Polluted Waterways Help Fuel Drug-Resistant Bacteria: Report
Thu, September 29, 2022

Polluted Waterways Help Fuel Drug-Resistant Bacteria: Report

Environmental chemists from the University of York in England reported that they found 66% of antibiotics in 711 rivers from over 72 countries. / Photo by: rootstocks via 123rf


Antibiotics save millions of lives each year as these medications destroy or slow down the growth of bacteria, interfering with either the formation of the bacterial cell wall or its cell contents. However, the populations of the bacteria that antibiotics fight against can change and morph in ways that let them progress inside our bodies. This means that infections, although addressed with antibiotics, are harder, and sometimes impossible, to treat.

Prof. Dame Sally Davies, UK Medical Chief, stated that the problem of antibiotic resistance is getting a lot worse each year. A 2016 report showed that around 700,000 people across the world die of infections that are resistant to the antibiotics annually. This problem poses a “catastrophic threat” to doctors' ability to treat basic infections in the future. Another UK-commissioned study warned that antimicrobial-resistant infections could be the leading cause of death worldwide by 2050.

UNEP, the leading global environmental authority that sets the global environmental agenda, reported that antibiotic resistance has become one of the biggest threats to global health, food security, environment, and development today. A growing number of infections are becoming a lot more difficult to treat as the antibiotics used to treat them become less effective. 

A recent study warned that disease-causing bacteria may spread from birds to humans, livestock and pets. This is after researchers discovered that 20 percent of silver gulls in Australia carry pathogenic bacteria resistant to antibiotics. Unfortunately, the current status of the world’s waterways is fuelling drug-resistance in bacteria. 


A disease-causing bacteria may spread from birds to humans after researchers discovered that 20% of silver gulls in Australia carry pathogenic bacteria resistant to antibiotics. / Photo by: Ianos Borbely via 123rf


Excess Antibiotics Can Enter Natural Systems

A recent study conducted by environmental chemist Alistair Boxall and colleague John Wilkinson from the University of York in England reported that they found 66 percent of antibiotics in 711 rivers from over 72 countries. The first question that most of us would think of is, how do antibiotics end up in these rivers? 

According to Chemistry World, a monthly chemistry news magazine that addresses current events in the world of chemistry including research, international business news, and government policy, between 30 to 90 percent of the active compound found in antibiotics will get excreted and flushed down the bathroom whenever we use one. This means sewage and waterways are filled with a city’s medicine. 

“It’s quite scary and depressing. We could have large parts of the environment that have got antibiotics at levels high enough to affect resistance,” co-author Alistair Boxall, an environmental scientist at the University of York, said.

Animals also contribute to this. It was reported that two-thirds of antibiotics produced across the world are used by animals. They secrete them onto land and into slurry pits. This would eventually end up in rivers, groundwater, or lakes. Fish farms, particularly in low- and middle-income countries, produce antibiotic waste. Also, pharmaceutical factories pollute waterways.

The Antibiotic Pollution

The recent study showed that 470 sites that were examined tested positive for at least one of the 14 types of antibiotics. The Guardian, a British daily newspaper, reported that some of the world’s best-known rivers, including the Thames, are contaminated with antibiotics. Some of these rivers were detected to have antibiotics at unsafe levels. This means that drug-resistant bacteria is likely to develop and spread. Also, these are no ordinary antibiotics because they are classified as critically important for the treatment of serious infections. 

For instance, the researchers found seven antibiotics at nearly four times the level considered safe from the Danube in Austria. This includes clarithromycin, an antibiotic used to treat respiratory tract infections such as pneumonia and bronchitis. One of Europe’s cleanest rivers, the Thames, was also contaminated. They found a mixture of five antibiotics, including ciprofloxacin, which treats infections of the skin and urinary tract. The said drug peaked at more than three times safe levels.

Prof. William Gaze, a microbial ecologist at the University of Exeter who studies antimicrobial resistance but was not involved in the study, stated that rivers that are contaminated with low levels of antibiotics are also considered a threat. “Even the low concentrations seen in Europe can drive the evolution of resistance and increase the likelihood that resistance genes transfer to human pathogens,” he said. 

Antibiotics are not only found in waterways but also in groundwater. Recently, a study conducted by researchers from the University of Southern California showed that the spread of antibiotic-resistant genes (ARGs) through the water system could put public safety at risk. Science Daily, an American website that aggregates press releases and publishes lightly edited press releases about science, reported that the spread of ARGs in water treatment systems is a result of the overuse of antibiotics in general. 

The researchers detected differences in ARG concentrations by examining and comparing samples from an advanced groundwater treatment facility in California. They found out that new and emerging contaminant ARGs pose a potential hazard to public safety and water security. This includes the increasing development of antibiotic-resistant superbugs.

This antibiotic pollution influence bacteria living in the waterways to progress. This helps speed along with the development of resistant strains. At the same time, antibiotic pollution disrupts the delicate ecological balances in rivers and streams, which can change the makeup of bacterial communities.

Additionally, a UNEP study found out that antibiotics, which are classified under ‘emerging pollutants’, are harming our environment. Unfortunately, there has been much research about this because these potential threats are not yet widely regulated by national or international law. Most of the emerging pollutants, including antibiotics, analgesics, anti-inflammatory drugs, psychiatric drugs, steroids and hormones, and more, are not included in international agreements with routine monitoring programs. This why their impacts on our planet are not well understood as of now. 

The findings of these studies show that there are several potential threats that we still have no sufficient knowledge about. Unfortunately, addressing these problems won’t happen immediately, but this opens up an opportunity for researchers to study the link between antibiotics and our environment.