Antibiotic Resistance

Question 1

what are the ESKAPE pathogens (bacteria most likely to become resistant)

Answer 1

i. Enterococcus faecium (VRE)
ii. Staph aureus (MRSA)
iii. Klebsiella pneumoniae
iv. Acinetobacter baumannii
v. Pseudomonas aeruginosa
vi. Enterobacter species

Question 2

Patient RFs for infections w/ antibiotic resistant organisms

Answer 2

a. HA-MRSA: debilitated or immunocompromised
b. CA-MRSA: children, military personnel, prisoners and athletes
c. VRE: prolonged hospitalization, use of abx, acuity of illness, and surgery.
d. Carbapenemases (Klebsiella, Pseudomonas, Enterobacter, Salmonella): patients with multiple comorbidities, ICU stays, prolonged hospitalization
e. Acinetobacter baumannii: ICU units, repatriated combat casualties (who acquired infection in contaminated field hospitals)

Question 3

MRSA transmission

Answer 3

horizontal spread; possible droplet spread if in the sputum

Question 4

VRE transmission

Answer 4

• patients may become colonized with it on skin, wounds and rectum – most frequent site is urinary tract. -Degree of contamination increases with rectal carriage and diarrhea.
• A room previously occupied by VRE+ patient increases risk of VRE acquisition of subsequent patient.

Question 5

acinetobacter baumannii transmission

Answer 5

able to survive/thrive in the hospital environment because of its tolerance of a wide range of physical conditions and high degree of innate resistance to antibiotics and disinfectants

Question 6

What types of genes confer antibiotic resistance?

Answer 6

a. Gram-negative resistance has multiple mechanisms
i. Porin mutations
ii. Overexpression of efflux pumps
iii. Penicillin-binding protein mutations
iv. Production of inactivating beta-lactamase enzymes

Question 7

2 mechanisms of high-level resistance

Answer 7

1. Production of extended spectrum beta-lactamases (ESBLs)

2. Production of carbapenemases

Question 8

contact precautions

Answer 8

gowns and gloves upon room entry
i. VRE; MRSA; ESBL-producing gram negatives and other highly resistant gram negative bacteria; c. diff w/ active diarrhea

Question 9

droplet precautions

Answer 9

surgical mask upon room entry

i. Influenza; meningococcal meningitis; rubella; pertussis; mycoplasma

Question 10

airborne precautions

Answer 10

Negative pressure room and N95 mask upon room entry
i. Pulmonary TB; varicella zoster; herpes zoster; disseminated herpes simplex infection in an immunocompromised pt; measles