-
Moist areas
increased numbers of bacteria than dry areas
-
Defensins
antibiotics produced by human skin
-
Secretions:
sebum and perspiration
-
Normal Microbiota
- gram + cocci and coagulase -
- staph epidermididis (main organism surrounding skin)
- propion bacteria (metabolizes oily secretions)
- malascezia furfur (grow on oils-may be cause of dandruff)
-
S. Aureus
- Coagulase +
- 20% of people always have S. aureus in their nasal cavities
- 60% sometimes have it
MRSA
-
Impetiga
- highly contagious in children 2-5 years old
- caused by s. aureus
-
Folliculitis
- inflammation of hair follicle
- caused by s. aureus
- if on eyelash called sty
-
Furnicle
- boil
- type of absess caused by s. aureus
-
Toxic Shock Syndrome
- caused by s. aureus
- potentially life threatening
-
Streptococcal Skin Infections Classifications
classified by hemolytic enzymes, alpha, beta, gamma or cell wall antigens
-
S. pyogenes
- main pathogen
- beta hemolytic
- completely lyses RBCs
- caused by strep
-
-
M Protein, erythrogenic toxin, deoxyribonuclease, streptokinase, hyaluronidase
- severe and rapid tissue destruction
- necrotizing faciitis
- 15,000 cases per year
- 40% mortalitiy
- caused by strep
-
Spyogenes
- serious if it gets into dermis
- caused by strep
-
Pseudomonads
Gram - rods found in soil and water
-
Pseudomonads dermatitis
- 2 weeks self limiting rash
- bacterial
-
Pseudomonads aeruginoa
- produces endo and exotoxins
- causes otis externa, respiratiory infections, burn infections and dermatitis (blue/green pus)
- bacteria
-
Buruli Ulcer
- bacterial
- found in west and central Africa and Mexico, S. America and Austraila
- very deep ulcer thats very damaging
-
Acne
- 85% of teenagers (17 million in US)
- propion bacterium acnes (oils/hormones)
- bacterial
-
Warts
- papillomavirus
- direct contact
- can be removed chemically or physically
- virus
-
Small Pox
- In middle ages 80% of Europe contracted small pox
- 20% mortality rate
- Transmitted by respiratory droplets
- Vaccination has erradicated this disease
-
Chicken Pox and Shingles
- varicella and herpes zoster
- vesicular rash
- can remain latent for life
-
Herpes Simplex
- cold sores, occassionaly encephilitis
- lysogenic (remains dormant)
- transmitted orally or respiratiory
-
Measles
- Respiratory transmission
- Spots
- Very dangerous to infants and old people
- vaccination works 95% and gives long term immunity
- virus
-
-
Rubella
- german measles
- much milder
- can be asymptomatic
- virus
-
Cutaneous Mycoses
- can grow on keratin containing surfaces (skin, hair nails)
- ringworm
- athletes foot
- fungi
-
Subcutaneous Mycoses
- through wound (below epidermidis)
- soil fungus: sporotrichosis
-
Candidiases
- Candida albicans (thrush, vaginitis)
- oppurtunistic
- fungal
-
Scabies
- Mites
- 500,000 people per year in US
- treated with permethrin
-
Pediculosis
- Lice
- different areas of body are different strains
-
Conjunctivitis
- Red eye
- haemophilus influenza or adenovirus
- causes can also include allergies or improperlly disinfected contact lenses
-
Ophthalmia Neonatorum
- neisseria gonorrhoea given to infant from mother during childbirth
- big cause of blindness
- silver nitrate replaced by antibiotics at birth
-
Inclusion Conjnctiviits
chlamydia trachomatis
-
Trachoma
- scar tissue
- c. trachamati
- transmission by hands, fomites and maybe flies
-
Bacterial Meningitis
over 50 species of opportunistic bacteria
-
Types of Bacterial Meningitis
- 1) Haemophilus Influenza
- 2) Neisseira meningitis
- 3) Streptococcs pneumonia
-
Haemophilus Influenza
- bacterial meningitis
- part of normal throat microbiota but causes disease if it enters blood stream
- Mortality rate: 6%
- causes 45% of meningitis cases
- gram negative
-
Neisseria Meningitis
- bacterial meningitis
- found in throats of healthy carriers but causes disease when gets into blood
- often affects college students
- Mortality rate: 9-12% with treatment, 80% without
- gram negative
-
Streptococcus pneumonia
- bacterial meningitis
- most commonly found in nasopharynx
- Mortality rate: 30% in children, 80% in elderly
- gram positive
-
Meningitis diagnostic tests
- Gram stain
- cultures
- serological tests
-
Listeriosis
- Listeria monocytogenes
- causes meningitis in newborns, pregnant women and cancer patients
- ingestion of contaminated food (deli meats)
- can cross placenta and cause still births
- 50% overall
- 60% infant rate
-
Tetanus
- Clostridium tetanii
- produces neurotoxin (tetanospasmin) which casues spasms of muscles
- Immunization/booster available every 10 years
-
Botulism
- Clostridium botulinum
- difficulty speaking/blurred vision
- death in 1-10 days
-
Infant botulism
- from babies being fed honey or canned foods too early
- causes SIDS
-
Wound Botulism
- rare
- if spores get deep into wound where little O2 is found it can cause tissue death
-
Leprosy
- Mycobacterium Leprae
- Tuberculoid form: loss of sensation in skin nodules
- Lepromatous form: many diisseminated nodules and tissue death occurs
- leads to death from secondary bacterial infections
- Diagnosis: acid fast skin biopsy
- Treatment: sulfone drugs
-
Sepsis
infection of blood
-
Gram - Sepsis
- usually endotoxin
- leads to very low blood pressure
- bacterial
-
Gram + Sepsis
- puperal sepsis: causes disease in unsanitary childbirth conditions
- Antibody resistant enterococci
- Group B streptococcus
-
Diseases that directly damage heart tissue
- Alphahemolytic strep
- S. Aureus
- Enterococci
-
Rheumatic Fever
- S. pyogenes
- immune system produces antibodies agaginst antigens that cause symptoms
- starts as sore throat and moves to blood stream
-
Tularemia
- francisella tularensis
- rabbits and other mammals
- pneumonia and septiciemia
- 30% mortality
-
Brucellosis
- B. suis/B. abortus/B. melitensis
- enters through tiny break in skin and moves rapidly to liver, spleen and mone marrow
- reproduces in macrophages
- fever at night
- most common zoonosis
-
Anthrax
- bacillus anthracis
- kills you when in blood stream
- Cutaneous: through break in skin 20% MR
- GI: Least common. 50% MR
- Inhalation: terrorists 100% MR
-
Gangrene
- Clostriduim perfringes
- soft tissue death from loss of blood supply
- anaerobic
- produces CO2
-
Cat Scratch Disease
- yersinia
- pasteruella multocida
- bartonella henselae
found in cat saliva
-
Rat Bite Fever
Streptobacillus monilliformis
-
Plague
- yersinia pestis
- flea bites
- killed 2/3 of Europe in middle ages
-
Lyme Disease
- Barrelia Burgdorferi
- ticks
- field mice are animal resivoir
- controlled by poison cottonballs
-
-
Typhus
- Rickettsia
- Spread by arthropod vectors
- 1) Rocky Mountain Spotted Fever (ticks)
- 2) Epidemic thypus (louse)
- 3) Endemic murine thyphus (rodents)
-
Burkitts Lymphoma
- Epstein Barr Virus
- oppurtunsitc
- oncogenic virus (can cause tumors in jaw or GI)
-
Cytomegalovirus
- very large herpes virus
- transmitted by saliva and other fluids
- can be asymptomatic, mild or fatal
-
Chickungunya Fever
- Viral
- high fever, extreme joint pain
- Aegypti mosquito
-
Yellow Fever
- yellow fever virus
- aedes agegypti mosquito
- fever, chills, headache, nausea, jaundice
- 20% MR
- Monkeys natural resiovoir
-
Dengue Fever
- Dengue Fever Virus
- aedes aegypti mosquito
- endemic in tropical place
- fever, muscle/joint pain and rash
can cause death in children in hours (leading cause of child death in SE Asia)
-
Emerging Viral Hemorrhagic Fevers
- Marburg Virus
- Lassa Fever
- Ebola
- Argentine and Bolivian hemorrhagic fever
- Hanta Virus
-
Chagas Disease
- Trypanosoma cruzi
- transmission from bite of kissing bug
-
Toxoplasmosis cased by Toxoplasma gondii
- Definiteve Host: domesticated cat
- Shed in feces or by undercooked meat
- dangerous for pregnant women (kitty litter)
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