Bactericide minimum bactericidal concentration

Vancomycin is bactericidal to most susceptible bacteria at concentrations near its minimum inhibitory concentration (MIC) and is an inhibitor of bacterial cell wall peptidoglycan synthesis, although at a site different from that of j3-lactam antibiotics (Chapter 9). 

Minimum bactericidal concentration The lowest concentration of antibiotic that will eliminate 3 logs or 99.9% of bacteria. 

The evaluation of patients treated for IE includes assessment of signs and symptoms, blood cultures, microbiologic tests (e.g., MIC, minimum bactericidal concentration [MBC], or serum bactericidal titers), serum drug concentrations, and other tests to evaluate organ function. 

Minimal Risk Level (MRL), 25 239 Minimum allowable continuous stable flow (MCSF) limits, for pumps, 21 83 Minimum bactericidal concentrations (MBCs), 18 262... 

In severe bacterial infections that are difficult to eradicate, such as endocarditis or osteomyehtis, it may be important to ensure that the patient s serum remains bactericidal at the lowest, or trough, concentration in the dosing interval. Dilutions of patient s serum can be incubated with the organism isolated from the patient and the minimum bactericidal concentration determined through serial dilutions. Treatment is considered adequate if the serum remains bactericidal at a dilution of 1 8. 

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. 

Table 9. Antimicrobial activity of compounds 11 and 49-53 Minimum Inhibitory Concentration, Minimum Bactericidal Concentration is reported in parentheses (fig/ml)...

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,... 

Molnar, Beladii, and Foldes [69] studied antimycobacterial activity of five phenothiazine derivatives including chlorpromazine, levomeprazine, promazine, promethazine, and diethazine. The growth of Mycobacterium tuberculosis, Mycobacterium bovis, and Mycobacterium butyricum was found to be inhibited by chlorpromazine at practically identical concentrations. The minimum inhibitory concentrations for Mycobacterium tuberculosis were chlorpromazine and levomeprazine 10 xg/ml diethazine and promethazine 20 xg/ml whilst chlorpromazine sulphoxide was ineffective even at 100 xg/ml. Chlorpromazine and promethazine exerted a measurable bactericidal activity on Mycobacterium tuberculosis at 50 xg/ml total destruction of the organism and loss of acid fastness in part of the cells were shown at 300 xg/ml. Preliminary studies in mouse experiments revealed that phenothiazine derivatives were ineffective. 

Isoniazid is the hydrazide of isonicotinic acid. It is a first-line drug for therapy and prophylaxis of tuberculosis. It is bactericidal for rapidly dividing mycobacteria, but bacteriostatic for resting bacilli . Among non-tuberculous mycobacteria, only a few strains, such as Mycobacterium kansasii, are susceptible. As a rule, sensitivity should always be tested in vitro, since the minimum inhibitory concentration varies greatly. 

In the laboratory, the relationship between an antimicrobial drug and a pathogen is described by the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC). The MIC is the lowest drug concentration that inhibits bacterial growth. The MBC is the lowest drug concentration that kills 99.9% of the bacteria. 

Minimum bactericidal concentration (MBC) testing is required for the evaluation of novel antimicrobials. The MBC is the lowest concentration (in mg/L) of antimicrobial that results in >99.9% killing of the bacterium under test. The 99.9% cutoff is an arbitrary in vitro value with 95% confidence limits that has uncertain clinical relevance. 

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