02b_Microscan_Panel_111509 - Clinical Unknown[Another Day 2...

Clinical Unknown [Another Day 2]:
Rapid Multitest Panels for Identification of
Bacteria and for Antibiotic Susceptibility
Testing
LABORATORY EXERCISE #2
Rev: 3/10/10
Materials and Methods
Bacterial Isolates and Media Specimens were obtained by the Flamingham Bored of
Health (Flamingham MA) from food handlers (nasopharangeal swabs), animals found on
the premises (oral swabs), food items, and patients (vomitis) with clear-cut diagnoses of
infection. Bacteria were isolated using standard media: trypticase soy agar (TSA),
phenylethyl alcohol agar, blood agar, and MacDConkey agar (Difco; Sparks,MD).
Staphylocicci were tested for coagulase production (BBL  Staphyloside  ; Becton
Dickinson Microbiological Systems, Cockysville MD) and identified using the Microscan 
PC-12 Panel (Semens Healthcare Diagnostics Inc., W. Sacramento CA). The strains
were maintained on TSA supplemented with 1% dextrose (TSA/dex); they were
subcultured weekly (grown on TSA/dex for 18hr at 37°C, checked for purity, then sealed
in plastic bags and stored at 4°C).
For decades biochemical procedures have been used to identify the bacteria that cause
human, veterinary, and plant diseases. In many clinical labs, these series of tests have
been called “long sets” - a series of various media in plates or tubes, each had to be
individually inoculated and “read” the next day. Today there are numerous standardized
and miniaturized versions of those biochemical procedures. The various tests are
assembled into panels that have been designed to make them inoculated and read by
machines, therefore allowing computer analysis of the results and direct reporting of the
results to the physician. The inclusion of antibiotic sensitivity tests has increased the
usefulness of the panels. Hence, the data generated by a single panel will allow the
identification of a bacterium (or yeast/fungus) to the level of both genus and species and
provides sufficient information to guide the physician as he/she chooses the appropriate
antibiotic(s) to be used in chemotherapy.