Understanding and reducing the spread of antibiotic resistance in anaerobic sludge digestion

People excrete antibiotics and many types of bacteria, and this mixture can become concentrated in wastewater treatment plants. A specific part of the wastewater treatment process, ‘anaerobic digestion’, is particularly associated with the selection, emergence, and growth of antibiotic-resistant bacteria. These scientists want to find out if different ‘anaerobic digestion’ conditions are associated with increases, or decreases, in the numbers of antibiotic-resistant bacteria. They plan to find out by setting up relatively small, bench-sized anaerobic digesters in their laboratory, inoculating them with sludge from a full-scale working digester, then study the effects of different physico-chemical conditions on the incidence and frequency of DNA sequences of antibiotic-resistant genes and the ribosomal RNA sequences commonly used to identify different species of bacteria.