They are very small–individually not more than one single cell–however there are normally millions of them together, for they can multiply really fast. A number of bacteria cause disease, these are called pathogenic bacteria. Fortunately our immune system knows how to deal with them. However not all bacteria are ‘bad guys’. We need bacteria to stay alive. Bacteria are prokaryotes (single cells that do not contain a nucleus). Microbiology is the study of prokaryotes, eukaryotes and viruses. Did you know that bacteria can get sick too.
Bacteriophages are able to attach themselves to certain types of bacteria and inject their genetic material in the bacterial cell. Then, using the bacterial machinery, the DNA multiplies itself. Eventually from this multiplied genetic information so many new bacteriophages are formed that the cell bursts. The offspring of the bacteriophage has destroyed its bacterial host, and in so doing millions of new bacteriophages are released. These can attach themselves to new bacteria to complete their life cycle.
With our immune system we defend ourselves against a bacterial infection. Antibiotics can help us win the battle. When you report a bacterial infection to your physician, you are probably prescribed antibiotics. The term ‘antibiotics’ (literally ‘against living things’) is mainly used for substances that kill or prevent the growth of bacteria, as opposed to antiviral or antifungal substances. Antibiotics are not active against viral infections. Antibiotics are extremely important in medicine, but unfortunately bacteria can become resistant to them.
Antibiotics have probably been around nearly as long as microorganisms have, and nature has provided bacteria with means to overcome their action. Resistance to antibiotics can become problematic, for it makes these powerful medicines completely ineffective. Some bacteria have learned to deal with practically all types of antibiotics we have available, and this can cause real problems in health institutions. Strict quarantine measures are needed to prevent the spread of such superbugs for we have little weapons left against them.