Introduction Medical instruments are routinely sterilized using autoclave or by gas sterilization using ethylene oxide. However this method of sterilization is insufficient to destroy pyrogen because it is thermostable as a matter of fact, pyrogens will be formed from the dead gram-negative bacteria that is killed during the sterilization process. The pyrogen substance that is produces is called endotoxin. Medical instruments (such as surgical instruments and in certain cases of implants) may contain endotoxin on the surface of the instruments, due to this the LAL test is performed (Mazzotti et al, 2007). Endotoxin is released into the environment during bacterial cell death or cell division occurs.
Durham’s tubes filled with the broth were placed in each of the test tubes in an inverted position. Then the tubes were sterilized. After sterilization, the test tubes were inoculated with fresh bacterial cultures and one test tube was kept as control. The inoculated tubes were incubated at 37±1o C for 24-48 h (Aneja, 2001). After incubation, tubes were observed for the colour change in medium due to the production of acid and gas production.
The bacteria were heat-killed, and these respective components were extracted and the composition resulted in being similar to that of DNA. They also treated the bacteria with multiple enzymes, such as trypsin, chymotrypsin, ribonuclease and deoxyribonucleodepolymerase, where it was found that only the deoxyribonucleodepolymerase inhibited the formation of smooth Pneumococcus colonies. [Downie. A. W. (1972)] Thus, they confirmed that DNA was the transformation principle in Griffith's experiments. The Avery and MacLeod experiment was replicated in the laboratories at the University of the Witwatersrand.
The bacteria was plated in mid-log phase, this was done for two possible reasons. One being conjugation is highly efficient and successful during mid log phase and because kanamycin is an antibiotic that inhibits protein synthesis in growing bacteria by binding to the 30S subunit of the bacteria ribosome. This blocks the tRNA binding which stops the bacteria from making proteins for growth (Bacteriostatic). If the conjugation was successful the growing bacteria would be able to block kanamycin
The alcohol usually ethanol, isopropanol or n-propanol in concentrations between 60 to 85 percent deactivates bacteria and viruses without using antibiotics. These alcohols deactivate a broad range of microbial agents and are more effective at killing microbes than antibacterial or plain soaps. Additionally, the alcohol quickly evaporates limiting the time bacteria and viruses are exposed to the sanitizer. Bacteria require prolonged exposure to antibiotics to develop resistance. Hand sanitizers contain no antibiotics.
Since DNA can unwind because of the removal of the enzymes that do that bacteria can’t multiply. Tetracycline which is used to treat acne, respiratory tract infections and other conditions kill bacteria by inhibiting protein synthesis. This is done by stopping molecules to bind on a certain area of the cell called ribosome. Since key molecules can bind to ribosomes which is the site where protein synthesis happens the bacteria will die because it can’t carry out vital functions including asexual reproduction. Some antibiotics kill bacteria by stopping the production of folic acid which is an essential vitamin for proper functioning of the cell’s
The pickles are then submerged in water to remove all of the salt they may have obtained during the cure. From this point, the pickles are moved along a transporter to a slicing machine which cuts the pickles to the correct size depending on the type of product desired. Microflora: • Lactic acid bacteria • L.plantarum • L.brevis • Leuconostoc
Anti-bacterial agents kill or inhibit bacterial growth. My conductive research consisted of making agar, growing bacteria that I received from the inside of a human’s mouth and using different toothpastes to see which brands work better. Introducing bacteria What is bacteria Bacteria is a member of a large group of unicellular microorganisms which
• Soaking and pre-rinsing dishes and pots The subject is cleaning and sanitizing. Cleaning is the process of removing food and other types of soil from a surface (what you can see). Sanitizing is the process of reducing the number of microorganisms on a clean surface to safe levels (removing microorganisms you cannot see). Both can be done with heat or chemicals. Before loading dishes into dishwashing machines and washing pots, items should be soaked and pre-rinsed to remove as much food as possible.
Chlorine is able to kill pathogens and microorganisms by destroying their cellular structure. However, one disadvantage of this method is that residual chlorine in water is harmful to useful aquatic life. • Ozone In this method, ozone is produced by exposing oxygen to high voltages. Ozone is very effective when killing pathogens and it decomposes back to oxygen. However, one disadvantage of this method is that it uses a lot of energy which translates to a higher