THE IMPORTANCE OF GRAM STAINING IN BACTERIA

Various kinds of bacteria we often hear in everyday life, starting from what hurts us (pathogens) or bacteria that help the metabolic processes in our body (normal flora). Bacteria grouped in the kingdom Protista which is divided into two groups called Prokaryotes and Eukaryotes. Bacteria and blue algae include prokaryotes while fungi, other algae, molds and protozoa are eukaryotes. Both of these major sections reduce the many branches and types of species of bacteria and fungi that are usually studied at the campus level, in this case in the world of veterinary medicine. The difference between the two is very striking, ranging from differences in walls, nuclei, DNA structure, and so on.

After reading several of research journals and several student reports that carried out bacterial examinations in the laboratory, I was able to draw the initial conclusion that the bacteria that are often found in animals are only a few bacteria including the types of Staphylococcus, Streptococcus and Enterobacteriaceae groups (Salmonella, E. coli, Yersinia pestis, Klebsiella, Shigella, Proteus, Enterobacter, Serratia, and Citrobacter). Although there are many causes of bacterial diseases such as Bacillus anthracis, Clostridium, Brucella and others, but bacteria that often appear or are popular there must always be a few Staphylococcus, Streptococcus or Enterobacteriaceae groups if sample was taken in the field. An easy way to identify the bacteria that often appear above can be by using gram staining, a simple way that is very helpful in the early identification of bacteria.

The Gram staining technique was developed in 1884 by the Danish bacteriologist Hans Christian Gram [2], when he was trying to identify a bacterial agent in the lungs that had pneumonia in the morgue in the city of Berlin [3]. Gram staining, in general, can provide information of gram types and bacterial forms when viewed through a microscope, gram staining can be done by coloring bacteria with crystal violet and safranin so that through the gram type colors and bacterial shapes can be seen clearly. Gram bacteria divided into gram positive will turn purple because the walls absorb the color of crystal violet and gram negative will turn red because it does not absorb crystal violet but absorbs safranin, the difference between the two grams lies in the bacterial wall where if the gram positive wall is dominated by thick peptidoglycan and the negative gram has cell wall is more complex, three layers, namely the outer layer in the form of lipoprotein, the middle layer in the form of lipopolysaccharide and the inner layer in the form of peptidoglycan [4]. While the form of bacteria consists of cocci, bacilli, vibrios, and spirals (Spirilium and Spirochetes).

Through these two parameters, gram type and bacterial forms, we can identify the initial bacteria easier to be further tested to find out the exact species, for example, Staphylococcus and Streptococcus are gram-positive coccus bacteria and coccus-shaped, and Enterobactericeae groups are all rod-shaped and gram-negative. Gram-positive groups that often appear are usually only a descendant of the genus Staphylococcus or Streptococcus species, such as Staphylococcus aureus and Streptococcus suis. While gram-negative is more diverse and is composed of descendants of the family Enterobacteriaceae which need further testing to determine the genus and species. Although there are many ways to identify bacteria, gram staining is very helpful in classifying bacteria at the initial examination.

Reference

[1] Al-mohanna, Moshtaq & H., quine. (2016). MORPHOLOGY AND CLASSIFICATION OF BACTERIA.

[2] Gram, H.C. (1884). "Über die isolierte Färbung der Schizomyceten in Schnitt- und Trockenpräparaten". Fortschritte der Medizin (in German). 2: 185–189.

[3] Sandle, Tim. (2004). Gram’s Stain: History and Explanation of the Fundamental Technique of Determinative Bacteriology. Institute of Science Technology Journal.

[4] Cooper GM, Hausman RE. 2007. The Cell: A Molecular Approach. 4th ed. Sunderland: Sinauer Associates, Inc