This post is initially a biology report, based on an experimental study.
1.0 Purpose
The purpose of this study and associated report is to examine the resistance to the concept of theoretical and practical level, and examine resistance in selected bacteria with selected antibiotic.
2.0 Theory
2.1 Microbiology
Microbiology is the study which examines the smallest living organisms exist on Earth. Microorganisms are limits to how small life can be. All life is also originated from simple unicellular organisms (see Figure 1) approx. 4 billion years back, and the next 3 billion years comprised all life on earth by these simple creatures. We have found many examples of the hundreds of millions of years old, microorganisms, fungi, algae and bacteria in the resin, and from these studies can be seen that the morphology and anatomy of these organisms have not changed significantly, and one adds to it with the many different species there are, it gives a picture of this class of organisms is important additional survival and talented.
Most microorganisms reproduce rapidly and in large numbers (approximate exponentially), and this mixed with the characteristic that they can often exchange genes across families (horizontal re-exchanges), and have a high mutation rate makes microorganisms able to develop through natural selection, and this istandgør them for survival anywhere on the globe and in virtually any environment. However, there is also seen with human nature, a disadvantage of this rapid adaptation: In this task, we must examine microorganisms resistant to antibiotics, and these organisms rapidly adapt and immunized, resistance will be a very widespread problem, especially in environments with high consumption of just antibiotic (see a later chapter).
Historically, always known for microorganisms, although in many years without even knowing it. It was characteristic of micro-organisms are made vindruesaft to wine, served alcohol in beer and got food to go to decay. This time it was believed that life could arise spontaneously abiogenesis, that is an abiotic origin / creation. But in 1676 discovering the Dutchman Anton van Leeuwenhoek microscope operation microorganisms. But it was not him directly was convinced that it was the micro-life that created the above processes, but he discovered that there was life less than what the human eye could detect it in the light of this discovery that he often called mikrobiologie father.
The immediate breakdown in microorganisms are known prokaryotes and eukaryotes: prokaryotes is as the name suggests pro (pre) kernel, so these organisms have no nucleus for the protection of genetic material. Because they do not have a nuclear genetic material is free in the cytoplasm. Within prokaryotes divide Man in bacteria and arkæer. The second group of prokaryotes are all other creatures on earth. Animals, plants, slime sponges, but also many microorganisms, including fungi, algae and other things. Here follows a list of the various classes of microorganisms:
- Bacteria (prokaryotic)
- Arkæer (prokaryotic)
- Mushrooms (eukaryotic)
- Algiers (eukaryotic)
- Protozoa (eukaryotic)
- Multicellular animals (eukaryotic)
- (Virus) becomes to many not counted as an actual living organism [1]
[1] A lecturer at the Faculty of Life Sciences (former KVL) referred to a prøveforlæsning in connection with the open house event that you do not count them as living, as the virus can only reproduce inside other cells, eg in bacteria, plants and animals and also because of the lack of virus autonomously metabolism, but the dependence of the host cell's metabolic apparatus as it takes over and diverts to produce more viruses.
Below is a family tree (Figure 1) of the temporal family tree:
Being held arkæer to be more similar to eukaryotes, because that in and around their genetic material is protein hist tions, which also includes eukaryotes.
Figure 1 shows a family tree of the different classes of bacteria (prokaryotic), arkæer (prokaryotic) and all eukaryotes. By: Janus H. Magnussen, after Wikipedia.org
Click on the picture to get it up in a larger version (readable)
As the name suggests, these organisms can only be (individually) in the microscope, but these microscopes can also gain insight into the great diversity there is among, different shapes, colors, size, surface form and movement patterns and methods. However, long multicellular algae (seaweed) and colonies of bacteria and fungi (eg, mold) seen with the naked eye. Below is a graph (Figure 2) which shows the relative size of prokaryotes, eukaryotes, molecules and atoms:
Figure 2 shows the relative sizes of different organisms and biomolecules. 2. axis is a logarithmic metric system which starts at 10-9 m (1 nm) and ends at 10-3 m (1mm). By: Janus H. Magnussen, after Wikipedia.org
Click on the picture to get it up in a larger version (readable)
2.2 Resistance
Resistance is the ability to resist. The word comes from the Latin; resistentis, which means "to stand, to resist" In our experiments, we are investigating, as mentioned resistance of bacteria to different antibiotic. Resistance is in itself not necessarily a bad (we are even resistant to many drugs!) But the problem occurs if the resistance of a harmless bacterium spread to other more dangerous bacteria.
2.2.1 Antibacterials
Antibiotic word says it all: anti: against bios: life, so that the two substances can not exist in each other's proximity. The fact that some substances have the effect of other substances, molecules and organisms exploit Man in medicine to produce drugs that inhibit or kill pathogenic microorganisms. Antibiotic is not an enzyme but a molecule that can go in and work on microorganisms in several ways. They can enter the cell membrane and inhibit it from expanding, ie. that bacteria can not grow or divide. It can also modify the cell wall, for the same inhibition. Additionally, they inhibit protein synthesis in different places, either in transcription, translation or it may simply go in and change vital parts of the gene pool.
In our experiments we work with 7 different types of antibiotic:
1: tetracycline (ing)
2: ampicillin (amp)
3: sulfonamides (sul)
4: penicillin (pen)
5: bactracin (bac)
6: chloramphemicol (CHL)
7: stroptomysin (str)
2.2.2 Physiological factors that can produce resistance
Resistance may occur in different ways and be manifested in different ways. But change is always caused by natural selection, or in other cases programmed evolution. Natural selection is a part of Darwin's hereditary clarity and origin learn. Antibiotic activities can be viewed as an environmentally related pressures on the bacteria are exposed to it. Therefore, there will be a strong selection pressure to resist, ergo, the bacteria mutates to resistance have an advantage, and their genes will be in the form of new individuals be maintained. This can be illustrated by the following figure:
Figure 3: Schematic presentation of how antibiotic resistance develops through natural selection. The upper part "prior selection" represent a population of bacteria before addition of the antibiotic in the next stage is the selection made, it will say that some bacterial strains are selected from, and only those with the resistance survives. The third phase is the new generation of resistant Bakt. An additional comment could also be linked to, if the antibiotic was changed a bit, would the bacteria located in the second highest level of resistance to be more vulnerable than those with the highest level. From here one more selection to take place. By: Janus H. Magnussen, after Wikipedia.org
Click on the picture to get it up in a larger version (readable)
The forms of resistance could be developed in the final population (see Figure 3) could be a really passive resistance to the substance, for example, if the antibiotic is no longer able to bind to its target site, but a worse kind of resistance would be the production of an enzyme actively able to destroy the antibiotic, such as stafylokokkbakterien Staphylococcus aureus can produce penicillinase (enzyme that cleaves penicillin). The reason for this mutation, associated modification / creation of (new) enzyme, is worse than the passive form of resistance is that the new gene for the enzyme could be shared horizontally between bacteria, unlike the passive defense (which will often be species-specific)
2.2.3 Anatomical factors that can produce resistance
In bacteria may be cited as a form of passive resistance. A species of this type of resistance has its source in the bacterial cell wall - they can be either thick or thin. The difference between a thick and a thin cell wall, can be found by nærstudier of these. Looking at them both you will see that outside the cell membrane around this wall, which is constructed of chemically peptidoglykan (which is a combination of peptide and amino sugars glykan). In addition, there are some differences between the two types:
1: The bacteria have thin cell wall beyond the wall a second membrane in structure very similar to the cell membrane, however, there are embedded in the membrane of different substances as lipopolysakkerider and lipoproteins, and when they are built up by particular lipid, they will be embedded in the membrane lipophilic interior.
2: The bacteria with thick cell wall and no extra membrane
In order to identify the two types, the Dane Christian Gram developed a method by which the bacteria with thin cell wall is not stained, ie. gram negative, and where the bacteria with thick cell wall is stained, ie. gram positive. This kind of classification is relevant to our experiments, when the bacteria are gram-positive are generally more susceptible to penicillin, which gives us that Gram-negative bacteria are more resistant, so a passive resistance arising as a result of bacterial anatomical relationship. In our experiments we work with three different bacteria: Bacillus cereus (which is a soil bacterium), Esceria coli, and an unknown bacterium from soil samples, which I call Bacillus Magnussenae (but may be doubts about the purity of this colony). B. cereus is g + while E. coli is grams, this we can use in our hypothesis.
2.2.4 Resistance Transfer
As mentioned earlier, bacteria can exchange genetic material horizontally. This can happen when bacteria containing plasmids, which is a separate ring-shaped piece of DNA material, which in itself does not code for anything substantial (for example, propagation, metabolism, etc.) but instead may contain genes which may increase the organism's survival, if the activated in a given situation. However, these plasmids can be relatively easily transferred to other bacteria, which can happen in three ways:
1: Conjugation: As is a process where two cells independently exchange and combine genetic material. It happens when the two cell membranes fuse together, forming a pilus. What happens is that one cell (a) wraps up its plasmid and transfers it to the cell (b) of both cells to DNA polymerase (or an equivalent) affixing free nucleotides in the free seats.
2: Transformation: Bacterial a door, and the plasmids are now free-floating. Bacterial b recording this hereditary material and embed it into its own. It is the same technique to use in genetic engineering.
3: transduction: A technique in which hereditary material from one cell is transferred to another by a adenoral virus. This is also used in gentransplantation where you want a property, such as production of a particular enzyme, this gene can then be spliced into the genome of a bacterium, which then produces the desired enzyme, which then can be collected.
3.0 Hypothesis
A proper hypothesis can not be found because I do not know anything about the different antibiotic suchlike bacteria. However, I have the hypothesis that the type of bacteria that are gram positive will attack better to penicillin. In addition, I expect to see the markings of bakteriehæmning around antibiotic tablets, for the three different types of bacteria. It might be "lucky" to see a form of resistance. This could be seen as small colonies of bacteria in an otherwise growth inhibitory zone. The reason I put quotation marks at Lucky, is even said: Have we created a resistant family of one of the represented bacteria, this could spread. And since we work with "real" antibiotic resistance is real.
4.0 Results
4.1 Schematic
Below is a schematic overview of the results (Table 1):
The places where it has been set into question, says that it was not possible to read the result. By B. cereus, it is because vækshæmmende zones from other antibiotic was so great that a result could not be read. By E. coli, the entire Petri dish, covered only by væksmedie, suggesting that the antibiotic has diffused into the entire plate, and thus has killed all bacteria. Sorry.
Form in the left column shows the type of antibiotic that is measured, and in the next three columns are listed the various bacteria. The result is written to the radius of the dwarfed zone in millimeters. The places with the result 0 is an indication that there was no sterile zone, and therefore, they grew close to the given antibiotic. Below I've made yet another table (Table 2), illustrating the effect of individual antibiotics v. each bacterium (but not E. coli)
5.0 Discussion
As shown in Table 2 are not many similarities between the known bacteria B. cereus and the unknown soil bacterium (B. Magnussenae). It may, however, surprising that B. cereus did not respond to penicillin, because it is gram negative. Generally one can say about the experiment, it was good in some areas and less well on others. For example, it was a good workflow, as for my part was instructive, and many of the results was also satisfactory good, but it was a shame that the outcome of E. coli could not be used, and that many of the other groups attempt went in rags, a broad comparison would be advantageous, since it would also be better able to determine different resistance patterns. As I've mentioned above, there are not many equal units between B. cereus and the unknown soil bacteria, but does one B. cereus up, there really is a ground-living bacteria (thereby not said that soil living bacteria necessarily react the same).
Another interesting observation which emerged in connection with the treatment result was detected by individual bacterial colonies that lived in the otherwise dead zones. This showed that the resistance? One might fear it, a source of error as other bacteria indsluppet the petri dish, I may be excluded because the pattern of growth of the colonies did not indicate this. Had it been a type of resistant bacteria from the start, growth area would be larger - at least we took no chances, and disinfected equipment autoklavemaskinen.
5.1 Antibiotic resistance - a social evil
If, as mentioned above were developed resistance, it would respond well to what is happening in many places in the "real" world - I refer particularly to the agricultural sector, where resistance due to overuse of antibiotics is unfortunately a reality. The problem of antibiotic consumption in Danish primary sector, is it better used as a preventive - that is a prophylactic overuse. It represents therefore an image where diseases tackled before it is used, which translated into figures mean that half of all Danish dairy cows (in traditional agriculture that still accounts for a majority) in the course of a year are treated with antibiotic in order to keep disease below. But a study shows that antibiotic consumption can be reduced substantially without compromising the animals' health. Dairy farmers from this, have partially changed their farming so that the need for preventive antibiotic therapy reduced. These include reflected in the change of housing the design where conventional housing is opmurede buildings with the general high temperature and high humidity caused by lack of air circulation - a paradise for microorganisms. This has the peasants from the experiment eliminated by building stables sit outside walls so that fresh air can circulate. Disease is still prevention, but without medication - for example by spreading of seashells, which prevents the mud around the hooves and udders (which is pathogenic, as again and create good living conditions for microorganisms). Thus it is proved that by relatively simple changes can reduce the need for antibiotics by 50% and still without compromising animal welfare, which is beneficial for all.
