Lecture 5 Flashcards
What does “staphyle” mean in Greek?
bunch of grapes
What does coccus mean in latin?
berry-shaped
What are characteristics of staphylococcus?
gram+, grape-like morphology, 1 µm in diameter, resitant to drying, no endospores, catalase+
Where is staphylococcus found?
human microbiota
How many different diseases can staphylococcus bacteria cause?
many different diseases = produce many toxins
About how many different staphylococcus species are there and which 3 do we need to know?
~40; S. aureus, S, epidermidis, S. saprophyticus
What does “aureus” mean?
golden
What does “epidermidis” mean?
outer skin
What does “sapros” and “phyton” mean?
rotten and plant
Which type of bacteria tend to be more resistant to dry conditions?
gram+
What is the best way to differentiate between a staphylococcus and a streptococcus?
catalase test; streptococcus = negative
What does “toxinoses” mean?
damage caused by an exotoxin
What diseases does S.aureus cause?
septicemia, bacteremia and different diseases depending on the site
What diseases does S. epidermidis cause?
endocarditis, implant-related inections
What disease does S. saprophyticus cause?
UTI
Which of the 3 staphylococcus species is resistant to novobiocin?
S. saprophyticus
Which of the 3 staphylococcus species is susceptible to novobiocin but is negative for coagulase?
S. epidermidis
Which of the 3 staphylococcus species has a yellow colony color?
S. aureus
When was S. aureus first identified?
1880
What are some characteristics of S. aureus?
non-motile, survives on fomites, found in 30% healthy people, can be transmitted via aerosols or direct contact
Where on the human microbiota would you find S. aureus?
nose and skin
What is the “main reservoir”?
human microbiota
What are the types of diseases caused by S. aureus?
impetigo/boils/scalded skin syndrome; abscess; TSS (toxic shock syndrome); scepticemia, pneumonia, food-bourne illness, bone infection, plastic implants infection
What are some examples of S.aureus mediated diseases?
eye stye; bacterial infection after surgery; wound infections (from WWII)
What is the Ritter disease?
Staphylococcal Scalded Skin Syndrome || condition that has to do with the skin, exfoliative dermatitis
In what patients is Ritter disease common in?
kids and immuno-compromised adults
How does the Ritter disease begin to proliferate?
site of infection dictates where the bacteria entered the host
What is the mortality rate of this disease?
less that 5% kids and about 60% in immuno-compromised adults
What are the 2 types of Ritter disease?
generalized (all over) and localized (bullus impetigo)
What is exfoliative dermatitis?
redness/inflammation around mouth = spreads throughout body and blisters
What is the recovery time for Ritter’s disease?
7-10 days
What toxin causes Ritter disease?
exfoliative toxins (ETA and ETB)
When was the first outbreak of toxic shock syndrome (TSS) and what happened?
1928 in australia | vacccines were accidentally contaminated with S.aureus = got into bloodstream of kids = caused infection and death
What toxin does S.aureus produce to cause TSS? What type of toxin is it?
toxic shock syndrome toxin 1 (TSST-1); superantigen toxin
What kind of disease is TSS?
recurrent = can’t develop protective a = immunity against the condition
How can a woman get TSS?
use not 100% hyper-absorbent tampons ; toxin produced in the vagina and enters into bloodstream = many organs can get infected = death
Where does staphylococcal food poisoning occur?
GI tract
How does staphylococcal food poisoning occur?
person prepping food contaminates it (by not washing hands, etc) = S.aureus grows and produces toxin on food = food posioning
What toxins cause staphylococcal food posioning?
staphylococcal enterotoxins
What are the most commonly contaminated food?
processed meats, custard-filled pastries, potato salad, ice cream
Symptoms of staphylococcal food posioning?
severe vomiting, watery diarrhea, abdominal pain, nausea
What are cutaneous staphylococcal infections?
localized pyogenic staphylococcal infections
4 types of cutaneous staphylococcal infections?
imetigo, folliculitis, boils, carbuncles
What is impetigo?
localzed cutaneous infection characterized by pus-filled vesicles
What is folliculitis?
impetigo involving hair follicles
What are boils?
large, painful, pus-filled cutaneous nodules
What are carbuncles?
when boils extend to deeper subcutaneous tissue
What does MSCRAMM adhesin stand for?
microbial surface components recognizing adhesive matrix molecule
What does MSCRAMM do?
bind to ECM proteins like collagen and fibronectin
How can a capsule act as a virulence factor?
inhibits phagocytosis, protects from hsot cell immune defenses
How can peptidoglycan act as a virulence factor?
endotoxin-like activity and contributes to inflammation, pieces of murein will act as endotoxin when bacteria dies
How can teichoic acids act as a virulence factor?
contribute to inflammation and binding to mucosal cells
How can Protein A act as a virulence factor?
sort of nan adhesion that binds to areas on the body at Fc terminus of IgG antibodies
What can you use to identify a microbe?
biochemical assays
What is current for vaccines against S. aureus?
currently under development
What antibiotics can we use against Staphylococcus species?
methicillin and vancomycin
What are 2 antibiotic resistant strains of S. aureus?
methicillin-resistant and vancomycin-resistant
What are methicillin-resistant S. aureus treated with?
vancomycin
What are vancomycin-resistant S. aureus treated with?
new antimicrobials
What are characteristics of S. epidermidis?
white colonies that are coagulase negative and forms biofilms on plastic, colony morphology = less grape-like
Where are S. epidermidis found on in the body?
skin
What are some diseases associated with S. epidermidis?
prosthetic-using patients (biofilm formation) and hospitalized patients; endocarditis
What are the virulence factors associated with S. epidermidis?
LTA (lipoteichoic acid) and polysaccharide slime
What are some characteristics of S. saprophyticus?
colonizes skin and vaginal tract
What is the disease that S. saprophyticus is mostly associated with?
UTI
What are the virulence factors associated with S. saprophyticus?
surface adhesin that binds to bladder cells
