Question

1) Why are cutting boards often responsible for cross contamination and subsequent food poisoning?

2) What are the criteria for dishwashing procedures in public establishments?

3) The bismuth sulfite agar is used specifically to test for salmonella. What are three other pathogens that can be found on food, and what is a differential medium you can use to test for each.

4) What is a pathogen you might find on: YOUR TOOTHBRUSH, YOUR DOG, AND SOFT SOAP DISPENSER.

Answer 1

1) Cutting boards are commonly perceived as important fomites in cross-contamination of foods with agents such as Salmonella spp. Over time, any cutting board (plastic or wood) can trap bacteria in fissures and transfer them to food the next time you use it.

2) Manual Dishwashing procedure:

Step One: Scrape. Scrape, sort, and pre-rinse before washing.

Step Two: Wash in the first compartment. Wash with warm water and detergent solution capable of removing grease.

Step Three: Rinse in the second compartment.

Step Four: Sanitize in the third compartment.

Step Five: Air Dry.

3) Foodborne pathogens include Vibrio vulnificus, Vibrio cholera, Listeria monocytogenes and Clostridium botulinum.

V. Cholerae can be isolated from stool using selective media such as thiosulfate citrate bile sucrose (TCBS) agar or taurocholate tellurite gelatin agar (TTGA). TCBS agar was originally developed for the isolation of Vibrio spp. that are pathogenic in humans.

Although VVM agar seems to be more stressful than TCBS agar, it allows much clearer differentiation of V. Vulnificus.

BSM agar is a selective and differential media used for the presumptive identification of Clostridium botulinum from food or fecal samples.

4) Your toothbrush is home to more than 100 million bacteria including E. coli and staphylococci (Staph) bacteria.

Common types of pathogenic bacteria in dogs include: Salmonella, Leptospirosis, Campylobacter.

Bacteria from the “bulk” or refillable soap dispenser will remain on the users' hands even after using the soap. These include fecal bacteria, which are very tolerant to soap, as well as pseudomonas arogenosa, which causes skins and eye infections.