Infectious Disease Flashcards
Gram positive cocci in clusters likely organism?
Staphylococcus spp. including MRSA and MSSA
Gram positive cocci in pairs or chains likely organisms? 3 specifically
- Strep pneumoniae (diplococci)
- Streptococcus spp. (including Strep. Pyrogenes)
- Enterococcus spp (including VRE)
Gram positive rods likley organisms?
Lester was a positive nimRod
- Listeria monocytogenes
Gram positive spores anaerobes?
PAC
- Peptostreptococcus
- Actinomyces spp
- Clostridium spp
Atypicals which dont stain well
4
- Chlamydia
- Legionella
- Mycoplasma pneumoniae
- Mycobacterium tuberculosis
Gram negative (pink)
Cocci
- Neisseria spp
Gram negative rods
enteric colonization
PEKSEC
- Proteus mirabilis
- E. Coli
- Klebsiella
- Serratia
- Enterobacter cloace
- Citrobacter spp
G (-) rods that do not colonize in the gut
PHP
- Pseudomonas aerogenosa
- Haemophilus influenzae
- Providencia spp
G - rods curved or spiral shaped
5
- H. pylori
- Campylobacter spp
- Treponema
- Borrelia
- Leptospira
Gram - coccibacilli ABM
- Acinetobacter baum
- Bordetella pertussis
- Moraxella catarrhalis
Gram - anaerobes
Baby Penguins are Mean and dont breathe
- Bacteroides fragilis
- prevetella
What two classes can sometimes be used synergistically to treat gram positive endocarditis?
AGs and beta-lactams
Beta-lactam opens the cell up so the AG can get to the ribosome and be effective
Antibiograms
Provide susceptibility patterns usually over one year
Aid in selecting empiric therapy and track resistance over time
Mechanisms of Resistance
Intrinsic resistance: natural to the organism
Selection pressure: susceptible bacteria are killed leaving only resistant bacteria
Enzyme Inactivation: Beta lactamases, extended spectrum beta lactamases (treated with carbapenems or newer cephalosporin beta lactamase inhbitors)
Carbapenem-resistant enterobactericae (MDR gram negative organisms): produce carbapenemase: combination treatment with polymyxins
Common Resistant Pathogens 7
Kill Each and Every Strong Pathogen
- Klebsiella pneumonae (ESBL, CRE)
- Eschericha Coli (ESLB, CRE
- Acinetobacter baumannii
- Enterococcus faecalis, Enterococcus faecium (VRE)
- Staph aureus (MRSA)
- Pseudomonas Aeroginosa
Folic Acid Synthesis Inhibitors
- Sulfonamides
- Trimethoprim
- Dapsone
Cell wall inhibitors:
BMVDTO
- Beta-lactams (penicillins, cephalosporins, carbapenems)
- Monobactams (aztreonam)
- Vanc, dalbavancin, televancin, oritavancin
Protein synthesis inhibitors: 7
AMTCLTQ/D
- AGs
- Macrolides
- Tetracyclines
- Clindamycin
- Linezolid, tedilozid
- Quinu/Dalfo
Cell membrane inhibitors:
PDTO
- Polymyxins
- Daptomycin
- Televancin
- Oritavancin
DNA/RNA Inhibitors
- Quinolones (DNA gyrase, topoisomerase IV)
- Metronidazole, tinidazole
- Rifampin
Hydrophilic agents 5 and attributes
- Beta lactams
- AGs
- Glycopeptides
- Dapto
- Polymyxins
- Small Vd: Poor tissue penetration
- Renal elimination: nephrotoxicity
- Low intracellular concentrations: Not active against atypicals
- Increased clearances or distribution in sepsis: consider loading dose and aggresive dosing in sepsis
- Poor-moderate bioavailability Not used PO or IV PO ratio is not 1:1
Lipophilic Agents 6 and attributes
QMRLTC
- Quinolones
- Macrolides
- Rifampin
- Linezolid
- Tetracyclines
- Chloramphenicol
- Large Vd: great tissue penetration
- Hepatic metabolism: hepatotoxic and DDI
- Achieve intracellular concentrations: active against atypicals
- Clearance and distribution is not changed by sepsis
- Great bioavailability: IV:PO is usually 1:1
Concentration dependent killing
AGs, quinolones, dapto
can be dosed less frequently and at higher doses to maximize concentration above the MIC
Time dependent killing
Beta lactams
Dose more frequently to maximize time above MIC
AUC: MIC abxs 4
Vanc, macrolides, tetracyclines, polymyxins
As a class beta lactams are not active against?
Atypicals and MRSA
Natural Penicillin coverage
- Gram:+ cocci: Streptococci and Enterococci DO NOT COVER STAPH, and gram + anaerobes
- Little activity for gram negative
Aminopenicillins
- Strepto, entero, and gram positive anaerobes (mouth flora)
- Addition of amino group gives them gram negative coverage HNPEK, Haemophilus, Neisseria, Proteus, E. Coli and Klebsiella
Aminopenicillins in combination with Beta-lactamase inhibitors have what increased coverage?
- Covers MSSA
- more resistant gram negative HNPEK strains and gram negative anaerobes (B.fragilis)
Extended spectrum penicillin coverage
- Pip/tazo
- expanded coverage of gram negative bacteria including citrobacter, acinetobacter, providencia, enterobacter, serratia CAPES and Pseudomonas aeroginosa
Antistaph penicillins coverage
- cover strep
- and enhanced activity against MSSA
- No enterococcus activity or gram (-) and anaerobes
natural penicillins 2
Penicillin V, Penicllin G
Aminopenicillins 4
Amoxicillin
Amoxicillin/Clavuanate (augmentin)
Ampicillin
Amp/sulbactam (Unasyn)
Extended Spectrum Penicillins
Piperacillin/Tazobactam
Antistaph penicillins
Dicloxacillin
Nafcillin (only injection)
Oxacillin (injection)
What natural penicllin in not for IV use and why
Pen G benzathine not for IV use causes cardiorespiratory arrest
Augmentin and Unasyn contraindication
- Hx of cholestatic jaundice or hepatic dysfunction associated with previous use
Contraindications for penicillins
Severe renal impairment CrCl < 30 mL/min do not use ER amoxicillin and augmentin XR or 875 mg strength of amox/clav
Side effects of beta lactams
Seizures with accumulation, GI upset, diarrhea, rash, hemolytic anemia increased LFTs, myelosupression
Beta lactam monitoring?
Renal function, anaphylaxis with first dose, CBC LFT, with prolonged course
Beta lactam notes
Aminopenicllins
- Amp PO is rarely used due to bioavailability amoxicillin is preferred if switching to PO
- IV amp and unasyn should be diluted with NS only
Extended spectrum notes
- 65 grams Na per 1 gram piperacillin