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.
All age groups can become infected with EHEC however, children and the elderly tend to be most susceptible to disease. O157:H7 is found in the gut of many animals, including cattle, goats, sheep, deer, and elk; cattle are the main source of human disease. Despite the tremendous clinical impact these organisms can have on the human host, in these animals the bacteria do not generally cause disease. Transmission of the bacteria is primarily through the fecal to oral route; transmission through direct contact with cattle can also oc...
... middle of paper ...
...tion is a crucial factor. A limitation of the Girard et al., study is the amount of time it will take for renal cells to decrease expression of Gb3. Miglustat was shown to be most protective after pre-treatment of renal cells for 48 hours [5]. In a clinical setting, this is impractical because treatment is sought after the person is already infected with bacteria and toxin is already being produced. Combination therapy may provide the best approach to reduce toxin-mediated damage. VNHs target the toxin itself, therefore their actions are more rapid and can be used during the acute infection. Miglustat, however, takes time. Rather than being used to treat the acute infection, it’s use may be best to prevent any further damage the toxin may cause. Taken together, these studies opened a new window of potential therapeutic options for individuals with O157:H7 infection.
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.
Enterococcus faecalis is a genus of gram positive cocci and form short chains or are arranged in pairs. They are nonmotile, facultative anaerobic organisms and can survive in harsh conditions in nature. There are over 15 species of the Enterococcus genus but about 90% of clinical isolates are E. faecalis. E. faecalis is a nosocomial pathogen because it is commonly found in the hospital environment and can cause life-threatening infections in humans. It is a bacterium that normally inhabits the intestinal tract in humans and animals but when found in other body locations it can cause serious infections. The most common sites for E. faecalis infections are the heart, bloodstream, urinary tract, and skin wounds. Due to vancomycin-resistant Enterococci, many antibiotics have been shown ineffective in the treatment. In this paper, I will describe the ecology and pathology of E. faecalis; the antibacterial resistance; treatment; and, what you can do to prevent Enterococcus infection.
Many children around the world , especially in third world countries suffer many bacterial infection of the gastrointestinal system as a result of lack of awareness and the spread of the disease in the less attention to hygiene and the environment . In order to explain this word gastrointestinal tract infection , especially the stomach and intestines , it can result from infection by bacteria or virus or other parasites (1) . Some of the causes of inflammation as a result of eating food poisoning , especially meat and eggs . However , some symptoms of severe cases are headache , nausea , vomiting , general weakness , diarrhea and pain , the illness begins suddenly with high fever , vomiting , abdominal pain and stool liquid to water that may contain some blood and mucus . The result of drought through loss of fluids and salts and lead an alliance with the poisoning to the collapse of the circulatory system in diseases such as cholera (2) . It must be conducted in diagnosing bacterial to find the source of infection because it causes illness and death of millions in the third world and in particularly children as mentioned . In this report will refer to the most common types of bacteria cause gastrointestinal tract infection for example , Shigella , Salmonella , Vibrio and Campylobacter (3) . First of all , Shigella is gram negative , nonmotile , non lactose fermenting and H2S production . There are four important species , S. sonnei , S. flexneri , S. boydii and S. dysenteriae is the most serious . Next is Salmonella which is gram negative as well , non lactose fermenting and production H2S . These species are S. typhi and S. paratyphi found in humans and animals . Finally , Campylobacter is gram negati...
Escherichia coli, commonly known as E. coli, is a bacterium that is associated with food poisoning. Both in the medical community and the general public there are growing concerns about the health dangers that are associated with Escherichia coli. One major area of concern is its apparent resistance to certain core antibiotics. The bacterium Escherichia coli, is found in both foods and lakes. In terms of food it is mostly beef and dairy products, and sometimes in vegetables due to the fertilizer being partially cow feces. In terms of lakes, E coli can be in any of them. This bacterium causes humans to
perfringens is the most common cause of foodborne illness in the United States, with a million cases each year (CDC, 2014). C. perfringens is able to produce up to 15 different toxins, making it versatile. These toxins are used to isolate the five different types of C. perfringes: type A, B, C, D, and E. The four toxins that are primarily used to isolate the different types include alpha, beta, epsilon, and iota-toxins. Type A is the most common and most variable, and subdivided into entertoxigenic and non-enterotoxigenic strains (Herholz et al., 1999). Enterotoxigenic type A and C are associated with equine enterocolitis, gas gangrene, infections, avian and canine necrotic enteritis, colitis in horses, and diarrhea in pigs (Divers and Ball, 1996). Types B, C, D, and E can cause severe enteritis, dysentery, toxemia, and high mortality rates in young lambs, calves, pigs, and foals. Types B, C, D, and E have been intermittently associated with foal enterocolitis, and equine antibiotic associated diarrhea (Divers and Ball, 1996). Even though the alpha toxin is noted to be relatively nonpathogenic, the beta2 toxin plays a significant role in digestive disease, specifically, enterocolitis in equine (Herholz et al., 1999). This is mainly due to the C. perfringens entertoxin (CPE), the main virulence factor that initiates many critical gastrointestinal diseases across species (Herholz et al. 1999). CPE works in a four-step mechanism against membrane action (CDC, 2014). First,
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 is a pathogenic bacteria that can be in the intestine of warm blooded animals and humans. It can help break down food in the gut, and allows vitamin K to be absorbed. Its full name is Escherichia Coli, and although many strains are harmless, some can cause food poisoning in humans by making harmful chemicals.
Background Information and Research: Inserting a gene from the Aequorea victoria jelly fish into the DNA of rabbits, pigs, and mice genetically modifies them to glow-in-the-dark. The production of specific genes are coded by genes. This particular type of jelly fish naturally glows in the dark because a gene coded for a green fluorescent protein (GFP). The goal of genetically modifying organisms is to have the modified organism produce a protein that has been coded by the inserted gene thus causing the modified organism to express the new trait. Genetically modifying organisms is important because it has had health benefits in the development of vaccines. E.coli is a rod-shaped bacteria that is a part of the Escherichia genus and is commonly found in the intestines. When demonstrating how to genetically modify an organism, E.coli bacteria is commonly used because it is a simple organism whose process for protein production, gene expression, is the same as a complex organisms’ process. In this experiment, a GFP was inserted into E.coli as well as a gene that causes E.coli’s resistance to ampicillin. Half of the agar plates that the bacteria was growing on had ampicillin. Ampicillin kills E.coli, so the successfully modified bacteria will have been grown on those ampicillin plates. Plasmids contain genes that are resistant to antibiotic ampicillin; scientists have used plasmids in the manipulation of genes. Plasmids were used because it is resistant to the ampicillin used, so if the bacteria was
EHD can be contracted only in cases where the animal is bitten by a fly. So as to finish the life cycle of the virus, the female midge sucks the blood of an ungulate in order to take in protein from the blood. In North America, the main path for EHD is C. variipennis. Nevertheless, several species of mosquitoes and midges are able to spread virus. The virus can last for almost two months in an infected deer as it takes between five to ten days for the disease to
When researching diseases that affect animals, I chose to research one that deals with cattle. This disease would be a reproductive venereal disease called vibriosis. Vibriosis can affect all breeds of cattle, male or female, and is the most important cause of infertility in female cattle along with occasional abortions. This disease is caused by bacteria that live in the crevices of a bull’s prepuce, of a bull aged four years or older (Hansen, 1914). Age is a factor because the foreskin of a bull does not develop until then. The disease is spread from an infected bull to a cow during breeding. A bull might be clean, but then infected by a cow who was infected by a bull before him. Many bulls can go years without showing any signs of this disease, whereas female cattle may lose a calf to an abortion the next coming calving season.
The true hosts of M. bovis are cattle but disease has been reported also in many other domesticated and non-domesticated animals (buffaloes, sheep, goats, camels, pigs, equines a...
Certain structures of bacteria are indispensable for causing sepsis. All sepsis causing bacteria have S-layer and produce capsules, slime layer and biofilm (see tab. ). These structures protect the bacteria in the tissues against phagocytosis, ROS, lytic enzymes, immune complexes, etc., whereas in the bloodstream capsule and slime layer prevent triboelectric charging, attraction and fixation on the surface of erythrocytes, oxidation and killing by the oxygen released from erythrocytes [33 ].
In some cases, this infection can cause a dangerous complication called hemolytic uremic syndrome (HUS).
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.
It is estimated that over one-half of the antibiotics in the U.S. are used in food animal production. The overuse of antimicrobials in food animal production is an under-appreciated problem. In both human and veterinary medicine, the risk of developing resistance rises each time bacteria are exposed to antimicrobials. Resistance opens the door to treatment failure for even the most common pathogens and leads to an increasing number of infections. The mounting evidence of the relationship between antimicrobial use in animal husbandry and the increase in bacterial resistance in humans has prompted several reviews of agricultural practices by scientific authorities in a number of countries, including the US.