Immunology Flashcards
How does Staphylococcus appear?
Gram +ve cocci in clusters
How does Staph grow?
Aerobic and facultatively anaerobic
What are the 2 important kinds of staph?
1) Coagulase +ve [only staph aureus]
2) Coagulase -ve [staph. epidermis, staph. saprophyticus etc
What colour is Staph Aureus when grown on agar?
Golden
What colour is staph coagulase -ve when grown of agar?
White
Staph aureus produced coagulase, what does this do to the body?
Clots plasma
What toxins can staph aureus produce?
Enterotxoin
Staph scolded skin syndrome toxin (SSST)
Panton Valentine Leukocidin (PVL)
What infection does staph -ve coagulase usually cause?
Infections associated with artificial material in the body e.g. artificial joint, artificial heart valves, intravenous catheters
What makes it hard for antibiotics to get rid of staph -ve coagulase bacteria?
The bacteria produced a biofilm (a slime)
What does Staph. Saprophyticus commonly cause?
UTI in females of child bearing age
How does Streptococcus appear?
Grame +ve cocci in chains
In what environment does strep grow?
Aerobically and facultatively anaerobically
How are different kinds of strep classified?
Haemolysis of blood agar
What is alpha haemolysis?
Partial haemoysis
What is beta haemolysis?
Complete haemolysis
What is gammae haemolysis?
No haemolysis
What are the two groups of beta haemolytic strep?
Group A (sore throats, severe skin infections -strep pyogens) Group B (neonate meningitis)
What are the two important categories of alpha haemolytic strep?
Strep pneumoniae (commonest cause of pneumonia) Strep Viridans (commensals of mouth, throat, vagina, rarely causes infection)
What are the bacteria associated with gamma haemolytic strep?
Enterococcus species (E. faecalis, E. Faecium) Commensels of bowel and cause UTIs
What are the competitive bacterial flora of the skin?
Staph Epidermidis
Corynebacterium Sp.
Proprionbacterium Sp.
What skin infections does Staph Aureus cause?
Cellulitis Infected eczema Impetigo Wound infection Staphylococcal scalded skin syndrome
What infections does Strep Pyogens cause?
Infected eczema Impetigo Cellulitis Erysipelas Necrotisisng Faciitis
What is Erysipelas?
Infection of the upper dermis and superficial lymphatics
What antibiotics used to treat staph aureus?
Flucloxacillin
What antibiotic used to treat Strep. Pyogens?
Penecillin
Treatment for necrotising faciitis?
Surgical debribement
Antibiotics
What are the 2 types of Necrotising Faciitis?
Tpye 1: Mixed anaerobes and coliforms, usually post abdo surgery
Type 2; Group A strep Infection
When would you take swabs of a leg ulcer?
If there were signs of infection e.g. cellulitis
What is the stererotypical appearance of fungal infection?
two ringed target
What tissue does Dermatophytes infect?
Keratin
What dermatophyte most commonly affects children scalps?
Ring worm
What dermatophyte infection is caught from humans?
Anthropophilic fungi
What dermatophyte infection is caught from animals?
Zoophilic fungi
What dermatophyte infection is caught from soil?
Geophilic fungi
What is the most common humanly transmitted fungal infection?
Trichophyton rubrum
What is the second most common humanly transmitted fungal infection?
Trichophyton Mentagraphytes
What is the most common animal transmitted fungal infection?
Microsporum fungi
How to diagnose fungal infections?
Clinical appearance Woods light (fluroescence) Skin scrapings, nail clippings, hair send to lab in a "dermapack"
How to treat fungal infection of small skin area/nails?
Clotrimazole cream
Topical nail pain (amorolfine)
What kind of areas on the body does candid infect?
warm and moist areas e.g.
Under breast, groin, abdominal skin folds, nappy area in babies
How to diagnose candida?
Swab
Treatment for candida?
Clotrimazole cream
Fluconazole oral
What parasite caused “scabies”?
Sarcoptes Scabiei
What is the incubation period for scabies?
6 weeks
Where does scabies affect on the body?
finger webs, wrists, genital area
Scabies treatment?
Malathion lotion - applied over night to whole body and washed off in the morning Benzyl Benzoate (avoid in children)
What parasite is the head louse?
Pediculus capitis
What parasite is the body louse?
Pediculus corporis
What disease is caused by Pediculus Corporis?
Vegabond’s disease
What parasite is the genital louse?
Phthirus pubis
What is the treatments for head, body and genital louse?
Malathion
What infections cause a patient to be in isolation?
Group A strep
MRSA
Scabies
What is xeroderma pigmentosum?
a rare hereditary defect of the enzyme system that repairs DNA after damage from ultraviolet rays, resulting in extreme sensitivity to sunlight and a tendency to develop skin cancer.
Is xeroderma pigmentosum, which nucleotide is defective?
7
What age does xeroderma pigmentosum have its onset?
8
With xeroderma pigmentosum you have an increased photosensitivty, what skin damage does this cause?
BCC SCC AKs Melanomas Fibrosarcomas
What are the signs of Solar Photosensitivty?
At the age of only 2 patients starts to show symptoms: Burn to the slightest sunlight Solar lentigines Dryness Atrophy Telangiectases Actinic Keratoses Produce skin cancers
What is Nevoid BCC Syndrome?
Also known as Gorlin Syndrome. hereditary condition characterized by multiple basal cell skin cancers.
Symptoms and Signs of Nevoid BCC Syndrome?
Early onset multiple BCCs Plamar pits Jaw cysts Ectopic calcification falx Skeletal abnormalities OFC >97th centile Cardiac/ovarian fibroma Medulloblastoma
What is the most common skin cancer?
BCC
How do BCCs present?
Painful, slow growing lumps or non-healing ulcers
What is another word for a BCC?
Rodent ulcer