Transcript Fungal Pathogens

Fungal Pathogens
Microbes and Society
Meningitis
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Cryptococcus neoformans causes swelling in the
membranous covering of the spinal cord.
Organism is found in pigeon droppings which
dry out and are carried in the wind or eucalyptus
trees and decaying wood forming hollows in
living trees
Organism is a fungus with a capsule that helps it
avoid the immune system.
Why doesn’t everybody get cryptococcosis?
Why isn’t everyone infected?
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Because the immune
system handles the yeast
normally. This is a
problem of the
immunocompromised,
especially AIDS patients.
What anatomical sites are infected
with this fungus
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Central Nervous System (CNS) and lungs
Remember, we breathe it in first! Can cause
pulmonary problems too.
Other Eukaryotic Pathogens that
Cause Meningitis
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Histoplasma (another bird dropping fungus)
Coccidioides (soil fungus)
Toxoplasma (protozoa found in cat feces and/or
undercooked meat)
Naegleria fowleri (amoeba that caused those 3 boys
to die in Florida)
Blastomyces dermititidis (another bird dropping
fungus)
Some Prokaryotic Organisms that
cause Meningitis
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Bacterial
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Haemophilus influenzae type b,
Neisseria meningitidis,
Streptococcus pneumoniae
Bacteria are spread by close contact (like in dorms!)
Can be treated with antibiotics
Can be VERY serious, leading to brain damage and/or death
There is a vaccine!
Viral Meningitis
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Many different viruses cause viral meningitis
Makes individuals very ill, but rarely kills
Nicknamed “aseptic meningitis”
No treatment, but usually clears up on its own
More common in summer and fall and is
transmitted through direct contact of respiratory
secretions
Need to determine which meningitis you have
so you can get proper treatment
Fingernail Fungus
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Wide variety of dermatophytes cause this
condition
Condition is called onychomycosis
Organisms thrive on keratinized tissue
VERY common problem (as seen by TV ads)
Definitive Diagnosis
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Nail scraping can identify if it is fungal
Can also cause scalp or skin problems
Treatment for Fingernail
Dermatophytes
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Best to see a physician to rule out metabolic
conditions or chronic diseases.
Topical treatments such as itraconazole or
terbinafine may or may not be effective and may
take as little as 3 months and as long as 12
months to treat.
Even the super expensive oral treatments are not
100%
Diligence and patience is required!
Common Dermatophyte Conditions
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Athlete’s feet
Jock Itch
Ring Worm
All these surface
mycoses (mycology = study of fungus) are capable
of digesting keratin and are stubborn when
treating.
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Ringworm is not a WORM!
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Usually has a defined
round edge and is scaly
Can treat with athlete’s
foot medicine
Treat for 1 week after
lesion has gone away
Ringworm is contagious!
Yeast Infection
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Caused by the yeast Candida albicans that is
normally found in women during their
childbearing years.
Normally the lactobacilli (lactic acid producing
bacteria) keep the level of Candida low
Candida are “opportunistic” pathogens
Predisposition Factors for Yeast
Infections
Things that change the pH of the vagina such as
birth control pills, pregancy, use of broad
spectrum antibiotics, diabetes mellitus or
sometimes it is sexually transmitted.
 HIV infected individuals usually have frequent
yeast infections
(both vaginally or
orally as in thrush)
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Treatment
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Oral and vaginal over the counter treatments are
effective
Recurrent infections should be seen by a
physician to rule of HIV or other
immunocompromised complications
Yeast infections rarely cause serious pathology,
though in immunocompromised individuals they
could lead to a fatal bloodstream infection
Prevention
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If taking oral antibiotics you may also treat
prophylatically for yeast infection
Eat a lot of yogurt of other lactobacillus (live)
infused foods.