MO Growth
5 environmental conditions that affect the rate of MO growth
1. temperature
2. pH
3. osmotic pressure
4. moisture
5. nutrients
2 types of Culture Media
1. selective culture media
2. differential culture media
A method of MO control that removes the water needed for survival from the cell.
Dessication
Chemotherapy
A drug used to kill rapidly dividing cancer cells
What are some global concerns about Antimicrobial Drug Resistance?
antibiotic storage, rapid global spread of multiresistant bacteria,
Medical Implication of the Log and Stationary Phase
Log: Symptoms are developing
Stationary: The body catches up to MO rate replication OR body is unable to handle infection
Blood Agar
used to differentiate bacteria based on their hemolytic ( ability to destroy RBC) properties.
identifies bacteria that can hemolyze RBC
Sanitization
What are the two major types of Spectrum Activity and describe them.
Broad Spectrum: affects a larger range of bacteria and is most useful for treating an infection prior to identification of MO
Narrow Spectrum: smaller range of affected MO species and requires more knowledge of MO idenitity.
Proper Use of Antibiotics
take them as prescribed, do not save for later, do not share, all drugs have possible side effects.
4 steps of bacterial Reproduction
1. cell elongates & DNA replicates
2. the cell wall & plasma membrane begin to constrict
3. cross-wall forms, separating the two DNA copies
4. cell separates.
True or False: Streptococci grow well on Mannitol Salt Agar?
False, the high levels of salt in the agar favour the growth of staphylococci, but not streptococci.
Explain the Chemical Method of MO control and give an example
Used for cleaning surfaces. Phenols, Phenolics, and Biphenol
Bacteriostatic vs Bacteriocidal
Bacteriostatic: Prevent Growth, Stationary Phase
Bacteriocidial: Kills bacteria
Bacteria responsible for most common fungal infection
Candia auris
Name and describe the four phases of Microbial Growth
Lag: prep for intense activity preparing for population growth
Log: increase in population
Stationary: period of equilibrium, death and new cells
Death: the population is decreasing
Differential Media
Different MO's have different properties on the media and can be divided into different groups.
8 types of Microbial Growth Control
Sterilization, Sanitization, Disinfection, Antisepsis, Asepsis, Degerming, Biocide/Germicide, and Bacteriostasis.
Mechanism for Drug Resistance
1. blocking entry
2. inactivation by enzymes
3. alteration of the target molecule
4. efflux of antibiotic
Potential Solution to Antibiotic Resistance
approval of certain new antibiotics
promote public awareness
encouraging the development of new drugs
4 physical methods of MO control
Heat
Filtration
Dessication
Radiation
Selective Culture
encourages the growth of particular MO & prevents growth of others
Name and describe the two types of Radiation
Ionizing: more powerful, gamma rays, xrays, electron beams, sterilization of food.
Non-ionizing: less powerful, UV lamps/light,
How are Antibiotics differentiated?
How they target MOs (bacteria, fungi, mycobacterium
Mode of Action (structures targeted)
Chemical Structure
4 mechanisms for drug resistance
1. blocking entry
2. inactivation by enzymes
3. alteration of target molecule
4. efflux of antibiotic