Formative assessments Flashcards by Basel selim

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Which of the following bacterial structures is antigenic?

a) Peptidoglycan
b) Flagella
c) Cytoplasmic membrane
d) Ribosomes

b) Flagella

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Your lab partner has mixed a dead tryptophan bacterial strain with a live tryptophan bacterial strain and observe that her bacterial culture is now tryptophan+, What is the most likely explanation for this?

a) Transduction
b) Transformation
c) Conjugation
d) Mutation

b) Transformation

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As a microbiologist, you work in a research laboratory and discover a chemical that prevents capsule formation, which of the following properties will the bacteria lose?

a) Attachment to surfaces
b) Protection against phagocytosis
c) Motility
d) Conjugation

b) Protection against phagocytosis

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What is the proper chemical disinfectant used for decontamination of blood
spills?

a) Ethyl alcohol (70%)
b) Glutaraldehyde
c) Hydrogen peroxide (6%)
d) Chlorine compounds (5.25%)

d) Chlorine compounds (5.25%)

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Which viral structure is responsible for viral virulence?

a) Envelope
b) Capsid
c) Core
d) Genome

d) Genome

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Regarding moulds, which statement is CORRECT?

a) They are obligate anaerobes.
b) They may form pseudohyphae.
c) They form mycelium on culture media.
d) They reproduce by budding.

c) They form mycelium on culture media.

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Which organ is a primary lymphoid organ?

a) Spleen
b) Lymph nodes
c) Mucosal associated lymphoid tissue
d) Bone marrow

d) Bone marrow

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Which cell possesses granules containing inflammatory mediators and plays an important role in allergy?

a) Neutrophils
b) Mast cells
c) Natural killer cells
d) Macrophages

b) Mast cells

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Which of the following is a characteristic feature of innate immune response?

a) It is specific
b) It is delayed but effective
c) It does not increase with repeated exposure
d) It depends on T and B lymphocytes

c) It does not increase with repeated exposure

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Which cell is the main phagocytic cell in blood?

a) Neutrophils
b) Eosinophils
c) Basophils
d) Mast cells

a) Neutrophils

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What is the second signal necessary for I cell activation?

a Binding of CD28 on the T cell to B7 on the antigen presenting cell
b. Binding of CD40L on T cell to CD40 on the antigen presenting cell
c Binding of CD3 on the T cell to the MHC on the antigen presenting cell
d. Binding of the Fas ligand on the T cell to Fas on the antigen presenting cell

a Binding of CD28 on the T cell to B7 on the antigen presenting cell

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Which cell can recognize and kill abnormal cells by antibody-dependent cellular cytotoxicity (ADCC)?

a. B cell
b. Natural killer cell
c. T cytotoxic cell
d. T helper cell

b. Natural killer cell

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Which cytokine is a proinflammatory cytokine?

a. IL-2
b. IL-5
c. IL-6
d. IL-10

c. IL-6

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4- Which term best describes the binding of an
antibody-coated pathogen to the Fc receptor on phagocytic cells to help phagocytosis?

a) Agglutination
b) Complement activation
c) Neutralization
d) Opsonization

d) Opsonization

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Which class of immunoglobulins indicates recent (acute) infection?

a) IgA
b) IgE
c) IgG
d) IgM

d) IgM

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Which complement protein is responsible for clearance of immune complexes?

a. C3b
b. C5a
c. Factor B
d. Factor D

a. C3b

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What is the main specific immune response against established viral infections?

a) Humoral immune response
b) Killing by cytotoxic T cells
c) Killing by natural killer cells
d) Macrophage activation

b) Killing by cytotoxic T cells

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Which antibiotic can be used to treat methicillin resistant Staphylococcus aureus?

a) Cephalosporins
b) Oxacillin
c) Penicillin
d) Vancomycin

d) Vancomycin

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What is the drug of choice to prevent repeated attacks of post-streptococcal rheumatic fever?

a) Ceftriaxone
b) Long-acting penicillin
c) Tetracycline
d) Vancomycin

b) Long-acting penicillin

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Which of the following is involved in Type IV hypersensitivity?

a) Activated Th 1 cells
b) Antibodies
c) Complement
d) Histamine

a) Activated Th 1 cells

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Which type of Escherichia coli may cause haemolytic uraemic syndrome?

a) Enteroaggregative E. coli
b) Enterohaemorrhagic E. coli
c) Enteroinvasive E. coli
d) Enteerotoxigenic E. coli

b) Enterohaemorrhagic E. coli

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Which statement is CORRECT regarding Widal test?

a) It is diagnostic during the first week of illness
b) Antibody titre of 1:320 is insignificant
c) Early antibiotic treatment gives false negative result
d) Recently vaccinated individual have only H antibodies

c) Early antibiotic treatment gives false negative result

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Which immunodeficiency disease is caused by a defect in the migration of leucocytes?

a) Chronic granulomatous disease
b) Di George syndrome
c) Hereditary angioedema
d) Leucocyte adhesion deficiency

d) Leucocyte adhesion deficiency

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An acid-fast smear of a patient's sputum is positive. However, tuberculin skin test is negative. Regarding these findings, Which statement is CORRECT? a) The patient is the state of anergy b) The positive sputum smear is due to BCG vaccination c) The patient is infected with M. leprae d) The patient is not infectious

b) The positive sputum smear is due to BCG vaccination

Which disease caused by Mycoplasma? a) Atypical pneumonia b) Inclusion conjunctivitis c) Relapse fever d) Infectious jaundice

a) Atypical pneumonia

Which fungus is the causative agent of tinea capitis? a) Candida b) Cryptococcus c) Malassezia d) Trichophyton

d) Trichophyton

A 23-year-old woman presented with a gradual onset of fever, hepatomegaly and abdominal pain. Hepatitis panel revealed; HBsAG-positive, Anti-HBs-negative, Anti-HBc IgM-positive, and Anti-HAV IgG-positive. What is the most likely diagnosis of this patient? a) Acute infection with HBV b) Chronic infection with HAV c) Coinfection with HAV and HBV d) Vaccination against HBV

a) Acute infection with HBV

Which of the following criteria is used to define a patient to have AIDS? a) Anti-HIV antibodies are detectable in his serum b) CD4 count is lower than 200 cells/mm3 c) Exposure to HIV in the last year d) Infection with HIV for 5 years

b) CD4 count is lower than 200 cells/mm3

1. Which of the following organisms most likely causes neonatal meningitis? a) Streptococcus pyogenes b) Listeria monocytogene c) Staphylococcus aureus d) Mycobacterium tuberculosis

b) Listeria monocytogene

2. Regarding pneumococci, which statement is correct? a) 25% of pregnant females are vaginal carriers. b) They have an important role in dental caries. c) They have a thick polysaccharide capsule. d) They are the commonest cause of acute follicular tonsillitis.

c) They have a thick polysaccharide capsule.

3. Which serogroup is not included in the polyvalent vaccine against meningococcal meningitis? a) C b) A c) W-135 d) B

d) B

4. Which of the following diseases is not caused by Haemophilus influenzae? a) Pneumonia b) Meningitis c) Food poisoning d) Otitis media

c) Food poisoning

6. What is the mechanism of the paralytic effect of the poliomyelitis virus? a) Toxin secretion b) Damage of motor neurons c) Blocking release of acetylcholine d) Blocking release of inhibitory mediators.

b) Damage of motor neurons

7. Which statement is CORRECT regarding tetanus? a) Clostridium tetani travels via the nerves to the anterior horn cells in the spinal cord. b) The diagnosis depends mainly on microscopic identification. c) Tetanospasmin blocks the release of inhibitory neurotransmitters. d) The patient should be given antibiotics only

c) Tetanospasmin blocks the release of inhibitory neurotransmitters.

8. The presence of Negri inclusion bodies in host cells is a characteristic finding of which of the following diseases? a) Mumps b) Infectious mononucleosis c) Congenital rubella d) Rabies

d) Rabies

Which statement is TRUE regarding rubella virus? a) It belongs to orthomyxoviruses. b) It has many antigenic types. c) It is transmitted by blood transfusion. d) Detection of IgM anti- rubella antibodies in a newborn confirms intrauterine infection.

d) Detection of IgM anti- rubella antibodies in a newborn confirms intrauterine infection.

Regarding human papilloma virus (HPV), which statement is INCORRECT? a) It infects squamous epithelium causing hyperkeratosis and warts. b) It is transmitted by direct contact, including sexual contact. c) HPV 1 -4 are frequently associated with cervical cancer. d) Recombinant vaccines containing capsid proteins are available.

c) HPV 1 -4 are frequently associated with cervical cancer.

Which statement best describes herpes simplex virus-1 (HSV-1)? a) It is transmitted mainly by sexual contact. b) It replicates in the cytoplasm of infected cells. c) Its primary infection is acute gingivostomatitis. d) It remains latent in sacral ganglia.

c) Its primary infection is acute gingivostomatitis.

Which statement best characterizes actinomycosis? a) It is caused mainly by Nocardia asteroides. b) Infection occurs by inhalation. c) Broad spectrum antibiotic treatment is a predisposing factor. d) Cervicofacial actinomycosis is the commonest clinical form.

d) Cervicofacial actinomycosis is the commonest clinical form.

Which statement regarding scalded skin syndrome is TRUE? a) It is an invasive disease with severe tissue destruction. b) It is prevalent in young menstruating females using tampons. c) It is a skin infection with bullae formation under the epidermis. d) It may follow streptococcal infection.

c) It is a skin infection with bullae formation under the epidermis.

Which statement about Bacillus anthracis is INCORRECT? a) It is a Gram positive spore forming rod. b) It causes malignant pustule. c) It has a polysaccharide capsule. d) It produces a potent exotoxin.

c) It has a polysaccharide capsule.

Which statement is INCORRECT regarding Clostridium perfringens? a) It is normally present in the large intestine of man and animals. b) Its principal toxin is the alpha toxin. c) It is a strict aerobic bacterium. d) It is the commonest cause of gas gangrene.

c) It is a strict aerobic bacterium.

Which statement best characterizes Mycobacterium leprae? a) It can be stained by Gram’s stain. b) It can be cultivated in-vitro. c) It causes wound infections. d) It is considered an obligate intracellular pathogen.

d) It is considered an obligate intracellular pathogen.

All statements regarding varicella-zoster virus (VZV) are correct EXCEPT: a) It has two antigenic types. b) Primary infection with VZV causes chicken pox. c) It may be transmitted by the transplacental route. d) Zoster results from reactivation of latent varicella infection in neurons.

a) It has two antigenic types.

Group A streptococcal infection can be followed by serious sequelae. Which disease represents one of these sequelae? a) Acute glomerulonephritis b) Cellulitis c) Malignant pustule d) Toxic shock syndrome

a) Acute glomerulonephritis

Which virus represents an agent of bio-terrorism? a) Measles virus b) Human herpes virus-8 c) Small pox virus d) Varicella-zoster virus

c) Small pox virus

Concerning pityriasis versicolor, which statement is INCORRECT? a) It is caused by Malassezia furfur. b) It affects subcutaneous tissue. c) It affects the upper part of the trunk and the neck. d) It appears as scaly macules either hypo- or hyper-pigmented.

b) It affects subcutaneous tissue.

Regarding dermatophytes, which statement is TRUE? a) They are oval budding yeast cells. b) They may be transmitted from animals to man. c) Two genera only can infect man. d) They can cause systemic mycosis.

b) They may be transmitted from animals to man.

Which statement best describes eumycotic mycetoma? a) It responds to antibiotics. b) It is caused by Actinomyces israelii. c) It presents as hard swelling draining pus with sulfur granules. d) The causative organisms are usually present in water.

d) The causative organisms are usually present in water.

1) W hich statement is TRUE regarding rubella virus? a) It belongs to orthomyxoviruses. b) It is transmitted by blood transfusion. c) It can be prevented by a live attenuated vaccine. d) It has many antigenic types.

Regarding rotavirus, which statement is CORRECT? a) A live attenuated vaccine against rotavirus is available. b) The virus genome is double-stranded DNA c) The virus is a major cause of diarrhoea among hospitalized adults. d) The virus is unable to live for extended periods on different surfaces.

a) A live attenuated vaccine against rotavirus is available.

Which hepatitis virus is transmitted faeco-orally? a) Hepatitis A virus b) Hepatitis B virus c) Hepatitis C virus d) Hepatitis D virus

a) Hepatitis A virus

Which statement regarding hepatitis B virus is INCORRECT? a) Clinical symptoms appear after an incubation period of 6 weeks to 6 months. b) Cytotoxic T-cells react with viral antigens on infected hepatocytes causing cell destruction. c) Deposition of immune complexes in tissues results in extra-hepatic manifestations. d) Hepatitis B virus causes cytopathic effects in liver cells.

d) Hepatitis B virus causes cytopathic effects in liver cells.

The emetic type of Bacillus cereus food poisoning is characterized by which of the following? a) Activation of adenylate cyclase enzyme b) Long incubation period (8 to 16 hours) c) Severe diarrhoea and abdominal cramps d) The production of a heat-stable enterotoxin

d) The production of a heat-stable enterotoxin

Which microorganisms is an important member of the normal flora of the colon? a) Bacteroides fragilis b) Helicobacter pylori c) Staphylococcus aureus d) Streptococcus agalactia

a) Bacteroides fragilis

Which statement best describes Campylobacter jejuni? a) It is Gram negative non-motile bacilli. b) It causes gastric ulcer. c) It is a strict anaerobe. d) It is oxidase positive.

d) It is oxidase positive.

Which microorganism can produce a shiga-like toxin? a) Enterohaemoirhagic Escherichia, coli b) Salmonella Typhimurium c) Shigella flexneri d) Yersinia enterocolitica

a) Enterohaemoirhagic Escherichia, coli

Which statement regarding Salmonella food poisoning is CORRECT? a) Antibiotic therapy should be started immediately. b) Blood culture is needed for the diagnosis. c) It is caused by Salmonella Typhi. d) It is mediated by invasion of intestinal epithelial cells.

d) It is mediated by invasion of intestinal epithelial cells.

A patient with a peptic ulcer was admitted to the hospital and a gastric biopsy was performed. Cultures at 37°C grew urease-positive curved bacteria. W hat is the most likely causative agent? a) Campylobacter jejuni b) Helicobacter pylori c) Shigella dysenteriae d) Vibrio parahaemolyticus

b) Helicobacter pylori

Which microorganism causes Q fever? a) Borrelia vincentii b) Coxiella burnetii c) Vibrio cholerae d) Mycobacterium bovis

b) Coxiella burnetii

Superinfection by Candida albicans occurs as a result of which predisposing factor? a) Broad-spectrum antibiotic treatment b) Immunosuppressive drugs c) Prolonged exposure to water d) Steroid therapy

a) Broad-spectrum antibiotic treatment

Formative assessments Flashcards

(62 cards)