Yes, Today, at this very moment, I am typing up something amazing for you to read. Not really… That was a bad joke… wanna hear a worse one?
‘Cuz he’s a fungi!
Get it?… Well down to business.
- More than 70000 species = 300 are pathogens in human and animals
- some are superficial, others are life threatening
- Likes moist conditions
- systemic forms have become a much more serious problem.
Types of Infection:
Superficial Mycoses 1
- fungus grows on body surfaces
- eg: Tinea vericolour and Epidermophyton
Cutaneous Mycoses 2
- fungus grows on body surfaces
- deeper than Superficial Mycoses
- eg: Athlets foot – Tinea pedis, Ringworm – Tinea corporis, Jocks Itch – Tinea cruis
Subcutaneous Mycoses 3
- deeper than Cutaneous and Superficial Mycoses
- Chronic and localized infection of skin
- nails and deeper layers of skin are involved
- Systemic and deep Mycoses – involves internal organs, very strong.
Transmission via inhalation or toxins in food:
- spreads person to person
- animal to human
- via skin penetration
- opportunistic on immune compromised people
- Useful – yeast and mushrooms ( not to mention all this cool stuff : penicillin from a fungus, beer and bread from yeast)
They are classified by:
- the growth – multicellular or single cell
- They type of infection they cause.
Multi cellular – Filamentous (Hyphae) Fungi; form mycelium (moulds) (Live in the environment: outside the body)
Single Cell – Yeast (Live inside the body in humans)
The Study of Fungi is called Mycology.
The study of fungal infections is called Mycoses
Fungus’s are split into two groups. Yeasts and Moulds
- Now there are very few true fungi pathogens.
- Eucaryotic (Different to plants and animals)
- large range of fungi, from single cell yeast to multicellular
- they have no chlorophyll
- they cant photosynthesize and have a cell wall
- They also require an organic source of carbon for growth
- Some fungi are part of the bodies normal flora – but some can cause infection of skin and hair.
All in all fungi play a important role in breaking down organic matter that cant be broken down by bacteria due to their weakness to extreme conditions, but they aren’t all good, they can cause a lot of loss in agriculture and cause a lot of problems for farmers and food spoilage . But again on the plus side, think of beer and all smell of bread… and penicillin, we couldn’t have that, cephalopsorin or cyclosporin without fungi.
They usually take up nutrients directly from host, for example off the skin, or in a Saprophytes case, feeding off dead woody plant materials.
- Single cell
- Oval In shape
- Larger than bacteria
- Contains various sub-cellular organelles
- growth is A-Sexual (Budding)
- Small outgrowth – which gradually extends and eventually separates
Dimophism > ability of fungi to grow in two separate forms, usually filamentous at room temp, but in the body they grow as yeast.
Did someone say Thrush?
Ewww. that’s not cool, should I say Candida albicans?
- Candida albicans is responsible for thrush most commonly and Candida albicans is the most common candida.
- It grows in the body at temp over 28 degrees celcious.
- It often pops up when your immune system is down, or you have just taken a course of antibiotics. The normal flora that would usually stop Candida from popping up. Lets put it simply, Candida is opportunistic, it likes to get you when you are down.
- The colony is white
Candida spp is found in:
- 40%-80% of normal human beings – it can be commensal or pathogenic
Candida can cause:
- Endocarditis in immune compromised hosts.
The treatment for candida
Candida is tested/ diagnosed through the use of germ tubes. But because fungi takes so long to grow it can be harder to identify
Once diagnosed the treatment can be:
For Cutaneous mycose:
- topical Nystain
- Fluconazole (Usually for aids or immune compromised people)
For Systemic Infections (different locations on body):
- Amehotericin B
- Can grow lots of places
- long filaments – called hyphae
- Hyphae can grow by extending terminal cell at tip of filament
- reproduction is via production of spores
- easily inhaled
- a more common human pathogen
- derives from decaying or dead organic matter
- produces spores- easily inhailed- fungus ball forms – can be mistaken for TB in X-rays
- air vents
Patients will usually cough up fungus element. Aggressive tissue invasion, it affects mainly lungs (due to inhalation of spores), but it can invade any organs.
- takes 1-3 weeks for growth
- variety of colours
- species differentiation is based on spore formation; as well as colour and shape.
- Specimen taken of sputum; lung biopsy
*likes a more acid environment.
Harmful Effects of Fungi
- Bronchopulmonary reaction as a result from repeated inhalation of mould spores
- Farmer are at risk to Aspergillus spp
- some fungus produce chemicals that are toxic
- poisonous effect of eating toadstools
- damage to body
- muscle spasms
- death may occur
Aflatoxin – toxin form of Asperillus,
Flavus – grows on grains and peanuts < Carconagenic and Liver cancer.
is difficult to diagnose as it grows slowly
Symptoms aren’t definitive
Fungal infection is suspected if the Patient is immuno compromised
- Drug Therapies – anti neoplastic, Steriods, Immunosuperessive drugs
- Over use will alter the normal flora = fungal overgrowth