Broth

After incubation for the SIM test the Kovac’s reagent was added and the top of the broth did not turn a dark red, it was decided that this was a negative test for Indole. With the negative Indole test result this eliminates E. coli and P. vulgaris. The last test I did was use a Urea broth test for #29. The results from this test were negative which means there was no production of urease to break down urea and produce a pH change to…

Introduction: Antibiotic sensitivity testing is used in clinical laboratories to predict the effectiveness or failure of antibiotics in vivo by testing in vitro. The need for antibiotic sensitivity testing is urgent due to the surge of antimicrobial resistant pathogens in recent years. Antimicrobial resistance hinders the prevention and treatment of the infections caused by parasites, bacteria, fungi and viruses. Antimicrobial resistance is the resistance of a pathogen to an antimicrobial that…

The possibilities of two unknown microorganisms lead to phenylalanine deaminase test. The detection of phenylalanine deaminase enzyme was carried out by adding ferric chloride to phenyaline slant. When ferric chloride was added to phenylalanine deaminase tube, it turned into army green color( positive result) which indicated that unknown microorganism contains phenylalanine deaminase enzyme. On the other hand, no color change in the slant indicates negative result for this test. The choices…

During the phase and process of the bacterial unknown project, vast amounts of test were performed in order to determine an unknown species of bacteria. Within the many procedures of identifying the unknown bacteria, I was first given a tube with the unknown bacteria, from which later on I started subcultures by streaking bacteria from the original tube onto a tryptic soy agar (TSA) slant. Throughout the process of identifying the unknown, new subcultures were produced in order to use the newest…

This medium are use to test the metabolic characteristics of the unknown bacteria. In order to identify the unknown bacteria from other bacterias the following medium was used: MSA plate, SIM plate, nitrate reduction test Nutrient gelatin and Urease broth. For Metabolic tests, only Catalase test were performed on the unknown bacteria. These tests were best use gram negative bacteria to indicated what the unknown microbe is. For the Catalase test, the use of hydrogen preoxide on the sample of…

Listeria monocytogenes is a Gram-positive rod-shaped bacterium. It is the agent of listeriosis, a serious infection caused by eating food contaminated with the bacteria (Todar, 2008). The disease primarily affects older adults, pregnant women, new born, and adults with weakened immune systems. Babies can be born with listeriosis if their mothers eat contaminated food during pregnancy. However, healthy people may consume contaminated foods without becoming ill. Listeria monocytogenes is commonly…

Objective I. To learn how to inoculate the nutrient broth properly in preventing contamination to the nutrient broth and the culture Escherichia Coli. This is done by sterilized the loop and sterilized the neck of the tub with heat from before use and before put the cape on. II. To learn how to do a simple streak of an E. coli culture on a nutrient agar plate with one stroke from start to end like a “Z”. III. To learn how to do a complex streak where we grow E. coli culture on the nutrient…

After gram staining both the gram positive and gram-negative bacteria, the groupings were observed. For the unknown gram-positive bacteria, the cells were arranged in a cocci cluster, while in the gram-negative bacteria, the cells were arranged in a rod cluster. Both the gram negative and gram-positive bacteria exhibit a small yellow colony on the TSA plate. After 48 hours, the MSA plate was observed. Individual isolated colonies were found throughout the plate, with a yellowish color. The…

After we identify our unknown bacterium, we had to repeat the same step for the citrate agar and nitrate broth. We inoculated the loop, took a small amount of our unknown bacterium, and mixed it in our two tubes containing the citrate agar and the nitrate broth and waited until next lab to continue the process. When we came back next week, we then added two drops of reagent in the nitrate broth to see if the color would change. After doing every experiment, it appeared that the nitrate color was…

Foodborne illness is probably the most common public health problem in the United States and around the world. It is estimated that millions and millions of Americans gets sick by consuming contaminated food or water each year. Hence it is important to detect the presence of disease-causing bacteria in drinking water. One the simplest way to tell if there is a disease-causing pathogen in the water is the presence of coliform. Just like most of the microorganisms, coliform bacteria, a…