Clinical features of different bacteria

Question 1

Appearance of staphylococcus on microscopy

Answer 1

Clusters of cocci (bunch of grapes)

Question 2

Tests used to differentiate between staphylococcus aureus and other staphylococcus strains

Answer 2

Coagulase test = positive
DNase test = positive
Surface protein A is present

Question 3

Exotoxins produced by staphylococcus aureus

Answer 3

Toxic Shock Syndrome toxin
Enterotoxins A-E
Epidermolytic toxin (scalded skin syndrome)

Question 4

Which bacteria can cause toxic shock and which test can be used to differentiate between them

Answer 4

Group A streptococcus (pyogenes) and staphylococcus aureus - GAS is catalase negative, Staph A is catalase positive

Question 5

What kind of bacteria is listeria?

Answer 5

A gram positive, bacillus, facultative anaerobe, beta haemolysis on agar, intracellular pathogen (hides within phagocytic cells), produces flagella at room temp

Question 6

Signs and symptoms of listeriosis

Answer 6

Flu-like illness, high fever, diarrhoea

Question 7

Incidence of listeriosis

Answer 7

1 in 10,000

Question 8

Neonatal mortality rate with listeriosis

Answer 8

Up to 60%

Question 9

Transmission of listeria

Answer 9

Undercooked food, unpasteurised milk, soft cheeses, pate

Question 10

What kind of bacteria is E.coli?

Answer 10

Gram negative rod, a non-lactose fermenter, facultative anaerobe

Question 11

What are the microbiological characteristics of neiserria species?

Answer 11

Gram negative, diplococci, obligate aerobes, oxidase and catalase positive, often require a rich media to grow and thrive in the presence of high CO2

Question 12

What levels of CO2 do Neisseria species prefer to grow in?

Answer 12

High levels

Question 13

What does Treponema pallidum pertenue cause?

Answer 13

Yaws - (Yaw(n)s around the mouth) periositis, yellow papillomatous skin lesions

Question 14

What is Yaws disease?

Answer 14

Disease caused by treponea pallidum pertenue = periositis, yellow papillomatous skin lesions

Question 15

What does Treponema carrateum cause?

Answer 15

Pinta - (“tinta” of the skin) - achromic lesions and papulosquamous skin lesions

Question 16

What is Pinta disease?

Answer 16

Caused by treponema carrateum - (“tinta” of the skin) - achromic lesions and papulosquamous skin lesions

Question 17

What is Bejel disease?

Answer 17

Caused by terponema pallidum endemicum - oral mucosal lesions, mucus patches, condylomata lata, gummas

Question 18

What does Treponema pallidum endemicum cause?

Answer 18

Bejel diseased - (“tinta” of the skin) - achromic lesions and papulosquamous skin lesions

Question 19

What does Treponema pallidum pallidum cause?

Answer 19

Syphyllis

Question 20

What are the features of congenital syphyllis?

Answer 20

Stillbirth
Before 2 years - maculopapular rash on hands and feet, snuffles, hepatosplenomegaly, optic neuritis
after 2 years - saber shins, saddle shaped nose, hearing loss, Hutchinson teeth (notches in teeth)

Question 21

What are the features of primary syphilis?

Answer 21

1-3 weeks - painless chancre

Question 22

What are the features of secondary syphillis

Answer 22

6-12 weeks - highly infectious, generalised lymphadenopathy, non-itchy maculopapular rash on body, condyloma lata

Question 23

What are condyloma lata?

Answer 23

White, smoth, warty painless lumps around the genitals and anus that form during secondary syphillis

Question 24

What are the features of tertiary syphilis?

Answer 24

Neuro - tabes dorsalis (posterior spinal column - loss of vibration and proprioception), anterior spinal column ( loss of sensation + weakness), neuro (altered mental state, memory loss, slurred speech, loss of coordination), CVs (aortic aneurysm), eye (aryll Robertson pupil), gumma

Question 25

What is tabes dorsalis?

Answer 25

Damage to the posterior spinal cord (occurs in tertiary syphilis) - results in loss of proprioception and vibration sense

Question 26

What is a Gumma?

Answer 26

Seen in tertiary syphilis - a ball of immune cells, surrounded by fibroblasts, with a necrotic centre which forms as an inflammatory response to the spirochaetes

Question 27

What type of hypersensitivity reaction is tertiary syphilis?

Answer 27

Type 4 (T cell mediated)

Question 28

What are the features of an Argyll Robertson pupil?

Answer 28

Accomodates but does not react to light (prostitutes pupil - seen in tertiary syphilis)

Question 29

A-Which organism causes gas gangrene?
B- Which organism causes necrotising fasciitis?
C- most common cause of surgical site infection?

Answer 29

Clostridium perfringens
Streptococcus pyogenes
Staphylococcus aureus

Question 30

Which bacteria are commonly found in breast abscesses?

Answer 30

Actinomyces and bacteroides

Question 31

Which group of patients does a campylobacter jejuni infection typically effect?

Answer 31

Children and young adults

Question 32

What disease does campylobacter jejuni typically cause?

Answer 32

Colitis (food poisoning)

Question 33

What kind of bacteria is campylobacter jejuni?

Answer 33

Helical shaped, gram negative

Question 34

What is the most common source of campylobacter jejuni?

Answer 34

Infected food or water (typically from infected faeces of domestic or farm animals)

Question 35

Which antibiotics are effective against campylobacter jejuni?

Answer 35

Ciprofloxacin and erythromycin