C-10 concept map Flashcards
Staphylococcus aureus
diseases caused: Folliculitis (furuncles, carbuncles, styes, pimples); MRSA, Scalded Skin Syndrome, Impetigo
gm+
virulence: Adehsins, lipase, catalase, slime layer, coagulase, hyaluronidase, cytolytic toxins and enzymes, beta-lactamase. SSSS – exfoliative toxin
transmission: direct, indirect, endogenous
signs:
- Impetigo: crusty superficial blisters
- Folliculitis: red swelling with pus
- SSSS: peeling skin
diagnosis: clinical exam, culture, staph is catalase positive
treatment: Macrolides, Tetracyclines, aminoglycosides, semi-synthetic beta-lactams
prevention: cover wounds, wash hands
Staphylococcus epidermidis
- not disease causing
- gm+
- makes adhesions, lipase, catalase, slime layer
- coagulase negative
Streptococcus pyogenes
diseases caused: Impetigo, erysipelas, necrotizing fasciitis
gm+
virulence: Adhesins (M protein), capsule, pyrogenic toxins. Necrotizing fasciitis – toxins like streptolysin S and enzymes like hyaluronidase, streptokinase, DNase
transmission: endogenous, direct, indirect
signs:
- Impetigo: crusty superficial blisters
- Erysipelas: deep, red rash with clear margin
- Necrotizing fasciitis: red, swollen, and black dying tissue
diagnosis: clinical exam, culture, strep is catalase negative
treatment:
- Penicillin or macrolides
- NF: IV macrolide (clindamycin) plus penicillin / removal of dead tissue
prevention: cover wounds, wash hands
Clostridium perfringens
causes: gas gangrene
gm+
virulence: Adhesins, endospores, fast generation time, 17 cytolytic toxins (alpha toxin and perfringolysin O)
transmission: Introduction of endospores from trauma or deep wounds (anaerobes)
signs: Black/purple necrotic tissue with gas bubbles, sickly odor, low BP, high HR
diagnosis: clinical exam, culturing, imaging (gas in tissues)
treatment: IV beta-lactam (penicillin) plus macrolide (clindamycin)
prevention: clean wounds
Pseudomonas aeruginosa
causes: burn infections
gm-
virulence: Adhesins, capsule, cytolytic enzymes, endotoxin, exotoxins, and pyocyanin, highly drug resistant
transmission: direct, indirect
signs: Green pigmentation - fruity smell
diagnosis: clinical exam, culture (Kirby-assay test)
treatment: Beta-lactam or aminoglycosides
prevention: housekeeping with burn patients, hand hygiene
propionibacterium (Cutibacterium) acnes
causes: acne
gm+
virulence: adhesions, lipase, hyaluronidase
tranmission: endogenous
signs: Swollen, inflamed sebaceous glands – papules, pustules, nodules, and cysts
diagnosis: clinical exam
treatment: Tetracycline or macrolide (clindamycin), hormonal birth control, isotretinoin, spironolactone, topicals
prevention: Decrease oil production with hormone or dietary interventions
Candida albicans
causes: yeast infections
virulence: adhesions, dimorphism
transmission: endogenous
signs: patchy rash with redness and intense itching
diagnosis: clinical exam, KOH and microscopy
treatment: azoles or polyenes
prevent: keep skin dry and wear breathable garments
tinea
causes: ringworm/athletes foot
virulence: adhesions, dimorphism
transmission: direct or indirect
signs: red, itchy skin, some scaling
diagnosis: Clinical exam; KOH and microscopy
treatment: Azoles or polyenes
prevention: keep skin dry and clean, avoid contact with active infection
Varicella-Zoster Virus (VZV)
causes: Chickenpox and Shingles
virulence: adhesions
transmission: Direct contact with fluid from vesicles; respiratory droplets
signs:
- Chickenpox: Fever, itchy fluid-filled lesions on face, trunk, and limbs
- Shingles: Painful, burning red lesions
diagnosis: Clinical exam, PCR, or serological tests
treatment: Managing symptoms, acyclovir
prevention: Attenuated VZV or MMRV vaccine
Measles Virus AKA Rubeola
causes: measles
virulence: Adhesins, syncytia, immune amnesia
transmission: Respiratory droplets/aerosols
signs: Fever, sore throat, widespread rash, Koplik’s spots on oral mucosa
diagnosis: Clinical exam, PCR, or serological tests
treatment: Managing symptoms, post-exposure prophylaxis
prevention: Attenuated MMR or MMRV vaccine
Rubella Virus AKA German Measles
causes: rubella
virulence: adhesions
transmission: Respiratory droplets/aerosols
signs: Fever, swollen lymph nodes, sometimes widespread rash. Congenital Rubella Syndrome
diagnosis: Clinical exam, serological tests
treatment: Managing symptoms
prevention: Attenuated MMR or MMRV vaccine
Papillomaviruses
causes: warts
virulence: Adhesins, oncoproteins E6 and E7 (disrupts cell cycle)
transmission: direct or indirect
signs: Appearance of textured growths – usually on hands or feet
diagnosis: clinical exam, PCR
treatment: removal
prevention: Cancer and genital wart-causing HPVs are vaccine preventable not common warts
Herpes Simplex Virus-1 (HSV-1)
causes: Herpes (mainly cold
sores, whitlow)
virulence: Adhesins, syncytia
transmission: Direct contact
signs: Watery lesions on skin;
typically around the mouth (cold sores) or on hands (whitlow)
diagnosis: Clinical exam, PCR
treatment: Acyclovir
prevention: No vaccine
Herpes Simplex Virus-2 (HSV-2)
causes: Herpes (mainly genital herpes)
virulence: Adhesins, syncytia
transmission: direct contact
signs: Watery lesions on genitals
diagnosis: Clinical exam, PCR
treatment: Acyclovir
prevention: no vaccine
