Bacterial resistance has become one of the most pressing scientific issues of our century, but not many outside of the microbiology community are aware of what it is and its effects on our lives. This resistance to antibacterial antibiotics occurs when antibiotics are misused or misprescribed, leading to unnecessary exposure of the bacteria to the antibiotic and giving it a chance to mutate in order to become immune to it. Health professionals and scientists around the globe have been trying to solve this issue. Their research has revealed that mutations in the bacterium’s genetic sequence have led to these detrimental resistance patterns. For years, antibiotics have been used as a cure-all for many types of nonbacterial ailments and diseases, but this misuse has proved to lead to more mutations and resistance than is necessary. Therefore, we, as the public, are responsible for making sure that antibiotics are used, prescribed, and distributed correctly.
Bacterial Resistance and Its Impact on Our Everyday Lives
Antibiotics have become a huge part of modern history. In fact, many diseases have become eliminated worldwide as a result of the proper distribution and use of antibiotics. This is thanks to many scientists, but most notoriously, Alexander Fleming. Fleming first discovered the effectiveness of penicillin as a vaccine in 1928. At the time, he was not sure of the cause of the zones of inhibition on his agar plates filled with staphylococcus colonies. Once plated on a new plate, he discovered that the fungus at the center of the clearing contained properties that killed certain kinds of bacteria. Now, we know that a fungal spore of Penicillium chrysogenum landed on his plate, causing the large circle of clearance. With the new pure colonies of penicillin, the discovery was made that the beta-lactam ring in its chemical structure was able to cease production of peptidoglycan in actively growing gram-positive bacteria, which is necessary for the cell wall, and consequently, the cell’s survival (Fleming, 1945). This selectivity of the penicillin, allowing it to cease synthesis of a structure that is not present in humans, made it safe to use as an antibiotic medicine. However, penicillin is not an effective drug in many cases today due to different types of bacteria’s increased resistance to it. Bacterial resistance has proved to be a nasty problem in modern medical history because of its negative effects on antibiotic effectiveness. This topic can be explored further by discussing what bacterial resistance is, how bacteria acquire this resistance, what scientists and health professionals have done to combat this, and finally, how this issue applies to the general public.
To begin, what exactly is bacterial resistance, and what role do antibiotics play in it? Bacterial resistance is defined by the Center for Disease Control as “the ability of bacteria to resist the effects of an antibiotic,” (Center for Disease Control, 2017). Simply put, bacterial resistance is a genetic mutation in the bacterium that decreases the effectiveness of an antibacterial antibiotic. It can be observed in a bacterium where a certain antibiotic used to be effective at killing it, but due to a recent mutation in the bacterium, it is now resistant towards that antibiotic. Antibiotics are very effective in some bacteria, but not in others. Why is this? There are two main types of bacteria: gram-positive and gram-negative. Their main difference lies in their cell wall composition. In gram-positive bacteria, a phospholipid bilayer is present closest to the cytoplasm with the outer peptidoglycan thick cell wall surrounding the cell. In gram-negative bacteria, there are two phospholipid bilayers present with a think peptidoglycan cell wall in between the two (Tortora, 2016). This allows the gram-negative bacteria to be naturally resistant to antibiotics such as penicillin, and explains why not all bacteria were killed by penicillin in Fleming’s first experiments (Fleming, 1945). This shows us that bacterial resistance to antibiotics is not always caused by mutation, but can be caused by other protective features of the bacterium.
There are two types of ways that bacteria can receive resistance genes. One way is vertical gene transfer, and the other is called horizontal gene transfer. Vertical gene transfer is the transfer of genes via bacteria replication. This is the simplest kind of gene transfer and is by far the most common in nature. Horizontal gene transfer has three subtypes: conjugation, transduction, and transformation. According to Holmes and Jobling, conjugation occurs when a donor bacterium produces a pilus, which is a hair-like structure that allows for DNA to be transferred between two cells. The pilus then attaches to the recipient bacterium and a small piece of single-stranded DNA from a plasmid is transferred from the donor to the recipient cell. The recipient cell then produces a complementary strand to finish the DNA. The gene is now present and is available for expression in the recipient bacterium (Holmes & Jobling, 1996). Transduction occurs when a virus transfers the resistant genes in the DNA to other host bacterial cells. It is the only type of gene transfer that is mediated by a non-bacterial source. The final subtype of horizontal gene transfer, transformation, occurs when a bacterium that contains a resistant gene lyses. Its contents then are released and absorbed by other bacteria. One of the types of content that is released is its resistant DNA. The cell that absorbs the resistant DNA is then able to express the gene for resistance against a certain antibiotic (Hasudungan, 2014).
Now that we’ve uncovered the process of how a bacterium becomes resistant to an antibiotic, what are health professionals and scientists doing to combat this pressing issue? To start, none of this knowledge would even be available to collect if it wasn’t for the care and concern of microbiologists. It’s hard to believe that just over seventy years ago, the first antibiotics were being widely distributed. Now, we know that the overdistribution leads to an increase in bacterial resistance. Many large organizations such as the World Health Organization (WHO) and the Centers for Disease Control and Prevention (CDC) list antibacterial antibiotic resistance as a prevalent public health issue. Specifically, WHO states that health professionals should ensure that all of their equipment and environments are sterilized so that infections are not spread as often. They also recommend prescribing antibiotics very sparingly so that bacteria do not have the chance to develop resistance towards them, and to never prescribe an antibiotic for a viral infection such as a common cold or flu. Health professionals can also encourage their patients to do the same things, and dispose of their unused antibiotics (WHO, 2017). Scientists across the globe are working on developing new antibiotics that bacteria will not be resistant towards. Dr. David Livermore speaks on this when he says that in order to combat bacterial resistance, a balance between the resistance occurring and the introduction of new antibiotics must be upheld (Livermore, 2003). However, a long-term solution to this issue has not been presented, which brings a lot of stress to our medical community today.
This brings us to ask ourselves: what could we do as a society to bring change to bacterial resistance? While a large majority of the general public does not have access to laboratories or equipment useful for discovering new antibiotics, there are a number of things to be done that are much simpler. The World Health Organization lays out several options on their website. One of the biggest ways to eliminate antibiotic misuse is by correctly using the antibiotics that a patient is given. This includes taking the full dosage administered, not sharing it or saving it, and disposing of any extra one finds themselves with. Another large part of this is not pressuring one’s doctor to prescribe an antibiotic when the cause of a disease is unknown. In many cases, the cause is viral and cannot be cured by an antibiotic. Another way to eliminate bacterial resistance is by preparing food properly, washing your hands, and making sure that all household surfaces are being disinfected regularly (WHO, 2017).
Bacterial resistance has proved to be a nasty problem in modern medical history because of its negative effects on antibiotic effectiveness. We discussed this in four parts: what bacterial resistance is, how bacteria acquire this resistance, what scientists and health professionals are doing to combat this, and finally, how this issue applies to the general public.