BIO488L Medical Microbiology Lab Exercise 4

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					BIO488L: Medical Microbiology
       Lab Exercise 4



           Spring 2006
        T.A.: Sami Kemper
                       Today
●   Quiz 2
●   Staphylococcus and Streptococcus Lab
    –   You will need to check these cultures several
        times this week!
●   Continue Identification of Clinical
    Unknowns
●   Enterobacteriaceae unknown paper due
    today
●   Staph/Strep paper due next week
             Staphylococcus
●   Part of the normal flora of the skin and
    mucosa
●   Wound infections, food poisoning, TSS
●   MRSA
●   Staph. Aureus and Staph. epidermidis
                    Tests
●   Coagulase test from Stph Ident kit
●   Innoculate BEA, BAP, MSA and TSA
●   ½ plates for known cultures
●   1 plate for personal sample (nose, skin or
    throat
●   Choose 1 colony from personal swab
    tomorrow to innoculate on BAP, check at
    24 hrs and perform Gram stain plus
    catalase and oxidase tests
              Streptococcus
●   Part of the normal skin and mucosal flora
●   Streptococcal pharyngitis, scarlet fever,
    rheumatic fever, neonatal sepsis, and
    necrotizing fascitis
●   Strep. agalactiae, Strep. faecalis, and
    Strep. pyogenes
                     Tests
●   Same procedure as for Staph. Except we
    sill be using a Streptococcal Grouping kit to
    determine the Lancefiled group of each
    species.
●   MSA- Mannitol Salt Agar
    –   Selective for Staphylococcus
    –   Staphylococcus aureus ferments mannitol to
        produce golden colonies with yellow zones
●   BEA: Bile Esculin Agar
    –   Group D streptococci and Enterococcus spp.
        can hydrolyze esculin to produce esculetin and
        forms a brown/black precipitate
●   BAP: Blood Agar
    –   Test for a and b hemolysis
    –   Grow fastidious organisms


                   b          b      a