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Antimicrobial Agents and Chemotherapy May 1981Induction of a major outer membrane protein, H1, in Pseudomonas aeruginosa resulted in decreased susceptibility to gentamicin and streptomycin. Mutants which overproduce...
Induction of a major outer membrane protein, H1, in Pseudomonas aeruginosa resulted in decreased susceptibility to gentamicin and streptomycin. Mutants which overproduce protein H1 and cells in which H1 is induced in response to growth conditions had altered kinetics of uptake and killing. It was further demonstrated that gentamicin and streptomycin interact with the outer membrane to permeabilize it to lysozyme and to increase the permeation of a chromogenic beta-lactam, nitrocefin. Experiments with inhibitors of aminoglycoside uptake showed that uptake was not required to increase permeability. Mg2+ at 1 mM totally inhibited aminoglycoside-mediated outer membrane permeabilization. We propose that the uptake and killing by these aminoglycosides requires interaction with an Mg2+ binding site at the outer membrane, permitting aminoglycoside uptake into the periplasm.
Topics: Aminoglycosides; Bacterial Proteins; Cell Membrane Permeability; Cell Wall; DNA-Binding Proteins; Drug Resistance, Microbial; Gentamicins; Magnesium; Pseudomonas aeruginosa; Streptomycin
PubMed: 6794444
DOI: 10.1128/AAC.19.5.777 -
Scientific Reports Nov 2017Gene regulation systems are mimicked by simple quantitative detection of non-nucleic acid molecular targets such as protein and metabolite. Here, we describe a one-tube,...
Gene regulation systems are mimicked by simple quantitative detection of non-nucleic acid molecular targets such as protein and metabolite. Here, we describe a one-tube, one-step real-time quantitative detection methodology for isothermal signal amplification of those targets. Using this system, real-time quantitative detection of thrombin and streptomycin, which were used as examples for protein and metabolite targets, was successfully demonstrated with detection limits of at most 50 pM and 75 nM, respectively. Notably, the dynamic range of target concentrations could be obtained for over four orders of magnitude. Thus, our method is expected to serve as a point-of-care or on-site test for medical diagnosis and food and environmental hygiene.
Topics: Biosensing Techniques; Molecular Diagnostic Techniques; Point-of-Care Systems; Streptomycin; Thrombin; Transcription, Genetic
PubMed: 29123195
DOI: 10.1038/s41598-017-15697-8 -
Journal of Bacteriology Oct 1985An str gene cluster containing at least four genes (strR, strA, strB, and strC) involved in streptomycin biosynthesis or streptomycin resistance or both was self-cloned...
An str gene cluster containing at least four genes (strR, strA, strB, and strC) involved in streptomycin biosynthesis or streptomycin resistance or both was self-cloned in Streptomyces griseus by using plasmid pOA154. The strA gene was verified to encode streptomycin 6-phosphotransferase, a streptomycin resistance factor in S. griseus, by examining the gene product expressed in Escherichia coli. The other three genes were determined by complementation tests with streptomycin-nonproducing mutants whose biochemical lesions were clearly identified. strR complemented streptomycin-sensitive mutant SM196 which exhibited impaired activity of both streptomycin 6-phosphotransferase and amidinotransferase (one of the streptomycin biosynthetic enzymes) due to a regulatory mutation; strB complemented strain SD141, which was specifically deficient in amidinotransferase; and strC complemented strain SD245, which was deficient in linkage between streptidine 6-phosphate and dihydrostreptose. By deletion analysis of plasmids with appropriate restriction endonucleases, the order of the four genes was determined to be strR-strA-strB-strC. Transformation of S. griseus with plasmids carrying both strR and strB genes enhanced amidinotransferase activity in the transformed cells. Based on the gene dosage effect and the biological characteristics of the mutants complemented by strR and strB, it was concluded that strB encodes amidinotransferase and strR encodes a positive effector required for the full expression of strA and strB genes. Furthermore, it was found that amplification of a specific 0.7-kilobase region of the cloned DNA on a plasmid inhibited streptomycin biosynthesis of the transformants. This DNA region might contain a regulatory apparatus that participates in the control of streptomycin biosynthesis.
Topics: Amidinotransferases; Cloning, Molecular; Genes, Bacterial; Mutation; Phosphotransferases; Phosphotransferases (Alcohol Group Acceptor); R Factors; Streptomyces griseus; Streptomycin
PubMed: 2995326
DOI: 10.1128/jb.164.1.85-94.1985 -
Journal of Bacteriology Jun 1966Orias, E. (University of California, Santa Barbara), and T. K. Gartner. Suppression of amber and ochre rII mutants of bacteriophage T4 by streptomycin. J. Bacteriol....
Orias, E. (University of California, Santa Barbara), and T. K. Gartner. Suppression of amber and ochre rII mutants of bacteriophage T4 by streptomycin. J. Bacteriol. 91:2210-2215. 1966.-Streptomycin-induced suppression of amber and ochre rII mutants of phage T4 was studied in a streptomycin-sensitive strain of Escherichia coli and four nearly isogenic streptomycin-resistant derivatives of this strain, in the presence and in the absence of an ochre suppressor. Most of the 12 rII mutants tested were suppressed by streptomycin in the streptomycin-sensitive su(-) strain. This streptomycin-induced suppression in the su(-) strain was eliminated by the independent action of at least two of the four nonidentical mutations to streptomycin resistance. In two of the su(+)str-r strains, streptomycin markedly augmented the suppression caused by the ochre suppressor. In those su(-)str-r hosts in which significant streptomycin-induced suppression could be measured, the amber mutants were more suppressible than the ochre mutants.
Topics: Chromosome Mapping; Coliphages; Drug Resistance, Microbial; In Vitro Techniques; Mutation; Streptomycin
PubMed: 5943936
DOI: 10.1128/jb.91.6.2210-2215.1966 -
The Journal of Biological Chemistry Dec 1970
Streptomycin biosynthesis and metabolism. Enzymatic phosphorylation of dihydrostreptobiosamine moieties of dihydro-streptomycin-(streptidino) phosphate and dihydrostreptomycin by Streptomyces extracts.
Topics: Adenosine Triphosphate; Alkaline Phosphatase; Boron Compounds; Chromatography, Paper; Dihydrostreptomycin Sulfate; Electrophoresis; Esters; Glucosamine; Oxidation-Reduction; Phosphoric Acids; Phosphoric Monoester Hydrolases; Phosphorus Isotopes; Phosphotransferases; Streptomyces; Streptomycin; Tritium
PubMed: 4099008
DOI: No ID Found -
Antimicrobial Agents and Chemotherapy Nov 1986In vitro studies with penicillin and [3H]streptomycin in four strains of streptococci (S. faecalis, S. sanguis, and S. mitis) were performed by simultaneously measuring...
In vitro studies with penicillin and [3H]streptomycin in four strains of streptococci (S. faecalis, S. sanguis, and S. mitis) were performed by simultaneously measuring the rates of bacterial killing and uptake of streptomycin. In S. faecalis, penicillin stimulated streptomycin uptake, as has been shown by Moellering and Weinberg (R. C. Moellering, Jr., and A. N. Weinberg, J. Clin. Invest. 50:2580-2584, 1971). Moreover, the antibiotic combination was associated with an enhanced bactericidal rate which temporally correlated with beta-lactam-induced aminoglycoside uptake. In contrast, in viridans group streptococci (S. sanguis and S. mitis) penicillin had no effect on streptomycin uptake and a minimal effect on bactericidal rate when compared with either drug alone. These data suggested that the stimulation of streptomycin uptake in streptococci by penicillin is strain or species specific and that important differences exist between enterococci and viridans group streptococci regarding the mechanisms of beta-lactam-aminoglycoside potentiation.
Topics: Aminoglycosides; Dose-Response Relationship, Drug; Drug Synergism; Drug Therapy, Combination; Penicillins; Streptococcal Infections; Streptococcus; Streptomycin; Time Factors
PubMed: 3800352
DOI: 10.1128/AAC.30.5.763 -
The Ulster Medical Journal May 1954
Topics: Acute Disease; Anti-Bacterial Agents; Appendicitis; Humans; Streptomycin; Tetracycline; Tetracyclines
PubMed: 13187736
DOI: No ID Found -
Journal of the Association For Research... Jun 2001Many studies have sought to document ototoxic damage and to study repair and regeneration of mammalian vestibular sensory epithelia. However, linear density analysis of...
Many studies have sought to document ototoxic damage and to study repair and regeneration of mammalian vestibular sensory epithelia. However, linear density analysis of the sensory cells or use of methods that focus on detection of actin in the stereocilia and cuticular plates at the reticular lamina detect only the disappearance of "hair cells" as defined by a narrow set of criteria. The research presented here focuses on the effects of two ototoxic drugs (gentamicin and streptomycin). We used light microscopic analysis of semithin sections to observe changes in the distribution of sensory and supporting cell nuclei and to elucidate other, previously undetected, morphological changes that occurred within the vestibular epithelia. Age-matched untreated and vehicle-treated controls showed that the gerbil posterior crista is asymmetrical on either side of the septum cruciatum; the longer end is taller and narrower than the shorter end. In cross sections taken throughout the length of each posterior crista, the thickness of the sensory epithelium along the sides (peripheral zone) is greater than at the apex (central zone). In tissue sections of the sensory epithelium, the ratio of sensory cell nuclei to support cell nuclei is slightly over 1:1.5 in all regions except the septum cruciatum where most sensory cells are absent and supporting cells predominate. In tissue sections from the most damaged drug-treated specimens, there was a decrease in the linear density of nuclei in the sensory cell layer, with a compensatory increase in the linear density of nuclei in the support cell layer of the sensory epithelia. In these specimens, linear density of total nuclei/tissue section remained the same. In these regions, the width of the epithelium became up to 50% thinner. The ratio of sensory to supporting cell nuclei changed to 1:6. Drug exposure led additionally to a decrease in length of the cristas, but there was not a linear relationship between the change in length of the crista and length of the septum cruciatum in these shorter cristas. In drug-treated cristas, other changes included a decrease in calculated surface area and volume of the epithelia. Thus, while linear density measurements of sensory cell nuclei provide an indication of damage, there are additional anatomic changes to the cristas and caution is advised with regard to interpreting changes as "loss" of cells.
Topics: Animals; Gentamicins; Gerbillinae; Injections; Semicircular Canals; Streptomycin; Tympanic Membrane
PubMed: 11550524
DOI: 10.1007/s101620010063 -
Journal of Bacteriology Nov 1965Ravin, Arnold W. (University of Rochester, Rochester, N.Y.), and Ajit K. Mishra. Relative frequencies of different kinds of spontaneous and induced mutants of...
Ravin, Arnold W. (University of Rochester, Rochester, N.Y.), and Ajit K. Mishra. Relative frequencies of different kinds of spontaneous and induced mutants of pneumococci and streptococci capable of growth in the presence of streptomycin. J. Bacteriol. 90:1161-1173. 1965.-Mutations conferring ability to grow in the presence of streptomycin arise spontaneously and can be induced in pneumococci and streptococci. They prove to be of several phenotypic and genetic types, which may be classified as follows: VLR, LR, and HR, which confer resistance, respectively, to less than 50, between 50 and 500, and 500 or more mug/ml of streptomycin. VLR and LR mutations recombine with each other, whereas HR mutations generally replace (do not recombine with) several of the VLR and LR mutations. Spontaneously, the VLR type is several times more frequent than the LR and HR types, which are equally frequent relative to each other. Nitrous acid treatment of deoxyribonucleic acid (DNA) in vitro or ultraviolet irradiation of cells tends to produce the VLR and LR type of mutation. Streptomycin-dependent mutations are rare in the pneumococci and streptococci. One such mutation, requiring 500 to 1,000 mug/ml of streptomycin for optimal growth, arose spontaneously in a group A streptococcal strain, and was transferred via a DNA-mediated transformation to a pneumococcal strain. In the latter, the mutation proved to be very closely linked to the genetic locus at which the streptomycin-resistance mutations arise.
Topics: Drug Resistance, Microbial; In Vitro Techniques; Mutation; Streptococcus; Streptococcus pneumoniae; Streptomycin
PubMed: 4379002
DOI: 10.1128/jb.90.5.1161-1173.1965 -
Antimicrobial Agents and Chemotherapy Nov 1986We used two strains of streptomycin-susceptible enterococci (MIC, 64 and 128 micrograms of streptomycin per ml, respectively) isolated from patients with infective...
We used two strains of streptomycin-susceptible enterococci (MIC, 64 and 128 micrograms of streptomycin per ml, respectively) isolated from patients with infective endocarditis. When combined with penicillin, 20 micrograms of streptomycin per ml killed both strains synergistically in vitro whereas combinations of 5 and 10 micrograms of streptomycin per ml did not act synergistically against either strain. By using the rabbit model of enterococcal experimental endocarditis, animals were treated for 3 days with procaine penicillin (1.2 X 10(6) U intramuscularly three times daily) together with low-dose streptomycin (3.5 mg/kg) or high-dose streptomycin (10 mg/kg) intramuscularly three times daily. The peak concentrations of streptomycin in serum at 0.5 h were 9.2 and 26.8 micrograms/ml in the low- or high-dose group, respectively. When combined with procaine penicillin, both dosages of streptomycin were more effective (P less than 0.01) than procaine penicillin alone for the treatment of enterococcal experimental endocarditis. There was no significant difference in the efficacy of procaine penicillin plus low-dose streptomycin versus procaine penicillin plus high-dose streptomycin therapy of enterococcal experimental endocarditis.
Topics: Animals; Drug Therapy, Combination; Endocarditis, Bacterial; Penicillins; Rabbits; Streptococcal Infections; Streptomycin
PubMed: 3800348
DOI: 10.1128/AAC.30.5.725