micro skin intro Flashcards Preview

Micro > micro skin intro > Flashcards

Flashcards in micro skin intro Deck (41)
Loading flashcards...
1
Q

skin normal flora:

skin pathogens:

A

Propionibacterium acnes.
diphtheroids.
coagulase-negative staphylococci.

P. aeruginosa in axilla, perineum

2
Q

Nail or nail bed lesions

A

Distal subungual onychomycosis.
White superficial onychomycosis (Leukonychia mycotica).
Proximal subungual onychomycosis found in patients with

3
Q

Agents of Nail or nail bed infections

A

Half caused by fungi.
Tinea unguium (Onychomycosis) Ringworm of the nails: Trichophyton rubrum and
T. metagrophytes account for 90% of dermatophytic nail infections, Epidermophyton
no hair the remainder

Paronychial or onychomycotic candidosis/ Candidal onychomycosis (NOT a
dermatophytic manifestation) Candida sp./C. albicans.

GNR (esp. P. aeruginosa).

4
Q

agents of Stratum Cornium (color change) infection

A

Pityriasis versicolor/Tinea versicolor:
Malassezia furfur
Hortaea (Exophiala) werneckii

5
Q

agents of Keratin Layer infections

A

(Highly variable; papulosquamous to vesicular):
Ringworm/Dermatophyte fungi:
Microsporum, Epidermophyton, Trichophyton

6
Q

Agents of Epidermis Including Hair and Sebaceous Gland infections

A

Maculopapular which may become  vesicular:

  • Erythema infectiosum: Parvovirus B19,
  • Exanthem subitum: HHV6, HHV7,
  • Measles/Rubeola: rubeola/measles virus
  • 3-day Measles/Rubella: rubella virus
  • Enteroviral infections: ECHOvirus (enteric cytopathic human orphan virus – many [31] serotypes);Coxsackie viruses (A and B - many [30] serotypes;) Enteroviruses 68- 71
  • Karposi sarcoma: HHV-8,
  • Chicken pox-Shingles: Varicella zoster virus (HHV3)
7
Q

MORE Agents of Epidermis Including Hair and Sebaceous Gland infections

A
  • Cold Sores: HSV-1 and 2
  • Scarlet fever: Streptococcus pyogenes,
  • Bullous impetigo: Staphylococcus aureus
  • Epidemic impetigo: (Staphylococcus aureus, Streptococcus pyogenes)
  • Dermatomycosis: Cutaneous Candidiasis
8
Q

Agents of Hair Endothrix or Ectothrix infections

A
  • White Piedra: Trichosporon biegelii resembles nits and lice- Ectothrix
  • Tinea capitis: Microsporum and Trichophyton spp.- Ectothrix
  • Black Piedra: Piedra hortai (resembles endothrix of Trichophyton)
  • Tinea favosa: Trichophyton – endothrix.
9
Q

agents of Hair and face (bearded areas of face) infections

A
Tinea barbae (Barber’ s itch): anthropophilic strains of Trichophyton rubrum and zoophilic strains of T. mentagrophytes or T. verrucosum
Microsporum, Epidermophyton
10
Q

agents of Hair and scalp infections

A

Tinea capitis (Ringworm of the scalp and hair): Microsporum or Trichophyton species. M. audouinii and M. canis are responsible for most infections in US.

11
Q

agents of Hair and scalp or Hair and glabrous skin infections

A

Tinea favosa (Honeycomb ringworm) T. schoenleinii.

12
Q

Dermis: Lymphatic infections

A

Cervicofacial lymphadenitis in children (Mycobacterium haemophilum).
Erysipelas (Streptococcus pyogenes)
Sporotrichosis (Sporothrix schenckii)
Onchocerciasis, or River Blindness (Onchocerca volvulus)

13
Q

agents of Hair follicle and sebaceous gland with surrounding tissue (Pustular lesions) infections

A

Acne vulgaris - inflammatory: Propionibacterium acnes
Folliculitis (Superficial infection of individual hair follicle and apocrine regions): S. aureus, GNR, M. furfur
Furuncles( boils): S. aureus
Carbuncles: S. aureus
Small Pox: Variola major virus
Tinea barbae: Microsporum, Epidermophyton, Trichophyton

14
Q

agents of Subcutaneous fat and tissue infection

A

Cellulitis: bacteria, fungi, viruses
Ecthyma: B-hemolytic Streptococcus pyogenes
Erysipelas: B-hemolytic Streptococcus pyogenes
Sporotrichosis: Sporothrix schenckii
Mycetoma: bacteria and fungi [large numbers of various microorganisms are associated
with mycetoma formation including Actinomyces israelii]).
Lobomycosis/Lobo’s Disease: Loboa loboi
Chromoblastomycosis: fungi
Phaeomycotic cysts: over 30 different fungal agents
Onchocerciasis, or River Blindness: Onchocerca volvulus

15
Q

Fascia infections

A

necrotizing fasciitis: S. pyogenes; mixed anaerobic infection, etc.

16
Q

muscle infections: myonecrosis

A

-Gas gangrene/clostridial myonecrosis: Clostridium perfringens, etc.
-Pyomyositis: pyogenic infection of striated muscle with abscess formation: S. aureus
-Trichniosis helminthic infection of striated muscle - Trichinella spiralis.
-Rhabdomyolysis infection of striated muscle: Legionella; pneumococcus,
influenzavirus

17
Q

muscle infections: myopathy

A

Rheumatic fever: an autoimmune disease due to cross-reactive bacterial (GAS) antigens, acute RF can also involve myocardium, not just valves. Second most commonly acquired-heart disease in US children

Kawasaki disease (AKA mucocutaneous lymph node syndrome): an acute vasculitis of infants and young children. Most commonly acquired-heart disease (aortic aneurism) in US children

Infectious Endocarditis

18
Q

Infectious disease of muscle (All are rare): Acute myopathy: viral etiology

A
Influenza virus A, B;
Coxsackieviruses A, B (esp. type B);
HIV;
Human Parvovirus B19,
Parainfluenzavirus
adenovirus
mumps
echoviruses
polio viruses
herpes simplex virus 2
Epstein Barr virus
CMV
Hepatitis A or C.
19
Q

Infectious disease of muscle (All are rare): Acute myopathy: bacterial etiology

A
S. aureus.
Streptococcus pyogenes (GAS).
streptococcal &/or polymicrobic infections.
Clostridia perfringens, type A.
actinomycetes.
MTB.
M. leprae.
Lyme disease.
syphilis.
Legionella.
diphtheria (heart).
20
Q

Infectious disease of muscle (All are rare): Acute myopathy: fungal etiology

A

candidiasis, coccidioidomycosis, sporotrichosis

21
Q

Infectious disease of muscle (All are rare): Acute myopathy: protozoans

A

toxoplasmosis
schistosomiasis
Trypanosoma cruzi and the inflammatory disease of the heart associated with
Chagas’ disease.

22
Q

Infectious disease of muscle (All are rare): Acute myopathy: Helminths

A

Trichinosis - Trichinella spiralis - LEARN,
cysticercosis
echinococcosis.

23
Q

Infectious disease of muscle: pyomyositis

A

abscess formation in striated muscle: S. aureus.

24
Q

Infectious disease of muscle: rhabdomyolysis:

A

a clinical syndrome characterized by muscle pain, release of creatine kinase and myoglobin from muscle caused by:

infection (bacterial, most commonly Legionella spp.; viral, e.g., influenzavirus).
trauma
hyperthermia
ischemia
drugs
toxin,
electrolyte disorders.
25
Q

infections of muscle: Kawaski disease

A

vasculitis

26
Q

infections of muscle: myonecrosis- LEARN

A

monomicrobic:

a. C. perfringens, type A
b. S. aureus
c. GAS

polymicrobic.

27
Q

G- rods (anaerobic bacteria)

A

Aggregatibacter (AKA Actinobacillus actinomycetemcomitans;(obligate anaerobe).
Bacteroides fragilis, ureolyticus, forsythus (obligate anaerobe).
Bilophila wadsworthia (obligate anaerobe).
Fusobacterium spp. (obligate anaerobe long rods with tapered ends).
Pasteurella multocida, pestis.
Porphyromonas gingivalis (obligate anaerobe).
Prevotella intermedia (obligate anaerobe).

28
Q

G- Cell Wall Architecture (anaerobic bacteria)

A

Spirochetes ( internal flagella):

Treponema denticola, T. vincentii (obligate anaerobes)

29
Q

G+ cocci (anaerobic)

A

Enterococcus faecalis, faecium. (cocci in pairs and chains -
aerotolerant anaerobes).

Peptostreptococcus spp. (obligate anaerobic, cocci in chains) Taxonomic validity of
grouping agents anaerobic, cocci in chains in this genus is in doubt.

Streptococci (cocci in chains - aerotolerant anaerobes):

  • Streptococcus agalactiae – Group B strep (GBS),  hemolytic.
  • Streptococcus bovis (GIT streptococci),  hemolytic.
  • Streptococcus mutans, sanguis, salivarius, mitis (oral streptococci).
  • Streptococcus pneumoniae – (lancet shaped diplococci,  hemolytic)
  • Streptococcus pyogenes – Group A strep (GAS),  hemolytic
30
Q

G+ rods

A

Bifidobacterium spp. (obligate anaerobe).
Clostridium species (short rod, anaerobic, spore former[endosores])
a. C. perfringens, type A
b. C. septicum
c. C. noveyi
-Lactobacillus spp. (box-car shaped, aerotolerant anaerobe).
-Gram-positive, thin, branching filaments with clubbed ends (Actinomycetes):
-Clubbed-shaped rod – Propionibacterium acnes (anaerobe).

31
Q

Gram-positive cell wall structure but stain Gram-variableGram-negative:

A

Rods/pleomorphic shapes: Gardnerella vaginalis (obligate anaerobe).

Curved rods: Mobiluncus morphotypes/spp. (obligate anaerobe).

32
Q

risk: Recurrent hospital admissions

A

MRSA

33
Q

risk: Contact sports, recurrent boils/abscesses, visiting certain states in the USA

A

MRSA; MSSA producing Panton-Valentine leukocidin

34
Q

risk: DM

A

MRSA; MSSA; group B streptococci; anaerobes; Gram- negative bacilli

35
Q

risk: neutropenia

A

Gram-negative bacilli; Pseudomonas aeruginosa

36
Q

risk: bite wounds

A

human: Human oral flora (Ekinella)
cat: Pasteurella multocida
dog: Capnocytophaga canimorsus
rat: Streptobacillus moniliformis (also consider tetanus and rabies)

37
Q

risk: animal contact

A

Campylobacter spp.; dermatophyte infection; Bartonella henselae; Francisella tularensis; Bacillus anthracis; Yersinia pestis

38
Q

risk: water exposure

A

Vibrio spp.; Aeromonas hydrophila; Mycobacterium marinum; Ps. aeruginosa

39
Q

risk: reptile contact

A

Salmonella spp.

40
Q

risk: IVDU

A

MRSA; Clostridium botulinum; Clostridium tetani

41
Q

risk: Travel to tropical regions of Africa or America

A

Leishmaniasis; cutaneous larva migrans; myiasis;

Cordylobia anthropophaga; Dermatobia hominis

Decks in Micro Class (61):