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PubMed1957

Effect of pituitary adrenocorticotropic and growth hormones on the resistance of rats infected with Pasteurella pestis.

The influence of highly purified pituitary adrenocorticotropic (ACTH) and growth (somatotropic, STH) hormones on resistance of normal, young adult rats infected with Pasteurella pestis organisms (EV 76) has been studied. The daily dosage of ACTH was 0.1 mg. (25 I.U per mg.) and that of STH was 1.0 mg. When these hormones were administered for 3 days prior to infection (1 LD(50)) and for 4 days thereafter, ACTH treatment resulted in a significant depression of resistance (p = < 0.001). The simultaneous administration of STH not only resulted in a definite counteraction of the depression (p = < 0.001), but resistance was increased to a level significantly above that of the non-hormone treated controls (p = < 0.001). Treatment with STH alone also showed a significantly higher protection when compared to the same controls (p = < 0.05). The results of experiments in which the challenge dose was 1 LD(50) suggested that greater alterations in resistance, whether it be a depression or enhancement, could be obtained by continuing hormone treatment after challenge instead of discontinuing on the day prior to challenge. When animals were treated with a relatively high daily dose (1.0 mg.) of ACTH and challenged with only (1/4) of an LD(50) of organisms, the majority of animals died within 4 to 7 days, whereas either the ACTH treatment or the bacterial dose alone resulted in no deaths. If the hormones were administered for 2 weeks prior to challenge with a high, toxic dose of organisms (4 LD(50)), and discontinued thereafter, there were significant differences in mortality in the various groups during the first 24 hours post challenge. The ACTH treated group showed a marked drop in resistance (p = < 0.001). STH, when given alone, exercised a significant protection (p = < 0.02), and in combination with ACTH, effectively counteracted the depression of resistance to acute, toxic deaths induced by the latter hormone (p = < 0.001). In this particular experiment, practically all animals died within 4 to 5 days, owing to the high challenge dose; the few survivors were in the group that had been pretreated with growth hormone. The maximal loss in body weight following an LD(50) challenge dose occurred by the 3rd day post challenge in all groups except in the ACTH-treated animals. At this time the LD(50) control group had lost an average of 14 gm. per rat, the STH group only 3 gm. per rat, whereas the group receiving both hormones lost an average of 7.5 gm. per rat. The ACTH-treated animals showed the greatest weight loss on the 4th day. Thus, under the conditions of the experiment, the beneficial effect of STH on the maintenance of body weight was demonstrated during the period of acute infection. The peak incidence of death in controls or hormone-treated animals following infection with 1 LD(50) of living organisms occurred on the 4th to 5th day post challenge; the earliest deaths occurred on the 3rd day, while the latest occurred on the 7th day. The peak incidence of death after the 4 LD(50) challenge dose occurred earlier, falling on the 2nd to 3rd day. Death was always accompanied by the characteristic gross pathology which results from infection with Pasteurella pestis organisms, particularly in the animals which succumbed after the 3rd day. Bacterial cultures usually revealed the presence of numerous Pasteurella pestis organisms in the spleen and heart blood at the time of death.

Adrenocorticotropic Hormone↗
PubMed1962

Influence of guinea pig plasma factors on phagocytosis of Pasteurella pestis. I. Plasma from normal guinea pigs.

Stanziale, W. G. (Fort Detrick, Frederick, Md.) and J. D. White. Influence of guinea pig plasma factors on phagocytosis of Pasteurella pestis. I. Plasma from normal guinea pigs. J. Bacteriol. 83:175-181. 1962.-The existence of an enhancing effect of normal guinea pig plasma on the phagocytosis of Pasteurella pestis has been reaffirmed, using a test system consisting of neutrophils from normal nonimmune guinea pigs as the phagocytes. This enhancing influence was found to be attributable to the interplay of a thermolabile and a thermostable plasma component. The data suggest a consideration of complement as the thermolabile component, since the enhancing activity of plasma is destroyed by heating to 56 C and restored by addition of fresh plasma. The possibility that the thermolabile plasma component is opsonin was discounted. Surface alterations which did occur resulted in preserving the integrity of the envelope substance of the plague bacillus. Treatment of neutrophils with plasma prior to phagocytosis did not increase their phagocytic capacity. The thermostable enhancing component was not demonstrated to be present in any of three purified serum protein fractions tested. In fact, all of these fractions inhibited phagocytosis of P. pestis. An enhancing effect of purified fibrinogen could not be demonstrated.

Animals↗
PubMed1964

SELECTIVE INHIBITION BY TRYPTOPHAN ANALOGUES OF MURINE TOXIN SYNTHESIS IN PASTEURELLA PESTIS.

Montie, Thomas C. (Albert Einstein Medical Center, Philadelphia, Pa.), and Samuel J. Ajl. Selective inhibition by tryptophan analogues of murine toxin synthesis in Pasteurella pestis. J. Bacteriol. 88:1467-1475. 1964.-Washed-cell suspensions of Pasteurella pestis, avirulent strain "Tjiwidej," exhibited a preferential inhibition of toxin synthesis relative to total protein formation, when grown in the presence of various tryptophan analogues. Growth was partially inhibited in the presence of methyl analogues. High concentrations of 5-fluorotryptophan induced slight growth-inhibitory effects. However, toxin production was more sensitive to these levels of the analogue. Growth inhibition appeared not to relate to toxin inhibition. Inhibition of toxin synthesis by analogues was reversed by l-tryptophan and indole. Shikimic acid but not anthranilic acid antagonized the action of 4-methyltryptophan on selective toxin synthesis. The formation of tryptophanless protein accounted for continued protein synthesis in tryptophan-depleted cells. Protein resolved by acrylamide gel electrophoresis from crude cell extracts exhibited two toxic protein bands. The synthesis of one toxin-protein band, the less-mobile of the two, appeared to be associated with the membrane fraction of the cell, and was selectively blocked in cells grown in the presence of tryptophan analogues. Cellular tryptophan levels may determine the quantity and quality of proteins made.

Animals↗
PubMed1964

SELECTIVE MEDIA FOR THE ISOLATION OF PASTEURELLA PESTIS.

Knisely, Ralph F. (U.S. Army Biological Laboratories, Fort Detrick, Frederick, Md.), Lois M. Swaney, and Harold Friedlander. Selective media for the isolation of Pasteurella pestis. J. Bacteriol. 88:491-496. 1964.-Several selective media are described that were successfully used to isolate virulent and avirulent strains of Pasteurella pestis from material heavily contaminated with other organisms. These media are comparatively easy to prepare, consist of readily available ingredients, and usually require no adjustment of the pH. One of the selective media described permits excellent recovery and the growth of large, easily distinguishable colonies of P. pestis in 48 hr at 26 C, and also allows the detection of fewer numbers of P. pestis organisms in soil than a previously recommended selective medium. The inhibition of other organisms frequently present in clinical specimens is described.

Culture Media↗
PubMed1962

Influence of guinea pig plasma factors on phagocytosis of Pasteurella pestis. II. Plasma from plague-infected guinea pigs.

Stanziale, W. G. (Fort Detrick, Frederick, Md.) and J. D. White. Influence of guinea pig plasma factors on phagocytosis of Pasteurella pestis. II. Plasma from plague-infected guinea pigs. J. Bacteriol. 83:182-186. 1962.-The phagocytosis enhancing property of normal guinea pig plasma was altered during experimental plague infection. The most notable changes occurred in the plasma from afebrile, moribund animals and from those convalescing from acute infection. The plasma of the moribund guinea pigs, which was obtained 7 to 8 days after exposure to Pasteurella pestis, inhibited phagocytosis to a considerable degree. Plasma from convalescent guinea pigs enhanced phagocytosis to a higher degree than the plasma of normal animals. In contrast, plasma from recovered guinea pigs in which cultural or serological evidence of infection was not demonstrated enhanced phagocytosis to a degree equivalent to that of normal plasma. Plasma taken from guinea pigs during the febrile phase of plague infection enhanced phagocytosis to a lower degree than did normal plasma.

Animals↗
PubMed1964

EFFECTS OF BICARBONATE ON GROWTH OF PASTEURELLA PESTIS. I. DIFFERENTIAL RESPONSE OF VIRULENT AND AVIRULENT CELLS.

Surgalla, M. J. (Fort Detrick, Frederick, Md.), A. W. Andrews, and C. L. Baugh. Effects of bicarbonate on growth of Pasteurella pestis. I. Differential response of virulent and avirulent cells. J. Bacteriol. 88:269-272. 1964.-Virulent Pasteurella pestis and the avirulent mutants always present in a virulent inoculum have been demonstrated to give growth responses in opposite directions upon addition of bicarbonate to broth cultures under certain conditions. The effect of supplemental bicarbonate on initiation of growth from a virulent inoculum was found to be either stimulation of both virulent and avirulent cells at low levels of added bicarbonate, depression of both virulent and avirulent cells at higher initial concentrations, or depression of avirulent mutants with simultaneous stimulation of virulent cells at a narrow range of intermediate levels.

Animals↗
PubMed1964

EFFECTS OF BICARBONATE ON GROWTH OF PASTEURELLA PESTIS. 3. REPLACEMENT OF BICARBONATE BY PYRIMIDINES.

Baugh, C. L. (Fort Detrick, Frederick, Md.), A. W. Andrews, and M. J. Surgalla. Effects of bicarbonate on growth of Pasteurella pestis. III. Replacement of bicarbonate by pyrimidines. J. Bacteriol. 88:1394-1398. 1964.-The effect of carbon dioxide on the growth of virulent Pasteurella pestis cultures at 37 C with aeration was studied by substituting known products of carbon dioxide fixation for bicarbonate in the test system. The growth of the virulent cells in the inoculum is stimulated and the culture remains virulent, if bicarbonate is replaced by orotic acid. The addition of cytosine, uracil, or citrulline also results in the retention of virulence, but the effect on the growth of the virulent cells is not as pronounced as with bicarbonate or orotic acid. It is proposed that an impaired pyrimidine synthesis due to a deficiency in carbomyl phosphate is responsible for the loss of virulence by P. pestis in aerated broth cultures at 37 C. The carbamyl phosphate deficiency may be enhanced by the loss of metabolically produced carbon dioxide at 37 C.

Arginine↗
PubMed1963

BIOLOGICAL ACTIVITIES IN EXTRACTS OF PASTEURELLA PESTIS AND THEIR RELATION TO THE "PH 6 ANTIGEN".

Bichowsky-Slomnicki, Leah (The Weizmann Institute of Science, Rehovoth, Israel) and Shlomo Ben-Efraim. Biological activities in extracts of Pasteurella pestis and their relation to the "pH 6 antigen." J. Bacteriol. 86:101-111. 1963.-Three kinds of biological activities could be found in crude extracts prepared from all the tested strains of Pasteurella pestis: cytotoxicity for monocytes, ability to agglutinate red blood cells, and induction of primary inflammatory reactions of the skin. All these biological activities were related to the presence of the "pH 6 antigen." In addition, fractions of the pH 6 antigen devoid of agglutinating activity against red blood cells, but possessing the other biological activities, could be isolated. The active biological principles appear to be protein in nature. The possible role of the described biological activities in the pathogenesis of plague is discussed.

Antigens↗
PubMed1969

Congo red-agar plating medium for detecting pigmentation in Pasteurella pestis.

Ability to detect pigmented and nonpigmented Pasteurella pestis is essential in plague research, and is currently dependent on use of the synthetic hemin-agar of Jackson and Burrows. We have devised a new differential medium for this purpose, containing Congo red dye and common, commercially available laboratory media. The ease and simplicity of preparation make the Congo red-agar a practical routine laboratory tool in plague research. These findings, possibly indicating a common binding site for hematin and Congo red, should be useful in efforts to determine the chemical nature of a bacterial component associated with high virulence in P. pestis.

Agar↗
PubMed1964

EFFECTS OF BICARBONATE ON GROWTH OF PASTEURELLA PESTIS. II. CARBON DIOXIDE FIXATION INTO OXALACETATE BY CELL-FREE EXTRACTS.

Baugh, C. L. (Fort Detrick, Frederick, Md.), J. W. Lanham, and M. J. Surgalla. Effects of bicarbonate on growth of Pasteurella pestis. II. Carbon dioxide fixation into oxalacetate by cell-free extracts. J. Bacteriol. 88:553-558. 1964.-Enzyme preparations from Pasteurella pestis will carboxylate phosphoenolpyruvate to form oxalacetate by two distinct reactions. The reactions are similar to those catalyzed by the enzymes, phosphoenolpyruvic carboxylase and phosphoenolpyruvate carboxykinase. No significant differences in enzyme characteristics or enzyme content were found when virulent cells were compared with avirulent under the conditions of our experiments. The carboxykinase of P. pestis differs from that of animal origin, because it is dependent upon adenine derivatives rather than inosine or guanosine nucleotides. The latter two nucleotides can act indirectly by way of adenosine nucleotides, because nucleoside diphosphokinase and myokinase are present in the extract.

Acetates↗