MICRO Flashcards
what happens if you can’t add the D-alanine to the LTA
bacteria become less virulent
What normally has to happen before pathogens can have a foothold?
mechanical disruption of barrier
Infections confined to most superficial layers are gen. considered ___________
less severe (deeper into the dermis the more serious the infection)
what is so important about quorum sensing?
very important in the development and dispersal of biofilms
why are biofilms a medical problem
bacteria arent susceptible to antibiotics
what is happening to bacteria within the biofilms that makes it even more difficult to kill the microbes
they slow their growth (antibiotics don’t work as well)
and antibiotics can’t penetrate the extracellular materials that bacteria form around themselves
what are the 5 stages of biofilm formation?
adhesion colonization microcolony fomration maturation dispersal
what are some s. aureus diseases
furuncles (boils), carbuncles (many boils) wound infections (traumatic surgical) folliculitis styes impetigo scalded skin brain abscesses embolic GI epidural abscesses
what is chalazion?
inflammation due to blockage of Meibomian gland
what are the risk factors for getting S. Aureus Pneumonia
CF
diabetes
alcoholism
What is the prognosis with S. Aureus pneumonia
poor prognosis with high mortality (necrotizing pneumonia)
what are the symptoms associated with toxic shock syndrome from Stahphyloccus
i. Fever
ii. Vomiting
iii. Diarrhea
iv. Sore throat
v. Skin rash (blanches w/ pressure)
would blood culture be positive in toxic shock syndrome
probably not
would serology for TSST-1 be positive in toxic shock syndrome
YES
after you have eaten food with staphylococcal toxins in it, how long will it take you to get sick
2-6 hours until violent vomiting
what is the major virulence factor for group b strep?
CAPSULE!
which microbe is associated with lesions of the bowels like colon cancers
Strep. Bovis
_________________ are the 3rd most common cause of Infective endocarditis
group D. enterococci (usually subacute)
what is the new name for Group D strep. bovis and what is it associated w/?
new name is streptococcus gallolyticus, freq. associated w/ lesions of the large bowel, especially cancer
which bug is associated with IV drug users and prosthetic valve endocarditis?
Pseudomonas aeruginosa
what is the most common cause of culture negative endocarditis
prior abx (may also be due to fastidious bugs, HACEK gropu, fungi, bartonella)
which valve is most commonly infected with IE in IVDU?
tricuspid
what is the most common pathogen overall w/ IF in IVDU?
staph aureus (recurrent infection is common, mortality is substantial, most have normal valves anatomically)
the atypical clinical presentation of infective endocarditis is found in what pt population
elderly or immunocompromised in whom fever is often absent
prev. abx may obscure diagnosis
