Past papers Flashcards

1
Q

An immunosuppressed patient presents with focal neurological signs and CT shows multiple ring enhancing lesions. What is it?

CMV
Toxoplasma
Aspergillus
HSV

A

Toxoplasma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Match clinical picture to diagnosis.

A. Patient with dysphagia and liver lesions
B. Patient with dyspnoea and crescent halo in lung CT
C. Haematuria in AIDS
D. Leukopenia in renal transplant

  1. CMV
  2. Aspergillus
  3. Candida
  4. BK virus
A

A - candida - can cause discrete liver abscesses

B - aspergillus

C - BK virus

D - CMV

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Dengue haemorrhagic fever occurs in those previously infected with a different strain of Dengue Fever. What is the mechanism causing this effect?

a) Autoimmunity
b) Antibody-mediated enhancement
c) Cytokine storm

A

b) Antibody-mediated enhancement

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

A 14 month old child has polio virus type 2 isolated from a stool sample.
The child is investigated for immunological deficit. What is the most
likely finding?

Normal child
Antibody deficiency
Complement C7 deficiency
Cellular immunity deficiency

A

Normal child

polio virus type 2 was erradicated in 2015. This is likely vaccine derived polio virus

Polio vaccine given at 
8 weeks
12 weeks
16 weeks
3 years
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

A 2 yr old boy with recurrent skin abscesses has a positive nitroblue tetrazolium test. His underlying diagnosis is:

  • Job’s syndrome
  • Di George syndrome
  • Purine nucleoside phosphorylase deficiency
  • Chronic granulomatous disease
  • X-linked agammaglobulinaemia
A

Jobs syndrome - hyper-IgE syndrome with impaired lymphocytes.
Presents in childhood with recurrent skin infections

Nitroblue tetrazolium test is a screening test for chronic granulomatous disease

The colorless compound Nitroblue tetrazolium (NBT), is reduced to blue formazan by the activity of the phox enzyme system, by normal phagocyte activity

Negative nitroblue tetrazolium test (stays colourless/ yellow) - indicates chronic granulomatous disease
Positive nitroblue tetrazolium test (turns blue) - indicates normal function

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Match these diseases to causative organism

  1. A 2 year old boy presents with non-tender cervical lymph node, no overlying inflammation. No TB contacts. Biopsy is performed and acid fast bacilli are seen on microscopy
  2. A 20 year old CF patient presents with a chest infection. Sputum show AFB on microscopy. It grows on culture at 370C within one week
  3. A 32 year old man presents with a pleural effusion. Nothing is seen on gram stain but cultures grow at 370C within a week.
  4. A recent immigrant from Africa presents with a chronic painless ulcer on his ?foot
Mycobacterium tuberculosis 
Mycobacterium bovis
Mycobacterium leprae
Mycobacterium avium 
Mycobacterium gordonae
Mycobacterium abscessus 
Mycobacterium ulcerans 
Mycobacterium paratuberculosis
Mycobacterium haemophilum
Mycobacterium marinum
A
  1. A 2 year old boy presents with non-tender cervical lymph node, no overlying inflammation. Biopsy is performed and acid fast bacilli are seen on microscopy
    M avium - 80% cases
    M scrofulacaecum
    M haemophilum
  2. A 20 year old CF patient presents with a chest infection. Sputum show AFB on microscopy. It grows on culture at 370C within one week
    Mycobacterium abscessus and Mycobacterium avium, most common causes of non-tuberculous mycobacteria infection (NTM). M gordonae is rarer cause. M abscessus grows quickly within one week
  3. A 32 year old man presents with a pleural effusion. Nothing is seen on gram stain but cultures grow at 370C within a week.
    Mycobacterium TB
  4. A recent immigrant from Africa presents with a chronic painless ulcer on his ?foot
    Mycobacterium ulcerans
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Mycobacterium tuberculosis can be described as:

A. Non-chromogen, slow grower, does not reduce nitrate, growth at 37°C
B. Non-chromogen, slow grower, reduces nitrate, growth at 37°C
C. Scotochromogen, slow grower reduces nitrate, growth at 25-41°C
D. Photochromogen, slow grower reduces nitrate, growth at 30°C
E. Non-chromogen, slow grower, reduces nitrate, growth at 25-41°C

A

B. Non-chromogen, slow grower, reduces nitrate, growth at 37°C

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Patient with pulmonary disease grows mycobacterium on LJ slopes at 37ºC after 4 weeks and has bright yellow colonies. Which of the following is it likely to be?

a. M. fortuitum,
b. M. chelonoae,
c. M. kansasii,
d. M. malmoense,
e. M. paratuberculosis

A

c. M. kansasii,

Mycobacterium kansasii grows on 7H11 media and Lowenstein-Jensen (LJ) slants. The colonies appear smooth or rough and unpigmented when isolated in the dark. Upon exposure to light, colonies turn bright lemon yellow due to enhanced b-carotene production, which makes M. kansasii a photochromogen.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Which of the following anti-tuberculous medication achieves the highest CSF concentration?

a) Ethambutol
b) Isoniazid
c) Pyrazinamide
d) Rifampicin
e) Streptomycin

A

Isoniazid?

The CSF penetration of isoniazid, pyrazinamide, rifampin, and streptomycin was about 89%, 91%, 5%, and 20%, respectively

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

25 yr old woman recently returned from touring about Africa and the Middle East where she consumed all local food. Admitted to hospital with a 1 wk history of fever and night sweats. On exam, she has splenomegaly and tenderness in the lumbosacral area. The best diagnosis is:

  • Salmonella typhi
  • Visceral Leishmaniasis
  • Brucellosis
  • Mycobacterium tuberculosis
A

Brucellosis

Time of onset rules out TB/ leishmaniasis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the Runyon classification, and what is it used for?

A

The Runyon classification of nontuberculous mycobacteria based on the rate of growth, production of yellow pigment and whether this pigment was produced in the dark or only after exposure to light.

It was introduced by Ernest Runyon in 1959

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are the 4 groups of the Runyon classification?

A

Photochromogens - produce yellow pigment when exposed to light

Scotochromogens - yellow pigment when in light or dark

Nonchromogens - never produce pigment

Rapid growers - produce colonies within 5-7 days

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Mycobacteria classification. What are examples of -

photochromogens - 2

scotochromogens - 2

A

photochromogens - M kansasii, M marinum

scotochromogens - M gordonae, M scrofulaceum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Mycobacteria classification. What are examples of -

nonchromogens - 2

Rapid growers - 2

A

nonchromogens - M avium/ M intracellulare (MAC), M ulcerans

Rapid growers - M abscessus/ M chelonae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is organisms make up Mycobacterium Avium Complex?

A

M avium and M intracellulare make up MAC

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Match disease with organism -

A.	Type 2 necrotising fascitis
B.	Gas gangrene following trauma
C.	Hot tub folliculitis
D.	Ludwigs angina
E.	Acute pyomyositis

i. Fusobacterium necrophorum
ii. Clostridium perfringenes
iii. Staph aureus
iv. Streptococcus anginosus
v. Streptococcus pyogenes
vi. Pseudomonas aeruginosa
vii. Clostridium septicum

A

A. Type 2 necrotising fascitis
Streptococcus pyogenes

B. Gas gangrene following trauma
Clostridium perfringens

C. Hot tub folliculitis
pseudomonas

D. Ludwigs angina
Fusobacterium necophorum. Cellulitis involving floor of mouth. Often anaerobes

E. Acute pyomyositis
S aureus. Bacterial infection with abscesses in muscles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What disease can Clostridum septicum cause?

A

It can cause necrotising fasciitis similar to C perfringens

But it does not require trauma

C. perfringes requries trauma to infect

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is hot tub folliculitis?

A

Diffuse rash due to pseudomonas, causing infection of hair follicles

Can be hot tub/ pool

Usually appears a few days after event

disinfect water, shower after being in water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Necrotising fasciitis is a very serious bacterial infection of the soft tissue and fascia (a sheath of tissue covering the muscle). The bacteria multiply and release toxins and enzymes that result in thrombosis (clotting) in the blood vessels. The result is the destruction of the soft tissues and fascia.

What are different classifications of infection?

A

Type I - polymicrobial

Type II - due to group A streptococcus, staphylococci

Type III - gas gangrene due to clostridum perfringens/ septicum

Type IV - other causes -vibrio species, aeromonas, candida. Category is not technically used

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Match culture media to specific organism -

A.	Cefoxitin cyclosporin agar
B.	Thiosulphate citrate bile salt sucrose
C.	Tellurite medium
D.	Buffered charcoal yeast extract
E.	Cephalexin charcoal horse blood agar

i. Shigella
ii. Yersinia enterocolitica
iii. Clostridium difficile
iv. Corynebacterium diphtheriae
v. Vibrio species
vi. Legionella pneumophila
vii. Bordetella x

A

A. Cefoxitin cyclosporin agar
Clostridium difficile

B. Thiosulphate citrate bile salt sucrose
Vibrio species

C. Tellurite medium aka Hoyle’s tellurite
Corynebacterium

D. Buffered charcoal yeast extract
Legionella

E. Cephalexin charcoal horse blood agar
Bordetella

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Which of these infections is least likely to spread person-person?

Salmonella Typhi
Coxiella burnetti
Bordetella Pertussis

A

Coxiella burnetti

People get infected by breathing in dust that has been contaminated by infected animal feces, urine, milk, and birth products that contain Coxiella burnetii. Direct contact (e.g. touching, being licked) with an animal is not required to become sick with Q fever.

22
Q

Young man presents with cellulitis. He had been swimming in sea on holiday.

You suspect rare vibrio cause.

What vibrio species is likely cause?

A

Vibrio vulnifucus

23
Q

A gram negative coccus has been isolated from a patient with fever of unknown origin. It is oxidase positive, can’t grow without blood and can ferment glucose but not maltose. What is it likely to be?

N. meningitidis
N. gonorrhoea
Moraxella catarrhalis
Acinetobacter

A

N meningitidis - always ferments glucose. Sometimes can or cannot ferment maltose

Gram neg cocci oxidase positive-
Neisseria
Moraxella

Gram neg rod, oxidase positive -
pseudomonas
H pylori
Vibrio
Campylobacter

. Many Gram-negative, spiral curved rods are also oxidase-positive, which includes Helicobacter pylori, Vibrio cholerae, and Campylobacter jejun

Moraxella does not ferment carbohydrates

24
Q

Match the following organisms with the clinical pictures

a-	streptococcus pyogenes
b-	streptococcus pneumoniae
c-	streptococcus agalactiae 
d-	strept  suis 
e-	strept equis
f-	strept bovis 
g-	strept anginosus
h-	strept milleri 
i-	strept group G
  • septicaemia in patients with cancer colon
  • meningitis in neonates
  • spontaneous bacterial peritonitis
  • meningitis in abattoir workers
  • subphrenic abcess in patient undergoing colon surgery
A
  • septicaemia in patients with cancer colon
    strept bovis aka strep galloyticus

-meningitis in neonates
streptococcus agalactiae - GBS

-spontaneous bacterial peritonitis
strep pneumoniae - usually cirrhotic patients at risk of encapsulated infection

-meningitis in abattoir workers
strep suis. Common in swine industry

-subphrenic abscess in patient undergoing colon surgery
strep milleri - intestinal flora translocating during surgery

Strep anginosus is in milleri group?

25
Q

What organisms are included in strep milleri group?

Where does this organism live?

A

The Streptococcus milleri group of bacteria (Streptococcus anginosus, Streptococcus constellatus and Streptococcus intermedius

part of intestinal flora

26
Q

What are causes of sub-phrenic abscesses

A

Usually due to GI perforation

Escherichia coli
Klebsiella spp
Enterobacter spp
Pseudomonas aeruginosa.

Streptococcus spp
Enterococcus spp.

Bacteroides fragilis

27
Q

A selective and indicator media for the culture of salmonella species from faeces would be:

A. Sorbitol macconkey agar
B. Sellinite broth
C. Xylose lysine decarboxylase (XLD) agar
D. Urea broth
E. Cystine lactose electrolyte deficient agar (CLED)

A

C. Xylose lysine decarboxylase (XLD) agar

Selective for salmonella and shigella

Salmonella red colonies black centre
Shigella red colonies

28
Q

Pneumonia

A Streptococcus  pyogenes 
B Streptococcus pneumonia 
C Pseudomonas aeruginosa 
D Coxiella burnetti 
E Staphylococcus aureus 
F Mycoplasma pneumonia 
G Legionella pneumophila 
H Histoplasmosis capsulatum 

Organisms MOST likely to be causative in the following scenario:

  1. Atypical pneumonia, characterised by bradycardia, tender hepatomegaly, and on occasion endocarditis
  2. Pneumonia due to hospital aspiration, often resulting in pneumatoceles
  3. Post influenza pneumonia, often resulting in either pleural effusion or empyema
  4. Pneumonia often classed as atypical, and can present with bradycardia, vomiting and diarrhoea and mental confusion
A
  1. Atypical pneumonia, characterised by bradycardia, tender hepatomegaly, and on occasion endocarditis
    Coxiella burnetti
    Coxiella burnetti/ Legionella - less likely as answer number 4
  2. Pneumonia due to hospital aspiration, often resulting in pneumatoceles
    Staph aureus?
    Pseudomonas does not cause pneumatoceles
  3. Post influenza pneumonia, often resulting in either pleural effusion or empyema
    Staph aureus
  4. Pneumonia often classed as atypical, and can present with bradycardia, vomiting and diarrhoea and mental confusion
    Legionella
29
Q

Pneumonia

A Streptococcus  pyogenes
B Streptococcus pneumonia 
C Pseudomonas aeruginosa 
D Coxiella burnetti 
E Staphylococcus aureus 
F Mycoplasma pneumoniae 
G Legionella pneumophila 
H Histoplasmosis capsulatum 
  1. Pneumonia common in the ICU burn patient, characterised by green sputum, necrotising with small or large abscess
  2. Atypical pneumonia , characterised by rales, prolonged cough, haemolytic anaemia and pleural effusion
  3. Pneumonia in the elderly, rusty sputum, lancet shaped gram positive diplococci
  4. Acute self-limiting influenza-like illness, common in the US, characterised by bilateral hilar adenopathy and erythema nodosum
A
  1. Pneumonia common in the ICU burn patient, characterised by green sputum, necrotising with small or large abscess
    Strep pyogenes - skin breach can cause disseminated infection. Including pulmonary abscess
  2. Atypical pneumonia , characterised by rales, prolonged cough, haemolytic anaemia and pleural effusion
    Mycoplasma pneumoniae
  3. Pneumonia in the elderly, rusty sputum, lancet shaped gram positive diplococci
    Strep pneumoniae
  4. Acute self-limiting influenza-like illness, common in the US, characterised by bilateral hilar adenopathy and erythema nodosum
    Histoplasmosis
30
Q

What are most common causes of HAP?

A

Pseudomonas aeruginosa
Staphylococcus aureus
Enterobacter

31
Q

Which organisms cause lung abscesses?

Often polymicrobial

Gram neg
Gram pos
Fungal

A
Gram neg -
Bacteroides
Fusobacterium 
Klebsiella
E. coli
Pseudomonas
Gram pos -
Staph aureus
Strep pneumoniae
Strep pyogenes - e.g burn patient
Strep anginosus
Nocardia
Fungal -
Aspergillus
Cryptococcus
Histoplasma
Blastomycosis
Coccidiomycosis

Protozoa -
E histolytica
Paragonimus westermani

32
Q

What bacterial infection is associated with reactivated herpes?

A

Strep pneumoniae

33
Q

What is a pneumatocele?

A

Pneumatoceles are intrapulmonary gas-filled cystic spaces that can have a variety of sizes and appearances. They may contain gas-fluid levels and are usually the result of ventilator-induced lung injury in neonates or post-infectious. They should not be mistaken for a cavitating lung mass.

Most common - 
Staph aureus
Strep pneumoniae
E. coli
Klebsiella
34
Q

Match organism to appearance -

Clostridium tetani
Actinomyces israelli 
pasturella multocida
haemophilus ducreyi
kingella kingae
lactobacillus
Corynebacterium diphteriae
clostridium perfringes
bacillus cereus
  1. Gram positive branching filaments
  2. Small ovoid organisms which show bipolar staining
  3. Gram positive bacilli resembling Chinese writing
  4. Oval gram negative bacilli which appear in clinical specimens en masse like shoals of fish
  5. Gram variable bacillus with rounded end like a drumstick
A
  1. Gram positive branching filaments
    Actinomyces israelli
  2. Small ovoid organisms which show bipolar staining
    Pasturella
  3. Gram positive bacilli resembling Chinese writing
    Corynebacterium diptheriae
  4. Oval gram negative bacilli which appear in clinical specimens en masse like shoals of fish
    Haemophilus ducreyi - chancroid
  5. Gram variable bacillus with rounded end like a drumstick
    Clostridium tetani
35
Q

What are examples of small ovoid organisms which show bipolar staining?

A

Pasteurella

Tularaemia

Yersinia

36
Q

A neonate with meningitis. Gram positive bacilli have been isolated from blood cultures. Which of the following would be a helpful confirmatory test?

catalase
coagulase
oxidase
alpha-haemolysis
tumbling motility
A

Gram pos bacilli - Listeria monocytogenes - tumbling motility is most specific test in list to give diagnosis between Listeria/ GBS

GBS is other common cause -
Gram pos cocci
Catalase negative
Oxidase negative
Beta-haemolytic

Coagulase test just used for Staph aureus

37
Q

What is treatment of viral encephalitis?

What is duration?

A

Aciclovir IV 10mg/kg TDS

14 days
21 days if <12 years old or immunosuppressed

38
Q

Match organism to disease -

E.coli
Listeria
Group B streptococcus 
Chlamydia trachomatis
Chlamydia pneumoniae
Herpes Simplex 
Nisseria gonorrhoea
  1. Neonate becomes septic during the first day
  2. Neonate develops meningitis at day 8 post delivery
  3. Normal PV delivery, neonate develops pneumonia
A
  1. Neonate becomes septic during the first day
    GBS most likely
    Listeria possibility
    E. coli possibility
  2. Neonate develops meningitis at day 8 post delivery
    GBS
    E. coli - most likely given duration of onset
  3. Normal PV delivery, neonate develops pneumonia
    Chlamydia trachomatis

unclear what correct answers are

39
Q

What are options for meningococcal prophylaxis for close contacts?

Close contact (past 7 days) -
household member
partner
sharing dormitory

A

Cipro 500mg one dose

Rifampicin 600mg BD 2 days

40
Q

For each of the following clinical scenarios, choose the most likely causative organism.
(Each answer can only be used once)

Cryptococcus neoformans x
Escherichia coli x
Listeria monocytogenes x
Neisseria meningitidis type B
Neisseria meningitidis type C
Staphylococcus aureus x
Streptococcus pneumoniae
Toxoplasma gondii

(a) 18 year old female 24 weeks gestation with acute meningitis
(b) 40 year old HIV+ve male with a CD4 count of 50, presents with new onset of seizures
(c) premature baby presenting on 4th day of life with septicaemia. CSF microscopy reveals a WCC of 800/mm3
(d) 50 year old female post-clipping of aneurysm developes headache and neck stiffness with fever
(e) 66 year old male with a history of alcohol abuse presents with meningism and a red hot swollen knee

A

(a) 18 year old female 24 weeks gestation with acute meningitis
Listeria monocytogenes

(b) 40 year old HIV+ve male with a CD4 count of 50, presents with new onset of seizures
Cryptococcus neoformans
Toxoplasma - less likely

(c) premature baby presenting on 4th day of life with septicaemia. CSF microscopy reveals a WCC of 800/mm3
E. coli - most likely
Listeria
GBS - not on list

(d) 50 year old female post-clipping of aneurysm develops headache and neck stiffness with fever
Staph aureus - CoNS?
E. coli?

(e) 66 year old male with a history of alcohol abuse presents with meningism and a red hot swollen knee
Neisseria meningitidis type C

41
Q

For each of the following clinical scenarios, choose the most likely causative organism.
(Each answer can only be used once)

Cryptococcus neoformans 
Escherichia coli 
Listeria monocytogenes 
Neisseria meningitidis type B 
Neisseria meningitidis type C 
Staphylococcus aureus  
Streptococcus pneumoniae
Toxoplasma gondii 

(a) 18 year old female 24 weeks gestation with acute meningitis
(b) 40 year old HIV+ve male with a CD4 count of 50, presents with new onset of seizures
(c) premature baby presenting on 4th day of life with septicaemia. CSF microscopy reveals a WCC of 800/mm3
(d) 50 year old female post-clipping of aneurysm developes headache and neck stiffness with fever
(e) 66 year old male with a history of alcohol abuse presents with meningism and a red hot swollen knee

A

(a) 18 year old female 24 weeks gestation with acute meningitis
- Streptococcus pneumoniae - most likely
- Listeria monocytogenes - usually causes mild disease for mother, and severe disease for foetus. Can cause meningitis in healthy adults.

(b) 40 year old HIV+ve male with a CD4 count of 50, presents with new onset of seizures
- Cryptococcus neoformans
- Toxoplasma - less likely

(c) premature baby presenting on 4th day of life with septicaemia. CSF microscopy reveals a WCC of 800/mm3
- E. coli - most likely
- Listeria
- GBS - not on list, but is also most likely

(d) 50 year old female post-clipping of aneurysm develops headache and neck stiffness with fever
- Staph aureus - CoNS

(e) 66 year old male with a history of alcohol abuse presents with meningism and a red hot swollen knee
- Neisseria meningitidis type C

42
Q

A. Patient with alcoholic liver disease , chronic smoker, presents with chest infection and LLL consolidation
B. Pneumonia following an attack of influenza
C. 45yrs old male,travels to Mexico, presenting with a rash followed by pneumonia, CXR: cavitating lesion
D. 75yrs old male, travels to canary islands, develops pneumonia
E. Pregnant female, develops a vesicular rash followed by chest infection 2 days later

Options

i. Staphylococcus aureus
ii. CMV
iii. Legionella
iv. Candida
v. Coccidiodes
vi. VZV
vii. Streptococcus pneumoniae

A

A. Patient with alcoholic liver disease , chronic smoker, presents with chest infection and LLL consolidation
Strep pneumoniae

B. Pneumonia following an attack of influenza
Staph aureus

C. 45yrs old male,travels to Mexico, presenting with a rash followed by pneumonia, CXR: cavitating lesion
coccidiodes

D. 75yrs old male, travels to canary islands, develops pneumonia
Legionella

E. Pregnant female, develops a vesicular rash followed by chest infection 2 days later
VZV

43
Q

A. Outbreak of pneumonia in abattoir workers
B. Outbreak of encephalitis in a pig farm in malaysia
C. Pneumonia spread by rat urine
D. Outbreak of pneumonia in health care workers looking after a patient with severe respiratory infection
E. Outbreak of respiratory infection and conjunctivits in poultry farm workers in Netherlands

Options

i. Hendra virus
ii. Nipah virus
iii. H7N7
iv. H5N1
v. Lassa fever
vi. Ebola virus
vii. SARS
viii. Q fever

A

A. Outbreak of pneumonia in abattoir workers
Q fever

B. Outbreak of encephalitis in a pig farm in malaysia
Nipah

C. Pneumonia spread by rat urine
Lassa

D. Outbreak of pneumonia in health care workers
looking after a patient with severe respiratory infection
SARS

E. Outbreak of respiratory infection and conjunctivits in poultry farm workers in Netherlands
H7N7 - H7 unique in causing conjunctivitis
H5/H7 are highly pathogenic strains

44
Q

Immunocompromised patient

A. Post renal transplant, develops pneumonia with weak acid and alcohol fast bacilli in sputum
B. Post renal transplant with fever and leucopenia
C. Haemorrhagic cystitis
D. 6 weeks post transplant, fever not responding to antibiotics, multiple hepatic and splenic lesions on CT
E. Multiple ring enhancing lesions on CT brain

i. Toxoplasma
ii. CMV
iii. Nocardia
iv. Candida
v. Cryptococcus
vi. BK virus

A

A. Post renal transplant, develops pneumonia with weak acid and alcohol fast bacilli in sputum
Nocardia

B. Post renal transplant with fever and leucopenia
CMV

C. Haemorrhagic cystitis
BK virus

D. 6 weeks post transplant, fever not responding to antibiotics, multiple hepatic and splenic lesions on CT
Candida

E. Multiple ring enhancing lesions on CT brain
Toxoplasma

45
Q

What is relationship between Mycobacteria and Nocardia?

A

The genera Mycobacterium and Nocardia have been grouped into the family Mycobacteriaceae within the order Actinomycetales based upon similarities in staining and motility, lack of spore formation, and catalase production. These genera are characterized by the presence of long-chain fatty acids, called mycolic aids, which have the following general structures in their cell walls:

Nocardia will also be AAFB positive in sputum

46
Q

Clinical scenarios
A. Post transplant chest infection. Crescent shaped shadow in lung
B. Outbreak of respiratoy infection in pet shop workers
C. Meningitis following swimming in fresh water pool

i. Naeglaria
ii. Chlamydia psitacci
iii. Mycoplasma pneumoniae
iv. Aspergillus fumigatus
v. Candida albicans

A

A. Post transplant chest infection. Crescent shaped shadow in lung
Candida

B. Outbreak of respiratory infection in pet shop workers
Chlamydia psitacci

C. Meningitis following swimming in fresh water pool
Naegleria

47
Q

Patient is a 30yr old man, HIV +ve, history of Pneumocystis pneumonia 2 years ago. He now has an ulcerating lesion on the side of his tongue. A Giemsa stain of the biopsy specimen reveals budding yeasts within macrophages. A culture of the specimen grows an organism that is a budding yeast at 37°C but produces hyphae at 25-30°C.

Which one of the following is the organism MOST likely to cause this infection:

A. Coccidioides immitis 
B. Aspergillus fumigates 
C. Histoplasma capsulatum 
D. Cryptococcus neoformans  
E. Candida albicans
A

Histoplasma capsulatum

Yeasts + hyphae - dimorphic fungi

Dimorphic fungi grow

  • as yeasts at 37 deg
  • as moulds at 25 deg

Coccidioides immitis is rarer possibility of ulcerating lesion, but depends on travel history - USA

Cryptococcus not considered dimorphic fungi, as primarily exists as a yeast.

48
Q
  1. A female at 20/40 has fever and choramnionitis resulting in septic abortion
  2. A neonate with rash on cheek which spreads within 8 hours to shoulder and neck
  3. A neonate presents at one month with encephalopathy, pneumonia and pancytopenia.
  4. A neonate with sticky eyes at 4/7 followed by pneumonitis.
  • Chlamydia
  • Listeria
  • Strep pyogenes
  • HSV
  • HIV
A
  1. A female at 20/40 has fever and choramnionitis resulting in septic abortion
    Listeria
  2. A neonate with rash on cheek which spreads within 8 hours to shoulder and neck
    Strep pyogenes
  3. A neonate presents at one month with encephalopathy, pneumonia and pancytopenia.
    HSV
  4. A neonate with sticky eyes at 4/7 followed by pneumonitis.
    Chlamydia trachomatis
49
Q

Male child from Nigeria with patchy skin discoloration.

Suspect fungal cause

What is organism?

A

Pityriasis versicolor - caused by yeasts such as Malassezia furfur

50
Q

Match the following antibiotics with their mechanism of action.

inhibit DNA polymerase
inhibit RNA polymerase
inhibit DNA gyrase 
inhibit peptidyl transferase
inhibit beta-(1,3) D-glucan synthesis
inhibit amino acyl transfer RNA 
  1. tetracycline
  2. Aciclovir
  3. caspofungin
  4. chloramphenicol
  5. ciprofloxacin
A
  1. tetracycline
    inhibit amino acyl transfer RNA
  2. Aciclovir
    inhibit DNA polymerase - targets viral DNA polymerase, causing chain termination
  3. caspofungin
    inhibit beta-(1,3) D-glucan synthesis
  4. chloramphenicol
    inhibit peptidyl transferase - prevents protein elongation in ribosome
  5. ciprofloxacin
    inhibit DNA gyrase
51
Q

The diagnosis of the fungus responsible for rhinocerebral zygomycosis is via:

A KOH clearance and light microscopy
B Serology
C Lactophenol cotton blue slide stain

A

Lactophenol cotton blue slide stain

KOH is often used for other fungal pathogens