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Antibiotic resistance review article
Antibiotic resistance review article
Antibiotic resistance review article
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Research Question
Are synthetic antimicrobial substances (Dettol and Ajax) more effective at inhibiting the growth of the Escherichia coli bacterium than natural substances (Eucalyptus oil and tea tree oil)?
Background Information
Escherichia coli, also referred to as E.coli, is a rod-shaped, gram-negative bacterium. It is about 1-3 micrometres long, and around 0.25 micrometres in diameter (Microbe Wiki. 2004). The bacterium is typically found within the lower intestine of the digestive tracts of warm-blooded organisms, including those of a human. (Zhang Lab. N/A)
(Health News. 2011)
Generally, they are part of a healthy human intestinal tract and thus are harmless. However, some strains of the bacteria are pathogenic, and can cause
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Close the lid, flip it over and close it tightly with parafilm tape
5. Label plate with the name of bacterium (E.coli),
6. Repeat step 3~4 four more times.
7. Place agar plates in an incubator upside down to stop moisture trapped inside falling upon the samples.
8. After 24 hours, remove agar plates from incubator and measure the greatest length from the filter discs of bacteria inhibition. Leave plates closed.
Results
Qualitative Data
During the experiment, it was observed that the area of inhibition of the E.coli bacterium was significantly larger on average with the filter discs treated with natural antimicrobial substances (tea tree oil and eucalyptus oil), compared to the synthetic substances (Ajax and Dettol). The tea tree oil’s diameter of area of inhibition recorded 8.0mm, and eucalyptus with 13.9mm. Ajax recorded 2.6mm, and Dettol with 7.0mm. However, trial 5 of the tea tree oil was recorded as 0, meaning it had no effect on the bacteria.
Quantitative Data (Raw and Processed)
Antimicrobial substance Diameter of inhibited bacterial growth (mm ± 0.1) Trial 1 Trial 2 Trial 3 Trial 4 Trial 5 Average Standard deviation
Ajax 2.0 3.0 2.0 2.0 4.0 2.6 0.8
Dettol 9.0 6.0 6.0 8.0 6.0 7.0 1.3 Tea Tree Oil 15.0 10.0 5.0 10.0 0.0 8.0
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This was clearly shown through the average diameter of the inhibited growth of the bacterium, with tea tree oil having the diameter of 8.0mm and eucalyptus oil of 13.9mm, compared to Ajax of 2.6mm and Dettol of 7.0mm in diameter.
The results objects the hypothesis of this investigation, which stated that synthetic substances would have had more effect on the bacteria than natural substances.
Evaluation
Evaluation of Results and Method
In this investigation, there were some limited factors. The experiment of each substance was done by different groups, which could have affected the experiment on factors such as how well the bacteria were spread across the agar plate. Also, the procedure stated to evenly spread the filter disks; the distance was not measured during the experiment. This could have had impact on the results, as some disks may have been closer to each
I identified the genus and species of an unknown bacterial culture, #16, and I applied the following knowledge of morphologic, cultural and metabolic characteristics of the unknown microorganism according to the laboratory manual as well as my class notes and power point print outs. I was given an incubated agar slant labeled #16 and a rack of different tests to either examine or perform myself; the tests are as follows: Gram Stain; Nutrient Gelatin Test; Carbohydrate Fermentation; Dextrose, Lactose and Sucrose; IMVIC tests; Citrate, Indole, Mythel-Red and Vogues Proskauer test; as well as a Urease and TSI Test. Materials and Methods/Results Upon receiving the Microorganism (M.O.) #16, I prepared a slide by cleaning and drying it. Then, using a bottle of water I placed a sterile drop of water on the slide and used an inoculating loop, flame sterilized, I took a small sample of the unknown growth in my agar slant and smeared it onto the slide in a dime sized circle and then heat fixed it for ten minutes.
The first day an unknown sample was assigned to each group of students. The first test applied was a gram stain to test for gram positive or gram-negative bacteria. The morphology of the two types of bacteria was viewed under the microscope and recorded. Then the sample was put on agar plates using the quadrant streak method for isolation. There were three agar plates; one was incubated at room temperature, the second at 30 degrees Celsius, and the third at 37 degrees Celsius. By placing each plate at a different temperature optimal growth temperature can be predicted for both species of bacteria.
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.
Inconsistencies in this lab could have caused variations in data collecting. Collecting data from one petri dish was challenging because something could have been different on other petri dishes if this experiment was tested on several petri dishes. This could have been different because the other petri dishes could have had more micro-organisms in Section 2 instead of Section 1, or no bacteria could have grown at all in every section of the petri dish.- Second, nothing grew in section B even though there were no disinfectants in that section. The reason why the bacteria and mold might have grown in sections 1, 2, and 3 was because in the process of making the experiment, the coffee filter papers were touched with glove free hands and were not clean. If this lab was run again, some changes would be to wear rubber gloves, do not pour the hand sanitizers on the coffee filter paper but just pour one pump straight into the petri dish, have more than one petri dish to collect data off of, and check when the last time someone cleaned the door knob
Over the years humans have tried every possibility to overcome the health problems, spread of epidemics and infections, disease control and have worked towards a healthy society free of disease and health problems. They have succeeded to a great extent. The book “Good germs, bad germs” describes that though the life expectancy is now far more as it was in previous eras. Epidemic problems and infectious diseases are now getting lesser and lesser and humans are being treated successfully. The hygienic conditions have also been improved so as to ensure least growth of microbes, germs, parasites and bacteria. Antibiotics have been invented to address diseases and infections caused by bacteria and viruses. With all these substantial efforts the biologists, physicians and scientists have triggered another epidemic which is even more severe. They have killed those microbes and bacterial species which were human friendly and as a result of either their disruption or mutation, pathogenic bacteria have even become more active and resistant to treatments. This has led to increased ineffectiveness of antibiotic drugs, low immunity and various infections and inflammatory diseases. The chlorinated water for drinking and food processing along with excessive hygienic conditions indicates our fight against these bacteria and germs. Further, these antibiotics are even given to the livestock which becomes our food and as result many of their resistant germs end up in our digestive tract and other organs. Thus, the war against microbes through excessive cleanliness and use of antibiotics has resulted in antibiotic resistance among humans, which has become one of the prominent problems of medical science
Planning Firstly here is a list of equipment I used. Boiling tubes Weighing scales Knife Paper towels 100% solution 0% solution (distilled water) measuring beakers potato chips Cork borer. We planned to start our experiment by doing some preliminary work. We planned to set up our experiment in the following way.
Antibiotics basically refer to chemical substances that can inhibit and destroy the growth of microorganisms (Gottileb,1976; Katz and Demain,1977). Antibiotic term was first used in 1942 by Selman Waksman to describe any substance produced by a microorganism which interfere with the growth of other microorganism (SA Waksman, 1947). Each antibiotic is produced by a relatively limited number of species and is inherited from specific set of genes. These are the products of secondary metabolism which can be produced commercially by microbial fermentation after active growth has declined. These compounds are generally synthesized in stationary phase especially idiophase (unbalanced growth phase) so these are sometimes called as idiolites(walker, 1974). Their formation is highly influenced not only by the growth conditions but also by the composition of the culture medium.
A self-sterilizing formula is one that either prevents microbial growth (bacteriostatic) or kills-microorganisms (bactericidal /microbicidal).a self –preserving formula may or may not contain antimicrobial preservatives. Relatively anhydrous products (e.g. talcum powder, corn starch, mineral oil, and stick deodorants) do not require preservatives because they do not have sufficient water content to supply microbial growth. However, manufactures may incorporate preservatives in to these products to prevent microbial growth that may occur due to addition of water by consumer during use or abuse. The physicochemical make-up of the product, including low water activity (aw), high or low pH, and multifunctional materials that have antimicrobial properties (e.g. alcohol, surfactants, quaternary ammonium companies) determines whether a formula is self-preserving. Aqueous products in multiuse containers generally require the addition of preservation if they do not prevent microbial growth. The type of packaging and consumer use habits determines the preservation requirements of a
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
There were five test solutions used in this experiment, water being the control, which were mixed with a yeast solution to cause fermentation. A 1ml pipetman was used to measure 1 ml of each of the test solutions and placed them in separated test tubes. The 1 ml pipetman was then used to take 1ml of the yeast solution, and placed 1ml of yeast into the five test tubes all containing 1 ml of the test solutions. A 1ml graduated pipette was placed separately in each of the test tubes and extracted 1ml of the solutions into it. Once the mixture was in the pipette, someone from the group placed a piece of parafilm securely on the open end of the pipette and upon completion removed the top part of the graduated pipette.
E. coli are bacteria that can cause an infection in various parts of your body, including your intestines. E. coli bacteria normally live in the intestines of people and animals. Most types of E. coli do not cause infections, but some produce a poison (toxin) that can cause diarrhea. Depending on the toxin, this can cause mild or severe diarrhea.
Bacterial fossils have been discovered that date back 3.5 billion years ago. There are over 5,000 different species of bacteria known, many of which are harmful or pathogenic (i.e. can cause disease) and some of which are beneficial and can have many uses, for example, the bacterial species Lactobacillus is used in the production of cheese and yoghurt. The bacteria Bifidobacterium adolescentis is used for yoghurt making and Brevibacterium aurantiacum is used for cheese making. Also yeast is used in the production of beers and alcohols like wine and it also plays a role in bread rising. As well as bacteria being used for food production there are also many types of bacteria used in medicine production with nearly a different bacteria used for each different disease contractible in humans, for example the bacteria Moraxella lacunta is used to produce medicine for conjunctivitis and Klebsiellapneumoniae would be used to produce medicine for pneumonia.
2. In the large beaker, put water and boil it completely. After that, remove the beaker from heat. 3. Sample tubes (A-D) should be labeled and capped tightly.
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.