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LAT certification
Chapter 5
Question | Answer |
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What is the design of an animal facility largely determined by? | The nature of the research and testing activities |
What are the different sections of an animal facility? | Cage wash areas, animal housing areas, surgery suites, procedure rooms, mechanical spaces (HVAC systems) and personnel facilities such as locker rooms and break rooms |
The circulation pattern of people, animals and equipment through a facility can have an impact on what status of the animals? | Microbiological status |
What are the four common corridor floor plans? | Single-corridor, Dual-corridor, Three-corridor and Mixed floor plan |
What is a single-corridor floor plan? Where is it a common design? | Single-corridor floor plan consists of a central corridor with no separation of traffic by clean and dirty status. Most common design for conventional facilties |
What is an airlock? | A passageway with two locking doors that cannot be opened simultaneously |
What is a two-corridor floor plan? | A two-corridor floor plan separates clean and dirty traffic in designated corridors to reduce possibility of contamination of clean equipment, materials and animals. Traffic flow is one-way in each corridor. |
What is a three-corridor floor plan? | Modification used in large facilities, where a single clean corridor serves rooms on both sides. Each room has exit doors to a dirty corridor that wraps around the periphery. |
What is a mixed floor plan? | Combination of one-way and two-way circulation patterns. |
What is bioexclusion? | To prevent entry of microorganisms (protecting the animals) |
What are some possible features of a barrier facility designed for bioexclusion? | Staff wear sterilized PPE, shower in to the facility, all work completed in laminar flow cabinet, all materials sterilized prior to animal holding room, air pressure remains positive to surrounding areas |
What is modified SPF? | describes a barrier with less stringent procedures than for bioexclusion, while still requiring some effort to prevent contamination of the animals within. |
What is biocontainment? | To prevent pathogens from leaving the room (protecting the people and animals elsewhere in the facility) |
What are some possible features of a barrier facility designed for biocontainment? | contamination controls and worker protection are determined by biosafety personnel, PPE might include eye and respiratory protection, signs outside room indicate hazardous agent, air pressure is negative relative to surrounding area |
What are some procedures and precautions that can protect animals from unwanted exposure to microorganisms? | acquiring SPF animals from trusted sources, establishing a pest control program, wearing PPE, operating a health surveillance program |
What is the Guide's recommendation for relative humidity for most mammalian species? | 30-70% |
What condition in mice and rats has been associated with low relative humidity? | Ringtail |
What is relative humidity? | An indication of the amount of water present in air; expressed as a percentage of the maximum amount of water the air is able to hold at the current temperature. |
What is dry-bulb temperature? | Refers to the protection of the thermometer bulb from moisture; this type of thermometer simply measures the air temperature |
What is wet-bulb temperature? | Determined from a moistened thermometer bulb; the temperature reading reflects the effect of evaporative cooling on the bulb, always less than dry-bulb, used as a measure of humidity |
What is the guideline for room air exchanges per hour in animal rooms? | 10 to 15 |
What is an anemometer? | A handheld device that measures the velocity of air passing through an air vent. |
How can room air changes per hour be calculated? | 1. Convert CFM to cubic feet per hour (CFH) 2. Calculate the volume (in cubic feet) of the room 3. Divide the airflow rate (CFH) by the room volume to determine the number of air changes per hour |
How does air flow if it is at positive pressure? | Air flows from the room out to adjoining areas when a door is opened, keeping contaminants from entering the room. |
What are examples of rooms with positive-pressure ventilation? | Surgical Suites, Barrier Rooms, Animal rooms |
How does air flow if it is at negative pressure? | Air flows from the hallway into the room when the door is opened, keeping contaminants from exiting the room. |
What are examples of rooms with negative-pressure ventilation? | Animal quarantine, rooms where infectious agents or biohazards are present |
What do Laminar air flow cabinets or cubicles provide? | A cage or rack environment with a large volume of slow-moving, linear-flowing, sterile filtered air which reduces or eliminates air turbulence which could stir up particles or aerosols causing microbial contamination |
Describe the flow of air in a laminar flow cabinet | Air is drawn through a prefilter and forced into a plenum (distribution chamber), then through HEPA filters and over the work surface. |
How effective are HEPA filters in removing particulate matter? | 99.97% effective |
How do ventilated cage racks work? | Provide HEPA-filtered air to individual cage. The rack can be adjusted to provide relative positive or negative pressure to the cages. Provides a cage-level carrier with added advantage of continuous airflow |
What are two critical factors pertaining to animal room lighting? | Light intensity and light cycle |
Where are light intensity measurements generally taken? | 1 meter above the floor |
What is a recommended light cycle for most species? | 12:12 |
What are some stress responses that could be caused by exposure to high noise levels? | Enlarged adrenal glands, reduced breeding efficiency, increased blood pressure, auditory damage, behavioral disorders. |
What is the Guide's recommendation around social housing? | All social species should be housed in pairs or groups in a laboratory setting unless permission to singly house the animals is obtained from the IACUC or veterinarian. |
What is the goal of environmental enrichment? | To improve the research animal's environment by permitting animals to engage in species-type behaviors |
Name some examples of enrichment | Structural (cage components), sensory or motor stimulation, activities such as exercise, exploration or social interaction |
What two species does the AWA mandate a written plan for environmental enrichment? | Dogs-exercise plan; Non-human primate-psychological well-being or enrichment plan |
What factors are included in an effective sanitation and hygiene program? | facility design, equipment selection, employee training, standard operating procedures, and the selection of cleaning and decontamination agents. |
What is the definition of a sanitizer? | Sanitizers reduce, but do not necessarily eliminate, microbes from the inanimate environment to levels considered safe by public health code |
What is the definition of a disinfectant? | Disinfectants destroy or irreversibly inactivate infectious fungi and bacteria, but not necessarily spores. Divided into two major types: hospital and general use |
What is the definition of a sterilizer? | Sterilizers, or sporicides, kill all forms of microbial life and their spores-including fungi, viruses and all forms of bacteria. |
What is an antiseptic? | An antiseptic prevents infection and decay by inhibiting microbial growth. Used on live humans or animals |
What is the first step in decontamination? | Cleaning, which is the complete removal of all visible debris from a surface. |
What should a sanitation program include? | A procedure for cleaning and a procedure for sanitizing or disinfecting. |
What three factors determine whether a decontamination or sterilization will be successful? | Distribution, penetration and contact time of the agent |
What is contact time? | The period in which an effective concentration of the agent is maintained. |
What are some aspects that should be taken into consideration when choosing the appropriate chemical for a task? | Label claims, spectrum of activity, effectiveness in hard water, pH stability, dilution, contact time, temperature, toxicity, safety |
Which chemical compound is toxic to cats and amphibians? | Phenols |
What factors affect the selection of PPE when applying a chemical? | The chemical to be used, the physical state of the chemical, the quantity to be applied, and the application method. |
Where is the use of iodophors appropriate? | Hand-washing soaps, surgical soaps and antiseptics |
What are common sterilization techniques? | Application of chemicals, moist heat, dry heat, and radiation |
Chemical sterilizer systems us a _____________ | Sterilizing gas or vapor |
What are two common chemical sterilizers? | Vaporized hydrogen peroxide (VHP) and chlorine dioxide gas (CD) |
What are the two different processes used to achieve VHP decontamination? | Dry process and Wet process. Dry process refers to VHP in the vapor state, and Wet Process refers to the formation of VHP condensation. |
How is chlorine dioxide generated in the dry method? | By flowing dilute chlorine gas over solid sodium chlorite to generate pure chlorine dioxide gas for fumigation |
How can chlorine dioxide in the wet method be used? | Can be used for fogging a room, as well as manually spraying and wiping nonporous surfaces |
What is ethylene oxide used for? | Medical device sterilization. Commonly used to sterilize the surface of heat-sensitive materials such as surgical sutures, cannulas or electronic probes |
What is a steam autoclave used for? | Primary means of sterilizing supplies and caging systems that cannot be readily sterilized by chemicals |
What are some common features and requirements for an autoclave? | Central chamber surrounded by a jacket, steam is saturated with water vapor and heated under pressure, a baffle diffuses the steam, drain is located at the lowest point of the chamber, valves permit the exit of air and steam, safety release valve |
What is needed for effective sterilization using an autoclave? | All air must be removed from the chamber, allowing only steam to come in contact with every part of the chamber contents. |
What is the most common dry heat method of sterilization? | Use of a hot air oven |
What type of radiation is used for sterilization? | Ionizing (gamma and beta) and nonionizing (ultraviolet or UV) |
What are some methods to monitor and evaluate the effectiveness of a sanitization or sterilization procedure? | Visual inspection, temperature-sensitive indicators, biological indicators, microbial swabs, RODAC plates, Bioluminescence Monitoring systems |
What is the most commonly used biological indicator? | The bacterium Bacillus stearothermophilus |
What does RODAC stand for? | Replicate Organism Detection and Counting |
What do RODAC plates allow for? | Direct sampling of the area onto the agar plate, with the advantage of reducing the potential for sample cross-contamination |
What are some noninvasive methods to control pest infestations? | Traps, sticky boards, boric acid, or silica powder with a stringent sanitation and housekeeping program. |
What is a fomite? | Any inanimate object or substance capable of being contaminated with infectious organisms, including parasites, which can then infect the individual handling the fomite. |
What are some measures that can be taken to prevent allergen exposure as well as exposure to potential pathogens? | Wear PPE, change cages within airflow-controlled changing stations, open cages only within laminar flow hoods, wash hands frequently, use materials that produce fewer airborne particles, remove contaminated PPE before entering support areas or going home. |
Describe Biosafety Level 1 (BSL-1) | Hazardous agents-agents that do not consistently cause disease in health adults and do not pose a risk to personnel and the environment. Requirements-basic level of containment, no special practices |
Describe Biosafety Level 2 (BSL-2) | Hazardous agents-indigenous organisms that pose a moderate risk of disease Requirements-training on how to work safely with the agent, signs at lab entrance stating agent and precautions, biosafety cabinets for procedures that may produce aerosols |
Describe Biosafety Level 3 (BSL-3) | Hazardous agents-agents that can cause serious or lethal disease when inhaled Requirements-all manipulations done in BSC, appropriate PPE includes respirators and eye and face protection, all materials must be decontaminated prior to removal from lab |
Describe Biosafety Level 4 (BSL-4) | Hazardous agents-pose a great risk of deadly disease and aerosol transmission, or related to a highly infectious agent with unknown risk of transmission Requirements-work in Class III BSC or workers in impervious positive pressure suit in Class II BSC |
How do ABSL levels differ from BSL levels? | Applicable to animal facilities-contain some animal facility-specific precautions and recommendations. |
What precautions are recommended for all ABSL levels? | The animal facility should be separated from the general traffic pattern in the building, all research animals should be approved by an IACUC, facility should be operated according to the Guide |
What precautions are recommended for levels ABSL- 2 and higher? | Contaminated bedding, cages, carcasses and equipment be decontaminated before removal from animal housing areas |
What precautions are recommended for ABSL-3 and higher? | All manipulations with infected animals should be done within a BSC. |
What does the level BSL-3-Agriculture (BSL-3-Ag) address? | Additional BSL level that addresses activities involving large or loose-housed animals or studies involving agents designated as High Consequence Pathogens by the USDA |
What are High Consequence Pathogens? | Agents that are considered veterinary risks for agricultural animals, rather than public health-aim to protect against the economic impact of animal disease on agricultural commerce |
Protective equipment used in biosafety work is categorized as? | Primary or secondary barriers. |
Primary barriers are defined as? | Immediate barrier preventing the exposure of humans, animals and the environment to hazardous biological agents |
What are examples of primary barriers? | PPE and engineering controls such as biological safety cabinets (BSC) or a microisolation-type mouse cage outfitted with seals and a locking mechanism |
Define a Class I BSC | Also called open-front or open-face cabinets, suitable for most microbiological procedures. Airflow within the cabinet prevents escape of material from the cabinet, and exhaust air passes through a HEPA filter |
Define a Class II BSC | provides protection similar to a Class I, with the added feature of HEPA filtered incoming air flow to protect the research material from external contamination |
Define a Class III BSC | Gas-tight space with a nonopening view window. Materials are brought into the cabinet through a dunk tank or a double-door pass-through box. HEPA filtered exhaust and supply air. Work done inside cabinet with heavy-duty rubber gloves |
What does effective operation of a BSC depend on? | Inward flow of air |
What activities have been shown to alter airflow in a BSC? | repeated insertion of arms into the cabinet, improper placement of materials within the cabinet, high traffic flow in front of the cabinet, repeated opening and closing of doors in the room |
When should BSC be tested ? | At installation, when moved to a new location, and at least annually as routine maintenance |
What are secondary barriers? | Design features of the facility that enhance the protection of people, other animals and the environment from contamination by pathogens. |
Some examples of secondary barriers are? | Airlocks, locker rooms, shower areas, differential airflow, HEPA filters on the HVAC systems and handwashing sinks |