1.
Mycoplasmas are pleomorphic organisms that have a cell wall.
Correct Answer
B. False
Explanation
Mycoplasmas are pleomorphic organisms that do not have a cell wall.
2.
Why are Mycoplasma resistant to antibiotics such as penicillin and cephalosporins?
Correct Answer
B. Their lack of a cell wall make them resistant
Explanation
Mycoplasma is resistant to antibiotics such as penicillin and cephalosporins because they lack a cell wall. The cell wall of bacteria is the target for many antibiotics, including penicillin and cephalosporins, as it is responsible for maintaining the structural integrity of the bacteria. Without a cell wall, these antibiotics are unable to effectively target and kill the Mycoplasma bacteria, leading to their resistance.
3.
Mycoplasma grows _____ and are highly fastidious, facultative anerobes.
Correct Answer
B. Slowly
Explanation
Mycoplasma grows slowly because they are highly fastidious, meaning they have specific nutritional requirements and are sensitive to changes in their environment. They are also facultative anaerobes, which means they can survive with or without oxygen. Their slow growth rate is due to their small size and lack of a cell wall, which makes them more susceptible to environmental conditions and limits their ability to replicate quickly.
4.
Mycoplasma need complex media contain _______ and _______ for growth.
Correct Answer
C. Cholesterol and fatty acids
Explanation
Mycoplasma is a type of bacteria that lacks a cell wall, making it highly dependent on its environment for nutrients. Cholesterol and fatty acids are essential components for the growth and survival of Mycoplasma. These substances are required for the synthesis of cell membranes and the maintenance of membrane fluidity. Without cholesterol and fatty acids in their growth media, Mycoplasma would not be able to obtain these crucial components and would fail to grow. Therefore, complex media containing cholesterol and fatty acids are necessary for the growth of Mycoplasma.
5.
Mycoplasma species grow embedded _____ the surface of the solid media.
Correct Answer
B. Beneath
Explanation
Mycoplasma species grow embedded beneath the surface of the solid media. This means that they are located or situated below the surface of the media. They do not grow on top or over the surface, but rather underneath it.
6.
On solid media, some species of Mycoplasma form colonies with a slightly raised center giving a "_______" appearance.
Correct Answer
C. Fried egg
Explanation
Some species of Mycoplasma form colonies with a slightly raised center, resembling the appearance of a fried egg. This means that the colonies have a flat periphery and a rounded, elevated center, similar to the shape of a fried egg. This characteristic appearance helps in the identification and differentiation of these species on solid media.
7.
M. hominis is found in the lower genitourinary tract of about half of healthy adults; not a cause of __________.
Correct Answer
C. NGU
Explanation
M. hominis is a type of bacteria that is commonly found in the lower genitourinary tract of healthy adults. It is not known to be a cause of NGU (Non-Gonococcal Urethritis), which is an inflammation of the urethra that is not caused by gonorrhea. Therefore, the correct answer is NGU.
8.
Since mycoplasma organisms lack a ______, they will not stain with Gram stain.
Correct Answer
D. Cell wall
Explanation
Mycoplasma organisms do not have a cell wall, which is a characteristic feature of most bacteria. The Gram stain method relies on the presence of a cell wall to differentiate between Gram-positive and Gram-negative bacteria. Without a cell wall, mycoplasma organisms are unable to retain the crystal violet stain used in the Gram stain procedure, resulting in them being unable to stain with the Gram stain.
9.
A DNA fluorescent stain using (acridine ________) can be used but this is not specific.
Correct Answer
C. Orange
Explanation
Acridine orange is a DNA fluorescent stain that can be used to visualize DNA under a microscope. It intercalates between the base pairs of DNA, causing the DNA to emit orange fluorescence when exposed to specific wavelengths of light. However, acridine orange is not specific to DNA and can also bind to RNA and other cellular components. Therefore, while it can be used as a DNA stain, it is not considered a specific stain for DNA.
10.
M. penumoniae requires what substrate to grow in culture?
Correct Answer
A. Glucose
Explanation
M. penumoniae requires glucose as a substrate to grow in culture. Glucose is a simple sugar that provides energy for the bacterial cells to carry out their metabolic processes. Without glucose, the bacteria would not be able to grow and multiply in the culture medium. Other substrates mentioned, such as arginine and urea, may be used by other bacteria for growth but are not specifically required by M. penumoniae. The pH of the media near 6.0 may be important for the optimal growth of M. penumoniae, but it is not the primary substrate needed for its growth.
11.
Mycoplasma hominis requires what substrate to grow in culture?
Correct Answer
B. Arginine
Explanation
Mycoplasma hominis requires arginine as a substrate to grow in culture. Arginine is an amino acid that serves as a source of nitrogen for the bacteria. It is an essential component for the synthesis of proteins and other important cellular processes. Without arginine, Mycoplasma hominis would not be able to obtain the necessary nutrients for growth and survival in a laboratory culture.
12.
Ureaplasma species requires what substrate to grow in culture?
Correct Answer
C. Urea and media with a pH near 6.0
Explanation
Ureaplasma species require urea and media with a pH near 6.0 to grow in culture. Urea is necessary because Ureaplasma species produce the enzyme urease, which breaks down urea into ammonia and carbon dioxide. The production of ammonia helps maintain the pH near 6.0, which is the optimal pH for Ureaplasma growth. Therefore, both urea and media with a pH near 6.0 are essential for the growth of Ureaplasma species in culture.
13.
What is the major way M. pneumoniae is diagnosed?
Correct Answer
B. Serology
Explanation
Serology is the major way M. pneumoniae is diagnosed. Serology involves testing for the presence of antibodies in the blood that are specific to M. pneumoniae. This can be done through various methods such as enzyme immunoassay or indirect immunofluorescence assay. By detecting the antibodies, it indicates a current or past infection with M. pneumoniae. PCR (Polymerase Chain Reaction) is another diagnostic method but it is not the major way M. pneumoniae is diagnosed. PCR is used to detect the DNA of the bacteria in samples such as respiratory secretions.
14.
What would be the best way to make a diagnosis of Mycoplasma pneumoniae?
Correct Answer
A. Collect two specimens 2-3 weeks apart
Explanation
Collecting two specimens 2-3 weeks apart would be the best way to make a diagnosis of Mycoplasma pneumoniae. This is because Mycoplasma pneumoniae is a slow-growing bacteria that can take several weeks to be detectable in a patient's respiratory specimens. By collecting two specimens 2-3 weeks apart, it increases the chances of detecting the bacteria if it is present in the patient's respiratory system. Collecting one specimen 1 week apart or collecting two specimens 7 days apart may not allow enough time for the bacteria to grow and be detected, while collecting three specimens 2-3 weeks apart may be unnecessary and time-consuming.
15.
Cold agglutininins is a sensitive and specific for Mycoplasma pneumoniae.
Correct Answer
B. False
Explanation
Cold agglutinins for many years were used as an indicator of primary atypical pneumonia.It is insensitive and nonspecific for Mycoplasma pneumoniae.
16.
Most reference labs utilize the ______ fixation technique for the presence of antibodies.
Correct Answer
C. Complement
Explanation
The given question is asking about the fixation technique used by most reference labs to detect the presence of antibodies. The correct answer is "complement." Complement fixation is a technique used to determine the presence of specific antibodies in a patient's blood sample. It involves mixing the patient's serum with a known antigen and complement proteins. If the patient has antibodies against the antigen, they will bind to it, activating the complement system and resulting in the lysis of red blood cells. This reaction indicates the presence of antibodies in the patient's blood.
17.
Due to the absence of a cell wall, Mycoplasma organisms are resistant to all Beta lactam antibiotics.
Correct Answer
A. True
Explanation
Mycoplasma organisms are unique because they lack a cell wall. This characteristic makes them resistant to all Beta lactam antibiotics, as these antibiotics target and disrupt the cell wall of bacteria. Without a cell wall, Mycoplasma organisms are able to evade the effects of Beta lactam antibiotics, making the statement true.
18.
Mycoplasma pneumoniae remain susceptible to _______, newer quinolones and macrolides are used.
Correct Answer
A. Tetracycline
Explanation
Mycoplasma pneumoniae remains susceptible to tetracycline. Therefore, newer quinolones and macrolides are used as alternative treatment options.