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PubMed1986

In vitro activity of antimicrobial agents against Acinetobacter calcoaceticus.

The aim of this study was to evaluate the in vitro activity of several new microbial agents against 96 Acinetobacter calcoaceticus isolates. Among several new beta-lactams, imipenem, a new, broad-spectrum, highly potent penem, was the most active drug in vitro against these strains, with a geometric mean MIC of about 0.3 mg/l. Ceftazidime and ceftizoxime also demonstrated good in vitro activity with geometric mean MICs of 6 mg/l and 7 mg/l respectively. Among new quinolones, ciprofloxacin, ofloxacin and pefloxacin were substantially active in vitro: geometric means were 0.8, 0.9 and 1.5 mg/l respectively. A progressive increase in resistance to aminoglycosides has been observed and 80 to 90% of isolates were resistant to all but amikacin, tobramycin and habekacin, which showed geometric mean MICs of 7.0, 6.0 and 1.2 mg/l.

Acinetobacter↗
PubMed1986

[Cell envelope-bound proteinase activities of Acinetobacter calcoaceticus].

Acinetobacter calcoaceticus contains proteolytic activity after growth on various culture media. The enzyme activity could be found in the cytosolic fraction as well as in the cell envelopes (also containing the intracytoplasmic membranes). The highest proteolytic activity could be detected during the transition from the logarithmic growth phase to the stationary phase and in the early stationary phase, respectively. In the culture medium proteolytic activity was only evident in the later stationary phase. This activity was very instable and was liberated apparently by autolysis of the cells. The concentration of the nitrogen source (NH4+) in the medium (i.g. with acetate as carbon source) influences the proteinase activities of the cells. When nitrogen is limited, the proteolytic activity increases strongly in the stationary phase. The pH-profile of the azocaseinolytic activities of the cytosol was nearly the same as that of the cell envelopes (pH-optima are between 7 and 9). A partial inhibition of the proteolytic activities in the cytosol as well as in the cell envelopes could be attained by serine proteinase inhibitors. Inhibitors of thiol- and metalloproteinases showed no effects.

Acetates↗
PubMedDate not supplied

[Acinetobacter calcoaceticus strain with a wide spectrum of utilizing aromatic compounds and carrying a plasmid for resorcin degradation].

A bacterial strain was isolated from soil and identified as Acinetobacter calcoaceticus var. lwoffii. The strain can utilize a wide spectrum of aromatic compounds. It carries a transmissive plasmid pBSW13 which determines resorcin utilization via the ortho pathway including the following steps: resorcin-hydroxyhydroquinone-maleylacetate-beta-ketoadipi c acid. The plasmid has been transferred by conjugation into the recipient strains of A. calcoaceticus 5734 CCM rifr, Escherichia coli J-53 met-pro-rifr and Klebsiella sp. Plasmid DNA with a molecular mass close to that of phage gamma was detected by electrophoresis in the donor and recombinant strains. The degradation of other substrates is not a phenotypic expression of the genes of this plasmid.

Acinetobacter↗
PubMed1986

[Bacteria of the genus Acinetobacter. Methods for their isolation and primary identification].

A liquid accumulation medium and a solid isolation medium for primary identification of bacteria of the genus Acinetobacter have been proposed. Both media have identical composition and contain ethanol as the only source of carbon and energy and sodium ammonium phosphate as the source of nitrogen. Besides, the modification of Baumann's medium with sodium acetate as the source of carbon and potassium nitrate as the source of nitrogen has been developed. This modified medium has simplified composition and is not inferior to the above-mentioned media in selectivity, though its use gives less satisfactory results. The two proposed media, both liquid and solid, are recommended for wide use.

Acinetobacter↗
PubMed1987

[Kinetics of membrane-bound aldehyde dehydrogenase from Acinetobacter calcoaceticus].

In recent investigations we were able to demonstrate that the NADP-dependent aldehyde dehydrogenase of Acinetobacter calcoaceticus is an inducible enzyme localized in intracytoplasmic membranes limiting alkane inclusions. Long-chain aliphatic hydrocarbons and alkanols are inducers of the enzyme. It was purified by us and now kinetically characterized using the enzyme-micelle form, which contains bacterial phospholipids and a detergent (sodium cholate), too. The pH optimum of aldehyde dehydrogenase was determined to be at pH 10. The enzyme showed substrate inhibition (by aldehyde excess). The Ks and Km values of the leading substrate NADP+ were found to be 8.6 X 10(-5) and 10.3 X 10(-5)M independent of the chain-length of the aldehydes. The Km values of the aldehydes decreased depending on increasing chain-length (butanal: 1.6 X 10(-3), decanal: 1.5 X 10(-6)M). The Ki values (for inhibition by aldehyde excess) showed a similar behaviour (butanal: 7.5 X 10(-3), decanal: 3.5 X 10(-5)M) as well as the optimal aldehyde concentrations inducing the "maximal" reaction velocity (butanal: 5mM, decanal: 6 microM). The number of inhibiting aldehyde molecules per enzyme-substrate complex was determined to be n = 1. NADPH showed product inhibition kinetics (Ki(NADPH) = 2.2 X 10(-4)M), fatty acids did not. We were unable to measure a reverse reaction. The following ions and organic compounds were non-competitive inhibitors of the enzyme: Sn2+, Fe2+, Cu2+, BO3(3-), CN-, EDTA, o-phenanthroline, p-chloromercuri-benzoate, mercaptoethanol, phenylmethylsulfonyl fluoride, and diisopropylfluorophosphate; iodoacetate did not influence enzyme activity. Chloral hydrate was a competitive inhibitor of the aldehydes. Ethyl butyrate activates the enzyme, dependent on the chain-length of the aldehyde substrates.

Acinetobacter↗
PubMed1986

[Temperature dependence of membrane-bound aldehyde dehydrogenase from Acinetobacter: effect of solubilization and chain length of the substrates].

The NADP+-dependent aldehyde dehydrogenase of intracytoplasmic membranes of Acinetobacter calcoaceticus shows a characteristic behaviour of its reaction velocities in dependence on temperature. The calculated "real" activation energies depend on the increasing chain-length of the homologous aldehydes and grow appropriate to the membrane-bound and to the micellar form of the enzyme with 6.2 and 7.3 kJ/mole CH2-group, respectively. The values of the activation energy of the membrane-bound enzyme are - for each aldehyde of the homologous series - 12 kJ/mole larger than those of the solubilized enzyme (present as mixed micelles of enzyme, cholate and bacterial phospholipids).

Acinetobacter↗
PubMedDate not supplied

[Utilization of 3-chlorobenzoic acid by Acinetobacter calcoaceticus].

A strain of Acinetobacter calcoaceticus assimilating 3-chlorobenzoic acid (3-CBA) as a sole source of carbon and energy was isolated from soil near Moscow. When 3-CBA is utilized, 2-chloro-cis, cis-muconic acid is accumulated in the medium. The liberation of chlorine atoms is 50--60% of the theoretically possible value. The oxidation of 3-CBA yields 3-chloropyrocatechol (3-CPC) and 4-chloropyrocatechol (4-CPC). 4-CPC serves as a source of nutrition for A. calcoaceticus. The oxidation of 3-CPC yields 2-chloro-cis, cis-muconic acid which is accumulated in the cultural broth without further utilization. The enzyme system of 3-CBA is inducible.

Acinetobacter↗
PubMed1985

Tissue nitrogen-sparing effect of high protein diet in mice with or without ascites tumor treated with Acinetobacter glutaminase-asparaginase.

Forty-eight tumor-free mice and 32 mice bearing Ehrlich ascites tumor were randomized into 2 treatments, Acinetobacter glutaminase-asparaginase (AGA) (600 IU/kg/day for 7 days) and 0.9% NaCl controls, and into 2 or 3 isocaloric diets, normal protein (NP) (20 g protein/100 g diet), high protein (HP) (58 g protein/100 g diet), and zero protein (ZP) (tumor-free mice only). In tumor-free, NP-fed mice, AGA caused percentage reductions (P less than 0.01) in the nitrogen content of liver (50%), intestine (42%), thymus (89%), spleen (75%), and carcass (20%), but HP prevented this effect on intestine and carcass and caused percentage increases in the nitrogen content of liver (53%), intestine (36%), thymus (122%), and carcass (25%). In Ehrlich ascites tumor mice (NP or HP fed) AGA caused markedly lower (P less than 0.01) tumor burdens and increased nitrogen content of intestine (HP), kidney (NP and HP), and spleen (NP and HP). Ehrlich ascites tumor, AGA-treated, HP-fed mice ate 31% less food (P less than 0.01) (compared to NP) but HP resulted in percentage increases in the nitrogen content of liver (18%; P = 0.05), intestine (25%; P less than 0.05), and thymus (164%; P less than 0.01). In the Ehrlich ascites tumor, AGA group the HP diet caused higher hematocrit and serum total protein (both, P less than 0.05). Adverse nutritional effects of AGA seen in normal mice were markedly diminished in tumor-bearing animals. The observed nitrogen-sparing effects of the high protein: energy ratio may be relevant to humans and to other forms of neoplasia and chemotherapy.

Acinetobacter↗
PubMed1979

[Purification and physico-chemical properties of collagenase synthesized by a bacterium of the type Acinetobacter sp].

The Acinetobacter spec collagenase has been almost completely purified. This enzyme is a true collagenase the activity of which is high on collagen. The enzyme is active on insoluble collagen, gelatin and the synthetic Pz-peptide, but has no proteolytic activity on casein or bovine serum-albumin. The collagenase was obtained on a simple medium with gelatin and yeast extract. The enzyme was purified by (NH4)2SO4 precipitation. DEAE cellulose column chromatography, Sephadex G 200 gel-filtration. The molecular weight of the enzyme was found to be 102 000 daltons, and its isoelectric point was found to be 7,7 +/- 0,2. The optimum pH and temperature for insoluble collagen hydrolysis were 7.6 and 37 degrees C, respectively; so, this collagenase corresponds to true collagenase. Hydrolysis of Pz-peptide is activated by Ca2+ and inhibited by metal ions (Cu2+, Fe3+, Zn2+, Pb2+, Hg2+). EDTA and o-phenanthroline induced a very significant reduction in enzyme activity. Iodoacetate and p-CMB induced a slight reduction in enzyme activity only at high concentrations (10-2M). The collagenase is most stable for temperatures less than or equal to 50 degrees C.

Acinetobacter↗
PubMed1979

[A case of meningitis due to Acinetobacter calcoaceticus].

Meningitis due to Acinetobacter calcoaceticus is rare. These rare bacteria were isolated from culture fluid in patient resembling to Neisseria meningitis with clinical and laboratory findings. The patient was treated with sensitive antibiotic.

Acinetobacter Infections↗
PubMed1977

[Uptake of acetate by Acinetobacter calcoaceticus].

The uptake of acetate by intact nongrowing cells of Acinetobacter calcoaceticus was studied in dependence on the C-source (acetate, n-alcanes, yeast extract, succinate, L-malate) and the growth phase. Single kinetic parameters of acetate uptake were determined. The best acetate uptake was observed with cells cultivated with acetate as the only C-source. Bacteria in the early growth phase were found to transfer acetate twice as fast as cells of the late logarithmic growth phase. The uptake of acetate can be described by a biphasic saturation kinetics with 2 Km values: the Km value for the first phase being 1.10(-5) M, and for the second one, 1.8 .10(-4) M. The corresponding maximal uptake rates are 8 and 37 mM/min/mg dry weight, respectively. Alpha-ketoglutarate, fumarate, L-malate, and oxalacetate inhibit the initial uptake of acetate. Uranylacetate, inhibitors of the respiratory chain and proton conductors in part completely inhibit the uptake of acetate.

Acetates↗
PubMedDate not supplied

[Activity of sulbactam and clavulanic acid, alone and combined, on Acinetobacter calcoaceticus].

Sulbactam and clavulanic acid, both beta-lactamase inhibitors, were studied alone or associated on 85 isolates of Acinetobacter calcoaceticus. When sulbactam was tested alone the minimal inhibitory concentration (MIC) was less than 2 micrograms/ml with the carbenicillin-sensitive strains of A. Calcoaceticus and between 8 to 16 micrograms/ml with the carbenicillin-resistant strains. In the presence of clavulanic acid (5 or 10 micrograms/ml) the MIC of sulbactam on all the carbenicillin-resistant strains decreased to less than 4 micrograms/ml.

Acinetobacter↗
PubMed1983

[Clinical importance of Acinetobacter calcoaceticus isolations from blood and venous catheters].

From 1980 to 1982 Acinetobacter calcoaceticus (A.c.) derived from blood cultures and venous catheters of 29 patients could be grown. 6 patients with clinical signs of Gram-negative septicemia had two or more blood cultures positive for A.c. Thus, the role of A.c. as the etiologically relevant pathogen seems to be evident. In 14 cases with clinical signs of septicemia but only one set of blood cultures positive for A.c. it is felt to be the causative agent since no other cause could be found. In 9 cases isolation of A.c. seems to be due to contamination - most likely from skin -, because neither evidence of septicemia nor relationship to the diseases present of A.c. existed.

Acinetobacter Infections↗
PubMed1983

Factors affecting quantitative transformation of streptomycin resistance markers in Acinetobacter calcoaceticus.

Quantitative transformation of Acinetobacter calcoaceticus BD4-Ss exposed to autologous DNA in a liquid system was examined with streptomycin resistance as a marker. The exposure to DNA was terminated by addition of DNase at set intervals. The variables tested were concentrations of autologous Sr-DNA, exposure time, growth phase, recipient cell density, and the pH of the liquid transformation system. The ratio of transformants to total number of recipient cells (T/R-ratio) was proportional to the DNA concentration up to a level of about 10 micrograms/ml. There was a constant increase of transformant numbers upon time of exposure. The T/R ratio was highest at the early growth phase, but the total number of transformed cells per ml culture aliquot was only raised by a factor approximately 10 from the earlier to the later growth phases and non increase was observed in recipients grown for more than 3 hours. There was a marked relationship between the relative number of transformants per total number of recipients in that the T/R-ratio was markedly higher with fewer cells per ml in the transformation broth system where exposure to DNA occurred. The transformation was higher at a pH of 7.3 than 7.0. The results enabled definition of the optimal test system for quantitative transformation of A. calcoaceticus with the strain BD4 as recipient.

Acinetobacter↗
PubMed1981

Evolutionarily homologous alpha 2 beta 2 oligomeric structures in beta-ketoadipate succinyl-CoA transferases from Acinetobacter calcoaceticus and Pseudomonas putida.

Homogeneous beta-ketoadipate succinyl-CoA transferase (EC 2.8.3.6) preparations were obtained from extracts of Acinetobacter calcoaceticus and Pseudomonas putida. Gel filtration indicated that the respective transferases have similar molecular weights of 108,000 and 109,000; each transferase appears to have an alpha 2 beta 2 oligomeric structure formed by association of nonidentical subunits with a molecular weight of about 25,000. The subunits were separated by sodium dodecyl sulfate-gel electrophoresis, and differences in their primary structures were revealed by determination of the NH2-terminal amino acid sequences of the oligomers. The transferases cross-react immunologically and possess similar amino acid compositions. These are remarkably similar to the amino acid compositions of gamma-carboxymuconolactone decarboxylases (EC 4.1.1.44) and beta-ketoadipate enol-lactone hydrolases (EC 3.1.1.24), enzymes that mediate consecutive reactions preceding the transferase step in the beta-ketoadipate pathway.

Acinetobacter↗
PubMed1982

[Comparative activity of cefsulodin on Pseudomonas aeruginosa, Acinetobacter and Enterobacteriaceae (author's transl)].

Cefsulodin, a new semi-synthetic cephalosporin, is characterized by its activity against P. aeruginosa. In this study the authors compared this new molecule with other four betalactamines, carbenicillin, ticarcillin, azlocillin and mezlocillin, and two aminoglycosides, amikacin and netilmicin. Two hundred and forty five strains studied were 100 Pseudomonas aeruginosa, 20 Acinetobacter, 42 Proteus, 21 Serratia, 22 Enterobacter, 20 Klebsiella and 20 E. coli. One hundred twenty strains of these showed carbenicillin resistant phenotype. MIC were determined by the agar dilution method. Cefsulodin was only active on Pseudomonas aeruginosa. MICs were at least 16 mg/l in the other species. On carbenicillin susceptible P. aeruginosa strains, the average MIC of cefsulodin, amikacin and netilmicin was 1 mg/l, and MICs of azlocillin, mezlocillin, ticarcillin and carbenicillin were 4-8 mg/l, 8 mg/l, 16 mg/l and 32 mg/l, respectively. On carbenicillin resistant P. aeruginosa, ticarcillin and mezlocillin were not effective and MICs of azlocillin and cefsulodin were 16 mg/l and 4-8 mg/l, respectively. However, MICs were between 64 and 128 mg/l in 20 p. cent of carbenicillin resistant strains.

Acinetobacter↗
PubMed1982

Clinical evaluation of succinylated Acinetobacter glutaminase-asparaginase in adult leukemia.

We treated 13 adult patients with acute leukemia or chronic myelocytic leukemia (CML) in blast phase using succinylated Acinetobacter glutaminase-asparaginase (SAGA) administered on a daily dose schedule. SAGA reduced the peripheral blast count in two patients with acute lymphoblastic leukemia and two with blastic CML; however, no patient achieved either complete or partial remission. Marked central nervous system toxic effects (encephalopathy and coma) were observed, limiting treatment in patients whose disease appeared responsive; this effect finally prompted early discontinuance of the trial. Other toxic effects observed included nausea, hyperglycemia, and respiratory alkalosis. Hypersensitivity reactions to the enzyme were not seen. Pharmacologic analyses showed that prolonged blood glutamine depletion was achieved only by daily enzyme administration; however, we noted the importance of performing amino acid analysis on blood which was deproteinized immediately following phlebotomy. Our results demonstrate excessive central nervous system toxicity when glutaminase-asparaginase is administered on a daily schedule. Because of this effect, we propose that future trials of similar enzymes be limited to short courses of enzyme therapy, possibly with the addition of antimetabolites or amino acid analogs, which could enhance the antitumor effect without increasing toxicity.

Acinetobacter↗