bluuebunny/crossref_metadata_2025 huggingface dataset:
Adherence of Candida albicans to a fibrin-platelet matrix formed in vitro
Authors: Maisch P A , Calderone R A
Published: January 2020

The adherence of Candida albicans to a fibrin-platelet matrix formed in vitro was studied. Platelet-rich plasma obtained from rabbits was incubated with thrombin and CaCl2 to form a clot in tissue culture dishes. Such clots were then infected with 3 x 10(7) C. albicans cells per 0.3 ml prelabeled with [U14C]-glucose, and the percent adherence was measured after 30 min of incubation by counting the radioactivity in saline washes of the clot as well as a streptokinase-streptodornase digest of the corresponding clot. Heat- and formaldehyde-killed cells did not adhere as well as viable cells. Pretreatment of C. albicans with trypsin, chymotrypsin, and pronase reduced adherence to the clots. Normal rabbit serum and anti-Candida antiserum also inhibited adherence 40 and 100%, respectively, Diethylaminoethyl-purified anti-Candida gamma globulin (1:8) completely inhibited adherence, whereas purified normal serum gamma globulin did not. Several Candida spp. and Saccharomyces cerevisiae showed differences in their ability to adhere to clots. C. albicans and C. stellatoidea presented the highest adherence, whereas C. krusei, C. guilliermondii, and S. cerevisiae adhered less readily. Other species were intermediate in their ability to adhere.
Anti-Inulin [β-(2→1)-Linked Polyfructose] and Anti-Grass Levan [β-(2→6)-Linked Polyfructose] Antibody Response in Mice
Authors: Chien C. C.
Published: January 2020

Anti-inulin [β-(2 → 1) polyfructosan
Brucella abortus
(InuBA)] and anti-grass levan [β-(2 → 6) polyfructosan] antibody responses in BALB/c and C57BL mice and in their F
1
and backcross progeny, as well as in immunoglobulin congenic and Bailey recombinant inbred strains derived from BALB/c and C57BL mice, were examined. The anti-inulin antibodies could accommodate both β-(2 → 1)- and β-(2 → 6)-linked polyfructosans, and 97% of the anti-inulin plaque-forming cells (PFC) from BALB/c mice expressed the cross-reactive idiotypes (InuIdX) shared by the BALB/c inulin- and levan-binding myeloma proteins. Of the C57BL mice, only 25% produced high anti-inulin response, and none exhibited the InuIdX of BALB/c anti-inulin antibodies. The percentages of InuIdX
+
anti-inulin PFC were also examined in other strains with high anti-inulin response. In C58 and AL mice, 80% of anti-inulin PFC were InuIdX
+
, whereas in A/He and RIII mice, only 40% were InuIdX
+
. All strains examined developed high anti-grass levan response, and the antibodies were specific for β-(2 → 6) structures and did not exhibit InuIdX. Comparison of the magnitude of the anti-inulin antibody titers in response to InuBA in BALB/c, C57BL, and their F
1
and backcross progeny, as well as in immunoglobulin congenic (i.e., B.C-8, BAB-14, and C.B-20) and recombinant inbred strains derived from BALB/c and C57BL mice, showed that all mice having the IgCH
a
(BALB/c) allotype gave high anti-inulin response. In addition to the InuIdX structural genes, the effects of allotype-linked or unlinked “regulatory” genes were also indicated by the lower anti-inulin response in B.C-8 and BAB-14 mice compared with BALB/c mice and the higher anti-inulin response in C.B-20 mice compared with C57BL mice. A multigene interaction in controlling the production of the anti-inulin antibodies was implicated.
Carbon dioxide metabolism by Capnocytophaga ochracea: identification, characterization, and regulation of a phosphoenolpyruvate carboxykinase
Authors: Kapke P A , Brown A T , Lillich T T
Published: January 2020

Cell suspensions of Capnocytophaga ochracea incorporated [14C]NaHCO3 into a major four-carbon fermentation product, succinate, and cell-free extracts from this organism contained high levels of phosphoenolpyruvate carboxykinase (PEPCK). PEPCK is the major, if not the only, CO2(HCO-3)-fixing enzyme in C. ochracea since cell-free extracts were devoid of pyruvate-dependent and other phosphoenolpyruvate (PEP)-dependent CO2(HCO-3)-fixing enzymes. The reaction products of the enzyme, which was partially purified by diethylaminoethylcellulose column chromatography, were identified as adenosine 5'-triphosphate (ATP) and oxalacetate. The enzyme showed maximum activity when manganese (Mn2+) was the divalent cation in the incubation mixture, and it had an absolute requirement for the nucleoside 5-'diphosphate adenosine 5'-diphosphate (ADP). PEPCK showed a sigmoidal kinetic response to the Mn2+ concentration and homotropic interactions in its kinetic responses to each of its three substrates PEP, ADP, and CO2(HCO-3). The (S)0.5v values for Mn2+, PEP, ADP, and CO2(CHO-3) were approximately 0.08, 0.3, 0.1, and 10 mM, respectively, and Hill coefficients for these same ligands were 2.60, 1.7, 1.9, and 3.0, respectively. In addition, C. ochracea PEPCK is under metabolic control by the nucleoside -5'-triphosphate ATP, and it also showed a sigmoidal kinetic response to this allosteric effector. The Hill coefficient for ATP was 2.70.
Effects of Serum Components on Gram-Negative Bacteria During Bactericidal Reactions
Authors: Melching Lee , Vas Stephen I.
Published: January 2020

Biochemical changes which occur in a smooth strain of
Escherichia coli
were investigated with hyperimmune rabbit serum as a source of antibody and fresh normal guinea pig serum as a source of complement. Ribonucleic acid synthesis, as shown by incorporation of
3
H-uridine, was decreased as early as 5 min, and deoxyribonucleic acid synthesis, shown by incorporation of
3
H-thymidine, was decreased after 15 min of reaction. Incorporation of glycerol-
2
-
3
H
into membrane lipid ceased after 25 to 30 min, probably as a result of functional or physical disruption of the membrane, or both. Permeability control (as indicated by loss of
3
H-uridine-labeled compounds and by decrease in optical density) and protein synthesis were subsequently shown to be affected after 30 min. The metabolic state of the bacteria was found to be important in determining the outcome of the reaction. This was shown by the influence of the type of medium on the reaction. A complex nutrient medium decreased susceptibility as compared with a simple medium. The energy sources glycerol and acetate also decreased susceptibility. It is postulated that the ability of the cell to prevent or repair damage to the cell membrane may be involved. Therefore, metabolic conditions which allow retention of vital processes associated with the cytoplasmic membrane and cell surface will mitigate the bactericidal effect. Such conditions may occur in vivo during bactericidal reactions.
Relationship Between the Staining Quality of
Mycobacterium leprae
and Infectivity for Mice
Authors: McRae Dorothy H. , Shepard Charles C.
Published: January 2020

The proposal has been made that only solidly staining forms of
Mycobacterium leprae
are viable. On the basis of a previous study, solidly staining bacilli were defined as those that stained completely and darkly throughout their length. A study was carried out to correlate the proportion of solidly staining bacilli in inocula with the infectivity and rate of appearance of bacillary growth in inoculated mice. The inocula originated in skin biopsy specimens of patients and in mouse passage material; there were 347 inocula suitable for study. The rate of appearance of bacillary growth in inoculated mice confirmed the hypothesis that nonsolid bacilli are inert and nonviable and that all growth originates from the solidly staining organisms. The minimal infectious dose was determined in four suspensions and was found to range from 40 to 3 solidly staining bacilli.
Morphology, Physiology, and Virulence of Some Mutants of
Candida albicans
Authors: Savage N. , Balish E.
Published: January 2020

Five mutagens were used to induce mutants of
Candida albicans.
Ultraviolet light,
N
-nitroso-
N
′-methyl-
N
-nitrosoguanidine, and
N
-nitroso-
N
-methylurethane were effective mutagens which induced stable auxotrophs.
N
-nitroso-
N
-methylurethane produced the largest number and variety of mutants. Nitrous acid and hydroxylamine were ineffective as mutagens although they killed
C. albicans.
All mutagenic agents employed induced colonial variants, especially small colony forms. The morphology, physiology, and virulence of one methionine and two adenine auxotrophs was compared to that of the prototroph. The auxotrophs exhibited yeast-like morphology in complex media and had sugar fermentation patterns typical of
C. albicans
, and all were agglutinated by
C. albicans
antiserum. Chlamydospore production was absent in the nonpigmented adenine mutant, and the chlamydospores produced by the methionine auxotroph were distorted. Germ tubes were formed in human serum by the auxotrophs and prototroph. Virulence for mice was retained by all auxotrophs but generally at a reduced level. The methionine auxotroph, only slightly less virulent than the prototroph, was more virulent than a pigmented adenine mutant and a practically avirulent nonpigmented adenine auxotroph.
Effect of Purified Rabbit Anti-
Salmonella typhimurium
Antibodies on the Fate of Intravenously Injected Bacteria
Authors: Schulkind Martin L. , Rabins Peter
Published: January 2020

Purified IgM and IgG antibodies to
Salmonella typhimurium
“O” antigen were prepared from rabbit serum collected “early” (6 to 8 days) and “late” (30 to 32 days) during the course of the immune response. The effect which these passively administered antibodies had upon the reticuloendothelial organ sequestration of intravenously injected
125
I-labeled heat-killed
S. typhimurium
in nonimmune rabbits was studied. In the absence of specific antibody, the spleen (per gram) sequestered more organisms than did the liver, kidneys, and lungs. In the presence of “early” antibody to
S. typhimurium
, sequestration of organisms in the spleen was two to three times greater than sequestration in the spleen of animals that had received “late” antibody to
S. typhimurium
, heterologous antibody or no antibody. Although “late” antibody did not increase sequestration of organisms in the spleen, it did result in a per gram liver sequestration of bacteria which was two times greater than that observed in animals that had received “early” antibodies to
S. typhimurium
, heterologous antibody or no antibody. The presence of passively administered antibody had no detectable effect upon the sequestration of bacteria in the kidneys and the lungs. Thus, it would seem that antibodies isolated early in the immune response increase the efficiency of splenic sequestration of blood-borne particulate material, whereas “late” antibody favors sequestration in the liver.
Incidence of Cytomegaloviremia in Blood-Bank Donors and in Infants with Congenital Cytomegalic Inclusion Disease
Authors: Mirkovic R. , Werch J. , South M. A. , Benyesh-Melnick M.
Published: January 2020

During a 15-month period, cytomegalovirus (CMV) isolations were attempted from leukocytes derived from 290 healthy blood-bank donors. The major proportion of the specimens were tested 2 to 5 hr after donation. However, CMV was not recovered from any of the specimens examined. At the time of donation, 75% of donors had CMV complement-fixing antibodies demonstrable in titers of 10 to ≥320. The age of the study group ranged from 17 to 57 years. During the same time period and with the use of identical isolation techniques, postnatal cytomegaloviremia was demonstrated in four infants with cytomegalic inclusion disease. Failure to detect cytomegaloviremia in 290 normal blood donors questions its occurrence outside pathological conditions. These results do not support the concept that CMV infection, concurrent with post-transfusion mononucleosis syndrome, is transmitted through the blood donor's leukocytes.
Antigens of
Bordetella pertussis
V. Separation of Agglutinogen
1
and Mouse-Protective Antigen
Authors: Ross R. F. , Munoz J.
Published: January 2020

Agglutinogen
1
of
Bordetella pertussis
strain 353/Z (serotype
1
) was separated from protective antigen and histamine-sensitizing factor by starch-block electrophoresis. Most of the agglutinogen
1
migrated towards the cathode in starch-block electrophoresis, although some remained near the origin. Fractions containing most of the agglutinogen
1
were free of detectable mouse-protecting or histamine-sensitizing activities. Agglutinogen
1
from a serotype
1, 3 B. pertussis
strain (J20) migrated similarly to the agglutinogen
1
from strain 353/Z. All agglutinogen
3
activity was found at the point of application in the starch block. No clear relationship was found between agglutinogen
1
and mouse-protecting antigen or histamine-sensitizing factor.
Mouse Resistance Against Foot-and-Mouth Disease Virus Induced by Injections of Pyran
Authors: Richmond Jonathan Y.
Published: January 2020

Mouse resistance to foot-and-mouth disease virus (FMDV) was induced by intraperitoneal injections of pyran copolymer. A biphasic pattern of protection occurred with greatest resistance 4 and 48 hr after injection of this polyanion. Viremia was not detectable in pretreated mice challenge-exposed with FMDV. Incubation of virus with pyran did not alter viral infectivity in mice or tissue culture. Serum interferon was demonstrated 1 and 2 days after pyran administration.
Immunological Study on the Host Cell Penetration Factor of
Toxoplasma gondii
Authors: Norrby Ragnar
Published: January 2020

The host cell penetration factor (PEF) of
Toxoplasma gondii
was studied by biochemical and immunological techniques. Sephadex gel filtration of an ammonium sulfate-precipitated PEF yielded two components with different molecular weight, but both having penetration-enhancing activity. The methods for purification removed at least 99.9% of extraneous protein. For demonstration of a significant enhancement of penetration, 0.001 μg of protein was sufficient. Biochemically, they appeared to be acid proteins with the same electrophoretic mobility. Both components showed maximal enhancement of penetration at
p
H 7.6 and 37 C. PEF antisera reduced the penetrative capacity of
Toxoplasma
parasites. The penetration-enhancing effect of the two components of PEF was inhibited by antiserum against any of them. Moreover, immunologically identical immunoprecipitates were obtained when antiserum reacted with the two components. The results thus indicated that the two components of PEF were immunogenically identical and that the difference in molecular weights might result from aggregation. Immunofluorescence indicated that PEF was related to cytoplasmic structures located in the anterior end of
Toxoplasma
. A possible relation between these structures and the paired organelle or the convoluted tubes was discussed. The number of parasites with immunofluorescence was low shortly after host cell penetration and increased during the intracellular life of the parasites after kinetics, previously observed for synthesis of PEF as well as for lysosomal activity of
Toxoplasma
.
Effect of
l
-Homoserine on the Growth of
Mycobacterium tuberculosis
Authors: O'Barr Thomas P. , Everett Karen A.
Published: January 2020

l
-Homoserine was observed to inhibit the growth of
Mycobacterium tuberculosis.
In the metabolism of
M. tuberculosis
,
l
-homoserine was found to be a precursor of threonine, isoleucine, and methionine.
l
-Homoserine-inhibited cells contained elevated levels of the enzyme acetohydroxy acid synthetase. In addition, washed cell suspensions of
M. tuberculosis
formed significant amounts of alpha-amino-
n
-butyric acid from supplements of
l
-homoserine.
dl
-Alpha-amino-
n
-butyric acid proved to be much more inhibitory for growth than
l
-homoserine. Growth antagonism by
l
-homoserine was reversed by
l
-lysine,
l
-threonine, and combinations of
l
-leucine with
l
-valine. At the cellular level, these amino acids reduced the amount of acetohydroxy acid synthetase in cells grown with
l
-homoserine and competed with
dl
-homoserine-
4
-
14
C
for entrance into the extractable cell pool.
l
-Isoleucine also antagonized the conversion of
l
-homoserine to alpha-amino-
n
-butyric acid. Available data indicated that the effect of
l
-homoserine was related to its conversion to alpha-amino-
n
-butyric acid which subsequently inhibited growth
Cecal Enlargement and Microbial Flora in Suckling Mice Given Antibacterial Drugs
Authors: Savage Dwayne C. , McAllister Julia Sue
Published: January 2020

Enlargement and microbial colonization of the cecum were examined in neonatal mice suckling mothers drinking either water or an aqueous solution of penicillin. The full ceca increased in weight at the same rate in both drug-treated and control mice during the first 15 to 17 days after birth. Thereafter, cecal weight increased at a greater rate in the drug-treated animals than in the untreated controls. At weaning, the ceca in treated mice were two to three times the size of control organs and remained enlarged as long as penicillin was given. The enlarged ceca did not differ histologically from those in controls. From birth, the cecal microflora in the drug-treated mice differed qualitatively and quantitatively and in colonization pattern from the flora of control mice. The ceca of untreated animals were colonized primarily by large populations of lactobacilli during the first week after birth, small populations of coliforms and enterococci during the second week, and enormous populations of bacteroides and certain gram-negative fusiform-shaped anaerobic bacteria during the third week. In contrast, the organs of the treated mice were populated by large populations of coliforms and enterococci during the first week and enormous populations of clostridia and unusual gram-negative nonsporeforming bacteria during the third week. These large abnormal populations were present in the ceca as they enlarged during the third week after birth in the drug-treated animals. These findings confirm that only certain populations of anaerobic bacteria can act to maintain cecal size in normal animals.
Inhibition of Deoxyribonucleic Acid Synthesis in Synchronized Populations of L Cells Infected with
Chlamydia psittaci
Authors: Tribby Ilse I. E. , Moulder James W.
Published: January 2020

Infection of L cells with
Chlamydia psittaci
inhibited the burst of deoxyribonucleic acid synthesis that occurs when the host cells are released from a double thymidine block.
Immunodiffusion Studies of Purified Equine Infectious Anemia Virus
Authors: Nakajima Hideo , Ushimi Chuzo
Published: January 2020

Antigenicity of purified equine infectious anemia (EIA) virus was examined by immunodiffusion against sera obtained from horses experimentally infected with EIA virus. The purified virus reacted with the infected horse serum, and virus-specific precipitating antibody was demonstrated. Furthermore, it was found that purified EIA virus reacted against the serum of horses infected with all strains of EIA virus which were antigenically different from one another. From the result, group-specific components of the virus rather than strain-specific ones were considered to be involved in the reaction. Serological reactivity was lost by adding antiserum from the infected horse to the antigen. The precipitating antibody usually appeared in the serum 1 to 2 weeks after the first febrile attack of EIA and remained for a longer period. Some characteristics of the purified antigen and specificity of the reaction for EIA are described.
Separation of Mycobacterial Soluble Antigens by Isoelectric Focusing
Authors: Moulton R. G. , Dietz T. M. , Marcus S.
Published: January 2020

Ion-exchange chromatography and gel filtration have been reported to yield partial separation of mycobacterial antigens. These procedures were used in combination with isoelectric focusing in an attempt to purify antigens of
Mycobacterium tuberculosis
strain H37Ra. The fractionating action of isoelectric focusing is dependent upon differences in the isoelectric points of the proteins to be separated. Culture filtrate of
M. tuberculosis
H37Ra was chromatographed on Sephadex G-200. This resulted in two widely separated peaks. The first peak, presumably containing high-molecular-weight substances, was then fractionated on a diethylaminoethyl Sephadex anion-exchange column. Three peaks were collected, and each was subjected to isoelectric focusing. Each peak was further separated into two or more fractions. The serological reactivity of each fraction was determined by immunodiffusion and immunoelectrophoresis. Sensitized guinea pigs were also skin-tested with the fractions. Two of the fractions contained only a single precipitinogen. One fraction contained two precipitinogens. A fourth fraction contained three precipitinogens and was also the only fraction to display sensitin activity. Four of the fractions were inactive either as precipitinogens or sensitins. The results suggest that the methods described are useful for the separation of mycobacterial antigens.
Properties of a Cold Hemagglutin in Associated with Leptospiral Hemolytic Anemia of Sheep
Authors: Bhasin J. L. , Freeman M. J. , Morter R. L.
Published: January 2020

The cold hemagglutinin which appears after leptospiral infection of sheep was isolated consistently from the plasma by absorption to autologous erythrocyte stroma at 4 C and subsequent elution at 25 C. Immunoelectrophoretic tests disclosed that the purified preparations consisted primarily of a single detectable component with the electrophoretic, positional, and antigenic characteristics of ovine immunoglobulin M. The properties of the cold hemagglutinin included a rapid sedimentation rate, elution in the leading peak from G-200 Sephadex, high anionic-binding capacity, and rapid electrophoretic mobility. Thus, these methods also supported the identification of the cold hemagglutinin as a homogeneous protein with properties like immunoglobulin M. The occurrence of the cold hemagglutinin after the phase of leptospiremia and concurrent to the onset of hemolytic anemia suggests that this antibody may play a significant role in the genesis of leptospiral acquired hemolytic anemia.
Intracellular and Extracellular Mineral Crystal Formation Induced by Viral Infection of Cell Cultures
Authors: Fabricant C. G. , Gillespie J. H. , Krook L.
Published: January 2020

Intracellular mineral crystals were observed in cell cultures infected with one or more feline viruses. One was a feline syncytium-forming virus, and the other was a new feline virus which produced intranuclear inclusions in cell cultures. Crystals were noted both in autogenous cell cultures from trypsinization of kidneys and urinary bladders of infected cats (three passages) and in subcultures of culture fluids from these, made in a stable feline kidney cell line. Free mineral crystals were also noted in the fluids of the cell cultures. In two bladder and two kidney infected autogenous cultures, structures resembling the urinary calculi observed in obstructed cats were seen. These consisted of mineral crystals in a matrix of cellular debris.
Cycloserine Induction, Propagation, and Antimicrobial Susceptibility of Wall-Defective
Staphylococcus aureus
Authors: Watanakunakorn Chatrchai
Published: January 2020

A method of induction of L colonies of
Staphylococcus aureus
by cycloserine, the propagation of wall-defective staphylococci (WDS), and the development and antimicrobial susceptibility of stable WDS are presented. The growth and morphology of the cycloserine-induced L colonies and WDS were indistinguishable from those induced by methicillin or lysostaphin. The antimicrobial susceptibility of the stable cycloserine-induced WDS was similar to that of the stable methicillin-induced and lysostaphin-induced WDS by both broth dilution and agar diffusion techniques. A survey of the English literature reveals that wall-defective bacteria are always resistent to antimicrobial agents which inhibit cell wall synthesis (cycloserine, penicillins, and cephalosporins). They are virtually all susceptible to antimicrobial agents which have other modes of action. The susceptibility to vancomycin and bacitracin varied from study to study.
Further Observations on the Antibacterial Nature of Prostatic Fluid
Authors: Fair William R. , Wehner Nancy
Published: January 2020

A growth media has been developed which will not inhibit the antibacterial activity of the prostatic antibacterial factor. The use of spermine-resistant organisms and spermine assay procedures have clearly excluded spermine as being the active antibacterial agent in canine prostatic fluid.
Identification of Two Widely Separated Loci Conferring Nicotinic Acid Dependence on Wild-Type
Shigella flexneri
2a
Authors: Gemski P. , Formal Samuel B. , Baron L. S.
Published: January 2020

Two widely separated loci causing the nicotinic acid dependence of wild-type
Shigella flexneri
2a were identified by intergeneric mating procedures and found to be closely linked to the
gal
and
fuc
chromosomal determinants.
Derivation of a Borg Strain of
Chlamydia psittaci
Attenuated for Mice
Authors: Hearn Henry J. , Herring Albert S.
Published: January 2020

The method of derivation and virulence of a new attenuated variant (ABG) obtained during passage of the virulent Borg strain in embryonated eggs in the presence of
p
-aminobenzoic acid are described.
Immunogenicity of
Mycoplasma pneumoniae
Authors: Kenny George E.
Published: January 2020

The immunogenicity of
Mycoplasma pneumoniae
for New Zealand white female rabbits was studied by using an immunization scheme which employed initial intramuscular immunization with vaccine in incomplete Freund adjuvant followed 3 weeks later by a series of five intravenous injections of fluid vaccine. Small doses of immunogen (15 to 150 μg of mycoplasmic protein per rabbit) gave rise to sera which contained antilipid complement-fixing antibody, produced one to three precipitin lines, but gave poor growth-inhibition on agar. Larger doses of immunogen (1.5 to 15 mg per rabbit) gave rise to sera which gave higher antilipid complement-fixing titers, four to eight precipitin lines, and good growth-inhibition. Doses smaller than 15 μg per rabbit failed to give rise to detectable antibody. Growth-inhibiting antibody was produced later than the other antibodies. The number of precipitin lines was controlled more critically by the quality of the antisera, as determined by the amount of immunogen, than by the quantity of serological test antigen. All sera which gave any precipitin lines produced a common precipitin line which stained for lipid.
Demonstration of Serologically Different Capsular Types Among Strains of
Staphylococcus aureus
by the Serum-Soft Agar Technique
Authors: Yoshida Kosaku
Published: January 2020

Colonies of
Staphylococcus aureus
exhibiting diffuse-type growth in regular serum-soft agar containing 7.5% sodium chloride were isolated. After isolation, further identification of the encapsulated strains of
S. aureus
was performed. With this procedure, 19 encapsulated strains were obtained from 103 clinical specimens (18.4%). With these strains, three serologically distinct diffuse types of organisms were observed by the conversion of diffuse to compact type colonial morphology in serum-soft agar containing specific antidiffuse sera. Capsule-inhibiting activity of antisera was adsorbable with homologous encapsulated organisms and not adsorbed with either heterologous encapsulated organisms nor the derived compact variant, suggesting a specific activity for the antispecific capsular antibody. Fourteen strains were similar to the Smith diffuse-type strain, four strains were the same as NS58D, and one was identical to NS41D. These were provisionally designated as capsule types A, B, and C, respectively.
Mechanism of Tuberculostasis in Mammalian Serum III. Neutralization of Serum Tuberculostasis by Mycobactin
Authors: Kochan Ivan , Pellis Neal R. , Golden Carole A.
Published: January 2020

Tubercle bacilli exposed to an iron-poor medium multiplied at a slower rate but released more of the serum-tuberculostasis neutralizing factor (TNF) than the bacilli in an iron-rich medium. This growth-promoting factor found in spent medium exhibited characteristics which suggested its relationship to or identity with mycobactin. The identity of these two bacillary products was established by showing that both iron-free mycobactin and TNF promoted bacillary multiplication in tuberculostatic serum. This study resolved a long-standing controversy as to whether mycobactin serves as a growth factor or as a carrier of iron for tubercle bacilli. It was found that the tuberculostasis in mycobactin-neutralized serum was reconstituted by the addition of iron-free transferrin (Tr). The investigation of the interplay between mycobactin and Tr revealed that mycobactin does not serve as a growth factor but as a carrier of growth-essential iron which mycobactin (as contrasted to Tr) provides to tubercle bacilli in a utilizable form.
Properties of the Hemolytic Activities of
Escherichia coli
Authors: Short Everett C. , Kurtz Harold J.
Published: January 2020

Some properties of the cell-free and cell-associated hemolysins of
Escherichia coli
were studied. Several strains of
E. coli
that were isolated from intestines of pigs with edema disease produce large quantities of cell-free hemolysin when grown in the presence of an extract of meat. The component of meat that stimulates production of cell-free hemolysin is not extracted by lipid solvents and is not dialyzable. The cell-free hemolysin is an acidic substance that occurs in two forms. It is inactivated by trypsin but not by lecithinase, lysozyme, ribonuclease, or deoxyribonuclease, shows optimum activity between
p
H 7 and 8, and requires calcium ion for activity. It does not appear to be an enzyme. The kinetics of the lytic reaction are most consistent with the hypothesis that one molecule of cell-free hemolysin is sufficient to lyse one erythrocyte and that it is inactivated in the lytic reaction. The cell-free hemolysin does not sufficiently damage the cell during the prelytic period to cause lysis after the hemolysin-calcium-erythrocyte complex has been disrupted. The cell-associated hemolysin was not separated from the cell by autolysis, freezing, sonic treatment, or treatment with trypsin or lysozyme. It appears to be closely associated with the metabolic status of the cell. Organisms that are highly hemolytic under usual conditions of assay immediately lose most of their hemolytic capability in the presence of sodium cyanide, streptomycin, nalidixic acid, and rifampin.
Relationships Between
Mycoplasma pneumoniae
and Human Respiratory Epithelium
Authors: Collier Albert M. , Clyde Wallace A.
Published: January 2020

The interaction was studied between
Mycoplasma pneumoniae
and its natural host cell, the human respiratory epithelium. Organized, ciliated cells provided by fetal trachea in organ culture enabled examination of the host-parasite relationship by light, immunofluorescence, and electron microscopy. Impairment of cellular function was reflected by disorganization and loss of ciliary motion; this was associated with a sequence of cytopathological changes denoting progressive cell injury. The organisms were found concentrated on the luminal surface of ciliated epithelium and cells lining the submucosal glands. A differentiated portion of the
Mycoplasma
, consisting of an extension of the unit membrane containing an electron-dense core surrounded by a lucent space, served as the means of attachment to host cells. The findings suggest that the pathogenicity of
M. pneumoniae
depends upon intimate extracellular infection with production of functional and structural changes initiated by host cell membrane injury.
Immunosuppressive Agents in Intracellular Infection: Besnoitiosis in Hamsters
Authors: Wilson H. R. , Frenkel J. K.
Published: January 2020

When tested for their activity in suppressing the acquisition of immunity during acute
Besnoitia
infection of hamsters, antilymphocyte serum (ALS), aminopterin, cyclophosphamide, cortisol, and whole-body irradiation were the most active agents and effectively blocked the development of immunity during 4 to 12 days of immunization. Actinomycin D and chlorambucil were moderately active, and nitrogen mustard, 6-mercaptopurine, and vinblastine exhibited slight immunosuppressive activity. Established immunity was especially labile to cortisol and cortisone administration with generalized
Besnoitia
relapse occurring consistently in all hamsters; this occurred infrequently during cyclophosphamide treatment. Focal relapse was seen in chronically irradiated and ALS-treated hamsters, but the location of the lesions differed. Irradiated hamsters had lesions in the lungs and brain, whereas ALS-treated hamsters showed splenic relapse. Acquisition of immunity was more sensitive to suppression than established immunity and did not necessarily parallel antibody development and vice versa, emphasizing the importance of cellular over humoral factors in immunity to this intracellular parasite.
Antiphagocytic Effect of Slime from a Mucoid Strain of
Pseudomonas aeruginosa
Authors: Schwarzmann Stephen , Boring John R.
Published: January 2020

Mucoid strains of
Pseudomonas aeruginosa
produce a viscid slime when grown on the surface of agar media. These strains are known to colonize persistently the tracheobronchial tree of children with cystic fibrosis. Colonization may result from inhibition of phagocytosis due to slime produced by the organism. Slime separated from one mucoid strain was examined to determine whether it possessed antiphagocytic activity in vitro. Cells of
P. aeruginosa, Escherichia coli
, and
Staphylococcus aureus
were rapidly phagocytized by rabbit polymorphonuclear leukocytes when mixtures were rotated for 2 hr at 37 C in the absence of slime. The addition of relatively small amounts of slime to bacteria and leukocytes inhibited phagocytosis as measured by phagocytic killing of the organisms. Inhibition was found to be most complete with
P. aeruginosa
.
Correlation of Staphylococcal Bacteriophage Types to L-Form Colony Production
Authors: Dalton Harry P. , Escobar Mario R. , Allison Marvin J.
Published: January 2020

The ability of 258 strains of
Staphylococcus aureus
and 132 strains of
S. epidermidis
to produce L-form colonies in a standard environment was investigated. Production of these colonies by
S. aureus
was correlated with their phage type. Phage type 7 strains produced L-form colonies in larger numbers and more consistently than those of phage type 80/81. No L-form colonies were produced by the
S. epidermidis
strains tested.
Effect of Interferon and Interferon Inducers on Infections with a Nonviral Intracellular Microorganism,
Chlamydia trachomatis
Authors: Kazar J. , Gillmore J. D. , Gordon F. B.
Published: January 2020

The effect of mouse interferon (IF) on the multiplication of
Chlamydia trachomatis
(strain MRC-1/G) in homologous (L-929) cell cultures and the effect of the IF inducers Newcastle disease virus (NDV) and polyriboinosinic acid-polyribocytidylic acid complex (poly I:C) on the experimental infection of mice with aerosolized
C. trachomatis
(strain MoPn) were investigated. Treatment of infected cell cultures with IF reduced the number of cells containing chlamydial inclusions and depressed the yield of chlamydiae as determined by titrations for infectivity. Growth of chlamydiae was reduced when cultures were exposed to IF 6 or 18 hr before infection, and slight reduction of the yield was also detectable in cell cultures treated with IF at early intervals (0 or 4 hr) after chlamydial infection. No effect of IF on penetration of chlamydiae into mouse cells was observed, whether phagocytic cells from peritoneal washings or L-929 cells were used, indicating that the inhibitory effect of IF occurs after chlamydiae enter the host cell. Additional evidence was obtained that a significant effect of IF occurs at an early stage in maturation of the intracellular chlamydiae. In mice exposed repeatedly to NDV aerosols and challenged with aerosolized MoPn 8 hr after the first exposure to NDV, mortality was delayed by 2 to 3 days and lung consolidation was slightly reduced at 3 days after infection. Yields of chlamydiae from lung pools of NDV-treated mice, taken at 3, 6, and 9 days after challenge, were not significantly different from those of controls. Similar results were obtained when mice were challenged with MoPn 8 hr after intranasal injection with 100 μg of poly I:C or 24 hr after intravenous injection with 200 μg of poly I:C. In contrast, administration of 0.2 ml of NDV (10
8.3
plaque-forming units) intravenously 10 hr before or 24 hr after challenge with MoPn accelerated mortality of mice by 2 to 3 days. In all experiments, detectable levels of IF in sera or 20% lung suspensions were found only up to 48 to 72 hr after exposure of mice to IF inducers.
Effect of Carbohydrates on Hemolysin Production by
Escherichia coli
Authors: Rennie R. P. , Arbuthnott J. P.
Published: January 2020

The production of hemolysin by
Escherichia coli
after adding various carbohydrates to starved cultures was investigated.
Location of
Vibrio fetus
var.
venerealis
Within the Endometrium of the Cow
Authors: Wilkie B. N. , Winter A. J.
Published: January 2020

Vibrio fetus
was located by immunofluorescence within the endometrial epithelium of experimentally infected heifers. Bacterium-like structures were also located by electron microscopy within endometrial epithelial cells.
Further characteristics of beta2-microglobulin binding to oral streptococci
Authors: Ericson D , Björck L , Kronvall G
Published: January 2020

A total of 85 strains of oral bacteria representing Streptococcus mutans, S. sanguis, S. Mitior, S. salivarious, S. milleri, S. infrequens, S. durans, S. lactis, S. faecalis, S. faecium, S. equinus, Streptococcus species group E, Actinomyces, and one group A Streptococcus were tested for binding of aggregated human beta 2-microglobulin. Positive affinity between bacteria and aggregated human beta 2-microglobulin was detected in 36% of the strains. No apparent correlation with bacterial species, serotype, or group was noted. No positive strains were detected among seven group I:A S. sanguis strains (P < 0.01). Binding constants for one S. mutans strain indicated heterogeneous binding structures on the bacterial surface. The number of binding sites for aggregates of human beta 2-microglobulin involving multipoint attachment varied from 70 to 1,700 per bacterial cell. With whole saliva as buffer, a general increase in affinity was seen. Variations in salt concentrations of the buffers revealed different salt-dependent species-associated uptake patterns. Oral bacteria tended to have an uptake maximum at a salt concentration similar to that seen in saliva. Binding structures for aggregated beta 2-microglobulin on oral streptococci were sensitive to pepsin, heat, and formaldehyde treatment. Bacterial binding structures for aggregated beta 2-microglobulin might represent one of several factors of importance for bacterial attachment in the oral cavity. Experimental conditions reflecting the salivary milieu increased the degree of interaction, emphasizing the importance of physiological test systems for such studies.
Seroconversion to virus-specific pre-early nuclear antigens in infants with primary cytomegalovirus infection
Authors: Chiba S , Motokawa T , Tamura T , Hanazono H , Kamada M , Chiba Y , Nakao T
Published: January 2020

Antibodies to human cytomegalovirus (CMV)-specific antigens were determined in sera serially collected from 10 infants with primary CMV infection. Antibodies to pre-early nuclear antigens (PENA), which are detectable in human embryonic lung cells within 3 h of CMV infection by anticomplement immunofluorescence staining, developed in all the patients. However, in contrast to the early response of anti-early antigens (EA), anti-late antigens (LA), and immunoglobulin M antimembrane antigens (MA), seroconversion or the maximum antibody response to PENA was usually observed 1 or more months later. Immunoglobulin M antibody to MA became undetectable soon after recovery from illness, followed by a decrease in anti-EA, anti-PENA, and then anti-LA titers. Results indicated analogy of the clinical significance of anti-PENA in CMV infection to that of anti-Epstein-Barr nuclear antigen in infectious mononucleosis and support the idea that parallel determinations of anti-PENA and IgM anti-MA antibodies can be useful for identifying the acute or chronic phase of primary CMV infection.
Purification and immunological characterization of a rhamnose-glucose antigen from Streptococcus mutans 6517-T2 (serotype g)
Authors: Prakobphol A , Linzer R
Published: January 2020

The serotype antigens of Streptococcus mutans have been described as cell wall-associated polysaccharides. In this study, an additional wall polysaccharide antigen was purified and characterized from S. mutans strain 6715-T2, a mutant of 6715 (serotype g). Strain 6715-T2 lost the serotype antigen during animal passage. Rhamnose-containing carbohydrate fractions were solubilized from bacterial cells by extraction with 5% trichloroacetic acid at 4 degrees C for 18 h and with 0.01 N HCl at 100 degrees C for 20 min. Extracts were combined and purified on columns of diethylaminoethyl-Sephadex A-25 and Sephadex G-100. The purified sample contained 59% rhamnose, 31% glucose, 2.2% protein, and 0.24% phosphorus. The purified rhamnose-glucose polysaccharide (RGP/6715-T2) reacted strongly with antisera to whole cells of 6715-T2. Agar gel diffusion and comparative immunoelectrophoresis studies revealed that RGP/6715-T2 was serologically distinct from the serotype g and d polysaccharide antigens. These techniques also indicated immunological identity between RGP/6715-T2 and RGP/B13, a rhamnose-glucose polymer previously isolated from S. mutans B13, a serotype d strain. Antigen immunologically identical to RGP/6715-T2 was detected both in Rantz-Randall extracts from whole cells of S. mutans strains 6715, OMZ-65, and 6715-PT and in extracts from cells of 6715-T2 and C307, two mutant serotype g strains that lacked the serotype g antigen.
Activation of the alternative complement pathway by Histoplasma capsulatum
Authors: Ratnoff W D , Pepple J M , Winkelstein J A
Published: January 2020

The present study was performed to determine whether Histoplasma capsulatum (yeast phase) is able to activate the alternative complement pathway. H. capsulatum yeasts were shown to consume C3 in C4-deficient guinea pig serum. Immunoelectrophoretic conversion of alternative pathway component factor B confirmed that C3 consumption was mediated by activation of the alternative pathway. These results demonstrate that H. capsulatum is able to activate the alternative complement pathway.
Adherence of Streptococcus salivarius HB and HB-7 to oral surfaces and saliva-coated hydroxyapatite
Authors: Weerkamp A H , McBride B C
Published: January 2020

We compared the binding of Streptococcus salivarius HB and the mutant HB-7 to oral surfaces in vivo. Mutant HB-7 does not aggregate with saliva nor does it bind to buccal epithelium, but it does retain its ability to coaggregate with Veillonella and Fusobacterium. At 1 h after inoculation into the oral cavity of six volunteers, significantly more S. salivarius HB than HB-7 cells were found adhering to the buccal mucosa (P < 0.05) and to a cleaned tooth surface (P < 0.01); there was no significant difference in the numbers adhering to the tongue. The ratio of HB to HB-7 on the tongue increased in samples taken 1, 3, and 9 days after inoculation. The average time required to clear the mutant HB-7 from the oral cavity was 7 days, whereas that for the parent HB was greater than 20 days, and in some cases strain HB was still present 3 months after its inoculation. A representative S. salivarius serotype II strain, designated T3, behaved similarly to mutant HB-7 with respect to its adherence to the buccal mucosa. Strain HB adhered better to hydroxyapatite treated with human saliva than mutant HB-7; both strains adhered in similar numbers to untreated hydroxyapatite. Hydroxyapatite treated with rat saliva bound less HB than hydroxyapatite treated with human saliva, corresponding to the lower aggregating activity of rat saliva. Extraction of saliva with aggregating strains of S. salivarius reduced the ability of saliva to mediate attachment of strain HB to hydroxyapatite.
Lymphocyte blastogenesis and interferon production in adult human leukocyte cultures stimulated with cytomegalovirus antigens
Authors: Starr S E , Dalton B , Garrabrant T , Paucker K , Plotkin S A
Published: January 2020

Lymphocyte blastogenesis and interferon production were measured in adult human leukocyte cultures stimulated with purified or crude cytomegalovirus antigens. Leukocytes from seropositive adults underwent blastogenesis when stimulated with purified or crude Towne strain antigen, whereas neither antigen stimulated blastogenesis in cultures from seronegative donors. The concentrations of antigens yielding maximal blastogenesis varied among the individuals tested. When cultures from seropositive individuals were stimulated with antigens prepared from three different CMV strains--AD-169, Towne, and Davis--comparable levels of blastogenesis were detected. Type 1 interferon was detected in supernatants of cultures stimulated with crude antigens regardless of the immune status of the donor. In contrast, when purified antigen was used as the stimulant, only cultures obtained from seropositive individuals produced detectable levels of interferon, which appeared to be predominantly type 2 or immune interferon.
Kinetics of Interaction and Fate of
Pasteurella hemolytica
in Bovine Alveolar Macrophages
Authors: Maheswaran S. K. , Berggren K. A. , Simonson R. R. , Ward G. E. , Muscoplat C. C.
Published: January 2020

To study the role of pulmonary alveolar macrophages (PAMs) in phagocytizing
Pasteurella hemolytica
, we developed an in vitro cultivation method for preparing them. This procedure provided an adherent monolayer of PAMs which were nonspecific esterase-positive and phagocytized latex beads. The phagocytosis and fate of
P. hemolytica
(biotype A, serotype 1) by PAMs in suspension were studied. The kinetics of phagocytosis were determined by quantitatively measuring the uptake of 24-h [
3
H]thymidine-labeled bacteria by the PAMs in the presence of opsonins. Results showed that the uptake of
P. hemolytica
was enhanced in the presence of normal serum or antiserum. A total of 90% of the bacteria were phagocytized in the presence of normal adult bovine serum, and up to 95% were phagocytized in the presence of an antiserum. These studies also showed that normal serum, but not fetal calf serum, contained heat-stable natural antibodies which readily initiated the opsonization of
P. hemolytica
. The heat-labile complement system was also involved in the opsonization. The fate of
P. hemolytica
inside the PAMs was investigated by transmission electron microscopy and by the viable plate count method. Approximately 90% of the normal serum- or antiserum-opsonized
P. hemolytica
were phagocytized by PAMs at a bacteria/PAM ratio of 20:1 and were completely degraded after 60 min of exposure. Prolonged incubation of this mixture of bacteria and PAMs resulted in cytotoxic changes and destruction of PAMs. At a low bacteria/PAM ratio (10:1 or less), there was phagocytosis and killing of bacteria but no cytotoxic changes on the PAMs. The exact mechanism which initiated this phenomenon was not demonstrated. Perhaps toxic substance(s) released by the excess unphagocytized bacteria caused the cytotoxic changes to the PAMs.