Adenosine-induced bacteriostasis in Micrococcus sodonensis

1973 ◽  
Vol 19 (9) ◽  
pp. 1083-1092 ◽  
Author(s):  
Charles R. Shobe ◽  
J. N. Campbell
Keyword(s):  
Growth Inhibition ◽  
Growth Medium ◽  
Chromatographic Analysis ◽  
De Novo ◽  
Pyrimidine Biosynthesis ◽  
Bacteriostatic Effect ◽  
Purine Bases ◽  
De Novo Biosynthesis ◽  
Synthetic Growth Medium ◽  
Synthetic Growth

In a synthetic growth medium at a concentration of 1.0 mM, adenosine had a marked bacteriostatic effect on the growth of Micrococcus sodonensis. With the exceptions of hypoxanthine and inosine, which were slightly inhibitory, other purine bases and ribonucleosides did not inhibit the growth of the organism. When incubation of adenosine-supplemented cultures was prolonged, the organism was able to recover from the growth inhibition after a period of time which varied directly with the initial adenosine concentrations. Chromatographic analysis of the supernatants of those cultures revealed that exogenous adenosine concentrations declined steadily and the termination of the inhibited phase of growth correlated with the exhaustion of exogenous adenosine.It was observed that de novo biosynthesis of thiamine was inhibited in adenosine-supplemented cultures and that this inhibition was also relieved upon the exhaustion of exogenous adenosine. Bacteriostasis could be prevented by including either thiamine or its pyrimidine precursor (B1-pyrimidine) in adenosine-supplemented cultures and it was concluded that the observed growth inhibition reflected a depletion of the intracellular thiamine pool resulting from an adenosine-associated inhibition of B1-pyrimidine biosynthesis.

An improved synthetic growth medium for Halobacterium cutirubrum

1976 ◽  
Vol 22 (3) ◽  
pp. 440-442 ◽  
Author(s):  
V. L. Grey ◽  
P. S. Fitt
Keyword(s):  
Growth Medium ◽  
Synthetic Medium ◽  
Complex Media ◽  
Synthetic Growth Medium ◽  
Synthetic Growth

A synthetic medium is described in which Halobacterium cutirubrum grows as well as in complex media.

Fetal fuels. V. Ketone bodies inhibit pyrimidine biosynthesis in fetal rat brain

1982 ◽  
Vol 243 (3) ◽  
pp. E234-E239
Author(s):  
S. Bhasin ◽  
G. E. Shambaugh
Keyword(s):  
Rat Brain ◽  
Orotic Acid ◽  
Ketone Body ◽  
De Novo ◽  
Ketone Bodies ◽  
Pyrimidine Biosynthesis ◽  
De Novo Biosynthesis ◽  
Fetal Rat ◽  
Beta Hydroxybutyrate ◽  
Fetal Rat Brain

Ketonemic states complicating late pregnancy are accompanied by lower brain weights in the newborn. Potential mechanisms whereby ketone bodies might inhibit cell proliferation were therefore examined in the fetal rat brain slice by measuring their impact on the de novo pathway for pyrimidine biosynthesis. DL-beta-hydroxybutyrate (10.8 mM) and acetoacetate (5.4 mM) were both found to diminish the incorporation of NaH14CO3 into [14C]UMP by 30%. This effect was similar in fetal tissues from fed and 48-h starved mothers. Graded concentrations of DL-beta-hydroxybutyrate (1.4-43.2 mM) resulted in a progressive inhibition that could not be explained either by isotope dilution consequent to ketone body oxidation or by a generalized inhibition of protein synthesis. The inhibition was not reversed with 10 mM glutamine, the principal nitrogen substrate for de novo biosynthesis of pyrimidines. When the conversion of orotic acid into UMP was blocked with 6-azauridine, DL-beta-hydroxybutyrate (10.8 mM) inhibited the incorporation of NaH14CO3 into orotic acid by 28%. By contrast, maximally inhibitory concentrations of this ketone body (43.2 mM) had no effect on the incorporation of [6-14C]orotic acid into [14C]UMP. Is is concluded that ketone bodies inhibit the de novo biosynthesis of pyrimidines in fetal brain slices and that they do so at a site proximal to orotic acid formation.

scholarly journals Detection and location of the enzymes of de novo pyrimidine biosynthesis in mammalian spermatozoa

Reproduction ◽  
2002 ◽  
pp. 757-768 ◽  
Author(s):  
EA Carrey ◽  
C Dietz ◽  
DM Glubb ◽  
M Loffler ◽  
JM Lucocq ◽  
...  
Keyword(s):  
De Novo ◽  
Pyrimidine Biosynthesis ◽  
Dihydroorotate Dehydrogenase ◽  
Aspartate Transcarbamylase ◽  
Carbamyl Phosphate ◽  
Pyrimidine Nucleotides ◽  
Carbamyl Phosphate Synthetase ◽  
De Novo Biosynthesis ◽  
Ump Synthase ◽  
Mammalian Spermatozoa

Enzymes of the pathway for de novo biosynthesis of pyrimidine nucleotides have been reported in spermatozoa from fruitfly and mammals. The aim of the present study was to test the hypothesis that the enzymes for biosynthesis of uridine monophosphate (UMP) are concentrated near the mitochondria, which are segregated in the mid-piece of spermatozoa. Baby hamster kidney fibroblasts were compared with spermatozoa from rams, boars, bulls and men. Antibodies raised against synthetic peptides from sequences of the multienzyme polypeptides containing glutamine-dependent carbamyl phosphate synthetase, aspartate transcarbamylase and dihydroorotase (CAD) and UMP synthase, which catalyse reactions 1-3 and 5-6, respectively, were used, together with an affinity-purified antibody raised against dihydroorotate dehydrogenase (DHODH), the mitochondrial enzyme for step 4. Western blot analysis, immunofluorescent microscopy and immunoelectron microscopy confirmed that CAD and UMP synthase are found in the cytoplasm around and outside the mitochondria; DHODH is found exclusively inside the mitochondria. CAD was also located in the nucleus, where it has been reported in the nuclear matrix, and in the cytoplasm, apparently associated with the cytoskeleton. It is possible that CAD in the cytoplasm has a role unconnected with pyrimidine biosynthesis.

scholarly journals Antiviral Activity of Inhibitors of Pyrimidine De-Novo Biosynthesis

1996 ◽  
Vol 7 (1) ◽  
pp. 7-13 ◽  
Author(s):  
M. Wachsman ◽  
F. M. Hamzeh ◽  
N. B. Assadi ◽  
P. S. Lietman
Keyword(s):  
Antiviral Activity ◽  
Human Cytomegalovirus ◽  
Hcmv Infection ◽  
De Novo ◽  
Antiviral Effect ◽  
Pyrimidine Biosynthesis ◽  
Dihydroorotate Dehydrogenase ◽  
Dot Blot ◽  
De Novo Biosynthesis ◽  
Biosynthesis Inhibitors

Evaluation of the elevation of host cell biosynthesis of deoxynucleoside triphosphates (dNTP's) induced by human cytomegalovirus (HCMV) infection as a target for antiviral therapeutics was carried out. The concentrations of all four intracellular dNTP's rose rapidly following HCMV infection, and were markedly above baseline by 8 h post infection (p.i.). All four deoxynucleoside triphosphates remained elevated above baseline for at least 72 h p.i. The effects of inhibitors of the de-novo pathway of pyrimidine biosynthesis on HCMV viral replication-were quantified by DNA dot blot. All pyrimidine biosynthesis inhibitors examined inhibited the HCMV DNA replication at concentrations that were non-toxic to the cell. These drugs were also more effective against HCMV, which is highly dependent on host denovo synthesis, than against HSV-1 which encodes enzymes capable of increasing the supply of dNTP's. The antiviral effect of brequinar, an inhibitor of one of the enzymes of the de-novo pathway (dihydroorotate dehydrogenase), was examined to determine if it coincided with a decrease in dNTP's. HCMV-infected fibroblasts and uninfected control cells were treated with a concentration of brequinar able to inhibit HCMV DNA levels 90%. It was found that brequinar markedly lowered the levels of dTTP found in treated cells compared to untreated cells in both HCMV-infected and uninfected cells.

scholarly journals Selective synthetic growth medium “Acinetobacter phenylalanine agar” for isolation and identification of Acinetobacter calcoaceticus — Acinetobacter baumannii complex species

2020 ◽  
Vol 10 (3) ◽  
pp. 591-596
Author(s):  
E. P. Sivolodskii ◽  
G. V. Gorelova ◽  
S. P. Bogoslovskaya ◽  
E. V. Zueva
Keyword(s):  
Growth Medium ◽  
Acinetobacter Calcoaceticus ◽  
Selective Growth ◽  
Isolation And Identification ◽  
Complex Species ◽  
Synthetic Growth Medium ◽  
Acinetobacter Baumannii Complex ◽  
Acinetobacter Spp ◽  
Routine Assay ◽  
Synthetic Growth

The aim of the study was to carry out clinical and microbiological testing of selective growth medium Acinetobacter phenylalanine agar to isolate and identify bacterial species belonging to the Acinetobacter calcoaceticus — Acinetobacter baumannii complex (ACB complex). For this, 400 samples of clinical material (wound discharge, blood, urine, bronchoalveolar lavage) were examined in 2018 in the Clinical and Bacteriological Laboratory of the Military Medical Academy by using routine assays (seeding on blood agar growth medium, pure culture isolation and identification by using biochemical assays as well as VITEK 2 microbial identification system, bioMerieux) and plating together with growth medium Acinetobacter phenylalanine agar selective to Acinetobacter spp. owing to L-phenylalanine as a sole nitrogen and carbon source additional selected with trimethoprim. ACB complex Acinetobacters were identified 18–24 hours later after incubation at 37°C by emergence of typical colonies on selective medium. Control tests for cytochrome oxidase as well as oxidative/fermentation (OF)-glucose test by using peroxide-hydrogen microvolume method (for 1 h) allowed to rapidly distinguish ACB complex Acinetobacters from other bacteria as well as from Acinetobacter spp. unable to glucose oxidation. Next, species identity for all isolated Acinetobacter strains was established by using matrix-activated laser desorption/ionization with time-of-flight mass spectrometry (MALDI-TOF MS). It was found that by using novel vs. routine assay Acinetobacter spps. were isolated in 26 (18 samples — in monoculture, 8 — in association with Pseudomonas aeruginosa or Klebsiella pneumoniae subsp. pneumoniae with tiny associate colonies) vs. 20 (7 — in monoculture, 13 — in association with Pseudomonas aeruginosa, Klebsiella, Escherichia, Citrobacter, Providencia, Staphylococcus, Enterococcus, C. albicans). Using MALDI-TOF MS method revealed that 25 out of 26 Acinetobacter strains isolated on selective growth medium belonged to the ACB complex (A. baumannii — 23, A. pittii — 2), whereas one strain (A. baylyi) did not belong to ACB complex. Hence, the diagnostic specificity of the Acinetobacter phenylalanine agar synthetic growth medium for isolation and identification of the A. calcoaceticus — A. baumannii complex species comprised 96.2%, with diagnostic sensitivity exceeding that one for routine assay by 25%. Use of selective growth medium accelerates research by allowing to isolate and identify ACB complex Acinetobacter spp. 18–24 h later after plating clinical material. Selectivity of growth medium was potentially stable, as its major trophic selection factor did not depend on acquired bacterial antibiotic resistance, which is also suitable as a synthetic growth medium for standardized studies.

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