2005). Gram-negative bacteria stain pink because after the wash of alcohol and acetone they do not retain the crystal violet dye leaving them decolorized. A counterstain of safranin is added which stains the bacteria pink. Gram-negative bacteria have only a few layers of peptidoglycan that are surrounded by an outer membrane of phospholipids, lipopolysaccharide and lipoprotein. There is a space between the peptidoglycan and the secondary cell membrane called the periplasmic space (Betsy, T., & Keogh, J.
Viruses j. C. Fungi k. D. Bacteria Ans: A and D 6. A bacterial cell is found to be motile and resistant to high temperature and phagocytosis. This cell probably has: l. Endospore, flagella, capsule 7. Nitrogen is a major bioelement that can be found in: m. a. proteins n. b. Nucleic acids o. c. Polysaccharides p. D. Lipids Ans: a and b 8. All of the following are polysaccharides except: q. Glucose 9.
Once feared microorganisms like Staphylococcus epidermises, Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli are able to be battled with different antibiotics. With many antibiotics being misused, many micro bacteria are becoming immune to once effective drugs. A useful test in measuring the effectiveness of antibiotics to bacteria is the Kirby Bauer test. The Kirby Bauer test is an experiment in which antibiotic soaked disks are placed on a known bacterium, if the bacteria are susceptible to the antibiotic you will see a clearing or halo around the disk; this
Once introduced to an antibiotic, if not eradicated, the bacteria will produce “offspring” that are resistant to that particular antibiotic (VanMeter, VanMeter, & Hubert, 2010). In addition, plasmids (freely-moving pieces of DNA in the cytoplasm) often carry genetic material for resistance and can transfer it from one cell to another, even crossing bacterial species (McKinney, 2013). Compounding the issue, the overuse of antibiotics has given resistance to many strains and many species that otherwise would never have been exposed. Practices like prescribing a much more powerful antibiotic than is necessary combined with patients’ tendencies to stop treatment once they feel a relief of symptoms have only strengthened latent bacteria (Aziz, 2013). Some doctors report that they feel obligated to provide a prescription to a patient, even when the cause of the illness is not yet proven to be bacterial (Bersch, 2010).
MRSA: Methicillin-Resistant Staphylococcus Aureus Date: 12/17/2013 MRSA stands for Methicillin-resistant Staphylococcus Aureus. It is a staph bacteria that is resistant to methicillin antibiotics, which are normally used to treat staph infections. Since it is resistant to these antibiotics, it is commonly referred to as a super bug. It becomes resistant due to improper and overuse of antibiotics. The overuse of antibiotics enables the bacteria to build up immunity to antibiotics so that they are less effective.
There are four natural forms of botulism: food borne, infant, wound, and adult intestinal colonization (1). Food borne botulism (typically type A, B, or E toxins) is caused by ingesting food that has been in contact with contaminated soil and contains the spores. Improper canned goods and garlic/pepper infused oils with low acidity, high water activity, low concentration of salt, and no preservatives offer the organism a favorable anaerobic and nutritional environment to grow and produce the toxin (4). The spores are heat resistant and can survive improper prepared foods (5). Although, boiling canned goods for more than ten minutes will destroy the toxin (2, 5).
Next I observed the isolation streak on my Blood Agar Plate and found pinpoint, round, entire and flat colony morphology as well as an alpha hemolytic reaction pattern, indicating red blood cell ion leakage which is characteristic of S. epidermidis. The final test used Mannitol Salt Agar that selects for Staphylococcus bacteria because they are salt tolerant and differentiates between species based on agar color. The agar remained red after incubation with my unknown culture indicating that the Mannitol-D sugar was not fermented. After running this series of test I can accurately conclude that my unknown #14 culture was Staphylococcus epidermidis. At age 11, Jonathan Markway was diagnosed with congenital heart disease.
Mary Riddell 9/26/11 Period 3 The Zone of Inhibition Created by an Antiseptic, Disinfectant, or an Antibiotic Abstract: The purpose for conducing this experiment was to determine which bacterial inhibitor would create the largest zone of inhibition on bacteria streaked petri dish. In the experiment it was made clear that the antibiotic had the largest zone of inhibition, the antiseptics had the second largest zone of inhibition, and the disinfectant had the smallest zone of inhibition. The antibiotic worked the best because antibiotics work on the inside of the cell to break them down while the others are meant to sit on top of the surface to kill them. Introduction: The purpose for conducting this test was to determine which bacterial inhibitor would have the largest zone of inhibition on a bacteria streaked perti dish. The bacterial inhibitors in the experiment that were chosen were, an antiseptic, (hydrogen peroxide), a disinfectant (ammonia), and an antibiotic (tetracycline).
Staphylococcus aureus, (S aureus) or ‘Golden Staph’ as it is more commonly as, is a bacteria that is generally harmless to humans. This fact is true with the exception of when it’s host is weakened by disease and or traumatic injury in which case it can prove fatal. Genetic variation and mutation of the bacteria has been likened to the Darwinist theory of Evolution. Treatment of the Staphylococcus bacteria has become increasingly more complex over time. The genetic evolution of this bacteria has caused some strains of the infection to become resistant to the antibiotics on the market for the treatment of S aueus.
Selective Media Lab Report Introduction Biological media acts as food for the bacteria and allows the growth of bacteria. There are two types growth media, selective media and differential media. Selective media used is when trying to promote the growth of only one bacteria, while differential media is used when trying to distinguish one media from another growing on the same plate. This experiment uses one type of differential media, Blood agar, which is differential for detecting hemolytic activity. Three types of selective media are used: Phenyl Ethyl Alcohol (PEA) are both selective for gram positive agar and Deoxycholate Citrate Agar (DCA) is selective for enteric pathogens.