bluuebunny/crossref_metadata_2025 huggingface dataset:
Antagonistic activity of the food-related filamentous fungus Penicillium nalgiovense by the production of penicillin
Authors: Färber P , Geisen R
Published: January 2020

Defined strains of the genus Penicillium used as starter cultures for food and strains isolated from mold-fermented foods were analyzed for their ability to inhibit the growth of Micrococcus luteus DSM 348 used as an indicator organism. Most of the strains belonging to the species Penicillium nalgiovense showed antagonistic activity in agar diffusion assays. Penicillium camemberti and Penicillium roqueforti strains proved to be inactive in these tests. The inhibitory substance excreted by P. nalgiovense strains was totally inactivated when treated with beta-lactamase (penicillinase), indicating that a beta-lactam antibiotic is produced by these strains. This observation was verified by PCRs with primer sets specific to the [delta-(L-alpha-aminoadipyl)-L-cysteinyl-D-valine] synthetase gene (pcbAB), the isopenicillin-N-synthase gene (pcbC), and the acyl coenzyme A:6-aminopenicillanic acid acyltransferase gene (penDE) from Penicillium chrysogenum using chromosomal DNA of the fungal strains as a template. These results indicate that penicillin biosynthesis is a characteristic often found in strains of P. nalgiovense. No specific PCR signal could be identified with DNA from P. camemberti and P. roqueforti.
Analysis of the pediocin AcH gene cluster from plasmid pSMB74 and its expression in a pediocin-negative Pediococcus acidilactici strain
Authors: Bukhtiyarova M , Yang R , Ray B
Published: January 2020

The 3,500-bp pap operon in the 8,877-bp plasmid pSMB74 contains a cluster of four genes, papABCD, of which papA encodes prepediocin (A. M. Motlagh, M. Bukhtiyarova, and B. Ray, Lett. Appl. Microbiol. 18:305-312, 1994). The cluster without the promoter was cloned in the shuttle vector pHPS9. An Escherichia coli strain and a pediocin-sensitive Pediococcus acidilactici strain transformed with the recombinant plasmid, pMBR1.0, produced pediocin AcH. Deletion analysis by introducing mutations in the four genes in pMBR1.0 revealed that only papA and papD were required for pediocin AcH production and that the gene product of papD has both translocation and processing functions. In the transformed minicells of E. coli chi 925 the proteins of the pap cluster were synthesized, indicating no polar effect due to deletion.
Presence of Two Sets of Ribosomal Genes in Phytopathogenic Mollicutes
Authors: Schneider B. , Seemüller E.
Published: January 2020

DNA from 28 strains of phytopathogenic mycoplasmalike organisms that represented five primary taxonomic clusters was digested with restriction endonucleases and hybridized with several ribosomal probes. The results indicate the presence of two sets of ribosomal genes in all strains examined. Restriction maps of the two ribosomal operons for a group of 12 aster yellows mycoplasmalike organisms were constructed.
Production of an inducible sucrase activity by Serpulina hyodysenteriae
Authors: Jensen N S , Stanton T B
Published: January 2020

Strains of Serpulina hyodysenteriae and Serpulina innocens produced a cell-associated sucrase activity when grown in a medium containing sucrose. S. hyodysenteriae B204 sucrase activity cleaved sucrose and, to a lesser extent, raffinose and had a pH optimum of 5.7 to 6.2. This is the first report of an inducible enzyme produced by either S. hyodysenteriae or S. innocens.
Growth Kinetics of the Endosymbiont
Buchnera aphidicola
in the Aphid
Schizaphis graminum
Authors: Baumann Linda , Baumann Paul
Published: January 2020

The aphid
Schizaphis graminum
is dependent on its prokaryotic endosymbiont,
Buchnera aphidicola.
As a means of determining
B. aphidicola
numbers during the growth cycle of the aphid we have used the quantitative PCR to measure the number of copies of
rrs
(the gene coding for 16S rRNA, which is present as one copy in the
B. aphidicola
genome). In addition we have measured the aphid wet weight and the DNA and protein content. The results indicate an approximately parallel (23- to 31-fold) increase of these properties during the period of aphid growth. A 1-day-old aphid (24 μg [wet weight]) has 0.2 × 10
6
copies of
rrs
, while a 9-day-old aphid (497 μg [wet weight]) has 5.6 × 10
6
copies. The coupling of endosymbiont and aphid growth is consistent with the requirement of the endosymbiont for growth and reproduction of the aphid.
Comparison of Methods for Inhibiting Bacterial Activity in Sediment
Authors: Tuominen Liisa , Kairesalo Timo , Hartikainen Helinä
Published: January 2020

Dilute formaldehyde was the most suitable treatment to inhibit sediment bacteria, since bacterial activity remained low during long-term incubations and the chemical changes in the sediment were minimal. The inhibiting effects of HgCl
2
, autoclaving, and gamma radiation were diminished during longer incubations; these treatments also caused increases in dissolved nutrients.
Purification and Antigenicity of an M-Like Protein of
Streptococcus equi
Authors: Woolcock John B.
Published: January 2020

A cell wall component of
Streptococcus equi
analogous to the M protein of group A streptococci has been identified and purified. A highly purified product has been obtained from cells by hot acid extraction, followed by acid precipitation, ammonium sulfate fractionation, and column chromatography. This product reacts with
S. equi
antiserum. The existence of this fraction in
S. equi
has been confirmed by the failure of trypsin-treated cells and their extracts to remove the long-chaining capacity of
S. equi
antiserum. The antigenicity of this M-like protein when incorporated in adjuvant has been assessed in rabbits and horses. In the rabbit, multiple doses of as low as 10 μg resulted in the production of serum capable of inducing long-chain formation and opsonizing and mouse protective antibody. Two doses of 100 μg elicited similar responses. The bactericidal capacity of this serum could be eliminated by absorption with whole
S. equi
cells or their extracts, but not by absorption with trypsin-treated cells or extracts therefrom. Horses vaccinated 15 months previously with a whole-cell killed vaccine and given 200 μg of the purified protein intramuscularly showed evidence of an anamnestic response to the antigen.
Tissue-Binding Properties of the Cholera Toxin
Authors: Peterson Johnny W.
Published: January 2020

[
125
I]choleragen was employed to study further the tissue-binding properties of highly purified choleragen. It was observed that [
125
I]choleragen was bound when combined with mucosal homogenates from all regions of the gastrointestinal tract of adult guinea pigs. Gastric, duodenal, jejunal, and ileal mucosa appeared equally effective in toxin-binding capacity. Preparations of large intestinal mucosa could bind an exceptionally larger amount of toxin. The binding property of small intestinal homogenates could not be attributed to any particular fraction after differential centrifugation; rather, the toxin receptor appeared to be associated with several sizes of particles containing cell membrane components. Although binding to mammalian cells was easily demonstrable, no binding to several types of bacterial cells was observed. The toxin receptor was found to be a “universal component” of many mammalian cell membranes, since specific binding of the toxin to a variety of guinea pig tissues was clearly demonstrated. [
125
I]choleragen binding to all tissues, with the exception of those prepared from brain and large intestinal mucosa, could be inhibited by preincubation of the tissue homogenates with unlabeled choleragen but not with comparable concentrations of normal rabbit serum proteins. The determination of the specificity of [
125
I]choleragen binding to brain and large intestinal mucosal homogenates was hampered by the continual release of soluble receptor from the homogenates, both of which contained the highest concentration of cholera toxin receptor. The data support and extend observations that cholera toxin binding to tissue receptor(s) is a very specific reaction, and further indicate that binding may occur with a variety of tissues to different degrees.
Virulence of
Pseudomonas aeruginosa
and Spontaneous Spread of Pseudomonas Pneumonia in a Mink Ranch
Authors: Shimizu Takeshi , Homma J. Yuzuru , Aoyama Tomozo , Onodera Takashi , Noda Hiroshi
Published: January 2020

Comparative studies on the virulence of two strains of
Pseudomonas aeruginosa
isolated from otic pus and mink pneumonic lesion, respectively, were made by means of intranasal inoculation in mink. The minimal lethal dose of the former (strain NC-5, highly virulent for mice) was 10
10
, and that of the latter (strain No. 5, moderately virulent for mice) was 5.5 × 10
6
. By planting droplets of
P. aeruginosa
suspension on the mink in the wire cages, an enzootic lethal pneumonia was brought about in a ranch. This disease spread to the neighboring 12 mink in turn, in one direction, with new cases occurring every day or every other day for 13 days.
Protection of Suckling Mice from Experimental Cholera by Maternal Immunization: Comparison of the Efficacy of Whole-Cell, Ribosomal-Derived, and Enterotoxin Immunogens
Authors: Guentzel M. N. , Berry L. J.
Published: January 2020

The susceptibility of suckling mice to oral infection with several different
Vibrio cholerae
was determined. Mice up to 10 days of age were uniformly susceptible to oral infection with 10
8
colony-forming units of virulent organisms. Age-dependent resistance occurred thereafter to a maximum at about 15 days of age. The efficacy of selected vaccines was compared by oral challenge of 8-day-old, passively immunized CFW mice. An Ogawa-derived ribosomal antigen was found to be superior to a commercial whole-cell vaccine or to purified cholera enterotoxin. The ribosomal antigen was 50- to 100-fold more protective than the other vaccines on a weight basis against otherwise lethal challenge with Ogawa, Inaba, or El Tor Ogawa serotypes.
Fish Rhabdovirus Replication in Non-Piscine Cell Culture: New System for the Study of Rhabdovirus-Cell Interaction in Which the Virus and Cell Have Different Temperature Optima
Authors: Clark H Fred , Soriano Elvira Z.
Published: January 2020

The replication of three rhabdoviruses associated with diseases of fish has been demonstrated in cells of continuously cultivated non-piscine cell lines. Spring viremia of carp (SVC) virus and the salmonid fish viruses, Egtved and infectious hematopoietic necrosis virus, all replicated in mammalian WI-38 (human diploid cell strain) and BHK/21 cells and in cells of one or more reptilian cell lines at the temperatures commonly used to propagate these viruses in fish cells. The infections were cytopathic: SVC virus plaque assays may be performed in several types of mammalian cell culture. “Autointerference” apparently mediated by abortive “T” particle formation was observed during serial nondiluted passages of SVC virus in BHK/21 and TH1 cells, but not in RTG-2 or WI-38 cells. Optimal temperatures for replication of SVC and Egtved viruses in BHK/21 cells were identical to those determined in poikilothermic vertebrate cell cultures. However, these viruses replicated relatively more efficiently at suboptimal temperatures in “cold-blooded” vertebrate cells than in the hamster cells. Studies of [
3
H]uridine incorporation into uninfected BHK/21 cells incubated at different temperatures revealed that [
3
H]uridine uptake is sharply reduced at temperatures below 24.5 C. Growth curve studies of SVC virus in BHK/21 cells incubated at 23 C revealed that a clear-cut large excess of virus-induced [
3
H]uridine incorporation could be demonstrated in the absence of actinomycin D. Actinomycin D treatment (1 μg/ml) led to efficient inhibition of control cell [
3
H]uridine uptake, but also markedly reduced the total counts per minute of virus-induced [
3
H]uridine uptake, without depressing the yield of released infectious virus. Actinomycin D added to SVC virus-infected BHK/21 cell cultures at concentrations as low as 0.01 μg/ml caused a significant decrease in the level of virus-induced [
3
H]uridine uptake, despite the fact that this concentration is insufficient to efficiently suppress “background” cellular [
3
H]uridine incorporation.
Involvement of the Host Cell Nuclear Envelope Membranes in the Replication of Japanese Encephalitis Virus
Authors: Zebovitz E. , Leong J. K. L. , Doughty S. C.
Published: January 2020

The distribution of viral ribonucleic acid (RNA) on various cell membrane fractions derived from a porcine kidney cell line infected with Japanese encephalitis virus was investigated. At 40 h postinfection, after virus growth had reached its peak, three viral RNAs, 45
S
, 27
S
, and 20
S
, were associated with the cytoplasmic membranes and intact nuclei. The amount of each RNA associated with the nucleus was two- to fivefold greater than that present with the cytoplasmic membranes. Treatment of washed infected nuclei with 1.0% Triton X-100, which removed the outer nuclear envelope membrane, also removed the viral RNA. When the nucleus was fractionated into nuclear envelope membranes and a large particle fraction which sedimented at 600 ×
g
, nearly all of the viral RNA remained associated with the envelope membranes. The nuclear envelope membranes contained higher viral RNA polymerase activity than the cytoplasmic membranes derived from the same cells. These data suggest that major sites for Japanese encephalitis virus RNA synthesis may be localized on or in very close association with the nuclear envelope membranes.
Streptococcus mutans
in a Wild, Sucrose-Eating Rat Population
Authors: Coykendall Alan L. , Specht Patricia A. , Samol Harry H.
Published: January 2020

Streptococcus mutans
, an organism implicated in dental caries and not previously found outside of man and certain laboratory animals, was isolated from the mouths of wild rats which ate sugar cane. The strains isolated fermented mannitol and sorbitol, and failed to grow in 6.5% NaCl or at 45 C. They formed in vitro plaques on nichrome wires when grown in sucrose broth. They also stored intracellular polysaccharide which could be catabolized by washed, resting cells. Deoxyribonucleic acid-deoxyribonucleic acid reassociations revealed two genetic types. One type shared extensive deoxyribonucleic acid base sequences with
S. mutans
strains HS6 and OMZ61, two members of a genetic type found in man and laboratory hamsters. The other type seemed unrelated to any
S. mutans
genetic type previously encountered. It is concluded that the ecological triad of tooth-sucrose-
S. mutans
is not a phenomenon unique to man and experimental animals.
Characterization of Cell-Associated Dextransucrase Activity from Glucose-Grown Cells of
Streptococcus mutans
Authors: Kuramitsu Howard K.
Published: January 2020

Two distinct forms of cell-associated dextransucrase activity have been extracted from glucose-grown cells of
Streptococcus mutans
GS-5. One form can be washed from cells by treatment with hypertonic salt solutions. This activity is located on the exterior of the cell since it is susceptible to inactivation by proteolytic enzymes. Gel filtration of the extracted enzyme indicates that the enzyme exists as a highly aggregated complex which dissociates into a smaller soluble species in the presence of hypertonic salt solutions. This form of the enzyme also plays a role in sucrose-dependent adherence of whole cells to smooth surfaces. Hypertonic salt solutions also elute most of the cell-associated dextransucrase activity from strain FA-1 but not from strain HS-6. The second cell-associated activity of strain GS-5 is released after disruption of washed cells, is not susceptible to proteolytic enzyme treatment of whole cells, and represents the intracellular form of the enzyme. A comparison of the gel filtration properties. pH and temperature optima, kinetic constants, and insoluble dextran-synthesizing activities of the two cell-associated forms of the enzyme with the extracellular enzyme did not reveal any major differences.
Immunocytoadherence During Experimental Histoplasmosis
Authors: Roberts Glenn D. , Larsh Howard W.
Published: January 2020

Immunocytoadherence was investigated as a method of detecting active histoplasmosis in two groups of infected New Zealand white rabbits. Yeast-phase
Histoplasma capsulatum
was given intravenously to one group and intratracheally to the other. There was a striking correlation between the clinical condition of the animals and the number of rosettes seen. This number increased as the infection progressed and decreased as it regressed. The immunocytoadherence technique might be of value in detecting active histoplasmosis, and investigation in humans is warranted.
Yeast- and Mycelial-Phase Antigens of
Blastomyces dermatitidis
: Comparison Using Disc Gel Electrophoresis
Authors: Cox Rebecca A. , Larsh Howard W.
Published: January 2020

The disc gel electrophoretic patterns obtained with skin test-active (mycelial and yeast) antigens of
Blastomyces dermatitidis
were compared. As would be expected, the blastomycins (mycelial-phase) and the cytoplasmic ultrafiltrates (yeast-phase) were heterogeneous mixtures containing proteins, glycoproteins, lipoproteins, and carbohydrates. The skin test-active cytoplasmic ultrafiltrates and the blastomycins contained glycoproteins that had similar
R
f
values which allows the possibility that one or more of these components is responsible for the skin-test reactivity of these antigens. The electrophoretic migration of the alkali-soluble, water-soluble cell wall antigen differed from those of the cytoplasmic antigens and the two blastomycins. Electrophoresis, Sephadex chromatography, and ultrafiltration studies showed that the alkali-soluble, water-soluble cell wall antigen is comprised of lipid, polysaccharide, and protein and has a molecular weight range of 30,000 to 50,000. The increased number and mobility of both the protein and carbohydrate bands after denaturation and electrophoresis of this antigen in sodium dodecyl sulfate indicate that there are several cross-linkages between the polysaccharide and/or protein moieties, possibly via lipid or disulfide bridges.
Infection and Immunoglobulin Concentrations in Chediak-Higashi Mice
Authors: Elin Ronald J. , Edelin Joseph B. , Wolff Sheldon M.
Published: January 2020

The Chediak-Higashi syndrome (CHS) has been reported in man, cattle, mink, and mice. CHS humans and cattle have an increased incidence of pyogenic infections, whereas CHS mink are more susceptible to Aleutian disease. Age- and sex-matched groups of CHS mice (mutant strain) and C57 Bl/6N (parent strain) were challenged with
Candida albicans, Escherichia coli, Klebsiella pneumoniae
, and
Staphylococcus aureus
intravenously and
Streptococcus pneumoniae
intraperitoneally. A significant increase (
P
< 0.001) in mortality rate for the CHS mice was demonstrated with all five challenge organisms. Heterozygous mice challenged with
C. albicans
had a mortality rate essentially the same as C57 Bl/6N mice. The serum immunoglobulin concentrations of CHS mice were found to be the same or greater than the control or heterozygous mice. CHS mice have an increased susceptibility to pyogenic infections, which is not due to immunoglobulin deficiency. These mice may provide a useful laboratory model for the study of increased susceptibility to infection.
Extracellular Polysaccharides of
Actinomyces viscosus
Authors: Rosan Burton , Hammond Benjamin F.
Published: January 2020

Polysaccharide(s) have been isolated from supernatants of broth cultures of
Actinomyces viscosus
, strain T6. The organism produces significant quantities (2 mg/mg of cell [dry weight], 108 mg/liter) of this polysaccharide in the absence of sucrose. Chemical analysis indicated that
N
-acetylglucosamine (62%) was the major component; galactose (7%), glucose (4%), uronic acid (3%), and smaller amounts of glycerol, rhamnose, arabinose, and xylose were also present. The polysaccharide(s) is only slightly soluble in aqueous solutions. Although further purification of the polysaccharides will be necessary before definitive chemical and structural studies, the formation of extracellular polysaccharides is significant because it offers a possible explanation for plaque formation by these organisms.
Pathogenicity and Immunogenicity for Mice of Temperature-Sensitive Mutants of Vesicular Stomatitis Virus
Authors: Wagner Robert R.
Published: January 2020

Temperature-sensitive (
ts
) mutants of vesicular stomatitis (VS) virus were tested for their pathogenicity and immunogenicity in weanling mice. Compared with the wild-type virus (
ts
+
),
ts
mutants representing genetic complementation groups I, II, and IV were considerably less pathogenic for mice infected by the intracerebral route and caused few deaths after intranasal inoculation. Mice were completely resistant to
ts
+
and
ts
mutants by the intraperitoneal route. Resistance to intracerebral challenge with
ts
+
VS virus was only minimal in mice vaccinated intraperitoneally with
ts
+
or
ts
mutants and only moderate in mice vaccinated intranasally with three
ts
mutants. Intranasal vaccination, particularly with group IV mutants, resulted in solid immunity within 3 days to intranasal challenge with
ts
+
virus. VS viral neutralizing antibody was present in the bronchial secretions of mice by 12 h after intranasal inoculation of mutant
ts
IV44; the bronchial antibody titers declined to undetectable levels between 3 and 7 days after vaccination. Neutralizing antibody was detected in the serum of mice by the third day after intranasal vaccination with
ts
IV44 and persisted at high level for at least 11 days. Certain classes of
ts
mutants would appear to be promising candidates for use as attenuated, live virus vaccines.
Persistence of
Diplococcus pneumoniae
after Influenza Virus Infection in
Macaca mulatta
Authors: Berendt Richard F. , McDonough William E. , Walker Jerry S.
Published: January 2020

Exposure of monkeys to aerosols of influenza virus followed later by aerosols of
Diplococcus pneumoniae
resulted in persistence of the bacteria in the upper respiratory tract for an average of 28 days. Examination of selected tissues for pneumococci revealed that pneumococci were widely disseminated throughout the respiratory tract at 3 and 7 days after exposure, but were cleared from lower respiratory tissues and were found mainly in tonsils, oropharynx, and posterior nasopharynx after 14 days.
Differences in Acute and Convalescent-Phase Antibodies of Cats Infected with Feline Picornaviruses
Authors: Olsen Richard G. , Kahn Donald E. , Hoover Edward A. , Saxe Nancy J. , Yohn David S.
Published: January 2020

Complement fixation inhibiting and complement-fixing antibodies were demonstrated in sera from cats during the acute and convalescent stages, respectively, of feline picornavirus infections. Complement-fixing antibody activity was present in 19
S
and 7
S
globulins, whereas complement fixation inhibiting antibody activity was confined to the 7
S
globulins. Sera with complement-fixing antibody and sera with complement fixation inhibiting antibody were also shown to have neutralizing and precipitating antibodies. In a study of antibody responses to homotypic and heterotypic strains of feline picornavirus, less serological cross-reactions were observed between strains of feline picornavirus in sera from cats in the acute phase of feline picornavirus infection than in the convalescent phase. The temporal relationship of complement fixation inhibiting and complement-fixing antibody responses of cats after acute viral respiratory infections is contrasted with previously observed antibody response in cats to feline leukemia virus.
Detection of Dengue Cell-Surface Antigens by Peroxidase-Labeled Antibodies and Immune Cytolysis
Authors: Catanzaro P. J. , Brandt W. E. , Hogrefe W. R. , Russell P. K.
Published: January 2020

The appearance of dengue-specific plasma membrane (DSPM) antigens in infected LLC-MK
2
cell cultures was studied by
51
Cr release in immune cytolysis and at an ultrastructural level using peroxidase-labeled antibodies. DSPM antigen was first detected at 36 h with electron microscopy in approximately 30% of the cells, and this percentage did not increase with time. However, both surface staining with peroxidase-labeled antibodies and
51
Cr release indicated that the amount of DSPM antigen per cell increases with time. The appearance of
51
Cr release in immune cytolysis experiments with dengue-infected cells occurred much later than the peak of infectious virus release. This was in sharp contrast to immune cytolysis with a group A arbovirus, Eastern equine encephalitis, in which the kinetics of release of infectious virus and
51
Cr release were identical. This suggests different mechanisms of insertion of viral plasma membrane antigens in Eastern equine encephalitis and dengue-infected LLC-MK
2
cells.
Absence of Photoreactivating Enzyme in
Candida albicans, Candida stellatoidea
, and
Candida tropicalis
Authors: Miller Glendon R. , Sarachek Alvin
Published: January 2020

In vitro assays demonstrate photoreactivating enzyme activity in extracts of
Candida pseudotropicalis
but not in extracts of
Candida albicans, Candida stellatoidea
, or
Candida tropicalis.
Linkage Between Reproductive Capacity at Increased Temperature and Neurotropic Activity in A/NWS HONi (H
0
N
1
) Influenza Virus
Authors: Svobodová Jaroslava , Tučková Eva , Vonka Vladimír
Published: January 2020

We investigated the rate of covariation between the ability of the NWS strain of influenza virus to reproduce at increased temperature and its neurotropic properties. Results indicated that increased growth at 39 C was related to increased neurovirulence, and acquisition of the temperature-sensitive character was related to loss of neurovirulence.
Inhibition by
Mycoplasma dispar
of Ciliary Activity in Tracheal Organ Cultures
Authors: Howard C. J. , Thomas L. H.
Published: January 2020

The inhibition by
Mycoplasma dispar
of ciliary activity of organ cultures of bovine fetal trachea was found to be dependent on the presence of serum in the maintenance medium. Inhibitory activity was unaffected by catalase and no toxic substance was demonstrated in organ culture supernatant fluid.
Enhanced Interferon Response to Murine Leukemia Virus by Ascorbic Acid
Authors: Siegel Benjamin V.
Published: January 2020

BALB/cJ mice, on an ad libitum regimen of 250 mg%
l
-ascorbate in their drinking water, displayed augmented levels of circulating interferon after stimulation with murine leukemia virus.
Local Antibody Production in Experimental Pyelonephritis: Amount, Avidity, and Immunoglobulin Class
Authors: Smith J. , Holmgren J. , Ahlstedt S. , Hanson L. A.
Published: January 2020

Local antibody formation in infected rabbit kidneys was studied with three techniques: the ammonium sulfate precipitation technique, the enzyme-linked immunosorbent assay, and by binding of newly synthesized
14
C-labeled antibodies to heat-killed bacteria. Local antibody was detected by day 11 of infection with all three techniques, and a significant correlation was found in titers by all three methods. In these studies, antibody synthesized early was in IgG and IgA class, whereas IgM antibodies appeared later (day 20) in the antibody response. No maturation of avidity of local antibody was noted with time. Since it was necessary to use different animals at each test occasion, individual differences in avidity could account for failure to note an increase in avidity with time.
Immunoglobulin Classes and Biological Functions of
Campylobacter (Vibrio) fetus
Antibodies in Serum and Cervicovaginal Mucus
Authors: Corbeil L. B. , Schurig G. D. , Duncan J. R. , Corbeil R. R. , Winter A. J.
Published: January 2020

Serum and cervicovaginal mucus (CVM) antibodies from heifers after genital infection or systemic immunization with
Campylobacter (Vibrio) fetus
were classified according to their immunoglobulin class, antigenic specificities, and biological functions. Only immunoglobulin (Ig) A antibodies, specific both for O and superficial, heat-labile, whole-cell (W) antigens, were detected in CVM of convalescent animals. After systemic immunization, antibodies in serum were directed principally to W antigens and were located in IgG
1
, IgG
2
, and IgM classes; CVM antibodies of the same specificity were detected only in the IgG subclasses. Functional tests revealed that antibodies of W specificity, whether of the IgA or IgG class, were capable of immobilizing the organism. However, IgG antibodies immobilized with clumping, whereas IgA antibodies immobilized single organisms within the 3-min period. None of the antibody preparations was bactericidal in the presence of homologous complement when the infecting strain was used as the target organism, but a bactericidal effect was observed when the target strain was rough and non-encapsulated. Both serum and CVM from systemically immunized animals opsonized
C. fetus
organisms, but CVM from locally immunized animals containing IgA antibodies was not opsonic. It is hypothesized that functions of immobilization for IgA and IgG and of opsonization for IgG are important features of protective immunity in venereal vibriosis.
Inflammatory Lymphocyte in Cell-Mediated Antibacterial Immunity: Factors Governing the Accumulation of Mediator T Cells in Peritoneal Exudates
Authors: North R. J. , Spitalny G.
Published: January 2020

The lymphocytes which mediate immunity to infection with
Listeria monocytogenes
in the mouse accumulated in casein-induced peritoneal exudates. They were T cells, as evidenced by their susceptibility to anti-θ serum, but some were also destroyed by anti-immunoglobulin serum. For a given number of cells, exudate cells were at least six times more efficient than spleen cells in protecting normal recipients against lethal challenge. The extent to which mediator cells accumulated in exudates was found to be governed by the level of their production in responding lymphoid tissue and by the time available for them to migrate into an exudate. An intraperitoneal injection of casein at any stage of infection resulted in a progressive accumulation of mediator cells that continued for 3 days. The accumulation was not caused by continuous entry of cells during the whole of this period, but resulted from division of a limited number of cells that entered during the first 24 h. Accumulation of mediator cells in an exudate was associated with the conversion of a population of dividing cells into a population of nondividing T cells with a relatively short life-span.
Effects of High Ambient Temperature on Various Stages of Rabies Virus Infection in Mice
Authors: Bell J. F. , Moore G. J.
Published: January 2020

Effects of high ambient temperatures on various stages of rabies virus infection have been studied. Ambient temperature increased within the tolerated range was found to have little effect upon body temperature of normal mice, but caused marked elevation of temperature during illness. Temperatures at onset of patent illness in mice were lower than normal. Increased body temperature in the higher thermic ambience during the incubation period was associated with decreased mortality and frequent abortive infections. Exposure to high ambient temperature late in the incubation period delayed onset of illness, decreased mortality, and increased frequency of abortive infections, but exposure to high ambient temperature after onset of patent illness did not affect the course of the disease.
Experimental Infection with Western Equine Encephalomyelitis Virus in Wild Rodents Indigenous to Kern County, California
Authors: Hardy J. L. , Reeves W. C. , Rush W. A. , Nir Y. D.
Published: January 2020

Six species of rodents from Kern County, California, were inoculated subcutaneously with western equine encephalomyelitis (WEE) virus to determine their susceptibility to infection and their potential as natural hosts.
Ammospermophilus nelsoni, Citellus beecheyi, Dipodomys heermanni, Dipodomys nitratoides, Peromyscus maniculatus
, and
Sciurus griseus
were readily infected. Infection was usually fatal in
Dipodomys
species,
C. beecheyi
, and
S. griseus
, but was clinically inapparent in other species. Viremic responses varied greatly in magnitude and duration in different species and with different viral strains. Viremic animals that survived developed high titers of hemagglutination-inhibiting antibody. Hemagglutination-inhibiting and neutralizing antibodies persisted at high titers for at least 8 to 58 weeks after infection, except in
P. maniculatus.
If animals died during or shortly after the viremic phase of infection, the virus usually was recoverable from numerous organs. Long-term survival of virus could not be demonstrated in
A. nelsoni
and
Dipodomys
species. It is concluded that
A. nelsoni
and
P. maniculatus
are not important natural hosts of WEE virus; they are susceptible to infection and develop antibodies, but serological surveys of the same species rarely reveal evidence of infection.
S. griseus, D. heermanni, D. nitratoides
, and possibly
C. beecheyi
are aberrant hosts of WEE virus since most of them died when infected. Two species of ticks that are ectoparasitic on rodents in Kern County were evaluated as vectors of WEE virus.
Dermacentor parumapertus
failed to become infected after feeding on viremic hosts, and
Ornithodorus parkeri
became infected but failed to transmit virus.
Reactions in the Periodontium to Continuous Antigenic Stimulation in Sensitized Gnotobiotic Rats
Authors: Guggenheim B. , Schroeder H. E.
Published: January 2020

The purpose of our experiment was to evaluate the destructive potential of a strain of
Actinomyces viscosus
on the periodontium of sensitized rodents, describing the induced lesions on the basis of quantitative cytology. The experimental design comprised in principle the following procedures. Young germfree rats were immunized either by intravenous or intradermal injections with heat-killed cells of
A. viscosus
Ny 1 or sham immunized intradermally with physiological saline. After a period suitable for activation of the humoral and cell-mediated immune systems, Ny 1 was monoassociated in all animals by oral implantation. During the ensuing 42 days the animals were allowed to react against the continuous peripheral oral antigen challenge. Since
A. viscosus
is known as a heavy dental plaque-forming organism, the animals could be expected to develop local immunopathological lesions in the periodontal tissues. These lesions were then studied by quantitative cytology after sampling procedures allowing optimal tissue preservation. The degree of bone loss observed in all treatments was unrelated to the destructive capacity of the infiltrates, suggesting the presence of distinct mechanisms responsible for the activation of osteoclasts and factors interfering with fibroblast activity. Although the cellular composition of the infiltrated tissues was analyzed at the end of the experiment only, distinct stages of the lesions in the different treatments allowed reconstruction of the sequence of events. After an acute inflammatory phase, a classic delayed hypersensitivity reaction developed which was transformed after some time by a large superimposed plasma cell accumulation. The particular but undefined immune status was the significant factor determining the final type of peripheral infiltrative reaction.
Infectious Bronchitis and Mixed Infections of
Mycoplasma synoviae
and
Escherichia coli
in Gnotobiotic Chickens I. Synergistic Role in the Airsacculitis Syndrome
Authors: Springer W. T. , Luskus Carol , Pourciau Susan S.
Published: January 2020

The synergistic role of infectious bronchitis virus (IBV) and mixed infections of
Mycoplasma synoviae
(MS) and
Escherichia coli
(EC) in the airsacculitis syndrome was evaluated in gnotobiotic chickens. Relative air sac lesion score indexes, in descending order of severity, from various combinations of organisms were: 9.5—IBV, MS, EC; 6.8—IBV, EC; 4.5—IBV, MS; 2.7—IBV; and 0.5—MS, EC. Infectious bronchitis virus caused a mild fibrinous inflammation.
M. synoviae
combined with IBV increased heterophilic and follicular lymphoid infiltration and mortality.
E. coli
combined with IBV increased exudation and prolonged airsacculitis. Concentrations of fibrinogen, gamma globulin, and total plasma proteins were elevated significantly by combined infections of IBV, MS, and EC (
P
< 0.01).
Serological Comparison of Five Arginine-Utilizing
Mycoplasma
Species by Two-Dimensional Immunoelectrophoresis
Authors: Thirkill Charles E. , Kenny George E.
Published: January 2020

Five arginine-utilizing, nonglycolytic
Mycoplasma
species were compared serologically by two dimensional immunoelectrophoresis. The survey included:
Mycoplasma hominis, Mycoplasma arthritidis, Mycoplasma gateae, Mycoplasma gallinarum
, and three strains of
Mycoplasma arginini
. Although the
M. arginini
strains showed strong cross-reactions, each strain produced a different antigenic profile which was distinct and which indicated significant antigenic differences between strains. The
M. arginini
strains showed strong relationships with
M. gateae
; lesser cross-reactions were observed with other strains. Common antigens were demonstrable in the entire group. When all these species were compared with a glycolytic species,
Mycoplasma gallisepticum
, no cross-reactions were observed. Two-dimensional immunoelectrophoresis was a far more sensitive technique than double-immunodiffusion since as many as 20 components could be resolved.
Macrophage-Dependent Lymphocyte Immunostimulation in Cattle Infected with
Mycobacterium bovis
and with
Mycobacterium avium
Authors: Muscoplat Charles C. , Thoen Charles O. , Chen Amy W. , Johnson Donald W.
Published: January 2020

Cultures of bovine peripheral blood leukocytes were prepared from calves inoculated with
Mycobacterium bovis
and with
M. avium.
Suitable lymphocyte stimulation was obtained with specific and nonspecific mycobacterial mitogens. Leukocyte cultures depleted of adherent, macrophage-type cells did not respond to stimulation with purified protein derivative, although they were responsive to phytohemagglutinin.
Host Defense Mechanisms Against Infectious Bovine Rhinotracheitis Virus: In Vitro Stimulation of Sensitized Lymphocytes by Virus Antigen
Authors: Rouse Barry T. , Babiuk Lorne A.
Published: January 2020

Isolated peripheral blood lymphocytes (PBL) from cattle immunized or infected with infectious bovine rhinotracheitis (IBR) virus were cultured in vitro with ultraviolet light-inactivated IBR virus, and the degree of lymphocyte blastogenesis was quantitated by measurement of the uptake of [
3
H]thymidine into acid-insoluble material. Lymphocyte blastogenesis only occurred with PBL from immunized or infected animals. The optimal conditions for lymphocyte blastogenesis were defined. Blastogenesis was specific since cells from animals immunized against IBR failed to react with two other herpesvirus antigens tested, herpes simplex and equine rhinopneumonitis viruses. Blastogenesis could be prevented by reacting IBR antigen with IBR-specific antibody before adding to cultures, but incorporating IBR-specific antibody in the culture medium after adding free antigen failed to inhibit blastogenesis. With intranasally infected animals, lymphocyte blastogenesis was detectable after 5 days, reached peak levels between days 7 and 10, and then declined to low levels by day 19. In contrast, levels of neutralizing antibody were barely detectable on day 7 and reached maximal concentrations on day 19. The lymphocyte blastogenesis assay was emphasized as a convenient and useful in vitro correlate of cell-mediated immunity that should help define the role of cell-mediated immunity in immunity to herpesviruses.
Cholera Toxoid Boosts Serum
Escherichia coli
Antitoxin in Humans
Authors: Nalin D. R. , Al-Mahmud A. , Curlin G. , Ahmed A. , Peterson J.
Published: January 2020

Sera from individuals vaccinated with a cholera toxoid were tested to determine if sera with significant titers of cholera antitoxin could neutralize
Escherichia coli
thermolabile enterotoxin. Individuals who responded to immunization with significant increases in serum cholera antitoxin titers also showed increases in serum
E. coli
enterotoxin-neutralizing capacity. These findings suggested the possibility that the cholera toxoid vaccine may be useful in preventing disease caused by
E. coli.
Antigen-Induced Proliferative Response to Murine Thymus Cells in Vitro
Authors: Lyle L. R. , Eisen S. A. , Parker C. W.
Published: January 2020

Thymus cells from 5- to 6-week-old normal (unimmunized) BALB/c mice showed an increased incorporation of [
3
H]thymidine in the presence of 2,4-dinitrophenyl-bovine serum albumin, fluorescein-bovine serum albumin, and bovine serum albumin (BSA) in tissue culture. The concentrations of antigen (BSA and haptenated proteins) required for stimulation were approximately 25- to 50-fold higher than those of the nonspecific mitogen, concanavalin A. In contrast to the stimulation by concanavalin A, which was maximal at 24 to 72 h, the stimulation by antigen was most marked earlier in the culture period (6 to 24 h). The BSA response was diminished to a statistically significant degree (especially at low BSA concentrations) in thymocytes from animals injected 72 h previously with BSA, indicating that the stimulation is immunologically specific.
Cellular Immune Activity of a Galactomannan-Protein Complex from Mycelia of
Histoplasma capsulatum
Authors: Reiss E. , Mitchell W. O. , Stone S. H. , Hasenclever H. F.
Published: January 2020

A galactomannan-protein complex was extracted from defatted mycelium of
Histoplasma capsulatum
with 0.25 N alkali at 25 C. It accounted for 7.5% of the cell dry weight in nondialyzable form and had a galactose-mannose ratio of 2:5. The complex containing 68% protein was separated into polysaccharide and glycoprotein components by ion-exchange chromatography. The galactomannan formed a single precipitate in immunodiffusion, sharing a common antigen with the glycoprotein which contained two precipitating antigens. The glycoprotein elicited delayed-type hypersensitivity in guinea pigs as measured by skin-test and macrophage migration inhibitory factor assay, with 5 μg resulting in 86% specific inhibition. The galactomannan was skin-test negative, but 10 μg resulted in 80% specific inhibition of migration.
Virus Production and Release, Cell Longevity, and Cloning Efficiency of Chicken Embryo Fibroblasts Infected with Rous Sarcoma Virus
Authors: Volkmann Keith R. , Morgan Herbert R.
Published: January 2020

Continuous virus production is a characteristic of chicken embryo fibroblasts (CEF) infected and transformed by a nondefective Schmidt-Ruppin subgroup A Rous sarcoma virus. This virus production has been examined with particular attention to the amount of newly budded virus which remained cell-associated, and to the amount and degree of viral aggregation at the cell surface and in the fluid tissue culture medium. The total biologically active virus associated with a Schmidt-Ruppin subgroup A Rous sarcoma virus-infected CEF culture was divided almost equally between that portion of virus which was present in the fluid medium and that portion which was cell-associated. Various mechanical and enzymatic methods were used to remove cell-bound virus and to disperse aggregates of virus in the tissue culture medium to assess cell production of virus per hour accurately, which was determined as an average of 16.4 focus-forming units per cell per hour. With appropriate culture conditions, it was found that Schmidt-Ruppin subgroup A Rous sarcoma virus-infected and -transformed CEF replicated faster, could be passaged more times, and grew to higher cell densities than did normal CEF and CEF infected with a subgroup A Rous associated virus. Subgroup A Rous sárcoma virus-infected CEF cloned with much lower efficiency than did subgroup A Rous associated virus-infected CEF or normal CEF. Experiments employing a temperature-sensitive mutant of subgroup A Schmidt-Ruppin Rous sarcoma virus- and Rous associated virus-infected CEF indicated that the poor cloning efficiency of Schmidt-Ruppin subgroup A Rous sarcoma virus infected cells was not due to the constant production of virus but was probably related to some property associated with transformation of the cell by Rous sarcoma virus.
Blastogenesis and Lymphokine Synthesis by T and B Lymphocytes from Patients with Periodontal Disease
Authors: Mackler B. F. , Altman L. C. , Wahl S. , Rosenstreich D. L. , Oppenheim J. J. , Mergenhagen S. E.
Published: January 2020

Thymus-derived (T) and bone marrow-derived (B) lymphocytes were isolated from human peripheral blood and cultured with various mitogens and antigens. Purified protein derivative of tuberculin stimulated both purified T and B cells from patients with positive skin reactivity to purified protein derivative but did not stimulate nonimmune lymphocytes. Similarly, both T and B lymphocytes from patients with periodontal disease were stimulated to proliferate when incubated with dental plaque, whereas cells from normal individuals without gingivitis were unresponsive. In contrast, one component of plaque, bacterial endotoxins (lipopolysaccharide), minimally stimulated B lymphocytes from both normal or gingivitis patients. T lymphocytes from patients with periodontal disease were also stimulated by plaque antigen to produce chemotactic lymphokine activity (CTX) for human monocytes. B cells purified by the EAC rosetting method nonspecifically produced CTX without concomitant blastogenesis; however, after dissociation of adherent EAC these immune B cells did not spontaneously produce CTX. Lymphokine synthesis by B cells was not dependent on concomitant blastogenesis. Dissociated B cells from periodontitis patients also produced CTX activity after stimulation with dental plaque antigen. Therefore, both T and B lymphocytes, after stimulation with nonendotoxin antigenic components of plaque, proliferated and produced lymphokines, which are presumed to contribute to the pathogenesis of periodontal disease.
New Type of Exfoliatin Obtained from Staphylococcal Strains, Belonging to Phage Groups Other than Group II, Isolated from Patients with Impetigo and Ritter's Disease
Authors: Kondo Isamu , Sakurai Susumu , Sarai Yasunaga
Published: January 2020

Four strains of
Staphylococcus aureus
of a phage type other than the second group, isolated from patients with impetigo and Ritter's disease, were found to produce an exotoxin similar to those reported by Melish et al. (1972), Kapral and Miller (1971), and Arbuthnott et al. (1973). This toxin could elicit a general exfoliation of the epidermis with the so-called Nikolsky sign when subcutaneously inoculated into neonatal mice within 4 days after birth. The new toxin was serologically different from exfoliatin produced by the phage group II staphylococci previously reported (Kondo et al., 1973) and showed an electrophoretic pattern corresponding to that of the B-type toxin of the latter in acrylamide disc electrophoresis. It had the same molecular weight as that of the latter, which was estimated to be about 24,000. It was thermolabile and lost its toxic activity by heating at 60 C for 30 min; in addition, most of the toxicity was lost within 1 month of storage even at −30 C. We propose to designate the old typical heat-stable exfoliatin as
S. aureus
exfoliatin A and the new heat-susceptible exfoliatin as
S. aureus
exfoliatin B.
Ultrastructure of Pili and Annular Structures on the Cell Wall Surface of
Neisseria meningitidis
Authors: Devoe I. W. , Gilchrist J. E.
Published: January 2020

In a survey of negatively stained preparations of the prototype strains of
Neisseria meningitidis
, pili were detected on three strains. However, these pili were detected on fewer than 5% of cells in populations of these three strains. Those individual cells with pili were seldom observed to contain more than two or three pili per cell. In contrast, nearly all cells of the nonprototype group B strain ATCC 13090 had numerous pili on their surfaces. When viewed in frozen-etched replicas, a few pili were observed lying on the cell surface of this latter strain. An annular structure was also found in frozen-etched replicas. This structure usually consisted of a series of concentric rings that were always found on the flat side of these bean-shaped cells. It is concluded that such structures represent a differentiated portion of the cell wall, which is involved in cross-wall formation during synthesis of the cell septum in dividing cells.