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PubMed1983

Genetic, molecular, and functional analysis of Streptococcus faecalis R plasmid pJH1.

Streptococcus faecalis JH1 contains two conjugative plasmids, pJH1, an R plasmid that codes for resistance to kanamycin, streptomycin, erythromycin, and tetracycline, and pJH2, a hemolysin-bacteriocin plasmid. Strain JH1 was used as an antibiotic resistance donor in conjugation experiments with two plasmid-free S. faecalis recipient strains, JH2-2 and OG1-RF1. Plasmid pJH1 was purified from one transconjugant, DL77, and subjected to restriction endonuclease analyses. Five restriction enzymes, EcoRI, XbaI, BamHI, SalI, and XhoI, yielding 10, 9, 3, 2, and 2 fragments, respectively, were used to determine the size (80.7 kilobases) of pJH1 and to construct a restriction endonuclease map of the plasmid. Twenty-eight percent of the antibiotic-resistant transconjugants examined expressed only part of the resistance pattern (Kmr Smr Emr Tcr) associated with pJH1, that is, they were resistant to kanamycin, streptomycin, and erythromycin; to erythromycin and tetracycline; or to erythromycin or to tetracycline only. Most of these strains also produced hemolysin and bacteriocin, and several contained a hybrid plasmid consisting of pJH2 and specific segments of pJH1 DNA. Several of these hybrid plasmids, as well as a deletion derivative of pJH1 that coded for resistance to tetracycline but not to kanamycin, streptomycin, or erythromycin, were purified and used to confirm the arrangement of restriction endonuclease fragments on the pJH1 map and to locate the resistance determinants on this map.

DNA Restriction Enzymes↗

PubMed1984

Kinetic analysis of tetracycline accumulation by Streptococcus faecalis.

Tetracycline transport by Streptococcus faecalis occurs by an energy-dependent, carrier-mediated process. The Michaelis constant for transport was unchanged, but the maximal velocity was increased when an energy source, glucose, was present. Accumulation levels, sometimes 25-fold greater than the external concentration, were controlled by the transport system.

Biological Transport, Active↗

PubMed1980

Isolation of a variant of Streptococcus faecalis with enhanced barotolerance.

Streptococcus faecalis ATCC 9790 was adapted to grow at pressures as high as 1000 atm (1 atm = 101.325 kPa) at 37 degrees C by gradually increasing the growth pressure for agar stab subcultures in steps of 50 atm from 750 atm, the maximum growth pressure for unadapted cultures. A stable variant with enhanced barotolerance designated APR-11 was characterized. Similar variants could be obtained repeatedly from S. faecalis cultures by following the indicated procedure, APR-11 was able to grow in liquid media at pressures some 200 atm greater than the maximum for the parent. It appeared to have a regulatory defect in the arginine dihydrolase system and produced ammonia during glycolysis even in the presence of high concentrations of glucose. The ammonia acted to neutralize metabolic acids and to confer a type of acid tolerance. This acid tolerance may be involved in barotolerance since pressure is known to render S. faecalis hypersensitive to acid conditions. In all, it appeared that pressure can be used as a selection agent for isolation of rare barotolerant variants in normal bacterial populations.

Ammonia↗

PubMed1985

In vitro inhibition of Neisseria gonorrhoeae growth by a urogenital strain of Streptococcus faecalis.

A strain of Streptococcus faecalis isolated from the urogenital flora was selected for its ability to inhibit the in vitro growth of Neisseria gonorrhoeae. Initially, the inhibitory activity was demonstrated on solid medium only when the inhibitor and the target strains were growing simultaneously, such as in the spot-lawn and flip-flop agar overlay methods. The antigonococcal effect was not due to a shift in the pH or depletion of nutrient in the medium. This activity was not produced in liquid medium nor could it be extracted in a soluble form from either the solid medium or the streptococcal cells. The production of the inhibitory activity could not be enhanced by ultraviolet irradiation or treatment with mitomycin C. The composition of the medium was found to affect the size of the inhibitory zone produced. The inhibitory activity showed a wide antigonococcal spectrum and was susceptible to trypsin and pronase but resistant to alpha- and beta-amylases and catalase. This activity passed through a filtering membrane and was also dialyzable and had an apparent molecular weight of less than 1,000. The addition of bovine serum albumin to solid medium enabled us to show an inhibition even when the producer and the target strains were grown sequentially, thus suggesting that part of the difficulty of studying such inhibitory activity could be due to its instability.

Anti-Bacterial Agents↗

PubMed1982

Influence of Escherichia coli on Streptococcus faecalis in mixed cultures and experimental animal infections.

Strains of Escherichia coli (four strains) and Streptococcus faecalis (three strains) randomly isolated from faecal samples were cultured together in vitro and in experimental animal infections in order to evaluate the interaction of these two species. Streptococcus faecalis was eliminated from mixed cultures and infections at population ratios of Escherichia coli to Streptococcus faecalis of 10-100:1. The mechanism involved was probably an antibiotic substance produced by Escherichia coli which was antagonistic to Streptococcus faecalis. The substance appeared to be diffusible, water-soluble, of low molecular weight and insensitive to the protease trypsin. It was produced and remained active in vitro and in vivo and can probably be classified as a microcin.

Animals↗

PubMed1977

Resistance mechanism of chloramphenicol in Streptococcus haemolyticus, Streptococcus pneumoniae and Streptococcus faecalis.

The chloramphenicol resistance of Streptococcus haemolyticus, Streptococcus pneumoniae and Streptococcus faecalis isolated from clinical materials was proved to be due to an inactivating enzyme produced by these bacteria. The inactivated products of chloramphenicol were identified as 1-acetoxy, 3-acetoxy and 1,3-diacetoxy derivatives by thin-layer chromatography and infrared spectroscopy. The responsible enzyme was thus confirmed to be chloramphenicol acetyltransferase. The enzyme was inducible. It was partially purified by ammonium sulfate precipitation, DEAE-cellulose chromatography and gel filtration on Sephadex G-150. The enzymes obtained from S. haemolyticus, S. pneumoniae and S. faecalis have been compared with the conclusion that they are identical with respect to molecular weight (approximately 75,000-80,000), optimum pH and heat stability.

Acetyltransferases↗

PubMed1987

Arginine modification with butanedione inhibits the potassium ATPase of Streptococcus faecalis.

The K+-ATPase of Streptococcus faecalis is inhibited by incubation with the arginine-modifying reagent 2,3-butanedione. The inactivation proceeds by pseudo - first order kinetics and a double-logarithmic plot of the pseudo - first order rate constants versus reagent concentrations yields a reaction order of 1.14 with respect to butanedione. Partially inactivated ATPase exhibits a decreased maximal velocity but the same affinity for ATP, as compared to the native enzyme. Butanedione modification is inhibited by adenine nucleotides. These results indicate the involvement of most likely one crucial arginyl residue in adenine nucleotide binding by the ATPase.

Adenosine Triphosphatases↗

PubMed1986

Isolation and structure of the Streptococcus faecalis sex pheromone, cAM373.

The Streptococcus faecalis sex pheromone, cAM373, which induces a mating response of donor cells harboring plasmid pAM373 and is also produced by Staphylococcus aureus, was isolated and its structure determined. Supernatant from an overnight culture of a recipient strain was subjected to successive purification procedures, and 4.4 micrograms cAM373 was obtained. The isolated pheromone showed activity at a concentration as low as 5 X 10(-11) M. Sequence analysis indicated that cAM373 was a heptapeptide, H-Ala-Ile-Phe-Ile-Leu-Ala-Ser-OH, and that its Mr was 733. A synthetic replicate of the peptide showed the same biological activity and chromatographic behavior as the native cAM373.

Amino Acid Sequence↗

PubMed1979

Plasmid-related transmissibility and multiple drug resistance in Streptococcus faecalis subsp. zymogenes strain DS16.

Streptococcus faecalis subsp. zymogenes strain DS16 was found to harbor two plasmids, designated pAD1 (35 megadaltons) and pAD2 (15 megadaltons). pAD1 is transmissible and determines a hemolysin-bacteriocin, whereas pAD2 is non-conjugative and determines resistance to erythromycin, streptomycin, and kanamycin. pAD2 could be mobilized by pAD1, but usually involved formation of a pAD1-pAD2 cointegrate.

Conjugation, Genetic↗

PubMed1971

Balanced macromolecular biosynthesis in "protoplasts" of Streptococcus faecalis.

Osmotically fragile forms of Streptococcus faecalis 9790 were grown in 0.5 m sucrose- or 0.5 m NH(4)Cl-stabilized medium. The "protoplast" cultures exhibit an average growth rate constant of 0.66 to 0.94 mass doublings/hr. In a variety of experiments, turbidity and the net content of protein, ribonucleic acid (RNA) and deoxyribonucleic acid increase at the same rate, indicating balanced macromolecular biosynthesis. A total of two to three mass doublings was obtained, with no evidence of cell division. After osmotic shock, "protoplast" cultures released 93 to 94% of their RNA content in a form not sedimentable at 12,800 x g for 15 min, in contrast to streptococci, which released 7% of their RNA content after the same treatment.

Ammonium Chloride↗

PubMed1975

Self-transferable plasmids determining the hemolysin and bacteriocin of Streptococcus faecalis var. zymogenes.

Strains of Streptococcus faecalis var. zymogenes, designated JH1 and JH3, produced a hemolysin and a bacteriocin. Hemolytic activity was lost from a low percentage of cells grown in broth at either 37 or 45 C. All nonhemolytic (Hly-) variants had lost bacteriocin activity (Ben-), and those from strain JH3 had also lost resistance to the bacteriocin (Bnr-). The majority of Hly-, Ben- variants from JH1 retained bacteriocin resistance (Bnrplus). Strains JH1 and JH3 contained a plasmid deoxyribonucleic acid species of molecular weight 38 times 10-6 (plasmids pJH2 and pJH3, respectively), and strain JH1 also contained a 50 times 10-6 molecular weight plasmid (pJH1) which has previously been shown to carry the genes determining resistance to the antibiotics kanamycin, neomycin, streptomycin, erythromycin, and tetracycline. Hly-, Bcn-, Bnr- variants of strain JH3 had completely lost plasmid pJH3. Hly-, Bcn-, Bnr- variants of strain JH1 had completely lost plasmid pJH2 and retained plasmid pJH1, but Hly-, Bcn-, Bnrplus variants had retained both plasmids pJH2 and pJH1. The Hlyplus, Bcnplus, Bnrplus traits from both parental strains were transferable to nonhemolytic S. faecalis strains during mixed incubation in broth at 37 C, and hemolytic recipient strains were found to have received plasmid pJH2 from strain JH1 and pJH3 from JH3. We conclude that the Hlyplus, Bnrplus traits are borne on plasmid pJH2 in strain JH1 and pJH3 in strain JH3 and that, in Hly-, Bcn-, Bnrplus variants of strain JH1, plasmic pJH2 has suffered a mutation affecting hemolysin and bacteriocin expression. We infer that the plasmids transfer by conjugation. Beta-hemolytic activity is the only property distinguishing the zymogenes variety from S. faecalis. Since we have shown that this activity is plasmid borne in strains JH1 and JH3, we endorse the view that the varietal status of zymogenes should be dropped.

Anaerobiosis↗

PubMed1989

Crystallization and preliminary x-ray diffraction study of the flavoprotein NADH peroxidase from Streptococcus faecalis 10C1.

NADH peroxidase from Streptococcus faecalis 10C1 has been crystallized from ammonium sulfate solutions using the hanging drop vapor diffusion method. Depending on pH, the crystals grew in the orthorhombic space group I222 or one of its subgroups P222 or P2(1)2(1)2 (or one of its two permutations). In both cases the unit cell axes are a = 76.6 A, b = 132.9 A, and c = 145.7 A. There are two monomers/asymmetric unit in the body-centered crystal form and four in the primitive one. The enzyme is catalytically active in the crystalline state. The crystals diffract to at least 2.5 A resolution; they are stable in the x-ray beam and hence suitable for detailed three-dimensional structure determination.

Crystallization↗

PubMed1980

ATP-linked sodium transport in Streptococcus faecalis. I. The sodium circulation.

Streptococcus faecalis, like other bacteria, expels Na+ and accumulates K+. Sodium movements in several bacterial species have been attributed to secondary antiport of Na+ for H+, energized by the proton-motive force. We find a more complex pattern: a circulation of Na+ across the plasma membrane. One limb is the diffusion of Na+, into the cells or out, by a low affinity pathway in response to gradients of concentration and of electrical potential; Na+ movements are enhanced in metabolizing cells. The other limb is the vectorial extrusion of Na+ by a transport system that requires "ATP" (either ATP itself or a related metabolite), even when Na+ is moving downhill. Cells glycolyzing at alkaline pH in buffer containing excess K+ can expel Na+ against a concentration gradient of 100-fold, even in the presence of reagents that block or short circuit the proton circulation (pH gradient and membrane potential both zero). Evidently, under these conditions "ATP" can serve as the energy donor for a primary sodium pump. However, at acid pH, or in presence of low levels of K+, sodium extrusion requires both "ATP" and the proton-motive force. A mutant is described that retains the leak pathway but lacks the "ATP"-linked transport system.

Adenosine Triphosphate↗

PubMed1973

A method for the specific labeling of the glycerol in glyceride-containing lipids of Streptococcus faecalis ATCC 9790.

Cells of Streptococcus faecalis incorporate radioactive glycerol exclusively into the glycerol moieties of monoglucosyl diglyceride, diglucosyl diglyceride, phosphatidyl diglucosyl diglyceride, phosphatidylglycerol, diphosphatidylglycerol, phosphatidic acid, diglyceride, and a phospholipid tentatively identified as an amino acyl phosphatidylglycerol. Phosphatidylglycerol is one of the major radioactive lipids synthesized and contains an equal amount of radioactivity in each of its two glycerol moieties.

Carbon Radioisotopes↗

PubMed1972

Trimethoprim-sulphamethoxazole in urinary tract infection due to Streptococcus faecalis.

In-vitro sensitivities were performed on 140 specimens of urine which grew Streptococcus faecalis of more than 100 000 organisms/ml between March 1970 and February 1971. Although the combination of trimethoprim and sulphamethoxazole definitely appeared to be more effective than sulphonamide alone and as effective as ampicillin, its use for more than two weeks in 14 cases of uncomplicated urinary tract infection due to Streptococcus faecalis led to development of resistance. As in these cases organisms were resistant to sulphonamide to start with, it is suggested that the combination should be used in prolonged treatment only where the organisms are sensitive to both the individual antibiotics. Ampicillin is still the drug of choice in urinary tract infection due to Streptococcus faecalis. The alternative appears to be rotational therapy with other potent antibiotics.

Ampicillin↗

PubMed1976

Transformation of Streptococcus sanguis Challis by plasmid deoxyribonucleic acid from Streptococcus faecalis.

Plasmid deoxyribonucleic acid (DNA) from Streptococcus faecalis, strain DS5, was transferred to the Challis strain of Streptococcus sanguis by transformation. Two antibiotic resistance markers carried by the beta plasmid from strain DS5, erythromycin and lincomycin, were transferred to S. sanguis at a maximum frequency of 1.8 x 10-5/colony-forming unit. Approximately 70% of the covalently closed circular DNA isolated from transformant cultures by dye buoyant density gradients was shown to be hybridizable to beta plasmid DNA. Two major differences were observed between the beta plasmid from S. faecalis and the plasmid isolated from transformed S. sanguis: (i) the beta plasmid from strain DS5 sedimented in velocity gradients at 43S, whereas the covalently closed circular DNA from transformed Challis sedimented at 41S, suggesting a 1.5-Mdal deletion from the beta plasmid occurred; (ii) although the 43S beta plasmid remained in the supercoiled configuration for several weeks after isolation, the 41S plasmid was rapidly converted to a linear double-stranded molecule. Attempts to transform S. sanguis with the alpha plasmid from S. faecalis, strain DS5, were unsuccessful.

DNA, Bacterial↗

PubMed1964

STABILIZATION OF STREPTOCOCCUS FAECALIS PROTOPLASTS BY SPERMINE.

Harold, F. M. (National Jewish Hospital, Denver, Colo.). Stabilization of Streptococcus faecalis protoplasts by spermine. J. Bacteriol. 88:1416-1420. 1964.-Lysis of protoplasts of Streptococcus faecalis subjected to osmotic shock was prevented by the presence of 10(-3)m spermine and other divalent cations. Protein and nucleic acids were largely retained, but compounds of low molecular weight were discharged into the medium and the capacity for glycolysis was lost. Under these conditions, spermine was bound to the protoplasts. It could not be removed by washing with water or nonelectrolytes, but was displaced by salts, polyanions, and polycations. Removal of the spermine restored the osmotic fragility of the protoplasts, which could once again be protected from lysis by impermeant solutes. Protoplasts were also stabilized, in the absence of osmotic shock, by prolonged incubation with cations in 0.5 m sucrose. By either procedure, the protoplasts became resistant not only to osmotic lysis but also to sonic oscillation. It is concluded that the stabilization of protoplasts resulted from ionic binding of the cation to acidic sites on the external surface of the plasma membrane. This conferred upon the membrane additional mechanical strength, perhaps by the cross-linking of subunits, but did not alter its permeability to extracellular solutes.

Bacteriolysis↗

PubMed1978

Superoxide dismutase and oxygen metabolism in Streptococcus faecalis and comparisons with other organisms.

Streptococcus faecalis contains a single superoxide dismutase that has been purified to homogeneity with a 55% yield. This enzyme has a molecular weight of 45,000 and is composed of two subunits of equal size. It contains 1.3 atoms of manganese per molecule. Its amino acid composition was determined and is compared with that for the superoxide dismutases from Escherichia coli, Streptococcus mutans, and Mycobacterium lepraemurium. When used as an antigen in rabbits, the S. faecalis enzyme elicited the formation of a precipitating and inhibiting antibody. This antibody cross-reacted with the superoxide dismutase present in another strain of S. faecalis, but neither inhibited nor precipitated the superoxide dismutases in a wide range of other bacteria, including several other streptococci, such as S. pyogenes, S. pneumoniae, and S. lactis. The inhibiting antibody was used to suppress the superoxide dismutase activity present in cell extracts of S. faecalis and thus allow the demonstration that 17% of the total oxygen consumption by such extracts, in the presence of reduced nicotinamide adenine dinucleotide, was associated with the production of O(2) (-). A variety of bacterial species were surveyed for their content of superoxide dismutases. The iron-containing enzyme was distinguished from the manganese-containing enzyme through the use of H(2)O(2), which inactivates the former more readily than the latter. Some of the bacteria appeared to contain only the iron enzyme, others only the manganese enzyme, and still others both. Indeed, some had multiple, electrophoretically distinct superoxide dismutases in both categories. There was no discernible absolute relationship between the types of superoxide dismutases in a particular organism and their Gram-stain reaction.

Amino Acids↗