Mycoses: Fungal Infections

What are some characteristics of mycoses?

-generally chronic because of the slow growth of fungi

-characterized by tissue involvement

-most slow growing chronic fungi

Why is mycoses hard to treat?

Close relation to animal cells, drugs that affect fungal cells also affect human cells.

Mycoses are classified into 5 groups according to what?

the degree of tissue involvement

-mode of entry into the house

Systemic Mycoses

fungal disease deep within the body

-not found in any particular region

-Inhaled from soil; infection starts in the lungs (can become septic)

-Not spread from human to human

-Histoplasmosis

-Can get into lymphsys, bats and pigeons can carry it.

Histoplasma Capsulatum

Primarily affects the lungs

-usually self-limiting

-may spread (blood, lymph, all organs) with heavy incoulum or immuocompromised patient

-Dimorphic: mold and yeast form

Histoplasmosis is a major killer where?

3rd world countries

Histoplasmosis is limited range in the US. How many deaths per year? In some states, what % of population have antibodies against the disease?

50

-75%

Subcutaneous mycoses

found beneath the skin- parenteral route

-more serious than cutaneous mycosis

-sporothrix- sporotrichosis

-caused by saprobes in soil or on vegetation- usually gardeners, ag workers, farmers

-Starts with lesions on the hands and spreads through lymphatic system

-dimorphic

Cutaneous Mycoses

Affects the hair, epidermis of skin, and nails

-called dermatophytes

-secretes keratinase that degrades keratin

-Transmitted from human to human or animal to human by direct contact

Superficial Mycoses

-localized e.g., hair shafts and surface epidermal cells

Opportunistic Mycoses

-caused by normal microbiota or environmental fungi

-generally harmless but can become pathogenic in a host who is

-traumatized

-immunosuppressed

-on extensive antibiotic treatment

-pneumocystis

-Candida yeast infection

Describe the shape of yeasts

single celled, round or oval fungi

How do yeasts reproduce?

asexual reproduction by budding and fission

Candid, oral thrush:

yeast infection of the mouth

-occurs in infants; antibiotics, mother's birth canal infected, decreased immune function.

-usually opportunistic if immunocompromised

Candida, adult thrush:

immunocompromised, smokers

Vaginal yeasts infections

-discharge, odor, irritation, itching

-associated with antibiotic and oral contraceptive use, pregnancy.

Penecilium

produces penicillin which kills bacteria by disrupting cell wall synthesis.

-named from latin word penicillus, meaning paintbrush, produces condiaspores

-some species are toxic

-some cheeses are ripened with the species and are safe to eat.

Plant diseases appear as what?

-powdery mildews grow on leaves on fruit

-whitish/gray color that spreads quickly

-may be more severe when nitrogen levels are low in the soil

-Diseases are transmitted by vectors mainly

Plant diseases are economically important why?

they destroy crops

-parasitize cereal crops such as wheat, corn, oats, and rye

Plant disease can replace the grain with what?

Ergot

(hard, purple-black bodies made of hyphae)

During bread making, when the rye is ground, the fungus releases a toxic chemical when diseased that causes what?

vomiting, muscle pain, and lesions of hands and feet, hallucinations and hysteria

Diseased plants can contain ________________ which LSD is made from.

Lysergic acid

Lichens

mutually beneficial symbiotic relationship between fungi and algae (or cyanobacteria)

What are the three types of lichens?

Foliose

crustose

fruiticose