Term
|
Definition
small gram-positive, non-spore forming bacillus
that causes *listeriosis*, a *chronic intracellular infection* that can cause meningitis and stillbirth.
produces an *adhesin* that lets it attach to host cells and an *invasin* that induces the host cell to phagocytize it.
a pore forming protein called *listeriolycin O* that allows it to escape from phagosomes into cytoplasm
It induces actin to form microfilaments that propel it
around the cytoplasm of its host cell & into adjacent host
cells, infecting new cells without ever leaving cytoplasm. |
|
|
Term
|
Definition
Listeria monocytogenes is ubiquitous in the environment. ingest attach to intestinal epithelial cells and are phagocytized by them. evade phagosme, induce actin in host to make microfilaments to propel them around cell and sometimes into adjacent cells which helps them evade hosts immune defense
causes intestinal inflamation and diarrhea when host mounts cellular immune response against L.m. infected intestinal mucosal cells
infected monocytes in circulation cause fever and flu-like symptoms.
healthy host mild flu like infection
in immunosuppressed life threatening that can cause meningitis 20% mortality rate with treatment |
|
|
Term
|
Definition
most important pathogen in the genus is Corynebacterium diphtheriae, which causes the life-threatening disease *diphtheria*
Other Corynebacterium species can be opportunistic pathogens for humansVirulent strains produce a potent *cytotoxin called diphtheria toxin* that causes diphtheria. |
|
|
Term
|
Definition
caused by
infection of a wound with toxin-
producing C. diphtheriae.
characterized by inflammation,
oozing of a fibrin-rich fluid that can
form a pseudomembrane and failure
of the wound to heal. |
|
|
Term
|
Definition
immediate administration of specific antibodies
(antitoxins) that neutralize diphtheria toxin.
A. This is the *primary and only effective treatment*
Antibiotics can also be given as a supplemental treatment |
|
|
Term
|
Definition
commonly found on skin and in hair follicles. metabolizes the lipids in sebum
Propionibacterium acnes is the most common cause of infections in humans.
A. It is the most common cause of acne in adolescents and young adults
Hormonal changes associated
with adolescence stimulate excessive sebum production,causing P. acnes to overgrow in hair follicles and pores. |
|
|
Term
|
Definition
Nocardia pulmonary infections
inhalation of Nocardia cells from soil into the lungs
Nocardia asteroides is the most important Nocardia pathogen in the U.S.
A. The initial infection can cause pneumonia or localized
abscesses in the lungs that slowly enlarge and form a
draining sinus tract or cavity.
B. Pus from the lesions contains microcolonies of Nocardia
filaments and individual cells.
C. Nocardia cells can enter the bloodstream and form
abscesses in other parts of the body. The most common dissemination sites are the *brain*, kidneys and skin. |
|
|
Term
|
Definition
opportunistic pathogens from soil that can cause chronic, suppurative, granulomatous infections in
the lungs, skin and central nervous system. |
|
|
Term
|
Definition
anaerobic or microaerophilic,branching filaments.
opportunistic pathogens that can
cause a chronic, suppurative, granulomatous infection called *actinomycosis*.
Human actinomycosis most commonly occurs in the head and neck
characterized by minor pain and formation of a hard, nodular, pus-filled swelling in the jaw or neck
form one or more draining tracts
histologically supparative inflammation
pus contains yelloish particles called sulfur granules which are microcolonies of actinomyces filaments covered with a yellowish amorhphs eosinophilic plague
Treatment of actinomycosis consists
of draining the lesions and giving
antimicrobials for 4-12 weeks.
2. Prevention is by good hygiene. |
|
|
