Quinolone: The Discovery Of Antibiotics That Kill Bacteria

Everyone knows how useful penicillin is today in the modern age as an antibiotic. Some people might even know about the story behind its discovery. What they don’t know about is the long history behind this medical discovery. They especially don’t know about the hard work of several scientists who brought the idea of penicillin to life. From the earliest discovery of penicillin in 1896 by Ernest Duchesne to the start of its mass production in 1948 and now the modern world of the twenty-first century, it has come a long way. In fact, penicillin has risen from just a bit of Penicillium mold and a mistaken discovery to the life-saving antibiotic agent it is today.

Antibiotics either stop the bacterial cell from reproducing or kill the cell. They can disrupt the bacteria by deterring

Antibiotics, composed of microorganisms such as streptomycin and penicillin, kill other infectious microorganisms in the human body. At one point, antibiotics were considered to have “basically wiped out infection in the United States”, but due to their overuse and evolutionary

The misuse of penicillin and other antibiotics however is causing the growing problem of antibiotic resistance in which seemingly harmless infections turn to be deadly and dangerous. Antibiotics are not only casually used as treatments for bacterial infections, but are also used in agriculture and veterinary medicine, creating controversy on the proper uses of antibiotics. As advancements in the medical fields proved to be beneficial for a short period of time, today the misuse of these innovations are creating more and more problems that have proven to be dangerous to the accustomed health of the global population. Antibiotics were not always considered to be a superficial medication and, in fact, have been naturally used for millions of years, like with ants and their symbiosis with antibiotic producing fungi. Humans do not fully realize the value that antibiotics have brought to the population and do not take measures to preserve their use. In contrast, humans take for advantage the natural benefits that is given to them to overly benefit themselves, such as while creating revenue through mass production despite warning from scientists. This selfish misuse leads to consequences in which the future will have to provide solutions for, and perhaps even follow in the ants’ footsteps.

Antibiotics have played an essential role in the fight against diseases and infections since the 1940’s. Antibiotics are a leading cause for the rise of global average life expectancy in the 20th and 21st century. They have greatly reduced illnesses and deaths due to diseases. With the introductions of antibiotics in the 1940’s, like penicillin into clinical practice, formally deadly illnesses became immediately curable and saved thousands of lives (Yim 2006). Antibiotic use has been beneficial and when prescribed and taken correctly their effects on patients are exceedingly valuable. However, because these drugs have been used so widely and for such a long period of time the bacteria that the antibiotics are designed to kill have adapted,

These mutations, no matter what process that has led to their occurrence, block the action of antibiotics by interfering with their mechanism of action (1). Currently, antibiotics attack bacteria through one of two mechanisms. In both mechanisms the antibiotic enters the microbe and interferes with production of the components needed to form new bacterial cells. Some antibiotics act on the cell membrane, causing increased permeability and leakage of cell contents. Other antibiotics interfere with protein synthesis in cells. They block one or more of the steps involved in the transformation of nucleic acids into proteins.

Antibiotic resistance is a major topic talked about today in the scientific and medical communities because of the increased rate it is occurring. Antibiotics are medicines used to treat foreign bacteria in the body. In 1928, Alexander Fleming discovered the first antibiotic, penicillin, when testing the bacteria pathogen Staphylococcus aureus; the mold in his lab was capable of killing bacteria. Taking too many antibiotics can destroy the microbes in the gut, which help fight the bacteria in the first place. When bacteria changes DNA in the cell, the newly formed bacteria infection is now resistant to the former antibiotic treatments used previously ("Facts about Antibiotic Resistance" 2016). Once the bacteria cannot be inhibited by the antibiotic,

Antibiotics target specific structure or process of the cell. Such as, inhibition of cell wall synthesis, Inhibition of protein synthesis, Injury to plasma membrane, & Inhibition of nucleic acid synthesis. These drugs include, such as B lactam drugs that are bactericidal & kill bacteria by interfering with the synthesis of the cell wall, Polymyxin B drugs that injures the plasma membrane allowing the cell to burst. Tetracycline & Chloramphenicol that are bacteriostatic drugs, and inhibits protein synthesis. Fluoroquinolones & Rifamycin that are bactericidal drugs & interfere with the synthesis of nucleic acid. The pathogens can develop resistance against these drugs that are used to treat them. Resistance to antibiotics can be acquired by mutation

Antibiotic have been essential tools for fight against bacterial infections since the early 20th century. Antibiotics fall under different groups based on the method of treatment. There are basically 3 main groups of antibiotics based on their mechanism of action, i.e Cell wall Disruptive Antibiotics like beta lactams, Protein synthesis inhibitors and nucleic acid

The discovery of penicillin, one of the world’s first antibiotics, marked a turning point in human history. Doctors finally had medicine that could completely cure and prevent infectious diseases.

Agents are created to interact in a particular path with a specific pathogen and will not have the same cellular impact when used incorrectly. For example, agents that lead to a bacteria's demise include inhibition of bacteria cell synthesis, replication of deoxyribonucleic acid (DNA), and interference with protein synthesis (Arcangelo & Peterson, 2013). Penicillin and beta-lactam/beta-lactamase inhibitors work to stop cell synthesis (Arcangelo & Peterson, 2013). Fluoroquinolones work to inhibit the bacteria's DNA and macrolides work by inhibition of protein synthesis (Arcangelo & Peterson, 2013). These agents would not be effective on a virus because the virus is protected in the host cell. Antibacterial agents are designed to inhibit the cell wall and replication of bacteria. Differentiation between a virus and bacterial infection will help the clinician select the right antimicrobial agent that can target a specific

It is necessary to target treatment more specifically against the offending bacterium in order to reduce the risk of resistance emerging in other bacterial groups. Some antibiotics are narrow spectrum, more effective against Gram-positive or Gram-negative bacteria, and little activity against the other.

Antibiotics have been used to treat a wide variety of illnesses some of which could possibly lead to death. In the early years, new antibiotics were developed faster than bacteria could develop resistance to them ( refer to appendix 1). Antibiotic Resistance continues to be a serious public health threat worldwide deemed by the ECDC (European Centre for Disease Prevention and Control). Some reasons for the widespread use of antibiotics include: increasing global availability over a period of time and uncontrolled sale in many low or middle income countries, where they can be obtained over the counter without a prescription. In Alexander Flemings Noble Peace Prize acceptance speech he also spoke of the danger of Antibiotic Resistance.

The problems with antibiotic resistance is not a recent phenomenon. When Alexander Fleming received his Nobel Prize in 1945 for the discovery of penicillin, he warned that the overuse of penicillin could have future consequences of becoming ineffective. In 1977, the problem of antibiotic resistance to penicillin and other antibiotics was prevalent enough that the FDA considered withdrawing the use in animals; but Congress put them through hoops of conducting studies to prove their findings. To

The principle of antibiotic resistance revolve around how antibiotics work. Antibiotics target certain structures on bacteria such as their cell wall, proteins, and nucleic acids that results in the disruption and/or inhibition of their growth. These disturbances can sometimes lead to bacterial death. In order to survive, bacteria have developed countermeasures to fight against the harmful drugs. This was carried out by targeting the antibiotics themselves. The way antibiotics function is based on their chemical structure. Because many antibiotics have similar structures, they are also grouped in that way. Each class (or family) have similarities in their structure and in turn, have similarities in their target of action. Consequently, these similarities make it easy for the bacteria to construct resistance to different and multiple classes of antibiotics. Mechanisms that will be discussed all involve bacteria’s ability to prevent antibiotics from reaching its target by means of target alteration, drug detoxification, impermeability and efflux.