4. Infectious diseases Flashcards
- Plasmodium falciparum merozoites:
a. Are injected into the human bloodstream by an Anopheles mosquito
b. Possess specialised apical organelles
c. Represent asexual forms of the parasite
d. Interact with vascular endothelial receptors
e. Cause cerebral malaria
- Plasmodium falciparum merozoites:
a. Are injected into the human bloodstream by an Anopheles mosquito [F]
b. Possess specialised apical organelles [T]
c. Represent asexual forms of the parasite [T]
d. Interact with vascular endothelial receptors [F]
e. Cause cerebral malaria [F]
- Red blood cell invasion by Plasmodium falciparum involves the following steps:
a. Initial attachment
b. Reorientation to bring the apical end into contact with the red cell membrane
c. Interaction with CD36
d. Secretion of proteins from the micronemes
e. Passive entry through the red cell membrane
- Red blood cell invasion by Plasmodium falciparum involves the following steps:
a. Initial attachment [T]
b. Reorientation to bring the apical end into contact with the red cell membrane [T]
c. Interaction with CD36 [F]
d. Secretion of proteins from the micronemes [T]
e. Passive entry through the red cell membrane [F]
- Severe anaemia in malaria patients infected with Plasmodium falciparum is caused by:
a. Haemolysis of infected red blood cells every 72 hours
b. Haemolysis of uninfected bystander red blood cells
c. Cytoadherence of infected red blood cells
d. Destruction of infected red blood cells in the spleen
e. Impaired erythropoiesis
- Severe anaemia in malaria patients infected with Plasmodium falciparum is caused by:
a. Haemolysis of infected red blood cells every 72 hours [F]
b. Haemolysis of uninfected bystander red blood cells [T]
c. Cytoadherence of infected red blood cells [F]
d. Destruction of infected red blood cells in the spleen [T]
e. Impaired erythropoiesis [T]
- Rapid diagnostic tests (RDTs) for malaria:
a. Are quantitative
b. Are time consuming
c. Can give false positive results
d. Can identify different Plasmodium species
e. Can detect other pathogens
- Rapid diagnostic tests (RDTs) for malaria:
a. Are quantitative [F]
b. Are time consuming [F]
c. Can give false positive results [T]
d. Can identify different Plasmodium species [T]
e. Can detect other pathogens [F]
- Regarding the HIV genome and structure:
a. The long terminal repeats (LTRs) encode the HIV envelope proteins
b. The Tat and Rev are accessory proteins and do not play an important role in regulating HIV replication
c. The viral envelope contains cellular proteins obtained from the host cell
d. In an immature virus, the gag proteins and HIV enzymes are present in the form of poly-proteins
e. HIV uses the co-receptors only to enhance infection
- Regarding the HIV genome and structure:
a. The long terminal repeats (LTRs) encode the HIV envelope proteins [F]
b. The Tat and Rev are accessory proteins and do not play an important role in regulating HIV replication [F]
c. The viral envelope contains cellular proteins obtained from the host cell [T]
d. In an immature virus, the gag proteins and HIV enzymes are present in the form of poly-proteins [T]
e. HIV uses the co-receptors only to enhance infection [F]
- Regarding antiretroviral drugs and treatment:
a. ARVs inhibits HIV replication in a non-specific way
b. Standard ART treatment consists of a combination of 3 different drugs
c. Treatment with protease inhibitors requires boosting with ritonavir
d. NRTIs inhibit reverse transcriptase by allosteric inhibition
e. Integrase inhibitors inhibit the 3’-processing step of integration
- Regarding antiretroviral drugs and treatment:
a. ARVs inhibits HIV replication in a non-specific way [F]
b. Standard ART treatment consists of a combination of 3 different drugs [T]
c. Treatment with protease inhibitors requires boosting with ritonavir [T]
d. NRTIs inhibit reverse transcriptase by allosteric inhibition [F]
e. Integrase inhibitors inhibit the 3’-processing step of integration [F]
- Regarding HIV cure and latency:
a. Hematopoietic stem cell transplantation can be used successfully for a sterilizing cure of infection by CXCR4-tropic HIV-1
b. Antiretroviral treatment can be used to cure a patient from an HIV-1 infection
c. The “shock and kill” approach makes use of latency reversal agents to reactivate latent HIV
d. Early antiretroviral treatment can be used to limit the viral reservoir size
e. ARVs may not penetrate viral reservoirs
- Regarding HIV cure and latency:
a. Hematopoietic stem cell transplantation can be used successfully for a sterilizing cure of infection by CXCR4-tropic HIV-1 [F]
b. Antiretroviral treatment can be used to cure a patient from an HIV-1 infection [F]
c. The “shock and kill” approach makes use of latency reversal agents to reactivate latent HIV [T]
d. Early antiretroviral treatment can be used to limit the viral reservoir size [T]
e. ARVs may not penetrate viral reservoirs [T]
- Non-cultivable bacteria include:
a. Brucella
b. Spirochaetes
c. Enterobacteriaceae
d. Mycobacteria
e. Staphylococcus species
- Non-cultivable bacteria include:
a. Brucella
b. Spirochaetes
- Cell components found in prokaryotic organisms include:
a. Golgi apparatus
b. 80s ribosomes
c. 70s ribosomes
d. Nucleoid
e. Mitochondria
- Cell components found in prokaryotic organisms include:
c. 70s ribosomes
d. Nucleoid
- Microorganisms are classified into autotrophs and heterotrophs on the basis of which of the following?
a. Nature of nitrogen source
b. Nature of energy source
c. Nature of carbon source
d. Nature of electron source
e. Nature of nutritional source
- Microorganisms are classified into autotrophs and heterotrophs on the basis of which of the following?
a. Nature of nitrogen source
c. Nature of carbon source
e. Nature of nutritional source
- Bacterial endospores are resistant to:
a. Antibodies
b. Antigens
c. Heat
d. Chemical disinfectants
e. UV irradiation
- Bacterial endospores are resistant to:
c. Heat
d. Chemical disinfectants
e. UV irradiation
- Plasmids:
a. May be passed on to other bacteria
b. Are extrachromosomal circular pieces of DNA
c. Are usually supercoiled to fit inside the cell
d. Vary in number within a cell
e. Are attached to the cytoplasmic membrane
- Plasmids:
a. May be passed on to other bacteria
b. Are extrachromosomal circular pieces of DNA
d. Vary in number within a cell
- The following are current approaches to managing biofilm-related infections:
a. Phage therapy
b. Rigorous antisepsis
c. Quorum-quenching enzymes
d. Antimicrobial lock therapy
e. Antimicrobial impregnated devices
- The following are current approaches to managing biofilm-related infections:
b. Rigorous antisepsis
d. Antimicrobial lock therapy
e. Antimicrobial impregnated devices
- With regard to bacterial toxins:
a. In the A-B toxin structure, the B represents the enzymatically active component
b. Diphtheria toxin inhibits protein synthesis
c. Bordetella pertussis toxin activates secondary messenger pathways
d. Pyrogenic toxins target the Rho G proteins
e. Toxins release will always lead to cellular death
- With regard to bacterial toxins:
b. Diphtheria toxin inhibits protein synthesis
c. Bordetella pertussis toxin activates secondary messenger pathways
- The following antibiotics affect bacterial DNA
a. Penicillin
b. Amikacin
c. Ciprofloxacin
d. Rifampicin
e. Doxycycline
- The following antibiotics affect bacterial DNA
c. Ciprofloxacin
d. Rifampicin
- Appropriate personal protective equipment for a health care worker dressing a septic wound include:
a. Wearing of gloves
b. Using goggles
c. Wearing a surgical mask
d. Wearing a disposable plastic apron
e. Using a N95 respirator
- Appropriate personal protective equipment for a health care worker dressing a septic wound include:
a. Wearing of gloves
d. Wearing a disposable plastic apron
- Multidrug resistant tuberculosis (MDR-TB) is by definition TB that is resistant to the following drugs:
a. Fluoroquinolones
b. Rifampicin
c. Isoniazid
d. Second line injectable agents
e. Bedaquiline
- Multidrug resistant tuberculosis (MDR-TB) is by definition TB that is resistant to the following drugs:
b. Rifampicin
c. Isoniazid
- Which of the following virulence factors of Yersinia pestis are temperature-dependent?
a. Endotoxin
b. Exotoxin
c. Fraction 1 antigen
d. Coagulase
e. Flagella
- Which of the following virulence factors of Yersinia pestis are temperature-dependent?
c. Fraction 1 antigen
d. Coagulase
- With respect to the mycobacterial cell wall:
a. It has the same structure as Gram positive bacteria
b. It contains mycolic acid
c. It stains Gram positive
d. It stains Gram negative
e. It stains positive with the acid fast staining procedure
b. It contains mycolic acid
e. It stains positive with the acid fast staining procedure
- Multi-drug resistant (MDR) tuberculosis (TB) refers to
a. Isolate that is resistant to isoniazid and rifampicin
b. Isolate that is resistant to either isoniazid or rifampicin
c. Isolate that is resistant to isoniazid, rifampicin and any fluoroquinolone
d. Isolate that resistant to rifampicin only
e. Isolate that is resistant to rifampicin and bedaquiline
a. Isolate that is resistant to isoniazid and rifampicin
- With respect to the microorganisms living in association with humans:
a. the term “microbiome” refers to the genes contained in the microorganisms
b. all known phyla of bacteria are represented
c. each body surface contains a specific collection of microorganisms
d. fungi form part of our normal collection of microorganisms
e. the human foetus does not have any associated microorganisms
- With respect to the microorganisms living in association with humans:
a. the term “microbiome” refers to the genes contained in the microorganisms
c. each body surface contains a specific collection of microorganisms
e. the human foetus does not have any associated microorganisms
- The following statements regarding aminoglycosides are true:
a. They are protein synthesis inhibitors
b. Act on the 30S ribosomal unit in bacteria
c. Act on the 50S ribosomal unit in bacteria
d. An example of an antibiotic from this class is doxycycline
e. An example of an antibiotic from this class is streptomycin
- The following statements regarding aminoglycosides are true:
a. They are protein synthesis inhibitors
b. Act on the 30S ribosomal unit in bacteria
e. An example of an antibiotic from this class is streptomycin
- With respect to interventions in the prevention and control of infectious diseases:
a. Passive immunoprophylaxis is the administration of childhood vaccines.
b. Use of anti-malarials prior to, during and after visiting a malaria area is considered a form of chemoprophylaxis.
c. Prevention of hospital-acquired infections is primarily dependent on immunoprophylaxis strategies.
d. Hand hygiene is a key strategy in the prevention and control of infectious diseases.
e. “Bundles of care” are useful in the prevention of hospital-acquired infections and may comprise both pharmacological and non-pharmacological components.
- With respect to interventions in the prevention and control of infectious diseases:
b. Use of anti-malarials prior to, during and after visiting a malaria area is considered a form of chemoprophylaxis.
d. Hand hygiene is a key strategy in the prevention and control of infectious diseases.
e. “Bundles of care” are useful in the prevention of hospital-acquired infections and may comprise both pharmacological and non-pharmacological components.
- With respect to the damage-response framework:
a. A pathogen is a microbe that causes infection.
b. Virulence is the relative capacity of the pathogen to cause infection.
c. Colonization is a state of infection that results in a continuum of damage with the final outcome of the interaction dependent on the host response.
d. Damage can be induced by both the host and the microbe.
e. By definition, infection leads to clinical signs and symptoms of disease
- With respect to the damage-response framework:
c. Colonization is a state of infection that results in a continuum of damage with the final outcome of the interaction dependent on the host response.
d. Damage can be induced by both the host and the microbe.
- Prokaryotes:
a. Include viruses and intestinal parasites such e.g. helminths
b. Characteristically possess a nucleus that is surrounded by a nuclear membrane
c. Replicate by binary fission
d. Contain 70S ribosomes
e. Are not implicated in human infections
- Prokaryotes:
c. Replicate by binary fission
d. Contain 70S ribosomes
- Bacterial capsules:
a. Are mostly composed of polysaccharides
b. Are antigenic
c. Facilitate phagocytosis of bacterial cells
d. Are weak immunogens
e. Are present as part of the cell wall in all bacterial species
- Bacterial capsules:
a. Are mostly composed of polysaccharides
b. Are antigenic
- Vaccines that are currently available to protect against infection caused by encapsulated pathogens include:
a. S aureus vaccine
b. S agalaciae vaccine
c. Haemophilus influenzae type B vaccine
d. Pneumococcal vaccine
e. Meningococcal vaccine
- Vaccines that are currently available to protect against infection caused by encapsulated pathogens include:
c. Haemophilus influenzae type B vaccine
d. Pneumococcal vaccine
e. Meningococcal vaccine
Transmission precautions against influenza include:
a. Isolating the infected patient
b. Providing chlorhexidine baths for the patient
c. Treating secondary bacterial infection with an appropriate antibiotic
d. Health care worker to use a respirator while nursing the patient
e. Appropriate decontamination of medical equipment used for the patient
Transmission precautions against influenza include:
a. Isolating the infected patient
d. Health care worker to use a respirator while nursing the patient
e. Appropriate decontamination of medical equipment used for the patient
- Virulence factors which allow a pathogen to avoid the host immune system include:
a. The ability to chelate metals such as copper in the human body
b. Use of Streptococcal M protein by Streptococcus pneumoniae
c. Use of Streptococcal M protein by Streptococcus pyogenes
d. Preventing phagosome-lyzozome fusion
e. Salmonella Typhi is able to avoid phagocytosis
- Virulence factors which allow a pathogen to avoid the host immune system include:
c. Use of Streptococcal M protein by Streptococcus pyogenes
d. Preventing phagosome-lyzozome fusion
e. Salmonella Typhi is able to avoid phagocytosis
Which of the following organisms are known to avoid phagocytosis as a result of a capsule?
a. Neisseria meningitidis
b. Salmonella Typhi
c. Streptococcus pyogenes
d. Streptococcus pneumoniae
e. Haemophilus influenzae
Which of the following organisms are known to avoid phagocytosis as a result of a capsule?
a. Neisseria meningitidis
d. Streptococcus pneumoniae
e. Haemophilus influenzae
- Which of the following statements are true regarding toxin mediated infections?
a. Onset of disease is slow
b. Antibiotics must always be given to patients with toxin mediated disease
c. The organism only causes symptoms in the affected organ system
d. Toxin production is common with viruses
e. Symptoms and tissue damage usually occurs at a site distant from the site of replication
- Which of the following statements are true regarding toxin mediated infections?
e. Symptoms and tissue damage usually occurs at a site distant from the site of replication
- Which of the following statements about pyogenic bacterial infections is/are true?
a. Streptococcal pharyngitis is an example of such an infection
b. An abscess is an example of such an infection
c. Antibiotics may help to terminate the infection
d. This type of infection usually develops within months to a few years
e. The incubation period is typically a few days
- Which of the following statements about pyogenic bacterial infections is/are true?
a. Streptococcal pharyngitis is an example of such an infection
b. An abscess is an example of such an infection
c. Antibiotics may help to terminate the infection
e. The incubation period is typically a few days
- Which of the following statements regarding the pathogenicity and virulence of microorganisms are true?
a. Pathogenicity is the capacity of an organism to cause disease
b. Virulence is not affected by genetic mutations
c. Molecular switching enables organism survival
d. Gram positive organisms are more pathogenic than Gram negative organisms
e. Cell wall components contribute to organism virulence
- Which of the following statements regarding the pathogenicity and virulence of microorganisms are true?
a. Pathogenicity is the capacity of an organism to cause disease
c. Molecular switching enables organism survival
e. Cell wall components contribute to organism virulence
- Which of the following statements is true regarding chronic bacterial infections?
a. Staphylococcus aureus bacteraemia is a chronic infection
b. Brucellosis is typically a chronic infection
c. Mycoplasma pneumoniae pneumonia presents as a chronic infection
d. Development of a granuloma is common in chronic infections
e. Pulmonary tuberculosis is a classic example of a chronic infection
- Which of the following statements is true regarding chronic bacterial infections?
b. Brucellosis is typically a chronic infection
d. Development of a granuloma is common in chronic infections
e. Pulmonary tuberculosis is a classic example of a chronic infection
- Choose the correct and incorrect statement (s) regarding bacterial morphology:
a. The Gram negative cell wall contains a large periplasmic space
b. Bacterial nuclear material is surrounded by an envelope
c. Metabolic processes within the cytoplasm can be potential targets for antimicrobials
d. Efflux pumps through the outer membrane allow entry of cell nutrients and antimicrobials
e. The cell wall is the target for beta-lactam agents
- Choose the correct and incorrect statement (s) regarding bacterial morphology:
a. The Gram negative cell wall contains a large periplasmic space
c. Metabolic processes within the cytoplasm can be potential targets for antimicrobials
e. The cell wall is the target for beta-lactam agents
- Regarding bacterial genetics:
a. Transformation occurs through plasmid transfer
b. Bacterial conjugation occurs through flagella
c. Point mutations occur during selective pressure
d. Bacteriophage is a parasite that can transfer genetic material
e. Transduction is mediated via pilli formation
- Regarding bacterial genetics:
c. Point mutations occur during selective pressure