Laboratory Read Session Flashcards
What did you put up for your enterococcus?
MacConkey plate
-> Ents should grow -> streps wont
Bile aesculin
-> Ents should grow -> streps wont
What did you put up for your bacteroides?
MID8 Mastring
- Rifampicin
- Erythromycin
- Collostin Sulphate
- Penicillin
- Kanamycin
- Vancomycin
Should have put up Metronidazole to prove anaerobic growth
-> there was a zone of suscpetibility on the blood agar but still should have put up to see clearly etc
The MID8 AST is used for what 8 organism?
B. fragilis
B. oralis
B. ureolyticus
F. mortiferum
Pr. melaninogenica
F. necrophorum
GPC
GNC
The MID8 AST is used for what 8 organism?
B. fragilis
B. oralis
B. ureolyticus
F. mortiferum
Pr. melaninogenica
F. necrophorum
GPC
GNC
What is the resistance profile of B. fragilis?
Erythromycin susceptible
Rifampicin susceptible
Collistin sulphate resistant
Penicillin resistant*
Kanamycin resistant
Vancomycin resistant
Talk about the clinical significance of the Enterococcus idetified, how relevant is it to the clinical picture
Likely causative of infection
Likely collonisation of the bowel originally which then spread to the blood stream infection
This is likely infectious and not just contamination due to the pure growth of the organism on the blood culture aerobic sample
Talk about the significance of a enterococcus bloodstream infection
Can cause infectious endocarditis (5% of IE are caused by enterococci)
Enterococcus BSIs have a high rate of in-hospital mortality (as high as 30-50% in one study)
Talk about resistance in enterococcus species
Resistance can be see against vancomycin and ampicillin
- 42% of Ents are vanc resisitant in Ireland
- E. faecium is amp resistant
There is the risk of the Enteroccus being a VRE ie. being resistant against vancomycin
- Direct sensitivites or VITEK sens can be put up to determine is VRE
Ampicillin resistant enterococci seen in patients on extended-spectrum cephalosporins and agents with potent activity against anaerobes
How should the ennterococcus BSI be treated?
Monotherapies such as penicillin or ampicllin or amoxicillin
If query IE send patient for echocardiograph
In IE active combination therapy is required - at least 2 drugs - at least 15 days of active antimicrobial treatment
In general what should you do with your enterococcus in the lab?
Speciate it using the MALDI
VITEK/Direct sens for Vancomycin:
- Ampicillin, Vancomycin, Linezolid, Nitrofuranton
Treat patient
Talk about ampicillin resistance in enterococcus
E. faecium = Ampicillin resistant but E. facalis = Amp susceptible
Why do we put up linezolid and nitro for ents
Linzolid is our last line of treatment -> we want susceptiblity -> if linezolid resistant then should slope -> any resistance are sent out
Nitro is reportable for the use of E. faecalis UTIs
Talk about the clinical significance of the bacteroides
Likely causative of infection
-> in blood stream
Bacteroides is also part of the normal gut flora -> infiltrated blood -> most commonly isolated anaerobe in blood cultures
Lots of growth on blood culture agar
60% mortality if left untreated
How should you treat your bacteroides?
Should be treated with MTZ -> antibiotic of choice
What organisms did you have across all plates
Enterococcus + Bacteroides in blood cultures
Pseudomonas + enterobacterales in wound -> havent infected blood yet -> contaminants?
