Antibiotic-Resistant Bacteria in Clams-A Study on Mussels in the River Rhine

Area of Science:

• Environmental microbiology
• Public health
• Aquatic ecology

Background:

• Antibiotic resistance is a growing global health concern, complicating infectious disease treatment.
• Antibiotic-resistant bacteria (ARB) in surface waters pose risks for recreation and irrigation.
• Sewage treatment plant (STP) discharges are a known source of ARB entering aquatic environments.

Purpose of the Study:

• To investigate the influence of STP discharge on the presence and concentration of E. coli in mussels.
• To detect antibiotic-resistant bacteria in mussels as potential bio-indicators of river contamination.
• To assess the public health relevance of ARB found in mussels from the Rhine River.

Main Methods:

• Sampling of mussels and river water at various sites along the Rhine River.
• Microbiological analysis to quantify E. coli concentrations.
• Culturing and identification of bacteria from mussels to determine antibiotic resistance profiles.

Main Results:

• Significantly higher concentrations of E. coli were found in mussels downstream of the STP discharge.
• Antibiotic-resistant bacteria, resistant to one or two classes of antibiotics, were detected in mussels.
• No multidrug-resistant bacteria were isolated from mussels, though present in surrounding water samples.

Conclusions:

• Mussels can serve as effective bio-indicators for monitoring bacterial contamination, including antibiotic resistance, from sewage discharge.
• STP effluent contributes to the presence of clinically relevant antibiotic-resistant bacteria in aquatic ecosystems.
• While multidrug resistance was not found in mussels, the presence of single/double resistance highlights potential risks to surface water quality.