Minimum inhibitory concentration tests

Minimum Inhibitory Concentration measured by dilution of test compound in agar inoculated with microorganism. 

Graded doses ofthe test substance are incorporated into broth dispensed in McCartney boules and the bottles inoculated with the test organism and incubated. The point at which no growth occurs is taken as the bacteriostatic concentration (minimum inhibitory concentration, MIC). It is essential when performing these tests to determine the size of the inoculum as the position of the end-point varies considerably with inoculum size, which should always be defined in any description of result. 

LFT, liver function tests MIC, minimum inhibitory concentration. Adapted, with permission, from ref. 14. 

LFT, liver function tests MIC, minimum inhibitory concentration. 

The microdilution method was employed for antibacterial and antifungal activity tests. Media were placed into each well of the 96 well-microplate. Extract solutions at 1,024 pg/ml were added into first raw of microplates and twofold dilutions of the compounds (512-0.25 pg/ml) were made by dispensing the solutions to the remaining wells. Ten microliters of culture suspensions were inoculated into all the wells. The sealed microplates were incubated at 35°C for 24 and 48 h in humid chamber. The lowest concentration of the extracts that completely inhibit macroscopic growth was determined and minimum inhibitory concentrations (MICs) were... 

To compare the bactericidal efficacy of silver nanoparticles and silver ions, the minimum inhibitory concentration (MIC) assays were conducted for gram-negative bacterium E. coli, gram-positive bacteria S. aureus and B. subtilis and fungus P. phoeniceum. The data on MICs are summarized in Table 18.1. The results demonstrated that the antimicrobial activity of silver ions was superior to that of silver nanoparticles against all microbes tested. 

Despite the lack of agreed guidelines for the tests involved, tests do exist and they comprise studies in human volunteers, studies in germ-free rats the intestines of which harbor human gut bacteria, and in vitro studies with bacterial populations. However, the selection of the most appropriate test system remains an open question. All tests investigate minimum inhibitory concentrations (MICs) that can be used in ADI calculations however, such ADI calculations tend to... 

Structure—Activity Relationships. Biological evaluation of penicillins yields information such as in vitro and in vivo antibacterial activities, minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), protective effectiveness in laboratory animals (PD50), and pharmacokinetic characteristics including efficiency of absorption, serum levels, tissue distribution, urinary excretion, recycling, etc. Penicillins are also tested for ability to resist inactivation by (S-lactamase produced by both gram-positive and gram-negative bacteria,... 

The degree of resistance of the mutant clones to the relevant PRP may be assayed by a number of methods. The broth microdiluition susceptibility test, a reference method for determination of the Minimum Inhibitory Concentration (MIC), may be performed according to the guidelines of the National Committee for Clinical Laboratory Standard (NCCLS) as described (20). An example of the increase in the MIC values for Bac7(l-35) in mutagenized HB101 is shown in Table 1. Another suitable and simple method, here described, is the count of bacterial viable cells after incubation with the peptide. 

Organotin complexes of di(2-pyridyl) ketone 2-thenoylhydrazone, 1 and 2, with 6- and 5-coordinated tin atom are less active than the parent organotins67,68. Compound 2 showed good results in tests against Bacillus subtilis, Staphylococcus aureus and also toward several Bacilli with minimum inhibitory concentration ranging from 1.5 to 3 pgml-167. At the same time this complex is devoid of DNA-damaging activity in the Bacillus subtilis rec-... 

Antibiotic Number of strains tested Minimum inhibitory concentration (figlml) ... 

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