Gram-positive bacteria

Escherichia coli (Gram-positive), Staphylococcus aureus (Gram-negative), and the unknown sample were heat fixed onto a slide via inoculating loop. A series of different stains (Crystal violet, Gram’s iodine, and Safranin) and alcohol are applied to the slide to reveal whether the unknown sample turned Gram-negative or positive. Using two SBA plates in the hemolytic test will distinguish between different types of Gram-positive cocci. Gram-positive microorganisms produce enzymes or by-products after

first day, I received my unknown bacteria number 110 and I stared to observe that tube. The tube has normal color, creamy, and little bit cloudy. First, I made two new slants to get the strong and alive bacteria for further text. One tube was incubated at 250C and other at 370C. Next, I started to do my Gram Stain. After I finished the smear, heat fix, and cover the slide with all chemical, I saw the pink color stick onto the slide. I knew that this bacterium is gram negative. Then, I looked up the

Matthew Crane Lab Section: 13151 Comparative Analysis of Antibiotic Growth Suppression of Staphylococcus Aureus Introduction Staphylococcus Aureus is a gram negative bacterium that may be pathogenic or exist as a commensal organism in humans. Unevolved strains are susceptible to nearly all antibiotics (Chambers & DeLeo, 2009). Among the many antibiotic options, penicillin is particularly effective against S. Aureus. This is due to the mechanism of action by which penicillin replaces key structures

The strategy used to determine the unknown organism was to first perform a gram stain to determine if the organism was either a gram negative or gram positive bacteria based on the color of cells. A TSA plate was inoculated to streak for isolation and purity. After colonies were incubated characteristics of colony morphology were recorded and a TSB broth and TSA slant were inoculated to determine characteristics of growth in broth and slant. Another TSA plate was inoculated to determine growth

why it is essential that gram stain and microscopic examinations are the first step in identifying pathogenic bacteria. Gram stains are an important procedure because it can determine the stain of the cell wall of bacteria sample. It also allows laboratory technicians to classify the bacteria in to either gram positive or negative as well as allowing them to analyse and study the morphology and arrangement of bacteria. Whilst determining the bacteria type and type of gram stain, the test also allows

additional tests can be performed to further differentiate the three bacteria from one another. One example is the BactiStaph test for the Staphylococcus genus (in this case S. aureus) (Summers, Brookings and Waites, 1998). Which relies on the principle of detecting coagulase (clumping factor) using fibrinogen, and detecting protein A with immunoglobulin G. As result of these surface markers present on most strains of S. aureus will test positive for BactiStaph test (Summers, Brookings and Waites, 1998; Harris

unknown bacteria, the microbiology student started by inoculating a sample on a slide to stain with Gram’s stain; resulting a gram positive cocci. He continued by looking at the dichotomous key in the Lab Manual, afterwards doing a catalase test on an inoculated slide to differentiate it from being either a Streptococcus or a Staphylococcus (2). He then put the hydrogen peroxide on the inoculated slide, it immediately reacts, resulting on an excessive bubbling reaction, concluding that the Gram positive

Introduction Streptococcus agalactiae, also known as Group B Streptococcus is identified as a gram-positive bacterium. S. agalactiae is a commensal bacterium found in the human digestive and genitourinary tract (Rosinski-Chupin, et al., 2015). S. agalactiae causes various diseases such as septicemia, meningitis, and pneumonia. Also, S. agalactiae infections occur predominately in pregnant women, neonates and elderly persons (Louvois, 1980). Due to the formation of its polysaccharide capsule, S

The Gram-negative bacterium for Unknown 13B was Salmonella typhimurium. Unknown 13B had similar reactivity patterns to S. typhimurium. A comparison of Unknown 13B and S. typhimurium can be compared in Table 2. The Catalase test and the Methyl Red test for Unknown 13B and S. typhimurium both obtained positive results (Table 2). Negative results were acquired through the Indole test for Unknown 13B and S. typhimurium (Table 2). For the Lactose Ferment and the Sucrose Ferment test, negative reactions

of this, 2 more tests were run to confirm that the organism was gram positive. 4) A MSA plate test was run on a sample of the organism and the results were consistent with the given results for M. Luteus. The results showed a fair amount of growth on the plate, and the color of the agar around the growth remained red. The MSA test is selective in that the salt will inhibit most gram negative organisms and select for gram positives. If there is growth and the color of the agar turns yellow around