Microbiology 7S RTIs

Question 1

what does a double heart border/ Sail sign on CXR suggest

Answer 1

Left lower lobe collapse

Question 2

3 results on investigation which point towards S.pneumonia

Answer 2

Alpha haemolytic (green)
Optochin sensitive
High virulence
gram +ve cocci

Question 3

Clinical features classically seen in Strep pneumonia

Answer 3

Rusty coloured sputum

Lobar pneumonia

Question 4

Name a high virulent and low virulent Streptococcus strain

Answer 4

High virulence: Strep pneumonia

Low virulence: Strep viridans

Question 5

most common cause of CAP

Answer 5

S.pneumonia

Question 6

Main organisms involved in cAP

Answer 6

S.pneumonia
Haemophilus influenza
Klebsiella
mORAXella
S.aureus

Question 7

4 main organisms causing atypical pneumonia

Answer 7

Legionella
Mycoplasma
Coxiella burnetii (Q fever)
Chlamydia

Question 8

2 features of Coxiella burnetii (Q fever)

Answer 8

faRM ANImals

Hepatitis

Question 9

splenomegaly, rash, haemolytic anaemia, bird exposure

Answer 9

Chlamydia psittaci

Question 10

3 organisms which often cause cavitating lesions on CXR

Answer 10

S.aureus
TB
Klebsiella

Question 11

3 most common causative organisms of pneumonia in 1-6 month old?

Answer 11

Chlamydia trachomatis
RSV
S.aureus

Question 12

CURB-65?

Criteria for admission

Answer 12

Confusion
Urea >7mmol/L
RR >30
BP <90/60
<65 years

1 = oral amoxicillin at home 5 days
2 = consider admission
3-5 = SEVERE, admit +/- ITU co-amox + clari

Question 13

what is the definition of bronchitis?

Answer 13

Inflammation of medium sized vessels

Question 14

CXR in bronchitis

Answer 14

NORMAL

Question 15

cause of pneumonia in pt with pre-existing lung disease + smoker, gram negative coccobacili

Answer 15

H.influenza

Question 16

which bacterium is grown on a cHARCOAL YEAST EXTRACT

Answer 16

Legionella pneumophilia

Question 17

urinary antigens seen in pneumonia caused by which 2 organisms?

Answer 17

Legionella + streptococcus pneumonia

Question 18

which organisms cause atypical pneumonia?

Answer 18

Legionella
Mycoplasma
CHlamydia
Coxiella

Question 19

Why can atypicals not be treated with penicillins?

Answer 19

The organisms DO NOT HAVE CELL WALLS therefore need to be treated with antibiotics which disrupt protein synthesis e.g. macrolides or tetracyclines

Question 20

what is characteristic of atypical pneumonia?

Answer 20

Extra-pulmonary manifestations e.g. hepatitis

Question 21

how is coxiella burnetti transmitted?

Answer 21

aerosol or milk (farm animals0

Question 22

which part of the lung does TB have a predilection for?

Answer 22

Upper zones

Question 23

which 2 stains are used in TB?

Answer 23

Auramine stain and Ziehl-Neelsen

Question 24

definition of HAP

Answer 24

A pneumonia with onset >48 hours post admission

Question 25

main causative organisms in HAP

Answer 25

Enterobacteriacae e.g. E.coli, Klebsiella S.aureus Pseudomonas

Question 26

• 64 year old, treated for lymph node TB, increasing SOB over one month, non-productive cough and bilateral-ground glass shadowing on CT (“bats wings”)

Answer 26

Pneumocystic jirovecii pneumonia (PCP)

Question 27

what type of organism is pneumocystis jirovecii?

Answer 27

FUNGUS

Question 28

useful investigation for pCP

Answer 28

Walk test will show desaturation on exertion

Question 29

Prophylaxis and treatment for PCP

Answer 29

Co-trimoxazole (septrin)

Question 30

3 main conditions caused by aspergillus fumigatus

Answer 30

Allergic bronchopulmonary aspergillosis (ABPA) Aspergilloma (pre-existing cavity) Invasive aspergillosis (immunocompromised)

Question 31

Treatment for invasive aspergillosis

Answer 31

Amphotericin B

Question 32

neutropenia --> prone to which LRTIs?

Answer 32

Fungi, especially aspergillus

Question 33

Splenectomy --> ?LRTIs

Answer 33

S.pneumonia, Haemophilus, neisseria + malaria

Question 34

when can antibody test be used in diagnosis of pneumonia?

Answer 34

only if there is a paired sample i.e. a sample when the patient was well

Question 35

investigations to detect PCP

Answer 35

Immunofluorescence + SILVER STAIN

Question 36

SILVER STAIN

Answer 36

PCP

Question 37

CAP empirical therapy for mild-mod and mod-severe

Answer 37

Mild - mod: oral amoxicillin | Mod-severe: Co-amoxiclav (augmentin) + clarithromycin

Question 38

HAP empirical therapy 1st line + 2nd line/ITU

Answer 38

1st line = ciprofloxacin + vancomycin | 2nd = piptazobactam + vancomycin

Question 39

specific therapy for pseudomonas

Answer 39

piptaz OR cipro +/- gentamicin