Hospital Acquired Infections Flashcards
Define the following:
a. Antimicrobial
b. Antibacterial
c. Antibiotic
a. Antimicrobial
Interferes with growth and reproduction of a microbe
b. Antibacterial
Commonly used to describe agents that reduce or eliminate harmful bacteria
c. Antibiotic
Type of antimicrobial that is used as medicine for humans and animals
What is a health-care associated infection?
Infections that occur after exposure to healthcare
Infection starts >48 hours after admission to hospital
Why do health-care associated infections cost money to the healthcare system?
They increase the length of stay at hospital
List some medical interventions that can increase the risk of infection.
Catheterisation
Intubation
Lines (e.g. central venous lines)
Chemotherapy
Prosthetic material
Prophylactic antibiotics/Inappropriate prescribing
State the 3 factors that increase the risk of infection in the hospital setting.
Interventions
Dissemination by healthcare staff
Concentration of ill patients
What are the ESCAPE pathogens?
Enterococcus faecium
Staphylococcus aureus
Clostridium difficile
Acinetobacter baumanii
Pseudomonas aeruginosa
Enterobacteriaceae
NOTE:
ESC are Gram-positive
APE are Gram-negative
What is the main problem with the escape pathogens?
They are antibiotic resistant
What is the most frequent cause of bacteraemia by a Gram-negative bacterium?
E. coli
What does E. coli frequently cause?
UTI
Which antibiotics is E. coli resistant to in many countries?
Cephalosporins
Which antibiotics is E. coli still sensitive to?
Carbapenems
What is ESBL encoded on?
Plasmid
What are carbapenemases encoded on?
Transposon
What types of infections does Klebsiella pneumoniae tend to cause?
UTI
Respiratory tract
Which group of patients are at risk of Klebsiella infection?
Immunocompromised
Which classes of antibiotics are Klebsiella widely resistant to?
Cephalosporins, fluoroquinolones and aminoglycosides
Carbapenem resistance in the US
Which group of patients are at risk of P. aeruginosa infection?
Immunocompromised
Which class of antibiotics is P. aeruginosa widely resistant to?
Carbapenems
What is the most important cause of antimicrobial resistant infection in the world?
MRSA
What is Enterococcus faecium widely resistant to?
Vancomycin
What are the most common HAI?
surgical site infections
urinary tract infection
pneumonia
bloodstream infections
gastrointestinal infections
What is the class, target pathway and target protein of Cephalosporins?
class of b-lactam antibiotics
Target pathway:
Inhibit peptidoglycan
synthesis
Target protein:
Inhibit the activity
of penicillin binding
proteins (PBPs)
What is the mechanism of resistance to Cephalosporins?
Extended spectrum
b-lactamase (ESBL)
coded on a mobile plasmid
ESBL enzyme cleaves cephalosporin
What is the class, target pathway and target protein of Carbapenems?
A class of b-lactam antibiotics
Target pathway:
Inhibit peptidoglycan
synthesis
Target protein:
Inhibit the activity
of penicillin binding
proteins (PBPs)
What is the mechanism of resistance to Carbapenems?
carbapenemase enzyme,
blakpc
encoded on a tranposon
mobile genetic element
enzyme cleaves carbapenem
What is the class, target pathway and target protein of Methicillin?
Is a b-lactam antibiotics
Target pathway:
Inhibit peptidoglycan
synthesis
Target protein:
Inhibit the activity
of penicillin binding
proteins (PBPs)
What is the mechanism of resistance to Methicillin?
Expression of additional
penicillin binding protein
PBP2A has low affinity for methicillin and can still function in the presence of the antibiotic
MRSA strains can synthesis peptidoglycan and survive in the presence of methicillin
What is the target pathway and target protein of Vancomycin?
Target pathway:
Inhibit peptidoglycan
synthesis
Target:
binds to peptidoglycan precursor
What is the mechanism of resistance to vancomycin?
multiple proteins
genes encoded on plasmid or transposon
Results in the synthesis of a different PG precursor
What does Enterococcus faecium cause?
Blood stream infections
