Tainted ham
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Transcript of Tainted ham
BY:JULIA BURTON
MARIA CHIAFFARANO
Nothing Worse than Tainted Ham!
Background Information
Local Festival was held in Palm Beach County90 people became ill
Symptoms: nausea, vomiting, diarrhea
17 victims sought medical attention Most cured within 24 hours
It’s thought that the origin of the infection was from ham sold at the festival
The Affected System
Digestive System is made up of the Espohagus Liver Small intestine Large intestine Gallbladder Pancreas Rectum
Our Job
Given a culture from one of the 17 patients Identify the cause of the outbreak Identify antibiotics that may be used to treat the
infection if necessary
Possible Causes
Escherichia coliPseudomonas aeruginosaSalmonella entericaStaphylococcus aureus Streptococcus pyogenesHaemophilus influenzae
Possible Cures
Antibiotics Penicillin Tetracycline Chloramphenicol Streptomycin Vancomycin Gentamycin
Procedure
Gram Stain provided the cultureCulture organism on selective/ differential
mediaAntimicrobial susceptibility test
Gram Stain
Information: Gram positive stains (using MSA agar) and Gram
negative stains (using MacConkey agar)
What we chose: Gram positive plate (Mannitol salt agar or MSA plate)
Gram Stain
Why? Helps to differentiate the two distinct bacterial
species (negative and positive) Faster than bacterial culture approach Significant in identifying a working diagnosis of
certain disease conditions
Gram Negative
Doesn’t react to crystal violet Stains pinkish-redCan be decolorized in accepting safranin
(counter stain) Uses MacConkey Agar
Differential plating medium used in detection and isolate of all types of dysenter
Used (generally) to differentiate strains of salmanella Colonies of bacteria are brick red in color
Gram Positive
Reacts with crystal violet dye (stains dark purple)
Unique cell wall (composed of several peptidoglycan layers, multilayered, thick)
Presence of techoic acids Lacks lipopolysaccaride content, peryplasmic
space and outer membrane (makes it low in lipoprotein and lipid composition)
Release exotoxins Uses MSA agar
MSA Agar
Selective and differential mediumHigh concentration of salt selects for
members of the staph bacteria since they can tolerate high saline levels
Contains sugar mannitol and pH indicator phenol red
Acidic byproduct is formed which causes the phenol red to turn yellow
Selective Differential Media
We chose the MSA plate because it is used for gram positive bacteria
Throughout our testing, we discovered that our bacteria was gram positive and would only grow on the MSA plate
Results: The Staphylococcus aureus grew at a fast rate, the
E.coli did not grow at all (it is gram negative), and the patient’s bacteria did not grow either However, due to technical difficulties, the patient’s
bacteria was supposed to grow, therefore giving a positive result for Staph
Staphylococcus aureus
Gram positive spherical bacteria Occur in microscopic clusters
Cells divide successively in three perpendicular planes
Fermentation of glucose produces mainly lactic acid
Ferments mannitol Golden yellow colony on agar
Antimicrobial Susceptibility Test
Information: Gram positive bacteria are easier to treat (with
antibiotic) than gram negative bacteria This is because gram positive bacteria lacks a membrane
whereas gram negative bacteria contain two membranes which regulate what goes in and out of the cell
Procedure: For the lab, we put the patient’s bacteria on a plate
along with six different types of antibiotics to see which antibiotic would be most effective to cure the patient
Results
Antibiotics used: Penicillin 32 mm diameter - Sensitive
Tetracycline - 24 mm diameter- Sensitive
Chloramphenicol- 19 mm diameter- Sensitive
Streptomycin- 12 mm diameter- Resistant
Vancomycin- 13 mm diameter- Sensitive
Gentamycin- 23 mm diameter- Sensitive
Results (cont.)
These results told us that the bacteria was sensitive to most of the antibiotics (gram positive bacteria) Most sensitive to Penicillin Resistant to Streptomycin