bluuebunny/crossref_metadata_2025 huggingface dataset:
Clostridium perfringens
Type A Food Poisoning I. Response of the Rabbit Ileum as an Indication of Enteropathogenicity of Strains of
Clostridium perfringens
in Monkeys
Authors: Duncan Charles L. , Strong Dorothy H.
Published: January 2020

Diarrhea and vomiting have been experimentally produced in monkeys after oral challenge with viable cells or culture filtrates of certain strains of
Clostridium perfringens
that previously had been shown to produce either fluid accumulation in the ligated ileum or overt diarrhea in the nonligated ileum of the rabbit, or both. Strains (or their culture filtrates) which did not produce a response in the rabbit likewise produced no symptoms in monkeys.
Role of Biological Mimicry in the Pathogenesis of Rat Arthritis Induced by
Mycoplasma arthritidis
Authors: Cahill J. F. , Cole B. C. , Wiley B. B. , Ward J. R.
Published: January 2020

Complement fixation (CF), immunofluorescence, and agar gel double-diffusion tests were used to demonstrate an antigenic relationship between rat tissues and
Mycoplasma arthritidis.
Rabbit antisera against six strains of
M. arthritidis
exhibited positive reactions in the CF test with an ethyl alcohol-saline extract of rat muscle, whereas only 6 of 18 antisera against other
Mycoplasma
species were positive. With the use of gel diffusion techniques, absorption of various
M. arthritidis
antigens with antiserum against rat muscle removed at least one precipitin band when the absorbed mycoplasma antigens were reacted against homologous antisera. Rabbit antiserum against
M. arthritidis
was conjugated with fluorescein isothiocyanate and reacted against frozen sections of muscle tissues of various animals. As controls, unlabeled normal rabbit serum and rabbit anti-
M. arthritidis
serum were included to determine the specificity of the reaction. Rat, hamster, and mouse skeletal muscle exhibited specific fluorescence, whereas chicken, beef, frog, and turtle muscles exhibited no specific fluorescence. Mice injected at birth with rat lymphocytes were found to be more susceptible to subsequent infection by
M. arthritidis
than were normal mice or mice injected at birth with mouse lymphocytes. These results indicate the occurrence of a heterogenetic antigen(s) common to
M. arthritidis
and rat tissues. Preliminary evidence suggests that this heterogenetic antigen(s) may enable the mycoplasmas to become established in their host.
Effect of Ca
2+
on the Synthesis of Deoxyribonucleic Acid in Virulent and Avirulent
Yersinia
Authors: Yang Gene C. H. , Brubaker R. R.
Published: January 2020

Virulent and potentially virulent cells of
Yersinia
(
Pasteurella
)
pestis
produce virulence or V and W antigens (VW
+
) but remain static at 37 C during aeration in enriched Ca
2+
-deficient media containing 0.02
m
Mg
2+
. In this environment, which simulates mammalian intracellular fluid, VW
+
cells possessed a functional cytoplasmic membrane as judged by concentration of
14
C-isoleucine, release of
32
P, and consumption of oxygen at rates comparable to those of dividing cells cultivated with Ca
2+
. Furthermore, rates of protein and ribonucleic acid synthesis were essentially identical in dividing and static VW
+
cells and in mutant VW
−
organisms. However, the rate of deoxyribonucleic acid (DNA) synthesis in static cells was about 10% of that observed in dividing organisms. Accordingly, bacteriostasis of VW
+
cells in the simulated intracellular environment is evidently caused by reactions directly associated with cessation of DNA synthesis rather than by alterations in the regulatory capacity of the cytoplasmic membrane.
Effect of Medium on H
2
O
2
Levels and Peroxidase-Like Activity by
Mycoplasma pneumoniae
Authors: Low I. E.
Published: January 2020

H
2
O
2
levels accumulated by
Mycoplasma pneumoniae
can be influenced by carbon source, different horse sera, yeast extract, thallium acetate, or growth in a simplified, dialyzed medium. Thus, increased levels of H
2
O
2
were detected by growth in glycerol, by omission of thallium acetate, and by the use of dialyzed medium. The ability of
M. pneumoniae
in the presence of glucose, but not with fructose, mannose, or glycerol, to remove both endogenous and exogenous H
2
O
2
suggests an inducible peroxidase similar to bacterial enzymes in streptococci. This peroxidase-like activity is in turn influenced by the complex interplay of medium components, explaining perhaps some of the variability of H
2
O
2
accumulations observed with glucose. A survival value has been suggested for this “peroxidase-like” activity.
Cellular and Humoral Antibody Responses of Normal Pastel and Sapphire Mink to Goat Erythrocytes
Authors: Lodmell D. L. , Bergman R. K. , Hadlow W. J. , Munoz J. J.
Published: January 2020

This study was undertaken to determine whether normal sapphire and royal pastel mink differ immunologically at the cellular and humoral levels. Two days after primary intraperitoneal (ip) inoculation of goat erythrocytes (GE), essentially no 19 or 7
S
plaque-forming cells (PFC) per 10
6
cells were detected in spleen or in abdominal and peripheral lymph nodes of either color phase. On the 4th day, more 19
S
PFC were detected in pastel than in sapphire tissues; pastel tissues also contained 7
S
PFC, whereas essentially none was present in sapphires until the 6th day. After an ip booster inoculation, the number of PFC was markedly different between the two color phases. These differences were most apparent in spleen and peripheral lymph nodes. In parallel with differences observed in PFC responses between the color phases, total hemolysin and 2-mercaptoethanol-resistant hemolysin titers of pastels exceeded those of sapphires in all but one interval after the primary, and at every interval after the booster, inoculation. These data indicate that sapphire mink are not immunological cripples, nor are they immunologically hyperactive, but that differences do exist between sapphire and royal pastel mink, especially in the response to booster injections of GE.
Age-Dependent Resistance of Mice to Sindbis Virus Infection: Viral Replication as a Function of Host Age
Authors: Reinarz A. B. G. , Broome M. G. , Sagik B. P.
Published: January 2020

The development of resistance of outbred white mice to two plaque size variants of Sindbis virus was studied as a function of host age. A sudden drop in mortality occurred over a 3-day period. As little as 1 plaque-forming unit (PFU) per mouse was lethal in 1-day-old animals, whereas inocula of 10
9
PFU per mouse failed to produce high mortality in weanlings. A comparison of viral growth kinetics shows that early replication was similar in newborns and weanlings but that after 6 to 8 hr the production rate and, therefore, the maximal viral titer were suppressed in weanlings. The data demonstrate a lethal viral threshold. Titers in excess of this level lead to mortality, whereas those below it allow survival.
Effect of Antilymphocyte Serum on Reovirus Infection of Mice
Authors: Ida Shiroh , Hinuma Yorio
Published: January 2020

Reovirus type 3 infection in mice was investigated, with particular reference to the effect of antilymphocyte serum. With virus inoculation, a characteristic acute disease was manifested in the mice younger than 5 days old but not in mice 7 days old or older. However, a single injection of antilymphocyte serum, which was prepared in rabbits immunized with mouse thymocytes, followed by virus inoculation induced the acute disease in mice 7 days old or older. The latter result suggests that this production of the acute disease may be due to a suppression of the cellular immune mechanism sensitive to antilymphocyte serum.
Group A Streptococcal Polysaccharide Antigens
Authors: Matsuno Takashi , Slade Hutton D.
Published: January 2020

Cold trichloroacetic acid extracts of group A, type 3 streptococci were fractionated on Sephadex G50 and ECTEOLA cellulose columns. A glucose-
N
-acetylglucosamine polymer was isolated and shown by chemical, electrophoretic, and antigenic analysis to be distinct from the group A polysaccharide. The antigenic specificity was due to the glucosamine. A glycerol-phosphate-alanine-glucosamine teichoic acid polymer was isolated. The antigenic specificity was due to
N
-acetylglucosamine and
d
-alanine methyl ester, with the former possessing principal responsibility. The glucosamine and ester-linked alanine appear to be labile to the method of extraction and fractionation. Group A streptococcal whole cell antiserum, after adsorption with cells of a heterologous serological group and group A polysaccharide antigen, contained antibodies against both polymers.
Effect of Antibiotic Treatment on the Incidence of Infectious Drug Resistance Among Intestinal Lactose-Fermenting Bacteria Isolated from Burn Patients
Authors: Sturtevant Alton B. , Cassell Gail H. , Bobo Raymond A. , Feary Thomas W.
Published: January 2020

Antibiotic-resistant lactose-fermenting bacteria were recovered from the feces of 20 of 25 burn patients studied. Of the
Escherichia coli
isolated from patients receiving antibiotic treatment, 81.5% were shown to be infectiously resistant; only 32% of the
E. coli
recovered from patients not receiving antibiotics were shown to be harboring R factors. Three resistance patterns, ampicillin-chloramphenicol-streptomycin-kanamycin, ampicillin-tetracycline, and ampicillin-streptomycin, accounted for 25.2, 20.3, and 15.4%, respectively, of the total R factors identified.
Production and Properties of Antisera to Membrane Glycolipids of
Mycoplasma pneumoniae
Authors: Razin S. , Prescott B. , James W. D. , Caldes G. , Valdesuso J. , Chanock R. M.
Published: January 2020

The glycolipid haptens of
Mycoplasma pneumoniae
became immunogenic when bound to membrane proteins of
Acholeplasma laidlawii
by reaggregation. This process consisted of the solubilization of lipid-depleted
A. laidlawii
membranes and
M. pneumoniae
glycolipids in 20 m
m
sodium dodecyl sulfate and dialysis of the mixed solutions against 20 m
m
Mg
2+
. The antibodies produced in rabbits to the reaggregated glycolipids inhibited the metabolism of
M. pneumoniae
, fixed complement with
M. pneumoniae
glycolipids or whole cells, precipitated
M. pneumoniae
glycolipids, and agglutinated
M. pneumoniae
cells. All these antibody activities could be blocked or absorbed by the purified glycolipids but not by a series of carbohydrates containing glucose and galactose. It was concluded that the antiserum to the reaggregated glycolipids may be regarded as a specific serum to membrane glycolipids of
M. pneumoniae
, since the antibodies to
A. laidlawii
membrane proteins, present in this serum, did not react with the glycolipids or with any other cell component of
M. pneumoniae.
Interferon System in Cells from Human Tumors and from Persons Predisposed to Cancer
Authors: Worthington Michael , Aaronson Stuart A.
Published: January 2020

In the present study, the interferon system was evaluated in fibroblasts from persons predisposed to leukemia or other cancers, in fibroblasts from persons with neoplastic disease, and in human tumor cells. Of 31 normal fibroblast strains from patients with tumors or diseases associated with a high incidence of malignancy, only one cell strain had a poor response to either of the two interferon inducers used, polyinosinic-polycytidylic acid and Chikungunya virus. On the other hand, cell cultures of five human tumors were much less sensitive to the antiviral effect of these interferon inducers and of human interferon and produced less interferon in response to Chikungunya virus than any of the nontumor tissues studied.
Effect of Antilymphocyte Serium on Tacaribe Virus Infection in Infant Mice
Authors: Borden Ernest C. , Murphy Frederick A. , Nathanson Neal , Monath Thomas P. C.
Published: January 2020

Tacaribe virus, a member of the arenovirus group, was demonstrated to have similarities in pathogenesis to the prototype virus of this group, lymphocytic choriomeningitis (LCM) virus. Treatment with antilymphocyte serum (ALS) doubled the survival time of mice neonatally infected with a lethal dose of Tacaribe virus. Twenty-one per cent of ALS-treated infected animals survived more than 30 days. All animals had recoverable virus in brains and serum for the duration of life, and there was no difference between virus growth curves of ALS-treated and control animals. No neutralizing or complement-fixing antibodies were present in infected animals at time of death, with the exception of one long-surviving ALS-treated animal. Certain differences between infections of mice with LCM and Tacaribe viruses were apparent. Tacaribe virus pathogenicity decreased with increasing mouse age, and earlier infection and a more prolonged course of ALS treatment than was needed for LCM virus were necessary to achieve increased survival. Histopathological changes observed in Tacaribe virus-infected control mice were focal choroiditis and focal cerebellar necrosis; these changes were not seen in asymptomic infected mice during the period of transient protection by ALS.
Intestinal Strangulation in
Clostridium perfringens
-Monocontaminated Rats
Authors: Yale Charles E. , Balish Edward
Published: January 2020

Ischemic and hemorrhagic strangulation of closed intestinal segments was studied in germ-free rats individually contaminated with one of seven separate strains of
Clostridium perfringens
type A. The principal findings were that (i) the monocontaminated rats with ischemic or hemorrhagic intestinal strangulation died at the same rapid rate; (ii) intraintestinal blood did not augment the action of
C. perfringens
in the presence of ischemic strangulation; (iii) although some strains were more toxic than others, several food-poisoning strains were as rapidly fatal as the classical strains; and (iv) the massive amounts of gas produced by some of these strains probably led to the early rupture of the closed segments and rapid death of the animals. The secondary findings were that (i) the injection of
C. perfringens
into the lumen of the distal small intestine of the germ-free rat produced the typical lesions of pneumatosis cystoides intestinalis; and (ii) most of the strains of
C. perfringens
established themselves throughout the gastrointestinal tract of the unoperated germ-free rat.
Protection of
Mycobacterium smegmatis
from Ethambutol and Streptomycin Inhibition by MgSO
4
and Polyamines
Authors: Beggs William H. , Williams Nancy E.
Published: January 2020

Polyamines protected
Mycobacterium smegmatis
from ethambutol inhibition but not from streptomycin inhibition, whereas MgSO
4
neutralized growth inhibition by both drugs.
Role of Complement During Experimental
Candida
Infection in Mice
Authors: Morelli Remo , Rosenberg Leon T.
Published: January 2020

The role of complement during experimental
Candida albicans
infection was investigated in mice. It was found that complement-positive CF-1 mice, infected with the test organism, survived significantly longer than complement-deficient mice of the same strain. This implies the participation of the relatively late acting complement component in host defense mechanisms directed against this systemic mycotic infection.
Antigenic Differences Between
Mycobacterium bovis
Strain BCG and an Isoniazid-Resistant Mutant
Authors: Minden Percy , McClatchy J. Kenneth , Bardana Emil J. , Farr Richard S.
Published: January 2020

The antigenicities of
Mycobacterium bovis
strain BCG and an isoniazid (INH) - resistant mutant were compared. Sonic extracts of heat-killed, washed bacteria were injected into rabbits, and antisera were produced (anti-BCG and anti-BCG-R). The sonic extracts were also subjected to ultracentrifugation, and test antigens were prepared from the resulting supernatants (BCG and BCG-R). The antigens were labeled with
131
I, and the antisera were tested for their capacity to bind
131
I-BCG and
131
I-BCG-R by precipitating
131
I-antigen-antibody complexes with anti-rabbit gamma globulin. Significant differences were detected between the two test antigens. Immunodiffusion studies with unabsorbed antisera and antisera absorbed with BCG and BCG-R suggested that an antigenic component in BCG is lacking or diminished in BCG-R and that anti-BCG has antibodies not found in anti-BCG-R. These quantitative and qualitative differences were confirmed by inhibition studies. Complete inhibition was achieved in all systems by both test antigens when either was added in sufficient concentration. As expected, BCG-R inhibited the binding of
131
I-BCG-R by anti-BCG-R or anti-BCG (or both) to a greater extent than BCG, and BCG was a better inhibitor in an
131
I-BCG-anti-BCG-R system. However, in an
131
I-BCG-anti-BCG test system, BCG was the better inhibitor only at high concentrations. It was concluded that the test antigens possess different proportions of identical or cross-reacting components and that INH-sensitive organisms possess a component(s) that is diminished or absent in the INH-resistant mutant. Whether this component(s) is responsible for INH-resistance is not known.
Cephalexin: Absorption and Excretion as Related to Renal Function and Hemodialysis
Authors: Reisberg Boris E. , Mandelbaum Jorge M.
Published: January 2020

Cephalexin is a new semisynthetic cephalosporin C derivative, which is well absorbed from the gastrointestinal tract and excreted in high concentration in the urine. Even in patients with impaired renal function, the concentrations of cephalexin present in the urine are adequate for the treatment of most urinary tract infections produced by
Escherichia coli, Klebsiella
, and
Proteus mirabilis
. In anephric patients, single doses of 250 or 500 mg of cephalexin resulted in high, prolonged serum concentrations. Peak levels were usually observed within 1 hr. However, in two of six anephric patients, peak levels were reached after 6 and 12 hr due to delayed absorption. Hemodialysis for 6 hr reduced the serum concentration of cephalexin by 58%.
Lymphoid Cells in Delayed Hypersensitivity II. In Vitro Phagocytosis and Cellular Immunity
Authors: Salvin S. B. , Cheng Shu-Lan
Published: January 2020

Guinea pigs which develop delayed hypersensitivity, as measured by skin test, after intraperitoneal infection with
Candida albicans
have mononuclear cells (macrophages and lymphocytes) which show migration inhibition in vitro in the presence of soluble antigen. Macrophages from such animals phagocytose in vitro fewer numbers of
C. albicans
per cell than those of normal animals, and lower numbers of macrophages are phagocytic in vitro. Nevertheless, such sensitized animals have lower numbers of pathogens in their tissues than the controls, after both groups have been challenged. Thus, the result of macrophages from sensitized guinea pigs being less mobile, less phagocytic, and more destructive than those from normal animals may be a more limited spread of the infectious agent throughout the tissues; the animal would seem more resistant.
Immunogenicity of Purified Venezuelan Equine Encephalitis Virus Inactivated by Ionizing Radiation
Authors: Gruber Jack
Published: January 2020

Purified and concentrated Venezuelan equine encephalitis (VEE) virus derived from tissue cultures, rendered noninfectious by ionizing radiation with retention of in vitro serological activity, also retained a high level of immunogenicity. In mice, fluid vaccines afforded excellent protection against lethal challenge with homologous Trinidad strain VEE virus. A direct relationship was observed between concentration of vaccine or number of injections and survival. One intraperitoneal inoculation of undiluted vaccine protected essentially all mice challenged 21 days later with 100,000 mouse intraperitoneal LD
50
of virus. Similarly, mice receiving three injections of vaccines diluted 1:100 were completely protected. Noninfectious VEE virus preparations combined with adjuvant 65, a nontoxic metabolizable vehicle, were likewise very effective in protecting mice immunized intraperitoneally or subcutaneously against lethal challenge. Guinea pigs immunized subcutaneously with adjuvant-combined vaccine survived lethal challenge of 1,000,000 guinea pig intraperitoneal LD
50
.
Mutations Influencing the Assimilation of Nitrogen by
Yersinia pestis
Authors: Brubaker R. R. , Sulen A.
Published: January 2020

Cells of 20 isolates of
Yersinia
(
Pasteurella
)
pestis
exhibited an unusual nutritional requirement which could be fulfilled by glycine or
l
-threonine. Meiotrophic mutants which required neither of these amino acids (Gly/Thr
+
) were isolated from cultures of all 20 strains at a frequency of 10
−7
. Wild-type and Gly/Thr
+
cells of 14 strains failed to utilize
l
-amino acids or urea (0.01
m
) as primary sources of nitrogen and grew slowly in the presence of low concentrations of NH
4
+
(≦ 5 m
m
). Cells of six strains (termed N
+
) utilized certain
l
-amino acids and urea (0.01
m
) as primary sources of nitrogen and grew rapidly in the presence of ≦ 5 m
m
NH
4
+
. N
+
but not N
−
organisms cultivated with NH
4
+
(0.01
m
) as a primary source of nitrogen excreted a complete spectrum of naturally occurring amino acids; under this condition of growth the aspartase and particulate nicotinamide adenine dinucleotide phosphate transhydrogenase activities of N
+
and N
−
cells were repressed. N
+
meiotrophs arose at a frequency of 10
−6
in cultures of all 14 N
−
isolates, and urease-positive meiotrophs could be selected at a frequency of 10
−7
from N
+
but not N
−
cells of all 20 strains on a medium containing urea (0.01
m
) as a primary source of nitrogen. These findings illustrate a reversible loss of genetic potential which has occurred during the evolution of
Y. pestis
as an obligate parasite and suggest that this organism is unable to efficiently remove dispensable deoxyribonucleic acid from its chromosome.
Response to Experimental Infection with Mumps Virus in Rhesus Monkeys
Authors: Flanagan Thomas D. , Andrada Juan A. , Barron Almen L. , Witebsky Ernest
Published: January 2020

Experiments were conducted in which rhesus monkeys were infected with mumps virus by inoculation into the parotid gland. Virus was isolated from buccal swab specimens from animals up to 6 days after inoculation. Immunofluorescence staining for mumps antigen was positive, and infectious virus was recovered from tissue biopsies of inoculated glands. Histological examination of biopsied glands revealed lymphocytic infiltration of the tissue. Virus was not isolated from urine, buffy coat, or biopsies of thyroid and spleen. In other experiments, animals were infected by inoculation into the thyroid gland. Virus was not isolated from buccal swabs, urine specimens, or thyroid tissues from these monkeys. All inoculated animals responded immunologically to mumps virus regardless of route of infection. Previously infected animals did not shed virus when challenged with mumps virus. A histological response to challenge in glandular tissue was observed which suggested a hypersensitivity to mumps antigen. The response was qualitatively identical to that in acutely infected tissue but more intense. None of the animals infected developed antibodies to thyroid tissue regardless of route of injection of virus or site of challenge of immune monkeys.
Pathogenesis of
Clostridium botulinum
Type A: Study of In Vivo Toxin Release by Implantation of Diffusion Chambers Containing Spores, Vegetative Cells, and Free Toxin
Authors: Suzuki J. B. , Booth R. , Benedik A. , Grecz N.
Published: January 2020

Millipore diffusion chambers (MDC) with 0.22-μm filters loaded with spores or vegetative cells of
Clostridium botulinum
were surgically implanted intraperitoneally (ip) into guinea pigs. MDC expose
C. botulinum
spores or vegetative cells to body fluids yet protect them from phagocytes. Guinea pigs receiving MDC containing 10
9
spores plus 10
8
polymorphonuclear (PMN) leukocytes and MDC with 10
9
vegetative cells died within 48 hr, indicating that toxin was released and diffused out. MDC with 10
9
spores alone allowed 90% of animals to survive for at least 96 hr. Microscopically, it was observed that vegetative cells in MDC were disintegrated and leukocytes plus spores were phagocytized and germinated; spores alone remained intact and phase bright. Chemotactic attraction of leukocytes to MDC walls was also observed. Apparently, body fluids do not attack spores; thus, PMN leukocyte engulfment is essential for germination and release of spore-bound toxin in this type of
C. botulinum
pathogenesis. However, vegetative cells appear to be attacked by bacteriolytic enzymes (e.g., lysozyme) in body fluids, and leukocyte engulfment is not essential for toxin release.
Activity of Lipid Extracts from a Group A
Streptococcus
against Ehrlich Ascites Carcinoma in Mice
Authors: Kigoshi Shigeru
Published: January 2020

Lipid extracts derived from a group A
Streptococcus
, when preincubated with tumor cells before inoculation, were shown to prevent completely the development of Ehrlich ascites tumor in mice.
Fatty Acid Requirements of the Kazan 5 and Reiter Strains of
Treponema pallidum
Authors: Johnson Russell C. , Eggebraten Laura M.
Published: January 2020

The fatty acid requirements of two avirulent treponemes were investigated by using a “lipid-poor” albumin-thioglycolate medium. The Kazan 5 and the Reiter stains of
Treponema pallidum
required a pair of fatty acids for growth. One member of the pair was saturated and the other was unsaturated. The saturated fatty acids could contain either an odd or even number of carbon atoms, but a chain length of at least 14 carbon atoms was necessary. Unsaturated fatty acids with one, two, or three double bonds were satisfactory if they contained 15 or more carbon atoms. The pair of fatty acids could be replaced with a single 18-carbon monounsaturated fatty acid if it was in the
trans
configuration rather than the naturally occurring
cis
form.
Cellular Response of the Rabbit Eye to Primary Intravitreal Injection of
Neisseria meningitidis
Authors: Pribnow James F. , Hall Joan M. , Bradley Diane , Vedros Neylan A.
Published: January 2020

New Zealand White rabbits were injected intravitreally with approximately 2,500 viable or heat-killed meningococci. The rabbits were killed at intervals from 30 min to 14 days after injection. None of the rabbits produced detectable antibodies. Local antibody production by uveal tract, spleen, or preauricular lymph node cells was not demonstrated. Viable organisms were recovered from the vitreous at periods from 30 min to 48 hr after injection. Failure to recover viable organisms could be correlated with the appearance of large numbers of polymorphonuclear neutrophiles (PMN) throughout the vitreous. Animals injected with viable meningococci demonstrated a progressive inflammatory reaction characterized by an early accumulation of PMN in the vitreous, limbus, and conjunctiva. The cellular infiltrate gradually became mononuclear. By the 14th day postinjection only a few residual inflammatory cells remained at the limbus. This extensive cellular response was lacking in recipients of heat-killed organisms. The defense of the rabbit against intraocular introduction of meningococci therefore seems to be predominantly a cellular mechanism.
Measurement of Candidacidal Activity of Specific Leukocyte Types in Mixed Cell Populations II. Normal and Chronic Granulomatous Disease Eosinophils
Authors: Lehrer Robert I.
Published: January 2020

Normal human eosinophils possess appreciable intrinsic candidacidal activity. The leukocyte microbicidal deficiency of chronic granulomatous disease is manifested by eosinophils as well as by neutrophils and monocytes.
Biosynthesis of the K99 surface antigen is repressed by alanine
Authors: de Graaf F K , Klaasen-Boor P , van Hees J E
Published: January 2020

The amino acid alanine induced a direct and specific repression of the biosynthesis of the K99 surface antigen in Escherichia coli strains harboring the K99 plasmid. In minimal medium with 0.5% glucose, 1 mM L-alanine was sufficient to reduce the K99 production by about 95%. The low production of the K99 antigen by strains growing on commercially available nutrient media seemed to be a result of the inhibitory effect alanine on the K99 biosynthesis.
Pathogenicity of wild-type and temperature-sensitive mutants of herpes simplex virus type 2 in guinea pigs
Authors: Anderson C A , August M J , Hsiung G D
Published: January 2020

The pathogenicity of herpes simplex virus type 2 strain 186, the wild-type (WT) strain, and four temperature-sensitive (ts) mutants was studied after genital inoculation of female guinea pigs. Infection with the WT virus was generally severe, with extensive skin lesions in 89% and mortality in 37% of inoculated animals. Guinea pigs inoculated with ts mutants manifest remarkably mild disease, with lesions occurring in only 16% of the guinea pits and a mortality rate of 7%. WT virus was recovered from nerve and non-nerve tissues of all acutely infected animals and from the majority of latently infected animals (71%). Virus was isolated from nerve or genital tissues from only 13% of ts mutant-inoculated animals during acute infection and from 7% during latent infection. Three of the seven isolates from mutant-infected animals appeared to be WT virus. Identification of WT and ts mutant isolates was done by biological characterization in selective cell cultures at permissive (33 degrees C) and nonpermissive (38 degrees C) temperatures. One month after initial infection with WT virus, guinea pigs were challenged with the same virus and were completely resistant to overt clinical disease. Animals inoculated with ts mutants A1b and C2b had mild manifestations of disease after challenge with WT virus; however, the capacity of WT virus to establish latent infection was conserved. Although complement-required neutralizing antibodies were detectable after challenge in animals previously inoculated with mutant virus A1b, C2b, or D6b, there was no significant protection against subsequent infection with WT virus. No complement-required neutralizing antibodies were detected in F3b animals after challenge. The present study of WT and ts mutants of herpes simplex virus type 2 in the guinea pig model provides a means for better understanding the mechanisms of pathogenesis and latency after genital infection.
Partial characterization of a bactericidal system in staphylococcal abscesses
Authors: Dye E S , Kapral F A
Published: January 2020

Since leukocytes comprise a major portion of staphylococcal abscesses, the properties of the bactericidal material in abscess homogenates were compared with those of bactericidal systems associated with leukocyte lysosomes. The bactericidal material in abscess homogenates was distinguished from the myeloperoxidase system by its resistance to heat (100 degrees C, 30 min), lack of solubility in dilute acid (0.005 N HCl), resistance to strong acid (pH 1), and insensitivity to catalase. It was differentiated from the cationic proteins by its lack of solubility in dilute acid, insensitivity to iron (0.1 mM) or trypsin (5 mg/ml), and greater activity in solutions of increased ionic strength. These characteristics, together with its sensitivity to Ca2+ or albumin, suggested that the material might be lipid. Subsequent studies revealed that all the bactericidal activity resided in the lipid fraction recovered after extraction of abscess homogenates by the Dole procedure.
Preparation and crossed immunoelectrophoretic analysis of cytoplasmic and outer membrane fractions from Neisseria gonorrhoeae
Authors: Collins M L , Salton M R
Published: January 2020

Cell envelopes were obtained from lysates of Neisseria gonorrhoeae, colony type T1, prepared with lysozyme, ethylenediaminetetraacetate, and Brij 58. This preparation was separated into cytoplasmic (inner) and outer membrane fractions by equilibrium sucrose density gradient centrifugation. The former fraction was 10-fold enriched in L-lactate dehydrogenase activity with respect to the latter. On the basis of buoyant density in sucrose, polypeptide patterns in sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and enzymatic activity, these preparations appear similar to cytoplasmic and outer membrane preparations from other gram-negative bacteria. The membrane preparations were analyzed by high-resolution crossed immunoelectrophoretic procedures. This technique permitted the identification of antigens originating from the structural components of the gonococcal cell. Among those found to be cytoplasmic membrane components was the fast-moving antigen which occurs widely in gram-negative bacteria.
Mechanism of cellular suppression induced by oral tilorone treatment of mice
Authors: Collins F M
Published: January 2020

Specific-pathogen-free B6D2 F1 hybrid mice were treated orally with tilorone hydrochloride (100 mg/kg of body weight per day) and infected with sublethal doses of Listeria monocytogenes, Salmonella enteritidis, Mycobacterium bovis (BCG Pasteur), or M. tuberculosis Erdman. Daily tilorone treatment inhibited the cell-mediated response to all of the intracellular parasites, and most of the mice succumbed to the challenge. Tilorone suppressed delayed hypersensitivity responses to the microbial sensitins as well as to sheep erythrocytes. However, humoral responses (immediate hypersensitivity reactions) were stimulated. The types of growth curves obtained in the tilorone-treated mice were quite different from those observed in T-cell-depleted mice and tended to resemble those seen in sublethally irradiated (400 rads) animals. Leukocyte counts were depressed 10-fold by daily tilorone treatment. Both monocyte and granulocyte (but not large-lymphocyte) counts were depressed. There was an initial drop in small-lymphocyte counts with a later recovery phase. Tilorone treatment reduced the granulomatous response within the Salmonella-infected liver, suggesting that the drug interferes with the mobilization of the mononuclear defenses within the normal host.
Partial purification and properties of a mannofructokinase from Streptococcus mutans SL-1
Authors: Porter E V , Chassy B M , Holmlund C E
Published: January 2020

Fructokinase activity was demonstrated in seven strains of oral streptococci. The enzyme purified from Streptococcus mutans SL-1 was capable of phosphorylating both D-fructose and D-mmannose to their respective 6-phosphates. Phosphorylation of both fructose and mannose was dependent on adenosine 5'-triphosphate and a divalent metal ion. The molecular weight of the purified enzyme was estimated to be 49,000. The apparent Km of the enzyme for fructose was 0.63 mM. This enzyme also utilized mannose as a substrate, with an apparent Km for mannose of 0.37 mM. Since the activities of the enzyme toward mannose and fructose were not separated upon purification of the enzyme and since mannose was a competitive inhibitor of fructose phosphorylation, the purified kinase is a single enzyme, mannofructokinase, with dual specificity for both mannose and fructose. A role for this enzyme in carbohydrate metabolism in S. mutans is postulated.
In vitro virulence marker: growth of dengue-2 virus in human leukocyte suspension cultures
Authors: Halstead S B , Tom M C , Elm J L
Published: January 2020

We wished to find a simple, biologically relevant method to evaluate the virulence of dengue viruses for human beings. Since cells of mononuclear phagocyte lineage may be important sites of dengue infection in primates, we evaluated the permissiveness of these cells to dengue virus as a correlate of virus virulence. Two wild-type, large-plaque, monkey-virulent dengue-2 virus strains and two small-plaque, monkey-avirulent dengue-2 virus strains were evaluated for their ability to replicate in human peripheral blood leukocyte cultures supplemented with enhancing antibody. One of the small-plaque strains was demonstrated to have reduced virulence for man. Wild-type dengue-2 viruses replicated readily in peripheral blood leukocyte suspension cultures, whereas small-plaque dengue-2 strains did not. Differences between our data and results obtained by other workers employing adherent peripheral blood leukocytes are discussed. Antibody-enhanced growth of dengue virus in suspension cultures of human peripheral blood leukocytes gives promise of being a simple in vitro system for characterizing dengue virus virulence.
Virulence of Streptococcus mutans: characterization of a serotype g antigen-defective mutants and its revertants
Authors: Otake S , Hirasawa M , Brown T A , Kawabata Y , Kiyono H , Michalek S M , McGhee J R , Shiota T
Published: January 2020

A mutant of Streptococcus mutans 6715 HSR, which is defective in serotype antigen and designated C307, was shown to exhibit full virulence on buccal, sulcal, and proximal surfaces similar to that of 6715 HSR. In addition, this bacterium caused significant decay on the lingual surfaces. Its colonial morphology and certain biochemical activities which may be related to caries production were distinct from those of 6715 HSR. This mutant adsorbed to saliva-treated hydroxyapatite beads in greater amounts and aggregated in the presence of either sucrose or dextran in excess of that seen with the parent strain. The abilities of C307 to grow and to produce acid from sucrose and to adhere to glass surfaces were similar to that of 6715 HSR. Although revertants of C307 exhibited biological activities and a content of serotype g antigen similar to that of 6715 HSR, the virulence pattern was still unlike the parent strain. These results suggest that the serotype g antigen is not required for the adherence of cells to smooth surfaces or for caries formation and that the loss of this antigen may alter the surface of cells causing enhanced ability of the cells to aggregate and to adsorb to saliva-treated hydroxyapatite beads.
Role of host cell metabolism in the pathogenesis of Mycoplasma pneumoniae infection
Authors: Upchurch S , Gabridge M G
Published: January 2020

Human lung fibroblasts develop a cytopathic effect (CPE) when infected with Mycoplasma pneumoniae. This study was designed to determine the relationship between host cell metabolism and the formation of the CPE. Human lung fibroblasts were grown in different serum concentrations, plated at different densities, and grown for different periods of time to alter the metabolic activity of the cells. Deoxyribonucleic acid, ribonucleic acid, and protein syntheses were measured by the ability of the cells to incorporate thymidine, uridine, and leucine, respectively. With each treatment, leucine incorporation remained constant. Thymidine and uridine incorporation was higher when the cells were in high serum, at low cell densities, or grown for 2 or 3 days. The appearance of an observable CPE, which was corroborated with a protein synthesis assay, correlated closely with thymidine and uridine incorporation. A more pronounced CPE was seen when thymidine and uridine incorporation was high. In addition, it was found that the first 2 h after infection by M. pneumoniae were the critical hours in determining whether a CPE would develop. This was accomplished by altering the serum concentration of the culture medium at different times postinfection and thereby altering the metabolism of the fibroblasts. These results demonstrate the importance of the metabolic state of the host cells in studying mycoplasma infections and establish a correlation between the nucleic acid metabolism of the cells and the production of a CPE.
Evaluation of the opsonic requirements for phagocytosis of Streptococcus pneumoniae serotypes VII, XIV, and XIX by chemiluminescence assay
Authors: Matthay K K , Mentzer W C , Wara D W , Preisler H K , Lameris N B , Ammann A J
Published: January 2020

A luminol-enhanced chemiluminescence assay was used to investigate opsonic requirements for phagocytosis of STreptococcus pneumoniae serotypes VII, XIV, and XIX. After opsonization with whole immune sera (with antibody and total complement pathway), heat-inactivated immune sera (with antibody alone), or magnesium dichloride-ethylene glycol tetraacetic acid-chelated immune sera (with antibody and alternative complement pathway), live S. pneumoniae cells were incubated at 37 degrees C with normal polymorphonuclear leukocytes while serial chemiluminescence measurements were recorded. The amount of chemiluminescence observed correlated closely with evidence of phagocytosis as observed by microscopy. Complement was required for efficient opsonization, since all three serotypes showed a slower rise and less integral chemiluminescence after opsonization with heat-inactivated serum as compared with whole serum. The alternative pathway provided opsonic activity equal to that of the total complement pathway for type XIX, but only intermediate activity for types VII and XIV. Type-specific antibody was also required for effective opsonization of all three serotypes since chemiluminescence was markedly reduced when bacteria were opsonized with antibody-depleted serum (serum absorbed with type-specific S. pneumoniae cells at 4 degrees C). Thus, chemiluminescence proved to be an effective means of defining the requirement for both antibody and complement in the opsonization and phagocytosis of S. pneumoniae.
Bacteriocin-like substance (melaninocin) from oral Bacteroides melaninogenicus
Authors: Nakamura T , Fujimura S , Obata N , Yamazaki N
Published: January 2020

A bacteriocin-like substance, designated melaninocin, was extracted from a strain of Bacteroides melaninogenicus by ultrasonic treatment and purified. Melaninocin was heat labile and was destroyed by digestion by several proteolytic enzymes. Among the oral indigenous microorganisms, Bacteroides, Actinomyces, and streptococci were found to be sensitive to melaninocin.
Dissociation of the anti-hapten and anti-carrier responses of mice injected with dinitrophenylated lipopolysaccharide
Authors: Von Eschen K B , Rudbach J A
Published: January 2020

The quantitative and qualitative nature of the antibody responses of euthymic (normal, RML) and athymic (nude) mice injected with dinitrophenylated (DNP) lipopolysaccharide (LPS) was evaluated. Antibody responses to both the haptenic (DNP) and carrier (LPS) determinants were measured. On a quantitative basis, RML and nude mice stimulated with DNP-LPS produced only primary anti-DNP responses, whereas both primary and secondary anti-LPS responses were elicited by this conjugate. The failure of DNP-LPS to trigger secondary anti-DNP responses was not dependent on the amount of DNP-LPS given in the primary or secondary doses and could not be overcome by repeated injections of DNP-LPS. Also, the anti-DNP responses of RML mice injected repeatedly with DNP-LPS were restricted to immunoglobulin M antibodies whereas both immunoglobulin M and G anti-LPS responses were elicited. Nude mice also produced immunoglobulin G antibodies to the LPS determinants. These data showed a dissociation of the anti-hapten and anti-carrier antibody responses and suggested that different immunological signals were functioning in the respective anti-DNP and anti-LPS responses.
Role of autolysin in generating the pneumococcal purpura-producing principle
Authors: Chetty C , Kreger A
Published: January 2020

The results of four studies described in this paper support the idea that pneumococcal autolysin (N-acetylmuramyl-L-alanine amidase) plays a key role in generating the pneumococcal purpura-producing principle (PPP) from the bacterial cell wall. This conclusion is based on the observation that (i) concentrates of pneumococcal cell-free extracts prepared at a pH which is inhibitory to autolysin activity contained significantly less PPP activity than extract concentrates prepared at a pH which is optimal for autolysin activity; (ii) PPP activity was not detectable in concentrates of cell-free extracts prepared from cells which contained ethanolamine in the cell wall, but a normal amount of activity was found in extract concentrates derived from cells containing choline in the cell wall; (iii) PPP activity was not detectable in concentrates of cell-free extracts prepared from an autolysin-defective mutant, but a normal amount of activity was found in extract concentrates derived from the wild-type strains; and (iv) incubation of purified wild-type strain cell walls with pneumococcal autolysin resulted in a significant increase in the amount of purpurogenic activity in the supernatant fluids of the incubation mixtures.
Role of sulfhydryls in in vitro growth of Mycobacterium lepraemurium
Authors: Dhople A M , Hanks J H
Published: January 2020

In an attempt to evaluate various factors that influence the growth of Mycobacterium lepraemurium in NC-5 medium, the effects of sulfur and --SH compounds were investigated. Cysteine could be replaced by equimolar concentrations of other --SH compounds containing carboxyl group, and at lower concentrations by nonpolar sulfhydryl compounds. The oxidized form of sulfhydryls, as well as certain organic and inorganic reducing agents, did not support growth. The results suggest that the function of sulfhydryl compounds is to maintain low reducing potential in the medium and also to participate in metabolic or biosynthetic pathways or both. A combination of dithiothreitol and thioglycolate gave better results than when these compounds were incorporated individually in the medium. This suggests the protective action of dithiothreitol in preventing oxidation of monothiols.
Isolation and partial characterization of culture-derived soluble Babesia bovis antigens
Authors: James M A , Levy M G , Ristic M
Published: January 2020

Immunochemical analyses of soluble antigens derived from microaerophilous stationary phase cultures of Babesia bovis demonstrated that at least three parasite antigens were released in vitro. These antigens have molecular weights within the range of 37,000 to 40,000, fast electrophoretic mobility in the albumin and alpha 1 regions, and are proteinaceous in nature as determined by the sensitivity to proteolytic enzymes trypsin and papain. Purification of these antigens should allow complete characterization of their respective physiochemical and immunogenic properties.
Antibody responses of monkeys to oral and local immunization with Streptococcus mutans
Authors: Walker J
Published: January 2020

Monkeys were immunized with Streptococcus mutans by a number of routes in an attempt to elicit exclusively a secretory immunoglobulin A (IgA) response. Antibody responses were detected by a sensitive radioimmunoassay. Monkeys primed subcutaneously and boosted submucosally with formolized cells of S. mutans had high serum IgG, IgA, and IgM radioimmunoassay titers and only slight salivary IgG titers. Instillation of killed cells of S. mutans into the right parotid salivary duct elicited good IgG, IgA, and IgM responses in both the right parotid saliva and serum, but only a weak IgM response was detected in the left parotid saliva. Administration of killed cells of S. mutans in enterically coated capsules did not elicit a detectable antibody response or have a discernible effect on the antibody response to subsequent immunization by instillation. No increase in antibody titer was detected in the serum or whole saliva from monkeys orally immunized with enterically coated capsules containing viable S. mutans or in the serum, whole saliva, or intestinal contents from monkeys immunized with uncoated capsules containing killed cells of the same organism. These results do not support the concept that oral immunization with S. mutans is effective in stimulating a generalized secretory IgA response in primates.