Fluoroquinolone resistance appears to be increasing in many species of bacteria, particularly in those causing nosocomial infections. However, the accuracy of some antimicrobial susceptibility testing methods for detecting fluoroquinolone resistance remains uncertain. Therefore, we compared the accuracy of the results of agar dilution, disk diffusion, MicroScan Walk Away Neg Combo 15 convention...

The transformation frequency of Escherichia coli C-600, continuously cultivated in a chemostat operated at constant dilution rate, increased with increase in agitation rate (impeller speed). Cell counts at each impeller speed remained approximately constant. The phenomenon correlated with changes in mean cell volume associated with the changes in agitation rate.

Maintenance energy expenditures were mesured for five rumen bacteria, Selenomonas ruminantium, Butyrivibrio fibrisolvens, Bacteroides ruminicola, Megasphaera elsdenii, and Streptococcus bovis, by using a complex medium with glucose as the carbon source. Large differences (as high as 8.5-fold) in maintenance energy expenditures were seen among these bacteria. The suggestion is made that maintena...

The generally accepted hypothesis on cerebrospinal fluid (CSF) hydrodynamics suggests that CSF is actively formed mainly by the choroid plexuses, circulates unidirectionally along the brain ventricles and subarachnoid space, and is passively absorbed mainly into the dural venous sinuses. CSF formation rate (Vf) has been extensively studied using the ventriculo-cisternal perfusion technique and ...

The time-dependent loss of enzymic activity and tetrameric structure of chicken liver pyruvate carboxylase (EC 6.4.1.1) after dilution below 2 units/ml was apparently monophasic and first-order. When examined over a range of initial enzyme concentrations, both activity and tetrameric structure decayed to equilibrium levels which were dependent on the initial concentration. The observed rate con...

background : these days, the antibiotic resistance of pseudomonas aeruginosa isolates to imipenem has significantly increased. therefore the study of resistance to imipenem in this organism to imipenem in determining the appropriate treatment is crucial and necessary. the goal of this study is to compare three phenotypic methods of e-test, disk diffusion and micro broth dilution in the study of...

Irrespective of the nature of the growth-limiting substance, the potassium content of Aerobacter aerogenes (growing in a chemostat at a fixed dilution rate) increased progressively from about 1.3 % to 4-2 yo of the bacterial dry weight with changes in culture NaCl concentration from o to 40 g./l. Similarly, the potassium content of glycerol-limited A. aerogenes organisms, growing in a low ionic...

An analysis of regeneration by dilution of a covalently modified protein is presented. It is shown that, when protein regeneration is realized through the intermediacy of a protein-modifying agent adsorptive complex, the reaction is described by a summation of two exponential functions of reaction time plus a constant-term equation. The conditions whereby this equation reduces to a single-expon...