Antibiotic Resistance is Prevalent in South Africa’s Water Supply Systems

Antimicrobial resistance (AMR) is the ability of harmful microorganisms to withstand treatments like antibiotics.

Often dubbed a silent pandemic, it results in roughly 1.27 million deaths each year, with Africa facing the greatest impact.

Initiatives to tackle antibiotic resistance have mainly focused on hospitals and clinics, where antibiotic use is common and resistant infections often emerge. However, this problem extends beyond just healthcare environments.

Resistant bacteria can reproduce and spread their resistance or exchange resistance genes with other bacteria. This transmission can happen outside of hospitals via wastewater or through human carriers.

Researchers are increasingly recognizing the role of the environment in this issue. Rivers, lakes, and wastewater systems serve as intersection points for bacteria, antibiotic residues, and various pollutants.

Wastewater treatment plants have to deal with this complexity. They process waste from residences, healthcare facilities, and industries, purifying it before discharging it back into rivers or repurposing it. These systems have significantly reduced the threat from infectious diseases.

However, a major oversight exists.

Through the African Microbiome Project, we are studying the presence of antibiotic-resistant bacteria and resistance genes in wastewater discharges and their adjacent environments.

Our research reveals that resistant bacteria are still detectable downstream, even after treatment has reduced the overall bacterial counts. Therefore, we sought to understand the mechanisms involved.

We pursued this line of inquiry because prior studies suggested that when bacteria are eliminated during treatment, their cells break down, releasing DNA into the aquatic environment.

This genetic material, known as extracellular DNA, exists outside of cells and can harbor antibiotic resistance genes, remaining in treated water that is released into the environment. Some microorganisms can subsequently absorb this genetic material.

As a result, resistance can spread even without the original bacteria. Our studies in South Africa indicate that a significant pathway for the spread of antibiotic resistance is often neglected.

Furthermore, our findings suggest that current evaluation methods for treatment success may be inadequate. While reducing live bacteria is crucial, it might not capture the entire risk if the genetic components of resistance persist.

Thus, adopting advanced treatment technologies, such as ultraviolet treatment, enzymatic degradation, and advanced oxidation, should be prioritized.

These technologies have demonstrated effectiveness in degrading extracellular DNA in wastewater, thereby reducing its potential to transfer resistance genes.

The Evidence

We examined wastewater from various treatment facilities in the City of Tshwane and discovered that even post-standard treatment, extracellular DNA containing antimicrobial resistance genes remained present in the discharged water.

Some of these genes are linked to resistance against last-resort antibiotics, vital for treating severe infections in both humans and animals.

This doesn’t imply that treated wastewater directly causes disease; however, it highlights a pathway through which resistance can survive treatment and potentially re-enter communities via drinking water, agricultural practices, or recreational activities.

Similar phenomena have been observed worldwide, prompting some countries to adopt advanced treatment technologies aimed at eliminating or degrading extracellular DNA.

What’s Needed

Developing nations face greater challenges than developed ones for several reasons.

Treated wastewater is often released into rivers, reused in agriculture, or cycled back into domestic water supplies.

The lack of access to safe water and sanitation may increase opportunities for antibiotic resistance genes to circulate from these environmental reservoirs to local communities.

Moreover, water scarcity is more acute in developing countries.

In water-stressed regions like South Africa, where infrastructure problems persist, communities may encounter direct exposure to contaminated water sources, aiding the spread of resistance genes.

These challenges underline the necessity for a fundamental shift in how we understand antibiotic resistance. It is not just a healthcare issue but also an environmental one, requiring changes in both spheres.

First, monitoring systems must be improved. Globally, water quality assessments seldom include genetic material; detecting it requires specialized molecular techniques.

While these methods necessitate specific equipment and expertise, many laboratories already have them, and they could be integrated into monitoring programs as costs decrease and testing capabilities grow.

Second, wastewater treatment technologies may need to be adapted. Advanced techniques, such as ozonation (utilizing ozone to decompose contaminants), ultrafiltration membranes that physically filter particles and genetic material, and DNA-degrading enzymes are under research but are not yet widely applied.

The implementation of these technologies has mainly taken place in Europe, North America, and Asia. Positive signs of uptake can be seen in South Africa, where updates to wastewater treatment plants in Cape Town now include UV treatment.

Third, stronger collaboration among different sectors is essential. Antibiotic resistance isn’t just a health issue, and water management is more than an engineering problem.

Policymakers, engineers, microbiologists, and public health professionals must work together on this interconnected challenge.

Lastly, raising public awareness is vital. Most people are unaware that antibiotic resistance can spread through water. Clearly conveying this risk can generate support for the required changes.

While individuals may not always control the quality of their water supply, understanding the risks can inspire simple protective measures, such as boiling water and disposing of medications responsibly.

Antibiotic resistance and water insecurity are linked through the systems that sustain everyday life. As pressures on global water systems increase, understanding and managing these interconnections will become increasingly important.

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Thulani P Makhalanyane, Professor of Microbiology, Stellenbosch University, and John Paul Makumbi, Postdoctoral Fellow at the Department of Microbiology, Stellenbosch University