The first test conducted on unknown bacteria 32 was the Gram stain. From this stain, unknown 32 was found to be a Gram-positive cocci. This test eliminated all possible Gram-negative bacteria, Gram-positive rods and Gram-positive spirillium. Next, the endospore test determined whether or not the Gram-positive bacteria contained endospores. With the use of malachite green, steam, and safranin it was found that unknown bacteria 32 did not contain endospores.…
The results show that tea tree and eucalyptus have about the same antibacterial activity as the positive control (ampicillin) used in this experiment. Oregano and colloidal silver’s zone of inhibition were closer to h2O, which concludes that at the amount used for both there is no antibacterial…
The purpose of this experiment was to isolate two unknown bacteria and perform a series of selective and differential tests to correctly identify each. After the bacteria was isolated a series of differential and selective tests following the dichotomous key attached were used to identify each bacteria. The Gram-positive bacteria were identified as Staphylococcus aureus with a positive confirmatory test, mannitol salt agar, showing consistent results as well for S. aureus. The Gram-negative bacteria were Pseudomonas aeruginosa with a positive confirmatory…
The purpose of the unknown bacteria lab assignment was to select an unknown bacteria culture and, through a series of metabolic tests, identify which bacteria genus resided in the pure culture received. A nutrient broth inoculated with bacterial culture (numbered 45, henceforth referenced as U45) was selected and a streak plate was made to isolate a pure culture for use throughout the assignment.…
The purpose of this lab was to determine the identity of an unknown bacteria slant culture using a series of differential tests. The tests used to identify the unknown bacterial culture included: Gram stain, mannitol salt agar, coagulase tube test, and an antimicrobial susceptibility test. The tests selected were based on the results of a gram stain.…
In this lab, we isolated and compared bacteria from our skin and throat. We created two nutrient agar plates, three mannitol agar plates and two blood agar plates (seven in total). These plates were streaked with bacteria from either the skin or the throat. The skin streaks were done before and after washing the face and then incubated at 37 degrees for 48 hours. The throat streaks were also incubated at 37 degrees for 48 hours. On both the Mannitol Salt Agar plate and Nutrient Agar plate the number of bacterial colonies was too numerous to count before washing, as seen in the results. After washing the Mannitol Salt Agar plate had about ten bacterial colonies and the Nutrient agar plate had zero, as seen in the results. In the second lab, we observed the colonies after incubation and chose a new colony for restreak and incubation. After performing gram stains, we were unable to determine for the throat swab due to an error in the overuse of crystallized violent. In the third lab we examined the Mannitol Salt agar and Blood Agar restreak plates and found that the colonies were the same as the originals. For the throat and face restreak after performing the gram stain we were able to determine that the isolated bacteria was gram negative. The type of hemolysis observed on the throat swab was beta hemolysis, more…
The purpose of this lab was to identify two unknown bacteria cultures using various differential tests. The identification of these unknown cultures was accomplished by separating and differentiating possible bacteria based on specific biochemical characteristics. Whether the tests performed identified specific enzymatic reactions or metabolic pathways, each was used in a way to help recognize those specifics and identify the unknown cultures. The differential tests used to identify the unknown cultures were oxidase, catalase, lactose and sucrose fermentation, Kugler/iron agar, nitrate reduction, gelatin hydrolysis, starch hydrolysis, manitol salt, MR-VP, citrate, bile esculin, indole, urease, DNase, and coagulase.…
The purpose of this experiment was to find the identity two unknown bacteria in the given test tube.…
The possible identity of the unknown organisms in the mixed culture was limited to bacteria that we had worked with previously in lab. Initially a Gram stain was conducted in order to distinguish the unknown bacterium as a Gram-positive and/or a Gram-negative organism (Lancaster and Bennett, 2012; Kellenberger, 2001). Based upon the results, both Gram-negative and Gram-positive bacteria were observed in the unknown mixed culture (Table 1 and Table 2; Kellenberger, 2001). In order to isolate the two different bacteria, colonies that grew on the MSA were used to inoculate Gram-positive tests, where as MacConkey Agar colonies were used to inoculate Gram-negative tests.…
After the gram stain test I carried out a catalase test. This test was carried out to investigate if my unknown was streptococci (negative) or staphylococci (positive) and or micrococci (positive). The catalase test result indicated that my unknown was negative because no bubbles formed when I placed a loop of the organism into hydrogen peroxide.…
An unknown labeled with number 8 was given out by the lab instructor. The goal at this point was to determine unknown gram positive vacteria. The procedures performed consisted of sterile technique in addition to being followed as stated in the referenced course laboratory manual by Matar (1) , unless otherwise noted.…
When looking back on military history over the past two hundred years, it is tempting to argue that battles and entire wars are exactly as they seem. This common problem is readily found in two wars fought in the 1860s: the American Civil War (1861-1865) and the Austro-Prussian War (1866). However, while it is easy to consider the American Civil War as simply a war fought by the Union to maintain territorial integrity throughout the relatively young United States, and the Austro-Prussian War as merely the “middle” war of the three wars of German Unification meant to expand “German” territory, this is not the case. In reality, the American Civil War and Wars of German Unification (as opposed to simply the Austro-Prussian War), when compared through the lenses of military, socio-political, and personal factors, are in fact quite similar and if one compares these two series of events under the assumption that the Wars of German Unification were in fact driven by the desire to found a unified German state, one can readily come to the conclusion that the American Civil War was also a war fought to establish, as opposed to maintain, a unified American state. However, before one can start comparing the two series of events, it is necessary to point out the inherent differences between the two that makes a comparison between the two somewhat thornier to defend.…
My journey to the unknown started about three weeks before the end of my microbiology class at Brunswick Community College. This journey started out with a media plate cultured with an unknown species of bacteria. I was then instructed by my professor to use all of my previous knowledge to identify the unknown bacterial pathogen. This lab led me to master my skills of using the Gram stain, testing for catalase, testing for coagulase and using the oxacillin screen. Now I am going to take you with me on the journey to the unknown.…
The secretion yielded gram-positive cocci after 2-day incubation at 37°C on 5% sheep-blood agar under anaerobic atmosphere.Biochemical testing gave a positive result of α hemolysis and a negative result for production of catalase. The cocci wereidentified by using the BD Phoneix-100 system (Becton Dickinson, New Jersey, USA) as Alloiococcus otitis, by using VITEK 2-compact system (bioMérieux, Lyons, France)as Micrococcus Kristinae, and by using matrix-assisted laser desorption/ionization time of flight (MALDI-TOF) mass spectrometry (Bruker, Leipzig, Germany) as “not reliable identification”.Sequencing the 16S rDNA PCR product obtained from the isolate yielded 1406/1419 bases (99%) sequence similarity with the homologous sequence of D. pigrum reference strain (GenBank accession no. X70907.1) by BLAST analysis…
In order to be able to adequately study and characterize a certain microorganism, microbiologists need to separate and isolate this microorganism from the many other microorganisms with which it usually shares its natural environment or habitat; proper and professional execution of bacterial isolation techniques are at the centre of routine activities in any professional microbiology laboratory. The task of the microbiologist is to isolate the microorganism under investigation from the mixed culture of the sample and to create a pure culture. A pure culture is defined as a population of cells which arose from a single cell by repeated cell division.…