Microbial Control Methods Quiz

Contributions to Microbiology

• Lazzaro Spallanzani discovered that no growth took place in a sealed flask, not exposed to the environment.
• Robert Koch showed that a specific microorganism causes a particular disease, and discovered bacteria such as Bacillus anthracis, Mycobacterium tuberculosis, and Vibrio cholerae.
• Robert Koch developed Koch's Postulate, which states that:
  • Microorganisms are observed in a diseased animal.
  • The same microorganisms are cultivated in the laboratory.
  • The same microorganisms are injected into a healthy animal.
  • The healthy animal then develops the same disease.
  • The same microorganisms are cultivated from the diseased animal.
• Alexander Fleming discovered penicillin and its curative effect in various diseases.

The Human Microbiome

• The human microbiome acts as symbiotic partners, supplying essential nutrients, and shaping morphological and physiological attributes.
• Eubiosis refers to health, while dysbiosis refers to disease.
• Microbial infections result from host-microbe interaction, and can lead to a burden of disease.

Microbial Infection and Disease

• Symbionts are organisms living in symbiosis.
• Pathogens are disease-causing microorganisms that can lead to a burden of disease.
• Burden of disease refers to death and loss of health due to microbial pathogens.
• Burden of microbial infection refers to naturally occurring microorganisms that constitute a global catastrophic biological risk.

Antibiotics and Antimicrobial Resistance

• Antibiotics kill a vast majority of susceptible bacteria quickly by disrupting their metabolism, DNA, or outer layer.
• Some bacteria have found ways to protect themselves from antibiotics, such as intercepting antibiotics and changing molecules, or investing energy in pumps that eject antibiotics.
• Antibiotics should be treated as a last-resort drug.
• Spreading of antibiotic immunity can occur through gene transfer via conjugation.

Microbial Control Methods

• Microbial control methods can be classified into three modes: physical agents, chemical agents, and mechanical removal methods.
• Factors affecting the efficiency of microbial control methods include contact hours, length of time, and temperature applied.
• Antimicrobial agents can be classified into three types: natural, semi-synthetic, and synthetic.
• Antimicrobial agents can be used to inhibit cell wall synthesis, directly damage proteins or nucleic acids, or disrupt cytoplasmic membrane function.

One Health

• The concept of One Health emphasizes that the health of one is the health of everyone, and achieving optimal health and well-being outcomes.
• Human health is connected to the health of animals, plants, and the environment.

Microscopic Organisms and Treatment

• Microscopic organisms are too small to be seen by the naked eye, except for fungi.
• Treatments against microscopic organisms include antibiotics, disinfection, and antisepsis.
• The mechanical removal of most microbes is a method of microbial control.

Microbial Control Methods (continued)

• Physical agents of microbial control include heat, radiation, and dry and moist methods.
• Chemical agents of microbial control include liquids, gases, and animates and inanimate objects.
• Mechanical removal methods include filtration, air, and liquid.
• Factors affecting the efficiency of microbial control methods include contact hours, length of time, and temperature applied.

Antimicrobial Actions

• Antimicrobial actions can be classified into two types: bactericidal and bacteriostatic.
• Bactericidal antimicrobial actions destroy or kill bacteria, while bacteriostatic antimicrobial actions stop or inhibit the growth of bacteria.

Principles of Microbial Control

• Sterilization is the process of destroying all living organisms and viruses, including endospores.
• Disinfection is the use of physical or chemical agents to kill vegetative bacteria or pathogens, except for endospores.
• Decontamination is the treatment of an inanimate object or surface to make it safe to handle or use.