germ theory and history mycology

germ theory of disease

• accepted theory explaining the cause of infectious diseases

• specific pathogens “germs” are the root cause of specific infectious illnesses

Louis Pasteur

• showed that fermentation and putrefaction are caused by organisms in the air, his experiments disproved the idea of spontaneous generation and provided evidence they reproduce

• precursor to joesph lister antiseptic surgery

• proposed pasteurization

• four vaccines

• established the theory itself

joseph lister

• in glasgow, surgeon made carbolic acid spray during one of his first antiseptic operations circa 1865

• based on pasteur he though to sanitize the air and make a chemical barrier

koch postulates

• conclusively established that a particular bacterium could cause a specific disease

  • koch infected mice with blood from anthrax-stricken cows, the mice also developed anthrax

  • these criteria are known as koch’s postulates and are still used today, postulate 3 the disease must be reproduced when a pure culture is inoculated into a healthy, susceptible host

what doesn’t work with koch’s postulate

• viral diseases because they weren’t known yet

  • didn’t work with HIV/ AIDS

louis pasteur in the usual history of the germ theory of disease

• 1865 he demonstratd that spoilage of wine was due to abnormal microorganisms then asked french gov to study pebrine a disease of silk worms and showed it was caused by a protozoan

robert koch in the usual history of the germ theory of disease

• rival of pasteur raced to find the cause of anthrax disease of sheep and cattle, first to show bacterial agent to be pathogen

  • used criteria suggested by his teacher, henle, now the postulates criteria by which a bacterium may be said to cause a disease

agostino bassi

• was a pioneer italian microbiologist preceded pasteur by ten years

• discovered muscardine ins silk worms whch is a microscopic parasitic fungus

• in 1844 proposed the hypothesis that not only insect disease but human diseases are caused by living microrganisms too

medical mycology and how many fungal pathogens infect humans

• study of infectious diseases caused by fungi that occur in humans

• 150 fungi cause human diseases, and they need to grow at human body temp 37C

mycoses

• fungal infections are called mycoses

mycetoma

“madura foot” but not always on a foot

• it is an example of a single disease caused by several different organisms

  • actinomycetes former fungi and some filamentous fungi (eumycetoma) can cause disease

• chronic tropical disease that is neglected

• progresses slowly and it generally painless until its really progressed

thrush and favus

• mentioned in hippocratic writings 5th century bce

• “porrigo'“ is obselete nonspecific term for any dermopathy of the scalp

• favus: honeycomb psutules on someone’s head

  • it lowk couldve been confused for leprosy

ringworm

• fungal infection of the keratinized layer of the skin or of the hair or nails in some forms manifesting itself as circular patches

• tineas = MALASSEZIA

who are the two fathers of medical mycology

1. david gruby

2. raymond sabouraud

Gruby - father of mycology 1

• demonstrated favus is caused by a fungus by growing it on slices of potatoes and carrying out inoculation experiments on healthy tissues

• this experiment demonstrated for the first time that a microorganism was the cause of human disease

• he also found sycosis barbae which is that beard disease

• he aksi foudh microsporum audouni which makes tinea or ringworm aka gruby’s disease

raymond sabourad 1864-1938 - father of mycology

sabourad’s medium!

• low PH and high concetration of sugar in agar, can b gel or liquid which is still used today most universally

specialized in dermatology and mycology and was also an accomplished painter and sculptor

how does media affect fungus

• every media leads to a different morphology

where is the suffix “ome”

• molelcular biologist use ome as a suffic to refer to a totality of some sort, but it is used two ways

  • microbiome

  • genome

microbiome definition

• usually conducted by isolating nucleic acids from a sample not by isolating the organisms

• refers from everything in the environment but aso the combined genetic materials of the microorganisms in a particular environment

• microbiome = bacteriome + mycobiome

internal transcribed spacer ITS in fungi

• highly diverse in fungi in sequencea dnd lengths

• usually different enough to clasify fungi

mycobiota in gut

only 0.1% but they are large cells

biofilms

• make eps matrix and all microrganisms

dysbiosis

refers to any icrobial imbalance in or on the body sites includng the gastrointestinal tract the skin and exposed mucosal surfaces such as the lungs vagina or mouth

• thrush with candida

genus candida

• 200 species, but six are mostly commonly associated with human infection

• most ommon cause of human fungal infections

• opportunistic pathogens, can me mucosal or systemic infections

  • yeast spreads easily, and the filamentous form can penetrate easy

• dimorphic