What chapter is surface disinfection and treatment room preparation?
Chapter 7 surface disinfection and treatment room preparation STUDY Flashcards Learn Write Spell Test PLAY Match Gravity Created by feliciamvargas Key Concepts: Terms in this set (30)
What is surface sampling used for in epidemiology?
Surface sampling is used currently for research, as part of an epidemiologic investigation, or as part of a comprehensive approach for specific quality assurance purposes. As a research tool, surface sampling has been used to determine potential environmental reservoirs of pathogens, 564, 1230–1232
Is surface sampling cost-effective in health-care settings?
4. Environmental Surface Sampling Routine environmental-surface sampling (e.g., surveillance cultures) in health-care settings is neither cost-effective nor warranted. 951, 1225 When indicated, surface sampling should be conducted with multidisciplinary approval in adherence to carefully considered plans of action and policy (Box 15). Box 15.
How do you do surface sampling in microbiology?
Effective sampling of surfaces requires moisture, either already present on the surface to be sampled or via moistened swabs, sponges, wipes, agar surfaces, or membrane filters. 1214, 1234–1236 Dilution fluids and rinse fluids include various buffers or general purpose broth media (Table 24).
Why is it important that you disinfect your work area both before and after working with bacteria?
Why should you decontaminate your work area prior to beginning lab work? To prevent the potential transfer of microbes to you and your experiment. While removing a clean glass culture tube from its box, you accidentally drop the tube, and it shatters on the floor.
How would you determine if your aseptic transfer was successful?
Success is presence of growth. If any of your transfers were unsuccessful, suggest possible errors that may have been made in the transfer process. Failure is no growth; or growth of a wide variety of colonies, signaling contamination.
How do you obtain bacterial samples?
Dry swabs are recommended for wet surfaces and wet swabs for dry surfaces.Wear suitable gloves.Remove swab from tube (If using swabs with a wetting agent, drain most of it on the sides of the tube before sampling)Swab the test surface by rolling the swab lightly back and forth.More items...
What are the precautionary measures to be observed before during and after applying the aseptic culture technique?
Sterilize all materials before beginning....Keep the cover over the plate bottom to prevent dust and microbes from falling onto the agar.Wear gloves whenever you may come in contact with any type of microbe.If your gloves become contaminated, remove them and put on a new pair.Report any spills to me immediately!
Why is it important to obtain sample in microbiology thru aseptic technique?
In the microbiology lab we use aseptic technique to: Prevent contamination of the specific microorganism we are working with. Prevent contamination of the room and personnel with the microorganism we are working with.
How do you know that you have used aseptic technique correctly and have achieved a pure culture?
Proof of proper aseptic technique in producing a pure culture is achieved by isolating and growing a single type of colony. If there are more than one colonies growing on the same medium, then pure culture as not been acheived.
How do you collect samples from the surface?
0:351:41Collecting Samples from Stainless Steel Surfaces - YouTubeYouTubeStart of suggested clipEnd of suggested clipTurn swab to opposite side and swab approximately. Ten times in a horizontal side-to-side motionMoreTurn swab to opposite side and swab approximately. Ten times in a horizontal side-to-side motion over the surface area being sampled.
How do you collect bacteria samples from surfaces?
SwabsUse sterile swabs. ... Remove the outer packaging of the sterile swab.It is often recommended to follow the instructions on the outer packaging to moisten the swab before sampling to help improve collection efficiency. ... Swab the area of concern. ... Return the swab into the tube.
How do you test for bacteria on the surface?
Rub a sterile swab over the areas of your counter most prone to collecting bacteria. Check a variety of different areas, focusing on where you most often handle your food. For example, you can collect samples from the edges of the sink, as well as the back of your spice rack and the bottom of your knife block.
What are the precautionary measures that must be observed to ensure that the culture media are free from contamination?
How To Prevent Cell Culture ContaminationWear gloves, lab-coats and use hoods. ... Use your hood correctly. ... Clean your incubator and water bath regularly. ... Spray EVERYTHING with ethanol or IMS. ... Minimize exposure of cells to non-sterile environments.
What are the various aseptic techniques and contamination control which you should follow while working in the ATC lab?
Sterile handlingAlways wipe your hands and your work area with 70% ethanol.Wipe the outside of the containers, flasks, plates, and dishes with 70% ethanol before placing them in the cell culture hood.Avoid pouring media and reagents directly from bottles or flasks.More items...
What are the precaution to be taken during the preparation of a culture solution?
Care should be taken to avoid contact with skin, eyes, or mucous membranes when handling culture media or any laboratory reagent, stain, fixative, or chemical. If contact occurs, flush immediately with running water. Contact a physician, hospital, or poison control center if overexposure or irritation exists.
What does aseptic transfer mean and why was it important?
Microbiologists use aseptic technique for a variety of procedures such as transferring cultures, inoculating media, isolation of pure cultures, and for performing microbiological tests. Proper aseptic technique prevents contamination of cultures from foreign bacteria inherent in the environment.
How do you do aseptic transfer?
The procedure for aseptically transferring microorganisms is as follows:Using a microincinerator to sterilize the inoculating loop.Microincinerators enable the sterilization of inoculating loops without having to use an open flame of a Bunsen burner. ... Remove the inoculum.Transfer the Inoculum to the Sterile Medium.
How do you aseptically transfer bacteria?
1:356:00Aseptic Technique - YouTubeYouTubeStart of suggested clipEnd of suggested clipTransfer the bacteria to your Petri plate lift the lid of the plate. And hold it over the base as aMoreTransfer the bacteria to your Petri plate lift the lid of the plate. And hold it over the base as a shield to prevent contaminants from falling onto the plate spread.
Which of the following may indicate that you have correctly transferred an organism from a broth to a slant select all that apply?
Which of the following may indicate that you have correctly transferred an organism from a broth to a slant? After Gram staining a smear prepared from the slant, all of the cells have similar color and morphology under the microscope. The slant shows only one color of growth.
What is microbiology sampling?
Microbiologic sampling of air, water, and inanimate surfaces (i.e., environmental sampling) is an expensive and time-consuming process that is complicated by many variables in protocol, analysis, and interpretation.
Why is microbiology used in air sampling?
Microbiologic air sampling is used as needed to determine the numbers and types of microorganisms, or particulates, in indoor air. 289 Air sampling for quality control is, however, problematic because of lack of uniform air-quality standards.
What are the principles of microbiology?
1. General Principles: Microbiologic Sampling of the Environment. Before 1970, U.S. hospitals conducted regularly scheduled culturing of the air and environmental surfaces (e.g., floors, walls, and table tops). 1202 By 1970, CDC and the American Hospital Association (AHA) were advocating the discontinuation of routine environmental culturing ...
What factors determine the survival of microorganisms within a bioaerosol?
Factors that determine the survival of microorganisms within a bioaerosol include. the suspending medium, temperature, relative humidity, oxygen sensitivity, and.
What are biological contaminants?
Biological contaminants occur in the air as aerosols and may include bacteria, fungi, viruses, and pollens. 1215, 1216 Aerosols are characterized as solid or liquid particles suspended in air. Talking for 5 minutes and coughing each can produce 3,000 droplet nuclei; sneezing can generate approximately 40,000 droplets which then evaporate to particles in the size range of 0.5–12 μm. 137, 1217 Particles in a biological aerosol usually vary in size from <1 μm to ≥50 μm. These particles may consist of a single, unattached organism or may occur in the form of clumps composed of a number of bacteria. Clumps can also include dust and dried organic or inorganic material. Vegetative forms of bacterial cells and viruses may be present in the air in a lesser number than bacterial spores or fungal spores. Factors that determine the survival of microorganisms within a bioaerosol include
Is air sampling unjustified?
Conducting quality-assurance sampling on an extended basis, especially in the absence of an adverse outcome, is usually unjustified. A possible exception might be the use of air sampling during major construction periods to qualitatively detect breaks in environmental infection-control measures.
Why is contamination likely when dispensing stock medium onto the place?
Contamination probably occurred while dispensing stock medium onto the place because is is found in all levels of medium (indicating the agar was liquid when contaminated). It is not likely due to contamination of the stock medium because only one plate shows contamination. e.
What is the purpose of a Gram stain?
A Gram stain or another streak plate can be used to verify colony purity. If the colony is not pure, then it should be re-streaked (or, the streak plate used to verify purity could be used) and a colony of the "correct" organism should be picked from this second plate and used to start a pure culture.
Why is the medium undefined?
It is undefined due to the casein and soybean in the medium. Casein is really a related family of proteins, not one specific molecule found in the milk of all mammals so its exact composition is unknown, and soybean is a mixture of unknown biochemicals. Either one of these would make the medium undefined.
What are some examples of chemically defined media?
Contains a variety of ingredients and there is no exact chemical formula for ingredients (can be highly variable). Examples include: Nutrient Broth, Blood agar, and chocolate agar. Click again to see term 👆. Tap again to see term 👆. Chemically Defined Media. Click card to see definition 👆.
Is S. epidermis pure?
Explain your answer. The slant and broth cultures of S. epidermis should be pure, meaning that only S. epidermis is growing in them. Making transfers from each should result in only one microbial type on/in the receiving medium. Colonies usually arise from single or joined cells in the same species.
Do all plates in a batch have the same type and density of contaminants?
All plates in a batch have the same type and density of contaminants. g. Only a few plates in a batch are contaminated, and each looks different. a. Since the broth is sterilized after it is dispensed into the container prior to sterilization, so any contamination is removed during autoclaving. The medium has already been sterilized ...
Does MacConkey agar affect sensitivity?
It probably wouldn't affect sensitivity , because you would still be able to detect growth of organisms that "should" grow on it as well as detect the pink color indicative of lactose fermentation. Suppose a mistake is made in preparing a batch of MacConkey agar and he starting pH is 7.6 instead of 6.9-7.3.
Why do disinfectants need to be tested?
Disinfectants used in hospitals and laboratories must be tested periodically to ascertain its potency and efficacy. As certain disinfectants lose potency on standing and addition of organic matter, their efficacy must be tested. While certain methods help in selecting the right dilution of disinfectant for use others test the efficacy ...
What are the different methods of testing disinfectants?
All these tests can be allocated to one of the following disinfectant tests: carrier test, suspension test, capacity test, practical test, field test or in-use test.
How to perform a bactericidal test?
Bactericidal tests:- A bactericidal test must include the following sequence of steps: 1 The test organism is exposed to a suitable concentration of the disinfectant. 2 Samples are taken at specified times and added immediately to a diluent or culture medium containing the appropriate disinfectant inactivator. 3 The treated samples are cultured for surviving microorganisms.
What is the objective of a surface test?
The objective is to verify whether the proposed use dilution is still adequate in the conditions under which it would be used. The best known practical tests are the surface disinfection tests. Surface tests assess the effectiveness of the selected sanitizer against surface-adhered microorganisms.
What organisms are tested for disinfectant?
Depending on the type of disinfectant, a single test organism is selected from S. aureus, P. aeruginosa, P. vulgaris and E. coli. The method can be carried out under ‘clean’ or ‘dirty’ conditions. The dilutions of the disinfectant are made in hard water for clean conditions and in yeast suspension for dirty conditions.
What is a suspension test?
Suspension tests are preferred to carrier tests as the bacteria are uniformly exposed to the disinfectant. There are different kinds of suspension tests: the qualitative suspension tests, the test for the determination of the phenol coefficient (Rideal and Walker, 1903) and the quantitative suspension tests.
What is the third phase of disinfection?
The third phase comprises the field tests or pilot studies , and the variant of in-use tests.
General Principles: Microbiologic Sampling of The Environment
Air Sampling
- Biological contaminants occur in the air as aerosols and may include bacteria, fungi, viruses, and pollens.1215, 1216 Aerosols are characterized as solid or liquid particles suspended in air. Talking for 5 minutes and coughing each can produce 3,000 droplet nuclei; sneezing can generate approximately 40,000 droplets which then evaporate to particle...
Water Sampling
- A detailed discussion of the principles and practices of water sampling has been published.945Water sampling in health-care settings is used detect waterborne pathogens of clinical significance or to determine the quality of finished water in a facility’s distribution system. Routine testing of the water in a health-care facility is usually not indicated, but sampling in supp…
Environmental Surface Sampling
- Routine environmental-surface sampling (e.g., surveillance cultures) in health-care settings is neither cost-effective nor warranted.951, 1225When indicated, surface sampling should be conducted with multidisciplinary approval in adherence to carefully considered plans of action and policy (Box 15). *The material in this box is compiled from reference 1214. Top of Page Surf…