Yersinia - Spirillum

Question 1

This is a Gram (-) rod that exhibits bipolar staining (looks like safety pin). It is a lactose non-fermenter and is oxidase negative and urease negative. Colonies look like a fried egg.

Answer 1

Yersnia pestis

Question 2

Yersnia pestis is a bioterrorism threat transmitted from rodents to humans by ____

Answer 2

fleas

Question 3

Yersnia pestis causes Bubonic plaque. Describe the incubation, symptoms and progression.

Answer 3

incubation: 2-8 d
symptoms: fever, chills, myalgia, arthralgia, HA, within 1 day proximal lymph node becomes tender, enlarging into a pianful bubo (large black bulge)
progression: sepsis and multiorgan failure

Question 4

What two diseases does Yersnia pestis cause?

Answer 4

Bubonic plague and Pneumonic plague

Question 5

Describe the incubation period and symptoms of Pneumonic plague caused by Yersnia pestis

Answer 5

incubation: 2-4 d
symptoms: fever, chills, myalgia; becomes more severe after 1 d; bloody sputum, chest pain, dyspnea, cyanosis, death by 24 h

note: can be transmitted from person to person (terrorist attack)

Question 6

The LPS/endotoxin is a virulence factor of Yersnia pestis that is important in sepsis. How does it work?

Answer 6

travels to lymph nodes via lymphatics, infects monocytes and disseminates throughout the body (bacteremia)

Question 7

This is a very small Gram (-) rod. It is ID’d on patients from endemic areas with symptoms; blood/tissue gram stains (weakly stain); requires cysteine or cystine; has unique long chain fatty acids.

Answer 7

Francisella tularenis

Question 8

Francisella tularenis grows on ____ agar in 3-5 days

Answer 8

BYCE

note: also grows on chocolate agar

Question 9

How is Francisella tularenis spread?

Answer 9

contact with infected animals - rabbits and squirrels
tick bites (no human to human spread)

Question 10

Francisella is a bioterrorism threat because why?

Answer 10

it can be aerosolized

Question 11

This disease cuased by Francisella tularenis starts with sudden onset of fever, myalagia, arthralgia. There are several froms based on clinical manifestation: ulceroglandular (cutaneous ulcer and lymphadenopathy), oculoglandular, typhoidal, pneumonic, oropharyngeal, and GI.

Answer 11

Tularemia (rabbit/tick/deer fly fever)

Question 12

Francisella lives intracellularly. How does it survive?

Answer 12

survives in macrophage by preventing phagosome lysosome fusion

Question 13

In regard to virulence factors, virulent strains of Francisella are ____

Answer 13

encapsulated

Question 14

The Francisella antigen can cross-react with _____

Answer 14

Brucella

Question 15

This is a Gram (-) coccobacilli that requires high CO2. It has 3 species.

Answer 15

Bartonella sp.

Question 16

For each of the following species of Bartonella, describe how its transmitted:
B. quintoana
B. bacilliformis
B. henselae

Answer 16

B. quintoana: body louse
B. bacilliformis: sand fly
B. henselae: cat scratch

Question 17

For the following disease, give the species of Bartonella that causes it and the symptoms: Trench Fever

Answer 17

B. quintana - severe HA, fever, weakness, pain in long bones, fever recurs in 5 days (10-12 episodes); may cause bacteremia and endocarditis

Question 18

For the following disease, give the species of Bartonella that causes it and the symptoms: Bacillary Angiomatosis

Answer 18

B quintana and B. henselae - vascular proliferative disorder in AIDS/IC; skin lesions may ulcerate and drain (Dx: pcr)

Question 19

For the following disease, give the species of Bartonella that causes it and the symptoms: Cat Scratch Disease

Answer 19

B. henselae - 2-3 days after a cat scratch, a papule develops and progresses to a vesicle; the lesions persist 1-3 wks; chornic proximal lymphadenopathy 2-3 wks later that persists for months

Question 20

For the following disease, give the species of Bartonella that causes it and the symptoms: Carrion’s Disease - Oroya Fever and Verrugo Peruana

Answer 20

B. bacilliformis - transmitted by sand fly in Andes Mts. - bacteria invade RBCs -> serious anemia, muscle/joint pain, fever, HA, coma, followed by chronic cutaneous lesions

Question 21

This is a Gram (-) coccobacilli. It grows well on blood agar. It is commensal in URT of domestic pets and is given to humans via animal bite, scratch, or lick (similar to cat scratch fever)

Answer 21

Pasteurella multicida

Question 22

Local cellulitis or lymphadenitis, Septicemia, and local septic arthritis are all disease caused by what bacterium?

Answer 22

Pasteurella multicida

Question 23

This bacterium has 2 species: S. moniliformis and S. minus. It is a Gram (-) long thin rod.

Answer 23

Streptobacillus

Question 24

How is S. moniliformis ID’d?

Answer 24

has L shaped colones

Question 25

How is S. minus ID’d?

Answer 25

darkfeield or giemsa smears (spaghetti and meatballs appearance)

Question 26

Where is Streptobacillus usually found? How is it transmitted to humans?

Answer 26

nasopharynx of rats or other small rodents - humans get it from bite or bodily secretions of the rodents

Question 27

What disease does Streptobacillus cause? Give incubation period and symptoms.

Answer 27

Rat Bite Fever
Incubation: 2-10 days and then abrupt onset
symptoms: fever, HA, chills, muscle pain and migratory polyarthralgias and rash on abdomen and feet

Question 28

What is the diagnostic triad associated with Rat Bite Fever?

Answer 28

rash, rate bite, and migratory polyarthritis