Effect Of E. Coli On Antibiotic Resistance

Smith H. 1969. TRANSFER OF ANTIBIOTIC RESISTANCE FROM ANIMAL AND HUMAN STRAINS OF ESCHERICHIA COLI TO RESIDENT E. COLI IN THE ALIMENTARY TRACT OF MAN. Science Direct [Internet]. [Cited 2015 Dec 1]. Available from:

Escherichia coli, or E. coli, is a common bacterium that can be found in diverse environments all over the planet, including the gastrointestinal tracts of animals and humans. Many of these strains of E. Coli are essential mechanisms in the digestive tract, while others are pathogens that can cause complications in urinary and intestinal tracts. (Payne & Sparks) In research, E. Coli is commonly used as a model organism, meaning they are widely studied by scientists for a variety of purposes due to their experimental advantages. E. Coli is comparatively simple, and there are many advantages to studying these prokaryotic cells in the fields of biochemistry and molecular biology. E. Coli has this simplicity and is relatively easy to propagate in a lab environment. Their genome has been completely sequenced and many things we know about DNA, protein synthesis, and gene linkage have been derived from studies regarding this particular organism. (Cooper)

When a person contracts a UTI, drugs are usually the first thing taken to try to get rid of the UTI. But, in recent studies, e.coli’s resistance to common UTI drugs is rising. Veronique Greenwood conducted a study in 2012 that showed the rise in drug resistance of e.coli bacterias. The study showed a 14% increase in resistance in the drug ciprofloxacin, a 6% increase in trimethoprim-sulfamethoxazole, the two most prescribed drugs. As the e.coli becomes resistant to these drugs, large problems can arise for many people. For instance, when the drugs become fully ineffective, a large population of people can become sick from the e.coli bacteria, or become harmed from the toxic drugs doctors would have moved onto. Also, is the bacteria is left untreated, the infection can spread from the urinary tract to the bladder and eventually to the kidneys causing kidney failure. In brief, whether contracted from a fecal incident, or unsanitized food, e.coli can be extremely dangerous and can result in a sickness or

Bactericidal antibiotics kill bacteria by interfering with the cell wall or organelle formation. (News Medical, 2004) Bacteriostatic antibiotics interfere with the cell’s metabolic processes, such as DNA replication and protein synthesis. (News Medical, 2004) Both actions inhibit the cells vital processes, causing cell death. (Crierie & Grieg, 2010) However, superbugs, such as strains of Staphylococcus aureus, and Mycobacterium tuberculosis are deadly as they are very difficult to treat due to their resistance to multiple antibiotics. (NPS MedicineWise, 2012) Previously, Staphylococcus aureus was treated with benzyl penicillin. Currently, however, the bacteria cannot be controlled through this method, as they have developed resistance, which occurs because bacteria have the ability to mutate. After antibiotic contact, bacteria can alter their DNA in a way that enables them to resist the antibiotics. Bacteria are prokaryotic organisms and produce asexually by binary fission, thus their offspring have no genetic diversity. The only source of genetic variation in bacteria is through mutation. (Crierie & Grieg, 2010) Mutation refers to changes in gene sequences, resulting in variation in subsequent generations. This process occurs in every millionth to ten-millionth cell. (Alliance for the Prudent Use of Antibiotics, 2014) Certain types of mutations cause different types of resistance. They may enable

For a bacterium to become resistant a change in its DNA must occur. This can happen in more than one way. Bacterium may gain resistance through spontaneous mutation within the bacterium’s DNA. This occurs when a single amino acid that makes up a protein changes arrangement, the order of the peptide chain (made up of amino acids, joined together to make up proteins) then the purpose of the protein in the DNA changes. This causes the genetic makeup of the cell to alter. If the mutation is of benefit and gives the bacteria resistance, once all the other none resistant strains of bacteria are killed, the resistant bacteria multiplies and reproduces, creating a new strain of bacteria which is resistant to the antibiotic in hand. Once a resistance gene is obtained and inserted into the DNA, the bacterium can dominate other bacteria and

Like any other organism, bacterium are subject to evolutionary pressure. Antibiotic resistance in bacteria is rarely the result of a single mutation leading to full resistance, but rather the result of a series of mutations that incrementally increased antibiotic resistance. For example, in the case of fluoroquinolone resistance, resistance started with a mutation in the efflux pump, granting Streptococcus pneumoniae the ability to survive certain treatment regimens (13). This became an issue when people started to misuse their antibiotics. In this particular example, because patients did not follow their prescription regimens, they only killed the bacteria not resistant to fluoroquinolone. This selective pressure drove bacteria to further develop fluoroquinolone resistance, meaning that the initial infection remained untreated, and would now require a

Genetic change in a bacterium can have an effect in resistance. Most bacteria work by inactivating an essential bacterial protein. Genetic change can remove that protein and also mutations in the target protein can prevent the antibiotic from binding. Production of the antibiotics target enzyme can also be increased by genetic change meaning that there are too many and the antibiotics cannot inactivate them all. Not only

Without horizontal gene transfer, antibiotic resistance develops in most bacteria by mutation in the gene that codes for the enzyme that targets the antibiotic. (B-lactamases in case of B-lactams.)2

Each time an antibiotic is used it creates a “selective pressure” on the microbial community. The bacteria, which are susceptible to the antibiotic treatment, will be killed. This allows for the non-susceptible bacteria to grow without competition, and accordingly become the dominant population (8). Antibiotic resistance in bacteria occurs by two mechanisms. The first mechanism is a rare mutation in the genome, which allows the cell to

Antibiotics are derived from microbes that work by inhibiting the growth or by killing other bacteria (Tortora, Funke, and Case 549). Usually our body’s immune system is an ample defense by stopping microbes from replicating or killing them. However, sometimes the body can become overwhelmed and that is when antibiotics are used to help out our immune systems. An important dilemma in medicine is the increasing occurrence of antibiotic resistance, which occurs when bacteria are exposed to the same antibiotics over and over and eventually makes them less effective (Tortora, Funke, and Case 549). Antibiotic-resistant bacteria are bacteria that are not killed by common antibiotics (“Antibiotics”, 2007, para.6). There are several ways bacteria can develop antibiotic resistance: by altering of the drug target, altering membrane permeability, by developing enzymes that can inactivate the drug, developing alternate synthetic pathways, or acquire resistance by exposure to microbe with resistance genes. This spreading of genes is the result of plasmids that transfer R factors which contain two groups of genes: a resistance transfer factor and the r-determinant, which has the resistance genes (Tortora, Funke, and Case 232). R factors can be a problem in the healthcare field because of the misuse of antibiotics. This leads to preferential selection of bacteria that have R factors and results in populations of resistant bacteria growing larger and larger (Tortora, Funke,

The development of antibiotics was an important advancement in 20th century medicine. Previously deadly infectious diseases are now routinely treated with antibiotics. Moreover, for modern-day medical procedures such as chemotherapy treatment to be successful, antibiotic use is necessary. For these reasons, the prospect of bacteria developing widespread resistance to antibiotics is a major concern as it would render many modern-day medical therapies unviable.

Today, the use of antibiotics is very common. The gene that causes antibiotic resistance typically arises naturally or from a mutation. When bacteria are exposed to antibiotics, the bacteria with antibiotic resistance genes within the plasmid survive; this is called selective advantage. This process of the survival of bacteria that are resistant to antibiotics is a method of natural selection, causing more antibiotic resistant bacteria to be reproduced. They are rapidly reproduced by binary fission, conjugation, transformation,

Antibiotic resistance is a growing problem throughout the globe. Besides using antibiotics for medical use, they are being used in the agriculture industry. In animals, antibiotics are being used to treat diseases, but also to prevent diseases from occurring and to increase the growth of animals (Mehndiratta, 2014, p.340). In recent years, the evidence of farmers using antibiotics for non-traditional ways has sparked major controversy. In agriculture 90% of antibiotics are used for growth-promoting and prophylactic agents with the other 10% being used to treat diseases (Khachatourians, 1998, p.2). To understand why this occurs, we first must understand the genetic basis for antibiotic resistance and the occurrence of antibiotic resistance in selected organisms. By farmers doing this an increase in the number and types of microorganisms resistant to drugs, has increased public health problems. Finally, management options for reducing antibiotics in the environment have to occur. If farmers continue to use antibiotics for non-traditional uses, as humans we can be affected greatly not just by food supply, but by water runoff, the air, and even the soil. Also, more public health problems will occur.

However, antibiotic use has not been without consequence and several factors had contributed to the development of resistance. Some resistances are due to spontaneous mutation and these mutations are for select antibiotic resistance whilst other bacteria tend to steal the deoxyribonucleic acid (DNA) from their counterparts who are already familiar with antibiotics (Mims, 2004; Tenover, 2006).

Antibiotics have the ability to kill or hinder the growth of bacteria. Antibiotics contain compounds that are naturally produced by organisms to combat diseases caused by microbes. Discovery of penicillin by Sir Alexander Fleming became the first stepping stone of many new antibiotics of today’s modern medicine. Antibiotics typically invade the very components that make up bacteria, such as cell walls and metabolic pathways (Sato et al., 2014). However, frequent mutations of bacteria cause today’s strains to become more resistant. One of many ways which bacteria undergo mutation is through horizontal transfer of genes (Lindsay J.A., 2013). The war against disease is a battle that humanity has fought for centuries, and only