How wastewater is fuelling antibiotic resistance

Scientists have found how antibiotic resistance is being fuelled by wastewater. 

Antibiotic resistance is the ability of a microorganism to withstand the effects of antibiotics. It evolves via natural selection acting upon random mutation, but it can also be engineered by applying an evolutionary stress on a population. . 

The scientists revealed that the unique characteristics of wastewater, which allow ‘resistance genes’ to grow against harmless bacteria,  provide more potent environment.    
They investigated what they described as the relative abundance and prevalence of 22 known origin species. 

In a study published in the journal Communications Biology, the researchers at the Centre for Antibiotic Resistance Research in Gothenburg, Sweden, presented evidence for where the genes could gain their ability to move. “It is known that wastewaters contain residues of antibiotics and could favour the development of antibiotic-resistant bacteria. New evidence shows that wastewaters also have characteristics that allow the resistance genes to start their journey from harmless bacteria to disease-causing bacteria, “they highlighted. 

They explained that microorganisms produced antibiotic molecules long before humans started to use them as medicines. Accordingly, the ability of many environmental bacteria to defend themselves against antibiotics is ancient.

“Since the introduction of antibiotics in clinics, disease-causing bacteria have also started to accumulate more and more resistance genes in their DNA. This still-ongoing process requires that genes, which were previously well anchored in the chromosomes of certain bacterial species, first gain the ability to move around and eventually jump between species, “the study notes. 

Fanny Berglund, a researcher at the Sahlgrenska academy at University of Gothenburg and the lead author of the study  said that by studying DNA from thousands of samples from different environments, the researchers could identify where all the key components came together. 

To the authors’ surprise, it was not in the gut of humans or animals, it was in wastewaters sampled across the world.

“In order to fight antibiotic resistance, we cannot focus only on preventing the spread of those types of resistant bacteria that are already in circulation, we also need to prevent or delay the emergence of new ones,” the lead researcher said. 

According to the researcher, the environment harbours a huge variety of different resistance genes, many more than the resistance genes that we see today in bacteria causing disease. 

“This makes the environment a vast source for new resistance genes that one after the other acquire the ability to jump between species, to eventually end up in pathogens.”

 The authors conclude that favouring this development by polluting the environment with antibiotics is not a good idea.

 “There is a lot of focus on reducing antibiotic use in humans and animals. This is of course important, but our study shows that we also need to pay attention to our waste streams, as this seems to be a place where new variants of antibiotic resistance could emerge,” concludes Berglund.

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