Elaboration of a rapid method of determining the sensitivity of Brucella to antibiotics]

Optimal conditions were developed for determination of antibiotic sensitivity in Brucella by using enzyme immunoassay directly in the primary cultures of the material tested. The Brucella concentration in the material tested should be not lower than 1.10(6) microbial cells/ml and the time of culture incubation be 24 hours at 37 degrees C. The obligatory condition is to use a liquid medium, i.e. the Albimi broth with 1% glucose. To inhibit the foreign microflora it is recommended to use polymyxin B and amphoglucamine in a concentration of 3 microgram/ml. The use of enzyme immunoassay was shown that it was possible to determine the antibiotic sensitivity of Brucella in practice.     

Development of a method for the quantitative assessment of microorganism sensitivity to antibiotics using discs. The study of different nutrient media for determining microorganism sensitivity to antibiotics

Five nutrient media used for determination of microbial sensitivity to antibiotics, i.e. beaf-peptone agar, Hottinger pancreatic beaf infusion agar, sprat hydrolysate nutrient agar of the Dagestan Research Institute of Nutrient Media, Muller-Chintone agar from Bulgaria and "Oxoid" agar for determination of microbial sensitivity were studied comparatively. The media were compared with respect to the growth density with the use of different test-cultures and the clearance of the inhibition growth zones around the discs containing different antibiotics. The best results were obtained with the use of sprat hydrolysate nutrient agar. Further studies on the medium standardization are necessary.     

A new method for the evaluation of antibody affinity based on serial dilutions of studied antibody-antigen mixture

A new method for the evaluation of the affinity of bivalent antibodies were suggested. This method is based on the previously published by the author the idea of using so-called coordinates of dilutions. It was shown that the suggested method allows to evaluate the affinity of antibodies with high accuracy using this simple approach. It is supposed that at some conditions the suggested method could have substantial advantages in comparison to the traditional methods. This method allows to analyze situations when antibodies are already in a mixture with antigen, for example in the bloodstream in the case of infections or autoimmune diseases. The method provides useful approach for the evaluation not only antibody affinity, but also the concentration of circulated antigen.     

A method for determining the sensitivity of the causative agents of suppurative infection to iodopiron

Bacterial suspensions of cultures (10(7) PFU) of pathogenic Staphylococcus, vulgar Proteus and pyocyanic bacterium are resistant to 2.9-46.87 mg per disc of iodopyron in 100% of cases. Sensitivity of 32 and 100% of cultures of pyocyanic bacteria (of 25 under study) being in the suspension (10(5) PFU) to 11.71 and 23.43-9.375 mg of idopyron, respectively, in a hole has been established. To determine sensitivity of pyocyanic bacteria to iodopyron it is suggested to use the procedure of adding of 11.71 mg of the preparation (water solution) to the holes in MPA.     

Standardization of the methods of determining microorganism sensitivity to antibiotics. The effect of the size of the inoculate on the results of determining microorganism sensitivity to antibiotics and its standardization

The literature data and personal observations of the authors on the effect of the inoculate amount on the results of determination of microbial sensitivity to antibiotics by the methods of serial dilutions in the liquid and solid nutrient media and agar diffusion are discussed. It was shown that the inoculate of the density of 3.6.10(7) to 4.25.10(7) microbial bodies per 1 ml was optimal for the methods of agar diffusion and serial dilutions in agar. Recommendations for simplifying standardization and dilution of the inoculate are presented.     

Choice of a method for determining the sensitivity of Escherichia coli to silver

Different methods (methods of discs, of stamps and of minimal inhibitory concentration determination) aimed to determine the Escherichia coli sensitivity to the action of silver on the nutrient media are studied. It is shown possible to use the method of stamps for preliminary estimation under extensive tests. It is established that the data obtained by these methods correlate between themselves with a high degree of trustworthiness and do not correlate with those data obtained in the studies of the antimicrobic action of silver in water.     

A rapid immunofluorescent method of determining the antibiotic sensitivity of brucella

Optimal conditions for rapid assay of Brucella antibiotic sensitivity with the immunofluorescent method were developed. With this method high sensitivity of the main Brucella species to tetracycline, doxycycline and rifampicin was confirmed. It was found actually possible to use the immunofluorescent method for rapid assay of Brucella antibiotic sensitivity in practice.     

A simple method for determining specific esterase activity in tissue extracts.

A simple procedure for estimating specificB-naphthyl esterase enzyme content and activity in small amounts of crude tissue extract is described. Esterase activity is determined by quantitative densitometry of histochemically stained acrylamide gels. Activity measured this way is linear with the extract volume applied. Esterase content is determined by isotopic labeling with a stoichiometric covalently binding enzyme inhibitor, diisopropylfluorophosphate; followed by electrophoresis and gel slice counting.     

A simple matrix method for determining flux control coefficients in complex pathways

Flux control coefficients express in quantitative terms the extent to which the steady state flux through a metabolic pathway is controlled by a particular parameter. Enzyme flux control coefficients can be calculated using matrix algebra methods which express the control coefficients in terms of parameters which can be determined experimentally (enzyme elasticities, flux ratios, metabolite ratios). This paper describes an algorithm based on a 'constraint' matrix which enables expressions for enzyme control coefficients to be written for pathways of any complexity.     

Reliability of the method of levels for determining cutaneous temperature sensitivity

Determination of the thermal thresholds is used clinically for evaluation of peripheral nervous system function. The aim of this study was to evaluate reliability of the method of levels performed with a new, low cost device for determining cutaneous temperature sensitivity. Nineteen male subjects were included in the study. Thermal thresholds were tested on the right side at the volar surface of mid-forearm, lateral surface of mid-upper arm and front area of mid-thigh. Thermal testing was carried out by the method of levels with an initial temperature step of 2°C. Variability of thermal thresholds was expressed by means of the ratio between the second and the first testing, coefficient of variation (CV), coefficient of repeatability (CR), intraclass correlation coefficient (ICC), mean difference between sessions (S1-S2diff), standard error of measurement (SEM) and minimally detectable change (MDC). There were no statistically significant changes between sessions for warm or cold thresholds, or between warm and cold thresholds. Within-subject CVs were acceptable. The CR estimates for warm thresholds ranged from 0.74°C to 1.06°C and from 0.67°C to 1.07°C for cold thresholds. The ICC values for intra-rater reliability ranged from 0.41 to 0.72 for warm thresholds and from 0.67 to 0.84 for cold thresholds. S1-S2diff ranged from -0.15°C to 0.07°C for warm thresholds, and from -0.08°C to 0.07°C for cold thresholds. SEM ranged from 0.26°C to 0.38°C for warm thresholds, and from 0.23°C to 0.38°C for cold thresholds. Estimated MDC values were between 0.60°C and 0.88°C for warm thresholds, and 0.53°C and 0.88°C for cold thresholds. The method of levels for determining cutaneous temperature sensitivity has acceptable reliability.