Term
What type of bacteria are:
Strep pneumoniae
S. pyogenes (Group A)
Staphylococcus aureus
Enterococcus |
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Definition
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Term
What type of bacteria are:
Clostridium sp.
Listeria
Bacillus anthracis |
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Definition
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Term
| What is the order of susceptibility of the previously listed gram-positive cocci (most to least)? |
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Definition
| S. pyogenes > S. pneumoniae > Staph aureus >> Enterococcus |
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Term
| What is the smallest free living organism, has no cell wall, and has an incubation period of 3 weeks? |
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Definition
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Term
| What is an intracellular gram-negative parasite related to Chlamydia? |
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Definition
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Term
| What is the relationship b/t MIC and resistancy? |
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Definition
| the higher the MIC, more likely the bacteria will be resistant |
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Term
| What is the resistance breakpoint of Cefazolin, Ceftriaxone, and Ciprofloxacin? |
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Definition
8 mg/L, 16 mg/L, 1 mg/L respectively.
if resistance breakpoint = MIC, add 2nd drug for synergy |
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Term
Empiric or Targeted therapy?
no gram stain or culture to guide tx. choice of abx depends on inf, most likely organisms, resistance pattern, severity, location, immune status. Tend to use broad spectrum abx. Greater chance failure and adverse effects |
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Definition
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Term
Empiric vs Targeted therapy?
identity of organism by gram stain or culture |
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Definition
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Term
| What is the first choice tx for Group A Strep pharyngitis? |
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Definition
Oral: Penicillin V x 10 days 250mg bid/tid kids. 250mg tid/qid adults
IM: Benzathine Penicillin G x 1 dose
If pen allergy: Erythromycin x 10 days, 1st gen cephalosporin x 10 days if no hx of IgE-mediated rxn |
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Term
| A penicillin allergy is a rxn to what? |
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Definition
| the B-lactam ring structure so you can use any non B-lactam ring abx to substitute. Differentiate b/t immediate onset IgE-mediated rxn and delayed onset rxn (rash). Cephalosporins safe except if hx of IgE-mediated rxn |
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Term
| How do you treat cellulitis assuming there's no MRSA present? |
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Definition
MILD TO MOD INF: oral tx, dicloxacillin or cephalexin. if severe allergy - erythromycin or clindamycin but more GI effects.
SEVERE INF: IV tx, nafcillin or cefazolin. if severe allergy - vancomycin |
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Term
| What gene codes for HA-MRSA? CA-MRSA? |
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Definition
HA-MRSA: Mec A types 1-3
CA-MRSA: Mec A types 4-5 |
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Term
| What is HA-MRSA resistant to? |
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Definition
| ALL B-lactam abx, multiple drug resistance to sulfonamides, macrolides, tetracyclines, and clindamycin |
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Term
| What is the drug of choice for HA-MRSA? |
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Definition
| Vancomycin, may combine with gentamicin and/or rifampin. Biggest fear: acquisition of Van A gene from vancomycin-resistant Enterococcus |
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Term
| What are 3 alternatives to vanco for HA-MRSA? |
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Definition
1. Linezolid (Zyvox): bacteriostatic. AE - thrombocytopenia. DI - MAO inhibitor
2. Daptomycin (Cubicin): bactericidal, IV
3. Mupirocin ointment (Bactroban): special formula for nares to reduce carriage. resistance can develop |
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Term
What is CA-MRSA resistant and sensitive to?
CA if cx <72hrs after admission |
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Definition
Resistant to ALL B-lactam abx.
Sensitive to clindamycin, doxycycline, and TMP-SMX. |
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Term
| What sort of effects/infections do you see with CA-MRSA? |
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Definition
| Skin, soft tissue, and abscess infections. 6-10% cases invasive - necrotizing PNA. Produces leukocidin (PVL) that lyses leukocytes. |
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Term
| What is the most common infection in children treated with abx? |
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Definition
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Term
| What is Recommendation 3A for treatment of AOM? |
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Definition
| Observation without use of abx. An option for some children based on diagnostic certainty, age, illness severity, and assurance of follow-up. |
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Term
| What is recommendation 3B for treatment of AOM? |
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Definition
| If a decision is made to treat with abx, clinician should Rx amoxicillin 80-90 mg/kg/day. Usually given in 2 doses/day for 5-7 days if >6 y/o and for 10 days if <6 y/o. |
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Term
| What are the 2nd and 3rd choice treatments for AOM? |
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Definition
2. High dose amoxicillin-clavulanate 90 mg/kg/day in 2-3 divided doses. For AOM with fever and/or ear pain, after initial failure with amoxicillin.
3. Ceftriaxone 50 mg/kg daily IV or IM for 3 days. For AOM after treatment failure w/other agents and w/fever and/or ear pain. |
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Term
| What is the 5th most common dx for which abx are prescribed and was traditionally thought of as a bacterial infection by primary care providers? |
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Definition
rhinosinusitis.
acute bacterial infection is usually a secondary infection resulting from sinus ostia obstruction |
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Term
| What is principle 3 for treating rhinosinusitis in adults? |
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Definition
| Sinus radiography is not recommended for dx in routine cases. |
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Term
| What is principle 4 for treating rhinosinusitis in adults? |
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Definition
| Acute rhinosinusitis resolves w/o abx treatment in most cases. Reserve abx treatment for acute baterial infection to cover S. pneumoniae and H. influenza. (more likely if symptoms >7 days w/maxillary pain and purulent nasal discharge) |
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Term
| What is recommendation 3 for treating rhinosinusitis in children? |
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Definition
| Abx recommended for the mgmt of acute bacterial sinusitis to achieve a more rapid clinical cure. Most common pathogens: Strep pneumoniae, H. influenza, Moraxella catarrhalis. |
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Term
| What are the top 3 most prevalent microbes of community acquired pneumonia (CAP)? |
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Definition
1. Streptococcus pneumoniae
2. Mycoplasma pneumoniae
3. Hemophilus influenzae |
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Term
| What is the outpatient treatment for CAP? |
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Definition
Macrolide (1st choice) or doxycycline (2nd choice) if previously healthy and no risk factors for DRSP.
Respiratory fluroquinolone if comorbidities and other risks for DRSP.
High dose amoxicillin or amoxicillin-clavulanate PLUS a macrolide if comorbidities and other risks for DRSP. |
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Term
| What are the MICs for penicillin sensitivity/resistance in drug resistant Strep Pneumoiae? |
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Definition
Penicillin sensitive: MIC <0.1 mcg/ml
Intermediate PCN resistance: MIC = 0.1-2.0 mcg/ml
High level PCN resistance: MIC > 2.0 mcg/ml |
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Term
| What is the process that Strep pneumoniae takes to become drug resistant? |
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Definition
| Chromosomal genes change PBP 1 and 2 in slow stepwise process with stable isolates able to spread. |
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Term
| What are 6 risk factors for DRSP? |
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Definition
1. B-lactam tx w/in previous 3 mos (most significant risk)
2. age <2 or >65
3. alcoholism
4. medical comorbidities
5. immunosuppressive illness or drug tx
6. exposure to child in day care center |
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Term
| What abx can be used for intermediate penicillin resistant Strep pneumoniae? |
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Definition
High dose amoxicillin or amoxicillin-clavulanate.
Respiratory fluoroquinolone.
Ceftriaxone or cefotaxime for meningitis. |
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Term
| What abx can be used for high level penicillin resistant Strep pneumoniae? |
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Definition
Ceftriaxone or cefotaxime.
Respiratory fluoroquinolone.
Vancomycin and rifampin for meningitis. |
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