bluuebunny/crossref_metadata_2025 huggingface dataset:
Involvement of Phosphoenolpyruvate in the Catabolism of Caries-Conducive Dĭsaccharides by
Streptococcus mutans
: Lactose Transport
Authors: Calmes Robert
Published: January 2020

The mechanisms for transport and hydrolysis of lactose were investigated in five cariogenic strains (HS6, AHT, FA1, NCTC 10449, and SL1) representing the four serogenetic groups of
Streptococcus mutans.
The systems for transport and hydrolysis of lactose had the characteristics of a phosphoenolpyruvate (PEP)-dependent lactose (Lac) phosphotransferase (PT) system and phospho-β-galactosidase (P-β-gal), respectively, in all strains tested, except strain HS6. Decryptified cells required PEP and Mg
2+
for transport of the non-metabolizable model β-galactosides
o
-nitrophenyl-β-
d
-galactopyranoside (ONPG) and thiomethyl-β-
d
-galactopyranoside (TMG). Substitution of 2-phosphoglycerate (2-PG) for PEP also stimulated the Lac PT system. Other potential high-energy phosphate donors (adenosine tri-, di-, and monophosphates and guanosine triphosphate) did not stimulate the Lac PT system. Sodium fluoride had no effect upon the PEP-dependent Lac PT system in decryptified cells with PEP as the energy source; however, when 2-PG was used as the energy source, F
−
inhibited ONPG phosphorylation. With intact cells which must generate PEP endogenously, the presence of F
−
in concentration ≥ 10 mM completely inhibited the Lac PT system, presumably through inhibition of 2-PG hydrolyase (EC 4.2.1.11; enolase). Both intact and decryptified cells accumulated a phosphorylated derivative of TMG that behaved chromatographically as TMG-phosphate. After alkaline phosphatase treatment, the derivative had an
R

f

identical to that of TMG. No β-galactosidase (β-gal) activity was detected with ONPG as the substrate; hydrolysis occurred only when ONPG-6-phosphate was supplied as the substrate. Strain HS6 apparently transported lactose by an active transport-type system in which the accumulated intracellular product was the free disaccharide based on the following criteria: (i) ONPG transport and hydrolysis in decryptified cells was not stimulated by PEP; (ii) ONPG hydrolysis occurred in the absence of PEP; and (iii) ONPG-6-phosphate was not hydrolyzed. These data indicate that, in all strains tested except strain HS6, lactose transport was mediated by a PEP-dependent Lac PT system, resulting in accumulation of lactose-phosphate that was hydrolyzed by an enzyme similar to the P-β-gal of group N streptococci and
Staphylococcus aureus;
conversely, strain HS6 transported and hydrolyzed lactose by a PEP-independent transport system and β-gal, respectively.
Characterization and Comparative Genital Tract Pathogenicity of Bovine Mycoplasmas
Authors: Hirth R. S. , Nielsen S. W. , Tourtellotte M. E.
Published: January 2020

Sixteen bovine genital mycoplasmal isolates obtained from semen and prepuce of bulls and from aborted fetuses were compared physiologically and serologically with the Donetta strain (tentatively
Mycoplasma agalactiae
var.
bovis
), a known pathogen. All isolates were distinct from the Donetta organism. Four appeared to be saprophytes, and the remainder were placed in one group which could not be further separated by the biochemical or serological methods used. Two of the organisms in the latter group have been subsequently identified as
M. bovigenitalium.
Uterine infusion of broth cultures of four isolates into virgin heifers failed to produce clinical evidence of disease, and significant lesions were not present at necropsy. The mycoplasmas were recovered from cervicovaginal mucus of only three heifers, and never for more than 3 days postinfusion. Since the organisms were not recovered from any organs at necropsy, it appears that the mycoplasmas were incapable of surviving in the clinically normal virgin female reproductive tract.
Cytopathic Effects and Ultrastructure of
Mycoplasma agalactiae
var.
bovis
(Donetta strain)
Authors: Hirth R. S. , Tourtellotte M. E. , Nielsen S. W.
Published: January 2020

An electron microscopic examination of the pathogenic Donetta strain mycoplasma (tentatively
Mycoplasma agalactiae
var.
bovis
), in broth and cell cultures, revealed that this organism possessed considerable pleomorphism. A membranelined space occurred in a number of the organisms, and some of these were considered to represent deep, cuplike invaginations of the outer limiting membrane. In cell cultures, the mycoplasmas were located almost exclusively in extracellular locations but often in close association to the host-cell membrane. The cytopathic effects (CPE) were not considered to be caused primarily by cytoplasmic invasion. Serum was necessary for the development of the CPE and multiplication of the mycoplasmas in cell cultures. An effort to determine the basic cause of the CPE was unsuccessful but did eliminate causes previously reported for other strains of mycoplasma.
Intranuclear Growth of
Rickettsia canada
, a Member of the Typhus Group
Authors: Burgdorfer Willy , Brinton Lyle P.
Published: January 2020

Intranuclear development of
Rickettsia canada
, a typhus-group rickettsia, in cells of tick tissues is described and illustrated.
Responses of the Peyer's Patches in Germ-Free Mice to Antigenic Stimulation
Authors: Pollard Morris , Sharon Nehama
Published: January 2020

Lymph nodes, spleens, and Peyer's patches of germ-free mice are relatively inactive. The tissues are small and contain rare, small, indistinct, germinal zones. When exposed to antigenic stimuli (
Salmonella paratyphi
A and lymphocytic choriomeningitis virus), the tissues become larger and germinal zones appear coincident with antibodies in the blood. The Peyer's patches were activated if antigen was absorbed from the intestinal lumen into the circulation but not if the antigen was administered parenterally. There was no demonstrable immunological response by the germ-free mouse to
Streptococcus faecalis
.
Bactericidal Activity of Human Macrophages: Analysis of Factors Influencing the Killing of
Listeria monocytogenes
Authors: Cline Martin J.
Published: January 2020

A technique is described for the measurement of listericidal activity of human macrophages grown from blood monocytes. Phagocytosis of
Listeria monocytogenes
was inhibited by a glycolytic poison (NaF) but was unaffected by anaerobic conditions, cyanide, or 2,4-dinitrophenol (DNP). Killing by macrophages was slower than that by neutrophils, and
Listeria
phagocytized by macrophages began to synthesize deoxyribonucleic acid within 3 hr of the time of ingestion. Differentiated macrophages ingested and killed more organisms per cell than newly isolated monocytes. Maximal killing of
Listeria
required oxygen but was unaffected by cyanide or DNP. Macrophages isolated from patients with chronic intracellular infection (leprosy, tuberculosis, fungal diseases) and from patients with active Hodgkin's disease were more bactericidal than macrophages from normal subjects.
Host Cell Penetration of
Toxoplasma gondii
Authors: Norrby Ragnar
Published: January 2020

The host cell penetration of
Toxoplasma gondii
was studied with reference to synthesis of a penetration-enhancing factor and the penetrative capacity of the parasites during the various phases of the infectious cycle. HeLa cells as suspension or monolayer cultures were infected with
Toxoplasma
. After a lag phase shorter than 1 hr, there was a synthesis of penetration-enhancing factor demonstrable in the parasites. Exposure of the factor to host cells resulted in disappearance of its penetration-enhancing activity. The findings were in accord with the hypothesis that
Toxoplasma gondii
is capable of synthesizing an enzyme-like factor, reacting with the host cell surface, and, thereby, facilitating the penetration of the parasites. This hypothesis was further supported by the observations that the penetrative capacity of extracellular parasites gradually was reduced in presence of host cells and that intracellular parasites released artificially from host cells shortly after penetration were found to have a reduced penetrative capacity. Parasites allowed to remain for 4 hr or more intracellularly could restore and markedly improve their penetrative capacity.
Serological Comparison of the Two Morphological Phases of
Paracoccidioides brasiliensis
Authors: Restrepo-Moreno Angela
Published: January 2020

The antigenic relationship of six different strains of
Paracoccidioides brasiliensis
was investigated by the agar-gel immunodiffusion test. Soluble antigens prepared from the two morphological phases of the fungus were diffused against human sera obtained from eight patients with paracoccidioidomycosis (South American blastomycosis). The mycelial phase showed common antigenic determinants as revealed by the formation of identical precipitin bands. The yeast phase proved to be more complex. Most of the strains produced a common antigen, but reactions of partial identity and of nonidentity were recorded for two strains. Antigens common to both mycelial and yeast phases were observed in five strains. The remaining strains, however, contained different antigenic determinants. The results of the experiment suggest that
P. brasiliensis
in its yeast form is not an antigenically homogeneous organism.
Pathogenesis and Transmission of Kilham Rat Virus Infection in Rats
Authors: Novotny James F. , Hetrick Frank M.
Published: January 2020

The Kilham rat virus (RV) was found to produce mortality in newborn rats after intracerebral, intravenous, or subcutaneous administration of virus. Both infectious virus and viral hemagglutinins were detected in a variety of tissues and in the blood and urine of experimentally infected rats. Contact control rats housed with infected littermates did not develop disease but did produce antibody to RV. Horizontal virus transmission was also evidenced by the seroconversion of antibody-negative mothers whose litters were infected with RV. The level of maternal antibody was found to be the determining factor in the susceptibility or refractiveness of newborn rats to RV infection. If the mother had no detectable hemagglutination-inhibiting (HI) antibody titer (less than 10) or a low antibody titer (10 or 20), her offspring were highly susceptible to RV. However, the litters of rats with HI titers of 40 or greater were afforded protection when challenged with RV; the higher the maternal antibody level the more solid was the protection conferred. Vertical transmission of RV was also demonstrated. Litters born of mothers infected with RV several days before delivery died within 7 to 9 days of a disease identical to that seen in infected newborns and virus was recovered from a variety of tissues. Results of mother-litter exchange experiments also indicated vertical transmission (rather than transmission through milk) occurs, since litters of infected mothers developed the disease when nursed by normal mothers, whereas litters of normal mothers remained normal although they were nursed by infected mothers.
Antibody production and protection against influenza virus in immunodeficient mice
Authors: Lucas S J , Barry D W , Kind P
Published: January 2020

The roles of T and B cells in the immune response to influenza virus were studied by using mice deficient in either T cells (athymic nude) or immunoglobulin production (CBA/N). The serological responses of these mice to either whole or disrupted A/Aichi/2/68 influenza virus vaccines were examined, and the protective effect of these inoculations was tested by challenge infection with mouse-adapted A/Aichi/2/68 influenza virus. In contrast to normal mice, neither strain of immunodeficient mouse produced detectable serum antibody after inoculation with either type of vaccine. CBA/N mice immunized with intact virus vaccine were protected, however, against subsequent lethal challenge. CBA/N mice inoculated with disrupted virus vaccine and nude mice inoculated with either disrupted or whole virus vaccine were not protected against viral challenge. Evidence of immunological memory was observed in CBA/N and nude mice that had survived live virus challenge after immunization with inactivated vaccine.
Experimental pathogenicity and mortality in ligated ileal loop studies of the newly reported halophilic lactose-positive Vibrio sp
Authors: Poole M D , Oliver J D
Published: January 2020

Laboratory animals were challenged subcutaneously, intraperitoneally, and intravenously with the halophilic lactose-positive Vibrio. Intraperitoneal inocula of 10(8) organisms proved to be rapidly lethal in mice, rats, and hamsters. The 50% lethal doese in ICR strain mice was estimatd to be 8 X 10(5) live cells, injected intraperitoneally or subcutaneously. Subtaneous inocula in mice resulted in severe local infections, characterized by gross edema, and for those animals surviving longer than 48 h, tissue necrosis. Intravenous, intraperitoneal, and subcutaneous injections of 10(8) cells in mice resulted in death within 3 to 6 h. These animals rapidly developed Vibrio bacteremia after injections. V. parahaemolyticus, studied for comparative purposes, produced no morbidity or mortality when injected subcutaneously. Injections of live lactose-positive Vibrio into ligated ileal loops in rats and rabbits consistently proved to be lethal with a high-density bacteremia resulting.
Induction of a pH-stable interferon in sheep lymphocytes by Mycoplasmatales virus MVL2
Authors: Lombardi P S , Cole B C
Published: January 2020

The data presented in this report show that the enveloped Mycoplasmatales virus MVL2 is capable of interferon induction in sheep peripheral blood lymphocytes. The phenomenon was dose dependent, requiring approximately 10(8) plaque-forming units of virus per 2 X 10(6) lymphocytes. The interferon was stable to pH 2.0 treatment, was produced in moderately high levels (greater than 1,000 units), and met many of the criteria for classification as a type I interferon. Heat-inactivated MLV2 lost its ability to induce interferon, whereas ultraviolet-inactivated virus retained its capacity to induce levels comparable to untreated virus. Whereas the MVL2 used in these studies was contaminated with several host cell proteins as determined by sodium dodecyl sulfate-containing polyacrylamide gel electrophoresis, the contaminants probably did not play a role in the induction because isolated cell membranes or soluble cell contents from Achoplasma laidlawii are inactive as inducers. Also presented in this report is a preliminary description of the structural polypeptides of MVL2.
Effect of immunosuppression on Rickettsia rickettsii infection in guinea pigs
Authors: Walker D H , Henderson F W
Published: January 2020

The role of the immune response in the pathogenesis of Rickettsia rickettsii infection in guinea pigs was investigated by immunosuppression, using antilymphocyte serum. Twenty guinea pigs were inoculated with R. rickettsii, Sheila Smith strain, on day 0. Fifteen animals received antilymphocyte serum on days --1, 0, 2, 4, and 6. Five animals received normal rabbit serum on the same schedule. At necropsy, specimens were collected for histological examination, rickettsial immunofluorescence, rickettsial titration, and antirickettsial antibody titration. All normal rabbit serum recipients and 12 of 15 antilymphocyte serum recipients developed typical disease. Comparison of animals in terminal stages of disease revealed the same clinical course and gross lesions, but differing rickettsial burden and cellular response. Immunosuppressed animals had higher titers of splenic rickettsiae and greater numbers of immunofluorescent rickettsiae. Thus, although antibody was undetectable in both groups, there appeared to be an inhibition of antirickettsial immunity. Microscopic vasculitis was similar quantitatively, but differed qualitatively, with immunocompetent animals having the typical monouclear/lymphocytic inflammation and immunosuppressed animals having neutrophilic predominance. This study demonstrates that immunopathological mechanisms are not necessary for the pathogenesis of experimental Rocky Mountain spotted fever. The rickettsiae themselves seem capable of causing cellular and tissue damage.
Candida albicans
Endocarditis: Ultrastructural Studies of Vegetation Formation
Authors: Calderone R. A. , Rotondo M. F. , Sande M. A.
Published: January 2020

Candida albicans
endocarditis was established in rabbits after transaortic catherization. Within 30 to 90 min after infection,
C. albicans
was observed by scanning electron microscopy on the valve surface. The organisms were predominantly associated with host deposits of erythrocytes, phagocytes, platelets, and fibrinous-appearing material, which collectively appeared on the valve surface in response to trauma. Within 48 h after infection, vegetations composed of these same host components were observed on the heart valves, although
Candida
cells were not demonstrable on the valve or vegetation surface. When the vegetations were examined by transmission electron microscopy,
Candida
blastospores were only observed within phagocytic cells (predominantly monocytes) enmeshed within the vegetation matrix. Many of the intracellular organisms were undergoing degradation, as evidenced by a reduction in electron density of the cell wall. Other fungi had highly electron-dense cell walls and germ tubes. Phagocytic cells containing germinating
Candida
were highly vacuolated and were observed at various stages of cell lysis. After 7 days of infection, the vegetation contained a dense meshwork of fibrin and
Candida
pseudohyphae with 10
8
to 10
9
colony-forming units/g of vegetation. The mature vegetation was devoid of phagocytic cells and continued to grow until the death of the animal.
Protection against ascending Escherichia coli pyelonephritis in rats and significance of local immunity
Authors: Kaijser B , Larsson P , Olling S
Published: January 2020

Acute pyelonephritis in rats caused by Escherichia coli O6K13H1 produced serum and urinary antibodies against O6 and K13 antigens. This was also seen after intravesical immunization with Formalin-killed bacteria. Both intraperitoneal and intravesical immunization with these Formalin-killed bacteria protected against ascending urinary tract infection induced by homologous bacteria. Passive transfer of urine containing both O6 and K13 antibodies also protected against infection. By absorption experiments it was shown that K13 antibodies were especially important.
Strain-specific local and systemic cell-mediated immune responses to cytomegalovirus in humans
Authors: Beutner K R , Morag A , Deibel R , Morag B , Raiken D , Ogra P L
Published: January 2020

Employing the techniques of complement fixation, immunofluorescence, and in vitro lymphocyte transformation assay, the antibody and cell-mediated immunity to cytomegalovirus (CMV) were studied in the serum, peripheral blood lymphocytes, tonsillar lymphocytes, and cord blood lymphocytes. The study population consisted of 32 children undergoing tonsillectomy and adenoidectomy. In the lymphocyte transformation assay, three strains of CMV (AD-169, ADH-1-41, and Davis), herpes simplex type 1, and phytohemagglutinin were employed as antigens. Sixty-five percent of the subjects were found to have CMV-specific antibody activity. The lymphocyte transformation response to phytohemagglutinin was similar in all subjects. No CMV-specific lymphocyte transformation activity was detected in cultures of cord blood lymphocytes. Significant cell-mediated immunity was observed in the tonsillar lymphocytes of 30% (3/10) of the seronegative individuals and in the peripheral blood lymphocytes obtained from one such subject. Over 75% (16/21) of the seropositive subjects demonstrated cell-mediated immunity against one or more strains of CMV in the peripheral blood lymphocytes and tonsillar lymphocytes. In the lymphocyte transformation assay, no cross-reactivity was apparent between CMV and herpes simplex type 1. These studies demonstrate the presence of strain-specific systemic and mucosal cell-mediated immune response to CMV in humans. The frequency and distribution of lymphocyte transformation responses to the three CMV strains suggest antigenic heterogeneity of CMV.
Listeria monocytogenes
Cell Walls Induce Decreased Resistance to Infection
Authors: Baker Lawrence A. , Campbell Priscilla A.
Published: January 2020

A significant decrease in murine resistance to
Listeria monocytogenes
was induced by using crude
Listeria
cell wall fraction (LCWF) and purified
Listeria
cell walls (PF). When equal amounts of these materials were injected, PF was more effective than LCWF in decreasing resistance. The PF effect was dose dependent when measured either as a decrease in 50% lethal dose of the
Listeria
challenge or as a decrease in survival time of the infected mice. PF apparently does not act directly on the
Listeria
since it (i) did not cause a change in in vitro growth of
Listeria
and (ii) did not increase the virulence of
Listeria
passaged in vivo or in vitro. The greatest decrease in resistance was observed when both PF and the
Listeria
challenge were injected intraperitoneally, which may suggest a localized effect. A decrease in resistance was seen when PF was given as early as 3 days before challenge. There was little or no decrease in resistance when PF was given 2 days after the
Listeria
challenge. Mice previously immunized with live
Listeria
were immune to
Listeria
challenge. However, after PF injection the immune mice showed a decreased resistance which was of the same order of magnitude as that seen in unimmunized mice. The effect of PF seems to be at least partially nonspecific, since a decrease in resistance to
Salmonella typhimurium
could also be demonstrated in PF-treated mice. Phagocytosis of
Listeria
both in vivo and in vitro did not appear to be inhibited by PF, although the ability of PF-treated mice to kill
Listeria
in the peritoneal cavity was inhibited.
Purification and characterization of an immunologically distinct delta-hemolysin from a canine strain of Staphylococcus aureus
Authors: Turner W H
Published: January 2020

Culture supernatants of 26 strains of Staphylococcus aureus possessing delta-hemolytic activity have been tested by immunodiffusion against a serum raised against purified delta-hemolysin from S. aureus CN 4108 (Newman D2). Supernatants from 14 strains of canine origin gave a reaction of partial identity with delta-hemolysin from CN 4108, whereas supernatants from all other strains had full identity. Delta hemolysin from one of these canine strains, CN 7450, was purified by ammonium sulfate fractionation and precipitation at pH 4.5. The physical, chemical, and biological properties of this toxin were compared with those of delta-hemolysin from CN 4108. Differences in molecular weight (as judged by Sepharose 6B chromatography), isoelectric point, and amino acid composition were found. Both toxins caused dermonecrosis in rabbits, lysed erythrocytes from several different species, and were inhibited by normal sera and phospholipids. Unlike delta-hemolysin from CN 4108, the hemolytic activity of delta-hemolysin from CN 7450 was found to be dependent on the incubation temperature over the range of 25 to 37 degrees C. Immunodiffusion results obtained with antisera raised against purified delta-hemolysin from CN 7450 indicated that delta-hemolysins from the canine strains were probably identical and confirmed that these differ immunologically from delta-hemolysin from CN 4108.
Antigenic analysis of coccidioidin and spherulin determined by two-dimensional immunoelectrophoresis
Authors: Huppert M , Spratt N S , Vukovich K R , Sun S H , Rice E H
Published: January 2020

Immunological tests are valuable aids for diagnosis of mycotic infections and, in some cases, as objective guides for clinical management and prognosis. The usefulness of these procedures is limited to the extents that crude antigen preparations are employed, that these are difficult to standardize uniformly, and that they contain antigens common to several species of pathogenic fungi. Analysis by two-dimensional immunoelectrophoresis methods of the two crude preparations used for coccidioidomycosis demonstrated that coccidioidin contained at least 26 antigens, with 10 of these found also in spherulin. In addition, spherulin contained two antigens not demonstrated in coccidioidin. No single test detected all antigens present, and multiple procedures were required to display the complete array of antigens. A reference system was established for coccidioidin and precipitated immunoglobulins from a burro hyperimmunized with coccidioidin. Evaluation of the reference system demonstrated that it was highly reproducible with respect to the reagents used, to repeated tests by the same person, and to comparative tests by two individuals using the same reagents. Applications of this reference system for standardization of reagents, for detecting common antigens, for monitoring successive steps during fractionation of crude preparations, and for fingerprinting strains for ecological and epidemiological studies are presented.
Contrast of Glycogenesis and protein synthesis in monkey kidney cells and HeLa cells infected with Chlamydia trachomatis lymphogranuloma venereum
Authors: Weigent D A , Jenkin H M
Published: January 2020

Glycogen metabolism of monkey kidney (LLC-MK-2) cells and HeLa 229 cells infected with a Chlamydia trachomatis lymphogranuloma venereum 440 L (LGV) was studied. The growth cycle of LGV in both host cells was similar; however, a greater number of infectious organism developed intracellularly and were released into the medium during LGV infection of HeLa 229 cells than MK-2 cells. A rapid infection accompanied by a high rate of glycogen synthesis and a short period of accumulation was found in GeLa 229 cells infected with LGV. LGV infected MK-2 cells started to accumulate glycogen about the same time as HeLa 229 cells; however, the rate of glycogen synthesis was lower and the period of accumulation was longer. The LGV agent grew in cycloheximide-treated cells in the absence of host cell protein synthesis. Protein synthesis associated with LGV throughout the developmental cycle was similar in both cell types and could be abolished by chloramphenicol. The continued synthesis of glycogen in the presence of cycloheximide suggested that the synthesis of glycogen was directed by the organism in both MK-2 cells and HeLa 229 cells.
Splenomegaly, enhanced phagocytosis, and anemia are thymus-dependent responses to malaria
Authors: Roberts D W , Weidanz W P
Published: January 2020

Immunologically competent mice and mice with defined immunological deficiencies were infected with Plasmodium yoelii. Splenomegaly, enhanced phagocytosis, and anemia were most marked in infected mice having intact thymic tissue. Whereas the spleens of infected nude mice increased minimally in size, the relative blood hemoglobin levels and the rates of carbon clearance in these mice were similar to those of noninfected, immunologically intact mice. Thymus-reconstituted nude mice and B-cell-deficient mice responded to infection in a manner similar to that of infected immunocompetent mice. These data demonstrate that the hallmarks of malaria, i.e., splenomegaly, enhanced phagocytosis, and anemia, are thymus-dependent responses to infection.
Meningeal exudate cells in vaccinia meningitis of mice: role of local T cells
Authors: Morishima T , Hayashi K
Published: January 2020

Intracerebral inoculation of vaccinia virus into adult DDD mice produced intensive meningitis several days after infection. The inflammatory reaction could be quantitated by counting cells obtained from this inflammatory lesion. The local virus titer increased until day 5 and subsequently decreased rapidly with time. Concomitant with this titer decrease, numerous meningeal exudate cells appeared in the lesion. The cytotoxic activity of these cells against vaccinia virus infected cells was studied after removal of glass-adherent cells. The results showed that these meningeal exudate cells possessed cytotoxic activity against the virus-infected cells and moreover inhibited plaque formation by vaccinia virus. The magnitude of this activity was much larger than that of spleen cells obtained from the same animals. After treatment with antithymocyte serum, or with antitheta serum plus complement, the meningeal cells lost their inhibitory activity, suggesting that the cells which exerted the effect were mainly T lymphocytes. The meningeal exudate cells obtained on day 7 postinfection were further characterized. A greater part, approximately 80%, of the cell population was composed of theta-positive cells. Less than 1% carried immunoglobulin, 7% possessed neither theta antigen nor immunoglobulin on the surface, and 12% represented glass-adherent cells.
Correlation between intestinal synthesis of specific immunoglobulin A and protection against experimental cholera in mice
Authors: Svennerholm A , Lange S , Holmgren J
Published: January 2020

The importance of locally and systemically formed antibodies of various classes for protection against experimental cholera has been studied in mice immunized with cholera toxin. Groups of mice were given various numbers of peroral or intravenous immunizations, or a combination of both. Serum antibodies and antibodies synthesized by spleen and small intestine in vitro during tissue culture were measured by the enzyme-linked immunosorbent assay, and protective immunity against intestinal toxin challenge was determined by means of a small-bowel loop assay. Regression analyses showed a close correlation between the magnitude of intestinal synthesis of specific immunoglobulin A (IgA) antibodies and protection (r = 0.98), whereas neither the local formation of IgG or IgM nor the production of antitoxin antibodies of any immunoglobulin class by spleen showed any significant correlation with protection. The serum titers of IgG and IgM antibodies did not show any such relation, whereas the level of specific IgA in serum, probably mainly derived from the intestine, correlated significantly (r = 0.90).
Further characterization of Mycobacterium ulcerans toxin
Authors: Hockmeyer W T , Krieg R E , Reich M , Johnson R D
Published: January 2020

Mycobacterium ulcerans produces an exotoxin in culture which, when inoculated into guinea pig skin, causes inflammation, necrosis, edema, and other histopathological changes resembling those in infections of humans. The toxin was resistant to heat and to alkalies and was moderately acid labile. Toxic activity was destroyed by Pronase, phospholipase, lipase, amylase, and glucosidase but not by trypsin, collagenase, cellulase, lysozyme, hyaluronidase, or neuraminidase. Toxic activity was resistant to treatment with 2-mercaptoethanol, urea, guanidine hydrochloride, p-chloromercuribenzoate, ethylenediaminetetraacetate, and sodium deoxycholate but was destroyed by sodium m-periodate and sodium dodecyl sulfate. The toxin was precipitated by a wide range of ammonium sulfate concentrations. Extraction with chlorofrom-methanol or petroleum ether destroyed its activity. Isopycnic density gradient ultracentrifugation in KBr produced a high-density lipoprotein layer with a 24-fold increase in specific activity. The results indicate that this toxin is a high-molecular-weight phospholipoprotein-polysaccharide complex.
Antigenicity of purified glutaraldehyde-treated cholera toxoid administered orally
Authors: Levine M M , Hughes T P , Young C R , O'Donnell S , Craig J P , Holley H P , Bergquist E J
Published: January 2020

The antigenicity of orally administered glutaraldehyde-treated cholera toxoid was investigated in healthy volunteers. Fourteen volunteers ingested two or three 2-mg doses of toxoid with saline, with the doses spaced at 28-day intervals. Thirteen other volunteers received comparable toxoid doses with NaHCO3 and milk to neutralize gastric acid. Increments in circulating antitoxin levels were used to assay the antigenicity of oral toxoid. Antitoxin was measured by adrenal cell, rabbit skin permeability factor, and passive hemagglutination assays in sera collected on days 0, 28, 35, 56, 63, and 84 after primary immunization. Adrenal cell and rabbit skin assays exhibited identical sensitivity in detecting antitoxin rises in the 27 vaccinees (19/27) and were significantly more sensitive than passive hemagglutination (11/27) (P less than 0.03). Volunteers who ingested toxoid with NaHCO3 and milk had a higher rate of seroconversion (77%) than those who received toxoid with saline (64%); they also had earlier rises in antitoxin titer and consistently higher geometric mean titers on all days tested. These studies demonstrate that purified cholera toxoid is antigenic in humans after oral administration. The possible role of oral toxoid in enhancing the protective effect of killed whole-cell vaccines can now be investigated.
Microassay for immunoglobulin G antibodies to Treponema pallidum with radioiodinated protein A from staphylococcus aureus: immunoglobulin G response in experimental syphilis in rabbits
Authors: Zeltzer P M , Pepose J S , Bishop N H , Miller J N
Published: January 2020

Radioiodinated staphylococcal protein A (SpA) was used to detect the immunoglobulin G (IgG) antibody response to Treponema pallidum in experimental syphilis. This solid-phase assay is based on the principle that SpA binds avidly to the Fc portion of mammalian IgG. The optimal number of organisms for detection of antibody was 10(5) per microwell. Of eight fixatives, 10% ethanol gave an optimum immune binding ratio of infected to normal rabbit serus at a 1:100 serum dilution. Kinetic studies demonstrated maximum binding and the highest immune binding ratio (15:1) with a 60-min incubation each for antibody and (125)I-SpA, respectively. The IgG response in rabbits intratesticularly infected with live T. pallidum and bled at -1, 9, 30, 90, 180, and 480 days was detected first at 9 days, reached a peak at 30 days, and remained elevated for 480 days. Absorption studies with an extract of T. phagedenis biotype reiterii demonstrated that 65 to 85% of the total antitreponemal IgG response was specific for T. pallidum throughout the course of infection. The microassay was quantitative and detected less than 2 ng of antibody.
Analyses of Glucans from Cariogenic and Mutant
Streptococcus mutans
Authors: Freedman M. , Birked D. , Granath K.
Published: January 2020

The extracellular, water-soluble and cell-associated, 1 N NaOH-soluble glucans from cariogenic
Streptococcus mutans
6715-13 “wild type” (WT) and glucan synthesis-defective mutants with diminished virulence have been quantitatively and qualitatively analyzed by methylation analysis and gel chromatography. The mutants synthesized more of a highly branched α-(1 → 6)-rich extracellular polymer than WT, and some of this glucan was also found to be cell associated in all but one case. WT, in distinction to the mutants, also synthesized a highly branched, α-(1 → 3)-rich, cell-associated polymer. Treatment of these two distinct polymer types with dextranase or an α-(1 → 3)-hydrolyzing enzyme indicated they were composed of both α-(1 → 3) and α-(1 → 6) linkages and of α-(1 → 6) with branches at the 3-position, rather than of separate α-(1 → 3) and α-(1 → 6) homopolymer mixtures. Gel chromatography before enzymatic hydrolysis disclosed a high degree of polydispersity in both glucan classes. After hydrolysis polydispersity was reduced, again without resolution of two glucan populations. These findings suggest that (i) there are two distinct glucan classes, one α-(1 → 3) rich and the other α-(1 → 6) rich in WT, (ii) diminution of virulence in the mutants is probably ascribable to a failure to form the α-(1 → 3)-rich component, (iii) both α-(1 → 6)- and α-(1 → 3)-rich glucans are found in association with the cell, and (iv) both highly branched glucan types are dextranase and α-(1 → 3)-hydrolase sensitive, and methylation analysis and gel chromatography suggest polymers with highly polydisperse molecular weights which contain mixtures of linkage types.
Induction of a Mucosal Antitoxin Response and Its Role in Immunity to Experimental Canine Cholera
Authors: Pierce Nathaniel F. , Cray William C. , Sircar Bimal K.
Published: January 2020

The induction of a jejunal antitoxin response was studied in dogs immunized with cholera toxin or toxoid. Single doses of toxoid given subcutaneously (s.c.) or of toxin given intraluminally (i.l.) were each effective in priming the mucosal immune system, whereas toxoid given i.l. was much less effective. In contrast, toxin and toxoid given i.l. were each effective as booster antigens. The local secondary response was rapid and brief, the peak occurring at about 7 days after i.l. boosting and declining by 90% after 2 more weeks. After s.c. priming and i.l. boosting with toxoid, antitoxin-containing plasma cells appeared predominantly in the portion of jejunum exposed to the i.l. booster. The appearance of antitoxin-containing plasma cells in jejunal lamina propria correlated with the amount of antitoxin recovered in jejunal washings which, in turn, correlated with protection against challenge with cholera toxin. Thus, lamina propria antitoxin-containing plasma cells appeared to be the source of protective antitoxin. However, after sequential s.c.-oral immunization with toxoid, protection against challenge with
Vibrio cholerae
far outlasted the major systemic and local antitoxin responses and was not obviously explained by either. These studies reveal methods for induction of a mucosal antitoxin response, but leave in question the mechanism of prolonged protection induced by s.c.-oral immunization of dogs.
Genetic mapping of mutations in independently isolated nontoxinogenic mutants of Vibrio cholerae
Authors: Baine W B , Vasil M L , Holmes R K
Published: January 2020

Conjugal mating experiments were performed between donor strains of Vibrio cholerae carrying the vibrio sex plasmid P and recipient strains lacking the P plasmid. Donor and recipient genotypes differed with respect to toxinogenicity (tox), nutritional requirements, and antibiotic susceptibilities. Recombinants carrying selected donor and recipient markers were produced at low frequencies in conjugal matings. Mapping of tox markers was accomplished by scoring for the frequency of coinheritance of the donor tox allele with selected and unselected donor markers. Four independently isolated tox markers were analyzed. Each of these four tox markers was shown to be linked to the his-1 site in linkage group I on the genetic map of V. cholerae. In matings between a recipient strain carrying the tox-1 marker and donor strains carrying either tox-2, tox-3, or tox-4, all selected his+ recombinants remained nontoxinogenic. Matings between multiply marked strains demonstrated that the position of tox-1 with respect to other genetic loci in linkage group I is as follows: met-2--trp-1--asp-1--nal-1--his-1--tox-1. These findings demonstrate that a chromosomal determinant linked to his-1 in linkage group I on the genetic map of V. cholerae is essential for toxinogenesis and suggest that tox-1,tox-2, tox-3, and tox-4 may be alleles of a single tox gene.
Effect of pH on the growth and glucose metabolism of Neisseria gonorrhoeae
Authors: Morse S A , Hebeler B H
Published: January 2020

This study examined the effect of pH on the metabolism of glucose by Neisseria gonorrhoeae. Radiorespirometric studies revealed that cells growing at pH 7.2 or 8.0 metabolized glucose primarily (ca. 80%) via the Entner-Doudoroff pathway. The remainder of the glucose was metabolized via the pentose phosphate pathway (ca. 20%). The tricarboxylic acid cycle was not active during glucose catabolism at either pH 7.2 or 8.0, and acetate accumulated in the medium. Cells growing at pH 6.0 had markedly increased pentose phosphate pathway activity (ca. 50%) and a functioning tricarboxylic acid cycle. The alteration in pathways was not due to differences in growth rate, but to the pH of the medium. Chemical fractionation of labeled cells and total hexose analyses revealed that growth pH markedly affected the composition of the gonococcus.
In vitro adhesion of Escherichia coli to porcine small intestinal epithelial cells: pili as adhesive factors
Authors: Isaacson R E , Fusco P C , Brinton C C , Moon H W
Published: January 2020

Escherichia coli strains with pili (K99 or 987P) known to facilitate intestinal colonization adhered in vitro to porcine intestinal epithelial cells. These strains adhered equally to both ileal and jejunal epithelial cells. A laboratory E. coli strain that has type 1 pili also adhered to porcine intestinal epithelial cells. When nonpiliated cells derived from 987P+, K99+, or type 1 pilus+ strains were used for in vitro adhesion assays, they failed to adhere. The attachment of piliated bacteria to epithelial cells was a saturable process that plateaued at 30 to 40 bacterial cells attached per epithelial cell. Competitive inhibition of bacterial cell attachment to epithelial cells with purified pili showed that only purified 987P competed against the 987P+ strain and only purified type 1 pili competed against the type 1 pilus+ strain. Competition between a K99+ strain and K99 was not consistently achieved. K99+, 987P+, and type 1 pilus+ bacteria could be prevented from adhering to epithelial cells by Fab fragments specific for K99, 987P, or type 1 pili, respectively. Fab fragments specific for non-K99 bacterial surface antigens did not inhibit adhesion of the K99+ strain. It is concluded that adhesion of E. coli to porcine intestinal epithelial cells in vitro is mediated by pili and that the epithelial cells used apparently had different receptors for different pili.
Effect of concurrent cytomegaloviral infection and undernutrition on the growth and immune response of mice
Authors: Cruz J R , Waner J L
Published: January 2020

Mice were inoculated with murine cytomegalovirus (MCMV) passaged in cell cultures within 24 h of birth and subsequently fed an adequate or a low-protein diet after weaning; increases in body weight, the blastogenic response of lymphocytes to T and B cell mitogens, and the capability to produce antibodies to T or B cell-dependent antigens were observed for the first 28 to 42 days of life. Neonatal infection resulted in immunosuppression and retarded physical growth through the first 4 weeks of life. After weaning (3 weeks), the effect of MCMV infection of well-nourished mice paralleled the effect of undernutrition in uninfected animals. Undernutrition and MCMV infection functioned synergistically.
Serological cross-reactivity among Sporothrix schenckii, Ceratocystis, Europhium, and Graphium species
Authors: Ishizaki H , Wheat R W , Kiel D P , Conant N F
Published: January 2020

Ethanol-precipitable culture filtrate antigens of 100 strains of 75 species of the Sporothrix-Ceratocystis-Europhium-Graphium complex and 1 species of Botrytis were examined for neutral sugar components and for serological cross-reactivity with S. schenckii rabbit antiserum and human sporotrichosis sera by capillary precipitin and double immunodiffusion assay. Results revealed that cross-reactive species (60 of 77, ca. 80%) produced exoconidial forms and rhamnose- and mannose-containing polysaccharides and included Ceratocystis, the three known Europhium, and several Graphium-form species. Endoconidial-form Ceratocystis species did not cross-react.
Homogeneous Enzyme Immune Assay for Staphylococcal Enterotoxin B
Authors: Morita T. N. , Woodburn M. J.
Published: January 2020

A simple homogeneous enzyme immune assay was developed for detection of staphylococcal enterotoxin B by a conjugate of β-amylase coupled with the enterotoxin.
Factors affecting the aggregation of Actinomyces naeslundii during growth and in washed cell suspensions
Authors: Miller C H , Palenik C J , Stamper K E
Published: January 2020

Various factors affecting the aggregation of Actinomyces naeslundii strain 12104 were studied. When the pH of glucose-supplemented growth medium fell below 5.5, the cells aggregated and formed microbial masses which tenaciously adhered to the culture vessels. When the organism was cultured in the same medium in the absence of glucose, maximum growth was reduced and the final culture pH values remained above 6.5, but the cells were more dispersed and nonadherent. Adjusting the final pH of these cultures to below 5.5 with HCl caused the cells to aggregate. Cells from unsupplemented cultures with final pH values of 6.7 were washed by centrifugation, dispersed by vigorous shaking, and suspended in buffer at pH values ranging from 4.5 to 8.0. Aggregation (expressed as the percent reduction of optical density at 520 nm after incubation at 37 degrees C) occurred rapidly at pH values below 6.0 but did not readily occur at higher pH values. Aggregation of strain 12104 in washed cell suspensions was induced by low pH and influenced by cell concentration and ionic strength of the environment. Low pH values also induced aggregation in washed cell suspensions of Streptococcus mutans, Streptococcus sanguis, Streptococcus salivarius, and Actinomyces viscosus.
Lymphocyte-mediated cytotoxicity in humans during revaccination with vaccinia virus
Authors: Møller-Larsen A , Haahr S , Heron I
Published: January 2020

Fifteen healthy human volunteers were revaccinated with vaccinia virus. Blood samples (4 to 7) were obtained during the 3 weeks after revaccination. Peripheral blood lymphocytes were washed extensively and tested for cytotoxicity against vaccinia-infected autologous and/or homologous skin fibroblasts. Without addition of antibodies, peak levels of killing were observed on days 7 to 9. The killing did not depend on common HLA markers. On days with peak activity, extensively washed lymphocytes showed higher levels of killing than normally washed lymphocytes. By cell separation experiments, the cell most active in killing proved to be a nonadherent, non-phagocytizing lymphocyte with Fc receptors. Serum antibodies tested in two sensitive serological assays peaked on days 14 to 17. The question of whether the killing observed is dependent on or independent of antibodies is not clarified in the present study.
Delayed hypersensitivity responses of experimental animals to histoplasmin from the yeast and mycelial phases of Histoplasma capsulatum
Authors: Scalarone G M , Levine H B , Chaparas S D
Published: January 2020

Controlled yeast lysate (CYL) and controlled mycelial lysate (CML) histoplasmins were produced from Histoplasma capsulatum grown in a nutritionally lean, chemically defined medium. The lysates were assayed for skin-test activity in guinea pigs sensitized by infection with the homologous organism. In some studies, nonliving vaccine preparations were employed also. Inter-lot biological variation was minimal, and 20 lots of the CYL reagent elicited strong dermal reactions with high specificity. Further, CYL reagents were nonreactive in guinea pigs infected with Coccidioides immitis, whereas the commercial Food and Drug Administration preparations cross-reacted to some degree. The CML histoplasmins were generally less reactive than the CYL preparations and exhibited somewhat more inter-lot variation in sensitivity and specificity. No correlation between potency and protein:polysaccharide ratios were observed with either reagent. An intradermal test with the CYL reagent did not induce significant changes in the complement-fixing titer of sensitized guinea pigs. Such changes in sensitized animals were elicited by a skin test with commercial histoplasmin.