Hospital-acquired infections Flashcards
What is an antimicrobial
agent which interferes with growth and reproduction of a microbe
What is an antibacterial
agent used to reduce or eliminate harmful bacteria
What is an antibiotic
type of antimicrobial agent; originally referred to one of organic origin
What are healthcare-associated infections (HAIs)
Infections that occur after exposure to healthcare. Infection starts over 48 hours after admission
1/18 patients in hospital acquires an HAI
What are the most frequent types of HAIs
Surgical site infections Urinary tract infections Pneumonia Bloodstream infections Gastrointestinal infections.
What factors contribute to high rates of HAIs
Spread is very easy in hospitals, both via staff and when patients are moved between different wards or departments.
Higher concentration of sick people
Use of interventions
Prophylactic antibiotics can lead to drug-resistant infection
What interventions used in hospitals do HAIs often occur through
Catheters Lines (IV, central, artery) Intubation Prophylactic antibiotics Other prosthetic material
What us the most important feature of the most important HAIs
Drug resistance
What are the most important HAIs
ESCAPE Enterococcus faecium Staphylococcus aureus Clostridium difficile Acinetobacter baumanii Pseudomonas aeruginosa Enterobacteriaceae family
Give examples of bacteria in the Enterobacteriaceae family
E. coli
Klebsiella pneumoniae
Enterobacter sp.
Which of the HAIs are gram positive
Enterococcus faecium
Staphylococcus aureus
Clostridium difficile
Which of the HAIs are gram negative
Acinetobacter baumanii
Pseudomonas aeruginosa
Enterobacteriaceae family
What are the problems that arise when treating the ESCAPE pathogens
Clinicians are forced to use older, previously discarded drugs, such as colistin, that are associated with significant toxicity and for which there is a lack of robust data to guide selection of dosage regimen or duration of therapy
Which antibiotics are Enterococcus faecium resistant to
Vancomycin
60% vancomycin-resistant, as the bacterium synthesises a different PG precursor.
Describe S. aureus as a drug-resistant infection
Resistance to Methicillin (MRSA)
most common drug-resistant infection worldwide.
Methicillin is another β-lactam antibiotic, but resistance to it comes via expression of an additional PBP, one with a lower affinity for methicillin.
What can K. pneumoniae cause in immunocompromised and what is it resistant to
UTIs and RTIs
often cephalosporin and/or carbapenem resistant
What can P. aeruginosa cause in immunocompromised and what is it resistant to
Infects the immunocompromised, most notably battlefield trauma cases
What pathogen is the most frequent hospital-acquired cause of gram -ve bacteraemia
E. coli
What pathogen is the most frequent case of call urinary tract infections
E. coli
Which drugs is E. coli resistant to
Cephalosporins
Carbapanems
Describe Cephalosporins
a class of β-lactam antibiotics that block peptidoglycan (PG) synthesis by inhibiting penicillin binding proteins (PBPs)
Describe the resistance of bacteria to Cephalosporins (epidemiology and mechanism)
Resistance is up to 20% in some countries, and the - method is an extended spectrum β-lactamase (ESβL) enzyme which cleaves the cephalosporin
Describe Carbapanems
class of β-lactam antibiotics which inhibit the same pathway. Most cephalosporin-resistant strains are still sensitive to carbapenems.
Describe how resistance to Carbapanems develops
Resistance can develop through a carbapenemase enzyme (encoded on a transposon as opposed to ESβL’s plasmid)
