InfectiousDisease-Basics

Question 1

Standard parameters for bacterial classification

Answer 1

Morphology Staining O2-requirement

Question 2

Bacterial-morphology: most bacteria are

Answer 2

Cocci Bacilli

Question 3

Bacterial O2 requirement:

Answer 3

Anaerobic-aerobic spectrum

Question 4

Which bacteria do not fit neatly into the standard classification parameters (shape, Gram, O2-requirements)?

Answer 4

Mycobacteria Spirochaetes Rickettsiae Chlamydiae

Question 5

Are Mycobacteria Gram +ve or Gram -ve?

Answer 5

Very weakly Gram-positive or not at all

Question 6

Mycobacterial cell walls contain

Answer 6

Mycolic acid

Question 7

Rickettsiae, Chlamydiae: Gram +ve or Gram -ve?

Answer 7

stain poorly with Gram … - more closely related to Gram-negatives

Question 8

Obligate intracellular parasites that lack cell walls

Answer 8

Rickettsiae Chlamydiae

Question 9

Medically important Gram-+ve, aerobic cocci

Answer 9

Staph Strep Entero

Question 10

Medically important Gram-+ve, anaerobic cocci

Answer 10

Anaerobic streptococci

Question 11

Gram +ve, aerobic bacilli

Answer 11

Corynebacterium Bacillus Listeria monocytogenes Nocardia asteroides

Question 12

Gram +ve, anaerobic bacilli

Answer 12

Clostridium sp. Lactobacillus sp. Actinomyces sp.

Question 13

Gram -ve, aerobic cocci

Answer 13

• Neissira meningitidis - N. gonorrhea

Question 14

Gram -ve, anaerobic cocci

Answer 14

None

Question 15

Gram -ve, aerobic bacilli

Answer 15

Enterobacteria Pseudomonads Coccobacilli Curved Gram–ve rods (Eg: Vibrio)

Question 16

Gram -ve, anaerobic bacilli

Answer 16

Bacteroides Fusobacterium

Question 17

Neissira meningitidis and N. gonorrhea: classical scheme

Answer 17

Gram -ve, aerobic, cocci

Question 18

Staphylococci

Answer 18

MSSA MRSA Toxin producing Staph. aureus S. epidermidis S. saprophyticus

Question 19

Example of Coagulase negative Staph.:

Answer 19

Staph. epidermidis

Question 20

Rx: MSSA

Answer 20

Flucloxacillin

Question 21

Rx: MRSA

Answer 21

Vancomycin Doxycycline Rifampicin

Question 22

Rx: TSS

Answer 22

Clindamycin

Question 23

Disease syndrome caused by Staph. saprophyticus

Answer 23

UTI in young women

Question 24

Rx: Staph saprophyticus

Answer 24

Trimethoprim

Question 25

Disease syndromes: CNS Staph.

Answer 25

Prosthetic infection

Question 26

Rx: CN Staph

Answer 26

- Remove prosthesis - Prolonged vanc or teico

Question 27

Which Staph infection may need Rx with IVIG

Answer 27

STSS

Question 28

Strep are classified by:

Answer 28

Hemolysis pattern: α, β, γ Lancefield antibody groups: A, B, D Lancefield group will identify a Strep more precisely

Question 29

Strep hemolysis patterns

Answer 29

α: partial, β: clear, γ: none

Question 30

Strep. pyogenes: Lancefield

Answer 30

GAS

Question 31

Respiratory colonisizer organism demonstrating α-hemolysis: agar under the colony is dark and greenish.

Answer 31

Streptococcus pneumoniae

Question 32

Alpha hemolytic, mouth commensal causing endocarditis, line infections in neutropenic host

Answer 32

Strep. viridans

Question 33

– formerly classified as part of the group D Streptococcus system – is a Gram-positive, commensal bacterium inhabiting the GI tract.

Answer 33

E. faecalis

Question 34

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Answer 34

Hemolyses of Streptococcus spp. 1. (left) α-hemolysis (S. pneumoniae), 2. (middle) β-hemolysis (S. pyogenes); 3. (right) γ-hemolysis (= non-hemolytic, S. salivarius)

Question 35

Gram +ve aerobic bacillus found in pate and soft cheeses, causes meningitis, neonatal infection

Answer 35

L monoctyogenes

Question 36

What is common to Corynebacteria, Bacillus sp, Listeria, Nocardia, Clostridia, Actinomyces?

Answer 36

All Gram +ve aerobic bacilli

Question 37

Rx: Nocardia

Answer 37

Bactrim, amikacin, imipenem

Question 38

Rx: Listeria monocytogenes

Answer 38

Ampicillin + gentamicin

Question 39

Rx: C botulinum

Answer 39

Antitoxin

Question 40

Rx: C perfringens, C tetani, Corynebacterium, Bacillus anthracis

Answer 40

Penicillin

Question 41

Rx: Streptococci

Answer 41

Penicillin except S pneumoniae (ceftriaxone)

Question 42

Meningococcal meningitis is well treated with ___ once the isolate is proven to be penicillin susceptible

Answer 42

Penicillin G

Question 43

Rx: suspected bacterial meningitis

Answer 43

Cefotaxime or ceftriaxone + vancomycin

Question 44

Should dexamethasone be given to a patient with meningococcal meningitis?

Answer 44

No ## Footnote - Dexamethasone: known or suspected pneumococcal meningitis in selected adults and in children with Haemophilus influenzae type b meningitis. - Given while awaiting microbiologic data. - Not been shown to be of benefit in meningococcal meningitis - Stop once this diagnosis is established.

Question 45

E. coli causes pneumonia in

Answer 45

1. Hospital acquired 2. debilitated patients

Question 46

E. coli causes meningitis in:

Answer 46

1. Neonates 2. Elderly

Question 47

Enterotoxigenic E. coli (ETEC) causes:

Answer 47

Watery diarrhea

Question 48

Medically important E coli

Answer 48

1. Enterotoxigenic E. coli (ETEC) : watery diarrhea. 2. Enteropathogenic E. coli (EPEC): do not produce Shiga toxin, sporadic diarrhea 3. Enterohemorrhagic E. coli (EHEC) : produce Shiga toxin, 0157:H7, O104:H4, large outbreaks of bloody diarrhea, HUS 4. Enteroinvasive E. coli (EIEC): similar to shigellosis: watery diarrhea +- progress to bloody diarrhea. 5. Enteroaggregative E. coli (EAEC): persistent and acute diarrheal illnesses

Question 49

E. coli causing HUS

Answer 49

EHEC ## Footnote HUS: MAHA, thrombocytopenia, AKI Most common cause: Shiga toxin-producing Escherichia coli (STEC)

Question 51

Genus: E coli, Klebsiella, Proteus, Salmonella, Shigella, Yersinia, Pseudomonas aeruginosa, Burkholderia cepacia, Burkholderia pseudomallei: staining, morphology, O2-requirement

Answer 51

Gram -ve, bacilli, aerobic All Enterobacter except for Pseudomonas and Burkholderia sp.

Question 52

Rx: E. coli

Answer 52

Susceptibility guided

Question 53

Rx: Proteus, E coli, Klebsiella

Answer 53

Susceptibility, local empiric guidelines

Question 54

Rx: Pseudomonas in neutropenia, sepsis, neutropenia and bacteremia, severe burns

Answer 54

beta-lactam with an aminoglycoside.

Question 56

Sexually active women \< 25: Screen for

Answer 56

Chlamydia, gonorrhea and HIV