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At least 19 recordsLinked to original sources
PubMed1970

Mechanism of D-cycloserine action: transport systems for D-alanine, D-cycloserine, L-alanine, and glycine.

The accumulation of d-alanine, l-alanine, glycine, and d-cycloserine in Escherichia coli was found to be mediated by at least two transport systems. The systems for d-alanine and glycine are related, and are separate from that involved in the accumulation of l-alanine. d-Cycloserine appears to be primarily transported by the d-alanine-glycine system. The accumulation of d-alanine, glycine, and d-cycloserine was characterized by two line segments in the Lineweaver-Burk analysis, whereas the accumulation of l-alanine was characterized by a single line segment. d-Cycloserine was an effective inhibitor of glycine and d-alanine accumulation, and l-cycloserine was an effective inhibitor of l-alanine transport. The systems were further differentiated by effects of azide, enhancement under various growth conditions, and additional inhibitor studies. Since the primary access of d-cycloserine in E. coli is via the d-alanine-glycine system, glycine might be expected to be a better antagonist of d-cycloserine inhibition than l-alanine. Glycine and d-alanine at 10(-5)m antagonized the effect of d-cycloserine in E. coli, whereas this concentration of l-alanine had no effect.

Alanine↗
PubMed1991

Evaluation of cycloserine-cefoxitin-fructose agar and cycloserine-cefoxitin-fructose broth for recovery of Clostridium difficile from environmental sites.

Cycloserine-cefoxitin-fructose agar (CCFA) and cycloserine-cefoxitin-fructose broth (CCFB) containing either 500 or 250 micrograms of cycloserine per ml were compared for efficacy in the isolation of Clostridium difficile from hospital ward environmental sites. A RODAC imprint technique was used to inoculate prereduced CCFA. Moistened swabs were used to inoculate prereduced CCFB from environmental sites immediately adjacent to the RODAC sample sites. CCFA (6% positive) was significantly more sensitive than CCFB (3% positive; P less than 0.005), regardless of the cycloserine concentration. When the CCFA cycloserine concentration was decreased from 500 to 250 micrograms/ml, the overall rate of positive cultures rose from 4 to 17%. Medium containing 500 micrograms of cycloserine per ml may be too inhibitory to isolate many moderately sensitive strains of C. difficile from environmental sites. Regardless of the cycloserine concentration, the CCFA RODAC imprint technique is superior to the CCFB method.

Agar↗
PubMed1971

Mechanism of D-cycloserine action: transport mutants for D-alanine, D-cycloserine, and glycine.

The accumulation of d-alanine and the accumulation of glycine in Escherichia coli are related and appear to be separate from the transport of l-alanine. The analysis of four d-cycloserine-resistant mutants provides additional support for this conclusion. The first-step mutant from E. coli K-12 that is resistant to d-cycloserine was characterized by the loss of the high-affinity line segment of the d-alanine-glycine transport system in the Lineweaver-Burk plot. This mutation, which is linked to the met(1) locus, also resulted in the loss of the ability to transport d-cycloserine. The second-step mutation that is located 0.5 min from the first-step mutation resulted in the loss of the low-affinity line segment for the d-alanine-glycine transport system. The transport of l-alanine was decreased only 20 to 30% in each of these mutants. A multistep mutant from E. coli W that is 80-fold resistant to d-cycloserine lost >90% of the transport activity for d-alanine and glycine, whereas 75% of the transport activity for l-alanine was retained. E. coli W could utilize either d- or l-alanine as a carbon source, whereas the multistep mutant could only utilize l-alanine. Thus, a functioning transport system for d-alanine and glycine is required for both d-cycloserine action and growth on d-alanine.

Alanine↗
PubMed1997

Comparison of a new, bismuth-iron-sulfite-cycloserine agar for isolation of Clostridium perfringens with the tryptose-sulfite-cycloserine and blood agars.

A new differential and selective, bismuth-iron-sulfite-cycloserine (BISC) medium, for isolation and enumeration of Clostridium perfringens from food and feces, was developed. The medium was compared with the widely-used tryptose-sulfite-cycloserine (TSC) medium and blood agar (BA) in recovering actively growing cells, cold- (refrigerated and frozen) stressed, and heat-stressed C. perfringens cells, and heat-activated spores from human feces. Both selective media were satisfactory in recovering actively growing cells and heat-activated spores of C. perfringens. Both were inferior to non-inhibitory blood agar in recovering heat or cold-stressed cells. The advantages of the new BISC medium over the TSC medium were: elimination of the need to prepare pour- or overlay-agar plates, which simplified inoculation of specimens on the medium and simplified the subcultures of colonies for confirmatory identification. All colonies of C. perfringens developed on BISC were black or dark gray. This was contrary to TSC medium, which gave, on average, 39.6% of white colonies when inoculated with the pure cultures of C. perfringens.

Bacteriological Techniques↗
PubMed1965

Kinetic and genetic analyses of D-cycloserine inhibition and resistance in Escherichia coli.

Curtiss, Roy, III (Oak Ridge National Laboratory, Oak Ridge, Tenn.), Leigh J. Charamella, Claire M. Berg, and Paula E. Harris. Kinetic and genetic analyses of d-cycloserine inhibition and resistance in Escherichia coli. J. Bacteriol. 90:1238-1250.1965.-Wild-type cells of Escherichia coli growing at 37 C in mineral salts-glucose medium with vigorous aeration were lysed at maximal exponential rates by 10(-4) to 10(-2)md-cycloserine. At concentrations above 2 x 10(-2)m, d-cycloserine was bacteriostatic. Low levels of d-cycloserine (10(-5)m) and pencillin G (10 units per ml) interacted synergistically to cause a rapid exponential rate of lysis. Spontaneous mutations to d-cycloserine resistance occurred in discrete steps at frequencies of 10(-6) to 10(-7) for each step. First-, second-, and third-step d-cycloserine-resistant mutants were lysed at maximal exponential rates by d-cycloserine concentrations of 10(-3), 3 x 10(-3), and 5 x 10(-3)m, respectively. d-Alanine, l-alanine, and dl-alanyl-dl-alanine reversed d-cycloserine-induced lysis, in that order of effectiveness. On the basis of these observations, a d-cycloserine-enrichment cycling technique was developed for isolation of auxotrophic mutants. d-Cycloserine at 2 x 10(-3)m was as efficient as penicillin G (1,000 units per ml) for mutant enrichment in E. coli and should be useful for isolation of mutants in penicillin-resistant microorganisms. Bacterial conjugation experiments indicated that all three mutations conferring d-cycloserine resistance were linked to the met(1) locus. Transduction experiments showed that the mutation conferring first-step resistance was at least 0.5 min away from the mutations conferring second- and third-step resistance. The latter two mutations possibly occurred in the same gene, since they were sometimes carried in the same transducing phage. Studies on expression of d-cycloserine resistance indicated that these mutations were neither dominant nor recessive to each other nor to the d-cycloserine-sensitivity allele. Each allelic state exerted its influence on the phenotype independently of the others. These results are discussed in terms of the known inhibition of alanine racemase and d-alanyl-d-alanine synthetase by d-cycloserine.

Alanine↗
PubMed1977

Inducible resistance to D-cycloserine in Bacillus subtilis 168.

Resistance to d-cycloserine could be induced in Bacillus subtilis 168 by sublethal concentrations of d-cycloserine. Sensitivity to the antibiotic could be regained by growth in the absence of d-cycloserine. The bactericidal activity of d-cycloserine apparently was not altered by resistant cells, and peptidoglycan synthesis was still inhibited by d-cycloserine in resistant cells. The d-cycloserine resistance apparently resulted from a decreased uptake of the antibiotic. The decrease in d-cycloserine transport could be prevented by simultaneous treatment of the cells with rifampin and d-cycloserine. d-Cycloserine was transported by the same system as glycine in B. subtilis. d-Cycloserine was able to exchange for intracellular glycine in both sensitive and resistant cells, suggesting that d-cycloserine is not excluded from the cell in resistant cultures.

Bacillus subtilis↗