Corynebacterium, Listeria, Erysipelothrix, and Bacillus

Corynebacterium

Gram-positive

Non-motile

Facultative anaerobe

Corynebacterium metabolism

Reduces tellurite

fermentative

catalase positive

Corynebacterium diphtheriae

Aerobic Gram-positive, "club" shaped, bacillus

Three biotypes: gravis, mitis, and intermedius

diphtheriae toxin

encoded in phage tox gene

binds to CD9 antigen and affect translation

diphtheriae outcomes

Anterior nasal•

Pharyngeal•

Laryngeal•

Cutaneous•

Ocular•

Genital

can be treated with penicillin or erythromycin

Listeria

Gram positive•

Motile: Flagella and Actin-based (ActA)

nonsporing

non-acid fast

not encapsulated

Facultative anaerobe•

Listeria metabolism

Psychrophilic•

Grow intracellularly

fermentative

catalase positive

oxidase negative

Listeria monocytogenes virulence factors

Internalin A&B - cell surface adhesins

Listeriolysin O (LLO) - pore-forming toxins

ActA - facilitates intracellular movement

Listeriosis

mainly affects pregnant women and immunocompromised people

Erysipelothrix

Gram positive•

Non-motile•

Facultative anaerobe

no capsule

weak fermentative

catalase negative

Erysipelothrix rhusiopathiae outcomes

Swine Erysipelas (hogs) and Erysipeloid (human)

Bacillus

Gram positive•

Motile•

Sporulating•

Aerobic or facultative anaerobic

usually catalase positive

Bacillus anthracis virulence factors

Lethal factor (LF) - disrupts MAPK pathway

Edema factor (EF) - causes osmotic stress

Protective antigen (PA) - carries LF and EF into the cytoplasm

Anthrax types

Cutaneous•

Inhalation•

Gastrointestinal

treated mainly by antibiotics

Anthrax vaccines

work against PA

restricted

serious adverse effects