Modules 1-3 Objectives Flashcards
Robert Hooke’s contributions
Discovered cells
Cell theory
first microscope
Edward Jenner’s contributions
Found smallpox cure
first vaccine
took cowpox scrapings
Louis Pasteur’s contributions
Theory that germs cause disease
disproved the theory of spontaneous generation
Microbial life can be destroyed by heat and can block access of airborne microorganisms
basis of aseptic techniques
discovered pasteurization
found why vaccines worked
used weakened cells for vaccine
Joseph Lister’s contributions
applied germ theory to medical procedures
discovered the first disinfectant (phenol)
Robert Koche’s contributions
First proof that bacteria caused disease (Koch’s postulate)
Worked with Petri to develop the petri dish
Paul Ehrlich’s contributions
discovered arsphenamine (Salvarsan), the first effective medicinal treatment for syphilis
developed a chemical theory to explain the body’s immune response and did important work in chemotherapy, coining the term magic bullet
Alexander Fleming’s Contributions
discovered penicillin
Wendall Stanelys’ contributions
discovered the tobacco mosaic virus
smaller than bacteria and could pass through a filter
could be crystalized like chemicals
Define microorganisms
Minute living organisms that are individually too small to be seen with the naked eye
benefits of microorganisms
form basis of food chains in oceans, lakes, and rivers
help break down wastes in sewage disposal
Photosynthesis
Present in intestine for digestion and synthesis of vitamin k and vitamin b
used in the synthesis of chemical products
used in food industry to produce foods
Describe microbial classifications
bacteria
fungi
protozoans
microscopic algae
viruses
Scientific nomenclature for bacterial names
The genus:
Capitalized
first
italicized
The species:
lowercase
second
italicized
Compare and contrast prokaryotic and eukaryotic cytoplasmic and cell envelope structures and functions
Like a prokaryotic cell, a eukaryotic cell has a plasma membrane, cytoplasm, and ribosomes, but a eukaryotic cell is typically larger than a prokaryotic cell, has a true nucleus (meaning its DNA is surrounded by a membrane), and has other membrane-bound organelles that allow for compartmentalization of functions.
The three basic shapes of microorganisms
cocci (sphere)
bacilli (rod)
Spirochetes (spiral)
Describe the reproductive process of bacteria, and the stages in growth of the bacterial cells
bacteria reproduce primarily by fission, or direct division. During mitosis, a parent cell is divided into 2 daughter cells by creating a septum that directly separates the parent cell in half
Differentiate between gram positive and gram negative bacteria
Gram positive:
thicker layer of peptidoglycan
cell walls contain teichoic acid
teichoic acid help prevent cell wall lysis
Gram negative:
small amounts of peptidoglycan
no teichoic acids
peptidoglycan layer surrounded by an outer membrane consisting of lipopolysaccharides (LPS), lipoproteins, and phospholipids
alkaline dye of gram stain washes out
atmospheric requirements of obligate aerobes, microaerophiles, facultative anaerobes and obligate anaerobes
The bacteria are obligate (strict) aerobes that cannot grow without an abundant supply of oxygen.
Those are obligate anaerobes, which are killed by oxygen.
Facultative anaerobes are organisms that thrive in the presence of oxygen but also grow in its absence by relying on fermentation or anaerobic respiration, if there is a suitable electron acceptor other than oxygen and the organism is able to perform anaerobic respiration.
The aerotolerant anaerobes in tube D are indifferent to the presence of oxygen. They do not use oxygen because they usually have a fermentative metabolism, but they are not harmed by the presence of oxygen as obligate anaerobes are.
These microaerophiles are bacteria that require a minimum level of oxygen for growth, about 1%–10%, well below the 21% found in the atmosphere.
Define atmospheric requirements of microorganisms
If oxygen is acceptable or not for growth
List the possible routes of laboratory-acquired infections
Inhalation (see aerosols)
Percutaneous inoculation (needle and syringe, cuts or abrasions from contaminated items and animal bites)
Contact between mucous membranes and contaminated material (hands or surfaces)
Ingestion (aspiration through a pipette, smoking or eating)
List the agencies that govern laboratory safety in the microbiology department
Occupational Safety and Health Administration (OHSA)
National Fire Protection Agency (NFPA)
The Joint Commission (TJC)
College of American Pathologists (CAP)
Delineate the roles the laboratory technologist plays in an infection control program
Monitors infections in the facility
Infection control procedure development
The primary objective of biological safety is preventing the completion of the chain of infection
Correlate the role of the laboratory with the safety guidelines and the prevention of nosocomial infections
Appropriate safety measures should include a routine, deep cleaning of all areas of the hospital, both in-patient and out-patient, to minimize communicable transmission infectious diseases.
Define sterilization
The process of destroying all forms of microbial life on an object or in a material
define bacteriostatic
A condition in which bacterial growth and multiplication are inhibited, but the bacteria is not killed
define disinfection
The process of destroying vegetative pathogens, but not necessarily endospores or viruses
Reduce or inhibit growth
define bactericidal
kills bacteria
Differentiate the functions and purpose of a disinfectant and an antiseptic
Disinfection:
Process of destroying vegetative pathogens, but not necessarily endospores or viruses. Chemical applied to object or material
Antisepsis:
Chemical disinfection of the skin, mucous membranes, or other living tissues
Describe what is meant by antimicrobial action
bacteriostatic or bacteriocidal
Describe the way each physical agent control the growth of microorganisms
Temperature extremes, including heat and cold: While low temperatures can slow down the growth of microorganisms, heat represents a highly effective method for killing microbes.
List the mechanism of action for each type of chemical agent commonly used in antimicrobial reagents
(1) interference with cell wall synthesis
(2) inhibition of protein synthesis
(3) Interference with nucleic acid synthesis
(4) inhibition of a metabolic pathway
(5) inhibition of membrane function
(6) inhibition of ATP Synthase
Differentiate the use and application of skin antiseptics used in a hospital setting
Antiseptics are chemical agents applied to the skin to reduce the microbial count and reduce the risk of surgical site infections
Describe the heat methods used for microorganism control
Moist heat sterilization
dry heat
pasteurization
low temperature
Describe and differentiate the various types of biological safety cabinets
There are three classes of BSCs: Class I, II and III. While all three classes afford personnel and environmental protection, only Class II and III cabinets provide product protection. Class I BSCs are suitable for work involving low to moderate-risk agents.
Quality control in microbiology testing
Quality control involves testing units and determining if they are within the specifications for the final product.
