To fight against the infectious disease produced by the bacteria and to ensure the success of a medical procedure or treatment devoid of any infections, antibiotics are widely administered.
The administration of antibiotics aroused an evolutionary and survival response among the bacteria producing resistance to the antibiotics, consequently making the bacteria antibiotic-resistant.
Therefore, the only reason for antibiotic resistance is the ?antibiotics? itself. Antibiotics stood in the way of bacteria?s survival and like any other organism, bacteria responded by evolving for its survival, becoming resistant to antibiotics.
However, 6 major human-driven factors exerting selective pressure on the bacteria to become antibiotic-resistant are,
Causes of antibiotic resistance
- Overuse of antibiotics
- Inappropriate prescribing
- Abuse of antibiotics in agriculture
- Poor infection control in health care settings
- Urbanization and global travel
- Absence of new antibiotics being discovered
1. Overuse of antibiotics
Antibiotics became the ?miracle drugs? for treating people with bacterial infectious diseases without extreme detrimental side effects.
This striking effectiveness of the antibiotics bought the confidence of the general public causing the widespread usage of antibiotics as the first instance of almost all illnesses over the other drugs.
The overuse of antibiotics is the major driving factor of antibiotic resistance by applying a selective pressure on the bacteria.
In bacteria, antibiotic resistance genes can be inherited or acquired by horizontal gene transfer (HGT) allowing the antibiotic resistance to be transferred among different species of bacteria. Antibiotic resistance can also occur spontaneously through mutation.
?Read my blog post Antibiotic resistance mechanism to learn more about HGT.
Antibiotics destroy the sensitive bacteria leaving resistant bacteria to reproduce as a result of natural selection without competitors.
?Sir Alexander Fleming who discovered the first antibiotic penicillin in 1928 raised the concern of antibiotic overuse as early as 1945.
In 1945 he won the Nobel Prize for the discovery of penicillin and in an interview with The New York Times the same year; he warned that the overuse and misuse of antibiotics would lead to antibiotic resistance.
Antibiotic resistance began to emerge within the 10 years of the wide-scale use of penicillin.
In countries with poor pharmaceutical regulations, antibiotics are available as over the counter medication without a prescription, making the antibiotics easily accessible promoting the overuse.
The online purchase of antibiotics also promotes overuse by making it accessible in countries where antibiotics are regulated.
?According to an article published in The Lancet, the consumption of antibiotics increased by 35% between the years 2000 and 2010, with a 45% increase in the consumption of carbapenems and 13% in polymixins.
2. Inappropriate prescription of antibiotics
Inappropriate prescriptions of antibiotics could also promote antibiotic resistance in the bacteria.
When a patient visits the consulting physician for a mild illness probably because of an infectious pathogen, the physician often prescribes antibiotics relying on past experiences and local epidemiology.
This approach reduces the time to cure the illness rather than testing the patient sample for the causative bacteria and sensitivity to those particular bacteria to several antibiotics, as long as the physician guessed it right.
It seemed, more often the initially advised antibiotics are not appropriate, leading to multiple follow-up visits and serial courses of different antibiotics until the situation resolves.
However, oftentimes the prescription of antibiotics could be a demand from the patient for immediate relief by circumventing the control of the physician.
Moreover, there are certain online consultants and websites capable of prescribing antibiotics online just by doing an online consultation without proper examination and testing.
This process of inappropriate prescription puts an intensive selective pressure on the patient?s microbiota (specific microorganisms found in a particular environment) encouraging the development of antibiotic resistance.
?3. Abuse of antibiotics in agriculture
The extensive use of antibiotics in livestock and crops could also advance the antibiotic resistance. Antibiotics are used in livestock to prevent infection and thereby promoting growth, improving overall health, and producing larger yields.
However, unfortunately, the antibiotics used in the livestock are passed on to humans through food products including, meat, milk, egg, etc.
Furthermore, the transfer of antibiotic-resistant bacteria to humans was identified in a study conducted in farmers. In that study, the intestinal flora of farm animals and the farmers constituted high rates of antibiotic-resistant bacteria.
Moreover, the antibiotics used in livestock have detrimental effects on the environment. A good percent of antibiotics are excreted in the urine, feces of farm animals causing the environment contaminated with the antibiotic consequently promoting the antibiotic resistance in nature.
Antibiotics are sprayed on the crops and fruit trees, though this use only accounts for a smaller proportion compared to the overall use of antibiotics. But this application could alter the ecology by disturbing the balance of antibiotic-resistant bacteria and susceptible bacteria in nature.
Cleaning agents with antibacterial products also contribute to this crisis compromising the versatility of the immune system.
?4. Poor infection control in healthcare settings
Most of the antibiotic-resistant infections are acquired from the hospitals and are called hospital-acquired infections (HAIs).
Healthcare settings including the hospitals, nursing homes, and primary health centers are breeding ground for antibiotic-resistant bacteria as many patients are administering antibiotics. Poor infection control in healthcare settings is a major driving factor for antibiotic resistance.
A usual track of development and transmission of antibiotic-resistant bacteria in a healthcare setting would be like:
- A patient with a particular infection receives antibiotics as part of the treatment
- One outcome would be the bacteria are sensitive to the administered antibiotics and the infection resolves. The other possible outcome would be bacteria have a gene for resistance and this resistant bacteria flourishes inside the patient without competition from the other bacteria (as other sensitive bacteria could have been destroyed by the antibiotic).
- The patient uses the washroom in the hospital and fails to wash the hands or fails to follow personal hygiene leading to the contamination of surfaces such as bed rails, tables, countertops, bed linens, medical equipment, etc.
- Someone else including the healthcare workers come in contact with these contaminated surfaces, contracts the antibiotic-resistant infection.
Healthcare workers such as nurses, doctors, technicians, and whoever in direct contact with the patients must follow good hygiene practices to prevent the transmission of bacteria from patient to another.
Healthcare settings should strictly adhere to the policies and guidelines of the regulatory bodies to maintain a clean and safe environment, consequently preventing the development of antibiotic resistance.
You could be interested in my blog post on the sterilization of medical devices
Healthcare workers in their uniforms enjoying a cup of coffee or snack in the hospital cafeteria are an ordinary sight, though it facilitates the easy transmission of infection.
The world health organization (WHO) launched a global ?Clean Care is Safer Care? campaign in 2005 as an infection prevention and control measure.
The campaign included many practical tools, illustrations, and empowered the participation of many countries. This campaign reduced half of the hospital-acquired infections through improved hand hygiene after 10 years of operation.
5. Urbanization and global travel
Urbanization is also an important factor to consider in the antibiotic resistance. Large numbers of people are living in close proximity providing substantial opportunity for the fast and easy spread of infections.
Besides, there are certain ideal conditions or environments for the transfer of antibiotic resistance genes among the bacteria such as sewage, wastewater treatment plants, and hospital effluents.
In addition to urbanization, global travel is an important element in the spread of antibiotic-resistant bacteria. People could travel and access most of the places in the world within a period of one or two days.
This means microorganisms could also travel and access any part of the world or any other population within one or two days. Therefore, the ease of global travel could rapidly transport an infected individual carrying an infectious agent and facilitate transmission even before the first symptom or diagnosis occurs, making it difficult to contain.
?6. Absence of new antibiotics being discovered
One of the common strategies used in the past to address antibiotic resistance was the development of new antibiotics.
However, this strategy is currently ineffective as there are very few antibiotics being developed by pharmaceutical companies because of the economic obstacles.
For example, following the advice of microbiologists and infectious disease specialists, physicians restrain the use of new antibiotics introduced in the market (rather than prescribing it immediately), holding it as the last reserve drug.
This mode of practice could result in the reduced use of new antibiotics and thereby affecting the investment returns of the manufacturing company.
Moreover, the development of new antibiotics cannot solve the antibiotic resistance completely because when we start using the new antibiotics, the emergence of antibiotic-resistant bacteria is inevitable.
In short, all the above-mentioned causes of antibiotic resistance are due to the human behavior encouraging the bacteria that is capable of evolving and adapting according to its surroundings by its survival mechanisms.
Furthermore, a common misconception encircling the public is an individual (or a community) becomes resistant to antibiotics. I would pronounce it as a myth.
The truth is by the overuse of antibiotics or any of the above-mentioned reasons, the bacteria become resistant to antibiotics, not humans become resistant to antibiotics, and in the future, if we encounter an infection with antibiotic-resistant bacteria, there starts a series of problems.
Therefore, it is not an individual plight. The collective effort of the community is required to untangle this problem.
Antibiotic resistance is a global crisis affecting the worldwide population. The antibiotic resistance can increase human misery by leaving no option for treatment and thereby increasing the healthcare cost.
This could lead to a global economic crisis as well. The wise and moderate usage of antibiotics and strict adherence to hygiene practices would be able to make things a little better though.
Among the 6 causes mentioned as the reason for antibiotic resistance, which reason could be the most potent threat in developing antibiotic resistance in your opinion?
Or maybe you have a question about something that you read.
Let me know in the comments below, I would love to hear from you!