Agar diffusion test results

The first study was performed by Venturini [97, 98] in both rats and dogs by using a microbiological assay (i.e. agar diffusion test and S. aureus 209 P FDA as test organism). Conversely from rifampicin, whose serum levels were already detectable 30 min after the administration and still measurable after 48 h, only trace amounts (i.e. 0.2 pg/ml) of rifaximin were detected in serum of fed rats 4 h later (fig. 6). The amount of detectable antibiotic was reduced by 50% in fasted animals. Similar results have been obtained in dogs after oral administration of 25 mg/ kg of both rifamycin derivatives [97, 98], No detectable amount of rifaximin was found in serum at any time. 

Agar-diffusion tests with the anti-isomaltose, myeloma protein and several dextran preparations showed that the protein does indeed combine with a number of dextrans. Results of gel electrophoresis of the sample showed that the purified myeloma protein consisted of several multimolecular forms.107 This observation is at variance with a report that the W3129 myeloma protein isolated from the same type of serum was homogeneous.168 Additional studies are needed in order to establish whether the anti-isomaltose, myeloma protein is synthesized as a homogeneous protein or in multimolecular form. 

That both components were antibodies was established by agar diffusion tests with these preparations and solutions of the glycan performed in the usual manner. The results of the agar diffusion tests are shown in Figure 3, right plate. The two preparations of antibodies have been designated as anti-galactose (anti-gal) antibodies and anti-lactose (anti-lac) antibodies and some of the properties of the two sets of antibodies are described in a later section. 

The three antisera and the anti-glycosyl antibodies isolated from these antisera have been tested in agar diffusion tests for cross-reactivity with the three iirmunogens and with bovine serum albumin. These results are shown in Figure 8. 

Delivery of antibiotics from such formulations resulted in suppressed bacterial growth, and thus antibacterial activity, in an in vivo rabbit model. Furthermore, these formulations have proven to be effective in an agar diffusion test, direct contact test, mouse model, and rabbit osteomyelitis model without disturbing normal bone ingrowth. 

Okerman et al. compared the performance of a Tetrasensor with three microbial inhibition assays for the analysis of tetracycline antibiotics in tissue. The group concluded that when large numbers of samples have to be analyzed without the requirement for immediate results, classical agar diffusion tests with thin plates and performed as prescribed for the EPT still seem the most economical choice. However, the receptor-based test Tetrasensor was recommended for use in official surveys and also in cases when immediate results are required. Unlike the inhibition tests, this receptor test does not require a well-equipped laboratory for use and is more suited for the meat industry. ... 

The inhibitory data itself differ considerably from each other when results of different examiners are compared as it can be seen, for example, by the activities of lemon oil toward Escherichia coli ( ve tests inactive and four tests active) in the agar diffusion test (Table 14.43) or by the MIC values of rosemary oil against Staphylococcus aureus (Table 14.67), which cover a range from 20 to 50,000 pg/mL in nine examinations. Even if the unit of the low value of 20 was confused—this... 

The Agar diffusion test which gives a semi-quantitative result ... 

Test results Antibacterial effect in the agar diffusion test according to SN 195 920 with Staphylococcus aureus ATCC 6538 ... 

With respect to three of the microbes, namely Klebsiella pneumoniae ATCC 4352, Pseudomonas aeruginosa ATCC 15442 and Staphylococcus aureus ATCC 6538, very good results were achieved. However, against the microbe Escherichia coli ATCC 11229, rather poor results were seen. This was all the more surprising, as in the agar diffusion test according to SN 195 920 the same... 

The position of the precipitation lines depends on, e.g., the diffusion rate of the different HpHb complexes, of the HBG and of the antibodies. The molecular size (the type) of the HpHb complex will therefore influence the result of the diffusion tests in agar. The technique seems to be simple and promising. So far, the data available on the sensitivity and reliability of the method is not sufficient to warrant recommendation of the procedure. 

The specificity of the antibodies can be verified by inhibition tests using agar diffusion data [35], The results of such experiments with anti-lactose... 

The specificity of the antibodies was also verified by hapten-inhibition tests, the results of which are shown in Fig. 8. In these tests decreasing amounts of antigen were used with the pure antibodies and with antibodies that had been treated with potential inhibitors for 2 h. Agar diffusion was used to observe the rate of formation of precipitin bands with the various amounts of antigen. A comparison of the amount of antigen required to... 

Electrofocusing of the preparations showed that differences in the mobilities of the members for the sets of isoantibodies did occur (Fig. 33, Nos. 1 and 2). It is apparent from the results that the two sets of isoantibodies are composed of several different isomeric proteins. To test whether all the protein isomers possessed antibody activity, a coupled isoelectrofocus-ing and agar-diffusion method was used. The results are shown in areas 3, 4, 5, and 6 of Fig. 33. Two different precipitin complexes were formed by the gum and the anti-gum isoantibodies in the precipitin area (5) the top group corresponded to Set 2 antibodies and the lower group to Set 1 antibodies. A precipitin complex formed opposite all of the protein compo-... 

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