Most Common Bacteria - Disease State // Circumstance

Question 1

Bacteremic pneumonia cases

Answer 1

Streptococcus pneumoniae

Question 2

More likely in patients post influenza

Answer 2

Staphylococcus aureus

Question 3

Alcoholism

Answer 3

S. pneumoniae (including DRSP), oral anaerobes, K. pneumoniae, M. tuberculosis

Question 4

COPD/Smoker

Answer 4

H. influenzae, L. pneumophila

Question 5

Aspiration

Answer 5

Gram negative bacilli, oral anaerobes

Question 6

Lung abscess

Answer 6

CA-MRSA, oral anaerobes, endemic fungal pneumonia, M. tuberculosis

Question 7

Exposure to bat or bird droppings

Answer 7

Histoplasma capsulatum

Question 8

Exposure to birds

Answer 8

Chlamydophila psittaci

Question 9

Exposure to rabbirts

Answer 9

Francisella tularensis

Question 10

Exposure to farm animals

Answer 10

Coxiella burnetti

Question 11

HIV infection (early)

Answer 11

S. pneumoniae, H. influenzae, M. tuberculosis

Question 12

HIV infection (late)

Answer 12

Above plus Pneumocystis jiroveci, Cryptococcus neoformans

Question 13

Hotel or cruise ship stay in previous 2 weeks

Answer 13

Legionella pneumophila

Question 14

Influenza in community

Answer 14

Influenza, S. pneumonia, S. aureus (CA-MRSA), H. influenzae

Question 15

Structural lung disease (bronchiectasis, CF)

Answer 15

P. aeruginosa, S. aureus, Burkholderia cepacia

Question 16

Injection drug use

Answer 16

S. aureus, anaerobes, M. tuberculosis, S. pneumoniae

Question 17

Endobronchial obstruction

Answer 17

Anaerobes, S. pneumoniae, H. influenzae, S. aureus

Question 18

Nursing home residency

Answer 18

S. pneumoniae, Gram-negative bacilli, H. influenzae, S.

aureus, anaerobes, C. pneumoniae

Question 19

Poor dental hygiene

Answer 19

Anaerobes

Question 20

Travel to or residence in

southwestern USA

Answer 20

Coccidioides immitis, Hantavirus

Question 21

In context of bioterrorism

Answer 21

Bacillus anthracis (anthrax), Yersinia pestis (plague),
Francisella tularensis (tularemia)

Question 22

CAP: Rust colored sputum

Answer 22

S. pneumoniae

Question 23

CAP: Mucoid sputum

Answer 23

K. pneumoniae

Question 24

HAP/VAP

Answer 24

Aerobic gram-negative bacilli = 70%
~P. aeruginosa = 10 - 20%

S. aureus (especially MRSA) = 20 - 30%

Question 25

Acute bronchitis

Answer 25

TRICK QUESTION = NO ANTIBACTERIAL THERAPY

Question 26

Acute exacerbations of chronic bronchitis

Answer 26

Bacterial cause = H. influenzae (45%) Chronic inhalation of irritants compromises normal secretory and mucociliary function

Question 27

Acute Pharyngitis

Answer 27

Bacterial cause = Streptococcus pyogenes (10 - 30%) Viruses (rhinovirus, coronavirus, adenovirus) = most common

Question 28

Acute bacterial rhinosinusitis

Answer 28

H. influenzae Streptococcus pneumoniae Moraxella catarrhalis

Question 29

Impetigo

Answer 29

S. aureus and/or S. pyogenes (Group A streptococcus)

Question 30

Erysipelas (variant of cellulitis)

Answer 30

Beta hemolytic streptococci

Question 31

Cellulitis: Infants, children

Answer 31

H. influenzae, S. pyogenes , S. aureus, group B strep in neonates

Question 32

Cellulitis: Adults, post operative

Answer 32

S. aureus, S. pyogenes, other group strep

Question 33

Cellulitis: Injection Drug Users

Answer 33

S. aureus (including MRSA), S. pyogenes, anaerobes, fungi

Question 34

Cellulitis: Diabetics

Answer 34

S. aureus, S. pyogenes, group B strep, | Gram negative bacilli, anaerobes

Question 35

Cellulitis: Immunocompromised

Answer 35

Gram negative bacilli, fungi

Question 36

Cellulitis: Necrotizing Infections

Answer 36

S. pyogenes*** , Clostridium perfringens

Question 37

2 most common causative organisms of SSTIs

Answer 37

S. pyogenes, S. aureus

Question 38

Most common causes of moderate DFIs

Answer 38

S. pyogenes, S. aureus

Question 39

Intraabdominal Infections

Answer 39

Gram negative E. coli | Gram positive = Streptococcus species

Question 40

Endocarditis

Answer 40

Staphylococci (Usually S. aureus)

Question 41

Clostridioides difficile

Answer 41

Clostridioides difficile

Question 42

Osteomyelitis

Answer 42

S. aureus

Question 43

Septic arthritis: Neonates + children

Answer 43

S. aureus

Question 44

Septic arthritis: Adults 15 - 40

Answer 44

Neisseria gonorrhoeae

Question 45

Septic arthritis: cat or dog bite

Answer 45

Pasteurella multocida

Question 46

Septic arthritis:

Answer 46

Eikenella corrodens, anaerobes, oral flora

Question 47

Prosthetic joint infection

Answer 47

Staphylococcus aureus (MSSA and MRSA), Streptococci, Enterococci, Pseudomonas aeruginosa, Enterobacteriaceae

Question 48

UTI (females and males)

Answer 48

E. coli E. coli E. coli

Question 49

GU in males

Answer 49

Gram negative = Enterobacteriaceae (E. coli, proteus) Gram positive = Enterococcus spp., S. aureus

Question 50

Urethritis in males

Answer 50

Neisseria gonorrhea

Question 51

Epididymitis

Answer 51

Chlamydia