Essay on The Gram Staining Method

By definition, the Gram stain refers to the staining method used for classifying as well as distinguishing species of bacteria into two large groups. Specifically, these groups include the gram-negative and gram-positive (Gostin, 2006). Bacteria is differentiated by Gram staining by the use of both physical and chemical properties of their cell walls. In this lab, the Gram-positive, negative catalase cocci genera were identified in the streptococcus. An increase in the number of genera that must be identified by microbiologist has three major reasons. In the first place, the relationship of some genera has been genetically studied by taxonomists. Here, the lactococci and enterococci were split from the streptococcus (Thompson, Wrubel & Berkowitz, 2017). Even though this lab is based on skills, differences in the Gram negative and positive bacteria will be seen.

Studies of DNA homology have also indicated that those two types of genera have distinct and separate entities. On the same basis, the vagococci were additionally split from the Lactococcus genus. Because of its different genes from other genus members, the tetragenococci were split from the pediococcus genus. Until the mid-1980’s, the pediococci and leuconostocs were considered non-pathogenic (Gostin, 2006). It is believed that the isolation of species of the two genera increases with the rise in the use of vancomycin. All the species of pediococcus and leuconostoc genera appear to be intrinsically resistant to vancomycin (Thompson et al., 2017). In this case, all the susceptible strains that allow the resistant strains to colonize the tract of genitourinary are eliminated by the vancomycin. The main objective/ purpose of this lab is to identify the catalase negative, Gram-positive genera.

Materials and Methods

Initially, all the equipment such as test tube holder, latex gloves, microscopic slides, and Bunsen burner were assembled in the right place. Afterward, the three microscopic slides were prepared before applying smears. At this point, the Gram’s crystal violet stain was used to flood the smears for about thirty seconds. After that, the smears were rinsed gently using the Gram’s iodine. After the complete removal of the Gram’s crystal violet, the smears were flooded with Gram’s iodine for about one minute. The slide was then held over the sink and rinsed with acetone/ ethanol. After this process, the slide was lowed to air dry. This information was helpful in completing the data table in the section of results.

Results

Table 1: Gram-Positive Log Sheet.

Test or stain performed

Result

Comments of notes

Catalase

Negative

Streptococcus

Hemolysis

Alpha

S x T

R

Negative

Bile Scullin

Positive

Non enterococcus

Camp test

Negative

Optochin “P” disc

R

Negative

Bacitracin ”A” disc

R

Negative

NaCl 6.5% both

Negative

Clear

Figure 1: Experimental Test tubes

Figure 2: Display of Microscopic Slides

Table 1 helps in presenting the experimental results. It lists different test or stains performed as well as their respective results, and of course a few notes for each. In the same way, different figures are used to enhance the visual analysis of the experiment. In Figure 1, for example, the test tubes are displayed to show the catalase negative, Gram-positive genera. Additionally, Figure 2, present the microscopic results. These results are then used in the discussion and conclusion of the lab.

Discussion and Conclusion

            As can be seen in Table 1, different results are produced by various test or stain performed. For example, the catalase is negative, meaning that it is streptococcus. Also, the hemolysis is alpha. Other negative results are also produced by NaCl 6.5% and camp test. The ‘R’ results are also shown in Bacitracin ”A” disc, S x T, and Optochin ”P” disc. Only bile presented a positive result in this experiment, and it is also non-enterococcus. The results for all the ”R” values are negative. 

It can be said that only parts of the cells were selected by the differential stains stain. There are at least three steps or components required by all these differential stains. Simple stains usually work best when the shape of the various bacteria need to be seen (Gostin, 2006). Moreover, differential stains are an important tool for the visualization of specific structures as shown in Figure 2. Normally, Gram stain fails to work with an organism that lacks a cell wall but instead has only a cell membrane. Even though this Gram stain lab achieved its primary goal, there were some problems encountered during the experiment. It was hard working with the equipment. Next time, however, the student should be allowed to work in groups to reduce the possibilities of errors. 

The unknown of this experiment has clinical significance. It causes bacterial infections. Also, the root transmission of this disease involves secreting various types of toxins affecting the individual cells (Center for Disease Control, 2010). However, the infection can be treated and prevented by stopping the immune reaction through lipopolysaccharides. When infection is suspected, the Gram stains are performed on the biopsy or body fluid to deal with the disease. Most importantly, it should be noted that Gram staining cannot be used to definitively classify all bacteria even though the technique is a valuable tool of diagnosis in both research and clinical settings (Gostin, 2006).

References

Gostin, L. (2006). Federal Executive Power and Communicable Disease Control: CDC Quarantine Regulations. Hastings Center Report, 36(2), 10-11. doi: 10.1353/hcr.2006.0023

Survey to Determine Compliance with Center for Disease Control (CDC) Recommendations for Vaccination among Pregnant Women. (2010). American Journal of Infection Control, 38(5), e128-e129. doi: 10.1016/j.ajic.2010.05.011

Thompson, A., Wrubel, D., & Berkowitz, F. (2017). Gram-Positive Rods on a Cerebrospinal Fluid Gram Stain. Open Forum Infectious Diseases, 4(4). doi: 10.1093/ofid/ofx240