4.2.1 Corynebacterium spp.

Question 1

A virulence factor of C. diphtheriae that blocks protein synthesis in eukaryotic cells by inhibiting __________

Answer 1

Diphtheria toxin

Translocation

Question 2

Diphtheria toxin is encoded by what gene?

Answer 2

tox gene

Question 3

What are the 2 fragments of Diphtheria toxin?

Answer 3

Fragment A (Toxicity)
Fragment B (Mediates entry)

Question 4

What fragment of Diphtheria toxin is responsible for toxicity?

Answer 4

Fragment A

Question 5

What fragment of Diphtheria toxin is responsible for entry of toxicity?

Answer 5

Fragment B (Mediates entry)

Question 6

How Diphtheria toxin works?

Answer 6

1. Fragment B binds to receptors on the eukaryotic cells to mediate the entry of fragment A
2. Fragment A then creates the toxicity by inhibiting elongation factor 2 to prevent protein synthesis in ribosome leading to death

Question 7

Diphtheria toxin In vitro production depends on?

Answer 7

pH 7.8 - 8
O2
Iron

Question 8

How C. diphtheriae produces Diphtheria toxin?

Answer 8

Infected by lysogenic beta-phage

Question 9

What is the MOT of C. diphtheriae

Answer 9

Airborne droplet
Direct contact

Question 10

Pharyngitis characterized by the development of an exudate membrane which is coded by tox gene

Answer 10

Respiratory diphtheria

Question 11

What exudate membrane mean?

Answer 11

Pseudomembrane

Question 12

Non-healing ulcers, necrotic lesions and membrane formation

Answer 12

Cutaneous diphtheria

Question 13

What is the virulence factor of C. jeikeium

Answer 13

Multiple antibiotic resistance

Question 14

What is the characteristics of C. jeikeium?

Answer 14

Lipophilic
Non-hemolytic
Obligate aerobe

Question 15

What are the clinical infections of C. jeikeium

Answer 15

Septicemia
Wound infection
Endocarditis

(SEW)

Affects compromised with IV catheters

Question 16

Common on skin and most frequently recovered species

Answer 16

C. amycolatum

Question 17

What are the clinical infections of C. amycolatum?

Answer 17

Prosthetic joint infections
Sepsis
Endocarditis

(PES)

Question 18

A Corynebacterium species that is contact with sheep dermonecrotic toxin

Answer 18

C. pseudotuberculosis

Question 19

A Corynebacterium species that is rare infections normal flora

Answer 19

C. striatum

Question 20

A Corynebacterium species that has Mastitis in cattle (Infection in the breast)

Contact with animals or unpasteurized milk

Answer 20

C. ulcerans

Question 21

A Corynebacterium species that has Urinary pathogen and highly urease positive

Answer 21

C. urealyticum

Question 22

A Corynebacterium species that is often endocarditis

Answer 22

C. pseudodiphtheriticum

Question 23

What are the species of Corynebacterium?

Answer 23

Jeikeium
Amycolatum
pseudotuberculosis
striatum
ulcerans
urealyticum
pseudodiphtheriticum

(JAPSUUP)

Question 24

A rare gram positive bacterial organisms that is normal oral flora?

Answer 24

Rothia dentocariosa

Question 25

What diagnostic test is positive for Rothia dentocariosa?

Answer 25

Nitrate ( Creates Red)
Esculin hydrolysis

Question 26

What diagnostic test is negative for Rothia dentocariosa?

Answer 26

Motility and urease