Which Of The Following Items Should Be Autoclaved

Question: Who and/or what is protected by lab safety protocols?

Answer: - students doing lab activities- lab instructors and technical assistants - anyone who walks into the lab - the physical lab spaced and he equipment housed within the lab

Question: Which of the following items can be washed in the sink after use in the laboratory?

Answer: - dissection tools- glassware that was not used with hazardous chemicals - dissection trays

Question: Which of the following items may be on the laboratory bench top while doing lab work?

Answer: - cultures (broth, agar plates, agar slants)- equipment items specifically needed to complete the lab activity - pencil or pen

Question: Infectious laboratory waste is sterilized prior to disposal by

Answer: autoclaving (steam autoclave)

Question: What is used to sterilize infectious items prior to cleaning or disposal?

Answer: autoclave

Question: You have just washed you hands after completing your lab work. Where should the paper towels used to dry your hands be discarded?

Answer: regular trash receptacle

Question: Which of these items should be placed in the sharps container?

Answer: cover slips

Question: What is the best source of information regarding the potential hazards, proper handling, and disposal instructions for a particular chemical?

Answer: MSDS (Material Safety Data Sheet)

Question: Which of the following items should be autoclaved?

Answer: - glass culture tubes- biohazard bag

Question: Soap should be applied to __________ hands.

Answer: wet

Question: Which of the following activities should never take place in the laboratory?

Answer: - eating and/or drinking- handling contact lenses- applying make-up

Question: long hair should always be tied back when working in the laboratory.

Answer: TRUE

Question: Which is the most appropriate disposal for a swab used to culture your throat during lab?

Answer: biohazard bag

Question: Which of the following steps are part of a thorough hand washing protocol?

Answer: - removal of bracelets, watches, and rings- lathering with soap, rubbing hands together for at least 20 seconds- using a brush and wooden stick, clean well under finger nails

Question: Which of the following represent important safety procedures for microbiology students?

Answer: - Wash your hands before and after laboratory procedures.- Disinfect your lab bench at the beginning and end of the lab period.- Take extra care around the flame of a Bunsen burner by tying up hair and keeping it from combustibles.

Question: Match each item with its most appropriate means of disposal.

Answer: - sharps container: broken glass slide- normal trash receptacle: paper towels used to dry hands after hand washing - rack for autoclaving: glass culture tubes containing broth cultures of Staphylococcus epidermidis- biohazard bag: used culture plates

Question: Watches, bracelets, and rings should be removed prior to washing hands.

Answer: TRUE

Question: Which of the following are reasons for washing hands before and after lab activities?

Answer: - Hands may be a source of contamination of lab experiments.- Hands may become contaminated with infectious bacteria during lab experiments.- Hands may become stained during lab.- Hands may be contaminated with irritating chemicals during experiments.

Question: Identify the correct statements about lab coats

Answer: - Lab coats provide some protection against contamination with infectious microorganisms.- Lab coats provide some protection against exposure to corrosive chemicals

Question: Bacteria are _______, meaning that they are distributed everywhere.

Answer: ubiquitous

Question: You exposed this TSA plate to the air of the laboratory for 30 minutes, and then you incubated the plate for 24 hours at 37 degrees Celsius. What would be the correct quantitative evaluation of the degree of contamination on this plate?

Answer: 50-100 colonies

Question: Which objective lens requires oil to be applied?

Answer: 100x

Question: Complete the calculations for total magnification produced by various combinations of the eyepiece and objective lenses. Remember, to calculate the total magnification achieved when using a particular objective, multiply the power of the eyepiece by the power of the objective used.

Answer: - When the scanning (4x) objective is used the total magnification will be 40x- When the low power (10x) objective is used the total magnification will be 100x- When the high power (40x) objective is used the total magnification will be 400x- When the oil immersion (100x) objective is used the total magnification will be 1000x

Question: The total magnification achieved using a 10× objective lens with a 10× eyepiece lens is 20×

Answer: FALSE

Question: When preparing a wet mount specimen for viewing, the specimen should be covered with

Answer: a coverslip

Question: Match the names of the microscope parts in column A with the descriptions in column B. Place the letter of your choice in the space provided.

Answer: - stage(slide) clip: holds a microscope slide in position - arm: serves as a handle for carrying the microscope - eyepiece (ocular): contains a sense at the top of the body tube - nosepiece: Part to which the objective lenses are attached- field of view: Circular area seen through the eyepiece

Question: Which objective lens provides the highest total magnification?

Answer: oil immersion

Question: The __________ causes the stage to move upward or downward.

Answer: coarse adjustment knob

Question: Using oil immersion is useful because

Answer: oil immersion increases the resolving power of the specimen.

Question: What were previously known as "blue-green algae?"

Answer: Cyanobacteria

Question: You are looking at a drop of pond water and in the field of view, you observe a moving unicellular organism with short hairlike structures surrounding the outside surface of the cell. You are most likely observing an example of a/an ________.

Answer: protozoan

Question: Asexual spores that form within a thin-walled sac are referred to as ________.

Answer: sporangiospores

Question: You exposed this TSA plate to the air of the laboratory for 30 minutes, and then you incubated the plate for 24 hours at 37 degrees Celsius. What would be the correct quantitative evaluation of the degree of contamination on this plate?

Answer: 50-100 colonies

Question: What medium is commonly used when culturing molds on agar plates?

Answer: Sabouraud's agar

Question: Which organisms have centrioles?

Answer: animals

Question: Plant cells often have a large membrane-bound sac that is used for storing water and other substances called a:

Answer: central vacuole.

Question: The cell wall is a common feature to

Answer: prokaryotic and plant cells.

Question: Which structure surrounds the cytoplasm of the cell and separates the interior of the cell from the external environment?

Answer: plasma membrane

Question: Which of the following are found in both plant and animal cells?

Answer: - mitochondria- Golgi complexes- endoplasmic reticulum

Question: As the concentration of solutes in a solution increases, the water concentration increases.

Answer: FALSE

Question: A bacterial species that cannot tolerate the presence of oxygen and will only grow in the absence of oxygen is classified as a(n):

Answer: obligate anaerobe

Question: obligate anaerobe

Answer: alkaline

Question: Listeria monocytogenes is a human pathogen, growing readily in the human body. It poses a problem in food storage because of its ability to grow in refrigerated foods, such as unpasteurized milk or deli meats. An organism that prefers moderate temperatures, such as 25 - 40C but is capable of growth at refrigerator temperatures is known as a:

Answer: psychrotroph

Question: Acetobacter aceti is a bacterial species involved in the production of acetic acid during vinegar production. Which category would this bacteria be classified within?

Answer: acidophile

Question: Some organisms exhibit flexibility in terms of their energy harvesting reactions. If provided with oxygen, they will obtain energy through aerobic respiration. If in an environment without oxygen, they will turn to fermentation to satisfy their energy needs. These organisms are classified as:

Answer: facultative aerobes

Question: Select all of the following that are substrates lactic acid fermentation.

Answer: - glucose-

Question: Respirometers were set up that contained yeast and 2% glucose solution. Each respirometer was placed at a different temperature. The height of the bubble contained in the respirometer was measured every 5 minutes for 20 minutes. What is the independent variable in this experiment?

Answer: temperature

Question: Which carbohydrate is the primary or preferred starting compound for glycolysis and the fermentation pathway?

Answer: glucose

Question: Which of the following substrates is fermented most easily by yeast?

Answer: glucose

Question: A process common to all living organisms, whether aerobic or anaerobic, is

Answer: glycolysis

Question: Yeast cells under anaerobic conditions

Answer: produce ethyl alcohol (ethanol).

Question: Microorganisms are found in nearly every environment and are said to be ____________________.

Answer: ubiquitous

Question: What type of medium provides the best opportunity for growing and observing the morphology of isolated colonies?

Answer: agar plates

Question: Observation of a broth after transfer can show whether or not contamination has occurred.

Answer: FALSE

Question: How is air contamination prevented when an inoculating loop is used to introduce or remove organisms from an agar plate?

Answer: The plate lid is kept closed or lifted only slightly when inoculating.

Question: Which of the following are appropriate tools for making bacterial transfers from one medium to another?(Check all that apply)

Answer: - inoculating loop- inoculating wire

Question: When completing a quadrant streak, when do you flame the loop?

Answer: - Before you pick up a loopful of organisms from the original culture- Before you streak quadrant two and three- Before you return the loop to the receptacle

Question: A ______ is a mound of cells on a solid medium that represents the progeny from one original bacterial cell.

Answer: colony

Question: Which of the following may indicate that you have correctly subcultured an organism from a plate to a slant?

Answer: - 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.

Question: Which are advantages of the streak-plate method when compared to the pour-plate method?

Answer: - It requires less materials.- It is a very quick process.

Question: Which of the following CANNOT serve as a nitrogen source?

Answer: agar

Question: you are interested in studying the gram-negative bacteria that may be found in ground meat. You would like to use a medium that will enable the growth of most species of gram-negative bacteria, while inhibiting gram-positive bacteria. This would be a __________________ medium.

Answer: selective

Question: Predict the effect of endospores on preservation of a bacterial culture.

Answer: Endospores will promote and enable culture preservation.

Question: Which of the following terms are used to describe the appearance of the edge or margin of a colony growing on an agar surface?

Answer: - smooth- wavy- irregular

Question: Indicate which of the following observations can be made when observing growth on nutrient agar.

Answer: - Amount of growth- Opacity/clarity of colonies- Color of colonies- Shape and /or pattern of growth

Question: The terms crateriform, umbonate, convex, flat, and raised are all used to describe the _______ of a colony.

Answer: elevation

Question: A total of 145 colonies were counted on the plate that received 1.0 mL of the 1:10,000 dilution of a specimen. What is the bacterial count for the original specimen?

Answer: 1,450,000 colonies/mL

Question: When performing a Standard Plate Count, plates that contain __________________ colonies are selected for counting with the Quebec Colony Counter.

Answer: 30-300 colonies

Question: A total of 75 colonies were counted on the plate that received 1 mL of a diluted specimen. After calculating, it is determined that the total bacterial count in the original specimen was 75,000,000 colonies per mL. What was the dilution factor for the plated sample?

Answer: 1:1,000,000

Question: Please choose the answer that best completes the blanks of this sentence in the correct order. The ______ plate method involves spreading an inoculum onto the surface of a plate in a pattern that results in isolated colonies in some areas of the plate after incubation, whereas the ______ plate method involves diluting an inoculum into several melted agar tubes and then adding their contents into plates for solidification and incubation.

Answer: streak; pour

Question: Place the following steps in order to demonstrate your understanding of the pour plate method.

Answer: - Liquefy nutrient agar tubes and maintain at 50 degrees Celsius.- Remove loopful of organisms from culture using aseptic technique.- Add loopful of organisms to an agar tube.- Transfer one loopful from one agar tube into another agar tube, and repeat this again with a third agar tube.- Pour liquefied agar tubes into empty plates.- Incubate for 24-48 hours.

Question: What advantage does the pour-plate method have over the streak-plate method?

Answer: It requires less skill.

Question: 0.1 mL of an original sample is diluted into 9.9 mL of water and then 0.1 mL of this is spread on a plate. 54 colonies grew. What was the original cell density of the sample?

Answer: 5.4 X 10^4 CFU/mL

Question: The number of serial dilutions that are necessary for a standard plate count assay will depend on

Answer: the estimated density of cells in the original sample

Question: When determining the cell density of a sample by the standard plate count method, the final density of cells is reported as

Answer: colony forming units (CFU)/mL

Question: If you wanted to prepare a 1:10,000 dilution of your sample and cannot measure out quantities of less than 1 mL, and have dilution blanks that can hold only 10 mL, how many dilution blanks will you need?

Answer: 4

Question: What is one limitation to the usefulness of UV radiation?

Answer: Direct contact only

Question: Detergents are

Answer: low-level germicides

Question: What media is used for testing antibiotic susceptibility?

Answer: Mueller Hinton agar

Question: Narrow spectrum antibiotics are effective against a wide range of both Gram positive and Gram negative bacteria.

Answer: FALSE

Question: Why is antimicrobial sensitivity testing done?

Answer: To determine what antimicrobials would be most effective for treating the infection

Question: A compound such as cephalothin that is made by a species of mold and is able to kill or inhibit a number of different bacteria is correctly referred to as

Answer: an antibiotic.

Question: Which of the following are destroyed by alcohol?

Answer: - Enveloped viruses- Vegetative bacterial cells

Question: The higher the concentration of alcohol, the more effective its antimicrobial activity, with 100% alcohol being the most effective

Answer: False ( 70 % is the most effective)

Question: Which parts of a cell are most affected by temperature?

Answer: - Membrane fluidity- Ribosomes- Enzymes

Question: Which of the following infectious agents is least likely to be damaged by UV exposure?

Answer: Prions

Question: Select the statements that represent goals in correct smear preparation.

Answer: - The cells must be heat fixed to the slide to prevent removal when stain is washed off the slide.- It is important to minimize any artifacts or distortion of the cells for accurate viewing after staining.- Smears must be thin to allow for observation of single cells

Question: What is a major limitation to a simple stain technique?

Answer: Does not differentiate cellular structures

Question: You make a smear of E. coli and then simple stain the slide with methylene blue. If you failed to use correct aseptic technique by not sterilizing the loop before picking up the bacterial sample for the smear, what results may be seen under the microscope?

Answer: There may be cells of different shapes, sizes, and arrangements.

Question: It is important that the smear is thick in order to ensure that the stain will be retained on the slide.

Answer: FALSE

Question: What is heat fixation?

Answer: Passing the slide through the flame of a burner several times after the smear has completely dried.

Question: Order these statements to indicate correct aseptic procedure for removing organisms from a culture for application to a slide

Answer: - Heat inoculating loop and wire to red-hot.- Remove the cap of the culture tube and flame the mouth of the tube.- Remove a loopful of organisms from the culture.- Flame the mouth of the culture tube.- Return the cap to the culture tube.- Place organisms onto the slide in the center of the target circle.- Flame the loop red-hot before setting aside.

Question: Flame the loop red-hot before setting aside.

Answer: - Bacterial endospores are highly resistant to heat, drying and radiation.- Endospores can exist in the environment for indefinite periods of time.- Endospores resist boiling and therefore steam must be used to destroy endospores present in food.

Question: Order the reagents used in the acid-fast staining procedure.

Answer: - Carbolfuchsin- Acid-alcohol- Methylene blue

Question: Please choose the answer that best completes the blanks of this sentence in the correct order. _______ is used to stain the endospore, and _______ is the stain used to stain the vegetative cell in the Schaeffer-Fulton method of spore staining.

Answer: Malachite green; safranin

Question: After capsular staining, the cells are clear and the capsule is a dark purple ring.

Answer: FALSE

Question: The goal of ______ technique is to minimize the contamination of both original and newly inoculated cultures as well as protect the laboratory handler from contamination.

Answer: aseptic

Question: A disinfectant is used on your work surface

Answer: All of the choices are correct. (this one)after any spill of live microorganisms.after all work is complete.before the beginning of laboratory procedures.

Question: How is air contamination prevented when an inoculating loop is used to introduce or remove organisms from an agar plate?

Answer: The plate lid is kept closed or lifted only slightly when inoculating.

Question: Which types of culture media are solid?

Answer: - slants- agar plates

Question: The majority of heterotrophic microorganisms are chemoheterotrophs that derive both energy and carbon from organic compounds.

Answer: TRUE

Question: What type of medium provides the best opportunity for growing and observing the morphology of isolated colonies?

Answer: agar colonies

Question: You have cultured several different objects and surfaces in the environment. Which of the following indicates a more abundant bacterial population?

Answer: The item with the greatest number of microbial colonies on an agar plate

Question: Indicate the sites where microorganisms are likely to be found:

Answer: AirHandsComputer keyboardLaboratory bench surface

Question: Why is the mouth of a culture tube passed through the Bunsen burner flame after removing and before replacing the cap?

Answer: To prevent the entry of ambient air which might introduce contaminants.

Question: Select all of the following pathways that produce ATP during cellular respiration.

Answer: - electron transport chain- Krebs cycle- glycolysis

Question: Which is incorrect about fermentation?

Answer: It generates oxygen.

Question: What must occur before sucrose is used in cellular respiration? (Sucrose is fructose and glucose bonded together)

Answer: Sucrase enzyme breaks it down to glucose and fructose.

Question: Infectious laboratory waste is sterilized prior to disposal by

Answer: autoclaving (steam autoclave)

Question: Using a cell phone in lab is permissible since it can be used for timing experiments.

Answer: FALSE

Question: In which circumstance is food and/or beverage allowed in the laboratory?

Answer: never

Question: Paper towels should be discarded in a biohazard container after washing hands.

Answer: FALSE

Question: What is the oxygen requirement for the organism in Tube "A"?

Answer: aerobe

Question: How does pH negatively affect the metabolism of microorganisms?

Answer: pH changes can denature enzymes

Question: A bacterial species that cannot tolerate the presence of oxygen and will only grow in the absence of oxygen is classified as a(n):

Answer: obligate anaerobe

Question: What is the zone of inhibition for Vancomycin (VA) in this Kirby-Bauer test? (mark is at the 2nd line to the right of the line for number 2 on a metric ruler)

Answer: 18 mm

Question: Why is antimicrobial sensitivity testing done?

Answer: 18 mm

Question: A compound such as cephalothin that is made by a species of mold and is able to kill or inhibit a number of different bacteria is correctly referred to as

Answer: an antibiotic.

Question: An agent that stops the growth of bacteria but does not kill them is described

Answer: bacteriostatic.

Question: The higher the concentration of alcohol, the more effective its antimicrobial activity, with 100% alcohol being the most effective

Answer: FALSE

Question: Which of the following are destroyed by alcohol?

Answer: - Vegetative bacterial cells- Enveloped viruses

Question: Which of the following would be appropriately sterilized using UV radiation?

Answer: Stainless steel surface in biological safety cabinet used for media preparation

Question: Endospores are less susceptible to UV damage because ________. (Check all that apply.)

Answer: - the DNA of endospores is protected by small proteins that protect it from photochemical damage- UV light generates a product in endospores that functions in the enzymatic repair of damaged DNA

Question: Which parts of a cell are most affected by temperature?

Answer: - Enzymes- Ribosomes- membrane fluidity

Question: When preparing a wet mount specimen for viewing, the specimen should be covered with

Answer: a coverslip

Question: The total magnification achieved using a 10× objective lens with a 10× eyepiece lens is 20×.

Answer: FALSE

Question: The objective lenses of the compound light microscope are attached to the

Answer: rotating nosepiece

Question: An indirect method of estimating bacterial numbers is based on the turbidity of the sample. A ________ can be used to determine the turbidity by measuring absorbance.

Answer: spectrophotometer

Question: When performing a Standard Plate Count, plates that contain __________________ colonies are selected for counting with the Quebec Colony Counter.

Answer: 30-300 colonies

Question: Please choose the answer that best completes the blanks of this sentence in the correct order. After acid-fast staining, Mycobacterium tuberculosis would be _______ in color, whereas Proteus vulgaris would be ________ in color.

Answer: red; blue

Question: For every bacterial cell that undergoes sporulation, there are two resulting bacterial cells.

Answer: FALSE

Question: What makes Mycobacterium particularly resistant to staining?

Answer: The presence of mycolic acid in their cell walls

Question: Please order the following choices to reflect the appropriate sequence of materials used in the Gram staining procedure

Answer: - Crystal violet- Gram's Iodine- Alcohol/Acetone- Safranin

Question: Please choose the answer that best fills in the blanks of this sentence in the correct order. Gram-________ cells stain purple whereas gram-_______ cells stain pink or red when using the Gram stain technique.

Answer: positive; negative

Question: How does smear preparation of cells from a liquid medium differ from preparation of cells from a solid medium?

Answer: Water is applied to the slide before emulsifying cells from a solid medium.

Question: Mitochondria can be found in the cells of:

Answer: - animals- plants

Question: Examples of prokaryotes include:

Answer: - bacteria- archaea

Question: Please choose the answer that best fills in the blanks of this sentence in the correct order. Algae and protozoa are in Domain ______ and cyanobacteria are in Domain _______

Answer: Eukarya; Bacteria

Question: True or False:When performing a standard plate count, the bacterial count reached is a reflection of the total count NOT the viable count.

Answer: FALSE

Question: The ovoid bodies are _______________ which stained green due to the uptake of __________ dye.

Answer: Endospores, Malachite green

Question: The rod shaped cells represent _______________ which stained pink/red due to the uptake of the _______________ dye.

Answer: Vegetative cells, Safranin

Question: Blood is a biohazard that requires special safety precautions.

Answer: TRUE

Question: Which of the following statements best describes what you would expect to happen if a transfusion recipient had blood type 0 and a donor had blood type AB?

Answer: Agglutination would occur as the recipient's antibodies bind to the donors antigens

Question: If the blood from an individual with type AB blood is mixed with anti-A serum in one well and anti-B serum in a second separate well

Answer: the anti-A serum well and the anti-B serum well will show agglutination.

Question: The plasma of a person with type A blood has:

Answer: anti-B antibodies.

Question: Select all of the following antibodies found in the blood of a person with blood type O.

Answer: - anti-A antibodies- anti-B antibodies

Question: An Rh negative individual typically has anti-Rh antibodies in their plasma.

Answer: FALSE

Question: Testing for the Rh antigen differs from testing for the A and B antigens in which of the following ways?

Answer: - Rh testing should be done on whole blood or plasma-suspended red blood cells - NOT saline-suspended red blood cells- Rh testing should be done at higher temperatures, 37 °Celsius for the tube test and 45 °Celsius for the slide test.

Question: Order the reagents used in an indirect ELISA for HIV detection.

Answer: - HIV antigen- patient serum- anti-IgG antibody linked to enzyme - colorless substrate

Question: The formation of visible clumps when antibodies react with whole cell antigens is specifically called __________.

Answer: agglutination

Question: For each blood type, match the antibodies found in the plasma.

Answer: type A serum: anti-B antibodies type B serum: Anti-A antibodiestype AB serum: neitherType O serum: both

Question: When a vaccine is administered the body produces which type of immune response?

Answer: Primary Immune Response

Question: The study of the frequency and distribution of disease and health-related factors in human populations is called

Answer: epidemiology

Question: The principle where most of the population is immune to a particular pathogen thus protecting those who are not from encountering the pathogen is known as _____.

Answer: herd immunity

Question: Which of the following statements apply to a host-to-host epidemic?

Answer: Vaccination, hygiene, and antibacterial/antiviral medications may help control the spread.

Question: If a population drops below the threshold percent for herd immunity, what will happen?

Answer: Outbreaks will occur and be more frequent

Question: Disease incidence can be reduced in a population through the use of vaccines.

Answer: TRUE

Question: Infectious organisms can follow which of the following patterns of transmission?

Answer: Indirect contactVector transmissionCorrect! All choices are correctDirect contactVehicle transmission

Question: Which groups within the population typically benefit the most from the principle of herd immunity? (choose all that apply)

Answer: - young children - infants- elderly- immunocompromised

Question: If the addition of Kovac's reagent produces a floating red layer on a SIM medium culture, this indicates the organism is

Answer: positive for tryptophanase

Question: What enzyme do bacteria produce to detoxify hydrogen peroxide?

Answer: Catalase

Question: The enzyme necessary to hydrolyze urea into ammonia and carbon dioxide is

Answer: urease

Question: SIM medium will assay for

Answer: motilitysulfur reductionCorrect! all of the aboveindole production

Question: A positive reaction for motility in SIM medium would produce

Answer: a haze throughout the tube

Question: The function of the iodine in the starch hydrolysis test is to

Answer: make starch visible

Question: Why does the solid medium become liquified for an organism that produces gelatinase in the nutrient gelatin medium?

Answer: The gelatin serves as the solidifying agent

Question: The coagulase test detects

Answer: the ability to clot plasma

Question: Which Gram negative organisms are unable to ferment lactose? (select all that apply)

Answer: - Proteus sp.- Shigella sp.- Salmonella sp.- Yersinia sp.

Question: The differential ingredient in EMB is bile salts.

Answer: FALSE

Question: Which organism causes serious problems with Methicillin and Vancomycin resistant strains?

Answer: Staphylococcus aureus

Question: The selective ingredient in EMB media is lactose.

Answer: FALSE

Question: Which organism is typically grown in a candle jar? And what environment is obtained within the candle jar?

Answer: - decrease oxygen, increased carbon dioxide- Streptococcus pneumoniae

Question: You have a human isolate unknown culture that appears as Gram-positive cocci. It demonstrates bubbling upon the addition of hydrogen peroxide. Which of the following is a likely candidate to suspect?

Answer: Staphylococcus epidermidis

Question: What is the first step in differentiating the Enterobacteriaceae?

Answer: Lactose fermentation

Question: E.coli, S. aureus, Candida spp. and Klebsiella spp are all considered common causes of

Answer: Healthcare Associated Infections (HAIs)