1. Case Study 1: Peanut Butter is Tainted Suma and Kathryn
2. Background Information 425 people from 44 states were ill Diarrhea, fever, abdominal cramps Illness usually lasted 4-7 days, some cases of diarrhea were so severe patient needed to be hospitalized Out of 351, 71 (20%) were hospitalized No deaths Onset dates ranged from August 1st to February 16th, and 67% of cases occurred after December 1st
7. Gram stain Procedure Add bacteria sample, E.coli(negative control), and S. aureus (positive control)to individual drops of water Let dry Heat fix slide Cover smears with crystal violet dye for one minute, then rinse with DI water Repeat with Gram’s iodine, but rinse with decolorizer acetone alcohol Repeat with safranin, rinse with DI water Blot dry, view using oil immersion
8. Results (Gram stain) Expected results What do these results mean? Pink- Gram negative Purple- Gram positive Eliminate S. aureus and S. pyogenus Patient sample (1000x) E. Coli (1000x) S. aureus(1000x)
9. Selective/differential plate Procedure Use MacConkey Agar because patient sample is gram negative Spread E. coli (positive control), S. aureus (negative control), and patient sample in a V-formation on the plate Incubate
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11. Results (Antimicrobial Susceptibility) Tetracyclin = 20 mm (S) Penicillin = 16 mm (R) Streptomycin = 14 mm (I) Vancomycin = NA (R) Gentamicin = 14 mm (I) Chloramphenicol= 22 (S) What do these results mean? Patient sample is: Resistant to penicillin, vancomycin Intermediate to streptomycin, gentamicin Sensitive to tetracyclin, chloramphenicol Eliminate P. aeuroginosa Resistant to chloramphenicol Eliminate H. influenzae Different symptoms (meningitis)
13. Salmonella enterica Arranged in a cluster- tetrad form Anaerobic- can live with low oxygen conditions Affects gastrointestinal region, through the fecal oral route Injects a protein called SipA to enter cell Disturbs the membrane, causes levels of free calcium to rise and disorganizes cytoplasm
14. Epidemiology Causes diarrhea, fever, vomiting, abdominal cramps Can spread from intestine to blood stream, cause bacteremia raw meat, eggs (can be found on any food surface) Normal bacterial flora in reptiles and amphibians contaminated water or soil Salmonellosis can be prevented by Cooking food thoroughly Washing hands and cooking surfaces refrigeration Single most common cause of food poisoning in the US Salmonellosis