DNALC Blogs » bacteria

Bacteria and Antibiotics

Erin McKechnie — Fri, 11 Nov 2011 21:31:20 +0000

There are a number of various types of bacteria that naturally exist in our bodies and help us in different ways. Unfortunately, bacteria get a bad reputation. Most people are unaware of how important these organisms are. It is estimated that in a healthy person, there are about ten times as many bacteria cells as human cells! Fluctuations in the level of these bacterial cells can lead to problems such as digestive issues, skin problems, obesity, and more. It is important to think about the way bacteria cells function and evolve when we consider our own health.

If an individual becomes infected with harmful bacteria they may be prescribed antibiotics to rid the body of that infection. As the antibiotic begins to work, the harmful (and some helpful) cells will be killed off but not all of them. When start to eliminate a number of the bacteria making you ill, you will probably start to feel significantly better. At this point it is important to continue to take the antibiotic until the prescription is complete. The reason is that after a few days of the antibiotic some of the harmful cells will still be alive in your body. It is possible that these cells will take up genes for resistance to the antibiotic from some of the other bacteria that are already living inside of you. These harmful cells with newly acquired resistance genes will divide and produce clones of themselves. Unfortunately you will start to feel sick again and if you tried to take the remainder of your antibiotic they would have a defense against it.

The fact that different types of bacteria can share genes enables them to survive under selective pressure. Just one of the amazing charactericstics of these simple cells. Although we may think of bacteria as a nuisance they have much to teach us.

Cockroach Brains as Medicine

Erin McKechnie — Wed, 22 Sep 2010 16:05:01 +0000

Each day your body works to defend you against invaders. Harmful bacteria, viruses, and fungi can enter your system and cause diseases. In addition to relying on your immune system, it is helpful to avoid contact with germs by thoroughly washing your hands and keeping your environment clean.

How is it possible that some organisms have the ability to survive in some of the dirtiest places on earth? What survival mechanisms do they have that differ from ours?

Scientists ground up the brains and other nerve tissues from two species of insects, the American cockroach and the desert locust. Material extracted from the samples was shown to kill more than 90 percent of a harmful type of E.coli bacteria. In addition, the tissue extracts killed a type of staph bacteria. There seem to be nine molecules within the tissue that are involved in defense against microbes.

Although the nine molecules have not been identified, scientists may be able to utilize the molecules in the future as a form of disease prevention in humans.

Lighting-Up Landmines

Tedi Setton — Mon, 07 Dec 2009 21:13:06 +0000

Engineering students at Edinburgh University have created bacteria that can be used to detect landmines! The cheaply engineered bacteria can be mixed into a colorless fluid which would be sprayed over suspect soil. Chemicals that leak out of old landmines stimulate the bacteria to make a green protein, producing large patches of bright green where bacteria encounter explosive material.

According to the United Nations, between 15,000 and 20,000 people are injured or killed by landmines that litter more than 80 countries including Sudan, Somalia, Iraq, and Afghanistan. The bacteria would likely fail to identify those mines that do not leak, and would detect chemical remnants where mines were once, but are no longer, active. But as the students’ advisor, Alistair Elfick points out, “this anti-mine sensor is a great example of how innovation in science can be of benefit to wider society.”