4.2.1 Corynebacterium spp. Flashcards
A virulence factor of C. diphtheriae that blocks protein synthesis in eukaryotic cells by inhibiting __________
Diphtheria toxin
Translocation
Diphtheria toxin is encoded by what gene?
tox gene
What are the 2 fragments of Diphtheria toxin?
Fragment A (Toxicity)
Fragment B (Mediates entry)
What fragment of Diphtheria toxin is responsible for toxicity?
Fragment A
What fragment of Diphtheria toxin is responsible for entry of toxicity?
Fragment B (Mediates entry)
How Diphtheria toxin works?
- Fragment B binds to receptors on the eukaryotic cells to mediate the entry of fragment A
- Fragment A then creates the toxicity by inhibiting elongation factor 2 to prevent protein synthesis in ribosome leading to death
Diphtheria toxin In vitro production depends on?
pH 7.8 - 8
O2
Iron
How C. diphtheriae produces Diphtheria toxin?
Infected by lysogenic beta-phage
What is the MOT of C. diphtheriae
Airborne droplet
Direct contact
Pharyngitis characterized by the development of an exudate membrane which is coded by tox gene
Respiratory diphtheria
What exudate membrane mean?
Pseudomembrane
Non-healing ulcers, necrotic lesions and membrane formation
Cutaneous diphtheria
What is the virulence factor of C. jeikeium
Multiple antibiotic resistance
What is the characteristics of C. jeikeium?
Lipophilic
Non-hemolytic
Obligate aerobe
What are the clinical infections of C. jeikeium
Septicemia
Wound infection
Endocarditis
(SEW)
Affects compromised with IV catheters
Common on skin and most frequently recovered species
C. amycolatum
What are the clinical infections of C. amycolatum?
Prosthetic joint infections
Sepsis
Endocarditis
(PES)
A Corynebacterium species that is contact with sheep dermonecrotic toxin
C. pseudotuberculosis
A Corynebacterium species that is rare infections normal flora
C. striatum
A Corynebacterium species that has Mastitis in cattle (Infection in the breast)
Contact with animals or unpasteurized milk
C. ulcerans
A Corynebacterium species that has Urinary pathogen and highly urease positive
C. urealyticum
A Corynebacterium species that is often endocarditis
C. pseudodiphtheriticum
What are the species of Corynebacterium?
Jeikeium
Amycolatum
pseudotuberculosis
striatum
ulcerans
urealyticum
pseudodiphtheriticum
(JAPSUUP)
A rare gram positive bacterial organisms that is normal oral flora?
Rothia dentocariosa
What diagnostic test is positive for Rothia dentocariosa?
Nitrate ( Creates Red)
Esculin hydrolysis
What diagnostic test is negative for Rothia dentocariosa?
Motility and urease
