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PubMed1969

Nature of lactose-fermenting Salmonella strains obtained from clinical sources.

Six of seven lactose-fermenting (lac(+)) Salmonella strains obtained from clinical sources were found to be capable of transferring the lac(+) property by conjugation to Salmonella typhosa WR4204. All of the six S. typhosa strains which received the lac(+) property transferred it in turn to S. typhimurium WR5000 at the high frequencies typical of extrachromosomal F-merogenotes. These six lac elements were also transmissible from S. typhosa WR4204 to Proteus mirabilis and to some strains of Escherichia coli K-12; moreover, they were capable of promoting low frequency transfer of chromosomal genes from S. typhimurium WR5000 to S. typhosa WR4204. One of these lac elements was shown also to be capable of promoting low frequency chromosome transfer in E. coli K-12. E. coli K-12 strains harboring these lac elements exhibited sensitivity to the male specific phage R-17. Sensitivity to R-17 was not detected in Salmonella strains containing the elements. Examination of the lac elements in P. mirabilis by cesium chloride density gradient centrifugation showed that each element had a guanine plus cytosine content of 50%. The sizes of the elements varied from 0.8 to 3% of the total Proteus deoxyribonucleic acid. The amount of beta-galactosidase produced by induced and uninduced cultures of S. typhimurium WR5000 and S. typhosa WR4204 containing the lac elements was lower than that produced by these strains with the F-lac episome. The heat sensitivity of beta-galactosidase produced by the lac elements in their original Salmonella hosts indicated that the enzyme made by these strains differs from E. coli beta-galactosidase.

Bacteriophages↗
PubMed1978

Dry-heat destruction of lipopolysaccharide: dry-heat destruction kinetics.

Dry-heat destruction kinetics of lipopolysaccharides from Escherichia coli, Serratia marcescens, and Salmonella typhosa at 170 to 250 degrees C are described. The destruction rate seems to follow the second order and can be linearized by the equation, log y = a + b . -10cx. Because c is the slope, 1/c = D3. Both a and b are constant at a given temperature and are linear functions of temperature. The D(3)170, D(3)190, D(3)210, D(3)230, and D(3)250 values for E. coli lipopolysaccharide are 251, 99.4, 33.3, 12.3, and 4.99 min, respectively, with a z value of 46.4 min. The D values for lipopolysaccharides from S. marcescens and S. typhosa are not significantly different from those from E. coli lipopolysaccharide.

Escherichia coli↗
PubMed1969

Combined effects of diphenyliodonium chloride, pine oils, and mustard oil soaps on certain microorganisms.

Bactericidal and bacteriostatic activities of an emulsion containing 10.0% (v/v) terpineol, 0.5% (w/v) diphenyliodonium chloride, 11.0% (v/v) ethyl alcohol, and 5.62% saponified mustard oil were tested against a number of different types of organisms. The bactericidal concentration for Salmonella typhosa was 1:400. In the presence of 5.0% horse serum, it increased to 1:250. The bacteriostatic concentration varied from organism to organism; Escherichia coli and Staphylococcus aureus required 4,000 mug/ml for complete bacteriostasis, whereas Corynebacterium diphtheriae, Salmonella paratyphi-A, and Shigella required only 2,000 mug/ml for complete inhibition. A 4.0% concentration of the emulsion killed the spores of Bacillus subtilis within 6 hr.

Bacteriological Techniques↗
PubMed1979

Further studies on mobilization of CFUs.

Mobilization of CFUs from haemopoietic tissues into circulation was studied after injection of different bacterial lipopolysaccharides (LPS), zymosan, phytohaemagglutinin (PHA), concanavalin A (Con A), trypsin and di-isopropyl-fluorophosphate-inhibited trypsin. All bacterial LPS used gave an increase of CFUs in the peripheral blood at 1 h after i.v. injection. Some variation in activity could not be excluded. As with Salmonella typhosa LPS, zymosan gave an increase in circulating CFUs during the first few hr and a second peak a few days later. After injection of zymosan as well as S. typhosa LPS the second peak in the blood was accompanied by a large increase in CFUs numbers in the spleen. PHA gave an immediate mobilization of CFUs, but the mobilization after injection of Con A during the first few hr occurred more slowly. After injection of S. typhosa LPS, zymosan and PHA the blood C3 level was found to be depressed considerably. This might indicate that the complement system is involved in the early mobilization of CFUs. Dexamethasone, a synthetic hormone which has been reported to give sequestration of several cell types in the bone marrow, did not inhibit the early and late mobilization of CFUs which normally occurs after injection of S. typhosa LPS.

Animals↗
PubMed1979

Identification of gallbladder typhoid carriers by a string device.

The efficiency of a gelatin capsule containing a nylon string for collection of duodenal specimens was investigated in carriers of Salmonella typhosa (typhi). Cultures of duodenal specimens obtained by means of the string capsule were compared with cultures of duodenal specimens obtained by a conventional duodenal tube and with stool cultures Duodenal contents obtained with either the string or tube were more often positive for S. typhosa than were stool cultures. The string, which is as efficient as tube collection but simpler and more comfortable, may be useful in identifying carriers of S. typhosa.

Adult↗
PubMed1969

Immunological response of the rabbit to Vi antigen.

Vi antibody response of rabbits varied depending on whether Vi antigen was administered in particulate or soluble state. Vi antigen in particulate form induced hemagglutinins, bacterial agglutinins, and passive cutaneous anaphylaxis (PCA) antibodies, whereas soluble Vi antigen induced only hemagglutinins. Guinea pigs passively sensitized with antisera against particulate Vi antigen gave PCA reactions when challenged with either soluble or cellular Vi antigen; antisera against soluble Vi antigen were negative for PCA. The specificity of PCA was demonstrated by its dependence on the Vi concentration and by absorption of PCA activity from antisera with V-form cells of Salmonella typhosa.

Agglutination Tests↗
PubMed1975

Antimicrobial properties of mannopeptins.

Mannopeptins show in vitro antimicrobial activity against gram-positive and some gram-negative bacteria. The antimicrobial activity is unaffected by the addition of serum, and potentiated by alkaline pH or decrease in inoculum size. The antibiotics exert bectericidal effect at doses twice as high as the minimum inhibitory concentration. When the antibiotics were injected into mice through either intravenous, intraperitoneal, intramuscular or subcutaneous routes, the antimicrobial activity appeared within 15 minutes in the serum of mice and was slowly excreted in the urine. However, the antibiotics were poorly absorbed by the oral route. The antibiotics were capable of protecting mice from lethal infection produced by the intravenous injection of Staphylococcus aureus, Streptococcus pyogenes and the intraperitoneal injection of Shigella sp. and Escherichia coli, but ineffective against Salmonella typhosa.

Administration, Oral↗
PubMed1966

Interaction of Vi antigen with proteins.

Whiteside, Roberta E. (Boston University School of Medicine, Boston, Mass.), and Edgar E. Baker. Interaction of Vi antigen with proteins. J. Bacteriol. 92:1597-1603. 1966.-Purified Vi antigen (Vi) mixed in equal amounts with bovine serum albumin (BSA) or human gamma globulin (HGG) at pH values above 4.7 formed a complex which was not precipitated by trichloroacetic acid or tungstic acid. At pH values below 4.7, the interaction between Vi and either BSA or HGG produced insoluble complexes except when excess Vi antigen was present. When sufficient Vi was present at the lower pH values, the soluble complex was not precipitated by trichloroacetic acid. Other acid polysaccharides tested did not form trichloroacetic acid-soluble complexes with BSA. When subjected to immunoelectrophoresis, the Vi-BSA complex migrated in agar at a rate different from that of either BSA or Vi alone. The complex reacted with both Vi and BSA antiserum. The addition of either BSA or Vi antiserum to a Vi-BSA complex resulted in dissociation of the complex and precipitation of either Vi or BSA, depending upon the antiserum used. Vi antigen mixed with purified O antigen from Salmonella typhosa formed a complex which migrated in agar at a rate different from that of either component alone when subjected to immunoelectrophoresis.

Antigens↗
PubMed1969

The role of endotoxin during typhoid fever and tularemia in man. IV. The integrity of the endotoxin tolerance mechanisms during infection.

Volunteers infected with Salmonella typhosa develop a remarkable hyperreactivity to the pyrogenic and subjective toxic activities of homologous (S. typhos) and heterologous (Pseudomonas) endotoxins. The present studies quantitate this augmented reactivity and demonstrate by three differing approaches that significant tolerance to these endotoxins can be readily induced within the framework of the hyperreactive state. Thus, (a) tolerance induced before illness by repeated daily intravenous injections of the endotoxins remained demonstrable during overt illness, (b) daily intravenous injections of the endotoxins begun during overt illness evoked progressively increasing tolerance, and (c) continuous intravenous infusions of S. typhosa endotoxin during illness rapidly induced a pyrogenic refractory state. Despite unequivocal activation of the endotoxin tolerance mechanisms by any of the above methods, the febrile and toxic course of typhoid fever proceeded unabated. Similarly, in other volunteers with Pasteurella tularensis infection, continuous intravenous infusions of S. typhosa endotoxin evoked initial hyperreactive febrile and subjective toxic responses followed by rapid appearance of a pyrogenic refractory state without modification of the underlying clinical illness. These observations suggest that circulating endotoxin plays no major role in pathogenesis of the sustained fever and toxemia during typhoid fever and tularemia in man. The mechanisms responsible for the systemic hyperreactivity to endotoxin during typhoid fever and tularemia were further investigated. Low grade endotoxemia, nonspecific effects of tissue injury, impaired ability of the reticuloendothelial system to clear circulating endotoxin, and production of cytophilic antibodies capable of sensitizing leukocytes to endotoxin did not appear responsible. Inflammatory reactions to intradermal S. typhosa endotoxin increased significantly during typhoid fever. However, since no such dermal hyperreactivity developed to Pseudomonas endotoxin during typhoid fever nor to S. typhosa endotoxin during tularemia, the systemic hyperreactivity to bacterial endotoxins during typhoid fever and tularemia could not presently be ascribed to enhanced levels of acquired hypersensitivity.

Adult↗
PubMed1968

Pyrogenic responses to staphylococcal enterotoxins A and B in cats.

Pyrogenic responses, ranging up to 4.8 F, were induced in cats by oral administration of highly purified staphylococcal enterotoxin B in doses from 10 to 100 mug/kg. Fever was a more sensitive indicator of intoxication than was emesis. Highly purified preparations of enterotoxin A, whether administered intravenously (0.01 to 1.0 mug/kg), orally (10 to 25 mug/kg), or into the cerebral ventricles (0.005 to 0.020 mug in 0.20 ml), were also pyrogenic in cats. Tolerance to the pyrogenic activity was produced by repeated intravenous injection of a given dose of enterotoxin A but not by repeated intracerebroventricular injection. Enterotoxin A was more potent than enterotoxin B after intravenous injection in causing both fever and emesis. Cross-tolerance could not be demonstrated between enterotoxin A and enterotoxin B or Salmonella typhosa endotoxin. This lack of cross-tolerance plus the inability of large oral doses (100 to 4,700 mug/kg) of endotoxin to cause fever or emesis indicate that the reported responses were attributable to the specific toxins administered and not to contamination by other pyrogens.

Animals↗
PubMed1978

Effect of bacterial lipopolysaccharide on proliferation of CFU-S.

Multiple injections of S. typhosa LPS increased the number of CFU-S in the spleen 20-50 fold and decreased the number in the femur to one half or less. LPS injections did not affect the growth rates of CFU-S in the spleen or femur of lethally irradiated mice. The plateau levels which were attained in these mice after proliferation, corresponded with the levels in LPS-treated non-irradiated mice. Local irradiation of the spleen with 3000 rad hardly affected the capacity of the spleen to accommodate the increased CFU-S numbers after LPS injection. These results suggest that irradiation resistant microenvironmental factors in the spleen determine the CFU-S accumulation in this organ after injection of Salmonella typhosa LPS. The increased number of CFU-S in the blood after LPS injection was maintained in splenectomized mice as well as in mice which received a local splenic x-irradiation with 3000 rad, indicating that this rise of blood CFU-S numbers is independent of the spleen.

Animals↗
PubMed1962

A contribution to the laboratory assay of typhoid vaccines.

In the laboratory assay of typhoid vaccines many questions still remain open. The results of experiments are at times ambiguous, and there is no satisfactory agreement between them and the results of the various field trials. The authors of the present paper have attempted to clear up some of the causes of discrepancy. They have concluded that in evaluating the efficacy of various types of vaccine much depends on the vaccine and challenge doses used. By employing low or high doses of vaccine, it is possible to obtain different results in respect of the qualities of the vaccines compared. The time interval between vaccination and challenge also has a certain influence.Experimentally infected mice were examined for the presence of Salmonella typhosa in the peritoneum and in the blood. The authors' experiments show that bacteraemia, observable 30 minutes after intraperitoneal challenge, represents an important indicator of vaccine efficacy. This approach enabled them to obtain clearer and more detailed information regarding the protective power of the vaccine employed than would have been revealed by the more death or survival of the test animals.

Animals↗
PubMed1988

Endotoxin stimulates prostaglandin E2 production by human amnion.

The studies presented in this report were designed to evaluate whether bacterial endotoxin alters the rate of biosynthesis of prostaglandin E2 (PGE2) by human amnion. Amnion cells were established in primary monolayer culture from women undergoing elective cesarean sections. Endotoxin from Escherichia coli and Salmonella typhosa were incubated with amnion cells for 16 hours, and radioimmunoassay was used to measure PGE2 released into the media. Bacterial endotoxin demonstrated a concentration-dependent stimulatory effect on the rate of PGE2 synthesis by amnion cells. These observations suggest a mechanism for the onset of labor associated with intra-amniotic infection.

Amnion↗
PubMed1977

Sera and the in vitro induction of immune responses. III. Adjuvant obtained from gliding bacteria with properties distinct from enteric bacterial lipopolysaccharide.

We have extended our studies on the role of bacterial contamination in the generation of fetal calf sera which support primary in vitro humoral responses by cultured mouse spleen cells. Gram-negative, gliding bacteria were isolated from a strongly supportive sample of fetal calf sera. Medium conditioned by the growth of these microorganisms had strong adjuvant effects in cultures of mouse spleen cells supplemented with a non supportive, deficient sera. The adjuvant and mitogenic activities of the bacterial conditioned medium were then compared to those of bacterial lipopolysaccharide from Salmonella typhosa 0901 in cultures of LPS responder and LPS nonresponder spleen cells. From the results of these comparative studies, we conclude that the active factor(s) obtained from the gliding bacteria is an adjuvant with properties very distinct from those of highly purified enteric bacterial LPS.

Adjuvants, Immunologic↗