Diagnosis of an Infected Patient

M2A1 Essay: Diagnosis of an Infected Patient Essay

Upon receiving a sputum sample from a patient that may be infected with a bacterium from one of the following genera: Bacillus, Escherichia, or Mycoplasma; the first thought that comes to my mind is to isolate each bacteria by using various staining techniques. The use of either the Gram stain or the Acid-fast stain will provide an abundant amount of information regarding the bacteria. It is also important to be aware of how each suspect bacteria reacts to each stain and how those results will lead us in a diagnosis.

The first technique that I would employ is the Gram stain. To prepare a bacteria for the Gram stain “the heat-fixed smear is covered with a basic purple dye, usually crystal violet. Because the purple stain imparts its color to all cells, it is referred to as a primary stain. After a short time, the purple dye is washed off, and the smear is covered with iodine, a mordant. When the iodine is washed off, both the gram-positive and gram-negative bacteria appear dark violet or purple. Next, the slide is washed with alcohol or an alcohol-acetone solution. This solution is a decolorizing agent, which removes the purple from the cells of some species but not from others. The alcohol is rinsed off, and the slide is then stained with safranin, a basic red dye. The smear is washed again, blotted dry, and examined microscopically” (Tortora, G.J.). The bacteria that retain the purple color are classified gram-positive and those that lose the purple color is classified as gram-negative. This is important information regarding my bacteria because Gram-positive bacteria are more likely to be killed by penicillin and cephalosporin while Gram-negative bacteria can be more resistant to bacteria.

Another technique that can be used to assist in identifying the bacteria in the sputum sample is acid fast staining. “In the acid-fast staining procedure, the red dye carbolfuchsin is applied to a fixed smear, and the...