Mechanisms of antibiotic drug action + resistance
how do we reduce the creation of resistant bacteria?
need more eudcaiton, dual therapy, drugs to potentiate activty of existing drugs, better stewardship of antibiotics, greater hygiene,
Examples of bacterial causes of pneumonia
Typical:
Staphylococcus aurues
Streptococcus pneumonia
atypical:
mycobacterium pneumonia
Legionella pneumophila
what is the 'R' factor?
the reproduction number is the average number of new individuals who will get infection from a single person
Considering the oedematous nature of pneumonia and the secretion of Interleukin 1 and Tumor Necrosis factor alpha, discuss the involvement of the complament and polymorphonuclear immune cells in the production of neutriphil extracellular traps withing the alvecolar spaces? how does the level of inflammation and exudate comensurate with the concentration of infection? Furthermore, elaborate on what is pertinent for the treatment of atypical pneumonias caused by, for example, pneumocystis jirovecii, and the photosynthesis and oxidative phosphorylation that occurs within the mitochonria of these fungal cells. hehe
Free 400 points :) pick again.
what are the 3 major mechanisms of antibiotic resistant bacteria?
modify the antiviotic target, remove antibiotic (either through efflux or reduction in penetration), enzymeatic inactivation.
3 types of pneumonia based on where/location of infection?
Community
Hospital
Ventilator
what are individual factors that affects the liklehood of infection?
Immunosupression - extremes of age, illness, medical treatment
Genetics - reduce/increase risk e.g. SCA, CTFR
lifestyle factors - alchohol, nutrition, drug usage
????
if team lower then +100 points
if team higher then -100 points
why do some bacteria have innate resistance to antibiotics?
the target of the antibiotic is not present in the bacteria. for example ,aminoglycosides enter a bacterium through an oxygen dependent pathway. therefore anaerobes will have an innate resistance as they do not respire.
2 types of pneumonia based on how it infects the lung? what is the differentce?
Bronchopneumonia
lobar pneumonia
Broncho is more focal and bilateral whilst libar is more diffuse and affecting usually one lobe/lung
what is the chain of infection?
Microorganism
resevoir
path from resevoir
mode of transmission
pathy of entry
susceptible hosts
How are chest x-rays used for pneumonia?
Can see if here is loss of borders of the heart, diaphram, costophrenic angle.
Look at pattern of infiltrations e.g. lobular, no meniscus sign, in patches (sugesting bronchopneumonia), reticular pattern suggesting interstitial pneumonia
https://www.youtube.com/watch?v=HBS-DJ9ez-c
symptoms of pneumonia?
findings on physical examination?
cough - productive purluent sputum with blood
Pleuritic chest pain
fever
myalgia
malaise
dyspnoea
decreased/bronchial breath sounds
egophony, tactile fremitus
crackles on auscultation
dullness on percussion
how to cephalsporins work?
cephalosporins such as cefradine or cefuroxime work like penicillins with their integrated beta lactam ring but instead physically blocks the cross linkage in the cell wall.
Congratulation!!!
-100 points :( pick again
how to reduce HCAIs?
education
screening
isolation
disinfection
environemental cleaning
PPE
audits
hand hyigene
good communicaiton
other tests that are offered for investigation of pneumonia?
Blood test - check for C reactive protein. inreases with inflammation.
Blood and sputum cultures
Pneumococcoal/ legionaaires antigen test
CRB65 score - Confusion, Resipiratory rate, low Blood pressure, age 65 or more,
What is the incidence of pneumonia in the UK?
220,000 people per year in uk
5-10 per 1000 for CAP
5-12% of all LRTI managed by GP.
22-42% of admisssion to hospital
LRTIs leading cause of infectious death
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7150259/
https://www.ncbi.nlm.nih.gov/books/NBK430749/
https://cks.nice.org.uk/topics/chest-infections-adult/background-information/prevalence/
examples of drug classes that inibit protein syntehsis? which ribosome?
give example of classes of drugs that inhibit cell wall synthesis?
30S Aminoglycosides, tetracyclines
50S Macrolide, chloramphenicol
glycopeptide
penicillin (beta lactam)
cephalosporins
described the 4 stages of pathology of lobar pneumonia
Congestion - protient rich exudate with venous congestion
Red hepatisation - neutrophils, lymphocytes, macrophages, RBCs extravasate . lung is solid, red, airless
Grey hepatisation - destruction of WBC and RBCs making it grey
Resolution - exudate resporbed by enxymatic degredation
what affects groups of people getting infections?
population density - higher probabilty for someone who is infected to meet someone who is susceptible
sanitation - faecal oral outbreaks
vaccination coverage - herd immunity
deprivation - less preventive action, underlying health condition, lesss able to access healthcare
access to healthcare
travel
What is CURB 65?
1 point for each prognostic feature
C - Confusion - abbreviated mental test score of less than 8
U - blood Urea - over 7mmol/litre
R - Respiratory rate over 30/min
B - Blood pressure under 90/60 (either value under)
65 - over 65 years old
0-1 - x<3% mortaility
2-3 - 3%<x<15% mortalilty
3-5 x>15% mortailty
Use CURB65 score along with clinical judgemet to assess wether it can be managed at home, the ordering of microbiology tests, triaging, speed of treatment
what is the minimum inhibitory concentration in regards to antibiotics?
minimum conc of antibactieral is the amount required to inhibit growth of bacteria