Fact or Fiction

NDSU Microbiology
by NDSU Microbiology

Guest Blogger: Stephanie Kobiela, Undergraduate in Microbiology

Let’s face it, misconceptions or “myths” are sometimes hard not to believe. Have you ever wondered if an apple a day really keeps the doctor away or if a swallowed piece of gum will really stay in your digestive tract for seven years? The veterinary medicine and microbiology world is full of these myths, and my goal is to shine some light on four of these tricky topics that people may commonly misconstrue.

1. Being cold causes colds – Fiction

If your childhood was anything like mine, going outside in the winter meant about five layers of cloths. Wool socks, mittens, two hats and a scarf were a must before Mom would even consider letting us walk through the door. Unfortunately, Mom’s theory of catching a cold from playing in the snow was incorrect. The common cold is not caused by getting cold, but by being in close proximity to infected individuals!

Rhinoviruses are the leading cause of the common cold and can be transmitted to others in two ways: respiratory droplets and by direct contact with infected objects, including other people. According to scientists, there are close to 100 different strains of human rhinovirus; no wonder we end up getting sick at least once a year! So instead of staying in the stuffy house this winter, consider getting a little fresh air!

2. Touching a frog or toad will give you warts – Fiction

It may be hard to believe, but this is a legend that is absolutely incorrect. It was once believed that picking up frogs would give us warts because of the wart-like bumps on their backs. However, the bumps on our amphibian friends' backs are nothing like the human wart.

Warts are actually caused by a virus, human papilloma virus (HPV) to be exact. This is a very common virus that most people have come in contact with at some point in their lives. Warts are more commonly seen in children and young adults because as we age, we become more immune to the virus and it struggles to survive. Most forms of HPV are passed by direct contact with fomites or inanimate objects, including other people, though some strains can also be passed by sexual contact.

3. The Five-Second Rule – Fiction

If I have said it once, I have said it a thousand times, and don’t lie, I know you have too. I think we can all admit that at one point in time, we have dropped something on our not so clean floor, immediately picked it up and continued to place it right into our mouths. The truth is it really isn’t a matter or IF the dropped food picks up bacteria, it is HOW MUCH bacteria the food picks up.

Prof. Paul L. Dawson from Clemson and his associates completed a study to answer the daunting “how much” question. Salmonella was their bacterium of choice, and they used tile, wood flooring, and carpet as their test surfaces. For the test foods, the researchers used bologna and bread slices. They found that food left on any surface, contaminated eight hours earlier, for five seconds and then removed, contained anywhere from 150 to 8000 bacterial cells. Food items left longer had even more! So in a sense it is true, there will be less bacteria at five seconds, but for some strains of bacteria such as certain kinds of Salmonella, it only takes as few as 10 cells to cause a severe infection.

4. Letting your dog lick your wounds speeds healing – Fiction

Most people reading this will either be in veterinary medicine, microbiology, or both, and I am fairly certain they will all agree this is absolute fiction! Do I even need to explain? I guess what I am trying to say is, do people not realize that the tongue a dog uses to bathe himself is also the tongue he uses as toilet paper?!

A case study completed by Stephanie Chaing-Mei Low and John Edward Greenwood illustrates just how serious a dog lick infection can be. A 48-year-old woman was admitted to the Mildura Base Hospital, Australia, for abdominal pain, diarrhea, rigors, and headaches. At the time, she left out the fact that three weeks prior, she had scalded her foot with hot water, left it untreated and allowed her puppy to lick the wound. Shorty following her admission to the hospital, she was diagnosed with septic shock and multi-organ failure. It was later determined that she had become infected with Capnocytophaga canimorsus, a common gram-negative animal oral commensal bacterium. Now this is just one example of the bacteria that can reside in the mouths of our canine friends. So please, please, please, do yourself a favor and don’t let Fido lick your wounds!

These are just a few of the myths of microbiology and veterinary medicine unraveled. I found them fascinating and hope you did too! So go ahead, do a little research and solve some of your own mysteries!

This entry is part of the fall MICR 354 scientific writing students' blog series.

Rhinovirus Image: AJ Cann

HPV Image: NIH

Salmonella Image: NIAID

Gram stain Image: CDC/Dr. Gilda Jones


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