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Enterobacteriaceae coli
Enterobacteriaceae coli
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Escherichia coli, which is the most common bacillus of the human intestine is only about two micrometers long. Propelled by long whip like threads called flagellum, which is a singular flagellum, an E coli can move about ten times its own length in one second. Swimming seems easy for a creature virtually unaffected by a gravitational forces and moving through a easily yielding and supporting fluid. Howard C. Berg demonstrated how flagella operate compared to the bacterium that move in water to try and swim through asphalt. The bacteria cannot move because if its flagella stops moving it comes to an abrupt stop within about a millionth of its body length. The flagella works good in some circumstances. Berg modified the microscope to track individual
E. Coli 0157, written by Mary Heersink, is a nerve-racking, adrenaline-filled story of a mother's experience with a then unknown deadly bacteria. The book brings up many reactions in its readers, especially the questioning of the practice of doctors in hospitals. The reader's knowledge base of scientific procedures in emergency centers was widened as well as the knowledge of how to the human body reacts to different agents in its system.
ABSTRACT: Water samples from local ponds and lakes and snow runoff were collected and tested for coliform as well as Escherichia coli. Humans as well as animals come into contact with these areas, some are used for recreational activities such as swimming and some are a source of drinking water for both animals and humans The main goal of this experiment was to see which lakes, snow run off and ponds tested positive for coliform or Escherichia coli and to come up with some reasoning as to why. It was found that the more remote pond with less contact contained the most Escherichia coli. However, another lake that many swim in and use as their drinking water indeed tested positive for a small amount of Escherichia coli. The two samples from the snow showed negative results for both coliform and Escherichia coli and the two more public ponds that aren’t as commonly used as a source of human drinking water but animal drinking water tested in the higher range for coliforms but in the little to no Escherichia coli range. It was concluded that the remote pond should be avoided as it’s not a safe source of drinking water for humans or animals. Other than that, the the other ponds are likely to be safe from Escherichia coli, but coliforms are a risk factor.
Purpose: The purpose of Lab Exercise 6: The Ubiquity of Bacteria is to introduce to the microbiology student, the proper techniques for acquiring bacteria cultures from natural sources and appreciate that bacteria are found everywhere.
N fowleri has three stages of their cycle. In the amoeboid trophozoite stage, they are infectious and measure 10-35 µm long. The trophozoite transforms to a non-feeding flagellate when food sources are limited. Flagellates are motile and measure 10-20 µm in length. The amoeba or flagellate will form a cyst, the dormant stage, if the environment is too cold and not conducive to continued feeding and growth. When the organism is in the cyst stage, it has a single layered wall and only one nucleus. The cyst measures 7-1...
Escherichia coli (E. coli) is a member of the Enterobacteriaceae family of organisms. It is a non-spore forming, facultative anaerobic, gram negative rod capable of growing on a variety of media and, similar to other members of the Enterobacteriaceae family, contains the enterobacterial common antigen. Most E. coli are part of the normal flora of the human gastrointestinal tract, however some strains are pathogenic and capable of causing clinical disease. Epidemiologic classification of E. coli is based on the expression of certain surface antigens. The three of greatest importance are the somatic O polysaccharide (part of the lipopolysaccharide or Gram negative endotoxin), the K antigens (part of the capsule), and the H antigens (flagellin proteins). The bacteria regulate the expression of these antigens through antigenic phase variation. This process allows the organism to selectively express or not express the antigens, which aids in protection from antibody-mediated cell death. Enterohemorrhagic E. coli (EHEC) are strains that produce exotoxins (particularly verotoxins) that result in hemorrhage of the intestinal mucosa. There are several serotypes of EHEC; the most clinically significant is O157:H7.
The simplest explanation of the Salmonella infection is that a sufficient amount of salmonellae reach the small intestine and invade the lumen (the space within the intestine) where they mul...
A Prokaryote is a single cell organisms that does not have a nucleus, which is divided into two major groups: archaeabacteria and bacteria. Prokaryotes are usually found in three common structures, such as bacillus is rod shaped, crocus is spherical-shaped, and spirillum is long shape. Although there are prokaryotes that are responsible for diseases there are also good types of bacteria that we need. Prokaryotes provide essential services to biological systems for instance food and agriculture.
Coli. The most prominent growth was seen on the plate with Luria-Bertoni (LB) broth and ampicillin (amp) treated with +pGLO, as there were four separate and defined bacterial colonies with surrounding satellite colonies, each of which contained upwards of 20 cells visible to the human eye. Similarly, the plate with LB, amp, and arabinose (ara) treated with +pGLO showed three defined colonies, but no satellite growths. However, when the UV light was used to examine the bacterial colonies of that plate, they gave off a green fluorescence absent from other plates. Comparatively, the LB plate treated with +pGLO showed approximately equal growth to both the LB/amp/ara, and LB/amp plates. However, when examining the -pGLO plates, it was clear that there was conclusively no growth nor was there any fluorescence when the UV light was shown on the cells on either of the plates containing ampicillin or arabinose. However, the LB plate did show immense growth, such that the cells formed a bacterial lawn, yet the cells were not fluorescent under UV
(ii) Motility and chemotaxis. In addition to their role in the attachment of microorganisms to plant roots, functional flagella are important for bacterial motility. The crucial role of motility for successful rhizosphere colonization is somewhat controversial because some studies have indicated that motility of Pseudomonas is not required for root colonization in wheat and soybean (Howie et al. 1987). However, flagella were shown to be essential for colonization of potato roots (de Weger et al. 1987). Studies confirming the role of motility in the colonization process were performed in the absence of percolating water, and it was assumed that motile or non-motile introduced bacterial strains were transported by the growing roots. However, under more natural conditions the presence of percolating water will affect the dispersal of bacterial strains regardless of their ability to swim.
Bacterial Lab Report- Elevator Bacteria is a living organism found almost everywhere. There are three different shapes of bacteria; Bacillus, Coccus, and Spirillum. They are so tiny, and it makes it difficult for scientists to identify them. Scientists have to use special equipment to be able to see how bacteria looks and where can they be found. There are more than 50 thousand species of bacteria but only less than 8,000 of them have been found.
The Evolution of Antibiotic Resistant Bacteria. Since antibiotics, such as penicillin, became widely available in the 1940s, they have been called miracle drugs. They have been able to eliminate bacteria without significantly harming the other cells of the host. Now with each passing year, bacteria that are immune to antibiotics have become more and more common.
Bacterial cells, like plant cells, are surrounded by a cell wall. However, bacterial cell walls are made up of polysaccharide chains linked to amino acids, while plant cell walls are made up of cellulose, which contains no amino acids. Many bacteria secrete a slimy capsule around the outside of the cell wall. The capsule provides additional protection for the cell. Many of the bacteria that cause diseases in animals are surrounded by a capsule. The capsule prevents the white blood cells and antibodies from destroying the invading bacterium. Inside the capsule and the cell wall is the cell membrane. In aerobic bacteria, the reactions of cellular respiration take place on fingerlike infoldings of the cell membrane. Ribosomes are scattered throughout the cytoplasm, and the DNA is generally found in the center of the cell. Many bacilli and spirilla have flagella, which are used for locomotion in water. A few types of bacteria that lack flagella move by gliding on a surface. However, the mechanism of this gliding motion is unknown. Most bacteria are aerobic, they require free oxygen to carry on cellular respiration. Some bacteria, called facultatibe anaerobes can live in either the presence or absence of free oxygen. They obtain energy either by aerobic respiration when oxygen is present or by fermentation when oxygen is absent. Still other bacteria cannot live in the presence of oxygen. These are called obligate anaerobes. Such bacteria obtain energy only fermentation. Through fermentation, different groups of bacteria produce a wide variety of organic compounds. Besides ethyl alcohol and lactic acid, bacterial fermentation can produce acetic acid, acetone, butyl alcohol, glycol, butyric acid, propionic acid, and methane, the main component of natural gas. Most bacteria are heterotrophic bacteria are either saprophytes or parasites. Saprophytes feed on the remains of dead plants and animals, and ordinarily do not cause disease. They release digestive enzymes onto the organic matter. The enzymes breakdown the large food molecules into smaller molecules, which are absorbed by the bacterial cells. Parasites live on or in living organisms, and may cause disease. A few types of bacteria are Autotrophic, they can synthesize the organic nutrients they require from inorganic substances. Autotrophic bacteria are either photosynthetic or Chemosynthetic. The photosynthetic bacteria contain chlorophyll that are different from the plant chlorophyll. In bacterial photosynthesis, hydrogen is obtained by the splitting of compounds other than water.
Prescott, Harley & Klein (1990) describe bacteria as prokaryotic cells (cells that lack a true membrane enclosed nucleus). Bacteria are both small and simple in structure; they usually are between o.5 and 5cmm yet they have many characteristic shapes and sizes. Some bacteria are circular or oval shaped, they are known as cocci bacteria. Other bacteria are rod-shaped, they are known as bacilli bacteria, and some bacteria are spiral and coil-shaped and it is know as spirilla bacteria.
The migrating motor complex takes food remnants and bacteria away from the upper gastrointestinal tract and into the large intestines. This begins in between meals when a series of contractions occur in the stomach passing gradually from section to section. The two remaining patterns of motility can occur during and following a meal. Peristalsis involves circular muscles that contract in order to move food materials down the intestinal tract. Peristalsis pushes food to the receiving segment in a progressive wave that allows the bolus to travel. Finally, in segmental contractions segments of the small intestine will contract and relax randomly or at certain intervals. Its purpose is to churn the content of the intestines allowing them to remain in contact with the absorbing
Every organism requires a specific environment in order to survive. Bacteria alike, different types of bacteria are able to survive and reproduce in different types of environment. Some factors that affect the growth of bacteria include temperature, presence of certain gases and pH of the medium it is in.