Let’s make informed decisions: Antimicrobial awareness

World Antibiotic Awareness week falls between 18-24 November this year, with the theme “Spread Awareness and Stop Resistance”. We have witnessed a tremendous increase in global antibiotic consumption, and with it, a rise in antibiotic resistance. This is a global crisis that needs urgent attention. In this regard, we spoke to University of Peradeniya Faculty of Medicine Department of Microbiology Senior Lecturer Dr. Veranja Liyanapathirana. 

University of Peradeniya Faculty of Medicine Department of Microbiology Senior Lecturer Dr. Veranja Liyanapathirana

What are the best practices when it comes to antibiotic use? 

Before coming to the best practices in antibiotic use, let’s start with defining an antibiotic. A couple of studies we did recently found that there is room for improvement in our understanding of what an antibiotic is. We feel that this may also contribute to the misuse of antibiotics. 

An antibiotic is a drug that can destroy bacteria. These do it by either killing them or interfering with their growth. There are different species of bacteria, and there are different groups of antibiotics too. Not all antibiotics are active against all bacteria; there are specific antibiotics that can be used to treat infections caused by specific ones. Further, antibiotics are not effective against viral infections like the common cold, flu, Covid-19, most febrile illnesses, and even diarrhea, as antibiotics do not kill or destroy viruses. Therefore, antibiotics are warranted only for bacterial infections, or to prevent secondary bacterial infection following a viral illness. 

The best practices in antibiotic use for the public is to take antibiotics only when given by a qualified medical practitioner. If one is given an antibiotic by a medical practitioner, the course should be completed and the dosage regime should be followed as instructed. These doses and time intervals have been calculated based on many properties, including the distribution of the antibiotic in different organs, how the antibiotic is degraded in the body, how long it takes for the concentration of the antibiotic to halve, and the method of excretion of the antibiotic from the body. 

What is antibiotic resistance and how does it occur?

Antibiotic resistance occurs when bacteria develop ways to overcome the actions or “resist” the activity of antibiotics. This makes the antibiotic ineffective in treating infections caused by these resistant bacteria. 

Antibiotic resistance is a natural phenomenon. When you take a population of bacteria, the ability to resist antibiotic actions may be present in one or two cells. These are coded by the genomic material of bacteria. 

Kirby-Bauer disk diffusion susceptibility test on coagulase-negative ‘staphylococcus aureus’ grown on Mueller-Hinton agar. Microorganisms used in therapeutic design such as bacteria should be susceptible to antibiotics. The zones of clearing are measured to determine susceptibility to tested drugs

When bacteria are in an environment with antibiotics, the ones that have the capability of survival in that environment, i.e. having resistant genes, will thrive, multiply, and become the predominant species.  That is why overuse and misuse of antibiotics contribute to the emergence of antibiotic-resistant bacterial strains. 

Another fascinating thing about bacteria is that they contribute to resistance in their genetics. Bacteria have a remarkable ability to pass their genetic material across different species or genera. Some of this occurs through mobile pieces of genes. Therefore, the emergence of a single bacterial strain with resistance is not an isolated issue; it sets off a chain of actions. 

Poor hygienic measures will help such strains to spread rapidly. Further, when such a bacterial strain emerges in a part of the world, global travel helps it to travel to the furthest corners of the world.  

What precautions can the public take to reduce antibiotic use/resistance?

The public has to play a major role if we are to effectively prevent the emergence and spread of resistance. They can do this in two main ways; by reducing the need for antibiotics, and by correctly following antibiotic treatment plans when one is given antibiotics while not misusing them. 

  1. Prevent the need to take antibiotics as much as possible by practicing proper infection prevention methods. These include taking vaccines when available, hand hygiene, respiratory etiquette, food safety, safe sex, and almost other general hygienic measures 
  2. Do not take antibiotics over the counter, do not ask from friends or family, and do not use the ones that are leftovers from another time. Seek medical attention and when you do, if the doctor is not giving antibiotics, do not demand it. If your pet falls ill, take it to a qualified veterinary practitioner. If you are engaged in animal husbandry, follow the regulations on antibiotic use

At the same time, if you are ill and need antibiotic treatment, please take the ones that are prescribed, as antibiotics are life-saving drugs and should be taken promptly in given situations. 

What are the unwarranted effects, other than drug resistance, when antibiotics are used in excess?

Our body has many bacteria as a part of our healthy status. We call these our normal flora or the microbiome. When we take antibiotics, these normal-flora are also altered, in addition to the pathogen or the disease-causing bacteria in our body at that time. Some of these alterations may lead to adverse, harmful effects. One example is antibiotic-associated diarrhea.  

What are drug-resistant infections and should the public be worried about? Are they increasing in number?


Drug resistant infections are infections caused by microorganisms that are resistant to treatment. For the scope of this article, we will restrict it to bacterial infections caused by antibiotic-resistant bacteria. However, there are viruses such as HIV that become resistant to specific antivirals, fungi that have become resistant to antifungals, and protozoa like the malaria-causing plasmodium that have become resistant to antimalarial drugs. 

Back to antibiotic resistant bacterial infections. These are increasing globally. Initially, resistant bacterial infections occurred when someone in health care for a long time developed resistance. However, now we can get such infections from the community too, as drug resistant bacteria are increasingly being found from the community. 

A wide variety of infections can be caused by antibiotic resistant bacteria, urinary infections, pneumonia, and meningitis. Name any bacterial infection; the bacteria that cause it can be resistant to the antibiotics that are used to treat it. When an infection is caused by an antibiotic resistant bacteria, the available treatment options are limited. It has been shown globally that infections with antibiotic resistant bacteria lead to increased hospitalisations, prolonged hospitalisations, or treatment and increased death. To show figures, I will quote the World Health Organisation: “Drug-resistant diseases already cause at least 700,000 deaths globally a year, including 230,000 deaths from multidrug-resistant tuberculosis, a figure that could increase to 10 million deaths globally per year by 2050  under the most alarming scenario if no action is taken.”

These figures have led multiple global organisations to identify antibiotic resistance as a “silent pandemic” and a major global health issue. Further, we are almost at the start of a “post-antibiotic” era. 

What steps are the medical practitioners taking to curb issues related to excessive use of antibiotics and antibiotic resistance? 

Excess use of antibiotics in the health sector is only one of the drivers of antibiotic resistance. Its excess use in veterinary practice, aquaculture, agriculture, and animal husbandry are equally responsible for this. 

  • Sri Lanka has a national strategic plan to combat antibiotic resistance. This is in keeping with that of the World Health Organisation. Regularising antibiotic use and improving infection prevention and control measures are two of the main areas where medical practitioners contribute to minimise the impact of antibiotic resistance 
  • Relevant bodies in the medical community have guidelines to streamline the use of antibiotics, so that excess use is minimised but appropriate, timely use where indicated is promoted 
  • Identifying the bacteria causing an infection through lab tests before starting treatment is another step that medical practitioners take to prevent excessive use of antibiotics. These lab tests will not only identify the bacteria responsible for an infection, but will also identify the antibiotics that are effective in treating the given infection
  • Further, minimising infections, in general, is also partly the responsibility of medical practitioners, which falls under “infection prevention and control” in healthcare settings. One of the key infection prevention strategies for Covid-19 – hand hygiene – is a key component in minimising the effects of antibiotic resistance too 
  • There is a concept called “antibiotic stewardship”. This is not that well practiced in Sri Lanka. However, globally, this practice aims to safeguard antibiotics so that they are used correctly where appropriate but avoided when unnecessary. This practice requires the support of not only the medical practitioners but other health care workers such as nurses and pharmacists too. All healthcare workers have a responsibility to become an “antibiotic guardian”. 

Finally, Dr. Liyanapathirana said that a lot more needs to be done from the sides of both medical practitioners and healthcare workers, other stakeholders such as veterinarians, agriculture specialists, and environmental scientists, as well as the public if we are to effectively overcome antibiotic resistance.