1. Infectious Disease I Flashcards

1
Q

Identify the basic identification process of gram negative and gram positive organism.

A

Gram Positive

  • appear purple/violet under microscope
  • contain THICK peptidoglycan layer

Gram Negative

  • appear red/pink under microscope
  • contain THIN peptidoglycan layer
  • contain second outer membrane
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q
  1. Compare susceptibility and resistance with emphasis on the Kirby-Bauer antibiotic testing plate.
  2. Identify the clinical importance of the KB test in determining antibiotic treatment.
A

Susceptibility - determine which antibiotics effectively inhibit the growth of a given bacterial isolate

Resistance - no inhibition of growth of the bacterial

Kirby-Bauer test

  • qualitative (susceptible v. intermediate v. resistant)
  • zone of inhibition

Clinical importance

  • reference method for organism-microbial combinations
  • allows practitioner to know which antibiotics are susceptible to the bacteria and prescribe antibiotic therapy for patient
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Identify Minimum Inhibitory Concentration (MIC) and explain the importance of its use when determining an antibiotic regimen.

A

Minimum Inhibitory Concentration (MIC)

  • lowest concentration of antimicrobial that inhibits visible growth of bacteria
  • quantitative measure of antimicrobial susceptibility, required to determine best therapeutic

Influences level of toxicity, cost, resistance, removal of “good bacteria” in the body allowing for opportunistic infections.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Explain how to interpret and apply the antibiogram of UW.

A

Angiogram - regional profile of antimicrobial susceptibility testing results or specific microorganisms to antimicrobial drugs.

Under each antibiotic, values are based as percentage (%) of susceptibility of organism to antibiotic.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Identify Methicillin-resistant Staphylococcus aureus (MRSA)

  1. Gram stain structure
  2. Specific generic first choice antibiotics/drug that is effective against MRSA
A
  1. Gram positive cocci, clusters
  2. First choice - Vancomycin
    - - Alternative drugs: Doxycycline, Sulfamethoxazole / Trimethoprim (TMP-SMZ), Minocycline
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Moraxella catarrhalis

  1. Gram stain structure
  2. Most common clinical diagnosis
  3. First choice antibiotics/drug class
A
  1. Gram negative cocci.
  2. Acute otitis media (children), acute exacerbation of COPD, acute bacterial rhinosinusitis
  3. Cefuroxime (FLQ)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Neisseria gonorrhoeae (gonococcus)

  1. Gram stain structure
  2. Most common clinical diagnosis
  3. First choice antibiotics/drug class
A
  1. Gram negative cocci.
  2. Gonorrhea (urogenital infection)
  3. Ceftriaxone + Azithromycin or Doxycycline
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Neisseria meningitidis (meningococcus)

  1. Gram stain structure
  2. Most common clinical diagnosis
  3. First choice antibiotics/drug class
A
  1. Gram negative cocci.
  2. Meningitis (bacterial or community acquired)
  3. Penicillin
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Staphylococcus, Methicillin-resistant

  1. Gram stain structure
  2. Most common clinical diagnosis
  3. First choice antibiotics/drug class
A
  1. Gram positive cocci
  2. MRSA
  3. Vancomycin
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Streptococcus pyogenes (group A)

  1. Gram stain structure
  2. Most common clinical diagnosis
  3. First choice antibiotics/drug class
A
  1. Gram positive cocci
  2. Streptococcus pharyngitis
  3. Penicillin
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Streptococcus agalactiae (group B)

  1. Gram stain structure
  2. Most common clinical diagnosis
  3. First choice antibiotics/drug class
A
  1. Gram positive cocci
  2. Neonatal bacteremia with meningitis and/or pneumonia
  3. Penicillin
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Enterococcus species

  1. Gram stain structure
  2. Most common clinical diagnosis
  3. First choice antibiotics/drug class
A
  1. Gram positive cocci
  2. UTI, bacteremia, endocarditis, meningitis
  3. Ampicillin +/- gentamicin (faecalis), Vancomycin +/- gentamicin (faecium)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Haemophilus species

  1. Gram stain structure
  2. Most common clinical diagnosis
  3. First choice antibiotics/drug class
A
  1. Gram negative rods
  2. Meningitis, respiratory infections, otitis
  3. Ampicillin-clavulanate (resp. infection, otitis), Ceftriaxone (serious infections)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Escherichia coli

  1. Gram stain structure
  2. Most common clinical diagnosis
  3. First choice antibiotics/drug class
A
  1. Gram negative rods
  2. UTI, sepsis
  3. Nitrofurantoin, fosfomycin (UTI); Cefotaxime, ceftriaxone (sepsis)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Klebsiella pneumonia

  1. Gram stain structure
  2. Most common clinical diagnosis
  3. First choice antibiotics/drug class
A
  1. Gram negative rods
  2. Pneumonia
  3. Cephalosporins (TMP-SMZ, aminoglycoside)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Pseudomonas species

  1. Gram stain structure
  2. Most common clinical diagnosis
  3. First choice antibiotics/drug class
A
  1. Gram negative rods
  2. Pyelonephritis (recurrent UTI)
  3. Piperacillin-tazobactam, ceftazidime/cefepime, imipenem/meropenem/doripenem/aztreonam, +/- aminoglycoside
17
Q

Campylobacter jejuni

  1. Gram stain structure
  2. Most common clinical diagnosis
  3. First choice antibiotics/drug class
A
  1. Gram negative rods
  2. Food poisoning
  3. Azithromycin
18
Q

Clostridium species

  1. Gram stain structure
  2. Most common clinical diagnosis
  3. First choice antibiotics/drug class
A
  1. Gram positive rods
  2. Gas gangrene, tetanus
  3. Penicillin
19
Q

What is empiric antibiotic treatment and identify the importance of determining whether or not to start empiric treatment?

A

Antibiotics prescribed prior to confirming the pathogen and its susceptibility. Best educated guess based on source of infection.

Rarely helpful and may delay diagnosis if etiology is infectious (reduce sensitivity of blood cultures).

20
Q

CYTOMEGALOVIRUS (CMV)

  1. Identify brief clinical findings of primary CMV infection.
A

CMV

  1. Clinical findings:

Immunocompromised
— Retinitis, retinopathy, esophagitis, IBD symptoms, cough, dyspnea, sputum, polyradiculopathy, myelitis, encephalitis

Immunocompetent
— fever, malaise, myalgias, arthralgias, splenomegaly

21
Q

CYTOMEGALOVIRUS (CMV)

  1. Identify laboratory testing available for CMV.
A
  1. Laboratory test

Immunocompromised
— PCR assay (CMV DNA), tissue biopsy (organ involvement), ophthalmology refererral

Immunocompetent
— CBC (lymphocytosis, atypical), Chemistry (LFT), CMV DNA (IgM, IgG), viral load

22
Q

CYTOMEGALOVIRUS (CMV)

  1. Explain treatment for CMV.

When to admit to hospital?

A
  1. Treatment

HIV/AIDS
- Antiretroviral therapy (ART), antiviral medications (Ganciclovir IV + foscarnet, valganciclovir, cidofovir)

Post-transplant, non-severe
- Valganciclovir PO, Ganciclovir IV

Severe CMV
- Ganciclovir IV

23
Q

CYTOMEGALOVIRUS (CMV)

  1. When is hospital admission necessary?
A
  • escalating CMV viral load at onset of illness
  • risk of colonic perforation
  • evaluation of unexplained, advanced encephalopathy
  • initiation of treatment with IV anti-CMV agents
24
Q

EPSTEIN BARR VIRUS (EBV)

  1. Identify clinical findings for typical patient with EBV.
A

Clinical findings

  • Infectious mononucleosis (fever, sore throat, malaise, fatigue, anorexia, and myalgia)
  • maculopapular rash (strep throat sx), conjunctival hemorrhage
  • lymphadenopathy (posterior cervical) and splenomegaly
  • upper eyelid edema
25
Q

EPSTEIN BARR VIRUS (EBV)

  1. Explain the pitfalls and clinical use of Monospot test?
A

Clinical use:
- Serology test for IgG/IgM antibodies to EB virus capsid antigen

Pitfalls:

  • Specific but not sensitive
  • Positive after 4 weeks of onset
26
Q

EPSTEIN BARR VIRUS (EBV)

  1. Treatment options for EBV
A

Treatment

  • uncomplicated: supportive treatment (NSAIDS, salt rinses)
  • complicated: corticosteroids, splenectomy
27
Q

EPSTEIN BARR VIRUS (EBV)

  1. Identify complications and counseling for patient with EBV infections.
A

Complications

  • bacterial pharyngitis
  • splenic rupture, hepatitis, cholestasis, pericarditis, myocarditis
  • malignancy

Counseling
- NO CONTACT SPORTS

28
Q

INFLUENZA

  1. Explain the clinical findings for patient with seasonal influenza.
A

Clinical findings:

  • fevers, chills, headache, malaise, myalgias
  • runny/stuffy nose, sore throat, hoarseness, cough
  • mild pharyngeal injection, flushed face, conjunctival redness, enlarged cervical LN
29
Q

INFLUENZA

  1. Identify the transmission of influenza.
A

Transmission

Respiratory route by droplets.

30
Q

INFLUENZA

  1. Identify the laboratory findings associated with influenza virus and diagnostic test.
A

Laboratory Findings and Diagnostic Tests

CBC - leukopenia
UA - proteinuria

Nasal and throat swabs have suboptimal sensitivity (60-80%)
Chest X ray usually negative.

31
Q

INFLUENZA

  1. Identify complications associated with influenza and criteria for admission in patient with influenza.
A

Complications
- viral pneumonitis, shock, necrosis of respiratory epithelium, MI, PE, CVD, seizures, infection during pregnancy, Reye syndrome (fatty liver with encephalopathy in children)

Admissions Criteria
- limited availability of supporting services, pneumonia or decreased O2 saturation, changes in mental state, pregnancy

32
Q

INFLUENZA

  1. Distinguish treatment options for influenza and timeframe for efficacious treatment.
A

Treatment options

  • OSELTAMIVIR (tamiflu) - PO, 75 mg BID for 5 days
  • Zanamivir - inhaled, 2 puffs BID for 5 days
  • Peramivir - IV, 600mg or daily for 5 days (inpatient)

Timeframe
- Earlier the better, benefits of antiviral therapy after 48 hours is reduced.

33
Q

INFLUENZA

  1. Explain the immunization efficacy of influenza virus.
A

Immunization efficacy

  • prevent influenza and complications
  • reduce hospitalization
  • decreased mortality among hospitalized patients