Infectious Disease Pt 1 Flashcards
(65 cards)
1
Q
Classification of Bacteria
- Gram positive vs. gram negative via Gram ____
- Microbiological identification system based on _____ structure
- Differ in structural components, sh____
- Aerobic vs. anaerobic
- Differing ____ requirements for survival
-
Gram _____ has a thicker peptidoglycan layer
- also looks more _____ color under microscope
A
- Stain
- cellular
- shapes
- Aerobic vs. anaerobic
- oxygen
-
Positive = thicker
- purple
2
Q
+Gram Stain
- Gram negative shape =
- _______ aeruginosa
- Gram positive shape =
- _______ aureus
General rule
- GPC in clusters =
- GPC in chains =
A
- rods
- Pseudomonas
- cocci in clusters
- Staphylococcus
- staphylococcus species
- streptococcus species
- Gram negative = pink and rod like shape*
- Gram positive = purple and in clusters (cocci- grape like appearance)*
3
Q
Gram Positive Organisms of Importance
(8)
A
-
Staphylococcus aureus
- Methicillin-susceptible (MSSA)
- Methicillin resistant (MRSA)
- Coagulase-negative S**taphylococcus (CoNs)
- Streptococcus pneumoniae
- Streptococcus viridans
- Streptococcus pyogenes (Group A Strep)
- Streptococcus agalactiae (Group B Strep)
- Enterococcus faecalis and Enterococcus faecium
- Clostridium difficule (anaerobic)
- CoNs - often on skin - potentially a contaminant to blood cultures*
- Staph aureus never really a contaminant/found on skin so def treat it*
- Streps are not contaminants*
4
Q
Gram-Negative Organisms of Importance
(8)
A
- Escherichia coli (E.coli)
- Klebsiella pneumoniae
- Enterobacter cloacae
- Pseudomonas aeruginosa
- Acinetobacter baumannii
- Haemophilus influenzae
- Mycoplasma pneumoniae
- Bacteroides fragilis (anaerobic)
Pseudomonas like MRSA is an umbrella term - if a drug covers these, probably will cover others under it
5
Q
Minimum Inhibitory Concentration (MIC)
What is it?
A
Lowest drug oncentration required to inhibit the growth of an organism at 24 hours (Value determines if sensitive, intermediate, or resistant)
6
Q
On the Susceptibility Panel, what does it mean when there are all S’s on the right side?
A
The bacteria is PANSENSTIVE - can be treated with all the abx listed
7
Q
Poll 1
- Blood cx has come back with preliminary results:
- Gram-positive cocci (GPC) in clusters on gram-stain
- Which of the following organisms fits the description?
- Bacteroides fragilis
- Staphylococcus aureus
- Streptococcus pneumoniae
- Pseudomonas aeruginosa
A
Staphylococcus aureus
8
Q
Poll 2
Which of the following is considered a gram-positive anaerobic organism?
- Streptococcus pneumoniae
- Bacteroides fragilis
- Clostridium difficile
- Streptococcus pyogenes
A
Clostridium Difficile
9
Q
S/S of Infection
A
- Fever > 38.3 or 100.9F
- Elevated WBC (leukocytosis)
- AMS
- Altered hemodynamics (hypotension, tachycardia)
- Fatigue
- N/V
- Site specific sx (pain, difficulty, breathing, redness, others)
10
Q
Fever Causes
- Roughly 75% of fever in hospitalized pts is _____
- Remaining causes (4)
A
- pyrogenic
- malignancy, tissue ischemia, drug-induced, neurogenic
Keep in mind, not all fevers are infectious such as in cancer or seizure pts
11
Q
Fevers the Good vs. Bad
Pros (4)
Fever > ___/___ C harm outweighs benefit
Cons (3)
A
- Fevers are designed to be good - mostly the beginning of the fever but if a fever is unaddressed, extended esp > 39/40 can cause lots of bad things*
- Ie) pediatric febrile seizures (not uncommon in peds)*
- Ex of taking advantage of some of the pros: doc says hold the tylenol until fever is >39*
12
Q
Identifying the Source
- CNS
- Respiratory
- CV
- GI
- Urinary
- Integumentary
- Skeletal
A
Work by organ system from head to toe
- Meningitis
- PNA
- Endocarditis, Blood infections
- Colitis, food borne illness
- UTI
- Skin infections
- Osteomyelitis
13
Q
Normal Human Flora
- Oral (2)
- Pulmonary (3)
- GI (6)
- GU (3)
- Integumentary (2)
A
- Streptococcus spp, Gram-positive anaerobes
- Streptococcus spp, Haemophilus inf, Mycoplasma spp
- E. coli, Klebsiella pneumoniae, streptococcus spp, Candida spp, Gram - anaerobes, other gram negatives
- Streptococcus spp, E.coli, Candida spp
- Streptococcus spp, Staphylococcus spp.
- After identifying the source - think about whats normally there?-* Translocation of our normal bacteria when we have infections
- Ex) treating cellulitis on my leg - targeting strep and staph*
14
Q
Pharmacokinetics (PK)
- The study of the actions the ____ has on the ____
- Concerned with concentration/drug availability
- Incorporates four major body processes
- ______ - drug into the body
- ______ - drug into various tissues
- _______-changing drug into other molecules
- ______ - removal of drug from body
- Imp: above processes ___ the same in all patients
- Genetics: age, comorbities, organ function
A
body has on the drug
4 processes
- Absorption
- Distribtuion
- Metaboism
- Excretion
NOT
depending on severity of infection/keep in mind PO drugs not fully absorbed compared to IV
15
Q
Pharmacodynamics (PD)
- The study of actions the ____ has on the ____
- E_____ of drug activity
- Unique in ID- targets bacterial pathogens instead of human receptors/target sites
A
- drug on the body
- Efficacy
16
Q
+Time vs. Concentration Dependent
-
Time dependent
- Greater bactericidal (killing) activity as:
- PKPD parameter: __ > ___
- Example: ___-____ abx
- Greater bactericidal (killing) activity as:
-
Concentration Dependent
- Greater bactericidial (killing) activity as:
- PKPD parameter: C__/____ or AUC/MIC
- Example: _______
- Greater bactericidial (killing) activity as:
A
- Time Dependent
-
Drug concentrations remain above the MIC
- T > MIC
- Beta-lactam
-
Drug concentrations remain above the MIC
- Concentration Dependent
-
Drug concentrations (Cmax) exceed the MIC
- Cmax/MIC
- Aminoglycoside
-
Drug concentrations (Cmax) exceed the MIC
17
Q
PKPD Parameters
- Concentration dependent - ____ a day, get to that ____
- Time dependent - _____ concentration for as long as possible, dosing more ____*
A
- once, peak
- maintain, frequent
18
Q
Mechanism of Action Overview
- Targeting diff parts of the cell
-
Two main classes
- Intracellular =
- Extracellular =
A
- inhibits protein synthesis
- inhibits cell wall synthesis
19
Q
+Beta Lactams
(4)
A
Natural Penicillins
Anti-Staphylococcal Penicillins
Amino-Penicillin
Anti-Pseudomonal Penicillins
20
Q
+Penicillin Evolution
All belong to the ___-____ family
MOA
Increasing spectrum of gram _____ organisms
A
Beta-Lactam
Bind to penicillin binding proteins (PBPs) within the cell wall -> inhibiting cell wall synthesis -> cell lysis -> destruction
negative
21
Q
+Natural Penicillins
(2)
Discovered in 1928, forever changed medicine
A
Penicillin G
Penicillin V
Prior to discovery of penicillins, we really didn’t have much to treat infections…a slow agonizing death, really reserved for skin infections, doesn’t really cover gram -
22
Q
+Natural Penicillins
Spectrum
A
Staph aureus (penicillin-susceptible); Streptococcus spp, others
Minimal to NO gram-negative activity
23
Q
+Natural Penicillins
Indications
A
- Initially excellent for skin infections
- Resistance developed over time
- Drug of choice for: Syphilis
24
Q
+Natural Penicillins
Routes
- Pencillin G
- Penicillin V
A
- IV, IM as Pen G benzathine
- PO - low absoprtion of oral tablet limits its use
Limitiation with Oral beta lactams - poorly absorbed so with serious infections not good enough
25
**+Anti-Staphylococcal Penicillins**
| (3)
**Oxacillin**
**Nafcillin**
**Dicloxacillin**
26
**+Anti-Staphylococcal Penicillins**
Spectrum
Developed to treat Penicillin**-RESISTANT** *Staph Aureus*
* Originally methicillin-since discontinued (dt hepatotoxicity)
Methicillin-Susceptible *Staph Aureus* (MSSA)
27
**+Anti-Staphylococcal Penicillins**
Indications
Drug of Choice for?
Serious MSSA infections (e.g blood stream)
28
**+Anti-Staphylococcal Penicillins HF/Dosing**
Half life is long or short?
Dosed how frequently?
Very short
Every 4 hours (requires frequent dosing) -\> not commonly used
29
**+Anti-Staphylococcal Penicillins**
Clearance
Liver = no renal adjustments
**Unique** - most of the other beta-lactams renally adjusted
30
**+Anti-Staphylococcal Penicillins**
Routes
PO option for dicloxacillin
31
**+Amino-Penicillin**
| (2)
**Amoxicillin (Amoxil)**
**Ampicillin**
32
**+Amino-Penicillin**
Developed to provide?
Spectrum
_Gram negative_ in addition to gram positive coverage
*Streptococcus spp, E.coli, Haemophilus influenzae, Enterococcus faecalis*
Not reliable for *Staph aureus* (often resistant dt beta-lactamase production)
*Expanded spectrum to include gram neg, however is a more advanced penicillin that doesn't work on staph aureus, only these organisms above though -doesn't really cover hospital infections (Pseudomonas)*
33
**+Amino Penicillin**
Routes
1. Amoxicillin
2. Ampicillin
1. PO, used as oral therapy (better bioavailability)
2. PO and IV, mainly used in IV form (oral with poor bioavailability) *compared to PO amoxicillin*
34
+Amino-Penicillin Indications
## Footnote
Clinical Use (2)
Not used empirically for?
Otitis Media, Acute Pharyngitis
Not used for hospital infections -\> Gram-negatives are usually resistant
35
Anti-Pseudomonal Penicillins
## Footnote
(1)
* Developed to include coverage of _______ (hospital associated, gram-negative organism)
* Spectrum:
* Route: only ___ used in hospital combined with _____ for hospital acquired infections (\_\_\_\_\_)
* Not used _____ (ie. with tazobactam) due to \_\_\_\_\_\_\_
* \_\_\_\_\_-\_\_\_\_\_\_\_\_
**Piperacillin**
* *Pseudomonas aeruginosa*
* Same as Aminopenicillins (+ *Pseudomonas)*
* IV, tazobactam, Zosyn
* alone, resistance
* Beta-lactamases
*Again if a drug can cover pseudomonas, it can probably cover other gram negatives*
36
**What is Beta-Lactamase?**
* ______ that hydrolyzes the beta-lactam _____ -\> antibiotic becomes \_\_\_\_\_
* 1,000's of beta lactamases - classified based on s\_\_\_\_/a\_\_\_\_ it inactivates
* ______ beta lactamases vs. _____ beta-lactamases vs. others
* Enzyme, ring, inactive
* structure/antibiotic
* simple, expanded
*Beta-lactamases are enzymes produced by bacteria that provide multi-resistance to β-lactam antibiotics such as penicillins, cephalosporins, cephamycins, and carbapenems (ertapenem), although carbapenems are relatively resistant to beta-lactamase.*
37
**+Beta Lactamase Inhibitors**
| (3)
**Amoxicillin-_Clavulanate_ (Augmentin)**
**Ampicillin- _Sulbactam_** _(_**Unasyn)**
**Piperacillin-_Tazobactam_ (Zosyn)**
38
+Beta Lactamase Inhibitors
## Footnote
* Developed to: _____ the activity of simple \_\_\_\_\_\_\_\_\_
* P\_\_\_\_\_/e\_\_\_\_\_ the activity of its \_\_\_\_\_\_
* Routes: Unasyn/Zosyn -\_\_\_ only, Augmentin - __ only
* Indication:
* Also includes **\_\_\_\_\_\_\_\_ activity** (with the exception of \_\_\_\_\_)
* Augmentin associated with high rates of ___ complaints
* **inhibit the activity of simple beta-lactamases**
* Preserve/expand, counterpart
* IV, PO
* Used empirically for hospital infections due to their expanded spectrum of activity
* **anaerobic,** X c.diff
* GI
39
Example of Beta-Lactamase Producing Organism
## Footnote
How can you tell if something is producing beta-lactamase?
Resistant to Ampicillin vs. Sensitive to Ampicillin-Sulbactam
40
**+Penicillin Class AE**
| (3)
1. **Hypersensitivity** reactions
* 10% of US population reports being allergic- Rash most common
2. Almost all agents are **R****enally eliminated** (require adjustments)
* Notable Exception: **Oxacillin** and **Nafcillin** (hepatically eliminated, must monitor LFTs and avoid in elevated LFTs at baseline)
3. **GI** intolerances (ie diarrhea)
* more commonly with oral agents
41
Cephalosporins
## Footnote
* Inhibits \_\_\_\_-\_\_\_\_ synthesis (same as _____ class - \_\_\_-\_\_\_\_family)
* MANY DRUGS IN THIS CLASS (will almost always begin with \_\_\_/\_\_\_)
* Grouped into *\_\_\_\_\_\_\_* based on spectrum of activity/characteristics
* cell-wall, penicillin, beta-lactam
* ceph/cef
* *generations*
42
**+ First Generation Cephalosporins**
(2)
Routes
**Cephalexin (Keflex)** PO
**Cefazoline** (**Acnef)** IV
43
**+First Generation Cephalosporins Indications**
* **\_\_\_\_\_\_\_** to Anti-staphylococccal ______ (e.g. oxacillin/nafcillin/dicloxacillin)
* Very commonly used for ____ infections and _____ prior to \_\_\_\_\_
* **Alternative**, penicillins
* skin, prophylaxis to surgeries
44
**+First Generation Cephalosporins**
Spectrum
Streptococcus, Staph aureus (MSSA)
NOT MRSA
Minimal gram-negative activity (resistance)
45
**+First Generation Cephalosporins**
Half Life
Dosing
Short half-life
3-4x/day
46
**+Third Generation Cephalosporins**
(4)
Routes
**Ceftazidime (Fortaz)** IV
**Ceftriaxone (Rocephin)** IV
**Cefpodoxime (Vantin)** PO
**Cefdinir (Omnicef)** PO
*Very important class: Extended spectrum beta lactams*
47
**+Third Generation Cephalosporins Spectrum**
* Developed to further _____ gram-\_\_\_\_ spectrum
* These beta-lactams have an **\_\_\_\_\_\_ spectrum**
* Spectrum (5)
* **EXCEPTIONS:** ______ ONLY one in the group that does ___ cover gram-positive organisms and only one that covers *\_\_\_\_\_\_\_ aeruginosa*
* *\_\_\_\_\_\_* stability against beta-lactamases
* expand, gram-negative
* **Extended**
* *Streptococcus spp, MSSA, E.coli, K. penumoniae, Proteus spp*
* _Ceftazidime_, NOT +, yes *Pseudomonas*
* Increased
*Ceftaz = TAZMANIAN DEVIL -\> covers pseudomonas and doesn't cover the gramp positive strep and MSSA*
48
**+Third Generation Cephalosporins**
Inactivated by?
**Extended-spectrum** beta lactamases (ESBLs)
*ESBLs will inactivate these drugs (very prominent in the Northeast)*
49
**+Third Generation Cephalosporins PK**
Half Life
Dosing Frequency
Elimination
Longer half life
Once daily for most infections
_Hepatically_ eliminated = no renal adjustments (unique for cephalosporin class)
*Ceftriaxone and Oxacillin class not renally dose adjusted*
50
**+Third Generation Cephalosporins**
Indications
Commonly used in hospital and outpatient (community-acquired PNA, UTI, skin, bacteremia, osteomyelitis, CNS infections)
51
Example of an ESBL Producing Organism
52
Fourth Generation Cephalosporins
## Footnote
(1) Route
* Further expanded gram-\_\_\_\_\_ coverage
* Spectrum:
* Reserved for serious \_\_\_\_-associated infections
* Concern for _____ (including seizure) if not dosed properly
* Risk highest in e\_\_\_\_, ____ impairment
**Cefepime (Maxipime)** IV
* expanded gram-negative coverage
* Same as 3rd gen + additional gram negs including *Pseudomonas Aeruginosa*
* serious hospital
* encephalopathy
* elderly, renal
53
Fifth Generation Cephalosporines
(1) Route
* _____ the rule
* Spectrum:
* "Think Cetriaxone with *\_\_\_\_* coverage"
* Approved for (2)
* Used off label for b\_\_\_\_, endo\_\_\_\_ and osteo\_\_\_\_ (as salvage therapy)
**Ceftaroline (Teflaro)** IV
* Breaks
* Expands gram positive, doesn't cover pseudomonas but does cover MRSA by binding to PBP-2a
* MRSA
* CAP, ABSSSI
* bacteremia, endocarditis, osteomyelitis
54
**+Cephalosporins AE**
* Overall:
* _____ less commonly seen as compared to penicillin
* \<\_\_% cross reactivity seen in those allergic to penicllins
* Clinically okay to challenge if pt experienced just a \_\_\_\_
* Requires allergy testing or avoid use if: H\_\_\_, S\_\_\_\_, A\_\_\_\_
* ______ if not dosed properly (more common with what drug?)
* well tolerated
* Hypersensitivity
* \<5%
* Rash
* Hives, Swelling, Anaphylaxis
* Seizure (Cefepime)
55
Poll 3
## Footnote
How do beta-lactams exhibit their mechanism of action?
* Inhibiting cell wall synthesis
* Mixed martial arts
* Inhibiting protein synthesis
* Hydrolyzing the beta lactam ring
Inhibiting cell wall synthesis
56
Poll 4
## Footnote
This third generation cephalosporin is the only third generation to have activity against *Pseudomonas aeruginosa* making it a useful option when treating ventilator associated PNA
* Cetriaxone
* Ceftazidime
* Cefepime
* Ceftaroline
Ceftazidime
57
Poll 5
## Footnote
Which of the following requires hepatic elimination?
* Cefepime
* Penicillin
* Cefazolin
* Oxacillin
Oxacillin
*Hepatic adjustment is really just avoiding it*
58
Poll 6
## Footnote
People speak highly of me. For example, I am considered an agent who protects my couterpart, similar to a body guard. I am also known to enhance my counterpart's spectrum of activity. What class of drug am I considered?
* Cephalosporin
* Penicillin
* Beta-Lactamase Inhibitor
* Beta Lactam
What is an example of a drug in that class? (Beta-Lactamase Inhibitor)
* Cefepime
* Sulbactam
* Oxacillin
* Piperacillin
Beta Lactamase Inhibitor
Sulbactam
59
Poll 6
## Footnote
Which of the following in the class can treat Pseudomonas aeruginosa?
* Amoxicillin-clavulanate
* Ampicillin-sulbactam
* Piperacillin-tazobactam
* None of the above
Piperacillin-tazobactam
60
Poll 6
## Footnote
Which of the following in the class can treat MRSA?
* Amoxicillin-clavulanate
* Ampicillin-sulbactam
* Piperacillin-tazobactam
* None of the above
None of the above
61
Poll 6
## Footnote
Which of the following in the class can treat anaerobic organisms (with the exception of C.diff)
* Amoxicillin-clavulanate
* Ampicillin-sulbactam
* Piperacillin-tazobactam
* All of the above
All of the above
62
**+CarbaPENEMs**
(4)
Routes
**Ertapenem (Invanz)** IV, IM
**Meropenem (Merrem)** IV
**Imipenem/cilastatin (Primaxin)** IV
**Doripenem (Doribax)** IV
63
**+CarbaPENEMs Spectrum**
* **\_\_\_\_\_\_\_** beta-lactam class (also inhibits cell wall synthesis)
* Spectrum:
* \_\_\_\_\_\_\*\*\*\* does not cover *Pseudomonas*
Broadest
*Streptococcus, MSSA,* all GNR (including Pseudomonas aeruginosa) and **anaerobic gram-negatives**
**Ertapenem**
* On exam: ERRRRTT does not cover pseudomonas*
* The only 2 so far that cover gram negative anaerobes - penems and beta lactam combos*
64
**+CarbaPENEMS Indications**
Drug of choice for \_\_\_\_\_\_
Used as \_\_\_-line options in gram-negative _____ infections
Stable against many?
ESBL's
last line - gram neg resistant
ESBLs
* Can use penems for ESBL's (drug of choice or serious ESBL producing organisms)*
* ONly gram negative organisms produce ESBL*
65
Poll 7
## Footnote
AB is a 43 M admitted to the hospital with an intra-abdominal infection. He is allergic to penicillin (rash). AB has had several hospital admissions this year including 2 operations. You would like to empirically treat broadly for gram-negatives including Pseudomonas aeruginosa. In addition you would like to cover anaerobic organisms. Which of the following would be a viable option for AB?
* Ceftazidime
* Ertapenem
* Piperacillin-tazobactam
* Meropenem
Meropenem
* Cef does not cover the anaerobes*
* Ert does not cover pseudomonas*
* Penicillin rash - not going to give piperacillin*
