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Summer 2004 - Article 2

From The Lab
Viruses vs. Bacteria

In the last issue of Essentially Speaking, we explored viruses - what they are, how they work and their effect on humans and other animals. In this issue, we'll take a closer look at bacterium.

Bacteria are one-celled living organisms. All are surrounded by a rigid cell wall (see illustration) followed by a thin, rubbery cell membrane. Beyond the cell membrane you'll find the inner workings of a bacterium - the chromosomes, protein and ribosomes that are used to make copies of itself and thus propagate. In the proper environment, one bacterium can reproduce into a colony of more than two million in just seven hours.

Bacteria are essential to life. The human body is home to 10 times as many bacterial cells as human cells. Indeed, about 100 trillion (yes, trillion!) bacterial cells from more than 500 different species, reside in the human gut, lungs and skin. Although some of these organisms can cause disease, fully 99% of all bacteria are considered beneficial or "good". The "good bacteria" found on and in our bodies actually help defend against disease-causing microbes. For instance, the bacteria in our digestive tract are meant to be there and are responsible for digestion, breaking down waste products and for producing essential vitamins.

Not all is rosy in the world of bacteria though. Some create strong toxins that produce a variety of effects, often with devastating consequences like flesh-eating bacteria (Necrotizing fasciitis). These pathogenic bacteria can induce vomiting and diarrhea, cause nerve damage and paralysis, produce muscle cramps or cause severe pain and fever. The good news is that antibiotics, when administered properly, control and cure diseases caused by pathogenic bacteria.

What about antibiotic resistance and superbugs and its relationship to cleaning and disinfecting? Well, the good news is that unlike antibiotics, which are specific in action, disinfectants are broad spectrum and are used in high concentrations to kill micro-organisms so resistance is seldom an issue.