Infectious Disease 1: Background & Antibiotics By Drug Class Flashcards
What is the definition for a Transmissible Disease?
How is it spread? What is it also referred to as?
Person to Person
“Communicable”
“Contagious”
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What are 3 primary factors that impact ID treatment decisions?
- Bug (pathogen)
- Drug (antibiotic)
- Patient (host)
*must be considered together - these are not separate entities
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What are key infection characteristics?
Antibiotic Selection
- Infection site
- Infection severity
- Community- or Hospital-acquired
*presence determined by signs & symptoms
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What are key antibiotic characteristics?
Antibiotic Selection
- Spectrum of Activity
- Penetration Ability to Infxn Site
lipophilic drugs ~ better tissue pentration
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What are key patient characteristics?
Antibiotic Selection
- Age & Body Weight
- Renal & Hepatic Functions
- Allergies & Comorbidities
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CNS / Meningitis
Common Bacterial Pathogens for Select Sites of Infection
- Neiserria meningitidis (GN cocci)
- Strep pneumo (GP diplococci) & H. influenzae (GN rods)
- Listeria (GP rods), Group B Strep, & E. Coli (enteric GN rods)
Group 3 pathogens occur in younger & older patients
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Mouth
Common Bacterial Pathogens for Select Sites of Infection
- Peptostreptococcus mouth flora (GP anaerobes, spores)
- Prevotella & B. fragilis (GNR anaerobes)
- Strep viridans
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Upper Respiratory
Common Bacterial Pathogens for Select Sites of Infection
- Strep pyogenes (GP diplococci)
- Strep pneumo & H. influenzae (GN rod)
- M. catarrhalis (GN coccobacilli)
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Heart / Endocarditis
Common Bacterial Pathogens for Select Sites of Infection
- MSSA & MRSA (GP clusters)
- Streptococci & Entercocci (GP diplococci)
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Skin / Soft Tissue
Common Bacterial Pathogens for Select Sites of Infection
- MSSA & MRSA (GP clusters)
- Strep pyogenes (GP dipolocci)
- Pasteurella multocida (GNR)
Pasteurella in Diabetes ~ think diabetic foot Infections!
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Intra-Abdominal
Common Bacterial Pathogens for Select Sites of Infection
- Enteric GNR (PEK, Citrobacter, Enterobacter, Serratia)
- B. fragilis (GNR anaerobes)
- Streptococci & Enterococci (GP diplococci)
Bone / Joint
Common Bacterial Pathogens for Select Sites of Infection
- MSSA / MRSA (GP clusters)
- Streptococci (GP diplococci)
- Neisseria gonorrhoeae (GN cocci)
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Urinary Tract
Common Bacterial Pathogens for Select Sites of Infection
- E. Coli, Proteus, Klebsiella (PEK, enteric GNR)
- Staph saprophyticus (GP cluster) & Enterococci (GP diplococci)
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Lower Respiratory (Community)
Common Bacterial Pathogens for Select Sites of Infection
- Atypicals (Legionella, Mycoplasma, Chlamydophilia)
- Strep pneumo (GP diplococci) & H. influenzae (GN rods)
Alcohol Use Disorder? Enteric GNRs may show up
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Lower Respiratory (Hospital)
Common Bacterial Pathogens for Select Sites of Infection
- MSSA & MRSA (GP clusters)
- Pseudomonas (GN rods)
- Enteric GNRs (PEK, Citro- / Enterobacter, Serratia; ESBLs, MRDOs)
- Strep pneumo (GP diplococci) & Acinetobacter (GN coccobacilli)
Proteus, E. Coli, Klebsiella
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What are characteristics and organisms for Gram + stains?
Gram Stain for Select Bacterial Organisms - Color & Shape
- Positive = Purple!
- Cocci clusters - Staph
- Diplococci (pairs) - Strep & Enterococcus
- Bacilli rods - Listeria & Corynebacterium
- Anaerobes - Peptostrepto & C. diff
Thick cell walls
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What are characteristics and organisms for Gram - stains?
Gram Stain for Select Bacterial Organisms - Color & Shape
- Pink color!
- Cocci - Neisseria
- Coccobacilli - BAM ~Acinetobacter, B. pertussis, M. catarrhalis
- Anaerobes - BP ~ B. fragilis, Prevotella
- Enteric Rods - PEK, CES ~ PEK, Citrobacter, Enterobacter, Serratia
- Non-Enteric Rods - PH ~ Psuedomonas, H. influenzae
- Spiral Rods - THC ~H. pylori, Campylobacter, Treponema
Thin cell walls absorb safranin counterstain
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What are characteristics and organisms for Atypical stains?
Gram Stain for Select Bacterial Organisms - Color & Shape
- No stain!
- Chlamydia, Legionella, Mycoplasma, Mycobacterium
No cell walls
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What is the definition of Synergy?
Antibiotic Treatment
The effect of 2 antibiotics have an effect greater than the sum of the individual drugs
Aminoglycosides + Beta-Lactams for gram(+) infective endocarditis
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What are key monitoring parameters for antibiotic treatment response?
Assessment of Treatment
- Fever trend
- WBC trend
- Reduction in infxn signs & symptoms
O2 saturation, mental status, pain/inflammation, negative repeat culture
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Intrinsic Resistance
Common Mechanisms of Antibiotic Resistance
Natural resistance
Vancomycin cannot treat E. Coli because it can’t penetrate the cell wall
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Selection Pressure
Common Mechanisms of Antibiotic Resistance
Antibiotics kill susceptible bacteria & leave resistant strains behind to multiply
Vancomycin kill Enterococci, leading to VRE strains
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Acquired Resistance
Common Mechanisms of Antibiotic Resistance
- DNA resistant genes transferred between species
- DNA resistant genes picked up from dead bacterial fragments
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Enzyme Inactivation
What are some major bacterial resistant enzymes? What are some antibiotics used to treat such organisms?
Common Mechanisms of Antibiotic Resistance
- Bacterial enzymes break down drug - beta-lactamase
- Beta-lactamase inhibitors (BLI): clavulanate, sulbactam, tazobactam, avibactam
- ESBLs: treated w/ carbapenems or newer cephalosporin/BLI
- Carbapenem-resistant Enterobacter (CRE): MDROs that create carbapenemase; treated w/ polymyxins or Avycaz
CRE MDROs: E. Coli, Klebsiella
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What are Common Resistant Pathogens?
“Kill Each and Every Strong Pathogen”
- Klebsiella (ESBL, CRE)
- E. Coli (ESBL, CRE)
- Acinetobacter
- Enterococcus faecalis/faecium (VRE)
- Staph aureus (MRSA)
- Pseudomonas
Gram (+): Enterococcus, Staph
All antibiotics have a risk warning for what? What antibiotics have the highest risk for this?
- C. diff Infection (CDI)
- Symptoms: loose stools, cramping, & pseudomembranous colitis (colectomy, fatal)
- Clindamycin! broad penicillins & cephalosporins, quinolones, carbapenems
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