Agar Diffusion Method

Modified natural foam rubber exhibiting antimicrobial activities and unmodified foam materials were placed in separate positions on MHA plates under aseptic conditions. Another thin layer of MHA was poured onto the foam samples so that foam materials were sandwiched between the MHA layers. For the lower layer, 15 ml of MHA was poured into sterilised Petri dishes under aseptic conditions. For the upper thin layer, 10 ml of MHA was poured onto the two pieces of rubber and material. The bacterial 

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Assay Methods. The primary assay for the streptovaricins is the microbiological assay using the agar diffusion method or a turbidimetric procedure (60). The streptovaricins can also be identified by paper (60,88) or thin-layer chromatography (3). 

The agar diffusion method is the typical choice for bioassays of antibiotics, but is unsuitable for antibiotics consisting of heterogeneous mixtures of closely related compoimds, which are scarcely soluble in water and diffuse poorly in agar gel. In addition, those antibiotics that are unstable in bright sunlight and produce zones of inhibition that may be neither clear nor proportional in size to the logarithm of the antibiotic concentration are difficult to assay by this method. 

Antimicrobial activity of the medication was determined by the agar diffusion method [4, 5]. A wide spectrum of pyogenic microflora (Table 16.1) as well as Candida spp. and Helicobacter pylori were studied as test cultures. 

By the dialysis method, the protein binding of moxalactam was 43 percent and by the agar-diffusion method, 40 percent (6). By an ultrafiltration method, the binding of moxalactam in pooled fresh human plasma was 50.7 percent at physiologic temperature and pH (38). 

The fermentation batches are incubated aerobically under stirring at 28°-30°C. At intervals the antibiotic activity is assayed microbiologically by the agar diffusion method using Sarcina lutea as the test organism. The maximum activity is reached after 96-120 h of fermentation. 

Fig. (9). Inhibition of anti-lactose antibodies by increasing amounts of methyl P-lactoside and lactose (A) and by the agar diffusion method (B).

Aspergillus niger, S. cerevisiae, Mycoderma sp., Lactobacillus acidophilus and B. cereus, as estimated by the paper disc agar diffusion method (Meena and Sethi, 1994). The oil also inhibits the growth of Fusarium verticilloides (Veluti et al., 2004). Clove oil (1% v/w) inhibits Listeria monocytogenes in chicken frankfurters (Mytle et al., 2006). It has excellent antimicrobial properties and is used in food preservation (Smith Palmer etal., 1998, 2001). 

The antimicrobial activity of ajowan oils against Aspergillus niger, S. cerevisiae, Mycoderma sp., Lactobacillus acidophilus and B. cereus, as estimated by the paper disc agar diffusion method, has been reported by Meena and Sethi (1994). 

On gel electrophoresis, the purified antibody preparations yield single bands when the gel is stained for proteins. However, on gel isoelectrofocus-ing, differences in the results maybe noted, as shown in Fig. 15. Several protein isomers were present in each antibody preparation, with 7 isomers being detected in the anti-BSA antibodies (B) and 11 isomers in the anti-fucose antibodies (F). The coupled electrofocusing-agar diffusion method showed that each isomer of the anti-fucose set possessed the same antibody activity with the antigen, a-L-fucosyl-BSA. 

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-... 

A comparative in vitro study of the release of sulfacetamide sodium from eye ointments by dissolution and agar diffusion methods has been made and the effect of viscosity and particle size on the release examined. The aqueous based ointment gives a higher release of the drug than the greasy-based products. A linear relationship exists between agar diffusion release and the quantity of sulfacetamide released after sixty minutes as determined by the dissolution method (29). 

The agar diffusion method (Kirby—Bauer) is also sometimes used for the evaluation of antibacterial activity of textiles. This is a relatively quick and easily executed semiquantitative method to determine antibacterial activity of diffusible antimicrobial agents on treated textile material. The bacteria are grown in nutrient broth medium and after appropriate dilution (e.g., lOOx) from the culture, test organisms are swabbed over the surface of agar plates. Ten-millimetre-diameter disks of the test fabric and control fabric are then gently pressed onto the surface of the plate. The plates are then incubated at 37 °C for 18—24 h. The antibacterial activity of the fabrics is demonstrated by the diameter of the zone of inhibition in comparison to the control textile sample. 

Figure 19.46 Determination of antimicrobial activity of chitosan and nano-chitosan-treated cotton fabric by agar diffusion method Ca) CHT-D5N (5. aureus), [b] CHT-D5N ( coli), fc] CHT-D5N +Ag nano (5. aureus) and (d] CHT-D5N+Ag nano ( , coif).

Antimicrobial characterization of formed film was obtained by the agar diffusion method and liquid culture test. The agar diflEiision test was intended to impersonate the antibacterial activities of the film on the solid food surface and liquid culture test on the other hand infers the antibacterial activities of the film on liquid-form food. 

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