Streptococci

Question 1

Streptococcus is gram negative. True or false?

Answer 1

False

gram positive

Question 2

What are the virulence factors of Strep?

Answer 2

Bacterial capsule
Exotoxin production
Immune invasion
Dissemination

Question 3

What infections are caused by GAS?

Answer 3

sore throat, impetigo, cellulitis, scarlet fever, necrotizing fasciitis

Question 4

Strep is present in oral microbiota. True or false?

Answer 4

True

Question 5

Strep throat is usually transmitted in winter. True or false?

Answer 5

False

Spring and autumn

Question 6

What are the signs and symptoms of strep throat?

Answer 6

Swollen tonsils

Discomfort when swallowing liquids

Question 7

What are three ways in which strep throat can be diagnosed?

Answer 7

Physical examination
Throat swabs of affected tissue
Blood test - antibodies

Question 8

Often no treatment is needed for strep throat. True or false?

Answer 8

True, give OTC analgesics, antibacterial lozenges, sprays, mouthwashes.

If they have fever and pain give AB such as Phenoxymethylpenicillin or clarithromycin

Question 9

Rheumatic heart disease is a complication of GAS. True or false?

Answer 9

True

Question 10

What are some complications of GAS?

Answer 10

Necrotising fasciitis, Strep toxic shock syndrome, acute rheumatic fever

Question 11

What is cellulitis?

Answer 11

an acute bacterial infection of the skin that involves dermis and subcutaneous tissues

Question 12

IV drug use can cause cellulitis. True or false?

Answer 12

True

Question 13

Patients with chicken pox are prone to cellulitis. True or false?

Answer 13

True

Question 14

Obese patients are not at risk of cellulitis. True or false?

Answer 14

False

Question 15

GAS can be carried in the vagina and anus. True or false?

Answer 15

True

Question 16

What are the signs and symptoms of cellulitis?

Answer 16

Skin becomes red, hot, swollen and tender

Commonly affects the legs

Blisters

Question 17

Cellulitis patients need to be referred to hospital. Why?

Answer 17

They need IV antibiotics

Question 18

What are some danger signs of cellulitis that would indicate referral to hospital is needed?

Answer 18

Spreading of redness in an area

High temp of 38+

Change in mental state

Nausea or vomiting

Rapid heartbeat & breathing

Question 19

What are the three ways in which cellulitis is diagnosed?

Answer 19

Blood tests
Skin swab
Physical examination

Question 20

How is a mild infection with cellulitis treated?

Answer 20

pain management, adequate fluid intake, 7-14 day oral AB at home eg phenoxymethylpenicillin

Question 21

How is an advanced infection of cellulitis treated?

Answer 21

Hospital admission for IV AB – benzylpenicillin

Question 22

What are some complications of cellulitis?

Answer 22

Septicaemia, necrotising fasciitis, facial cellulitis

Question 23

In cellulitis how does the causative agent enter body?

Answer 23

through breaks in skin from cut, burn, bite, skin ulcer, etc

Question 24

What are some differential diagnoses for strep throat?

Answer 24

glandular fever (viral infection), cancer (persistent sore throat), quinsy (abscess, painful collection of pus), epiglottitis (inflammation of epiglottis)

Question 25

What are some danger symptoms of strep throat?

Answer 25

difficulty breathing, obstruction of airways, high fever etc.

Question 26

Scarlet fever is more common at what age and in what season?

Answer 26

aged 10 or younger and in winter/spring months

Question 27

What are the initial symptoms of scarlet fever?

Answer 27

initial flu-like symptoms such as high temp, sore throat and swollen neck glands

Question 28

What are some later symptoms of scarlet fever?

Answer 28

eventual rash development post fever, coarse rash and skin may peel. May also develop strawberry tongue 48 hours post fever. White coating may disappear to form red strawberry tongue.

Question 29

How is scarlet fever managed/treated?

Answer 29

If suspected but person not unwell give Phenoxymethyl penicillin (PenV) & if allergic to penicillin give azithromycin, also manage pain and itching with paracetamol/ibuprofen and calamine lotion/antihistamines

Question 30

Describe structure of streptococcus pneumoniae

Answer 30

gram positive diplococcus, non-motile

Question 31

What are some risk factors for pneumonia?

Answer 31

smoking, contact with children, age and alcohol abuse

Question 32

Pneumococci can be transiently carried in what part of the body?

Answer 32

Nasopharynx

Question 33

How long does the carrier state persist?

Answer 33

14 days after initial exposure but is typically asymptomatic

Question 34

In some cases, there is a switch from carrier to invasive infection, what can this cause?

Answer 34

initially mild irritation of upper airway, fever, malaise, dyspnoea, productive cough

Question 35

In order to switch, SP needs virulence factors, describe some of them

Answer 35

Polysaccharide capsule which works through a charge effect, the SP virulence it associated with the capsule’s thickness

high surface charge interferes with phagocyte interactions and reduces complement deposition at surface of bacteria

pneumolysin is a pore forming toxin produced by lysed Sp cells, causes induction of cytokine release and can damage cilia movement

Question 36

Severity assessment of CAP is determined through clinical judgement and the CRB-65 scoring, explain what the CRB scoring is

Answer 36

1 point given for each of the following prognostic features: confusion, respiratory rate (>/= 30 breaths/min), BP (= 60 diastolic of <90 systolic ) & Age (>/= 65)

Question 37

How would a low score be managed?

Answer 37

community management, amoxicillin, alternative options are azithromycin or clarithromycin (if pen allergy)

Question 38

How would a moderate score be managed?

Answer 38

consider hospital assessment, amoxicillin + clarithromycin (if atypical suspected) or erythromycin (in pregnancy)

Question 39

How would a sever score be managed?

Answer 39

urgent hospital admission, IV antibiotics: co-amoxiclav with clarithromycin or erythromycin (if pregnant)