Minimum microbicidal concentration

Table 119. Minimum Microbicidal Concentrations of CTAB (MMC) after 24 h at 22°C...

Doxycycline-loaded chitosan microspheres were developed using a novel water-inoil emulsion technique, involving oil phase ionic gelation. Assessment of antibacterial activity showed that doxycycline was able to exhibit a minimum microbicidal concentration (MIC) of 16.5,17.4,11.2 and 98.3 pg a gdinst Klebsiella pneumoniae (ATCC 15380), Escherichia coli (ATCC 25922), Staphylococcus aureus (ATCC 9144) and Pseudomonas aeruginosa (ATCC 25619), respectively. The scope of this investigation was the use of doxycycline-loaded chitosan microspheres for healing infected wounds [86]. 

Table 13 Minimum microbicidal concentration (%) of glutaraldehyde (50%) (with and without soiling —0.2% albumin -) at contact time (source THOR Biocides Division)...

Further to these results, the microbicidal activities of FIBCIDE-KF and KATHON WT were evaluated. The minimum inhibitory concentrations (MIC) for Pseudomonas aeruginosa, Pseudomonas putida, Bacillus subtilis and Microbacterium sp. are identical for both compounds, so the microbicidal effect has not diminished (Figure 10). It appears that the biocidal effects are similar because the Cl-MIT in the inclusion complex is released into water, as shown in Figure 6. 

The minimum inhibition concentrations of PCP listed in Table 43 demonstrate its extraordinary broad and equalized activity spectrum. Moreover PCP exhibits strong algicidal effectiveness in concentrations of 2-5-5 mg/litre. It is indeed more than a simple microbicide, namely a biocide that is also highly toxic for plants, fish, molluscs, insects and mammals. 

A -(2-methylnaphthyl)maleinimide has been found to be a microbicide capable of protecting fabrics, plastics, paints, etc., from fungal and bacterial attack (Becker Gurnee, 1979). As can be seen from the minimum inhibition concentrations in Table 84, it is, however, particularly effective against fungi and yeasts. This activity of the product in combination with its heat stability and low water solubility makes the activity especially recommendable for the antimicrobial treatment of plastics. 

In standard concentrations TCC primarily inhibits the growth of Gram-positive bacteria Staphylococcus aureus is especially sensitive to TCC. Microbicidal activity results only if the application concentration is many times the minimum inhibition concentration (MIC). 

The activity spectrum of Captan covers Gram-positive and Gram-negative bacteria, fungi and yeasts the minimum inhibition concentrations are in the range of 25-100 mg Captan/ml nutrient agar. Captan has been recommended for the microbicidal treatment of coatings and plastic materials, especially PVC mixtures. 

Hexachlorodimethylsulphone is a reactive microbicide which exhibits a broad spectrum of activity. The minimum inhibition concentrations for bacteria, fungi, yeasts and algae range between 10 and 100 mg/litre. The slime forming bacteria described by Kato Fukumura (1962) are especially sensitive to hexachlorodimethylsulphone MIC 0-5 mg/litre. In consequence of its limited stability in water the compound is mainly used as a non-persistent slimicide and algicide in process water circuits, e.g. in the paper industry, and not so much as a preservative. 

As can be seen from the minimum inhibition concentrations listed in Table 7. the mixture exhibits a moderate antimicrobial activity in consequence it is mainly used in combination with other microbicides. Its activity is largely independent of pH. 

The a-glycerolether is prepared by condensing equimolar amounts of 4-chlorophenol (7.5.1.) and 2,3-epoxy-l-propanol (Glycidol) in the presence of a tertiary amine or a QAC as catalyst. Minimum inhibiton concentrations (source Kabara, 1984, e.g. 1250 mg/1 for Staphylococcus aureus, 2500 mg/1 for Pseudomonas aeruginosa and Aspergillus niger, 1250 mg for Candida albicans) present Chlorphenesin as a microbicide of moderate efficacy. Optimum pH range 4-6. Chlorphenesin is used as a preservative in cosmetic and pharmaceutical products. In the EEC Cosmetic Directive it is listed with a maximum permitted concentration of 0.3%. 

Table 118 Minimum inhibition concentrations (MIC) (mg/litre) of A -trihalomethylthio microbicides pounds with N-S-CCI3 compounds...

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