Sticky Test

There are many reasons for identifying an unknown bacterium. The reasons range from medical purposes, such as determining if the unknown could cause ailments in living things or knowing what microorganisms are needed to make antibiotics. The experiment was done by applying methods in order to identify an unknown bacterium.

The first step to identifying the unknown bacteria residing on the blood agar plate sent in from Khokana was to do a Gram stain on it. This is an important first step because it dictates further testing that will be necessary to arrive at a final conclusive result. Viewing the fixed and stained slide under the microscope revealed round chains of bacteria in a purple color signaling Gram-positive streptococci. A catalase test was performed with no bubbling present indicating a negative result. This further confirmed the shape and arrangement seen under microscopy. With this mind, the coagulase test was not done, as it would be of no use since that specifies for staphylococcus, specifically for Staphylococcus aureus. For streptococcus, an examination of hemolysis was necessary at this point. Shifting attention back to the original blood agar plate, gamma hemolysis was noted, thus narrowing the field down to two choices left. The unknown bacteria was either Streptococcus bovis or Entercoccus faecalis. This also means the Optochin and Bacitracin sensitivity tests would not be needed as those pinpoint alpha- and

This experiment was conducted to find the genus and species of an unknown bacteria prescribed by the lab teacher, which was unknown bacteria GA3 in my case. Identification of unknown bacteria techniques are used on an every day basis to figure out what type of bacteria it is and to find the best method of how to treat a patient with this bacteria (1). All five “I’s” of Microbiology were used in the testing for the unknown culture. Inoculation was used several times to put the unknown culture into agar plates or into biochemical test tubes. After Inoculation of these tubes or plates, they always were placed into the incubator for further growth and development. Isolation was used to make sure we got the correct bacteria we were testing for. After each further isolation, we gram stained the culture and inspected the culture under a microscope to further help in the identification process of the unknown bacteria. Multiple tests were done on the unknown culture to make sure we were confident in what kind of bacteria the unknown was.

The main idea of this experiment was to correctly identify the unknown bacteria, #3. Identification of unknown bacteria yields multiple benefits in many different areas in the research of microorganisms. In this experiment I performed many different test dealing with things such as the presence of enzymes, fermentation abilities and different chemical reactions. Observations made from the tests were then compared to a gram negative unknown chart in order to identify the bacteria. Based off of my results and the chart, I concluded the bacteria #3 was the bacteria Escherichia coli. E. coli is most commonly found in the intestines of warm blooded organisms. Most E. coli strands are non pathogenic however, there are strands

There are many reasons for knowing the identity of microorganisms. The reasons range from knowing the causative agent of a disease in a patient, so as to know how it can be treated, to knowing the correct microorganism to be used for making certain foods or antibiotics. This study was done by applying all of the methods that I have been learned so far in the microbiology laboratory class for the identification of an unknown bacterium.

A highly conserved gene will be used to identify a prokaryotic species isolated from the body. Fundamental lab techniques will be also explored and utilized, such as amplifying using PCR, cloning, and transforming the gene into a host cell. DNA electrophoresis and specific substrate plating will serve as analysis check points. The final product will be sequenced and compared to similar species to observe phylogenetic relationships.

The bacteria that was contained within Unknown tube #12 is believed to be Pseudomonas aeruginosa, Figure 1. The bacteria tested to be Gram Stain negative, producing a pink, red color retained from the staining process. When the species of bacteria was plated on nutrient media, the cells produced an irregular and spreading configuration as shown in Figure 2. This same plating test provided the margins and elevation, lobate and hilly, respectively. The specimen was stabbed in a Fluid Thioglycollate Medium (FTM) tube using an inoculated loop of the bacteria. The results of this experimentation indicate the type of oxygen requirement of the bacteria. The test found the bacteria to be aerobic as colonies of the bacteria began to form along the top of the FTM tube (Manual 2017).

Table 3 shows Gram stain results that indicated C. Freundii as a gram negative bacterium in rod shapes scattered in singles and some in pairs. Each gram stain produced the same results. The Bartholomew and Mittwer method of endospore staining indicated that C. Freundii tested negative for endospore formation. Table 4 shows the biochemical test results of the unknown and the official test results for comparison.

This experiment was centered on metabolic and biochemical testing procedures. The rationale of performing these tests was to distinguish six different microbes from one another and to compare how their metabolic and biochemical processes differ from species to species to determine the unknown sample.

Two smears of the unknown bacterium #5 were inoculated while the second smear was used for a back up. The unknown bacterium dried for at least forty minutes. After the smears dried, the slides were heat fixed two times to ensure the stability of the organism. The slide was placed on top of the staining rack then over the small sink.

Title Page  Introduction The purpose of this lab is to use several techniques to determine the identity of an unknown bacterium. Many of these tests involve the differences between Gram-positive and Gram-negative bacteria. Gram-positive bacteria have a thick peptidoglycan wall while Gram-negative bacteria have a much thinner peptidoglycan wall. This leads to a number of differences in what media each kind of bacteria can grow on and their physical properties. Techniques used in this experiment include growth tests on different media, microscopy of a wet mount, PCR amplification and purification, gel electrophoresis, the catalase test, MSA plates, the KOH string test, and cycle sequencing.

Introduction: Through the conduction of numerous experiments, the identity of two bacterial isolates was determined. The tested specimen was an unknown sample of a mixed culture of two different species of bacteria. The first step that was taken was obtaining a pure culture of each species of bacteria by isolating one species from the other. Once isolation was complete, the isolated cultures were tested using procedures and tests that had been performed during previous lab sessions. Each mixed culture that was tested had one gram positive and one gram negative bacterial species. The possible species of bacteria that could have been isolated from the mixtures included the following: Bacillus subtilis, Corynebacterium glutamicum, Escherichia coli, Staphylococcus aureus, Enterococcus faecalis, Enterobacter aerogenes, Salmonella enterica, and Pseudomonas aeruginosa. The identities of the unknown species were determined through comparing the experimental data against data acquired from previous experimentation.

A series of biochemical tests were conducted in order to determine the identity of an unknown gram negative bacterium. The unknown had the potential to be one of six different gram negative bacteria: Escherichia coli, Pseudomonas aeruginosa, Enterobacter aerogenes, Proteus mirabilis, Klebsiella pneumonia, or Salmonella typhirmurium. After using the T-streak method to isolate pure colonies and confirming the gram negative nature of the unknown bacterium the unknown was subjected to seven biochemical tests and the results compared to the results of the six known bacteria for the same tests. After performing the Triple Sugar Iron Agar Test, Sulfur Indole Motility Test, Methyl Red Test, Voges-Proskauer Test, Citrate Test, Urease Test, and Gelatin Test it was confirmed that identity of Unknown #15 was Salmonella typhirmurium.

In the world of microbiology it is vitally important to be able to discern the identities of microorganisms. Not only is it important in a lab setting but as well as in healthcare in general. Properly identify what strain of bacteria a person has will aid in the proper medicine and dose given. Throughout the semester we have learned about different types of bacteria and certain test that can clearly identify them. The purpose of this lab report is to identify a Gram-positive or Gram-negative bacterium. Using all the knowledge of procedures and lab techniques identify the unknown and discuss all the tests you performed.

The Unknown Bacteria 36/Bacteria # 2 on a TSA plate was examined by the naked eye and under a dissecting microscope. Bacteria # 2 was approximately 3 - 4 mm in diameter. They were circular in form with an entire margin and a flat elevation. The colonies were rough (granular), translucent, and white brownish color with black granules. The Gram stain resulted in a Gram negative rod. After the Gram stain was completed, the bacteria were streaked on an Eosin -Methylene Blue Agar plate and an Enterotube II was inoculated.