Page 174 - MNU-PM502- Pharmaeutical Microbiology Theoritical Book

Pharm D- Clinical Pharmacy Program Third Level Pharmaceutical Microbiology& Antimicrobials (PM 502)

Vitek II

• Broth micro dilution-based AST system

o uses 64-well plastic cards containing 17–20 antimicrobial agents

o If the bacterial isolate is not previously identified, one card is used for bacterial
identification (ID card) and the other for antimicrobial susceptibility testing (AST
card).

• Two Vitek 2 instruments are available with test card (ID and AST) capacities of 60

cards (Vitek 2) and 120 cards (Vitek 2 XL).

• Results are reported in 4–18 h, containing MIC and category of susceptibility

• The Vitek II consists of:-

• A computer module analyses the growth curve and the biochemical id & compares
it to a database.

• An “expert” software analysis module recognises new / unusual / inconsistent

results, highlights “alert” organisms (e.g. MRSA).
• The “expert” system has built-in antibiotic interpretation rules

Advantages

• Decrease turnover time for AST

• Can give rapid “expert” results for identification & susceptibility.

• It decreases the incidence of operator error

Disadvantages

• It is very expensive.

• It needs regular software updates & expert analysis.

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