Being able to identify unknown microbes from systematic testing is what makes the field of microbiology so important, especially in infectious disease control. Using the testing procedure laid out by the microbiology field we are able to identify unknown bacteria present in our everyday lives, and along the way learn a lot about their characteristics that separate them from other types of bacteria. Being able to do this is vital in order for us to understand why microbes are present in certain places, how they are able to grow and what restricts their growth, that way they can be combatted if necessary. These techniques for determining unknowns are also important for isolating and testing infectious disease microbes in order to prevent spreading. Another important aspect of being able to identify unknown microbes is the
According to the series of test that 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 acceptor in the electron transport chain (ETC).
Our world is composed of many bacteria’s’ that can either help or destroy us. Therefore, its’s imperative to learn and study them. The purpose of the lab was to put into action the methods that have been learned in the laboratory to determine our unknown bacteria.
The purpose of this lab report is to employ a myriad of skills, tools and, methods learned throughout this semester to perform the appropriate tests for the identification of the assigned unknown bacteria. Add more background information here!!! The most important tools and techniques used during this identification include aseptic technique, microscopic examination and, the use of selective and differential media.
In this experiment, we cultivated an unknown specimen containing two microorganisms. The purpose of this experiment was to use a variety of biochemical test previously learned in the lab to identify the unknown bacteria. The identification of unknown bacteria is a major part of microbiology. Microbiologist observe samples such as blood and sputum in the laboratory for the presence of microorganisms. Identifying unknown bacteria is extremely important in clinical settings because it helps physicians find treatment for infections. I expect to learn the biochemical differences in bacteria from this lab. Also, how to identify different species of bacteria.
The purpose of this experiment was to apply all knowledge gained from the entire semester while in the lab and apply it to be able to identify an unknown genus and species gram positive bacteria. Each student was given a petri dish with an unknown Gram positive bacterium inside. The petri dish with the unknown gram positive bacteria that was used in my experiment was #8. The possible bacteria inside my petri dish could be any of the following:
Although the nature of this kind experiment was unable to provide us with numerical data, our graph was constructed using the average percent of E. Coli killed for each pair of cultures. To determine these percents for each substance we used the process of elimination. We put the two petri dishes side by side and used a checklist ranging from 1-100% to narrow down the possibilities. After obtaining a small range of possible percents, we made an estimate to determine the percent. After doing this for both the of cultures for that pair we averaged the two numbers. We repeated this for all of the culture pairs in our experiment.
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.
This experiment was performed by two groups using antibiotics Amoxicillin and Vancomycin by each group. Vancomycin data were collected by our group. After the incubation period of the diluted tubes containing antibiotic Vancomycin against S. epidermidis, the results were obtained as below,
Throughout the past five decades the misuse of antibiotics for animals and individuals has evolved into antimicrobial resistance making it more difficult to kill infectious organisms (FDA, 2014).The overpopulated and over medicated farms degrades our public health and contributes to our illnesses. Consequently, the steady stream of low dose antibiotics has created superbugs creating a resistance to the antibiotics (Prince, 2015).
Biochemical tests are the tests used for the identification of bacterial species based on the differences in the biochemical 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 60-90% of the Gram-positive bacterial cell wall is made up of peptidoglycan and interwoven teichoic acid, while only
Prokaryotic organisms normally have a cytoplasmic membrane, cell wall, and sometimes a capsule. Bacterial cells are most commonly either coccus or bacillus in shape. The cell wall is either Gram positive or Gram negative. When the cell is Gram negative, the cell has an extra layer of lipopolysaccharides. The Gram positive has a thick layer of peptidoglycan. Bacteria usually have capsules, but archaea rarely have one. Inside the prokaryote is cytoplasm and a nucleoid. The nucleus is not enclosed inside of a membrane in prokaryotes. The cell may have appendages to adhere to certain surfaces or for motility. The prokaryotic cell is smaller than the eukaryotic cell and has different qualities that make the cell less complex than a eukaryotic cell.
After a gram stain was done unknown #257 was identified as a gram positive organism because when observed under the microscope the organism appeared purple with cocci in clusters. The organism was also catalase positive which means that it produced enzyme catalase and bubbled when hydrogen peroxide was added to it.
The majority of cells making up the human body are diploid cells carrying identical DNA, with the exception of haploid gametes and red blood cells. Several types of biological evidence such as blood and hair are commonly used in forensic science, which is the scientific study of evidence for crime scene investigations and other legal matters. Forensic science is used for the purpose of DNA analysis, this is the analysis of DNA samples to determine if it came from a particular individual. DNA analysis is done by obtaining DNA samples from an individual; next, a large sample of DNA is produced from amplified selected sequences from the DNA collected. Finally, the amplified DNA regions are compare using a gel. DNA Profiling