L.12 Antimicrobial Resistant Organisms Flashcards
1
Q
What has enabled huge advances in medicine over the last 70 years?
A
Antibiotics
Their contribution has altered life expectancy.
2
Q
What has increased at an alarming rate over the last two decades?
A
Antimicrobial resistance
This trend represents a serious clinical problem.
3
Q
What are the two main issues caused by the emergence of antimicrobial resistance?
A
- Multi-drug resistance
- Cross infection
These issues limit treatment options and facilitate the spread of pathogens.
4
Q
What does the WHO identify as a major threat to public health?
A
Global epidemic of antimicrobial resistance (AMR)
This leads to mounting healthcare costs, treatment failure, and deaths.
5
Q
What has become severely limited due to antibiotic resistance?
A
Antibiotic choices
This limitation affects treatment options.
6
Q
What does PDR stand for?
A
Pan Drug resistance
It refers to resistance to all currently available antimicrobial classes.
7
Q
What is the definition of XDR?
A
Extensively Drug resistance
It indicates resistance to ≤ 2 antimicrobial classes.
8
Q
What is the definition of MDR?
A
Multi drug resistance
It refers to resistance to ≥ 3 antimicrobial classes.
9
Q
What is the predicted mortality rate due to antibiotic resistance by 2050?
A
10 million deaths
This highlights the significant burden of AMR.
10
Q
What is the estimated healthcare cost due to antibiotic resistance per year?
A
€66 billion
This reflects the financial burden on healthcare systems.
11
Q
What is the estimated direct cause of deaths per year in Ireland due to AMR?
A
5,000 deaths
This statistic underscores the human impact of antibiotic resistance.
12
Q
How much more likely are patients with HCAI to die in hospital?
A
X 7 more likely
This statistic emphasizes the severity of healthcare-associated infections.
13
Q
By how many days does HCAI delay patient discharge on average?
A
11 days
This impacts hospital efficiency and patient flow.
14
Q
What are the four mechanisms of resistance?
A
- Extrusion of antibiotics
- Decreased permeability
- Production of drug modifying enzymes
- Modification of drug target
These mechanisms contribute to the development of antibiotic resistance.
15
Q
What does AMRO stand for?
A
Antimicrobial Resistant Organisms
AMRO includes various resistant pathogens that were traditionally associated with healthcare settings but are now becoming common in communities.
16
Q
List three examples of AMRO.
A
- Methicillin Resistant Staphylococcus aureus (MRSA)
- Vancomycin Resistant Enterococci (VRE)
- Extended Spectrum B-lactamase Producing GNBs (ESBLs)
17
Q
What are Carbapenemase Producing Organisms (CPO)?
A
Non-fermenting Gram-negative bacteria such as Pseudomonas and Acinetobacter
CPO includes organisms that produce enzymes capable of breaking down carbapenems, making them resistant.
18
Q
What are the ESKAPEEs?
A
- E.faecium = VRE
- S.aureus = MRSA
- Klebsiella = ESBLs
- Acinetobacter = MDR, Carbapenemases
- Pseudomonas = MDR
- Enterobacter = ESBLs
- E.coli = ESBLs
19
Q
How many of the ESKAPEEs are Gram-negative?
A
5 out of 7
This highlights the prevalence of Gram-negative bacteria among the most concerning resistant organisms.
20
Q
What is the trend regarding reliance on carbapenems?
A
Increasing reliance on carbapenems
Carbapenems are often used as a last resort for treating resistant infections.
21
Q
What is required for infection prevention and control (IPC) and public health regarding AMR?
A
Detection of ESBLs and carbapenemases
Identifying these resistant enzymes is crucial for managing infections and public health strategies.
22
Q
What are low-grade healthcare associated pathogens mentioned in AMR trends?
A
Vancomycin Resistant Enterococci (VRE)
These pathogens are increasingly found outside of healthcare settings.
23
Q
What is the significance of PDR in Acinetobacter?
A
Acinetobacter is resistant to all currently available antimicrobials (PDR)
PDR stands for pan-drug resistant, indicating a severe level of resistance.
24
Q
What is the definition of XDR?
A
Extensively Drug Resistant
XDR refers to pathogens that are resistant to all but 1 or 2 antimicrobial classes.
25
What is a notable trend regarding the boundary between hospital and community pathogens?
The boundary is increasingly blurred, with MDR pathogens causing both hospital- and community-onset infections
## Footnote
This indicates the spread of resistant organisms from healthcare settings to the general population.
26
Fill in the blank: MRSA and CPEs are increasing in the community, with MDR resistance to _______ antibiotic classes.
≥3
## Footnote
This indicates a significant level of resistance in community-acquired infections.
27
Name two community pathogens showing progressive less susceptibility.
* S. pneumonia
* N. gonorrhoeae
## Footnote
These pathogens are becoming increasingly resistant to available treatments.
28
What does XDR stand for in the context of tuberculosis (TB)?
Extensively Drug Resistant
## Footnote
XDR TB is a form of tuberculosis that is resistant to the most effective anti-TB drugs.
29
What is Ireland’s Second One Health National Action Plan focused on?
Antimicrobial Resistance
## Footnote
The plan includes improving awareness, enhancing surveillance, reducing infection spread, optimizing antimicrobial use, and promoting research.
30
What are the goals of the One Health National Action Plan on Antimicrobial Resistance?
* Improve awareness and knowledge
* Enhance surveillance of antibiotic resistance and antibiotic use
* Reduce spread of infection and disease
* Optimize use of antimicrobials in humans and animal health
* Promote research and sustainable investment in new medicines, diagnostic tools and vaccines
## Footnote
Includes investment in antimicrobial stewardship and increased research funding.
31
What organism is MRSA a strain of?
Staphylococcus aureus
## Footnote
MRSA stands for Methicillin-Resistant Staphylococcus aureus.
32
What defines MRSA?
A strain of S. aureus that has acquired resistance to all β-lactam antibiotics due to a modified penicillin-binding protein (PBP2a).
## Footnote
This resistance complicates treatment options.
33
What gene is primarily responsible for MRSA resistance?
mecA
## Footnote
A less common variant is mecC.
34
What does the mecA gene encode?
Altered penicillin-binding protein 2a (PBP2a)
## Footnote
PBP2a has a low affinity for β-lactam antibiotics.
35
What is the effect of PBP2a on β-lactam antibiotics?
Prevents these drugs from inhibiting cell wall synthesis, leading to resistance.
## Footnote
This mechanism makes MRSA difficult to treat.
36
What are the two main types of MRSA?
* Healthcare-associated MRSA (HA-MRSA)
* Community-associated MRSA (CA-MRSA)
## Footnote
Each type has distinct features and settings of acquisition.
37
What characterizes Healthcare-associated MRSA (HA-MRSA)?
Found in hospital settings, often multidrug-resistant, major cause of hospital-acquired infections (HCAIs).
## Footnote
Common HCAIs include bloodstream infections and pneumonia.
38
What are common infections caused by Community-associated MRSA (CA-MRSA)?
Skin and soft tissue infections, such as boils and abscesses.
## Footnote
CA-MRSA may carry the PVL toxin linked to severe infections.
39
When was MRSA first detected and where?
1961 in the UK
## Footnote
Its emergence was considered a major setback in antimicrobial therapy.
40
What recent trends have been observed in MRSA rates?
Declining rates across many regions due to improved infection control and surveillance.
## Footnote
Europe saw a decrease from 12.7% (2019) to 9.7% (2023).
41
What percentage of invasive S. aureus isolates were MRSA in Ireland in 2023?
24%
## Footnote
This figure reflects the current epidemiological status in Ireland.
42
What is the EU average percentage of MRSA in invasive S. aureus isolates?
17.6%
## Footnote
This is a comparative statistic to understand MRSA prevalence in the EU.
43
What is the purpose of screening and surveillance for MRSA?
To detect colonisation in high-risk individuals (e.g. pre-operative patients, ICU admissions)
## Footnote
High-risk individuals are more susceptible to MRSA infections.
44
What are common screening sites for MRSA detection?
* Nasal swabs
* Groin
* Axilla
## Footnote
These sites are often where MRSA colonization occurs.
45
What is chromogenic agar and its role in MRSA detection?
Chromogenic agar (e.g. CHROMagar MRSA) is used for rapid presumptive identification of MRSA through color change based on metabolic activity.
## Footnote
This method allows for quick identification in laboratory settings.
46
What does a cefoxitin disk diffusion test indicate for MRSA?
A zone diameter <22 mm indicates MRSA.
## Footnote
Cefoxitin is preferred as a surrogate for methicillin in MRSA detection.
47
What cefoxitin MIC value indicates methicillin resistance?
Cefoxitin MIC >4 mg/L indicates methicillin-resistant.
## Footnote
This measurement helps in determining the susceptibility of the strain.
48
What does the latex agglutination test detect in MRSA?
It detects PBP2a protein (mecA product).
## Footnote
This test is useful for confirming MRSA but does not detect mecC-positive strains.
49
Why is oxacillin or methicillin disk diffusion discouraged in MRSA detection?
Due to poor reproducibility; no longer used in EUCAST/CLSI breakpoints.
## Footnote
This change reflects advancements in detection methods.
50
What are the genotypic methods for detecting MRSA?
PCR for direct detection of mecA or mecC gene, often part of real-time multiplex PCR platforms.
## Footnote
These methods provide rapid, sensitive, and specific detection.
51
Name two platforms that use multiplex PCR for MRSA detection.
* Xpert MRSA (GeneXpert)
* FilmArray or LAMP assays
## Footnote
These platforms enhance the speed and accuracy of MRSA detection.
52
What is the primary resistance of MRSA?
MRSA is resistant to all β-lactams, including:
* Penicillins (e.g. flucloxacillin)
* Cephalosporins (e.g. cefalexin)
* Carbapenems (e.g. meropenem)
## Footnote
This broad resistance complicates treatment options.
53
What is the first-line treatment for systemic MRSA infections?
Vancomycin
## Footnote
Vancomycin is commonly used due to its effectiveness against MRSA.
54
What is another common treatment option for MRSA apart from vancomycin?
Teicoplanin
## Footnote
Teicoplanin is an alternative antibiotic used for treating MRSA infections.
55
What does VRE stand for?
Vancomycin-Resistant Enterococcus
56
Which organisms are primarily involved in VRE infections?
* Enterococcus faecalis
* Enterococcus faecium
57
Define VRE.
Strains of Enterococcus species that have acquired resistance to vancomycin
58
What is the concern with VRE?
It is frequently multidrug-resistant, with some strains classified as XDR (Extensively Drug-Resistant)
59
What are the main van genes associated with VRE resistance?
* VanA
* VanB
60
How does VRE achieve resistance to vancomycin?
By altering the D-Ala-D-Ala termini of peptidoglycan precursors to D-Ala-D-Lac or D-Ala-D-Ser
61
What does the VanA gene cluster confer?
High-level resistance to vancomycin and teicoplanin
62
What is the clinical significance of Enterococci?
Typically low-virulence organisms that can cause opportunistic healthcare-associated infections
63
Name common infections caused by VRE.
* Bloodstream infections (BSI)
* Urinary tract infections (UTIs)
* Endocarditis
* Intra-abdominal infections
64
What is the key concern regarding VRE infections?
They are difficult to treat and associated with higher morbidity and mortality
65
When did VRE first emerge?
Early 1990s
66
What were the VREfm rates in Ireland from 2019 to 2023?
Declined from 38.6% to 21.4%
67
What was the EU/EEA average for VREfm in 2023?
16.8%
68
What is a common screening specimen for VRE detection?
Rectal swabs
69
What culture media is used to differentiate E. faecalis and E. faecium?
Chromogenic agar (e.g. CHROMagar VRE)
70
What is the Minimum Inhibitory Concentration (MIC) for high-level resistance (VanA)?
MIC ≥ 64 mg/L
71
What is the MIC for low-level resistance (VanB)?
MIC ~4 mg/L
72
What does a zone diameter of <12 mm in a vancomycin disk diffusion test indicate?
Resistant
73
What are the treatment options for confirmed VRE infections?
Linezolid is the mainstay of treatment
74
What is the role of PCR testing in VRE detection?
Detects VanA, VanB, and other van genes for rapid identification
75
True or False: Automated systems like VITEK are recommended for VRE detection.
False
76
Fill in the blank: VRE strains are often resistant to all established classes, necessitating _______ testing to guide therapy.
susceptibility
77
What does MDR-GNB stand for?
Multi Drug Resistant Gram-Negative Bacteria
## Footnote
MDR-GNB are a growing public health threat due to their resistance to multiple antibiotic classes.
78
What is a major characteristic of MDR-GNB?
Ability to resist multiple classes of antibiotics, often through β-lactamase production
## Footnote
This resistance is contributing to healthcare-associated infections (HCAIs) and is spreading into community settings.
79
What are Extended-Spectrum β-Lactamases (ESBLs)?
Enzymes that hydrolyse β-lactams including penicillins and 1st–3rd generation cephalosporins
## Footnote
They do not hydrolyse carbapenems or cephamycins and are inhibited by clavulanic acid, tazobactam, and sulbactam.
80
Which antibiotics are not hydrolysed by ESBLs?
Carbapenems and cephamycins
## Footnote
This characteristic makes carbapenems a crucial option for treating infections caused by ESBL-producing organisms.
81
What are AmpC β-Lactamases?
Enzymes that confer resistance to cephamycins and many penicillins and cephalosporins
## Footnote
They can be chromosomally encoded or plasmid-mediated and are not inhibited by β-lactamase inhibitors.
82
List some organisms that can produce chromosomally encoded AmpC β-Lactamases.
* Enterobacter cloacae
* Citrobacter freundii
* Serratia marcescens
* Morganella morganii
* Pseudomonas aeruginosa
## Footnote
These organisms can either have chromosomal or plasmid-mediated AmpC β-lactamases.
83
What are carbapenemases?
β-lactamases that inactivate carbapenems
## Footnote
They are often last-resort antibiotics and include KPC, NDM, VIM, OXA-48, and IMP types.
84
Which organisms are commonly associated with carbapenemases?
* Pseudomonas aeruginosa
* Klebsiella pneumoniae
* Other Enterobacterales
## Footnote
Carbapenemases represent a major global health concern due to their resistance.
85
What is the resistance profile of ESBL-producing organisms?
* Resistance to penicillins
* Resistance to extended-spectrum cephalosporins (e.g., cefotaxime, ceftriaxone, ceftazidime)
* Resistance to aztreonam
## Footnote
These organisms are often associated with co-resistance to fluoroquinolones, aminoglycosides, and sulfonamides.
86
When were ESBL-producing organisms first detected?
In the 1990s
## Footnote
Their emergence has been linked to the spread of plasmids encoding ESBL genes.
87
What is the significance of CTX-M, TEM, and SHV in relation to ESBLs?
They are examples of genes encoding ESBLs
## Footnote
These genes spread via plasmids and contribute to the increasing prevalence of ESBL-producing organisms.
88
Fill in the blank: MDR-GNBs are often resistant to not only β-lactams but also _______.
aminoglycosides, fluoroquinolones, and sometimes polymyxins.
89
What are the implications of MDR-GNB infections in healthcare?
Longer hospital stays, higher healthcare costs, and increased mortality
## Footnote
These infections are difficult to treat due to their resistance patterns.
90
What is the rate of invasive ESBL-producing E. coli and K. pneumoniae in Ireland over the last 5 years?
Around 10%
## Footnote
This rate has remained stable, although ESBL prevalence is increasing globally.
91
What is the trend of ESBL prevalence in community-acquired infections?
Increasing globally
92
What are the initial susceptibility testing results that indicate reduced susceptibility for ESBL detection?
* Cefotaxime
* Ceftazidime
* Aztreonam
93
What is the purpose of confirmatory testing in ESBL detection?
To confirm ESBL production
94
What combination disk tests are used in confirmatory testing for ESBLs?
* Ceftazidime ± clavulanic acid
* Cefotaxime ± clavulanic acid
95
What does a ≥5 mm increase in inhibition zone indicate?
ESBL production
96
What types of tests can be used for confirmatory testing of ESBLs?
* MIC-based tests (e.g., E-tests)
* Automated systems (e.g., VITEK, BD Phoenix)
97
What is a key distinction between ESBLs and AmpC β-lactamases?
ESBLs are inhibited by clavulanic acid; AmpC is not
98
What distinguishes ESBLs from Carbapenemase producers?
Carbapenemase producers show resistance to carbapenems
99
What specific detection methods are required for Carbapenemase producers?
* Modified Hodge test
* Carba NP
* Molecular PCR for bla_KPC, bla_NDM, etc.
100
How is ESBL transmission often facilitated in healthcare settings?
Via contaminated hands, instruments, or surfaces
101
What infection control measures are required for managing ESBL infections?
* Strict hygiene
* Contact precautions
* Environmental cleaning
102
What treatment options are available for ESBL infections?
* Carbapenems
* Ceftazidime/avibactam
* Fosfomycin
* Colistin depending on resistance pattern
103
What is the primary method used for conventional ESBL screening?
Chromogenic selective media used with rectal swabs for surveillance and detection
## Footnote
Chromogenic media helps in identifying ESBL-producing strains.
104
What are the common chromogenic media used for ESBL detection?
* CHROMagar: Sensitivity 98%, Specificity 72%
* ChromID: Sensitivity 98%, Specificity 73%
* Brilliance: Sensitivity 99%, Specificity 58%
## Footnote
These media have varying levels of sensitivity and specificity in detecting ESBLs.
105
What is a limitation of chromogenic media in ESBL detection?
No medium is 100% selective for ESBLs
## Footnote
This limitation can lead to false positives.
106
What can cause false positives in ESBL screening?
* Derepressed AmpC β-lactamase producers
* Pseudomonas aeruginosa
## Footnote
These organisms may interfere with accurate ESBL detection.
107
What is the takeaway from culture-based ESBL screening?
Must be followed by confirmatory tests to ensure accuracy
## Footnote
Confirmatory tests are essential to validate initial screening results.
108
What method is used for molecular surveillance of ESBLs?
PCR-based molecular detection directly from clinical samples
## Footnote
This method allows for rapid identification of ESBLs from samples like rectal swabs.
109
What is an example of a PCR assay for ESBL detection?
Check-Direct ESBL PCR Assay
## Footnote
This assay provides timely results for ESBL identification.
110
How quickly does the Check-Direct ESBL PCR Assay provide results?
Approximately 2 hours
## Footnote
This rapid result delivery is crucial for timely clinical decisions.
111
What major ESBL genotypes are detected by molecular methods?
* CTX-M groups: CTX-M-1, CTX-M-2, CTX-M-9
* SHV-ESBLs
## Footnote
These genotypes are significant in understanding ESBL-producing organisms.
112
How does the sensitivity of molecular methods compare to traditional culture methods?
Shows higher sensitivity than traditional culture methods in early evaluations
## Footnote
This advantage makes molecular methods preferable in certain clinical situations.
113
What is the variant diversity of CTX-M, TEM, and SHV variants?
* ~80 CTX-M variants
* ~160 TEM variants
* ~110 SHV variants
## Footnote
The diversity of these variants highlights the complexity of ESBL epidemiology.
114
What is a benefit of rapid identification of colonized patients?
Supports early infection control interventions
## Footnote
Early identification can significantly impact patient management and control of infections.
115
What is the Combination Disk Test (CDT) used for?
To compare inhibition zones of cephalosporin disk alone vs. cephalosporin + clavulanic acid
116
What indicates an ESBL positive result in the Combination Disk Test?
≥5 mm increase in inhibition zone
117
What additional tests can be performed to assess for co-existing AmpC β-lactamase?
Add cefepime/clavulanate or AmpC inhibitor
118
What is the purpose of the Double-Disk Synergy Test (DDST)?
To look for enhanced inhibition zone between cephalosporins and amoxicillin/clavulanate disks
119
What does a 'keyhole' appearance in the DDST indicate?
ESBL positivity
120
How far apart should the disks be placed in the Double-Disk Synergy Test?
20–30 mm apart
121
What factors affect disk spacing in the DDST?
* Narrow for high-level resistance
* Wider for low-level resistance
122
What can be used to block AmpC interference in the DDST?
Cloxacillin
123
What is the purpose of Gradient Strip Tests (e.g., Etest)?
To test antibiotic ± clavulanate on the same strip
124
What indicates ESBL positivity in Gradient Strip Tests?
* ≥8-fold MIC reduction
* ‘Phantom’ inhibition zone
* Deformed ellipse shape
125
What should be done if results are 'non-determinable' in Gradient Strip Tests?
Perform additional testing using cefepime/clavulanate or cefotetan/cloxacillin
126
Which organism is often naturally susceptible to clavulanate and should not routinely be tested for ESBLs?
Acinetobacter spp.
127
Why is Pseudomonas aeruginosa screening for ESBLs not recommended?
Rare ESBL producers; screening not recommended unless resistance observed
128
What enzyme does Stenotrophomonas maltophilia produce that may lead to false-positive ESBL results?
L-2 chromosomal β-lactamase
129
What are Carbapenemase-producing organisms?
Gram-negative bacteria that produce carbapenem-hydrolyzing β-lactamases, conferring resistance to carbapenems and often many other antibiotics.
## Footnote
These organisms are a critical global health concern due to their rapid spread and association with high mortality.
130
What are the main groups of causative organisms for Carbapenemase-producing organisms?
* Enterobacterales (e.g. Klebsiella pneumoniae, Escherichia coli)
* Non-fermenters: Acinetobacter baumannii, Pseudomonas aeruginosa
## Footnote
These groups are known for their significant role in antibiotic resistance.
131
What is the antibiotic resistance profile of Carbapenemase-producing organisms?
* Resistance to all β-lactams (including penicillins, cephalosporins, carbapenems)
* Often co-resistant to:
* Aminoglycosides
* Fluoroquinolones
* Sulfonamides
## Footnote
This extensive resistance complicates treatment options.
132
What is the mechanism of resistance in Carbapenemase-producing organisms?
Production of carbapenemases: β-lactamase enzymes that hydrolyze carbapenems.
## Footnote
This mechanism is crucial for their resistance.
133
What are the 'Big 5' Carbapenemases?
* KPC – Klebsiella pneumoniae carbapenemase
* OXA-48 – Oxacillinase-type
* NDM – New Delhi metallo-β-lactamase
* IMP – Imipenemase
* VIM – Verona integron-encoded metallo-β-lactamase
## Footnote
These enzymes are significant contributors to antibiotic resistance.
134
True or False: All Carbapenemase-producing organisms are phenotypically resistant to carbapenems.
False
## Footnote
Not all CPOs are phenotypically resistant to carbapenems, making detection difficult using routine susceptibility tests.
135
Fill in the blank: The type of β-lactamase that hydrolyzes carbapenems is known as _______.
[carbapenemases]
136
What is intrinsic resistance in the context of carbapenem resistance?
Resistance mechanisms that are naturally present in certain bacteria, such as Stenotrophomonas maltophilia, Aeromonas spp., and Chryseobacterium spp.
137
Which species can express intrinsic OXA-type carbapenemases?
Acinetobacter baumannii
138
What is a non-carbapenemase resistance mechanism that may not be transferable?
ESBL or AmpC + porin loss, particularly in Klebsiella, Enterobacter, and sometimes E. coli
139
What role do efflux pumps and porin mutations play in carbapenem resistance?
They contribute to resistance, especially in Pseudomonas aeruginosa
140
Which species exhibit poor imipenem activity?
Serratia spp. and Proteeae
141
Which type of bacteria are intrinsically resistant to ertapenem?
Non-fermenters
142
Are combinations of resistance mechanisms likely to cause outbreaks?
No, they rarely cause outbreaks but complicate phenotypic detection.
143
Are CPOs primarily associated with healthcare or community spread?
Healthcare-associated
144
What is the mortality rate from KPC bloodstream infections?
Can exceed 50%
145
When was KPC first detected in Ireland?
2009
146
What significant trend has been observed globally regarding carbapenem resistance since 2019?
Increased significantly
147
What percentage increase in carbapenem resistance has been seen in Europe since 2019?
50%
148
What strain of K. pneumoniae is increasing rapidly in Europe?
Hypervirulent ST23-K1 K. pneumoniae strains
149
What was the rise in carbapenem resistance in Ireland since 2019?
1.5%
150
How many CPE outbreaks were reported in Ireland in 2022?
26 CPE outbreaks
151
What percentage of total CPE isolates in Ireland were confirmed in 2022?
861 confirmed
152
What percentage of CPE isolates in Ireland were colonizations?
88%
153
What was the dominant enzyme among CPE isolates in Ireland?
OXA-48 (73–74% of all isolates)
154
What was the trend for OXA-48 from 2018 to 2022?
↑ OXA-48: +12%
155
What was the trend for KPC from 2018 to 2022?
↓ KPC: −25%
156
What was the trend for NDM from 2018 to 2022?
↑ NDM: +185%
157
What was the trend for VIM from 2018 to 2022?
↑ VIM: +200%
158
What public health response was activated in Ireland due to the threat of CPE?
National Public Health Emergency Plan in 2017
159
What measures were implemented as part of the public health response to CPE?
Enhanced infection control, environmental screening, and contact tracing protocols
160
What is a significant challenge in the detection of Carbapenemase-Producing Enterobacterales (CPE)?
No universal method due to enzyme diversity, variable expression levels, and no single carbapenem ideal for screening all enzyme types
## Footnote
Enzyme diversity includes types such as KPC, OXA-48, NDM, VIM, and IMP.
161
What are the goals of testing for CPE?
* Screen for potential CPE
* Confirm carbapenemase production
* Characterise the type of carbapenemase
* Distinguish from AmpC β-lactamases and ESBL mechanisms
## Footnote
These goals help in understanding the presence and type of resistance mechanisms.
162
Which medium has good general sensitivity for CPE screening?
Brilliance CRE ~82%
## Footnote
This medium is commonly used for rectal swab screening of asymptomatic carriers.
163
What medium has the highest overall sensitivity for detecting CPE?
CHROMID / Super-CARBA >95%
## Footnote
This medium is noted for its high sensitivity in screening.
164
What is a significant limitation of all media used for CPE detection?
Poor sensitivity for OXA-48-type producers, often <30% recovery
## Footnote
This limitation highlights the challenge in detecting certain types of carbapenemase producers.
165
What does split agar combine for improved sensitivity?
Combines chromID CARBA + OXA-48 selective agar
## Footnote
This combination boosts OXA-48 sensitivity to ~61%.
166
Fill in the blank: No single medium efficiently detects all CPE, especially poor sensitivity for _______.
OXA-48-type producers
## Footnote
This emphasizes the need for varied approaches in screening.
167
What is Combination Disk Testing?
A method that relies on synergy between carbapenem and inhibitors
## Footnote
Examples include Rosco or MAST testing methods.
168
What indicates a positive test in Combination Disk Testing?
Larger zone around meropenem + inhibitor compared to meropenem alone
169
How can Combination Disk Testing help differentiate carbapenemase classes?
By using specific combinations of meropenem and inhibitors:
* KPC / Class A → meropenem + boronic acid
* AmpC → meropenem + cloxacillin
* MBLs → meropenem + dipicolinic acid
* OXA-48 → use temocillin disk (30 µg); no zone = positive
170
What are Immunochromatographic Lateral Flow Tests?
Rapid tests that yield results in <15 minutes
171
What types of samples can be tested using Immunochromatographic Lateral Flow Tests?
Direct testing from colonies or blood cultures
172
What are common assays used in Immunochromatographic Lateral Flow Tests?
* Coris RESIST-4: detects KPC, OXA-48, NDM, VIM
* NG-Test CARBA-5: detects KPC, OXA-48, NDM, VIM, IMP
173
What is a limitation of Immunochromatographic Lateral Flow Tests?
Occasional false negatives reported
174
What is the best practice for using Immunochromatographic Lateral Flow Tests?
Best used alongside phenotypic methods
175
What is the trend of carbapenem resistance in Europe?
Carbapenem resistance (CRA) is a major issue, especially in Eastern and Southern Europe
176
What percentage of countries report CRA >60% in Europe?
11 countries
177
What was the EU/EEA weighted average of CRA in 2020?
38%
178
What was the CRA percentage in Ireland in 2020?
0%
179
Why is Acinetobacter baumannii considered a top-priority pathogen?
* High carbapenem resistance rates
* Limited treatment options
180
What is critical to address the pipeline crisis in antibiotic development?
Few new antibiotic classes in late-stage development
## Footnote
This includes the emergence of resistance despite some successes with antibiotics like Linezolid and Daptomycin.
181
Which infections lack reliable treatment due to antibiotic resistance?
CPE/CPO infections, especially from Pseudomonas and Acinetobacter
## Footnote
These infections highlight the urgent need for novel agents targeting Gram-negative resistance.
182
What is the primary goal of antibiotic stewardship?
Promote judicious use of antibiotics in all healthcare settings
## Footnote
This aims to minimize resistance development and improve patient outcomes.
183
List the key components of antibiotic stewardship.
* Choosing the most appropriate agent
* Shorter treatment courses
* Cyclic antibiotic use to reduce resistance pressure
## Footnote
These strategies help optimize antibiotic use and reduce the risk of resistance.
184
What are the implementation strategies for antibiotic stewardship?
* National guidance from HSE and AMRIC
* Regular audits to monitor prescribing practices
## Footnote
These measures ensure adherence to best practices in antibiotic prescribing.
185
What are the goals of surveillance in controlling antimicrobial resistance?
* Monitor resistance patterns locally and nationally
* Guide empiric therapy and containment measures
## Footnote
Surveillance is crucial for effective infection control and treatment.
186
What responsibilities do clinical labs have in antimicrobial resistance surveillance?
* Provide accurate AST (antibiotic susceptibility testing)
* Use and develop robust resistance detection methods
* Report to surveillance networks (e.g., EARS-Net)
## Footnote
These actions are essential for tracking and responding to resistance patterns.
187
What must healthcare facilities invest in to control infections?
IPC programmes
## Footnote
Infection Prevention and Control (IPC) programmes are vital for reducing the spread of resistant infections.
188
What are essential practices in infection prevention and control (IPC)?
* Hand hygiene
* Transmission-based precautions
* Patient isolation
* Environmental cleaning protocols
## Footnote
These practices help minimize the risk of infection transmission within healthcare settings.
