BIOL 240: Assignment One
1876:
Validation of the germ theory of disease| Robert Koch
After conducting studies on Anthrax, Koch published a paper blaming a particular bacteria as the root of the disease, validating germ theory. The validation of germ theory helped pioneer the field of clinical microbiology. By understanding that certain microorganisms cause disease, the community made huge advances in anti-biotics and hygiene. In this course, we study Koch’s postulates, the four criteria that generally need to be fulfilled to conclude that a microorganism is responsible for a disease.
1881:
Development of solid culture medium| Robert Koch
The development of solid culture medium helped eliminate the disadvantages and frustrations experienced by the use of
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This process is needed because bacteria generally reproduce by binary fission, making the offspring genetically identical to the parent. Conjugation helps add the genetic diversity that is crucial for the organisms’ continued existence. In modern clinical microbiology, conjugation is the explanation behind why certain bacteria become antibiotic resistant. Like bacteria transform, conjugation helps us understand genetic diversity within the bacteria domain. 1960:
Development of the operon concept| Francois Jacob, David Perrin, Carmen Sanchez, Jacques Monod
An operon can be defined as a gene regulatory system, found in bacteria and bacteriophages, where certain genes that code particular proteins are clumped together on DNA. This design allows for protein synthesis to be strategically controlled, based on the personal needs of the cell, allowing for energy conservation. The development of the operon model helped us understand the process behind gene regulation in microbes, and how they maintain energy efficiency despite the apparent lack of design sophistication compared to eukaryotes.
Fermentation is the biological process which allows humans to brew beer, or any other alcoholic beverage. This process occurs in the absence of oxygen, as a means for the cell to produce adenosine triphosphate (ATP), the source of cellular energy. Though little energy can be produced in this manner, it allows the yeast to survive in t...
Thomas disccuseed thr “paranoid delusions on a societal scale,” that we have against human diseases or our “enemies.” The book contiuniuously uses anaphora by saying that diseases result from “inconclusive negoitions for symbiosis” and misinterpretation of biology” The fact that bacteria can only be harmful from practiacally harming themselves is an interesting point to point out. That shows the reader that the only way they could be harmed from bacteria, wouls be if the bacteria had gotten itself “sick” first. Thomas talks about certain microorganisms that have “advantages in their ability to affect himan beinhg, but that there is nothing to be gained, in an evolutionary sense, by the capacity to caue illness or death.” Another reassuraing statement for readers is when he says, pathogenicy is a disadvantage for most microbes because they are carrying
Jennifer Ackerman's main focus in her article The Ultimate Social Network, is that of the functions concerning bacteria within humans. Although scientists have had presumptions about humans being proficient in governing their body’s innermost structure, they soon come to recognize the sophistication of our inner space which holds an extensive plethora of bacteria and other microorganisms that lie within each and every one of us. Moreover, scientists' new and emerging view of how the human body operates, and the cause of increasing present-day diseases (i.e. obesity and different autoimmune disorders) are uncovered by analyzing effects of certain microbe species in our bodies. By italicizing on points such as the above, in conjunction with bacteria's genetic variations, and modern computing technology, the author proves that scientists are quickly progressing with the characterization the most prevalent species of microbes, which, in her opinion, is definitely paying off.
Again, at the time of Dr. Snow’s practice, germ theory wasn’t even in its infancy. It might be more appropriate to say the theory was still in utero. It was understood that there was some causative agent behind illness, but with limited ability to detect and identify the actual agents of disease – in the case of cholera the cause was a bacteria – it was nearly impossible to definitively place blame. Proponents of the miasma theory believed that impure air could cause disease, and in some ways they were correct. For example, inhaling smoke, a form of impure air, can cause a range of pulmonary diseases in addition to an immediate cough. Dr. Snow, on the other hand, was hesitant to blame air on everything. If bad air alone was to blame, why did it not affect all who breathed it equally? With such questions in mind, he set out to scientifically gather evidence towards his theory surrounding water
This paper discusses the development and history of Microbiology and its impact on human health over time. This includes an examination of historical events that led to the development of techniques and procedures used for the handling of microorganisms, and
Of these three, the one I will be focused on is the hygiene hypothesis. The hygiene hypothesis, essentially says we are too clean for our own good! But wait is that possible? The belief is with little to no contact with infectious entities the body can mistake common food proteins as an invading germ or germ that the body recognizes as a threat. I believe that the theory, Hygiene hypothesis is most plausible because it makes the most sense. Here is why I believe that statement. In the last 20 years hygiene in the Western world has become increasingly more popular and widespread. If we think back to the time of our parents and grandparents there were still allergies but much less. Kids would run around in bare feet ate mud and got dirty. On top of this they would not put much thought into washing hands or take a shower every day, hence there was more time for the body to decipher what is bad and what is good. In our day now everybody and their uncle have allergies if you think back to the nineties and two thousand's there was a lot of talk about being extremely or you will be sick. So we made sure to wash our face and hands after
Medical College of Wisconsin. “Facts About Anthrax and Smallpox as Bioterrorism Weapons.” Healthlink. 12 Nov. 2001. Medical College of Wisconsin. 24 July 2008 .
Infectious diseases are the disorders caused by organisms such as bacteria, viruses, fungi or parasite who live both inside and outside our bodies and are normally helpful but can cause infectious diseases to the human (body) system under certain conditions. And for a disease to be infectious, there is what is called ‘’chain of infection’’ that takes place before. And this can be seen in the below diagram:
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.
Bacterial resistance to antibiotics has presented many problems in our society, including an increased chance of fatality due to infections that could have otherwise been treated with success. Antibiotics are used to treat bacterial infections, but overexposure to these drugs give the bacteria more opportunities to mutate, forming resistant strains. Through natural selection, those few mutated bacteria are able to survive treatments of antibiotics and then pass on their genes to other bacterial cells through lateral gene transfer (Zhaxybayeva, 2011). Once resistance builds in one patient, it is possible for the strain to be transmitted to others through improper hygiene and failure to isolate patients in hospitals.
A remarkable breakthrough in medicine occurred in the late 1800s through the work of Louis Pasteur. Pasteur's experiments showed that bacteria reproduce like other living things and travel from place to place. Using the results of his findings, he developed pasteurization, which is the process of heating liquids to kill bacteria and prevent fermentation. He also produced an anthrax vaccine as well as a way to weaken the rabies virus. After studying Pasteur's work, Joseph Lister developed antisepsis, which is the process of killing disease-causing germs. In 1865 before an operation, he cleansed a leg wound first with carbolic acid, and performed the surgery with sterilized (by heat) instruments. The wound healed, and the patient survived. Prior to surgery, the patient would've needed an amputation. However, by incorporating these antiseptic procedures in all of his surgeries, he decreased postoperative deaths. The use of antiseptics eventually helped reduce bacterial infection not only in surgery but also in childbirth and in the treatment of battle wounds. Another man that made discoveries that reinforced those of Pasteur's was Robert Koch. Robert Koch isolated the germ that causes tuberculosis, identified the germ responsible for Asiatic cholera, and developed sanitary measures to prevent disease. (1)
Koch created four guidelines to determine the causal agents of disease in humans, animals, and plants. Koch proved that a disease-causing agent could be transferred from one organism to another and create the same illness. Isolation of pure cultures and the introduction of the disease-causing agent to a healthy organism will transmit the disease and infect the inoculated organism. Koch’s four guidelines by which one must follow to transmit a disease from an infected organism to a healthy one are as followed:
On the other hand, cells that have resistance from the start or acquire it later may survive. At the same time, when antibiotics attack disease-causing bacteria, they also attack benign bacteria. This process eliminates drug-susceptible bacteria and favors bacteria that are resistant. Two things happen, populations of non-resistant and harmless bacteria are diminished, and because of the reduction of competition from these harmless and/or susceptible bacteria, resistant forms of disease-causing bacteria proliferate. As the resistant forms of the bacteria proliferate, there is more opportunity for genetic or chromosomal mutation (spontaneous DNA mutation (1)) or transformation, that comes about either through a form of microbial sex (1) or through the transference of plasmids, small circles of DNA (1), which allow bacteria to interchange genes with ease.
The birth of genetic engineering and recombinant DNA began in Stanford University, in the year 1970 (Hein). Biochemistry and medicine researchers were pursuing separate research pathways, yet these pathways converged to form what is now known as biotechnology (Hein). The biochemistry department was, at the time, focusing on an animal virus, and found a method of slicing DNA so cleanly that it would reform and go on to infect other cells. (Hein) The medical department focused on bacteria and developed a microscopic molecular messenger, that could not only carry a foreign “blueprint”, or message, but could also get the bacteria to read and copy the information. (Hein) One concept is needed to understand what happened at Stanford: how a bacterial “factory” turns “on” or “off”. (Hein) When a cell is dividing or producing a protein, it uses promoters (“on switches”) to start the process and terminators (“off switches”) to stop the process. (Hein) To form proteins, promoters and terminators are used to tell where the protein begins and where it ends. (Hein) In 1972 Herbert Boyer, a biochemist, provided Stanford with a bacterial enzyme called Eco R1. (Hein) This enzyme is used by bacteria to defend themselves against bacteriophages, or bacterial viruses. (Hein) The biochemistry department used this enzyme as a “molecular scalpel”, to cut a monkey virus called SV40. (Hein) What the Stanford researchers observed was that, when they did this, the virus reformed at the cleaved site in a circular manner. It later went on to infect other cells as if nothing had happened. (Hein) This proved that EcoR1 could cut the bonding sites on two different DNA strands, which could be combined using the “sticky ends” at the sites. (Hein). The contribution towards genetic engineering from the biochemistry department was the observations of EcoR1’s cleavage of
Bacteria are single celled microbes. Bacteria reproduce by binary fission. In this process, the bacterium, which is a single cell, divides into two identical daughter cells. Binary