Medical Microbiology - Essay Example

In contrast, prokaryotic cells are considered more primitive, and most bacteria are prokaryotic. These cells contain no organelles, and their DNA is loose in the cell rather than enclosed in a nucleus, and there is generally less than in eukaryotic cells (Levinson, 2006). These distinctions are important in terms of controlling and understanding the behavior of microbes, especially in terms of containment of disease, vaccines and treatments. Bacteria tend to be prokaryotic cells. They have a range of different shapes, with some being shaped as rods, some as spirals and others circular.

In addition, the cell walls of bacteria differ between gram-positive and gram-negative. The terms refer to how the cell walls are structured, in particular the size of the peptidoglycan layer, but also to a form of staining known as gram-staining which is used to differentiate between the two types of wall structure. The shape of bacteria as well as the type of cell wall allows different bacteria to be identified by looking at them microscopically. Bacteria are generally treated using antibiotics; these attack the cell walls of bacteria.

As these are very different than our own cell walls, it is easy to make drugs that differentiate between the cells of the bacteria and the host cells (Levinson, 2006). In contrast, viruses are often considered to be non-living. They share many of the characteristics of living cells, such as reproduction, nutrition and movement; however they lack respiration, making them difficult to define as either living or non-living. Unlike bacteria or other cell, viruses contain only DNA or RNA, they do not contain both.

Viruses have an unusual form of pathology. Once present in the host’s system, they invade the cells of the host, using the machinery of the cell to replicate themselves. When they have replicated sufficiently, the new viruses burst out of the host cell and move to infect other cells. Because of this