Gram-negative bacteria Essays

  • Gram-Negative Anaerobic Bacteria

    990 Words  | 4 Pages

    polymicrobial, typically dominated by obligatory anaerobic bacteria. The most commonly isolated microorganisms before root canal treatment include Gram-negative anaerobic rods, Gram-positive anaerobic cocci, Gram-positive anaerobic and facultative rods, Lactobacillus species and Gram-positive facultative Streptococcus species.83 The obligate anaerobes are rather easily eradicated during root canal treatment. In contrast, facultative bacteria such as non-mutans Streptococci, Enterococci, and Lactobacilli

  • Bacteria And Bacteria Pros And Cons

    1872 Words  | 8 Pages

    know, bacteria is a very complex organism and the subject can be very broad. In this essay, the focus will be on bacteria and the bacterial cell structure. Different forms of bacteria, its pros and cons, the cell structure, diseases and resistance will be explained and listed. First bacteria and cell structure is explained, and then moving on to different bacterial forms and diseases, and how diseases can be prevented or even cured. Then finishing the essay will be the conclusion. Bacteria The

  • Kinetic Report

    759 Words  | 4 Pages

    Gentamicin, which is a broad spectrum aminoglycoside antibiotic (Fig. 1), belongs to the class of medicinal compounds capable of inhibiting the growth of Gram-positive and Gram-negative bacteria [1]. Gentamicin is one of the most effective drugs used in the treatment of serious suppurative and septic processes, especially those that are caused by Gram-negative microorganisms. The advantages of gentamicin over other aminoglycosides (kanamycin, neomycin) are its activity towards Pseudomonas aeruginosa and

  • Nitrogen Fixing Bacteria Lab Report

    1448 Words  | 6 Pages

    fixing bacteria from rhizosphere Hypothesis: Rhizospheric Nitrogen fixing bacteria show optimal growth at PH: 6-7, Temperature: 30 °C and Salinity level: 0.005 – 0.010M NaCl INTRODUCTION: There is a huge bacterial diversity in rhizospheric soil. Gram-negative, non-sporulating baccilli which respond to root exudates are predominant in the rhizosphere (Pseudomonas, Agrobacterium). While Gram-positive bacilli, Cocci and aerobic spore forming bacteria like

  • The Importance Of Water In Long Island

    1411 Words  | 6 Pages

    Every organism in the universe requires water for its survival. Arguing out that water is good or bad is inconclusive. Water for human consumption is supposed to be subjected to quality tests so as to determine its safety for consumption and usage. A number of water sources around the globe suffer from some form of impurities. This makes it unsafe and unhealthy for individuals to use it. Challenges such as unsafe water, insufficient or the lack of quality healthy water has been an issue which has

  • Colistin Case Study

    2242 Words  | 9 Pages

    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.

  • Hydroquinone Study

    1068 Words  | 5 Pages

    The hydroquinone metabolite purified from B. methylotrophicus MHC10 was evaluated for its antibacterial activity against a panel of several Gram-positive and Gram-negative bacterial pathogens. The zone of inhibition was used to evaluate the antagonistic activity of the metabolite. The standard antibiotics Ampicillin and Gentamycin were used as the positive control. Both antibiotics showed high antagonistic activity against all test pathogens. But in the case of P. aeruginosa, the hydroquinone treatment

  • Shigella Synthesis Essay Sample

    1343 Words  | 6 Pages

    different species – Shigella boydii, Shigella dysenteriae, Shigella sonnei, and Shigella flexneri. Several serotypes occur for each species based on O - antigen variations (Jennison & Verma, 2004; Morona, et al., 1995). Members of the genus are gram-negative, highly infective facultative intracellular pathogens, recognized as etiological agents of bacillary dysentery (shigellosis) (Kotloff, et al., 1999; Sansonetti, 2001). Shigella ranks third among the most common causes of bacterial gastroenteritis

  • Choolera Toxin

    1259 Words  | 6 Pages

    4. The mechanism of action of cholera toxin The cholera toxin is an enterotoxin which is secreted by the gram-negative bacteria Vibrio cholerae. The toxin is an protein complex which is made up by six subunits, one A subunit and five B subunits. The A subunit is the enzymatic subunit and the B subunit is the binding subunit [9]. The cholera toxin is released from the bacteria and once in the intestinal lumen it adheres to the apical surface of the epithelial cell. The B subunit of the toxin binds

  • NRC-04 Lab Report

    8201 Words  | 33 Pages

    different types of membrane, our team did experiments on NRC-04 with negatively charged bacterial surface membrane mimetic micelles sodium dodecyl sulphate(SDS), zwitterionic eukaryotic middle membrane mimetic micelles dodecylphosphocholine(DPC), gram-negative bacteria outer membrane mimetic micelles Lipopolysaccharide(LPS) and bacterial inner membrane mimetic micelles 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoglycerol(POPG). Fluorescence test shows that the C-terminus tryptophan residue of NRC-04 interacts

  • Unknown Bacteria Lab Report

    1034 Words  | 5 Pages

    the lab was to put into action the methods that have been learned in the laboratory to determine our unknown bacteria. Bacteria’s can have different features, shapes, and or arrangements that help microbiologist determined their role in our life (whether they are good or bad for humans). Bacteria can be classified as gram positive or negative (difference in call wall). Gram positive bacteria have a thick cell wall of peptidoglycan (“polymer of disaccharides cross-linked by shorts chains of amino acids”)

  • Mystery Microbiology Test

    906 Words  | 4 Pages

    identify a specific bacterial species is an important skill. In order to discover and being able to identify any microbial bacteria, there a list of test one must perform in order to come with the right microorganism. It is fundamental to be aware of the risk of toxify, the resistance to antibiotics and determining how to prevent its growth and being able to destroy this bacteria. By being able to run both physical and chemical test to determine the identity of the mystery microbe is a unique and useful

  • Lab Report: Citrobacter Aerogenes, Staphyloccus

    513 Words  | 3 Pages

    The six bacteria used in this lab were, Citrobacter freundii, Bacillus subtillis, Enterobacter aerogenes, Staphylococcus epidermis, Enterococcus durans, and Escherichia coli. Citrobacter freundii is a Gram-negative rod shape bacteria. The MSA plate will grow Citrobacter freundii, Bacillus subtillis, Enterobacter aerogenes and will have a yellow color change while Staphylococcus epidermis will not grow nor have a color change to yellow. The MacConkey agar will have growth with Escherichia coli, Enterococcus

  • Unknown Bacteria

    557 Words  | 3 Pages

    different bacteria was selected. The sample contained one gram-positive, one gram-negative paracolon, and one gram-negative coliform. The purpose of the experiment is to identify each of the three species that the mixture contained. After receiving an unknown mixture, the sample was streaked for isolation onto TSA, blood agar, and MacConkey plates. Each plate serves as a first step to identify the unknowns. The TSA (tryptic soy agar) can be used to do a gram stain, which differentiates gram-negatives

  • Biochemical Test Lab Report

    1371 Words  | 6 Pages

    activities of different bacteria. Bacterial physiology differs from one species to the other. These differences in carbohydrate metabolism, protein metabolism, fat metabolism, production of certain enzymes and ability to utilize a particular compound help them to be identified by the biochemical tests. Gram’s stain was originally devised by histologist Hans Christian Gram in 1884. Gram-positive bacteria stain purple, while Gram-negative bacteria stain pink when subjected to Gram staining. Approximately

  • Microflora Lab Report

    1368 Words  | 6 Pages

    different types of media plates affect the growth of skin microflora mainly microflora in the nostril It was hypothesized that the nostril microflora were gram-positive bacteria that belong to the genera Streptococcus, Staphylococcus and Propionibacteria. Results showed that the nostril microfloras were gram-positive (stained purple). However, gram staining was not enough to prove that the bacterium obtained from the nostril are Streptococcus, Staphylococcus, and Propionibacteria spp. The results do

  • Macconkey Agar Lab Report

    266 Words  | 2 Pages

    “Post-Lab Questions” What ingredient(s) makes MacConkey agar selective for Gram-negative bacteria? The ingredients that make MacConkey’s Agar selective is a pH indicator (neutral red), and a disaccharide ( Lactose) “2. What types of bacteria are inhibited on MacConkey agar?” Gram-Positive bacteria that are inhibited with MacConkey agar due to crystal violet and bile salt presence . “3. What ingredient(s) makes MacConkey agar differential?” MacConkey agar are inhibited by a pH indicator (neutral

  • Gram Stain Lab Report

    1274 Words  | 6 Pages

    of the unknown was made a Gram stain was conducted to determine the gram nature and morphology of the organism which was Gram negative bacilli. Based on those results a citrate utilization test was performed resulting in a positive test. Following the flow chart the next test to conduct was a motility test which also had a positive outcome. Lastly, a glucose fermentation test was conducted to determine the unknown organism. The glucose fermentation test yielded negative results indicating that the

  • Alcaligenes Faecalis Experiment

    636 Words  | 3 Pages

    my group ran for our unknown specimen, we had a match with the bacteria known as Alcaligenes Faecalis. This bacterium belongs to one of the major group of gram-negative bacteria (Phylum Proteobacteria). Alcaligenes Faecalis (Genus, species) is a rod shaped (bacillus), 0.5-1.2 x 1.0-3.0 µm, round with scalloped margin (colony configuration growth), motile (with one to nine peritrichous flagella), gram-negative, non-fermentative bacteria, obligate aerobic, having oxygen as the principal terminal electron

  • Unknown # 10 Essay

    650 Words  | 3 Pages

    macroscopic characteristics as a broth, so the first step was to Gram stain a loopful to determine the microscopic characteristics. Gram staining not only helped identify Unknown #10’s microscopic morphology but it also helped ensure the specimen was a pure culture—no other bacteria were visible when Unknown #10 was Gram stained and observed under the microscope. Unknown #10’s key microscopic morphology was that it was a very small, Gram negative bacillus. Though bacilli can possibly form endospores, no