(1)Type of microbiology
Sterilization is a process that eliminates all forms of microorganisms, including bacterial spores. And disinfection is a process that eliminates many kind of microorganisms, but except bacterial spores. In addition, some type of bacteria may resistance some sterilization process or disinfection process. For example, spore-forming organisms are most resistant to sterilization.
(2)Number of microbiology
It is an exponential relationship between the number of microorganisms and the time taken to eliminate them. It means that the larger number of microorganisms need the more time to destroy all of them.
(3)Location of microbiology
If the microorganisms are in a place that the germicide cannot attend then the efficacy of the disinfection and sterilization will be compromised.
(4) Innate resistance of microorganisms
For example some bacterial can secrete beta-lactamase to inhibit beta-lactam and break the beta-lactam ring, it cause bacterial resistant beta-lactam of antibiotic such as penicillin.
Fig 1 .Penicillinase:
Beta-lactamase break the beta-lactam ring and inhibit pencillin active.
(5)Biofilm
Biofilm accumulation reduces efficacy of sterilization by impairing exposure of the sterilant to the microbial cell.
Fig 2 Biofilm resistance to antibacterial agents
(6)Organic and inorganic matter
Organic matter includes serum, blood, fecal and pus. Those can interfere with antimicrobial activity. The organic matter have chemical reaction between germicide, forming a non-germicidal complex. And the organic matter protect the microorganism from germicide, acting as a physical barrier.
More information:
More information:
1. Healthcare Infection Control Practices Advisory Committee (HICPAC)
2.WHO - Infection Control Guidelines for Transmissible Spongiform Encephalopathies
Writte by Chang,yi-chu (Blythe)
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