Antimicrobials

Question 1

What is neonatal sepsis?

Answer 1

Whole body inflammatory state (systemic inflammatory response syndrome) and the presence of a known or suspected infection.

Question 2

How is neonatal sepsis classified?

Answer 2

Classified as either early-onset or late-onset depending on timing of the episode.

Question 3

What are the etiologies of early-onset sepsis?

Answer 3

• E. coli
• Group B strep (most common)
• Listeria monocytogenes (rare)
• Enterococci

Question 4

What is the typical timing for early-onset sepsis?

Answer 4

First 72 hours after birth.

Question 5

What are common causes of late-onset sepsis?

Answer 5

• Coagulase-negative staphylococcus
• Staph aureus
• Enterococci
• Multi-drug resistant gram-negative rods
• Candida

Question 6

What is a significant risk factor for late-onset sepsis?

Answer 6

Infants born before the third trimester are most susceptible.

Question 7

What are the clinical signs of neonatal sepsis?

Answer 7

Non-specific clinical features which can mimic many other conditions.

Question 8

True or False: Neonatal sepsis has reliable diagnostic markers.

Answer 8

False.

Question 9

What types of bacteria are frequently causing infections in NICU?

Answer 9

• Gram positive
• Gram negative
• Atypical bacteria (mycoplasma)
• Spirochetes
• Fungus
• Virus
• Protozoa

Question 10

What is the structural characteristic of gram-positive bacteria?

Answer 10

Thicker cell wall, rich in peptidoglycan.

Question 11

What distinguishes gram-negative bacteria?

Answer 11

Cell wall is rich in lipopolysaccharide.

Question 12

Fill in the blank: Gram positive bacteria lack an _______.

Answer 12

outer membrane.

Question 13

Name an example of an atypical bacteria.

Answer 13

• Mycoplasma
• Rickettsia
• Coxiella
• Chlamydia

Question 14

What are beta-lactam antibiotics known for?

Answer 14

Contain a beta-lactam ring in their chemical structure.

Question 15

What is the mechanism of action of most beta-lactam antibiotics?

Answer 15

Inhibit cell wall biosynthesis in the bacterial organism.

Question 16

What are common examples of beta-lactam antibiotics?

Answer 16

• Penicillin derivatives
• Cephalosporins
• Carbapenems

Question 17

What is the purpose of beta-lactamase inhibitors?

Answer 17

Prevent antimicrobial resistance and inhibit beta-lactamase from working.

Question 18

What is the role of vancomycin?

Answer 18

Treatment of serious infections by gram-positive bacteria unresponsive to other antibiotics.

Question 19

What does MIC stand for?

Answer 19

Minimum Inhibitory Concentration.

Question 20

What are the classifications of antifungals?

Answer 20

• Polyenes
• Azoles
• Echinocandins

Question 21

What is the mechanism of action of polyenes?

Answer 21

Bind to ergosterol in fungal cell membranes, causing cell death.

Question 22

What is the recommended treatment for early onset sepsis (EOS)?

Answer 22

Ampicillin and gentamicin.

Question 23

What should be used for late onset sepsis (LOS) if MRSA is suspected?

Answer 23

Vancomycin.

Question 24

What pathogens are commonly associated with early onset sepsis?

Answer 24

• Group B Streptococcus
• E. coli

Question 25

What percentage of women are colonized with Group B Streptococcus?

Answer 25

10-40%.

Question 26

What is the significance of ESBL?

Answer 26

Extended spectrum beta-lactamases confer resistance to certain antibiotics.

Question 27

What are the risks associated with aminoglycosides?

Answer 27

* Inner ear toxicity * Kidney damage

Question 28

Fill in the blank: Cloxacillin is indicated for _______ infections.

Answer 28

MSSA.

Question 29

What is the recommended prophylaxis for RSV?

Answer 29

Palivizumab (Synagis).

Question 30

What is the caution associated with vancomycin administration?

Answer 30

Monitor for serum concentrations to avoid treatment failures.

Question 31

What is the significance of the 60-minute administration time for vancomycin?

Answer 31

To avoid red man syndrome.

Question 32

What is the first generation of cephalosporins introduced?

Answer 32

1960s

Question 33

What type of enzymes are B-lactamase?

Answer 33

A heterogeneous group of resistance enzymes

Question 34

Which family of bacteria commonly expresses plasmid-encoded B lactamases?

Answer 34

Enterobacteriaceae

Question 35

What do B-lactamases confer resistance to?

Answer 35

* Penicillins * Narrow spectrum cephalosporins

Question 36

Are B-lactamases effective against higher generation cephalosporins?

Answer 36

No, they are not effective against those with an oxyimino side chain

Question 37

Which higher generation cephalosporins are mentioned?

Answer 37

* Cefotaxime * Ceftazidime * Ceftriaxone * Cefepime

Question 38

What does ESBL stand for?

Answer 38

Extended-spectrum beta-lactamases

Question 39

What are ESBL capable of hydrolyzing?

Answer 39

* Penicillins * Cephalosporins * Monobactam aztreonam

Question 40

What are AmpC beta-lactamases clinically important for?

Answer 40

Mediate resistance to cephalosporin antibiotics

Question 41

What antibiotics do AmpC beta-lactamases mediate resistance to?

Answer 41

* Cephalothin * Cefazolin * Cefoxitin * Most penicillins * Beta lactamase inhibitor-beta lactam combinations

Question 42

What is a common treatment for infections due to AmpC producing bacteria?

Answer 42

Carbapenems

Question 43

True or False: Meropenem should be used for treating enterobacter infections regardless of susceptibility reports.

Answer 43

True

Question 44

What are the consequences of improper antibiotic use?

Answer 44

* Increased risk of candida colonization * Increased risk of death with 3rd generation cephalosporin * Increased odds of NEC or death with empirical treatment >5 days

Question 45

What is the most common pathogen in early onset sepsis (EOS) in preterm infants?

Answer 45

E. coli

Question 46

What is the strongest predictor of early onset sepsis (EOS)?

Answer 46

Gestational age

Question 47

What are the two major risk factors for late onset sepsis (LOS)?

Answer 47

* Preterm birth * Low birth weight

Question 48

What is the gold standard for diagnosing urinary tract infections (UTIs)?

Answer 48

Urine sample obtained by suprapubic aspiration or catheter

Question 49

What is the recommended empirical antibiotic treatment for urinary tract infections (UTIs)?

Answer 49

* Ampicillin * Gentamicin or Cefotaxime

Question 50

What is the recommended prophylactic antibiotic for clean-contaminated surgical procedures?

Answer 50

Single dose of cefazolin

Question 51

What antibiotic combination is recommended for colorectal surgeries as prophylaxis?

Answer 51

* Cefazolin * Metronidazole

Question 52

What is the recommended empirical coverage for gastroschisis?

Answer 52

Beta lactamase resistant penicillin derivative combined with an aminoglycoside

Question 53

Fill in the blank: The recommended empirical antibiotics for EOS are _______ and _______.

Answer 53

Ampicillin, Gentamicin

Question 54

What is associated with increased odds of infection in diagnostic tests for EOS?

Answer 54

* Low WBCs * Low absolute neutrophil count * High immature to total neutrophil ratios

Question 55

What is the typical duration of antibiotic treatment for meningitis?

Answer 55

14-21 days

Question 56

What is the main pathogen of late onset sepsis (LOS) in NICUs?

Answer 56

Coagulase negative staphylococcus (CoNS)

Question 57

True or False: Empirical antibiotics for LOS should always include vancomycin.

Answer 57

False

Question 58

What should be favored in non-critically ill neonates for empiric antibiotic therapy?

Answer 58

Narrow spectrum therapy

Question 59

What is the recommendation for the duration of antibiotic therapy for NEC?

Answer 59

No evidence regarding optimal duration

Question 60

What is the accepted threshold of pathogen growth in urine for UTIs?

Answer 60

>5 x 10^7