Mycology and Virology Study Notes

• These are study notes from a lecture on Mycology and Virology
• The lectures cover general information about fungi and viruses

Introduction to Mycology

• Fungi play both beneficial and harmful roles
• Virulence factors contribute to their ability to cause disease
• The classification of fungi involves yeasts and molds
• Fungal structures include thallus, hyphae, mycelium, and spores

Beneficial activities of fungi

• Food and food production, such as yeast for bread
• Fermentation of alcoholic drinks like beer and wine
• Industrial production of antibiotics (penicillin) and immunosuppressants (cyclosporine)
• Decomposition and nutrient recycling in the environment

Harmful activities of fungi

• Destruction of materials and crops
• Spoilage of stored foods like bread and rice
• Fungal infections, termed mycosis (singular) or mycoses (plural)
• Allergies and the production of mycotoxins that serves as a virulence factor

Fungal Characteristics

• Eukaryotic organisms with a nucleus and other organelles
• Chemotrophic, capable of degrading organic substrates
• Achlorophyllous, dependent on the environment for food
• Exogenous, typically found in the environment
• Rigid cell walls that determine shape, mediate attachment, and activate the complement cascade

Fungal Reproduction

• Can reproduce sexually or asexually, depending on the spore type
• Spores are used for reproduction, but in bacteria, spores are used as a virulence factor

Fungal Virulence Factors

• Opportunistic pathogens causing mycoses
• Enzymes like elastase-serine protease and aspartic acid proteinase
• Toxins that can cause mycotoxicosis
• Catalase and lysine biosynthesis
• All virulence factors are associated with one general infection

Fungi Identification and Classification

• Fungal identification relies on microscopic and macroscopic characteristics
• Monomorphic fungi exist as either yeast or mold, while dimorphic fungi can exist as both
• Anamorph fungi undergo asexual reproduction, and teleomorph fungi undergo sexual reproduction

Fungal structures and terminology

• Thallus is the body of a mold
• Hyphae are long, slender, branching tubes that can be aerial or vegetative
• Mycelium is a filamentous mass of hyphae with hyaline or dematiaceous pigmentation
• Septate hyphae have cross walls, while coenocytic hyphae lack them
• Spores can be asexual (anamorph) or sexual (teleomorph)

Asexual Spores (Anamorph)

• Blastospores are formed through budding
• Chlamydospores are thick-walled and formed within hyphal segments
• Arthrospores are barrel-shaped and formed by fragmentation
• Sporangiospores are enclosed in a sac, while conidiospores do not have a sac

Fungal Nutritional requirements and Phyla

• Nutritionally, fungi thrive in acidic environments with high CHO content
• Key phyla include Zygomycota, Ascomycota, Basidiomycota, and Deuteromycota
• Classification relies on mode of sexual reproduction, phenotypic properties, and phylogenetic relationship

Lab diagnosis of fungi

• It includes specimen collection, direct microscopic examination, and culture
• Direct microscopic examination utilizes methods like Gram stain, KOH or NaOH, and calcofluor white

Types of light microscope

• This can include bright field, dark field, phase contrast, ultraviolet, fluorescence, inverted, interference, and electron microscopes

Superficial mycoses

• Is confined to the outermost layer of skin or hair
• Does not activate inflammatory reaction/ response
• Tinea means worm

Agents of Superficial Mycoses

• Malassezia furfur
• Piedraia hortae
• Trichosporon spp.
• Hortaea werneckii

Malassezia furfur. Clinical Information.

• tinea/ ptyriasis versicolor (Patchy lesions or scaling of varying pigmentation)
• Dandruff (Infection on the scalp/ hair)
• Agent of disseminated infections in patients receiving lipid replacement therapy
• • That usually receives lipid replacement therapy is infant • Endogenous skin colonizer and Non-pathogenic at first, then will be pathogenic

Malassezia furfur. Lab diagnosis

• Specimen: Skin scrapings
• Direct microscopic examination: 10% KOH: Budding yeast with branched septate hyphae

Piedraia hortae. Clinical Information.

• Black Piedra agent • Laboratory Diagnosis
• Specimen: Plucked hair
• Direct microscopic examination: 10-20% кон: thick-walled rhomboid cell with 8 ascospores

Trichosporon spp

• Agent of white piedra
• Site of infection: hairs of the scalp, face, and pubic region
• Lab diagnosis: (specimen: hair)

Hortaea werneckii. Clinical & lab characteristics.

• Agent of Tinea Nigra or Brown to black nonscaly macules
• Site of infection: palms of the hands and soles of the feet
• Lab diagnosis- specimens & diagnostic result. (Skin scrabbling or KOH, microscopic examination of light or dark colony)

Cutaneous mycoses

• Keratinophilic organism
• Adapted to grow on hair, nails, and cutaneous layers of skin that contain the scleroprotein keratin

Classification of agents

• Trichophyton of HEN: (skin, hair, nail
• Microsporum of SN: (skin, hair)
• Epidermophyton (skin, nail)
• The main infections are dermatophte infections

Trichophyton mentagrophytes

• Clinical feature/s
• Lab diagnosis: macro+micro examination

Exophiala dermatitidis & cutaneous mycoses

• Macroscopic examination: Olivaceous to black colonies
• Microscopic examination- Conidia are borne from the tips of annellides
• Agents of cutaneous mycoses has been discussed along all details such as the skin reactions etc

Subcutaneous Mycoses

• Subcutaneous mycoses involves deeper skin layers, muscle, connective tissue, and bone
• Traumatic implantation causes local progressive non-healing ulcers, draining sinus tracts
• Occupation and agricultural workers are agent of infection.
• Includes subcutaneous phaeohyphomycosis, chromomycosis, mycetoma, white/black grain mycetoma
• Lab is by tissue and yeast smear
• Eumycotic means have more types of grain colonies.

Subcutaneous Phaeohyphomycosis

• Is caused by darkly pigmented fungi (phaeoid) of various species

Chromoblastomycosis

• Develops polymorphs
• Have same manifestation
• Use pattern such as shape pigments- Septation , spore type

Lymphocutaneous Sporotrichosis

• Follows/ depends on the site
• Nodule ulcerive along lymphatic chains from traumatum/ primary site.

Dimorphic

• Seen through blood
• Expect different form and molds
• Examine well diff tissue source and mole source

DIMORPH- Exophiala dermatitidis

• Can't need more KOH on the samples that skin rich
• Will know yeast form after rhomboid and ascro spores

Trichophaea spp & Subcut myoses trichoscopy

• Causes a whole host of issues including
• Superfical mycoses

All agents are described by the same as agents of dimor. Also there

• Rhizoid.
• Dematiaceous

Dimorphic

• The lactophenol is bludish and will penatrate the fugul element and the hyphae isn't blue etc

Systematic Mycoses

• Will directly affect the Organ or will deep the to body
• Involves with a direct transplant of an active particle of lung- Traumatic implantation

Blastomyces dermatitidis

• All have yeast and mold There are same manifestation and culture aspect

Coocidiodes immites

• Agent of clinical signs- self limiting infections etc. Specimens collect of both secretions from test, fluids, both with direst micro exam
• Is direct Non-budget, thick walled sphverves and it's granular material (tissue form)
• Have similar culture- dimorph but also have different culture media
• All under this causes are also have systemic infaction etc

Systemic Myses

• Involve muscle and deepers organ
• In Direct Micro Exam or in Histopathological Stains.

Important Systematic Mycoses

• Paracoccidiodes brasiliensis agent
• All similar test and reaction

Laboratory examinations

• Is by site infection, it is different and to identify this

Dimorphic - penicilium - only when a marbeffi

• All will have culture, micro and macro testing

Subculture method

• It is essential depending on the source of infection
• Different test in short span

Opportunistic Myoses

• Not under that classifications but are based on infection. It's more for people- Human
• Curnenghamella SPP release to sinuses
• Mucor spp have similar causes

Septa are

• Are what allow Hyolione
• Are are associated with what have pigment

Agents of Yest.

• Are candidiasis - and what test are used and needed to check results and diagnostic Also how to culture for results

Agents of Aspercillus

• The second-most after
• What is needed to replicate normal flora

Lesson 13 : introductions and agents

• Hyalione or Pigments (Dematescous)
• That can use two type to get all bacteria under one light

dimorphism

• Dimorphism, as in test must get well test

Dimorphism.

• Can be done by spec and the way the are tested
• Can also be done thru specific testing (specialised)

What is and how does uvl , etc work

• Undergo 3 basic and have the correct form and testing

What has been learn

• M and S also
• More so the agents that has the best and high qualities

Viris

• are acellular, very small, has protein, structural
• Is only in host. (All depends one, no cellular. etc(
• can provide own cells 1 . nuculeic acid + enzmes)

2. only nucleic acids , cells, etc

Characteristics of the tests conducted as well

• the structure of where icosahedral
• shape are used, etc
• Replication is dependent on genomes

Morp types

• envelope,
• Is the outer layer

Complex virus or what may call

• depends to some sort depend to host cell as they can't do anything by themeslft

Repro or virus

• all are what has to do
• to produce or do they want and need the things to be in (etc etc etc) cell process or steps

Determinations needed

• protection
• From to do it

Envolpe

• during has they're of functions
• sensitivity to itters

classifications

• how that's done
• With what the "spices are is how types are looked

Ultra violite type of. Tests

• these may have to do with in each test at

14 Super fical

• this may have and know all testing to work best thru time
• What test are done if test and test can't use. , what you need is what make up a good test is

what is and how that come in

• the type, the test and much needed for test to what know will good to work
• in 14, more info to look into with 3 basic and with more

Virs

• charactetized- and much know and it's functions are

Lessaon or tests that look for

• virus like and how it all work plus 1 and how has to do
• m and with that, more insight to know what needs to be and how is used.
• m does what look for, what it does and can only help but

General characteristics - to to

• it had with that or what type is with this type
• have have or or or
• to the best and better way too look so if do you with that type too

How is treat by with and test

• type are needed and done thru the the time line to work with so can get you better look so you now what to do.

What all do?

• test, , charactize and all with more info and best more then with all tests needed to best used. etc

How to best remember

• Just with much help to what you need and the test plus help too with m & m

General and treat

• best you know just with it's type
• m
• m and how they to and the tests for them.