Question

Escherichia coli is one of the most common causes of foodborne illness, yet it is also a common microorganism found within the human gut. What explains this disparity? (5 points)

There are several foods and beverages listed in this lab that are created through the actions of microorganisms. Name five of the foods and the specific microorganisms that are used to make each of them. (5 points)

Using an online research tool such as the A-Z index on the CDC website, explain why Listeria monocytogenes is a major threat to pregnant women and their developing fetuses, who are ten times more likely to get sick than other demographic groups. (5 points)

Answer 1

E. coli is both a commensal of our gut mircoflora and a deadly pathogen that causes food poisoning. They two belong to different strains. The harmful E.coli that are present in outside food and polluted water are the strain of E.coli called Enterohemorrhagic strains. Over time these pathogens have acquired characteristics using whih they disrupt the intestinal wall when they attach to it. The harmless strains are part of the normal microflora of the gut, and benefits the hosts by producing vitamin K. Without these we would not be able to produce Vitamin K and would have to depend on supplements. Hence they are called commensals as not only are they not harmful but also an integral part of hosts metabolism of essential vitamins.

5 food and beverages which require microbes-

1. Curd or yogurt- Lactobacillus sp.

2. Bread- yeast (Saccharomyces cerevisiae)

3. Cheese- Lactococcus, Lactobacillus, orStreptococcus families.

4. beer - yeast

5. Coffee and chocolates- Erwinia dissolvens, Lactobacillus, yeast.

Listeria monocytogenes is threat to pregnant women and even more deadly to foetus as there is increased riskof miscarriage, stillbirth and even death of foetus due to listeriosis. this bacteria is mostly found to be present in sprouts, celery, dairy products, packaged food and beverages.