Study Design - AST Flashcards
What are the four ways resistance mechanisms can work together
individual classes of drugs inactivated by more than one mechanism of resistance
Individual organisms may employ different mechanisms to generate resistance to single drug and to different classes of drugs - mechanisms interact to determine te actual level of resistance
Genes that encode resistance determinants are often present on mobile genetic elements e.g. plasmids, phages etc
Spread of resistance between species, genera and even families
How are we combating resistance?
WHO and numerous other groups and researchers agree that the spread of AMR is an urgent issue requiring a global, coordinated action plan to address
HSE folloeing the ‘one health’ approach
GLASS was also launched
What are the 5 objectives of the WHO action plan?
To improve awareness annd understanding of antimicrobial resistance though effective communication, education and training
To strengthen the knowledge and evidence base through surveillance and research
To reduce the incidence of infection through effecive sanitation, hygiene and infection prevention measures
To optimise the use of atimcrobial medicines in human and animal health
To develop the economic case for sustainable ivestment in new medicines, diagnostic tools, vaccines and other interventions
What is the ‘Naughty List’?
A list of organims create by the UN General Assembly when they held a high-level meeting on AMR in Sept 2024 to address the global threat of AMR
What organisms are on the UN Naughty List
MRSA
VRE
ESBL producing GNBS
CPEs
CPOs
What does CPO stand for and give two examples?
Carbapenemase Producing Organisms Non-fermenting e.g. Pseudomonas or Acinetobacter
How are HCA caused by resistance organisms classified
Low grade-healtchare associated infections
- not very virulent but very resistant
Virulent pathogens -> susceptible to few antimicrobials
-> more virulent but not as resistant
What are considered low grade-healthcare associated infections?
VRE
LRE
Acinetobacter
Pandrug resistance
What are considered virulent HCAI pathogens
CPE
MRSA
ESBL
Extensively drug resistant (XDR)
Whst is meant by XDR
Susceptible to 1-2 antibiotics
What are the trends in AMRs
HCAI are crossing into the community
-> MRSA +CPEs increasing in the community with MDR > 3 antibiotic classes
Resistance is emerging in what were traditionally community pathogens e.g. s. pneumonia, N. gonorrhoea, Shigella (progressively less susceptibly)
-> XDR in TB
What is iNAP 2
Irelandd National Action Plan on AMR
Put in place in November 2021
Irelands second action plan
To be ran from 2021 to 2025
What are the five aims of INPA 2
To improve awareness and knowledge
To enhance surveillance of antibiotic resistance and antibiotic use
Reduce the spread of infection and disease
Optimise the use of antimicrobials in human and animal health
Promte research and sustainable investments in new medicines, diagnostic tools, vaccines and other interventions
How is Ireland increasing surveillance
HPSC - new division AMRIC surveillance - hope for more comprehensive resistance surveillance
Investment in antimicrobial stewardship
Increased research funding to 2.2 million
How does surveillance data allow for action on resistance?
Through:
- timely data collection
- validation
- analysis
- feedback and reporting
By monitoring trends over time:
- detecting the emergence and spread of new AMR phenotypes before theyre a problem
- inform policy makers
- effect of interventions, e.g. following introductions of a vaccine etc
What is EARSS
European Antimicrobial Resistance Surveillance System
It was estbalished in 1998
It was coordinated by the dutch national institute for pubic health and the environment (RIVM)
How has EARSS developed?
Starting with just 2 pahogens: S. aureus and S. pneumonia
Incidence across 13 countries whereby only 12 labs were reporting
It was transferred to the ECDC in 2010 where it was renames EARS-NET
What is EARS-NET
EARSS taken over by the ECDC in 2010
As of 2023 there are now 30 countries reporting to the network
Other non-EU/EEA countries participate to CAESAR the sister project ran by WHO
What is CAESAR?
The sister project of EARS_NET for non EU countries ran by WHO
How does EARS-NET define what data it will collect
They collect antimicrobial resistance data on the first invasive isolate per patient per year for eight pathogens
What eight pathogens does EARSS NET collect data on, list in order of frequency
E. Coli (blood or CSF)
S. aureus (blood only)
E. faecium (blood only)
K. pneumoniae (blood or CSF)
E. faecalis (blood only)
P. aeruginosa (bloof or CSF)
Ainetobacter species (blood or CSF)
*sample types are important as strains have to be invasive
Talk about reporting to EARS-NET in Ireland
Most micro labs 33/36 in ireland partcipate although at times labs may stop submitting due to local resource issues despite the fact that 7 of the 8 pathogens are notifiable
What kind of data does EARS NET collect?
Their data is most qualitative i.e. RIS data
Some quantitative is specifically requested as this helps with interpretation e.g. penicillin and cefotaxime for S. pneumoniae
Data are collected locally by labs usind different methods
What are the three ways data can be collected for EARS
WHONET +/- BacLink -> translates data from a LIMS file to SQLite or dBase
LIMS extract which sends data directly
Excel tool developed in house at HPSC mostly used by smaller labs
Talk about MRSA in Ireland
A challenge because of its antibiotic resistance but also because of its potential for cross-infection within hospitals
CA-MRSA emerged in the 1990s, infecting individuals without prior contact with healthcare facilities
Unlike Hospital acquired MRsA, CA-MRsA exibits less antibiotic cross-resistance but retains the virulence of its MSSA ancestors -> its often linked to the production of proton-valentine leukocidin toxin
The movement of MRSA between hospital and community settings raises signiicant concerns about its control an prevention
Livestock-Associated MRSA has also been identified as an emerging threat
When did CA-MRSA emerge?
Emerged in the 1990s
How does CA-MRSA differ from HA-MRSA?
CA exhibits less antibiotic cross-resistance but retains the virulence of it MSSA ancestors
The production of what is seen in CA-MRSA and not HA-MRSA?
Production of Panton-Valentine Leukocidin Toxin
In recent years what has been identified as an emerging threat for MRSA?
Livestock associated MRSA
Talk about MRSA in Irish hospitals
MRSA emerged as a prominent concern in Irish hospitals in the late 20th century
Prevalence rates steadily rose though the 1990s and early 2000s
More recently the spread of CA-MRSA has emerged as a more important concern
How has Ireland MRSA rates faired compared to Europe?
Ireland was historically categorised among European countries with relatively high levels of MRSA, comparable to the UK and southern European countries
Give some examplesof CA-MRSA outbreaks in Ireland
Outbreaks have been reported in schools, sports teams and other community groups, highlighting the need for enhanced surveiallance and community education
How is MRSA resistance acquired?
Through a chromosomal gene such as mecA or mecC
How does mecA or mecC induce MRSA resistance?
These genes lead to the production of an altered penicillin-binding protein (PBP) called PBP2a
How does PBP2a induce resistance?
PBP2a has a reduced affinity for methicillin and other B-lactams, resulting in high-level resistance to these antibiotics
Talk about MR in S. epidermidis
There is a comparable gene and resistance mechanism to that of MRSA found in S. epidermidis
