NON-LACTOSE FERMENTING GRAM NEGATIVE RODS

Question 1

motile
OXIDASE (-)
H2S producer

Answer 1

Salmonella spp

Question 2

nonmotile
OXIDASE (-)
H2S non producer

Answer 2

Shigella spp

Question 3

swarming
OXIDASE (-)
H2S producer
UREASE

Answer 3

Proteus mirabilis

Question 4

H2S non producer
OXIDASE (+)
obligate aerobe

Answer 4

Pseudomonas aeruginosa

Question 5

ENTEROCOLITIS

-invasion of the epithelial and subepithelial tissue of the small and large intestines

Answer 5

S. enteritidis/S. typhimurium

Question 6

TYPHOID FEVER
-d.t. Vi (virulence) capsular antigen

• organisms enter, multiply in the PEYER PATCHES and spread in reticuloendothelial system
• predilection for invasion of the GALLBLADDER – chronic carrier state
• FEVER and BRADYCARDIA (pulse fever disproportion)
• ROSE SPOTS

Answer 6

S. typhi

Question 7

Septicemia

• bacteremia results in the seeding of many organs
• MC sequelae - osteomyelitis, pneumonia and meningitis

Answer 7

S. choleraesuis

-commonly in patients w/ SICKLE CELL ANEMIA or cancer

Question 8

incubation period - 12-48 hrs

nausea and vomiting – abdominal pain and nonbloody diarrhea

Answer 8

Enterocolitis

Question 9

Culture Source (Typhoid Fever) - WEEK 1
*stepwise fever, anorexia, malaise, relative bradycardia and bacteremia

Answer 9

BLOOD

bone marrow

Question 10

Culture Source (Typhoid Fever) - WEEK 2

*abdominal pain, bloating, constipation, ROSE SPOTS, hepatosplenomegaly, jaundice

Answer 10

URINE
rose spots
bone marrow

Question 11

Culture Source (Typhoid Fever) - WEEK 3

• bleeding ileitis - ulceration in hyperplastic follicles
• pneumonia

Answer 11

STOOL

bone marrow

Question 12

Culture Source (Typhoid Fever) - WEEK 4

*recovery or death

Answer 12

bone marrow

Question 13

POST - chronic carrier state

Answer 13

BILE
stool
bone marrow

Question 14

Treatment for Uncomplicated Typhoid Fever

Answer 14

Ampicillin

Amoxicillin

Question 15

Treatment for Complicated Typhoid Fever

Answer 15

Ceftriaxone

Question 16

8 y/o African male with sickle cell anemia develops osteomyelitis. Which is the most likely etiology

Answer 16

Salmonella

HEALTHY - Staphylococcus aureus

Question 17

Osteomyelitis in a specific conditions

Answer 17

BURNS - Pseudomonas aeruginosa

IV DRUG ABUSERS - Staphylococcus aureus and Pseudomonas aeruginosa

SICKLE CELL ANEMIA - Salmonella choleraesuis

Question 18

Species and strains of Shigella

Answer 18

Shigella sonnei - Duval’s bacillus
*MCC OF BACILLARY DYSENTERY

Shigella dysenteriae type I - Shiga bacillus

• MOST SEVERE FORM OF BACILLARY DYSENTERY
• MCC of EPIDEMIC DYSENTERY

Question 19

Common cause of UTI and nosocomial infections

can cause STAGHORN CALCULI

Answer 19

Proteus mirabilis

Question 20

Proteus mirabilis pathogenesis

Answer 20

UREASE hydrolyzes the urea to form AMMONIA

• raise pH – ALKALINE URINE
• encourage the formation of STRUVITE stones - MAGNESIUM AMMONIUM PHOSPHATE

Question 21

SWEET GRAPE LIKE ODOR

has FLUROSCEIN and PYOCYANIN and PYOVERDIN

grown on CETRIMIDE AGAR

Answer 21

Pseudomonas aeruginosa

Question 22

MCC of otitis externa

Answer 22

Pseudomonas aeruginosa

Question 23

VAP

Necrotizing pneumonia

fleur de lis pattern

Answer 23

Pseudomonas aeruginosa

Question 24

3rd MCC of nosocomial UTI

Answer 24

Pseudomonas aeruginosa

Question 25

Predominant anaerobe of the human colon ABDOMINAL ABSCESS PERITONITIS PERICARDITIS ENDOCARDITIS CEREBRAL ABSCESS

Answer 25

Bacteroides fragilis

Question 26

37 y/o woman hx of UTI (+) burning on urination + frequency and urgency urine - smells like ammonia

Answer 26

Proteus mirabilis

Question 27

``` 27 y/o woman fever, anorexia, headache, weakness diarrheal illness - 36 hrs temp - 39 C HR - 68 bpm BP - 120/80 RR - 18 ``` (+) rose spots

Answer 27

Salmonella enterica subspecies enterica serotype Typhi (Salmonella typhi) O ANTIGEN 139 (O139)

Question 28

18 y/o student (+) abdominal cramps and diarrhea MacConkey agar - gram (-) rods Triple Sugar Iron Agar - screen isolates for salmonellae and shigellae A result suggesting one of these pathogens would be A. production of urease B. motility in the medium C. inability to ferment lactose and sucrose D. fermentation of glucose

Answer 28

C. inability to ferment lactose and sucrose

Question 29

43 y/o man (+) diabetis, (+) non healing wound Culture: Staphylococcus aureus, Bacteroides fragilis, gram (-) bacillus that SWARMS across the blood plate agar covering the entire surface of the agar after 36 hrs. The gram (-) is a member of the genus

Answer 29

Proteus

Question 30

The MC pathogen isolated from patients who have been HOSPITALIZED > 1 week. A frequent cause of nosocomial infections

Answer 30

Pseudomonas aeruginosa

Question 31

PSEUDOMONAS

Answer 31

``` Pneumonia, pyocyanin Sepsis Ecthyma gangrenosum UTIs Diabetes Osteomyelitis Mucoid Polysaccharide capsule Otitis externa Nosocomial infections Exotoxin A Skin infections ```

Question 32

A sputum culture of a patient w/ cystic fibrosis grows Pseudomonas aeruginosa that form very mucoid colonies The implication of this observation is

Answer 32

P. aeruginosa have formed a biofilm in the patient's airway

Question 33

The mechanism of action of exotoxin A of Pseudomonas aeruginosa

Answer 33

block the elongation factor 2 (EF 2)

Question 34

Long term carriage and shedding is most likely to occur after GIT infection w/ which of the ff species? ``` A. E. coli B. Shigella dysenteriae C. Vibrio cholerae D. Campylobacter jejuni E. Salmonella typhi ```

Answer 34

E. Salmonella typhi

Question 35

63 y/o, visited oyster restaurant and ate 2 dozen oysters 2 days later - abrupt onset of chills, fever and light headedness (+) erythematous skin lesions -- hemorrhagic bullae -- ulcers

Answer 35

Vibrio vulnificus

Question 36

Bacteremia associated w/ GIT infection

Answer 36

Campylobacter jejuni