Short Notes

Question 1

Processing sputa

Answer 1

○ Grade sputa: salivary, mucoid, purulent, bloodstained etc
○ Eppendorf for send outs
○ Sputasol -> equal parts -> vortex -> 20 mins
○ 10ul to inoculate blood, chocolate, dilution, 1/4 candida
§ Dilution = 10ml sterile distilled water
○ C30 disc on chocolate
Optochin on blood agar

Question 2

Expected organisms in COPD sputa

Answer 2

○ Pseudomonas aeruginosa is the most common bacteria in COPD
○ Followed by mycoplasma pneumoniae
Viruses such as rhinoviruses, Influenza, parainfluenza, coronavirus, and adenovirus are also common

Question 3

Processing CSF

Answer 3

○ Describe appearance
○ Serial red cell count
○ White cell count on last sample
○ >5 wbcs -> differential
○ Polymorphonuclear vs mononuclear
○ Film array
○ Culture:
Blood + chocolate

Question 4

Neonate specific bacterial meningitis

Answer 4

○ Group B strep -> transferred from mother to baby
Listeria -> transferred from mother to baby

Question 5

Meningitis in adults

Answer 5

• Bacterial meningitis in adults:
  ○ Haemophilus influenzae, S. pneumo, N. meningitidis
  
  • Viral meningitis in adults:
    Enterovirus

Question 6

Viral meningitis in children

Answer 6

Adenovirus

Question 7

How to detect VRE

Answer 7

• Rectal swabs
  
  • 42% of Ents are VREs in Ireland
  • Vancomycin resistant enterococci
  • Screen using VRE brilliance chromagar
    ○ Purple colonies = E. faecium
    ○ Green colonies = E. faecalis
  • Any positives get a blood purity plate for Vitek ID and Sens
  • Manual Sens
    ○ Vancomycin
    ○ Ampicillin
    ○ Linezolid
    ○ Nitrofuranton/nitro
    § Only for e. faecalis for UTIs
  • We see a lot more E. faecalis then E. faecium but E. faecium is way more likely to be a VRE
  • Sloped and frozen -> kept indefinitely
  • E.faecalis must be ampicillin susceptible
  • E.faecium must be ampicilin resistant
  • Must be linezolid susceptible -> if resistant then send out
  • If manual sens doesn’t match Vitek sens then send out
    Only need to report Vanc resistant or susceptible to docs -> they don’t need to know anything else

Question 8

Processing for CPO

Answer 8

• Samples = first morning urine or rectal swab
  
  • PCR for genes
  • Flow flex PCR for CPE genes (KPC, OXA48, NDM, VIM, IMP)
  • Resist 5 lateral flow
  • Chromogenic SuperCarba Agar
    ○ If it grows:
    § Resist 5 lateral flow
    § MALDI ID
    § Sensitivities
    □ Merapenem and ertapanem Etests
  • Sensitivities:
    ○ Release all sens so docs have access if necessary
    We send out any CPEs not and CPOs

Question 9

What are the five CPE genes

Answer 9

KPC
OXA48
VIM
IMP
NDM

Question 10

CPE lateral flow

Answer 10

Resist 5 lateral flow

Question 11

CPE E tests

Answer 11

Meropenem
Ertapenem

Question 12

Ventilator associated infection

Answer 12

○ Staphylococcus aureus (44%)
§ Think commensal of skin -> contaminant on tube etc etc
○ Gram negative bacilli -> Acinetobacter baumanii (30%), Pseudomonas (12%), Klebsiella pneumoniae, Serratio etc etc
○ SA and AB most common
○ Seen in those in ICU
○ High mortality for those who end up with ventilater associated pneumoniae
○ Seen in sputa samples, BALs especially
○ Large rate of methicillin resistaance in the SAS isolated -> 100% were MRSA in one study
Imipenem resistance seen in Acinetbacter

Question 13

Resistance in Acinetobacter VAP

Answer 13

Imipenem

Question 14

Sensitivities for MRSA

Answer 14

Oxacillin (methicilin) (resistant)
Cefoxitin (resistant)
linexolid (want to be susceptible)

Question 15

Manual Sens for VREs

Answer 15

Vancomycin (resistant)
Ampicillin (Faecium = susc, Faecalis = resis)
Linezolid (want to be susceptible)
Nitrofuranton (only for E. faecalis UTIs)