Eosin Methylene Blue Agar

Words: 684
Pages: 3
Open Document
After looking at the organism under the light microscope, it was clear to say that it has a Gram-negative cell wall and it was in the form of a bacillus. The selective and differential media that were used to determine the Gram group the organism belongs to were the columbia CNA blood agar, phenylethanol agar, Eosin Methylene Blue agar, and Hektoen Enteric agar. Three out of the four agar tests showed that the organism was Gram-negative. There was no growth on the phenylethanol agar due to the ethanol inhibiting the growth of Gram-negative organisms. The unknown organism grew and produced a light purple color on the Eosin Methylene Blue agar. This means that it is a slow lactose fermenter. The unknown microbe produced an orange-yellow color …show more content…
The first option was the S. flexneri and it had 15 out of 22 biochemical test matches to the unknown organism. The next choice was P. vulgaris which had 18 out of 22 biochemical test matches to the unknown microbe. Finally, the S. marcescens had 14 out of 22 similar biochemical test matches to the unknown organism. After careful consideration, it was clear to state that the unknown organism that was labeled as 24 was the P. vulgaris. There were some experiments that did not match the P. vulgaris. One of the tests was the mobility test that gave a false negative. This could be due to the organisms not moving in the media. Another test that gave a false negative was the methyl red test. This could have been misread or there was not enough methyl red added into the tube. The urea hydrolysis was another test that gave a false negative. This reading could have been caused by misreading the color that was produced. It was difficult to distinguish between which color it was producing. The last test that gave a false positive was the DNase test. The organism could have produced a false halo and it was read as a true …show more content…
The first biochemical test that was on the chart was the citrate test. This divides the reference organisms in half and examines which organisms can break down the citrate. If the citrate is broken down, then the color of the media will change from a green to blue. If the organism cannot break it down, then the media will stay green and the next test the organism goes through is the indole test. This will test to see if the microbe contains tryptophanase to break down tryptophan. If the organism is able to break it down, then the Kovac’s solution turns into a red or pink color then it will run the final test which is the gelatin test. If the organism can utilize gelatinase enzymes to break down the gelatin, a large amount of liquid will form on top of the gelatin which then identifies the organism as P.
Show More

Related Documents: Eosin Methylene Blue Agar

Eosin Methylene Blue Agar Gram Stain

the Gram-negative bacteria. The results show the differences between the cells walls of the bacteria. The Phenylethyl Alcohol Agar is a selected media that allows the growth of a Gram-negative bacteria while inhibiting the DNA synthesis of Gram Negative bacteria. The Eosin Methylene Blue Agar which contains Peptone, lactose, sucrose and the dyes eosin Y and Methylene blue. These are the sugars that are fermentable by the fecal coliforms, which are the gram negative facultative anaerobic rods. The…

Words 1419 - Pages 6

Antibacterial Media Effect On Bacteria

EMB agar is used as a differential selective media as it allows to distinguish between lactose fermenting and non-lactose fermenting organisms and inhibit the growth of gram-positive bacteria. The key component in the agar is lactose. The methylene blue dye in the EMB causes the lactose fermenting bacteria to produce a green metallic sheen which is caused by the accumulation of eosin and methylene blue. Bacteria that ferment lactose at a slower rate produce…

Words 597 - Pages 3

Essay about Micro 1

isolated colony, under the microscope showed gram positive and gram negative. A TSA, Trip tic Soy Agar using the quadrant streak method. Isolation and sterilization steps were taken. The plate was incubated at 37 degrees for 24-48 hours. After this period plate was examined for growth and color. Following procedure for the Gram positive unknown #7, Phenylethyl Alcohol Agar (PEA) was used, which is a selective medium that encourages growth of Gram positive organisms while…

Words 877 - Pages 4

Tryptic Soy Agar Lab Report

first step of identifying the unknown was to immediately gram stain the bacteria. The gram stain results yielded short, gram negative rods with a clustered to random arrangement. Following the gram stain, a streak test was performed on a Tryptic Soy Agar (TSA) plate. After incubation for forty-eight hours, the TSA plate was analyzed to identify a vast amount of pure colonies. The single isolation colonies were circular in form, the elevation was convex, and the margin was entire. Upon the growth of…

Words 687 - Pages 3

E. G Mrsa Abstract

Abstract: Intro Staphylococcus aureus is a facultative anaerobic gram positive bacterium, known to cause skin infection, respiratory disease and food poisoning. It causes infections by producing potent protein toxins and expressing cell-surface proteins that inactivates antibodies. In clinical medicine, the emergence of antibiotic-resistant forms of S. aureus (e.g. MRSA) is a global pathogenic issue. Physiological and genetic differentiation are important for bacterial identification and cellular…

Words 3511 - Pages 15

Article1380811710 Ziarlarimi Et Al Essay

distilled water had no inhibitory effect on the activity of E. coli. In this experiment, each of the aqueous extracts was prepared by using distilled water in 6 concentrations: 0.5, 1, 2.5, 5, 10 and 20%, and was poured into the cavities in nutrient agar medium, and then the plates were kept in incubator at 37°C for 24 h. The results indicated that MIC of the garlic aqueous extract was 5%, but E. coli was resistant to the aqueous extracts of onion and mint. Key words: Herbal extracts, garlic, onion…

Words 2011 - Pages 9

Microbio notes Essay

Branches of Microbiology: Bacteriology, Parasitology, Protozoology, Phycology (algae), Mycology, Immunology Distinguishes between 6 types of microorganisms: Protozoa Fungi Algae Viruses Bacteria Archaea -Single-celled -Eukaryotes -Lack cell wall -Classified by motion type (flagella, pseudopod, cilia) -No movement in adult form -Help digest cellulose -Few are pathogenic -Eukaryotes -Chitin in cell wall -Decompose organic matter -Yeasts (unicellular) & molds (hyphae) -Affects 1/5…

Words 6946 - Pages 28