-
Question 1
Incorrect
-
One of the following pathogens is a conditional pathogen:
Your Answer: Mycobacterium tuberculosis
Correct Answer: Neisseria meningitidis
Explanation:Obligate pathogens include Mycobacterium TB, HIV, Treponema pallidum, and Neisseria gonorrhoeae. Neisseria meningitidis, on the other hand, is a conditional pathogen.
-
This question is part of the following fields:
- Microbiology
- Principles
-
-
Question 2
Correct
-
Which of the following is NOT typically present in the nasopharyngeal flora:
Your Answer: Bacteroides spp.
Explanation:Bacteroides spp. are typically found in the normal flora of the lower gastrointestinal tract. Species commonly found in the flora of the nasopharynx include: Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae, Neisseria meningitidis, Haemophilus influenzae, Corynebacterium spp., Moraxella spp. and Candida spp.
-
This question is part of the following fields:
- Microbiology
- Principles
-
-
Question 3
Correct
-
Bordetella pertussis causes which of the following infectious diseases:
Your Answer: Whooping cough
Explanation:Bordetella pertussis causes whooping cough. Acute bronchiolitis is typically caused by respiratory syncytial virus. Parainfluenza virus is the most common cause of croup. Acute epiglottitis is usually caused by an infection with Haemophilus influenzae type b (Hib) bacteria. The common cold may be caused by a number of viruses including rhinovirus and coronavirus.
-
This question is part of the following fields:
- Microbiology
- Pathogens
-
-
Question 4
Correct
-
Which of the following problems is associated with Helicobacter pylori infection?
Your Answer: Gastric malignancy
Explanation:Helicobacter pylori is a ubiquitous organism that is present in about 50% of the global population. Chronic infection with H pylori causes atrophic and even metaplastic changes in the stomach, and it has a known association with peptic ulcer disease. The most common route of H pylori infection is either oral-to-oral or faecal-to-oral contact.
-
This question is part of the following fields:
- Microbiology
- Pathogens
-
-
Question 5
Correct
-
Cryptococcus neoformans is primarily implicated in which of the following conditions:
Your Answer: Chronic lymphocytic meningitis
Explanation:Cryptococcus neoformans typically causes a chronic lymphocytic meningitis in immunosuppressed patients or those with intense exposure e.g. pigeon fanciers.
-
This question is part of the following fields:
- Microbiology
- Pathogens
-
-
Question 6
Correct
-
Herpes simplex virus is transmitted most commonly through which of the following routes:
Your Answer: Direct contact spread
Explanation:Herpes simplex virus is the most common cause of infective encephalitis and has a predilection for the temporal lobes. Herpes simplex is transmitted through direct contact. It invades skin locally producing skin vesicles by its cytolytic activity.
-
This question is part of the following fields:
- Microbiology
- Pathogens
-
-
Question 7
Correct
-
Regarding Clostridium tetani, which of the following statements is CORRECT:
Your Answer: Metronidazole is usually the antibiotic of choice for tetanus infection.
Explanation:Clostridium tetani infection is predominantly derived from animal faeces and soil. Clostridium tetani has exotoxin-mediated effects, predominantly by tetanospasmin which inhibits the release of GABA at the presynaptic membrane throughout the central and peripheral nervous system. Metronidazole has overtaken penicillin as the antibiotic of choice for treatment of tetanus (together with surgical debridement, tetanus toxoid immunisation, and human tetanus immunoglobulin).
-
This question is part of the following fields:
- Microbiology
- Pathogens
-
-
Question 8
Correct
-
A 22-year-old man comes to the emergency department with a human bite injury to his hand received from a punch during a fight 3 hours earlier outside a bar. On closer inspection, you discover bite marks on his first and second knuckles. Which of the following is the best treatment option for this patient:
Your Answer: Oral co-amoxiclav for 7 days
Explanation:Even if there is no evidence of infection, prophylactic antibiotics should be administered for all human bite wounds that are less than 72 hours old. The first-line therapy is 7 days of co-amoxiclav. In penicillin-allergic people, metronidazole + doxycycline is an option. Streptococcus spp., Staphylococcus aureus, Haemophilus spp., Eikenella corrodens, Bacteroides spp., and other anaerobes are the most prevalent organisms found in human bites.
-
This question is part of the following fields:
- Infections
- Microbiology
-
-
Question 9
Incorrect
-
Which of the following organisms can penetrate intact skin:
Your Answer: Staphylococcus epidermidis
Correct Answer: Leptospira spp.
Explanation:Leptospirosis is a bacterial disease caused byLeptospira spp. It is the most common zoonotic infection worldwide.
It is usually contracted by exposure to water contaminated with the urine of infected animals (such as rodents, cattle, and dogs). The most important reservoirs are rodents, and rats are the most common source worldwide.
The bacteria enter the body through the skin or mucous membranes. This is more likely if the skin is broken by leptospirosis is somewhat unusual in that it can enter the body through intact skin. -
This question is part of the following fields:
- Microbiology
- Principles
-
-
Question 10
Correct
-
On his stool culture, a patient with a diarrhoeal illness grows Escherichia coli.
What SINGLE statement about Escherichia coli is true?
Your Answer: Most serotypes are harmless
Explanation:Escherichia coli is a Gram-negative, non-spore forming, facultative anaerobic, rod-shaped bacterium.
Although some can cause serious food poisoning, most serotypes are harmless.
Escherichia coli is transmitted via the faeco-oral route.
-
This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
-
-
Question 11
Correct
-
Which of the following could denote a diagnosis of acquired immunodeficiency syndrome (AIDS) in a patient infected with HIV:
Your Answer: CD4 count < 200 cells/uL
Explanation:A diagnosis of AIDS can be made in a patient infected with HIV if the patient has a CD4 count < 200 cells/uL, or an AIDS-defining illness. Antiretroviral treatment should be considered in patients with CD4 counts < 350 cells/uL.
Oral candidiasis is not an AIDS defining illness – candidiasis of the bronchi, trachea, lungs or of the oesophagus is an AIDS defining illness.
A positive p24 antigen test seen in early HIV infection and does not indicate the development of AIDS.
-
This question is part of the following fields:
- Microbiology
- Pathogens
-
-
Question 12
Correct
-
A 18-year-old man returns from a trip to Ibiza with a severely painful left eye. He has copious mucopurulent discharge, is febrile and has left-sided tender preauricular lymphadenopathy. He attends the local eye casualty and is diagnosed with hyperacute conjunctivitis.
What is the SINGLE most likely causatiave organism?Your Answer: Neisseria gonorrhoeae
Explanation:Hyperacute bacterial conjunctivitis is a severe, sight-threatening ocular infection that warrants immediate ophthalmic work-up and management. The infection has an abrupt onset and is characterized by a copious yellow-green purulent discharge that reaccumulates after being wiped away. Typically caused by infection with Neisseria gonorrhoeae.
-
This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
-
-
Question 13
Correct
-
Which of the following antibiotics is the first line of treatment for a patient who has been diagnosed with chlamydia infection?
Your Answer: Azithromycin
Explanation:The Centres for Disease Control and Prevention (CDC) recommends azithromycin, a single 1 g dose, and doxycycline, 100 mg bd for 7 days, as first-line medications for chlamydial infection treatment.
Second-line medications (such as erythromycin, penicillins, and sulfamethoxazole) are less effective and have more side effects
-
This question is part of the following fields:
- Microbiology
- Pathogens
-
-
Question 14
Incorrect
-
A newborn baby is born by vaginal delivery to a mother who has a Chlamydia infection and who is started on treatment after the delivery. The neonate subsequently develops an infection also.
Which one of these is the most common neonatal manifestation of Chlamydia trachomatis infection?Your Answer: Pneumonia
Correct Answer: Conjunctivitis
Explanation:Conjunctivitis is the most common neonatal manifestation of Chlamydia trachomatis infection. The second commonest neonatal manifestation is pneumonia
Ophthalmia neonatorum refers to any conjunctivitis in the newborn period, irrespective of causative organism. Presently, chlamydia is the single most common cause, accounting for up to 40% of cases. Ophthalmia neonatorum caused by chlamydia typically presents 5 to 14 days after birth with unilateral or bilateral watery discharge that progressively becomes more copious and purulent. There is no associated risk of ulceration and perforation, and the eyes are less inflamed.
-
This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
-
-
Question 15
Correct
-
You are planning on starting antibiotic therapy for a patient with a diagnosis of gonorrhoea.
Which of these is the MOST appropriate antibiotic combination?Your Answer: Ceftriaxone and azithromycin
Explanation:Currently, ceftriaxone in combination with azithromycin or doxycycline is the combination of antibiotics used in the treatment of gonorrhoea.
-
This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
-
-
Question 16
Correct
-
Question 17
Correct
-
Question 18
Correct
-
A 59-year-old man is complaining of pain in his perineal area, a recent onset of urinary frequency and urgency, fever, chills, and muscle aches. He has a long history of nocturia and terminal dribbling. On rectal examination you find an exquisitely tender prostate.
Which of these antibacterial agents would be most appropriate in this case?
Your Answer: Ciprofloxacin for 14 days
Explanation:An acute focal or diffuse suppurative inflammation of the prostate gland is called acute bacterial prostatitis.
According to the National Institute for Health and Care Excellence (NICE), acute prostatitis should be suspected in a man presenting with:
A feverish illness of sudden onset which may be associated with rigors, arthralgia, or myalgia; Irritative urinary voiding symptoms; acute urinary retention; perineal or suprapubic pain and an exquisitely tender prostate on rectal examination.Treatment of acute prostatitis as recommended by NICE and the BNFare:
Ciprofloxacin or ofloxacin for 14 days
Alternatively, trimethoprim can be used. Duration of treatment is still 14 days -
This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
-
-
Question 19
Incorrect
-
The causative organism for an infection in a patient you are reviewing is a facultative anaerobe.
Which of these is a facultative anaerobic organism?Your Answer: Mycobacterium tuberculosis
Correct Answer: Staphylococcus aureus
Explanation:Facultative anaerobic bacteria make energy in the form of ATP by aerobic respiration in an oxygen rich environment and can switch to fermentation in an oxygen poor environment.
Examples of facultative anaerobes are:
Staphylococcus spp.
Listeria spp.
Streptococcus spp.
Escherichia coliMycobacterium tuberculosis, and Pseudomonas aeruginosa are obligate aerobe. They require oxygen to grow
Campylobacter jejuni and Clostridium spp are obligate anaerobes.
They live and grow in the absence of oxygen. -
This question is part of the following fields:
- Microbiology
- Principles Of Microbiology
-
-
Question 20
Correct
-
The most common source of healthcare-associated bacteraemia is:
Your Answer: Intravenous cannula
Explanation:Healthcare-associated bacteraemia is most commonly caused by intravenous access. Any intravenous device that is left in place for a long time increases the risk of infection. It allows bacteria like Staphylococcus aureus and Staphylococcus epidermidis to enter the body.
-
This question is part of the following fields:
- Microbiology
- Principles
-
-
Question 21
Incorrect
-
Regarding control of hospital acquired infection (HAI), which of the following statements is CORRECT:
Your Answer: Autoclaving is a method of disinfection.
Correct Answer: Chlorhexidine is an anti-staphylococcal agent.
Explanation:Chlorhexidine is an anti-staphylococcal agent. Cleaning is the removal of foreign material from areas or objects to a point at which they are visually free from debris. Disinfection is the reduction in the number of infectious particles. Isopropyl alcohol is not effective against C. difficile spores. Autoclaving is a method of sterilisation.
-
This question is part of the following fields:
- Microbiology
- Principles
-
-
Question 22
Correct
-
A young patient presents with the features of an easily recognisable infectious disease.
Which of the following infectious diseases typically has an incubation period of less than 1 week? Select ONE answer only.Your Answer: Cholera
Explanation:Cholera has an incubation period of 12 hours to 6 days.
Other infectious disease that have an incubation period of less than 1 week include:
Staphylococcal enteritis (1-6 hours)
Salmonella enteritis (12-24 hours)
Botulism (18-36 hours)
Gas gangrene (6 hours to 4 days)
Scarlet fever (1-4 days)
Diphtheria (2-5 days)
Gonorrhoea (3-5 days)
Yellow fever (3-6 days)
Meningococcaemia (1-7 days)
Brucellosis has an incubation period of 7-21 days.
Measles has an incubation period of 14-18 days.
Falciparum malaria usually has an incubation period of 7-14 days. The other forms of malaria have a longer incubation period of 12-40 days.
Rubella has an incubation period of 14-21 days. -
This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
-
-
Question 23
Correct
-
Among the following infectious diseases, which is typically considered to have an incubation period of 3 weeks and longer?
Your Answer: Infectious mononucleosis
Explanation:Infectious mononucleosis is caused by Epstein-Barr virus (EBV). The incubation period for EBV varies from 2 weeks to 2 months.
The usual incubation period for rubella is 14 days; with a range of 12 to 23 days.
Gonorrhoea has a short incubation period of approximately 2 to 7 days.
The mumps virus can be isolated from infected saliva and swabs rubbed over the Stensen’s duct from 9 days before onset of symptoms until 8 days after parotitis appears.
Scarlet fever, which appears within 1 to 2 days after bacterial infection, is characterized by a diffuse red rash that appears on the upper chest and spreads to the trunk and extremities. The rash disappears over the next 5 to
7 days and is followed by desquamation. -
This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
-
-
Question 24
Correct
-
Diagnosis of HIV is predominantly made through which of the following:
Your Answer: Antibody detection
Explanation:Diagnosis of HIV is predominantly made through detection of HIV antibody and p24 antigen. Viral load (viral PCR) and CD4 count are used to monitor progression of disease.
-
This question is part of the following fields:
- Microbiology
- Pathogens
-
-
Question 25
Correct
-
An very unwell patient is receiving treatment in your hospital's HDU and is found to have an Escherichia coli O157 infection.
Which one of these statements about Escherichia coli O157 is true?Your Answer: Haemolytic uraemic syndrome develops in approximately 6% of patients
Explanation:Escherichia coli O157 is a serotype of Escherichia coli.
The Escherichia coliO157 strain is ‘enterohaemorrhagic’ and causes severe forms of acute haemorrhagic diarrhoea. It can also cause non-haemorrhagic diarrhoea.Incubation period of Escherichia coli O157 is usually 3-4 days and bloody diarrhoea usually begins on the 3rd or 4th day of the infection.
Infections with Escherichia coliO157 are more common during the warmer months than in winter.
Haemolytic uraemic syndrome develops in approximately 6% of patients. It is commonly seen in children and in the elderly.
Escherichia coli O157 can also cause:
Haemorrhagic colitis
Haemolytic uraemic syndrome
Thrombotic thrombocytopenic purpura but not immune thrombocytopenic purpura. -
This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
-
-
Question 26
Correct
-
A 45-year-old businessman returns from a trip to West Africa with headaches and intermittent fevers. Thick and thin films are sent to the lab and a diagnosis is made of malaria. The patient is started on treatment but his condition deteriorates and he develops jaundice, renal failure and haemoglobinuria.
Which of the following is the MOST likely causative organism? Select ONE answer only.Your Answer: Plasmodium falciparum
Explanation:Malaria is an infectious disease transmitted by female of theAnophelesgenus of mosquito. It is a parasitic infection caused by the genusPlasmodium. Five species are recognized as causing disease in humans;Plasmodium falciparum,Plasmodium ovale,Plasmodium vivax,Plasmodium malariaeandPlasmodium knowlesi.
The classic symptom of malaria is the malarial paroxysm, a cyclical occurrence of a cold phase, where the patient experiences intense chills, a hot stage, where the patient feels extremely hot and finally a sweating stage, where the fever declines and the patient sweats profusely. On examination the patient may show signs of anaemia, jaundice and have hepatosplenomegaly without evidence of lymphadenopathy.Plasmodium falciparum is the most serious form and is responsible for most deaths. Severe or complicated malaria is suggested by the presence of impaired consciousness, seizures, hypoglycaemia, anaemia, renal impairment, respiratory distress and spontaneous bleeding.
Plasmodium falciparum is the most likely type in this case in view of the presentation.
Haemoglobinuria and renal failure following treatment is suggestive of blackwater fever, which is caused byPlasmodium falciparum. An autoimmune reaction between the parasite and quinine causes haemolysis, haemoglobinuria, jaundice and renal failure. This can be fatal.
The benign malarias: P.vivax, P. malariae and P.ovale are usually treated with chloroquine. A course of primaquine is also required in P.vivax and P.ovale infection. Artesunate is the drug treatment of choice for Plasmodium falciparum malaria. Quinine can still be used where artesunate is not available. Often combination therapy with drugs such as doxycycline or fansidar is also required. -
This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
-
-
Question 27
Correct
-
You received a patient with a 2-day history of diarrhoea and vomiting. Later, after examination, the patient was found to have progressive symmetric descending flaccid paralysis, initial development of blurred vision, dysphagia, and weakness of the upper limbs. The patient is apyrexial and his observations are all normal. Which of the following pathogens is responsible for the said symptoms?
Your Answer: Clostridium botulinum
Explanation:A botulism infection results in neuroparalysis caused by the neurotoxin generated by Clostridium botulinum.
Food-borne botulism symptoms often appear 12-36 hours after ingestion of the toxin-containing food and may include nausea, vomiting, stomach discomfort, and diarrhoea at first. The most common neurological pattern is an acute onset of bilateral cranial neuropathies with symmetric declining weakening.
Other distinguishing characteristics include the absence of fever, the absence of cognitive abnormalities, the presence of a normal heart rate and blood pressure, and the absence of sensory defects.
-
This question is part of the following fields:
- Microbiology
- Pathogens
-
-
Question 28
Correct
-
Regarding the varicella zoster virus, which of the following statements is CORRECT:
Your Answer: Contracting chickenpox infection while pregnant is associated with a higher risk of developing varicella pneumonitis.
Explanation:Chickenpox infection in neonates, adults/adolescents and pregnant women is associated with more severe disease. Varicella zoster pneumonitis typically occurs in pregnant women or immunocompromised individuals and is associated with a high mortality. A live attenuated-virus vaccine is available and recommended for non-immune healthcare workers but is not part of the routine childhood immunisation schedule. Antiviral treatment is not typically recommended in childhood chickenpox but is indicated for shingles.
-
This question is part of the following fields:
- Microbiology
- Pathogens
-
-
Question 29
Correct
-
You suspected typhoid disease in a patient who had recently returned from South America and presented to the emergency department with fever, constipation, and a rose spot rash. Which of the following antibiotics will be administered to this patient?
Your Answer: Cefotaxime
Explanation:Typhoid fever, often known as enteric fever, is a potentially fatal multi-systemic sickness caused predominantly by Salmonella enterica serotype typhi and, to a lesser extent, paratyphi A, B, and C.
Cefotaxime is the first-line treatment for typhoid fever (or ceftriaxone). In cases of mild or moderate sickness caused by multiresistant pathogens, azithromycin is an option. If the bacterium is sensitive, ciprofloxacin is an option.
-
This question is part of the following fields:
- Microbiology
- Pathogens
-
-
Question 30
Correct
-
A 65-year-old man presents with cough and shortness of breath. His sputum is rusty in colour and is suffering from a fever. Upon examination, it was noted that he has crackles in the right upper lobe. A chest X-ray showed the presence of a right upper lobe cavitation.
Among the following microorganisms, which is considered to be mostly associated with a cavitating upper lobe pneumonia?Your Answer: Klebsiella pneumoniae
Explanation:Klebsiella pneumoniae is among the most common Gram-negative bacteria encountered by physicians worldwide and accounts for 0.5-5.0% of all cases of pneumonia. This organism can cause extensive pulmonary necrosis and frequent cavitation.
It is one of the causes that could be suspected when there is cavitatory pneumonia with or without a bulging fissure sign. Often, there can be extensive lobar opacification with air bronchograms.
A helpful feature which may help to distinguish from pneumococcal pneumonia is that Klebsiella pneumoniae develops cavitation in 30-50% of cases (in comparison, cavitation is rare in pneumococcal pneumonia). This occurs early and progresses quickly.
-
This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
-
SESSION STATS - PERFORMANCE PER SPECIALTY
