The bacterial negative gram bacilli group Enterobacterriaceae have both motile and non-mitole relationships with peritrichouse flagella. Both types of bacteria, however, have the ability to fermet glucose and get nitrite from nitrates, as well as produce gas. They are a common find in greenhouses, and there are hundreds of species of this microorganism, including Proteus, Escherichia coli, Klebsiella, Salmonella Enterobacter, pneomoniae, etc. The pathogenic types of this bacteria have the ability to bring about diseases in animals and humans.
In this test, two varying types of Enterobacteriaceae will be identified (Klebsiella pneumonia and Escherichia coli. This will be accomplished through several biochemical procedures, and we will search for what sets these two bacteria types apart, from their chemical makeup to their structure.
In the following table, you will find E.coli and K. pneumonia colony characteristics, in addition to what was found in the biochemical procedures that the experiment consists of.
According to the above table, K. pneumonia and E.coli share many similarities and also present quite a few differences. Once the lactose and MacConkeys agar fermented, the growth in both types of bacteria was colored the same shade of pink. Both bacteria also had a red color and were rod-shaped, making them gram negative. However, while both types grew aerobically, E.coli also grew anaerobically. The motility test was the biggest test to inflict upon these bacteria types: Though K. pneumonia turned out to be non motile, E. coli presented great motility. What’s more, indole production was found in E.coli, due to the fact the peptone water turned red; this indicates Indole was being produced from tryptophan. At the same time, no color change was found with K. pneumonia, and as such was negative for indole production.
Citrate Untilization also presented a great difference between the two types: while K. pneumonia was positive, E.coli turned up nothing in the results. What’s more, K. pneumonia was positive for the urease test, displaying a purplish pink color in the fluid being used to test, and E.coli showed no color change.
In the Micrococcaceae family, there are two gram positive cocci, which are staphylococcus and micrococcus. (Baren et al., 2002) For the most part, the skin normally possesses staphylococci, and it does not make a person ill. Unfortunately, boils and pimples can occur when this bacteria comes into the body through breaks in skin. In addition to that, pneumonia and infections to the bloodstream and surgical wounds can be caused by staph. On the other hand, micrococcus can be found in dust, soil, water and many other types of environments. Micrococci often are seen in tetrads, and they possess spherical cells which are gram-positive, with diameters of up to 3 micrometers.
This test is meant to show the differences between Staphylococcus and Micrococcus, with the help of biochemical processes to show which bacteria is which. In addition to that, we will look over the different Staphylococcus species that exist.
Given the results that we have seen, gram positivity was found in each of these bacteria types. Looking through a microscope, we saw a cocci shape for S. aureus, but a rod shape with M. luteus. When O2 growth was tested, it was found that S. aureus can grow either way, but O2 is required for M. luteus to grow. The colony morphology exam demonstrated this clearly. What’s more, the baird-parker glucose OF tests showed positive results for S.aureus, meaning that respiration and fermentation are both possible. At the same time, the acid aerobicality test was positive for M. luteus but there was a negative result for the acid anaerobicality test. Therefore, we can conclude that M. luteus is not able to live in a fermentation environment, but can in an oxidized environment. Finally, there were also some differences between bacteria’s reactions to antibiotics.
Both S.epidermidis and S.seprophyticus were expected to have positive urease test reactions; as they did not, there may have been flaws in the results due to time inaccuracies or insufficient amounts of the bacteria.
Staphylococcus had different reactions to the tests depending on the strain.
S.aureus showed positivity in all the tests, and was susceptible to novobiocin.
S.epidermidis had a positive urease test, but negative on the remaining tests. S.seprophyticus was the only type of bacteria that had a novobiocin resistance. Finally, there was S.haemolyticus, which had negative results for all the tests, with a susceptibility to novobiocin, making it simple to find.
3. Disc susceptibility test:
More and more, antibiotics are being used in studies throughout the globe to learn how they work against new bacteria. Their reactions to the bacteria help to identify what organism it is. There are antibiotics that will kill this bacteria, and others that will just shop it from growing. Antibiotics can be used to exert growth control on this bacteria.
This test is meant to determine if staphylococcus aureus has a resistance or susceptibility to six different antibiotic varieties.
Table 4 showcases every antibiotic’s zone diameter, and Figure 4 shows the measurement of the zone size. They are compared to the following susceptibility range.
The results are valid because all of the control elements functioned correctly. The only exception is Cephalothin, due to the 100% concentration on that disc.
According to the above table, there are different reactions of Staphylococcus aureus with the six antibiotics chosen for this study – Penicillin G, Erythromycin, Cephalothin, Gentamicin, Oxacillin and Chloramphenicol. Every one of these antibiotics worked effectively on the bacteria, showing that it is susceptible. Every antibiotic had a different reaction to each of the three strains of Staphylococcus aureus that was tested. The A strain was the clear winner in sensitivity, and the C strain showed the greatest resistance to all of these antibiotics.