2. Gram-negative bacteria appear red under Gram staining because they have thin cell walls that cannot hold the violet-iodine complex, but they can hold safranin. Reproduction: Bacteria reproduce asexually through a process called binary fission. This is when a cell (also known as the parent cell) divides into two identical cells (also called daughter cells) of identical DNA composition. The genetic material within the parent cell duplicates and moves to the opposite ends of the cell, invagination occurs, a cross wall forms and the cell splits forming two new daughter cells of identical DNA
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
From number of trials and field experiments d’Herelle discovered the importance of bacteriophage as an antimicrobial agent that was thousand times more potent against bacteria than any agent known at that time. Felix d’Herelle developed the idea of ‘phage therapy’ which is a therapeutic and prophylactic treatment designed to take advantage of phage in the cellular destruction of pathogenic bacteria while remaining completely innocuous to host cells
Most antibiotics including penicillin attack the cell wall of the bacteria that prevents them from synthesizing peptidoglycan which is a molecule that provides the bacteria strength to survive in the human body. However, there are multiple ways on how an antibiotic affects the peptidoglycan. For example is vancomycin, it affects the peptidoglycan but not in same manner as penicillin. A different class of antibiotics called quinolones targets DNA gyrase which unwinds DNA for replication. Since DNA can unwind because of the removal of the enzymes that do that bacteria can’t multiply.
The disks are then placed on an agar plate that has been cultivated with the targeted bacteria , the disinfectant diffuse out of the disks into the agar where the bacteria have been cultivated . As the of bacteria start to grows , zones of inhibition of microbial growth are showen as clear areas around the disks . larger zones typically correlate to increased inhibition effectiveness of the disinfectant agent. • Use-Dilution Test The dilution test is commonly used to detect the disinfection efficiency . first , a cylinder of stainless steel is put in a culture of a microorganism and then dried .
The testing for affectability of a life form to antimicrobial agent is normally done utilizing agar dissemination or disk diffusion test. The parameters of this test were indicated (or institutionalized) by the researchers W. M. M. Kirby and A. W. Bauer and is likewise alluded to as the Kirby-Bauer antibiotic testing. In this technique, anti-toxins or antibiotic are impregnated on a specific extraordinary kind of paper circles and are put on the surface of agar containing the bacterium and parasitic (fungi) of our interest. This outcomes in the dispersion of antimicrobial agent into the surrounding medium. The diameter of the zone of inhibition will decide the adequacy or sensitivity of the antibiotic; the bigger the diameter, the more noteworthy will be the affectability of the bacterium or fungi to the antibiotic.
4. The discovery of what causes a disease was made by Louis Pasteur. Pasteur developed the Germ Theory, this states that a microorganism called the “Germ” can cause dangerous diseases. He discovered the germ in a food conversion, the germ was infecting the food and beverages causing people to get
Q1A: What is the mechanism of action of colistin? Colistin is an antibiotic that works best against Gram-negative bacteria. It works by binding to LPSs (lipopolysaccrides) and phospholipids in the outer cell membrane of the bacteria. This, in turn, disrupts the outer cell membrane by displacing cations and leaking the intracellular contents, combining it with outer cellular contents, causing the bacteria to be unable to differentiate the bacteria’s intra and outer cellular contents from one another. This ultimately leads to the bacteria’s death.
Docking studies of Nitroimidazo-oxazine with Pyridoxine 5'-Phosphate Oxidase M Sathish kumar1 , UCA Jaleel2 CSIR OSDD Research Unit , Bangalore Abstract Mycobacterium tuberculosis continues to be one of the world’s most debilitating and deadly pathogens. PA-824 is a nitroimidazole that has demonstrated bactericidal and sterilizing activity against drug-resistant and non drug-resistant tuberculosis. PA-824 is activated by either a bacterial enzyme or a cofactor, which is a compound that binds to a protein. This prodrug was used as a ligand to bind with the protein PDB ID:1XXO (Pyridoxine 5'-phosphate oxidase complexed with pyridoxal 5'-phosphate). Pyridoxine 5-phosphate oxidase is the enzyme that catalyzes the rate limited step of the
Abstract. Many of commercial waterless hand sanitizers are available in locally markets. All those products often confirm that they are capable of killing 99.9 % of the microorganisms. The aim of this work was an evaluation of efficacy of waterless hand sanitizer produced by Dettol Company that is frequently market in Saudi Arabia. The aim also included an isolation of hand sanitizer resistant bacteria and study of their susceptibility to several of standard antibiotics.