Pollutants Boost Antibiotic Resistance in Wastewater

You might think that the biggest problem with antibiotic production wastewater is the leftover antibiotics. But there's more to worry about. This wastewater also has high amounts of organic pollutants, which can be very harmful on their own or when mixed with antibiotics. One study looked at how these pollutants affect the growth of antibiotic resistance in wastewater treatment systems. They used a common type of bacteria, Escherichia coli, and exposed it to six different organic pollutants found in wastewater, both alone and with the antibiotic ampicillin. When the bacteria were only exposed to the pollutants, there wasn't much change in their resistance. But when the pollutants were mixed with the antibiotic, things got serious. One pollutant, d-p-hydroxyphenylglycine (DHPG), made the bacteria much more resistant to multiple antibiotics. In fact, the combination of DHPG and ampicillin increased resistance by up to 2928. 9 times in a specific pattern related to dose and time. The two together also made the bacteria stronger against antibiotics and caused more stress from oxidation. They even boosted the bacteria's ability to pump out the antibiotics. This shows that the mix of antibiotics and organic pollutants in wastewater can make bacteria much more resistant to antibiotics, which is a serious problem.