Micro Flashcards
1
Q
A 50 year old marine biologist was bitten by a fish three weeks ago. There is now an eruption of nodules around the bite, which has healed poorly.
The GP sends off a wound swab after discussing with a microbiologist and the swab is positive for an atypical mycobacterium.
What is the likely cultured organism?
A
Mycobacterium marinum
2
Q
What organism is responsible for the sexually transmitted infection Chancroid, which causes multiple painful ulcers.
A
Haemophilus ducreyi
3
Q
What disease is caused by Borrelia burgdorferi?
A
Lyme disease
4
Q
What gram positive organism is associated with tumbling motility and rockets?
A
Listeria monocytogenes
5
Q
What diagnostic test is used to diagnose chlamydia infection?
A
Nucleic Acid Amplification Tests
6
Q
A 33 year old man presents to their GP with multiple elevated, small, pink lesions with a dimple in the center over his abdomen.
He denies any pain, itching or bleeding. They are not obviously infected. He has no history of cold sores and had chickenpox as a child.
What infection must be ruled out in a person presenting with this characteristic rash?
A
HIV
7
Q
What is the first line antimicrobial for treatment of Lyme Disease?
If no medication is indicated, please type “N/A”
A
Doxycycline
8
Q
A 72 year old man with COPD and poorly controlled HIV presents to the emergency department following a severe episode of haemoptysis. He reports no other symptoms.
A high resolution CT scan reveals multiple large bullae and a large left upper lobe rounded mass surrounded by a crescent of air.
Serum galactomannan is positive.
What is the diagnosis?
A
Aspergilloma
9
Q
A previously well 53 year old plumber is seen in A&E after a worsening of his symptoms. He was treated in the community by his GP five days ago for a “simple chest infection”.
On examination, he appears clinically unwell, has a fever of 37.9, is tachycardic and tachypnoeic. There are crepitations in the R base. A CXR has been ordered.
What organism is likely to be responsible for his symptoms?
A
Legionella pneumophilia
10
Q
What is the first line antibiotic for the treatment of acute otitis media in a patient with no known allergies?
A
Amoxicillin
11
Q
What is the full scientific name of the organism responsible for Q Fever?
A
Coxiella burnetii
12
Q
To what phylum do the organisms Leptospira spp, Borrelia spp, Treponema spp and Brachypsira spp belong?
A
Spirochaetes
13
Q
What is the name of the neurological sign of a pupil that accommodates, but does not react to light?
A
Argyll Robertson pupil
14
Q
What organism is responsible for the sexually transmitted infection Chancroid, which causes multiple painful ulcers.
A
Haemophilus ducreyi
15
Q
How is Q fever typically diagnosed?
A
Serology
Q Fever (Coxiella Burnetii) is a disease characterised by abrupt onset of flu-like symptoms, fever, headache, muscle pain, chills which may progress (for exam purposes) to an atypical pneumonia and ARDS or endocarditis. However, most patients are asymptomatic.
Diagnosis is via serology and it is treated effectively with doxycycline or ciprofloxacin. Only one bacterium is required to cause infection.
Typically Q fever is transmitted via contaminated dust or contact with the bodily fluids of infected animals (milk, urine, feces of cows, sheep, goats)
Typically only found in people at high risk of infection e.g. vets, farmers.
16
Q
A 50 year old lady of previous good health presents to her GP with multiple unsightly, discoloured, brittle toenails. Underneath each toenail is a chalky material.
The GP suspects multiple fungal nail infections. Nail scrapings grew dermatophytes and a PoC HIV ELISA is negative.
Prior to starting terbinafine, a systemic antifungal, what blood test should be ordered?
A
LFTs
17
Q
What is the scientific name of the pork tapeworm?
A
Taenia solium
18
Q
A 46-year-old man with poor adherence to his HIV medication presents to his GP with neck stiffness, fever and photophobia. The GP arranges for an ambulance.
In the emergency department, an LP is performed.
India ink staining of CSF gives following report: “CSF sample positive for yeast cells with a gelatinous capsule. Positive halo sign.”
What is the causative organism?
A
Cryptococcus neoformans
19
Q
A 73 year old alcoholic is admitted to the respiratory ward from the Emergency Department due to a severe chest infection.
There are crepitations in the mid right zone and this is associated with consolidation on X ray.
On examination he is visibly drunk and his level of self care is poor. He is tachycardic and pyrexial with a fever of 38.
Sputum culture showed Gram Positive Diplococci.
What organism is responsible for his chest infection?
A
Streptococcus pneumoniae
20
Q
A sexually active homosexual man received treatment two hours ago for genital primary syphilis.
He was given a single of dose of IM benzylpenicillin.
He presents to the emergency department reporting he has become unwell, with a fever, headache and muscle aches. He is concerned he is having an allergic reaction.
He is pyrexial at 38C and his blood pressure is 98/76.
What syndrome is he suffering from?
A
Jarisch Herxheimer reaction
21
Q
A 25-year-old man presents for an STI check. He is sexually active with multiple female and male partners over the last year. He reports being inconsistent with use of condoms.
He reports occasional mild genital itching and sores on the penile shaft which come and go.
On examination he is circumcised with no inguinal lymphadenopathy, no visible lesions on the penile shaft and no urethral discharge.
What drug could be initiated if his symptoms recur?
A
Aciclovir
22
Q
What is the treatment for human tapeworms in adults?
A
Praziquantel
23
Q
Which first-line Tuberculosis medication causes visual disturbances?
A
Ethambutol
The standard first-line treatment regime for Mycobacterium tuberculosis lung infection is RIPE:
Rifampicin Isoniazid Pyrazinamide Ethambutol
All four antibiotics are given for 2 months. Rifampicin and Isoniazid are continued for a further 4 months.
Side effects of TB medication include:
Rifampicin: Hepatotoxicity (deranged LFTs), Drug interactions (induces cytochrome P450), Orange secretions
Isoniazid: Hepatotoxicity, Peripheral neuropathy
Pyrazinamide: Hepatotoxicity, Hyperuricaemia
Ethambutol: Optic neuritis
24
Q
What disease is caused by Borrelia burgdorferi?
A
Lyme disease
25
A 73-year-old immunocompromised man presents to the Emergency Department with a 3-day history of fever, dry cough, muscle ache and severe headache. There is no sign of meningism. Respiratory and cardiovascular exam is normal.
A rapid flu swab is positive for Influenza A and RT-PCR for SARS-CoV-2 on a NP swab was negative.
What antiviral drug may be indicated for this patient?
Oseltamivir
26
Classically the urine of what animal transmits the spirochaete responsible for leptospirosis?
Rats
27
A patient is suspected to have a community acquired pneumonia. Their CURB 65 is 1. Atypical infection is not suspected.
If indicated, what is the first line antibiotic for the treatment of this patient?
(If you do not feel an antibiotic is indicated, type "N/A")
Amoxicillin
28
Presence of atypical lymphoycytes on a peripheral blood film suggests what diagnosis?
Infectious Mononucleosis
29
A 25 year old female presents for an STI screen.
She reports feeling feverish, has diffuse lower abdominal pain and dyspareunia.
A Nucleic Acid Amplification Test (PCR) is positive for the presence of a gram negative intracellular bacterium.
What is the likely causative organism?
Chlamydia trachomatis
30
What is the vector of Malaria?
Female Anopheles mosquito
Malaria is an infectious tropical disease that is transmitted by the female anopheles mosquito.
It is most common in tropical regions including Africa, Asia and Latin America.
It is caused by parasites called Plasmodium. There are five different species that are known to cause malaria: P. falciparum, P. vivax, P. ovale, P. malariae and P. knowlesi.
Typical signs and symptoms include fever, myalgia, lethargy, vomiting and headaches.
In severe cases, it may present with jaundice, splenomegaly, seizures and death.
Often, it presents with vague symptoms.
Investigations include thick and thin blood films to identify parasites and determine species respectively.
Rapid Diagnostic Tests can also be used to detect malaria antigens.
Treatment depends on severity.
Severe malaria is treated with IV artesunate.
31
What antimicrobial is first line for severe, widespread fungal nail infection in a an elderly patient with no known allergies?
Recent bloods including FBC, U&Es, LFTs and TFTs were all normal.
Terbinafine
32
Severe malaria is defined as parasitaemia of more than?
2%
Severe malaria presents with high parasitaemia (>2% of red blood cells), altered consciousness, respiratory distress, circulatory collapse, metabolic acidosis and organ failure.
Treatment includes IV artesunate
33
A 20 year old woman is seen in the sexual health clinic for offensive smelling, yellow-green discharge. This is associated with some dysuria.
What organism is likely to be responsible for her symptoms?
Trichomonas vaginalis
34
What viral enzyme is inhibited by oseltamivir?
Neuraminidase
35
What diagnostic test is used to diagnose chlamydia infection?
Nucleic Acid Amplification Tests
36
A child is suspected of having meningococcal septicaemia in the GP setting.
As you prescribe the medication, you note the child has a documented reaction to flucloxacillin, when they developed a mild rash.
What medication, if any, should the GP administer in the practice, before arranging immediate hospital admission?
If no medication is indicated, please type "N/A".
Benzylpenicillin
37
A 34 year old Indian gentleman has grown Mycobacterium tuberculosis in a sputum sample.
He is started on the RIPE treatment regime.
He presents to his GP after 5 days and says his tears are a strange colour.
Which anti-tuberculous medication is classically associated with this side effect?
Rifampicin
The standard first-line treatment regime for Mycobacterium tuberculosis lung infection is RIPE:
Rifampicin
Isoniazid
Pyrazinamide
Ethambutol
All four antibiotics are given for 2 months. Rifampicin and Isoniazid are continued for a further 4 months.
Side effects of TB medication include:
Rifampicin: Hepatotoxicity (deranged LFTs), Drug interactions (induces cytochrome P450), Orange secretions
Isoniazid: Hepatotoxicity, Peripheral neuropathy
Pyrazinamide: Hepatotoxicity, Hyperuricaemia
Ethambutol: Optic neuritis
38
A 33 year old man presents to their GP with multiple elevated, small, pink lesions with a dimple in the center over his abdomen.
He denies any pain, itching or bleeding. They are not obviously infected. He has no history of cold sores and had chickenpox as a child.
What infection must be ruled out in a person presenting with this characteristic rash?
HIV
39
What is the first line antimicrobial for treatment of Lyme Disease?
If no medication is indicated, please type "N/A"
Doxycycline
40
A patient undergoing allogeneic stem cell transplantation requires a blood transfusion.
All blood products are routinely screened for HIV.
What other virus must be screened for in the donor blood products prior to giving it to this patient?
Cytomegalovirus
41
A 40 year old woman presents to her GP complaining of malodorous vaginal discharge. She is sexually active with her partner only. She has no other symptoms.
The GP arranges for a pregnancy test which comes back as negative. An STI screen is negative. She is up to date with her smears and has never had an abnormal result.
What is the likely diagnosis?
Bacterial Vaginosis
42
During which trimester of pregnancy is the risk of HSV transmission to a neonate greatest?
Third Trimester
43
A 72 year old man with COPD and poorly controlled HIV presents to the emergency department following a severe episode of haemoptysis. He reports no other symptoms.
A high resolution CT scan reveals multiple large bullae and a large left upper lobe rounded mass surrounded by a crescent of air.
Serum galactomannan is positive.
What is the diagnosis?
Aspergilloma
44
What viral protein is responsible for the virulence and tropism of SARS-CoV-2?
Spike protein
SARS-CoV-2 is a member of the Coronaviridae family.
It is a small, single stranded RNA virus with the ability to cause Coronavirus Disease 19 (COVID-19) in humans.
Its main proteins include the S protein (required for binding to ACE2 on human cells) and the N protein - the nucleocapsid.
45
A previously well 53 year old plumber is seen in A&E after a worsening of his symptoms. He was treated in the community by his GP five days ago for a "simple chest infection".
On examination, he appears clinically unwell, has a fever of 37.9, is tachycardic and tachypnoeic. There are crepitations in the R base. A CXR has been ordered.
What organism is likely to be responsible for his symptoms?
Legionella pneumophilia
46
What is the first line antibiotic for the treatment of acute otitis media in a patient with no known allergies?
Amoxicillin
47
A 55 year old gentleman is referred to gastroenterology by his GP.
He has persistent dysphagia and weight loss. He has no other past medical history.
At endoscopy a diagnosis of oesophageal candidiasis is made.
What is the next most appropriate investigation?
HIV test
48
Chloramphenicol acts on which part of the bacterial ribosome?
50S subunit
There are 5 main groups of antimicrobial agents that work by inhibiting bacterial protein synthesis. These can be remembered using the acronym TAMCO:
Tetracyclines (e.g. Doxycycline)
Aminoglycosides (e.g. Gentamicin)
Macrolides (e.g. Erythromycin)
Chloramphenicol
Oxazilidinediones
Aminoglycosides and Tetracyclines work by binding to the 30S subunit of ribosomes.
Macrolides and Chloramphenicol work by binding to the 50S subunit of ribosomes.
Oxazilidinediones works by binding to the 23S component of the 50S subunit of ribosomes.
49
A 58 year old gentleman is undergoing chemotherapy for multiple myeloma. As per safetynetting advice he has received, he presents to the Emergency Department feeling unwell. In triage, his temperature is 38.9c.
He describes a history of 2-3 days of nonspecific malaise, which he attributed to his chemotherapy last week. This morning, he awoke sweating with intermittent rigors and a severe headache. You take a full history and find that he has pain in his lower back, hip and his right knee, which has a visible, tender, effusion.
On examination, he is curled up in bed with the sheets over his head - he says he is cold.
As part of your neurological examination, you ask him to flex his hips fully, flex and then extend his knees. With difficulty, he is able to extend his left knee, but he cannot to extend his right knee due to pain.
What condition explains the patient's symptoms?
Septic Arthritis
50
A patient is suspected to have a community acquired pneumonia. Their CRB 65 is 3 and they have no known allergies.
In addition to clarithromycin, what is the other first line antibiotic that should be prescribed for this patient?
Co-amoxiclav
51
What antibiotic should be prescribed for a penicillin allergic, clinically stable patient with cellulitis?
If no antibiotic is indicated, please type "N/A"
Clarithromycin
52
What antibiotic would you prescribe first line for an infective exacerbation of COPD with a suspected bacterial etiology?
Amoxicillin
53
A 55 year old lady presents with fever, pleuritic chest pain, shortness of breath and cough productive of rusty-coloured sputum.
What is the most likely causative organism?
Streptococcus pneumoniae
54
What is the full scientific name of the organism responsible for Q Fever?
Coxiella burnetii
Q Fever (Coxiella Burnetii) is a disease characterised by abrupt onset of flu-like symptoms, fever, headache, muscle pain, chills which may progress (for exam purposes) to an atypical pneumonia and ARDS or endocarditis. However, most patients are asymptomatic.
Diagnosis is via serology and it is treated effectively with doxycycline or ciprofloxacin. Only one bacterium is required to cause infection.
Typically Q fever is transmitted via contaminated dust or contact with the bodily fluids of infected animals (milk, urine, feces of cows, sheep, goats)
Typically only found in people at high risk of infection e.g. vets, farmers.
55
Kaposi's sarcoma is caused by what virus?
HHV8
56
To what phylum do the organisms Leptospira spp, Borrelia spp, Treponema spp and Brachypsira spp belong?
Spirochaetes
57
What is the full scientific name of the organism typically responsible for Listeriosis
Listeria monocytogenes
58
A 39 year old alcoholic is admitted to the respiratory ward due to a chest infection.
There are crepitations in the left mid zone and this is associated with consolidation on X ray.
Past medical history is unremarkable.
Sputum culture showed Gram Negative Rods in clusters.
What organism is responsible for his chest infection?
Klebsiella pneumoniae
59
A 32 year old is diagnosed with infective endocarditis.
They described an insidious illness history, with symptoms appearing over a period of 6 months, culminating in admission to the hyperacute stroke unit following a CVA.
Of note, you show the third year medical student shadowing you that this patient has obliteration of Schamroth's window. In addition, they have poor oral hygeine.
A transthoracic echocardiogram reveals a vegetation on the mitral valve.
What organism is most likely responsible?
Streptococcus viridans
60
What is the full scientific name of the organism responsible for Cat Scratch Disease?
Bartonella Henselae
61
Which malarial species presents with a 72 hour fever pattern?
Plasmodium malariae
Malaria presents with cyclical fevers occurring every two days (tertian fever) in P. falciparum, P. vivax and P. ovale infections, and every three days (quartan fever) for P. malariae.
62
There is an outbreak of diarrhoea and vomiting on a cruise ship.
The onset of symptoms in affected individuals is sudden and lasts for a few days. Spread of the virus has not been abated despite the rigorous use of alcohol gel by patrons aboard.
Affected individuals have eaten different food prepared in different kitchens.
What is the likely pathogen responsible?
Norovirus
63
A heavily pregnant (34+3) lady is newly diagnosed with HIV. Her viral load is 2,000 copies per mL of blood.
What medication should be given intrapartum to reduce the likelihood that her child will be infected by HIV?
Zidovudine
64
What antibiotic is used to treat bacterial vaginosis and may be given as either as a STAT dose or as a weekly course?
Metronidazole
65
A sample of CSF from an immunocompromised patient with suspected meningitis is stained using india ink.
The stain reveals the presence of an encapsulated yeast.
What specific organism is likely to have been identified?
Cryptococcus neoformans
66
A 30 year old gentleman develops severe nausea and diarrhoea after reheating rice based food in the microwave.
What organism is likely to be responsible for these symptoms?
Bacillus cereus
67
Infection with HPV subtypes 6 and 11 typically causes what condition?
Genital warts
68
What is the recommended antibiotic prophylaxis for bites by either cat, dog or human in a patient with no known allergies?
Co-amoxiclav
69
What is the scientific name of the beef tapeworm?
Taenia saginata
70
A 70 year old is brought to the emergency department by ambulance. She had an unprovoked seizure at home which self terminated after 5 minutes. After the seizure, she was very drowsy.
For the last 5 days she complained of worsening headache and feeling systemically unwell. Her husband says she has been vomiting, been feeling very sleepy and confused. Prior to this, he thought she had the flu.
On examination, she is pyrexial, very drowsy and kernig sign positive with a painful neck.
```
Heart Rate 99bpm
Blood Pressure 112/76
Respiratory Rate 16
Axillary Temperature 38.1
SpO2 (on room air) 98%
```
In addition to ceftriaxone and ampicillin, what other medication should be started empircally?
Acyclovir
71
What condition is a fetus at risk of if its mother is infected by Parvovirus B19?
Hydrops Fetalis
72
Cancer of what organ is commonly associated with schistosomiasis infection?
Bladder cancer
73
A pregnant woman at term (38+3) has her urine dipped which shows the presence of nitrites and leukocytes. However, she denies any dysuria or other symptoms. She is diagnosed with an asymptomatic bacteriuria.
If indicated, what is the first line antibiotic for the treatment of this patient?
(If you do not feel an antibiotic is indicated, type "N/A")
Amoxicillin
74
Tetracyclines act on which part of the bacterial ribosome?
30S
There are 5 main groups of antimicrobial agents that work by inhibiting bacterial protein synthesis. These can be remembered using the acronym TAMCO:
Tetracyclines (e.g. Doxycycline)
Aminoglycosides (e.g. Gentamicin)
Macrolides (e.g. Erythromycin)
Chloramphenicol
Oxazilidinediones
Aminoglycosides and Tetracyclines work by binding to the 30S subunit of ribosomes.
Macrolides and Chloramphenicol work by binding to the 50S subunit of ribosomes.
Oxazilidinediones works by binding to the 23S component of the 50S subunit of ribosomes.
75
A fine art student travels to New York, where he eats scrambled eggs.
12 hours later, he becomes unwell with vomiting and diarrhoea. He has diffuse abdominal pain with pain that comes and goes in waves.
What organism is likely responsible for his symptoms?
Salmonella enterica
76
What score may be used to classify the risk of mortality from pneumonia in the community?
CURB-65
77
What is the full scientific name of the organism responsible for syphillis?
Treponema pallidum
78
A 21-year-old man notes a painless penile ulcer. He has recently started a new relationship. He denies any other symptoms.
On examination, there is an ulcer at the base of the penile shaft and there is painless inguinal lymphadenopathy.
What is the most likely diagnosis?
Primary Syphilis
79
What is the most common cause of diarrhoea in returning travellers to the UK?
Escherichia coli
80
A 23 year old woman sees her GP complaining of deep dyspareunia with her new partner. She has never had an STI check before.
Speculum examination shows an erythematous, oedematous cervix.
A vaginal swab is taken and reveals a gram negative diplococcus.
Assuming she has no drug allergies, what would be the treatment of choice for this infection?
Ceftriaxone
81
Pseudomembranous colitis is associated with what GI infection?
Clostridium Difficile
82
Infection by HPV subtypes 16 and 18 typically causes what disease?
Cervical cancer
83
A 17 year old is diagnosed with chlamydia in a sexual health clinic.
What is the first line antimicrobial therapy for chlamydia, assuming the patient is not penicllin allergic?
Doxycycline
84
A 26 year old IV drug user is diagnosed with infective endocarditis. He described a short history, with symptoms appearing over a period of three weeks, culminating in admission to the hyperacute stroke unit following a CVA.
A transthoracic echocardiogram reveals a vegetation on the mitral valve.
What organism is most likely responsible?
Staphylococcus aureus
85
A 23 year old woman sees her GP complaining of deep dyspareunia with her new partner. She has never had an STI check before.
Speculum examination shows an erythematous, oedematous cervix.
A vaginal swab is taken and reveals a gram negative diplococcus.
What organism is likely responsible for her symptoms?
Neisseria gonorrhoeae
86
What family of virus does dengue virus belong to?
Flavivirus
Dengue fever is an infectious tropical disease that is spread by the female Aedes mosquito. It transmits the dengue flavivirus which causes symptoms 3-14 days after infection. Symptoms include saddle-back fever, headache, arthralgia and myalgia. It is usually a mild self-limiting disease and treatment is supportive.
87
A patient is suspected to have a community acquired pneumonia. Their CURB 65 is 0.
If indicated, what is the first line antibiotic for the treatment of this patient?
(If you do not feel an antibiotic is indicated, type "N/A")
Amoxicillin
88
A 23 year old medical student recently returned from her African medical elective presents with a 7 day history of of fever, myalgia and headaches.
What diagnostic investigation should be requested?
Thick blood film
Malaria is an infectious tropical disease that is transmitted by the female anopheles mosquito.
It is most common in tropical regions including Africa, Asia and Latin America.
It is caused by parasites called Plasmodium. There are five different species that are known to cause malaria: P. falciparum, P. vivax, P. ovale, P. malariae and P. knowlesi.
Typical signs and symptoms include fever, myalgia, lethargy, vomiting and headaches.
In severe cases, it may present with jaundice, splenomegaly, seizures and death.
Often, it presents with vague symptoms.
Investigations include thick and thin blood films to identify parasites and determine species respectively.
Rapid Diagnostic Tests can also be used to detect malaria antigens.
Treatment depends on severity.
Severe malaria is treated with IV artesunate.
89
A 50 year old woman is seen by her GP with 3 days of mild headache, sneezing and coughing. She also has a sore throat. She takes ramipril for hypertension but has no other past medical history.
On examination her chest is clear, there is no cervical lymphadenopathy and no visible exudate on the tonsils.
What is the likely responsible organism?
Rhinovirus
90
A 30 year old woman is diagnosed with a urinary tract infection. She has had one previous UTI in the three years. She had her appendix removed when she was 14.
She denies any allergies or other past medical history.
According to national guidelines, you prescribe modified release nitrofurantoin 100mg, to be taken twice a day.
What is the recommended duration of antibiotic therapy for this patient?
3 days
91
A pregnant woman in her first trimester is diagnosed with a urinary tract infection.
If indicated, what is the first line antibiotic for the treatment of this patient?
(If you do not feel an antibiotic is indicated, type "N/A")
Nitrofurantoin
92
What organism is usually responsible for thrush?
Candida albicans
93
Which first-line Tuberculosis medication causes orange secretions?
Rifampicin
The standard first-line treatment regime for Mycobacterium tuberculosis lung infection is RIPE:
Rifampicin
Isoniazid
Pyrazinamide
Ethambutol
All four antibiotics are given for 2 months. Rifampicin and Isoniazid are continued for a further 4 months.
Side effects of TB medication include:
Rifampicin: Hepatotoxicity (deranged LFTs), Drug interactions (induces cytochrome P450), Orange secretions
Isoniazid: Hepatotoxicity, Peripheral neuropathy
Pyrazinamide: Hepatotoxicity, Hyperuricaemia
Ethambutol: Optic neuritis
94
A 2 month old baby presents to the A&E with a fever of 39.5C, feeding <50% of normal and is very drowsy.
In addition to cefotaxime, what other antibiotic would you start empirically?
Ampicillin
Listeriosis - disseminated Listeria monocytogenes infection - is a concern in all immunocompromised patients, babies and elderly people.
It has up to 20% mortality due to the risk of meningitis, encephalitis or sepsis. However, most commonly, it causes a gastroenteritis.
The gram positive rod shaped bacterium is diagnosed via culture.
It is typically treated with ampicillin or amoxicillin.
95
To the nearest 10%, what proportion of the global population is believed to have a latent TB infection?
30%
96
A 34 year old is admitted to the respiratory ward due to a severe chest infection. There are crepitations in the right mid zone and this is associated with consolidation on X ray.
Past medical history is unremarkable. The patient says that he is recovering from the flu, which he had last week.
Sputum culture showed Gram Positive Cocci in clusters.
What organism is responsible for his chest infection?
Staphylococcus Aureus
97
What test is typically used to detect the presence of SARS-CoV-2 on a nasopharyngeal swab?
Polymerase Chain Reaction
Antigen Testing
Diagnosis of active SARS-CoV-2 is predominantly done through PCR (Polymerase Chain Reaction) testing of a nasopharyngeal swab.
Small sections of viral RNA (~30 base pairs long) are detected using a primer, then multiple, fluorescent copies of that RNA are transcribed. Eventually, after multiple cycles, the fluorescence can be detected. This is "antigen" testing.
Antibody Testing
Many different antibody tests exist. As of June 2020, the sensitivity and specificity vary. They mainly test for IgG directed against viral proteins.
One way of performing the test is using an ELISA test or EIA.
Simply, viral antigens are biochemically stuck to the bottom of a test well. Plasma from the patient is added. If there are antibodies, then these will bind to the viral antigens. The test well is then washed & all the other antibodies that haven't bound to antigen will wash away. A different, fluorescent, antibody that binds to human antibodies is then added. If the test machine detects fluorescence, then the anti-human antibody has bound to the antibody that's bound to the virus. Simple, right?
IgG typically is detectable >10 days after infection and remain for a long period of time. The exact amount of time is currently debated, thought to be at least month. It is not known if antibodies confer protection against repeated infection.
IgM is present much sooner, around 5 days, but levels quickly fall.
98
What is the treatment of choice in a woman with offensive yellow-green discharge and a flagellated protozoan visible on wet prep microscopy?
Metronidazole
99
A patient with suspected meningitis is asked by their consultant to lie supine, with a flexed hip and knee.
The consultant passively extends both knees slowly. However, the patient stops the doctor and refuses to extend the knee past 120 degrees of flexion due to pain.
What sign has the consultant elicited?
Kernig's Sign
100
Give an example of a scoring system which can be used in primary care to guide if antibiotics may be beneficial for a sore throat?
CENTOR
101
In immunocompetent patients, what is the typical presentation of listeriosis?
Gastroenteritis
Listeriosis - disseminated Listeria monocytogenes infection - is a concern in all immunocompromised patients, babies and elderly people.
It has up to 20% mortality due to the risk of meningitis, encephalitis or sepsis. However, most commonly, it causes a gastroenteritis.
The gram positive rod shaped bacterium is diagnosed via culture.
It is typically treated with ampicillin or amoxicillin.
102
What is the primary infective lesion produced by Mycobacterium tuberculosis called in the lungs?
Ghon Focus
103
A 34 year old mother of three presents to their GP with tiredness and weight loss. She has developed a cough over the last month which is non productive. She reports feeling more short of breath than usual. A recent full STI screen was normal.
On examination there is cervical lymphadenopathy, wheeze and fever.
A chest X ray shows bilateral hilar lymphadenopathy.
What infective cause of these symptoms must she be investigated for?
Tuberculosis
104
Which first-line Tuberculosis medication causes hyperuricaemia?
Pyrazinamide
The standard first-line treatment regime for Mycobacterium tuberculosis lung infection is RIPE:
Rifampicin
Isoniazid
Pyrazinamide
Ethambutol
All four antibiotics are given for 2 months. Rifampicin and Isoniazid are continued for a further 4 months.
Side effects of TB medication include:
Rifampicin: Hepatotoxicity (deranged LFTs), Drug interactions (induces cytochrome P450), Orange secretions
Isoniazid: Hepatotoxicity, Peripheral neuropathy
Pyrazinamide: Hepatotoxicity, Hyperuricaemia
Ethambutol: Optic neuritis
105
What is the first line antimicrobial for treatment of limited impetigo?
Fusidic acid
106
A man is diagnosed with a urinary tract infection. He has had no previous UTIs. He denies any allergies.
You consider prescribing trimethoprim 200mg BD. He asks how long he will need to take the antibiotics for.
What is the recommended duration of antibiotic therapy for this patient?
7 days
107
Hepatitis D is a subviral satellite that can only replicate in the presence of what other virus?
Hepatitis B
108
What is the vector of transmission for Dengue virus?
Female Aedes mosquito
Dengue fever is an infectious tropical disease that is spread by the female Aedes mosquito. It transmits the dengue flavivirus which causes symptoms 3-14 days after infection. Symptoms include saddle-back fever, headache, arthralgia and myalgia. It is usually a mild self-limiting disease and treatment is supportive.
109
Macrolides act on which part of the bacterial ribosome?
50S
There are 5 main groups of antimicrobial agents that work by inhibiting bacterial protein synthesis. These can be remembered using the acronym TAMCO:
Tetracyclines (e.g. Doxycycline)
Aminoglycosides (e.g. Gentamicin)
Macrolides (e.g. Erythromycin)
Chloramphenicol
Oxazilidinediones
Aminoglycosides and Tetracyclines work by binding to the 30S subunit of ribosomes.
Macrolides and Chloramphenicol work by binding to the 50S subunit of ribosomes.
Oxazilidinediones works by binding to the 23S component of the 50S subunit of ribosomes.
110
Which first-line Tuberculosis medication causes peripheral neuropathy?
Isoniazid
The standard first-line treatment regime for Mycobacterium tuberculosis lung infection is RIPE:
Rifampicin
Isoniazid
Pyrazinamide
Ethambutol
All four antibiotics are given for 2 months. Rifampicin and Isoniazid are continued for a further 4 months.
Side effects of TB medication include:
Rifampicin: Hepatotoxicity (deranged LFTs), Drug interactions (induces cytochrome P450), Orange secretions
Isoniazid: Hepatotoxicity, Peripheral neuropathy
Pyrazinamide: Hepatotoxicity, Hyperuricaemia
Ethambutol: Optic neuritis
111
A Löwenstein-Jensen medium is used to facilitate growth of what respiratory pathogen?
Mycobacterium tuberculosis
112
What assay is currently used to identify if someone has previously been infected with SARS-CoV-2?
Enzyme Linked Immunosorbent Assay
Antigen Testing
Diagnosis of active SARS-CoV-2 is predominantly done through PCR (Polymerase Chain Reaction) testing of a nasopharyngeal swab.
Small sections of viral RNA (~30 base pairs long) are detected using a primer, then multiple, fluorescent copies of that RNA are transcribed. Eventually, after multiple cycles, the fluorescence can be detected. This is "antigen" testing.
Antibody Testing
Many different antibody tests exist. As of June 2020, the sensitivity and specificity vary. They mainly test for IgG directed against viral proteins.
One way of performing the test is using an ELISA test or EIA.
Simply, viral antigens are biochemically stuck to the bottom of a test well. Plasma from the patient is added. If there are antibodies, then these will bind to the viral antigens. The test well is then washed & all the other antibodies that haven't bound to antigen will wash away. A different, fluorescent, antibody that binds to human antibodies is then added. If the test machine detects fluorescence, then the anti-human antibody has bound to the antibody that's bound to the virus. Simple, right?
IgG typically is detectable >10 days after infection and remain for a long period of time. The exact amount of time is currently debated, thought to be at least month. It is not known if antibodies confer protection against repeated infection.
IgM is present much sooner, around 5 days, but levels quickly fall.
113
Aminoglycosides act on which part of the bacterial ribosome?
30S Subunit
There are 5 main groups of antimicrobial agents that work by inhibiting bacterial protein synthesis. These can be remembered using the acronym TAMCO:
Tetracyclines (e.g. Doxycycline)
Aminoglycosides (e.g. Gentamicin)
Macrolides (e.g. Erythromycin)
Chloramphenicol
Oxazilidinediones
Aminoglycosides and Tetracyclines work by binding to the 30S subunit of ribosomes.
Macrolides and Chloramphenicol work by binding to the 50S subunit of ribosomes.
Oxazilidinediones works by binding to the 23S component of the 50S subunit of ribosomes.
114
What histological stain is used for Mycobacterium tuberculosis?
Ziehl-Neelsen stain
115
An 18-year-old woman who has recently started university is brought to the emergency department with a severe headache, neck stiffness and photophobia. There is also a non blanching rash on the lower limbs.
Blood cultures grow a Gram-negative diplococcus.
What is the most likely organism responsible?
Neisseria meningitidis
116
The presence of clue cells on microscopy of vaginal discharge suggests what diagnosis?
Bacterial Vaginosis
117
During infection with Plasmodium falciparum, typically how long does it take for the patient's temperature to peak, nadir, then return to the peak again?
48 hours
Malaria presents with cyclical fevers occurring every two days (tertian fever) in P. falciparum, P. vivax and P. ovale infections, and every three days (quartan fever) for P. malariae.
118
What treatment is used for severe malarial infection?
IV artesunate
119
A 20 year old white man presents to their GP having noticed the development of a rash on his back over the last few months. He reports no symptoms from it.
On examination, there are scaly areas of hypopigmentation across the back. There is no evidence of erythema or excoriation.
Under Wood's Lamp, the patch fluoresces a very faint orange colour.
What is the likely diagnosis?
Pityriasis versicolor
120
What class of organisms are classically the hosts for Coxiella Burnetii?
Mammals
Q Fever (Coxiella Burnetii) is a disease characterised by abrupt onset of flu-like symptoms, fever, headache, muscle pain, chills which may progress (for exam purposes) to an atypical pneumonia and ARDS or endocarditis. However, most patients are asymptomatic.
Diagnosis is via serology and it is treated effectively with doxycycline or ciprofloxacin. Only one bacterium is required to cause infection.
Typically Q fever is transmitted via contaminated dust or contact with the bodily fluids of infected animals (milk, urine, feces of cows, sheep, goats)
Typically only found in people at high risk of infection e.g. vets, farmers.
121
To what family of viruses does SARS-CoV-2 belong?
Coronaviridae
SARS-CoV-2 is a member of the Coronaviridae family.
It is a small, single stranded RNA virus with the ability to cause Coronavirus Disease 19 (COVID-19) in humans.
Its main proteins include the S protein (required for binding to ACE2 on human cells) and the N protein - the nucleocapsid.
122
A breastfeeding mother is diagnosed with mastitis. Her symptoms aren't improving after two days of effective milk removal from the affected breast.
What is the first line antibiotic therapy in this scenario if she has no known allergies?
Flucloxacillin
123
A 60 year old farmer presents to the emergency department feeling unwell with what he thinks is the flu. He said there was a sudden onset 4 days ago of chills, severe muscle aches and abdominal pain.
Today he is visibly jaundiced and is complaining of muscle pains. He says that he has a headache behind his eyes. He is mildly photophobic. There is a subconjunctival haemorrhage in the right eye.
You take a full history and find he has long standing arthritis of his knees but no other medical history of note. He has a fever of 38.5C and an ECG is normal. His observations are otherwise within normal limits.
```
Of note, you receive the following U&Es for this patient.
Na+ 138mmol/L
K+ 5.0mmol/L
Urea 12mmol/L
Creatinine 154umol/L
```
What condition is responsible for this patient's current symptoms?
Leptospirosis
124
A child is suspected of having meningococcal septicaemia in the GP setting. The child has no known allergies.
What medication should the GP immediately give in the practice, before arranging immediate hospital admission?
If no medication is indicated, please type "N/A".
Benzylpenicillin
125
A 18 year old is seen in a dermatology clinic about painless areas of skin hypopigmentation on his trunk.
Examination of skin under Wood's lamp shows the following: Doesn't fluoresce
What is the condition he is suffering from?
Tinea versicolor
126
What is the first line antibiotic for the treatment of a bacterial sore throat in a patient with a penicillin allergy?
Clarithromycin
127
A 15 year old swimmer present with a month long history of itching and scaling between the toes on his right foot.
On examination there is macerated skin between the 3rd and 4th toes on the right foot, associated with erythema and scaling.
What organism is most likely responsible for this presentation?
Trichophyton rubrum
128
A 16 year old athlete is seen by a pharmacist for an itchy white rash between his toes.
In addition to general hygiene advice, what topical antifungal cream may be used to treat this condition?
Clotrimazole
129
What subtype of Herpes Simplex Virus is typically implicated in encephalitis?
Herpes Simplex Virus Type 1
130
A 18 year old university student presents to her GP feeling after feeling very tired for the last 5 days. She has been sleeping 16 hours a day and reports a sore throat.
She is asking for some antibiotics so that she can start work on her first university assignment.
On examination she has cervical lymphadenopathy with a temperature of 38.1.
What is the likely diagnosis?
Infectious Mononucleosis
131
What is the host protein required for entry of SARS-CoV-2 into human cells?
Angiotensin Converting Enzyme 2
SARS-CoV-2 is a member of the Coronaviridae family.
It is a small, single stranded RNA virus with the ability to cause Coronavirus Disease 19 (COVID-19) in humans.
Its main proteins include the S protein (required for binding to ACE2 on human cells) and the N protein - the nucleocapsid.
132
To the nearest 10%, what is the lifetime risk of latent TB reactivation in an immunocompetent individual?
10%
133
A baby is born to a mother with no known past medical history.
The baby is noted to have large, bilateral cataracts, retinopathy and a heart murmur during the baby check. Automated otoacoustic emissions suggest bilateral hearing loss.
A paediatrician does a full examination and reveals a palpable mass in the upper left quadrant of the abdomen.
What virus was the mother likely exposed to during pregnancy which is responsible for this syndrome in her newborn?
Rubella
134
What is the first line antibiotic for the treatment of a bacterial sore throat in a patient with no known allergies?
Phenoxymethylpenicillin
