MDS PREP
Which of the following is a feature of HLA class I antigens?
1) Found on red blood cells
2) Involved in humoral immunity
3) Present on all nucleated cells
4) Only present in lymphocytes
HLA class I antigens are present on all nucleated cells, playing a crucial role in the immune response.
What are the typical clinical features of typhoid fever?
1) High fever, bradycardia, and a palpable spleen
2) Rash, joint pain, and respiratory symptoms
3) Diarrhea, abdominal cramps, and vomiting
4) Headache, photophobia, and neck stiffness
General Microbiology Answer: 1The typical clinical features of typhoid fever can be listed as follows:
1. High fever, bradycardia, and a palpable spleen: Typhoid fever is
characterized by a sustained high fever, often reaching 103°F to 104°F (39°C to
40°C). Bradycardia, or a slower than normal heart rate, occurs in some cases.
The spleen may also become enlarged and palpable due to the infection.
2. Rash, joint pain, and respiratory symptoms: Some patients may develop a rash
known as "Rose spots," which are small, red spots on the abdomen and chest.
Joint pain can occur, and respiratory symptoms may include a dry cough.
3. Diarrhea, abdominal cramps, and vomiting: Diarrhea and severe abdominal
cramps are common in the early stages of typhoid fever, which can lead to
significant dehydration and discomfort for the patient.
4. Headache, photophobia, and neck stiffness: Headaches and sensitivity to light
(photophobia) are often present, and in severe cases, neck stiffness can occur
due to inflammation of the meninges, known as meningitis.
On a medium containing 6% agar, 5% Fildes peptic digest of sheep blood, and 20% human serum, which of the following is NOT a typical characteristic of C1. Perfringens colonies?
1) They will be surrounded by a zone of opacity on the half without antitoxin due to the Nagler reaction
2) They are nonmotile
3) They are capsulated
4) They ferment lactose and produce bright pink colonies on MacConkey’s medium
General Microbiology Answer: 2
C1. Perfringens colonies are typically nonmotile and do not form capsules. They will be surrounded by a zone of opacity on the half without antitoxin due to the Nagler reaction (option 1) and will not ferment lactose to produce bright pink colonies on MacConkey’s medium
What is the characteristic appearance of Bacillus anthracis in gelatin stab culture?
1) Smooth liquefaction
2) Inverted fir tree appearance
3) No liquefaction
4) Uniform turbidity
The inverted fir tree appearance is characteristic of Bacillus anthracis in gelatin stab culture.
Which of the following tests uses killed Treponema pallidum?
1) TPI test
2) TPA test
3) RPCF test
4) FTA test
General Microbiology Answer: 2The Treponema pallidum agglutination test (TPA) utilizes killed Treponema pallidum organisms to detect antibodies in the serum of patients suspected of having syphilis. This test is more sensitive than other tests and is used for confirming syphilis infections.
What does one unit of antitoxin refer to in the context of diphtheria toxin?
1) The amount needed to neutralize 100 MLD of toxin
2) The amount of antitoxin that causes the toxin to flocculate
3) The amount that confers immunity to an individual
4) The amount of toxin that can cause disease in an average host
One unit of antitoxin refers to the amount needed to neutralize 100 MLD of diphtheria toxin.
Which of the following is a killed viral vaccine?
1) Sabin vaccine for poliomyelitis
2) Salk vaccine for poliomyelitis
3) MMR vaccine for measles, mumps, rubella
4) Varicella-zoster
General Microbiology Answer: 2
The Salk vaccine for poliomyelitis is a killed viral vaccine, effectively preventing the disease by using inactivated poliovirus.
Which of the following statements about the fermentation of sugars by Anthracoid bacilli is true?
1) Anthracoid bacilli ferment glucose, maltose, lactose, and sucrose, producing acid and gas.
2) Anthracoid bacilli do not ferment glucose but ferment maltose, lactose, and sucrose.
3) Anthracoid bacilli only ferment glucose.
4) Anthracoid bacilli ferment glucose, maltose, and lactose, but not sucrose.
Anthracoid bacilli ferment glucose, maltose, lactose, and sucrose, producing acid and gas.