Case Study 5: The Tacos are Trouble

The Tacos are TroubleMike and Yianni

Debriefing •67 people (from NJ, NY, PA, DE, and SC)

became ill from November to December in 2006

•Symptoms were bloody diarrhea and severe abdominal cramps

•51 (76%) people needed to be hospitalized

• 8 (12%) developed kidney failure called hemolytic-uremic syndrome (HUS)

• All individuals consumed raw Taco Bell food

The Digestive System

•We believe that the patients have Gastroenteritis (Stomach Flu)

•The stomach, large intestine, and rectum are affected

Possible Culprits

•Escherichia coli

•Pseudomonas aeruginosa

•Salmonella enterica

•Staphylococcus aureus

•Streptococcus pyogenes

•Haemophilus influenzae

Gram Test•Gram positive

•Cell wall is made of a thick layer of peptidoglycan

•Gram negative

•Thin layer of peptidoglycan

Gram positive bacteria are easier to treat than gram negative

Results of Gram Test

• Escherichia coli

• Gram negative

• Pseudomonas aeruginosa

• Gram negative

• Salmonella enterica

• Gram negative

• Staphylococcus aureus

• Gram positive

• Streptococcus pyogenes

• Gram positive

• Haemophilus influenzae

• Gram negative

LET'S GO TO THE VIDEO TAPE

Antibiotic  Diameter MM Resistance

Chloramphenicol 23 Effective (Sensitive)

Penicillian 0 Not effective (Resistant)

Vancomycin 0 Not effective (Resistant)

Tetracycline 19 Effective (Sensitive)

Gentamycin 18 Effective (Sensitive)

Strepomyocin 10 Not effective (Resistant)

Possible Cures

Our Culprit?

Escherichia coli(E. coli)

Information on E. coli

•Gram-negative

•Bacillus

•Rod shaped

•Not arranged in a chain

•Facultative anaerobe

•Mixed-acid fermentation

Extra Information•Found in lower intestine of

mammals

•Live in areas with low levels of hydrogen

•When infecting the body, it produces enterotoxins

•These toxins increase the levels of cAMP in a cell

•The cell reacts by secreting water and chlorine ions

Faecal-oral transmission

• Faecal particles are consumed

• Farm contamination due to manure fertilization

• Irrigation with contaminated water

• Consumption of:

• Contaminated water

• Raw ground beef

• Raw seed sprouts

The Cure

•Chloramphenicol is the most effective drug at curing E. coli.

– Tetracycline and Stroptomycin can also be used to treat this E. coli infection.