Lab Final Micro Flashcards
Which of the following represents a physical method of preventing the growth of microorganisms?
Gamma radiation, heat, and antibiotics
UV on microorganisms results in which of the following lesions to the DNA?
Thymine Dimmers
Which method will destroy bacterial endospores?
Autoclaving
What is an antibiotic?
antimicrobial agent made by microorganisms
Which of the following methods is most suitable for disinfection of a drinking water sample?
UV Light
What is the purpose of the Kirby-Bauer method?
to test the sensitivity of bacteria such as Malaria is present in some region of the world
Epidemiologically speaking, a disease such as Malaria is present in some region of the world.
ANS: Endemic
Your patient suffers from a blood infection; after isolation, you run a Kirby Bauer test to see which antibiotic is the most appropriate for the treatment. Which is more appropriate?
Preferred empiric monotherapy includes: meropenem, imipenem, piperacillin-tazobactam, or tigecycline.
Which microorganism produces penicillin?
ANS: Fungi
Variables in food safety that can promote food contamination.
Personal hygiene, time and temperature control, foodborne disease, and cross contamination.
Organisms may grow in the presence of salt.
ANS: Halophiles
What is Mannitol salt agar, its use, and composition?
ANS: Differential and selective
Metallic green-sheen growth on Eosin-Methylene blue agar is related to which microbes.
ANS: E.Coli
. Coliform bacteria in the water is an indicator of.
ANS: Recent fecal contamination
Typhoid fever carrier definition.
Because she did not have any signs and symptoms of the disease.
Typhoid fever is caused by.
the bacterium Salmonella typhi
Enzymes and their target substrate
Catalase
The electron transport chain is related to
none of the above
What is the function of cytochrome oxidase, and how to test it?
dark blue/purple
What is ELISA?
Enzyme-linked immunosorbent assay
A common laboratory testing technique that detects and counts certain antibodies, antigens, proteins, and hormones in bodily fluid samples.
What is direct and indirect ELISA? Uses?
Patients serum
Which bacteria are strong catalase-positive?
Staphylococcus
Which of the following enzymes in bacteria is detected by oxidase test?
Cytochrome C Oxidase
Be prepared to calculate bacterial populations in a solution and dilutions.
108
Department of Health and food-borne disease caused by microorganisms.
Listeria Monocytogenes
Oxidase-positive Gram-negative pathogens and corneal abrasion.
Pseudomonas Aruginosa
Food safety and farming practices impact health negatively.
all of the above
Saprobic chemoheterotrophs are?
none of the above
Fungal structures?
A cell wall with chitin
Difference between prokaryotic and eukaryotes.
mitochondria
Different types of antibiotics and their targets?
aminoglycorides
Disk diffusion Kirby-Bauer test.
Measures radius zone of inhibition in mm.
Calculating the MIC using the Etest.
Azithromycin
Sporangium and yeast.
Asci
Fungal structures related to the mycelium.
hyphole
What is a parasitic reservoir?
Reservoir
Etiological agents of sleeping sickness, Chagas, and Leishmaniasis.
Trypanosoma Brucei Rhodesiense
What happens in Schistosomiasis infection?
Schistosoma hematobium
Be able to differentiate between Trypanosoma, Plasmodium, Staphylococcal, and Escherichia infection.
Plasmodium
Variable in the incidence of nosocomial infections.
The use of medical devices
Infection control in nosocomial infections.
Hand washing
Disinfectants are used for?_____
They are used on inanimate surfaces.
Aseptic means…______
Free of pathogens
Methods of microbial control called.
Bacteriostatic
Boiling water as a means of microbial control.
both growing bacteria and enveloped viruses.
Ionizing and nonionizing radiation
ultraviolet light
Alcohol as antisepsis.
true
Protozoan cysts and disinfection.
TRUE
The cell walls of mycobacteria can be dissolved with.
FALSE
Soaps, degerming activity, and antimicrobial activity.
TRUE
Minimal Inhibitory Concentration and Minimal Bactericidal Concentration.
true
Drug toxicity of target organs.
candida
Fungi in the human body.
false
Intestinal parasites after ingestion of contaminated food.
tapeworm eggs
Human infestation with T. saginata.
Cysticerci
Children parasitosis in the US.
Enterobius Vernicularis
The amoeba as a parasite.
entamoebas
What are Chemoheterotrophs?
TRUE
Difference between sterilization, disinfection, and decontamination.
Sterilization
Thermal death time (TDT).
time it takes to kill all cells at a given temperature
Application of the disc diffusion method.
Diameter of the zone of inhibition.
Vegetative cells and spores.
FALSE
What are Antiseptics?
TRUE
Malarial control?
TRUE
Psychrotolerant microorganisms.
Refrigeration temperatures
Difference of dry heat and moist heat.
Denatures proteins and cell membrane
Effect of alcohol on eukaryotic microorganisms?
Dehydrates cell and denatures proteins.
Gram stain? Steps
BDAC
Crystal violet, iodine, alcohol-acetone, safranin
Nutrient agar composition and use.
peptone-beef extract
Bacterial isolation using the streak plate.
light source, condenser, specimen, objective lenses, ocular lens
Microscope parts?
Light source, condenser, specimen, objective lens, ocular lens
Microscope parts.
Correctly identify the microscope item C outlined in the diagram
ANS: Condenser
T Gram stain components and function.
Prevent the crystal violet from leaving the cells.
Smear preparation.
2,3,1
Colony numbers, counts, and dilutions.
36 cells
Oil immersion used in the microscope.
Fuzzy and poor resolution
Microbial color and arrangement in the Gram stain.
gram positive bacilli cluster.
Bacteriological media composition and examples.
complex medium
Bacterial smear preparation.
Affix the cells to the slide
Gram stain mechanics.
colorless
Magnification in the lab microscope.
400x
Pure cultures.
CFUs (colony forming units).
Difference between facultative anaerobe, obligate anaerobe, obligate aerobe, microaerophile and aerotolerant anaerobe.
Obligate anaerobe
What medium does a fastidious organism grow in?
enriched medium
Staining mordant.
decrease the solubility of dye molecules.
Blood agar use and application
differential media
Nature of clinical samples?
the lungs
Stages in bacterial growth.
logarithmic growth
what is Agar
TRUE
Recognize an Acid-fast Stain, steps, reagents, and staining results.
could be caused by improperly performing the decolorizing step resulting in the crystal violet to remain in the gram negative cells
A practical Disc-Diffusion exercise given a plate photo. Antibiotic selection.
All of the above
Use of the EMB Agar, to interpret results. Which organisms grow in this medium?
EMB Agar is used to isolate and differentiate Gram-negative enteric bacteria. Strong lactose fermenters, like Escherichia coli, produce dark purple to black colonies with a metallic green sheen. Non-lactose fermenters, like Salmonella and Shigella, produce colorless colonies.
Blood Agar hemolysis recognition.
Blood Agar is a rich medium used to differentiate bacterial species based on their hemolytic properties, which are their ability to lyse red blood cells. There are three main types of hemolysis:
Alpha Hemolysis (α-hemolysis):
Appearance: Partial hemolysis; greenish or brownish discoloration around the colonies.
Mechanism: Partial breakdown of hemoglobin to methemoglobin.
Examples of Organisms: Streptococcus pneumoniae, Streptococcus viridans group.
Beta Hemolysis (β-hemolysis):
Appearance: Complete hemolysis; clear, transparent zone surrounding the colonies.
Mechanism: Complete lysis of red blood cells and hemoglobin.
Examples of Organisms: Streptococcus pyogenes (Group A Strep), Staphylococcus aureus.
Gamma Hemolysis (γ-hemolysis or non-hemolysis):
Appearance: No hemolysis; no change in the appearance of the agar around the colonies.
Mechanism: No lysis of red blood cells.
Examples of Organisms: Enterococcus faecalis, Staphylococcus epidermidis.
Recognizing Hemolysis on Blood Agar
Alpha Hemolysis: Look for a greenish or brownish zone around colonies.
Beta Hemolysis: Look for a clear, transparent zone around colonies.
Gamma Hemolysis: Look for no change in the agar around colonies.
Chagas disease etiology and transmission
Triatoma
Heart
parenteral route
Plasmodium biological cycle.
anopheles mosquitoes
Plasmodium species
Schizonts
Oxidative catabolism and where occurs.
Oxidative catabolism occurs primarily in the mitochondria and involves the breakdown of molecules to produce ATP using oxygen. Key steps include glycolysis in the cytoplasm, followed by pyruvate oxidation, the citric acid cycle, and the electron transport chain in the mitochondria.
Blood Agar hemolysis.
Blood agar hemolysis refers to the breakdown of red blood cells (RBCs) in blood agar plates by bacterial enzymes called hemolysins. There are three types of hemolysis observed:
Alpha (α) Hemolysis: Partial hemolysis resulting in a greenish discoloration around colonies due to the partial breakdown of hemoglobin into methemoglobin. Example: Streptococcus pneumoniae.
Beta (β) Hemolysis: Complete hemolysis creating a clear zone around the colonies. Example: Streptococcus pyogenes.
Gamma (γ) Hemolysis: No hemolysis, with no change in the medium around the colonies. Example: Enterococcus faecalis.
Identify the various stages is bacterial growth.
The bacterial growth curve includes the following stages:
Lag Phase: Bacteria adapt to their new environment, and there is little to no cell division.
Log (Exponential) Phase: Bacteria multiply rapidly, and the population size doubles at a constant rate.
Stationary Phase: The growth rate slows as resources become limited, and the rate of cell division equals the rate of cell death.
Death (Decline) Phase: Nutrients are depleted, and waste products accumulate, leading to a decline in the bacterial population.
Identify the pattern of growth according to oxygen use
Bacteria can be classified based on their oxygen requirements:
Obligate Aerobes: Require oxygen for growth. Example: Mycobacterium tuberculosis.
Obligate Anaerobes: Cannot grow in the presence of oxygen. Example: Clostridium botulinum.
Facultative Anaerobes: Can grow with or without oxygen but grow better with oxygen. Example: Escherichia coli.
Microaerophiles: Require oxygen at lower concentrations than atmospheric levels. Example: Helicobacter pylori.
Aerotolerant Anaerobes: Do not require oxygen but are not harmed by its presence. Example: Lactobacillus spp.
