Add- Ons Flashcards
Types of care bundles
PVC care bundle
Vertical vs horizontal ipc programmes
Types of esbls
TEM and SHV
CTX-Ms
VEB and PER
GES
Endemic CTX
CTX-M-15
Endemic KPC CPE strain
ST-258
What CPE are we most concerned with
ST23-K1 - a hyper virulent and invasive K.pneumonia that’s spreading rapidly
Detection methods for cpes
Disks and mic etc
Colorimetric - Blue Carba
MALDI - hydrolysis
Immunochronatography - resist/carba-5
Check Direct CPE
GeneXpert CarbaR
LightMix
Resistance mechanisms in CRAB
Detecting CRAB
CHROMID-CARBA SMART bi plate
Coris Resist Oxa23
RAPIDEC CARBA NP - culture
RAPIDEC CARBA NP - blood culture
GeneXpert Carba R
Light Mix
Specific Adaptive tolerance of p. aeruginosa biofilm
Why three factors determine if a disinfection method might fail to work on biofilm
Biofilm thickness
Biofilm maturity
Presence of persister cells
DSB disinfection
P. Aeruginosa biofilm disinfection
Biofilm ast
Biofilm inhibitory concentration
Minimum biofilm eradication concentration
MIC of antimicrobials needed to remove biofilm in a patient
Biofilm ast on a surface methof
Modified Robbins device/Biofilm device reactor system
Biofilm novel strategies
C. Difficile hcai prevalence
Zoonotic c. Diff
RT 078
C. Difficile carriage
C. Difficile associated antibiotics
Region of tcd gene frequently mutated
CROP binding domain
Common ribotypes/sequence types in Ireland
ST11/RT027 predominates at 16%
ST8/RT002 follows at 13%
ST2/RT014 follows at 12%
Changing epidemiology of C.diff
Current C.diff treatment
Current C.diff treatment
New c.diff treatment
Bovine whey protein ‘mucomilk’
Tolevemer - linear polymer - toxin
Bezlotoxumab - MAB
Toxoid vaccines
Active vaccines
Disinfection for CDI
Alcohol rub not affected, soap needed
HW decreased from 16.75 to 9.49
ASW reduced c.diff by 32%
6 Ds of Antimicrobial Stewardship
CDI care bundle
MRSA strains
Sporadic: rarely cause infection
Epidemic: propensity to spread in HC environment
ST 22 predominates in Ireland, 80% of S.aures BSIs
Other mrsa infections by ST8, ST5, ST1
IPC of MRSA
HH reduces MrSA from 1.88 to 0.91, no affect on MSSA
Additional resistance in vre
Linezolid resistance since 2014
Mutation I’m 23S rRna inhibits it’s binding
Vre carriage study
Cuh study
0% community carriage
19.1% hospital carriage
87% vanA only
Vre infection control
Vre infection control
HCAI intro
5 aims of PPS
What % of HCA pneumonia was associated with intubation in 2023
8%, rates have halved since 2017
What % of HCA uTi was associated with catheterisation in 2023
40% an increase of 10% since 2017
What % of HCA BSI was associated with invasive devices in 2023
30%
Give percentages for each HCAI group for 2023
Pneumonia at 27% - down from 29 - up rank
UTI at 14.5% - no change - up rank
SSI at 14% - down from 18 - down rank x2
BSI at 8.6% - down from 10 - no change
Gastro at 8.5% - up from 8 - no change
Pps common organisms
15% e.coli
15% s.aures
9% covid
9% c.diff
6.0% e.faecium
6% k.pneumonia
Pps micro results
Types of plasmids
R plasmid
Virulence plasmid
Degradative plasmid - toluene
Conjugative/Fertility plasmids
4 types of mutations in vgt
Point -silent/missense/nonsense
Frame shift
Large scale
Spontaneous
Hgt methods
Transformation
- lysed outside dna
Transduction - phages
- generalised
- specialised
Conjugation
- Hfr conjugation
Pathogenicity islands
4 main transposable elements
Insertion sequences
Composite transposons
Non-composite transposons
Retrotransposons
Types of transposition
Transposons that carries resistance to Beta lactams
Tn3
Transposon for virulence
Tn916 in c.diff
Transposons for ESBLs
Tn3 ESBL production in e.coli and k.pneumoniae
Vre transposon
Tn1546
Tn for cre
Tn4401
Integrons in resistance
22-59% of GNs had integrons
Class 1 integrons in enterobacters carrying resistance to beta lactats, aminoglycosides and sulfonamides,
-> e.coli and k.pneumo esbls and aminoglucoside resistance
Class 1 in Salmonella against sulfonamides
Incidence of tb
8.6 million cases
1.4million deaths
Antibiotics have extended human life by how many years
23
How long and how much does it take to get an antibiotic to market
15 years
800 million
What are our novel antibiotics
Two precision antimicrobial strategies
Targeting biofilm using enzymes
Upec binding
- mannosides fir uti - stop fimH adhesion
New antimicrobial strategies
New antimicrobial strategies
Properties to consider when choosing an antibiotic
Bs antibiotic
Norfloxacin
An antibiotic that’s both bacteriostatic and cidal
Linezolid
Static to staph and enterococcus
Cidal to strep
Examples of toxicity
Aminoglycosides are nephrotoxic
Isoniazid is hepatotoxic
KADME
kinetics of absorption, distribution, metabolism, excretion
Concentration dependent antimicrobials
Aminoglycosides
Fluoroquinolones
Bactoprenol function
Transports NAM and NAG across cell membrane
Peptidoglycan formation
Liopoteichoic acid
Bringa about cell suicide - an autolysin
Trigger by B lactam antibiotics - bind BPB - NAM/NAGs build up and trigger liopteichoic acid
A synthetic Penicillin
Augmentin
Amoxicillin + clavulanate for activity against b-lactamase enzymes
Synthetic cephalosporin
Ceftazidime/avibactam for beta lactamase gns
Synthetic monobactam
Aztreonam/avibactam got resistant gns
Glycopeptides examples
Antibiotics that target nucleic acids
Fluoroquinolones - dna gyrase + topoisomerase
Nitroimidazoles - mtz - ROS damage
Nitrofurans - reactive intermediates
Novobiocin - dna gyrase - gyrB
Rifampicin - binds rna polymerase preventing mrna synthesis
Antibiotics targeting protein synthesis
30S:
- aminoglycosides (gentamycin, amikacin, tobramycin, streptomycin, neomycin)
- tetracyclines (tetracycline, doxyxycline, minocycline)
- glycylcyclines - tigecycline
50S:
- macrolides - azithreonam
- lincosamides - clindamycin
- chloramphenicol
- oxazolidines - linezolid
- streptogranins
Mechanisms of aminoglycosides and tetracyclines
Aminoglycosides bind 30s and cause misreading of mRNA
Tetracyclines bind 30S and preventing binding of tRNA needed for adding amino acids to the growing protein chain
Glycylcyclines such as tigecycline
NB - affective against acinetobacter one of only drugs that is
Lunezolid function
Targets 23s rRNA in 59S subunit which prevents the formation of a functional 70S
This inhibits protein synthesis
Improved linezolid
Tedizolid
Extended activity
Few gi side effects
Antibiotics that affect the cell membrane
Polymyxin
Polyenes
How is daptomycin great
Highly selective as it only targets liposomes containing phosphatidylglycerol which is only found in bacterial membranes - K+ efflux - death
Reduces expression of MecA in mrsa (not meC)
Competitive inhibitors
4 key characteristics of tb cell wall
Acid fast bacilli
Low permeability
High lipid content
Slow growers
Tb cell wall
Tripartite complex:
- cross linked peptidoglycan
- highly branched arabinogalactan polysacchraides
- long chain mycolic acids-> free lipids and glycolipids such as PGM and PDIM
TB pamps
