Tag Archives: bacteria

The Invisible Cold War: Bacteria Vs. Humanity

We are in a constant war and we don’t even realize it. No, it’s not the recent development in Ukraine or the crisis in Syria some time ago. It’s something much more subtle and dangerous. As you may have guessed it from the title, we are constantly fighting against bacteria with a type of weapon called antibiotics. Antibiotics are natural products used to kill bacteria by interfering with bacteria growth or replication. Unfortunately, we have been using our weapon inappropriately and now we are steadily losing this fight against bacteria.

Face of Danger (antibiotic-resistant bacteria, MRSA, at work. Image source: wikimedia)

However, researchers from the division of Healthcare Quality Promotion at the U.S. Centers for Disease Control and Prevention (CDC) found something we can do to fight against bacteria. According to the study done in 2013 by Fridkin, S.K. and Srinivasan, A. (associate director for Healthcare Associated Infection Prevention Programs), by fusing antimicrobial stewardship with their strategies, hospitals in the U.S. is able to create a sort of benchmark for all hospitals to follow (2014). This is necessary as there is no clear guideline about how much of antibiotics is “too much.” In order to do this, they went through a trial and error of implementing sound decisions and comparing outcomes within 200 hospitals in U.S..

Now, here is why you might be asking why this is necessary at all when antibiotics can kill bacteria and have been doing so for the longest time. That is only half right. While we have been killing bacteria with antibiotics, they have been evolving through exposure of antibiotics and have become immune to them. As they become immune to the only weapon we have against them, we are forced to create or modify the antibiotics. This is called, “evolutionary arms race.”

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While manufacturing new antibiotics would be good and all, there has been reports of misuse of antibiotics in hospitals and other medical centers as early as late 1950’s which resulted in rise of antibiotic-resistant bacteria (Fridkin, S.K. & Srinivasan, A., 2014). If this faulty practice continues, all the effort and money went into producing antibiotics would be in vain as they would develop immunity again due to overexposure. Therefore, a new practice of controlling distribution of antibiotics called, “antimicrobial stewardship,” has been developed.

Just like how it is not wise to show all your cards in your hand during a poker game, it is not wise to show every antibiotics we got by misusing them. While this study proves that we can set a guideline for all hospitals to follow, it also supports further improvements over their strategies. To prevent a certain future where no cure exists to fight against lethal bacteria, I believe there should be more improvements on the guidelines and if possible, we as citizens should also be smart about our usage of antibiotics.

References

Fridkin, S. K., & Srinivasan, A. (2014). Implementing a strategy for monitoring inpatient antimicrobial use among hospitals in the united states. Clinical Infectious Diseases, 58(3), 401-406.

– Jong Hwan Seo

 

5-Second Rule Backed Up by Science?

You have your favourite snack in hand and you’re about to eat it when an arbitrary gust of wind, an evil little leprechaun, or maybe just your own clumsiness causes you to drop it. Darn it! But nonetheless you pick it up, gently blow it off,  and eat it knowing that the “five second rule” is on your side. Or is it?

The Five Second Rule. Image: Pengo (Wikimedia Commons)

 It’s been an age old edibility debate but a new study from a team of students led by microbiology professor Anthony Hitlon at Aston University tells us that the five second rule holds true. They observed the transfer of E.coli and Staphylococcus aureus bacteria from a variety of indoor floor types (carpet, laminate, and tiled surfaces) onto a variety of foods (toast, pasta, cookies, ham, and most ominous, a “sticky dessert”).

 Their findings showed that food picked up just a few seconds after being dropped is less likely to contain bacteria than if it is left for longer periods of time. Therefore, time is a significant factor in the transfer of bacteria from a floor surface to a piece of food. But it’s not just the clock ticking while your meal is on the ground, the type of flooring also comes into play. For example, bacteria was least likely to transfer from carpeted surfaces and most likely to transfer from laminate or tiled surfaces to moist foods when in contact for more than 5 seconds.

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But I think you might want to take this with a grain of salt, and not the ones you’ve dropped on the floor either. Because Hilton notes “consuming food dropped on the floor still carries an infection risk as it very much depends on which bacteria are present on the floor at the time; however the findings of this study will bring some light relief to those who have been employing the five-second rule for years, despite a general consensus that it is purely a myth”. So the next time you drop a delicious snack, you can now breathe a sigh of relief that the five-second grace period has your back.

Written by: Sophia Hu

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Further reading:

http://gizmodo.com/the-five-second-rule-is-now-supported-by-actual-scienti-1542466695

http://www.forbes.com/sites/alicegwalton/2014/03/14/amazingly-science-backs-5-second-rule-for-dropped-food/

http://www.nhs.uk/Livewell/homehygiene/Pages/does-the-five-second-rule-really-work.aspx

http://www.sciencedaily.com/releases/2014/03/140310102212.htm

 

Airplane Colds

Airplane riding into the sunset. Source: Flickr Commons Kuster & Wildhaber Photography

If you were to walk into my room right now you would see cold medication, chicken noodle soup and a still unpacked suitcase from the trip I took over reading break. I rode an airplane twice in the past week and now I am getting a cold. Coincidence? I think not. And neither does science. According to a study done, a person’s chances of contracting a cold on an airplane are significantly higher than when on the ground (Hocking & Foster, 2004) .

There are several reasons of why people are more susceptible to colds and respiratory diseases after flying. Surprisingly, studies have proven that lack of air circulation is not to blame (Zitter, Mazonson, Miller, Hulley, & Balmes, 2002) . A common misconception is that the air on a plane is stagnant and not fresh, therefore letting airborne bacteria sit there longer. In reality, air in an airplane is cycled through very sophisticated filters 15 to 20 times an hour. (Lang et al., 2007) This is much higher than the number of times air is cycled in homes and offices, 5 and 12 respectively. (Lang et al., 2007)

So if stagnant air isn’t the culprit, what is? Dry air is the main culprit according to one source (Hocking & Foster, 2004) . When you’re flying, the relative humidity drops to levels around 10%. This drop in relative humidity is a very big difference from on the ground levels, where for example, in Vancouver on February 24, 2014 is 96%. These low levels of humidity due to highflying elevations cause people’s first line of defense to not function properly. Mucous in the nose cannot form and bacteria can therefore pass.

Other culprits include the ratio of people to space. Since person-to-person interactions are very high (think of climbing over someone to get up to go to the bathroom), there is an even higher number of possible infectants in the air. Although airplanes are cleaned regularly, high-traffic areas  that may not necessarily be cleaned thoroughly are thought to be possible bacteria rich areas. These areas include overhead bins, armrests, aisle seats and the seat-tray.

Here people can be seen touching the aisle seats. Source: Flick Commons Matt Hurst

One last reason that could contribute to getting sick after travelling is stress. A lot of people find travelling stressful and higher levels of stress can affect your immune system’s ability to ward off sickness (Glaser & Kiecolt-Glaser, 2005) .

So what can you do to ward off a cold when travelling by airplane? This article  has several great suggestions. The most important being staying hydrated and keeping your hands clean. Next time I travel by plane, I will definitely be taking better advantage of the free beverages offered inflight.

~Claire Curran

References

Glaser, R., & Kiecolt-Glaser, J. (2005). Science and society – stress-induced immune dysfunction: Implications for health. NATURE REVIEWS IMMUNOLOGY, 5(3), 243-251.

Hocking, M. B., & Foster, H. D. (2004). Common cold transmission in commercial aircraft: Industry and passenger implications. Journal of Environmental Health Research, 3(1), 7-12.

Lang, M., Amit, M., Cummings, C., Feldman, M., Ponti, M., Grabowski, J., & Community Paediat Comm. (2007). Air travel and children’s health issues. PAEDIATRICS & CHILD HEALTH, 12(1), 45-50.

Zitter, J. N., Mazonson, P. D., Miller, D. P., Hulley, S. B., & Balmes, J. R. (2002). Aircraft cabin air recirculation and symptoms of the common cold. JAMA : The Journal of the American Medical Association, 288(4), 483-486.