Infectious Diseases Flashcards
Which antibiotic groups work by Time above the MIC?
Beta lactams
Note: why beta lactams are giving at frequent dosing as opposed to higher doses
Which antibiotic group works as a concentration dependent killer (peak concentration)?
Aminoglycosides
Which antibiotic group works by AUC/MIC?
Vancomycin
Azithromycin
What is the mechanism of action of aminoglycosides?
Binds the 30s subunit
What is the mechanism of action of beta lactams?
Bind to penicillin binding
proteins (PBPs)
* Inhibit completion of
synthesis of peptidoglycans
* Leads to bacterial cell wall
lysis in dividing cells
What is the mechanism of action of augmentin?
Bind to the beta-lactamase enzyme of bacteria to inhibit it allowing Beta-lactam antibiotic to damage bacteria
– Improves activity vs.
* Gram negative bacilli (E.coli, K. pneumoniae etc..)
* Staphylococcus aureus
* Beta-lactam producing anaerobes
* No antipseudomonal coverage
In a child with meningitis what level must the MIC be in order to use penicillin alone?
MIC <0.06
What is the mechanism for resistance in MRSA?
Altered penicillin binding sites
What is the drug of choice for ESBL?
Carbapenams +/- aminoglycosides
In a newborn with congenital CMV when would you treat?
<28 days old + moderate symptoms
Oral valganciclovir for 6 months
What are the clinical features of congenital rubella infection?
- SNHL (58% of patients)
- Eyes ‐ cataracts, retinopathy, micropthalmia (43% of patients)
- Cardiac – PA stenosis and PDA
+ neurodevelopmental disability
When do neonates receive varicella immunoglobulin?
- Neonatal exposure following maternal varicella
- > 7days before delivery – no treatment
- <7 before – 2(Aus) or 7 (NZ) days after delivery – VZIG
- All <28 weeks gestation – VZIG
What medication can be given to mothers positive for toxoplasmosis with unaffected foetus?
Spiramycin - doesn’t cross the placenta
Treatment for congenital toxoplasmosis??
Pyrimethamine
Sulfadiazine
Folinic acids
What is the treatment of neonatal syphilis?
IV Benzylpenicillin for 10 days
When could you get a false positive HIV test result?
Patient who has previous had CART therapy
How would you test for HIV in a child <18months old?
Viral PCR
Can’t do antibody testing as could be transferred maternal antibodies
What is the first line therapy for HIV?
2 NRTIs + third drug (NNRTI, INSTI or PI)
Which class of HIV treatment is a CYP3A4 inhibitor?
Protease inhibitors
When is window treatment given for TB?
Child <5 years old who has been exposed to a confirmed case of TB less than 10 weeks prior whilst awaiting TST/IGRA testing.
What is the main side effect of ethambutol that is monitored for?
Optic neuritis and red/green colour blindness
What antibiotic is used to treat stenotrophomonas maltophilia?
IV Co-trimoxazole (also used in PJP)
What are the features of Aspergillus on high resolution CT scan?
Halo sign
Air crescent sign
What is first line treatment for invasive Aspergillus?
Voriconazole
