Bugs and Drugs Flashcards
most viral infections don’t need therapy. what’re the exceptions
HIV, HBV, HCV, CMV, HSC encephalitis, VZV
some bacteiral diseases dont need abx. such as?
- salmonella gastroenteritis, ecoli O157:H7
What are the associated pathogens of cellulitis?
Usual: Streptococcus pyogenes (GAS), Staphylococcus aureus Water history: Vibrio vulnificus, Aeromonas hydrophila
pathogens that cause community acquired pneumonia
typical: strep pneumo, haemophilus, moraxella ca.
atypical; legionella, myocplasma, chlamydia
I MD SOAPS acronym for ID exposure history.
I= immunizations
M = meds and antibiotics
D= dietary– raw meat, bad meat, unpasteurized milk
S= sexual
O= occupational, incarceration, homeless
A = animals, arthropod, activities
P = place
S = sick contacts
___ Pathogen: regularly cause disease in some proportion of susceptible individuals with apparently ___ defense systems e.g. Mycobacterium tuberculosis
___ (non-pathogen): organisms that are part of the normal human flora or environment that do not usually cause infection. E.g. Course 3 example: Neisseria species (not GC or N. meningitidis)
___ Pathogen: Organisms that have the ability to cause an infection when the immune defences are impaired.
E.g. Some are more virulent than others: S. pneumoniae, S. aureus; PJP etc
Primary Pathogen: regularly cause disease in some proportion of susceptible individuals with apparently intact defense systems e.g. Mycobacterium tuberculosis
Commensal (non-pathogen): organisms that are part of the normal human flora or environment that do not usually cause infection. E.g. Course 3 example: Neisseria species (not GC or N. meningitidis)
Opportunistic Pathogen: Organisms that have the ability to cause an infection when the immune defences are impaired.
E.g. Some are more virulent than others: S. pneumoniae, S. aureus; PJP etc
Microbial Pathogens causing Infective Endocarditis on a NATIVE VALVE
The HACEK organisms include Haemophilus species, Aggregatibacter actinomycetemcomitans, Cardiobacterium hominis, Eikenella corrodens, and Kingella kingae
Microbial Pathogens causing Infective Endocarditis on a PROSTHETIC VALVE
S. aureus (MSSA or MRSA)
- Coagulase negative staphylococci
- Enterococcus
- Viridans streptococci
HACEK organisms (all GNBs)
H aemophilus parainfluenzae and others
Aggregatibacter species*
Cardiobacterium hominis
Eikenella corrodens
Kingella kingae
HACEK organisms originate from the ___ flora
oral-pharyngeal flora
viridans strep, enterococcus originate from ___ flora
from gut flora
all Bacilli are gram negative except the gram positive ones lol. what are the gram positive bacilli? (ABCDLMNOP)
A= actinomyces
B= bacillus anthraxus
C= clostridium
D = diphtheria
L= listeria
M= mycobacterium
N= nocardia
P= proprionibacterium
all cocci are gram positive except the gram negative ones… NMV
neisseia Moraxella
veillonella.
atypical pneumonia pathogens
- Chlamydophila pneumoniae (no cell wall)
- Mycoplasma pneumoniae (no cell wall)
- Legionella pneumophila
3 classes of fungi
draw out this table from memory:
echinocandins can treat ___ types of fungi
yeast type. candda, aspergillus
IV administration: useful when absorption and distribution is ____ ___.
not predicctable. consider in critically ill or critical site of infection.
Drugs where PO= IV:
Metronidazole
Fluoroquinolones
Doxycycline
Clindamycin
TMP/SXT
CIDAL agents are generally needed for
__ infections, __ and ___ neutropenics
CIDAL agents are generally needed for
intravascular infections, meningitis and febrile neutropenics
bactericidal agents (BV FAM)
beta lactams
vancomycin
fluoroquinolones
aminoglycosides
metronidazole
bacteriostatic agents (MaCTeS)
Macrolides, clindamycin, tetracycline, sulfonamides
All antibiotics have potential to cause
__, __, __ and __
All antibiotics have potential to cause
nausea, vomiting, diarrhea and rash
T/F penicillins cannot be given to breast feeding or pregnant women
false. penicillins are safe.
comorbidites that might affect dose differences of abx
renal or hepatic disease-a ffects metabolism of drugs
T/f when giving an antibiotic, you sohuld give the shortest course possible
true.
antibacterial classes that inhibits cell walls by binding termianl pentapeptide or PBP.
- beta lactams (PCCM)
- penicillin
- cephalosprin
- carbapenems
- mono bactam - glycopeptides
- aztreonam
- vancomycin
inhibits protein synthesis (AMLOT) antibacterial classes and give examples
- aminoglycosides (gentamycin, tobramycin)
- macrolides (clarithromycin, azithromycin)
- lincosamide (clindamycin)
- tetracycline (doxy-cycline)
- oxazolidinone (linezolid)
antibcaterial class that disrupts DNA and NA synthesis. Give examples (RiFTN)
- fluoroquinolone (cipro)
- rifampin
- TMP SXT (Septra)
- Nitromidazoless (metronidazole)
antibacterial class that disrupts metabolsim/respiration
nitrofurantoin (macrobid)
Can you name 4 mechanisms that organisms can develop
to impart resistance to antibiotics?
- antibiotic structure alteraion
- target alteration
- deny entry to the antibiotic
- pump out antibiotic
mechanisms of baceria altering the antibiotic
- produce enzymes that modify the antibiotic into an inactive state.
- secreed by the bacteria into their surroundings. ex/ beta lactamases, or aminoglycoside modifying enzymes.
2 methods that bacteria can alter the antibiotic target
- bacteria can change the protein or molecule on which the drug is acting.
the “deny entry” mechanism of resistance is mostly done by ____
gram negatives.
antibiotics can pass through porins, but bacteria may alter the porins to prevent antibiotic entry. may also get pumped out.
mechanism of resistance :even after antibiotic has entered the bacteria, __ ___ allow the
drug to be pumped back into the extracellular space
efflux pumps.
used in the cell membranes of both Gram +’s and Gram -‘s
e.g. many bacteria vs. tetracycline
e.g. Streptococcus vs. erythromycin
e.g. Pseudomonas vs. a lot of
antibiotics
Regarding beta-lactams, which of following statements is FALSE
A. They bind to transpeptidase to inhibit cross linking of peptidoglycan.
B. Penicillin is more narrow spectrum than Ampicillin.
C. Beta-lactam and Beta-lactamase inhibitor combinations broaden the spectrum of activity of beta-lactam drugs.
D. 1st generation cephalosporins have good gram positive coverage.
E. Pipercillin-tazobactam and meropenem will solve all your problems.
F. Beta-lactams can have significant adverse effects.
A is TRUE: beta lactams prevent cell wall synthesis. inhibits the cross linking of peptidoglycan by binding to the penicillin binding protein.
B is TRUE. Penicillin (narrower)–> ampicillin –> piperacillin
C is true. beta lactamases can be a mechansim of resistance in bacteria that alter the beta lactam antibiotics. getting a beta lactamase inhibitor would prevent resistance.
D is TRUE. 1st gen cepharlosporins are more gram positive coverage than 4th gen.
E is FALSE. PIPTAZ is pretty good, but NO ATYPICAL COVERAGE (mycoplasma, mrsa, enterococcus)
F is true. Every antibiotic can have bad side effects. Comparatively though, it is decently safe and cant be given to pregnant women.
Anti-Staphylococcal Penicillins:
Cloxacillin, naficillin, methicillin
the combo pip taz is a powerful abx. what is tazobactam?
a beta lactamase inhibitor. Beta-lactamase inhibitor acts as a decoy to bind to beta-
lactamase and allow beta-lactam to do it’s usual job to
stop PG synthesis
T/F cephalosporins cover ENTEROCOCCUS, MRSA AND “ATYPICAL” PNEUMONIA PATHOGENS
false.DO NOT COVER: ENTEROCOCCUS, MRSA AND “ATYPICAL” PNEUMONIA PATHOGENS
cons of beta lactams
- common allergic
- Aes include nephrotoxicity
Methicillin resistant S. aureus (MRSA): alteration in __ ___ ___ (PBP2) This alteration confers resistance to all ß-lactams (beta-lactamase inhibitors no help here!)
Methicillin resistant S. aureus (MRSA): alteration in penicillin binding protein (PBP2) This alteration confers resistance to all ß-lactams (beta-lactamase inhibitors no help here!)
• PBP alterations primarily used by gram __ organisms
• PBP alterations primarily used by gram positive organisms
Regarding Vancomycin, which of the following statements are TRUE?
A. Vancomycin sterically inhibit cross-linking of peptidoglycan.
B. Vancomycin covers E. coli and Pseudomonas (gram
negatives).
C. Vancomycin is a STATIC antibiotic
. D. Vancomycin does not require monitoring of blood level
concentrations.
A is true. it inhibits cell wall synthesis
b. false– mostly gram positive coverage
c. false, it’s a cidal
d. false. vanco needs to be monitored becuase it can cause nephrotoxicity.
T/F: vancyomycin can kill many resistant gram positive organisms: MSSA and MRSA, coagulase negative staph, enterococcus, S. pneumoniae, C.dif
true.
ALL antimicrobials with a protein synthesis inhibition mechanism of action are BACTERIOSTATIC except for the ___.
aminoglycosides
Regarding macrolides, which of the following statements is false?
A. Macrolides have good atypical bacterial spectrum of activity.
B. Macrolides can be used to treat CAP in inpatient and
outpatient setting.
C. Macrolides are not associated with prolonged QT intervals.
A. Macrolides have good atypical bacterial spectrum of activity. TRUE.
B. Macrolides can be used to treat CAP in inpatient and
outpatient setting. False need IV.
C. Macrolides are not associated with prolonged QT intervals. FALSE: • Diarrhea (erythromycin), drug
interactions, prolonged QT
intervals are side effects.
resistance phenomenon of macrolides
resistance to one = resistant to all in the class. Efflux and target modification common mechanism of resistance.
macrolid side effects: • Diarrhea (erythromycin), drug
interactions, prolonged___
intervals
• Diarrhea (erythromycin), drug
interactions, prolonged QT
intervals
Regarding Clindamycin: Which of the following statements is FALSE?
A. Clindamycin has anaerobic coverage.
B. Clindamycin’s bioavailability PO IV
C. Clindamycin could be used to treat MRSA
endocarditis.
ALL OF THESE ARE TRUE???
A. Clindamycin has anaerobic coverage. TRUE.
B. Clindamycin’s bioavailability PO=IV. TRUE. good oral bioavailability.
C. Clindamycin could be used to treat MRSA
endocarditis. TRUE. can treat MRSA and nec fasc.
Regarding Tetracyclines, which of the following statements if FALSE?
A. Tetracyclines cover “atypical pathogens”.
B. Tetracyclines can be used safely in pregnancy
and kids.
B is false. it cannot be used in pregnancy.
the ___ ___ is the most common mechanism of resistance against tetracycline
efflux pump.
Regarding Fluoroquinolones, which of the following statements is TRUE?
A. Ciprofloxacin has good Streptococcus pneumoniae coverage
but not Pseudomonas coverage.
B. FQ PO bioavailability ≈ IV
C. FQ do not have any serious side effects
A is FALSE. levo!! cipro is better for gram negative.
B. TRUE.
C. FALSE. always has side effects
examples of fluoroquinolones. mechanism of actions?
MOA: DNA synthesis inhibition by blocking DNA gyrase/topoisomerase
- ciprofloxacin (gram negative drug)– good for UTI or GI
- levofloxacin : better gram positive and atypical pneumonia pathogens (pseudomonas, mycoplasma, chalmydia, legionella)
- moxifloxacin: similar coverage to levo EXCEPT pseudomonas
fluoroquinolones are bacterio___
cidal.
rewrite this
good antibiotics for a suspected infective endocarditis (native valve)
recall that native valves often can get infected by S. aureus, viridans strep, enterococcus, and HACEk.
if you don’t have the cultures back, do broad coverage.
VANCO AND CEFTRIAXONE! Can gover gram positive, MSSA, MRSA, enterococci
