Fungi Flashcards
Sabouraud’s agar is used to grow fungi . What kind of media is it
Selective and is mainly used for the isolation of dermatophytes
Name the forms of fungi and the growth characteristic of mounds and yeasts
Yeasts(single cells)
Connecting filaments or hyphae (mounds)
Mounds-grow by lateral branching
Elongation
Yeast-Budding
Classification of fungi that causes diseases . Name em
Yeasts- have oval cells which are mainly unicellular example of true yeast - Cryptococcus neoformans
Yeast like fungi- mostly have round oval cells which bud but may form elongated filamentpus cells Called pseudohyphae which resemble the hyphae of moulds. Example- Candida albicans
Moulds or filamentous fungi- grow as branching filaments called hyphae and form mycelium . Reproduction is asexual thru spores called conidiA example Asperillus fumigatus
Dimorphic fungi- exists as yeasts at 37 degrees(parasitic phase when causing infection) and as moulds at 22 defrees(saprophytic phase in environment)
Example-Histoplasma capsulatum
Name the types of fungal diseases
Hypersensitivity- body’s response to the moulds or spores. An allergic reaction is what causes a disease and not the fungi itself
Mycotoxicoses-poisoning of man by food containing fungi which then produces toxins
Mycetismus- fungi is a toxin. It’s ingested example mushroom poisoning
Infection- tissue invasion with host response
How are fungal diseases diagnosed
- Clinical suspicions (commonest way of diagnosing )
- Microscopy using India ink,wet preparation ( take skin scrapings for this and culture if infection is superficial and if systemic take blood or sputum)
- Culture: Sabouraud’s agar, neutral glucose peptone agar
- Histology: Grocott’s stain
- Antibody/Antigen example Candida precipitins
- Skin tests: example for histoplasma
Fungal conditions are grouped into three name them
Superficial mycosis- these affect hair,skin,nails and mucous membranes they include dermatophytosis and superficial candida infections
Subcutaneous and cutaneous mycosis- most develop from traumatic implantation of a fungi into the subcutaneous tissues example sporotrichosis
Systemic mycosis- spread of fungi in the blood leading to dissemination into many organs. The source may be an initial pulmonary infection. Example is invasive candida infections
Name three genera of dermatophytes
Epidermatophyton : example is Epidermophyton floccosum which affects the skin
Microsporum : example is Microsporum canis and M audouini which causes epidemics of ringworm of the scalp in kids
Trichophyton rubrum : which causes recurrent skin and nails infection
Types of Tinea
Tinea unguium-nails which can cause onychomycosis which can go deep into the nail bed so you don’t give medicine topical but orally else it’ll persist
Tinea corporis-skin
Tinea capitis- Scalp
Tinea cruris-groin
Tinea pedis-feet
Tinea manuum- palms
Ringworm can survive in keratinous material for how long and is it infectious
8months and yes it is
How to diagnose tinea,treatment as well and problems w treatment
Skin scrapings ,nail clippings and infected hair are collected for microscopy and samples can be culture on Sabouraud’s agar
Prevention and treatment: Clotrimazole, ,miconazole which are topical agents and oral agents such as terbinafine,Itraconazole
Name some candida species and what they ar em aptly associated w
Albicans
Glabrata
Tropicalis
And is associated w moist skin,skin folds example under breasts between the groins,nappy rashes and people who keep their hands in water for long but don’t dry in between their fingers
Superficial mycosis on vagina are what kind of pathogens
Opportunistic pathogens
Candida albicans is a commensalism or normal flora in the vagina,mouth,on skin, and git true or false
True
Oral candidiasis or thrush is not normally seen in normal people cuz it is due to very bad hygiene so which people can get it even tho they have good hygiene
HIV or immunocomrpomised people
Pain in throat when swallowing in a patient with thrush means the candida has gone into the the oesophageal tract true or false
True
What are the complications of candida
Chronic disseminated candidiasis this occurs when it goes into the eye,liver ,heart,brain
What re the predisposing factors for overgrowth of yeast like fungi
Diabetes mellitus Malignancy Contraceptive pills HIV Drugs example antibacterial drugs and corticosteroids (which is a dangerous medication if abused),Chronic renal failure,organ transplant
Treatment of candida
Topical agents such as Nystatin gel for oral infections and clotrimazole pessaries for vaginal infections
Itraconazole and Fluconazole are used for severe infections
Cryptococcal pulmonary infection behaves like TB . What are the symptoms of it?
Night sweats Cough Hemoptysis Weight loss Sputum production
Where is cryptococcus neoformans usually found,what can it result in, and what treatment is used for it
An encapsulated true yeast found in nature in soil contaminated with bird droppings and is transmitted by inhalation
It can result in acute pneumonia which can be complicated by dissemination of the fungus into the brains and other organs.
Treatment: use of IV Amphotericin B and in HIV patients it is followed by prophylactic use of Fluconazole which means it may be taken for years
Cryptococcal meningitis is mainly seen among which people
AIDS patients
Asperigillus behaves like asthma but is not asthma true or false
True
Which Aspergillus species usually cause ear infections
A. Niger
Spores of Aspergillus are ubiquitous in nature and more are found in construction sites. Inhalation leads to lung infections and in immunocompromised host can spread to sinuses and other organs which can be life threatening true or false
True
Which forms of Aspergillosis are there
Diffuse lung infection
Fungus ball(aspergilloma)
Allergic bronchopulmonary aspergillosis which mimics bronchial asthma but is not asthma
Invasive aspergillosis
Treatment of Aslergillosis
Treat w anti fungal medicine (Itraconazole,Amphotericin B)and then medicine to open the airways
Pneumocystis jirovecii is an opportunistic pathogen among severely immunocompromised clients true or false and what does it cause
True
It causes atypical pneumonia primarily but dissemination can occur. It can be due to primary infection,reinfection or one of reactivation
It is stage 4 in HIV clients
Treatment of Jirovecii
In HIV clients, use prophylactic co trimoxazole which is preventive for if the person hasn’t gotten it yet and treatment needs pentamidine if the person has gotten it but high dose of co trimoxazole is okay
Jirovecii is treated w antibiotics but is classified as a fungus(yeast ) it is an atypical fungus which is difficult to study.
It’s RNA dOesnt respond to normal antibiotics for pneumonia . It is rapidly fatal .
True or false
True
What is the contraindication for co trimoxazole
People allergic to sulphur can’t take it
Name three drugs taken by HIV patients as a prophylaxis
Ceptrine which is not routinely given
Co trimoxazole
Fluconazole
