bluuebunny/crossref_metadata_2025 huggingface dataset:
Processing of streptococcal cell walls by rat macrophages and human monocytes in vitro
Authors: Smialowicz R J , Schwab J H
Published: January 2020

Phagocytosis and degradation of cell walls by peritoneal macrophages obtained from Fischer 344 or Buffalo rats was measured in tissue culture. Group A cell wall antigen, detected by immunofluorescence, persisted in cultured rat macrophages for at least 40 days, whereas group D cell wall material was eliminated by 6 to 8 days. This same pattern of persistence of group A cell walls and elimination of group D cell walls was observed in cultures of human monocytes followed for 24 days in culture. Group A streptococcal cell walls labeled with either [14C]alanine or [14C]glucose were handled in a similar manner by macrophages from either Fischer 344 or Buffalo rats. In contrast, [14C]glucose-labeled group D cell walls were degraded at a much faster rate. Buffalo macrophages were more efficient than Fischer 344 macrophages in degrading group D cell walls. The inability of macrophages to degrade group A cell walls was not due to a failure of lysosomes to fuse with phagosomes. Neither serum lysozyme in the culture medium nor cell wall-associated autolysin contributed to the degradation of group D cell walls by macrophages. Neither immune serum nor macrophages obtained from specifically immunized rats influenced phagocytosis or persistence of group A cell walls.
Cryptococcus neoformans: size range of infectious particles from aerosolized soil
Authors: Neilson J B , Fromtling R A , Bulmer G S
Published: January 2020

Although cryptococcosis is characterized as a chronic central nervous system disease, it is generally accepted that the lungs are the primary portal of entry for the etiological agent. Despite this, there is a distinct lack of evidence that viable airborne particles of Cryptococcus neoformans are small enough to reach the alveoli. Two encapsulated strains and one nonencapsulated strain of C. neoformans were inoculated into 250-g quantities of sterile soil. Throughout the 0 to 12 weeks of incubation, this soil was aerosolized in a sealed chamber with a Waring blender. Samples of the resultant dust cloud were taken with an Anderson air sampler from which the numbers and sizes of viable airborne particles were determined. Of the viable organisms aspirated into the air sampler, 15% were 0.65 to 2 micron in diameter. As incubation time in soil increased, the size of the particles decreased, and increased numbers of C. neoformans cells 0.65 to 2 micron in diameter were isolated. The presence of viable cells less than 2 micron in soil aerosols indicated that, under certain conditions in nature, C. neoformans cells exist in sizes that are capable of deep lung deposition.
Increased resistance of iron-deficient mice to salmonella infection
Authors: Puschmann M , Ganzoni A M
Published: January 2020

Nutritional iron deficiency in mice attenuated Salmonella typhimurium infection compared with both iron-substituted littermates and normal diet control animals.
Characterization of SA12 as a simian virus 40-related papovavirus of chacma baboons
Authors: Valis J D , Newell N , Reissig M , Malherbe H , Kaschula V R , Shah K V
Published: January 2020

SA12 virus, originally isolated from an uninoculated South African vervet monkey kidney culture, was identified as a new member of the simian virus 40 (SV40)-polyoma subgroup of papovaviruses. The virus produced a cytopathic effect with nuclear enlargement in primary rhesus kidney cells. The virion had papovavirus morphology and a diameter of 44 to 45 nm. The DNA of the virus was a circular, double-stranded, superhelical molecule with a mean length 101% that of SV40 DNA and an estimated molecular weight of 3.3 X 10(6). The virus was found to be unrelated to other papovaviruses by neutralization, immune electron microscopy, and immunofluorescence tests with antiviral sera. SA12 virus-infected cells exhibited a capsid antigen, which has recently been found to be common to viruses of the SV40-polyoma subgroup. The virus readily transformed kideny cells from 10-day-old hamsters. Inoculation of transformed cells produced tumors in 3- to 4-week-old hamsters. The T antigens of SA12 and SV40 viruses were strongly and reciprocally cross-reactive. A high proportion of the sera of chacma baboons, Papio ursinus, and a comparatively lower proportion of the sera of vervet monkeys, Cercopithecus pygerythrus, had neutralizing antibodies to SA12 virus
Beta-Adrenergic Blocking Activity of
Yersinia pestis
Murine Toxin
Authors: Brown S. D. , Montie T. C.
Published: January 2020

Yersinia pestis
plague murine toxin has been found to inhibit the mobilization of free fatty acids in mice in a manner similar to that of beta-adrenergic blocking agents. The blockage is detectable 75 min after injection of the toxin (1 to 2 mean lethal doses). The degree of inhibition was directly correlated with the toxicity of a given toxin preparation. Agents such as cholera toxin or glucagon, with apparently distinct receptors from beta-adrenergic receptors, stimulated adenylate cyclase and lipolysis and effectively modified toxicity. Likewise, cyclic adenosine 3′,5′-monophosphate bypassed the toxin block and antagonized toxicity. Energy-rich compounds such as fatty acids, organic acids, and glucose effectively modified the intoxication process. The biological activity of plague toxin showed profound temperature sensitivity. Mice placed at 5°C were highly susceptible to the effects of the toxin, whereas mice placed at 37°C were totally resistant to intoxication. Results showed that plague toxin cannot block epinephrine-induced mobilization of free fatty acids in mice placed at 37°C. These studies suggested that plague toxin acts at the receptor level in a manner similar to that of beta-adrenergic blocking agents. A complete, analogous activity was shown between toxin and known beta-adrenergic antagonists in their effect on beta-adrenergic agonist action in stimulating lipolysis. It is hypothesized that, since toxin shows no in vitro activity, it is in some way modified in animals.
Interaction between cyclic nucleotides and herpes simplex viruses: productive infection
Authors: Stanwick T L , Anderson R W , Nahmias A J
Published: January 2020

Infection of human fibroblasts and HEp-2 cells with herpes simplex virus type 1 (HSV-1) produced a decrease in the intracellular levels of cyclic adenosine 5'- monophosphate (cAMP) and a concomitant increase in the cyclic guanosine 5'- monophosphate (cGMP) levels. In both cell cultures, changes in cyclic nucleotide levels were first observed at 6 h after viral inoculation and were maximal at 12 h. In human fibroblasts, the addition of theophylline, dibutyryl cAMP, or papaverine (cAMP-enhancing compounds) decreased significantly the yield of HSV-1, whereas the addition of insulin or dibutyryl cGMP (cGMP-enhancing compounds) increased the viral yield. In HEp-2 cells, only theophylline decreased the yield of HSV-1, and the cGMP-enhancing compounds had no apparent effect. Cyclic nucleotide enhancing compounds exhibited their effect only if added to either cell culture within the first 3 h after inoculation with HSV-1.
Nocardia infections in congenitally athymic (nude) mice and in other inbred mouse strains
Authors: Folb P I , Timme A , Horowitz A
Published: January 2020

The mortality rate and histopathological features of Nocardia asteroides and Nocardia brasiliensis infections in congenitally athymic (nude) mice of ICR and C3H/eB origins were quite different from what we found for Swiss white mice and other inbred mouse strains (namely, C57/BL/6J, New Zealand Black, BALB/c, CBA/LAC, and C3H/eB). The immunocompetent littermates of the congenitally athymic mice occupied an intermediate position between their athymic siblings and Swiss white mice in terms of their responses to both these organisms. Macrophage ingestion and destruction of N. brasiliensis, as demonstrated by electron microscopy, was found to occur. The T-lymphocyte appears to be an essential component in normal mouse resistance to infection by both N. asteroides and N. brasiliensis.
Factors affecting germination of Trichophyton mentagrophytes arthrospores
Authors: Hashimoto T , Blumenthal H J
Published: January 2020

Nutritional and environmental factors affecting germination of Trichophyton mentagrophytes arthrospores were investigated. Germination of dormant arthrospores occurred only in rich complex media such as Sabouraud dextrose broth or vitamin-free Casamino Acids. However, once activated, arthrospores were able to germinate under wide ranges of pH (5.5 to 8.0, optimal 6.5) and temperature (20 to 39 degrees C, optimal 37 degrees C) in the presence of certain single amino acids or oligopeptides known to be present in the human cutaneous tissues. Dormant arthrospores could be activated by incubation in distilled water at 25 degrees C for 24 h or by brief exposure to sublethal doses of heat (45 degrees C for 10 to 20 min). Approximately 20% of activated arthrospores underwent spontaneous germination at 37 degrees C during an additional 18 h of incubation in distilled water. All monosaccharides, purines, pyrimidines, and nucleosides tested failed to induce germination of T. mentagrophytes arthrospores. Germination rate was affected by the concentration of germination inducers as well as that of arthrospores. The germination process of T. mentagrophytes arthrospores was found to be oxygen dependent and was relatively tolerant to NaCl, clotrimazole, cycloheximide, griseofulvin, and tolnaftate.
Isolation and characterization of a parvovirus of rabbits
Authors: Matsunaga Y , Matsuno S , Mukoyama J
Published: January 2020

The isolation and characterization of a new virus from rabbit stool are described. The virus replicated in rabbit kidney cell cultures and agglutinated human group O erythrocytes at 4 degrees C. It was stable at acid pH and resistant to chloroform and heat treatment. The growth of the virus was inhibited by 5-iodo-2-deoxyuridine, and virions were stained red with acridine orange, suggesting that they contain single-stranded deoxyribonucleic acid. The density of virions was 1.41 to 1.44 g/ml in CsCl, and the sedimentation value was 137S in sucrose at 4 degrees C. The infectious particles had cubic symmetry and were 27 to 28 nm in diameter by electron microscopy. By these properties this virus can be classified as a member of the parvovirus group. Antibody response was demonstrated in the rabbit from which this virus was recovered. A number of rabbits from a commercial source were found to contain hemagglutination-inhibiting antibody to this virus.
Complement-fixing antibody response in pneumococcal pneumonia
Authors: Coonrod J D , Rylko-Bauer B
Published: January 2020

Previous studies of complement-fixing antibodies to pneumococcal capsular polysaccharides in humans have yielded conflicting results. We studied 65 sera from 25 patients with pneumococcal pneumonia, using both fresh sera and heat-inactivated sera with added human complement. Only 4 of the 25 patients developed detectable levels of complement-fixing anticapsular antibody. Of the 25 patients, 22 developed detectable levels of hemagglutinating anticapsular antibody, indicating that they were able to develop an immunological response during the infection. Most of the antibody detected by hemagglutination was sensitive to 2-mercaptoethanol, but some 2-mercaptoethanol-resistant antibody was also detected. In studies with rabbit antiserum, the complement fixation test was found to be as sensitive as the hemagglutination test for detection of anticapsular antibody. It is not clear why detectable levels of complement-fixing antibody do not develop more often in patients with pneumococcal pneumonia. Studies of purified anticapsular antibody would be of interest to determine whether or not these antibodies are restricted to immunoglobulin subclasses having a limited capacity to fix complement.
Defective neutrophil chemotaxis in juvenile periodontitis
Authors: Clark R A , Page R C , Wilde G
Published: January 2020

Neutrophil chemotaxis was evaluated in nine patients with juvenile periodontitis, with normal subjects and patients with the adult form of periodontitis as controls. Defective chemotactic responses were observed in neutrophils from seven of nine juvenile patients, and a reduced level of complement-derived chemotactic activity was demonstrated in serum from four patients. These determinations were normal in all the patients with adult periodontitis. Serum from five of the juvenile patients contained a heat-stable, non-dialyzable factor that markedly inhibited the chemotaxis of normal neutrophils. Thus the characteristic tissue destruction seen in juvenile periodontitis may be, at least in part, a consequence of a failure of host defense mechanisms.
Purification of beta-toxin from Clostridium perfringens type C
Authors: Sakurai J , Duncan C L
Published: January 2020

Beta-toxin was purified about 340-fold from culture supernatant fluid of Clostridium perfringens type C with a yield of about 24% in terms of biologically active beta-toxin. The purification involved ammonium sulfate fractionation, gel filtration through Sephadex G-100, isoelectrofocusing in a pH 3 to 6 gradient, and immunoaffinity chromatography. The purified beta-toxin gave a single band on polyacrylamide gel electrophoresis.
Development of antitoxin with each of two complementary fragments of Clostridium botulinum type B derivative toxin
Authors: Kozaki S , Miyazaki S , Sakaguchi G
Published: January 2020

Two fragments with molecular weights of 111,000 (fragment I) and 59,000 (fragment II) were separated from each other by gel filtration of dithiothreitol and urea-treated, trypsinized derivative toxin (molecular weight, 170,000) of the proteolytic Okra strain of Clostridium botulinum type B on a column of Sephadex G-200 (superfine) with a buffer containing dithiothreitol and urea. Upon removal of dithiothreitol and urea by dialysis, the two fragments reassembled to reconstruct the derivative toxin molecule. Both fragments were immunogenic, and both anti-fragments neutralized type B toxin. The neutralizing activities of both anti-fragment I and anti-fragment II were, however, lower than that of the anti-derivative toxin, suggesting that the molecular integrity of derivative toxin is essential for sufficient production of the neutralizing antibody. The immunological difference found between type B toxin from a proteolytic strain and that from a nonproteolytic strain was ascribed to the antigenic difference of fragment I.
In vitro guinea pig leukocyte reactions to Rickettsia rickettsii
Authors: Kenyon R H , Ascher M S , Kishimoto R A , Pedersen C E
Published: January 2020

The presence of cell-mediated immunity in Rocky Mountain spotted fever-infected guinea pigs was determined by two in vitro assays: whole blood lymphocyte transformation (LT) and macrophage migration inhibition. Increased LT was detected as early as 1 week in guinea pigs infected with Rickettsia rickettsii and treated with oxytetracycline and was detected by two weeks in infected but untreated guinea pigs. Elevated LT was still detectable at 10 weeks postinfection. Guinea pigs vaccinated with killed rickettsiae failed to develop lymphocyte responsiveness; however, there was a rapid lymphocyte response after challenge with live organisms, suggesting potentiation by the vaccine. Vaccinated guinea pigs that were challenged and then treated with antibiotic failed to develop LT, suggesting that infection is necessary for the observed response. Macrophage migration inhibition was detected in both infected and vaccinated guinea pigs by 1 week after infection, but this response was no longer detected 4 to 5 weeks later. Antibody appeared at 2 to 3 weeks postinfection and was present at low levels through week 10. Antibody-treated rickettsiae were phagocytized and destroyed by guinea pig peritoneal macrophages, whereas normal serum-treated rickettsiae replicated and eventually destroyed the phagocytes.
Quantitative measurements of cholera enterotoxin in cultures of toxinogenic wild-type and nontoxinogenic mutant strains of Vibrio cholerae by using a sensitive and specific reversed passive hemagglutination assay for cholera enerotoxin
Authors: Holmes R K , Baine W B , Vasil M L
Published: January 2020

A sensitive and specific reversed passive hemagglutination (RPHA) assay for cholera enterotoxin has been developed. Equine anti-choleragenoid antibodies purified by immunoadsorption were covalently coupled to formalinized sheep erythrocytes, using bis-diazotized benzidine, and the antitoxin-sensitized erythrocytes were shown to agglutinate specifically in the presence of cholera enterotoxin. In a microtiter RPHA assay system, the smallest quantity of enterotoxin that caused hemagglutination was approximately 20 pg. A sensitive assay for antibodies to enterotoxin was also developed, based on inhibition of RPHA. Using such assays, we demonstrated that several nontoxinogenic (tox-) strains of Vibrio cholerae produced small but detectable yields of enterotoxin, 4 to 16 ng/ml, under conditions where the highly toxinogenic strain 569B Inaba produced approximately 16 microgram of enterotoxin per ml. The enterotoxin produced in small quantities by these tox- strains was found to be identical to the enterotoxin from V. cholerae 569B Inaba iv its immunological and biological activities. Strains of V. cholerae that produce intermediate yields of enterotoxin have been obtained by two techniques: (i) as less toxinogenic mutants derived from highly toxinogenic strains and (ii) as more toxinogenic mutants derived from tox- strains. Thus, the yield of enterotoxin in cultures of V. cholerae grown under standardized conditions is is a genetically controlled trait that can be altered by mutation.
Humoral and cell-mediated immune responses in humans before and after revaccination with vaccinia virus
Authors: Møller-Larsen A , Haahr S
Published: January 2020

Twenty-six healthy males vaccinated 15 to 18 years ago with vaccinia virus were revaccinated. Blood samples were collected before vaccination and 3 weeks after. The lymphocytes were tested in a blast transformation assay with vaccinia antigen and phytohemagglutinin, and interferon production was measured. The sera were subjected to neutralization and antibody-dependent cell-mediated cytotoxicity (ADCC) tests. All results were compared with clinical responses. The only test showing immunity in all donors before vaccination was the ADCC. The other tests showed a very limited residual immunity or no immunity at all. After revaccination, immunity reactions were found in all tests in most of the donors. None of the tests made before vaccination could be used to predict clinical reactions. The ADCC is recommended as a sensitive serological test.
Lipid-free glycerol teichoic acids with potent membrane-binding activity
Authors: Cooper H R , Chorpenning F W , Roses S
Published: January 2020

Lipid analysis of several glycerol teichoic acid preparations strongly indicated that covalently bound lipid is not required for spontaneous adsorption of glycerol teichoic acid to erythrocyte membranes. Although fatty acids were detected in each of four batches, none were covalently bound. Chloroform-ether-extracted antigens retained potent erythrocyte membrane-binding activity as measured by passive hemagglutination, even though they were shown to contain less than one fatty acid residue per 4,869 teichoic acid chains. Mild ammonolysis abolished erythrocyte-sensitizing activity in passive hemagglutination, but further studies indicated the loss of activity was due to partial destruction of the polyglycerophosphate backbone and not to the removal of esterified lipid. The amount of hydrolyzed antigen required to produce 100% passive hemagglutination inhibition was between 170 and 330 times the amount required to produce the same result using unhydrolyzed glycerol teichoic acid. The average chain length was reduced from 19.1 to 9.7, 7.4, and 5.1 glycerophosphate residues for antigen samples hydrolyzed for 1, 5, and 16 h, respectively.
Comparative efficacy and toxicity of a ribosomal vaccine, acetone-killed cells, lipopolysaccharide, and a live cell vaccine prepared from Salmonella typhhimurium
Authors: Angerman C R , Eisenstein T K
Published: January 2020

The protective and toxic properties of a ribosomal vaccine prepared from Salmonella typhimurium W118-2 were systematicaly compared with those of an acetone-killed whole cell vaccine, purified lipopolysaccharide, and living cells in CD-1 mice. Tests of graded immunizing doses of each vaccine against several challenge doses of live strain W118-2 showed that, although the protection given by ribosomes approached the levels of protection conferred by living organisms, acetone-killed cells administered in appropriate dosages provided levels of protection comparable to that of ribosomes. Lipopolysaccharide was found to be significantly less protective than the other vaccines. On a dry-weight basis, ribosomes were the least toxic with a 50% toxic dose (TD50) of 5,000 microgram; acetone-killed cells had an intermediate TD50 of 1,400 microgram; and lipolysaccharide was the most toxic, with a TD50 of 320 microgram. The dose of each vaccine that protected 50% of the mice against a challenge of 1,00 times the 50% lethal dose was determined and divided by the TD50 to give the therapeutic index. This ratio also indicated that the ribosomes and acetone-killed cells were equally effective, whereas lipopolysaccharide was markedly inferior.
Purification of Pseudomonas aeruginosa proteases and microscopic characterization of pseudomonal protease-induced rabbit corneal damage
Authors: Kreger A S , Gray L D
Published: January 2020

Extracellular proteases of three cornea-virulent strains of Pseudomonas aeruginosa were isolated by sequential ammonium sulfate precipitation, Ultrogel AcA 54 gel filtration, and flat-bed isoelectric focusing. The purity of the preparations was determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis , thin-layer isoelectric focusing in polyacrylamide gel, immunodiffusion and immunoelectrophoretic procedures, and tests for the presence of other known pseudomonal products. Light and electron microscopic examination of rabbit corneal lesions observed 4 to 6 h after the intracorneal injection of submicrogram amounts of the proteases revealed: (i) degeneration and necrosis of epithelium, endothelium, and keratocytes, (ii) infiltration, degeneration, and necrosis of polymorphonuclear leukocytes, (iii) loss of the characteristic weblike pattern, colloidal iron staining, and ruthenium red staining of the stromal proteoglycan ground substance, (iv) dispersal of strucutrally normal appearing collagen fibrils, ground substance, (iv) dispersal of structurally normal appearing collagen fibrils, and (v) accumulation of plasma proteins and fibrin in the necrotic corneas. These structural alterations are very similar to those observed previously during experimental P. aeruginosa keratitis, and this similarity supports the idea that pseudomonal proteases are responsible, at least in part, for the rapid and extensive liquefaction necrosis characteristic of pseudomonal-induced keratitis. In addition, the results support the idea that pseudomonal proteases elicit severe corneal damage by causing the loss of the corneal proteoglycan ground substance, thus resulting in dispersal of undamaged collagen fibrils, weakening of the corneal stroma, and subsequent descemetocele formation and corneal perforation by the anterior chamber pressure.
Mode of action of immunological adjuvants: some physicochemical factors influencing the effectivity of polyacrylic adjuvants
Authors: Kreuter J , Haenzel I
Published: January 2020

The adjuvant effects of different polyacrylic products and monomers were tested. Influenza vaccine was used as a model antigen. Addition of monomers resulted in a decrease in the antibody response, though adjuvant activity of the monomers should be expected according to some theories on adjuvant action. The particle size of the polymer adjuvants proved to be a very important parameter for adjuvant activity. Particles of 0.1 to 0.2 micron yielded a good adjuvant effect, whereas conglomerates or particles bigger than 0.5 micron yielded only poor or no adjuvant effects. The adjuvant effect of 0.1- to 0.2-micron particles was much more reproducible than rat of Al(OH)3. Attention is drawn to the importance of using physiochemically reproducible materials, such as polymer particles, for experimental work.
Detection and characterization of colonization factor of enterotoxigenic Escherichia coli isolated from adults with diarrhea
Authors: Evans D G , Evans D J , Tjoa W S , DuPont H L
Published: January 2020

The fimbriate colonization factor antigen (CEA) of Escherichia coli strain H-1047 was isolated and used to prepare anti-CFA antiserum. Enterotoxigenic E. coli (ETEC) isolated from 29 adults with diarrhea acquired in Mexico were examined for CFA by using this serum. Retrospectively, it was found that ETEC possessing the H-10407-type CFA were isolated from 25 (86%) of these diarrhea cases as compared with 2 of 11 (18%) from asymptomatic controls from whom ETEC had been isolated. CFA was found onE. coli of various serotypes, as demonstrated by bacterial agglutination by the anti-CFA serum. Heat treating the cells at 65 degress C for 1 h prevented the agglutination. CFA-positive strains did not react with anti-CFA serum when the cultures were grown at a low incubation temperature (18 degrees C). E. coli isolates identified serologically as CFA positive were shown to adhere to the intestinal villous surfaces of infant rabbits. By the indirect immunofluorescence technique, it was found that adhesion occurred preferentially in the upper 20 cm of the small intestine. Also, the ability or inability of various isolates to adhere to intestinal mucosa in vivo correlated with the presence or absence of fimbriae on the cells when grown in vitro. Agglutinability with anti-CFA serum, fimbriae, and adhesiveness were spontaneously lost by many isolates after laboratory passage in a manner previously described with E. coli H-10407. These observations suggest that the H-10407-type CFA plays a role in the virulence of ETEC possessing this antigen.
Monocyte function in human neonates
Authors: Berman J D , Johnson W D
Published: January 2020

Monocytes of healthy, full-term newborns were isolated from cord blood, and functional and biochemical activities were quantitated. The yield of monocytes per milliliter of cord blood was 60% greater than that from the peripheral blood of healthy adults. Placental monocytes were initially less well spread than cells from adults, but no other morphological differences were noted. During 4 days of in vitro cultivation, placental monocytes secreted lysozyme at a constant rate, lost peroxidase activity, and increased 5'-nucleotidase activity 15- to 25-fold. Similar findings were obtained with monocytes from adults. Placental monocytes also displayed Fc and complement receptor activity. Ingestion and intracellular multiplication of Toxoplasma gondii were identical in normal placental and adult monocytes. Furthermore, toxoplasma multiplication was significantly inhibited by cells from both sources when the monocytes were preincubated with supernatants prepared from sensitized lymphocytes and toxoplasma antigen. Monocytes from newborns were competent cells in terms of the specific functions and activities we examined.
Invasiveness of
Salmonella
Administered Orally to Cold-Exposed Mice
Authors: Previte Joseph J. , Alden J. C. , Gagliardi M. , William M. , Shampine J.
Published: January 2020

Susceptibility to enteric infection with
Salmonella
was studied in mice housed at different temperatures. The oral doses of
S. typhimurium
SR-11 and RIA, which caused 50% mortality in animals at 10 C, were about 1/30 and 1/100 of the respective values at 23 C, and that of an avirulent strain of
S. enteritidis
was also lower in the cold-exposed mice. The frequency of mortality due to
Salmonella
infection was essentially the same in mice exposed to 34 to 23 C. The divergent responses in the cold and heat probably stem from basic differences in the physiological changes mediated by the two extremes. The pattern and extent of change in weight and rectal temperature were the same among infected mice housed at 10 and 23 C and controls at 10 C, but differed from controls at 23 C. The incidence of
Salmonella
in samples of liver-spleen, lung, colon, blood, or feces was similar among infected mice housed at 10 and 23 C during a 14-day period of observation. The increased frequency of mortality in cold-exposed infected animals is not due to alterations in invasiveness of the bacteria nor to greater impairment of the thermoregulatory capacity of the mice. It may be attributable, in part at least, to a greater effectiveness of
Salmonella
toxins as metabolic poisons at low temperatures.
Lipid Composition of the Hemagglutinating Active Fraction Obtained from Chick Embryos Infected with
Chlamydia psittaci
6BC
Authors: Jenkin Howard M. , Makino Shigeru , Townsend DeWayne , Riera Maria C. , Barron Almen L.
Published: January 2020

The lipid composition of the concentrated hemagglutininating active fraction (HF) of allantoic fluid from infected eggs, but free from
Chlamydia psittaci
6BC, was compared to concentrated normal allantoic fluid (NAF). Phosphatidyl-choline (PC) and phosphatidylethanolamine were the major lipid classes of the total phospholipid fraction. Some quantitative differences were found in the amount of PC and phosphatidylserine present in HF and NAF. Lysophosphatidylcholine was present in HF but absent in NAF. Triglycerides and sterols were the major lipid classes found in neutral lipids of HF and NAF. Quantitative data showed distinct differences in the amount of different neutral lipid classes present between HF and NAF. The fatty acids of various classes of lipids were examined, and differences were noted in a number of phospholipids, sterol esters, and the free fatty acids. Branched-chain saturated fatty acids were found in many lipid classes of the HF, particularly in the phosphatidylethanolamine fraction, but were absent in the NAF.
Cell-mediated immunity assayed by 51Cr release test in mice infected with mouse adenovirus
Authors: Inada T , Uetake H
Published: January 2020

Immune spleen cells (ISC) from mice immunized with a sublethal dose of mouse adenovirus (M-Ad) were shown by the 51Cr release test to be cytotoxic to target mouse embryonic cells or lymphoid cells infected with M-Ad. The number of ISC required for release of statistically significant amounts of 51Cr from target cells varied from one sample to another, ranging from 5 to greater than or equal to 30 ISC per target cell. When 24-h-infected mouse embryonic cells were used as targets, the release of 51Cr became evident in 6 h after the addition of ISC to the cells, gradually increased with time, and then leveled off. Cytolytic activity of M-Ad ISC is specific for M-Ad, since ISC do not lyse mouse embryonic cells infected with human adenovirus type 12 and vice versa. Kinetic study of the development of cell-mediated immunity to M-Ad assayed by 51Cr release showed that cytolytic activity of ISC in infected mice became detectable 4 days postinfection, reached its peak level about 7 to 10 days postinfection, and fell to undetectable levels about 10 days thereafter. This is consistent with the data obtained by inhibition of intracellular viral antigen synthesis or by the macrophage migration inhibition test in our prevous reports.
Adherence of Group A Streptococci to Human Epithelial Cells
Authors: Bartelt Margaret A. , Duncan James L.
Published: January 2020

The adherence of group A streptococci to epithelial cells was studied by using streptococcal strains labeled with [
3
H]uridine or fluorescein isothiocyanate. The ability of the labeled organisms to adhere to Detroit 562 epithelial cells, derived from a human pharyngeal carcinoma, as well as to epithelial cells scraped from the oral cavity was determined. Adherence to monolayer cultures or cell suspensions of Detroit cells compared favorably with adherence to suspensions of human oral epithelial cells. Initial experiments to determine the optimal conditions for adherence showed that adherence was temperature dependent and that the optimal incubation time was 15 min for adherence to epithelial cells in suspension and 30 to 60 min for monolayer cultures. Both streptococci and epithelial cells exhibited specificity in the adherence process. Different streptococcal strains varied in their ability to adhere. Adherence was also affected by the growth stage of the bacterial cultures. Trypsin treatment of the streptococci slightly decreased adherence, whereas hyaluronidase treatment increased the adherence of some strains. Streptococci were found to adhere to only about half of the epithelial cells. Those epithelial cells apparently have a limited number of receptor sites since they can be saturated by adding increasing concentrations of bacteria. Further support for limited receptor sites was provided by competition experiments. Adherence was inhibited by trypsin treatment of the epithelial cells, suggesting that proteins in the epithelial cell membrane may play a role in streptococcal adherence.
Inhibition of macrophage phagocytic activity by group A streptococcal cell walls
Authors: Smialowicz R J , Schwab J H
Published: January 2020

Group A streptococcal cell walls inhibited phagocytosis of polystyrene latex particles by rat peritoneal macrophages in vitro. This inhibition was not accompanied by a measurable loss of cell viability. Group D streptococcal cell walls were relatively ineffective in altering phagocytosis. The effectiveness of group A variant streptococcal cell walls and peptidoglycan derived from group A cell walls was increased if cell wall preparations were added to macrophage cultures 12 h before, rather than simultaneously with, latex particles.
Neisseria gonorrhoeae acquire a new principal outer-membrane protein when transformed to resistance to serum bactericidal activity
Authors: Hildebrandt J F , Mayer L W , Wang S P , Buchanan T M
Published: January 2020

Resistance to the complement-dependent bactericidal activity of normal human serum is found in nearly all Neisseria gonorrhoeae strains causing disseminated gonococcal infection. Transformation of serum-sensitive gonococcal strain NRL 7189 to serum resistance using deoxyribonucleic acid from three separate disseminated-infection gonococci was accompanied by simultaneous structural and antigenic changes in the principal outer-membrane protein (POMP) of the transformants. In each of 10 separate transformations, there was a reduction in subunit molecular weight of the POMP from that in the recipient (39,000) to that in the deoxyribonucleic acid donors (36,500). Also, in each instance the POMP antigenic type, as measured by enzyme-linked immunosorbent assay, converted from that of the recipient to an antigenic type common to each DGI donor strain. This conversion of POMP antigen was reflected in part by changes in the surface fluorescence of the transformed gonococci to the microimmunofluorescence pattern of the donor strains. These results suggested that serum resistance of gonococci is related to the possession of a POMP of characteristic subunit molecular weight and antigenicity.
Experimental murine candidiasis: cell-mediated immunity after cutaneous challenge
Authors: Domer J E , Moser S A
Published: January 2020

Attempts were made to isolate an antigen(s) from Candida albicans suitable for detecting hypersensitivity in a murine model of candidiasis. Using footpad reactivity in cutaneously infected animals as the assay, comparisons were made of two commercial extracts and cell wall and cytoplasmic preparations made in the laboratory. An extract of the cell wall, a glycoprotein (GP) removed with ethylenediamine, and an extract prepared from the membrane fraction of disrupted C. albicans blastospores proved most useful in demonstrating delayed hypersensitivity in the murine model. The activity of the GP fraction was considerably reduced by oxidation with periodate and was abrogated entirely by digestion with proteolytic enzymes. The extract from the membrane fraction was obtained by incubating the insoluble membrane fraction with phosphate-buffered saline, pH 7.4, at 50 degrees C, and the proteins in the extract were subsequently precipitated with ammonium sulfate to yield a test preparation that was approximately 75% protein and 25% carbohydrate. The precipitated extract was designated ppt-HEX. Footpad reactivity to ppt-HEX could be transferred with cells and not with serum if the cells were taken from animals at the appropriate time after sensitization. Since the membrane and GP fractions appear to elicit true delayed hypersensitivity reactions, further investigations into their specificity and biochemistry seem warranted.
Immunochemical studies on a Mycoplasma pneumoniae polysaccharide fraction: cross-reactions with type 23 and 32 antipneumococcal rabbit sera
Authors: Allen P Z , Prescott B
Published: January 2020

Lipid-free polysaccharide fraction 2 extracted from Mycoplasma pneumoniae strain FH by Prescott et al. (J. Bacteriol. 91:2117-2115, 1966) was examined for its ability to cross-precipitate antibody from type-specific rabbit antipneumococcal sera types 1 to 34 inclusive. Cross-precipitation in type-specific pneumococcal anti-type 23 and anti-type 32 sera was examined in detail and could be attributed to a rhamnose-galactose-rich component of crude M. pneumoniae polysaccharide fraction 2 recovered from immunoprecipitates formed with anti-type 23 serum. Immunochemically isolated mycoplasma polysaccharide was found to contain glucose, galactose, rhamnose, and mannose in 1:14:5:4 molar proportions. Comparison of the ability of 6-O-alpha-L-rhamnosyl-D-glucose and free L-rhamnose to inhibit precepitation by homologous pneumococcal and heterologous mycoplasma polysaccharide antigens indicates a combining site specificity for anti-type 23 and anti-type 32 antibodies directed largely against the alpha-linked L-rhamnosyl determinants and the occurrence of alpha-L-rhamnosyl units in type 32 and M. pneumoniae polysaccharides. Hapten inhibition of the cross-precipitation of pneumococcal type 23 capsular polysaccharide in anti-type 32 serum helps to establish that cross-reactivity can be attributed to interaction of recurrent, alpha-L-rhamnosyl units of type 23 with anit-alpha-L-rhamnoside combining sites of anti-type 32 antibodies.
Immunogenic properties of the glucosyltransferase from Streptococcus sanguis OMZ 9: kinetic study of inhibition by antibodies
Authors: Klein J P , Schöller M , Frank R M
Published: January 2020

An anti-glucosyltransferase serum was prepared against a pure enzyme preparation from Streptococcus sanguis OMZ 9, which synthesized both soluble and insoluble dextran. Sera, crude gamma globulins, and antibody fractions obtained after gel filtration on a Bio-Gel P200 column were used to study enzyme-antibody interactions. A strong inhibition of glucosyltransferase activity was obtained only with the purified antibody fraction. Kinetics studies showed that the anti-glucosyltransferase antibodies acted as noncompetitive inhibitors with respect to the substrate (sucrose). The addition of primer dextran in the reaction mixture during preincubation produced a diminution of the inhibition, and the antibodies acted as mixed type inhibitors with respect to dextran. The simultaneous addition of dextran and antibodies can protect the enxyme against antibody inhibition.
Relationship of macrophages to cell-mediated immunity in experimental Nocardia asteroides infection
Authors: Sundararaj T , Agarwal S C
Published: January 2020

Marked in vivo intracellular killing of Nocardia asteroides occurred in the peritoneal macrophages obtained 72 h after an intraperitoneal challenge with N. asteroides, in guinea pigs either actively immunized with ribonucleic acid protein or passively immunized by immune spleen cell transfer from actively immunized donor guinea pigs. This specific killing of N. asteroides in immune macrophages persisted for at least up to 60 days. Administration of antimacrophage sera before intravenous challenge with N. asteroides in the immune guinea pigs produced an early death of the animals, and the total tissue counts of N. asteroides in the liver, spleen, lungs, and heart remained the same in them as in unimmunized controls.
Cross-Protection in Mice After Immunization with H2N2, H3N2, and Heq2Neq2 Influenza Virus Strains
Authors: Anker W. J. J. , Bakker A. K. , Masurel N.
Published: January 2020

Mice were vaccinated with the influenza viruses A/Japan/57 (H2N2), A/Hong Kong/68 (H3N2), and A/Equi/Miami/63 (Heq2Neq2) and the hemagglutinin and neuraminidase recombinants derived from these viruses. After infection with the parent viruses, protection was compared with serological findings. It was found that influenza vaccine protects not only against infection with a strain identical or closely related to the vaccine strain, but against heterologous strains as well. Vaccination with Hong Kong/68 and its neuraminidase recombinant resulted in a heterologous neuraminidase inhibition titer against Japan/57 and in a protection against infection with Japan/57. By contrast, after vaccination with Japan/57 and its neuraminidase recombinant, no relevant heterologous neuraminidase inhibition titer against Hong Kong/68 was observed, whereas a protection against infection with Hong Kong/68 did exist. A cross-protection between Hong Kong/68 and Miami/63, but no relationship in the hemagglutination or neuraminidase inhibition tests, was established in the preinfection sera. A one-way antigenic relationship between these viruses was confirmed by the rise of hemagglutinin or neuraminidase antibodies against Hong Kong/68 in the postinfection sera. No cross-protection or serological relationship existed between Miami/63 and Japan/57. Besides the hemagglutinin and neuraminidase, a third factor, the “mouse-protecting antigen,” was considered to contribute to the protection obtained. According to the protection observed, the mouse-protecting antigen of Hong Kong/68 virus is related to that of Japan/57 as well as Miami/63 virus. The mouse-protecting antigens of both Japan/57 and Miami/63 are related to that of Hong Kong/68.
Respiration and Oxidative Phosphorylation in
Treponema pallidum
Authors: Lysko Paul G. , Cox C. D.
Published: January 2020

Exogenous and endogenously generated reduced pyridine nucleotides caused marked stimulation of O
2
uptake when added to treponemal cell-free extracts, which indicated that terminal electron transport was coupled to the consumption of O
2
. Oxidation of reduced nicotinamide adenine dinucleotide (NADH) was shown to correlate stoichiometrically with O
2
reduction, suggesting that NADH was being oxidized through a mainstream respiratory chain dehydrogenase. Oxygen evolution in treponemal extracts was observed after the completion of O
2
uptake which was stimulated by exogenous NADH and endogenously generated reduced NAD phosphate. Oxygen evolution was inhibited by both cyanide and pyruvate, which was consistent with O
2
release from H
2
O
2
by catalase. The addition of exogenous H
2
O
2
to treponemal extracts caused rapid O
2
evolution characteristic of a catalase reaction. A spectrophotometric assay was used to measure ATP formation in
T. pallidum
cell-free extracts that were stimulated with NADH. P/O ratios from 0.5 to 1.1 were calculated from the amounts of ATP formed versus NADH oxidized. Phosphorylating activity was dependent on P
i
concentration and was sensitive to cyanide,
N, N
′-dicyclohexylcarbodiimide, and carbonyl cyanide
m
-chlorophenyl hydrazone. Adenine nucleotide pools of
T. pallidum
were measured by the firefly luciferin-luciferase assay. Shifts in adenine nucleotide levels upon the addition of NADH to cell-free extracts were impossible to evaluate due to the presence of NAD
+
nucleosidase. However, when whole cells, previously incubated under an atmosphere of 95% N
2
-5% CO
2
, were sparged with air, ATP and ADP levels increased, while AMP levels decreased. The shift was attributed to both oxidative phosphorylation and to the presence of an adenylate kinase activity.
T. pallidum
was also found to possess an Mg
2+
- and Ca
2+
-stimulated ATPase activity which was sensitive to
N, N
′ -dicyclohexylcarbodiimide. These data indicated a capability for oxidative phosphorylation by
T. pallidum.
Influence of iron on Corynebacterium renale-induced pyelonephritis in a rat experimental model
Authors: Henderson L C , Kadis S , Chapman W L
Published: January 2020

Growth of Corynebacterium renale in vitro on low-iron medium (1.34 micron) was only slightly less than that on high-iron media (7.16 and 9.85 micron). However, studies on C. renale-induced pyelonephritis using the rat as an experimental model revealed that C. renale cultivated in high-iron media was capable of producing pyelonephritis, but when grown on low-iron medium, these bacteria were noninfective. This apparent avirulence of the bacteria cultivated on low levels of iron could be reversed by injecting the rats intramuscularly with ferric ammonium citrate.
Vascular permeability changes in the central nervous system of rats with hyperacute experimental allergic encephalomyelitis induced with the aid of a substance from Bordetella pertussis
Authors: Bergman R K , Munoz J J , Portis J L
Published: January 2020

Development of hyperacute experimental allergic encephalomyelitis in Lewis rats after intraperitoneal administration of a mixture of guinea pig spinal cord emulsion and pertussigen from Bordetella pertussis was accompanied by an increase in vascular permeability in the central nervous system. The increased permeability was most striking in the spinal cord and seemed to be associated with the ascending development of paralysis. Rats that had completely recovered from paralysis did not have any increased permeability in the central nervous system. Rats which developed paralysis after inoculation with either guinea pig spinal cord emulsion alone or with complete Freund adjuvant had only a small degree, if any, of increased permeability in the vascular system of the central nervous system.
New Surface-Associated Heat-Labile Colonization Factor Antigen (CFA/II) Produced by Enterotoxigenic
Escherichia coli
of Serogroups O6 and O8
Authors: Evans Dolores G. , Evans Doyle J.
Published: January 2020

Enterotoxigenic
Escherichia coli
(ETEC) belonging to serogroups O6 and O8 do not possess the H-10407-type colonization factor antigen (CFA/I). However, these frequently isolated ETEC were found to possess a second and distinct heat-labile surface-associated colonization factor antigen, termed CFA/II. Whereas CFA/I mediates mannose-resistant hemagglutination of human group A erythrocytes, CFA/II does not. CFA/II mediates mannose-resistant hemagglutination of bovine erythrocytes, and mannose-resistant hemagglutination is rapid only at reduced temperature (4°C). Because CFA/II, like CFA/I, is spontaneously lost by many ETEC isolates in the laboratory, it was possible to produce specific anti-CFA/II serum by preparing antiserum against living cells of a prototype strain (PB-176) and adsorbing this serum with living and heat-treated cells of its CFA/II-negative derivative strain PB-176-P. This serum, which neutralized the colonization factor activity of CFA/II-positive strains in infant rabbits, was employed to confirm the presence of CFA/II on ETEC which exhibited mannose-resistant hemagglutination of bovine but not human erythrocytes. CFA/II, like CFA/I, mediates adherence of the bacteria to the mucosal surface of the small intestine, as demonstrated by indirect immunofluorescence. CFA/II appears to be an important virulence factor for humans since CFA/II-positive ETEC are frequently isolated from diarrhea cases, particularly travelers' diarrhea, in Mexico; these ETEC were not uncommon in a collection of isolates from Bangladesh. The O6:H16 strain of ETEC responsible for an outbreak of diarrhea in the United States was also shown to be CFA/II positive. CFA/I and CFA/II were never found on the same serotypes of ETEC, but 98% of the heat-stable and heat-labile enterotoxin-producing ETEC belonging to the frequently isolated serogroups O6, O8, O15, O25, O63, and O78 were positive for either CFA/I or CFA/II.