Mlab 2534 Microbiology Midterm

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Mlab 2534 Microbiology Midterm - Quiz

You may move between the questions. Once you submit your test it is finalized. You have 200 minutes for this exam.


Questions and Answers
  • 1. 

    1. Identify the bacteria which is indole-negative and oxidase-positive?

    • A.

      A. Staphylococcus

    • B.

      B. Streptococcus

    • C.

      C. Neisseria

    • D.

      D. Pseudomonas

    Correct Answer
    D. D. Pseudomonas
    Explanation
    Pseudomonas is the correct answer because it is indole-negative and oxidase-positive. Indole is a compound produced by some bacteria as a byproduct of tryptophan metabolism, and a negative result indicates that the bacteria does not produce indole. Oxidase is an enzyme that helps bacteria break down certain compounds, and a positive result indicates that the bacteria produces this enzyme. Staphylococcus, Streptococcus, and Neisseria do not fit these characteristics, making Pseudomonas the only correct option.

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  • 2. 

    2. The most common cause of cystitis (after Escherichia coli) in healthy sexually active women

    • A.

      A. Staphylococcus saprophyticus

    • B.

      B. Proteus mirabilis

    • C.

      C. Pseudomonas aeruginosa

    • D.

      D. Klebsiella pneumoniae

    Correct Answer
    A. A. Staphylococcus saprophyticus
    Explanation
    Staphylococcus saprophyticus is the most common cause of cystitis in healthy sexually active women after Escherichia coli. This bacterium is a common inhabitant of the genital tract and can cause urinary tract infections when it enters the urethra and travels up into the bladder. It is more frequently isolated from women than men, and it is often associated with sexual activity. Staphylococcus saprophyticus is resistant to many antibiotics commonly used to treat urinary tract infections, making it important to accurately identify and treat infections caused by this bacterium.

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  • 3. 

    3. The bacterial sore throat is caused by

    • A.

      A. Staphylococcus aureus

    • B.

      B. Haemophilus spp

    • C.

      C. Streptococcus pyogenes

    • D.

      D. Mycoplasma pneumoniae

    Correct Answer
    C. C. Streptococcus pyogenes
    Explanation
    Streptococcus pyogenes is the correct answer because it is a common bacterial pathogen known to cause sore throat, specifically strep throat. This bacterium is highly contagious and can be transmitted through respiratory droplets. It is responsible for a range of infections, including pharyngitis, tonsillitis, and scarlet fever. Staphylococcus aureus can also cause sore throat, but it is less common compared to Streptococcus pyogenes. Haemophilus spp and Mycoplasma pneumoniae are not typically associated with bacterial sore throat.

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  • 4. 

    4. An example of enriched media is

    • A.

      A. MacConkey

    • B.

      B. Chocolate

    • C.

      C. CNA

    • D.

      D. MacConkey with Sorbitol

    Correct Answer
    B. B. Chocolate
    Explanation
    Enriched media refers to a type of culture medium that contains additional nutrients to support the growth of fastidious organisms. Chocolate agar is an example of enriched media as it contains blood, specifically red blood cells, which provides essential nutrients for the growth of certain bacteria. This type of media is commonly used in the laboratory to cultivate bacteria that require specific growth factors or nutrients not found in basic culture media.

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  • 5. 

    5. Staph Aureus appear on a gram stain as

    • A.

      A. Gram positive grape like clusters

    • B.

      B. Gram negative grape like clusters

    • C.

      C. Gram positive cocci in chains

    • D.

      D. Gram postive rods

    Correct Answer
    A. A. Gram positive grape like clusters
    Explanation
    Staph Aureus appears on a gram stain as gram positive grape-like clusters. This means that when stained using the Gram staining technique, Staph Aureus bacteria retain the violet crystal stain and appear purple under a microscope. The bacteria are arranged in clusters that resemble grapes. This characteristic staining pattern helps in the identification and classification of Staph Aureus bacteria.

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  • 6. 

    6. What does campylobactor look like on a gram stain?

    • A.

      A. Airplane wings

    • B.

      B. Gull wings

    • C.

      C. Spiral rod

    • D.

      D. Grape like clusters

    Correct Answer
    B. B. Gull wings
    Explanation
    Campylobactor is a type of bacteria that appears as spiral rods on a gram stain. The term "gull wings" is used to describe the shape of these spiral rods, resembling the wings of a seagull. Therefore, option B is the correct answer as it accurately describes the appearance of campylobactor on a gram stain.

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  • 7. 

    7. What does strep pneumo look like on a gram stain?

    • A.

      A. Gram positive lancet shaped dipplococci

    • B.

      B. Gram positive rods

    • C.

      C. Gram negative rods

    • D.

      D. Gull Wings

    Correct Answer
    A. A. Gram positive lancet shaped dipplococci
    Explanation
    Strep pneumo (Streptococcus pneumoniae) appears as gram positive lancet shaped dipplococci on a gram stain. This means that when stained using the Gram staining technique, the bacteria will retain the purple color and appear as pairs of oval-shaped cells with pointed ends. This characteristic morphology helps in the identification of Strep pneumo in the laboratory. Gram positive rods, gram negative rods, and gull wings are not the typical appearances of Strep pneumo on a gram stain.

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  • 8. 

    8. How do you test for inducible clindimiacyn?

    • A.

      A. A Test

    • B.

      B. B Test

    • C.

      C. C Test

    • D.

      D. D Test

    Correct Answer
    D. D. D Test
    Explanation
    The question is asking about the method used to test for inducible clindamycin resistance. The correct answer is D, which suggests that there is a specific test, referred to as the "D Test," that is used for this purpose. The explanation does not provide any further details about the D Test or how it is conducted, but it confirms that it is the correct answer to the question.

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  • 9. 

    9. What temperature do Pschycrophiles like?

    • A.

      A. 37 c

    • B.

      B. 42 c

    • C.

      C. 15 c

    • D.

      D 50 c

    Correct Answer
    C. C. 15 c
    Explanation
    Psychrophiles are microorganisms that thrive in extremely cold temperatures. They are adapted to survive and reproduce in environments with temperatures as low as 15 degrees Celsius. This is because their cellular processes and enzymes are specifically designed to function optimally at these low temperatures. Therefore, psychrophiles prefer and are most active at temperatures around 15 degrees Celsius.

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  • 10. 

    10. Obligate anaerobes are

    • A.

      A. enhanced by O2

    • B.

      B. harmed by O2

    • C.

      C. neither harmed or enhanced by O2

    • D.

      D. both harmed and enhanced by O2

    Correct Answer
    B. B. harmed by O2
    Explanation
    Obligate anaerobes are microorganisms that cannot survive in the presence of oxygen. Oxygen is toxic to them and can cause damage to their cellular structures and metabolic processes. Therefore, they are harmed by oxygen and require an oxygen-free environment to grow and survive.

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  • 11. 

    11. A method for incubating anaerobes is

    • A.

      A. hyperbaric chamber

    • B.

      B. O2 incubator

    • C.

      C. room air

    • D.

      D. Candle Jar

    Correct Answer
    D. D. Candle Jar
    Explanation
    A candle jar is a method for incubating anaerobes because it creates an anaerobic environment by burning a candle inside a sealed jar. As the candle burns, it consumes the oxygen inside the jar, creating a low-oxygen or oxygen-free environment suitable for the growth of anaerobic organisms. This method is commonly used in laboratories to culture anaerobic bacteria, as they cannot survive in the presence of oxygen.

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  • 12. 

    12. An example of a Capnophile is

    • A.

      A. E. Coli

    • B.

      B. K. Pneumo

    • C.

      C. Staph Aureus

    • D.

      D. Campylobactor

    Correct Answer
    D. D. Campylobactor
    Explanation
    Campylobacter is an example of a capnophile, which is an organism that thrives in environments with high levels of carbon dioxide. This bacterium is commonly found in the intestines of animals and can cause foodborne illnesses in humans. It is adapted to survive and grow in low-oxygen environments, such as the gastrointestinal tract, where carbon dioxide levels are higher. Campylobacter infections are typically caused by consuming contaminated food or water, and symptoms can include diarrhea, abdominal pain, and fever.

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  • 13. 

    13. Which completely kills bacteria?

    • A.

      A. Disinfectant

    • B.

      B. Bacterostatic

    • C.

      C. Bacteriocide

    • D.

      D. Alcohol

    Correct Answer
    C. C. Bacteriocide
    Explanation
    A bacteriocide is a substance that completely kills bacteria. Disinfectants are substances that kill or inhibit the growth of microorganisms, including bacteria, but they may not completely eliminate all bacteria. Bacterostatic substances inhibit the growth and reproduction of bacteria, but do not necessarily kill them. Alcohol can kill some bacteria, but it may not be effective against all types of bacteria. Therefore, the correct answer to the question is C. Bacteriocide.

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  • 14. 

    14. A Mueller Hinton Plate is mainly used for

    • A.

      A. Susceptibility

    • B.

      B. Organism ID

    • C.

      C. Yeast

    • D.

      D. Fungus

    Correct Answer
    A. A. Susceptibility
    Explanation
    A Mueller Hinton Plate is mainly used for susceptibility testing of bacteria. It is a standardized medium that provides consistent and reproducible results. The plate contains a specific concentration of nutrients and inhibitors to support the growth of bacteria and inhibit the growth of unwanted organisms. Susceptibility testing is performed to determine the effectiveness of antibiotics against specific bacteria, helping in the selection of appropriate treatment options for bacterial infections.

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  • 15. 

    15. 0.5 McFarland's contains approximately how many bacteria?

    • A.

      A. 10^2

    • B.

      B. 10^16

    • C.

      C. 10^12

    • D.

      D. 10^8

    Correct Answer
    C. C. 10^12
    Explanation
    McFarland's is a standard measure of bacterial concentration used in microbiology. A 0.5 McFarland's solution is equivalent to 1.5 x 10^8 colony-forming units (CFU) per milliliter. Therefore, it contains approximately 10^12 bacteria.

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  • 16. 

    16. ESBL stands for

    • A.

      A. Enhanced spectrum beta lactamase

    • B.

      B. Enriched spectrum beta lactamase

    • C.

      C. Evolved spectrum beta lactamase

    • D.

      D. Extended spectrum beta lactamase

    Correct Answer
    D. D. Extended spectrum beta lactamase
    Explanation
    ESBL stands for Extended Spectrum Beta Lactamase. This term refers to a group of enzymes produced by bacteria that can break down and inactivate certain antibiotics, specifically beta-lactam antibiotics. These enzymes are able to hydrolyze a wider range of beta-lactam antibiotics, including penicillins and cephalosporins, making them less effective in treating infections caused by bacteria that produce ESBLs. It is important to be aware of ESBL-producing bacteria in order to choose the appropriate antibiotics for treatment and prevent the spread of these resistant bacteria.

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  • 17. 

    17. If a K. Pneumo is found to be an ESBL, which antibiotics would automatically be reported as resistant?

    • A.

      A. Streptogramins, oxazdidinones, and macrolides

    • B.

      B. Glycopeptides, aminiglycides and tetracyclines

    • C.

      C. Cephalosporins, aztreoman, and pennicillins

    • D.

      D. Ciproflaxinc, norfloxacin, and clyndamycin

    Correct Answer
    C. C. Cephalosporins, aztreoman, and pennicillins
    Explanation
    If a K. Pneumo is found to be an ESBL, it means that it is producing extended-spectrum beta-lactamase enzymes, which can break down and inactivate certain antibiotics. Cephalosporins, aztreonam, and penicillins are all beta-lactam antibiotics, which means that they contain a beta-lactam ring structure that is susceptible to degradation by ESBL enzymes. Therefore, if a K. Pneumo is ESBL-positive, it would automatically be reported as resistant to these antibiotics.

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  • 18. 

    18. What organism do you streak down the center for a CAMP test?

    • A.

      A. Strep A

    • B.

      B. Staph Aureus

    • C.

      C. E. Coli

    • D.

      D. S. Sapro

    Correct Answer
    B. B. Staph Aureus
    Explanation
    The correct answer is B. Staph Aureus. The CAMP test is a microbiological test used to identify bacteria that produce a protein called CAMP factor. Staphylococcus aureus is one of the bacteria that produces this factor, so it is streaked down the center of the test plate to check for the characteristic arrowhead-shaped hemolysis that indicates a positive result. Strep A, E. Coli, and S. Sapro are not typically involved in the CAMP test.

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  • 19. 

    19. What is the leading cause of UTIs in females?

    • A.

      A. K. Pnuemo

    • B.

      B. E.Coli

    • C.

      C. Acintobactor

    • D.

      D. S. Sapro

    Correct Answer
    B. B. E.Coli
    Explanation
    E. Coli is the leading cause of UTIs in females. This is because E. Coli is a type of bacteria that is commonly found in the gastrointestinal tract and can easily travel from the anus to the urethra in females, leading to infection in the urinary tract.

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  • 20. 

    20. What is the second leading cause of UTIs in Females?

    • A.

      A. K. Pnuemo

    • B.

      B. E.Coli

    • C.

      C. Acintobactor

    • D.

      D. S. Sapro

    Correct Answer
    D. D. S. Sapro
    Explanation
    The correct answer is D. S. Sapro. S. Sapro stands for Staphylococcus saprophyticus, which is a type of bacteria that commonly causes urinary tract infections (UTIs) in females. While E. coli is the most common cause of UTIs in females, S. sapro is the second leading cause. K. Pnuemo and Acintobactor are not commonly associated with causing UTIs.

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  • 21. 

    21. Bordet- Gengou Agar is used to isolate

    • A.

      A. Legionella

    • B.

      B. Bordatella Pertussis

    • C.

      C. H. Pylori

    • D.

      D. Campylobactor

    Correct Answer
    B. B. Bordatella Pertussis
    Explanation
    Bordet-Gengou Agar is a selective medium that is specifically designed to isolate Bordetella pertussis, the causative agent of whooping cough. This agar contains potato infusion, glycerol, and agar, which provide the necessary nutrients for the growth of Bordetella pertussis. Additionally, it also contains blood, which provides essential factors for the growth of the bacteria. The selective agents, such as crystal violet and cephalexin, inhibit the growth of other organisms, allowing for the isolation of Bordetella pertussis. Therefore, Bordet-Gengou Agar is the appropriate medium for the isolation of Bordetella pertussis.

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  • 22. 

    22. What temperature does campylobactor prefer

    • A.

      A. 15 c

    • B.

      B. 35 c

    • C.

      C. 42 c

    • D.

      D. 50 c

    Correct Answer
    C. C. 42 c
    Explanation
    Campylobacter is a bacteria that causes foodborne illness in humans. It is commonly found in undercooked poultry and unpasteurized milk. The preferred temperature for Campylobacter to grow and multiply is 42 degrees Celsius. At this temperature, the bacteria can thrive and reproduce rapidly, increasing the risk of contamination and infection if proper food handling and cooking practices are not followed.

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  • 23. 

    23. What causes necrotizing fasciitis?

    • A.

      A. Strep A

    • B.

      B. Strep B.

    • C.

      C. Strep C.

    • D.

      D. Strep D

    Correct Answer
    A. A. Strep A
    Explanation
    Necrotizing fasciitis is caused by the bacteria Streptococcus pyogenes, also known as Group A Streptococcus (Strep A). This bacteria can invade the deep layers of the skin and soft tissues, causing severe infection and tissue death. Strep A is commonly found on the skin and throat, and can enter the body through cuts, burns, or surgical wounds. It releases toxins that destroy the surrounding tissue and can rapidly spread, leading to a life-threatening condition if not treated promptly.

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  • 24. 

    24. Rheumatic Fever is caused by which streptolysin of strep a

    • A.

      A. A

    • B.

      B. S

    • C.

      C. O

    • D.

      D. R

    Correct Answer
    C. C. O
    Explanation
    Rheumatic Fever is caused by the streptolysin O (SLO) produced by Streptococcus pyogenes bacteria. SLO is a potent toxin that causes damage to red blood cells, white blood cells, and platelets. It also contributes to the development of inflammation and tissue damage in the body, leading to the characteristic symptoms of Rheumatic Fever. Streptolysin A (SLA) is another toxin produced by Streptococcus pyogenes, but it is not directly associated with the development of Rheumatic Fever.

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  • 25. 

    25. Which organism would you use an optichin disk with

    • A.

      A. Strep Pneumo

    • B.

      B. Strep B (agalactaie)

    • C.

      C. Strep Pyogenes

    • D.

      D. Strep Bovis

    Correct Answer
    A. A. Strep Pneumo
    Explanation
    Optichin is an antibiotic that is used to test for the susceptibility of Streptococcus pneumoniae, also known as Strep Pneumo, to the drug. Therefore, the correct organism to use an optichin disk with is Strep Pneumo.

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  • 26. 

    26. Which organism is resistant to Novabiacin?

    • A.

      A. Strep Pneumo

    • B.

      B. Strep B (agalactaie)

    • C.

      C. Strep Pyogenes

    • D.

      D. Strep Sapro

    Correct Answer
    D. D. Strep Sapro
    Explanation
    Strep Sapro is the organism that is resistant to Novabiacin.

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  • 27. 

    27. Corynebacterium Diptheriae appears as what on a gram stain?

    • A.

      A. Palisades

    • B.

      B. Cocci

    • C.

      C. Dipplococci

    • D.

      D. Grape like clusters

    Correct Answer
    A. A. Palisades
    Explanation
    Corynebacterium Diptheriae appears as palisades on a gram stain. Palisades are a characteristic arrangement of bacteria where the cells align in a parallel manner, resembling a row of fence posts. This arrangement is commonly seen in Corynebacterium Diptheriae, which is a gram-positive bacterium that causes the respiratory disease diphtheria. The palisades arrangement helps in the identification of this bacterium on a gram stain.

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  • 28. 

    28. Which organism is one of the enterics?

    • A.

      A. Staph Aureus

    • B.

      B. Strep Pneumo

    • C.

      C. N. meningitidis

    • D.

      D. Salmonella

    Correct Answer
    D. D. Salmonella
    Explanation
    Salmonella is one of the enterics because it belongs to the Enterobacteriaceae family, which is a group of gram-negative bacteria that commonly inhabit the human gastrointestinal tract. Enterics are known for their ability to ferment glucose and produce acid and gas. Salmonella is a well-known enteric pathogen that can cause foodborne illnesses such as salmonellosis. Staph Aureus, Strep Pneumo, and N. meningitidis are not enterics as they do not belong to the Enterobacteriaceae family and do not possess the characteristic features of enteric bacteria.

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  • 29. 

    29. What food poisoning is associated with undercooked hamburger?

    • A.

      A. Salmonella

    • B.

      B. E.Coli

    • C.

      C. Pseudomonas Aeruginosa

    • D.

      D. Proteus Mirablis

    Correct Answer
    B. B. E.Coli
    Explanation
    Undercooked hamburger is commonly associated with E.Coli food poisoning. E.Coli, or Escherichia coli, is a type of bacteria that can be found in the intestines of animals, including cattle. When meat is not cooked thoroughly, the bacteria can survive and cause illness when consumed. Symptoms of E.Coli food poisoning may include diarrhea, abdominal pain, and vomiting. It is important to cook ground beef to a safe internal temperature to kill any potential bacteria and prevent food poisoning.

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  • 30. 

    30. What food poisoning is associated with undercooked poultry?

    • A.

      A. Salmonella

    • B.

      B. E.Coli

    • C.

      C. Pseudomonas Aeruginosa

    • D.

      D. Proteus Mirablis

    Correct Answer
    A. A. Salmonella
    Explanation
    Salmonella is a type of bacteria commonly found in undercooked poultry and can cause food poisoning. When poultry is not cooked thoroughly, the bacteria may survive and cause illness when consumed. Symptoms of Salmonella poisoning include diarrhea, vomiting, abdominal pain, and fever. It is important to cook poultry to the appropriate internal temperature to kill any bacteria present and prevent foodborne illnesses.

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  • 31. 

    31. Autoclave sterilization of lab media requires which of the following pressure, temperature, and time parameters?

    • A.

      A. 15 lb. pressure 115 c for 10 min

    • B.

      B. 15 lbs pressure 121 c for 15 min

    • C.

      C. 20 lbs pressure, 100 c for 15 min

    • D.

      D. 20 lbs pressure, 110 c for 10 min

    Correct Answer
    B. B. 15 lbs pressure 121 c for 15 min
    Explanation
    Autoclave sterilization is a process used to kill microorganisms and sterilize lab media. The correct parameters for autoclave sterilization include a pressure of 15 lbs, a temperature of 121°C, and a time of 15 minutes. This combination of pressure, temperature, and time ensures that the lab media is effectively sterilized and free from any potential contaminants.

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  • 32. 

    32 An H2S producing Salmonella would most likely appear as a ___________ colony

    • A.

      A. Pink

    • B.

      B. Tan

    • C.

      C. White

    • D.

      D. Black

    Correct Answer
    D. D. Black
    Explanation
    An H2S producing Salmonella would most likely appear as a black colony because the production of hydrogen sulfide (H2S) by Salmonella leads to the formation of black precipitates. This black coloration is due to the reaction between H2S and iron compounds in the growth medium. Therefore, a black colony would indicate the presence of Salmonella that produces H2S.

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  • 33. 

    33. The treatment of choice for MRSA is

    • A.

      A. Gentamycin

    • B.

      B. Tobramycin

    • C.

      C. Vancomycin

    • D.

      D. Penicillin

    Correct Answer
    C. C. Vancomycin
    Explanation
    Vancomycin is the treatment of choice for MRSA (methicillin-resistant Staphylococcus aureus) because it is one of the few antibiotics that is effective against this resistant strain of bacteria. MRSA is resistant to penicillin and other beta-lactam antibiotics, so penicillin (option D) is not an appropriate choice. Gentamycin (option A) and tobramycin (option B) are aminoglycoside antibiotics that are not typically used as the first-line treatment for MRSA. Therefore, the correct answer is C. Vancomycin.

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  • 34. 

    34. Blood Agar plates are primarily used for the detection of

    • A.

      A. Gram negative rods

    • B.

      B. Viruses

    • C.

      C. Hemolysis

    • D.

      D. Fungus

    Correct Answer
    C. C. Hemolysis
    Explanation
    Blood Agar plates are primarily used for the detection of hemolysis. Hemolysis refers to the breakdown of red blood cells, and it is often used as an indicator for certain bacteria. Different types of hemolysis can be observed on Blood Agar plates, including alpha-hemolysis (partial breakdown resulting in a greenish discoloration), beta-hemolysis (complete breakdown resulting in a clear zone around the bacterial colonies), and gamma-hemolysis (no breakdown). By observing the type of hemolysis, it can help in the identification and differentiation of bacteria. Therefore, the correct answer is C. Hemolysis.

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  • 35. 

    35. One of the primary media used to isolate anaerobes is

    • A.

      A. KV Laked Blood

    • B.

      B. MacConkeys

    • C.

      C. Campy blood agar

    • D.

      D. PEA

    Correct Answer
    A. A. KV Laked Blood
    Explanation
    One of the primary media used to isolate anaerobes is KV Laked Blood. This medium is commonly used in microbiology laboratories for the cultivation and isolation of anaerobic bacteria. It contains blood, which provides essential nutrients for bacterial growth, and is supplemented with a reducing agent to create an anaerobic environment. This medium supports the growth of anaerobes and inhibits the growth of aerobic bacteria, allowing for the isolation and identification of anaerobic organisms.

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  • 36. 

    36. Thioglycollate is mainly used as

    • A.

      A. A back-up in case a anaerobe is present

    • B.

      B. A back up in case PsA is present

    • C.

      C. A back up in case Staph Aureus is present

    • D.

      D. A back up in case Enterobactor is present

    Correct Answer
    A. A. A back-up in case a anaerobe is present
    Explanation
    Thioglycollate is mainly used as a back-up in case an anaerobe is present. This is because thioglycollate broth is a reducing medium that creates an environment suitable for the growth of anaerobic bacteria. It contains sodium thioglycollate, which acts as a reducing agent to remove oxygen from the medium. This allows the growth of anaerobic bacteria that cannot tolerate oxygen. Therefore, thioglycollate is commonly used in microbiology laboratories to support the growth of anaerobes and to determine their presence in a sample.

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  • 37. 

    37. A catalase negative grey pinpoint colony that is PYR positive is

    • A.

      A. Strep. A

    • B.

      B. Strep. B

    • C.

      C. Strep Pnuemo

    • D.

      D. Enterococcus

    Correct Answer
    D. D. Enterococcus
    Explanation
    A catalase negative grey pinpoint colony that is PYR positive is most likely Enterococcus. This is because Enterococcus is known to be catalase negative and can produce grey pinpoint colonies. Additionally, the PYR test is commonly used to differentiate between Enterococcus and other streptococci, as Enterococcus is PYR positive while most streptococci are PYR negative. Therefore, the combination of a catalase negative result, grey pinpoint colony morphology, and a positive PYR test strongly suggests Enterococcus.

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  • 38. 

    38. IMViC is the pneumonic for

    • A.

      A. Indole, Methyl Red, VP, Citrate

    • B.

      B. Indole, Methyl Red, VP, Catalase

    • C.

      C. Inducible, Methyl Red, VP, Citrate

    • D.

      D. Indole, Methyl Red, VP, Coagulase

    Correct Answer
    A. A. Indole, Methyl Red, VP, Citrate
    Explanation
    IMViC is a mnemonic that stands for Indole, Methyl Red, Voges-Proskauer, and Citrate. These are a series of biochemical tests used to identify and differentiate between different species of bacteria. Indole test determines the ability of bacteria to produce indole from the amino acid tryptophan, Methyl Red test detects the ability of bacteria to perform mixed acid fermentation, Voges-Proskauer test identifies bacteria that can produce acetoin, and Citrate test determines whether bacteria can utilize citrate as a carbon source. Therefore, option A is the correct answer as it includes all the correct components of the IMViC test.

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  • 39. 

    39 What organism is IMViC ++--

    • A.

      A. E. Coli

    • B.

      B. PsA

    • C.

      C. Staph Aureus

    • D.

      D. Citrobactor

    Correct Answer
    A. A. E. Coli
    Explanation
    The IMViC test is a series of tests used to differentiate between members of the Enterobacteriaceae family. The results of the test are indicated by the symbols ++--, which represent the presence or absence of certain metabolic activities. In this case, the ++-- pattern is characteristic of E. Coli, indicating that it is the correct answer. PsA, Staph Aureus, and Citrobactor do not exhibit this specific pattern of results in the IMViC test.

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  • 40. 

    40. What color does Shigella appear on a HE plate

    • A.

      A. green

    • B.

      B. Blue

    • C.

      C. Pink

    • D.

      D. White

    Correct Answer
    A. A. green
    Explanation
    Shigella appears green on a HE (Hektoen Enteric) plate. HE agar is a selective and differential medium used to isolate and identify enteric pathogens, such as Shigella. The green color is due to the fermentation of lactose by Shigella, resulting in the production of acid. This acid production causes a pH change in the agar, leading to the appearance of green colonies. Other organisms may appear blue, pink, or white on the HE plate, but Shigella specifically appears green.

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  • 41. 

    41. The primary cause for concern for Strep B in a pregnant woman is

    • A.

      A. It causes cystitis is the woman

    • B.

      B. It causes meningitis in the baby

    • C.

      C. It causes Down's Syndrome in the baby

    • D.

      D. It causes abdominal cramps

    Correct Answer
    B. B. It causes meningitis in the baby
    Explanation
    The primary cause for concern for Strep B in a pregnant woman is that it can cause meningitis in the baby. Strep B is a type of bacteria that can be present in the vagina or rectum of a pregnant woman. During childbirth, the baby can come into contact with the bacteria, which can lead to infection. If the bacteria enters the baby's bloodstream, it can cause meningitis, which is a serious infection of the membranes surrounding the brain and spinal cord. Meningitis can result in long-term complications or even death in newborns, making it a significant concern for pregnant women.

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  • 42. 

    42. You have gram stained a gram positive cocci. What test would you do next?

    • A.

      A. Catalase

    • B.

      B. Coagulase

    • C.

      C. Indole

    • D.

      D. Oxidase

    Correct Answer
    A. A. Catalase
    Explanation
    After gram staining a gram positive cocci, the next test to be done would be the Catalase test. This test is used to differentiate between catalase-positive and catalase-negative organisms. Catalase-positive organisms produce the enzyme catalase, which breaks down hydrogen peroxide into water and oxygen. This can be observed by adding hydrogen peroxide to the bacteria, and if bubbles are produced, it indicates a positive result for catalase.

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  • 43. 

    43. You have gram stained a gram negative rod that appears to be Pseudomonas Aeruginosa. What test would you do next.

    • A.

      A. Catalase

    • B.

      B. Coagulase

    • C.

      C. Indole

    • D.

      D. Oxidase

    Correct Answer
    D. D. Oxidase
    Explanation
    After gram staining the gram negative rod and identifying it as Pseudomonas Aeruginosa, the next test to be done would be the Oxidase test. This test is used to determine the presence of the enzyme cytochrome c oxidase, which is found in the electron transport chain of aerobic bacteria. Pseudomonas Aeruginosa is known to be oxidase positive, so performing the oxidase test would help confirm the identification of the bacteria. The other tests mentioned (Catalase, Coagulase, and Indole) are not specific for identifying Pseudomonas Aeruginosa.

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  • 44. 

    44. What is the toxin that E. Coli 0517:H7 carries

    • A.

      A. Shigella toxin

    • B.

      B. Shiga toxin

    • C.

      C. Coli Toxin

    • D.

      D. Hemorrhagic toxin

    Correct Answer
    B. B. Shiga toxin
    Explanation
    E. Coli 0517:H7 carries Shiga toxin. Shiga toxin is a toxin produced by certain strains of E. Coli bacteria, including the 0517:H7 strain. This toxin is responsible for causing severe symptoms such as bloody diarrhea and kidney damage in individuals infected with this strain of E. Coli.

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  • 45. 

    45. What two organisms are motility negative

    • A.

      A. Klebsiella and Shigella

    • B.

      B. Salmonella and Proteus

    • C.

      C. Enterobactor and Citrobactor

    • D.

      D. Proteus and Serratia

    Correct Answer
    A. A. Klebsiella and Shigella
    Explanation
    Klebsiella and Shigella are both motility negative organisms. Motility refers to the ability of an organism to move or exhibit self-propulsion. In the case of Klebsiella and Shigella, they lack the ability to move on their own. This is an important characteristic to note when identifying and differentiating between different types of bacteria. Salmonella and Proteus, Enterobactor and Citrobactor, and Proteus and Serratia are not both motility negative, so they are not the correct answer.

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  • 46. 

    46. Which organism is associated with colon cancer

    • A.

      A. Strep Pneumo

    • B.

      B. Group A

    • C.

      C. Group D

    • D.

      D. Strep Viridians

    Correct Answer
    C. C. Group D
    Explanation
    Group D organisms, specifically Enterococcus faecalis and Enterococcus faecium, have been associated with colon cancer. These bacteria have been found to promote inflammation and contribute to the development of colorectal tumors. Additionally, they have been shown to produce certain enzymes that can damage DNA and increase the risk of cancer. Therefore, Group D organisms are considered to be a potential risk factor for colon cancer.

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  • 47. 

    47. A positive tube Coagulase test for a gram positive cocci would be considered

    • A.

      A. presumptive positive

    • B.

      B. confirmed positive

    • C.

      C. negative

    • D.

      D. neither negative or positive

    Correct Answer
    B. B. confirmed positive
    Explanation
    A positive tube Coagulase test for a gram positive cocci would be considered confirmed positive because the test specifically detects the presence of the enzyme coagulase, which is produced by certain bacteria such as Staphylococcus aureus. A positive result indicates the presence of this specific enzyme and confirms the identification of the gram positive cocci as Staphylococcus aureus.

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  • 48. 

    48. Proteus is Urea Positive

    • A.

      True

    • B.

      False

    Correct Answer
    A. True
    Explanation
    Proteus is a genus of bacteria that is known to be urea positive. This means that it has the ability to break down urea, a waste product of protein metabolism, into ammonia and carbon dioxide. This characteristic is used as a diagnostic tool in identifying Proteus species in the laboratory. Therefore, the given statement is true.

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  • 49. 

    49. A fastidious organism

    • A.

      A. Grows fast

    • B.

      B. Grows slow

    • C.

      C. Grows about the same speed as most bacteria

    • D.

      D. Does not grow at all

    Correct Answer
    B. B. Grows slow
    Explanation
    The correct answer is B. Grows slow. A fastidious organism refers to an organism that has specific and strict nutritional requirements for growth. These organisms often grow slowly because they require specific conditions and nutrients to thrive.

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  • 50. 

    50. Beta Lactamases act by

    • A.

      A. Locking up the beta lactam

    • B.

      B. Destroying the beta lactam

    • C.

      C. Shrinking the beta lactam

    • D.

      D. Imploding the beta lactam

    Correct Answer
    A. A. Locking up the beta lactam
    Explanation
    Beta lactamases act by locking up the beta lactam. This enzyme is produced by bacteria and is responsible for breaking down the beta lactam ring structure found in many antibiotics, rendering them ineffective. By locking up the beta lactam, the enzyme prevents the antibiotic from binding to its target site and exerting its antimicrobial activity. This allows the bacteria to survive and continue to cause infection.

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Our quizzes are rigorously reviewed, monitored and continuously updated by our expert board to maintain accuracy, relevance, and timeliness.

  • Current Version
  • Mar 21, 2023
    Quiz Edited by
    ProProfs Editorial Team
  • Feb 12, 2015
    Quiz Created by
    Lveal
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