens which showed low activity. A comparative study of the salivary and other neuraminidases was carried out. It was found that both salivary neuraminidases were closely similar to the enzymes in submandibular-sublingual secretions and in human liver, but not to the oral streptococcal enzymes. The results suggest that the salivary neuraminidases might originate from cells such as epithelial cells or polymorphonuclear leukocytes, or both, in the oral cavity.
Inhibition of Enzymes by Human Salivary Immunoglobulin A
Authors: Fukui Yoshio , Fukui Kazuhiro , Moriyama Takafumi
Published: January 2020

Human whole saliva inhibited bacterial neuraminidases and the inhibition was found to reside in the salivary IgA fraction. Further, salivary immunoglobulin (Ig)A inhibited various bacterial enzymes and toxins: neuraminidases from
Streptococcus mitis, Streptococcus sanguis
, and
Clostridium perfringens
, hyaluronidase and chondroitin sulfatase from oral bacteria, diphtheria toxin, and streptolysin O. The inhibitory activity of salivary IgA did not correlate with that of serum on the basis of minimum inhibitory dose. A small amount of salivary IgA was required to inhibit oral bacterial neuraminidases, whereas a large amount was required to inhibit other bacterial neuraminidase. Therefore, it is concluded that the absence of neuraminidase activity of oral bacteria in whole saliva may be due to specific inhibition by salivary IgA.
Transmission of
lac
by the Sex Factor E in
Erwinia
Strains from Human Clinical Sources
Authors: Chatterjee Arun K. , Starr Mortimer P.
Published: January 2020

Lactose-utilizing (Lac
+
) strains of
Erwinia
spp. from human clinical material transfer
lac
by conjugation to plant strains of
Erwinia herbicola
and
Erwinia amylovora
, to other
Erwinia
strains from human clinical sources, and also to
Escherichia coli, Paracolobactrum arizonae, Salmonella typhimurium
, and
Shigella dysenteriae
. The frequency of this transfer varies with the donor and recipient strains employed. The
lac
genes appear stable in these exconjugants, and they are not cured by acridine orange. The Lac
+
exconjugants transfer
lac
to an
Escherichia coli
F
−
Lac
−
strain; the frequency of this transfer is high with
E. herbicola
and
S. typhimurium
exconjugants and relatively low with other exconjugants. The most studied
Erwinia
donor strain from human clinical material (EH133) and its Lac
+
exconjugants are insensitive to the F-specific phage, M13. P1-mediated transduction of
lac
, by using a Lac
+
exconjugant of
E. coli
as the donor and an
E. coli
F
−
Lac
−
strain as the recipient, revealed that all 50 Lac
+
transduced clones tested also inherited donor ability, suggesting a close linkage between the
Erwinia
sex factor (designated as E) and the
lac
genes. The
E. coli
culture harboring E-
lac
(E and the
lac
genes linked to it) does not restrict phages T1, T7, and λ
vir
. E-
lac
is compatible with F'
his
, R100
drd
-56 (F-like), and R64
drd
-11 (I-like); cells harboring F'
his
or one of the R factors do not show super-infection immunity to the incoming E-
lac
, and E-
lac
plus one of the other plasmids can coexist stably in the same cell. The fertility of cells harboring F'
his
or R100
drd
-56—as determined by the frequency of conjugal transfer of
his
or of the resistance determinant (Tet
r
in case of R100
drd
-56) and also by sensitivity to F-specific phage (M13)—is not altered by the presence of E-
lac
, and this suggests that the sex factor E might belong to the
fi
−
class.
Failure of Methylprednisolone to Protect Lead-Sensitized Rats Against Endotoxin
Authors: Jones Robert B. , Wise James L. , Kiesow Lutz A.
Published: January 2020

Methylprednisolone, in doses that protect normal rats against endotoxin, has no effect in lead-sensitized rats.
Virulence of Six Strains of
Mycobacterium bovis
(BCG) in Mice
Authors: Sher Neal A. , Chaparas Sotiros D. , Pearson Jack , Chirigos Michael
Published: January 2020

The abilities of six strains of
Mycobacterium bovis
strain BCG to replicate in vivo and to cause spleen enlargement in the CDF
1
male mouse were compared. The strains were grown in synthetic medium and harvested soon after complete pellicles were produced on liquid medium. In addition, two freeze-dried commercially available preparations were tested. The comparisons were made on the basis of injecting equal numbers of colony-forming units. Strain differences were marked. The Brazil strain was most effective in stimulating spleen enlargement, and the Japan strain was the least effective. This correlated with the number of colony-forming units isolated from the spleen.
Immunity to Syphilis I. Passive Transfer in Rabbits with Hyperimmune Serum
Authors: Perine Peter L. , Weiser Russell S. , Klebanoff Seymour J.
Published: January 2020

Passive transfer of humoral immunity to experimental syphilis in rabbits was accomplished with large doses of hyperimmune serum. When the serum was administered before inoculation of
Treponema pallidum
, the onset of chancres was delayed; when it was given early in the course of infection, a transient period of arrest and healing of the chancres was imposed.
Inhibition of Amino Acid Incorporation into Protein of Human Neutrophils by Phagocytosis
Authors: DeChatelet Lawrence R. , McCall Charles E. , McPhail Linda C.
Published: January 2020

The incorporation of uniformly labeled
14
C-amino acids into total protein of human polymorphonuclear leukocytes is inhibited when the cells are challenged with heat-killed
Escherichia coli
or latex particles. Parallel studies of amino acid incorporation and glucose oxidation indicate that the inhibition is dependent upon ingestion of the particles. It is suggested that the process of phagocytosis might inhibit the transport of amino acids into the cell either by competing for available energy or by internalizing specific transport sites.
Localization of Spirochetes with the Structural Characteristics of
Treponema hyodysenteriae
in the Lesions of Swine Dysentery
Authors: Glock R. D. , Harris D. L. , Kluge J. P.
Published: January 2020

The large intestines of pigs with swine dysentery were examined by phase, light, and electron microscopy at intervals up to 11 days after oral inoculation with mucosal scrapings from infected pigs. Large spirochetes with the structural characteristics of
Treponema hyodysenteriae
were found only in infected pigs and were first observed in small numbers in the lumen of the large intestine 2 days after inoculation. Numerous large spirochetes were present on the luminal surface and in mucosal crypts as lesions developed. Degenerative changes were first observed in the apical portion of epithelial cells in close contact with large spirochetes. These large spirochetes were found intact in goblet cells and epithelial cells in the early stages of the disease and were numerous within degenerating epithelial cells as lesions became more advanced. Invasion beyond the lamina propria was not detected. These observations demonstrated the relationship between pathogenic large spirochetes and the mucosa of the large intestine in a specific disease, swine dysentery.
Passive Transfer of Delayed-Type Hypersensitivity to Cell Walls of
Staphylococcus aureus
Authors: Targowski S. P. , Berman David T.
Published: January 2020

Protracted inflammatory dermal reactions to staphylococcal cell walls were observed in guinea pigs passively sensitized by transfer of peritoneal exudate cells but not by immune serum from guinea pigs actively sensitized with heat-killed cells of
Staphylococcus aureus.
The experiments verify the hypothesis that the protracted reaction is a cell-mediated immune response which is resolvable from the toxicity of the cell walls.
Pathogenesis of Rinderpest Virus Infection in Rabbits II. Effect of Rinderpest Virus on the Immune Functions of Rabbits
Authors: Yamanouchi Kazuya , Fukuda Akiko , Kobune Fumio , Yoshikawa Yasuhiro , Chino Fumitoshi
Published: January 2020

Rinderpest virus infection was shown to induce marked suppression of both humoral antibody response and cell-mediated immunity in rabbits. The virus exhibited a suppressive effect on primary antibody response as indicated by a decrease in numbers of plaque-forming cells (immunoglobulin [Ig]M) and hemagglutinating antibody titers of both IgM and IgG types to sheep red blood cells, whereas there was no detectable effect of the virus on the production of memory cells. Virus-induced suppression of cell-mediated immunity was demonstrated by a decreased rate of proliferative response of peripheral lymphocytes to phytohemagglutinin stimulus and by a depression of delayed-type skin reactions to purified protein derivative. Such suppressive effects were indicated to persist for 14 days or longer. Alteration in phagocytic activity of the reticuloendothelial system was not observed. The relevance of the virus-induced histological lesions in the lymphoid tissues to the virus-induced immunosuppression was discussed.
Development of a Purified Cholera Toxoid II. Preparation of a Stable, Antigenic Toxoid by Reaction of Purified Toxin with Glutaraldehyde
Authors: Rappaport Ruth S. , Bonde Geraldine , McCann Thomas , Rubin Benjamin A. , Tint Howard
Published: January 2020

Evidence is presented which confirms that cholera toxoids obtained by reaction of purified toxin with Formalin possess the ability to partially reactivate both in vivo and in vitro. At the same time, conditions are presented for the preparation of stable, antigenic cholera toxoids by reaction of purified toxin with glutaraldehyde. Treatment of purified cholera toxin with approximately 200 mol of glutaraldehyde per mol of toxin at pH 7.8 reproducibly resulted in the preparation of toxoids which: (i) possessed less than 20 bluing doses per 100 μg; (ii) did not reactivate in vivo or in vitro; (iii) precipitated with, and neutralized antitoxin; (iv) elevated prolonged serum antitoxin in immunized rabbits; (v) protected immunized guinea pigs against toxin skin challenge; and (vi) lent themselves to enhanced antigenicity by means of an in situ adjuvant system which may be suitable for man. Acrylamide gel electrophoresis and molecular sieve chromatography of a series of glutaraldehyde-derived toxoids suggested that the reaction products consisted of monomeric and polymeric species and that the proportion of higher-molecular-weight species was determined by the relative concentrations of toxin and glutaraldehyde. The results suggested a relationship between complete and irreversible elimination of toxicity and the formation of higher-molecular-weight toxoids.
Mechanism of Adherence of
Streptococcus mutans
to Smooth Surfaces II. Nature of the Binding Site and the Adsorption of Dextran-Levan Synthetase Enzymes on the Cell-Wall Surface of the Streptococcus
Authors: Mukasa Hidehiko , Slade Hutton D.
Published: January 2020

The mechanism of adsorption of the
Streptococcus mutans
enzymes responsible for the synthesis of insoluble dextran-levan to the
S. mutans
cell-wall binding sites has been studied. Certain characteristics of these binding sites are presented. The adsorption of these enzymes to the cell surface occurred rapidly without the addition of a source of energy and over a pH range of 3 to 11. The adsorption was inhibited by soluble dextran, probably due to the strong affinity of the polymer to the enzyme. All other polymers and sugars studied showed little or no inhibition. The adsorption was also inhibited by antibody globulin to the
a-d
immunologically specific group antigen surface polysaccharide of
S. mutans
and by anti-dextran globulin. The inhibition by anti-
a-d
globulin is considered to be due to a restriction of access of enzyme to the binding site of the enzyme which may be located in close proximity to the group antigen. On the other hand, anti-dextran globulin appeared to directly inhibit the adsorption by covering the binding site. Dextranase destroyed the binding site and released glucose from the
S. mutans
cells. These data indicate that
S. mutans
grown in media containing glucose possesses a small amount of dextran on the cell surface, and that this dextran is, or is a part of, the binding site for enzymes which synthesize the insoluble dextran-levan polymer. Trypsin inhibited the synthesis of insoluble polysaccharide and the adherence of cells. It is not clear in this case that destruction of the binding sites occurred. These data present a partial explanation of the processes which may be concerned in the formation of dental plaque on the smooth surfaces of teeth.
Identification and Characterization of a Second Feline Herpesvirus
Authors: Fabricant Catherine G. , Gillespie James H.
Published: January 2020

A feline virus isolate previously reported as adenovirus-like has more recently been identified and characterized as a new feline herpesvirus. This herpesvirus, which appears to be cell associated, has some characteristics of the cytomegaloviruses and has been found to induce chemical crystal formations in infected cell cultures.
Isolation of an Acidic Surface Antigen from a Conventional Strain of
Staphylococcus aureus
Authors: Karakawa W. W. , Kane J. A. , Smith M. R.
Published: January 2020

Staphylococcus aureus
strain 7007, a prototype isolated from a hospital burn unit, was shown to exhibit a significant degree of resistance to ingestion by mouse polymorphonuclear leukocytes. An acidic surface antigen was isolated from strain 7007 by a combination of 10% trichloroacetic acid extraction, ion-exchange chromatography, and gel filtration. Chemical analysis indicated that the surface antigen consists of an unknown aminouronic acid and an amino sugar. Immunochemical analysis suggested that the 7007 antigen is a common feature of all the strains collected from the burn unit. No cross-reactivity was observed between the carbohydrate preparations of various hospital staphylococcal strains and the 7007 heteropolymer. These results suggested the possibility that the surface antigen of strain 7007 represents a strain- or type-specific antigen.
Effects of Carbon Dust Inhalation on the Cell-Mediated Immune Response in Mice
Authors: Miller S. D. , Zarkower A.
Published: January 2020

The effects of carbon dust inhalation on the bone marrow-derived (B) and thymus-derived (T) lymphocyte populations of spleen and mediastinal lymph node (MLN) cultures were examined. The concanavalin A (Con A)-responsive cell population (T cells) in the spleen was found to be depressed after 7 days of pre-exposure to carbon dust. However, this effect was transient, and after 14, 21, and 28 days of pre-exposure to carbon dust, the Con A-responsive cells exhibited a 30 to 40% enhancement over control group responses. Conversely, Con A-responsive cells in the pooled MLN cultures exhibited depression, ranging from 22 to 33% below control group values, after 7, 14, and 28 days of pre-exposure to carbon dust. The lipopolysaccharide (LPS)-responsive cell population (B cells) in the spleens of carbon-exposed mice was found not to differ significantly from control group values after all times of pre-exposure. LPS-responsive cells in the MLN cultures exhibited enhancement, ranging from 49 to 74% above control values, after 14, 21, and 28 days of pre-exposure to carbon dust. The ability of carbon spleen cell cultures from carbon-exposed mice to undergo antigen induced blast transformation after sensitization with
Mycobacterium tuberculosis
H37Ra was also determined. Mice exposed to carbon dust inhalation 2 weeks before and 3 weeks after aerosol or subcutaneous immunization exhibited significantly enhanced ratios of transformation upon culture of their spleen lymphocytes with purified protein derivative of tuberculin.
Probable L-Forms of
Nocardia asteroides
Induced in Cultured Mouse Peritoneal Macrophages
Authors: Bourgeois L. , Beaman B. L.
Published: January 2020

Mouse peritoneal macrophages were infected with varying numbers of
Nocardia asteroides
10905, and the fate of the ingested organisms was determined by viable plate count (VPC), light microscopy (LM), immunofluorescent microscopy (IM), and electron microscopy (EM). The results obtained with these methods differed. VPC indicated that intracellular
Nocardia
decreased in numbers during the first 12 days, followed by significant increases after 16 days. LM suggested that
N. asteroides
10905 was slowly degraded by macrophages with no subsequent increases observed. In contrast, IM demonstrated large numbers of intracellular
Nocardia
throughout the experiment. EM studies of infected macrophages failed to demonstrate intact bacteria after 8 days; however, wall-less and spheroplast-like organisms were seen. These results suggested that
N. asteroides
10905 was present within the macrophages in an altered form. By using hypertonic culture medium, we were able to isolate, from infected macrophages, organisms which exhibited many of the properties of bacterial L-forms. IM demonstrated these variants to be of nocardial origin. These altered forms also reverted to typical nocardial cells either spontaneously or upon transfer into broth. These findings indicate that
N. asteroides
10905 is capable of existing within macrophages in an altered state. Further investigation is in progress to determine whether these altered forms represent L-forms or transitional-phase variants.
In Vitro Uptake of
14
C-Labeled Amino Acids by Preparations of Partially Purified
Anaplasma marginale
Bodies
Authors: Johns R. W. , Dimopoullos G. T.
Published: January 2020

Studies on the incorporation of three
14
C-labeled amino acids into preparations of partially purified
Anaplasma marginale
were conducted. Relatively high levels of uptake of radioactive isoleucine, glycine, and methionine were detected in both trichloroacetic acid-soluble and -insoluble fractions of these preparations, indicating that the parasite is capable of protein synthesis outside its erythrocytic environment. When erythrocytes (red blood cells) from infected calves were incubated with [
14
C]methionine and
Anaplasma
bodies were subsequently purified, it was found that some of the label detected was associated with the marginal bodies.
Enhancement of Resistance to Infectious Diseases by Oral Administration of Brewer's Yeast
Authors: Sinai Yehudith , Kaplun A. , Hai Y. , Halperin Bilha
Published: January 2020

The effect of oral administration of brewer's yeast on resistance to infectious diseases was studied in laboratory animals. It was shown that there was a significantly increased enhancement of resistance to seasonal respiratory and enteric infections in rhesus monkeys. Similarly, enhanced resistance to experimental chronic infections was observed in mice after yeast administration. A 2-week lag occurred between the initiation of yeast treatment and the expression of enhanced resistance. Study of the mechanism of the yeast-induced enhancement of resistance to infection leads to the conclusion that it is based on in vivo stimulation of phagocytosis, as measured by the “phagocytic index.” No effect of brewer's yeast on circulating antibody levels was detected.
Role in Virulence of
Shigella flexneri
Antigens Derived from Lysogenic Conversion
Authors: Kétyi I.
Published: January 2020

The virulence of
Shigella flexneri
var. Y (NTCC 4839), its lysogenic convertants characterized by antigens I, V, and 7, 8, and of a phage-free clone selected by means of antiphage serum was studied. The parent strain was avirulent in the guinea pig eye test and in the “mouse shigellosis” model, but chicken embryo tests indicated the presence of penetrating ability together with defective tissue-growing capacity. The lysogenic convertants failed to regain their virulence to the guinea pig eye and to the mouse, but showed an increased tissue-growing capacity for chicken embryos. The level of virulence of the phage-free derivative equaled that of the parent strain. We concluded that the terminal glucose component of O antigen, even of conversion origin, plays a role as one of the virulence factors in tissue-growing capacity.
Partial Chemical Characterization of a Toxic Lipopolysaccharide from
Coxiella burneti
Authors: Baca O. G. , Paretsky D.
Published: January 2020

Partial characterization of a hot phenol-water extract of
Coxiella burneti
demonstrates the presence of at least 8 sugar and 17 fatty acid residues, suggesting a complex lipopolysaccharide molecule.
Suppression of Growth of Ehrlich Ascites Tumor Cells in Mice by Trehalose-6, 6′ -Dimycolate (Cord Factor) and BCG
Authors: Yarkoni E. , Wang L. , Bekierkunst A.
Published: January 2020

Growth of Ehrlich ascites tumor cells in mice pretreated with cord factor was compared to growth of the tumor cells after pretreatment with Calmette-Guérin bacilli. Growth of Ehrlich ascites cells was strongly inhibited in the peritoneal cavities of mice pretreated with 80 μg of cord factor. The median survival time of the animals was prolonged (70 versus 17 days), and 40% of the mice survived more than 90 days. Tumor suppression was still detectable 36 days after administration of cord factor. The effect of cord factor was local. Comparable results were obtained with living or killed Calmette-Guérin bacilli. The results are discussed.
Pseudocompact-Type Growth and Conversion of Growth Types of Strains of
Staphylococcus aureus
In Vitro and In Vivo
Authors: Yoshida Kosaku , Takahashi Masami , Takeuchi Yoshio
Published: January 2020

Some strains of
Staphylococcus aureus
grew as compact colonies in Brain Heart Infusion–serum-soft agar but as diffuse colonies in a modified Staphylococcus 110–serum-soft agar. These strains were designated “pseudocompact.” Strains showing compact-type colonial morphology in both media were designated “compact,” whereas strains showing diffuse-type growth in both media were designated “diffuse.” It was observed that the most recently isolated strains of
S. aureus
were of the pseudocompact type, whereas most stock culture strains tested were of the compact type. Using cultures recently isolated from clinical material, it was shown that pseudocompact strains convert to compact-type growth after prolonged incubation. Interconversion of compact, diffuse, and pseudocompact growth forms could be induced in vitro by appropriate cultural conditions, and conversion of growth type was also observed in vivo. Femoral abscesses produced in mice by four different compact-type strains showed conversion to diffuse or pseudocompact-type growth during the course of the infection.
Multiple Forms of Lactate Dehydrogenase in
Staphylococcus aureus
Authors: Stockland A. E. , Clemente C. L. San
Published: January 2020

Activities for nicotinamide adenine dinucleotide (NAD)-dependent and NAD-independent forms of lactate dehydrogenase (LDH) were measured in cell-free extracts of
Staphylococcus aureus
strain PS 6 for the
d
and
l
isomers of lactate. Data obtained for the NAD-dependent lactate dehydrogenases indicate that oxidation of both isomers of lactate is due to both an
l
-lactate-specific LDH and a lactate racemase. After acrylamide gel electrophoresis, two bands exhibiting LDH activity were detected in crude or in partially purified cell-free extracts. The fast band exhibited LDH activity that was not NAD-dependent for both isomers of lactate, whereas, the slow band had very high NAD-dependent LDH activity for the
l
isomer but just detectable activity or the
d
isomer. Both bands appeared when
d
-lactate was used as the substrate, but only the slow band was formed when
l
-lactate was the substrate. NAD-dependent LDH, in apparent association with a nonspecific tetrazolium-reducing protein, is responsible for the production of the slow band.
Surface Structure of
Azotobacter vinelandii
Cysts as Revealed by Freeze-Cleaving
Authors: Koo Victoria M. , Lin L. P. , Sadoff H. L.
Published: January 2020

Micrographs of freeze-cleaved
Azotobacter vinelandii
cysts reveal that the surface is composed of several overlapping layers. This observation is consistent with the previously proposed structure of the outer cyst coat.
Antigenic Characteristics of Five Species of Human
Bacteroides
Authors: De La Cruz Enrique , Cuadra Carlos
Published: January 2020

The antigenic characteristics of five species of
Bacteroides
were determined by agglutination tests. No cross-reactivity among the species was observed.
Delayed Hypersensitivity in Relation to Suppression of Growth ofListeria monocytogenesby Guinea Pig Macrophages
Authors: Goihman-Yahr Mauricio , Raffel Sidney , Ferraresi Rodolfo W.
Published: January 2020

Prototypes of delayed hypersensitivity (tuberculin allergy, graft rejection immunity, and contact dermatitis) were established in guinea pigs. The macrophages from peritoneal exudates of such animals were examined for their capacities to suppress the growth ofListeria monocytogenesin vitro. Only the macrophages from animals sensitized to BCG clearly exhibited this property.
Methyl-Deficient Transfer Ribonucleic Acid and Macromolecular Synthesis in Methionine-Starved
Saccharomyces cerevisiae
Authors: Kjellin-Stråby Kerstin , Phillips John H.
Published: January 2020

Haploid methionine auxotrophs of
Saccharomyces cerevisiae
continue to multiply for several hours after withdrawal of a required amino acid from the medium. Macro-molecular synthesis continues during this period of residual growth, although the net ribonucleic acid (RNA) and protein content is constant during the later part of this period. In this study, growth after withdrawal of methionine was in some cases accompanied by accumulation of transfer RNA (tRNA), which was shown by methylation in vitro to be deficient in methyl groups. This phenomenon was shown by only four of nine methionine auxotrophs tested, but no evidence could be found that these four strains had “relaxed” control of RNA synthesis. The nine methionine-requiring strains represent mutations in five different positions in the methionine biosynthesis pathway, and only mutants blocked at two of these five positions accumulated methyl-deficient tRNA. This accumulation therefore appears to be correlated with the position of the strain's block in the pathway of methionine biosynthesis.
Influence of Methionine Pool Composition on the Formation of Methyl-Deficient Transfer Ribonucleic Acid in
Saccharomyces cerevisiae
Authors: Kjellin-Stråby Kerstin
Published: January 2020

Methionine auxotrophs of
Saccharomyces cerevisiae
continue to synthesize ribonucleic acid (RNA) after methionine withdrawal. The newly synthesized transfer RNA (tRNA) is methyl-deficient in some strains, but not in all. Whether such tRNA will accumulate depends on the position of the block in the methionine pathway that is carried by the mutant strain. Free methionine rapidly decreases in the intracellular pool of all strains after its removal from the medium. Certain metabolites derived from methionine are removed from the pool relatively slowly after methionine withdrawal. Notable among these is
S
-adenosylhomocysteine, which is depleted less rapidly from those strains that accumulate methyl-deficient tRNA than from others.
S
-adenosylhomocysteine is a potent inhibitor of tRNA-methylating enzymes in vitro.
Mutant of Yeast Sensitive to 2,6-Diaminopurine
Authors: Lomax Christopher A. , Woods Robin A.
Published: January 2020

A mutant of yeast sensitive to growth inhibition by 2,6-diaminopurine (2,6-DAP) was analyzed genetically and found to be a double mutant. One gene,
dap
, conferred approximately 30% sensitivity to the analogue. The other,
slw
, potentiated the inhibition such that the double mutant
dap slw
was inhibited 90%. The mutation
dap
conferred concomitant sensitivity to a number of other purine analogues. The activity of a purine phosphoribosyltransferase with 2,6-DAP in a strain carrying
dap
was found to be three times higher than in the wild type. It is inferred that the mutation alters the properties of a purine phosphoribosyltransferase. A possible mechanism for the effect of
slw
is also discussed.
Specific Action of Sodium Dodecyl Sulfate on the Sex Factor of
Escherichia coli
K-12 Hfr Strains
Authors: Inuzuka Noriko , Nakamura Sachiko , Inuzuka Manabu , Tomoeda Munemitsu
Published: January 2020

A specific action of sodium dodecyl sulfate (SDS) on the sex (F) factor in the integrated state of
Escherichia coli
K-12 Hfr H strain is reported. Growth of Hfr cells in Penassay Broth containing SDS results in the elimination of part or all of the F factor, yielding low and nonfertile variants of defective Hfr type and F
+
cells and also F
−
derivatives. Appearance of such variants was generally observed after the culture reached stationary phase. The frequencies of F
−
cells then increased. F
−
cells were usually isolated as the major population among survivors. Some defective variants of Hfr cells with an intermediate fertility between standard Hfr and F
+
cells had lost sensitivity toward the male-specific ribonucleic acid phage M12. Other defective Hfr variants with as much or less fertility than standard F
+
cells had also all lost sensitivity to phage M12. On single-colony isolation, they segregated nonfertile
female H
cells which, when infected with F, could restore high fertility with oriented transfer of the chromosome the same as that of the original Hfr H. Also, sensitivity to phage M12 was regained.
Female H
cells were characterized as those lacking fertility but still retaining a small segment of F or
sfa
locus at the original part of the chromosome, where newly infected F could attach. Similar results were obtained with two other Hfr strains. A possible mechanism of the specific action of SDS is discussed.
Basis for the Mutational Acquisition of the Ability of
Aerobacter aerogenes
to Grow on
l
-Mannose
Authors: Mayo Joseph W. , Anderson R. L.
Published: January 2020

Growth of
Aerobacter aerogenes
PRL-R3 on the unnatural hexose
l
-mannose as a sole carbon source is dependent upon the selection of a mutant. Growth of the mutant on
l
-mannose did not require the synthesis of novel enzymes for the degradation of
l
-mannose, since enzymes of the
l
-rhamnose degradative pathway could serve this function. However, unlike most other apparent gain mutations that have been described, the mutant was not constitutive for the degradative enzymes; isomerase, kinase, and aldolase activities functional in the degradation of both
l
-mannose and
l
-rhamnose were induced by either of these hexoses in the wild type as well as in the mutant. The fact that the wild type could metabolize
l
-mannose also ruled out the possibility that the cells were not permeable to
l
-mannose. Growth of the wild type on nutrient broth was severely inhibited by
l
-mannose coincident with the onset of
l
-mannose metabolism. A similar inhibition of growth of the mutant was overcome in about 2 hr. Both strains utilized
l
-rhamnose and
l
-mannose sequentially in a mineral medium containing both of these hexoses; at the onset of
l
-mannose metabolism, growth of the wild type, but not of the mutant, was inhibited. Thus, wild-type
A. aerogenes
cannot grow on
l
-mannose because of the toxicity of
l
-mannose or its metabolites. A mutation which overcomes the toxicity enables the organism to utilize
l
-mannose as a sole source of carbon and energy for growth.
Inhibitor-Induced Shift-Downs in
Escherichia coli
Authors: Nazar Ross N. , Wong J. Tze-Fei
Published: January 2020

A shift-down response in
Escherichia coli
cells has been brought about by moderate concentrations of azide or cyanide. Early events of the response included a preferential inhibition of ribonucleic acid relative to deoxyribonucleic acid synthesis, a degradation of polyribosomes, and an inhibition of protein synthesis followed by a transient relief. These changes were entirely comparable to those observed with nutrient-induced shift-downs. The influences of various nutrient supplements on an azide shift-down were examined, and methionine was found to relieve effectively the inhibition of ribonucleic acid synthesis in some strains of cells.
Protein Synthesis During Fungal Spore Germination IV. Transfer Ribonucleic Acid from Germinated and Ungerminated Spores
Authors: Van Etten James L. , Koski R. Kent , El-Olemy Mahmoud M.
Published: January 2020

Transfer ribonucleic acid (tRNA) fractions isolated from germinated and ungerminated spores of
Botryodiplodia theobromae
and
Rhizopus stolonifer
had acceptor activity for all 20 amino acids commonly found in protein, when tested with an enzyme fraction from germinated spores. Accordingly, it is unlikely that the absence of tRNA for a particular amino acid limits protein synthesis in fungal spores.
Cobaltous Ion Effect on Diauxie
Authors: Leahy J. J.
Published: January 2020

Cobaltous ions extended the duration of the diauxic lag in
Escherichia coli
K-12. Growth in glucose in the presence of Co
++
was necessary for the effect. Medium in which cells had been grown in the presence of Co
++
produced an extended lag when inoculated with fresh cells and lactose. Valine was found in this medium. Reversal of the extended lag was brought about by addition of
l
-isoleucine and related
l
-amino acids, but not by several metal ions. Cobaltous ion does not inhibit β-galactosidase or the galactoside permease. These results, together with the known growth sensitivity of K-12 to valine, indicate that Co
++
disturbs the normal valine-isoleucine balance.
Characterization and Relatedness of Marine Vibrios Pathogenic to Fish: Physiology, Serology, and Epidemiology
Authors: Pacha R. E. , Kiehn E. D.
Published: January 2020

Cultural characteristics and serological relationships of pathogenic marine vibrios isolated from fish in the Pacific Northwest were studied. These organisms were compared with cultures of
Vibrio anguillarum
, a known fish pathogen. On the basis of morphological and cultural characteristics, the Pacific Northwest strains of
Vibrio
were found to be closely related to
V. anguillarum
. Serological analyses of thermostable antigens served to distinguish three serotypes among the vibrios. Serotype 1 was composed of organisms isolated from Northwest salmonids; serotype 2 of strains of
V. anguillarum
from European waters; and serotype 3 of organisms isolated from Pacific herring. The epidemiology of vibrio disease among populations of fish in the Pacific Northwest is discussed.
Nonsense Mutations in the Maltose A Region of the Genetic Map of
Escherichia coli
Authors: Hatfield Dolph , Hofnung Maurice , Schwartz Maxime
Published: January 2020

The isolation of one
amber
mutation in
malQ
, one
ochre
mutation in
malP
, and seven
amber
mutations in
malT
is reported. A study of their phenotypic expressions in the presence of the
amber
suppressor
su
III
and the
ochre
suppressor
su
c
suggests that (i)
malQ
is the structural gene for amylomaltase; (ii)
malQ
and the structural gene for maltodextrin phosphorylase,
malP
, belong to the same operon; (iii) the
malT
product, which promotes the expression of the
malP-malQ
operon, is a protein synthesized in limiting amounts by the wild-type strain.
Protein Synthesis in Cell-Free Extracts of
Streptococcus faecalis
Authors: Herson D. S. , Pon C. L.
Published: January 2020

If a cell-free extract of
Streptococcus faecalis
is fractionated by way of a 10 to 70% sucrose gradient, at least three areas are found capable of protein synthesis having a density greater than can be accounted for by association of individual ribosomes. These areas represent distinct “polysome” peaks rather than random distribution of polymers of varied length. They appear to be membrane subunits. In addition there is a further particle with a density of about 150
S
, incapable of protein synthesis but which is capable of stimulating protein synthesis in some of the larger fractions found by gradient centrifugation.
Pyrimidine Synthesis in
Neurospora crassa:
Gene-Enzyme Relationships
Authors: Caroline Dina F.
Published: January 2020

A new series of pyrimidine-requiring mutants of
Neurospora
has been isolated and all enzymes involved in pyrimidine biosynthesis are represented by at least one mutant. Among these mutants is included a single isolate for a new locus,
pyr-6
. This mutant is deficient in dihydroorotase (DHOase) and represents the only enzymatic step in orotate synthesis for which no mutant previously had been found. This mutant, which mapped genetically on the right arm of linkage group V, is unlinked to any of the other pyrimidine mutants. The DHOase-deficient mutant is also characterized by an unexpected growth behavior. The
pyr-1
locus has been specifically associated with a lack of dihydroorotate dehydrogenase (DHOdehase). Mutants isolated in this series for other pyrimidine loci have been related to previously isolated mutants by allelism, recombination, and accumulation studies.
Osmotic Fragility of Lysozyme- and Thiol-Treated
Lactobacillus plantarum
Authors: Habbal Z. , Durr I. F.
Published: January 2020

Reduced but not oxidized thiols increased the sensitivity of lysozyme-treated cells of
Lactobacillus plantarum
to lysis by osmotic shock.
Ethidium Bromide Resistance, a New Marker on the Staphylococcal Penicillinase Plasmid
Authors: Johnston L. H. , Dyke K. G. H.
Published: January 2020

A strain of
Staphylococcus aureus
resistant to ethidium bromide is described. The genetic determinants for the resistance are present on the same plasmid as the penicillinase genes.
Stabilizing Effect of Colicin E2 on the “Spheroplast Membrane”
Authors: Nose K. , Ono M. , Mizuno D.
Published: January 2020

Cells of
Escherichia coli
W3110 and its thymineless mutant, both of which are colicin E2 sensitive, were treated with colicin E2, and then converted to spheroplasts. These spheroplasts seemed to be more stable than those from untreated cells; suspensions of spheroplasts of untreated cells were lysed spontaneously and the turbidity was reduced by approximately 45% on incubation with ethylenediaminetetraacetic acid-lysozyme, whereas suspensions of spheroplasts of colicin E2-treated cells showed 25% reduction in turbidity. This change was irreversible and 5 min of treatment with colicin E2 at 37 C was necessary for stabilization. This process was inhibited by 2,4-dinitrophenol or streptomycin. Cells harboring the colicin E2 factor were not affected by treatment in this way with colicin E2. Alteration of composition of phospholipids was not observed.
Repression of Phenolic Acid-Synthesizing Enzymes and Its Relation to Iron Uptake in
Bacillus subtilis
Authors: Downer D. N. , Davis W. B. , Byers B. R.
Published: January 2020

Excretion of the metal-chelating phenolic acid, 2,3-dihydroxybenzoate, by a tryptophan-requiring strain (M-13) of
Bacillus subtilis
was inversely proportional to the iron added to the medium. Addition of iron as the ferric chelates of two secondary hydroxamates (ferri-schizokinen and Desferal) markedly reduced excretion. Synthesis of 2,3-dihydroxybenzoate from chorismate by extracts of
B. subtilis
M-13, grown in low-iron medium, was unaltered by additions of FeSO
4
, FeCl
3
, ferrischizokinen, 2,3-dihydroxybenzoate, the 2,3-dihydroxybenzoate-iron complex, or by extracts of cells grown in high-iron medium (which contained no demonstrable 2,3-dihydroxybenzoate-synthesizing activity) to the extracts of “low-iron cells.” Iron control seemed to involve repression of synthesis of the enzymes in the 2,3-dihydroxybenzoate pathway. Both ferri-schizokinen and 2,3-dihydroxybenzoate plus iron enhanced considerably the otherwise minimal repressive effects of iron at low concentrations. Ferri-schizokinen delayed derepression of the pathway in
B. subtilis
M-13, and reduced its rate of synthesis after derepression. Addition of FeSO
4
to derepressed cells of
B. subtilis
M-13 halted synthesis of the enzymes after a lag period. The effect of the ferric hydroxamates was related to the capacity of
B. subtilis
M-13 to incorporate
59
Fe
3+
from Desferal-
59
Fe
3+
. Cellular accumulation of
59
Fe
3+
from Desferal-
59
Fe
3+
after 20 min was nearly double that incorporated from
59
FeCl
3
.
Macromolecular Synthesis During Microcycle Sporogenesis of
Bacillus cereus
T
Authors: MacKechnie Ian , Hanson R. S.
Published: January 2020

Microcycle sporogenesis induced in
Bacillus cereus
T by phosphate limitation occurs over a narrow range of phosphate to spore inoculum ratios. Sufficient phosphate is required to satisfy the demands for a twofold increase in deoxyribonucleic acid; net ribonucleic acid synthesis is not required. The total ribonucleic acid content of the culture was variable, and deoxyribonucleic acid synthesis was restricted to a twofold increase. Developmental changes during outgrowth occurred synchronously, whereas enzyme synthesis was periodic. The timing of the synthesis of tricarboxylic cycle enzymes, extracellular protease, arginase, histidase, and alkaline phosphatase was measured. Histidase could be induced after 2.5 hr throughout microcycle sporogenesis. Several other features of macromolecular synthesis during microcycle sporogenesis are described. Differences between this pattern and those observed during outgrowth leading to cell division are discussed. A technique for accurately estimating the levels and time of synthesis of incompletely extractable, labile enzymes is also presented.
Effect of β-Lysin on Isolated Cell Walls and Protoplasts of
Bacillus subtilis
Authors: Matheson Audria , Donaldson David M.
Published: January 2020

The cytoplasmic membrane is the site of β-lysin action. Protoplasts lysed rapidly in its presence, whereas cell walls and wall autolysis were unaffected.
Biochemical Studies of Bacterial Sporulation and Germination XXI. Temperature-Sensitive Mutants for Initiation of Germination
Authors: Vary James C. , Kornberg Arthur
Published: January 2020

Mutants of
Bacillus megaterium
have been isolated that are temperature-sensitive for the initiation of germination.
Early Energy-Dependent Step in the Entry of Transforming Deoxyribonucleic Acid
Authors: Strauss Norman
Published: January 2020

It was found that cyanide can partially reverse as well as arrest the transformation of a newly transformed deoxyribonuclease-treated culture for 6 to 8 min after the addition of the enzyme. These findings strongly suggest that deoxyribonucleic acid which attained deoxyribonuclease-insensitivity is not necessarily in the cell, but stored in some region peripheral to the membrane, and that a rate-limiting, energy-dependent step is required to transport this deoxyribonucleic acid into the cell.