MCB 100: Final Exam Questions and Correct
Answers
Biosafety levels
the type of work practices allowed to take place in a lab setting;
How are biosafety level defined?
-risk related to containment
-severity of potential infection
-origin of the microbe, host specificity
-Route of exposure, transmissibility of microbe
-Nature of the work conducted in the lab
Biosafety level 1
Microbe example: non-pathogentic E.coli
-Handling pathogens that do not cause disease in heealthy humans
-Precautions include handwashing with antibacterial soap and disinfecting surfaces
-Standard microbiological practices common to all labs
-no eating or drinking, wash hands, and route decontamination of work surfaces
Biosafety level 2
Microbe example: Bordetella pertussis
-Handling of moderately biohazardous agents
-Using personal protective equipment (PPE) -gloves, eye wear
-access to BSL-2 labs limited to trained personnel
-Extreme precautions are taken with contaminated sharp objects
-Procedures that might produce aerosols are conducted in biosafety cabinets
,Biosafety level 3
Microbe example: SARS-CoV-2, TB
-Handling of highly pathogenic, infectious, or toxic microbes is conducted in biosafety
cabinets using PPE
-Using a special BSL-3 facility where air leaving the room is filtered with high-efficiency
particulate air filters to prevent pathogen escape
-BSL-3 facility has specific design features for the laboratory, including entry through double
sets of doors and lower inside air pressure, such that opening the door only allows air to move
into the lab, and not out of the room Safe Handling of Pathogens and Biohazardous Material -
BSL-3
Biosafety level 4
Microbe example: Ebolavirus, Marburg virus
-Handling of highly infectious pathogens that cause deadly diseases (for which there is no
treatment)
-BSL-4 labs are separate buildings or completely isolated from other areas of the buildings.
-Labs require special lab facilities with special air-handling equipment and special PPE
-Entry and exit of the labs are strictly controlled through electronically sealed airlocks with
multiple showers, vacuum rooms, UV light rooms, and more
-Entire lab is pressurized, and air is handled so that pathogens are swept away from workers
Microbial control
Avoidance, Prevention, and Reduction
-Use PPE, avoid direct contact with sharps, and wash your hands
Steralization
, Removal of all forms of life from surfaces or substances
-achieved by treatment with heat, chemicals, irradiation, high pressure, or filtration
After the object is considered sterile or aseptic
Disinfectants and antimicrobial agents:
slow down or inhibit the growth of microbes
natural agents
antibiotics, natural acids such as vinegar or citrus juice, and alcohols
artfical agents
chemicals, drugs, detergents, gases
agents only used externally
Disinfectants and sanitizers
Agents only used on the body surfaces
antiseptics and germicides
Agents safe to ingest or inject
antibiotics and antimicrobial
Antomicrobial
any substance that kills or inhibits the growth of microbes
Microbicial (Germicidal)
kills the microbe (germ)
example: Bactericidal antibiotics lyse and kill bacteria. Note: Lysing of bacteria during sepsis
can lead to worse disease consequences due to release of endotoxin or other toxins.
Microbiostatic
Prevent the growth of the microbe (but do not kill it)
Example: Bacteriostatic antibiotics stop or slow down bacterial growth, but the bacteria are
Answers
Biosafety levels
the type of work practices allowed to take place in a lab setting;
How are biosafety level defined?
-risk related to containment
-severity of potential infection
-origin of the microbe, host specificity
-Route of exposure, transmissibility of microbe
-Nature of the work conducted in the lab
Biosafety level 1
Microbe example: non-pathogentic E.coli
-Handling pathogens that do not cause disease in heealthy humans
-Precautions include handwashing with antibacterial soap and disinfecting surfaces
-Standard microbiological practices common to all labs
-no eating or drinking, wash hands, and route decontamination of work surfaces
Biosafety level 2
Microbe example: Bordetella pertussis
-Handling of moderately biohazardous agents
-Using personal protective equipment (PPE) -gloves, eye wear
-access to BSL-2 labs limited to trained personnel
-Extreme precautions are taken with contaminated sharp objects
-Procedures that might produce aerosols are conducted in biosafety cabinets
,Biosafety level 3
Microbe example: SARS-CoV-2, TB
-Handling of highly pathogenic, infectious, or toxic microbes is conducted in biosafety
cabinets using PPE
-Using a special BSL-3 facility where air leaving the room is filtered with high-efficiency
particulate air filters to prevent pathogen escape
-BSL-3 facility has specific design features for the laboratory, including entry through double
sets of doors and lower inside air pressure, such that opening the door only allows air to move
into the lab, and not out of the room Safe Handling of Pathogens and Biohazardous Material -
BSL-3
Biosafety level 4
Microbe example: Ebolavirus, Marburg virus
-Handling of highly infectious pathogens that cause deadly diseases (for which there is no
treatment)
-BSL-4 labs are separate buildings or completely isolated from other areas of the buildings.
-Labs require special lab facilities with special air-handling equipment and special PPE
-Entry and exit of the labs are strictly controlled through electronically sealed airlocks with
multiple showers, vacuum rooms, UV light rooms, and more
-Entire lab is pressurized, and air is handled so that pathogens are swept away from workers
Microbial control
Avoidance, Prevention, and Reduction
-Use PPE, avoid direct contact with sharps, and wash your hands
Steralization
, Removal of all forms of life from surfaces or substances
-achieved by treatment with heat, chemicals, irradiation, high pressure, or filtration
After the object is considered sterile or aseptic
Disinfectants and antimicrobial agents:
slow down or inhibit the growth of microbes
natural agents
antibiotics, natural acids such as vinegar or citrus juice, and alcohols
artfical agents
chemicals, drugs, detergents, gases
agents only used externally
Disinfectants and sanitizers
Agents only used on the body surfaces
antiseptics and germicides
Agents safe to ingest or inject
antibiotics and antimicrobial
Antomicrobial
any substance that kills or inhibits the growth of microbes
Microbicial (Germicidal)
kills the microbe (germ)
example: Bactericidal antibiotics lyse and kill bacteria. Note: Lysing of bacteria during sepsis
can lead to worse disease consequences due to release of endotoxin or other toxins.
Microbiostatic
Prevent the growth of the microbe (but do not kill it)
Example: Bacteriostatic antibiotics stop or slow down bacterial growth, but the bacteria are
